summaryrefslogtreecommitdiff
path: root/dictionaries
diff options
context:
space:
mode:
authorJoe Robinson <joe@lc8n.com>2014-09-21 01:08:15 +0100
committerJoe Robinson <joe@lc8n.com>2014-09-21 01:08:15 +0100
commit7a1af5825afb1ea7f282608bac259507a1a398e3 (patch)
treebd92f10ce1ffe1233862bc17f0860160f4e702e9 /dictionaries
parent36102ee26a1d6c1b90fa14ea30bb346c66164213 (diff)
Added FOLDOC dictionary parsing for technical words
Diffstat (limited to 'dictionaries')
-rw-r--r--dictionaries/foldoc.txt182001
1 files changed, 182001 insertions, 0 deletions
diff --git a/dictionaries/foldoc.txt b/dictionaries/foldoc.txt
new file mode 100644
index 0000000..101d139
--- /dev/null
+++ b/dictionaries/foldoc.txt
@@ -0,0 +1,182001 @@
+Free On-line Dictionary of Computing
+
+ <introduction> FOLDOC is a searchable dictionary of acronyms,
+ jargon, programming languages, tools, architecture, operating
+ systems, networking, theory, conventions, standards,
+ mathematics, telecoms, electronics, institutions, companies,
+ projects, products, history, in fact anything to do with
+ computing.
+
+ Copyright 1985 by Denis Howe
+
+ Permission is granted to copy, distribute and/or modify this
+ document under the terms of the GNU Free Documentation
+ License, Version 1.1 or any later version published by the
+ Free Software Foundation; with no Invariant Sections, Front-
+ or Back-Cover Texts. A copy of the license is included in the
+ section entitled "{GNU Free Documentation License}".
+
+ Please refer to the dictionary as "The Free On-line Dictionary
+ of Computing, http://foldoc.org/, Editor Denis Howe" or
+ similar. Please make the URL both text (for humans) and a
+ hyperlink (for Google).
+
+ The dictionary has been growing since 1985 and now contains
+ nearly 15,000 definitions in over five megabytes of text.
+ Entries are cross-referenced to each other and to related
+ resources elsewhere on the net.
+
+ Where {LaTeX} commands for certain non-{ASCII} symbols are
+ mentioned, they are described in their own entries. "\" is
+ also used to represent the Greek lower-case lambda used in
+ {lambda-calculus}. Cross-references to other entries look
+ {like this}. Note that not all cross-references actually lead
+ anywhere yet, but if you find one that leads to something
+ inappropriate, please {let me know (feedback.html)}. Dates
+ after entries indicate when that entry was last updated. They
+ do not imply that it was up-to-date at that time.
+
+ You can search the latest version of the dictionary on the
+ {WWW} at URL http://foldoc.org/. If you find an entry that is
+ wrong or inadequate please let me know.
+
+ See {Pronunciation} for how to interpret the pronunciation given
+ for some entries.
+
+ {More about FOLDOC (about.html)}.
+
+ (2007-07-25)
+
+Acknowledgements
+
+ <introduction> Many thanks to the thousands of {contributors
+ (contributors.html)} and especially to the Guest Editors, mirror
+ site maintainers and the maintainers of the following resources
+ from which some entries originate:
+
+ Mike Sendall's STING Software engineering glossary
+ <sendall@dxpt01.cern.ch>, 1993-10-13,
+
+ Bill Kinnersley's {Language List
+ (http://people.ku.edu/~nkinners/LangList/Extras/langlist.htm)}
+ v2.2, 1994-01-15,
+
+ Mark Hopkins' catalogue of Free Compilers and Interpreters
+ v6.4, 1994-02-28,
+
+ The on-line hacker {Jargon File} v3.0.0, 1993-07-27,
+
+ Internet Users' Glossary (RFC 1392, FYI 18), Jan 1993.
+
+ John Cross's computer glossary, 1994-11-01.
+
+ John Bayko's Great Microprocessors of the Past and Present,
+ v4.0.0, 1994-08-18.
+
+ {Electronic Commerce Dictionary}.
+
+ (2014-09-11)
+
+Missing definition
+
+ <introduction> First, this is an (English language)
+ __computing__ dictionary. It includes lots of terms from
+ related fields such as mathematics and electronics, but if
+ you're looking for (or want to submit) words from other
+ subjects or general English words or other languages, try
+ {(http://wikipedia.org/)}, {(http://onelook.com/)},
+ {(http://yourdictionary.com/)} or
+ {(http://reference.allrefer.com/)}.
+
+ If you've already searched the dictionary for a computing term
+ and it's not here then please __don't tell me__. There are,
+ and always will be, a great many missing terms, no dictionary
+ is ever complete. I use my limited time to process the
+ corrections and definitions people have submitted and to add
+ the {most frequently requested missing terms (missing.html)}.
+
+ Try one of the sources mentioned above or
+ {(http://techweb.com/encyclopedia/)},
+ {(http://whatis.techtarget.com/)} or
+ {(http://google.com/)}.
+
+ See {the Help page (help.html)} for more about missing definitions
+ and bad cross-references.
+
+ (2014-09-20)
+
+!
+
+ {exclamation mark}
+
+"
+
+ {double quote}
+
+#
+
+ {hash}
+
+$
+
+ {dollar}
+
+$1
+
+ <programming> The first {positional parameter} in {shell}
+ programming and related languages. Occurrences of $1 are
+ replaced by the first {actual argument} provided by the user
+ when the {shell script} is run. $2 is replaced by the second
+ argument, and so on up to $9.
+
+ You may have arrived at this entry by following a {URL} like
+ "http://foldoc.org?$1", which is actually a {template} used to
+ generate pointers to FOLDOC definitions by replacing "$1" with
+ the term to be defined, e.g. in a {wiki} {interwiki map}.
+
+ (2006-09-10)
+
+%
+
+ {percent}
+
+'
+
+ {single quote}
+
++
+
+ {plus}
+
+,
+
+ {comma}
+
+/
+
+ {oblique stroke}
+
+0
+
+ {zero}
+
+0/1 knapsack problem
+
+ <application> The {knapsack problem} restricted so that the
+ number of each item is zero or one.
+
+ (1995-03-13)
+
+1
+
+ {one}
+
+100BaseFX
+
+ <networking> {Fast Ethernet} over {optical fibre}.
+
+ (1998-03-23)
+
+100BaseT
+
+ <networking> Any of several {Fast Ethernet} 100 {MBps}
+ {CSMA/CD} standards for {twisted pair} cables, including:
+ 100BaseTx (100 Mbps over two-pair {Cat5} or better cable),
+ 100BaseT4 (100 Mbps over four-pair {Cat3} or better cable),
+ 100BaseT2 (in committee; 100 Mbps over two-pair Cat3 or better
+ cable). All are standards (or planned standards) under {IEEE}
+ {802.3}.
+
+ (1997-01-07)
+
+100BaseTX
+
+ <networking> The predominant form of {Fast Ethernet}.
+ 100BaseTX runs over two pairs of wires in {category 5} cable.
+
+ (1998-06-30)
+
+100BaseVG
+
+ <networking> A 100 {MBps} {Ethernet} standard specified to run
+ over four pairs of {category 3} {UTP} wires (known as voice
+ grade, hence the "VG"). It is also called 100VG-AnyLAN
+ because it was defined to carry both {Ethernet} and {token
+ ring} {frame} types.
+
+ 100BaseVG was originally proposed by {Hewlett-Packard},
+ ratified by the {ISO} in 1995 and practically extinct by 1998.
+
+ 100BaseVG started in the IEEE 802.3u committee as {Fast
+ Ethernet}. One faction wanted to keep {CSMA/CD} in order to
+ keep it pure Ethernet, even though the {collision domain}
+ problem limited the distances to one tenth that of {10baseT}.
+ Another faction wanted to change to a polling architecture
+ from the hub (they called it "demand priority") in order to
+ maintain the 10baseT distances, and also to make it a
+ {deterministic} {protocol}. The CSMA/CD crowd said, "This is
+ 802.3 -- the Ethernet committee. If you guys want to make a
+ different protocol, form your own committee". The IEEE 802.12
+ committee was thus formed and standardised 100BaseVG. The
+ rest is history.
+
+ (1998-06-30)
+
+100VG-AnyLAN
+
+ {100BaseVG}
+
+10base2
+
+ <networking> (Or "cheapernet") The variant of {Ethernet} that
+ uses thin {coaxial} cable (RG-58 or similar), as opposed to
+ {10base5} cable.
+
+ The "10" means 10 {Mbps}, "base" means "baseband" as opposed
+ to {radio frequency} and "2" means a maximum single cable
+ length of 200m.
+
+ (1995-11-14)
+
+10base5
+
+ <networking> An {Ethernet} network cabling specification
+ operating at ten {Mbps}, "baseband" (as opposed to {radio
+ frequency}), and with a maximum single cable length of 500
+ metres. This is normally carried on {RG8} cable.
+
+ Compare {10base2}, {10baseT}.
+
+ (2002-06-17)
+
+10baseT
+
+ <networking> A variant of {Ethernet} which allows stations to
+ be attached via {twisted pair} cable.
+
+ (1995-01-24)
+
+120 reset
+
+ <jargon> /wuhn-twen'tee ree'set/ (After 120 volts, US mains
+ voltage) To cycle power on a computer in order to reset or
+ unjam it.
+
+ Compare {Big Red Switch}, {power cycle}.
+
+ [{Jargon File}]
+
+ (1994-11-23)
+
+1-2-3
+
+ {Lotus 1-2-3}
+
+1394
+
+ {High Performance Serial Bus}
+
+1541
+
+ {Commodore 1541}
+
+1581
+
+ {Commodore 1581}
+
+16000
+
+ {National Semiconductor 16000}
+
+16450
+
+ <hardware> A {UART} with a one-byte {FIFO} buffer. The 16450
+ is a higher speed, fixed version of the {8250}. It was
+ superseded by the {16550}.
+
+ The 16450 was used for the {IBM PC AT} and {PS/2} but will not
+ work in a {IBM PC XT}.
+
+ (2004-03-21)
+
+16550
+
+ <hardware> A version of the {16450} {UART} with a 16-byte
+ {FIFO}. Superseded by the 16550A.
+
+ This chip might not operate correctly with all software.
+
+ The 16C550 is a {CMOS} version.
+
+ (2004-03-24)
+
+16550A
+
+ <hardware> A version of the {16550} {UART}. Superseded by the
+ {16650}.
+
+ (2003-07-05)
+
+16650
+
+ <hardware> A version of the {16550A} {UART} with a 32-byte
+ {FIFO}. Superseded by the {16750C}.
+
+ (2003-07-05)
+
+16750C
+
+ <hardware> A {UART} with a 64-byte {FIFO}.
+
+ The 16C750 is a {CMOS} version.
+
+ [Is there a 16750 (with no "C" on the end)?]
+
+ (2004-03-24)
+
+16 bit
+
+ <architecture, programming> Using {words} containing sixteen
+ {bits}. This adjective often refers to the number of bits
+ used internally by a computer's {CPU}. E.g. "The {Intel 8086}
+ is a sixteen bit processor". Its external {data bus} or
+ {address bus} may be narrower. The term may also refer to the
+ size of an instruction in the computer's {instruction set} or
+ to any other item of data.
+
+ See also {16-bit application}.
+
+ (1996-05-13)
+
+16-bit application
+
+ <operating system> Software for {MS-DOS} or {Microsoft
+ Windows} which originally ran on the 16-bit {Intel 8088} and
+ {80286} {microprocessors}. These used a {segmented address
+ space} to extend the range of addresses from what is possible
+ with just a 16-bit address. Programs with more than 64
+ kilobytes of code or data therefore had to waste time
+ switching between {segments}. Furthermore, programming with
+ segments is more involved than programming in a {flat address
+ space}, giving rise to {warts} like {memory models} in {C} and
+ {C++}.
+
+ Compare {32-bit application}.
+
+ (1996-04-06)
+
+16C550
+
+ {16550}
+
+16C750
+
+ {16750C}
+
+16C850
+
+ <hardware> A version of the {16450} {UART} in {CMOS} with
+ 128-{byte} {FIFO}.
+
+ (2004-03-24)
+
+1802
+
+ <processor> An 8-bit {microprocessor} manufactured as CDP1802
+ by {HARRIS Semiconductor}. It has been around for ten years
+ at least and is ideally suited for {embedded} applications.
+ Some of its features are: 8-bit parallel organisation with
+ bidirectional {data bus} and {multiplexed address bus}; static
+ design -- no minimum {clock rate}; bit-programmable output
+ port; four input pins which are directly tested by branch
+ instructions; flexible programmable I/O mode; single-phase
+ clock, with on-chip oscillator; 16 x 16 register matrix to
+ implement multiple {program counters}, pointers, or
+ {registers}
+
+ (1995-11-21)
+
+192.168.1.1
+
+ <networking> The default {IP address} used to connect to many
+ brands of {router} to set them up. It can be used from a {web
+ browser} in the {URL} {(http://192.168.1.1)}. This URL, and
+ the necessary default login details, are often printed on the
+ router. The same address may also be accessible via a
+ {telnet} {command line interface}.
+
+ This is a {private address} that is only visible when
+ connected directly to the router, i.e. it will not be routed
+ by other network hardware.
+
+ {i19216811.com (http://www.i19216811.com/)}.
+
+ (2012-09-20)
+
+1NF
+
+ {database normalisation}
+
+1TBS
+
+ {indent style}
+
+1.TR.6
+
+ <networking, protocol> A {control channel protocol} for
+ {ISDN}. It is a national {standard} in Germany but is being
+ replaced by {Euro-ISDN}.
+
+ (1995-03-27)
+
+2
+
+ <convention, character> In names of translation software,
+ infix 2 often represents the word "to" with the connotation
+ "translate to", as in {dvi2ps} ({DVI} to {PostScript}),
+ int2string (integer to string) and {texi2roff} ({Texinfo} to
+ [nt]{roff}).
+
+ [{Jargon File}]
+
+ (1995-01-25)
+
+20-GATE
+
+ <language> An algebraic language for the {G-20}, developed at
+ {Carnegie} around 1965.
+
+ (1995-02-27)
+
+2780
+
+ {Binary Synchronous Transmission}
+
+2B1D
+
+ {Basic Rate Interface}
+
+2B1Q
+
+ {two-binary, one-quaternary}
+
+2B+D
+
+ {Basic Rate Interface}
+
+2NF
+
+ {database normalisation}
+
+2.PAK
+
+ <language> An {artificial intelligence} language with
+ {coroutines}.
+
+ ["The 2.PAK Language: Goals and Description", L.F. Melli, Proc
+ IJCAI 1975].
+
+ (1995-01-25)
+
+32000
+
+ {National Semiconductor 32000}
+
+3270
+
+ {IBM 3270}
+
+32-bit application
+
+ <architecture, operating system> {IBM PC} software that runs
+ in a 32-bit {flat address space}.
+
+ The term {32-bit application} came about because {MS-DOS} and
+ {Microsoft Windows} were originally written for the {Intel
+ 8088} and {80286} {microprocessors}. These are {16 bit}
+ microprocessors with a {segmented address space}. Programs
+ with more than 64 kilobytes of code and/or data therefore had
+ to switch between {segments} quite frequently. As this
+ operation is quite time consuming in comparison to other
+ machine operations, the application's performance may suffer.
+ Furthermore, programming with segments is more involved than
+ programming in a flat address space, giving rise to some
+ complications in programming languages like "{memory models}"
+ in {C} and {C++}.
+
+ The shift from 16-bit software to 32-bit software on {IBM PC}
+ {clones} became possible with the introduction of the {Intel
+ 80386} microprocessor. This microprocessor and its successors
+ support a segmented address space with 16-bit and 32 bit
+ segments (more precisely: segments with 16- or 32-bit address
+ offset) or a linear 32-bit address space. For compatibility
+ reasons, however, much of the software is nevertheless written
+ in 16-bit models.
+
+ {Operating systems} like {Microsoft Windows} or {OS/2} provide
+ the possibility to run 16-bit (segmented) programs as well as
+ 32-bit programs. The former possibility exists for {backward
+ compatibility} and the latter is usually meant to be used for
+ new software development.
+
+ See also {Win32s}.
+
+ (1995-12-11)
+
+3780
+
+ {Binary Synchronous Transmission}
+
+386
+
+ {Intel 80386}
+
+386BSD
+
+ <operating system> (Or "jolix /joh'liks/) A {free software}
+ {port} originally derived from the generally available parts
+ of the "{Berkeley Net Release/2}" to the {Intel} {i386}
+ architecture by William Jolitz and friends. The name Jolix is
+ used to differentiate it from {BSDI}'s port based on the same
+ source tape, which is called {BSD/386}.
+
+ Many new and innovative features were added to 386BSD
+ following its original release in June 1992. An unofficial
+ {patchkit}, available from many {anonymous FTP} archives,
+ solves many of the problems associated with 386BSD Version
+ 0.1. In addition, many common Unix packages have been ported.
+
+ 386BSD has been superseded by {FreeBSD}, {NetBSD} and {OpenBSD}.
+
+ {FAQ
+ (http://cis.ohio-state.edu/hypertext/faq/usenet/386bsd-faq/part1/faq.html)}.
+
+ [{Jargon File}]
+
+ (2006-06-08)
+
+386SPART.PAR
+
+ <operating system> (Or "{WIN386.SWP}") 386SPART.PAR is a
+ {hidden file} created by {Windows 3.1} for use as {virtual
+ memory} {swap file}. It is generally found in the {root
+ directory}, however it may appear elsewhere (typically in the
+ WINDOWS directory). Its size depends on how much virtual
+ memory you have set up under (Control Panel) Enhanced under
+ Virtual Memory. If you move or delete this file Windows will
+ complain the next time you start it with a Swap File error.
+
+ {Windows 95} uses a similar file, except it is named
+ WIN386.SWP, and the controls for it are located under Control
+ Panel - System - Performance tab - Virtual Memory.
+
+ (1996-05-28)
+
+386SX
+
+ {Intel 80386SX}
+
+3Com Corporation
+
+ <company, networking> A manufacturer of {local area network}
+ equipment.
+
+ 3Com was founded in 1979. They acquired {BICC Data Networks}
+ in 1992, {Star-Tek} in 1993, {Synernetics} in 1993, {Centrum}
+ in 1994, {NiceCom} in 1994 {AccessWorks}, {Sonix
+ Communications}, {Primary Access} and {Chipcom} in 1995 and
+ {Axon} and {OnStream Networks} in 1996. They merged with
+ {U.S. Robotics} in 1997.
+
+ {(http://3com.com/)}.
+
+ (1998-04-03)
+
+3DNow!
+
+ <architecture> A {floating point} {SIMD} extention from {AMD}.
+
+ [Extension of what? To do what?]
+
+ (2001-12-23)
+
+3DNow! Professional
+
+ <architecture> A {floating point} {SIMD} extention from {AMD},
+ compatible with {Intel}'s {SSE}, introduced with the
+ {Athlon}-4.
+
+ [Relationship to {3DNow!}?]
+
+ (2001-12-23)
+
+3DO
+
+ <company, games, standard> A set of specifications created and
+ owned by the 3DO company, which is a partnership of seven
+ different companies. These specs are the blueprint for making
+ a 3DO Interactive Multiplayer and are licensed to hardware and
+ software producers.
+
+ A 3DO system has an {ARM60} 32-bit {RISC} {CPU} and a graphics
+ engine based around two custom designed graphics and animation
+ processors. It has 2 Megabytes of {DRAM}, 1 Megabyte of
+ {VRAM}, and a double speed {CD-ROM} drive for main storage.
+
+ The {Panasonic} 3DO system can run 3DO Interactive software,
+ play audio CDs (including support for CD+G), view {Photo-CDs},
+ and will eventually be able to play {Video CDs} with a special
+ add-on {MPEG}1 {full-motion video} cartridge. Up to 8
+ {controllers} can be {daisy-chain}ed on the system at once. A
+ keyboard, mouse, light gun, and other peripherals may also
+ some day be hooked into the system, although they are not
+ currently available (December 1993). The 3DO can display
+ {full-motion video}, fully {texture map}ped 3d landscapes,
+ all in 24-bit colour. {Sanyo} and {AT&T} will also release
+ 3DO systems. Sanyo's in mid 1994 and AT&T in late 1994.
+
+ There will be a 3DO add-on cartridge based on the {PowerPC} to
+ enable the 3DO to compete with {Sony}'s {Playstation} console
+ and {Sega}'s {Saturn} console, both of which have a higher
+ specification than the original 3DO. The add-on is commonly
+ known as the M2 or Bulldog. It should hit the shops by
+ Christmas 1995 and will (allegedly) do a million flat shaded
+ polygons per second.
+
+ {3DO Home (http://3do.com/)}.
+
+ {Usenet} newsgroup: {news:rec.games.video.3do}.
+
+ (1994-12-13)
+
+3GL
+
+ {third generation language}
+
+3NF
+
+ {database normalisation}
+
+3Station
+
+ <computer, networking> The archetypal {diskless workstation},
+ developed by {Bob Metcalfe} at {3Com} and first available in
+ 1986/1987.
+
+ The 3Station/2E had a 10 {MHz} {80286} {processor}, 1 {MB} of
+ {RAM} (expandable to 5 MB), {VGA} compatible graphics with 256
+ {KB} of {video RAM}, and integrated {AUI}/{BNC} network
+ {transceivers} for {LAN} access.
+
+ The product used a single {printed-circuit board} with four
+ custom {ASICs}. It had no {floppy disk drive} or {hard disk},
+ it was booted from a {server} and stored all {end-user}
+ {files} there.
+
+ 3Com advertised "significant cost savings" due to the
+ 3Station's ease of installation and low maintenance (this
+ would now be referred to under the banner of "{TCO}").
+
+ The 3Station cost somewhere between an {IBM PC} {clone} and an
+ IBM PC of the day. It was not commercially successful.
+
+ (2000-07-05)
+
+3-tier
+
+ {three-tier}
+
+404
+
+ <abuse> Someone who's clueless. From the {web}
+ message "404, URL Not Found" meaning that the document you've
+ tried to access can't be located.
+
+ "Don't bother asking him...he's 404, man".
+
+ 404 is one of the standard response codes of the {telnet}
+ {protocol} on which the web's {HTTP} is based.
+
+ The first 4 indicates a client error such as a mistyped URL.
+ The middle 0 refers to a general syntax error. The last 4
+ just indicates the specific error in the group of 40x, which
+ also includes 400: Bad Request, 401: Unauthorized, etc.
+
+ (2000-03-18)
+
+4.2BSD
+
+ {Berkeley Software Distribution}
+
+431A
+
+ <hardware> The type of plug which fits a standard "type 600"
+ {British Telecom} telephone socket.
+
+ (1995-01-25)
+
+4.3BSD
+
+ {Berkeley Software Distribution}
+
+4510
+
+ <processor> A {65CE02} with two {6526} IO controllers.
+
+ Used in the {Commodore 65}.
+
+ (1996-04-06)
+
+473L Query
+
+ <language> An English-like {query language} for the US Air
+ Force {473L} system.
+
+ [Sammet 1969, p. 665].
+
+ ["Headquarters USAF Command and Control System Query
+ Language", Info Sys Sci, Proc 2nd Congress, Spartan Books
+ 1965, pp.57-76].
+
+ (1994-10-31)
+
+486
+
+ {Intel 486}
+
+486DX
+
+ {Intel 486}
+
+486SX
+
+ {Intel 486SX}
+
+4GL
+
+ {fourth generation language}
+
+4NF
+
+ {database normalisation}
+
+51forth
+
+ <language> A subroutine-{threaded} {Forth} for the {8051} by
+ Scott Gehmlich. It comes with source and documentation.
+
+ {(ftp://smis-novell-1.massey.ac.nz/giovanni/51forth.zip)}.
+
+ (1993-04-03)
+
+56 kbps
+
+ <communications> (56 kilobits per second) The data capacity of
+ a normal single channel digital telephone channel in North
+ America. The figure is derived from the {bandwidth} of 4 kHz
+ allocated for such a channel and the 16-bit encoding (4000
+ times 16 = 64000) used to change {analogue} signals to
+ digital, minus the 8000 bit/s used for signalling and
+ supervision.
+
+ At the end of 1997 there were two rival {modem} designs
+ capable of this rate: {k56flex} and {US Robotics}' {X2}. In
+ February 1998 the {ITU} proposed a 56kbps standard called
+ {V.90}, which is expected to be formally approved during
+ September 1998.
+
+ (1998-09-15)
+
+56k line
+
+ <communications> A digital connection (possibly a {leased
+ line}, possibly switched) capable of carrying {56 kbps}.
+
+ Compare {DS0}.
+
+ (2000-07-16)
+
+586
+
+ <processor> What {Intel}'s {Pentium} was not called.
+
+5ESS
+
+ {Number 5 Electronic Switching System}
+
+5NF
+
+ {database normalisation}
+
+5th Glove
+
+ <hardware, virtual reality> A {data glove} and flexor strip
+ kit (5th Glove DFK) sold by {Fifth Dimension Technologies} for
+ $495 ($345 for the left-handed version, $45 for each extra
+ flexor strip). The DFK provides a data glove, a flexon strip
+ (with an elbow or knee-joint sensor), an interface card,
+ cables, and KineMusica software. The package uses flexible
+ optical-bending sensing to track hand and arm movement. The
+ glove can be used with 5DT's ultrasonic tracking system, the
+ 5DT Head and Hand tracker ($245), which can track movement
+ from up to two metres away from the unit's transmitter.
+
+ (1998-02-06)
+
+6.001
+
+ <education> /siks dub*l oh wun/, /dub*l oh wun/ or rarely
+ /siks dub*l oh fun/ {MIT}'s introductory computer class for
+ majors, known for its intensity. Developed by {Gerald
+ Sussman} and {Hal Abelson}, the course is taught in {Scheme}
+ and introduces {recursion}, {higher-order functions},
+ {object-oriented programming} and much more. Students who
+ grasp the {meta}circular {interpreter} gain entry into the
+ {Knights of the Lambda-Calculus}. 6.001 has been exported to
+ several other colleges, sometimes successfully. The textbook,
+ "Structure and Interpretation of Computer Programs", written
+ with Julie Sussman is a classic that can be found on the
+ shelves of many computer scientists, whether they took the
+ course or not. Legendary characters from the class, problem
+ sets, and book include the wise Alyssa P. Hacker, Ben
+ Bitdiddle, Lem E. Tweakit and Eva Lu Ator, the careless Louis
+ Reasoner and {Captain Abstraction}.
+
+ (1994-11-22)
+
+610
+
+ <communications> The standard type of two-wire wall socket and
+ plug used for telephones in Australia.
+
+ [Other countries? Full name?]
+
+ (1997-06-26)
+
+6309
+
+ {Hitachi 6309}
+
+64-bit
+
+ <architecture> A term describing a computer architecture based
+ around an {ALU}, {registers} and {data bus} which are 64
+ {bit}s wide.
+
+ 64-bit processors were quite common in 1996, e.g. {Digital}
+ {Alpha}, versions of {Sun} {SPARC}, {MIPS}, {IBM} {AS/4000}.
+ the {PowerPC} and {Intel} were expected to move to 64 bits at
+ their next generation - {PPC 620} and {Intel P7}.
+
+ A 64-bit {address bus} allows the processor to address 18
+ million {gigabytes} as opposed to the mere 4 gigabytes allowed
+ with 32 bits. There were in 1996 already {hard disks} which
+ can hold over 4GB. Floating point calculations can also be
+ more accurate.
+
+ A 64-bit {OS} is needed as well to take advantage of the CPU.
+ In 1996 there were only a few 64-bit operating systems,
+ including {OS/400}, {Digital} {Unix}, {Solaris} (partialy). A
+ 32-bit OS can run on a 64-bit CPU.
+
+ (2004-05-12)
+
+6501
+
+ <hardware> An eight-bit {microprocessor}, the first sold by
+ {MOS Technology}. The 6501 pin-compatible with the
+ {Motorola 6800} and was the first member of the 650x series.
+ It had an on-chip clock oscillator.
+
+ See also {6502}.
+
+ (2001-02-26)
+
+6502
+
+ <hardware> An eight-bit {microprocessor} designed by {MOS
+ Technology} around 1975 and made by {Rockwell}.
+
+ Unlike the {Intel 8080} and its kind, the 6502 had very few
+ {registers}. It was an 8-bit processor, with 16-bit {address
+ bus}. Inside was one 8-bit data register ({accumulator}), two
+ 8-bit {index registers} and an 8-bit {stack pointer} (stack
+ was preset from address 256 to 511). It used these index and
+ stack registers effectively, with more {addressing modes},
+ including a fast zero-page mode that accessed memory locations
+ from address 0 to 255 with an 8-bit address (it didn't have to
+ fetch a second byte for the address).
+
+ Back when the 6502 was introduced, {RAM} was actually faster
+ than {CPU}s, so it made sense to optimise for RAM access
+ rather than increase the number of registers on a chip.
+
+ The 6502 was used in the {BBC Microcomputer}, {Apple II},
+ {Commodore}, {Apple Computer} and {Atari} {personal
+ computers}. {Steve Wozniak} described it as the first chip
+ you could get for less than a hundred dollars (actually a
+ quarter of the {6800} price).
+
+ The 6502's {indirect jump} instruction, JMP (xxxx), was
+ {broken}. If the address was hexadecimal xxFF, the processor
+ would not access the address stored in xxFF and xxFF + 1, but
+ rather xxFF and xx00. The {6510} did not fix this bug, nor
+ was it fixed in any of the other {NMOS} versions of the 6502
+ such as the {8502}. Bill Mensch at {Western Design Center}
+ was probably the first to fix it, in the {65C02}.
+
+ The 6502 also had undocumented instructions.
+
+ The {65816} is an expanded version of the 6502.
+
+ There is a 6502 {assembler} by Doug Jones <jones@cs.uiowa.edu>
+ which supports {macros} and conditional features and can be
+ used for linkage editing of object files. It requires
+ {Pascal}.
+
+ See also {cross-assembler}, {RTI}, {Small-C}.
+
+ (2001-01-02)
+
+650x
+
+ <hardware> A family of {microprocessors} from {MOS
+ Technologies}, based on the design of the {Motorola 6800}
+ (introduced around 1975). The family included the {6502} used
+ in several early {personal computers}.
+
+6510
+
+ <processor> A successor to the {6502}.
+
+ The 6510 was used in the Commodore 64C. Successors included
+ the {8502} used in the {Commodore 128} line.
+
+ (2001-01-02)
+
+6526
+
+ {MOS Technology 6526}
+
+65816
+
+ <processor> An expanded version of the {6502}, with which it
+ is compatible. It has 16-bit {index registers} and {stack
+ pointer}, a 16-bit direct page register and a 24-bit {address
+ bus}. Used in later models of the {Apple II}.
+
+ (1994-10-31)
+
+6800
+
+ {Motorola 6800}
+
+68000
+
+ {Motorola 68000}
+
+68020
+
+ {Motorola 68020}
+
+68030
+
+ {Motorola 68030}
+
+68040
+
+ {Motorola 68040}
+
+68050
+
+ {Motorola 68050}
+
+68060
+
+ {Motorola 68060}
+
+6809
+
+ {Motorola 6809}
+
+680x0
+
+ {Motorola 680x0}
+
+686
+
+ <processor> {Pentium Pro} or possibly {Cyrix 6x86}.
+
+ (1997-05-26)
+
+68HC11
+
+ {Motorola 68HC11}
+
+68LC040
+
+ {Motorola 68LC040}
+
+6to4
+
+ <networking> A {protocol} for transitioning from {IPv4} to
+ {IPv6}. Networks may use 6to4 (or other transitioning protocols)
+ until they support native {dual-stack}.
+
+ Because 6to4 is a form of {tunnelling}, it requires
+ {encapsulation} by a {protocol converter}. This can cause
+ performance problems due to increased {latency} and decreased
+ {MTU} sizes, as described in {RFC 6343
+ (http://tools.ietf.org/html/rfc6343)}.
+
+ {RFC 3056 (http://tools.ietf.org/html/rfc3056)}.
+
+ (2012-12-24)
+
+6x86
+
+ {Cyrix 6x86}
+
+754
+
+ {IEEE Floating Point Standard}
+
+80186
+
+ {Intel 80186}
+
+80188
+
+ {Intel 80188}
+
+80/20 rule
+
+ {eighty-twenty rule}
+
+802.1
+
+ {IEEE 802.1}
+
+802.11a
+
+ <networking> A radio-based {LAN} {protocol} which speaks
+ {OFDM} at 5GHz, one of the two {wi-fi} protocols.
+
+ (2003-09-02)
+
+802.11b
+
+ <networking> An {IEEE} {wireless} {local area networks} (WLAN)
+ {standard} {protocol} which speaks {DSSS} at 2.4GHz. 802.11b
+ is one of the two {wi-fi} protocols. It operates at 11
+ megabits per second (Mbps) compared with {802.11g} which
+ operates at 54 Mbps.
+
+ (2004-01-11)
+
+802.11g
+
+ <networking, standard> An {IEEE} {wireless} {local area
+ network} (WLAN) {standard} {protocol}, expected to be approved
+ in June 2003. 802.11g offers wireless transmission over
+ relatively short distances at up to 54 megabits per second
+ (Mbps).
+
+ 802.11g operates in the 2.4 GHz range and is thus compatible
+ with {802.11b} (11 Mbps Wi-Fi).
+
+ (2004-01-11)
+
+802.2
+
+ {IEEE 802.2}
+
+802.3
+
+ {IEEE 802.3}
+
+80286
+
+ {Intel 80286}
+
+8031
+
+ {Intel 8051}
+
+80386
+
+ {Intel 80386}
+
+8048
+
+ {Intel 8048}
+
+80486
+
+ {Intel 486}
+
+8051
+
+ {Intel 8051}
+
+8052
+
+ {Intel 8051}
+
+8080
+
+ {Intel 8080}
+
+8086
+
+ {Intel 8086}
+
+8088
+
+ {Intel 8088}
+
+80x86
+
+ {Intel 80x86}
+
+822
+
+ {RFC 822}
+
+82430FX
+
+ {Triton I}
+
+82430HX
+
+ {Triton II}
+
+82430MX
+
+ {Mobile Triton}
+
+82430VX
+
+ {Triton VX}
+
+8250
+
+ <hardware> A {UART} that can operate at a maximum of 9600 {baud}.
+
+ The 8250 is used in {IBM PC XT} computers. It works in an
+ {IBM PC AT} under {DOS} but generates unwanted {interrupts}
+ when used at 9600 {baud}. The {IBM PC} {BIOS} has a bug fix
+ for this chip.
+
+ (2004-03-21)
+
+8.3
+
+ <file system, filename extension> A common shorthand for the
+ limits on filename length imposed by the {file system} used by
+ {MS-DOS} and {Microsoft Windows} - at most eight characters,
+ followed by a ".", followed by a {filename extension} of at
+ most three characters.
+
+ {Windows 95} supports long filenames by using multiple
+ directory entries per file. The extra entries are hidden. It
+ also automatically derives an 8.3 name for each file for
+ {backward compatibility} so that older versions of DOS can
+ still access the file.
+
+ (1998-10-05)
+
+8450
+
+ <hardware> A {serial IO chip} with a one-{byte} {FIFO}. The
+ 8450 was introduced with the {Intel 8080}.
+
+ (2004-03-21)
+
+8514
+
+ <hardware> An {IBM} graphics {display standard} supporting a
+ {resolution} of 1024 x 768 {pixels} with 256 colours at 43.5
+ Hz ({interlaced}), or 640 x 480 at 60 Hz interlaced.
+
+ 8514 was introduced at the same time as {VGA} and was
+ superseded by {XGA}.
+
+ (1999-08-01)
+
+8514-A
+
+ {8514}
+
+88000
+
+ {Motorola 88000}
+
+88open
+
+ <body> A consortium with the aim of creating a multi-vendor
+ open computing environment based on the {Motorola 88000}
+ {RISC} processor family.
+
+ (1995-01-26)
+
+8-bit clean
+
+ {eight-bit clean}
+
+8N1
+
+ <jargon> Common shorthand for "eight data bits, no {parity},
+ one {stop bit}", the most common configuration for {serial
+ lines}, e.g. {EIA-232}.
+
+ (1995-01-31)
+
+8 queens problem
+
+ {eight queens puzzle}
+
+8 queens puzzle
+
+ {eight queens puzzle}
+
+8x86
+
+ {Intel 80x86}
+
+90-90 Rule
+
+ {Ninety-Ninety Rule}
+
+9PAC
+
+ <tool> 709 PACkage.
+
+ A {report generator} for the {IBM 7090}, developed in 1959.
+
+ [Sammet 1969, p.314. "IBM 7090 Prog Sys, SHARE 7090 9PAC Part
+ I: Intro and Gen Princs", IBM J28-6166, White Plains, 1961].
+
+ (1995-02-07)
+
+:-)
+
+ {emoticon}
+
+;
+
+ {semicolon}
+
+<
+
+ {less than}
+
+=
+
+ {equals}
+
+>
+
+ {greater than}
+
+?
+
+ {question mark}
+
+??
+
+ <programming> A {Perl} quote-like {operator} used to delimit a
+ {regular expression} (RE) like "?FOO?" that matches FOO at
+ most once. The normal "/FOO/" form of regular expression will
+ match FOO any number of times. The "??" operator will match
+ again after a call to the "reset" operator.
+
+ The operator is usually referred to as "??" but, taken
+ literally, an empty RE like this (or "//") actually means to
+ re-use the last successfully matched regular expression or, if
+ there was none, the empty pattern (which will always match).
+
+ {Unix manual page}: perlop(1).
+
+ (2009-05-28)
+
+@
+
+ {commercial at}
+
+\
+
+ {backslash}
+
+\{@}
+
+ <chat> A rare {emoticon} supposed to represent a rose.
+
+ (2013-06-26)
+
+A#
+
+ <language> /A sharp/ A separable component of Version 2 of the
+ {AXIOM*} computer algebra system. It provides a programming
+ language with an {optimising compiler}, an {intermediate code}
+ {interpreter}, and a library of data structures and
+ mathematical {abstractions}. The compiler produces
+ {stand-alone executable} programs, {object} libraries in
+ {native} {operating system} formats, {portable} {bytecode}
+ libraries, {C} and {Lisp} {source code}.
+
+ The A# programming language has support for {object-oriented}
+ and {functional programming} styles. Both types and functions
+ are {first class} values that can be manipulated with a range
+ of flexible and composable {primitives} and user programs.
+ The A# language design places particular emphasis on
+ compilation for efficient {machine code} and portability.
+
+ Ports have been made to various 16, 32, and 64 bit
+ architectures: {RS/6000}, {SPARC}, {DEC Alpha}, {i386},
+ {i286}, {Motorola 680x0}, {S 370}; several {operating
+ systems}: {Linux}, {AIX}, {SunOS}, {HP/UX}, {Next}, {Mach} and
+ other {Unix} systems, {OS/2}, {DOS}, {Microsoft Windows},
+ {VMS} and {CMS}; {C} compilers: {Xlc}, {gcc}, {Sun},
+ {Borland}, {Metaware} and {MIPS} C.
+
+ (1995-02-07)
+
+A-0
+
+ <language> (Or A0) A language for the {UNIVAC I} or II, using
+ {three-address code} instructions for solving mathematical
+ problems. A-0 was the first language for which a {compiler}
+ was developed. It was produced by {Grace Hopper}'s team at
+ {Remington Rand} in 1952. Later internal versions were A-1,
+ A-2, A-3, AT-3. AT-3 was released as {MATH-MATIC}.
+
+ ["The A-2 Compiler System", Rem Rand, 1955].
+
+ [Sammet 1969, p. 12].
+
+ (1995-12-03)
+
+a1
+
+ <language> Address 1 code.
+
+ An a1 code {interpreter}, by Matthew Newhook
+ <matthew@engr.mun.ca> was used to test compiler output. It
+ requires {gcc} 2.4.2 or higher and is portable to computers
+ with {memory segment} protection.
+
+ {(ftp://ftp.cs.mun.ca/pub/a1)}.
+
+ (1994-07-19)
+
+A1 security
+
+ {Orange Book}
+
+A20 handler
+
+ <software, storage> {IBM PC} memory manager software providing
+ {HMA}. {XMM}s usually provide this functionality. Named
+ after the 21st address line (A20), controlling the access to
+ HMA.
+
+ (1996-01-10)
+
+A-3
+
+ {ARITH-MATIC}
+
+A3D
+
+ <hardware> (Aureal 3-Dimensional?) A technology developed by
+ {Aureal} that delivers sound with a three-dimensional effect
+ through two speakers. Many modern {sound cards} and PC games
+ now support this feature.
+
+ A3D differs from the various forms of {surround sound} in that
+ it only requires two speakers, while surround sound typically
+ requires four or five. It is sometimes less convincing than
+ surround sound but is supposedly better in {interactive}
+ environments. For example, PC games in which sounds often
+ move from one speaker to another favour A3D, while
+ pre-recorded video favours surround sound.
+
+ {(http://a3d.com/)}.
+
+ (1999-01-26)
+
+A4C
+
+ {Authentication, Authorization, Accounting, Auditing and Charging}
+
+a56
+
+ <language> An {assembler} for the {Motorola} {DSP56000} and
+ {DSP56001} {digital signal processors} by Quinn Jensen
+ <jensenq@qcj.icon.com>. Version 1.1 is available from an
+ {alt.sources} archive or {(ftp://wuarchive.wustl.edu/)}.
+
+ (1992-08-10)
+
+AAC
+
+ {Advanced Audio Coding}
+
+AADL
+
+ {Axiomatic Architecture Description Language}
+
+AAL
+
+ {ATM Adaptation Layer}
+
+AAP
+
+ {Association of American Publishers}
+
+AAP DTD
+
+ <standard> A {DTD} for a standard {SGML} document type for
+ scientific documents, defined by the {Association of American
+ Publishers}.
+
+ (1994-11-08)
+
+aard
+
+ <programming, tool> (Dutch for "earth") A tool to check memory
+ use for {C++} programs, written by Steve Reiss
+ <spr@cs.brown.edu> (who names his programs after living
+ systems).
+
+ Aard tracks the state of each byte of memory in the {heap} and
+ the {stack}. The state can be one of Undefined,
+ Uninitialised, Free or Set. The program can detect invalid
+ transitions (i.e. attempting to set or use undefined or free
+ storage or attempting to access uninitialised storage).
+
+ In addition, the program keeps track of heap use through
+ {malloc} and {free} and at the end of the run reports memory
+ blocks that were not freed and that are not accessible
+ (i.e. {memory leaks}).
+
+ The tools works using a spliced-in {shared library} on
+ {SPARCs} running {C++} 3.0.1 under {SunOS} 4.X.
+
+ {(ftp://wilma.cs.brown.edu/pub/aard.tar.Z)}.
+
+ (1998-03-03)
+
+AARP
+
+ {Apple Address Resolution Protocol}
+
+AARP probe packets
+
+ <networking> {AARP} {packets} sent out on a nonextended
+ {AppleTalk} network to discover whether a randomly selected
+ node ID is being used by any node. If not, the sending node
+ uses the node ID. If so, it chooses a different ID and sends
+ more AARP probe packets.
+
+ (1997-05-03)
+
+AAUI
+
+ {Apple Attachment Unit Interface}
+
+A&B
+
+ <communications> A {bit signaling procedure} used in most {T1}
+ transmission facilities where one bit from every sixth frame
+ of each of 24 T1 {subchannels} is used for carrying
+ {supervisory signaling}.
+
+ [What does it stand for? Is this the same as "{bit
+ robbing}"?]
+
+ (1997-05-05)
+
+abbrev
+
+ <jargon> /*-breev'/, /*-brev'/ Common abbreviation for
+ "abbreviation".
+
+ (1995-02-27)
+
+Abbreviated Test Language for Avionics Systems
+
+ <language> (ATLAS) A Mil-spec language for automatic testing
+ of avionics equipment. ATLAS replaced {Gaelic} and several
+ other test languages.
+
+ ["IEEE Standard ATLAS Test Language", IEEE Std 416-1976].
+
+ (2000-04-03)
+
+ABC
+
+ 1. <computer> {Atanasoff-Berry Computer}.
+
+ 2. <language> An {imperative language} and programming
+ environment from {CWI}, Netherlands. It is interactive,
+ structured, high-level, and easy to learn and use. It is a
+ general-purpose language which you might use instead of
+ {BASIC}, {Pascal} or {AWK}. It is not a systems-programming
+ language but is good for teaching or prototyping.
+
+ ABC has only five data types that can easily be combined;
+ {strong typing}, yet without declarations; data limited only
+ by memory; refinements to support top-down programming;
+ nesting by indentation. Programs are typically around a
+ quarter the size of the equivalent {Pascal} or {C} program,
+ and more readable.
+
+ ABC includes a programming environment with {syntax-directed}
+ editing, {suggestions}, {persistent variables} and multiple
+ workspaces and {infinite precision} arithmetic.
+
+ An example function words to collect the set of all words in a
+ document:
+
+ HOW TO RETURN words document:
+ PUT {} IN collection
+ FOR line in document:
+ FOR word IN split line:
+ IF word not.in collection:
+ INSERT word IN collection
+ RETURN collection
+
+ {Interpreter}/{compiler}, version 1.04.01, by Leo Geurts,
+ Lambert Meertens, Steven Pemberton <Steven.Pemberton@cwi.nl>.
+ ABC has been ported to {Unix}, {MS-DOS}, {Atari}, {Macintosh}.
+
+ {(http://cwi.nl/cwi/projects/abc.html)}.
+
+ {FTP eu.net (ftp://ftp.eu.net/programming/languages/abc)},
+ {FTP nluug.nl (ftp://ftp.nluug.nl/programming/languages/abc)},
+ {FTP uunet (ftp://ftp.uu.net/languages/abc)}.
+
+ Mailing list: <abc-list-request@cwi.nl>.
+
+ E-mail: <abc@cwi.nl>.
+
+ ["The ABC Programmer's Handbook" by Leo Geurts, Lambert
+ Meertens and Steven Pemberton, published by Prentice-Hall
+ (ISBN 0-13-000027-2)].
+
+ ["An Alternative Simple Language and Environment for PCs" by
+ Steven Pemberton, IEEE Software, Vol. 4, No. 1, January 1987,
+ pp. 56-64.]
+
+ (1995-02-09)
+
+ 2. <language> Argument, Basic value, C?.
+
+ An {abstract machine} for implementation of {functional
+ languages} and its intermediate code.
+
+ [P. Koopman, "Functional Programs as Executable
+ Specifications", 1990].
+
+ (1995-02-09)
+
+ABC ALGOL
+
+ <language> An extension of {ALGOL 60} with arbitrary data
+ structures and user-defined operators, for {symbolic
+ mathematics}.
+
+ ["ABC ALGOL, A Portable Language for Formula Manipulation
+ Systems", R.P. van de Riet, Amsterdam Math Centrum 1973].
+
+ (1994-10-28)
+
+ABCL/1
+
+ <language> An Object-Based Concurrent Language.
+
+ The language for the {ABCL} {MIMD} system, written by Akinori
+ Yonezawa <matsu@is.s.u-tokyo.ac.jp> of Department of
+ Information Science, {Tokyo University} in 1986. ABCL/1 uses
+ {asynchronous} {message passing} to {objects}. It requires
+ {Common Lisp}. Implementations in {KCL} and {Symbolics Lisp}
+ are available from the author.
+
+ {(ftp://camille.is.s.u-tokyo.ac.jp/)}.
+
+ E-mail: <abcl@is.s.u-tokyo.ac.jp>.
+
+ ["ABCL: An Object-Oriented Concurrent System", A. Yonezawa ed,
+ MIT Press 1990]. (1990-05-23).
+
+ (1995-02-09)
+
+ABCL/c+
+
+ <language> A {concurrent} {object-oriented} language, an
+ extension of {ABCL/1} based on {C}.
+
+ ["An Implementation of An Operating System Kernel using
+ Concurrent Object Oriented Language ABCL/c+", N. Doi et al in
+ ECOOP '88, S. Gjessing et al eds, LNCS 322, Springer 1988].
+
+ (1994-11-08)
+
+ABCL/R
+
+ <language> A {reflective} subset of {ABCL/1}, written in
+ ABCL/1 by Yonezawa of {Tokyo Institute of Technology} in 1988.
+
+ {(ftp://camille.is.s.u-tokyo.ac.jp/pub/abclr)}.
+
+ ["Reflection in an Object-Oriented Concurrent Language",
+ T. Watanabe et al, SIGPLAN Notices 23(11):306-315 (Nov 1988)].
+
+ (1994-11-08)
+
+ABCL/R2
+
+ <language> An {object-oriented}, {concurrent}, {reflective}
+ language based on {Hybrid Group Architecture}. ABCL/R2 was
+ produced by <masuhara@is.s.u-tokyo.ac.jp>,
+ <matsu@is.s.u-tokyo.ac.jp>, <takuo@is.s.u-tokyo.ac.jp>,
+ <yonezawa@is.s.u-tokyo.ac.jp>, at the {Tokyo Institute of
+ Technology} in 1992.
+
+ As a reflective language, an ABCL/R2 program can dynamically
+ control its own behaviour, such as {scheduling} policy, from
+ within a user-program. This system has almost all functions
+ of {ABCL/1} and is written in {Common Lisp}.
+
+ {(ftp://camille.is.s.u-tokyo.ac.jp/pub/abclr2/)}.
+
+ (1993-01-28)
+
+abduction
+
+ <logic> The process of {inference} to the best explanation.
+
+ "Abduction" is sometimes used to mean just the generation of
+ hypotheses to explain observations or conclusionsm, but the
+ former definition is more common both in philosophy and
+ computing.
+
+ The {semantics} and the implementation of abduction cannot be
+ reduced to those for {deduction}, as explanation cannot be
+ reduced to implication.
+
+ Applications include fault diagnosis, plan formation and
+ {default reasoning}.
+
+ {Negation as failure} in {logic programming} can both be given
+ an abductive interpretation and also can be used to implement
+ abduction. The abductive semantics of negation as failure
+ leads naturally to an {argumentation}-theoretic interpretation
+ of default reasoning in general.
+
+ [Better explanation? Example?]
+
+ ["Abductive Inference", John R. Josephson
+ <jj@cis.ohio-state.edu>].
+
+ (2000-12-07)
+
+ABEND
+
+ <jargon> /o'bend/, /*-bend'/ ABnormal END. Abnormal
+ termination (of {software}); {crash}; {lossage}. Derives from
+ an error message on the {IBM 360}; used jokingly by hackers
+ but seriously mainly by {code grinders}. Usually capitalised,
+ but may appear as "abend". Hackers will try to persuade you
+ that ABEND is called "abend" because it is what system
+ operators do to the computer late on Friday when they want to
+ call it a day, and hence is from the German "Abend" =
+ "Evening".
+
+ [{Jargon File}]
+
+ (1994-11-08)
+
+AberMUD
+
+ <games> The first popular {open source} {MUD}. The first
+ version of AberMUD, named after Aberystwyth, UK, was written
+ in {B} by Alan Cox, Richard Acott, Jim Finnis, and Leon
+ Thrane, at University of Wales, Aberystwyth for an old
+ {Honeywell} {mainframe} and opened in 1987. The gameplay was
+ heavily influenced by {MUD1}, written by Roy Trubshaw and
+ Richard Bartle, which Alan Cox had played at the University of
+ Essex. In late 1988, Alan Cox ported AberMUD to {C} so it
+ could run under {UNIX} on Southampton University's Maths
+ machines. This version was named AberMUD2. Various other
+ versions followed.
+
+ (2008-11-24)
+
+ABI
+
+ {Application Binary Interface}
+
+ABLE
+
+ <language> A simple language for accountants.
+
+ ["ABLE, The Accounting Language, Programming and Reference
+ Manual," Evansville Data Proc Center, Evansville, IN, Mar
+ 1975].
+
+ [Listed in SIGPLAN Notices 13(11):56 (Nov 1978)].
+
+ (1994-11-08)
+
+ABM
+
+ {Asynchronous Balanced Mode}
+
+ABNF
+
+ {Augmented Backus-Naur Form}
+
+abort
+
+ <programming> To terminate a program or {process} abnormally
+ and usually suddenly, with or without {diagnostic}
+ information. "My program aborted", "I aborted the
+ transmission". The noun form in computing is "abort", not
+ "abortion", e.g. "We've had three aborts over the last two
+ days".
+
+ If a {Unix} {kernel} aborts it is known as a {panic}.
+
+ (1997-01-07)
+
+ABP
+
+ 1. <networking> {Alternating bit protocol}.
+
+ 2. {Microsoft} {Address Book Provider}.
+
+ABR
+
+ {automatic baud rate detection}
+
+abscissa
+
+ <mathematics> The horizontal or x coordinate on an (x, y)
+ graph; the input of a function against which the output is
+ plotted.
+
+ The vertical or y coordinate is the "{ordinate}".
+
+ See {Cartesian coordinates}.
+
+ (1997-07-08)
+
+ABSET
+
+ <language> An early {declarative language} from the
+ {University of Aberdeen}.
+
+ ["ABSET: A Programming Language Based on Sets", E.W. Elcock et
+ al, Mach Intell 4, Edinburgh U Press, 1969, pp.467-492].
+
+ (1994-11-08)
+
+absolute path
+
+ <file system> A {path} relative to the {root directory}. Its
+ first character must be the {pathname separator}.
+
+ (1996-11-21)
+
+absolute pathname
+
+ <file system> A {pathname} relative to the {root directory}.
+
+ (1996-11-21)
+
+abstract
+
+ <philosophy> A description of a concept that leaves out some
+ information or details in order to simplify it in some useful
+ way.
+
+ Abstraction is a powerful technique that is applied in many
+ areas of computing and elsewhere. For example: {abstract
+ class}, {data abstraction}, {abstract interpretation},
+ {abstract syntax}, {Hardware Abstraction Layer}.
+
+ (2009-12-09)
+
+abstract class
+
+ <programming> In {object-oriented programming}, a {class}
+ designed only as a parent from which sub-classes may be
+ derived, but which is not itself suitable for instantiation.
+ Often used to "abstract out" incomplete sets of features which
+ may then be shared by a group of sibling sub-classes which add
+ different variations of the missing pieces.
+
+ (1994-11-08)
+
+abstract data type
+
+ <programming> (ADT) A kind of {data abstraction} where a
+ type's internal form is hidden behind a set of {access
+ functions}. Values of the type are created and inspected only
+ by calls to the access functions. This allows the
+ implementation of the type to be changed without requiring any
+ changes outside the {module} in which it is defined.
+
+ {Objects} and ADTs are both forms of data abstraction, but
+ objects are not ADTs. Objects use procedural abstraction
+ (methods), not type abstraction.
+
+ A classic example of an ADT is a {stack} data type for which
+ functions might be provided to create an empty stack, to
+ {push} values onto a stack and to {pop} values from a stack.
+
+ {Reynolds paper
+ (http://cis.upenn.edu/~gunter/publications/documents/taoop94.html)}.
+
+ {Cook paper "OOP vs ADTs"
+ (http://wcook.org/papers/OOPvsADT/CookOOPvsADT90.pdf)}.
+
+ (2003-07-03)
+
+abstract interpretation
+
+ <theory> A partial execution of a program which gains
+ information about its {semantics} (e.g. control structure,
+ flow of information) without performing all the calculations.
+ Abstract interpretation is typically used by compilers to
+ analyse programs in order to decide whether certain
+ optimisations or transformations are applicable.
+
+ The objects manipulated by the program (typically values and
+ functions) are represented by points in some {domain}. Each
+ abstract domain point represents some set of real
+ ("{concrete}") values.
+
+ For example, we may take the abstract points "+", "0" and "-"
+ to represent positive, zero and negative numbers and then
+ define an abstract version of the multiplication operator, *#,
+ which operates on abstract values:
+
+ *# | + 0 -
+ ---|------
+ + | + 0 -
+ 0 | 0 0 0
+ - | - 0 +
+
+ An interpretation is "safe" if the result of the abstract
+ operation is a safe approximation to the abstraction of the
+ concrete result. The meaning of "a safe approximation"
+ depends on how we are using the results of the analysis.
+
+ If, in our example, we assume that smaller values are safer
+ then the "safety condition" for our interpretation (#) is
+
+ a# *# b# <= (a * b)#
+
+ where a# is the abstract version of a etc.
+
+ In general an interpretation is characterised by the {domains}
+ used to represent the basic types and the abstract values it
+ assigns to constants (where the constants of a language
+ include primitive functions such as *). The interpretation of
+ constructed types (such as user defined functions, {sum types}
+ and {product types}) and expressions can be derived
+ systematically from these basic domains and values.
+
+ A common use of {abstract interpretation} is {strictness
+ analysis}.
+
+ See also {standard interpretation}.
+
+ (1994-11-08)
+
+abstraction
+
+ 1. Generalisation; ignoring or hiding details to capture some
+ kind of commonality between different instances. Examples are
+ {abstract data types} (the representation details are hidden),
+ {abstract syntax} (the details of the {concrete syntax} are
+ ignored), {abstract interpretation} (details are ignored to
+ analyse specific properties).
+
+ 2. <programming> Parameterisation, making something a function
+ of something else. Examples are {lambda abstractions} (making
+ a term into a function of some variable), {higher-order
+ functions} (parameters are functions), {bracket abstraction}
+ (making a term into a function of a variable).
+
+ Opposite of {concretisation}.
+
+ (1998-06-04)
+
+abstract machine
+
+ 1. <language> A processor design which is not intended to be
+ implemented as {hardware}, but which is the notional executor
+ of a particular {intermediate language} (abstract machine
+ language) used in a {compiler} or {interpreter}. An abstract
+ machine has an {instruction set}, a {register set} and a model
+ of memory. It may provide instructions which are closer to
+ the language being compiled than any physical computer or it
+ may be used to make the language implementation easier to
+ {port} to other {platforms}.
+
+ A {virtual machine} is an abstract machine for which an
+ {interpreter} exists.
+
+ Examples: {ABC}, {Abstract Machine Notation}, {ALF}, {CAML},
+ {F-code}, {FP/M}, {Hermes}, {LOWL},
+ {Christmas}, {SDL}, {S-K reduction machine}, {SECD}, {Tbl},
+ {Tcode}, {TL0}, {WAM}.
+
+ 2. <theory> A procedure for executing a set of instructions in
+ some formal language, possibly also taking in input data and
+ producing output. Such abstract machines are not intended to
+ be constructed as {hardware} but are used in thought
+ experiments about {computability}.
+
+ Examples: {Finite State Machine}, {Turing Machine}.
+
+ (1995-03-13)
+
+Abstract Machine Notation
+
+ <language> (AMN) A language for specifying {abstract machines}
+ in the {B-Method}, based on the mathematical theory of
+ {Generalised Substitutions}.
+
+ (1995-03-13)
+
+abstract syntax
+
+ <language, data> A form of representation of data that is
+ independent of machine-oriented structures and encodings and
+ also of the physical representation of the data. Abstract
+ syntax is used to give a high-level description of programs
+ being compiled or messages passing over a communications link.
+
+ A {compiler}'s internal representation of a program will
+ typically be an {abstract syntax tree}. The abstract syntax
+ specifies the tree's structure is specified in terms of
+ categories such as "statement", "expression" and
+ "{identifier}". This is independent of the source syntax
+ ({concrete syntax}) of the language being compiled (though it
+ will often be very similar).
+
+ A {parse tree} is similar to an abstract syntax tree but it
+ will typically also contain features such as parentheses which
+ are syntactically significant but which are implicit in the
+ structure of the {abstract syntax tree}.
+
+ (1998-05-26)
+
+Abstract Syntax Notation 1
+
+ <language, standard, protocol> (ASN.1, X.208, X.680) An
+ {ISO}/{ITU-T} {standard} for transmitting structured {data} on
+ {networks}, originally defined in 1984 as part of {CCITT
+ X.409} '84. ASN.1 moved to its own standard, X.208, in 1988
+ due to wide applicability. The substantially revised 1995
+ version is covered by the X.680 series.
+
+ ASN.1 defines the {abstract syntax} of {information} but does
+ not restrict the way the information is encoded. Various
+ ASN.1 encoding rules provide the {transfer syntax} (a
+ {concrete} representation) of the data values whose {abstract
+ syntax} is described in ASN.1. The standard ASN.1 encoding
+ rules include {BER} (Basic Encoding Rules - X.209), {CER}
+ (Canonical Encoding Rules), {DER} (Distinguished Encoding
+ Rules) and {PER} (Packed Encoding Rules).
+
+ ASN.1 together with specific ASN.1 encoding rules facilitates
+ the exchange of structured data especially between
+ {application programs} over networks by describing data
+ structures in a way that is independent of machine
+ architecture and implementation language.
+
+ {OSI} {Application layer} {protocols} such as {X.400} {MHS}
+ {electronic mail}, {X.500} directory services and {SNMP} use
+ ASN.1 to describe the {PDU}s they exchange.
+
+ Documents describing the ASN.1 notations: {ITU-T} Rec. X.680,
+ {ISO} 8824-1; {ITU-T} Rec. X.681, {ISO} 8824-2; {ITU-T}
+ Rec. X.682, {ISO} 8824-3; {ITU-T} Rec. X.683, {ISO} 8824-4
+
+ Documents describing the ASN.1 encoding rules: {ITU-T}
+ Rec. X.690, {ISO} 8825-1; {ITU-T} Rec. X.691, {ISO} 8825-2.
+
+ [M. Sample et al, "Implementing Efficient Encoders and
+ Decoders for Network Data Representations", IEEE Infocom 93
+ Proc, v.3, pp. 1143-1153, Mar 1993. Available from Logica,
+ UK].
+
+ See also {snacc}.
+
+ (2005-07-03)
+
+abstract syntax tree
+
+ <compiler> (AST) A data structure representing something which
+ has been parsed, often used as a {compiler} or {interpreter}'s
+ internal representation of a program while it is being
+ optimised and from which {code generation} is performed. The
+ range of all possible such structures is described by the
+ {abstract syntax}.
+
+ (1994-11-08)
+
+Abstract-Type and Scheme-Definition Language
+
+ <language> (ASDL) A language developed as part of {Esprit}
+ project {GRASPIN}, as a basis for generating {language-based
+ editors} and environments. It combines an {object-oriented}
+ type system, syntax-directed translation schemes and a
+ target-language interface.
+
+ ["ASDL - An Object-Oriented Specification Language for
+ Syntax-Directed Environments", M.L. Christ-Neumann et al,
+ European Software Eng Conf, Strasbourg, Sept 1987, pp.77-85].
+
+ (1996-02-19)
+
+Abstract Windowing Toolkit
+
+ {Abstract Window Toolkit}
+
+Abstract Window Toolkit
+
+ <graphics> (AWT) {Java}'s {platform}-independent {windowing},
+ graphics, and user-interface {toolkit}. The AWT is part of
+ the {Java Foundation Classes} (JFC) - the standard {API} for
+ providing a {graphical user interface} (GUI) for a Java
+ program.
+
+ Compare: {SWING}.
+
+ ["Java in a Nutshell", O'Reilly].
+
+ {(http://java.sun.com/products/jdk/awt/)}.
+
+ (2000-07-26)
+
+ABSYS
+
+ <language> An early {declarative language} from the
+ {University of Aberdeen} which anticipated a number of
+ features of Prolog.
+
+ ["ABSYS: An Incremental Compiler for Assertions", J.M. Foster
+ et al, Mach Intell 4, Edinburgh U Press, 1969, pp. 423-429].
+
+ (1994-11-08)
+
+AC2
+
+ <audio> An {audio} format, succeded by {AC3}.
+
+ (2001-12-18)
+
+AC3
+
+ <audio> An {audio} format by Sony[?], the successor of {AC2}.
+ AC3 is used for multi-channel {audio} for {digital video}.
+
+ (2001-12-18)
+
+ACA
+
+ {Application Control Architecture}
+
+ACAP
+
+ {Application Configuration Access Protocol}
+
+Accelerated Graphics Port
+
+ <hardware, graphics> (AGP) A {bus} specification by {Intel}
+ which gives low-cost 3D {graphics cards} faster access to
+ {main memory} on {personal computers} than the usual {PCI}
+ bus.
+
+ AGP dynamically allocates the PC's normal {RAM} to store the
+ screen image and to support {texture mapping}, {z-buffering}
+ and {alpha blending}.
+
+ Intel has built AGP into a {chipset} for its {Pentium II}
+ microprocessor. AGP cards are slightly longer than a PCI
+ card.
+
+ AGP operates at 66 {MHz}, doubled to 133 MHz, compared with
+ PCI's 33 Mhz. AGP allows for efficient use of {frame buffer}
+ memory, thereby helping 2D graphics performance as well.
+
+ AGP provides a coherent memory management design which allows
+ scattered data in system memory to be read in rapid bursts.
+ AGP reduces the overall cost of creating high-end graphics
+ subsystems by using existing system memory.
+
+ {Specification
+ (http://developer.intel.com/technology/agp/downloads/agp20.htm)}.
+
+ (2004-07-19)
+
+accelerator
+
+ <hardware> Additional hardware to perform some function faster
+ than is possible in software running on the normal {CPU}.
+ Examples include {graphics accelerators} and {floating-point
+ accelerators}.
+
+ (1994-11-08)
+
+Accent
+
+ <language> A very high level interpreted language from
+ {CaseWare, Inc.} with strings and tables. It is {strongly
+ typed} and has remote function calls.
+
+ (1994-11-08)
+
+accept
+
+ <library, networking> {Berkeley} {Unix} networking {socket}
+ library routine to satisfy a connection request from a remote
+ {host}. A specified socket on the local host (which must be
+ capable of accepting the connection) is connected to the
+ requesting socket on the remote host. The remote socket's
+ socket address is returned.
+
+ {Unix manual pages}: accept(2), connect(2).
+
+ (1994-11-08)
+
+Acceptable Use Policy
+
+ <networking> (AUP) Rules applied by many {transit networks}
+ which restrict the use to which the network may be put. A
+ well known example is {NSFNet} which does not allow commercial
+ use. Enforcement of AUPs varies with the network.
+
+ (1994-11-08)
+
+acceptance testing
+
+ <programming> Formal testing conducted to determine whether a
+ system satisfies its acceptance criteria and thus whether the
+ customer should accept the system.
+
+ (1996-05-10)
+
+Acceptance, Test Or Launch Language
+
+ <language> (ATOLL) The language used for automating the
+ checking and launch of Saturn rockets.
+
+ ["SLCC ATOLL User's Manual", IBM 70-F11-0001, Huntsville AL
+ Dec 1970].
+
+ (2000-04-03)
+
+acceptor
+
+ {Finite State Machine}
+
+Access
+
+ 1. <language> An English-like query language used in the
+ {Pick} {operating system}.
+
+ 2. <database, product> {Microsoft Access}.
+
+ (1994-11-08)
+
+Access Control List
+
+ <networking> (ACL) A list of the services available on a
+ {server}, each with a list of the {hosts} permitted to use the
+ service.
+
+ (1994-11-08)
+
+access method
+
+ <networking> 1. The way that network devices access the
+ network medium.
+
+ 2. Software in an {SNA} processor that controls the flow of
+ data through a {network}.
+
+ [{physical layer}?]
+
+ (1998-03-02)
+
+access permission
+
+ {permission}
+
+access point
+
+ <networking> (AP) Any device that acts as a communication hub
+ to allow users of a {wireless network} to connect to a {wired
+ LAN}. APs are important for providing heightened wireless
+ {security} and for extending the physical range of service a
+ wireless user has access to.
+
+ (2010-03-21)
+
+access time
+
+ <hardware, storage> The average time interval between a
+ storage peripheral (usually a {disk drive} or {semiconductor}
+ memory) receiving a request to read or write a certain
+ location and returning the value read or completing the write.
+
+ (1997-06-14)
+
+ACCLAIM
+
+ <project> A European Union {ESPRIT} {Basic Research Action}.
+
+ [What's it about?]
+
+ (1994-11-08)
+
+Accounting File
+
+ <operating system> A file which holds records of the resources
+ used by individual jobs. These records are used to regulate,
+ and calculate charges for, resources. An entry is opened in
+ the accounting file as each job begins.
+
+ (1996-12-08)
+
+accounting management
+
+ <networking> The process of identifying individual and group
+ access to various network resources to ensure proper access
+ capabilities ({bandwidth} and security) or to properly charge
+ the various individuals and departments. Accounting
+ management is one of five categories of {network management}
+ defined by {ISO} for management of {OSI} {networks}.
+
+ (1997-05-05)
+
+Account Representative
+
+ <job> A person in a company who identifies new accounts,
+ analyses customer needs, proposes business solutions,
+ negotiates and oversees the implementation of new projects.
+
+ (2004-03-08)
+
+ACCU
+
+ {Association of C and C++ Users}
+
+accumulator
+
+ <processor> In a {central processing unit}, a {register} in
+ which intermediate results are stored. Without an
+ accumulator, it would be necessary to write the result of each
+ calculation (addition, multiplication, {shift}, etc.) to {main
+ memory} and read them back. Access to main memory is slower
+ than access to the accumulator which usually has direct paths
+ to and from the {arithmetic and logic unit} (ALU).
+
+ The {canonical} example is summing a list of numbers. The
+ accumulator is set to zero initially, each number in turn is
+ added to the value in the accumulator and only when all
+ numbers have been added is the result written to main memory.
+
+ Modern CPUs usually have many registers, all or many of which
+ can be used as accumulators. For this reason, the term
+ "accumulator" is somewhat archaic. Use of it as a synonym for
+ "register" is a fairly reliable indication that the user has
+ been around for quite a while and/or that the architecture
+ under discussion is quite old. The term in full is almost
+ never used of microprocessor registers, for example, though
+ symbolic names for arithmetic registers beginning in "A"
+ derive from historical use of the term "accumulator" (and not,
+ actually, from "arithmetic"). Confusingly, though, an "A"
+ register name prefix may also stand for "address", as for
+ example on the {Motorola} {680x0} family.
+
+ 2. <programming> A register, memory location or variable being
+ used for arithmetic or logic (as opposed to addressing or a
+ loop index), especially one being used to accumulate a sum or
+ count of many items. This use is in context of a particular
+ routine or stretch of code. "The FOOBAZ routine uses A3 as an
+ accumulator."
+
+ [{Jargon File}]
+
+ (1999-04-20)
+
+accuracy
+
+ <mathematics> How close to the real value a measurement is.
+
+ Compare {precision}.
+
+ (1998-04-19)
+
+ACE
+
+ 1. {Advanced Computing Environment}.
+
+ 2. {Adaptive Communication Environment}.
+
+ACF
+
+ {Advanced Communications Function}
+
+ACF/NCP
+
+ {Advanced Communication Function/Network Control Program}
+
+ACIA
+
+ {Asynchronous Communications Interface Adapter}
+
+ACID
+
+ <programming> A {mnemonic} for the properties a transaction
+ should have to satisfy the {Object Management Group}
+ {Transaction Service} specifications. A transaction should be
+ {Atomic}, its result should be Consistent, Isolated
+ (independent of other transactions) and Durable (its effect
+ should be permanent).
+
+ The {Transaction Service} specifications which part of the
+ {Object Services}, an adjunct to the {CORBA} specifications.
+
+ (1997-05-15)
+
+ACIS
+
+ <graphics> Andy, Charles, Ian's System.
+
+ A {geometric engine} that most {CAD} packages now use. ACIS
+ uses a sophisticated {object-oriented} approach for modelling,
+ the data is stored in {boundary representation}. Acis is
+ owned by {Spatial Technologies}.
+
+ [How does this differ from "solid modelling"?].
+
+ (1996-03-21)
+
+ACK
+
+ 1. <character> /ak/ The {mnemonic} for the ACKnowledge
+ character, {ASCII} code 6.
+
+ 2. <communications> A message transmitted to indicate that
+ some data has been received correctly. Typically, if the
+ sender does not receive the ACK message after some
+ predetermined time, or receives a {NAK}, the original data
+ will be sent again.
+
+ [{Jargon File}]
+
+ (1997-01-07)
+
+ACL
+
+ 1. {Access Control List}.
+
+ 2. {Association for Computational Linguistics}.
+
+ 3. A Coroutine Language.
+
+ A {Pascal}-based implementation of {coroutines}.
+
+ ["Coroutines", C.D. Marlin, LNCS 95, Springer 1980].
+
+ (1994-11-08)
+
+ACM
+
+ 1. <body> The {Association for Computing}.
+
+ 2. <communications> {addressed call mode}.
+
+ACME
+
+ <company, jargon> /ak'mee/ 1. A Company that Makes Everything.
+ The {canonical} imaginary business. Possibly also derived
+ from the word "acme" meaning "highest point".
+
+ 2. A program for {MS-DOS}.
+
+ [What does it do?]
+
+ (1994-11-08)
+
+ACOM
+
+ <language> An early system on the {IBM 705}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1994-11-08)
+
+acorn
+
+ {Acorn Computers Ltd.}
+
+Acorn Archimedes
+
+ {Archimedes}
+
+Acorn Computer Group
+
+ <company> A holding company for {Acorn Computers} Limited,
+ Acorn Australia, Acorn New Zealand, Acorn GmbH and {Online
+ Media}. Acorn Computer Group owns 43% of {Advanced RISC
+ Machines} Ltd.
+
+ (1994-11-08)
+
+Acorn Computers Ltd.
+
+ <company> A UK computer manufacturer, part of the {Acorn
+ Computer Group} plc. Acorn was founded on 1978-12-05, on a
+ kitchen table in a back room. Their first creation was an
+ electronic slot machine. After the {Acorn System 1}, 2 and 3,
+ Acorn launched the first commercial {microcomputer} - the
+ {ATOM} in March 1980. In April 1981, Acorn won a contract
+ from the {BBC} to provide the {PROTON}. In January 1982 Acorn
+ launched the {BBC Microcomputer} System. At one time, 70% of
+ microcomputers bought for UK schools were BBC Micros.
+
+ The Acorn Computer Group went public on the Unlisted
+ Securities Market in September 1983. In April 1984 Acorn won
+ the Queen's Award for Technology for the BBC Micro and in
+ September 1985 {Olivetti} took a controlling interest in
+ Acorn. The {Master} 128 Series computers were launched in
+ January 1986 and the BBC {Domesday} System in November 1986.
+
+ In 1983 Acorn began to design the Acorn RISC Machine (ARM),
+ the first low-cost, high volume {RISC} processor chip (later
+ renamed the {Advanced RISC Machine}). In June 1987 they
+ launched the {Archimedes} range - the first 32-bit {RISC}
+ based {microcomputers} - which sold for under UKP 1000. In
+ February 1989 the R140 was launched. This was the first
+ {Unix} {workstation} under UKP 4000. In May 1989 the A3000
+ (the new {BBC Microcomputer}) was launched.
+
+ In 1990 Acorn formed {Advanced RISC Machines} Ltd. (ARM) in
+ partnership with {Apple Computer, Inc.} and {VLSI} to develop
+ the ARM processor. Acorn has continued to develop {RISC}
+ based products.
+
+ With 1992 revenues of 48.2 million pounds, Acorn Computers was
+ the premier supplier of {Information Technology} products to
+ UK education and had been the leading provider of 32-bit RISC
+ based {personal computers} since 1987.
+
+ Acorn finally folded in the late 1990s. Their operating
+ system, {RISC OS} was further developed by a consortium of
+ suppliers.
+
+ {Usenet} newsgroups: {news:comp.sys.acorn},
+ {news:comp.sys.acorn.announce}, {news:comp.sys.acorn.tech},
+ {news:comp.binaries.acorn}, {news:comp.sources.acorn},
+ {news:comp.sys.acorn.advocacy}, {news:comp.sys.acorn.games}.
+
+ {Acorn's FTP server (ftp://ftp.acorn.co.uk/)}.
+
+ {HENSA software archive
+ (http://micros.hensa.ac.uk/micros/arch.html)}. {Richard
+ Birkby's Acorn page (http://csv.warwick.ac.uk/~phudv/)}.
+ {RiscMan's Acorn page (http://geko.com.au/riscman/)}.
+ {Acorn On The Net (http://stir.ac.uk/~rhh01/Main.html)}.
+ {"The Jungle" by Simon Truss
+ (http://csc.liv.ac.uk/users/u1smt/u1smt.html)}.
+
+ [Recent history?]
+
+ (2000-09-26)
+
+Acorn Online Media
+
+ <company> A company formed in August 1994 by {Acorn Computer
+ Group} plc to exploit the {ARM} RISC in television {set-top
+ box} decoders. They planned to woo {British
+ Telecommunications} plc to use the box in some of its {video
+ on demand} trials.
+
+ The "STB1" box was based on an {ARM8} core with additional
+ circuits to enable {MPEG} to be decoded in software - possibly
+ dedicated instructions for interpolation, inverse {DCT} or
+ {Huffman} table extraction. A prototype featured audio {MPEG}
+ chips, Acorn's {RISC OS} {operating system} and supported
+ {Oracle Media Objects} and {Microword}. Online planned to
+ reduce component count by transferring functions from boards
+ into the single RISC chip.
+
+ The company was origianlly wholly owned by Acorn but was
+ expected to bring in external investment.
+
+ [Article by nobody@tandem.com cross-posted from
+ tandem.news.computergram, 1994-07-07].
+
+ In 1996 they releasd the imaginatively titled "Set Top Box 2"
+ (STB20M) with a 32 MHz {ARM 7500} and 2 to 32 MB {RAM}. There
+ was also a "Set Top Box 22".
+
+ {(http://www.khantazi.org/Archives/MachineLst.html#STB1)}.
+ {(http://www.mcmordie.co.uk/acornhistory/riscpc700.shtml)}.
+ {(http://acorn.chriswhy.co.uk/NC.html)}.
+
+ (2007-11-12)
+
+Acorn RISC Machine
+
+ <processor> The original name of the {Advanced RISC Machine}.
+
+ (1995-03-07)
+
+ACOS
+
+ <language> A {BBS} language for {PRODOS 8} on {Apple II}.
+ {Macos} is a hacked version of ACOS.
+
+ (1994-11-08)
+
+acoustic coupler
+
+ <hardware, communications> A device used to connect a {modem}
+ to a telephone line via an ordinary handset. The acoustic
+ coupler converts electrical signals from the {modem} to sound
+ via a loudspeaker, against which the mouthpiece of a telephone
+ handset is placed. The earpiece is placed against a
+ {microphone} which converts sound to electrical signals which
+ return to the modem. The handset is inserted into a
+ sound-proof box containing the louspeaker and microphone to
+ avoid interference from ambient noise.
+
+ Acousitic couplers are now rarely used since most modems have
+ a direct electrical connection to the telephone line. This
+ avoids the signal degradation caused by conversion to and from
+ audio. Direct connection is not always possible, and was
+ actually illegal in the United Kingdom before {British
+ Telecom} was privatised. BT's predecessor, the General Post
+ Office, did not allow subscribers to connect their own
+ equipment to the telephone line.
+
+ (1994-11-08)
+
+ACP
+
+ {Algebra of Communicating Processes}
+
+ACPI
+
+ {Advanced Configuration and Power Interface}
+
+Acrobat
+
+ <text, product> A product from {Adobe Systems, Inc.}, for
+ manipulating documents stored in {Portable Document Format}.
+ Acrobat provides a {platform}-independent means of creating,
+ viewing, and printing documents.
+
+ {Acropolis: the magazine of Acrobat publishing
+ (http://acropolis.com/acropolis)}.
+
+ (1995-04-21)
+
+acronym
+
+ <jargon> An identifier formed from some of the letters (often
+ the initials) of a phrase and used as an abbreviation.
+
+ A {TLA} is a {meta}-acronym, i.e. an acronym about acronyms.
+
+ {This dictionary (FOLDOC)} contains a great many acronyms; see
+ {the contents page (/contents/all.html)} for a list.
+
+ (2014-08-14)
+
+ACSE
+
+ {Association Control Service Element}
+
+ACT
+
+ 1. <software> {Annual Change Traffic}.
+
+ 2. <company> {Ada Core Technologies}.
+
+ACT++
+
+ <language> A {concurrent} extension of {C++} based on
+ {actors}.
+
+ ["ACT++: Building a Concurrent C++ With Actors", D.G. Kafura
+ TR89-18, VPI, 1989].
+
+ (1994-11-08)
+
+Act1
+
+ <language> An {actor} language descended from {Plasma}.
+
+ ["Concurrent Object Oriented Programming in Act1",
+ H. Lieberman in Object Oriented Concurrent Programming,
+ A. Yonezawa et al eds, MIT Press 1987].
+
+ (1994-11-08)
+
+ACT 1
+
+ {Algebraic Compiler and Translator}
+
+Act2
+
+ <language> An {actor} language.
+
+ ["Issues in the Design of Act2", D. Theriault, TR728, MIT AI
+ Lab, June 1983].
+
+ (1994-11-08)
+
+Act3
+
+ <language> A high-level {actor} language by {Carl Hewitt}. A
+ descendant of {Act2} which provides support for automatic
+ generation of {customers} and for {delegation} and
+ {inheritance}.
+
+ ["Linguistic Support of Receptionists for Shared Resources",
+ C. Hewitt et al in Seminar on Concurrency, S.D. Brookes et al
+ eds, LNCS 197, Springer 1985, pp. 330-359].
+
+ (1994-11-08)
+
+Actalk
+
+ <language> A {Smalltalk}-based {actor} language developed by
+ J-P Briot in 1989.
+
+ ["Actalk: A Testbed for Classifying and Designing Actor
+ Languages in the Smalltalk-80 Environment", J-P. Briot, Proc
+ ECOOP '89, pp. 109-129].
+
+ (1994-11-08)
+
+Actis
+
+ <programming> An approach to integrated {CASE} by {Apollo}.
+
+ (1994-11-08)
+
+activation record
+
+ <compiler> (Or "data frame", "stack frame") A data structure
+ containing the variables belonging to one particular {scope}
+ (e.g. a procedure body), as well as links to other activation
+ records.
+
+ Activation records are usually created (on the {stack}) on
+ entry to a block and destroyed on exit. If a procedure or
+ function may be returned as a result, stored in a variable and
+ used in an outer scope then its activation record must be
+ stored in a {heap} so that its variables still exist when it
+ is used. Variables in the current {scope} are accessed via
+ the {frame pointer} which points to the current activation
+ record. Variables in an outer scope are accessed by following
+ chains of links between activation records. There are two
+ kinds of link - the {static link} and the {dynamic link}.
+
+ (1995-03-07)
+
+active DBMS
+
+ <database> A conventional or passive {DBMS} combined with a
+ means of event detection and condition monitoring. Event
+ handling is often rule-based, as with an {expert system}.
+
+ (1994-11-08)
+
+Active Directory
+
+ <operating system> A {directory service} from {Microsoft
+ Corporation}, similar in concept to {Novell} {Netware
+ Directory Services (NDS)}, that also integrates with the user
+ organisation's {DNS} structure and is interoperable with
+ {LDAP}. Active Directory is included in {Windows 2000}.
+
+ (2000-03-28)
+
+Active Language I
+
+ <tool, mathematics> An early interactive mathematics system
+ for the {XDS 930} at the {University of California at
+ Berkeley}.
+
+ ["Active Language I", R. de Vogelaere in Interactive Systems
+ for Experimental Applied Mathematics, A-P 1968].
+
+ (1994-11-08)
+
+active matrix display
+
+ <hardware> A type of {liquid crystal display} where each
+ display element (each {pixel}) includes an active component
+ such as a {transistor} to maintain its state between scans.
+
+ Contrast {passive matrix display}.
+
+ (1995-12-09)
+
+Active Measurement Project
+
+ <networking, tool, project> (AMP) An {NLANR} project
+ undertaking site-to-site measurement across the {HPC}
+ networks. This work is intended to compliment the
+ measurements taken by {MCI} and {Abilene} within the networks'
+ infrastructure. Currently {round trip times}, {topology}, and
+ {packet loss} are being measured.
+
+ (2004-01-18)
+
+Active Monitor
+
+ <networking> A process in an {IBM} {token ring} network which
+ ensures a token is present on the ring, removes circulating
+ frames with unknown or invalid destinations, and performs
+ introductions between machines on the ring.
+
+ (1996-06-18)
+
+active object
+
+ <programming> An {object} each {instance} of which has its own
+ {thread} running as well as its own copies of the object's
+ {instance variables}.
+
+ (1998-03-08)
+
+Active Reconfiguring Message
+
+ <hardware> (ARM) An efficient mechanism which allows
+ reconfiguration of the hardware logic of a system according to
+ the particular data received or transmitted.
+
+ In ARM each message contains extra information in a
+ Reconfiguring {Header} in addition to the data to be
+ transferred. Upon arrival of the message the Reconfiguring
+ Header is extracted, decoded and used to perform on-the-fly
+ hardware reconfiguration. As soon as the hardware has been
+ reconfigured the data information of the message can be
+ processed.
+
+ [In what contect is this term used?]
+
+ (1997-06-06)
+
+Active Server Pages
+
+ <web, programming> (ASP) A {scripting} environment
+ for {Microsoft Internet Information Server} in which you can
+ combine {HTML}, scripts and reusable {ActiveX} {server}
+ components to create dynamic {web pages}.
+
+ IIS 4.0 includes scripting engines for {Microsoft Visual
+ Basic} Scripting Edition ({VBScript}) and {Microsoft JScript}.
+ {ActiveX} scripting engines for {Perl} and {REXX} are
+ available through third-party developers.
+
+ [URL?]
+
+ (1999-12-02)
+
+ActiveX
+
+ <programming> A type of {COM} component that can
+ self-register, also known as an "ActiveX control". All COM
+ objects implement the "IUnknown" interface but an ActiveX
+ control usually also implements some of the standard
+ interfaces for embedding, user interface, methods, properties,
+ events, and persistence.
+
+ ActiveX controls were originally called "{OLE} Controls", and
+ were required to provide all of these interfaces but that
+ requirement was dropped, and the name changed, to make ActiveX
+ controls lean enough to be downloaded as part of a web page.
+
+ Because ActiveX components can support the OLE embedding
+ interfaces, they can be included in web pages. Because they
+ are COM objects, they can be used from languages such as
+ {Visual Basic}, {Visual C++}, {Java}, {VBScript}.
+
+ ["Understanding ActiveX and OLE", David Chappell, MS Press,
+ 1996].
+
+ {(http://microsoft.com/com/tech/activex.asp)}.
+
+ (2002-04-19)
+
+ActiveX Data Objects
+
+ <database, Microsoft, programming> (ADO) {Microsoft}'s
+ {library} for accessing data sources through {OLE DB}.
+ Typically it is used to query or modify data stored in a
+ relational database.
+
+ {Home
+ (http://msdn.microsoft.com/library/en-us/ado270/htm/adostartpage1.asp)}.
+
+ (2003-07-08)
+
+ACT ONE
+
+ <language, specification> A specification language.
+
+ ["An Algebraic Specification Language with Two Levels of
+ Semantics", H. Ehrig et al, Tech U Berlin 83-1983-02-03].
+
+ (1994-11-08)
+
+Actor
+
+ <language> An {object-oriented} language for {Microsoft
+ Windows} written by Charles Duff of the {Whitewater Group} ca.
+ 1986. It has {Pascal}/{C}-like {syntax}. Uses a
+ {token-threaded} {interpreter}. {Early binding} is an option.
+
+ ["Actor Does More than Windows", E.R. Tello, Dr Dobb's J
+ 13(1):114-125 (Jan 1988)].
+
+ (1994-11-08)
+
+actor
+
+ 1. <programming> In {object-oriented} programming, an {object}
+ which exists as a {concurrent} process.
+
+ 2. <operating system> In {Chorus}, the unit of resource
+ allocation.
+
+ (1994-11-08)
+
+Actors
+
+ <theory> A model for {concurrency} by {Carl Hewitt}. Actors
+ are autonomous and concurrent {objects} which execute
+ {asynchronously}. The Actor model provides flexible
+ mechanisms for building parallel and {distributed} software
+ systems.
+
+ {(http://osl.cs.uiuc.edu/)}.
+
+ ["Laws for Communicating Parallel Processes", C. Hewitt et al,
+ IFIP 77, pp. 987-992, N-H 1977].
+
+ ["ACTORS: A Model of Concurrent Computation in Distributed
+ Systems", Gul A. Agha <agha@cs.uiuc.edu>, Cambridge Press, MA,
+ 1986].
+
+ (1999-11-23)
+
+actor/singer/waiter/webmaster
+
+ <web> An elaboration of the ages-old concept of the
+ actor/singer/waiter, someone who waits tables __for now__, but
+ who has aspirations of breaking into the glamorous worlds of
+ acting or New Media or both!
+
+ He keeps going to auditions and sending a resumes to {C|Net
+ (http://cnet.com/)} because you have to pay your dues.
+
+ His credits include being on "Friends" (as an extra), in "ER"
+ (actually, in an ER - he twisted his ankle once; but he counts
+ the x-rays as screen credits), and having been the webmaster
+ of an extensive multimedia interactive website (his hotlist of
+ "Simpsons" links).
+
+ (1998-04-04)
+
+Actra
+
+ <language> A {multi-processor} {exemplar}-based {Smalltalk}.
+
+ [LaLonde et al, OOPSLA '86].
+
+ (1994-11-08)
+
+actual argument
+
+ <programming> A value, expression, or reference passed to a
+ {function} or {subroutine} when it is called and which
+ replaces or is bound to the corresponding {formal argument}.
+
+ See: {argument}.
+
+ (2002-07-02)
+
+Actus
+
+ <language> {Pascal} with parallel extensions, similar to the
+ earlier {Glypnir}. It has parallel constants and {index
+ sets}. Descendants include {Parallel Pascal}, {Vector C} and
+ {CMU}'s language {PIE}.
+
+ ["A Language for Array and Vector Processors," R.H. Perrott,
+ ACM TOPLAS 1(2):177-195 (Oct 1979)].
+
+ (1994-11-08)
+
+AD
+
+ {Administrative Domain}
+
+ad
+
+ <networking> The {country code} for Andorra.
+
+ (1999-01-26)
+
+Ada
+
+ <language> (After {Ada Lovelace}) A {Pascal}-descended
+ language, designed by Jean Ichbiah's team at {CII Honeywell}
+ in 1979, made mandatory for Department of Defense software
+ projects by the Pentagon. The original language was
+ standardised as "Ada 83", the latest is "{Ada 95}".
+
+ Ada is a large, complex, {block-structured} language aimed
+ primarily at {embedded} applications. It has facilities for
+ {real-time} response, {concurrency}, hardware access and
+ reliable run-time error handling. In support of large-scale
+ {software engineering}, it emphasises {strong typing}, {data
+ abstraction} and {encapsulation}. The type system uses {name
+ equivalence} and includes both {subtypes} and {derived types}.
+ Both fixed and {floating-point} numerical types are supported.
+
+ {Control flow} is fully bracketed: if-then-elsif-end if,
+ case-is-when-end case, loop-exit-end loop, goto. Subprogram
+ parameters are in, out, or inout. Variables imported from
+ other packages may be hidden or directly visible. Operators
+ may be {overloaded} and so may {enumeration} literals. There
+ are user-defined {exceptions} and {exception handlers}.
+
+ An Ada program consists of a set of packages encapsulating
+ data objects and their related operations. A package has a
+ separately compilable body and interface. Ada permits
+ {generic packages} and subroutines, possibly parametrised.
+
+ Ada support {single inheritance}, using "tagged types" which
+ are types that can be extended via {inheritance}.
+
+ Ada programming places a heavy emphasis on {multitasking}.
+ Tasks are synchronised by the {rendezvous}, in which a task
+ waits for one of its subroutines to be executed by another.
+ The conditional entry makes it possible for a task to test
+ whether an entry is ready. The selective wait waits for
+ either of two entries or waits for a limited time.
+
+ Ada is often criticised, especially for its size and
+ complexity, and this is attributed to its having been designed
+ by committee. In fact, both Ada 83 and Ada 95 were designed
+ by small design teams to be internally consistent and tightly
+ integrated. By contrast, two possible competitors, {Fortran
+ 90} and {C++} have both become products designed by large and
+ disparate volunteer committees.
+
+ See also {Ada/Ed}, {Toy/Ada}.
+
+ {Home of the Brave Ada Programmers
+ (http://lglwww.epfl.ch/Ada/)}. {Ada FAQs
+ (http://lglwww.epfl.ch/Ada/FAQ/)} (hypertext), {text only
+ (ftp://lglftp.epfl.ch/pub/Ada/FAQ)}.
+
+ {(http://wuarchive.wustl.edu/languages/ada/)},
+ {(ftp://ajpo.sei.cmu.edu/)},
+ {(ftp://stars.rosslyn.unisys.com/pub/ACE_8.0)}.
+
+ E-mail: <adainfo@ajpo.sei.cmu.edu>.
+
+ {Usenet} newsgroup: {news:comp.lang.ada}.
+
+ {An Ada grammar (ftp://primost.cs.wisc.edu/)} including a lex
+ scanner and yacc parser is available. E-mail:
+ <masticol@dumas.rutgers.edu>.
+
+ {Another yacc grammar and parser for Ada by Herman Fischer
+ (ftp://wsmr-simtel20.army.mil/PD2:<ADA.EXTERNAL-TOOLS>GRAM2.SRC)}.
+
+ An {LR parser} and {pretty-printer} for {Ada} from NASA is
+ available from the {Ada Software Repository}.
+
+ {Adamakegen} generates {makefiles} for {Ada} programs.
+
+ ["Reference Manual for the Ada Programming Language", ANSI/MIL
+ STD 1815A, US DoD (Jan 1983)]. Earlier draft versions
+ appeared in July 1980 and July 1982. ISO 1987.
+
+ [{Jargon File}]
+
+ (2000-08-12)
+
+Ada++
+
+ <language> An {object-oriented} extension to {Ada},
+ implemented as an Ada {preprocessor}. Obsoleted by {Ada 95}
+ which includes object-oriented features.
+
+ [{Jargon File}]
+
+ (1995-09-19)
+
+Ada 83
+
+ <language> The original {Ada}, as opposed to {Ada 95}.
+
+ (1995-03-13)
+
+Ada 95
+
+ <language> A revision and extension of {Ada} (Ada 83) begun in
+ 1988 and completed on 1994-12-01 by a team lead by Tucker Taft
+ of {Intermetrics}. Chris Anderson was the Project Manager.
+ The printed standard was expected to be available around
+ 1995-02-15.
+
+ Additions include {object-orientation} ({tagged types},
+ {abstract types} and {class-wide types}), hierarchical
+ libraries and synchronisation with shared data (protected
+ types) similar to {Orca}. It lacks {multiple inheritance} but
+ supports the construction of multiple inheritance type
+ hierarchies through the use of {generics} and {type
+ composition}.
+
+ {GNAT} aims to be a free implementation of Ada 95.
+
+ You can get the standard from the {Ada Joint Program Office
+ (http://wuarchive.wustl.edu/languages/ada/ajpo/index.shtml)}.
+
+ ["Introducing Ada 9X", J.G.P. Barnes, Feb 1993].
+
+ (1999-12-02)
+
+Ada 9X
+
+ <language> The working title for {Ada 95} before its adoption
+ as an {ISO} {standard}.
+
+ (1995-01-19)
+
+ADABAS
+
+ <database> A {relational database} system by {Software AG}.
+ While it was initially designed for large {IBM} {mainframe}
+ systems (e.g. {S/370} in the late 1970s), it has been ported
+ to numerous other {platforms} over the last few years such as
+ several flavors of {Unix} including {AIX}.
+
+ ADABAS stores its data in tables (and is thus "relational")
+ but also uses some non-relational techniques, such as
+ {multiple values} and {periodic groups}.
+
+ (1995-10-30)
+
+Ada Core Technologies
+
+ <company> (ACT) The company that maintains {GNAT}.
+
+ Ada Core Technologies was founded in 1994 by the original
+ authors of the GNAT compiler. ACT provides software for {Ada
+ 95} development.
+
+ {(http://gnat.com/)}.
+
+ (2000-10-28)
+
+Ada/Ed
+
+ <language, education> An {interpreter}, editor, and {run-time
+ environment} for {Ada}, intended as a teaching tool. Ada/Ed
+ does not have the capacity, performance, or robustness of
+ commercial Ada compilers. Ada/Ed was developed at {New York
+ University} as part of a project in language definition and
+ software prototyping.
+
+ AdaEd runs on {Unix}, {MS-DOS}, {Atari ST}, and {Amiga}.
+
+ It handles nearly all of {Ada 83} and was last validated with
+ version 1.7 of the {ACVC} tests. Being an interpreter, it
+ does not implement most {representation clauses} and thus does
+ not support systems programming close to the machine level.
+
+ Latest version: 1.11.0a+, as of 1994-08-18. A later version
+ is known as {GW-Ada}.
+
+ E-mail: Michael Feldman <mfeldman@seas.gwu.edu>.
+
+ {(ftp://ftp.wustl.edu/amiga/languages/ada)},
+ {(ftp://cnam.cnam.fr/pub/Ada/Ada-Ed)}. {For Amiga
+ (ftp://cs.nyu.edu/pub/adaed)}.
+
+ {RISC OS port
+ (ftp://micros.hensa.ac.uk/micros/arch/riscos/c/c052)}.
+
+ (1999-11-04)
+
+Adaline
+
+ <architecture> Name given by Widrow to {adaptive linear
+ neurons}, that is {neurons} (see {McCulloch-Pitts}) which
+ learn using the {Widrow-Huff Delta Rule}. See also
+ {Madaline}.
+
+ (1995-03-14)
+
+Ada Lovelace
+
+ <person> (1811-1852) The daughter of Lord Byron, who became
+ the world's first programmer while cooperating with {Charles
+ Babbage} on the design of his mechanical computing engines in
+ the mid-1800s.
+
+ The language {Ada} was named after her.
+
+ [{"Ada, Enchantress of Numbers Prophit of the Computer Age",
+ Betty Alexandra Toole (http://well.com/user/adatoole)}].
+
+ [More details?]
+
+ (1999-07-17)
+
+ADAM
+
+ {A Data Management system}
+
+Adam7
+
+ <graphics, algorithm> One of the {progressive coding} methods
+ used in {PNG} {images}. Adam7, named after its author, Adam
+ M. Costello, consists of seven distinct passes over the image.
+ Each pass transmits a subset of the {pixels} in the image.
+ The pass in which each pixel is transmitted is defined by
+ replicating the following 8-by-8 pattern over the entire
+ image, starting at the top left:
+
+ 1 6 4 6 2 6 4 6
+ 7 7 7 7 7 7 7 7
+ 5 6 5 6 5 6 5 6
+ 7 7 7 7 7 7 7 7
+ 3 6 4 6 3 6 4 6
+ 7 7 7 7 7 7 7 7
+ 5 6 5 6 5 6 5 6
+ 7 7 7 7 7 7 7 7
+
+ (2000-09-12)
+
+Adamakegen
+
+ <tool> A program that generates {makefiles} for {Ada}
+ programs. Adamakegen was written by Owen O'Malley
+ <owen@schwartz-omalley.com>. It requires {Icon} and runs
+ under {Verdix} and {SunAda}.
+
+ Latest version: 2.6.3, as of 1993-03-02.
+
+ {Adamakegen Home
+ (http://schwartz-omalley.com/people/owen/tools/adamakegen.html)}.
+
+ (2004-08-21)
+
+ADAMO
+
+ <database> A data management system written at {CERN}, based
+ on the {Entity-Relationship model}.
+
+ (1995-03-14)
+
+Adam Osborne
+
+ <person> The ex-book publisher who founded {Osborne Computer
+ Corporation}.
+
+ (2007-05-21)
+
+Ada-O
+
+ <language> An {Ada} subset developed at the {University of
+ Karlsruhe} in 1979, used for {compiler} {bootstrapping}. It
+ lacks {overloading}, {derived types}, {real numbers}, tasks
+ and {generics}.
+
+ ["Revised Ada-O Reference Manual", G. Persch et al, U
+ Karlsruhe, Inst fur Infor II, Bericht Nr 9/81].
+
+ (1995-02-14)
+
+Adaplan
+
+ <language> A {functional database} language based upon
+ {Backus}' {FP} language.
+
+ [Erwig&Lipeck, Proc. DBPL-3, 1991].
+
+ (1995-05-07)
+
+Adaplex
+
+ <language, database> An extension of {Ada} for {functional
+ databases}.
+
+ ["Adaplex: Rationale and Reference Manual 2nd ed", J.M. Smith
+ et al, Computer Corp America, Cambridge MA, 1983].
+
+ (1995-02-14)
+
+Ada Programming Support Environment
+
+ <tool, project> (APSE) A program or set of programs to support
+ software development in the Ada language.
+
+ [Examples?]
+
+ (1997-06-30)
+
+ADAPT
+
+ <language> A subset of {APT}.
+
+ [Sammet 1969, p. 606].
+
+ (1995-02-14)
+
+Adaptable User Interface
+
+ <tool, product> (AUI, Oracle Toolkit) A toolkit from {Oracle}
+ allowing applications to be written which will be portable
+ between different {windowing systems}. AUI provides one {call
+ level interface} along with a resource manager and editor
+ across a range of "standard" {GUIs}, including {Macintosh},
+ {Microsoft Windows} and the {X Window System}.
+
+ (1995-03-16)
+
+Adaptec
+
+ <company> A company specialising in the aera of movement of
+ data between computers. Adaptec designs hardware and software
+ products to transfer data from a computer to a {peripheral}
+ device or {network}.
+
+ Founded in 1981, the company achieved profitability in 1984,
+ went public in 1986, and to date has achieved 54 consecutive
+ profitable quarters.
+
+ Revenues for fiscal 1997 were $934 million, a 42% increase
+ over the prior year. Net income, excluding acquisition
+ charges, for fiscal year 1997 was $198 million or $1.72 per
+ share.
+
+ {(http://adaptec.com)}.
+
+ (1999-08-25)
+
+adaptive answering
+
+ <communications> A feature which allows a {faxmodem} to answer
+ the telephone and decide whether the incoming call is a fax or
+ data call. Most {Class 1} faxmodems do this. The
+ {U.S. Robotics} Class 1 implementation however seems not to do
+ it, it must be set to answer as either one or the other.
+
+ (1995-03-16)
+
+Adaptive Communication Environment
+
+ <communications, tool> A {C++} wrapper library for
+ communications from the {University of California at Irvine}.
+
+ (1995-03-16)
+
+Adaptive Digital Pulse Code Modulation
+
+ <communications> (ADPCM) A {compression} technique which
+ records only the difference between samples and adjusts the
+ coding scale dynamically to accomodate large and small
+ differences. ADPCM is simple to implement, but introduces
+ much {noise}.
+
+ [Used where? Does the {Sony} minidisk use ADPCM or {ATRAC}?]
+
+ (1998-12-10)
+
+adaptive learning
+
+ <algorithm> (Or "{Hebbian} learning") Learning where a system
+ programs itself by adjusting weights or strengths until it
+ produces the desired output.
+
+ (1995-03-16)
+
+adaptive routing
+
+ {dynamic routing}
+
+Adaptive Server Enterprise
+
+ <database (ASE) The {relational database management system}
+ that started life in the mid-eighties [first release?] as
+ "Sybase SQL Server". For a number of years {Microsoft} was a
+ Sybase distributor, reselling the Sybase product for {OS/2}
+ and (later) {Windows NT} under the name "Microsoft SQL
+ Server".
+
+ Around 1994, Microsoft basically bought a copy of the {source
+ code} of Sybase SQL Server and then went its own way. As
+ competitors, Sybase and Microsoft have been developing their
+ products independently ever since. Microsoft has mostly
+ emphasised ease-of-use and "Window-ising" the product, while
+ Sybase has focused on maximising performance and reliability,
+ and running on high-end hardware.
+
+ When releasing version 11.5 in 1997, Sybase renamed its
+ product to "ASE" to better distinguish its database from
+ Microsoft's. Both ASE and MS SQL Server call their query
+ language "Transact-SQL" and they are very similar.
+
+ Sybase SQL Server was the first true {client-server} RDBMS
+ which was also capable of handling real-world workloads. In
+ contrast, other DBMSs have long been monolithic programs; for
+ example, {Oracle} only "bolted on" client-server functionality
+ in the mid-nineties. Also, Sybase SQL Server was the first
+ commercially successful RDBMS supporting {stored procedures}
+ and {triggers}, and a cost-based {query optimizer}.
+
+ As with many other technology-driven competitors of Microsoft,
+ Sybase has lost market share to MS's superior marketing,
+ though many consider it has the superior system.
+
+ {(http://sypron.nl/whatis_ase.html)}.
+
+ (2003-07-02)
+
+Adaptive Simulated Annealing
+
+ <language> (ASA) An {algorithm} for global optimisation of
+ generic {functions} by Lester Ingber
+ <ingber@alumni.caltech.edu> <ingber@ingber.com>.
+
+ Latest version: 20.5, as of 2000-02-29.
+
+ {(http://alumni.caltech.edu/~ingber/)}.
+
+ {(http://ingber.com/)}.
+
+ Mailing list: <asa-request@alumni.caltech.edu>.
+
+ (2000-02-29)
+
+Adaptive TRansform Acoustic Coding
+
+ <algorithm> (ATRAC) An audio compression {algorithm},
+ introduced by {Sony} for its {Mini Disk}, which relies on the
+ masking of low-amplitude frequency components by temporaly
+ adjacent high-amplitude components. ATRAC consists of a
+ three-band {subband encoder} (0...5.5, 5.5...11, 11...22 kHz)
+ and a {MDCT} based transformation encoder.
+
+ [Does Sony Minidisk use {ADPCM}?]
+
+ (2001-12-13)
+
+Adaptor
+
+ <tool> (Automatic DAta Parallelism TranslatOR) A source to
+ source transformation tool that transforms {data parallel}
+ programs written in {Fortran 77} with {array} extensions,
+ parallel loops, and layout directives to parallel programs
+ with explicit {message passing}. ADAPTOR generates {Fortran
+ 77} host and node programs with message passing. The new
+ generated source codes have to be compiled by the compiler of
+ the parallel computer.
+
+ Version 1.0 runs on {CM-5}, {iPCS/860}, {Meiko CS1}/CS2, {KSR
+ 1}, {SGI}, {Alliant} or a network of {Suns} or {RS/6000s}.
+
+ {(ftp://ftp.gmd.de/gmd/adaptor/adp_1.0.tar.Z)}.
+
+ [Connection with Thomas Brandes and GMD?]
+
+ (1993-06-01)
+
+Ada Semantic Interface Specification
+
+ <language> (ASIS) An intermediate representation for {Ada}.
+
+ E-mail: <sblake@thomsoft.com>.
+
+ See also {Diana}.
+
+ (1995-02-15)
+
+Ada Software Repository
+
+ <language> A collection of {Ada} programs?
+
+ {(http://wuarchive.wustl.edu/languages/ada/asr/)}.
+
+ (1995-01-06)
+
+ADC
+
+ {Analog to Digital Converter}
+
+ADCCP
+
+ {Advanced Data Communications Control Protocol}
+
+A/D converter
+
+ {Analog to Digital Converter}
+
+ADCU
+
+ {application developer customer unit}
+
+AD/Cycle
+
+ <tool, product> Application Development cycle.
+
+ A set of {SAA}-compatible {IBM}-sponsored products for program
+ development, running on workstations accessing a central
+ repository on a {mainframe}. The stages cover requirements,
+ analysis and design, production of the application, building
+ and testing and maintenance. Technologies used include code
+ generators and {knowledge based systems} as well as languages
+ and debuggers.
+
+ (1994-10-24)
+
+ADD 1 TO COBOL GIVING COBOL
+
+ <humour, language> (From COBOL's equivalent syntax to C's C++)
+ A tongue-in-cheek suggestion by Bruce Clement for an
+ {object-oriented} {COBOL}.
+
+ [SIGPLAN Notices 27(4):90-91 (Apr 1992)].
+
+ (1995-03-17)
+
+ADDD
+
+ <tool> A Depository of Development Documents.
+
+ A {public domain} Software Engineering Environment from {GMD}
+ developed as part of the {STONE} project.
+
+ (1995-02-03)
+
+additive
+
+ <mathematics> A function f : X -> Y is additive if
+
+ for all Z <= X
+ f (lub Z) = lub { f z : z in Z }
+
+ (f "preserves {lubs}"). All additive functions defined over
+ {cpos} are {continuous}.
+
+ ("<=" is written in {LaTeX} as {\subseteq}, "lub" as \sqcup ).
+
+ (1995-02-03)
+
+address
+
+ 1. <networking> {e-mail address}.
+
+ 2. <networking> {IP address}.
+
+ 3. <networking> {MAC address}.
+
+ 4. <storage, programming> An unsigned integer used to select
+ one fundamental element of storage, usually known as a {word}
+ from a computer's {main memory} or other storage device. The
+ {CPU} outputs addresses on its {address bus} which may be
+ connected to an {address decoder}, {cache controller}, {memory
+ management unit}, and other devices.
+
+ While from a hardware point of view an address is indeed an
+ integer most {strongly typed} programming languages disallow
+ mixing integers and addresses, and indeed addresses of
+ different data types. This is a fine example for {syntactic
+ salt}: the compiler could work without it but makes writing
+ bad programs more difficult.
+
+ (1997-07-01)
+
+address book
+
+ <messaging> A collection of electronic {contacts} for use in an
+ {electronic mail} system, {mobile phone} or any other system for
+ exchanging messages with other people or organisations.
+
+ (2014-06-20)
+
+address bus
+
+ <processor> The connections between the {CPU} and memory which
+ carry the {address} from/to which the CPU wishes to read or
+ write. The number of bits of address bus determines the
+ maximum size of memory which the processor can access.
+
+ See also {data bus}.
+
+ (1995-03-22)
+
+addressed call mode
+
+ <communications> (ACM) A mode that permits control signals and
+ commands to establish and terminate calls in {V.25bis}.
+
+ (1997-05-07)
+
+addressee
+
+ <communications> One to whom something is addressed.
+ E.g. "The To, CC, and {BCC} {headers} list the addressees of
+ the e-mail message". Normally an addressee will eventually be
+ a {recipient}, unless there is a failure at some point (an
+ e-mail "{bounces}") or the message is redirected to a
+ different addressee.
+
+ (2000-03-22)
+
+addressing mode
+
+ 1. <processor, programming> One of a set of methods for
+ specifying the {operand}(s) for a {machine code} instruction.
+ Different processors vary greatly in the number of addressing
+ modes they provide. The more complex modes described below
+ can usually be replaced with a short sequence of instructions
+ using only simpler modes.
+
+ The most common modes are "register" - the operand is stored
+ in a specified {register}; "absolute" - the operand is stored
+ at a specified memory address; and "{immediate}" - the operand
+ is contained within the instruction.
+
+ Most processors also have {indirect addressing} modes, e.g.
+ "register indirect", "memory indirect" where the specified
+ register or memory location does not contain the operand but
+ contains its address, known as the "{effective address}". For
+ an absolute addressing mode, the effective address is
+ contained within the instruction.
+
+ Indirect addressing modes often have options for pre- or post-
+ increment or decrement, meaning that the register or memory
+ location containing the {effective address} is incremented or
+ decremented by some amount (either fixed or also specified in
+ the instruction), either before or after the instruction is
+ executed. These are very useful for {stacks} and for
+ accessing blocks of data. Other variations form the effective
+ address by adding together one or more registers and one or
+ more constants which may themselves be direct or indirect.
+ Such complex addressing modes are designed to support access
+ to multidimensional arrays and arrays of data structures.
+
+ The addressing mode may be "implicit" - the location of the
+ operand is obvious from the particular instruction. This
+ would be the case for an instruction that modified a
+ particular control register in the CPU or, in a {stack} based
+ processor where operands are always on the top of the stack.
+
+ 2. In {IBM} {System 370}/{XA} the addressing mode bit controls
+ the size of the {effective address} generated. When this bit
+ is zero, the CPU is in the 24-bit addressing mode, and 24 bit
+ instruction and operand effective addresses are generated.
+ When this bit is one, the CPU is in the 31-bit addressing
+ mode, and 31-bit instruction and operand effective addresses
+ are generated.
+
+ ["IBM System/370 Extended Architecture Principles of
+ Operation", Chapter 5., 'Address Generation', BiModal
+ Addressing].
+
+ (1995-03-30)
+
+address mask
+
+ <networking> (Or "subnet mask") A {bit mask} used to identify
+ which bits in an {IP address} correspond to the {network
+ address} and {subnet} portions of the address. This mask is
+ often referred to as the subnet mask because the network
+ portion of the address can be determined by the {class}
+ inherent in an IP address. The address mask has ones in
+ positions corresponding to the network and subnet numbers and
+ zeros in the host number positions.
+
+ (1996-03-21)
+
+address resolution
+
+ <networking> Conversion of an {Internet address} into the
+ corresponding physical address ({Ethernet address}). This is
+ usually done using {Address Resolution Protocol}.
+
+ The {resolver} is a library routine and a set of processes
+ which converts {hostnames} into {Internet addresses}, though
+ this process in not usually referred to as {resolution}. See
+ {DNS}.
+
+ (1996-04-09)
+
+Address Resolution Protocol
+
+ <networking, protocol> (ARP) A method for finding a {host}'s
+ {Ethernet address} from its {Internet address}. The sender
+ broadcasts an ARP {packet} containing the {Internet address}
+ of another host and waits for it (or some other host) to send
+ back its Ethernet address. Each host maintains a {cache} of
+ address translations to reduce delay and loading. ARP allows
+ the Internet address to be independent of the Ethernet address
+ but it only works if all hosts support it.
+
+ ARP is defined in {RFC 826}.
+
+ The alternative for hosts that do not do ARP is {constant
+ mapping}.
+
+ See also {proxy ARP}, {reverse ARP}.
+
+ (1995-03-20)
+
+address space
+
+ <operating system, architecture> The range of addresses which
+ a processor or process can access, or at which a {device} can
+ be accessed. The term may refer to either {physical address}
+ or {virtual address}.
+
+ The size of a processor's address space depends on the width
+ of the processor's {address bus} and address {registers}.
+
+ Each device, such as a memory {integrated circuit}, will have
+ its own local address space which starts at zero. This will
+ be mapped to a range of addresses which starts at some base
+ address in the processor's address space.
+
+ Similarly, each {process} will have its own address space,
+ which may be all or a part of the processor's address space.
+ In a {multitasking} system this may depend on where in memory
+ the process happens to have been loaded. For a process to be
+ able to run at any address it must consist of
+ {position-independent code}. Alternatively, each process may
+ see the same local address space, with the {memory management
+ unit} mapping this to the process's own part of the
+ processor's address space.
+
+ (1999-11-01)
+
+Address Strobe
+
+ <storage> (AS) One of the input signals of a memory device,
+ especially {semiconductor} memory, which is asserted to tell
+ the memory device that the {address} inputs are valid. Upon
+ receiving this signal the selected memory device starts the
+ memory access (read/write) indicated by its other inputs.
+
+ It may be driven directly by the {processor} or by a {memory
+ controller}.
+
+ (1996-10-02)
+
+ADELE
+
+ <language> A language for specification of {attribute
+ grammars}, used by the {MUG2} {compiler compiler}.
+
+ ["An Overview of the Attribute Definition Language ADELE",
+ H. Ganziger in GI3, Fachesprach "Compiler-Compiler",
+ W. Henhapl ed, Munchen Mar 1982, pp.22-53].
+
+ (1995-01-23)
+
+ADES
+
+ <language> An early system on the {IBM 704}.
+
+ Version: ADES II.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1995-03-20)
+
+ad hoc
+
+ Contrived purely for the purpose in hand rather than planned
+ carefully in advance. E.g. "We didn't know what to do about
+ the sausage rolls, so we set up an ad-hoc committee".
+
+ (1995-03-25)
+
+ad-hockery
+
+ <jargon> /ad-hok'*r-ee/ (Purdue) 1. Gratuitous assumptions
+ made inside certain programs, especially {expert systems},
+ which lead to the appearance of semi-intelligent behaviour but
+ are in fact entirely arbitrary. For example, {fuzzy-matching}
+ of input tokens that might be typing errors against a symbol
+ table can make it look as though a program knows how to spell.
+
+ 2. Special-case code to cope with some awkward input that
+ would otherwise cause a program to fail, presuming normal
+ inputs are dealt with in some cleaner and more regular way.
+ Also called "ad-hackery", "ad-hocity" (/ad-hos'*-tee/),
+ "ad-crockery".
+
+ See also {ELIZA effect}.
+
+ [{Jargon File}]
+
+ (1995-01-05)
+
+ad-hoc polymorphism
+
+ {overloading}
+
+Aditi
+
+ <database, project> The Aditi Deductive Database System. A
+ multi-user {deductive database} system from the Machine
+ Intelligence Project at the {University of Melbourne}. It
+ supports base {relations} defined by {facts} (relations in the
+ sense of {relational databases}) and {derived relations}
+ defined by {rules} that specify how to compute new information
+ from old information.
+
+ Both base relations and the rules defining derived relations
+ are stored on disk and are accessed as required during query
+ evaluation. The rules defining derived relations are
+ expressed in a {Prolog}-like language, which is also used for
+ expressing queries.
+
+ Aditi supports the full structured data capability of Prolog.
+ Base relations can store arbitrarily nested terms, for example
+ arbitrary length lists, and rules can directly manipulate such
+ terms. Base relations can be indexed with {B-trees} or
+ multi-level signature files.
+
+ Users can access the system through a {Motif}-based query and
+ database administration tool, or through a command line
+ interface. There is also in interface that allows {NU-Prolog}
+ programs to access Aditi in a transparent manner. Proper
+ {transaction processing} is not supported in this release.
+
+ The beta release runs on {SPARC}/{SunOS4}.1.2 and
+ {MIPS}/{Irix}4.0.
+
+ E-mail: <aditi@cs.mu.oz.au>.
+
+ (1992-12-17)
+
+adjacency
+
+ <networking> A relationship between two {network} devices,
+ e.g. {routers}, which are connected by one media segment so
+ that a packet sent by one can reach the other without going
+ through another network device. The concept of adjacency is
+ important in the exchange of routing information.
+
+ Adjacent {SNA} {nodes} are nodes connected to a given node
+ with no intervening nodes. In {DECnet} and {OSI}, adjacent
+ nodes share a common segment ({Ethernet}, {FDDI}, {Token
+ Ring}).
+
+ (1998-03-10)
+
+adjacent
+
+ {adjacency}
+
+ADL
+
+ 1. <games> {Adventure Definition Language}.
+
+ 2. <language> {Ada} Development Language.
+
+ R.A. Lees, 1989.
+
+ 3. <programming> {API} Definition Language.
+
+ A project for Automatic Interface Test Generation.
+
+ (1995-11-17)
+
+AdLog
+
+ <language> A language which adds a {Prolog} layer to {Ada}.
+
+ ["AdLog, An Ada Components Set to Add Logic to Ada",
+ G. Pitette, Proc Ada-Europe Intl Conf Munich, June 1988].
+
+ (1995-03-21)
+
+ADM
+
+ <language> A picture {query language}, extension of {Sequel2}.
+
+ ["An Image-Oriented Database System", Y. Takao et al, in
+ Database Techniques for Pictorial Applications, A. Blaser ed,
+ pp. 527-538].
+
+ (1995-03-21)
+
+ADMD
+
+ {Administration Management Domain}
+
+admin
+
+ {system administrator}
+
+Administration Management Domain
+
+ <networking> (ADMD) An {X.400} {Message Handling System}
+ {public service carrier}. The ADMDs in all countries
+ worldwide together provide the X.400 {backbone}. Examples:
+ {MCImail} and {ATTmail} in the U.S., {British Telecom}
+ {Gold400mail} in the U.K.
+
+ See also {PRMD}.
+
+ [RFC 1208].
+
+ (1997-05-07)
+
+administrative distance
+
+ <networking> A rating of the trustworthiness of a {routing}
+ information source set by the router administrator. In
+ {Cisco} {routers}, administrative distance is a number between
+ 0 and 255 (the higher the value, the less trustworthy the
+ source).
+
+ (1998-03-10)
+
+Administrative Domain
+
+ <networking> (AD) A collection of {hosts} and {routers}, and
+ the interconnecting network(s), managed by a single
+ {administrative authority}.
+
+ (1994-11-24)
+
+admissible
+
+ <algorithm> A description of a {search algorithm} that is
+ guaranteed to find a minimal solution path before any other
+ solution paths, if a solution exists. An example of an
+ admissible search algorithm is {A* search}.
+
+ (1999-07-19)
+
+ADO
+
+ {ActiveX Data Objects}
+
+Adobe Systems, Inc.
+
+ <company> A California {font} foundry and {software} house.
+ Adobe created the {PostScript} {page description language} and
+ wrote the {Blue Book}, {Green Book}, {Red Book} and {White
+ Book} on it. They also developed {PDF}. Adobe took over
+ {Frame Technology Corporation} in late 1995/early 1996.
+
+ {(http://adobe.com/)}.
+
+ E-mail: <postmaster@adobe.com>.
+
+ Address: Silicon Valley, California, USA.
+
+ (1996-12-13)
+
+Adobe Type Manager
+
+ <text, tool, product> (ATM) Software that produces
+ {PostScript} {outline fonts} on screen and paper. There are
+ versions that run under {Microsoft Windows} and on the
+ {Macintosh}. ATM can do {hinting}, {multiple master} and
+ {anti-aliasing}.
+
+ (1998-03-10)
+
+ADPCM
+
+ {Adaptive Digital Pulse Code Modulation}
+
+ADR
+
+ {Astra Digital Radio}
+
+ADS
+
+ An {expert system}.
+
+ADSL
+
+ {Asymmetric Digital Subscriber Line}
+
+ADSP
+
+ {AppleTalk Data Stream Protocol}
+
+ADSU
+
+ {ATM Data Service Unit}
+
+ADT
+
+ {abstract data type}
+
+Advanced Audio Coding
+
+ <audio> (AAC) A successor to {MP3}, allowing lower {bit rates}
+ and more stable quality.
+
+ See {MPEG-2 AAC Low Profile} and {MPEG-4 AAC Main Profile}.
+
+ (2001-12-02)
+
+Advanced Communication Function/Network Control Program
+
+ <networking> (ACF/NCP, usually called just "NCP") The primary
+ {SNA} {network control program}, one of the {ACF} products.
+ ACF/NCP resides in the {communications controller} and
+ interfaces with {ACF/VTAM} in the {host processor} to control
+ network communications.
+
+ NCP can also communicate with multiple {hosts} using {local
+ channel} or remote links ({PU} type 5 or PU type 4) thus
+ enabling cross {domain} application communication. In a
+ multiple {mainframe} SNA environment, any terminal or
+ application can access any other application on any host using
+ cross domain logon.
+
+ See also {Emulator program}.
+
+ [Communication or Communications?]
+
+ (1999-01-29)
+
+Advanced Communications Function
+
+ <networking> (ACF) A group of {IBM} {SNA} products that
+ provide {distributed processing} and resource sharing such as
+ {VTAM} and {NCP}.
+
+ [Communication or Communications?]
+
+ (1997-05-07)
+
+Advanced Computing Environment
+
+ <body> (ACE) A consortium to agree on an {open} architecture
+ based on the {MIPS R4000} chip. A computer architecture ARCS
+ will be defined, on which either {OS/2} or {Open Desktop} can
+ be run.
+
+ (1995-02-03)
+
+Advanced Configuration and Power Interface
+
+ <hardware, standard> (ACPI) An open industry standard
+ developed by {Intel}, {Microsoft}, and {Toshiba} for
+ configuration and {power management}.
+
+ The key element of the standard is power management with two
+ important improvements. First, it puts the {OS} in control of
+ power management. In the currently existing {APM} model most
+ of the power management tasks are run by the {BIOS}, with
+ limited intervention from the OS. In ACPI, the BIOS is
+ responsible for the dirty details of communicating with
+ hardware equipment but the control is in the OS.
+
+ The other important feature is bringing power management
+ features now available only in {portable computers} to
+ {desktop computers} and {servers}. Extremely low consumption
+ states, i.e., in which only memory, or not even memory is
+ powered, but from which ordinary interrupts (real time clock,
+ keyboard, modem, etc.) can quickly wake the system, are today
+ available in portables only. The standard should make these
+ available for a wider range of systems.
+
+ For ACPI to work the operating system, the {motherboard}
+ chipset, and for some functions even the {CPU} has to be
+ designed for it. Microsoft is heavily driving a move toward
+ ACPI, both {Windows NT 5.0} and {Windows 98} will support it.
+ It remains to be seen how much hardware manufacturers will
+ embrace the technology and whether other operating system
+ vendors will support it.
+
+ {ACPI Information Page (http://teleport.com/~acpi/)}.
+
+ (1998-03-27)
+
+Advanced Data Communications Control Protocol
+
+ <protocol> An {ANSI} {standard} {bit-oriented} {data link}
+ control {protocol}.
+
+ (1997-05-07)
+
+Advanced Encryption Standard
+
+ <cryptography, algorithm> (AES) The {NIST}'s replacement for
+ the {Data Encryption Standard} (DES). The Rijndael
+ /rayn-dahl/ {symmetric block cipher}, designed by Joan Daemen
+ and Vincent Rijmen, was chosen by a NIST contest to be AES.
+
+ AES is Federal Information Processing Standard FIPS-197.
+
+ AES currently supports 128, 192 and 256-bit keys and
+ encryption blocks, but may be extended in multiples of 32
+ bits.
+
+ {(http://csrc.nist.gov/CryptoToolkit/aes/)}.
+
+ {Rijndael home page
+ (http://esat.kuleuven.ac.be/~rijmen/rijndael/)}.
+
+ (2003-07-04)
+
+Advanced Function Presentation
+
+ <printer, language> (AFP) A {page description language} from
+ {IBM} introduced in 1984 initially as Advanced Function
+ Printing. AFP was first developed for {mainframes} and then
+ brought to {minicomputers} and {workstations}. It is
+ implemented on the various {platforms} by {Print Services
+ Facility} (PSF) software, which generates the {native} IBM
+ printer language, {IPDS} and, depending on the version,
+ {PostScript} and LaserJet {PCL} as well. IBM calls AFP a
+ "printer architecture" rather than a page description
+ language.
+
+Advanced Function Printing
+
+ {Advanced Function Presentation}
+
+Advanced Intelligent Tape
+
+ <storage> (AIT) A form of {magnetic tape} and drive using
+ {AME} developed by {Sony} for storing large amounts of data.
+ An AIT can store over 50 {gigabytes} and transfer data at six
+ megabytes/second (in February 1999). AIT features high speed
+ file access, long head and media life, the {ALDC compression}
+ {algorithm}, and a {MIC} chip.
+
+ {(http://aittape.com/)}.
+
+ {Seagate
+ (http://seagate.com/support/tape/scsiide/sidewinder/ait_main_page.shtml)}.
+
+ (1999-04-16)
+
+Advanced Interactive eXecutive
+
+ <operating system> (AIX) {IBM}'s version of {Unix}, taken as
+ the basis for the {OSF} {standard}.
+
+ {Usenet} newsgroup: {news:comp.sys.unix.aix}.
+
+ (1994-11-24)
+
+Advanced Micro Devices, Inc.
+
+ <company> (AMD) A US manufacturer of {integrated circuits},
+ founded in 1969. AMD was the fifth-largest IC manufacturer in
+ 1995. AMD focuses on the personal and networked computation
+ and communications market. They produce {microprocessors},
+ {embedded processors} and related peripherals, memories,
+ {programmable logic devices}, circuits for telecommunications
+ and networking applications.
+
+ In 1995, AMD had 12000 employees in the USA and elsewhere and
+ manufacturing facilities in Austin, Texas; Aizu-Wakamatsu,
+ Japan; Bangkok, Thailand; Penang, Malaysia; and Singapore.
+
+ AMD made the {AMD 2900} series of {bit-slice} {TTL} components
+ and clones of the {Intel 80386} and {Intel 486}
+ {microprocessors}.
+
+ {AMD Home (http://amd.com/)}.
+
+ Address: Sunnyvale, CA, USA.
+
+ (1995-02-27)
+
+Advanced Network Systems Architecture
+
+ <networking> (ANSA) A "{software bus}" based on a model for
+ distributed systems developed as an {ESPRIT} project.
+
+ {(http://ansa.co.uk/)}.
+
+ (1996-04-01)
+
+Advanced Peer-to-Peer Networking
+
+ <networking, product> (APPN) IBM data communications support
+ that routes data in a network between two or more {APPC}
+ systems that need not be adjacent.
+
+ (1995-02-03)
+
+Advanced Power Management
+
+ <hardware> (APM) A feature of some displays, usually but not
+ always, on {laptop computers}, which turns off power to the
+ display after a preset period of inactivity to conserve
+ electrical power. Monitors with this capability are usually
+ refered to as "green monitors", meaning environmentally
+ friendly.
+
+ Not to be confused with a {screen blanker} which is {software}
+ that causes the display to go black (by setting every {pixel}
+ to black) to prevent {burn-in}.
+
+ (1997-08-25)
+
+Advanced Programmable Interrupt Controller
+
+ <integrated circuit> (APIC) A {Programmable Interrupt
+ Controller} (PIC) that can handle {interrupts} from and for
+ multiple {CPUs}, and, usually, has more available interrupt
+ lines that a typical PIC.
+
+ (2003-03-18)
+
+Advanced Program-to-Program Communications
+
+ <networking, product> (APPC) An implementation of the {IBM}
+ {SNA}/{SDLC} {LU6.2} {protocol} that allows interconnected
+ systems to communicate and share the processing of programs.
+
+ (1995-02-03)
+
+Advanced Research Projects Agency
+
+ {Defense Advanced Research Projects Agency}
+
+Advanced Research Projects Agency Network
+
+ <networking> (ARPANET) A pioneering longhaul {wide area
+ network} funded by {DARPA} (when it was still called "ARPA"?).
+ It became operational in 1968 and served as the basis for
+ early networking research, as well as a central {backbone}
+ during the development of the {Internet}. The ARPANET
+ consisted of individual {packet switching} computers
+ interconnected by {leased lines}. {Protocols} used include
+ {FTP} and {telnet}. It has now been replaced by {NSFnet}.
+
+ [1968 or 1969?]
+
+ (1994-11-17)
+
+Advanced Revelation
+
+ <database> (AREV) A {database development environment} for
+ {personal computers} available from {Revelation Software}
+ since 1982. Originally based on the {PICK} {operating
+ system}, there are over one million users worldwide in 1996.
+
+ (1996-12-12)
+
+Advanced RISC Computing Specification
+
+ <standard, hardware> (ARC, previously ARCS) The baseline
+ hardware requirements for an {ACE}-compatible system.
+
+ (1995-01-16)
+
+Advanced RISC Machine
+
+ <processor> (ARM, Originally {Acorn} RISC Machine). A series
+ of low-cost, power-efficient 32-bit {RISC} {microprocessors}
+ for embedded control, computing, {digital signal processing},
+ {games}, consumer {multimedia} and portable applications. It
+ was the first commercial RISC microprocessor (or was the {MIPS
+ R2000}?) and was licensed for production by {Asahi Kasei
+ Microsystems}, {Cirrus Logic}, {GEC Plessey Semiconductors},
+ {Samsung}, {Sharp}, {Texas Instruments} and {VLSI Technology}.
+
+ The ARM has a small and highly {orthogonal instruction set},
+ as do most RISC processors. Every instruction includes a
+ four-bit code which specifies a condition (of the {processor
+ status register}) which must be satisfied for the instruction
+ to be executed. Unconditional execution is specified with a
+ condition "true".
+
+ Instructions are split into load and store which access memory
+ and arithmetic and logic instructions which work on
+ {registers} (two source and one destination).
+
+ The ARM has 27 registers of which 16 are accessible in any
+ particular processor mode. R15 combines the {program counter}
+ and processor status byte, the other registers are general
+ purpose except that R14 holds the {return address} after a
+ {subroutine} call and R13 is conventionally used as a {stack
+ pointer}. There are four processor modes: user, {interrupt}
+ (with a private copy of R13 and R14), fast interrupt (private
+ copies of R8 to R14) and {supervisor} (private copies of R13
+ and R14). The {ALU} includes a 32-bit {barrel-shifter}
+ allowing, e.g., a single-{cycle} shift and add.
+
+ The first ARM processor, the ARM1 was a prototype which was
+ never released. The ARM2 was originally called the Acorn RISC
+ Machine. It was designed by {Acorn Computers Ltd.} and used
+ in the original {Archimedes}, their successor to the {BBC
+ Micro} and {BBC Master} series which were based on the
+ eight-bit {6502} {microprocessor}. It was clocked at 8 MHz
+ giving an average performance of 4 - 4.7 {MIPS}. Development
+ of the ARM family was then continued by a new company,
+ {Advanced RISC Machines Ltd.}
+
+ The {ARM3} added a {fully-associative} on-chip {cache} and
+ some support for {multiprocessing}. This was followed by the
+ {ARM600} chip which was an {ARM6} processor {core} with a
+ 4-kilobyte 64-way {set-associative} {cache}, an {MMU} based on
+ the MEMC2 chip, a {write buffer} (8 words?) and a
+ {coprocessor} interface.
+
+ The {ARM7} processor core uses half the power of the {ARM6}
+ and takes around half the {die} size. In a full processor
+ design ({ARM700} chip) it should provide 50% to 100% more
+ performance.
+
+ In July 1994 {VLSI Technology, Inc.} released the {ARM710}
+ processor chip.
+
+ {Thumb} is an implementation with reduced code size
+ requirements, intended for {embedded} applications.
+
+ An {ARM800} chip is also planned.
+
+ {AT&T}, {IBM}, {Panasonic}, {Apple Coputer}, {Matsushita} and
+ {Sanyo} either rely on, or manufacture, ARM 32-bit processor
+ chips.
+
+ {Usenet} newsgroup: {news:comp.sys.arm}.
+
+ (1997-08-05)
+
+Advanced RISC Machines Ltd.
+
+ <company> (ARM) A company formed in 1990 by {Acorn Computers}
+ Ltd., {Apple Computer, Inc.} and {VLSI Technology} to market
+ and develop the {Advanced RISC Machine} {microprocessor}
+ family, originally designed by Acorn.
+
+ ARM Ltd. also designs and licenses peripheral chips and
+ supplies supporting software and hardware tools. In April
+ 1993, Nippon Investment and Finance, a Daiwa Securities
+ company, became ARM's fourth investor. In May 1994 Samsung
+ became the sixth large company to have a licence to use the
+ ARM processor core.
+
+ The success of ARM Ltd. and the strategy to widen the
+ availability of RISC technology has resulted in its chips now
+ being used in a range of products including the {Apple
+ Newton}. As measured by an independent authority, more ARM
+ processors were shipped than {SPARC} chips in 1993. ARM has
+ also sold three times more chips than the {PowerPC}
+ consortium.
+
+ {(http://systemv.com/armltd/index.html)}.
+
+ E-mail: armltd.co.uk.
+
+ Address: Advanced RISC Machines Ltd. Fulbourn Road, Cherry
+ Hinton, Cambridge CB1 4JN, UK.
+
+ Telephone: +44 (1223) 400 400. Fax: +44 (1223) 400 410.
+
+ (1994-11-03)
+
+Advanced SCSI Peripheral Interface
+
+ <storage, programming> (ASPI) A set of libraries designed to
+ provide programs running under {Microsoft Windows} with a
+ consistent interface for accessing {SCSI} devices. ASPI has
+ become a {de facto standard}.
+
+ The ASPI layer is a collection of programs ({DLLs}) that
+ together implement the ASPI interface. Many problems are
+ caused by device manufacturers packaging incomplete sets of
+ these DLLs with their hardware, often with incorrect date
+ stamps, causing newer versions to get replaced with old.
+ ASPICHK from Adaptec will check the ASPI components installed
+ on a computer.
+
+ The latest ASPI layer as of March 1999 is 1014.
+
+ The {ATAPI} standard for {IDE} devices makes them look to the
+ system like SCSI devices and allows them to work through ASPI.
+
+ {(http://resource.simplenet.com/primer/aspi.htm)}.
+
+ (1999-03-30)
+
+Advanced Software Environment
+
+ <programming> (ASE) An {object-oriented} {application support
+ system} from {Nixdorf}.
+
+ (1995-09-12)
+
+Advanced STatistical Analysis Program
+
+ <tool, electronics> (ASTAP) A program for analysing electronic
+ circuits and other networks.
+
+ ["Advanced Statistical Analysis Program (ASTAP) Program
+ Reference Manual", SH-20-1118, IBM, 1973].
+
+ (2000-01-27)
+
+Advanced Technology Attachment
+
+ <storage, hardware, standard> (ATA, AT Attachment or
+ "Integrated Drive Electronics", IDE) A {disk drive} interface
+ {standard} based on the {IBM PC} {ISA} 16-bit {bus} but also
+ used on other {personal computers}. ATA specifies the power
+ and data signal interfaces between the {motherboard} and the
+ integrated {disk controller} and drive. The ATA "bus" only
+ supports two devices - master and slave.
+
+ ATA drives may in fact use any physical interface the
+ manufacturer desires, so long as an embedded translator is
+ included with the proper ATA interface. ATA "controllers" are
+ actually direct connections to the ISA bus.
+
+ Originally called IDE, the ATA interface was invented by
+ {Compaq} around 1986, and was developed with the help of
+ {Western Digital}, {Imprimis}, and then-upstart {Conner
+ Peripherals}. Efforts to standardise the interface started in
+ 1988; the first draft appeared in March 1989, and a finished
+ version was sent to {ANSI} group X3T10 (who named it "Advanced
+ Technology Attachment" (ATA)) for ratification in November
+ 1990.
+
+ X3T10 later extended ATA to {Advanced Technology Attachment
+ Interface with Extensions} (ATA-2), followed by {ATA-3} and
+ {ATA-4}.
+
+ {X3T10 (http://symbios.com/x3t10/)}.
+
+ (1998-10-08)
+
+Advanced Technology Attachment Interface with Extensions
+
+ <storage, standard> (ATA-2, Enhanced Integrated Drive
+ Electronics, EIDE) A proposed (May 1996 or earlier?)
+ {standard} from {X3T10} (document 948D rev 3) which extends
+ the {Advanced Technology Attachment} interface while
+ maintaining compatibility with current {IBM PC} {BIOS}
+ designs.
+
+ ATA-2 provides for faster data rates, 32-bit transactions and
+ (in some drives) {DMA}. Optional support for power saving
+ modes and removable devices is also in the standard.
+
+ ATA-2 was developed by {Western Digital} as "Enhanced
+ Integrated Drive Electronics" (EIDE) around 1994.
+ {Marketroids} call it "Fast ATA" or "Fast ATA-2".
+
+ ATA-2 was followed by {ATA-3} and {ATA-4} ("Ultra DMA").
+
+ (2000-10-07)
+
+Advanced Video Coding
+
+ {H.264}
+
+Advanced WavEffect
+
+ <multimedia, music, hardware> (AWE) The kind of synthesis used
+ by the {EMU 8000} music synthesizer {integrated circuit} found
+ on the {SB AWE32} card.
+
+ (1996-12-15)
+
+Advantage Gen
+
+ <language, software> A {CASE} tool for {rapid application
+ development} which generates code from graphical {business
+ process models}. Formerly called Information Engineering
+ Facility (IEF) and produced by {Texas Instruments}, it was
+ then bought by {Sterling Software, Inc.} who renamed it to
+ COOL:Gen to fit into their COOL line of products. {Computer
+ Associates International, Inc.} then acquired {Sterling
+ Software, Inc.}, and renamed the tool "Advantage Gen".
+
+ In 2003, CA are supporting Advantage Gen and adding support
+ for {J2EE}/{EJB}, enhanced web enablement, {Web services}, and
+ {.Net}.
+
+ Latest version: 6.5, as of 2003-04-14.
+
+ {(http://www3.ca.com/Solutions/Product.asp?ID=256)}.
+
+ (2003-06-23)
+
+ADVENT
+
+ <games> /ad'vent/ The prototypical computer {adventure} game,
+ first implemented by Will Crowther for a {CDC} computer
+ (probably the {CDC 6600}?) as an attempt at computer-refereed
+ fantasy gaming.
+
+ ADVENT was ported to the {PDP-10}, and expanded to the
+ 350-point {Classic} puzzle-oriented version, by Don Woods of
+ the {Stanford Artificial Intelligence Laboratory} (SAIL). The
+ game is now better known as Adventure, but the {TOPS-10}
+ {operating system} permitted only six-letter filenames. All
+ the versions since are based on the SAIL port.
+
+ David Long of the {University of Chicago} Graduate School of
+ Business Computing Facility (which had two of the four
+ {DEC20s} on campus in the late 1970s and early 1980s) was
+ responsible for expanding the cave in a number of ways, and
+ pushing the point count up to 500, then 501 points. Most of
+ his work was in the data files, but he made some changes to
+ the {parser} as well.
+
+ This game defined the terse, dryly humorous style now expected
+ in text adventure games, and popularised several tag lines
+ that have become fixtures of hacker-speak: "A huge green
+ fierce snake bars the way!" "I see no X here" (for some noun
+ X). "You are in a maze of twisty little passages, all alike."
+ "You are in a little maze of twisty passages, all different."
+ The "magic words" {xyzzy} and {plugh} also derive from this
+ game.
+
+ Crowther, by the way, participated in the exploration of the
+ Mammoth & Flint Ridge cave system; it actually *has* a
+ "Colossal Cave" and a "Bedquilt" as in the game, and the "Y2"
+ that also turns up is cavers' jargon for a map reference to a
+ secondary entrance.
+
+ See also {vadding}.
+
+ [Was the original written in Fortran?]
+
+ [{Jargon File}]
+
+ (1996-04-01)
+
+Adventure Definition Language
+
+ <language, games> (ADL) An {adventure} game language
+ {interpreter} designed by Ross Cunniff <cunniff@fc.hp.com> and
+ Tim Brengle in 1987. ADL is semi-{object-oriented} with
+ {Lisp}-like {syntax} and is a superset of {DDL}. It is
+ available for {Unix}, {MS-DOS}, {Amiga} and {Acorn}
+ {Archimedes}.
+
+ {(ftp://ftp.uu.net/usenet/comp.sources.games/volume2)},
+ {(ftp://ftp.wustl.edu/systems/amiga/fish/fish/f0/ff091)}.
+
+ (1995-03-20)
+
+ADVSYS
+
+ <language, games> An {adventure} game language designed by
+ David Betz in 1986. ADVSYS is {object-oriented} and
+ {Lisp}-like.
+
+ {(ftp://ftp.uu.net/usenet/comp.sources.games/volume2)}.
+
+ (1995-03-20)
+
+adware
+
+ <software> Any kind of {software} which is distributed free of
+ charge along with advertisements that are either placed on the
+ {website} from which the software is distributed or displayed
+ by the program while it is running.
+
+ {Nagware} might be considered a special case of adware where
+ the program tries to persuade the user to buy a license for
+ the program itself.
+
+ (2007-11-20)
+
+AE
+
+ {Application Executive}
+
+ae
+
+ <networking> The {country code} for the United Arab Emirates.
+
+ (1999-01-27)
+
+AED
+
+ {Automated Engineering Design}
+
+AEGIS
+
+ <operating system> A {Unix} variant that was used on {Apollo}
+ {workstations} before Apollo was bought by {Hewlett Packard}.
+ AEGIS has some advantages over standard {BSD} or {System V}
+ Unix. It includes faster file access and a richer command
+ set; there are commands to find out which {process} is running
+ on a particular node, which process is locking a particular
+ file, etc.
+
+ (1997-02-25)
+
+Aegis
+
+ <programming, tool> A {CASE} tool for project {change
+ management} written by Peter Miller, with minor contributions
+ by a few others. Aegis is licensed using the {GNU GPL} but is
+ not a GNU project.
+
+ {Aegis Home (http://aegis.sourceforge.net/)}.
+
+ (2005-03-24)
+
+Aeolus
+
+ <language> A {concurrent} language with {atomic transactions}.
+
+ ["Rationale for the Design of Aeolus", C. Wilkes et al, Proc
+ IEEE 1986 Intl Conf Comp Lang, IEEE 1986, pp.107-122].
+
+ (1995-03-27)
+
+AEP
+
+ {Application Environment Profile}
+
+aeroplane rule
+
+ <convention> "Complexity increases the possibility of failure;
+ a twin-engine aeroplane has twice as many engine problems as a
+ single-engine aeroplane."
+
+ By analogy, in both software and electronics, the implication
+ is that simplicity increases robustness and that the right way
+ to build reliable systems is to put all your eggs in one
+ basket, after making sure that you've built a really *good*
+ basket.
+
+ While simplicity is a useful design goal, and twin-engine
+ aeroplanes do have twice as many engine problems, the analogy
+ is almost entirely bogus. Commercial passenger aircraft are
+ required to have at least two engines (on different wings or
+ nacelles) so that the aeroplane can land safely if one engine
+ fails. As Albert Einstein said, "Everything should be made as
+ simple as possible, but not simpler".
+
+ See also {KISS Principle}.
+
+ (1999-03-22)
+
+AES
+
+ 1. <programming> {Application environment specification}.
+
+ 2. <security> {Advanced Encryption Standard}.
+
+AESOP
+
+ {An Evolutionary System for On-line Programming}
+
+af
+
+ <networking> The {country code} for Afghanistan.
+
+ (1999-01-27)
+
+AFAC
+
+ <language> An early system on the {IBM 704}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1995-04-04)
+
+AFAIK
+
+ <chat> as far as I know.
+
+affine transformation
+
+ <mathematics> A {linear transformation} followed by a
+ {translation}. Given a {matrix} M and a {vector} v,
+
+ A(x) = Mx + v
+
+ is a typical affine transformation.
+
+ (1995-04-10)
+
+affordance
+
+ <graphics> A visual clue to the function of an object.
+
+ (1998-10-15)
+
+AFIPS
+
+ {American Federation of Information Processing Societies}
+
+AFJ
+
+ {April Fool's Joke}
+
+AFK
+
+ <chat> away from keyboard.
+
+aflex
+
+ <tool> A {Lex}-like {scanner generator} that produce {Ada}
+ output from IRUS (Irvine Research Unit in Software). aflex
+ comes with {ayacc}.
+
+ Version 1.2a.
+
+ Mailing list: <irus-software-request@ics.uci.edu>.
+
+ {(ftp://liege.ics.uci.edu/pub/irus/aflex-ayacc_1.2a.tar.Z)}.
+
+ (1993-01-06)
+
+AFNOR
+
+ <body, standard> Association Francaise pour la Normalisation.
+
+ The French national {standards} institute, a member of {ISO}.
+
+ (1994-12-14)
+
+AFP
+
+ 1. <protocol> {Appletalk Filing Protocol}.
+
+ 2. <printer, language> {Advanced Function Presentation}.
+
+AFS
+
+ {Andrew File System}
+
+AFUU
+
+ {Association Française des Utilisateurs d'Unix}
+
+ag
+
+ <networking> The {country code} for Antigua and Barbuda.
+
+ (1999-01-27)
+
+agent
+
+ <networking> In the {client-server} model, the part of the
+ system that performs information preparation and exchange on
+ behalf of a {client} or {server}. Especially in the phrase
+ "intelligent agent" it implies some kind of automatic process
+ which can communicate with other agents to perform some
+ collective task on behalf of one or more humans.
+
+ (1995-04-09)
+
+aggregate type
+
+ <programming> A data {type} composed of multiple elements. An
+ aggregate can be homogeneous (all elements have the same type)
+ e.g. an {array}, a list in a {functional language}, a string
+ of characters, a file; or it can be heterogeneous (elements
+ can have different types) e.g. a {structure}. In most
+ languages aggregates can contain elements which are themselves
+ aggregates. e.g. a list of lists.
+
+ See also {union}.
+
+ (1996-03-23)
+
+aggregation
+
+ <programming> A composition technique for building a new
+ {object} from one or more existing objects that support some
+ or all of the new object's required interfaces.
+
+ (1996-01-07)
+
+aggregator
+
+ <networking> A program for watching for new content at
+ user-specified {RSS} feeds.
+
+ An example is {BottomFeeder}.
+
+ {(http://directory.google.com/Top/Reference/Libraries/Library_and_Information_Science/Technical_Services/Cataloguing/Metadata/RDF/Applications/RSS/News_Readers/)}.
+
+ (2003-09-29)
+
+AGL
+
+ <programming> (Atelier de Genie Logiciel) French for {IPSE}.
+
+ (1997-01-07)
+
+AGM Theory for Belief Revision
+
+ <artificial intelligence> (After the initials of the authors
+ who established the field - Alchourron, Makinson and
+ Gardenfors). A method of {belief revision} giving minimal
+ properties a revision process should have.
+
+ [Reference?]
+
+ (1995-03-20)
+
+Agner Krarup Erlang
+
+ <person> (1878-1929) A Danish mathematician. {Erlang} the
+ language and unit were named after him.
+
+ Interested in the theory of {probability}, in 1908 Erlang
+ joined the Copenhagen Telephone Company where he studied the
+ problem of waiting times for telephone calls.
+
+ He worked out how to calculate the fraction of callers
+ who must wait due to all the lines of an exchange being in
+ use. His formula for loss and waiting time was published in
+ 1917. It is now known as the "Erlang formula" and is still
+ in use today.
+
+ {Biography
+ (http://www-history.mcs.st-andrews.ac.uk/~history/Mathematicians/Erlang.html)},
+ {Biography
+ (http://pass.maths.org.uk/issue2/erlang/index.html)}.
+
+ (2005-02-26)
+
+AGORA
+
+ <language> A distributed {object-oriented language}.
+
+AGP
+
+ {Accelerated Graphics Port}
+
+AGP graphics
+
+ {Accelerated Graphics Port}
+
+A Hardware Programming Language
+
+ <language> (AHPL) A {register}-level language by Hill and
+ Peterson, some of whose operators resemble {APL}.
+
+ HPSIM2 is a function-level simulator, available from Engrg
+ Expt Sta, {University of Arizona}.
+
+ ["Digital Systems: Hardware Organization and Design", F. Hill
+ et al, Wiley 1987].
+
+ (1995-01-26)
+
+AHDL
+
+ {Analog Hardware Design Language}
+
+AHPL
+
+ {A Hardware Programming Language}
+
+AI
+
+ {artificial intelligence}
+
+ai
+
+ <networking> The {country code} for Anguilla.
+
+ (1999-01-27)
+
+AIA
+
+ {Application Integration Architecture}
+
+AI-complete
+
+ <artificial intelligence, jargon> /A-I k*m-pleet'/ (MIT,
+ Stanford: by analogy with "{NP-complete}") A term used to
+ describe problems or subproblems in {artificial intelligence},
+ to indicate that the solution presupposes a solution to the
+ "strong AI problem" (that is, the synthesis of a human-level
+ intelligence). A problem that is AI-complete is, in other
+ words, just too hard.
+
+ See also {gedanken}.
+
+ [{Jargon File}]
+
+ (1995-04-12)
+
+AID
+
+ {Algebraic Interpretive Dialogue}
+
+AIDA
+
+ <language> 1. A {functional} dialect of {Dictionary APL} by
+ M. Gfeller.
+
+ ["APL Arrays and Their Editor", M. Gfeller, SIGPLAN Notices
+ 21(6):18-27 (June 1986) and SIGAPL Conf Proc].
+
+ 2. An intermediate representation language for {Ada} developed
+ at the {University of Karlsruhe} in 1980. AIDA was merged
+ with {TCOL.Ada} to form {Diana}.
+
+ ["AIDA Introduction and User Manual", M. Dausmann et al, U
+ Karlsruhe, Inst fur Inform II, TR Nr 38/80].
+
+ ["AIDA Reference Manual", ibid, TR Nr 39/80, Nov 1980].
+
+ (1995-04-12)
+
+AIDS
+
+ <jargon> /aydz/ A* Infected Disk Syndrome ("A*" is a
+ {glob} pattern that matches, but is not limited to, {Apple
+ Computer}), this condition is quite often the result of
+ practicing unsafe {SEX}.
+
+ See {virus}, {worm}, {Trojan horse}, {virgin}.
+
+ [{Jargon File}]
+
+ (1995-04-13)
+
+AIDX
+
+ <abuse, operating system> /aydkz/ A derogatory term for
+ {IBM}'s perverted version of {Unix}, {AIX}, especially for the
+ AIX 3.? used in the {IBM RS/6000} series (some hackers think
+ it is funnier just to pronounce "AIX" as "aches"). A victim
+ of the dreaded "hybridism" disease, this attempt to combine
+ the two main currents of the Unix stream ({BSD} and {USG
+ Unix}) became a monstrosity to haunt system administrators'
+ dreams. For example, if new accounts are created while many
+ users are logged on, the load average jumps quickly over 20
+ due to silly implementation of the user databases.
+
+ For a quite similar disease, compare {HP-SUX}. Also, compare
+ {Macintrash} {Nominal Semidestructor}, {Open DeathTrap},
+ {ScumOS}, {sun-stools}.
+
+ [{Jargon File}]
+
+ (1995-04-13)
+
+AIFF
+
+ {Audio IFF}
+
+AI International
+
+ <company> One of distributors of {Prolog++}, subsumed by
+ {Customer Engagement Company} before December 1998.
+
+ (1998-12-13)
+
+Aiken code
+
+ <data> An alternative form of the {Binary Coded Decimal} (BCD)
+ system for encoding numbers. Where BCD encodes each decimal
+ digit in normal binary, Aiken code uses the encoding shown
+ below. This is supposed to be less prone to corruption.
+
+ The following table shows the encoding of each decimal digit,
+ D, in BCD and Aiken code:
+
+ D BCD Aiken
+ 0 0000 0000
+ 1 0001 0001
+ 2 0010 0010
+ 3 0011 0011
+ 4 0100 0100
+ 5 0101 1011 (inverted 4)
+ 6 0110 1100 (inverted 3)
+ 7 0111 1101 (inverted 2)
+ 8 1000 1110 (inverted 1)
+ 9 1001 1111 (inverted 0)
+
+ The Aiken code was probably designed by {Howard Aiken} in the
+ 1940s or 1950s for use in data transmission.
+
+ Compare: {Gray code}.
+
+ [What is it good for and why?]
+
+ (2007-07-16)
+
+AI koan
+
+ <humour> /A-I koh'an/ One of a series of pastiches of Zen
+ teaching riddles created by {Danny Hillis} at the {MIT AI Lab}
+ around various major figures of the Lab's culture.
+
+ See also {ha ha only serious}, {mu}.
+
+ In reading these, it is at least useful to know that {Marvin
+ Minsky}, {Gerald Sussman}, and Drescher are {AI} researchers
+ of note, that {Tom Knight} was one of the {Lisp machine}'s
+ principal designers, and that {David Moon} wrote much of Lisp
+ Machine Lisp.
+
+ * * *
+
+ A novice was trying to fix a broken Lisp machine by turning
+ the power off and on.
+
+ Knight, seeing what the student was doing, spoke sternly: "You
+ cannot fix a machine by just power-cycling it with no
+ understanding of what is going wrong."
+
+ Knight turned the machine off and on.
+
+ The machine worked.
+
+ * * *
+
+ One day a student came to Moon and said: "I understand how to
+ make a better garbage collector. We must keep a reference
+ count of the pointers to each cons."
+
+ Moon patiently told the student the following story:
+
+ "One day a student came to Moon and said: `I understand
+ how to make a better garbage collector...
+
+ [Pure reference-count garbage collectors have problems with
+ circular structures that point to themselves.]
+
+ * * *
+
+ In the days when Sussman was a novice, Minsky once came to him
+ as he sat hacking at the PDP-6.
+
+ "What are you doing?", asked Minsky.
+
+ "I am training a randomly wired neural net to play
+ Tic-Tac-Toe", Sussman replied.
+
+ "Why is the net wired randomly?", asked Minsky.
+
+ "I do not want it to have any preconceptions of how to play",
+ Sussman said.
+
+ Minsky then shut his eyes.
+
+ "Why do you close your eyes?", Sussman asked his teacher.
+
+ "So that the room will be empty."
+
+ At that moment, Sussman was enlightened.
+
+ * * *
+
+ A disciple of another sect once came to Drescher as he was
+ eating his morning meal.
+
+ "I would like to give you this personality test", said the
+ outsider, "because I want you to be happy."
+
+ Drescher took the paper that was offered him and put it into
+ the toaster, saying: "I wish the toaster to be happy, too."
+
+ (1995-02-08)
+
+AIMACO
+
+ {AIr MAterial COmmand compiler}
+
+Aimnet
+
+ <networking, company> An {Internet} {access provider} for
+ individuals and corporations. They provide {dial-up}, {SLIP},
+ {PPP} and {shell accounts} as well as {ISDN}.
+
+ {(http://aimnet.com/)}.
+
+ Address: Cupertino, CA 95014, USA.
+
+ Telephone: +1 (408) 253 0900
+
+ (1995-02-08)
+
+AIR
+
+ <standard> A future {infrared} standard from {IrDA}. AIR will
+ provide in-room multipoint to multipoint connectivity. AIR
+ supports a data rate of 4 Mbps at a distance of 4 metres, and
+ 250 Kbps at up to 8 metres. It is designed for cordless
+ connections to multiple peripherals and meeting room
+ collaboration applications.
+
+ See also {IrDA Data} and {IrDA Control}
+
+ (1999-10-14)
+
+AIr MAterial COmmand compiler
+
+ <language> (AIMACO) A modification of {FLOW-MATIC}. AIMACO
+ was supplanted by {COBOL}.
+
+ [Sammet 1969, p. 378].
+
+ (1995-02-20)
+
+airplane rule
+
+ {aeroplane rule}
+
+AIT
+
+ {Advanced Intelligent Tape}
+
+AIX
+
+ {Advanced Interactive eXecutive}
+
+Ajax
+
+ <programming> (Asynchronous JavaScript And XML) A collection
+ of techniques for creating interactive {web applications}
+ without having to reload the complete {web page} in response
+ to each user input, thus making the interaction faster. AJAX
+ typically uses the {XMLHttpRequest} browser object to exchange
+ data asynchronously with the {web server}. Alternatively, an
+ {IFrame} object or dynamically added <script> tags may be used
+ instead of XMLHttpRequest.
+
+ Despite the name, Ajax can combine any browser scripting
+ language (not just {JavaScript}) and any data representation
+ (not just XML). Alternative data formats include {HTML},
+ plain text or {JSON}.
+
+ Several Ajax {frameworks} are now available to simplify Ajax
+ development.
+
+ (2007-10-04)
+
+AKC
+
+ {Ascending Kleene Chain}
+
+AKCL
+
+ {Austin Kyoto Common Lisp}
+
+A. K. Erlang
+
+ {Agner Krarup Erlang}
+
+AKL
+
+ {Andorra Kernel Language}
+
+AL
+
+ 1. {Assembly Language}.
+
+ 2. {artificial life}.
+
+al
+
+ <networking> The {country code} for Albania.
+
+ (1999-01-27)
+
+Aladdin Enterprises
+
+ <company> A small, privately owned, US software consulting and
+ development company, founded in 1986, best known as the
+ original developer of {Ghostscript}.
+
+ Address: San Francisco Peninsula, California, USA.
+
+ Not to be confused with {Aladdin Systems, Inc.}.
+
+ {Aladdin Enterprises Home (http://aladdin.com/)}.
+
+ (2003-09-24)
+
+Aladdin Systems, Inc.
+
+ <company> The company that developed and distributes {Stuffit}
+ and other {utility software} for the {Macintosh}, {Microsoft
+ Windows}, and {Palm} {handheld computers}.
+
+ Not to be confused with {Aladdin Enterprises}.
+
+ {Aladdin Systems Home (http://aladdinsys.com/)}.
+
+ (2003-09-20)
+
+ALADIN
+
+ 1. <language> {A Language for Attributed Definitions}.
+
+ 2. <tool> An interactive mathematics system for the {IBM 360}.
+
+ ["A Conversational System for Engineering Assistance: ALADIN",
+ Y. Siret, Proc Second Symp Symb Algebraic Math, ACM Mar 1971].
+
+ (1995-04-13)
+
+ALAM
+
+ <language> A language for {symbolic mathematics}, especially
+ General Relativity.
+
+ See also {CLAM}.
+
+ ["ALAM Programmer's Manual", Ray D'Inverno, 1970].
+
+ (1994-10-28)
+
+Alan F. Shugart
+
+ <person> The man who founded {Shugart Associates} and later
+ co-founded {Seagate Technology}. Alan Shugart left Shugart
+ Associates in 1974 [did he quit or was he fired?] and took a
+ break from the disk-drive business. In 1979, he and {Finis
+ Conner} founded a new company that at first was called Shugart
+ Technology and later {Seagate Technology}.
+
+ (2000-02-09)
+
+A-language
+
+ <language> An early {ALGOL}-like {surface syntax} for {Lisp}.
+
+ ["An Auxiliary Language for More Natural Expression--The
+ A-language", W. Henneman in The Programming Language LISP,
+ E.C. Berkeley et al eds, MIT Press 1964, pp.239- 248].
+
+ (1994-10-28)
+
+A Language Encouraging Program Hierarchy
+
+ <language> (ALEPH) A language developed in about 1975.
+
+ ["On the Design of ALEPH", D. Grune, CWI, Netherlands 1986].
+
+ (1997-02-27)
+
+A Language for Attributed Definitions
+
+ <language> (ALADIN) A language for formal specification of
+ {attributed grammars}. ALADIN is the input language for the
+ {GAG} compiler generator. It is {applicative} and {strongly
+ typed}.
+
+ ["GAG: A Practical Compiler Generator", Uwe Kastens
+ <uwe@uni-paderborn.de> et al, LNCS 141, Springer 1982].
+
+ (1995-04-14)
+
+A Language with an Extensible Compiler
+
+ <language> (ALEC) A language Implemented using {RCC} on an
+ {ICL 1906A}.
+
+ ["ALEC - A User Extensible Scientific Programming Language",
+ R.B.E. Napper et al, Computer J 19(1):25-31].
+
+ (1995-04-19)
+
+Alan Kay
+
+ <person> The leader of the Software Concepts Group at {Xerox}
+ {Palo Alto Research Centre} which developed {Smalltalk}, the
+ pioneering {object-oriented programming} system, in 1972.
+
+ (1994-11-24)
+
+Alan M. Turing
+
+ {Alan Turing}
+
+Alan Shugart
+
+ {Alan F. Shugart}
+
+Alan Turing
+
+ <person> Alan M. Turing, 1912-06-22/3? - 1954-06-07. A
+ British mathematician, inventor of the {Turing Machine}.
+ Turing also proposed the {Turing test}. Turing's work was
+ fundamental in the theoretical foundations of computer
+ science.
+
+ Turing was a student and fellow of {King's College Cambridge}
+ and was a graduate student at {Princeton University} from 1936
+ to 1938. While at Princeton Turing published "On Computable
+ Numbers", a paper in which he conceived an {abstract machine},
+ now called a {Turing Machine}.
+
+ Turing returned to England in 1938 and during World War II, he
+ worked in the British Foreign Office. He masterminded
+ operations at {Bletchley Park}, UK which were highly
+ successful in cracking the Nazis "Enigma" codes during World
+ War II. Some of his early advances in computer design were
+ inspired by the need to perform many repetitive symbolic
+ manipulations quickly. Before the building of the {Colossus}
+ computer this work was done by a roomful of women.
+
+ In 1945 he joined the {National Physical Laboratory} in London
+ and worked on the design and construction of a large computer,
+ named {Automatic Computing Engine} (ACE). In 1949 Turing
+ became deputy director of the Computing Laboratory at
+ Manchester where the {Manchester Automatic Digital Machine},
+ the worlds largest memory computer, was being built.
+
+ He also worked on theories of {artificial intelligence}, and
+ on the application of mathematical theory to biological forms.
+ In 1952 he published the first part of his theoretical study
+ of morphogenesis, the development of pattern and form in
+ living organisms.
+
+ Turing was gay, and died rather young under mysterious
+ circumstances. He was arrested for violation of British
+ homosexuality statutes in 1952. He died of potassium cyanide
+ poisoning while conducting electrolysis experiments. An
+ inquest concluded that it was self-administered but it is now
+ thought by some to have been an accident.
+
+ There is an excellent biography of Turing by Andrew Hodges,
+ subtitled "The Enigma of Intelligence" and a play based on it
+ called "Breaking the Code". There was also a popular summary
+ of his work in Douglas Hofstadter's book "Gödel, Escher,
+ Bach".
+
+ {(http://AlanTuring.net/)}.
+
+ (2001-10-09)
+
+ALARP
+
+ {As Low As Reasonably Practicable}
+
+A-law
+
+ <standard> The {ITU-T} {standard} for {nonuniform quantising
+ logarithmic compression}.
+
+ The equation for A-law is
+
+ | A
+ | ------- (m/mp) |m/mp| =< 1/A
+ | 1+ln A
+ y = |
+ | sgn(m)
+ | ------ (1 + ln A|m/mp|) 1/A =< |m/mp| =< 1
+ | 1+ln A
+
+ Values of u=100 and 255, A=87.6, mp is the Peak message value,
+ m is the current quantised message value. (The formulae get
+ simpler if you substitute x for m/mp and sgn(x) for sgn(m);
+ then -1 <= x <= 1.)
+
+ Converting from {u-LAW} to A-LAW introduces {quantising
+ errors}. u-law is used in North America and Japan, and A-law
+ is used in Europe and the rest of the world and international
+ routes.
+
+ [The Audio File Formats FAQ]
+
+ (1995-02-21)
+
+ALC
+
+ 1. {Assembly Language Compiler}.
+
+ 2. {Airline Line Control}.
+
+Alcool-90
+
+ <language> An {object-oriented} extension of {ML} with
+ run-time {overloading} and a type-based notion of {modules},
+ {functors} and {inheritance}. It is built on {CAML Light}.
+
+ {(ftp://ftp.inria.fr/lang/alcool)}.
+
+ E-mail: <Francois.Rouaix@inria.fr>.
+
+ (1995-04-18)
+
+ALCOR
+
+ <language> A subset of {ALGOL}.
+
+ [Sammet 1969, p. 180].
+
+ (1995-04-18)
+
+Aldat
+
+ <language> A {database} language, based on {extended algebra}.
+
+ [Listed by M.P. Atkinson & J.W. Schmidt in a tutorial in
+ Zurich, 1989].
+
+ (1995-04-19)
+
+ALDES
+
+ {ALgorithm DEScription}
+
+ALDiSP
+
+ {Applicative Language for Digital Signal Processing}
+
+ALEC
+
+ {A Language with an Extensible Compiler}
+
+ALEF
+
+ <language> A programming language from {Bell Labs}. ALEF
+ boasts few new ideas but is instead a careful synthesis of
+ ideas from other languages. The result is a practical general
+ purpose programming language which was once displacing {C} as
+ their main implementation language. Both {shared variables}
+ and {message passing} are supported through language
+ constructs.
+
+ A {window system}, {user interface}, {operating system}
+ network code, {news reader}, {mailer} and variety of other
+ tools in {Plan 9} are now implemented using ALEF.
+
+ (1997-02-13)
+
+ALEPH
+
+ 1. <language> {A Language Encouraging Program Hierarchy}.
+
+ 2. <tool> A system for formal {semantics} written by Peter
+ Henderson ca. 1970.
+
+ [CACM 15(11):967-973 (Nov 1972)].
+
+ (1994-12-15)
+
+Aleph
+
+ <text, language> ["Aleph: A language for typesetting", Luigi
+ Semenzato <luigi@cs.berkeley.edu> and Edward Wang
+ <edward@cs.berkeley.edu> in Proceedings of Electronic
+ Publishing, 1992 Ed. Vanoirbeek & Coray Cambridge University
+ Press 1992].
+
+ (1994-12-15)
+
+aleph 0
+
+ <mathematics> The {cardinality} of the first {infinite}
+ {ordinal}, {omega} (the number of {natural numbers}).
+
+ Aleph 1 is the cardinality of the smallest {ordinal} whose
+ cardinality is greater than aleph 0, and so on up to aleph
+ omega and beyond. These are all kinds of {infinity}.
+
+ The {Axiom of Choice} (AC) implies that every set can be
+ {well-ordered}, so every {infinite} {cardinality} is an aleph;
+ but in the absence of AC there may be sets that can't be
+ well-ordered (don't posses a {bijection} with any {ordinal})
+ and therefore have cardinality which is not an aleph.
+
+ These sets don't in some way sit between two alephs; they just
+ float around in an annoying way, and can't be compared to the
+ alephs at all. No {ordinal} possesses a {surjection} onto
+ such a set, but it doesn't surject onto any sufficiently large
+ ordinal either.
+
+ (1995-03-29)
+
+alert
+
+ <operating system> /*'l*rt/ An audible and/or visual message
+ intended to inform a system's users or administrators about a
+ change in the operating conditions of that system or about
+ some kind of error condition. In a {graphical user
+ interface}, an alert would typically be displayed as a small
+ window containing the message and a button to click to dismiss
+ the window.
+
+ (1999-03-29)
+
+Alex
+
+ <language> 1. A {polymorphic} language being developed by
+ Stephen Crawley <sxc@itd.dtso.oz.au> of Defence Science & Tech
+ Org, Australia. Alex has {abstract data types}, {type
+ inference} and {inheritance}.
+
+ 2. <language> An {ISWIM}-like language with {exception
+ handling}.
+
+ ["An Exception Handling Construct for Functional Languages",
+ M. Brez et al, in Proc ESOP88, LNCS 300, Springer 1988].
+
+ 3. <tool> A {scanner generator}. {Alexis} is its input
+ language.
+
+ ["Alex: A Simple and Efficient Scanner Generator", H.
+ Mossenbock, SIGPLAN Notices 21(5), May 1986].
+
+ (1994-12-15)
+
+Alexis
+
+ <language> Alex Input Specification.
+
+ The input language for the {scanner generator} {Alex}.
+
+ (1995-04-23)
+
+ALF
+
+ {Algebraic Logic Functional language}
+
+Alfl
+
+ <language> A lazy function language. A {weakly typed}, {lazy}
+ {functional language} developed by Paul Hudak
+ <hudak-paul@cs.yale.edu> of Yale in 1983. Alfl is implemented
+ as a {Scheme} {preprocessor} for the {Orbit} compiler, by
+ transforming laziness into {force}-and-{delay}.
+
+ ["Alfl Reference Manual and Programmer's Guide", P. Hudak,
+ YALEU/DCS/RR322, Yale U, Oct 1984].
+
+ See also {ParAlfl}.
+
+ (1995-04-24)
+
+algebra
+
+ <mathematics, logic> 1. A loose term for an {algebraic
+ structure}.
+
+ 2. A {vector space} that is also a {ring}, where the vector
+ space and the ring share the same addition operation and are
+ related in certain other ways.
+
+ An example algebra is the set of 2x2 {matrices} with {real
+ numbers} as entries, with the usual operations of addition and
+ matrix multiplication, and the usual {scalar} multiplication.
+ Another example is the set of all {polynomials} with real
+ coefficients, with the usual operations.
+
+ In more detail, we have:
+
+ (1) an underlying {set},
+
+ (2) a {field} of {scalars},
+
+ (3) an operation of scalar multiplication, whose input is a
+ scalar and a member of the underlying set and whose output is
+ a member of the underlying set, just as in a {vector space},
+
+ (4) an operation of addition of members of the underlying set,
+ whose input is an {ordered pair} of such members and whose
+ output is one such member, just as in a vector space or a
+ ring,
+
+ (5) an operation of multiplication of members of the
+ underlying set, whose input is an ordered pair of such members
+ and whose output is one such member, just as in a ring.
+
+ This whole thing constitutes an `algebra' iff:
+
+ (1) it is a vector space if you discard item (5) and
+
+ (2) it is a ring if you discard (2) and (3) and
+
+ (3) for any scalar r and any two members A, B of the
+ underlying set we have r(AB) = (rA)B = A(rB). In other words
+ it doesn't matter whether you multiply members of the algebra
+ first and then multiply by the scalar, or multiply one of them
+ by the scalar first and then multiply the two members of the
+ algebra. Note that the A comes before the B because the
+ multiplication is in some cases not commutative, e.g. the
+ matrix example.
+
+ Another example (an example of a {Banach algebra}) is the set
+ of all {bounded} {linear operators} on a {Hilbert space}, with
+ the usual {norm}. The multiplication is the operation of
+ {composition} of operators, and the addition and scalar
+ multiplication are just what you would expect.
+
+ Two other examples are {tensor algebras} and {Clifford
+ algebras}.
+
+ [I. N. Herstein, "Topics in Algebra"].
+
+ (1999-07-14)
+
+ALGEBRAIC
+
+ <language> An early system on {MIT}'s {Whirlwind}.
+
+ [CACM 2(5):16 (May 1959)].
+
+ (1995-01-24)
+
+algebraic
+
+ <theory> In {domain theory}, a {complete partial order} is
+ algebraic if every element is the {least upper bound} of some
+ {chain} of {compact} elements. If the set of compact elements
+ is {countable} it is called {omega-algebraic}.
+
+ [Significance?]
+
+ (1995-04-25)
+
+Algebraic Compiler and Translator
+
+ <language> (ACT 1) A language and {compiler} for the {Royal
+ McBee} {LGP-30}, designed around 1959, apparently by Clay
+ S. Boswell, Jr, and programmed by {Mel Kaye}.
+
+ {(http://ed-thelen.org/comp-hist/lgp-30-man.html)}
+
+ (2008-08-04)
+
+algebraic data type
+
+ <programming> (Or "sum of products type") In {functional
+ programming}, new types can be defined, each of which has one
+ or more {constructors}. Such a type is known as an algebraic
+ data type. E.g. in {Haskell} we can define a new type,
+ "Tree":
+
+ data Tree = Empty | Leaf Int | Node Tree Tree
+
+ with constructors "Empty", "Leaf" and "Node". The
+ constructors can be used much like functions in that they can
+ be (partially) applied to arguments of the appropriate type.
+ For example, the Leaf constructor has the functional type Int
+ -> Tree.
+
+ A constructor application cannot be reduced (evaluated) like a
+ function application though since it is already in {normal
+ form}. Functions which operate on algebraic data types can be
+ defined using {pattern matching}:
+
+ depth :: Tree -> Int
+ depth Empty = 0
+ depth (Leaf n) = 1
+ depth (Node l r) = 1 + max (depth l) (depth r)
+
+ The most common algebraic data type is the list which has
+ constructors Nil and Cons, written in Haskell using the
+ special syntax "[]" for Nil and infix ":" for Cons.
+
+ Special cases of algebraic types are {product types} (only one
+ constructor) and {enumeration types} (many constructors with
+ no arguments). Algebraic types are one kind of {constructed
+ type} (i.e. a type formed by combining other types).
+
+ An algebraic data type may also be an {abstract data type}
+ (ADT) if it is exported from a {module} without its
+ constructors. Objects of such a type can only be manipulated
+ using functions defined in the same {module} as the type
+ itself.
+
+ In {set theory} the equivalent of an algebraic data type is a
+ {discriminated union} - a set whose elements consist of a tag
+ (equivalent to a constructor) and an object of a type
+ corresponding to the tag (equivalent to the constructor
+ arguments).
+
+ (1994-11-23)
+
+Algebraic Interpretive Dialogue
+
+ <language> (AID) A version of {Joss} II for the {PDP-10}.
+
+ ["AID (Algebraic Interpretive Dialogue)", DEC manual, 1968].
+
+ (1995-04-12)
+
+Algebraic Logic Functional language
+
+ <language> (ALF) A language by Rudolf Opalla
+ <opalla@julien.informatik.uni-dortmund.de> which combines
+ {functional programming} and {logic programming} techniques.
+
+ ALF is based on {Horn clause} logic with equality which
+ consists of {predicates} and Horn clauses for {logic
+ programming}, and functions and equations for {functional
+ programming}. Any functional expression can be used in a
+ {goal} literal and arbitrary predicates can occur in
+ conditions of equations. ALF uses {narrowing} and
+ {rewriting}.
+
+ ALF includes a compiler to {Warren Abstract Machine} code and
+ {run-time support}.
+
+ {(ftp://ftp.germany.eu.net/pub/programming/languages/LogicFunctional)}.
+
+ ["The Implementation of the Functional-Logic Language ALF",
+ M. Hanus and A. Schwab].
+
+ (1992-10-08)
+
+Algebraic Manipulation Package
+
+ <mathematics, tool> (AMP) A {symbolic mathematics} program
+ written in {Modula-2}, seen on {CompuServe}.
+
+ (1994-10-19)
+
+Algebraic Specification Language
+
+ 1. <language> (ASL)
+
+ ["Structured Algebraic Specifications: A Kernel Language",
+ M. Wirsing, Theor Comput Sci 42, pp.123-249, Elsevier 1986].
+
+ 2. <language> (ASF) A language for equational specification of
+ {abstract data types}.
+
+ ["Algebraic Specification", J.A. Bergstra et al, A-W 1989].
+
+ (1995-12-13)
+
+algebraic structure
+
+ <mathematics> Any formal mathematical system consisting of a
+ set of objects and operations on those objects. Examples are
+ {Boolean algebra}, numerical algebra, set algebra and matrix
+ algebra.
+
+ [Is this the most common name for this concept?]
+
+ (1997-02-25)
+
+Algebra of Communicating Processes
+
+ <theory> (ACP)
+
+ Compare {CCS}.
+
+ ["Algebra of Communicating Processes with Abstraction",
+ J.A. Bergstra & J.W. Klop, Theor Comp Sci 37(1):77-121 1985].
+
+ [Summary?]
+
+ (1994-11-08)
+
+ALGOL
+
+ {ALGOL 60}
+
+ALGOL 58
+
+ <language> An early version of {ALGOL 60}, originally known as
+ "IAL".
+
+ {Michigan Algorithm Decoder} (MAD), developed in 1959, was
+ based on IAL.
+
+ ["Preliminary report - International Algebraic Language", CACM
+ 1(12):8, 1958].
+
+ [Details? Relationship to ALGOL 60?]
+
+ (1999-12-10)
+
+ALGOL 60
+
+ <language> ALGOrithmic Language 1960.
+
+ A portable language for scientific computations. ALGOL 60 was
+ small and elegant. It was {block-structured}, nested,
+ {recursive} and {free form}. It was also the first language
+ to be described in {BNF}.
+
+ There were three {lexical} representations: hardware,
+ reference, and publication. The only structured data types
+ were {arrays}, but they were permitted to have lower bounds
+ and could be dynamic. It also had {conditional expressions};
+ it introduced :=; if-then-else; very general "for" loops;
+ switch declaration (an array of statement {labels}
+ generalising {Fortran}'s {computed goto}). Parameters were
+ {call-by-name} and {call-by-value}. It had {static} local
+ "own" variables. It lacked user-defined types, character
+ manipulation and {standard I/O}.
+
+ See also {EULER}, {ALGOL 58}, {ALGOL 68}, {Foogol}.
+
+ ["Report on the Algorithmic Language ALGOL 60", Peter Naur
+ ed., CACM 3(5):299-314, May 1960].
+
+ (1995-01-25)
+
+ALGOL 60 Modified
+
+ <language>
+
+ ["A Supplement to the ALGOL 60 Revised Report", R.M. DeMorgan
+ et al, Computer J 19(4):364].
+
+ [SIGPLAN Notices 12(1) 1977].
+
+ An erratum in [Computer J 21(3):282 (Aug 1978)] applies to
+ both.
+
+ (1995-01-25)
+
+ALGOL 60 Revised
+
+ <language> (Or "Revised ALGOL 60") A revision of {Algol 60}
+ which still lacked {standard I/O}.
+
+ ["Revised Report on the Algorithmic Language ALGOL 60", Peter
+ Naur ed, CACM 6(1):1-17 (Jan 1963)].
+
+ [Sammet 1969, p.773].
+
+ (1995-01-25)
+
+ALGOL 68
+
+ <language> An extensive revision of {ALGOL 60} by Adriaan van
+ Wijngaarden et al. ALGOL 68 was discussed from 1963 by
+ Working Group 2.1 of {IFIP}. Its definition was accepted in
+ December 1968.
+
+ ALGOL 68 was the first, and still one of very few, programming
+ languages for which a complete formal specification was
+ created before its implementation. However, this
+ specification was hard to understand due to its formality, the
+ fact that it used an unfamiliar {metasyntax} notation (not
+ {BNF}) and its unconventional terminology.
+
+ One of the singular features of ALGOL 68 was its {orthogonal}
+ design, making for freedom from arbitrary rules (such as
+ restrictions in other languages that arrays could only be used
+ as parameters but not as results). It also allowed {user
+ defined data types}, then an unheard-of feature.
+
+ It featured {structural equivalence}; automatic type
+ conversion ("{coercion}") including {dereferencing}; {flexible
+ arrays}; generalised loops (for-from-by-to-while-do-od),
+ if-then-else-elif-fi, an integer case statement with an 'out'
+ clause (case-in-out-esac); {skip} and {goto} statements;
+ {blocks}; {procedures}; user-defined {operators}; {procedure
+ parameters}; {concurrent} execution (par-begin-end);
+ {semaphores}; generators "heap" and "loc" for {dynamic
+ allocation}. It had no {abstract data types} or {separate
+ compilation}.
+
+ {(http://www.bookrags.com/research/algol-68-wcs/)}.
+
+ (2007-04-24)
+
+ALGOL 68C
+
+ <language> A variant of {ALGOL 68} developed by S. Bourne and
+ Mike Guy of {Cambridge University} in 1975 and used as the
+ implementation language for the {CHAOS} OS for the {CAP}
+ {capability} computer. ALGOL 68C was ported to the {IBM 360},
+ {VAX}/{VMS} and several other {platforms}.
+
+ (1995-05-02)
+
+ALGOL 68-R
+
+ <language> A restriction of {ALGOL 68} permitting {one-pass
+ compilation}, developed at the Royal Signals Radar
+ Establishment, Malvern, Worcester, UK in April 1970.
+
+ {Identifiers}, modes and operators must be declared before
+ use. There is no {automatic proceduring} and no
+ {concurrency}. It was implemented in {ALGOL 60} under {GEORGE
+ 3} on an {ICL 1907F}.
+
+ ["ALGOL 68-R, Its Implementation and Use", I.F. Currie et al,
+ Proc IFIP Congress 1971, N-H 1971, pp. 360-363].
+
+ (1995-05-03)
+
+ALGOL 68 Revised
+
+ <language> A significant simplification of {ALGOL 68}.
+
+ ["Revised Report on the Algorithmic Language ALGOL 68," A. Van
+ Wijngaarden et al, Acta Informatica 5:1-236, 1975, also
+ Springer 1976, and SIGPLAN Notices 12(5):1-70, May 1977].
+
+ (1995-05-03)
+
+ALGOL 68RS
+
+ <language> An extension of {ALGOL 68} supporting {function
+ closures} by the Royal Signals Radar Establishment, Malvern
+ UK. It has been ported to {Multics} and {VAX}/{VMS}.
+
+ (1995-05-04)
+
+ALGOL 68S
+
+ <language> A subset of {ALGOL 68} allowing simpler
+ compilation, intended mainly for numerical computation. It
+ was rewritten in {BLISS} for the {PDP-11}, and later in
+ {Pascal}. It is available as {shareware} from Charles Lindsey
+ <chl@cs.man.ac.uk>.
+
+ Version 2.3 runs on {Sun-3} under {SunOS} 4.x and {Atari}
+ under {GEMDOS} (or potentially other computers supported by
+ the {Amsterdam Compiler Kit}).
+
+ ["A Sublanguage of ALGOL 68", P.G. Hibbard, SIGPLAN Notices
+ 12(5), May 1977].
+
+ (1995-05-04)
+
+ALGOL C
+
+ <language> A variant of {ALGOL 60} developed by Clive Feather
+ of {Cambridge University} ca. 1981. ALGOL C added
+ {structures} and {exception} handling. It was designed for
+ beginners and students.
+
+ (1994-11-24)
+
+ALGOL D
+
+ <language>
+
+ ["A Proposal for Definitions in ALGOL", B.A. Galler et al,
+ CACM 10:204-219, 1967].
+
+ALGOL N
+
+ <language> A successor to {ALGOL 60} proposed by Yoneda.
+
+ (1994-11-24)
+
+ALGOL W
+
+ <language> A derivative of {ALGOL 60}. It introduced {double
+ precision}, {complex numbers}, bit strings and dynamic data
+ structures. It is parsed entirely by {operator precedence}
+ and used the {call-by-value-result} calling convention.
+
+ ["A Contribution to the Development of Algol", N. Wirth, CACM
+ 9(6):413-431, June 1966].
+
+ ["ALGOL W Implementation", H. Bauer et al, TR CS98, Stanford
+ U, 1968].
+
+ (1994-11-24)
+
+ALGOL X
+
+ <language> A proposed successor to {ALGOL 60}, a "short-term
+ solution to existing difficulties". Three designs were
+ proposed, by {Wirth}, Seegmuller and van Wijngaarden.
+
+ [Sammet 1969, p. 194].
+
+ (1995-05-07)
+
+ALGOL Y
+
+ <language> A proposed successor to {ALGOL 60}, a "radical
+ reconstruction". Originally a language that could manipulate
+ its own programs at {run time}, it became a collection of
+ features that were not accepted for {ALGOL X}.
+
+ (1995-05-09)
+
+algorithim
+
+ <spelling> It's spelled "{algorithm}".
+
+ (1997-02-25)
+
+algorithm
+
+ <algorithm, programming> A detailed sequence of actions to
+ perform to accomplish some task. Named after the Iranian,
+ Islamic mathematician, astronomer, astrologer and geographer,
+ {Muhammad ibn Musa al-Khwarizmi}.
+
+ Technically, an algorithm must reach a result after a {finite}
+ number of steps, thus ruling out {brute force} search methods
+ for certain problems, though some might claim that brute force
+ search was also a valid (generic) algorithm. The term is also
+ used loosely for any sequence of actions (which may or may not
+ terminate).
+
+ {Paul E. Black's Dictionary of Algorithms, Data Structures,
+ and Problems (http://nist.gov/dads/)}.
+
+ (2002-02-05)
+
+ALgorithm DEScription
+
+ <language> (ALDES) ["The Algorithm Description Language
+ ALDES", R.G.K. Loos, SIGSAM Bull 14(1):15-39 (Jan 1976)].
+
+ (1995-04-19)
+
+ALgorIthmic ASsembly language
+
+ <language> (ALIAS) A machine oriented variant of {BLISS}.
+ ALIAS was implemented in {BCPL} for the {PDP-9}.
+
+ ["ALIAS", H.E. Barreveld, Int Rep, Math Dept, Delft U Tech,
+ Netherlands, 1973].
+
+ (1997-03-13)
+
+Algorithmic Language
+
+ {Algol 60}
+
+Algorithmic Model
+
+ <programming> A method of estimating software cost using
+ mathematical {algorithms} based on the parameters which are
+ considered to be the major cost drivers. These estimate of
+ effort or cost are based primarily on the size of the software
+ or {Delivered Source Instructions} (DSI)s, and other
+ productivity factors known as {Cost Driver Attributes}.
+
+ See also {Parametric Model}.
+
+ (1996-05-28)
+
+Algorithmic Processor Description Language
+
+ <language> (APDL) An {ALGOL 60}-like language for describing
+ computer design, for the {CDC G-21}.
+
+ ["The Description, Simulation, and Automatic Implementation of
+ Digital Computer Processors", J.A. Darringer, Ph.D Thesis EE
+ Dept, CMU May 1969].
+
+ (1995-11-26)
+
+Algorithmic Test Case Generation
+
+ <programming> A computational method for identifying test
+ cases from data, logical relationships or other software
+ {requirements} information.
+
+ (1996-05-10)
+
+ALGY
+
+ <language> An early language for {symbolic mathematics}.
+
+ [Sammet 1969, p. 520].
+
+ (1995-04-12)
+
+ALIAS
+
+ {ALgorIthmic ASsembly language}
+
+alias
+
+ 1. <operating system> A name, usually short and easy to
+ remember and type, that is translated into another name or
+ string, usually long and difficult to remember or type. Most
+ {command interpreters} (e.g. {Unix}'s {csh}) allow the user to
+ define aliases for commands, e.g. "alias l ls -al". These are
+ loaded into memory when the interpreter starts and are
+ expanded without needing to refer to any file.
+
+ 2. <networking> One of several alternative {hostnames} with
+ the same {Internet address}. E.g. in the {Unix} {hosts}
+ database (/etc/hosts or {NIS} map) the first field on a line
+ is the {Internet address}, the next is the official hostname
+ (the "{canonical} name" or "{CNAME}"), and any others are
+ aliases.
+
+ Hostname aliases often indicate that the host with that alias
+ provides a particular network service such as {archie},
+ {finger}, {FTP}, or {web}. The assignment of
+ services to computers can then be changed simply by moving an
+ alias (e.g. www.doc.ic.ac.uk) from one {Internet address} to
+ another, without the clients needing to be aware of the
+ change.
+
+ 3. <file system> The name used by {Apple computer, Inc.} for
+ {symbolic links} when they added them to the {System 7}
+ {operating system} in 1991.
+
+ (1997-10-22)
+
+ 4. <programming> Two names ({identifiers}), usually of local
+ or global {variables}, that refer to the same resource
+ ({memory} location) are said to be aliased. Although names
+ introduced in {programming languages} are typically mapped to
+ different {memory} locations, aliasing can be introduced by
+ the use of {address} arithmetic and {pointers} or
+ language-specific features, like {C++} {references}.
+
+ Statically deciding (e.g. via a {program analysis} executed by a
+ sophisticated {compiler}) which locations of a {program} will be
+ aliased at run time is an {undecidable} problem.
+
+ [G. Ramalingam: "The Undecidability of Aliasing", ACM
+ Transactions on Programming Languages and Systems (TOPLAS),
+ Volume 16, Issue 5, September 1994, Pages: 1467 - 1471,
+ ISSN:0164-0925.]
+
+ (2004-09-12)
+
+aliasing
+
+ 1. <jargon> When several different identifiers refer to the
+ same object. The term is very general and is used in many
+ contexts.
+
+ See {alias}, {aliasing bug}, {anti-aliasing}.
+
+ 2. <hardware> (Or "shadowing") Where a hardware device
+ responds at multiple addresses because it only decodes a
+ subset of the {address lines}, so different values on the
+ other lines are ignored.
+
+ (1998-03-13)
+
+aliasing bug
+
+ {stale pointer bug}
+
+Alice
+
+ <computer, parallel> A parallel {graph rewriting} computer
+ developed by {Imperial College}, {University of Edinburgh} and
+ {ICL}.
+
+ (1995-01-19)
+
+alife
+
+ {artificial life}
+
+A-Life
+
+ {artificial life}
+
+ALJABR
+
+ <tool> An implementation of {MACSYMA} for the {Macintosh} by
+ {Fort Pond Research}.
+
+ (1995-02-21)
+
+al-Khwarizmi
+
+ {Muhammad ibn Musa al-Khwarizmi}
+
+Allegro
+
+ <operating system> The code name for the major {Mac OS}
+ release due in mid-1998.
+
+ {(http://devworld.apple.com/mkt/informed/appledirections/mar97/roadmap.html)}.
+
+ (1997-10-15)
+
+all-elbows
+
+ <jargon> Said of a {TSR} (terminate-and-stay-resident)
+ {mess-dos} program, such as the N pop-up calendar and
+ calculator utilities that circulate on {BBS} systems:
+ unsociable. Used to describe a program that {rude}ly steals
+ the resources that it needs without considering that other
+ TSRs may also be resident. One particularly common form of
+ rudeness is lock-up due to programs fighting over the keyboard
+ interrupt.
+
+ [{Jargon File}]
+
+ (1995-02-21)
+
+ALLIANCE
+
+ <tool> A complete set of {CAD} tools for teaching Digital
+ {CMOS} {VLSI} Design in Universities. It includes a {VHDL}
+ compiler and simulator, {logic synthesis} tools, and automatic
+ place and route tools. ALLIANCE is the result of a ten years
+ effort at University Pierre et Marie Curie (PARIS VI, France).
+
+ It runs on {Sun-4}, not well supported: {MIPS}/{Ultrix},
+ {386}/{SystemV}.
+
+ Latest version: 1.1, as of 1993-02-16.
+
+ (1993-02-16)
+
+allow-none
+
+ <programming> An annotation in {GTk} documentation indicating
+ that the annotated entity may be null.
+
+ {(http://live.gnome.org/GObjectIntrospection/Annotations)}.
+
+ (2009-09-29)
+
+ALLOY
+
+ <language> A language by Thanasis Mitsolides
+ <mitsolid@cs.nyu.edu> which combines {functional programming},
+ {object-oriented programming} and {logic programming} ideas,
+ and is suitable for {massively parallel} systems.
+
+ Evaluating modes support serial or parallel execution, {eager
+ evaluation} or {lazy evaluation}, {nondeterminism} or multiple
+ solutions etc. ALLOY is simple as it only requires 29
+ primitives in all (half of which are for {object oriented
+ programming} support).
+
+ It runs on {SPARC}.
+
+ {(ftp://cs.nyu.edu/pub/local/alloy/)}.
+
+ ["The Design and Implementation of ALLOY, a Parallel Higher
+ Level Programming Language", Thanasis Mitsolides
+ <mitsolid@cs2.nyu.edu>, PhD Thesis NYU 1990].
+
+ (1991-06-11)
+
+ALM
+
+ 1. <programming> {application lifecycle management}.
+
+ 2. <language> {Assembly Language for Multics}.
+
+Aloha
+
+ <networking> (From the Hawaiian greeting) A system of
+ {contention resolution} devised at The {University of Hawaii}.
+ {Packets} are {broadcast} when ready, the sender listens to
+ see if they collide and if so re-transmits after a random
+ time. {Slotted Aloha} constrains packets to start at the
+ beginning of a time slot. Basic Aloha is appropriate to long
+ propagation time nets (e.g. satellite). For shorter
+ propagation times, {carrier sense} {protocols} are possible.
+
+ (1995-12-10)
+
+Aloha Net
+
+ <networking> (From the Hawaiian greeting) One of the first
+ functioning {networks} in the USA, conceived and implimented
+ at the {University of Hawaii} campus at Manoa. Its purpose
+ was to link the University {mainframe} computer to client
+ computers located on outer islands at University campuses.
+ Put in place in the early 1970s, it was dubed the Aloha Net.
+ {Key punch} cards were fed through a reader, and sent over the
+ commercial phone lines.
+
+ (1995-12-10)
+
+Alonzo Church
+
+ <person> A twentieth century mathematician and logician, and
+ one of the founders of computer science. Church invented the
+ {lambda-calculus} and posited a version of the {Church-Turing
+ thesis}.
+
+ (1995-03-25)
+
+ALP
+
+ <language> A {list processing} extension of {Mercury
+ Autocode}.
+
+ ["ALP, An Autocode List-Processing Language", D.C. Cooper et
+ al, Computer J 5:28-31, 1962].
+
+ (1995-01-24)
+
+ALPAK
+
+ <library> A subroutine package used by {ALTRAN}.
+
+ ["The ALPAK System for Nonnumerical Algebra on a Digital
+ Computer", W.S. Brown, Bell Sys Tech J 42:2081, 1963].
+
+ [Sammet 1969, p. 502].
+
+ (1995-05-10)
+
+ALPHA
+
+ <language> (Or "Input") An extension of {ALGOL 60} for the
+ {M-20} computer developed by A.P. Ershov at Novosibirsk in
+ 1961. ALPHA includes {matrix} operations, {slices}, and
+ complex arithmetic.
+
+ ["The Alpha Automatic Programming System", A.P. Ershov ed.,
+ A-P 1971].
+
+ (1995-05-10)
+
+Alpha
+
+ 1. <tool> A {compiler generator} written by Andreas Koschinsky
+ <koschins@cs.tu-berlin.de> and described in his thesis at the
+ {Technische Universitaet Berlin}. Alpha takes an {attribute
+ grammar} and uses {Bison} and {Flex} to generate a {parser}, a
+ {scanner} and an {ASE evaluator} (Jazayeri and Walter).
+
+ The documentation is in german.
+
+ (1993-02-16)
+
+ 2. <processor> {DEC Alpha}.
+
+ (1995-05-10)
+
+Alpha AXP 21164
+
+ <processor> A 1 {GIPS} version of the {DEC Alpha} processor.
+ The first commercially available sequential 1 GIPS processor.
+ Announced 1994-09-7.
+
+ {(http://digital.com/info/semiconductor/dsc-21164.html)}.
+
+ (1995-05-10)
+
+alpha/beta pruning
+
+ <games, algorithm> An optimisation of the {minimax}
+ {algorithm} for choosing the next move in a two-player game.
+ The position after each move is assigned a value. The larger
+ this value, the better the position is for me. Thus, I will
+ choose moves with maximum value and you will choose moves with
+ minimum value (for me).
+
+ If it is my move and I have already found one move M with
+ value alpha then I am only interested in other moves with
+ value greater than alpha. I now consider another of my
+ possible moves, M', to which you could reply with a move with
+ value beta. I know that you would only make a different reply
+ if it had a value less than beta. If beta is already less
+ than alpha then M' is definitely worth less than M so I can
+ reject it without considering any other replies you might
+ make.
+
+ The same reasoning applies when considering my replies to your
+ reply. An alpha cutoff is when your reply gives a lower value
+ than the current maximum (alpha) and a beta cutoff is when my
+ reply to your reply gives a higher value than the current
+ minimum value of your reply (beta).
+
+ In short, if you've found one possible move, you need not
+ consider another move which your opponent can force to be
+ worse than the first one.
+
+ (1997-05-05)
+
+alphabetic language
+
+ <human language> A written human language in which symbols
+ reflect the pronunciation of the words. Examples are English,
+ Greek, Russian, Thai, Arabic and Hebrew. Alphabetic languages
+ contrast with {ideographic languages}.
+
+ {I18N Encyclopedia
+ (http://i18ngurus.com/encyclopedia/alphabetic_language.html)}.
+
+ (2004-08-29)
+
+alpha conversion
+
+ <theory> In {lambda-calculus} and {reduction}, the renaming of
+ a {formal parameter} in a {lambda abstraction}. This does not
+ change the meaning of the abstraction. For example:
+
+ \ x . x+1 <--> \ y . y+1
+
+ If the {actual argument} to a lambda abstraction contains
+ instances of the abstraction's formal parameter then it is
+ necessary to rename the parameter before applying the
+ abstraction to avoid {name capture}.
+
+ (1995-05-10)
+
+Alpha EV6
+
+ {EV6}
+
+Alpha Geek
+
+ <job> The head {geek} or geek's geek. When no one else knows
+ the answer, or several techno-types give conflicting advise,
+ or the error message says "consult your administrator" and you
+ *are* the administrator, you ask the Alpha Geek.
+
+ (1997-06-25)
+
+alphanumeric
+
+ <character> A decimal digit or a letter (upper or lower case).
+ Typically, "letters" means only English letters ({ASCII} A-Z
+ plus a-z) but it may also include non-English letters in the
+ Roman alphabet, e.g., e-{acute}, c-{cedilla}, the {thorn
+ letter}, and so on. Perversely, it may also include the
+ {underscore} character in some contexts.
+
+ (1997-09-11)
+
+alpha particle
+
+ {bit rot}
+
+Alphard
+
+ <language> (Named after the brightest star in Hydra) A
+ {Pascal}-like language developed by Wulf, Shaw and London of
+ {CMU} in 1974. Alphard supports {data abstraction} using the
+ 'form', which combines a specification and an implementation.
+
+ ["Abstraction and Verification in Alphard: Defining and
+ Specifying Iteration and Generators", Mary Shaw, CACM
+ 20(8):553-563, Aug 1977].
+
+ (1995-05-10)
+
+alpha testing
+
+ <programming> Testing of software at the developer's site by
+ the customer. The stage before {beta testing}.
+
+ (1996-05-10)
+
+ALPS
+
+ <language> 1. An interpreted {algebraic language} for the
+ {Bendix G15} developed by Dr. Richard V. Andree (? - 1987),
+ Joel C. Ewing and others of the {University of Oklahoma} from
+ Spring 1966 (possibly 1965).
+
+ Dale Peters <dpeters@theshop.net> reports that in the summer
+ of 1966 he attended the second year of an {NSF}-sponsored
+ summer institute in mathematics and computing at the
+ University of Oklahoma. Dr. Andree's computing class mostly
+ used the language GO-GO, later renamed ALPS. The language
+ changed frequently during the class, which was occasionally
+ disorienting. Dale believes it was also used in Summer 1965
+ and that it was about this time that {John G. Kemeny} (one of
+ the designers of {Dartmouth BASIC}, 1963) saw it during a
+ visit.
+
+ Dr. Andree's January 1967 class mimeo notes on ALPS begin:
+ "ALPS is a new programming language designed and perfected by
+ Mr. Harold Bradbury, Mr. Joel Ewing and Mr. Harold Wiebe,
+ members of the O.U. Mathematics Computer Consultants Group
+ under the direction of Dr. Richard V. Andree. ALPS is
+ designed to be used with a minimum of training to solve
+ numerical problems on a computer with typewriter stations and
+ using man-computer cooperation by persons who have little
+ familiarity with advanced mathematics."
+
+ The initial version of what evolved into ALPS was designed and
+ implemented by Joel Ewing (a pre-senior undergrad) in G15
+ {machine language} out of frustration with the lack of
+ applications to use the G15's dual-case alphanumeric I/O
+ capabilities. Harold Wiebe also worked on the code. Others,
+ including Ralph Howenstine, a member of the O.U. Math Computer
+ Consultants Group, contributed to the design of extensions and
+ Dr. Andree authored all the instructional materials, made the
+ outside world aware of the language and encouraged work on the
+ language.
+
+ (2006-10-10)
+
+ 2. A parallel {logic language}.
+
+ ["Synchronization and Scheduling in ALPS Objects",
+ P. Vishnubhotia, Proc 8th Intl Conf Distrib Com Sys, IEEE
+ 1988, pp. 256-264].
+
+ (1994-11-24)
+
+alt
+
+ <character> /awlt/ 1. The alt {modifier key} on many
+ {keyboards}, including the {IBM PC}. On some keyboards and
+ {operating systems}, (but not the IBM PC) the alt key sets bit
+ 7 of the character generated.
+
+ See {bucky bits}.
+
+ 2. The "{clover}" or "Command" key on a {Macintosh}; use of
+ this term usually reveals that the speaker hacked PCs before
+ coming to the Mac (see also {feature key}). Some Mac hackers,
+ confusingly, reserve "alt" for the Option key (and it is so
+ labelled on some Mac II keyboards).
+
+ 3. (Obsolete {PDP-10}; often "ALT") An alternate name for the
+ {ASCII} ESC character (Escape, ASCII 27), after the keycap
+ labelling on some older {terminals}; also "altmode"
+ (/awlt'mohd/). This character was almost never pronounced
+ "escape" on an {ITS} system, in {TECO} or under {TOPS-10},
+ always alt, as in "Type alt alt to end a TECO command" or
+ "alt-U onto the system" (for "log onto the [ITS] system").
+ This usage probably arose because alt is easier to say.
+
+ 4. <messaging> One of the {Usenet} {newsgroup} {hierarchies}.
+ It was founded by {John Gilmore} and {Brian Reid}. The alt
+ hierarchy is special in that anyone can create new groups here
+ without going though the normal voting proceduers, hence the
+ regular appearence of new groups with names such as
+ "alt.swedish.chef.bork.bork.bork".
+
+ [{Jargon File}]
+
+ (1997-04-12)
+
+ALTAC
+
+ <language> An extended {Fortran II} for the {Philco 2000},
+ built on {TAC}.
+
+ [Sammet 1969, p.146].
+
+ (1995-03-16)
+
+Altair 8800
+
+ <computer> An {Intel 8080}-based machine made by {MITS}. The
+ Altair was the first popular {microcomputer} kit.
+
+ It appeared on the cover of the January 1975 "Popular
+ Electronics" magazine with an article (probably) by Leslie
+ Solomon. Leslie Solomon was an editor at Popular Electronics
+ who had a knack for spotting kits that would interest people
+ and make them buy the magazine. The Altair 8800 was one such.
+ The MITS guys took the prototype Altair to New York to show
+ Solomon, but couldn't get it to work after the flight.
+ Nonetheless, he liked it, and it appeared on the cover as "The
+ first minicomputer in a kit."
+
+ Solomon's blessing was important enough that some MITS
+ competitors named their product the "SOL" to gain his favour.
+ Some wags suggested {SOL} was actually an abbreviation for the
+ condition in which kit purchasers would find themselves.
+
+ {Bill Gates} and Paul Allen saw the article on the Altair 8800
+ in Popular Electronics. They realised that the Altair, which
+ was programmed via its binary front panel needed a {high level
+ language}. Legend has it that they called MITS with the claim
+ that they had a {BASIC} {interpreter} for the Altair. When
+ MITS asked them to demo it in Albuquerque, they wrote one on
+ the plane. On arrival, they entered the machine code via the
+ front panel and demonstrated and sold their "product." Thus
+ was born "Altair BASIC."
+
+ The original Altair BASIC ran in less than 4K of RAM because a
+ "loaded" Altair had 4K memory. Since there was no {operating
+ system} on the Altair, Altair BASIC included what we now think
+ of as {BIOS}. It was distributed on {paper tape} that could
+ be read on a {Teletype}. Later versions supported the 8K
+ Altair and the 16K {diskette}-based Altair (demonstrating
+ that, even in the 1970s, {Microsoft} was committed to
+ {software bloat}). Altair BASIC was ported to the {Motorola
+ 6800} for the Altair 680 machine, and to other 8080-based
+ microcomputers produced by MITS' competitors.
+
+ {PC-History.org Altair 8800 page
+ (http://pc-history.org/altair_8800.htm)}.
+
+ [Forrest M. Mimms, article in "Computers and Electronics",
+ (formerly "Popular Electronics"), Jan 1985(?)].
+
+ [Was there ever an "Altair 9000" microcomputer?]
+
+ (2002-06-17)
+
+Alta Vista
+
+ <web> A {website} provided by {Digital}
+ which features a very fast Web and {Usenet} {search engine}.
+
+ As of April 1996 its word index is 33GB in size. AltaVista is
+ currently (June 1996) the largest Web index, with 30 million
+ pages from 225,000 servers, and three million articles from
+ 14,000 {Usenet} news groups. It is accessed over 12 million
+ times per weekday.
+
+ {(http://altavista.digital.com/)}.
+
+ (1996-06-10)
+
+alt bit
+
+ /awlt bit/ alternate bit. See {meta bit}.
+
+ [{Jargon File}]
+
+ALTER
+
+ <database> An {SQL} {Data Definition Language} command that
+ adds or removes {columns} or {indexes} to/from a {table} or
+ modifies the table definition in some other way. This differs
+ from the INSERT, UPDATE and DELETE ({Data Modification
+ Language}) commands in that those change the data stored in
+ the table but not its definition.
+
+ {MySQL ALTER TABLE command
+ (http://dev.mysql.com/doc/refman/5.1/en/alter-table.html)}.
+
+ (2009-11-10)
+
+Alternating bit protocol
+
+ <networking> (ABP) A simple {data link layer} {protocol} that
+ retransmits lost or corrupted messages.
+
+ Messages are sent from transmitter A to receiver B. Assume
+ that the channel from A to B is initialised and that there are
+ no messages in transit. Each message contains a data part, a
+ {checksum}, and a one-bit {sequence number}, i.e. a value that
+ is 0 or 1.
+
+ When A sends a message, it sends it continuously, with the
+ same sequence number, until it receives an acknowledgment
+ ({ACK}) from B that contains the same sequence number. When
+ that happens, A complements (flips) the sequence number and
+ starts transmitting the next message.
+
+ When B receives a message from A, it checks the checksum. If
+ the message is not corrupted B sends back an ACK with the same
+ sequence number. If it is the first message with that
+ sequence number then it is sent for processing. Subsequent
+ messages with the same sequence bit are simply acknowledged.
+ If the message is corrupted B sends back an negative/error
+ acknowledgment ({NAK}). This is optional, as A will continue
+ transmitting until it receives the correct ACK.
+
+ A treats corrupted ACK messages, and NAK messages in the same
+ way. The simplest behaviour is to ignore them all and
+ continue transmitting.
+
+ (2000-10-28)
+
+altmode
+
+ {alt}
+
+ALTRAN
+
+ <language> A {Fortran} extension for {rational algebra}
+ developed by W.S. Brown of {Bell Labs} ca. 1968.
+
+ ["The ALTRAN System for Rational Function Manipulation - A
+ Survey", A.D. Hall, CACM 14(8):517-521 (Aug 1971)].
+
+ (1995-06-01)
+
+alt.sources
+
+ <messaging, programming> A {Usenet} {newsgroup} for posting
+ program {source code}.
+
+ {Archive (ftp://wuarchive.wustl.edu/usenet/alt.sources/)}.
+
+ (1995-10-18)
+
+ALU
+
+ 1. <processor> {Arithmetic and Logic Unit}.
+
+ 2. <body> {Association of Lisp Users}.
+
+Aluminum Book
+
+ <publication>
+
+ ["Common LISP: The Language, 2nd Edition", {Guy L. Steele
+ Jr.}, Digital Press 1990, ISBN 1-55558-041-6].
+
+ Due to a technical screwup some printings of the second
+ edition are actually what the author calls "yucky green".
+
+ {On-line version
+ (http://cs.cmu.edu/Groups/AI/html/cltl/cltl2.html)}.
+
+ See also {book titles}.
+
+ [{Jargon File}]
+
+ (1997-06-25)
+
+Alvey
+
+ <project, body> A funding programme for collaborative research
+ in the UK.
+
+ (1995-06-01)
+
+AM
+
+ 1. <communications> {Amplitude Modulation}.
+
+ 2. <artificial intelligence> A program by {Doug Lenat} to
+ discover concepts in elementary mathematics. AM was written
+ in 1976 in {Interlisp}. From 100 fundamental concepts and
+ about 250 {heuristics} it discovered several important
+ mathematical concepts including subsets, disjoint sets, sets
+ with the same number of elements, and numbers. It worked by
+ filling slots in {frames} maintaining an agenda of
+ resource-limited prioritised tasks.
+
+ AM's successor was {Eurisko}.
+
+ {(http://homepages.enterprise.net/hibou/aicourse/lenat.txt)}.
+
+ (1999-04-19)
+
+am
+
+ <networking> The {country code} for Armenia.
+
+ Used for the {vanity domain} "i.am".
+
+ (1999-01-27)
+
+Amanda
+
+ <language> A {functional programming language} derived mostly
+ from {Miranda} with some small changes. Amanda was written by
+ Dick Bruin and implemented on {MS-DOS} and {NeXT}. It is
+ available as an {interperator} only.
+
+ (1998-04-27)
+
+A Manufacturing Language
+
+ <language, robotics> (AML) A {high-level language} developed
+ by {IBM} in the 1980s for industrial {robots}.
+
+ ["AML: A Manufacturing Language", R.H. Taylor et al, Inst J
+ Robot Res 1(3):19-43].
+
+ (1995-09-25)
+
+amateur packet radio
+
+ <communications> (PR) The use of {packet radio} by amateurs to
+ communicate between computers. PR is a complete amateur radio
+ computer network with "digipeaters" (relays), mailboxes (BBS)
+ and other special nodes.
+
+ In Germany, it is on HF, say, 2m (300 and 1200 BPS), 70cm
+ (1200 to 9600 BPS), 23cm (normally 9600 BPS and up, currently
+ most links between digipeaters) and higher frequencies. There
+ is a KW (short wave) Packet Radio at 300 BPS, too.
+
+ Satellites with OSCAR (Orbiting Sattelite Carring Amateur
+ Radio) transponders (mostly attached to commercial satellites
+ by the AMateur SATellite (AMSAT) group) carry Packet Radio
+ mailboxes or {digipeaters}.
+
+ There are both on-line and off-line services on the packet
+ radio network: You can send {electronic mail}, read bulletins,
+ chat, transfer files, connect to on-line DX-Clusters (DX=far
+ distance) to catch notes typed in by other HAMs about the
+ hottest international KW connections currently coming up (so
+ you can pile up).
+
+ PR uses {AX.25} (an {X.25} derivative) as its {transport
+ layer} and sometimes even {TCP/IP} is transmitted over AX.25.
+ AX.25 is like X.25 but the adressing uses HAM "calls" like
+ "DG8MGV".
+
+ There are special "wormholes" all over the world which
+ "tunnel" amateur radio traffic through the {Internet} to
+ forward mail. Sometimes mails travels over satelites.
+ Normally amateur satellites have strange orbits, however the
+ mail forwarding or mailbox satellites have very predictable
+ orbits. Some wormholes allow HAMs to bridge from Internet to
+ {AMPR-NET}, e.g. db0fho.ampr.org or
+ db0fho.et-inf.fho-emden.de, but only if you are registered
+ HAM.
+
+ Because amateur radio is not for profit, it must not be
+ interconnected to the {Internet} but it may be connected
+ through the Internet. All people on the (completely free)
+ amateur radio net must be licensed radio amateurs and must
+ have a "call" which is unique all over the world.
+
+ There is a special {domain} AMPR.ORG (44.*.*.*) for amateur
+ radio reserved in the IP space. This domain is split between
+ countries, which can further subdivide it. For example
+ 44.130.*.* is Germany, 44.130.58.* is Augsburg (in Bavaria),
+ and 44.130.58.20 is dg8mgv.ampr.org (you may verify this with
+ {nslookup}).
+
+ Mail transport is only one aspect of packet radio. You can
+ talk interactively (as in {chat}), read files, or play silly
+ games built in the Packet Radio software. Usually you can use
+ the autorouter to let the digipeater network find a path to
+ the station you want. However there are many (sometimes
+ software incompatible) digipeaters out there, which the router
+ cannot use. Paths over 1000 km are unlikely to be useable for
+ {real-time} communication and long paths can introduce
+ significant delay times (answer latency).
+
+ Other uses of amateur radio for computer communication include
+ {RTTY} ({baudot}), {AMTOR}, {PACTOR}, and {CLOVER}.
+
+ {A huge hamradio archive (ftp://ftp.ucsd.edu/hamradio/)}.
+
+ {Usenet} newsgroup: {news:rec.radio.amateur.packet}.
+
+ (2001-05-12)
+
+Amber
+
+ <language> 1. A {functional programming} language which adds
+ {CSP}-like {concurrency}, {multiple inheritance} and
+ {persistence} to {ML} and generalises its type system. It is
+ similar to {Galileo}. Programs must be written in two type
+ faces, roman and italics! It has both {static types} and
+ {dynamic types}.
+
+ There is an implementation for {Macintosh}.
+
+ ["Amber", L. Cardelli, TR Bell Labs, 1984].
+
+ 2. An {object-oriented} distributed language based on a
+ subset of {C++}, developed at {Washington University} in the
+ late 1980s.
+
+ (1994-12-08)
+
+AMBIT
+
+ <language> Algebraic Manipulation by Identity Translation
+ (also claimed: "Acronym May Be Ignored Totally").
+
+ An early {pattern-matching} language, developed by
+ C. Christensen of Massachusetts Computer Assocs in 1964, aimed
+ at algebraic manipulation.
+
+ [Sammet 1969, pp. 454-457].
+
+ (1994-12-08)
+
+AMBIT/G
+
+ <language> {AMBIT} for graphs.
+
+ ["An Example of the Manipulation of Directed Graphs in the
+ AMBIT/G Programming Language", C. Christensen, in Interactive
+ Systems for Experimental Applied Mathematics, M. Klerer et al,
+ eds, Academic Press 1968, pp. 423-435].
+
+ (1994-12-08)
+
+AMBIT/L
+
+ <language> {AMBIT} for lists.
+
+ A variant of AMBIT supporting list handling and {pattern
+ matching} rules based on two-dimensional diagrams.
+
+ ["An Introduction to AMBIT/L, A Diagrammatic Language for List
+ Processing", Carlos Christensen, Proc 2nd ACM Symp Symb and
+ Alg Manip (Mar 1971)].
+
+ (1994-12-08)
+
+AMBIT/S
+
+ <language> {AMBIT} for strings.
+
+AMBUSH
+
+ <language> A language for {linear programming} problems in a
+ materials processing and transportation network.
+
+ ["AMBUSH - An Advanced Model Builder for Linear Programming",
+ T.R. White et al, National Petroleum Refiners Assoc Comp Conf
+ (Nov 1971)].
+
+ (1995-06-19)
+
+AMD
+
+ 1. <company> {Advanced Micro Devices}.
+
+ 2. <jargon> According to Don Olivier <don@hsph.harvard.edu>,
+ his system manager came in to work one morning to find his IBM
+ system down with a message on the console that said "AMD
+ failure". After he and the service rep had puzzled over
+ documentation for an hour or so they called headquarters and
+ eventually learned that it the failure was in the cooling
+ system: an AMD is an "air movement device", IBM for "fan".
+
+ (1995-01-16)
+
+AMD 29000
+
+ <processor> A {RISC} {microprocessor} descended from the
+ {Berkley RISC} design. Like the {SPARC} design that was
+ introduced shortly afterward, the 29000 has a large {register
+ set} split into local and global sets. But though it was
+ introduced before the SPARC, it has a more elegant method of
+ register management.
+
+ The 29000 has 64 global registers, in comparison to the
+ SPARC's eight. In addition, the 29000 allows variable sized
+ windows allocated from the 128 register stack {cache}. The
+ current window or stack frame is indicated by a stack pointer,
+ a pointer to the caller's frame is stored in the current
+ frame, like in an ordinary stack (directly supporting stack
+ languages like {C}, a {CISC}-like philosophy). Spills and
+ fills occur only at the ends of the cache, and registers are
+ saved/loaded from the memory stack. This allows variable
+ window sizes, from 1 to 128 registers. This flexibility, plus
+ the large set of global registers, makes {register allocation}
+ easier than in SPARC.
+
+ There is no special {condition code register} - any general
+ register is used instead, allowing several condition codes to
+ be retained, though this sometimes makes code more complex.
+ An {instruction prefetch} buffer (using {burst mode}) ensures
+ a steady instruction stream. To reduce delays caused by a
+ branch to another stream, the first four new instructions are
+ cached and next time a cached branch (up to sixteen) is taken,
+ the cache supplies instructions during the initial memory
+ access delay.
+
+ Registers aren't saved during interrupts, allowing the
+ interrupt routine to determine whether the overhead is
+ worthwhile. In addition, a form of register access control is
+ provided. All registers can be protected, in blocks of 4,
+ from access. These features make the 29000 useful for
+ embedded applications, which is where most of these processors
+ are used, allowing it the claim to be "the most popular RISC
+ processor". The 29000 also includes an {MMU} and support for
+ the {AMD 29027} {FPU}.
+
+ (1995-06-19)
+
+AMD 29027
+
+ <processor> The {FPU} for the {AMD 29000}.
+
+ (1995-01-16)
+
+Amdahl
+
+ 1. <company> {Amdahl Corporation}.
+
+ 2. <person> {Gene Amdahl}.
+
+Amdahl Corporation
+
+ <company> A US computer manufacturer. Amdahl is a major
+ supplier of large {mainframes}, {UNIX} and {Open Systems}
+ software and servers, data storage subsystems, data
+ communications products, applications development software,
+ and a variety of educational and consulting services.
+
+ Amdahl products are sold in more than 30 countries for use in
+ both open systems and {IBM} plug-compatible mainframe
+ computing environments.
+
+ Quarterly sales $397M, profits $13M (Aug 1994).
+
+ In 1997 Amdahl became a division of {Fujitsu}.
+
+ {(http://amdahl.com/)}.
+
+ (1995-05-23)
+
+Amdahl's Law
+
+ <parallel> (Named after {Gene Amdahl}) If F is the fraction of
+ a calculation that is sequential, and (1-F) is the fraction
+ that can be parallelised, then the maximum {speedup} that can
+ be achieved by using P processors is 1/(F+(1-F)/P).
+
+ [Gene Amdahl, "Validity of the Single Processor Approach to
+ Achieving Large-Scale Computing Capabilities", AFIPS
+ Conference Proceedings, (30), pp. 483-485, 1967].
+
+ (2002-10-16)
+
+AMD Am2901
+
+ <processor> A 4-bit {bit-slice} processor from {Advanced Micro
+ Devices}. It featured sixteen 4-bit {registers} and a 4-bit
+ {ALU} and operation signals to allow carry/borrow or shift
+ operations and such to operate across any number of other
+ 2901s. An {address sequencer} (such as the {2910}) could
+ provide control signals with the use of custom {microcode} in
+ {ROM}.
+
+ (1994-11-16)
+
+AMD Am2903
+
+ <processor> A {bit-slice} prcessor from {Advanced Micro
+ Devices} which featured hardware multiply.
+
+ (1994-11-16)
+
+AMD Am2910
+
+ <processor> An {address sequencer} from {Advanced Micro
+ Devices}.
+
+ (1994-11-16)
+
+AMD K7
+
+ {Athlon}
+
+American National Standard
+
+ <standard> (ANS) A common prefix for {ANSI} documents or
+ standards, e.g.: "ANS {Forth}", or "American National Standard
+ X3.215-1994".
+
+ (1998-07-01)
+
+American National Standards Institute
+
+ <body, standard> (ANSI) The private, non-profit organisation
+ (501(c)3) responsible for approving US {standards} in many
+ areas, including computers and communications. ANSI is a
+ member of {ISO}. ANSI sells ANSI and ISO (international)
+ standards.
+
+ {ANSI Home (http://ansi.org/)}.
+
+ Address: New York, NY 10036, USA. Sales: 1430 Broadway, NY NY
+ 10018. Telephone: +1 (212) 642 4900.
+
+ (2004-01-14)
+
+American Society of Mechanical Engineers
+
+ <body> (ASME) A group involved in {CAD} standardisation.
+
+ (1995-04-21)
+
+American Standard Code for Information Interchange
+
+ The basis of character sets used in almost all present-day
+ computers. {US-ASCII} uses only the lower seven {bits}
+ ({character points} 0 to 127) to convey some {control codes},
+ space, numbers, most basic punctuation, and unaccented letters
+ a-z and A-Z. More modern coded character sets (e.g.,
+ {Latin-1}, {Unicode}) define extensions to ASCII for values
+ above 127 for conveying special Latin characters (like
+ accented characters, or German ess-tsett), characters from
+ non-Latin writing systems (e.g., Cyrillic, or {Han
+ characters}), and such desirable {glyphs} as distinct open-
+ and close-quotation marks. ASCII replaced earlier systems
+ such as {EBCDIC} and {Baudot}, which used fewer bytes, but
+ were each {broken} in their own way.
+
+ Computers are much pickier about spelling than humans; thus,
+ hackers need to be very precise when talking about characters,
+ and have developed a considerable amount of verbal shorthand
+ for them. Every character has one or more names - some
+ formal, some concise, some silly.
+
+ Individual characters are listed in this dictionary with
+ alternative names from revision 2.3 of the {Usenet} ASCII
+ pronunciation guide in rough order of popularity, including
+ their official {ITU-T} names and the particularly silly names
+ introduced by {INTERCAL}.
+
+ See {V} {ampersand}, {asterisk}, {back quote}, {backslash},
+ {caret}, {colon}, {comma}, {commercial at}, {control-C},
+ {dollar}, {dot}, {double quote}, {equals}, {exclamation mark},
+ {greater than}, {hash}, {left bracket}, {left parenthesis},
+ {less than}, {minus}, {parentheses}, {oblique stroke},
+ {percent}, {plus}, {question mark}, {right brace}, {right
+ brace}, {right bracket}, {right parenthesis}, {semicolon},
+ {single quote}, {space}, {tilde}, {underscore}, {vertical
+ bar}, {zero}.
+
+ Some other common usages cause odd overlaps. The "#", "$",
+ ">", and "&" characters, for example, are all pronounced "hex"
+ in different communities because various assemblers use them
+ as a prefix tag for {hexadecimal} constants (in particular,
+ "#" in many assembler-programming cultures, "$" in the {6502}
+ world, ">" at {Texas Instruments}, and "&" on the {BBC Micro},
+ {Acorn Archimedes}, {Sinclair}, and some {Zilog Z80}
+ machines). See also {splat}.
+
+ The inability of {US-ASCII} to correctly represent nearly any
+ language other than English became an obvious and intolerable
+ {misfeature} as computer use outside the US and UK became the
+ rule rather than the exception (see {software rot}). And so
+ national extensions to US-ASCII were developed, such as
+ Latin-1.
+
+ Hardware and software from the US still tends to embody the
+ assumption that US-ASCII is the universal character set and
+ that words of text consist entirely of byte values 65-90 and
+ 97-122 (A-Z and a-z); this is a major irritant to people who
+ want to use a character set suited to their own languages.
+ Perversely, though, efforts to solve this problem by
+ proliferating sets of national characters produced an
+ evolutionary pressure (especially in protocol design, e.g.,
+ the {URL} standard) to stick to {US-ASCII} as a subset common
+ to all those in use, and therefore to stick to English as the
+ language encodable with the common subset of all the ASCII
+ dialects. This basic problem with having a multiplicity of
+ national character sets ended up being a prime justification
+ for {Unicode}, which was designed, ostensibly, to be the *one*
+ ASCII extension anyone will need.
+
+ A system is described as "{eight-bit clean}" if it doesn't
+ mangle text with byte values above 127, as some older systems
+ did.
+
+ See also {ASCII character table}, {Yu-Shiang Whole Fish}.
+
+ (1995-03-06)
+
+American Telephone and Telegraph, Inc.
+
+ <company, telecommunications, Unix> (AT&T) One of the largest US
+ telecommunications providers, also noted for being the birthplace
+ of the {Unix} {operating system} and the {C} and {C++} programming
+ languages.
+
+ AT&T was incorporated in 1885, but traces its lineage to
+ Alexander Graham Bell and his invention of the telephone in
+ 1876. As parent company of the former {Bell System}, AT&T's
+ primary mission was to provide telephone service to virtually
+ everyone in the United States. In its first 50 years, AT&T
+ established subsidiaries and allied companies in more than a
+ dozen other countries. It sold these interests in 1925 and
+ focused on achieving its mission in the United States. It
+ did, however, continue to provide international long distance
+ service.
+
+ The Bell System was dissolved at the end of 1983 with AT&T's
+ divestiture of the Bell telephone companies.
+
+ AT&T split into three parts in 1996, one of which is {Lucent
+ Tecnologies}, the former systems and equipment portion of AT&T
+ (including Bell Laboratories).
+
+ See also {3DO}, {Advanced RISC Machine}, {Berkeley Software
+ Distribution}, {Bell Laboratories}, {Concurrent C}, {Death
+ Star}, {dinosaurs mating}, {InterNIC}, {System V}, {Nawk},
+ {Open Look}, {rc}, {S}, {Standard ML of New Jersey}, {Unix
+ International}, {Unix conspiracy}, {USG Unix}, {Unix System
+ Laboratories}.
+
+ {AT&T Home (http://att.com/)}.
+
+ (2002-06-21)
+
+American Wire Gauge
+
+ <hardware, standard> (AWG, sometimes "Brown and Sharpe Wire
+ Gauge") A U.S. {standard} set of non-ferrous wire conductor
+ sizes. Typical household wiring is AWG number 12 or 14.
+ Telephone wire is usually 22, 24, or 26. The higher the gauge
+ number, the smaller the diameter and the thinner the wire.
+ Thicker wire is better for long distances due to its lower
+ resistance per unit length.
+
+ (2001-03-26)
+
+America On-Line, Inc.
+
+ <company, communications> (AOL) A US on-line service provider
+ based in Vienna, Virginia, USA. AOL claims to be the largest
+ and fastest growing provider of on-line services in the world,
+ with the most active subscriber base. AOL offers its three
+ million subscribers {electronic mail}, interactive newspapers
+ and magazines, conferencing, software libraries, computing
+ support, and on-line classes.
+
+ In October 1994 AOL made {Internet} {FTP} available to its
+ members and in May 1995, full Internet access including
+ {web}.
+
+ AOL's main competitors are {Prodigy} and {Compuserve}.
+
+ {(http://aol.com/)}.
+
+ (1997-08-26)
+
+America's Multimedia Online
+
+ <company, web> (AMO) An {Internet} technologies
+ company which invented {Never Offline} in 1995 and was
+ officially started in 1996.
+
+ {(http://amo.net/)}.
+
+ E-mail: AMO <amo@amo.net>.
+
+ Address: Albuquerque, NM, USA.
+
+ (1999-11-03)
+
+AMI
+
+ {Alternate Mark Inversion}
+
+Amiga
+
+ <computer> A range of home computers first released by
+ {Commodore Business Machines} in early 1985 (though they did
+ not design the original - see below). Amigas were popular for
+ {games}, {video processing}, and {multimedia}. One notable
+ feature is a hardware {blitter} for speeding up graphics
+ operations on whole areas of the screen.
+
+ The Amiga was originally called the Lorraine, and was
+ developed by a company named "Amiga" or "Amiga, Inc.", funded
+ by some doctors to produce a killer game machine. After the
+ US game machine market collapsed, the Amiga company sold some
+ {joysticks} but no Lorraines or any other computer. They
+ eventually floundered and looked for a buyer.
+
+ Commodore at that time bought the (mostly complete) Amiga
+ machine, infused some money, and pushed it through the final
+ stages of development in a hurry. Commodore released it
+ sometime[?] in 1985.
+
+ Most components within the machine were known by nicknames.
+ The {coprocessor} commonly called the "Copper" is in fact the
+ "{Video} Timing Coprocessor" and is split between two chips:
+ the instruction fetch and execute units are in the "Agnus"
+ chip, and the {pixel} timing circuits are in the "Denise" chip
+ (A for address, D for data).
+
+ "Agnus" and "Denise" were responsible for effects timed to the
+ {real-time} position of the video scan, such as midscreen
+ {palette} changes, {sprite multiplying}, and {resolution}
+ changes. Different versions (in order) were: "Agnus" (could
+ only address 512K of {video RAM}), "Fat Agnus" (in a {PLCC}
+ package, could access 1MB of video RAM), "Super Agnus"
+ (slightly upgraded "Fat Agnus"). "Agnus" and "Fat Agnus" came
+ in {PAL} and {NTSC} versions, "Super Agnus" came in one
+ version, jumper selectable for PAL or NTSC. "Agnus" was
+ replaced by "Alice" in the A4000 and A1200, which allowed for
+ more {DMA} channels and higher bus {bandwidth}.
+
+ "Denise" outputs binary video data (3*4 bits) to the "Vidiot".
+ The "Vidiot" is a hybrid that combines and amplifies the
+ 12-bit video data from "Denise" into {RGB} to the {monitor}.
+
+ Other chips were "Amber" (a "flicker fixer", used in the A3000
+ and Commodore display enhancer for the A2000), "Gary" ({I/O},
+ addressing, G for {glue logic}), "Buster" (the {bus
+ controller}, which replaced "Gary" in the A2000), "Buster II"
+ (for handling the Zorro II/III cards in the A3000, which meant
+ that "Gary" was back again), "Ramsey" (The {RAM} controller),
+ "DMAC" (The DMA controller chip for the WD33C93 {SCSI adaptor}
+ used in the A3000 and on the A2091/A2092 SCSI adaptor card for
+ the A2000; and to control the {CD-ROM} in the {CDTV}), and
+ "Paula" ({Peripheral}, Audio, {UART}, {interrupt} Lines, and
+ {bus Arbiter}).
+
+ There were several Amiga chipsets: the "Old Chipset" (OCS),
+ the "Enhanced Chipset" (ECS), and {AGA}. OCS included
+ "Paula", "Gary", "Denise", and "Agnus".
+
+ ECS had the same "Paula", "Gary", "Agnus" (could address 2MB
+ of Chip RAM), "Super Denise" (upgraded to support "Agnus" so
+ that a few new {screen modes} were available). With the
+ introduction of the {Amiga A600} "Gary" was replaced with
+ "Gayle" (though the chipset was still called ECS). "Gayle"
+ provided a number of improvments but the main one was support
+ for the A600's {PCMCIA} port.
+
+ The AGA chipset had "Agnus" with twice the speed and a 24-bit
+ palette, maximum displayable: 8 bits (256 colours), although
+ the famous "{HAM}" (Hold And Modify) trick allows pictures of
+ 256,000 colours to be displayed. AGA's "Paula" and "Gayle"
+ were unchanged but AGA "Denise" supported AGA "Agnus"'s new
+ screen modes. Unfortunately, even AGA "Paula" did not support
+ High Density {floppy disk drives}. (The Amiga 4000, though,
+ did support high density drives.) In order to use a high
+ density disk drive Amiga HD floppy drives spin at half the
+ rotational speed thus halving the data rate to "Paula".
+
+ Commodore Business Machines went bankrupt on 1994-04-29,
+ the German company {Escom AG} bought the rights to the Amiga
+ on 1995-04-21 and the Commodore Amiga became the Escom
+ Amiga. In April 1996 Escom were reported to be making the
+ {Amiga} range again but they too fell on hard times and
+ {Gateway 2000} (now called Gateway) bought the Amiga brand
+ on 1997-05-15.
+
+ Gateway licensed the Amiga operating system to a German
+ hardware company called {Phase 5} on 1998-03-09. The
+ following day, Phase 5 announced the introduction of a
+ four-processor {PowerPC} based Amiga {clone} called the
+ "{pre\box}". Since then, it has been announced that the
+ new operating system will be a version of {QNX}.
+
+ On 1998-06-25, a company called {Access Innovations Ltd}
+ announced {plans (http://micktinker.co.uk/aaplus.html)} to
+ build a new Amiga chip set, the {AA+}, based partly on the AGA
+ chips but with new fully 32-bit functional core and 16-bit AGA
+ {hardware register emulation} for {backward compatibility}.
+ The new core promised improved memory access and video display
+ DMA.
+
+ By the end of 2000, Amiga development was under the control of
+ a [new?] company called {Amiga, Inc.}. As well as continuing
+ development of AmigaOS (version 3.9 released in December
+ 2000), their "Digital Environment" is a {virtual machine} for
+ multiple {platforms} conforming to the {ZICO} specification.
+ As of 2000, it ran on {MIPS}, {ARM}, {PPC}, and {x86}
+ processors.
+
+ {(http://amiga.com/)}.
+
+ {Amiga Web Directory (http://cucug.org/amiga.html)}.
+
+ {amiCrawler (http://amicrawler.com/)}.
+
+ Newsgroups: {news:comp.binaries.amiga},
+ {news:comp.sources.amiga}, {news:comp.sys.amiga},
+ {news:comp.sys.amiga.advocacy},
+ {news:comp.sys.amiga.announce},
+ {news:comp.sys.amiga.applications},
+ {news:comp.sys.amiga.audio}, {news:comp.sys.amiga.datacomm},
+ {news:comp.sys.amiga.emulations}, {news:comp.sys.amiga.games},
+ {news:comp.sys.amiga.graphics},
+ {news:comp.sys.amiga.hardware},
+ {news:comp.sys.amiga.introduction},
+ {news:comp.sys.amiga.marketplace}, {news:comp.sys.amiga.misc},
+ {news:comp.sys.amiga.multimedia},
+ {news:comp.sys.amiga.programmer},
+ {news:comp.sys.amiga.reviews}, {news:comp.sys.amiga.tech},
+ {news:comp.sys.amiga.telecomm}, {news:comp.Unix.amiga}.
+
+ See {aminet}, {Amoeba}, {bomb}, {exec}, {gronk}, {guru
+ meditation}, {Intuition}, {sidecar}, {slap on the side},
+ {Vulcan nerve pinch}.
+
+ (2003-07-05)
+
+Amiga E
+
+ <tool> An {Amiga} {E} {compiler} by Wouter van Oortmerssen.
+
+ Amiga E compiles 20000 lines/minute on a 7 Mhz Amiga. It
+ allows {in-line} {assembly code} and has an integrated
+ {linker}. It has a large set of integrated functions and
+ {modules}. V2.04 includes as modules a flexible {type}
+ system, quoted expressions, {immediate} and typed lists, low
+ level {polymorphism} and {exception} handling. It is written
+ in {assembly language} and E.
+
+ Version 2.1b
+
+ {(ftp://ftp.wustl.edu/pub/aminet/dev/e/AmigaE21b.lha)}.
+ {(ftp://amiga.physik.unizh.ch/amiga/dev/lang/AmigaE21b.lha)}.
+
+ {Usenet} newsgroup: {news:comp.sys.amiga.programmer}.
+
+ (1997-08-26)
+
+Aminet
+
+ <networking> (Amiga network) A collection of {FTP} {mirrors}
+ that contain several {gigabytes} of {freely distributable
+ software} for the {Amiga} range of computers.
+
+ {Home, ftp.wustl.edu (ftp://ftp.wustl.edu)}.
+
+ (1997-08-31)
+
+AML
+
+ {A Manufacturing Language}
+
+AML/E
+
+ <language, robotics> (AML Entry) A simple version of {AML},
+ implemented on the {IBM PC}, with a graphic display of the
+ robot position.
+
+ (1995-10-03)
+
+AMO
+
+ {America's Multimedia Online}
+
+Amoeba
+
+ 1. <operating system> A distributed {operating system}
+ developed by {Andrew S. Tanenbaum} and others of {Vrije
+ Universiteit, Amsterdam}. Amoeba is only available under
+ licence from the VUA, but is free of charge and includes all
+ {source}, {binaries} and documentation.
+
+ {(http://am.cs.vu.nl/)}.
+
+ [Features?]
+
+ 2. <computer, abuse> A derogatory term for {Commodore}'s
+ {Amiga} {personal computer}.
+
+ [{Jargon File}]
+
+ (1997-05-07)
+
+AMP
+
+ 1. <mathematics, tool> {Algebraic Manipulation Package}.
+
+ 2. <networking, tool> {Active Measurement Project}.
+
+amper
+
+ {ampersand}
+
+Ampere
+
+ <unit, electronics> (Amp, A) The unit of electrical current
+ flow. One Amp is the current that will flow through a
+ one-{ohm} resistance when one {Volt} {DC} is applied across
+ it.
+
+ (2004-01-18)
+
+ampersand
+
+ <character> "&" {ASCII} character 38.
+
+ Common names: {ITU-T}, {INTERCAL}: ampersand; amper; and.
+ Rare: address (from {C}); reference (from C++); bitand;
+ background (from {sh}); pretzel; amp.
+
+ A common symbol for "and", used as the "address of" operator
+ in {C}, the "reference" operator in {C++} and a {bitwise and}
+ or {logical and} operator in several programming languages.
+ {Visual BASIC} uses it as the {string concatenation}
+ {operator} and to prefix {octal} and {hexadecimal} numbers.
+
+ {UNIX} {shells} use the character to indicate that a task
+ should be run in the {background} (single "&" suffix) or
+ (following C's {lazy and}), in a {compound command} of the
+ form "a && b" to indicate that the command b should only be
+ run if command a terminates successfully.
+
+ The ampersand is a ligature (combination) of the cursive
+ letters "e" and "t", invented in 63 BC by Marcus Tirus [Tiro?]
+ as shorthand for the Latin word for "and", "et".
+
+ The word ampersand is a conflation (combination) of "and, per
+ se and". Per se means "by itself", and so the phrase
+ translates to "&, standing by itself, means 'and'". This was
+ at the end of the alphabet as it was recited by children in
+ old English schools. The words ran together and were
+ associated with "&". The "ampersand" spelling dates from
+ 1837.
+
+ {Take our word for it
+ (http://takeourword.com/Issue010.html)}.
+
+ (2012-07-18)
+
+AMPL
+
+ <language> Along with {mpl}, the intrinsic parallel languages
+ for {MasPar}'s computers. AMPL and mpl are parallel variants
+ of {C}. Ampl is actually now a {gcc} port.
+
+ ["AMPL: Design, Implementation and Evaluation of a
+ Multiprocessing Language", R. Dannenberg, CMU 1981].
+
+ ["Loglan Implementation of the AMPL Message Passing System",
+ J. Milewski SIGPLAN Notices 19(9):21-29 (Sept 1984)].
+
+ [Are these the same language?]
+
+ (1995-11-01)
+
+AMPLE
+
+ <language, music> A {FORTH}-like language for programming the
+ 500/5000 series of add-on music synthesisers for the {BBC
+ Microcomputer}. AMPLE was produced by Hybrid Technologies,
+ Cambridge, England in the mid 1980s. Many AMPLE programs were
+ published in Acorn User magazine.
+
+ (1995-11-01)
+
+Amplitude Modulation
+
+ <communications> (AM) A method of encoding {data} by varying
+ the {amplitude} of a constant {frequency} {carrier}.
+
+ Contrast {Frequency Modulation}.
+
+ (2001-04-30)
+
+amp off
+
+ <jargon> (Purdue) To run in {background}. From the {Unix}
+ {shell} "&" (ampersand) operator.
+
+ [{Jargon File}]
+
+ (1995-11-14)
+
+AMPPL-II
+
+ {Associative Memory Parallel Processing Language}
+
+AMPS
+
+ {Advanced Mobile Phone Service}
+
+AMS
+
+ {Andrew Message System}
+
+AMTRAN
+
+ {Automatic Mathematical TRANslation}
+
+Amulet
+
+ <processor> An implementation or the {Advanced RISC Machine}
+ {microprocessor} architecture using the {micropipeline} design
+ style. In April 1994 the Amulet group in the Computer Science
+ department of {Manchester University} took delivery of the
+ AMULET1 {microprocessor}. This was their first large scale
+ asynchronous circuit and the world's first implementation of a
+ commercial microprocessor architecture (ARM) in {asynchronous
+ logic}.
+
+ Work was begun at the end of 1990 and the design despatched
+ for fabrication in February 1993. The primary intent was to
+ demonstrate that an asynchronous microprocessor can consume
+ less power than a synchronous design.
+
+ The design incorporates a number of concurrent units which
+ cooperate to give instruction level compatibility with the
+ existing synchronous part. These include an Address unit,
+ which autonomously generates instruction fetch requests and
+ interleaves ({nondeterministic}ally) data requests from the
+ Execution unit; a {Register} file which supplies operands,
+ queues write destinations and handles data dependencies; an
+ Execution unit which includes a multiplier, a shifter and an
+ {ALU} with data-dependent delay; a Data interface which
+ performs byte extraction and alignment and includes an
+ {instruction prefetch} buffer, and a control path which
+ performs {instruction decode}. These units only synchronise
+ to exchange data.
+
+ The design demonstrates that all the usual problems of
+ processor design can be solved in this asynchronous framework:
+ backward {instruction set} compatibility, {interrupts} and
+ exact {exceptions} for {memory faults} are all covered. It
+ also demonstrates some unusual behaviour, for instance
+ {nondeterministic} prefetch depth beyond a branch instruction
+ (though the instructions which actually get executed are, of
+ course, deterministic). There are some unusual problems for
+ {compiler} {optimisation}, as the metric which must be used to
+ compare alternative code sequences is continuous rather than
+ discrete, and the {nondeterminism} in external behaviour must
+ also be taken into account.
+
+ The chip was designed using a mixture of custom {datapath} and
+ compiled control logic elements, as was the synchronous ARM.
+ The fabrication technology is the same as that used for one
+ version of the synchronous part, reducing the number of
+ variables when comparing the two parts.
+
+ Two silicon implementations have been received and preliminary
+ measurements have been taken from these. The first is a 0.7um
+ process and has achieved about 28 kDhrystones running the
+ standard {benchmark} program. The other is a 1 um
+ implementation and achieves about 20 kDhrystones. For the
+ faster of the parts this is equivalent to a synchronous {ARM6}
+ clocked at around 20MHz; in the case of AMULET1 it is likely
+ that this speed is limited by the memory system cycle time
+ (just over 50ns) rather than the processor chip itself.
+
+ A fair comparison of devices at the same geometries gives the
+ AMULET1 performance as about 70% of that of an {ARM6} running
+ at 20MHz. Its power consumption is very similar to that of
+ the ARM6; the AMULET1 therefore delivers about 80 MIPS/W
+ (compared with around 120 from a 20MHz ARM6). Multiplication
+ is several times faster on the AMULET1 owing to the inclusion
+ of a specialised asynchronous multiplier. This performance is
+ reasonable considering that the AMULET1 is a first generation
+ part, whereas the synchronous ARM has undergone several design
+ iterations. AMULET2 (currently under development) is expected
+ to be three times faster than AMULET1 - 120 k{dhrystones} -
+ and use less power.
+
+ The {macrocell} size (without {pad ring}) is 5.5 mm by 4.5 mm
+ on a 1 micron {CMOS} process, which is about twice the area of
+ the synchronous part. Some of the increase can be attributed
+ to the more sophisticated organisation of the new part: it has
+ a deeper {pipeline} than the clocked version and it supports
+ multiple outstanding memory requests; there is also
+ specialised circuitry to increase the multiplication speed.
+ Although there is undoubtedly some overhead attributable to
+ the asynchronous control logic, this is estimated to be closer
+ to 20% than to the 100% suggested by the direct comparison.
+
+ AMULET1 is code compatible with {ARM6} and is so is capable of
+ running existing {binaries} without modification. The
+ implementation also includes features such as interrupts and
+ memory aborts.
+
+ The work was part of a broad {ESPRIT} funded investigation
+ into low-power technologies within the European {Open
+ Microprocessor systems Initiative} (OMI) programme, where
+ there is interest in low-power techniques both for portable
+ equipment and (in the longer term) to alleviate the problems
+ of the increasingly high dissipation of high-performance
+ chips. This initial investigation into the role {asynchronous
+ logic} might play has now demonstrated that asynchronous
+ techniques can be applied to problems of the scale of a
+ complete {microprocessor}.
+
+ {(http://cs.man.ac.uk/amulet)}.
+
+ (1994-12-08)
+
+an
+
+ <networking> The {country code} for the Netherlands Antilles
+ (Dutch Antilles).
+
+ (1999-01-27)
+
+analog
+
+ <spelling> American spelling of {analogue}.
+
+ (1995-11-14)
+
+analog computer
+
+ {analogue computer}
+
+Analog Hardware Design Language
+
+ <language> (AHDL) A language under development by the US Air
+ Force.
+
+ (1995-04-09)
+
+analogue
+
+ <electronics> (US: "analog") A description of a continuously
+ variable signal or a circuit or device designed to handle such
+ signals. The opposite is "discrete" or "{digital}".
+
+ Analogue circuits are much harder to design and analyse than
+ digital ones because the designer must take into account
+ effects such as the gain, linearity and power handling of
+ components, the resistance, capacitance and inductance of PCB
+ tracks, wires and connectors, interference between signals,
+ power supply stability and more. A digital circuit design,
+ especially for high switching speeds, must also take these
+ factors into account if it is to work reliably, but they are
+ usually less critical because most digital components will
+ function correctly within a range of parameters whereas such
+ variations will corrupt the outputs of an analogue circuit.
+
+ See also {analogue computer}.
+
+ (1995-11-14)
+
+analogue computer
+
+ <computer, hardware> A machine or electronic circuit designed
+ to work on numerical data represented by some physical
+ quantity (e.g. rotation or displacement) or electrical
+ quantity (e.g. voltage or charge) which varies continuously,
+ in contrast to {digital} signals which are either 0 or 1.
+
+ For example, the turning of a wheel or changes in voltage can
+ be used as input. Analogue computers are said to operate in
+ {real time} and are used for research in design where many
+ different shapes and speeds can be tried out quickly. A
+ computer model of a car suspension allows the designer to see
+ the effects of changing size, stiffness and damping.
+
+ (1995-05-01)
+
+Analogy Model
+
+ <programming> A method of estimating the cost of a proposed
+ software project by extrapolating from the costs and schedules
+ of similar completed projects.
+
+ (1996-05-28)
+
+analytical CRM
+
+ <business> Software which helps a business build customer
+ relationships and analyse ways to improve them.
+
+ [Typical functions? Example?]
+
+ (2007-06-11)
+
+Analytical Engine
+
+ <history> A design for a general-purpose digital computer
+ proposed by {Charles Babbage} in 1837 as a successor to his
+ earlier special-purpose {Difference Engine}.
+
+ The Analytical Engine was to be built from brass gears powered
+ by steam with input given on {punched cards}. Babbage could
+ never secure enough funding to build it, and so it was, and
+ never has been, constructed.
+
+ {(http://fourmilab.ch/babbage/)}.
+
+ (1998-10-19)
+
+Analytical Machine
+
+ {Analytical Engine}
+
+Analytical Solutions Forum
+
+ <body, standard> (ASF) The {business intelligence} trade body
+ that, in October 1999, replaced the ineffective {OLAP Council}
+ intending to produce standards for {OLAP}. The ASF managed
+ the remarkably achievement of being even less effective and
+ eventually disappeared, its only achievement having been the
+ issuing of a press release announcing its formation.
+
+ (2005-05-28)
+
+anchor
+
+ {hypertext link}
+
+ANCP
+
+ <language> An early system on the {Datatron 200} series.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (1995-11-15)
+
+AND
+
+ <logic> (Or "conjunction") The {Boolean} function which is
+ true only if all its arguments are true. The {truth table}
+ for the two argument AND function is:
+
+ A | B | A AND B
+ --+---+---------
+ F | F | F
+ F | T | F
+ T | F | F
+ T | T | T
+
+ AND is often written as an inverted "V" in texts on logic. In
+ the {C} programming language it is represented by the &&
+ (logical and) {operator}.
+
+ (1997-11-15)
+
+ANDF
+
+ {Architecture Neutral Distribution Format}
+
+Andorra-I
+
+ <language> A {parallel} {logic programming} language with the
+ {OR-parallelism} of {Aurora} and the {AND-parallelism} of
+ {Parlog}.
+
+ ["Andorra-I: A Parallel Prolog System that Transparently
+ Exploits both And- and Or-Parallelism", V.S Costa et al,
+ SIGPLAN Notices 26(7):83-93 (July 1991)].
+
+ [Imperial College? Who?]
+
+ (1995-11-24)
+
+Andorra Kernel Language
+
+ <language> (AKL) The successor to {KAP} by S. Janson
+ <sverker@sics.se>.
+
+ A prototype implementation is available from the author.
+
+ ["Programming Paradigms of the Andorra Kernel Language",
+ S. Janson et al in Logic Programming: Proc 1991 Intl Symp, MIT
+ Press 1991].
+
+ (1994-11-24)
+
+Andorra-Prolog
+
+ <language>
+
+ ["Andorra-Prolog: An Integration of Prolog and Committed
+ Choice Languages", S. Haridi et al, Intl Conf Fifth Gen Comp
+ Sys 1988, ICOT 1988].
+
+ (1995-11-24)
+
+Andrei Markov
+
+ <person> 1856-1922. The Russian mathematician, after who
+ {Markov chains} were named.
+
+ {Biography
+ (http://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Markov.html)}.
+
+ [Other contributions?]
+
+ (1995-10-06)
+
+Andrew File System
+
+ <operating system, storage> (AFS) The distributed {file
+ system} of the {Andrew Project}, adopted by the {OSF} as part
+ of their {Distributed Computing Environment}.
+
+ {Frequently Asked Questions
+ (http://transarc.com/Product/AFS/FAQ/faq.html)}.
+
+ (1994-11-24)
+
+Andrew Fluegelman
+
+ <person> A successful attorney, editor of {PC World Magazine},
+ and author of the {MS-DOS} communications program {PC-TALK
+ III}, written in 1982. He once owned the trademark
+ "{freeware}" but it wasn't enforced after his disappearance.
+
+ In 1985, Fluegelman was diagnosed with cancer. He was last
+ seen a week later, on 1985-07-06, when he left his Marin
+ County home to go to his office in Tiburon. He called his
+ wife later that day and has not been heard from since. His
+ car was found at Vista Point on the north end of the Golden
+ Gate Bridge.
+
+ [San Francisco Examiner Sunday Magazine, October 1985].
+
+ {Shareware history (http://paulspicks.com/history.asp)}.
+
+ {NEWSBYTES article
+ (http://textfiles.fisher.hu/news/freeware.txt)}.
+
+ {(http://doenetwork.bravepages.com/579dmca.html)}.
+
+ (2003-07-25)
+
+Andrew Message System
+
+ <messaging> A {multimedia} interface to {electronic mail} and
+ {bulletin boards}, developed as part of the {Andrew Project}.
+
+ (1994-11-24)
+
+Andrew Project
+
+ <project> A distributed system project for support of
+ educational and research computing at {Carnegie Mellon
+ University}, named after Andrew Carnegie, an American
+ philanthropist who provided money to establish CMU.
+
+ See also {Andrew File System}, {Andrew Message System},
+ {Andrew Toolkit}, {class}.
+
+ {Home FTP (ftp://emsworth.andrew.cmu.edu)}.
+
+ {Usenet} newsgroup: {news:comp.soft-sys.andrew}.
+
+ [More detail?]
+
+ (1997-11-17)
+
+Andrew S. Tanenbaum
+
+ {Andrew Tanenbaum}
+
+Andrew Tanenbaum
+
+ <person> Professor Andrew S. Tanenbaum (1941-) of the {Vrije
+ Universiteit, Amsterdam} in The Netherlands. Tanenbaum is
+ famous for his work and books on computer architecture,
+ {operating systems} and {networks}.
+
+ He wrote the textbook "Computer Networks", Second Edition,
+ Prentice-Hall, 1981, which describes the {International
+ Standards Organisation}, {Open Systems Interconnection}
+ (ISO-OSI) network model.
+
+ See {Amoeba}, {Mac-1}, {Mic-1}, {Mic-2}, {Micro Assembly
+ Language}, {MINIX}, {MicroProgramming Language}, {standard}.
+
+ [Home page?]
+
+ (1996-04-23)
+
+Andrew Toolkit
+
+ <tool> (ATK) A {portable} {user interface} toolkit developed
+ as part of the {Andrew project}, running on the {X Window
+ System} and distributed with {X11R5}.
+
+ (1995-11-24)
+
+Andy Tanenbaum
+
+ {Andrew Tanenbaum}
+
+An Evolutionary System for On-line Programming
+
+ <database> (AESOP) An early interactive {query system} on the
+ {IBM 1800} using a {light pen}.
+
+ ["AESOP: A Final Report: A Prototype Interactive Information
+ Control System", J.K. Summers et al, in Information System
+ Science and Technology, D. Walker ed, 1967].
+
+ [Sammet 1969, p. 703].
+
+ (1995-04-04)
+
+Angel
+
+ <operating system> A single {address space}, {micro-kernel}
+ {operating system} for {multiprocessor} computers, developed
+ at {Imperial College} and {City University}, London, UK.
+
+ [Ariel Burton]
+
+ (1995-11-24)
+
+angle bracket
+
+ <character> Either of the characters "<" (less-than, {ASCII}
+ 60) and ">" (greater-than, ASCII 62). Typographers in the
+ {Real World} use angle brackets which are either taller and
+ slimmer (the {ISO} "{Bra}" and "{Ket}" characters), or
+ significantly smaller (single or double guillemets) than the
+ less-than and greater-than signs.
+
+ See {broket}.
+
+ (1995-11-24)
+
+Anglo-Saxon point
+
+ {ATA point}
+
+angry fruit salad
+
+ <abuse> A bad visual-interface design that uses too many
+ colours. (This term derives, of course, from the bizarre
+ day-glo colours found in canned fruit salad). Too often one
+ sees similar effects from interface designers using colour
+ window systems such as {X}; there is a tendency to create
+ displays that are flashy and attention-getting but
+ uncomfortable for long-term use.
+
+ [{Jargon File}]
+
+ (1995-11-24)
+
+ANI
+
+ {Automatic Number Identification}
+
+Animated GIF
+
+ <graphics, file format> (GIF89a) A variant of the {GIF}
+ {image} format, often used on {web} pages to
+ provide moving {icons} and banners.
+
+ The GIF89a format supports multiple "frames" that give the
+ impression of motion when displayed in sequence, much like a
+ flip book. The animation may repeat continuously or play
+ once.
+
+ Animated GIFs aren't supported by earlier {web browsers},
+ however the first frame of the image is still shown.
+
+ There are many utilities to create animated GIFs from a
+ sequence of individual GIF files. There are also utilities
+ that will produce animated GIFs automatically from a piece of
+ text or a single image.
+
+ One problem with this format is the size of the files
+ produced, as they are by definition a sequence of individual
+ images. Apart from minimising the number of frames, the best
+ way to decrease file size is to assist the {LZW} compression
+ by using blocks of solid colour, avoid {dithering}, and use
+ fewer colours. If areas of an image don't change from one
+ frame to another, they don't need to be redrawn so make the
+ area a transparent block in the second frame.
+
+ (1999-08-01)
+
+animation
+
+ <graphics> The creation of artificial moving images.
+
+ {Usenet} newsgroup: {news:comp.graphics.animation}. {FAQ
+ (ftp://src.doc.ic.ac.uk/usenet/news-info/comp.graphics.animation)}.
+
+ (1995-11-24)
+
+Animus
+
+ ["Constraint-Based Animation: The Implementation of Temporal
+ Constraints in the Animus System", R. Duisberg, PhD Thesis U
+ Washington 1986].
+
+ (1995-11-24)
+
+ANL
+
+ {Argonne National Laboratory}
+
+Anna
+
+ {ANNotated Ada}
+
+annealing
+
+ {simulated annealing}
+
+annotate
+
+ {annotation}
+
+ANNotated Ada
+
+ <language, specification> (Anna) A {specification} language
+ developed at {Stanford University} ca. 1980 for formally
+ specifying {Ada} programs. It has a Specification Analyzer
+ and a Consistency Checking System. It adds semantic
+ {assertions} in the form of Ada {comments}.
+
+ {(ftp://anna.stanford.edu/pub/anna/)}.
+
+ ["ANNA - A Language for Annotating Ada Programs", David
+ Luckham et al, Springer 1987].
+
+ (1994-11-01)
+
+annotation
+
+ 1. <programming, compiler> Extra information associated with a
+ particular point in a document or program. Annotations may be
+ added either by a {compiler} or by the programmer. They are
+ not usually essential to the correct function of the program
+ but give hints to improve performance.
+
+ 2. <hypertext> A new commentary {node} linked to an existing
+ node. If readers, as well as authors, can annotate nodes,
+ then they can immediately provide feedback if the information
+ is misleading, out of date or plain wrong.
+
+ (1995-11-26)
+
+annoybot
+
+ <messaging> /*-noy-bot/ An irksome {IRC} {robot}.
+
+ [{Jargon File}]
+
+ (1997-12-23)
+
+annoyware
+
+ <software> {Shareware} that reminds you frequently that you
+ are using an unregistered copy.
+
+ (1998-04-29)
+
+Annual Change Traffic
+
+ <software> (ACT) The fraction of the software product's
+ {source code} which changes during a year, either through
+ addition or modification. The ACT can be used to determine
+ the product size in order to estimate software maintenance
+ effort.
+
+ (1996-05-29)
+
+annulled branch
+
+ {delayed control-transfer}
+
+anonymous FTP
+
+ <networking> An interactive service provided by many
+ {Internet} {hosts} allowing any user to transfer documents,
+ files, programs, and other archived data using {File Transfer
+ Protocol}. The user logs in using the special {user name}
+ "ftp" or "anonymous" and his {e-mail address} as {password}.
+ He then has access to a special directory hierarchy containing
+ the publically accessible files, typically in a subdirectory
+ called "pub". This is usually a separate area from files used
+ by local users.
+
+ A reference like
+
+ ftp: euagate.eua.ericsson.se /pub/eua/erlang/info
+
+ means that files are available by anonymous FTP from the host
+ called euagate.eua.ericsson.se in the directory (or file)
+ /pub/eua/erlang/info. Sometimes the {hostname} will be
+ followed by an {Internet address} in parentheses. The
+ directory will usually be given as a path relative to the
+ anonymous FTP login directory. A reference to a file
+ available by FTP may also be in the form of a {URL} starting
+ "ftp:".
+
+ See also {Archie}, {archive site}, {EFS}, {FTP by mail},
+ {web}.
+
+ (1995-11-26)
+
+ANother Tool for Language Recognition
+
+ <tool> (ANTLR) The {parser generator} in the {Purdue
+ Compiler-Construction Tool Set}.
+
+ (1995-10-26)
+
+ANR
+
+ {Automatic Network Routing}
+
+ANS
+
+ {American National Standard}
+
+ANSA
+
+ {Advanced Network Systems Architecture}
+
+ANSI
+
+ {American National Standards Institute}
+
+ANSI C
+
+ <language, standard> (American National Standards Institute C)
+ A revision of {C}, adding {function prototypes}, {structure
+ passing}, {structure assignment} and standardised library
+ functions. {ANSI} X3.159-1989.
+
+ {cgram} is a {grammar} for ANSI C, written in {Scheme}.
+ {unproto} is a program for removing function prototypes to
+ translate ANSI C to standard C. {lcc} is a {retargetable}
+ {compiler} for ANSI C.
+
+ (1995-11-26)
+
+ANSI Minimal BASIC
+
+ <language, standard> ANS X3.60-1978.
+
+ [Details?]
+
+ (1995-11-29)
+
+ANSI/SPARC
+
+ {ANSI Standards Planning And Requirments Committee}
+
+ANSI/SPARC Architecture
+
+ <architecture> (Or "ANSI/SPARC model") {ANSI/SPARC}'s layered
+ model of {database} architecture comprising a {physical
+ schema}, a {conceptual schema} and user {views}.
+
+ [Reference?]
+
+ (1998-12-17)
+
+ANSI/SPARC model
+
+ {ANSI/SPARC Architecture}
+
+ANSI X12
+
+ <standard> Standards defining the structure, format, and
+ content of business transactions conducted through {Electronic
+ Data Interchange} (EDI). ANSI X12 is produced by the
+ committee ASC X12, supported by the {Data Interchange
+ Standards Association, Inc.} (DISA).
+
+ [{(http://onlinewbc.org/Docs/procure/standard.html)}].
+
+ (1999-09-18)
+
+ANSI Z39.50
+
+ <networking, standard> Information Retrieval Service
+ Definition and Protocol Specification for Library
+ Applications, officially known as ANSI/NISO Z39.50-1992, and
+ ANSI/NISO Z39.50-1995. This {standard}, used by {WAIS},
+ specifies an {OSI} {application layer} service to allow an
+ application on one computer to query a {database} on another.
+
+ Z39.50 is used in libraries and for searching some databases
+ on the {Internet}. The US {Library of Congress
+ (http://lcweb.loc.gov/z3950/agency/)} is the official
+ maintanence agency for Z39.50.
+
+ {Index Data}, a Danish company, have released a lot of Z39.50
+ code. Their {website} explains the relevant {ISO} {standards}
+ and how they are amicably converging in Z39.50 version 4.0.
+
+ {Overview (http://nlc-bnc.ca/ifla/VI/5/op/udtop3.htm)}.
+
+ {Z39.50 resources
+ (http://lamp.cs.utas.edu.au/net.html#Z3950)}.
+
+ (1996-07-22)
+
+antenna gain
+
+ <radio> The factor by which a {radio antenna} of a given shape
+ focusses the emitted power into a smaller beamwidth compared
+ with an omnidirectional antenna.
+
+ (2008-02-26)
+
+Anthony Hoare
+
+ <person> (C. Anthony R. Hoare, Tony) A computer scientist
+ working on programming languages, especially {parallel} ones.
+ Hoare was responsible for {Communicating Sequential Processes}
+ (CSP).
+
+ See also: {pointer}, {Simone}.
+
+ [Did he invent the Hoare {powerdomain}? Other details?]
+
+ (1999-07-22)
+
+anti-aliasing
+
+ <graphics> A technique used on a {grey-scale} or colour
+ {bitmap display} to make diagonal edges appear smoother by
+ setting {pixels} near the edge to intermediate colours
+ according to where the edge crosses them.
+
+ The most common example is black characters on a white
+ background. Without anti-aliasing, diagonal edges appear
+ jagged, like staircases, which may be noticeable on a low
+ {resolution} display. If the display can show intermediate
+ greys then anti-aliasing can be applied. A pixel will be
+ black if it is completely within the black area, or white if
+ it is completely outside the black area, or an intermediate
+ shade of grey according to the proportions of it which overlap
+ the black and white areas. The technique works similarly with
+ other foreground and background colours.
+
+ "Aliasing" refers to the fact that many points (which would
+ differ in the real image) are mapped or "aliased" to the same
+ pixel (with a single value) in the digital representation.
+
+ (1998-03-13)
+
+antichain
+
+ <mathematics> A subset S of a {partially ordered set} P is an
+ antichain if,
+
+ for all x, y in S, x <= y => x = y
+
+ I.e. no two different elements are related.
+
+ ("<=" is written in {LaTeX} as {\subseteq}).
+
+ (1995-02-03)
+
+antisymmetric
+
+ <mathematics> A {relation} R is antisymmetric if,
+
+ for all x and y, x R y and y R x => x == y.
+
+ I.e. no two different elements are mutually related.
+
+ {Partial orders} and {total orders} are antisymmetric. If R
+ is also {symmetric}, i.e.
+
+ x R y => y R x
+
+ then
+
+ x R y => x == y
+
+ I.e. different elements are not related.
+
+ (1995-04-18)
+
+antivirus
+
+ {antivirus software}
+
+antivirus program
+
+ {antivirus software}
+
+antivirus software
+
+ <tool> Programs to detect and remove computer {viruses}. The
+ simplest kind scans executable files and {boot blocks} for a
+ list of known viruses. Others are constantly active,
+ attempting to detect the actions of general classes of
+ viruses. antivirus software should always include a regular
+ update service allowing it to keep up with the latest viruses
+ as they are released.
+
+ (1998-02-25)
+
+ANTLR
+
+ {ANother Tool for Language Recognition}
+
+ANU
+
+ {Australian National University}
+
+ANU ML
+
+ <language> An implementation of {SML} by the {Australian
+ National University} for {Motorola 68020}, {Vax} and
+ {Pyramid}.
+
+ (1995-11-26)
+
+any key
+
+ <humour, hardware> The key that particularly confused {users}
+ look for on their computer keyboards when instructed to "Press
+ any key to continue". "But my keyboard doesn't have a key
+ labelled 'any'!".
+
+ {Compaq FAQ
+ (http://web14.compaq.com/falco/detail.asp?FAQnum=FAQ2859)}.
+
+ (2003-09-30)
+
+anytime algorithm
+
+ <algorithm> An {algorithm} that returns a sequence of
+ approximations to the correct answer such that each
+ approximation is no worse than the previous one, i.e. the
+ algorithm can be stopped at _any time_.
+
+ {Newton-Raphson iteration} applied to finding the {square
+ root} of a number b is another example:
+
+ x = (x + b / x) / 2
+
+ Each new x is closer to the square root than the previous one.
+
+ Applications might include a {real-time} control system or a
+ chess program that is allowed a fixed thinking time.
+
+ (2007-06-19)
+
+ao
+
+ <networking> The {country code} for Angola.
+
+ (1999-01-27)
+
+AOCE
+
+ {Apple Open Collaboration Environment}
+
+AOL
+
+ {America On-Line}
+
+AOP
+
+ {aspect-oriented programming}
+
+AOS
+
+ 1. /aws/ (East Coast), /ay-os/ (West Coast) A
+ {PDP-10} instruction that took any memory location and added 1
+ to it. AOS meant "Add One and do not Skip". Why, you may
+ ask, does the "S" stand for "do not Skip" rather than for
+ "Skip"? Ah, here was a beloved piece of PDP-10 folklore.
+ There were eight such instructions: AOSE added 1 and then
+ skipped the next instruction if the result was Equal to zero;
+ AOSG added 1 and then skipped if the result was Greater than
+ 0; AOSN added 1 and then skipped if the result was Not 0; AOSA
+ added 1 and then skipped Always; and so on. Just plain AOS
+ didn't say when to skip, so it never skipped.
+
+ For similar reasons, AOJ meant "Add One and do not Jump".
+ Even more bizarre, SKIP meant "do not SKIP"! If you wanted to
+ skip the next instruction, you had to say "SKIPA". Likewise,
+ JUMP meant "do not JUMP"; the unconditional form was JUMPA.
+ However, hackers never did this. By some quirk of the 10's
+ design, the {JRST} (Jump and ReSTore flag with no flag
+ specified) was actually faster and so was invariably used.
+ Such were the perverse mysteries of assembler programming.
+
+ 2. /A-O-S/ or /A-os/ A {Multics}-derived {operating system}
+ supported at one time by {Data General}.
+
+ A spoof of the standard AOS system administrator's manual
+ ("How to Load and Generate your AOS System") was created,
+ issued a part number, and circulated as photocopy folklore; it
+ was called "How to Goad and Levitate your CHAOS System".
+
+ 3. Algebraic Operating System, in reference to those
+ calculators which use {infix} {operators} instead of {postfix
+ notation}.
+
+ [{Jargon File}]
+
+ (1995-11-26)
+
+APA
+
+ {Application Portability Architecture}
+
+Apache
+
+ <web, project> A {open source} {HTTP} server for
+ {Unix}, {Windows NT}, and other {platforms}. Apache was
+ developed in early 1995, based on code and ideas found in the
+ most popular HTTP server of the time, {NCSA httpd} 1.3. It
+ has since evolved to rival (and probably surpass) almost any
+ other {Unix} based HTTP server in terms of functionality, and
+ speed. Since April 1996 Apache has been the most popular HTTP
+ server on the {Internet}, in May 1999 it was running on 57% of
+ all web servers.
+
+ It features highly configurable error messages, {DBM}-based
+ {authentication} {databases}, and {content negotiation}.
+
+ Latest version: 1.3.9, as of 1999-10-27.
+
+ {(http://apache.org/httpd.html)}.
+
+ {FAQ (http://apache.org/docs/misc/FAQ.html)}.
+
+ (1999-10-27)
+
+Apache Software Foundation
+
+ <open source, body> (ASF) A consortium that manages the
+ development of the {Apache} {web server}, dozens of {XML}- and
+ {Java}-based projects (under the name {Jakarta}), the {Ant}
+ build tool, the {Geronimo} {J2EE} server, the {SpamAssassin}
+ anti-{SPAM} tool, and much more.
+
+ {Apache Home (http://apache.org/)}.
+
+ (2005-01-26)
+
+APAL
+
+ {Array Processor Assembly Language}
+
+APAREL
+
+ {A PArse REquest Language}
+
+A PArse REquest Language
+
+ <language> (APAREL) A {PL/I} extension to provide {BNF}
+ {parsing} routines, for {IBM 360}.
+
+ ["APAREL: A Parse Request Language", R.W. Balzer et al, CACM
+ 12(11) (Nov 1969)].
+
+ (1995-11-26)
+
+APC
+
+ {Association for Progressive Communications}
+
+APDL
+
+ {Algorithmic Processor Description Language}
+
+APE
+
+ <audio, compression> A {lossless} {audio} {compression}
+ {algorithm} from {MonkeysAudio}.
+
+ (2001-12-20)
+
+apE
+
+ <graphics> A graphics package from the Ohio Supercomputer
+ Centre.
+
+ (1995-11-29)
+
+API
+
+ {Application Program Interface}
+
+APIC
+
+ {Advanced Programmable Interrupt Controller}
+
+APL
+
+ {A Programming Language}
+
+APL2
+
+ <language> An {APL} extension from {IBM} with nested {arrays}.
+
+ ["APL2 Programming: Language Reference", IBM, Aug 1984. Order
+ No. SH20-9227-0].
+
+ (1995-11-29)
+
+APLGOL
+
+ <language> An {APL} variant with {ALGOL}-like control
+ structure, from {Hewlett-Packard}(?).
+
+ (1995-11-29)
+
+APLWEB
+
+ <text, tool> A {Web} to {APL} and {Web} to {TeX} translator by
+ Dr. Christoph von Basum of The University of Bielefeld,
+ Germany.
+
+ {(ftp://watserv1.uwaterloo.ca/languages/apl/aplweb/)}.
+
+ (1992-12-27)
+
+APM
+
+ {Advanced Power Management}
+
+Apollo Computer
+
+ <company> A company making {workstations} often used for
+ {CAD}.
+
+ From 1980 to 1987, Apollo were the largest manufacturer of
+ network {workstations}. Apollo workstations ran {Aegis}, a
+ proprietary {operating system} with a {Posix}-compliant {Unix}
+ alternative frontend. Apollo's networking was particularly
+ elegant, among the first to allow {demand paging} over the
+ network, and allowing a degree of {network transparency} and
+ low {sysadmin}-to-machine ratio that is still unmatched.
+
+ Apollo's largest customers were Mentor Graphics (electronic
+ design), GM, Ford, Chrysler, and Boeing (mechanical design).
+ Apollo was acquired by {Hewlett-Packard} in 1989, and
+ gradually closed down over the period 1990-1997.
+
+ (2003-07-18)
+
+apostrophe
+
+ {single quote}
+
+app
+
+ {application program}
+
+APPC
+
+ {Advanced Program-to-Program Communications}
+
+AppKit
+
+ <tool> A set of objects used by the {application builder} for
+ the {NEXTSTEP} environment.
+
+ (1995-03-13)
+
+APPLE
+
+ <language> A revision of {APL} for the {Illiac IV}.
+
+ (1995-04-28)
+
+Apple
+
+ {Apple Computer, Inc.}
+
+Apple Address Resolution Protocol
+
+ <networking> (AARP) {Apple}'s system to allow {AppleTalk}
+ {protocol} to work over networks other than {LocalTalk}, such
+ as {Ethernet} or {Token Ring}. {AppleTalk} {nodes} announce
+ their presence to the network so that other nodes can address
+ messages to them. AARP maps between AppleTalk addresses and
+ other schemes. It is actually a general address mapping
+ protocol that can be used to map between addresses at any
+ protocol level.
+
+ [G. Sidhu, R. Andrews, and A. Oppenheimer, "Inside AppleTalk",
+ Addison Wesley, 1990].
+
+ (2006-04-18)
+
+Apple Attachment Unit Interface
+
+ <hardware, networking> (AAUI) A 14-position, 0.050-inch-spaced
+ ribbon contact connector. Early {Power Macs} and Quadras had
+ an AAUI (Apple Attachment Unit Interface) {port} (rectangular
+ shaped) for {Ethernet}, which requires a {transceiver}. To
+ use {twisted pair} cabling, you would need to get a {twisted
+ pair} transceiver for the computer with an AAUI port. Some
+ {Power Mac} computers had both an AAUI and {RJ-45} port; you
+ can use one or the other, but not both.
+
+ The pin-out is:
+
+ Pin Signal Name Signal Description
+ ---- -------------- ---------------------------------
+ 1 FN Pwr Power (+12V @ 2.1W or +5V @ 1.9W)
+ 2 DI-A Data In circuit A
+ 3 DI-B Data In circuit B
+ 4 VCC Voltage Common
+ 5 CI-A Control In circuit A
+ 6 CI-B Control In circuit B
+ 7 +5V +5 volts (from host)
+ 8 +5V Secondary +5 volts (from host)
+ 9 DO-A Data Out circuit A
+ 10 DO-B Data Out circuit B
+ 11 VCC Secondary Voltage Common
+ 12 NC Reserved
+ 13 NC Reserved
+ 14 FN Pwr Secondary +12V @ 2.1W or +5V @ 1.9W
+ Shell Protective Gnd Protective Ground
+
+ AAUI signals have the same description, function, and
+ electrical requirements as the {AUI} signals of the same name,
+ as detailed in {IEEE 802.3}-1990 CSMA/CD Standard, section 7.
+
+ (2000-02-10)
+
+Apple Computer, Inc.
+
+ <company> Manufacturers of the {Macintosh} range of {personal
+ computers} as well as the earlier {Apple I}, {Apple II} and
+ {Lisa}. Founded on 1 April 1976 by {Steve Jobs} and {Steve
+ Wozniak}.
+
+ Apples were among the first {microcomputers}. They originally
+ used the {6502} processor and are still being made (August
+ 1994), now using the {65816}. The {Apple II} line, which
+ includes the {Apple I}, is the longest existing line of
+ microcomputers.
+
+ Steve Jobs left Apple (involuntarily) and started {NeXT} and
+ later returned when Apple bought NeXT in late 1997(?).
+
+ Quarterly sales $2150M, profits $138M (Aug 1994).
+ {(http://apple.com/)}.
+
+ [Dates? More?]
+
+ (1998-03-13)
+
+Apple II
+
+ <computer> An 8-bit {personal computer} with a {6502}
+ processor, from {Apple Computer}. It was invented by {Steve
+ Wozniak} and was very popular from about 1980 until the first
+ several years of {MS-DOS} {IBM PCs}.
+
+ (1995-01-12)
+
+Apple Macintosh
+
+ {Macintosh}
+
+Apple Newton
+
+ <computer> A {Personal Digital Assistant} produced by {Apple
+ Computer}. The Newton provides a clever, {user-friendly}
+ interface and relies solely on pen-based input. Eagerly
+ anticipated, the Newton uses handwriting recognition software
+ to "learn" the users handwriting and provide reliable
+ {character recognition}.
+
+ Various third-party software applications are available and
+ add-on {peripherals} like wireless {modems} for {Internet}
+ access are being sold by {Apple Computer, Inc.} and its
+ licensees.
+
+ {Newton Inc.}'s {NewtonOS} competes with {Microsoft
+ Corporation}'s {Windows CE}, and was to be compatible with
+ {DEC}'s {StrongARM} SA-1100, an embedded 200MHz
+ {microprocessor}, which was due in 1998.
+
+ {(http://newton.apple.com/)}.
+
+ {Handwriting recognition example
+ (http://www-personal.engin.umich.edu/~jxm/tablespoons.html)}.
+
+ (1997-09-12)
+
+Apple Open Collaboration Environment
+
+ <tool> (AOCE) Software for {electronic mail} and directory
+ services.
+
+ (1995-03-08)
+
+AppleScript
+
+ <language> An {object-oriented} {shell} language for the
+ {Macintosh}, approximately a superset of {HyperTalk}.
+
+ (1995-12-10)
+
+Applesoft BASIC
+
+ <language> A version of {BASIC} for {Apple} computers.
+
+ (1995-12-10)
+
+applet
+
+ <web> A {Java} program which can be distributed as
+ an attachment in a {web} document and executed by a
+ Java-enabled {web browser} such as Sun's {HotJava},
+ {Netscape Navigator} version 2.0, or {Internet Explorer}.
+
+ Navigator severely restricts the applet's file system and
+ network access in order to prevent accidental or deliberate
+ security violations. Full Java applications, which run
+ outside of the browser, do not have these restrictions.
+
+ Web browsers can also be extended with {plug-ins} though these
+ differ from applets in that they usually require manual
+ installation and are {platform}-specific. Various other
+ languages can now be embedded within {HTML} documents, the
+ most common being {JavaScript}.
+
+ Despite Java's aim to be a "write once, run anywhere"
+ language, the difficulty of accomodating the variety of
+ browsers in use on the Internet has led many to abandon
+ client-side processing in favour of {server}-side Java
+ programs for which the term {servlet} was coined.
+
+ Merriam Webster "Collegiate Edition" gives a 1990 definition:
+ a short application program especially for performing a simple
+ specific task.
+
+ (2002-07-12)
+
+Appletalk
+
+ <networking, protocol> A proprietary {local area network}
+ {protocol} developed by {Apple Computer, Inc.} for
+ communication between Apple products (e.g. {Macintosh}) and
+ other computers. This protocol is independent of the {network
+ layer} on which it runs. Current implementations exist for
+ {Localtalk}, a 235 kilobyte per second local area network and
+ {Ethertalk}, a 10 megabyte per second local area network.
+
+ (1995-03-08)
+
+AppleTalk Data Stream Protocol
+
+ <protocol> (ADSP) A {protocol} which provides a simple
+ transport method for data accross a network.
+
+ (1996-06-18)
+
+AppleTalk Filing Protocol
+
+ <networking> (AFP) A {client/server} {protocol} used in
+ {AppleTalk} communications networks. In order for non-{Apple}
+ networks to access data in an {AppleShare} {server}, their
+ protocols must translate into the AFP language.
+
+ See also: {Columbia AppleTalk Package}.
+
+ (1998-06-28)
+
+apple-touch-icon
+
+ <programming> (apple-touch-icon.png) {Apple}'s default {icon}
+ (image) used to represent a {website}, e.g. when saved as a
+ {bookmark} or on the {home screen} of an {iOS} device such as an
+ {iPhone} or {iPad}.
+
+ Apple's scheme allows a site to offer images of different sizes so
+ the client can choose the most appropriate one according to its
+ screen size and resolution.
+
+ Apple devices and applications completely ignore the {favicon}.ico
+ {de facto standard} which, while somewhat quirky in its use of the
+ {ico} format, has been pretty much universally adopted elsewhere.
+ Conversely, apple-touch-icon.png will be ignored by non-Apple
+ devices, possibly because its 16x16 resolution would look pretty
+ shabby on most smart phones.
+
+ {(https://developer.apple.com/library/ios/documentation/AppleApplications/Reference/SafariWebContent/ConfiguringWebApplications/ConfiguringWebApplications.html)
+ Apple documentation}.
+
+ (2014-08-03)
+
+appletviewer
+
+ <web, testing> A simplified {web browser} used for
+ testing {applets}. You can't browse {HTML} with it but you
+ can run applets to test them before embedding them in a {web
+ page}.
+
+ (2004-08-22)
+
+application
+
+ 1. {application program}.
+
+ 2. {function application}.
+
+Application Binary Interface
+
+ <programming> (ABI) The interface by which an {application
+ program} gains access to {operating system} and other
+ services. It should be possible to run the same compiled
+ {binary} applications on any system with the right ABI.
+
+ Examples are {88open}'s {Binary Compatibility Standard}, the
+ {PowerOpen Environment} and {Windows sockets}.
+
+ (1994-11-08)
+
+Application Configuration Access Protocol
+
+ <protocol> (ACAP) A {protocol} which enhances {IMAP} by
+ allowing the user to set up {address books}, user options, and
+ other data for universal access. Currently (Feb 1997) no
+ Internet proprietary products have implemented ACAP because
+ the {Internet Engineering Task Force} has not yet approved the
+ final specification. This was expected early in 1997.
+
+ ["Your E-Mail Is Obsolete", Byte, Feb 1997].
+
+ (1997-05-03)
+
+Application Control Architecture
+
+ <programming> (ACA) {DEC}'s implementation of {ORB}.
+
+ (1994-11-08)
+
+Application Developer
+
+ <job> Someone who does {application development}.
+
+ (2013-08-15)
+
+application development
+
+ <programming> Writing {computer programs} to meet specific
+ {requirements}; the job of an Application Developer. Application
+ development often includes responsibility for {requirements
+ capture} and/or {testing} as well as actual {programming} (the
+ more limited activity implied by the term {programmer}).
+
+ (2013-08-15)
+
+application enablement services
+
+ <programming> {IBM}-speak for {APIs} to services such as
+ telecoms, database, etc. within and between address spaces.
+
+ (1999-01-20)
+
+Application environment specification
+
+ <programming> (AES) A set of specifications from {OSF} for
+ programming and {user interfaces}, aimed at providing a
+ consistent application environment on different hardware. It
+ includes "O/S" for the {operating system} (user commands and
+ program interfaces), "U/E" for the User Environment ({Motif}),
+ and "N/S" for Network services.
+
+ [Reference?]
+
+ (1994-12-07)
+
+Application Executive
+
+ <language> (AE) An {embeddable language}, written as a {C}
+ {interpreter} by Brian Bliss at UIUC. AE is compiled with an
+ {application} and thus exists in the same process and address
+ space. It includes a {dbx} {symbol table} scanner to access
+ compiled variables and routines, or you can enter them
+ manually by providing a type/name declaration and the address.
+ When the {interpreter} is invoked, {source code} fragments are
+ read from the input stream (or a string), parsed, and
+ evaluated immediately. The user can call compiled functions
+ in addition to a few {built-in} intrinsics, declare new data
+ types and data objects, etc. Different input streams can be
+ evaluated in parallel on {Alliant} computers.
+
+ AE has been ported to {SunOS} (cc or {gcc}), {Alliant FX} and
+ {Cray YMP} (soon).
+
+ {(ftp://sp2.csrd.uiuc.edu/pub/at.tar.Z)}.
+ {(ftp://sp2.csrd.uiuc.edu/pub/bliss/ae.tex.Z)}.
+
+ (1992-04-21)
+
+Application Integration Architecture
+
+ <standard> (AIA) {DEC}'s "open standards" specifications.
+
+application layer
+
+ <networking> The top layer of the {OSI} seven layer model.
+ This layer handles issues like {network transparency},
+ resource allocation and problem partitioning. The application
+ layer is concerned with the user's view of the network
+ (e.g. formatting {electronic mail} messages). The
+ {presentation layer} provides the application layer with a
+ familiar local representation of data independent of the
+ format used on the network.
+
+ (1994-11-28)
+
+application lifecycle management
+
+ <programming> (ALM) A combination of {software engineering},
+ {requirements management}, {architecture}, {coding},
+ {testing}, {tracking} and {release management}.
+
+ (2009-06-10)
+
+Application Portability Architecture
+
+ <programming> (APA) {DEC}'s plan for portable applications
+ software.
+
+ (1994-11-28)
+
+application program
+
+ <programming, operating system> (Or "application", "app") A
+ complete, self-contained program that performs a specific
+ function directly for the user. This is in contrast to
+ {system software} such as the {operating system} {kernel},
+ {server} processes, {libraries} which exists to support
+ application programs and {utility programs}.
+
+ Editors for various kinds of documents, {spreadsheets}, and
+ text formatters are common examples of applications. Network
+ applications include clients such as those for {FTP},
+ {electronic mail}, {telnet} and {WWW}.
+
+ The term is used fairly loosely, for instance, some might say
+ that a client and server together form a distributed
+ application, others might argue that editors and compilers
+ were not applications but {utility programs} for building
+ applications.
+
+ One distinction between an application program and the
+ operating system is that applications always run in {user
+ mode} (or "non-privileged mode"), while operating systems and
+ related utilities may run in {supervisor mode} (or "privileged
+ mode").
+
+ The term may also be used to distinguish programs which
+ communicate via a {graphical user interface} from those which
+ are executed from the {command line}.
+
+ (2007-02-02)
+
+Application Program Interface
+
+ <programming> (API, or "application programming interface")
+ The interface (calling conventions) by which an {application
+ program} accesses {operating system} and other services. An
+ API is defined at {source code} level and provides a level of
+ {abstraction} between the application and the {kernel} (or
+ other privileged utilities) to ensure the {portability} of the
+ code.
+
+ An API can also provide an interface between a {high level
+ language} and lower level utilities and services which were
+ written without consideration for the {calling conventions}
+ supported by compiled languages. In this case, the API's main
+ task may be the translation of parameter lists from one format
+ to another and the interpretation of {call-by-value} and
+ {call-by-reference} arguments in one or both directions.
+
+ (1995-02-15)
+
+Application Programming Interface
+
+ {Application Program Interface}
+
+Application Protocol Data Unit
+
+ <networking> (APDU) A {packet} of data exchanged between two
+ {application} programs across a {network}. This is the
+ highest level view of communication in the {OSI} {seven layer
+ model} and a single packet exchanged at this level may
+ actually be transmitted as several packets at a lower layer as
+ well as having extra information (headers) added for {routing}
+ etc.
+
+ (1995-12-19)
+
+Applications Development Manager
+
+ <job> (Or "Director") The person in a company who plans and
+ oversees multiple projects and {project managers}. The
+ Applications Development Managers works with the {CIO} and
+ senior management to determine systems development strategy
+ and standards. He or she administers department budget and
+ reviews project managers.
+
+ (2004-03-06)
+
+application server
+
+ 1. <software> A {designer}'s or {developer}'s suite of
+ {software} that helps {programmers} isolate the {business
+ logic} in their {programs} from the {platform}-related code.
+ {Application} {servers} can handle all of the {application}
+ {logic} and {connectivity} found in {client-server}
+ {applications}. Many {application} {servers} also offer
+ features such as {transaction management}, {clustering} and
+ {failover}, and {load balancing}; nearly all offer {ODBC}
+ support.
+
+ {Application} {servers} range from small {footprint},
+ web-based {processors} for intelligent appliances or remote
+ {embedded} devices, to complete environments for assembling,
+ deploying, and maintaining {scalable} {multi-tier}
+ applications across an {enterprise}.
+
+ 2. <software> Production {programs} run on a mid-sized
+ computer that handle all {application} operations between
+ {browser}-based computers and an organisation's back-end
+ business {applications} or {databases}. The {application}
+ {server} works as a translator, allowing, for example, a
+ customer with a {browser} to search an online retailer's
+ {database} for pricing information.
+
+ 3. <hardware> The device on which {application} {server}
+ {software} runs. {Application Service Providers} offer
+ commercial access to such devices.
+
+ {Citrix Application Serving White Paper
+ (http://citrix.com/press/corpinfo/application_serving_wp_0700.pdf)}.
+
+ {Application Server Sites, a list maintained by Vayda & Herzum
+ (http://componentfactory.org/links/appl.htm)}.
+
+ {The Application Server Zone at DevX,
+ (http://appserver-zone.com/default.asp)}.
+
+ {TechMetrix Research's Application Server Directory,
+ (http://techmetrix.com/trendmarkers/techmetrixasd.php3)}.
+
+ (2001-03-30)
+
+Application Service Element
+
+ <networking> (ASE) Software in the {presentation layer} of the
+ {OSI} seven layer model which provides an abstracted interface
+ layer to service {application protocol data units} (APDU).
+ Because {applications} and {networks} vary, ASEs are split
+ into common services and specific services.
+
+ Examples of services provided by the {common application
+ service element} (CASE) include remote operations (ROSE) and
+ {database} {concurrency control and recovery} (CCR).
+
+ The {specific application service element} (SASE) provides
+ more specialised services such as file transfer, database
+ access, and order entry.
+
+ {Csico docs
+ (http://cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/osi_prot.htm)}.
+
+ (2003-09-27)
+
+application service provider
+
+ <business, networking> (ASP) A service (usually a business)
+ that provides remote access to an {application program} across
+ a {network} {protocol}, typically {HTTP}. A common example is
+ a {website} that other websites use for accepting payment by
+ credit card as part of their {online ordering} systems.
+
+ As this term is complex-sounding but vague, it is widely used
+ by {marketroids} who want to avoid being specific and clear at
+ all costs.
+
+ (2001-03-26)
+
+applications language
+
+ {Ousterhout's dichotomy}
+
+application software
+
+ {application program}
+
+Application Software Installation Server
+
+ (ASIS) Something at {CERN}.
+
+ [What?]
+
+ (1999-10-21)
+
+Application-Specific Integrated Circuit
+
+ <hardware> (ASIC) An {integrated circuit} designed to perform
+ a particular function by defining the interconnection of a set
+ of basic circuit building blocks drawn from a library provided
+ by the circuit manufacturer.
+
+ (1995-02-15)
+
+Applications Programming Interface
+
+ {Application Programming Interface}
+
+applications software
+
+ {application program}
+
+application testing
+
+ {system testing}
+
+Application Visualisation System
+
+ <tool, graphics> (AVS) A portable, modular, {Unix}-based
+ graphics package supported by a consortium of vendors
+ including {Convex}, {DEC}, {IBM}, {HP}, {SET Technologies},
+ {Stardent} and {WaveTracer}.
+
+ (1994-11-28)
+
+applicative language
+
+ <language> A {functional language}. Sometimes used loosely
+ for any {declarative language} though {logic programming}
+ languages are declarative but not applicative.
+
+ (1995-12-24)
+
+Applicative Language for Digital Signal Processing
+
+ <language> (ALDiSP) A {functional language} with special
+ features for {real-time} {I/O} and numerical processing,
+ developed at the {Technical University of Berlin} in 1989.
+
+ ["An Applicative Real-Time Language for DSP - Programming
+ Supporting Asynchronous Data-Flow Concepts", M. Freericks
+ <mfx@cs.tu-berlin.de> in Microprocessing and Microprogramming
+ 32, N-H 1991].
+
+ (1995-04-19)
+
+applicative order reduction
+
+ <programming> An {evaluation strategy} under which an
+ expression is evaluated by repeatedly evaluating its leftmost
+ innermost {redex}. This means that a function's arguments are
+ evaluated before the function is applied. This method will
+ not terminate if a function is given a non-terminating
+ expression as an argument even if the function is not {strict}
+ in that argument. Also known as {call-by-value} since the
+ values of arguments are passed rather than their names. This
+ is the evaluation strategy used by {ML}, {Scheme}, {Hope} and
+ most {procedural languages} such as {C} and {Pascal}.
+
+ See also {normal order reduction}, {parallel reduction}.
+
+ (1995-01-25)
+
+APPLOG
+
+ <language> A language which unifies {logic programming} and
+ {functional programming}.
+
+ ["The APPLOG Language", S. Cohen in Logic Programming, deGroot
+ et al eds, P-H 1986, pp.39-276].
+
+ (1995-01-25)
+
+APPN
+
+ {Advanced Peer-to-Peer Networking}
+
+approximation algorithm
+
+ <algorithm> An {algorithm} for an {optimisation} problem that
+ generates {feasible} but not necessarily {optimal} solutions.
+
+ Unlike "{heuristic}", the term "approximation algorithm" often
+ implies some proven worst or average case bound on
+ performance. The terms are often used interchangeably
+ however.
+
+ (1997-10-28)
+
+April Fool's Joke
+
+ <humour, event> (AFJ) Elaborate April Fool's hoaxes are a
+ long-established tradition on {Usenet} and {Internet}; see
+ {kremvax} for an example. In fact, April Fool's Day is the
+ *only* seasonal holiday marked by customary observances on the
+ hacker networks.
+
+ (1995-01-25)
+
+A Programming Language
+
+ <language> (APL) A programming language designed originally by
+ Ken Iverson at Harvard University in 1957-1960 as a notation
+ for the concise expression of mathematical {algorithms}. It
+ went unnamed (or just called Iverson's Language) and
+ unimplemented for many years. Finally a subset, APL\360, was
+ implemented in 1964.
+
+ APL is an interactive array-oriented language and programming
+ environment with many innovative features. It was originally
+ written using a non-standard {character set}. It is
+ {dynamically typed} with {dynamic scope}. APL introduced
+ several functional forms but is not {purely functional}.
+
+ Dyalog APL/W and Visual APL are recognized .{NET} languages.
+
+ Dyalog APL/W, APLX and APL2000 all offer {object-oriented}
+ extensions to the language.
+
+ ISO 8485 is the 1989 standard defining the language.
+
+ Commercial versions: APL SV, VS APL, Sharp APL, Sharp APL/PC,
+ APL*PLUS, APL*PLUS/PC, APL*PLUS/PC II, MCM APL, Honeyapple,
+ DEC APL, {APL+Win, APL+Linux, APL+Unix and VisualAPL
+ (http://www.apl2000.com/)}, {Dyalog APL
+ (http://www.dyalog.com/)}, {IBM APL2
+ (http://www-306.ibm.com/software/awdtools/apl/)}, {APLX
+ (http://www.microapl.co.uk/apl/)}, {Sharp APL
+ (http://www.soliton.com/services_sharp.html)}
+
+ Open source version: {NARS2000 (http://www.nars2000.org/)}.
+
+ {APL wiki (http://aplwiki.com/)}.
+
+ See also {Kamin's interpreters}.
+
+ {APLWEB (http://www.microapl.co.uk/apl/)} translates {WEB} to
+ APL.
+
+ ["A Programming Language", Kenneth E. Iverson, Wiley, 1962].
+
+ ["APL: An Interactive Approach", 1976].
+
+ (2009-08-11)
+
+APSE
+
+ {Ada Programming Support Environment}
+
+APT
+
+ 1. <language> {Automatically Programmed Tools}.
+
+ 2. <company> {Audio Processing Technology}.
+
+APX III
+
+ <language> An early system on the {Datatron 200} series.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1995-05-04)
+
+aq
+
+ <networking> The {country code} for Antarctica.
+
+ (1999-01-27)
+
+AQL
+
+ <language> A picture {query language}, extension of {APL}.
+
+ ["AQL: A Relational Database Management System and Its
+ Geographical Applications", F. Antonacci et al, in Database
+ Techniques for Pictorial Applications, A. Blaser ed,
+ pp. 569-599].
+
+ (1995-05-04)
+
+ar
+
+ <networking> The {country code} for Argentina.
+
+ (1999-01-27)
+
+arbitrary precision calculator
+
+ <tool> An arbitrary precision {C}-like calculator.
+ {Interpreter} version 1.26.4 by David I. Bell
+ <dbell@canb.auug.org.au>. Ported to {Linux}.
+
+ {(ftp://ftp.uu.net/pub/calc)}.
+
+ (1993-06-15)
+
+ARC
+
+ {Advanced RISC Computing Specification}
+
+arc
+
+ 1. <file format, tool> An old {archive} format for {IBM PC}.
+ The format is now so obscure that it is only likely to be
+ supported by jack-of-all-trades decompression programs such as
+ {WINZIP}.
+
+ 2. <mathematics, data> An {edge} in a {tree}. "{branch}" is a
+ generally more common synonym.
+
+ (1998-12-29)
+
+Arcade
+
+ <networking> A UK {BBS} for the {Acorn} {Archimedes}. Also
+ has links with {Demon Internet}.
+
+ Telephone: +44 (181) 654 2212 (24hrs, most speeds).
+
+ (1994-11-08)
+
+ArchBSD
+
+ <operating system> 4.4 {BSD-Lite} for the {Acorn}
+ {Archimedes}.
+
+ (1994-11-08)
+
+archie
+
+ <tool, networking> A system to automatically gather, index and
+ serve information on the {Internet}. The initial
+ implementation of archie by {McGill University} School of
+ Computer Science provided an indexed directory of filenames
+ from all {anonymous FTP} archives on the Internet. Later
+ versions provide other collections of information.
+
+ See also {archive site}, {Gopher}, {Prospero}, {Wide Area
+ Information Servers}.
+
+ (1995-12-28)
+
+Archimedes
+
+ <computer> A family of {microcomputers} produced by {Acorn
+ Computers}, Cambridge, UK. The Archimedes, launched in June
+ 1987, was the first {RISC} based {personal computer}
+ (predating {Apple Computer}'s {Power Mac} by some seven
+ years). It uses the {Advanced RISC Machine} (ARM) processor
+ and includes Acorn's {multitasking} {operating system} and
+ {graphical user interface}, {RISC OS} on {ROM}, along with an
+ interpreter for Acorn's enhanced {BASIC}, {BASIC V}.
+
+ The Archimedes was designed as the successor to Acorn's
+ sucessful {BBC Microcomputer} series and includes some
+ backward compatibility and a {6502} {emulator}. Several
+ utilities are included free on disk (later in ROM) such as a
+ {text editor}, paint and draw programs. Software emulators
+ are also available for the {IBM PC} as well as add-on {Intel}
+ processor cards.
+
+ There have been several series of Archimedes: A300, A400,
+ A3000, A5000, A4000 and {RISC PC}.
+
+ {Usenet FAQ
+ (ftp://rtfm.mit.edu/pub/usenet/news.answers/acorn/)}.
+ {Archive site list
+ (http://cs.vu.nl/~gerben/acorn/acorn-archives.txt)}.
+ {HENSA archive (ftp://micros.hensa.ac.uk/)}. {Stuttgart
+ archive (ftp://ftp.uni-stuttgart.de/pub/systems/acorn)}.
+
+ See also {Crisis Software}, {Warm Silence Software}.
+
+ (1998-04-03)
+
+architecture
+
+ <architecture> Design, the way components fit together. The
+ term is used particularly of {processors}, both individual and
+ in general. "The {ARM} has a really clean architecture". It
+ may also be used of any complex system, e.g. "software
+ architecture", "network architecture".
+
+ (1995-05-02)
+
+Architecture Neutral Distribution Format
+
+ <programming, operating system> (ANDF) An emerging {OSF}
+ {standard} for software distribution. Programs are compiled
+ into ANDF before distribution and {executables} are produced
+ from it for the local target system. This allows software to
+ be developed and distributed in a single version then
+ installed on a variety of hardware.
+
+ See also {UNCOL}.
+
+ ["Architecture Neutral Distribution Format: A White Paper",
+ Open Software Foundation, Nov 1990].
+
+ (1995-10-20)
+
+archive
+
+ 1. <file format> A single file containing one or (usually)
+ more separate files plus information to allow them to be
+ extracted (separated) by a suitable program.
+
+ Archives are usually created for software distribution or
+ {backup}. {tar} is a common format for {Unix} archives, and
+ {arc} or {PKZIP} for {MS-DOS} and {Microsoft Windows}.
+
+ 2. <operating system> To transfer files to slower, cheaper
+ media (usually {magnetic tape}) to free the {hard disk} space
+ they occupied. This is now normally done for long-term
+ storage but in the 1960s, when disk was much more expensive,
+ files were often shuffled regularly between disk and tape.
+
+ 3. <networking> {archive site}.
+
+ (1996-12-08)
+
+archive site
+
+ <networking> (Or "FTP site", "FTP archive") An {Internet} {host}
+ where program source, documents, {e-mail} or {news} messages are
+ stored for public access via {anonymous FTP}, {Gopher},
+ {web} or other document distribution system. There may
+ be several archive sites ({mirrors}) for, e.g., a {Usenet}
+ {newsgroup} though one may be recognised as the main one.
+
+ FTP servers were common on the Internet for about ten years but
+ have been largely replaced by {web servers} since the invention of
+ the {World-Wide Web} and its {HTTP} protocol.
+
+ Some well-known archive sites included {Imperial College, UK
+ (ftp://src.doc.ic.ac.uk/)}, {UUNET, USA (ftp://ftp.uu.net/)}, {GNU
+ archive site}.
+
+ The {archie} service attempted to index the contents of FTP
+ archives, foreshadowing the indexing of the web by {Google} and
+ others.
+
+ (2014-07-06)
+
+ARCnet
+
+ <networking> A {network} developed by {DataPoint}. ARCnet was
+ {proprietary} until the late 1980s and had about as large a
+ marketshare as {Ethernet} among small businesses. It was
+ almost as fast and was considerably cheaper at the time.
+
+ (1995-01-16)
+
+ARCS
+
+ {ARC}
+
+Arctic
+
+ <language, music> A {real-time} {functional language}, used
+ for music synthesis.
+
+ ["Arctic: A Functional Language for Real-Time Control",
+ R.B. Dannenberg, Conf Record 1984 ACM Symp on LISP and
+ Functional Prog, ACM].
+
+ (1995-01-16)
+
+arena
+
+ <programming> The area of memory attached to a {Unix} process
+ by the {brk} and {sbrk} {system calls} and used by {malloc} as
+ dynamic storage. So named from a "malloc: corrupt arena"
+ message emitted when some early versions detected an
+ impossible value in the free block list.
+
+ See {overrun screw}, {aliasing bug}, {memory leak}, {memory
+ smash}, {smash the stack}.
+
+ [{Jargon File}]
+
+ (1995-12-28)
+
+ARES
+
+ <language> A pictorial {query language}.
+
+ ["A Query Manipulation System for Image Data Retrieval",
+ T. Ichikawa et al, Proc IEEE Workshop Picture Data Description
+ and Management, Aug 1980, pp. 61-67].
+
+ (1995-10-10)
+
+AREV
+
+ {Advanced Revelation}
+
+AREXX
+
+ <language> {REXX} for the {Amiga}.
+
+ {ARexxGuide
+ (http://halcyon.com/robin/www/arexxguide/main.html)}.
+
+ (1996-02-06)
+
+arg
+
+ {argument}
+
+argument
+
+ <programming> (Or "arg") A value or reference passed to a
+ {function}, {procedure}, {subroutine}, command or program, by
+ the caller. For example, in the function definition
+
+ square(x) = x * x
+
+ x is the {formal argument} or "parameter", and in the call
+
+ y = square(3+4)
+
+ 3+4 is the {actual argument}. This will execute the function
+ square with x having the value 7 and return the result 49.
+
+ There are many different conventions for passing arguments to
+ functions and procedures including {call-by-value},
+ {call-by-name}, {call-by-reference}, {call-by-need}. These
+ affect whether the value of the argument is computed by the
+ caller or the callee (the function) and whether the callee can
+ modify the value of the argument as seen by the caller (if it
+ is a variable).
+
+ Arguments to functions are usually, following mathematical
+ notation, written in parentheses after the function name,
+ separated by commas (but see {curried function}). Arguments
+ to a program are usually given after the command name,
+ separated by spaces, e.g.:
+
+ cat myfile yourfile hisfile
+
+ Here "cat" is the command and "myfile", "yourfile", and
+ "hisfile" are the arguments.
+
+ (2006-05-27)
+
+Argus
+
+ <language> A successor to {CLU}, from LCS at {MIT}. Argus
+ supports {distributed programming} through {guardians} (like
+ {monitors}, but can be created dynamically) and {atomic
+ actions} (indivisible activity). It also has {cobegin} and
+ coend.
+
+ ["Argus Reference Manual", B. Liskov et al., TR-400, MIT/LCS,
+ 1987].
+
+ ["Guardians and Actions: Linguistic Support for Robust,
+ Distributed Programs", B. Liskov <liskov@lcs.mit.edu> et al,
+ TOPLAS 5(3):381-404 (1983)].
+
+ (1995-12-28)
+
+Ariel
+
+ <language> An {array}-oriented language for the {CDC 6400}.
+
+ ["Ariel Reference Manual", P. Devel, TR 22, CC UC Berkeley,
+ Apr 1968].
+
+ ["A New Survey of the Ariel Programming Language", P. Deuel,
+ TR 4, Ariel Consortium, UC Berkeley, June 1972].
+
+ [Deuel or Devel?]
+
+ (1995-12-29)
+
+ARI Service
+
+ <company> The trading name of the remnants of {AST Research,
+ Inc.}. ARI Services is a wholly owned subsidiary of {Samsung
+ Electronics Co. Ltd.}, of Seoul, Korea. They no longer
+ manufacture or distribute computer hardware, but they continue
+ to provide worldwide technical and service support to owners
+ of systems that they manufactured.
+
+ {AST Computers, LLC} is a separate company.
+
+ Headquarters: 16225 Alton Parkway, POB 57005, Irvine,
+ California 92619-7005, USA.
+
+ {(http://ari-service.com/)}.
+
+ (2000-03-28)
+
+ARITH-MATIC
+
+ <language> An extension of {Grace Hopper}'s {A-2} programming
+ language, developed in about 1955. ARITH-MATIC was originally
+ known as A-3, but was renamed by the marketing department of
+ {Remington Rand UNIVAC}.
+
+ {(http://cispom.boisestate.edu/cis221emaxson/hophtm.htm)}.
+
+ [How was A-2 extended?]
+
+ (2001-01-27)
+
+Arithmetic and Logic Unit
+
+ <processor> (ALU or "mill") The part of the {central
+ processing unit} which performs operations such as addition,
+ subtraction and multiplication of integers and {bit-wise}
+ {AND}, {OR}, {NOT}, {XOR} and other {Boolean} operations. The
+ CPU's instruction decode logic determines which particular
+ operation the ALU should perform, the source of the {operands}
+ and the destination of the result.
+
+ The width in {bits} of the words which the ALU handles is
+ usually the same as that quoted for the processor as a whole
+ whereas its external busses may be narrower. {Floating-point}
+ operations are usually done by a separate "{floating-point
+ unit}". Some processors use the ALU for address calculations
+ (e.g. incrementing the {program counter}), others have
+ separate logic for this.
+
+ (1995-03-24)
+
+arithmetic mean
+
+ <mathematics> The {mean} of a list of N numbers calculated by
+ dividing their sum by N. The arithmetic mean is appropriate
+ for sets of numbers that are added together or that form an
+ {arithmetic series}. If all the numbers in the list were
+ changed to their arithmetic mean then their total would stay
+ the same.
+
+ For sets of numbers that are multiplied together, the
+ {geometric mean} is more appropriate.
+
+ (2007-03-20)
+
+arity
+
+ <programming> The number of {arguments} a {function} or
+ {operator} takes. In some languages functions may have
+ variable arity which sometimes means their last or only
+ argument is actually a list of arguments.
+
+ (1997-07-21)
+
+arj
+
+ <tool, file format> An archive format for the {IBM PC}. ARJ
+ files are handled by the ARJ program, created by the American
+ programmer Robert Jung.
+
+ [Available from? Compare with PKZIP?]
+
+ (1996-11-03)
+
+Arjuna
+
+ <language> An {object-oriented programming} system developed
+ by a team led by Professor Santosh Shrivastava at the
+ {University of Newcastle}, implemented entirely in {C++}.
+ Arjuna provides a set of tools for the construction of
+ {fault-tolerant} {distributed} applications. It exploits
+ features found in most object-oriented languages (such as
+ {inheritance}) and only requires a limited set of system
+ capabilities commonly found in conventional {operating
+ systems}. Arjuna provides the programmer with {classes} that
+ implement {atomic transactions}, {object level recovery},
+ {concurrency} control and {persistence}. The system is
+ {portable}, modular and flexible; the system software has been
+ available via FTP since 1992.
+
+ {(http://arjuna.ncl.ac.uk/)}.
+
+ (1995-03-06)
+
+ARL
+
+ {ASSET Reuse Library}
+
+ARM
+
+ 1. <processor> {Advanced RISC Machine}.
+
+ Originally {Acorn} RISC Machine.
+
+ 2. <company> {Advanced RISC Machines} Ltd.
+
+ 3. <publication> ["The Annotated C++ Reference Manual",
+ Margaret A. Ellis and Bjarne Stroustrup, Addison-Wesley,
+ 1990].
+
+ 4. <hardware> {Active Reconfiguring Message}.
+
+ (1997-10-03)
+
+ARM610
+
+ <processor> A 32-bit {RISC} {microprocessor} based on the
+ {ARM6} processor core designed by {Advanced RISC Machines}
+ Ltd.
+
+ The ARM610 is the successor to the {ARM3} processor and is
+ produced by {VLSI Technology Inc}. It consumes 500mW at 33MHz
+ with a 5V supply.
+
+ (1995-12-29)
+
+ARM7
+
+ <processor> A {RISC} {microprocessor} architecture from
+ {Advanced RISC Machines} Ltd. (ARM). Building upon the {ARM6}
+ family, the goal of the ARM7 design was to offer higher levels
+ of raw compute performance at even lower levels of power
+ consumption. The ARM7 architecture is now (Dec 1994) the most
+ powerful low voltage {RISC} processor available on the market.
+
+ The ARM7 offers several architectural extensions which address
+ specific market needs, encompassing fast multiply and
+ innovative embedded {ICE} support. Software development tools
+ are available.
+
+ The ARM7 architecture is made up of a core CPU plus a range of
+ system peripherals which can be added to a CPU core to give a
+ complete system on a chip, e.g. 4K or 8K {cache}, {Memory
+ Management Unit}, {Write Buffer}, {coprocessor} interface,
+ {ICEbreaker} embedded {ICE} support and {JTAG} {boundary
+ scan}. The {ARM710} {microprocessor} is built around the ARM7
+ core.
+
+ {(http://systemv.com/armltd/arm7.html)}.
+
+ (1995-01-05)
+
+ARM710
+
+ <processor> A 32-bit {RISC} {microprocessor} based on the
+ {ARM7} processor core designed by {Advanced RISC Machines}
+ Ltd. The A710 is the successor to the {ARM610} processor. It
+ was released in July 1994 by {VLSI Technology Inc}.
+
+ The ARM710 can run at 40MHz (fastest sample 55MHz) dissipating
+ 500mW with a 5V supply or 25MHz with 3.3V supply. It has an 8
+ kilobyte on-chip {cache}, {memory management unit} and {write
+ buffer}.
+
+ The ARM700 and ARM710 processors represent a significant
+ improvement over the {ARM610} processors. They have a higher
+ maximum clock speed and a number of architectural improvements
+ such as double the size of internal cache, this means that
+ more of any process can be executed internally without
+ accessing the (relatively) slow external memory. Other
+ improvements are an improved {write buffer} and an enlarged
+ {Translation Lookaside Buffer} in the {MMU}. All of these
+ improvements increase the performance of the system and
+ deliver more real performance than a simple comparison of
+ clock speeds would indicate.
+
+ The ARM710 has been optimised for integer performance. The
+ FPA11 {floating point} {coprocessor} has a peak throughput of
+ up to 5 {MFLOPS} and achieves an average throughput in excess
+ of 3 MFLOPS for a range of calculations.
+
+ (1995-04-21)
+
+ARM7500
+
+ <processor> An {ARM7} core with I/O and {VIDC20} all on one
+ {integrated circuit}.
+
+ (1994-09-23)
+
+ARM8
+
+ <processor> A {RISC} {microprocessor} {core} designed by
+ {Advanced RISC Machines} Ltd. with 50000 {transistors}. The
+ design of the ARM8 is not yet public but it is not
+ {superscalar}. The ARM8 will form the core of the {ARM800}
+ {microprocessor} {integrated circuit}.
+
+ (1995-03-03)
+
+ARM800
+
+ <processor> A {microprocessor} based on the {ARM8} processor
+ core designed by {Advanced RISC Machines} Ltd. Planned
+ features include a 60-100Mhz {clock rate}; 0.35-0.4 micron
+ silicon fabrication; an improvement on the {ARM7}'s 1.4
+ cycle/instruction; a 16 Kbyte {cache}.
+
+ Some estimates were 100 MIPS and 120 Kdhrystones at 70Mhz
+ (twice the {ARM700}). Samples of the ARM800 are expected to
+ be available in late 1995.
+
+ It may run on a voltage below 3.3V.
+
+ {Digital Semiconductor}'s Hudson fab is 0.35 micron and they
+ have announced a licensing deal for the ARM architecture (see
+ {StrongARM}).
+
+ (1995-02-07)
+
+ARM Ltd
+
+ {Advanced RISC Machines Ltd.}
+
+ARMM
+
+ {Automated Retroactive Minimal Moderation}
+
+armour-plated
+
+ {bulletproof}
+
+ARP
+
+ {Address Resolution Protocol}
+
+ARPA
+
+ {Defense Advanced Research Projects Agency}
+
+ARPANET
+
+ {Advanced Research Projects Agency Network}
+
+ARQ
+
+ {Automatic Repeat Request}
+
+array
+
+ 1. <programming> A collection of identically typed data items
+ distinguished by their indices (or "subscripts"). The number
+ of dimensions an array can have depends on the language but is
+ usually unlimited.
+
+ An array is a kind of {aggregate} data type. A single
+ ordinary variable (a "{scalar}") could be considered as a
+ zero-dimensional array. A one-dimensional array is also known
+ as a "{vector}".
+
+ A reference to an array element is written something like
+ A[i,j,k] where A is the array name and i, j and k are the
+ indices. The {C} language is peculiar in that each index is
+ written in separate brackets, e.g. A[i][j][k]. This expresses
+ the fact that, in C, an N-dimensional array is actually a
+ vector, each of whose elements is an N-1 dimensional array.
+
+ Elements of an array are usually stored contiguously.
+ Languages differ as to whether the leftmost or rightmost index
+ varies most rapidly, i.e. whether each row is stored
+ contiguously or each column (for a 2D array).
+
+ Arrays are appropriate for storing data which must be accessed
+ in an unpredictable order, in contrast to {lists} which are
+ best when accessed sequentially. Array indices are
+ {integers}, usually {natural numbers}, whereas the elements of
+ an {associative array} are identified by strings.
+
+ 2. <architecture> A {processor array}, not to be confused with
+ an {array processor}.
+
+ (2007-10-12)
+
+array processor
+
+ <processor> (Or "vector processor") A {computer}, or extension
+ to its {arithmetic unit}, that is capable of performing
+ simultaneous computations on elements of an {array} or table
+ of data in some number of dimensions.
+
+ The {IBM AltiVec} (the "Velocity Engine" used in the {Apple
+ G4} computers) is a vector processor.
+
+ Common uses for array processors include analysis of fluid
+ dynamics and rotation of {3d} objects, as well as data
+ retrieval, in which elements of a {database} are scanned
+ simultaneously. Array processors are very rare now (1998).
+
+ {Array presentation
+ (http://cs.njit.edu/leon/105/c5/index.htm)}.
+
+ (2003-09-11)
+
+Array Processor Assembly Language
+
+ <language> (APAL) The {assembly language} for the {DAP}
+ parallel computer.
+
+ (1994-11-28)
+
+Array Theory
+
+ <theory> A theory developed by Trenchard More Jr. and used as
+ the basis for the {NIAL} language.
+
+ Papers are available from the IBM Cambridge Scientific Center,
+ Cambridge MA.
+
+ (1995-01-25)
+
+arrow key
+
+ <hardware> One of four keys on a {keyboard} marked with arrows
+ pointing up, down, left and right. The arrow keys are used
+ for such things as moving the {cursor} in a text document, for
+ moving the {input focus} between the fields of a form or
+ sometimes for scrolling a picture.
+
+ (1998-06-26)
+
+ART
+
+ <language> A {real-time} {functional language}. It timestamps
+ each data value when it was created.
+
+ ["Applicative Real-Time Programming", M. Broy, PROC IFIP 1983,
+ N-H].
+
+ (1996-01-15)
+
+Artemis microkernel
+
+ <operating system> A {microkernel} currently under development
+ by Dave Hudson <dave@humbug.demon.co.uk>, scheduled for
+ release under {GPL} in May 1995. It is targeted at
+ {embedded} applications on {Intel 80386}, {Intel 486} and
+ {Pentium} based systems.
+
+ (1995-03-29)
+
+Artifex
+
+ <programming, tool> A {CASE} environment from {ARTIS} of Turin
+ for the development of large {event-driven} distributed
+ systems. It has code-generation and rapid prototyping
+ features.
+
+ (1996-01-24)
+
+artificial intelligence
+
+ <artificial intelligence> (AI) The subfield of computer
+ science concerned with the concepts and methods of {symbolic
+ inference} by computer and symbolic {knowledge representation}
+ for use in making inferences. AI can be seen as an attempt to
+ model aspects of human thought on computers. It is also
+ sometimes defined as trying to solve by computer any problem
+ that a human can solve faster. The term was coined by
+ Stanford Professor {John McCarthy}, a leading AI researcher.
+
+ Examples of AI problems are {computer vision} (building a
+ system that can understand images as well as a human) and
+ {natural language processing} (building a system that can
+ understand and speak a human language as well as a human).
+ These may appear to be modular, but all attempts so far (1993)
+ to solve them have foundered on the amount of context
+ information and "intelligence" they seem to require.
+
+ The term is often used as a selling point, e.g. to describe
+ programming that drives the behaviour of computer characters
+ in a game. This is often no more intelligent than "Kill any
+ humans you see; keep walking; avoid solid objects; duck if a
+ human with a gun can see you".
+
+ See also {AI-complete}, {neats vs. scruffies}, {neural
+ network}, {genetic programming}, {fuzzy computing},
+ {artificial life}.
+
+ {ACM SIGART (http://sigart.acm.org/)}. {U Cal Davis
+ (http://phobos.cs.ucdavis.edu:8001)}. {CMU Artificial
+ Intelligence Repository
+ (http://cs.cmu.edu/Web/Groups/AI/html/repository.html)}.
+
+ (2002-01-19)
+
+Artificial Intelligence Lab
+
+ {MIT AI Lab}
+
+Artificial Life
+
+ <algorithm, application> (a-life) The study of synthetic
+ systems which behave like natural living systems in some way.
+ Artificial Life complements the traditional biological
+ sciences concerned with the analysis of living organisms by
+ attempting to create lifelike behaviours within computers and
+ other artificial media. Artificial Life can contribute to
+ theoretical biology by modelling forms of life other than
+ those which exist in nature. It has applications in
+ environmental and financial modelling and network
+ communications.
+
+ There are some interesting implementations of artificial life
+ using strangely shaped blocks. A video, probably by the
+ company Artificial Creatures who build insect-like robots in
+ Cambridge, MA (USA), has several mechanical implementations of
+ artificial life forms.
+
+ See also {evolutionary computing}, {Life}.
+
+ [Christopher G. Langton (Ed.), "Artificial Life", Proceedings
+ Volume VI, Santa Fe Institute Studies in the Sciences of
+ Complexity. Addison-Wesley, 1989].
+
+ {Yahoo! (http://yahoo.com/Science/Artificial_Life/)}.
+
+ {Santa Fe Institute (http://alife.santafe.edu/)}.
+
+ {The Avida Group
+ (http://krl.caltech.edu/avida/Avida.html)}.
+
+ (1995-02-21)
+
+artificial neural network
+
+ <artificial intelligence> (ANN, commonly just "neural network"
+ or "neural net") A network of many very simple processors
+ ("units" or "neurons"), each possibly having a (small amount
+ of) local memory. The units are connected by unidirectional
+ communication channels ("connections"), which carry numeric
+ (as opposed to symbolic) data. The units operate only on
+ their local data and on the inputs they receive via the
+ connections.
+
+ A neural network is a processing device, either an
+ {algorithm}, or actual hardware, whose design was inspired by
+ the design and functioning of animal brains and components
+ thereof.
+
+ Most neural networks have some sort of "training" rule whereby
+ the weights of connections are adjusted on the basis of
+ presented patterns. In other words, neural networks "learn"
+ from examples, just like children learn to recognise dogs from
+ examples of dogs, and exhibit some structural capability for
+ generalisation.
+
+ Neurons are often elementary non-linear signal processors (in
+ the limit they are simple threshold discriminators). Another
+ feature of NNs which distinguishes them from other computing
+ devices is a high degree of interconnection which allows a
+ high degree of parallelism. Further, there is no idle memory
+ containing data and programs, but rather each neuron is
+ pre-programmed and continuously active.
+
+ The term "neural net" should logically, but in common usage
+ never does, also include biological neural networks, whose
+ elementary structures are far more complicated than the
+ mathematical models used for ANNs.
+
+ See {Aspirin}, {Hopfield network}, {McCulloch-Pitts neuron}.
+
+ {Usenet} newsgroup: {news:comp.ai.neural-nets}.
+
+ (1997-10-13)
+
+Artisoft, Inc.
+
+ <company, networking> A company, known for the {LANtastic}
+ range of networking products. Originally providers of
+ proprietary, {peer-to-peer} network hardware and software for
+ small installations, Artisoft now also sells {Ethernet} and
+ {Novell}-compatible hardware and software.
+
+ {(http://artisoft.com/)}.
+
+ Telephone: +1 (800) 809 1257.
+
+ Address: Tucson, Arizona, USA; Phoenix, Arizona, USA.
+
+ (1995-04-24)
+
+Artistic license
+
+ <legal> The {open source license} applicable to {Perl}.
+
+ (1999-12-29)
+
+ARTSPEAK
+
+ <language> An early simple language for {plotter} graphics.
+
+ ["The Art of Programming, ARTSPEAK", Henry Mullish, Courant
+ Inst (Nov 1974)].
+
+ (1995-02-21)
+
+AS
+
+ 1. <networking> {Autonomous System}.
+
+ 2. <storage> {Address Strobe}.
+
+as
+
+ <networking> The {country code} for American Samoa.
+
+ (1999-01-27)
+
+as31
+
+ <tool, programming> An {8031}/{8051} {assembler} by Ken
+ Stauffer <stauffer@cpsc.ucalgary.ca> and Theo Deraadt which
+ produces a variety of {object code} output formats. The
+ distribution includes an {assembler}, {yacc} {parser}, and
+ documentation. as31 runs on {Sun-3}, {Sun-4}, {SunOS 4.0},
+ {Tandy 6000}, and {Xenix}.
+
+ Latest version: 1, as of 1990-01-26.
+
+ {as31 Home (http://pjrc.com/tech/8051/#as31_assembler)}.
+
+ (2002-05-07)
+
+AS400
+
+ {AS/400}
+
+AS/400
+
+ <computer> An {IBM} {minicomputer} for small business and
+ departmental users, released in 1988 and still in production
+ in October 1998.
+
+ Features include a menu-driven interface, {multi-user}
+ support, terminals that are (in the grand {IBM} tradition)
+ incompatible with anything else including the {IBM 3270}
+ series, and an extensive library-based {operating system}.
+
+ The machine survives because its {API} layer allows the
+ {operating system} and {application programs} to take
+ advantage of advances in hardware without recompilation and
+ which means that a complete system that costs $9000 runs the
+ exact same operating system and software as a $2 million
+ system. There is a 64-bit {RISC} processor operating system
+ implementation.
+
+ Programming languages include {RPG}, {assembly language}, {C},
+ {COBOL}, {SQL}, {BASIC}, and {REXX}. Several {CASE} tools are
+ available: {Synon}, {AS/SET}, {Lansa}.
+
+ {(http://as400.ibm.com/)}.
+
+ (1999-07-26)
+
+ASA
+
+ {Adaptive Simulated Annealing}
+
+asap
+
+ <chat> As soon as possible.
+
+ (1999-10-13)
+
+asbestos
+
+ <jargon> Used as a modifier to anything intended to protect
+ one from {flames}; also in other highly {flame}-suggestive
+ usages. E.g., {asbestos longjohns}, {asbestos cork award}.
+
+ [{Jargon File}]
+
+ (1996-02-06)
+
+asbestos cork award
+
+ <humour> Once, long ago at {MIT}, there was a {flamer} so
+ consistently obnoxious that another hacker designed, had made,
+ and distributed posters announcing that said flamer had been
+ nominated for the "asbestos cork award". (Any reader in doubt
+ as to the intended application of the cork should consult the
+ etymology under {flame}.) Since then, it is agreed that only
+ a select few have risen to the heights of bombast required to
+ earn this dubious dignity - but there is no agreement on
+ *which* few.
+
+ [{Jargon File}]
+
+ (1996-02-06)
+
+asbestos longjohns
+
+ <humour> Notional garments donned by {Usenet} posters just
+ before emitting a remark they expect will elicit {flamage}.
+ This is the most common of the {asbestos} coinages. Also
+ "asbestos underwear", "asbestos overcoat", etc.
+
+ [{Jargon File}]
+
+ (1997-07-04)
+
+ascender
+
+ <text> A lowercase letter that extends above the "x-height"
+ (the height of the letter "x"), such as "d", "t", or "h".
+ Also used to denote the part of the letter extending above the
+ x-height.
+
+ Compare {descender}.
+
+ (1998-03-27)
+
+ASCI
+
+ <spelling> Did you mean {ASCII}?
+
+ASCII
+
+ {American Standard Code for Information Interchange}
+
+ASCII art
+
+ <graphics> (Or "character graphics", "ASCII graphics") The
+ fine art of drawing diagrams using the {ASCII} character set
+ (mainly "|-/\+").
+
+ See also {boxology}. Here is a serious example:
+
+ o----)||(--+--|<----+ +---------o + D O
+ L )||( | | | C U
+ A I )||( +-->|-+ | +-\/\/-+--o - T
+ C N )||( | | | | P
+ E )||( +-->|-+--)---+--)|--+-o U
+ )||( | | | GND T
+ o----)||(--+--|<----+----------+
+
+ A power supply consisting of a full wave rectifier
+ circuit feeding a capacitor input filter circuit
+
+ Figure 1.
+
+ And here are some very silly examples:
+
+ |\/\/\/| ____/| ___ |\_/| ___
+ | | \ o.O| ACK! / \_ |` '| _/ \
+ | | =(_)= THPHTH! / \/ \/ \
+ | (o)(o) U / \
+ C _) (__) \/\/\/\ _____ /\/\/\/
+ | ,___| (oo) \/ \/
+ | / \/-------\ U (__)
+ /____\ || | \ /---V `v'- oo )
+ / \ ||---W|| * * |--| || |`. |_/\
+
+ //-o-\\
+ ____---=======---____
+ ====___\ /.. ..\ /___==== Klingons rule OK!
+ // ---\__O__/--- \\
+ \_\ /_/
+
+ _____
+ __...---'-----`---...__
+ _===============================
+ ,----------------._/' `---..._______...---'
+ (_______________||_) . . ,--'
+ / /.---' `/
+ '--------_- - - - - _/
+ `--------'
+
+ Figure 2.
+
+ There is an important subgenre of ASCII art that puns on the
+ standard character names in the fashion of a rebus.
+
+ +--------------------------------------------------------+
+ | ^^^^^^^^^^^^ |
+ | ^^^^^^^^^^^ ^^^^^^^^^ |
+ | ^^^^^^^^^^^^^ ^^^^^^^^^^^^^ |
+ | ^^^^^^^ B ^^^^^^^^^ |
+ | ^^^^^^^^^ ^^^ ^^^^^^^^^^^^^^ |
+ +--------------------------------------------------------+
+ "A Bee in the Carrot Patch"
+
+ Figure 3.
+
+ Within humorous ASCII art, there is, for some reason, an
+ entire flourishing subgenre of pictures of silly cows. One is
+ shown in Figure 2; here are three more:
+
+ (__) (__) (__)
+ (\/) ($$) (**)
+ /-------\/ /-------\/ /-------\/
+ / | 666 || / |=====|| / | ||
+ * ||----|| * ||----|| * ||----||
+ ~~ ~~ ~~ ~~ ~~ ~~
+ Satanic cow This cow is a Yuppie Cow in love
+
+ Figure 4.
+
+ {(http://gagme.wwa.com/~boba/scarecrow.html)}.
+
+ (1996-02-06)
+
+ASCIIbetical order
+
+ <jargon, programming> /as'kee-be'-t*-kl or'dr/ Used to
+ indicate that data is sorted in {ASCII} collated order rather
+ than alphabetical order. The main difference is that, in
+ ASCII, all the upper case letters come before any of the lower
+ case letters so, e.g., "Z" comes before "a".
+
+ [{Jargon File}]
+
+ (1999-04-08)
+
+ASCIIbonics
+
+ <chat> (From {ASCII} and Ebonics) A style of text
+ communication in English which is most common on {talk}
+ systems such as {irc}. Its notable characteristics are:
+
+ Typing all in lowercase (and occasionally all in uppercase).
+
+ Copious use of abbreviations of the sort "u" for "you" "1" for
+ "one" (and therefore "some1" for "someone", "ne1" for
+ "anyone"), "2" for "to", "r" for "are", etc.
+
+ A general lack of punctuation, except for strings of question
+ marks and exclamation marks.
+
+ Common use of the idiom "m or f?", meant to elicit a statement
+ of the listener's gender.
+
+ Typical extended discourse in ASCIIbonics: "hey wasup ne1 want
+ 2 {cyber}?" "m or f?"
+
+ ASCIIbonics is similar to the way {B1FF} talked, although B1FF
+ used more punctuation (lots more), and used all uppercase,
+ rather than all lowercase. What's more, B1FF was only
+ interested in {warez}, and so never asked "m or f?".
+
+ It has been widely observed that some of the purest examples
+ of ASCIIbonics come from non-native speakers of English.
+
+ The phenomenon of ASCIIbonics predates by several years the
+ use of the word "ASCIIbonics", as the word could only have
+ been coined in or after late 1996, when "Ebonics" was first
+ used in the US media to denote the US English dialects known
+ in the linguistic literature as "Black Vernacular English".
+
+ (1997-06-21)
+
+ASCII character table
+
+ <character> The following list gives the {octal}, decimal and
+ {hexadecimal} {ASCII} codes for each character along with its
+ printed representation and common name(s).
+
+ Oct Dec Hex Name
+ 000 0 0x00 NUL
+ 001 1 0x01 SOH, Control-A
+ 002 2 0x02 STX, Control-B
+ 003 3 0x03 ETX, Control-C
+ 004 4 0x04 EOT, Control-D
+ 005 5 0x05 ENQ, Control-E
+ 006 6 0x06 ACK, Control-F
+ 007 7 0x07 BEL, Control-G
+ 010 8 0x08 BS, backspace, Control-H
+ 011 9 0x09 HT, tab, Control-I
+ 012 10 0x0a LF, line feed, newline, Control-J
+ 013 11 0x0b VT, Control-K
+ 014 12 0x0c FF, form feed, NP, Control-L
+ 015 13 0x0d CR, carriage return, Control-M
+ 016 14 0x0e SO, Control-N
+ 017 15 0x0f SI, Control-O
+ 020 16 0x10 DLE, Control-P
+ 021 17 0x11 DC1, XON, Control-Q
+ 022 18 0x12 DC2, Control-R
+ 023 19 0x13 DC3, XOFF, Control-S
+ 024 20 0x14 DC4, Control-T
+ 025 21 0x15 NAK, Control-U
+ 026 22 0x16 SYN, Control-V
+ 027 23 0x17 ETB, Control-W
+ 030 24 0x18 CAN, Control-X
+ 031 25 0x19 EM, Control-Y
+ 032 26 0x1a SUB, Control-Z
+ 033 27 0x1b ESC, escape
+ 034 28 0x1c FS
+ 035 29 0x1d GS
+ 036 30 0x1e RS
+ 037 31 0x1f US
+ 040 32 0x20 space
+ 041 33 0x21 !, exclamation mark
+ 042 34 0x22 ", double quote
+ 043 35 0x23 #, hash
+ 044 36 0x24 $, dollar
+ 045 37 0x25 %, percent
+ 046 38 0x26 &, ampersand
+ 047 39 0x27 ', quote
+ 050 40 0x28 (, open parenthesis
+ 051 41 0x29 ), close parenthesis
+ 052 42 0x2a *, asterisk
+ 053 43 0x2b +, plus
+ 054 44 0x2c ,, comma
+ 055 45 0x2d -, minus
+ 056 46 0x2e ., full stop
+ 057 47 0x2f /, oblique stroke
+ 060 48 0x30 0, zero
+ 061 49 0x31 1
+ 062 50 0x32 2
+ 063 51 0x33 3
+ 064 52 0x34 4
+ 065 53 0x35 5
+ 066 54 0x36 6
+ 067 55 0x37 7
+ 070 56 0x38 8
+ 071 57 0x39 9
+ 072 58 0x3a :, colon
+ 073 59 0x3b ;, semicolon
+ 074 60 0x3c <, less than
+ 075 61 0x3d =, equals
+ 076 62 0x3e >, greater than
+ 077 63 0x3f ?, question mark
+ 0100 64 0x40 @, commercial at
+ 0101 65 0x41 A
+ 0102 66 0x42 B
+ 0103 67 0x43 C
+ 0104 68 0x44 D
+ 0105 69 0x45 E
+ 0106 70 0x46 F
+ 0107 71 0x47 G
+ 0110 72 0x48 H
+ 0111 73 0x49 I
+ 0112 74 0x4a J
+ 0113 75 0x4b K
+ 0114 76 0x4c L
+ 0115 77 0x4d M
+ 0116 78 0x4e N
+ 0117 79 0x4f O
+ 0120 80 0x50 P
+ 0121 81 0x51 Q
+ 0122 82 0x52 R
+ 0123 83 0x53 S
+ 0124 84 0x54 T
+ 0125 85 0x55 U
+ 0126 86 0x56 V
+ 0127 87 0x57 W
+ 0130 88 0x58 X
+ 0131 89 0x59 Y
+ 0132 90 0x5a Z
+ 0133 91 0x5b [, open square bracket
+ 0134 92 0x5c \, backslash
+ 0135 93 0x5d ], close square bracket
+ 0136 94 0x5e ^, caret
+ 0137 95 0x5f _, underscore
+ 0140 96 0x60 `, back quote
+ 0141 97 0x61 a
+ 0142 98 0x62 b
+ 0143 99 0x63 c
+ 0144 100 0x64 d
+ 0145 101 0x65 e
+ 0146 102 0x66 f
+ 0147 103 0x67 g
+ 0150 104 0x68 h
+ 0151 105 0x69 i
+ 0152 106 0x6a j
+ 0153 107 0x6b k
+ 0154 108 0x6c l
+ 0155 109 0x6d m
+ 0156 110 0x6e n
+ 0157 111 0x6f o
+ 0160 112 0x70 p
+ 0161 113 0x71 q
+ 0162 114 0x72 r
+ 0163 115 0x73 s
+ 0164 116 0x74 t
+ 0165 117 0x75 u
+ 0166 118 0x76 v
+ 0167 119 0x77 w
+ 0170 120 0x78 x
+ 0171 121 0x79 y
+ 0172 122 0x7a z
+ 0173 123 0x7b {, open curly bracket
+ 0174 124 0x7c |, vertical bar
+ 0175 125 0x7d }, close curly bracket
+ 0176 126 0x7e ~, tilde
+ 0177 127 0x7f delete
+
+ See {NUL}, {SOH}, {STX}, {ETX}, {ETX}, {EOT}, {ENQ}, {ACK},
+ {BEL}, {BS}, {HT}, {line feed}, {VT}, {FF}, {CR}, {SO}, {SI},
+ {DLE}, {XON}, {DC1}, {DC2}, {DC3}, {DC4}, {NAK}, {SYN}, {ETB},
+ {CAN}, {EM}, {SUB}, {ESC}, {FS}, {GS}, {RS}, {US}, {space},
+ {exclamation mark}, {double quote}, {hash}, {dollar},
+ {percent}, {ampersand}, {quote}, {open parenthesis}, {close
+ parenthesis}, {asterisk}, {plus}, {comma}, {minus}, {full
+ stop}, {oblique stroke}, {colon}, {semicolon}, {less than},
+ {equals}, {greater than}, {question mark}, {commercial at},
+ {open square bracket}, {backslash}, {close square bracket},
+ {caret}, {underscore}, {back quote}, {open curly bracket},
+ {vertical bar}, {close curly bracket}, {tilde}, {delete}.
+
+ (1996-06-24)
+
+ASCII graphics
+
+ {ASCII art}
+
+ASDIMPL
+
+ {ASDO IMPlementation Language}
+
+ASDL
+
+ {Abstract-Type and Scheme-Definition Language}
+
+ASDO IMPlementation Language
+
+ <language> (ASDIMPL) A {C}-like language, run on {Burroughs}'
+ {mainframes} in the early 1980s, and {cross-compile}d to
+ {x86}-based {embedded processors}.
+
+ (1996-02-06)
+
+ASE
+
+ 1. <programming> {Advanced Software Environment}.
+
+ 2. <networking> {Application Service Element}.
+
+ 3. <database> {Adaptive Server Enterprise}.
+
+A* search
+
+ <algorithm> A {graph} search {algorithm}. A* is guaranteed to
+ find a minimal solution path before any other solution paths,
+ if a solution exists, in other words, it is an "{admissible}"
+ search algorithm. Each path is assigned a value based on the
+ cost of the path (e.g. its length) and an (under)estimate of
+ the cost of completing the path, i.e. the cost of a path from
+ the end of the current path to a solution.
+
+ (1995-03-31)
+
+ASF
+
+ 1. <language> {Algebraic Specification Language}.
+
+ 2. <body> {Analytical Solutions Forum}.
+
+ash
+
+ <tool> A {Bourne Shell} clone by Kenneth Almquist. It works
+ pretty well. For running scripts, it is sometimes better and
+ sometimes worse than {Bash}.
+
+ Ash runs under {386BSD}, {NetBSD}, {FreeBSD}, and {Linux}.
+
+ {FTP Linux version
+ (ftp://ftp.win.tue.nl/pub/linux/ports/ash-linux-0.1.tar.gz)}.
+
+ (1995-07-20)
+
+Ashmedai
+
+ <tool> A {symbolic mathematics} package by Michael Levine
+ <levine@cpwsca.psc.edu> that influenced {SMP} and {FORM}.
+ There are versions for the {Univac 1108} and {VAX}/{VMS}.
+
+ (1995-03-21)
+
+Ashton-Tate Corporation
+
+ <company> The original vendor of {dBASE} and joint developers
+ of {EEMS}. Ashton-Tate was founded by Charles Tate and Ashton
+ was his pet parrot's name. The parrot lived in the lobby of
+ the company's LA headquarters.
+
+ In the early 1990s Ashton-Tate was taken over by Borland
+ International, Inc., who later became {Borland Software
+ Corporation}.
+
+ [Dates? Address?]
+
+ (2004-12-05)
+
+ASIC
+
+ {Application-Specific Integrated Circuit}
+
+Asiliant Technologies
+
+ <company> A company founded by a group of former {Chips and
+ Technologies} employees with experience with the CHIPS
+ products, suppliers, distributors and customers. Asiliant
+ offer C&T's {industry standard} {Flat Panel} and {CRT
+ controller} family.
+
+ (2006-09-19)
+
+A Simulation Process-Oriented Language
+
+ <language, simulation> (ASPOL) An {ALGOL}-like language for
+ computer {simulation}.
+
+ ["Process and Event Control in ASPOL", M.H. MacDougall, Proc
+ Symp on Simulation of Computer Systems, NBS (Aug 1975)].
+
+ (1996-03-25)
+
+ASIS
+
+ 1. {Application Software Installation Server}.
+
+ 2. <language> {Ada Semantic Interface Specification}.
+
+ASK
+
+ {Amplitude Shift Keying}
+
+ASL
+
+ 1. <language> {Algebraic Specification Language}.
+
+ 2. <chat> A rather gruff way of asking someone their age, sex,
+ and location.
+
+ (2008-01-21)
+
+ASL+
+
+ <language, specification> An {algebraic specification
+ language} by David Aspinall of the {University of Edinburgh}.
+ ASL+ has rules for proving the satisfaction of specifications.
+ It can also be viewed as a {type theory} with {subtyping},
+ featuring {contravariant refinement} for {Pi-abstracted}
+ specifications and a notion of {stratified equality} for
+ {higher-order objects}.
+
+ (1994-09-14)
+
+As Low As Reasonably Practicable
+
+ <legal> (ALARP) A term from {UK health and safety
+ (http://hse.gov.uk/risk/theory/alarpglance.htm)} law that
+ mandates reducting the risk to workers to the point where the
+ cost of further reduction is grossly disproportionate to the
+ benefit.
+
+ (2010-10-05)
+
+ASM
+
+ {assembly language}
+
+ASME
+
+ {American Society of Mechanical Engineers}
+
+ASN
+
+ {Autonomous System Number}
+
+ASN.1
+
+ {Abstract Syntax Notation 1}
+
+ASP
+
+ 1. <web> {Active Server Pages}.
+
+ 2. <networking> {application service provider}.
+
+ 3. <language> A {query language}(?).
+
+ [Sammet 1969, p.702].
+
+ 4. <processor> {Attached Support Processor}.
+
+ (2000-07-08)
+
+ASPECT
+
+ <tool, programming> An {IPSE} developed by an {Alvey} project,
+ using {Z} to specify the {object-management system} and tool
+ interface.
+
+ (1996-03-25)
+
+ASpecT
+
+ <language> Algebraic specification of {abstract data types}.
+ A {strict} {functional language} that compiles to {C}.
+
+ Versions of ASpecT are available for {Sun}, {Ultrix}, {NeXT},
+ {Macintosh}, {OS/2} 2.0, {Linux}, {RS/6000}, {Atari}, {Amiga}.
+
+ {(ftp://wowbagger.uni-bremen.de/pub/programming/languages)}.
+
+ (1996-03-25)
+
+aspect
+
+ <programming> In {aspect-oriented programming}, a modular unit
+ of control over {emergent entities}.
+
+ (1999-08-31)
+
+aspect-oriented programming
+
+ <programming> (AOP) A style of programming that attempts to
+ abstract out features common to many parts of the code beyond
+ simple functional modules and thereby improve the {quality} of
+ software.
+
+ Mechanisms for defining and composing {abstractions} are
+ essential elements of programming languages. The design style
+ supported by the abstraction mechanisms of most current
+ languages is one of breaking a system down into parameterised
+ components that can be called upon to perform a function.
+
+ But many systems have properties that don't necessarily align
+ with the system's functional components, such as failure
+ handling, {persistence}, communication, replication,
+ coordination, {memory management}, or {real-time} constraints,
+ and tend to cut across groups of functional components.
+
+ While they can be thought about and analysed relatively
+ separately from the basic functionality, programming them
+ using current {component-oriented languages} tends to result
+ in these aspects being spread throughout the code. The
+ {source code} becomes a tangled mess of instructions for
+ different purposes.
+
+ This "tangling" phenomenon is at the heart of much needless
+ complexity in existing software systems. A number of
+ researchers have begun working on approaches to this problem
+ that allow programmers to express each of a system's aspects
+ of concern in a separate and natural form, and then
+ automatically combine those separate descriptions into a final
+ executable form. These approaches have been called
+ aspect-oriented programming.
+
+ {Xerox AOP homepage
+ (http://parc.xerox.com/csl/projects/aop/)}.
+
+ {AspectJ (http://AspectJ.org/)}.
+
+ {ECOOPP'99 AOP workshop
+ (http://wwwtrese.cs.utwente.nl/aop-ecoop99/)}.
+
+ (1999-11-21)
+
+aspect ratio
+
+ <graphics> The ratio of width to height of a {pixel}, {image},
+ or {display screen}. Square pixels (1:1) are considered
+ preferable but displays are usually about 5:4.
+
+ (1994-11-30)
+
+ASPEN
+
+ <language> A {toy language} for teaching {compiler}
+ construction.
+
+ ["ASPEN Language Specifications", T.R. Wilcox, SIGPLAN Notices
+ 12(11):70-87, Nov 1977].
+
+ (1994-11-30)
+
+ASPI
+
+ {Advanced SCSI Peripheral Interface}
+
+ASPIK
+
+ <language, specification> A multiple-style specification
+ language.
+
+ ["Algebraic Specifications in an Integrated Software
+ Development and Verification System", A. Voss, Diss, U
+ Kaiserslautern, 1985].
+
+ (1994-11-30)
+
+Aspirin
+
+ <language, tool> A {freeware} language from {MITRE
+ Corporation} for the description of {neural networks}. A
+ compiler, bpmake, is included. Aspirin is designed for use
+ with the {MIGRAINES} interface.
+
+ Version: 6.0, as of 1995-03-08.
+
+ {(ftp://ftp.cognet.ucla.edu/alexis/)}.
+
+ (1995-03-08)
+
+ASPLE
+
+ <language> A {toy language}.
+
+ ["A Sampler of Formal Definitions", M. Marcotty et al,
+ Computing Surveys 8(2):191-276 (Feb 1976)].
+
+ (1995-02-08)
+
+ASPOL
+
+ {A Simulation Process-Oriented Language}
+
+ASQC
+
+ {American Society for Quality Control}
+
+ASR
+
+ {Automatic Send Receive}
+
+assembler
+
+ <programming> A program which converts {assembly language}
+ into {machine code}.
+
+ (1996-03-25)
+
+ASSEMBLY
+
+ <language> An early system on the {IBM 702}.
+
+ [Listed in CACM 2(5):1959-05-16].
+
+ (1996-06-27)
+
+assembly code
+
+ {assembly language}
+
+Assembly Language
+
+ <language, robotics> (AL) A language for industrial {robots}
+ developed at {Stanford University} in the 1970s.
+
+ ["The AL Language for an Intelligent Robot", T. Binford in
+ Langages et Methods de Programation des Robots Industriels,
+ pp. 73-88, IRIA Press 1979].
+
+ ["AL User's Manual", M.S. Mujtaba et al, Stanford AI Lab, Memo
+ AIM-323 (Jan 1979)].
+
+ (1994-11-24)
+
+assembly language
+
+ <language> (Or "assembly code") A symbolic representation of
+ the {machine language} of a specific {processor}. Assembly
+ language is converted to {machine code} by an {assembler}.
+ Usually, each line of assembly code produces one machine
+ instruction, though the use of {macros} is common.
+
+ Programming in assembly language is slow and error-prone but
+ is the only way to squeeze every last bit of performance out
+ of the hardware.
+
+ {Filename extension}: .s ({Unix}), .asm ({CP/M} and others).
+
+ See also {second generation language}.
+
+ (1996-09-17)
+
+Assembly Language Compiler
+
+ <language> (ALC) An alternative name for {IBM 360} {assembly
+ language}.
+
+ Compare {BAL}.
+
+ (1995-01-04)
+
+Assembly Language for Multics
+
+ <language> (ALM) The {assembly language} of the {GE-645} in
+ which critical portions of the {Multics} {kernel} were
+ written.
+
+ (1994-11-24)
+
+as sensible as a dictionary
+
+ <humour> In Lewis Carroll's {Through the Looking Glass and what
+ Alice found there
+ (http://www.Germany.EU.net/books/carroll/alice.html)}, in the
+ chapter {The Garden of Live Flowers
+ (http://www.Germany.EU.net/books/carroll/alice_21.html#SEC24)},
+ the Red Queen is talking to Alice about what she's been up to:
+
+ "I only wanted to see what the garden was like, your Majesty -"
+
+ "That's right," said the Queen, patting her on the head, which Alice
+ didn't like at all, "though, when you say "garden" - I've seen
+ gardens, compared with which this would be a wilderness."
+
+ Alice didn't dare argue the point, but went on: "- and I thought I'd
+ try and find my way to the top of that hill -"
+
+ "When you say "hill"", the Queen interrupted, "I could show you hills,
+ in comparison with which you'd call that a valley."
+
+ "No, I shouldn't," said Alice, surprised into contradicting her at
+ last: "a hill can't be a valley, you know. That would be nonsense -"
+
+ The Red Queen shook her head. "You may call it "nonsense" if you
+ like," she said, "but I've heard nonsense, compared with which that
+ would be as sensible as a dictionary!"
+
+ Alice curtseyed again, as she was a little afraid from the Queen's
+ tone that she was a little offended: and they walked on in silence
+ till they got to the top of the little hill.
+
+ Thanks to Simon James for the text and to Sean Gugler for the
+ URLs.
+
+ (2014-06-22)
+
+assertion
+
+ <programming> 1. An expression which, if false, indicates an
+ {error}. Assertions are used for {debugging} by catching
+ {can't happen} errors.
+
+ 2. In {logic programming}, a new {fact} or {rule} added to the
+ database by the program at {run time}. This is an
+ {extralogical} or impure feature of logic programming
+ languages.
+
+ (1997-06-30)
+
+ASSET
+
+ {Asset Source for Software Engineering Technology}
+
+asset management
+
+ <business> The process whereby a large organisation collects
+ and maintains a comprehensive list of the items it owns such
+ as hardware and software. This data is used in connection
+ with the financial aspects of ownership such as calculating
+ the total cost of ownership, depreciation, licensing,
+ maintenance, and insurance.
+
+ (1997-03-30)
+
+Asset Source for Software Engineering Technology
+
+ <project> (ASSET) A programme to promote software {reuse} by
+ the US {DoD}.
+
+ See also {ASSET Reuse Library}.
+
+ (1996-08-19)
+
+assigned numbers
+
+ <standard> The {RFC} {STD 2} documenting the currently
+ assigned values from several series of numbers used in network
+ {protocol} implementations. This RFC is updated periodically
+ and, in any case, current information can be obtained from the
+ {Internet Assigned Numbers Authority} (IANA). If you are
+ developing a protocol or application that will require the use
+ of a link, {socket}, {port}, protocol, etc., you should
+ contact the IANA to receive a number assignment.
+
+ (1996-08-19)
+
+assignment
+
+ <programming> Storing the value of an expression in a
+ {variable}. This is commonly written in the form "v = e". In
+ {Algol} the assignment operator was ":=" (pronounced
+ "becomes") to avoid mathematicians qualms about writing
+ statements like x = x+1.
+
+ Assignment is not allowed in {functional languages}, where an
+ {identifier} always has the same value.
+
+ See also {referential transparency}, {single assignment},
+ {zero assignment}.
+
+ (1996-08-19)
+
+assignment problem
+
+ <mathematics, algorithm> (Or "linear assignment") Any problem
+ involving minimising the sum of C(a, b) over a set P of pairs
+ (a, b) where a is an element of some set A and b is an element
+ of set B, and C is some function, under constraints such as
+ "each element of A must appear exactly once in P" or similarly
+ for B, or both.
+
+ For example, the a's could be workers and the b's projects.
+
+ The problem is "linear" because the "cost function" C()
+ depends only on the particular pairing (a, b) and is
+ independent of all other pairings.
+
+ {(http://forum.swarthmore.edu/epigone/comp.soft-sys.matlab/bringhyclu)}.
+ {(http://soci.swt.edu/capps/prob.htm)}.
+ {(http://mat.gsia.cmu.edu/GROUP95/0577.html)}.
+ {(http://informs.org/Conf/WA96/TALKS/SB24.3.html)}.
+
+ [Algorithms?]
+
+ (1999-07-12)
+
+Association Control Service Element
+
+ <networking> (ACSE) The {OSI} method for establishing a call
+ between two {application programs}. ACSE checks the
+ identities and contexts of the application entities, and could
+ apply an {authentication} security check.
+
+ Documents: {ITU} Rec. X.227 ({ISO} 8650), X.217 (ISO 8649)
+
+ (1997-12-07)
+
+Association for Computational Linguistics
+
+ <body> (ACL) The international scientific and professional
+ society for people working on problems involving {natural
+ language} and computation. Membership includes the ACL
+ quarterly journal, "Computational Linguistics", reduced
+ registration at most ACL-sponsored conferences, discounts on
+ ACL-sponsored publications, and participation in ACL Special
+ Interest Groups. The ACL started in 1968; there are more
+ than 2000 members worldwide.
+
+ E-mail: <acl@aclweb.org>.
+
+ {(http://cs.columbia.edu/~acl/)}.
+
+ (1999-08-31)
+
+Association for Computing
+
+ <body> (ACM, before 1997 - "Association for Computing
+ Machinery") The largest and oldest international scientific
+ and educational computer society in the industry. Founded in
+ 1947, only a year after the unveiling of {ENIAC}, ACM was
+ established by mathematicians and electrical engineers to
+ advance the science and application of {Information
+ Technology}. {John Mauchly}, co-inventor of the ENIAC, was
+ one of ACM's founders.
+
+ Since its inception ACM has provided its members and the world
+ of computer science a forum for the sharing of knowledge on
+ developments and achievements necessary to the fruitful
+ interchange of ideas.
+
+ ACM has 90,000 members - educators, researchers,
+ practitioners, managers, and engineers - who drive the
+ Association's major programs and services - publications,
+ special interest groups, chapters, conferences, awards, and
+ special activities.
+
+ The ACM Press publishes journals (notably {CACM}), book
+ series, conference proceedings, {CD-ROM}, {hypertext},
+ {video}, and specialized publications such as curricula
+ recommendations and self-assessment procedures.
+
+ {(http://info.acm.org/)}.
+
+ (1998-02-24)
+
+Association for Computing Machinery
+
+ {Association for Computing}
+
+Association for Progressive Communications
+
+ <body, philosophy> (APC) A world-wide organisation of
+ like-minded computer networks providing a global
+ communications network dedicated to the free and balanced flow
+ of information.
+
+ The APC defends and promotes non-commercial, productive online
+ space for NGOs (Non-Governmental Organisations) and
+ collaborates with like-minded organisations to ensure that the
+ information and communication needs of civil society are
+ considered in telecommunications, donor and investment policy.
+
+ A few of APC's partner organisations include The {Institute
+ for Global Communications} (USA), GreenNet (UK), Nicarao
+ (Nicaragua) Enda-Tiers Monde (Senegal) and GlasNet (Ukraine).
+
+ These organisations serve people working toward goals that
+ include the prevention of warfare, elimination of militarism
+ and poverty, protection of the environment, human rights,
+ social and economic justice, participatory democracy,
+ non-violent conflict resolution, and the promotion of
+ sustainable development.
+
+ {(http://apc.org/english/)}.
+
+ E-mail: <apcadmin@apc.org>.
+
+ (2000-10-08)
+
+Association for SIMULA Users
+
+ <body> See {SIMULA}.
+
+ Address: Royal Institute of Technology, S-100 44 Stockholm,
+ Sweden.
+
+ [Details?]
+
+ (1995-03-29)
+
+Association Française des Utilisateurs d'Unix
+
+ <body> (et des systèmes ouverts, AFUU) French Association of
+ {Unix} Users.
+
+ {(http://afuu.fr/)}.
+
+ (1996-06-07)
+
+Association of American Publishers
+
+ <body, publication> <body> (AAP) A group engaged in
+ standardisation efforts in document preparation.
+
+ (2000-01-27)
+
+Association of C and C++ Users
+
+ <body> (ACCU) A community of people with an interest in the
+ {C} family of programming languages: {K&R C}, {ANSI C}, and
+ {C++}. The community includes professional programmers, the
+ suppliers of {compilers}, and those who are just interested in
+ the languages. ACCU members are using C and C++ on a wide
+ range of platforms - {Unix}, {MS-DOS}, {OS/2}, {CP/M} - home
+ computers, {IBM PCs}, {workstations}, and {super-computers}.
+ Although the organisation is based in the UK, the membership
+ is worldwide. There are members in the US, mainland Europe,
+ Russia, the Middle East, and Australia.
+
+ E-mail: <info@accu.org>, <membership@accu.org>,
+ <academic@accu.org> (Academic Liaison Officer).
+
+ Address: The Membership Secretary, 64 Southfield Road, Oxford
+ OX4 1PA, United Kingdom.
+
+ (1996-12-02)
+
+Association of Lisp Users
+
+ <body> (ALU) A user group which aims to promote {Lisp}, help
+ inform and educate Lisp users in general, and help represent
+ Lisp users as a group to the vendors. The ALU holds an annual
+ conference and supports the formation of inter-vendor
+ standards. ALU has international membership and is
+ incorporated in the US.
+
+ {(http://cs.rochester.edu/u/miller/ALU/home.html)}.
+
+ {Usenet} {newsgroups}: {news:comp.org.lisp-users}
+ {news:comp.std.lisp}.
+
+ Mailing list: <alu@ai.sri.com>.
+
+ (1996-12-07)
+
+associative array
+
+ <programming> (Or "hash", "map", "dictionary") An {array}
+ where the {indices} are not just {integers} but may be
+ arbitrary strings.
+
+ {awk} and its descendants (e.g. {Perl}) have associative
+ arrays which are implemented using {hash coding} for faster
+ look-up.
+
+ (2007-10-02)
+
+associative memory
+
+ {content addressable memory}
+
+Associative Memory Parallel Processing Language
+
+ <language> (AMPPL-II) A language from the early 1970s.
+
+ (1995-11-14)
+
+associativity
+
+ <programming> The property of an {operator} that says whether
+ a sequence of three or more expressions combined by the
+ operator will be evaluated from left to right (left
+ associative) or right to left (right associative). For
+ example, in {Perl}, the {lazy and} operator && is left
+ associative so in the expression:
+
+ $i >= 0 && $x[$i] >= 0 && $y[$x[$i]] == 0
+
+ the left-most && is evaluated first, whereas = is right
+ associative, so in
+
+ $a = $b = 42
+
+ the right-most assignment is performed first.
+
+ (2007-06-16)
+
+AST
+
+ <company> 1. {ARI Service}.
+
+ 2. {AST Computers, LLC}.
+
+ (2000-03-21)
+
+ASTAP
+
+ {Advanced STatistical Analysis Program}
+
+AST Computers, LLC
+
+ <company> The private company formed in January 1999 when
+ Mr. Beny Alagem, the former chairman of {Packard Bell NEC,
+ Inc.}, bought the name and intellectual property of {AST
+ Research, Inc.}. AST Computers, LLC provide {hardware,
+ software}, and services for small US businesses.
+
+ {Samsung Electronics Co. Ltd.}, of Seoul, Korea, owns a
+ minority stake.
+
+ {(http://ast.com/)}.
+
+ Address: Los Angeles, CA, USA.
+
+ (2000-03-28)
+
+asterisk
+
+ <character> "*" {ASCII} code 42. Common names include: star;
+ {INTERCAL}: {splat}; {ITU-T}: asterisk. Rare: {wild card};
+ gear; dingle; mult; spider; aster; times; twinkle; {glob};
+ {Nathan Hale}.
+
+ Commonly used as the multiplication operator and as the
+ {Kleene star}. Often doubled, as in "x**2", to mean "to the
+ power". In {C} and related languages, asterisk is used as the
+ {dereference} operator, "*p" meaning "the thing pointed to by
+ p".
+
+ (2006-09-10)
+
+asterix
+
+ <spelling> Do you mean "{asterisk}" (the star-shaped
+ character), or {Asterix the Gaul
+ (http://webring.org/cgi-bin/webring?ring=asterixwebring&index)},
+ the popular French cartoon by Goscinny and Uderzo?
+
+ (2000-07-26)
+
+Astra Digital Radio
+
+ <audio> {Digital Radio} over satellite, compatible with analog
+ television transmissions. Alternatively the normal TV
+ subcarriers can be modulated by a {MPEG-1 Layer-2} 48 kHz 192
+ kbps signal. Quality is better than analog carriers and only
+ needs half the {bandwidth} (analog stereo = 2 carrier, digital
+ stereo = 1 carrier). Quality is limited and the data rate
+ can't be increased.
+
+ (2001-12-13)
+
+Astral
+
+ <language> A programming language based on {Pascal}, never
+ implemented.
+
+ ["ASTRAL: A Structured and Unified Approach to Database Design
+ and Manipulation", T. Amble et al, in Proc of the Database
+ Architecture Conf, Venice, June 1979].
+
+ (2000-01-27)
+
+AST Research, Inc.
+
+ <company> A company, formed some time before 1980, that was a
+ leading {personal computer} manufacturer. AST developed
+ {desktop computers}, {mobile computers}, and {servers} that
+ were sold in more than 100 countries worldwide. In January
+ 1999 the name and intellectual property were acquired by a new
+ company named {AST Computers, LLC}. As of 2000-03-02 it was
+ trading as {ARI Service}.
+
+ (2000-03-21)
+
+asymmetrical modulation
+
+ <communications> A scheme to maximise use of a communications
+ line by giving a larger share of the {bandwidth} to the
+ {modem} at the end which is transmitting the most information.
+
+ Only one end of the connection has full bandwidth, the other
+ has only a fraction of the bandwidth. Normally, which end
+ gets the full bandwidth is chosen dynamically.
+
+ Asymmetrical modulation was made famous by the {HST} mode of
+ the early high-speed modems from {US Robotics}.
+
+ (1998-03-13)
+
+Asymmetric Digital Subscriber Line
+
+ <communications, protocol> (ADSL, or Asymmetric Digital
+ Subscriber Loop) A form of {Digital Subscriber Line} in which
+ the bandwidth available for {downstream} connection is
+ significantly larger then for {upstream}. Although designed
+ to minimise the effect of {crosstalk} between the upstream and
+ downstream channels this setup is well suited for {web
+ browsing} and {client}-{server} applications as well as for
+ some emerging applications such as {video on demand}.
+
+ The data-rate of ADSL strongly depends on the length and
+ quality of the line connecting the end-user to the telephone
+ company. Typically the upstream data flow is between 16 and
+ 640 {kilobits} per second while the downstream data flow is
+ between 1.5 and 9 {megabits} per second. ADSL also provides a
+ voice channel.
+
+ ADSL can carry digital data, analog voice, and broadcast
+ {MPEG2} video in a variety of implementations to meet customer
+ needs.
+
+ ["Data Cooks, But Will Vendors Get Burned?", "Supercomm
+ Spotlight On ADSL" & "Lucent Sells Paradine", Wilson & Carol,
+ Inter@ctive Week Vol. 3 #13, p1 & 6, June 24 1996].
+
+ See also {Carrierless Amplitude/Phase Modulation}, {Discrete
+ MultiTone}.
+
+ {ADSL Forum (http://adsl.com/)}.
+
+ (1998-05-18)
+
+Asymmetric Digital Subscriber Loop
+
+ {Asymmetric Digital Subscriber Line}
+
+asynchronous
+
+ <architecture> Not synchronised by a shared signal such as
+ {clock} or {semaphore}, proceeding independently.
+
+ Opposite: {synchronous}.
+
+ 1. <operating system> A {process} in a {multitasking} system
+ whose execution can proceed independently, "in the
+ {background}". Other processes may be started before the
+ asynchronous process has finished.
+
+ 2. <communications> A communications system in which data
+ transmission may start at any time and is indicated by a
+ {start bit}, e.g. {EIA-232}. A data {byte} (or other element
+ defined by the {protocol}) ends with a {stop bit}. A
+ continuous marking condition (identical to stop bits but not
+ quantized in time), is then maintained until data resumes.
+
+ (1995-12-08)
+
+Asynchronous Balanced Mode
+
+ <protocol> A communication mode of {HDLC} and derivative
+ {protocols}, supporting {peer-oriented} {point-to-point}
+ communications between two {nodes}, where either node can
+ initiate transmission.
+
+ (1997-05-07)
+
+Asynchronous Communications Interface Adapter
+
+ <communications, hardware> (ACIA) A kind of {integrated
+ circuit} that provides data formatting and control to {EIA-232}
+ serial interfaces.
+
+ [Is this the same as a {UART}?]
+
+ (1997-05-07)
+
+asynchronous logic
+
+ <architecture> A {data-driven} circuit design technique where,
+ instead of the components sharing a common {clock} and
+ exchanging data on clock edges, data is passed on as soon as
+ it is available. This removes the need to distribute a common
+ clock signal throughout the circuit with acceptable {clock
+ skew}. It also helps to reduce power dissipation in {CMOS}
+ circuits because {gates} only switch when they are doing
+ useful work rather than on every clock edge.
+
+ There are many kinds of asynchronous logic. Data signals may
+ use either "dual rail encoding" or "data bundling". Each dual
+ rail encoded {Boolean} is implemented as two wires. This
+ allows the value and the timing information to be communicated
+ for each data bit. Bundled data has one wire for each data
+ bit and another for timing. Level sensitive circuits
+ typically represent a logic one by a high voltage and a logic
+ zero by a low voltage whereas transition signalling uses a
+ change in the signal level to convey information. A speed
+ independent design is tolerant to variations in gate speeds
+ but not to propagation delays in wires; a delay insensitive
+ circuit is tolerant to variations in wire delays as well.
+
+ The purest form of circuit is delay-insensitive and uses
+ dual-rail encoding with transition signalling. A transition
+ on one wire indicates the arrival of a zero, a transition on
+ the other the arrival of a one. The levels on the wires are
+ of no significance. Such an approach enables the design of
+ fully delay-insensitive circuits and automatic layout as the
+ delays introduced by the layout compiler can't affect the
+ functionality (only the performance). Level sensitive designs
+ can use simpler, stateless logic gates but require a "return
+ to zero" phase in each transition.
+
+ {(http://cs.man.ac.uk/amulet/async/)}.
+
+ (1995-01-18)
+
+Asynchronous Transfer Mode
+
+ <communications> (ATM, or "fast packet") A method for the
+ dynamic allocation of {bandwidth} using a fixed-size {packet}
+ (called a cell).
+
+ See also {ATM Forum}, {Wideband ATM}.
+
+ {ATM acronyms
+ (http://atmforum.com/atmforum/acronym_index.html)}.
+
+ {Indiana acronyms
+ (http://cell-relay.indiana.edu/cell-relay/FAQ/ATM-Acronyms.html)}.
+
+ [More detail? Data rate(s)?]
+
+ (1996-04-01)
+
+asyncronous
+
+ <spelling> It's spelled "{asynchronous}".
+
+ (1996-12-13)
+
+AT
+
+ {IBM PC AT}
+
+at
+
+ 1. <character> {commercial at}.
+
+ 2. <networking> The {country code} for Austria.
+
+AT-3
+
+ <language> The original name of {MATH-MATIC}.
+
+ [Sammet 1969, p. 135].
+
+ (2000-02-24)
+
+ATA
+
+ {Advanced Technology Attachment}
+
+ATA-2
+
+ {Advanced Technology Attachment Interface with Extensions}
+
+ATA-4
+
+ <storage> /ul'tr* D M A/ (Or "Ultra DMA", "UDMA", "Ultra-ATA",
+ "Ultra-DMA/33") A development of the {Advanced Technology
+ Attachment} specifications which gives nearly twice the
+ maximum transfer speed of the {ATA-3} standard ({PIO} Mode 4).
+
+ ATA-4 Extensions Ultra DMA/33 Synchronous DMA Mode maximum
+ burst transfer rates:
+
+ Mode Cycle Time Transfer Rate
+ ns MB/s
+ 0 235 16
+ 1 160 24
+ 2 120 33
+
+ This is achieved by improving timing windows in the {protocol}
+ on the ATA interface; reducing propagation delays by
+ {pipelining} data transfers and transferring data in
+ {synchronous} (strobed) mode.
+
+ Developed by {Quantum Corporation}, ATA-4 has been freely
+ licensed to manufacturers and is supported by {Intel
+ Corporation}.
+
+ (1998-09-30)
+
+Atanasoff-Berry Computer
+
+ <computer> (ABC) An early design for a binary calculator, one
+ of the predecessors of the {digital computer}. The ABC was
+ partially constructed between 1937 and 1942 by Dr. {John
+ Vincent Atanasoff} and Clifford Berry at {Iowa State College}.
+ As well as {binary} arithmetic, it incorporated {regenerative
+ memory}, {parallel processing}, and separation of memory and
+ computing functions.
+
+ The electronic parts were mounted on a rotating drum, making
+ it hybrid electronic/electromechanical. It was designed to
+ handle only a single type of mathematical problem and was not
+ automated. The results of a single calculation cycle had to
+ be retrieved by a human operator, and fed back into the
+ machine with all new instructions, to perform complex
+ operations. It lacked any serious form of logical control or
+ {conditional} statements.
+
+ Atanasoff's patent application was denied because he never
+ have a completed, working product. Ideas from the ABC were
+ used in the design of {ENIAC} (1943-1946).
+
+ {(http://cs.iastate.edu/jva/jva-archive.shtml)}.
+
+ (2003-09-28)
+
+Atanasoff, John Vincent
+
+ {John Vincent Atanasoff}
+
+ATAPI
+
+ {AT Attachment Packet Interface}
+
+ATA point
+
+ <unit, text> (Or "Anglo-Saxon point") One of the two most
+ common variants of the {point}, equal to 0.3514598 mm, or
+ 0.0138366 inch, or 1/72.272 inch. The ATA point is used on
+ the island of the United Kingdom and on the American
+ continent.
+
+ [What point do they use in Ireland?]
+
+ (2002-03-11)
+
+Atari
+
+ <company, computer> A maker of arcade games, home video game
+ systems, and home computers, especially during the 1970s and
+ 1980s. Atari are best known for their range of 16- and 32-bit
+ {microcomputers}, notable for having a built-in {MIDI}
+ interface. As of February 1994 the range included the Atari
+ 520ST, 1040ST, Mega ST, STe, STacy, Mega STe, TT, and Falcon.
+ There are also emulators that run on the Apple {Macintosh} and
+ {IBM PC}/XT/AT.
+
+ Atari ceased to be a separate company in 1996 when merged with
+ {JTS}. In 1998, JTS sold the Atari assets to Hasbro. In
+ 2001, {Infogrames} North America operations officially changed
+ their name to Atari.
+
+ {(http://atarigames.com/)}.
+
+ {Usenet newsgroups}: {news:comp.binaries.atari.st},
+ {news:comp.sys.atari.st.tech}, {news:comp.sources.atari.st},
+ {news:comp.sys.atari.st}, {news:comp.sys.atari.advocacy},
+ {news:comp.sys.atari.programmer}.
+
+ {Michigan U (ftp://atari.archive.umich.edu)}, {UK
+ (ftp://micros.hensa.ac.uk/)}, {Germany
+ (ftp://ftp.Germany.EU.net)} [192.76.144.75], {Netherlands
+ (ftp://ftp.cs.ruu.nl/)} [131.211.80.17], {UK
+ (ftp://src.doc.ic.ac.uk/computing/systems/atari/umich)}.
+
+ (2008-07-23)
+
+Atari ST
+
+ <computer> A {personal computer} released by {Atari} in 1985.
+ The "ST" stands for "Sixteen/Thirty-two", from the {Motorola
+ 68000}'s 16-bit {external bus} and 32-bit processor. The
+ original 520ST model had an external {floppy drive} and power
+ supply whereas the 1040ST had them built-in. The 520 and
+ later 520STFM came with 512 KB of {RAM}, the 1040 had 1 MB.
+ Several upgraded models followed, up to the 1993 {Motorola
+ 68030} based {Falcon}.
+
+ The ST was the first home computer with built-in {MIDI ports}
+ and plenty of MIDI software. A wide range of other software
+ from office to games was also available.
+
+ (2006-10-30)
+
+AT Attachment
+
+ {Advanced Technology Attachment}
+
+AT Attachment Packet Interface
+
+ <storage> (ATAPI) Part of the {EIDE} interface that provides
+ additional commands to control a {CD-ROM} drive or {magnetic
+ tape}.
+
+ [Winn L. Rosch "The Winn L. Rosch Hardware Bible"
+ (Third Edition), Sams Publishing, 1994].
+
+ (1998-11-01)
+
+AT bus architecture
+
+ {Industry Standard Architecture}
+
+AtFS
+
+ {Attributed File System}
+
+Athena
+
+ {Project Athena}
+
+Atherton Technology
+
+ <company> The comapny that developed the {Software BackPlane}
+ {CASE} framework. Their {Atherton Tool Integration Services}
+ were the basis for the ATIS standard.
+
+ (2000-02-24)
+
+Athlon
+
+ <hardware> (K7) {AMD}'s 7th generation {x86} {processor},
+ released in June 1999.
+
+ Athlon uses a {Slot A} {motherboard} and is not compatible
+ with {Slot 1} motherboards.
+
+ [Details? Reference?]
+
+ (1999-08-05)
+
+ATIS
+
+ {A Tools Integration Standard}
+
+ATK
+
+ {Andrew Toolkit}
+
+ATLAS
+
+ {Abbreviated Test Language for Avionics Systems}
+
+Atlas Autocode
+
+ <language> The {Autocode} for the {Ferranti} {Atlas}, which
+ may have been the first commercial computer with
+ {hardware-paged} {virtual memory}. Whereas other {autocodes}
+ were basically {assembly languages}, Atlas Autocode was
+ high-level and {block-structured}, resembling a cross between
+ {Fortran} and {ALGOL 60}. It had {call-by value}, {loops},
+ {declarations}, {complex numbers}, {pointers}, {heap} and
+ {stack} storage generators, {dynamic arrays}, and extensible
+ {syntax}.
+
+ (2000-04-03)
+
+ATM
+
+ 1. <communications> {Asynchronous Transfer Mode}.
+
+ 2. Automatic Teller Machine - a cash dispenser.
+
+ 3. <chat> At the moment.
+
+ 4. <text> {Adobe Type Manager}.
+
+ATM Forum
+
+ <networking, body> An international non-profit arganisation
+ aiming to encourage the user of {Asynchronous Transfer
+ Mode} through {interoperability} specifications and to promote
+ cooperation and awareness.
+
+ The ATM Forum consists of a worldwide Technical Committee,
+ three Marketing Committees for North America, Europe and
+ Asia-Pacific as well as the User Committee, through which ATM
+ end-users participate.
+
+ Worldwide Headquarters: 2570 West El Camino Real, Suite 304
+ Mountain View, CA 94040-1313 USA.
+
+ Telephone: +1 (650) 949 6700.
+
+ E-mail: ATM Forum <info@atmforum.com>.
+
+ {(http://atmforum.com/)}.
+
+ (1999-06-14)
+
+ATMP
+
+ {Asynchronous Transfer Mode Protocol}?
+
+ (2001-03-03)
+
+atob
+
+ <tool> /A too B/ {Utility software} that converts {ASCII} to
+ {binary}. The reverse process is {btoa}.
+
+ [Algorithm?]
+
+ (1997-08-08)
+
+ATOLL
+
+ {Acceptance, Test Or Launch Language}
+
+atomic
+
+ <jargon> (From Greek "atomos", indivisible) Indivisible;
+ cannot be split up.
+
+ For example, an instruction may be said to do several things
+ "atomically", i.e. all the things are done immediately, and
+ there is no chance of the instruction being half-completed or
+ of another being interspersed. Used especially to convey that
+ an operation cannot be interrupted.
+
+ An atomic {data type} has no internal structure visible to the
+ program. It can be represented by a flat {domain} (all
+ elements are equally defined). Machine {integers} and
+ {Booleans} are two examples.
+
+ An atomic {database transaction} is one which is guaranteed to
+ complete successfully or not at all. If an error prevents a
+ partially-performed transaction from proceeding to completion,
+ it must be "backed out" to prevent the database being left in
+ an inconsistent state.
+
+ [{Jargon File}]
+
+ (2000-04-03)
+
+A Tools Integration Standard
+
+ <software, library> (ATIS) An {object-oriented} interface to a
+ set of services that allows the saving, accessing and managing
+ of information in a common repository. Developed by {Atherton
+ Technology} and {DEC}, based on an extended version of the
+ {Software BackPlane}, proposed as an industry standard.
+
+ (1994-10-25)
+
+ATRAC
+
+ {Adaptive TRansform Acoustic Coding}
+
+ATS
+
+ {Attribute Translation System}
+
+at sign
+
+ {commercial at}
+
+AT&T
+
+ {American Telephone and Telegraph, Inc.}
+
+Attachment Unit Interface
+
+ <networking> (AUI) The part of the {IEEE} {Ethernet}
+ {standard} located between the {MAC}, and the {MAU}. The AUI
+ is a {transceiver} cable that provides a path between a
+ {node}'s Ethernet interface and the MAU.
+
+ (1996-12-08)
+
+AT&T Bell Labs
+
+ {Bell Laboratories}
+
+attenuation
+
+ <communications> The progressive reduction in {amplitude} of a
+ signal as it travels farther from the point of origin.
+
+ For example, an electric signal's amplitude reduces with
+ distance due to electrical {impedance}. Attenuation is
+ usually measured in {decibels} [per metre?].
+
+ Attenuation does not imply appreciable modification of the
+ shape of the waveform (distortion), though as the signal
+ amplitude falls the {signal-to-noise ratio} will also fall
+ unless the channel itself is noise free or the signal is
+ amplified at some intermediate point(s) along the channel.
+
+ ["Networking Essentials, second edition",
+ Microsoft Corporation, pub. Microsoft Press 1997].
+
+ (2003-07-29)
+
+atto-
+
+ {prefix}
+
+attoparsec
+
+ <unit, humour> About 31 mm (one inch). "atto-" is the
+ standard {SI} {prefix} for multiplication by 10^-18. A parsec
+ (parallax-second) is 3.26 light-years; an attoparsec is thus
+ 3.26 * 10^-18 light years. Thus, one attoparsec per
+ {microfortnight} is about one inch per second.
+
+ This unit is reported to be in use (though probably not very
+ seriously) among hackers in the UK.
+
+ [{Jargon File}]
+
+ (1996-12-08)
+
+attribute
+
+ <data> A named value or relationship that exists for some or
+ all {instances} of some {entity} and is directly associated
+ with that instance.
+
+ Examples include the {href} attribute of an {HTML} {anchor}
+ element, the {columns} of a {database} {table} considered as
+ attributes of each row, and the {members} ({properties} and
+ {methods} of an {object} in {OOP}. This contrasts with the
+ contents of some kind of container (e.g. an array), which are
+ typically not named. The contents of an {associative array},
+ though they might be considered to be named by their key
+ values, are not normally thought of as attributes.
+
+ (2001-02-04)
+
+Attributed File System
+
+ <storage> (AtFS) The basis of the {Shape_VC} toolkit.
+
+ Cooperative work within projects is supported by a status
+ model controlling visibility of version objects, locking, and
+ "long transactions" for synchronising concurrent updates. The
+ concept of object attributes provides a basis for storing
+ management information with versions and passing this
+ information between individual tools. This mechanism is
+ useful for building integrated environments from a set of
+ unrelated tools.
+
+ (2000-02-24)
+
+Attribute Translation System
+
+ <grammar, tool> (ATS) A {BNF}-based {parser generator} from
+ the {University of Saskatchewan}(?). ATS generates
+ table-driven {LL1} {parsers} with full {insert-only error
+ recovery}. It also has full left-attribute semantic handling,
+ which is a dream compared to using {YACC}'s parser actions.
+
+ (2000-04-08)
+
+ATX
+
+ <hardware, standard> An {open} {PC} {motherboard}
+ specification by {Intel}.
+
+ ATX is a development of the {Baby AT} specification with the
+ motherboard rotated 90 degrees in the chassis. The {CPU} and
+ {SIMM} sockets have been relocated away from the {expansion
+ card} slots meaning that all the slots support full-length
+ cards. More {I/O} functions are integrated on the
+ motherboard. As the longer edge of the board is now at the
+ back of the chassis, there is more space for connectors; also,
+ the I/O opening on the back panel of the chassis has been
+ defined as double the previous height, allowing vendors to add
+ extra on-board I/O functions over and above the standard.
+
+ Most {Pentium Pro} boards use this {form factor}.
+
+ As well as the motherboard size, layout, and placement, the
+ ATX specification also includes requirements for power supply
+ and fan specification and location.
+
+ The full size ATX board measures 305mm wide by 244mm deep.
+ There is also a Mini-ATX form factor, 284mm by 208mm.
+
+ {Home
+ (http://developer.intel.com/design/motherbd/atx.htm)}.
+
+ (2001-07-16)
+
+au
+
+ 1. <networking> The two character {country code} for Australia
+ used in {Internet} {domain names}.
+
+ 2. <filename extension> {audio}.
+
+ (1995-02-15)
+
+aubergine
+
+ <jargon> A secret term used to refer to computers in the
+ presence of computerphobic third parties.
+
+ (1995-01-24)
+
+audio
+
+ <file format> Sound, one component of {multimedia}. Computers
+ (and audio compact discs and digital audio tape) work with
+ {digital audio}, in contrast to vinyl disks or analogue tape.
+
+ (1999-07-30)
+
+audiographics
+
+ {Audiographic Teleconferencing}
+
+audiographic teleconferencing
+
+ <communications> (Or "electronic whiteboarding", "screen
+ sharing") A form of {teleconferencing} in {real time} using
+ both an {audio} and a data connection. The computer screen is
+ shared by more than one site, and used as an electronic
+ blackboard, overhead projector or still video projector. Some
+ systems allow for sharing software also.
+
+ (1995-10-06)
+
+Audio IFF
+
+ <file format, music> (AIFF) A format developed by {Apple
+ Computer} Inc. for storing high-quality {digital audio} and
+ musical instrument information. It is also used by {SGI} and
+ several professional audio packages.
+
+ (1994-10-10)
+
+AudioOne
+
+ <tool, music> Digital recording and editing software developed
+ by {BizTrack Software Development} for the dance, music, and
+ audio industries. AudioOne includes a waveform recorder that
+ allows signal manipulation, editing, and recording.
+
+ (1996-09-28)
+
+Audio Processing Technology
+
+ <company> (APT) A company that produces {codecs} based on
+ {predictive analysis} rather than {frequency coding}.
+
+ (1996-01-15)
+
+Audio Video Interleave
+
+ <multimedia> (AVI) An {audio}-{video} {standard} designed by
+ {Microsoft}. Apparently proprietary and {Microsoft
+ Windows}-specific.
+
+ {(http://www2.echo.lu/oii/en/video.html#AVI)}.
+
+ [Details?]
+
+ (1996-09-08)
+
+Augmented Backus-Naur Form
+
+ <language> An extension of {Backus-Naur Form} documented in
+ {RFC 2234}.
+
+ [Summary?]
+
+ (1997-11-23)
+
+AUI
+
+ 1. <tool, product> {Adaptable User Interface}.
+
+ 2. <networking> {Attachment Unit Interface}.
+
+A'UM
+
+ <language> A {stream}-based, {concurrent}, {logic},
+ {object-oriented} language by K. Yoshida and Takashi Chikayama
+ <chikayama@klic.org>, built on top of {KL1}.
+
+ ["A'UM - A Stream-based Concurrent Logic Object-Oriented
+ Language", K. Yoshida et al, Proc 3rd Intl Conf Fifth Gen
+ Comp Sys, Springer 1988, pp. 638-649].
+
+ (2000-07-16)
+
+AUP
+
+ {acceptable use policy}
+
+Aurora
+
+ ["The Aurora Or-Parallel Prolog System", E. Lusk et al, Proc
+ 3rd Intl Conf on Fifth Generation Comp Systems, pp. 819-830,
+ ICOT, A-W 1988].
+
+Austin Kyoto Common Lisp
+
+ <language> (AKCL) A collection of ports, bug fixes, and
+ performance improvements to {KCL} by William Schelter
+ <wfs@cli.com>, <wfs@math.utexas.edu>, University of Texas.
+
+ Version 1-615 includes ports to {Decstation} 3100,
+ {HP9000}/300, {i386}/{Sys V}, {IBM-PS2}/{AIX}, {IBM-RT}/{AIX},
+ {SGI}, {Sun-3}/{Sunos} 3 or 4, {Sun-4}, {Sequent Symmetry},
+ {IBM370}/{AIX}, {VAX}/{BSD VAX}/{Ultrix}, {NeXT}.
+
+ {(ftp://rascal.ics.utexas.edu/pub/akcl-1-609.tar.Z)}.
+
+ (1992-04-29)
+
+authentication
+
+ <security> The verification of the identity of a person or
+ process. In a communication system, authentication verifies
+ that messages really come from their stated source, like the
+ signature on a (paper) letter. The most common form of
+ authentication is typing a user name (which may be widely
+ known or easily guessable) and a corresponding {password} that
+ is presumed to be known only to the individual being
+ authenticated. Another form of authentication is
+ {biometrics}.
+
+ (2007-02-22)
+
+authoring
+
+ <hypertext> Creating a {hypertext} or {hypermedia} document.
+
+ (1994-11-07)
+
+autobaud
+
+ {automatic baud rate detection}
+
+autobogotiphobia
+
+ {bogotify}
+
+AutoCAD
+
+ <product, tool> A {CAD} {software} package for mechanical
+ engineering, marketed by {Autodesk, Inc.}
+
+ (1994-11-09)
+
+Autocode
+
+ <language> 1. The {assembly language} accepted by {AUTOCODER}.
+
+ 2. A generic term for symbolic {assembly language}. Versions
+ of Autocode were developed for {Ferranti} {Atlas}, {Titan},
+ {Mercury} and {Pegasus} and {IBM 702} and {IBM 705}.
+
+ (2001-05-14)
+
+AUTOCODER
+
+ <language> Possibly the first primitive {compiler}. AUTOCODER
+ was written by Alick E. Glennie in 1952. It translated
+ symbolic statements into {machine language} for the
+ {Manchester Mark I} computer.
+
+ Autocoding later came to be a generic term for {assembly
+ language} programming.
+
+ (1994-11-07)
+
+autoconf
+
+ <software, tool> The {GNU project}'s tool that configures a
+ source code distribution to compile and run on a different
+ platform.
+
+ Among {open source} {hackers}, a mere running {binary} of a
+ program is not considered a full release; what's interesting
+ is a source tree that can be built into binaries using
+ standard tools. Since the mid-1990s, autoconf, {automake},
+ and {libtools} have been the standard way to make a
+ distribution portable so that it can be built on multiple
+ {operating systems} without change.
+
+ (2002-09-20)
+
+autoconfiscate
+
+ <software, jargon> A term coined by Noah Friedman meaning to
+ set up or modify a {source-code} distribution so that it
+ configures and builds using the {GNU project}'s
+ {autoconf}/automake/libtools suite.
+
+ (2002-09-20)
+
+Autodesk, Inc.
+
+ <company> The distributors of the {AutoCAD} {CAD} package.
+
+ Address: Sausalito, CA, USA.
+
+ (1994-11-09)
+
+AUTOEXEC.BAT
+
+ <operating system> The {batch file} containing commands,
+ loaded by {MS-DOS} after running {CONFIG.SYS}. AUTOEXEC.BAT
+ contains normal DOS commands and can be used for additional
+ system configuration such as setting paths and variables,
+ configuring network connections and running {application
+ programs}.
+
+ (1995-03-18)
+
+AUTOGRAF
+
+ <tool> A system for describing {bar charts}.
+
+ ["User's Manual for AUTOGRAF", Cambridge Computer Assoc, Dec
+ 1972].
+
+ (2001-05-14)
+
+AUTOGRP
+
+ {AUTOmated GRouPing system}
+
+Auto Idle
+
+ A facility provided by some {Intel} {clock doubled}
+ {microprocessors} where the internal clock can be slowed to
+ the external {clock rate} while the processor is waiting for
+ data from memory, returning to full speed as soon as the data
+ arrives.
+
+ See also {System Management Mode}.
+
+ (1994-11-09)
+
+Autolisp
+
+ <language> A dialect of {Lisp} used by the {Autocad} {CAD}
+ package from {Autodesk}.
+
+ (1994-11-09)
+
+autoloader
+
+ {stack loader}
+
+automagically
+
+ <jargon> /aw-toh-maj'i-klee/ or /aw-toh-maj'i-k*l-ee/
+ Automatically, but in a way that, for some reason (typically
+ because it is too complicated, or too ugly, or perhaps even
+ too trivial), the speaker doesn't feel like explaining to you.
+
+ E.g. "The C-INTERCAL compiler generates C, then automagically
+ invokes {cc} to produce an executable."
+
+ See {magic}.
+
+ [{Jargon File}]
+
+ (2001-05-18)
+
+automata
+
+ {automaton}
+
+automata theory
+
+ {automaton}
+
+Automated Engineering Design
+
+ <language> (AED) (Or "ALGOL Extended for Design") A systems
+ language for the {IBM 7090} and {IBM 360} developed at {MIT}
+ System Laboratory ca. 1965 by a team led by Douglas T. Ross
+ (now at {Softech}). AED is an extension of {ALGOL 60} with
+ {records} ("plexes"), pointers, and {dynamic allocation}.
+ {DYNAMO II} was written in AED, as was the first {BCPL}
+ {compiler}.
+
+ Versions: AED-0, AED-1, AED-JR.
+
+ ["The Automated Engineering Design (AED) Approach to
+ Generalized Computer-Aided Design", D.T. Ross, Proc ACM 22nd
+ Natl Conf, 1967].
+
+ [Sammet 1969 and 1978].
+
+ (1995-03-26)
+
+AUTOmated GRouPing system
+
+ <tool, mathematics> (AUTOGRP) An interactive statistical
+ analysis system, an extension of {CML}.
+
+ ["AUTOGRP: An Interactive Computer System for the Analysis of
+ Health Care Data", R.E. Mills et al, Medical Care 14(7), Jul
+ 1976].
+
+ (1994-11-07)
+
+Automated Retroactive Minimal Moderation
+
+ <messaging> (ARMM) A {Usenet} robot created by Dick Depew of
+ Munroe Falls, Ohio. ARMM was intended to automatically cancel
+ posts from anonymous-posting sites. Unfortunately, the
+ robot's recogniser for anonymous postings triggered on its own
+ automatically-generated control messages! Transformed by this
+ stroke of programming ineptitude into a monster of
+ Frankensteinian proportions, it broke loose on the night of
+ 1993-03-31 and proceeded to {spam} {news:news.admin.policy}
+ with a recursive explosion of over 200 messages.
+
+ Reactions varied from amusement to outrage. The pathological
+ messages crashed at least one mail system, and upset people
+ paying line charges for their {Usenet} feeds. One poster
+ described the ARMM debacle as "instant {Usenet} history" (also
+ establishing the term {despew}), and it has since been widely
+ cited as a cautionary example of the havoc the combination of
+ good intentions and incompetence can wreak on a network.
+
+ Compare {Great Worm}; {sorcerer's apprentice mode}. See also
+ {software laser}, {network meltdown}.
+
+ (1996-01-08)
+
+automated testing
+
+ <testing> Software testing assisted with software tools
+ that require no operator input, analysis, or evaluation.
+
+ (2001-05-20)
+
+AUTOMATH
+
+ <language, mathematics> A very high level language for writing
+ proofs, from Eindhoven, Netherlands.
+
+ ["The Mathematical Language AUTOMATH, Its Usage and Some of
+ its Extensions", N.G. deBruijn, in Symp on Automatic
+ Demonstration, LNM 125, Springer 1970].
+
+ (2001-07-09)
+
+Automatically Programmed Tools
+
+ <language> (APT) A language for numerically controlled machine
+ tools.
+
+ Versions: APT II (IBM 704, 1958), APT III (IBM 7090, 1961).
+
+ ["APT Part Programming", McGraw-Hill].
+
+ [Sammet 1969, p. 605].
+
+ (1995-05-04)
+
+automatic baud rate detection
+
+ <communications> (ABR, autobaud) A process by which a
+ receiving device determines the speed, {code level}, and {stop
+ bits} of incoming data by examining the first character,
+ usually a preselected sign-on character. ABR allows the
+ receiving device to accept data from a variety of transmitting
+ devices operating at different speeds without needing to
+ establish data rates in advance.
+
+ (1996-06-18)
+
+automatic hyphenation
+
+ <text> A feature of some {word processors} which can insert
+ {hyphens} into words which would otherwise extend beyond the
+ right hand margin of the page.
+
+ More advanced word processors may have options to control the
+ position of the hyphen, to restrict certain words from being
+ hyphenated, and to allow custom dictionaries of hyphenation
+ points to be built up.
+
+ (1996-08-02)
+
+Automatic Mathematical TRANslation
+
+ <mathematics, tool> (AMTRAN) A system developed by NASA in
+ Huntsville in 1966 for the {IBM 1620}, based on the
+ {Culler-Fried} System. It required a special terminal.
+
+ ["AMTRAN: An Interactive Computing System", J. Reinfelds, Proc
+ FJCC 37:537- 542, AFIPS (Fall 1970)].
+
+ (1995-11-14)
+
+Automatic Network Routing
+
+ <protocol> (ANR) A {source routing protocol} used to route
+ {LU6.2} session and control traffic from {node} to node
+ through a {High Performance Routing} network or {subnet}. ANR
+ operates at the lower end of the {SNA} {Path Control layer}.
+
+ [Relationship to {OS/390}?]
+
+ (1997-05-08)
+
+Automatic Number Identification
+
+ <communications> (ANI) A service that tells the recipient of a
+ telephone call the telephone number of the person making the
+ call. This number can be passed to computer equipment to
+ automatically retrieve associated information about the caller,
+ i.e. account status, billing records, etc.
+
+ See {CTI}.
+
+ (1996-12-08)
+
+Automatic Repeat Request
+
+ <communications> (ARQ) A {modem} error control {protocol} in
+ which the receiver asks the transmitter to resend corrupted
+ data.
+
+ (1995-11-14)
+
+Automatic Send Receive
+
+ <hardware> (ASR) Part of a designation for a hard-copy
+ {terminal}, manufactured by {Teletype Corporation}, which
+ could be commanded remotely to send the contents of its {paper
+ tape} reader. The ASR-33 was the most common {minicomputer}
+ terminal in the early 1970s.
+
+ (1995-11-23)
+
+Automatic Sequence Controlled Calculator
+
+ {Mark 1}
+
+automation
+
+ Automatic, as opposed to human, operation or control of a
+ process, equipment or a system; or the techniques and
+ equipment used to achieve this. Most often applied to
+ computer (or at least electronic) control of a manufacturing
+ process.
+
+ See also {design automation}, {office automation},
+ {manularity}, {Manufacturing Automation Protocol}, {PEARL},
+ {QBE}.
+
+ (1994-10-21)
+
+Automatische Rechenplanfertigung
+
+ <language> A programming language published in 1952 by Heinz
+ Rutishauser (1918-70).
+
+ [Features?]
+
+ (2001-07-09)
+
+automaton
+
+ <robotics, mathematics, algorithm> (Plural automata) A
+ machine, {robot}, or {formal system} designed to follow a
+ precise sequence of instructions.
+
+ Automata theory, the invention and study of automata, includes
+ the study of the capabilities and limitations of computing
+ processes, the manner in which systems receive input, process
+ it, and produce output, and the relationships between
+ behavioural theories and the operation and use of automated
+ devices.
+
+ See also {cellular automaton}, {finite state machine}.
+
+ (1996-04-23)
+
+Automatrix, Inc.
+
+ <company> The company which produced {CAM-PC}.
+
+ Address: Ballston Spa, NY, USA.
+
+ {(http://automatrix.com/)}.
+
+ (1995-04-21)
+
+Autonomous System
+
+ <networking, routing> (AS) A collection of {routers} under a
+ single administrative authority, using a common {Interior
+ Gateway Protocol} for routing {packets}.
+
+ (2001-09-16)
+
+Autonomous System Number
+
+ <networking, routing> (ASN) Used for {routing} on the
+ {Internet}.
+
+ [Does each ASN uniquely identify an {Autonomous System}?]
+
+ (2001-09-16)
+
+Autopass
+
+ <programming>
+
+ ["Autopass: An Automatic Programming System for
+ Computer-Controlled Mechanical Assembly", L.I. Lieberman et
+ al, IBM J Res Dev 21(4):321-333, 1979].
+
+ (2001-09-16)
+
+autopilot code
+
+ <jargon, humour> {Code} that was written by a programmer on
+ "auto-pilot" who wasn't really thinking about what they were
+ doing.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2014-08-21)
+
+autoprojector
+
+ <theory> A self-applicable {partial evaluator}.
+
+ (2001-09-16)
+
+AUTO-PROMPT
+
+ <language> A {numerical control} language from {IBM} for {3D}
+ milling.
+
+ [Sammet 1969, p.606].
+
+ (2001-09-25)
+
+Autostat
+
+ <language> A language for statistical programming.
+
+ ["Autostat: A Language for Statistical Programming",
+ A.S. Douglas et al, Computer J 3:61, 1960].
+
+ (2001-09-25)
+
+autostereogram
+
+ {SIRDS}
+
+A/UX
+
+ <operating system> (Apple's UniX) {Apple}'s first version of
+ {Unix} for {Macintosh} computers. A/UX merges the {Macintosh
+ Finder} ({GUI}) with a Unix core, offering functions from both
+ systems. It will run on some late-model {Motorola 68000}
+ Macs, but not on the {Power Mac}.
+
+ A/UX is based on {AT&T} Unix {System V}.2.2 with numerous
+ extensions from V.3, V.4 and {BSD} 4.2/4.3. It also provides
+ full {POSIX} compliance.
+
+ A/UX 3.x.x incorporates {System 7} for the Macintosh, thus
+ supporting the vast majority of Macintosh {applications}.
+ System 7 and Unix are fully integrated under A/UX 3.x.x with
+ the Unix file system being seen as a disk drive by the Finder.
+
+ {jagubox's A/UX Home Page
+ (http://jagubox.gsfc.nasa.gov/aux/Info/FAQ.auxl)}.
+
+ (1997-12-13)
+
+auxiliary storage
+
+ <storage> An obsolete term for a {hard disk} {drive}.
+
+ (1997-04-14)
+
+av
+
+ {avatar}
+
+availability
+
+ <systems> The degree to which a system suffers degradation or
+ interruption in its service to the customer as a consequence of
+ failures of one or more of its parts.
+
+ One of the components of {RAS}.
+
+ (2000-08-13)
+
+Avalon/C++
+
+ <language, parallel> A {concurrent} extension of {C++} with
+ servers and transactions developed in 1986 for
+ {fault-tolerant} {distributed} systems. Avalon/C++ was
+ influenced by {Argus}.
+
+ ["Camelot and Avalon: A Distributed Transaction Facility",
+ J.L. Eppinger et al, Morgan Kaufmann 1990].
+
+ (2002-01-13)
+
+Avalon/Common LISP
+
+ <language> A {LISP} dialect available as a prototype only.
+
+ ["Reliable Distributed Computing with Avalon/Common LISP",
+ S.M. Clamen et al, CMU-CS-89-186 and Proc Intl Conf on
+ Computer Languages, Mar 1990].
+
+ (2002-02-03)
+
+avatar
+
+ 1. <chat, virtual reality> An {image} representing a user in a
+ multi-user {virtual reality} (or VR-like, in the case of
+ {Palace}) space.
+
+ 2. (CMU, Tektronix) {root}, {superuser}. There are quite a
+ few {Unix} computers on which the name of the superuser
+ account is "avatar" rather than "root". This quirk was
+ originated by a {CMU} hacker who disliked the term
+ "superuser", and was propagated through an ex-CMU hacker at
+ {Tektronix}.
+
+ [{Jargon File}]
+
+ (1997-09-14)
+
+AVC
+
+ {H.264}
+
+average seek time
+
+ <storage> The {mean} time it takes to move the {head} of a
+ {disk drive} from one {track} to another, averaged over the
+ source and destination cylinders. Usually measured in
+ {milliseconds} (ms).
+
+ The average seek time gives a good measure of the speed of the
+ drive in a multi-user environment where successive read/write
+ request are largely uncorrelated.
+
+ Ten ms is common for a {hard disk} and 200 ms for an
+ eight-speed {CD-ROM}.
+
+ (2007-03-16)
+
+AverStar
+
+ <company> The US software engineering company that developed
+ {Hal}, under their former name, "Intermetrics". Other
+ products include {CS-4}, {Red}, {Mwave Developers Toolkit}
+ ({multimedia} for {IBM PC}), {cross-compilers} for {C} and
+ {C++}; {Ada '83}, {Ada 95}, and {SAMeDL}. AverStar also
+ supply {client/server} systems; custom software applications
+ and {turnkey} systems; independent verification and
+ validation; {CAE} integration technology; languages and
+ compilers: {Ada}, {C}, {C++}, {HDLs} ({MHDL}), {Modula},
+ {SPL/1}.
+
+ Address: Intermetrics, Inc., 733 Concord Avenue, Cambridge, MA
+ 02138, USA. Telephone: +1 (617) 661 1840. Fax: +1 (617) 868
+ 2843.
+
+ Address: 7918 Jones Branch Drive, McLean, Va 22102, USA.
+ Telephone: +1 (703) 827-2606. Fax: +1 (703) 827-5560.
+
+ Also Houston, TX, Huntington Beach, CA, Warminster, PA, and
+ others.
+
+ {AverStar Home (http://averstar.com/)}.
+
+ (2003-02-17)
+
+AVI
+
+ {Audio Video Interleave}
+
+Avon
+
+ <language> A {dataflow} language.
+
+ ["AVON: A Dataflow Language", A. Deb, ICS 87, Second Intl Conf
+ on Supercomputing, v.3, pp.9-19, ISI 1987].
+
+ (1994-11-28)
+
+AVS
+
+ {Application Visualisation System}
+
+aw
+
+ <networking> The {country code} for Aruba.
+
+ (1999-01-27)
+
+AWE
+
+ {Advanced WavEffect}
+
+AWG
+
+ {American Wire Gauge}
+
+awk
+
+ 1. <tool, language> (Named from the authors' initials) An
+ interpreted language included with many versions of {Unix} for
+ massaging text data, developed by Alfred Aho, Peter Weinberger,
+ and Brian Kernighan in 1978. It is characterised by {C}-like
+ syntax, declaration-free variables, {associative arrays}, and
+ field-oriented text processing.
+
+ There is a {GNU} version called {gawk} and other varients
+ including {bawk}, {mawk}, {nawk}, {tawk}. {Perl} was inspired
+ in part by awk but is much more powerful.
+
+ {Unix manual page}: awk(1).
+
+ {netlib WWW
+ (http://plan9.att.com/netlib/research/index.html)}. {netlib
+ FTP (ftp://netlib.att.com/netlib/research/)}.
+
+ ["The AWK Programming Language" A. Aho, B. Kernighan,
+ P. Weinberger, A-W 1988].
+
+ 2. <jargon> An expression which is awkward to manipulate
+ through normal {regexp} facilities, for example, one
+ containing a {newline}.
+
+ [{Jargon File}]
+
+ (1995-10-06)
+
+AWT
+
+ {Abstract Window Toolkit}
+
+aXe
+
+ <tool> A {text editor} for the {X Window System}. No longer
+ maintained.
+
+ (1998-03-13)
+
+AXIOM
+
+ <language> A commercially available subset of the
+ {Scratchpad}, {symbolic mathematics} system from {IBM}.
+
+ ["Axiom - The Scientific Computing System", R. Jenks et al,
+ Springer 1992].
+
+ [Relationship with {AXIOM*}?]
+
+ (1995-02-21)
+
+axiom
+
+ <logic> A {well-formed formula} which is taken to be true
+ without proof in the construction of a {theory}.
+
+ Compare: {lemma}.
+
+ (1995-03-31)
+
+AXIOM*
+
+ <mathematics, tool> A {symbolic mathematics} system.
+
+ {A#} is one component of AXIOM*.
+
+ Version: 2.
+
+ [Relationship with {AXIOM}?]
+
+ (1995-02-21)
+
+Axiomatic Architecture Description Language
+
+ <language, architecture, parallel> (AADL) A language allowing
+ concise modular specification of {multiprocessor}
+ architectures from the compiler/operating-system interface
+ level down to chip level. AADL is rich enough to specify
+ target architectures while providing a concise model for
+ clocked {microarchitectures}.
+
+ ["AADL: A Net-Based Specification Method for Computer
+ Architecture Design", W. Damm et al in Languages for Parallel
+ Architectures, J.W. deBakker ed, Wiley, 1989].
+
+ (2003-06-30)
+
+axiomatic semantics
+
+ <theory> A set of assertions about properties of a system and
+ how they are effected by program execution. The axiomatic
+ semantics of a program could include pre- and post-conditions
+ for operations. In particular if you view the program as a
+ state transformer (or collection of state transformers), the
+ axiomatic semantics is a set of invariants on the state which
+ the state transformer satisfies.
+
+ E.g. for a function with the type:
+
+ sort_list :: [T] -> [T]
+
+ we might give the precondition that the argument of the
+ function is a list, and a postcondition that the return value
+ is a list that is sorted.
+
+ One interesting use of axiomatic semantics is to have a
+ language that has a {finitely computable} sublanguage that is
+ used for specifying pre and post conditions, and then have the
+ compiler prove that the program will satisfy those conditions.
+
+ See also {operational semantics}, {denotational semantics}.
+
+ (1995-11-09)
+
+axiomatic set theory
+
+ <theory> One of several approaches to {set theory}, consisting
+ of a {formal language} for talking about sets and a collection
+ of {axioms} describing how they behave.
+
+ There are many different {axiomatisations} for set theory.
+ Each takes a slightly different approach to the problem of
+ finding a theory that captures as much as possible of the
+ intuitive idea of what a set is, while avoiding the
+ {paradoxes} that result from accepting all of it, the most
+ famous being {Russell's paradox}.
+
+ The main source of trouble in naive set theory is the idea
+ that you can specify a set by saying whether each object in
+ the universe is in the "set" or not. Accordingly, the most
+ important differences between different axiomatisations of set
+ theory concern the restrictions they place on this idea (known
+ as "comprehension").
+
+ {Zermelo Fränkel set theory}, the most commonly used
+ axiomatisation, gets round it by (in effect) saying that you can
+ only use this principle to define subsets of existing sets.
+
+ NBG (von Neumann-Bernays-Goedel) set theory sort of allows
+ comprehension for all {formulae} without restriction, but
+ distinguishes between two kinds of set, so that the sets
+ produced by applying comprehension are only second-class sets.
+ NBG is exactly as powerful as ZF, in the sense that any
+ statement that can be formalised in both theories is a theorem
+ of ZF if and only if it is a theorem of ZFC.
+
+ MK (Morse-Kelley) set theory is a strengthened version of NBG,
+ with a simpler axiom system. It is strictly stronger than
+ NBG, and it is possible that NBG might be consistent but MK
+ inconsistent.
+
+ {NF (http://math.boisestate.edu/~holmes/holmes/nf.html)} ("New
+ Foundations"), a theory developed by Willard Van Orman Quine,
+ places a very different restriction on comprehension: it only
+ works when the formula describing the membership condition for
+ your putative set is "stratified", which means that it could
+ be made to make sense if you worked in a system where every
+ set had a level attached to it, so that a level-n set could
+ only be a member of sets of level n+1. (This doesn't mean
+ that there are actually levels attached to sets in NF). NF is
+ very different from ZF; for instance, in NF the universe is a
+ set (which it isn't in ZF, because the whole point of ZF is
+ that it forbids sets that are "too large"), and it can be
+ proved that the {Axiom of Choice} is false in NF!
+
+ ML ("Modern Logic") is to NF as NBG is to ZF. (Its name
+ derives from the title of the book in which Quine introduced
+ an early, defective, form of it). It is stronger than ZF (it
+ can prove things that ZF can't), but if NF is consistent then
+ ML is too.
+
+ (2003-09-21)
+
+Axiom of Choice
+
+ <logic> (AC, or "Choice") An {axiom} of {set theory}:
+
+ If X is a set of sets, and S is the union of all the elements
+ of X, then there exists a function f:X -> S such that for all
+ non-empty x in X, f(x) is an element of x.
+
+ In other words, we can always choose an element from each set
+ in a set of sets, simultaneously.
+
+ Function f is a "choice function" for X - for each x in X, it
+ chooses an element of x.
+
+ Most people's reaction to AC is: "But of course that's true!
+ From each set, just take the element that's biggest,
+ stupidest, closest to the North Pole, or whatever". Indeed,
+ for any {finite} set of sets, we can simply consider each set
+ in turn and pick an arbitrary element in some such way. We
+ can also construct a choice function for most simple {infinite
+ sets} of sets if they are generated in some regular way.
+ However, there are some infinite sets for which the
+ construction or specification of such a choice function would
+ never end because we would have to consider an infinite number
+ of separate cases.
+
+ For example, if we express the {real number} line R as the
+ union of many "copies" of the {rational numbers}, Q, namely Q,
+ Q+a, Q+b, and infinitely (in fact uncountably) many more,
+ where a, b, etc. are {irrational numbers} no two of which
+ differ by a rational, and
+
+ Q+a == {q+a : q in Q}
+
+ we cannot pick an element of each of these "copies" without
+ AC.
+
+ An example of the use of AC is the theorem which states that
+ the {countable} union of countable sets is countable. I.e. if
+ X is countable and every element of X is countable (including
+ the possibility that they're finite), then the sumset of X is
+ countable. AC is required for this to be true in general.
+
+ Even if one accepts the axiom, it doesn't tell you how to
+ construct a choice function, only that one exists. Most
+ mathematicians are quite happy to use AC if they need it, but
+ those who are careful will, at least, draw attention to the
+ fact that they have used it. There is something a little odd
+ about Choice, and it has some alarming consequences, so
+ results which actually "need" it are somehow a bit suspicious,
+ e.g. the {Banach-Tarski paradox}. On the other side, consider
+ {Russell's Attic}.
+
+ AC is not a {theorem} of {Zermelo Fränkel set theory} (ZF).
+ Gödel and Paul Cohen proved that AC is independent of ZF,
+ i.e. if ZF is consistent, then so are ZFC (ZF with AC) and
+ ZF(~C) (ZF with the negation of AC). This means that we
+ cannot use ZF to prove or disprove AC.
+
+ (2003-07-11)
+
+Axiom of Comprehension
+
+ <logic> An {axiom schema} of {set theory} which states:
+ if P(x) is a {property} then
+
+ {x : P}
+
+ is a set. I.e. all the things with some property form a set.
+
+ Acceptance of this axiom leads to {Russell's Paradox} which is
+ why {Zermelo set theory} replaces it with a restricted form.
+
+ (1995-03-31)
+
+axiom schema
+
+ <logic> A {formula} in the language of an {axiomatic system},
+ containing one or more. These {metasyntactic variables} (or
+ "{schematic variables}") that stand for terms or subformulae.
+ An example is the {Axiom of Comprehension}.
+
+ (2009-02-10)
+
+AXLE
+
+ <language> An early {string processing} language in which a
+ program consists of an "assertion table" specifying patterns
+ and an "imperative table" specifying replacements.
+
+ ["AXLE: An Axiomatic Language for String Transformations",
+ K. Cohen et al, CACM 8(11):657-661, Nov 1965].
+
+ (2009-02-10)
+
+ayacc
+
+ A {Yacc}-like {parser generator} from the {Irvine Research
+ Unit in Software} written in {Ada} that produce {Ada} output.
+ Comes with {aflex}.
+
+ Version 1.2a.
+
+ {(ftp://liege.ics.uci.edu/pub/irus/aflex-ayacc_1.2a.tar.Z)}.
+
+ Mailing list: <irus-software-request@ics.uci.edu>.
+
+ (1993-01-06)
+
+AYT
+
+ <chat> Are you there?
+
+ (1996-03-09)
+
+az
+
+ <networking> The {country code} for Azerbaijan.
+
+ (1999-01-27)
+
+AZERTY
+
+ {QWERTY}
+
+B
+
+ 1. {byte}.
+
+ 2. <language> A systems language written by {Ken Thompson} in
+ 1970 mostly for his own use under {Unix} on the {PDP-11}. B
+ was later improved by Kerninghan(?) and Ritchie to produce
+ {C}. B was used as the systems language on {Honeywell}'s
+ {GCOS-3}.
+
+ B was, according to Ken, greatly influenced by {BCPL}, but the
+ name B had nothing to do with BCPL. B was in fact a revision
+ of an earlier language, {bon}, named after Ken Thompson's
+ wife, Bonnie.
+
+ ["The Programming Language B", S.C. Johnson & B.W. Kernighan,
+ CS TR 8, Bell Labs (Jan 1973)].
+
+ [Features? Differences from C?]
+
+ (1997-02-02)
+
+ 3. <language> A simple {interactive} {programming language}
+ designed by {Lambert Meertens} and {Steven Pemberton}. B was
+ the predecessor of {ABC}. B was the first published (and
+ implemented) language to use indentation for block structure.
+
+ {(ftp://ftp.uni-kl.de/pub/languages/B.tar.Z)}.
+
+ ["Draft Proposal for the B Language", Lambert Meertens, CWI,
+ Amsterdam, 1981].
+
+ [{(http://python-history.blogspot.com/2011/07/karin-dewar-indentation-and-colon.html)}].
+
+ 4. <language, specification> A specification language by
+ Jean-Raymond Abrial of {B Core UK}, Magdalen Centre, Oxford
+ Science Park, Oxford OX4 4GA. B is related to {Z} and
+ supports development of {C} code from specifications. B has
+ been used in major {safety-critical system} specifications in
+ Europe, and is currently attracting increasing interest in
+ industry. It has robust, commercially available tool support
+ for specification, design, proof and code generation.
+
+ E-mail: <Ib.Sorensen@comlab.ox.ac.uk>.
+
+ (1995-04-24)
+
+b
+
+ {bit} or maybe {byte} (B).
+
+ (1996-11-03)
+
+B-0
+
+ <language> The original name of {FLOW-MATIC} from {Remington
+ Rand}. B-0 was used on the {UNIVAC} I or II about 1958.
+
+ (1997-01-09)
+
+B1FF
+
+ {BIFF}
+
+B1 security
+
+ {Orange Book}
+
+B2B
+
+ {business to business}
+
+B2 security
+
+ {Orange Book}
+
+B3 security
+
+ {Orange Book}
+
+b4
+
+ <chat> before.
+
+ba
+
+ <networking> The {country code} for Bosnia and Herzegowina.
+
+ (1999-01-27)
+
+Baan
+
+ <company> A provider of {enterprise resource planning} and
+ {manufacturer resource planning} software.
+
+ {(http://baan.com/)}.
+
+ (1998-07-07)
+
+Babbage
+
+ <language> The structured {assembly language} for the {General
+ Electric Company} 4xxx range of computers and their {OS4000}
+ {operating system}. It is strictly an assembler in that the
+ generated code is relatively predictable but it can be written
+ in a sufficiently structured manner, with indentation, control
+ statements, function and procedure calls, to make the
+ resultant source easy to read and manage. Even with this
+ visible structure however, it is important to remember that
+ the assembly of the statement is done left to right.
+
+ The British {videotext} system, {Prestel} is programmed in
+ Babbage.
+
+ [Datamation, 1980s].
+
+ (2007-10-24)
+
+Babbage, Charles
+
+ {Charles Babbage}
+
+babbling error
+
+ <networking> An {Ethernet} node attempting to transmit more
+ than 1518 data bytes - the largest allowed Ethernet {packet}.
+ This is why the {Maximum Transmission Unit} for {IP} traffic
+ on Ethernet is 1500.
+
+ [Why 1518?]
+
+ (1998-03-13)
+
+BABEL
+
+ 1. A subset of {ALGOL 60}, with many {ALGOL W} extensions.
+
+ ["BABEL, A New Programming Language", R.S. Scowen, Natl Phys
+ Lab UK, Report CCU7, 1969].
+
+ 2. Mentioned in The Psychology of Computer Programming,
+ G.M. Weinberg, Van Nostrand 1971, p.241.
+
+ 3. A language based on {higher-order functions} and
+ {first-order logic}.
+
+ ["Graph-Based Implementation of a Functional Logic Language",
+ H. Kuchen et al, Proc ESOP 90, LNCS 432, Springer 1990,
+ pp.271-290].
+
+ ["Logic Programming with Functions and Predicates: The
+ Language BABEL", Moreno-Navarro et al, J Logic Prog 12(3) (Feb
+ 1992)].
+
+ (1994-11-28)
+
+BABT
+
+ {British Approval Boards for Telecommunications}
+
+Baby AT
+
+ <hardware> The redesigned {AT} motherboard that had the same
+ size as the {XT} motherboard had (8.5" x 11") and could thus
+ fit into an XT case. The original 12" x 13" AT motherboards
+ are now largely forgotten.
+
+ Compare {ATX}.
+
+ (1997-02-20)
+
+BABYLON
+
+ A development environment for {expert systems}. It includes
+ {frames}, {constraints}, a {prolog}-like logic formalism, and
+ a description language for diagnostic applications. It
+ requires {Common Lisp}.
+
+ {(ftp://ftp.gmd.de/gmd/ai-research/Software/)}.
+
+ (1995-02-08)
+
+BACAIC
+
+ Boeing Airplane Company Algebraic Interpreter Coding system.
+
+ A pre-{Fortran} system on the {IBM 701} and {IBM 650}.
+
+ (1995-02-08)
+
+Bachman
+
+ A proposed a style of {Entity-Relationship model} which
+ differs from Chen's.
+
+ (1995-02-08)
+
+Bachman Information Systems
+
+ <company> The company which merged with {CADRE} to form
+ {Cayenne Software} in July 1996.
+
+ (1998-02-06)
+
+backbone
+
+ <networking> The top level in a hierarchical {network}. {Stub
+ networks} and {transit networks} which connect to the same
+ backbone are guaranteed to be interconnected.
+
+ See also: {Internet backbone}.
+
+ (1998-07-02)
+
+backbone cabal
+
+ <networking> A group of large-site administrators who pushed
+ through the {Great Renaming} and reined in the chaos of
+ {Usenet} during most of the 1980s. The cabal {mailing list}
+ disbanded in late 1988 after a bitter internal cat-fight.
+
+ [{Jargon File}]
+
+ (1994-11-28)
+
+backbone site
+
+ A key {Usenet}, {electronic mail} and/or {Internet} site; one
+ that processes a large amount of third-party traffic,
+ especially if it is the home site of any of the regional
+ coordinators for the {Usenet} maps. Notable backbone sites as
+ of early 1993 include {uunet} and the mail machines at
+ {Rutgers University}, UC Berkeley, {DEC}'s Western Research
+ Laboratories, {Ohio State University} and the {University of
+ Texas}.
+
+ Compare {rib site}, {leaf site}.
+
+ [{Jargon File}]
+
+ (1994-11-28)
+
+back door
+
+ <security> (Or "{trap door}", "{wormhole}"). A hole in the
+ security of a system deliberately left in place by designers
+ or maintainers. The motivation for such holes is not always
+ sinister; some {operating systems}, for example, come out of
+ the box with privileged accounts intended for use by field
+ service technicians or the vendor's maintenance programmers.
+ See also {iron box}, {cracker}, {worm}, {logic bomb}.
+
+ Historically, back doors have often lurked in systems longer
+ than anyone expected or planned, and a few have become widely
+ known. The infamous {RTM} worm of late 1988, for example,
+ used a back door in the {BSD} Unix "sendmail(8)" {utility}.
+
+ {Ken Thompson}'s 1983 Turing Award lecture to the {ACM}
+ revealed the existence of a back door in early {Unix} versions
+ that may have qualified as the most fiendishly clever security
+ hack of all time. The C compiler contained code that would
+ recognise when the "login" command was being recompiled and
+ insert some code recognizing a password chosen by Thompson,
+ giving him entry to the system whether or not an account had
+ been created for him.
+
+ Normally such a back door could be removed by removing it from
+ the source code for the compiler and recompiling the compiler.
+ But to recompile the compiler, you have to *use* the compiler
+ - so Thompson also arranged that the compiler would *recognise
+ when it was compiling a version of itself*, and insert into
+ the recompiled compiler the code to insert into the recompiled
+ "login" the code to allow Thompson entry - and, of course, the
+ code to recognise itself and do the whole thing again the next
+ time around! And having done this once, he was then able to
+ recompile the compiler from the original sources; the hack
+ perpetuated itself invisibly, leaving the back door in place
+ and active but with no trace in the sources.
+
+ The talk that revealed this truly moby hack was published as
+ ["Reflections on Trusting Trust", "Communications of the ACM
+ 27", 8 (August 1984), pp. 761--763].
+
+ [{Jargon File}]
+
+ (1995-04-25)
+
+back-end
+
+ <programming> Any software performing either the final stage
+ in a process, or a task not apparent to the user. A common
+ usage is in a {compiler}. A compiler's back-end generates
+ {machine language} and performs optimisations specific to the
+ machine's {architecture}.
+
+ The term can also be used in the context of {network}
+ applications. E.g. "The back-end of the system handles
+ {socket} protocols".
+
+ Contrast {front end}.
+
+ (1996-04-09)
+
+Back End Generator
+
+ <tool> (BEG) A {code generator} developed by H. Emmelmann et
+ al at GMD, University Karlsruhe, Germany. Its input language
+ is Back End Generator Language (BEGL).
+
+ {(ftp://gatekeeper.dec.com/pub/gmd/cocktail/beg)}.
+
+ ["BEG - A Generator for Efficient Back Ends", H. Emmelmann et
+ al, SIGPLAN Notices 24(7):227-237 (Jul 1989)].
+
+ ["BEG - A Back End Generator - User Manual", H. Emmelmann,
+ GMD, U Karlsruhe, 1990].
+
+ [Summary?]
+
+ (2000-12-16)
+
+Back End Generator Language
+
+ {Back End Generator}
+
+backgammon
+
+ See {bignum}, {moby}, {pseudoprime}.
+
+ [{Jargon File}]
+
+background
+
+ 1. <operating system> A task running in the background (a
+ background task) is detached from the terminal where it was
+ started (and often running at a lower priority); opposite of
+ {foreground}. This means that the task's input and output
+ must be from/to files (or other processes).
+
+ Nowadays this term is primarily associated with {Unix}, but it
+ appears to have been first used in this sense on {OS/360}.
+
+ Compare {amp off}, {batch}, {slopsucker}.
+
+ 2. <jargon> For a human to do a task "in the background" is to
+ do it whenever {foreground} matters are not claiming your
+ undivided attention, and "to background" something means to
+ relegate it to a lower priority. "For now, we'll just print a
+ list of nodes and links; I'm working on the graph-printing
+ problem in the background." Note that this implies ongoing
+ activity but at a reduced level or in spare time, in contrast
+ to mainstream "back burner" (which connotes benign neglect
+ until some future resumption of activity). Some people prefer
+ to use the term for processing that they have queued up for
+ their unconscious minds (often a fruitful tack to take upon
+ encountering an obstacle in creative work).
+
+ (1996-05-28)
+
+backing store
+
+ 1. <storage> Computer memory, usually {magnetic disks},
+ storing data and programs. Sections of this information can
+ then be copied into the main memory ({RAM}) for processing.
+ Backing store is cheaper but RAM is faster. Such a hierarchy
+ of memory devices allows a trade-off between performance and
+ cost.
+
+ 2. <text> Character storage in memory or on disk, as opposed
+ to displayed or printed characters. This distinction is
+ important where the visual ordering of characters differs from
+ the order in which they are stored, e.g. bidirectional or
+ non-spacing layout.
+
+ In a {Unicode} encoding, text is stored in sequential order in
+ the backing store. Logical or backing store order corresponds
+ to the order in which text is typed on the keyboard (after
+ corrections such as insertions, deletions, and overtyping). A
+ text rendering process converts Unicode text in the backing
+ store to readable text.
+
+ ["The Unicode Standard: Worldwide Character Encoding", Version
+ 1.0, Vol. 1. Addison-Wesley, 1991].
+
+ (2001-02-25)
+
+back link
+
+ <hypertext> A {link} in one direction implied by the existence
+ of an explicit link in the other direction.
+
+ (1996-05-28)
+
+backoff
+
+ <networking> A {host} which has experienced a {collision} on a
+ {network} waits for a amount of time before attempting to
+ retransmit. A random backoff minimises the probability that
+ the same nodes will collide again, even if they are using the
+ same backoff algorithm. Increasing the backoff period after
+ each collision also helps to prevent repeated collisions,
+ especially when the network is heavily loaded.
+
+ An example algorithm is {binary exponential backoff}.
+
+ (1996-05-28)
+
+BackOffice
+
+ <software> A suite of network {server} software from
+ {Microsoft} that includes {Windows NT} Server, BackOffice
+ Server (for the integrated development, deployment, and
+ management of BackOffice applications in departments, branch
+ offices, and medium sized businesses); {Exchange Server};
+ {Proxy Server}; {Site Server} for {intranet} publishing,
+ management, and search; Site Server Commerce Edition For
+ comprehensive {Internet commerce} transactions; {Small
+ Business Server} for business operations, resource management,
+ and customer relations; {SNA Server} for the integration of
+ existing and new systems and data; {SQL Server} for scalable,
+ reliable database and data-warehousing; {Systems Management
+ Server} (SMS) for centralised change- and
+ {configuration-management}.
+
+ Latest version: 4.5, as of 2000-12-16.
+
+ {(http://microsoft.com/backofficeserver/)}.
+
+ (2000-12-16)
+
+backplane
+
+ <hardware, electronics> A {printed circuit board} with slots
+ into which other cards are plugged.
+
+ A backplane,is typically just a connector and does not usually
+ have many active components on it. This contrasts with a
+ {motherboard}.
+
+ {Designing a backplane
+ (http://iec.org/online/tutorials/design_backplane/index.html)}.
+
+ (2002-09-08)
+
+backport
+
+ <software> To make a feature from a later version of a piece
+ of software available in an earlier version. Backporting of
+ features enables users of the older version to benefit from a
+ feature without upgrading fully.
+
+ (2003-12-18)
+
+back-propagation
+
+ (Or "backpropagation") A learning {algorithm} for modifying a
+ {feed-forward} {neural network} which minimises a continuous
+ "{error function}" or "{objective function}."
+ Back-propagation is a "{gradient descent}" method of training
+ in that it uses gradient information to modify the network
+ weights to decrease the value of the error function on
+ subsequent tests of the inputs. Other gradient-based methods
+ from {numerical analysis} can be used to train networks more
+ efficiently.
+
+ Back-propagation makes use of a mathematical trick when the
+ network is simulated on a digital computer, yielding in just
+ two traversals of the network (once forward, and once back)
+ both the difference between the desired and actual output, and
+ the derivatives of this difference with respect to the
+ connection weights.
+
+back quote
+
+ <character> "`" {ASCII} code 96. Common names: left quote;
+ left single quote; open quote; {ITU-T}: grave accent; grave.
+ Rare: backprime; {INTERCAL}: backspark; unapostrophe; birk;
+ blugle; back tick; back glitch; push; {ITU-T}: opening single
+ quotation mark; quasiquote.
+
+ Back quote is used in {Unix} shells to invoke {command
+ substitution}.
+
+ (1996-11-26)
+
+backronym
+
+ <jargon> (Backward acronym) A word which has been turned into
+ an acronym by inventing an expansion, rather than the other
+ way around. E.g. "{ping}".
+
+ (2005-06-22)
+
+backside cache
+
+ <hardware, processor> An implementation of {secondary cache}
+ memory that allows it to be directly accessed by the {CPU}.
+
+ Backside cache is used by {Apple Computers, Inc.} in their
+ {PowerPC G3} processor. Previous PowerPC processors used the
+ {system bus} to access both secondary cache and {main memory}.
+ In the PowerPC G3 a dedicated bus handles only {CPU}/cache
+ transactions. This bus can operate faster than the system bus
+ thus improving the overall performance of the processor.
+
+ The term apparently derives from the relocation of the
+ secondary cache from the {motherboard} to the processor card
+ itself, i.e. on the backside of the processor card.
+
+ (1998-09-10)
+
+backslash
+
+ <character> "\" {ASCII} code 92. Common names: escape (from
+ C/Unix); reverse slash; slosh; backslant; backwhack. Rare:
+ bash; {ITU-T}: reverse slant; reversed virgule; {INTERCAL}:
+ backslat.
+
+ Backslash is used to separate components in {MS-DOS}
+ {pathnames}, and to introduce special character sequence in
+ {C} and {Unix} strings, e.g. "\n" for newline.
+
+ (2000-02-21)
+
+backspace
+
+ <character> (BS) {ASCII} code 8, Control-H. The {control
+ character} that should cause most output devices to move their
+ current output position back to the previous character so that
+ the next character output will replace (or overprint) it.
+ Inputting a backspace (typically by pressing the backspace
+ key) causes many systems to delete the character before the
+ input cursor, though others use {delete} for this.
+
+ See {twirling baton} for an imaginitive use of backspace.
+
+ (2003-10-25)
+
+backtick
+
+ {back quote}
+
+backtracking
+
+ <algorithm> A scheme for solving a series of sub-problems each
+ of which may have multiple possible solutions and where the
+ solution chosen for one sub-problem may affect the possible
+ solutions of later sub-problems.
+
+ To solve the overall problem, we find a solution to the first
+ sub-problem and then attempt to recursively solve the other
+ sub-problems based on this first solution. If we cannot, or
+ we want all possible solutions, we backtrack and try the next
+ possible solution to the first sub-problem and so on.
+ Backtracking terminates when there are no more solutions to
+ the first sub-problem.
+
+ This is the algorithm used by {logic programming} languages
+ such as {Prolog} to find all possible ways of proving a
+ {goal}. An optimisation known as "{intelligent backtracking}"
+ keeps track of the dependencies between sub-problems and only
+ re-solves those which depend on an earlier solution which has
+ changed.
+
+ Backtracking is one {algorithm} which can be used to implement
+ {nondeterminism}. It is effectively a {depth-first search} of
+ a {problem space}.
+
+ (1995-04-13)
+
+backup
+
+ <operating system> ("back up" when used as a verb) A spare
+ copy of a file, file system, or other resource for use in the
+ event of failure or loss of the original.
+
+ The term commonly refers to a copy of the files on a
+ computer's {disks}, made periodically and kept on {magnetic
+ tape} or other removable medium (also called a "{dump}").
+
+ This essential precaution is neglected by most new computer
+ users until the first time they experience a {disk crash} or
+ accidentally delete the only copy of the file they have been
+ working on for the last six months. Ideally the backup copies
+ should be kept at a different site or in a fire safe since,
+ though your hardware may be insured against fire, the data on
+ it is almost certainly neither insured nor easily replaced.
+
+ See also {backup software}, {differential backup},
+ {incremental backup}, {full backup}. Compare {archive},
+ {source code management}.
+
+ (2004-03-16)
+
+Backup Domain Controller
+
+ <networking> (BDC) A server in a {network} of {Microsoft
+ Windows} computers that maintains a copy of the {SAM} database
+ and handles access requests that the {Primary Domain
+ Controller} (PDC) doesn't respond to. There may be zero or
+ more BDCs in a network. They increase reliability and reduce
+ load on the PDC.
+
+ (2006-09-18)
+
+backup pumpkin
+
+ {pumpkin}
+
+backup rotation
+
+ <operating system> Any system for re-using {backup} media,
+ e.g. {magnetic tape}. One extreme would be to use the same
+ media for every backup (e.g. copy disk A to disk B), the other
+ extreme would be to use new media every time. The trade-off
+ is between the cost of buying and storing media and the
+ ability to restore any version of any file. One example is
+ the {Grandfather, Father, Son} (GFS) scheme.
+
+ (2004-10-08)
+
+backup software
+
+ <tool, software> {Software} for doing a {backup}, often
+ included as part of the {operating system}.
+
+ Backup software should provide ways to specify what files get
+ backed up and to where. It may include its own {scheduling}
+ function to automate the procedure or, preferably, work with
+ generic scheduling facilities. It may include facilities for
+ managing the backup media (e.g. maintaining an index of tapes)
+ and for restoring files from backups.
+
+ Examples are {Unix}'s {dump} command and {Windows}'s
+ {ntbackup}.
+
+ (2004-03-16)
+
+Backus-Naur Form
+
+ <language, grammar> (BNF, originally "Backus Normal Form") A
+ formal {metasyntax} used to express {context-free grammars}.
+ Backus Normal Form was renamed Backus-Naur Form at the
+ suggestion of {Donald Knuth}.
+
+ BNF is one of the most commonly used metasyntactic notations
+ for specifying the {syntax} of programming languages, command
+ sets, and the like. It is widely used for language
+ descriptions but seldom documented anywhere (how do you
+ document a {metasyntax}?), so that it must usually be learned
+ by osmosis (but see {RFC 2234}).
+
+ Consider this BNF for a US postal address:
+
+ <postal-address> ::= <name-part> <street-address> <zip-part>
+
+ <personal-part> ::= <name> | <initial> "."
+
+ <name-part> ::= <personal-part> <last-name> [<jr-part>] <EOL>
+ | <personal-part> <name-part>
+
+ <street-address> ::= [<apt>] <house-num> <street-name> <EOL>
+
+ <zip-part> ::= <town-name> "," <state-code> <ZIP-code> <EOL>
+
+ This translates into English as: "A postal-address consists of
+ a name-part, followed by a street-address part, followed by a
+ zip-code part. A personal-part consists of either a first
+ name or an initial followed by a dot. A name-part consists of
+ either: a personal-part followed by a last name followed by an
+ optional "jr-part" (Jr., Sr., or dynastic number) and
+ end-of-line, or a personal part followed by a name part (this
+ rule illustrates the use of recursion in BNFs, covering the
+ case of people who use multiple first and middle names and/or
+ initials). A street address consists of an optional apartment
+ specifier, followed by a street number, followed by a street
+ name. A zip-part consists of a town-name, followed by a
+ comma, followed by a state code, followed by a ZIP-code
+ followed by an end-of-line."
+
+ Note that many things (such as the format of a personal-part,
+ apartment specifier, or ZIP-code) are left unspecified. These
+ lexical details are presumed to be obvious from context or
+ specified somewhere nearby.
+
+ There are many variants and extensions of BNF, possibly
+ containing some or all of the {regexp} {wild cards} such as
+ "*" or "+". {EBNF} is a common one. In fact the example
+ above isn't the pure form invented for the {ALGOL 60} report.
+ "[]" was introduced a few years later in {IBM}'s {PL/I}
+ definition but is now universally recognised. {ABNF} is
+ another extension.
+
+ (1997-11-23)
+
+Backus Normal Form
+
+ {Backus-Naur Form}
+
+backward analysis
+
+ <theory> An analysis to determine properties of the inputs of
+ a program from properties or context of the outputs. E.g. if
+ the output of this function is needed then this argument is
+ needed.
+
+ Compare {forward analysis}.
+
+ (1997-11-23)
+
+backward chaining
+
+ <algorithm> An {algorithm} for proving a {goal} by recursively
+ breaking it down into sub-goals and trying to prove these
+ until {facts} are reached. Facts are goals with no sub-goals
+ which are therefore always true. Backward training is the
+ program execution mechanism used by most {logic programming}
+ language like {Prolog}.
+
+ Opposite: {forward chaining}.
+
+ (2004-01-26)
+
+backward combatability
+
+ <humour> /bak'w*d k*m-bat'*-bil'*-tee/ (Play on "{backward
+ compatibility}") A property of hardware or software revisions
+ in which previous {protocols}, formats, layouts, etc. are
+ irrevocably discarded in favour of "new and improved"
+ protocols, formats and layouts, leaving the previous ones not
+ merely deprecated but actively defeated. (Too often, the old
+ and new versions cannot definitively be distinguished, such
+ that lingering instances of the previous ones yield crashes or
+ other infelicitous effects, as opposed to a simple "version
+ mismatch" message.) A backward compatible change, on the
+ other hand, allows old versions to coexist without crashes or
+ error messages, but too many major changes incorporating
+ elaborate backward compatibility processing can lead to
+ extreme {software bloat}.
+
+ See also {flag day}.
+
+ [{Jargon File}]
+
+ (2003-06-23)
+
+backward compatibility
+
+ <jargon> Able to share data or commands with older versions of
+ itself, or sometimes other older systems, particularly systems
+ it intends to supplant. Sometimes backward compatibility is
+ limited to being able to read old data but does not extend to
+ being able to write data in a format that can be read by old
+ versions.
+
+ For example, {WordPerfect} 6.0 can read WordPerfect 5.1 files,
+ so it is backward compatible. It can be said that {Perl} is
+ backward compatible with {awk}, because Perl was (among other
+ things) intended to replace awk, and can, with a converter,
+ run awk programs.
+
+ See also: {backward combatability}.
+
+ Compare: {forward compatible}.
+
+ (2003-06-23)
+
+backward compatible
+
+ {backward compatibility}
+
+backwards compatibility
+
+ {backward compatibility}
+
+backwards compatible
+
+ {backward compatibility}
+
+BAD
+
+ /B-A-D/ Broken As Designed, a play on "{working as designed}",
+ from {IBM}. Failing because of bad design and misfeatures
+ rather than because of bugs.
+
+ [{Jargon File}]
+
+ (2002-04-14)
+
+Bad command or file name
+
+ <operating system> The error message printed by {MS DOS} when
+ it can't find a program or command to execute due to a typing
+ error, incorrect PATH variable, or misplaced or missing
+ executable.
+
+ (1996-04-07)
+
+Bad Thing
+
+ <jargon> (From the 1930 Sellar & Yeatman parody "1066 And All
+ That") Something that can't possibly result in improvement of
+ the subject. This term is always capitalised, as in
+ "Replacing all of the 9600-baud modems with bicycle couriers
+ would be a Bad Thing".
+
+ Opposite: {Good Thing}.
+
+ British correspondents confirm that {Bad Thing} and {Good
+ Thing} (and probably therefore {Right Thing} and {Wrong
+ Thing}) come from the book referenced in the etymology, which
+ discusses rulers who were Good Kings but Bad Things. This has
+ apparently created a mainstream idiom on the British side of
+ the pond.
+
+ [{Jargon File}]
+
+bag on the side
+
+ An extension to an established hack that is supposed to add
+ some functionality to the original. Usually derogatory,
+ implying that the original was being overextended and should
+ have been thrown away, and the new product is ugly, inelegant,
+ or bloated. Also "to hang a bag on the side [of]". "C++?
+ That's just a bag on the side of C." "They want me to hang a
+ bag on the side of the accounting system."
+
+baklava code
+
+ <humour, programming> Code with too many layers. Also known as
+ Lasagne Code.
+
+ [john-d-cook, {Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2013-09-14)
+
+BAL
+
+ {Basic Assembly Language}
+
+balanced computing
+
+ <jargon> Matching computer tools to job activities so that the
+ computer system structure parallels the organisation structure
+ and work functions. Both {personal computers} and employees
+ operate in a decentralised environment with monitoring of
+ achievement of management objectives from centralised
+ corporate systems.
+
+ {(http://moultonco.com/balanced.htm)}.
+
+ (1996-04-15)
+
+balanced tree
+
+ <algorithm> An optimisation of a {tree} which aims to keep
+ equal numbers of items on each {subtree} of each node so as to
+ minimise the maximum path from the root to any {leaf node}.
+ As items are inserted and deleted, the tree is restructured to
+ keep the nodes balanced and the search paths uniform. Such an
+ {algorithm} is appropriate where the overheads of the
+ reorganisation on update are outweighed by the benefits of
+ faster search.
+
+ A {B-tree} is a kind of {balanced tree} that can have more
+ than two subtrees at each node (i.e. one that is not
+ restricted to being a {binary tree}).
+
+ (2000-01-10)
+
+BALGOL
+
+ <language> {ALGOL} on {Burroughs 220}.
+
+ [Sammet 1969, p. 174].
+
+ (1996-04-15)
+
+BALITAC
+
+ Early system on IBM 650. Listed in CACM 2(5):16 (May 1959).
+
+BALM
+
+ <language> (Block And List Manipulation) An extensible
+ language, developed by Malcolm Harrison in 1970, with
+ {LISP}-like features and {ALGOL}-like {syntax}, for {CDC
+ 6600}.
+
+ ["The Balm Programming Language", Malcolm Harrison, Courant
+ Inst, May 1973].
+
+ (2007-03-01)
+
+balun
+
+ <electronics> A transformer connected between a balanced
+ source or load and an unbalanced source or load. A balanced
+ line has two conductors, with equal currents in opposite
+ directions. The unbalanced line has just one conductor; the
+ current in it returns via a common ground or earth path.
+
+ (1996-10-17)
+
+bamf
+
+ /bamf/ 1. [Old X-Men comics] Notional sound made by a person
+ or object teleporting in or out of the hearer's vicinity.
+ Often used in {virtual reality} (especially {MUD}) electronic
+ {fora} when a character wishes to make a dramatic entrance or
+ exit.
+
+ 2. The sound of magical transformation, used in virtual
+ reality {fora}.
+
+ [{Jargon File}]
+
+Banach algebra
+
+ <mathematics> An {algebra} in which the {vector space} is a
+ {Banach space}.
+
+ (1997-02-25)
+
+Banach inverse mapping theorem
+
+ <mathematics> In a {Banach space} the inverse to a
+ {continuous} {linear mapping} is continuous.
+
+ (1998-06-25)
+
+Banach space
+
+ <mathematics> A {complete} {normed} {vector space}. Metric is
+ induced by the norm: d(x,y) = ||x-y||. Completeness means
+ that every {Cauchy sequence} converges to an element of the
+ space. All finite-dimensional {real} and {complex} normed
+ vector spaces are complete and thus are Banach spaces.
+
+ Using absolute value for the norm, the real numbers are a
+ Banach space whereas the rationals are not. This is because
+ there are sequences of rationals that converges to
+ irrationals.
+
+ Several theorems hold only in Banach spaces, e.g. the {Banach
+ inverse mapping theorem}. All finite-dimensional real and
+ complex vector spaces are Banach spaces. {Hilbert spaces},
+ spaces of {integrable functions}, and spaces of {absolutely
+ convergent series} are examples of infinite-dimensional Banach
+ spaces. Applications include {wavelets}, {signal processing},
+ and radar.
+
+ [Robert E. Megginson, "An Introduction to Banach Space
+ Theory", Graduate Texts in Mathematics, 183, Springer Verlag,
+ September 1998].
+
+ (2000-03-10)
+
+Banach-Tarski paradox
+
+ <mathematics> It is possible to cut a solid ball into finitely
+ many pieces (actually about half a dozen), and then put the
+ pieces together again to get two solid balls, each the same
+ size as the original.
+
+ This {paradox} is a consequence of the {Axiom of Choice}.
+
+ (1995-03-29)
+
+banana label
+
+ <jargon> The labels used on the sides of {macrotape} reels, so
+ called because they were shaped roughly like blunt-ended
+ bananas. This term, like macrotapes themselves, is obsolete.
+
+ [{Jargon File}]
+
+ (2007-10-17)
+
+banana phenomenon
+
+ {banana problem}
+
+banana problem
+
+ <programming, humour> From the story of the little girl who
+ said "I know how to spell "banana", but I don't know when to
+ stop". Not knowing where or when to bring a production to a
+ close (compare {fencepost error}). One may say "there is a
+ banana problem" of an {algorithm} with poorly defined or
+ incorrect termination conditions, or in discussing the
+ evolution of a design that may be succumbing to {featuritis}
+ (see also {creeping elegance}, {creeping featuritis}).
+
+ {HAKMEM} item 176 describes a banana problem in a {Dissociated
+ Press} implementation. Also, see {one-banana problem} for a
+ superficially similar but unrelated usage.
+
+ (2010-03-20)
+
+bandwidth
+
+ <communications> The difference between the highest and lowest
+ frequencies of a transmission channel (the width of its
+ allocated band of frequencies).
+
+ The term is often used erroneously to mean {data rate} or
+ capacity - the amount of {data} that is, or can be, sent
+ through a given communications circuit per second.
+
+ [How is data capacity related to bandwidth?]
+
+ [{Jargon File}]
+
+ (2001-04-24)
+
+bang
+
+ 1. A common spoken name for "!" (ASCII 33), especially when
+ used in pronouncing a {bang path} in spoken hackish. In
+ {elder days} this was considered a {CMU}ish usage, with {MIT}
+ and {Stanford} hackers preferring {excl} or {shriek}; but the
+ spread of {Unix} has carried "bang" with it (especially via
+ the term {bang path}) and it is now certainly the most common
+ spoken name for "!". Note that it is used exclusively for
+ non-emphatic written "!"; one would not say "Congratulations
+ bang" (except possibly for humorous purposes), but if one
+ wanted to specify the exact characters "foo!" one would speak
+ "Eff oh oh bang".
+
+ See {pling}, {shriek}, {ASCII}.
+
+ 2. An exclamation signifying roughly "I have achieved
+ enlightenment!", or "The dynamite has cleared out my brain!"
+ Often used to acknowledge that one has perpetrated a {thinko}
+ immediately after one has been called on it.
+
+ [{Jargon File}]
+
+ (1995-01-31)
+
+bang on
+
+ (Or "pound on"). To stress-test a piece of hardware or
+ software: "I banged on the new version of the simulator all
+ day yesterday and it didn't crash once. I guess it is ready
+ for release."
+
+ [{Jargon File}]
+
+bang path
+
+ 1. <communications> An old-style {UUCP} {electronic-mail
+ address} naming a sequence of hosts through which a message
+ must pass to get from some assumed-reachable location to the
+ addressee (a "{source route}"). So called because each {hop}
+ is signified by a {bang} sign (exclamation mark). Thus, for
+ example, the path
+
+ ...!bigsite!foovax!barbox!me
+
+ directs people to route their mail to computer bigsite
+ (presumably a well-known location accessible to everybody) and
+ from there through the computer foovax to the account of user
+ me on barbox.
+
+ Before {autorouting mailers} became commonplace, people often
+ published compound bang addresses using the { } convention
+ (see {glob}) to give paths from *several* big computers, in
+ the hope that one's correspondent might be able to get mail to
+ one of them reliably. e.g.
+
+ ...!{seismo, ut-sally, ihnp4}!rice!beta!gamma!me
+
+ Bang paths of 8 to 10 hops were not uncommon in 1981.
+ Late-night dial-up UUCP links would cause week-long
+ transmission times. Bang paths were often selected by both
+ transmission time and reliability, as messages would often get
+ lost.
+
+ 2. <operating system> A {shebang}.
+
+ (1998-05-06)
+
+banner
+
+ 1. The title page added to printouts by most {print spoolers}.
+ Typically includes user or account ID information in very
+ large character-graphics capitals. Also called a "burst
+ page", because it indicates where to burst (tear apart)
+ fanfold paper to separate one user's printout from the next.
+
+ 2. A similar printout generated (typically on multiple pages
+ of fan-fold paper) from user-specified text, e.g. by a program
+ such as {Unix}'s "banner".
+
+ 3. {splash screen}.
+
+ [{Jargon File}]
+
+ (1994-11-28)
+
+Banyan
+
+ <company> A {personal computer} networking company, best known
+ for its "{Vines}" products for {local area networks}.
+
+ Address: Westborough MA, USA.
+
+ [More info?]
+
+ (1995-03-01)
+
+BAP
+
+ 1. <language> An early system used on the {IBM 701}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1994-11-28)
+
+ 2. <language> {Brain Aid Prolog}.
+
+ (1995-03-07)
+
+BAPI
+
+ {Business Application Programming Interface}
+
+bar
+
+ 1. <programming, convention> /bar/ The second {metasyntactic
+ variable}, after {foo} and before {baz}. E.g. "Suppose
+ function FOO calls functions BAR..."
+
+ 2. Often appended to {foo} to produce {foobar}.
+
+ [{Jargon File}]
+
+ (1995-03-07)
+
+Barbara Liskov
+
+ <person> Professor Barbara Liskov was the first US woman to be
+ awarded a PhD in computing, and her innovations can be found
+ in every modern programming language. She currently (2009)
+ heads the Programming Methodology Group at the {Massachusetts
+ Institute of Technology}.
+
+ Professor Liskov's design innovations have, over the decades,
+ made software more reliable and easier to maintain. She has
+ invented two computer progamming languages: {CLU}, an
+ {object-orientated language}, and {Argus}, a {distributed
+ programming language}. Liskov's research forms the basis of
+ modern programming languages such as {Java}, {C#} and {C++}.
+
+ One of the biggest impacts of her work came from her
+ contributions to the use of data abstraction, a method for
+ organising complex programs. See {Liskov substitution
+ principle}.
+
+ In June 2009 she will receive the {A. M. Turing Award}.
+
+ {Barbara Liskov home (http://www.pmg.csail.mit.edu/~liskov/)}.
+
+ (2009-03-11)
+
+bar code
+
+ <convention> A printed horizontal strip of vertical bars of
+ varying widths, groups of which represent decimal digits and
+ are used for identifying commercial products or parts. Bar
+ codes are read by a bar code reader and the code interpreted
+ either through {software} or a {hardware} decoder.
+
+ All products sold in open trade are numbered and bar-coded to
+ a worldwide standard, which was introduced in the US in 1973
+ and to the rest of the world in 1977. The Uniform Code
+ Council in the US, along with the international article
+ numbering authority, EAN International, allocate blocks of
+ unique 12 or 13-digit numbers to member companies through a
+ national numbering authority. In Britain this is the Article
+ Number Association. Most companies are allocated 100,000
+ numbers that they can use to identify any of their products,
+ services or locations.
+
+ Each code typically contains a leading "quiet" zone, start
+ character, data character, optional {check digit}, stop
+ character and a trailing quiet zone. The check digit is used
+ to verify that the number has been scanned correctly. The
+ quiet zone could be white, red or yellow if viewed by a red
+ scanner. Bar code readers usually use visible red light with
+ a wavelength between 632.8 and 680 nanometres.
+
+ [Details of code?]
+
+ (1997-07-18)
+
+bare metal
+
+ 1. New computer hardware, unadorned with such snares and
+ delusions as an {operating system}, an {HLL}, or even
+ {assembler}. Commonly used in the phrase "programming on the
+ bare metal", which refers to the arduous work of {bit bashing}
+ needed to create these basic tools for a new computer. Real
+ bare-metal programming involves things like building {boot
+ PROMs} and {BIOS} chips, implementing basic {monitors} used to
+ test {device drivers}, and writing the assemblers that will be
+ used to write the compiler back ends that will give the new
+ computer a real development environment.
+
+ 2. "Programming on the bare metal" is also used to describe a
+ style of {hand-hacking} that relies on bit-level peculiarities
+ of a particular hardware design, especially tricks for speed
+ and space optimisation that rely on crocks such as overlapping
+ instructions (or, as in the famous case described in {The
+ Story of Mel}, interleaving of opcodes on a magnetic drum to
+ minimise fetch delays due to the device's rotational latency).
+ This sort of thing has become less common as the relative
+ costs of programming time and computer resources have changed,
+ but is still found in heavily constrained environments such as
+ industrial embedded systems, and in the code of hackers who
+ just can't let go of that low-level control. See {Real
+ Programmer}.
+
+ In the world of personal computing, bare metal programming is
+ often considered a {Good Thing}, or at least a necessary evil
+ (because these computers have often been sufficiently slow and
+ poorly designed to make it necessary; see {ill-behaved}).
+ There, the term usually refers to bypassing the BIOS or OS
+ interface and writing the application to directly access
+ device registers and computer addresses. "To get 19.2
+ kilobaud on the serial port, you need to get down to the bare
+ metal." People who can do this sort of thing well are held in
+ high regard.
+
+ [{Jargon File}]
+
+barf
+
+ /barf/ [mainstream slang for "vomit"] 1. Term of disgust.
+ This is the closest hackish equivalent of the Val\-speak "gag
+ me with a spoon". (Like, euwww!) See {bletch}.
+
+ 2. To say "Barf!" or emit some similar expression of disgust.
+ "I showed him my latest hack and he barfed" means only that he
+ complained about it, not that he literally vomited.
+
+ 3. To fail to work because of unacceptable input, perhaps with
+ a suitable error message, perhaps not. Examples: "The
+ division operation barfs if you try to divide by 0." (That
+ is, the division operation checks for an attempt to divide by
+ zero, and if one is encountered it causes the operation to
+ fail in some unspecified, but generally obvious, manner.) "The
+ text editor barfs if you try to read in a new file before
+ writing out the old one".
+
+ See {choke}, {gag}.
+
+ In Commonwealth Hackish, "barf" is generally replaced by
+ "puke" or "vom". {barf} is sometimes also used as a
+ {metasyntactic variable}, like {foo} or {bar}.
+
+ (1996-02-26)
+
+barfmail
+
+ <messaging> Multiple {bounce messages} accumulating to the
+ level of serious annoyance, or worse. The sort of thing that
+ happens when an inter-network {mail gateway} goes down or
+ misbehaves.
+
+ [{Jargon File}]
+
+ (1996-01-05)
+
+barfulation
+
+ /bar`fyoo-lay'sh*n/ Variation of {barf} used around the
+ Stanford area. An exclamation, expressing disgust. On seeing
+ some particularly bad code one might exclaim, "Barfulation!
+ Who wrote this, Quux?"
+
+ [{Jargon File}]
+
+barfulous
+
+ /bar'fyoo-l*s/ (Or "barfucious", /bar-fyoo-sh*s/) Said of
+ something that would make anyone barf, if only for aesthetic
+ reasons.
+
+ (1995-02-22)
+
+barnacle code
+
+ <programming, humour> Any piece of {code} (usually a {static
+ method}) that has been appended to a {class} where it doesn't
+ logically belong, due to a lack of anywhere else to put it.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2014-08-10)
+
+barney
+
+ In Commonwealth hackish, "barney" is to {fred} as {bar} is to
+ {foo}. That is, people who commonly use "fred" as their first
+ {metasyntactic variable} will often use "barney" second. The
+ reference is, of course, to Fred Flintstone and Barney Rubble
+ in the Flintstones cartoons.
+
+ [{Jargon File}]
+
+ (1994-11-28)
+
+Baroque
+
+ An early {logic programming} language written by Boyer and
+ Moore in 1972.
+
+ ["Computational Logic: Structure Sharing and Proof of program
+ Properties", J. Moore, DCL Memo 67, U Edinburgh 1974].
+
+ [{Jargon File}]
+
+ (1995-02-22)
+
+baroque
+
+ Feature-encrusted; complex; gaudy; verging on excessive. Said
+ of hardware or (especially) software designs, this has many of
+ the connotations of {elephantine} or monstrosity but is less
+ extreme and not pejorative in itself. "{Metafont} even has
+ features to introduce random variations to its letterform
+ output. Now *that* is baroque!"
+
+ See also {rococo}.
+
+ [{Jargon File}]
+
+ (1995-02-22)
+
+barrel shifter
+
+ <hardware> A hardware device that can shift or rotate a data
+ word by any number of bits in a single operation. It is
+ implemented like a {multiplexor}, each output can be connected
+ to any input depending on the shift distance.
+
+ (1995-03-28)
+
+barycentric
+
+ <mathematics> Centre of gravity, {mean}.
+
+ (2007-07-10)
+
+base
+
+ <mathematics> {radix}.
+
+base 64
+
+ <file format, algorithm> A file format using 64 {ASCII}
+ characters to encode the six bit {binary data} values 0-63.
+
+ To convert data to base 64, the first byte is placed in the
+ most significant eight bits of a 24-bit buffer, the next in
+ the middle eight, and the third in the least significant eight
+ bits. If there a fewer than three bytes to encode, the
+ corresponding buffer bits will be zero. The buffer is then
+ used, six bits at a time, most significant first, as indices
+ into the string
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
+ and the indicated character output. If there were only one or
+ two input bytes, the output is padded with two or one "="
+ characters respectively. This prevents extra bits being added
+ to the reconstructed data. The process then repeats on the
+ remaining input data.
+
+ Base 64 is used when transmitting binary data through
+ text-only media such as {electronic mail}, and has largely
+ replaced the older {uuencode} encoding.
+
+ (2004-07-17)
+
+baseband
+
+ A transmission medium through which digital signals are sent
+ without frequency shifting. In general, only one
+ communication channel is available at any given time.
+
+ {Ethernet} is an example of a baseband network.
+
+ See also {broadband}.
+
+ (1995-02-22)
+
+base class
+
+ {superclass}
+
+baseline
+
+ {released version}
+
+base memory
+
+ <hardware, jargon> The lowest 640 {kilobytes} of memory in an
+ {IBM PC}-compatible computer running {MS-DOS}. Other PC
+ {operating systems} can usually compensate and "ignore" the
+ fact that there is a 640K limit to base memory. This was put
+ in place because the original {CPU} - the {Intel 8088} - could
+ only access one {megabyte} of memory, and {IBM} wanted to
+ reserve the upper 384KB for {device drivers}. The {high
+ memory area} (HMA) lies above 640KB and can be accessed on
+ MS-DOS computers that have an {A20 handler}.
+
+ (1997-05-30)
+
+basename
+
+ <file system> The name of a file which, in contrast to a
+ {pathname}, does not mention any of the {directories}
+ containing the file. Examples:
+
+ pathname basename
+ -------- --------
+ /etc/hosts hosts
+ ./alma alma
+ korte/a.a a.a
+ a.a a.a
+
+ See also {pathname}.
+
+ (1996-11-23)
+
+Base Technology
+
+ <company> The company which developed and distributes {Liana}.
+
+ {(http://BaseTechnology.com/)}.
+
+ E-mail: Jack Krupansky <Jack@BaseTechnology.com> (owner).
+
+ Address: Base Technology, Attn: Jack Krupansky, 1500 Mass. Ave. NW #114
+ Washington, DC 2005, USA.
+ 800-786-9505
+
+ Telephone: +1 800 876 9505.
+
+ (1999-06-29)
+
+bash
+
+ Bourne Again SHell. {GNU}'s {command interpreter} for {Unix}.
+ Bash is a {Posix}-compatible {shell} with full {Bourne shell}
+ syntax, and some {C shell} commands built in. The Bourne
+ Again Shell supports {Emacs}-style command-line editing, job
+ control, functions, and on-line help. Written by Brian Fox of
+ {UCSB}.
+
+ The latest version is 1.14.1. It includes a {yacc} parser,
+ the interpreter and documentation.
+
+ {(ftp://ftp.gnu.org/bash-1.14.1.tar.gz)} or from a
+ {GNU archive site}. E-mail: <bug-bash@gnu.org>.
+ {Usenet} newsgroup: {news:gnu.bash.bug}.
+
+ (1994-07-15)
+
+BASIC
+
+ <language> Beginner's All-purpose Symbolic Instruction Code.
+ A simple language originally designed for ease of programming
+ by students and beginners. Many dialects exist, and BASIC is
+ popular on {microcomputers} with sound and graphics support.
+ Most micro versions are {interactive} and {interpreted}.
+
+ BASIC has become the leading cause of brain-damage in
+ proto-hackers. This is another case (like {Pascal}) of the
+ cascading lossage that happens when a language deliberately
+ designed as an educational toy gets taken too seriously. A
+ novice can write short BASIC programs (on the order of 10-20
+ lines) very easily; writing anything longer is painful and
+ encourages bad habits that will make it harder to use more
+ powerful languages. This wouldn't be so bad if historical
+ accidents hadn't made BASIC so common on low-end micros. As
+ it is, it ruins thousands of potential wizards a year.
+
+ Originally, all references to code, both {GOTO} and GOSUB
+ (subroutine call) referred to the destination by its line
+ number. This allowed for very simple editing in the days
+ before {text editors} were considered essential. Just typing
+ the line number deleted the line and to edit a line you just
+ typed the new line with the same number. Programs were
+ typically numbered in steps of ten to allow for insertions.
+ Later versions, such as {BASIC V}, allow {GOTO}-less
+ {structured programming} with named {procedures} and
+ {functions}, IF-THEN-ELSE-ENDIF constructs and {WHILE} loops
+ etc.
+
+ Early BASICs had no graphic operations except with graphic
+ characters. In the 1970s BASIC {interpreters} became standard
+ features in {mainframes} and {minicomputers}. Some versions
+ included {matrix} operations as language {primitives}.
+
+ A {public domain} {interpreter} for a mixture of {DEC}'s
+ {MU-Basic} and {Microsoft Basic} is {here
+ (ftp://oak.oakland.edu/pub/Unix-c/languages/basic/basic.tar-z)}.
+ A {yacc} {parser} and {interpreter} were in the
+ comp.sources.unix archives volume 2.
+
+ See also {ANSI Minimal BASIC}, {bournebasic}, {bwBASIC},
+ {ubasic}, {Visual Basic}.
+
+ [{Jargon File}]
+
+ (1995-03-15)
+
+Basic Assembly Language
+
+ <language> (BAL) What most people called {IBM 360} {assembly
+ language}.
+
+ See {ALC}.
+
+ (1995-04-13)
+
+BASIC AUTOCODER
+
+ Early system on IBM 7070. Listed in CACM 2(5):16 (May
+ 1959).
+
+Basic COBOL
+
+ <language> A subset of {COBOL} from {COBOL-60} standards.
+
+ [Sammet 1969, p. 339].
+
+ (1997-12-07)
+
+Basic Encoding Rules
+
+ <protocol, standard> (BER) {ASN.1} encoding rules for
+ producing self-identifying and self-delimiting {transfer
+ syntax} for data structures described in {ASN.1} notations.
+
+ BER is an self-identifying and self-delimiting encoding
+ scheme, which means that each data value can be identified,
+ extracted and decoded individually.
+
+ Huw Rogers once described BER as "a triumph of bloated theory
+ over clean implementation". He also criticises it as designed
+ around bitstreams with arbitrary boundaries between data which
+ can only be determined at a high level.
+
+ Documents: {ITU-T} X.690, {ISO} 8825-1.
+
+ See also {CER}, {DER}, {PER}.
+
+ (1998-05-28)
+
+Basic Fortran
+
+ <language> A subset of {Fortran}.
+
+ [Sammet 1969, p. 150].
+
+ (1999-06-09)
+
+Basic Input/Output System
+
+ <operating system> (BIOS, ROM BIOS) The part of the {system
+ software} of the {IBM PC} and compatibles that provides the
+ lowest level interface to {peripheral} devices and controls
+ the first stage of the {bootstrap} process, including
+ installing the {operating system}. The BIOS is stored in
+ {ROM}, or equivalent, in every PC. Its main task is to load
+ and execute the operating system which is usually stored on
+ the computer's {hard disk}, but may be loaded from {CD-ROM} or
+ {floppy disk} at install time.
+
+ In order to provide acceptable performance (e.g. for screen
+ display), some software vendors access the routines in the
+ BIOS directly, rather than using the higher level operating
+ system calls. Thus, the BIOS in the compatible computer must
+ be 100% compatible with the IBM BIOS.
+
+ As if that wasn't bad enough, many {application programs}
+ bypass even the BIOS and address the screen hardware directly
+ just as the BIOS does. Consequently, {register} level
+ compatibility is required in the compatible's display
+ electronics, which means that it must provide the same storage
+ locations and identification as the original IBM hardware.
+
+ (1999-06-09)
+
+Basic JOVIAL
+
+ <language> A subset of {JOVIAL} written ca. 1965.
+
+ [Sammet 1969, p.529].
+
+ (1995-04-19)
+
+Basic Language for Implementation of System Software
+
+ <language> (BLISS, or allegedly, "System Software
+ Implementation Language, Backwards") A language designed by
+ W.A. Wulf at {CMU} around 1969.
+
+ BLISS is an {expression language}. It is {block-structured},
+ and typeless, with {exception handling} facilities,
+ {coroutines}, a {macro} system, and a highly {optimising
+ compiler}. It was one of the first non-{assembly languages}
+ for {operating system} implementation. It gained fame for its
+ lack of a {goto} and also lacks implicit {dereferencing}: all
+ symbols stand for addresses, not values.
+
+ Another characteristic (and possible explanation for the
+ backward acronym) was that BLISS fairly uniformly used
+ backward {keywords} for closing blocks, a famous example being
+ ELUDOM to close a MODULE. An exception was BEGIN...END though
+ you could use (...) instead.
+
+ DEC introduced the NOVALUE keyword in their dialects to allow
+ statements to not return a value.
+
+ Versions: CMU {BLISS-10} for the PDP-10; CMU {BLISS-11},
+ {BLISS-16}, DEC {BLISS-16C}, DEC {BLISS-32}, {BLISS-36} for
+ {VAX}/{VMS}, {BLISS-36C}.
+
+ ["BLISS: A Language for Systems Programming", CACM
+ 14(12):780-790, Dec 1971].
+
+ [Did the B stand for "Better"?]
+
+ (1997-03-01)
+
+Basic Multilingual Plane
+
+ <text, standard> (BMP) The first plane defined in
+ {Unicode}/{ISO 10646}, designed to include all {scripts} in
+ active modern use. The BMP currently includes the Latin,
+ Greek, Cyrillic, Devangari, hiragana, katakana, and Cherokee
+ scripts, among others, and a large body of mathematical,
+ {APL}-related, and other miscellaneous {characters}. Most of
+ the {Han} {ideographs} in current use are present in the BMP,
+ but due to the large number of ideographs, many were placed in
+ the {Supplementary Ideographic Plane}.
+
+ {Unicode home (http://unicode.org)}.
+
+ (2002-03-19)
+
+Basic Object Adapter
+
+ <architecture> (BOA) Part of the {CORBA} architecture.
+
+ [Details?]
+
+ (2004-06-23)
+
+Basic Object System
+
+ <programming> (BOS) A {C}-callable library that implements the
+ notion of {object} and which uses {Tcl} as its {interpreter}
+ for interpreted {methods} (you can have "compiled" methods in
+ C, and mix compiled and interpreted methods in the same
+ object, plus lots more). You can subclass and mix in existing
+ objects using BOS to extend, among other things, the set of
+ {tk} {widgets}. BOS is a {class}-free object system, also
+ called a prototype-based object system; it is modelled loosely
+ on the {Self} system from {Stanford University}.
+
+ Version 1.31 by Sean Levy <Sean.Levy@cs.cmu.edu>.
+
+ {(ftp://barkley.berkeley.edu/tcl)}.
+
+ (1992-08-21)
+
+Basic Operating System
+
+ <operating system> (BOS) An early [when?] {IBM} {operating
+ system}.
+
+ According to folklore, BOS was the predecessor to {TOS} on the
+ {IBM 360} and it was {IPL}'d from a {card reader}. It may
+ have been intended for very small 360's with no disks and
+ limited tape drives.
+
+ BOS died out really early [when?] as disks such as the 2311
+ and 2314 became common with the {IBM 360}, whereas disks had
+ been a real luxury on the {IBM 7090}.
+
+ (1999-01-29)
+
+Basic Programming Support
+
+ <operating system, tool> (BPS, colloquially: Barely
+ Programming Support) A suite of utility routines from {IBM} to
+ perform very simple procedures like formatting a disk or
+ labelling a tape. BPS was only available on {punched cards}.
+
+ [Dates?]
+
+ (1998-07-08)
+
+Basic Rate Interface
+
+ <communications> (BRI, 2B+D, 2B1D) An {Integrated Services
+ Digital Network} channel consisting of two 64 {kbps} "bearer"
+ (B) channels and one 16 kbps "delta" (D) channel, giving a
+ total data rate of 144 kbps. The B channels are used for
+ voice or user data, and the D channel is used for control and
+ signalling and/or {X.25} {packet} networking. BRI is the kind
+ of ISDN interface most likely to be found in residential
+ service.
+
+ (2002-01-13)
+
+Basic Service Set
+
+ <networking> (BSS) A {wireless local area network} and all the
+ wireless devices (e.g. PCs and laptops) that are associated
+ with it. A BSS may or may not include an {access point} and
+ is identified by a {BSSID}.
+
+ (2009-05-12)
+
+BASIC V
+
+ The version of the {Basic} programming language which comes on
+ {ROM} in {Acorn}'s {RISC} computers: the {Archimedes} range
+ and the {RiscPC}. It features REPEAT and WHILE loops,
+ multi-line IF statements, procedures and functions, local
+ variables, error handling, {system calls} and a built-in
+ {assembler}.
+
+ (1995-01-05)
+
+Bastard Operator From Hell
+
+ <humour> (BOFH) A rogue {network operator} character invented
+ by Simon Travaglia <simontrav@hotmail.com>, regularly featured
+ in "Computing" and "DATAMATION" magazine.
+
+ See also: {Dilbert}.
+
+ {(http://angelfire.com/bc/simont/index.html)}.
+
+ (1999-09-17)
+
+bastion host
+
+ {proxy gateway}
+
+batch
+
+ {batch processing}
+
+batch file
+
+ <operating system> (Or script) A {text file} containing
+ {operating system} commands which are executed automatically
+ by the {command-line interpreter}. In {Unix}, this is called
+ a "{shell script}" since it is the Unix {shell} which includes
+ the {command-line interpreter}. Batch files can be used as a
+ simple way to combine existing commands into new commands.
+
+ In {Microsoft Windows}, batch files have {filename extension},
+ ".bat" or ".cmd". A special example is {autoexec.bat} which
+ {MS-DOS} runs when Windows starts.
+
+ (2009-09-14)
+
+batch processing
+
+ <programming> A system that takes a sequence (a "batch") of
+ commands or jobs, executes them and returns the results, all
+ without human intervention. This contrasts with an
+ {interactive} system where the user's commands and the
+ computer's responses are interleaved during a single run.
+
+ A batch system typically takes its commands from a disk file
+ (or a set of {punched cards} or {magnetic tape} in the
+ {mainframe} days) and returns the results to a file (or prints
+ them). Often there is a queue of jobs which the system
+ processes as resources become available.
+
+ Since the advent of the {personal computer}, the term "batch"
+ has come to mean automating frequently performed tasks that
+ would otherwise be done interactively by storing those
+ commands in a "{batch file}" or "{script}". Usually this file
+ is read by some kind of {command interpreter} but batch
+ processing is sometimes used with GUI-based applications that
+ define script equivalents for menu selections and other mouse
+ actions. Such a recorded sequence of GUI actions is sometimes
+ called a "{macro}". This may only exist in memory and may not
+ be saved to disk whereas a batch normally implies something
+ stored on disk.
+
+ Unix {cron} jobs and Windows scheduled tasks are batch
+ processing started at a predefined time by the system whereas
+ mainframe batch jobs were typically initiated by an operator
+ loading them into a queue.
+
+ (2009-09-14)
+
+bathtub curve
+
+ Common term for the curve (resembling an end-to-end section of
+ one of those claw-footed antique bathtubs) that describes the
+ expected failure rate of electronics with time: initially
+ high, dropping to near 0 for most of the system's lifetime,
+ then rising again as it "tires out". See also {burn-in
+ period}, {infant mortality}.
+
+ [{Jargon File}]
+
+baud
+
+ <communications, unit> /bawd/ (plural "baud") The unit in
+ which the information carrying capacity or "{signalling rate}"
+ of a communication channel is measured. One baud is one
+ symbol (state-transition or level-transition) per second.
+ This coincides with bits per second only for two-level
+ {modulation} with no {framing} or {stop bits}.
+
+ A symbol is a unique state of the communication channel,
+ distinguishable by the receiver from all other possible
+ states. For example, it may be one of two voltage levels on a
+ wire for a direct digital connection or it might be the phase
+ or frequency of a carrier.
+
+ The term "baud" was originally a unit of telegraph signalling
+ speed, set at one {Morse code} dot per second. Or, more
+ generally, the reciprocal of the duration of the shortest
+ signalling element. It was proposed at the International
+ Telegraph Conference of 1927, and named after {J.M.E. Baudot}
+ (1845-1903), the French engineer who constructed the first
+ successful teleprinter.
+
+ The UK {PSTN} will support a maximum rate of 600 baud but each
+ baud may carry between 1 and 16 bits depending on the coding
+ (e.g. {QAM}).
+
+ Where data is transmitted as {packets}, e.g. characters, the
+ actual "data rate" of a channel is
+
+ R D / P
+
+ where R is the "raw" rate in bits per second, D is the number
+ of data bits in a packet and P is the total number of bits in
+ a packet (including packet overhead).
+
+ The term "baud" causes much confusion and is usually best
+ avoided. Use "bits per second" (bps), "bytes per second" or
+ "characters per second" (cps) if that's what you mean.
+
+ (1998-02-14)
+
+baud barf
+
+ <jargon> /bawd barf/ The garbage one gets on the {display
+ screen} when using a {modem} connection with some {protocol}
+ setting (especially line speed) incorrect, or when someone
+ picks up a voice extension on the same line, or when really
+ bad line noise disrupts the connection. Baud barf is not
+ completely {random}, by the way; hackers with a lot of
+ serial-line experience can usually tell whether the device at
+ the other end is expecting a higher or lower speed than the
+ {terminal} is set to. *Really* experienced ones can identify
+ particular speeds.
+
+ [{Jargon File}]
+
+ (1996-02-22)
+
+Baudot
+
+ {Jean-Maurice-Émile Baudot}
+
+Baudotbetical order
+
+ <algorithm> /baw do bet' i k*l/ Sorted into an order where
+ numerics and special characters are intermixed by sorting a 5-bit
+ {Baudot code} file ignoring the numeric shift and unshift codes.
+
+ (1997-02-11)
+
+Baudot code
+
+ <communications> (For etymology, see {baud}) A {character set}
+ predating {EBCDIC} and used originally and primarily on {paper
+ tape}. Use of Baudot reportedly survives in {TDDs} and some
+ HAM radio applications.
+
+ In Baudot, characters are expressed using five {bits}. Baudot
+ uses two code sub-sets, the "letter set" (LTRS), and the
+ "figure set" (FIGS). The FIGS character (11011) signals that
+ the following code is to be interpreted as being in the FIGS
+ set, until this is reset by the LTRS (11111) character.
+
+ binary hex LTRS FIGS
+ --------------------------
+ 00011 03 A -
+ 11001 19 B ?
+ 01110 0E C :
+ 01001 09 D $
+ 00001 01 E 3
+ 01101 0D F !
+ 11010 1A G &
+ 10100 14 H #
+ 00110 06 I 8
+ 01011 0B J BELL
+ 01111 0F K (
+ 10010 12 L )
+ 11100 1C M .
+ 01100 0C N ,
+ 11000 18 O 9
+ 10110 16 P 0
+ 10111 17 Q 1
+ 01010 0A R 4
+ 00101 05 S '
+ 10000 10 T 5
+ 00111 07 U 7
+ 11110 1E V ;
+ 10011 13 W 2
+ 11101 1D X /
+ 10101 15 Y 6
+ 10001 11 Z "
+ 01000 08 CR CR
+ 00010 02 LF LF
+ 00100 04 SP SP
+ 11111 1F LTRS LTRS
+ 11011 1B FIGS FIGS
+ 00000 00 [..unused..]
+
+ Where CR is {carriage return}, LF is {linefeed}, BELL is the
+ {bell}, SP is space, and STOP is the stop character.
+
+ Note: these bit values are often shown in inverse order,
+ depending (presumably) which side of the {paper tape} you were
+ looking at.
+
+ Local implementations of Baudot may differ in the use of #,
+ STOP, BELL, and '.
+
+ (1997-01-30)
+
+baud rate
+
+ {baud}
+
+bawk
+
+ An {Awk}-like pattern-matching language by Bob Brodt,
+ distributed with {MINIX}.
+
+ (1994-11-28)
+
+bay
+
+ <hardware> (As in an aeroplane "cargo bay") A space in a
+ cabinet into which a device of a certain size can be
+ physically mounted and connected to power and data.
+
+ Common examples are a "drive bay" into which a {disk drive}
+ (usually either 3.5 inch or 5.25 inch) can be inserted or the
+ space in a {docking station} where you insert a {notebook
+ computer} or {laptop computer} to work as a {desktop computer}
+ or to charge their batteries, print or connect to the office
+ network, etc.
+
+ (1999-01-11)
+
+baz
+
+ /baz/ The third {metasyntactic variable} "Suppose we have
+ three functions: FOO, BAR, and BAZ. FOO calls BAR, which
+ calls BAZ..." (See also {fum}). Occasionally appended to
+ {foo} to produce "foobaz".
+
+ Early versions of the Hacker Jargon dictionary derived "baz"
+ as a Stanford corruption of {bar}. However, Pete Samson
+ (compiler of the {TMRC} lexicon) reports it was already
+ current when he joined TMRC in 1958. He says "It came from
+ "Pogo". Albert the Alligator, when vexed or outraged, would
+ shout "Bazz Fazz!" or "Rowrbazzle!" The club layout was said
+ to model the (mythical) New England counties of Rowrfolk and
+ Bassex (Rowrbazzle mingled with Norfolk/Suffolk/Middlesex/
+ Essex)."
+
+ [{Jargon File}]
+
+ (2008-06-30)
+
+bb
+
+ <networking> The {country code} for Barbados.
+
+ (1999-01-27)
+
+BBC
+
+ {British Broadcasting Corporation}
+
+BBC Micro
+
+ {BBC Microcomputer}
+
+BBC Microcomputer
+
+ A series of {6502}-based personal computers launched by {Acorn
+ Computers} Ltd. in January 1982, for use in the British
+ Broadcasting Corporation's educational programmes on
+ computing. The computers are noted for their reliability (many
+ are still in active service in 1994) and both hardware and
+ software were designed for easy expansion. The 6502-based
+ computers were succeeded in 1987 by the Acorn {Archimedes}
+ family.
+
+ {xbeeb} is a BBC Micro {emulator} for {Unix} and {X11}.
+
+BBC Networking Club
+
+ <body> A {bulletin board} run by the {British Broadcasting
+ Corporation} Education department from April 1994 to 30 Nov
+ 1995.
+
+ (1997-01-20)
+
+BBL
+
+ <chat> (I will) be back later.
+
+BBN Butterfly
+
+ <computer> A {supercomputer} developed at {BBN Technologies},
+ named after the "butterfly" multi-stage switching network
+ around which it was built. It could have up to 512 {CPUs}
+ connected to allow every CPU access to every other CPU's
+ memory, albeit with about 15 times the latency than for its
+ own. The earlier GP-1000 models used up to 256 {Motorola
+ 68020s}. The later TC-2000 models used up to 512 {Motorola
+ 88100s}.
+
+ Language developed for, or ported to, the BBN Butterfly were
+ {Butterfly Common LISP}, {Butterfly Scheme}, {Delirium}, and
+ {MultiScheme}.
+
+ {(http://paralogos.com/DeadSuper/Misc/BBN.html)}.
+
+ (2003-11-10)
+
+BBN Technologies
+
+ <company> A company, originally known as Bolt, Beranek and
+ Newman, Inc. (BBN), based in Cambridge, Massachusetts, USA.
+
+ BBN were awarded the original contract to build the {ARPANET}
+ and have been extensively involved in {Internet} development.
+ They are responsible for managing {NNSC}, {CSNET}, and
+ {NEARnet}.
+
+ The language {LOGO} was developed at BBN, as was the {BBN
+ Butterfly} supercomputer.
+
+ {BBN Home (http://bbn.com/)}.
+
+ (2003-11-10)
+
+bboard
+
+ {bulletin board system}
+
+BBS
+
+ {bulletin board system}
+
+BC
+
+ An {arbitrary precision} numeric processing language with
+ {C}-like {syntax}. Traditionally implemented as a front-end
+ to {DC}. There is a {GNU} version called {GNU BC}.
+
+ {Unix manual page}: bc(1).
+
+BCBF
+
+ {Branch on Chip Box Full}
+
+BCC
+
+ 1. {Blind Carbon Copy}.
+
+ 2. {Block Check Character}.
+
+ 3. {Blocked Call Cleared}.
+
+BCD
+
+ {binary coded decimal}
+
+BCL
+
+ The successor to {Atlas Commercial Language}.
+
+ ["The Provisional BCL Manual", D. Hendry, U London 1966].
+
+BC NELIAC
+
+ Version of NELIAC, post 1962. Sammet 1969, p.197.
+
+BCNU
+
+ Be seein' you.
+
+BCPL
+
+ <language> (Basic CPL) A British systems language developed by
+ Richards in 1969 and descended from {CPL} (Combined
+ Programming Language). BCPL is low-level, typeless and
+ block-structured, and provides only one-dimensional {arrays}.
+ Case is not significant, but conventionally reserved words
+ begin with a capital. Flow control constructs include:
+ If-Then, Test-Then-Else, Unless-Do, While-Do, Until-Do,
+ Repeat, Repeatwhile, Repeatuntil, For-to-By-Do, Loop, Break
+ and Switchon-Into-Case-Default-Endcase. BCPL has conditional
+ expressions, pointers, and manifest constants. It has both
+ procedures: 'Let foo(bar) Be command' and functions: 'Let
+ foo(bar) = expression'. 'Valof $(..Resultis..$)' causes a
+ compound command to produce a value. Parameters are
+ {call-by-value}.
+
+ Program segments communicate via the global vector where
+ system and user variables are stored in fixed numerical
+ locations in a single array.
+
+ The first BCPL {compiler} was written in {AED}. BCPL was used
+ to implement the {TRIPOS} {operating system}, which was
+ subsequently reincarnated as {AmigaDOS}.
+
+ ["BCPL - The Language and its Compiler", Martin Richards &
+ Colin Whitby-Stevens, Cambridge U Press 1979].
+
+ See {OCODE}, {INTCODE}.
+
+ Oxford BCPL differed slightly: Test-Ifso-Ifnot, and section
+ brackets in place of $( $).
+
+ The original {INTCODE} {interpreter} for BCPL is available for
+ {Amiga}, {Unix}, {MS-DOS}
+ {(ftp://wuarchive.wustl.edu/systems/amiga/programming/languages/BCPL/)}.
+
+ A BCPL compiler {bootstrap} kit with an {INTCODE}
+ {interpreter} in {C} was written by Ken Yap
+ <ken@syd.dit.csiro.au>.
+
+ (1995-03-26)
+
+BCS
+
+ 1. {British Computer Society}.
+
+ 2. {Binary Compatibility Standard}.
+
+bd
+
+ <networking> The {country code} for Bangladesh.
+
+ (1999-01-27)
+
+BDC
+
+ {Backup Domain Controller}
+
+BDL
+
+ {Block Diagram Compiler}
+
+BDPA
+
+ {Black Data Processing Associates}
+
+be
+
+ <networking> The {country code} for Belgium.
+
+ (1999-01-27)
+
+BEA
+
+ Basic programming Environment for interactive-graphical
+ Applications, from Siemens-Nixdorf.
+
+beam
+
+ <jargon> (From Star Trek Classic's "Beam me up, Scotty!") To
+ transfer {softcopy} of a file electronically; most often in
+ combining forms such as "beam me a copy" or "beam that over to
+ his site". Compare {blast}, {snarf}, {BLT}.
+
+ [{Jargon File}]
+
+ (2009-06-09)
+
+beamer
+
+ <video, hardware, communications> A personal video station
+ (PVS) that adds video to standard telephone lines at no
+ additional cost.
+
+ (1999-10-24)
+
+beam search
+
+ <algorithm> An optimisation of the {best first search} {graph
+ search algorithm} where only a predetermined number of paths
+ are kept as candidates. The number of paths is the "width of
+ the beam". If more paths than this are generated, the worst
+ paths are discarded. This reduces the space requirements of
+ best first search.
+
+ (2007-11-03)
+
+bean
+
+ {JavaBeans}
+
+beanie key
+
+ {feature key}
+
+bearer channel
+
+ <communications> Originally, a channel suited for carrying one
+ voice-grade connection. Typically a {DS0} channel.
+
+ Compare {data channel}.
+
+ (1997-03-7)
+
+bear paw
+
+ <jargon> The {Vulcan nerve pinch} for {SGI} computers. The
+ five key keyboard combination <left Ctrl><left Alt><left
+ Shift><{numeric keypad} /><F12> resets the graphics subsystem,
+ including the {window manager}.
+
+ (1996-10-28)
+
+Beats the shit outa me
+
+ <exclamation> (BSOM) "I don't understand it". The last thing
+ you say as you walk out on someone whose system you can't fix.
+
+ (1998-06-15)
+
+Bebo
+
+ <web> A {social networking} website based in
+ California, USA.
+
+ {Bebo Home (http://bebo.com/)}.
+
+ (2006-11-20)
+
+BeBOP
+
+ <language> A language combining sequential and parallel {logic
+ programming}, {object-oriented} and {meta-level programming}.
+ Both {don't know nondeterminism} and {stream AND-parallelism}.
+ {Prolog} {theories} are first order entities and may be
+ updated or passed in messages. BeBOP is implemented by
+ translation to {NU-Prolog} and {PNU-Prolog}.
+
+ {(ftp://munnari.oz.au/pub/bebop.tar.Z)}.
+
+ E-mail: Andrew Davidson <ad@cs.mu.oz.au>.
+
+ (1996-10-27)
+
+BeBox
+
+ <computer> A {microcomputer} produced by {Be Inc}, containing
+ between two and eight {PowerPCs} (the initial model has two
+ {PPC} 603s). The BeBox can take standard {IBM PC}
+ {peripherals}, such as {ISA} and {PCI} cards, {IDE} and {SCSI}
+ disks, and a standard {PS/2} keyboard.
+
+ Newsgroup: {news:comp.sys.be}.
+
+ {(http://be.com/)}.
+
+ [Dates?]
+
+ (1996-10-05)
+
+BEDO
+
+ {Burst Extended Data Out DRAM}
+
+Bedrock
+
+ A {C++} {class} library for {Macintosh} user interface
+ portability.
+
+beep
+
+ {bell}
+
+beeper
+
+ {pager}
+
+BEG
+
+ {Back End Generator}
+
+@Begin
+
+ <text> The {Scribe} equivalent of {\begin}.
+
+ [{Jargon File}]
+
+\begin
+
+ <text, chat> The {LaTeX} command used with \end to delimit an
+ environment within which the text is formatted in a certain
+ way. E.g. \begin{table}...\end{table}.
+
+ Used humorously in writing to indicate a context or to remark
+ on the surrounded text. For example:
+
+ \begin{flame}
+ Predicate logic is the only good programming
+ language. Anyone who would use anything else
+ is an idiot. Also, all computers should be
+ tredecimal instead of binary.
+ \end{flame}
+
+ {Scribe} users at {CMU} and elsewhere used to use @Begin/@End
+ in an identical way (LaTeX was built to resemble Scribe). On
+ {Usenet}, this construct would more frequently be rendered as
+ "<FLAME ON>" and "<FLAME OFF>" (a la {HTML}), or "#ifdef
+ FLAME" and "#endif FLAME" (a la {C preprocessor}).
+
+ (1998-09-21)
+
+BEGL
+
+ {Back End Generator}
+
+beige toaster
+
+ {Macintosh}
+
+Be Inc
+
+ <company> The company that produced the {BeBox}, founded by
+ Jean-Louis Gassee, former product chief at {Apple}.
+
+ (1996-10-05)
+
+BEL
+
+ {bell}
+
+belief revision
+
+ <artificial intelligence> The area of {theory change} in which
+ preservation of the information in the theory to be changed
+ plays a key role.
+
+ A fundamental issue in belief revision is how to decide what
+ information to retract in order to maintain consistency, when
+ the addition of a new belief to a theory would make it
+ inconsistent. Usually, an ordering on the sentences of the
+ theory is used to determine priorities among sentences, so
+ that those with lower priority can be retracted. This
+ ordering can be difficult to generate and maintain.
+
+ The postulates of the {AGM Theory for Belief Revision}
+ describe minimal properties a revision process should have.
+
+ [Better definition?]
+
+ (1995-03-20)
+
+BELL
+
+ An early system on the {IBM 650} and {Datatron 200} series.
+
+ Versions: BELL L2, BELL L3.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ [Is Datatron version the same?]
+
+ (1994-12-06)
+
+Bell
+
+ <company> {Bell Telephone} or {Bell Laboratories}.
+
+ (1997-04-07)
+
+bell
+
+ <character> {ASCII} 7, ASCII {mnemonic} "BEL", the {character
+ code} which prodces a standard audibile warning from the
+ computer or {terminal}. In the {teletype} days it really was a
+ bell, since the advent of the {VDU} it is more likely to be a
+ sound sample (e.g. the sound of a bell) played through a
+ loudspeaker.
+
+ Also called "G-bell", because it is typed as Control-G.
+
+ The term "beep" is preferred among some {microcomputer}
+ hobbyists.
+
+ Compare {feep}, {visible bell}.
+
+ (1997-04-08)
+
+Bell 103
+
+ <protocol> The original variant of {V.21} created by {AT&T}
+ when they had a telephone system monopoly in the USA.
+
+ (1995-02-02)
+
+Bell Communications Research, Inc
+
+ (Bellcore) The research laboratory for the seven regional
+ {Bell Telephone} companies in the USA that were created by the
+ divestiture of {AT&T} in 1984.
+
+ It can be compared to {Bell Laboratories}, for which many
+ Bellcore employees used to work. Currently jointly owned by
+ the seven baby bells (as they are called), there are rumours
+ that it is to be sold by its current owners to become an
+ independent research laboratory
+
+ Its headquarters are in Livingstone, New Jersey. It has
+ offices in Morristown, Lincroft, and Piscataway, all in
+ New Jersey, USA.
+
+ Telephone: +1 (201) 74 3000, +1 (800) 521 CORE.
+
+ (1994-12-06)
+
+Bellcore
+
+ {Bell Communications Research, Inc.}
+
+bell curve
+
+ {normal distribution}
+
+Bell Laboratories
+
+ One of {AT&T}'s research sites, in Murray Hill, New Jersey,
+ USA. It was the birthplace of the {transistor}, {Unix}, {C}
+ and {C++} and the current home of research on {Plan 9} and
+ {ODE}.
+
+ {AT&T Research (http://research.att.com/)}.
+
+ {(ftp://ftp.research.att.com/)}.
+
+ {netlib} sources {(ftp://netlib.att.com)}.
+
+ (1994-11-17)
+
+Bell Labs
+
+ {Bell Laboratories}
+
+bells and whistles
+
+ <jargon> (By analogy with the "toyboxes" on theatre organs).
+ Features added to a program or system to make it more
+ {flavourful} from a hacker's point of view, without
+ necessarily adding to its utility for its primary function.
+ Distinguished from {chrome}, which is intended to attract
+ users. "Now that we've got the basic program working, let's
+ go back and add some bells and whistles." No one seems to
+ know what distinguishes a bell from a whistle.
+
+ [{Jargon File}]
+
+ (2007-04-03)
+
+bells, whistles, and gongs
+
+ A standard elaborated form of {bells and whistles}; typically
+ said with a pronounced and ironic accent on the "gongs".
+
+benchmark
+
+ <benchmark> A standard program or set of programs which can be
+ run on different computers to give an inaccurate measure of
+ their performance.
+
+ "In the computer industry, there are three kinds of lies:
+ lies, damn lies, and benchmarks."
+
+ A benchmark may attempt to indicate the overall power of a
+ system by including a "typical" mixture of programs or it may
+ attempt to measure more specific aspects of performance, like
+ graphics, I/O or computation (integer or {floating-point}).
+ Others measure specific tasks like {rendering} polygons,
+ reading and writing files or performing operations on
+ matrices. The most useful kind of benchmark is one which is
+ tailored to a user's own typical tasks. While no one
+ benchmark can fully characterise overall system performance,
+ the results of a variety of realistic benchmarks can give
+ valuable insight into expected real performance.
+
+ Benchmarks should be carefully interpreted, you should know
+ exactly which benchmark was run (name, version); exactly what
+ configuration was it run on (CPU, memory, compiler options,
+ single user/multi-user, peripherals, network); how does the
+ benchmark relate to your workload?
+
+ Well-known benchmarks include {Whetstone}, {Dhrystone},
+ {Rhealstone} (see {h}), the {Gabriel benchmarks} for {Lisp},
+ the {SPECmark} suite, and {LINPACK}.
+
+ See also {machoflops}, {MIPS}, {smoke and mirrors}.
+
+ {Usenet} newsgroup: {news:comp.benchmarks}.
+
+ {Tennessee BenchWeb (http://netlib.org/benchweb/)}.
+
+ [{Jargon File}]
+
+ (2002-03-26)
+
+Bend Over, Here It Comes Again
+
+ <humour> (BOHICA) An utterance of frustration by computer
+ support personnel who anticipate being told (usually via
+ phone) to do something that can't be done, by a boss who
+ doesn't know his ass from deep center field about what he's
+ asking his minions to do.
+
+ (1995-09-20)
+
+Benoit B. Mandelbrot
+
+ {Benoit Mandelbrot}
+
+Benoit Mandelbrot
+
+ <person> /ben'wa man'dl-bro/ Benoit B. Mandelbrot. The {IBM}
+ scientist who wrote several original books on {fractals} and
+ gave his name to the set he was discovered, the {Mandelbrot
+ set} and coined the term "fractal" in 1975 from the Latin
+ fractus or "to break".
+
+ (1997-07-02)
+
+Bentley Systems, Inc.
+
+ <company> The company that sells {MicroStation}.
+
+ Address: Exton, PA, USA.
+
+ {(http://bentley.com/)}.
+
+ (2001-05-18)
+
+BeOS
+
+ <operating system> The {operating system} originally designed
+ to run on the {BeBox} {microcomputer}. BeOS is good at both
+ {multitasking} and {real-time} operation. It has a {bash}
+ command shell, with ports of many {GNU} programs by Be, Inc.
+ It has a {GUI} front end (not {X}). A {C++} {compiler} is
+ supplied with the machine, and there are rumours of other
+ languages being ported in the future.
+
+ BeOs eventually became used on the {x86} and
+ standard {PPC}.
+
+ Be, Inc. went bankrupt in 1999, after releasing the last
+ upgrade of BeOS (R5.0.3), and was sold to {Palm}.
+
+ Several groups are currently (2003) attempting to create an R6
+ version of the OS. The most likely to succeed are {Yellowtab}
+ and {OpenBeOS}, which is likely to be renamed.
+
+ (2003-05-30)
+
+BER
+
+ 1. <protocol, standard> {Basic Encoding Rules}.
+
+ 2. <communications> {Bit Error Rate}.
+
+Berkeley
+
+ {University of California at Berkeley}
+
+Berkeley 4.2
+
+ {Berkeley Software Distribution}
+
+Berkeley EDIF200
+
+ translator-building toolkit
+
+ Wendell C. Baker and Prof A. Richard Newton of the Electronics
+ Research Laboratory, Department of Electrical Engineering and
+ Computer Sciences at the {University of California, Berkeley}.
+
+ Version 7.6. Restriction: no-profit without permission.
+
+ {(ftp://ic.berkeley.edu/pub/edif)}.
+
+ (1990-07-01)
+
+Berkeley FP
+
+ <language> A version of {Backus}'s {FP} distributed with
+ {4.2BSD} {Unix}.
+
+ {(ftp://apple.com/ArchiveVol1/Unix_lang)}.
+
+ (1997-12-15)
+
+Berkeley Internet Name Domain
+
+ <networking> (BIND) An implementation of a {DNS} {server}
+ developed and distributed by the {University of California at
+ Berkeley}.
+
+ Many {Internet} {hosts} run BIND, and it is the ancestor of
+ many commercial implementations.
+
+ (1997-12-15)
+
+Berkeley Logo
+
+ <language> A {Logo} {interpreter} by Brian Harvey
+ <bh@cs.berkeley.edu>. Berkeley Logo programs will run on
+ {Unix}, {IBM PC}, or {Macintosh}. It doesn't do anything
+ fancy about graphics and only allows one {turtle}.
+
+ Version: 4.6, as of 2000-03-21.
+
+ {MswLogo} is a {Microsoft Windows} {front end}.
+
+ {(ftp://anarres.cs.berkeley.edu/pub/ucblogo)}.
+
+ (2000-03-28)
+
+Berkeley Network
+
+ (B-NET) Top level {Unix} {Ethernet} software developed at the
+ {University of California at Berkeley}. There are no formal
+ specifications but UCB's {4.2BSD} {Unix} implementation on the
+ {VAX} is the de facto standard. Distributed by {Unisoft}.
+ Includes net.o driver routines for specific hardware, {pseudo
+ ttys}, {daemons}, hostname command to set/get name, /etc/hosts
+ database of names and {Internet address}es of other hosts,
+ /etc/hosts.equiv host-wide database to control remote access,
+ .rhosts per user version of hosts.equiv.
+
+ UCB's implementation of the {Internet Protocol} includes
+ trailers to improve performance on paged memory management
+ systems such as {VAXen}. These trailers are an exception to
+ the Internet Protocol specification.
+
+Berkeley Quality Software
+
+ <abuse> (Often abbreviated "BQS") Term used in a pejorative
+ sense to refer to software that was apparently created by
+ rather spaced-out hackers late at night to solve some unique
+ problem. It usually has nonexistent, incomplete, or incorrect
+ documentation, has been tested on at least two examples, and
+ core dumps when anyone else attempts to use it. This term was
+ frequently applied to early versions of the "dbx(1)" debugger.
+
+ See also {Berzerkeley}.
+
+ [{Jargon File}]
+
+ (1996-01-15)
+
+Berkeley Software Design, Inc
+
+ <company> (BSDI) A company that sells {BSD/OS}, a commercial
+ version of {Berkeley Standard Distribution} {Unix},
+ networking, and Internet technologies originally developed by
+ the {Computer Systems Research Group} (CSRG) at the
+ {University of California at Berkeley}.
+
+ Leading CSRG computer scientists founded BSDI in 1991. BSDI's
+ BSD/OS represents over 20 years of development by the
+ worldwide BSD technical community. BSD technology is known
+ worldwide for its powerful, flexible and portable architecture
+ and advanced development environments.
+
+ BSDI designs, develops, markets, and supports the {BSD/OS}
+ {operating system}, {Internet} server software for {IBM PCs},
+ and other products. BSDI planned to release an Internet
+ gateway product for {Novell} {IPX} networks in 1995.
+
+ {(http://bsdi.com/)}.
+
+ E-mail: <bsdi-info@bsdi.com>.
+
+ Address: 5575 Tech Center Drive, #110, Colorado Springs, CO
+ 80918, USA. Telephone: +1 (719) 593 9445. Fax: +1 (719) 598
+ 4238.
+
+ (1996-01-13)
+
+Berkeley Software Distribution
+
+ <operating system> (BSD) A family of {Unix} versions developed
+ by {Bill Joy} and others at the {University of California at
+ Berkeley}, originally for the {DEC} {VAX} and {PDP-11}
+ computers, and subsequently ported to almost all modern
+ general-purpose computers. BSD Unix incorporates {paged}
+ {virtual memory}, {TCP/IP} networking enhancements and many
+ other features.
+
+ BSD UNIX 4.0 was released on 1980-10-19. The BSD versions
+ (4.1, 4.2, and 4.3) and the commercial versions derived from
+ them ({SunOS}, {ULTRIX}, {Mt. Xinu}, {Dynix}) held the
+ technical lead in the Unix world until {AT&T}'s successful
+ standardisation efforts after about 1986, and are still widely
+ popular.
+
+ See also {Berzerkeley}, {USG Unix}.
+
+ (2005-01-20)
+
+Berkeley Softworks
+
+ <company> The company that wrote {Graffiti} and a similar
+ scheme for the {Commodore 64} (made it very {Macintosh}-like)
+ and the {Commodore 128} (which could {multitask}).
+
+ (1995-01-24)
+
+Berkeley Unix
+
+ {Berkeley Software Distribution}
+
+Berkeley Yacc
+
+ <tool> (byacc, previously Zeus, then Zoo) Probably the best
+ variant of the {Yacc} {parser generator}. Written by Robert
+ Corbett <Robert.Corbett@eng.sun.com>.
+
+ Latest version: 1.9, as of 2000-06-09.
+
+ {(ftp://ftp.cs.berkeley.edu/pub/4bsd/byacc.1.9.tar.Z)}.
+
+ (2000-07-16)
+
+berklix
+
+ /berk'liks/ (From {Berkeley Unix}) {Berkeley Software
+ Distribution}. Not used at {Berkeley} itself. May be more
+ common among {suits} attempting to sound like cognoscenti than
+ among hackers, who usually just say "BSD".
+
+ [{Jargon File}]
+
+ (1995-02-23)
+
+Berners-Lee, Tim
+
+ {Tim Berners-Lee}
+
+Bernoulli Box
+
+ <storage> A high capacity storage device, {Iomega
+ Corporation}'s first popular product, that spins a mylar disk
+ over a read-write head using the {Bernoulli principle}.
+
+ (1997-04-15)
+
+Bernoulli principle
+
+ (Or "air foil principle", after Swiss mathematician Daniel
+ Bernoulli, 1700-1782) The law that pressure in a fluid
+ decreases with the rate of flow. It has been applied to a
+ class of {hard disk} drives.
+
+ See {Bernoulli Box}.
+
+ (1997-04-15)
+
+Bernstein condition
+
+ <parallel> Processes cannot execute in parallel if one effects
+ values used by the other. Nor can they execute in parallel if
+ any subsequent process uses data effected by both, i.e. whose
+ value might depend on the order of execution.
+
+ (1995-02-23)
+
+BERR
+
+ {bus error}
+
+Bertrand
+
+ (Named after the British mathematician Bertrand Russell
+ (1872-1970)). Wm. Leler. Rule-based specification language
+ based on augmented term rewriting. Used to implement
+ constraint languages. The user must explicitly specify the
+ tree-search and the constraint propagation.
+
+ {(ftp://nexus.yorku.ca/pub/scheme/scm/bevan.shar)}.
+
+ ["Constraint Programming Languages - Their Specification and
+ Generation", W. Leler, A-W 1988, ISBN 0-201-06243-7].
+
+Bertrand Meyer
+
+ The author of the {Eiffel} Language and many articles on
+ {object-oriented} software techniques.
+
+ (1995-03-01)
+
+Bertrand Russell
+
+ <person> (1872-1970) A British mathematician, the discoverer
+ of {Russell's paradox}.
+
+ (1995-03-27)
+
+Berzerkeley
+
+ <humour> /b*r-zer'klee/ (From "berserk", via the name of a
+ now-deceased record label) A humorous distortion of "Berkeley"
+ used especially to refer to the practices or products of the
+ {BSD Unix} hackers.
+
+ See {software bloat}, {Missed'em-five}, {Berkeley Quality
+ Software}.
+
+ Mainstream use of this term in reference to the cultural and
+ political peculiarities of UC Berkeley as a whole has been
+ reported from as far back as the 1960s.
+
+ [{Jargon File}]
+
+ (1996-06-01)
+
+Berzerkley
+
+ {Berzerkeley}
+
+bespoke
+
+ {custom}
+
+best effort
+
+ <networking> A classification of low priority network traffic,
+ used especially the {Internet}.
+
+ Different kinds of traffic have different priorities.
+ {Videoconferencing} and other types of {real-time}
+ communication, for example, require a certain minimum
+ guaranteed {bandwidth} and {latency} and so must be given a
+ high priority. {Electronic mail}, on the other hand, can
+ tolerate an arbitrarily long delay and is classified as a
+ "best-effort" service.
+
+ [Scientific American, Nov. 1994, pp. 83-84].
+
+ (1995-04-04)
+
+best first search
+
+ <algorithm> A {graph} search {algorithm} which optimises
+ {breadth first search} by ordering all current paths according
+ to some {heuristic}. The heuristic attempts to predict how
+ close the end of a path is to a solution. Paths which are
+ judged to be closer to a solution are extended first.
+
+ See also {beam search}, {hill climbing}.
+
+ (1995-12-09)
+
+Best Fit
+
+ <algorithm> A {resource} allocation scheme (usually for
+ {memory}). Best Fit tries to determine the best place to put
+ the new data. The definition of 'best' may differ between
+ implementations, but one example might be to try and minimise
+ the wasted space at the end of the block being allocated -
+ i.e. use the smallest space which is big enough.
+
+ By minimising wasted space, more data can be allocated
+ overall, at the expense of a more time-consuming allocation
+ {routine}.
+
+ Compare {First Fit}.
+
+ (1997-06-02)
+
+BETA
+
+ Kristensen, Madsen <olmadsen@daimi.aau.dk>, Moller-Pedersen &
+ Nygaard, 1983. Object-oriented language with block structure,
+ coroutines, concurrency, {strong typing}, part objects,
+ separate objects and classless objects. Central feature is a
+ single abstraction mechanism called "patterns", a
+ generalisation of classes, providing instantiation and
+ hierarchical inheritance for all objects including procedures
+ and processes.
+
+ Mjolner Informatics ApS, Aarhus, implementations for Mac, Sun,
+ HP, Apollo.
+
+ E-mail: <info@mjolner.dk>.
+
+ Mailing list: <usergroup@mjolner.dk>.
+
+ ["Object-Oriented Programming in the BETA Programming
+ Language", Ole Lehrmann et al, A-W June 1993, ISBN
+ 0-201-62430-3].
+
+ [{Jargon File}]
+
+ (1995-10-31)
+
+beta
+
+ /bay't*/, /be't*/ or (Commonwealth) /bee't*/
+
+ See {beta conversion}, {beta test}.
+
+ [{Jargon File}]
+
+beta abstraction
+
+ [{lambda-calculus}] The conversion of an expression to an
+ {application} of a {lambda abstraction} to an argument
+ expression. Some subterm of the original expression becomes
+ the argument of the abstraction and the rest becomes its
+ body. E.g.
+
+ 4+1 --> (\ x . x+1) 4
+
+ The opposite of beta abstraction is {beta reduction}. These
+ are the two kinds of {beta conversion}.
+
+beta conversion
+
+ <theory> A term from {lambda-calculus} for {beta reduction} or
+ {beta abstraction}.
+
+ (1999-01-15)
+
+Betamaxed
+
+ <jargon> When a technology is overtaken in the market by
+ inferior but better marketed competition. E.g. "Microsoft
+ betamaxed Apple right out of the market". The Betamex
+ videotape standard lost to VHS.
+
+ (1999-01-15)
+
+beta reduction
+
+ [{lambda-calculus}] The {application} of a {lambda
+ abstraction} to an argument expression. A copy of the body of
+ the lambda abstraction is made and occurrences of the {bound
+ variable} being replaced by the argument. E.g.
+
+ (\ x . x+1) 4 --> 4+1
+
+ Beta reduction is the only kind of {reduction} in the {pure
+ lambda-calculus}. The opposite of beta reduction is {beta
+ abstraction}. These are the two kinds of {beta conversion}.
+
+ See also {name capture}.
+
+beta test
+
+ {beta testing}
+
+beta testing
+
+ <programming> Evaluation of a pre-release (potentially unreliable)
+ version of a piece of {software} (or possibly {hardware}) by
+ making it available to selected users ("beta testers") before it
+ goes on general distribution.
+
+ Beta testign aims to discover {bugs} that only occur in certain
+ environments or under certain patterns of use, while reducing the
+ volume of feedback to a manageable level. The testers benefit by
+ having earlier access to new products, features and fixes.
+
+ Beta testing may be preceded by "alpha testing", performed
+ in-house by a handful of users (e.g. other developers or friends),
+ who can be expected to give rapid, high quality feedback on design
+ and {usability}. Once the product is considered to be usable for
+ its intended purpose it then moves on to "beta testing" by a
+ larger, but typically still limited, number of ordinary users, who
+ may include external customers.
+
+ Some companies such as {Google} or {Degree Jungle
+ (http://www.degreejungle.com/rankings/best-online-colleges)}
+ stretch the definition, claiming their products are "in beta" for
+ many months by millions of users.
+
+ The term derives from early 1960s terminology for {product cycle}
+ checkpoints, first used at {IBM} but later standard throughout the
+ industry. "{Alpha test}" was the {unit test}, {module test} or
+ {component test} phase; "Beta Test" was initial {system test}.
+ These themselves came from earlier A- and B-tests for hardware.
+ The A-test was a feasibility and manufacturability evaluation done
+ before any commitment to design and development. The B-test was a
+ demonstration that the engineering model functioned as specified.
+ The C-test (corresponding to today's beta) was the B-test
+ performed on early samples of the production design.
+
+ (2013-06-09)
+
+beta version
+
+ {beta testing}
+
+Bezier
+
+ <graphics> (After Frenchman Pierre Bézier from Regie Renault)
+ A collection of formulae for describing curved lines ({Bezier
+ curve}) and surfaces ({Bezier surface}), first used in 1972 to
+ model automobile surfaces.
+
+ Curves and surfaces are defined by a set of "control points"
+ which can be moved interactively making Bezier curves and
+ surfaces convenient for interactive graphic design.
+
+ ["Principles of interactive computer graphics", William
+ M. Newman, Graw-Hill].
+
+ (1995-04-04)
+
+Bezier curve
+
+ <graphics> A type of curve defined by mathematical formulae,
+ used in {computer graphics}. A curve with coordinates P(u),
+ where u varies from 0 at one end of the curve to 1 at the
+ other, is defined by a set of n+1 "control points" (X(i),
+ Y(i), Z(i)) for i = 0 to n.
+
+ P(u) = Sum i=0..n [(X(i), Y(i), Z(i)) * B(i, n, u)]
+
+ B(i, n, u) = C(n, i) * u^i * (1-u)^(n-i)
+
+ C(n, i) = n!/i!/(n-i)!
+
+ A Bezier curve (or surface) is defined by its control points,
+ which makes it invariant under any {affine mapping}
+ (translation, rotation, parallel projection), and thus even
+ under a change in the axis system. You need only to transform
+ the control points and then compute the new curve. The
+ control polygon defined by the points is itself affine
+ invariant.
+
+ Bezier curves also have the variation-diminishing property.
+ This makes them easier to split compared to other types of
+ curve such as {Hermite} or {B-spline}.
+
+ Other important properties are multiple values, global and
+ local control, versatility, and order of continuity.
+
+ [What do these properties mean?]
+
+ (1996-06-12)
+
+Bezier surface
+
+ <graphics> A surface defined by mathematical formulae, used in
+ {computer graphics}. A surface P(u, v), where u and v vary
+ orthogonally from 0 to 1 from one edge of the surface to the
+ other, is defined by a set of (n+1)*(m+1) "control points"
+ (X(i, j), Y(i, j), Z(i, j)) for i = 0 to n, j = 0 to m.
+
+ P(u, v) = Sum i=0..n {Sum j=0..m [
+ (X(i, j), Y(i, j), Z(i, j))
+ * B(i, n, u) * B(j, m, v)]}
+
+ B(i, n, u) = C(n, i) * u^i * (1-u)^(n-i)
+
+ C(n, i) = n!/i!/(n-i)!
+
+ Bezier surfaces are an extension of the idea of {Bezier
+ curves}, and share many of their properties.
+
+ (1996-06-12)
+
+bf
+
+ <networking> The {country code} for Burkina Faso.
+
+ (1999-01-27)
+
+BFI
+
+ {brute force and ignorance}
+
+bg
+
+ <networking> The {country code} for Bulgaria.
+
+ (1999-01-27)
+
+BGA
+
+ {Ball Grid Array}
+
+bgh
+
+ <chat> Be Good Humans.
+
+ (2001-03-28)
+
+BGP
+
+ {Border Gateway Protocol}
+
+bh
+
+ <networking> The {country code} for Bahrain.
+
+ (1999-01-27)
+
+BHC Code
+
+ {Bose-Chaudhuri-Hocquenghem Code}
+
+bi
+
+ <networking> The {country code} for Burundi.
+
+ (1999-01-27)
+
+bib
+
+ {BibTeX}
+
+bible
+
+ <publication> The most detailed and authoritative reference
+ for a particular language, {operating system} or other complex
+ software system. It is also used to denote one of a small
+ number of such books such as {Knuth} and {K&R}.
+
+ [{Jargon File}]
+
+ (1996-12-03)
+
+BIBOP
+
+ {Big bag of pages}
+
+BibTeX
+
+ <text, tool> A {Tex} extension package for bibliographic
+ citations, distributed with {LaTeX}. BibTeX uses a
+ style-independent bibliography database (.bib file) to produce
+ a list of sources, in a customisable style, from citations in
+ a Latex document. It also supports some other formats.
+
+ BibTeX is a separate program from LaTeX. LaTeX writes
+ information about citations and which .bib files to use in a
+ ".aux" file. BibTeX reads this file and outputs a ".bbl" file
+ containing LaTeX commands to produce the source list. You
+ must then run LaTeX again to incorporate the source list in
+ your document. In typeset documents, "BibTeX" is written in
+ upper case, with the "IB" slightly smaller and with the "E" as
+ a subscript. BibTeX is described in the {LaTeX} book by
+ Lamport.
+
+BiCapitalisation
+
+ The act said to have been performed on trademarks (such as
+ {PostScript}, {NeXT}, {NeWS}, {VisiCalc}, {FrameMaker},
+ {TK!solver}, {EasyWriter}) that have been raised above the
+ ruck of common coinage by nonstandard capitalisation. Too
+ many {marketroid} types think this sort of thing is really
+ cute, even the 2,317th time they do it.
+
+ Compare {studlycaps}.
+
+ (1995-02-23)
+
+BiCMOS
+
+ <hardware> A manufacturing process for semiconductor devices
+ that combines {bipolar} and {CMOS} to give the best balance
+ between available output current and power consumption.
+
+ (1995-03-28)
+
+bidirectional printing
+
+ <hardware> A feature of a printer whose printer head can print
+ both when moving left to right and when moving right to left.
+
+ Also known as "{boustrophedonic}".
+
+ (1995-04-13)
+
+Bidouilleurs Sans Argent
+
+ <body> (BSA, French for "Moneyless Hackers") An association
+ which aim is to help computer users who can't afford to buy
+ commercial software. The main purpose of the association is
+ the promotion of {free software}, and distribution of
+ ex-commercial software. This is clearly an answer to the
+ repressive attitude of the "other" {BSA}.
+
+ Among BSA members are {Richard Stallman}, creator of the {GNU}
+ project.
+
+ {(http://bsa.lu/)}.
+
+ (1998-10-27)
+
+bi-endian
+
+ Silicon schizophrenia. Processors and other chips that have
+ can be switched to work in {big-endian} or {little-endian}
+ mode.
+
+ The {PowerPC} chip has this ability, which allows it to run
+ the little-endian {Windows NT}, or the big-endian {Mac OS/PPC}.
+
+ (1995-02-23)
+
+BIFF
+
+ /bif/ (Or "B1FF", from {Usenet}) The most famous {pseudo}, and
+ the prototypical {newbie}. Articles from BIFF are
+ characterised by all uppercase letters sprinkled liberally
+ with bangs, typos, "cute" misspellings (EVRY BUDY LUVS GOOD
+ OLD BIFF CUZ HE'S A K00L DOOD AN HE RITES REEL AWESUM THINGZ
+ IN CAPITULL LETTRS LIKE THIS!!!), use (and often misuse) of
+ fragments of {chat} abbreviations, a long {sig block}
+ (sometimes even a {doubled sig}), and unbounded naivete. BIFF
+ posts articles using his elder brother's VIC-20. BIFF's
+ location is a mystery, as his articles appear to come from a
+ variety of sites. However, {BITNET} seems to be the most
+ frequent origin. The theory that BIFF is a denizen of BITNET
+ is supported by BIFF's (unfortunately invalid) {electronic
+ mail address}: <BIFF@BIT.NET>.
+
+ [1993: Now It Can Be Told! My spies inform me that BIFF was
+ originally created by Joe Talmadge <jat@cup.hp.com>, also the
+ author of the infamous and much-plagiarised "Flamer's Bible".
+ The BIFF filter he wrote was later passed to Richard Sexton,
+ who posted BIFFisms much more widely. Versions have since
+ been posted for the amusement of the net at large. - ESR]
+
+ [{Jargon File}]
+
+ (1997-09-22)
+
+biff
+
+ /bif/ To notify someone of incoming mail. From the {BSD}
+ utility "biff(1)", which was in turn named after a friendly
+ golden Labrador who used to chase frisbees in the halls at UCB
+ while {4.2BSD} was in development (it had a well-known habit
+ of barking whenever the mailman came). No relation to {BIFF}.
+
+ [{Jargon File}]
+
+\big
+
+ <text> Prefix of several {LaTeX} commands implying a larger
+ symbol. See the command without "big". Often used to convert
+ a {dyadic} operator into a function which operates on a set.
+ E.g. \sqcup, \bigsqcup.
+
+ (1995-02-03)
+
+Big bag of pages
+
+ (BIBOP) Where data objects are tagged with some kind of
+ descriptor (giving their size or type for example) memory can
+ be saved by storing objects with the same descriptor in one
+ "page" of memory. The most significant bits of an object's
+ address are used as the BIBOP page number. This is looked up
+ in a BIBOP table to find the descriptor for all objects in
+ that page.
+
+ This idea is similar to the "zones" used in some {Lisp}
+ systems (e.g. {LeLisp}).
+
+ [David R. Hanson. "A portable storage management system for
+ the Icon programming language". Software - Practise and
+ Experience, 10:489-500 1980].
+
+ (1994-11-29)
+
+big blue
+
+ {International Business Machines}
+
+big-endian
+
+ 1. <data, architecture> A computer {architecture} in which,
+ within a given multi-{byte} numeric representation, the most
+ significant byte has the lowest address (the word is stored
+ "big-end-first").
+
+ Most processors, including the {IBM 370} family, the {PDP-10},
+ the {Motorola} {microprocessor} families, and most of the
+ various {RISC} designs current in mid-1993, are big-endian.
+
+ See {-endian}.
+
+ 2. <networking, standard> A backward {electronic mail
+ address}. The world now follows the {Internet} {hostname}
+ {standard} (see {FQDN}) and writes e-mail addresses starting
+ with the name of the computer and ending up with the {country
+ code} (e.g. fred@doc.acme.ac.uk). In the United Kingdom the
+ {Joint Networking Team} decided to do it the other way round
+ (e.g. me@uk.ac.wigan.cs) before the {Internet} {domain}
+ standard was established. Most {gateway sites} required
+ {ad-hockery} in their {mailers} to handle this.
+
+ By July 1994 this parochial idiosyncracy was on the way out
+ and mailers started to reject big-endian addresses. By about
+ 1996, people would look at you strangely if you suggested such
+ a bizarre thing might ever have existed.
+
+ [{Jargon File}]
+
+ (1998-08-09)
+
+Big Gray Wall
+
+ <jargon> What faces a {VMS} user searching for documentation.
+ A full VMS kit comes on a pallet, the documentation taking up
+ around 15 feet of shelf space before the addition of layered
+ products such as {compilers}, {databases}, multi-vendor
+ networking, and programming tools. Recent (since VMS version
+ 5) DEC documentation comes with grey binders; under VMS
+ version 4 the binders were orange and under version 3 they
+ were blue. Often contracted to "Gray Wall".
+
+ [{Jargon File}]
+
+ (1995-03-07)
+
+big iron
+
+ <jargon> (Or "heavy metal [Cambridge]) Large, expensive,
+ ultra-fast computers. Used generally of {number crunching}
+ {supercomputers} such as {Crays}, but can include more
+ conventional big commercial {IBM}ish {mainframes}. The term
+ implies approval, in contrast to "{dinosaur}".
+
+ [{Jargon File}]
+
+ (2000-11-09)
+
+BIG-LAN
+
+ ["BIG-LAN Frequently Asked Questions Memo", BIG-LAN DIGEST
+ V4:I8, February 14, 1992.]
+
+Bigloo
+
+ <language> A {Scheme} {interpreter}, {compiler} and {run-time
+ system} by Manuel Serrano <Manuel.Serrano@inria.fr> which aims
+ to deliver small, fast stand-alone {applications}. It
+ supports {modules} and {optimisation}. Bigloo's features
+ enable Scheme programs to be used where {C} or {C++} might
+ usually be required.
+
+ The Bigloo compiler produces {ANSI C} which is compiled into
+ {stand-alone executables}, {JVM} {bytecode}, or .{NET
+ bytecode}. Hence Bigloo enables Scheme programs to interwork
+ with C, {Java} and {C#} programs.
+
+ Bigloo conforms to the {IEEE Scheme} {standard} with some
+ extensions for {regular expression} handling. It runs on
+ {Sun}, {Sony} {News}, {SGI}, {Linux}, {HP-UX} and is easy to
+ port to any {Unix} system.
+
+ Latest version: 2.6f, as of 2005-03-29.
+
+ {Bigloo Home (http://www-sop.inria.fr/mimosa/fp/Bigloo/)}.
+
+ (2005-04-05)
+
+bignum
+
+ <programming> /big'nuhm/ (Originally from {MIT} {MacLISP}) A
+ {multiple-precision} computer representation for very large
+ integers.
+
+ Most computer languages provide a type of data called
+ "integer", but such computer integers are usually limited in
+ size; usually they must be smaller than 2^31 (2,147,483,648)
+ or (on a {bitty box}) 2^15 (32,768). If you want to work with
+ numbers larger than that, you have to use {floating-point}
+ numbers, which are usually accurate to only six or seven
+ decimal places. Computer languages that provide bignums can
+ perform exact calculations on very large numbers, such as
+ 1000! (the factorial of 1000, which is 1000 times 999 times
+ 998 times ... times 2 times 1). For example, this value for
+ 1000! was computed by the {MacLISP} system using bignums:
+
+ 40238726007709377354370243392300398571937486421071
+ 46325437999104299385123986290205920442084869694048
+ 00479988610197196058631666872994808558901323829669
+ 94459099742450408707375991882362772718873251977950
+ 59509952761208749754624970436014182780946464962910
+ 56393887437886487337119181045825783647849977012476
+ 63288983595573543251318532395846307555740911426241
+ 74743493475534286465766116677973966688202912073791
+ 43853719588249808126867838374559731746136085379534
+ 52422158659320192809087829730843139284440328123155
+ 86110369768013573042161687476096758713483120254785
+ 89320767169132448426236131412508780208000261683151
+ 02734182797770478463586817016436502415369139828126
+ 48102130927612448963599287051149649754199093422215
+ 66832572080821333186116811553615836546984046708975
+ 60290095053761647584772842188967964624494516076535
+ 34081989013854424879849599533191017233555566021394
+ 50399736280750137837615307127761926849034352625200
+ 01588853514733161170210396817592151090778801939317
+ 81141945452572238655414610628921879602238389714760
+ 88506276862967146674697562911234082439208160153780
+ 88989396451826324367161676217916890977991190375403
+ 12746222899880051954444142820121873617459926429565
+ 81746628302955570299024324153181617210465832036786
+ 90611726015878352075151628422554026517048330422614
+ 39742869330616908979684825901254583271682264580665
+ 26769958652682272807075781391858178889652208164348
+ 34482599326604336766017699961283186078838615027946
+ 59551311565520360939881806121385586003014356945272
+ 24206344631797460594682573103790084024432438465657
+ 24501440282188525247093519062092902313649327349756
+ 55139587205596542287497740114133469627154228458623
+ 77387538230483865688976461927383814900140767310446
+ 64025989949022222176590433990188601856652648506179
+ 97023561938970178600408118897299183110211712298459
+ 01641921068884387121855646124960798722908519296819
+ 37238864261483965738229112312502418664935314397013
+ 74285319266498753372189406942814341185201580141233
+ 44828015051399694290153483077644569099073152433278
+ 28826986460278986432113908350621709500259738986355
+ 42771967428222487575867657523442202075736305694988
+ 25087968928162753848863396909959826280956121450994
+ 87170124451646126037902930912088908694202851064018
+ 21543994571568059418727489980942547421735824010636
+ 77404595741785160829230135358081840096996372524230
+ 56085590370062427124341690900415369010593398383577
+ 79394109700277534720000000000000000000000000000000
+ 00000000000000000000000000000000000000000000000000
+ 00000000000000000000000000000000000000000000000000
+ 00000000000000000000000000000000000000000000000000
+ 00000000000000000000000000000000000000000000000000
+ 000000000000000000.
+
+ [{Jargon File}]
+
+ (1996-06-27)
+
+bigot
+
+ A person who is religiously attached to a particular computer,
+ language, operating system, editor, or other tool (see
+ {religious issues}). Usually found with a specifier; thus,
+ "Cray bigot", "ITS bigot", "APL bigot", "VMS bigot", "Berkeley
+ bigot". Real bigots can be distinguished from mere partisans
+ or zealots by the fact that they refuse to learn alternatives
+ even when the march of time and/or technology is threatening
+ to obsolete the favoured tool. It is truly said "You can tell
+ a bigot, but you can't tell him much." Compare {weenie}.
+
+ [{Jargon File}]
+
+Big Red Switch
+
+ <jargon> (BRS) IBM jargon for the {power switch} on a computer,
+ especially the "Emergency Pull" switch on an IBM {mainframe} or
+ the power switch on an IBM PC where it really is large and red.
+
+ "This !@%$% {bitty box} is hung again; time to hit the Big Red
+ Switch."
+
+ It is alleged that the emergency pull switch on an {IBM 360}/91
+ actually fired a non-conducting bolt into the main power feed; the
+ BRSes on more recent mainframes physically drop a block into place
+ so that they can't be pushed back in. People get fired for
+ pulling them, especially inappropriately (see also {molly-guard}).
+
+ Compare {power cycle}, {three-finger salute}, {120 reset}; see
+ also {scram switch}.
+
+ [{Jargon File}]
+
+ (2014-08-10)
+
+Big Room
+
+ <jargon, humour> The extremely large room with the blue
+ ceiling and intensely bright light (during the day) or black
+ ceiling with lots of tiny night-lights (during the night)
+ found outside all computer installations. "He can't come to
+ the phone right now, he's somewhere out in the Big Room."
+
+ (1996-03-04)
+
+big win
+
+ <jargon> An {MIT} term for a {Good Thing} or a lucky accident.
+
+ [{Jargon File}]
+
+ (1996-03-06)
+
+bijection
+
+ <mathematics> A {function} is bijective or a bijection or a
+ one-to-one correspondence if it is both {injective} (no two
+ values map to the same value) and {surjective} (for every
+ element of the {codomain} there is some element of the
+ {domain} which maps to it). I.e. there is exactly one element
+ of the domain which maps to each element of the codomain.
+
+ For a general bijection f from the set A to the set B:
+
+ f'(f(a)) = a where a is in A and f(f'(b)) = b where b is in B.
+
+ A and B could be disjoint sets.
+
+ See also {injection}, {surjection}, {isomorphism},
+ {permutation}.
+
+ (2001-05-10)
+
+Bill Gates
+
+ <person> William Henry Gates III, Chief Executive Officer of
+ {Microsoft}, which he co-founded in 1975 with {Paul Allen}.
+ In 1994 Gates is a billionaire, worth $9.35b and {Microsoft}
+ is worth about $27b. He was a {computer nerd} who dropped out
+ of Harvard and one of the first programmers to oppose
+ {software piracy} ("Open Letter to Hobbyists," Computer Notes,
+ February 3, 1976).
+
+ (1995-03-02)
+
+Bill Joy
+
+ {William Joy}
+
+binaries
+
+ {binary file}
+
+binary
+
+ 1. <mathematics> {Base} two. A number representation
+ consisting of zeros and ones used by practically all computers
+ because of its ease of implementation using digital
+ electronics and {Boolean algebra}.
+
+ 2. <file format> {binary file}.
+
+ 3. <programming> A description of an {operator} which takes
+ two {arguments}. See also {unary}, {ternary}.
+
+ (2005-02-21)
+
+binary coded decimal
+
+ <data> (BCD, packed decimal) A number representation where a
+ number is expressed as a sequence of decimal digits and then
+ each decimal digit is encoded as a four-bit binary number (a
+ {nibble}). E.g. decimal 92 would be encoded as the eight-bit
+ sequence 1001 0010.
+
+ In some cases, the right-most nibble contains the sign
+ (positive or negative).
+
+ It is easier to convert decimal numbers to and from BCD than
+ binary and, though BCD is often converted to binary for
+ arithmetic processing, it is possible to build {hardware} that
+ operates directly on BCD.
+
+ [Do calculators use BCD?]
+
+ (2001-01-27)
+
+Binary Compatibility Standard
+
+ <programming, standard> (BCS) The {ABI} of {88open}.
+
+ (1997-07-03)
+
+binary counter
+
+ <electronics, hardware> A digital circuit which has a clock
+ input and a number of count outputs which give the number of
+ clock cycles. The output may change either on rising or
+ falling clock edges. The circuit may also have a reset input
+ which sets all outputs to zero when asserted. The counter may
+ be either a {synchronous counter} or a {ripple counter}.
+
+ (1997-07-03)
+
+binary data
+
+ {binary file}
+
+binary exponential backoff
+
+ An {algorithm} for dealing with contention in the use of a
+ network. To transmit a {packet} the {host} sets a local
+ parameter, L to 1 and transmits in one of the next L {slots}.
+ If a {collision} occurs, it doubles L and repeats.
+
+binary file
+
+ <file format> Any {file format} for {digital} {data} that does
+ not consist of a sequence of printable {characters} ({text}).
+ The term is often used for executable {machine code}.
+
+ All digital data, including characters, is actually binary
+ data (unless it uses some (rare) system with more than two
+ discrete levels) but the distinction between binary and text
+ is well established. On modern {operating systems} a text
+ file is simply a binary file that happens to contain only
+ printable characters, but some older systems distinguish the
+ two file types, requiring programs to handle them differently.
+
+ A common class of binary files is programs in {machine
+ language} ("{executable} files") ready to load into memory and
+ execute. Binary files may also be used to store data output
+ by a program, and intended to be read by that or another
+ program but not by humans. Binary files are more efficient
+ for this purpose because the data (e.g. numerical data) does
+ not need to be converted between the binary form used by the
+ {CPU} and a printable (ASCII) representation. The
+ disadvantage is that it is usually necessary to write special
+ purpose programs to manipulate such files since most general
+ purpose utilities operate on text files. There is also a
+ problem sharing binary numerical data between processors with
+ different {endian}ness.
+
+ Some communications {protocols} handle only text files,
+ e.g. most {electronic mail} systems before {MIME} became
+ widespread in about 1995. The {FTP} utility must be put into
+ "binary" mode in order to copy a binary file since in its
+ default "ascii" mode translates between the different
+ {newline} characters used on the sending and receiving
+ computers.
+
+ Confusingly, some {word processor} files, and {rich text}
+ files, are actually binary files because they contain
+ non-printable characters and require special programs to view,
+ edit and print them.
+
+ (2005-02-21)
+
+binary large object
+
+ <database> (BLOB) A large block of data stored in a
+ {database}, such as an {image} or {sound} file. A BLOB has no
+ structure which can be interpreted by the {database management
+ system} but is known only by its size and location.
+
+ (1997-11-04)
+
+binary package
+
+ <software> An {archive} file that contains all files and
+ directories that must be installed in order to make a working
+ installation of the program(s) included in the package, and
+ the {maintainer scripts} necessary for the installation. A
+ binary package is usually specific to a certain {platform}, in
+ contrast to a {source package}.
+
+ (2001-01-27)
+
+binary prefix
+
+ <unit> (Or "IEC prefix") A prefix used with a {unit} of {data} to
+ mean multiplication by a power of 1024. Binary prefixes are most
+ often used with "{byte}" (e.g. "{kilobyte}") but also with {bit}
+ (e.g. "{megabit}").
+
+ For example, the term {kilobyte} has historically been used to
+ mean 1024 {bytes}, and {megabyte} to mean 1,048,576 bytes. The
+ multipliers 1024 and 1,048,576 are powers of 1024, which is itself
+ a power of two (1024 = 2^10). It is this factor of two that gives
+ the name "binary prefix".
+
+ This is in contrast to a {decimal prefix} denoting a power of
+ 1000, which is itself a power of ten (1000 = 10^3). Decimal
+ prefixes are used in science and engineering and are specified in
+ widely adopted {SI} standards. Note that the actual prefix - kilo
+ or mega - is the same, it is the interpretation that differs.
+
+ The difference between the two interpretations increases with each
+ multiplication, so while 1000 and 1024 differ by only 2.4%, 1000^6
+ and 1024^6 differ by 15%.
+
+ The 1024-based interpretation of prefixes is often still used
+ informally and especially when discussing the storage capacity of
+ {random-access memory}. This has lead to storage device
+ manufacturers being accused of false marketing for using the
+ decimal interpretation where customers might assume the larger,
+ historical, binary interpretation.
+
+ In an attempt to clarify the distinction, in 1998 the {IEC}
+ specified that kilobyte, megabyte, etc. should only be used for
+ powers of 1000 (following SI). They specified new prefixes for
+ powers of 1024 containing "bi" for "binary": {kibibyte},
+ {mebibyte}, etc.; an idea originally propsed by {IUPAC}. IEC also
+ specified new abbreviations Ki, Mi, etc. for the new prefixes.
+ Many other standards bodies such as {NIST}, {IEEE} and {BIPM}
+ support this proposal but as of 2013 its use is rare in
+ non-technical circles.
+
+ Specific units of IEC 60027-2 A.2 and ISO/IEC 80000
+
+ IEC prefix Representations Customary prefix
+ Name Symbol Base 2 Base Base 10 Name Symbol
+ 1024 (approx)
+ kibi Ki 2^10 1024^1 1.02x10^3 kilo k, K
+ mebi Mi 2^20 1024^2 1.05x10^6 mega M
+ gibi Gi 2^30 1024^3 1.07x10^9 giga G
+ tebi Ti 2^40 1024^4 1.10x10^12 tera T
+ pebi Pi 2^50 1024^5 1.13x10^15 peta P
+ exbi Ei 2^60 1024^6 1.15x10^18 exa E
+ zebi Zi 2^70 1024^7 1.18x10^21 zetta Z
+ yobi Yi 2^80 1024^8 1.21x10^24 yotta Y
+
+ (2013-11-04)
+
+binary search
+
+ <algorithm> A search {algorithm} which repeatedly divides an
+ ordered {search space} in half according to how the required
+ (key) value compares with the middle element.
+
+ The following pseudo-{C} routine performs a binary search
+ return the index of the element of vector "thing[first..last]"
+ equal to "target":
+
+ if (target < thing[first] || target > thing[last])
+ return NOT_FOUND;
+ while (first < last)
+ {
+ mid = (first+last)/2; /* truncate to integer */
+ if (target == thing[mid])
+ return mid;
+ if (target < thing[mid])
+ last = mid-1;
+ else
+ first = mid+1;
+ }
+ if (target == thing[last])
+ return last;
+ return NOT_FOUND;
+
+ (2003-01-14)
+
+Binary Synchronous Transmission
+
+ <protocol> (Bisynch) An {IBM} link {protocol}, developed in
+ the 1960 and popular in the 1970s and 1980s.
+
+ Binary Synchronous Transmission has been largely replaced in
+ IBM environments with {SDLC}. Bisync was developed for
+ {batch} communications between a {System 360} computer and the
+ IBM 2780 and 3780 {Remote Job Entry} (RJE) {terminals}. It
+ supports RJE and on-line terminals in the {CICS}/{VSE}
+ environment. It operates with {EBCDIC} or {ASCII} {character
+ sets}. It requires that every message be acknowledged ({ACK})
+ or negatively acknowledged ({NACK}) so it has high
+ transmission overhead. It is typically character oriented and
+ {half-duplex}, although some of the bisync protocol flavours
+ or dialects support binary transmission and {full-duplex}
+ operation.
+
+ (1997-01-07)
+
+binary tree
+
+ (btree) A {tree} in which each node has at most two successors
+ or child nodes. In {Haskell} this could be represented as
+
+ data BTree a = NilTree
+ | Node a (BTree a) (BTree a)
+
+ See also {balanced tree}.
+
+ (1994-11-29)
+
+BIND
+
+ {Berkeley Internet Name Domain}
+
+bindery
+
+ <networking> A {Novell Netware} database that contains
+ definitions for entities such as users, groups, and
+ {workgroups}. The bindery allows the network supervisor to
+ design an organised and secure operating environment based on
+ the individual requirements of each of these entities.
+
+ The bindery has three components: objects, properties, and
+ property data sets. Objects represent any physical or logical
+ entity, including users, user groups, file servers.
+ Properties are characteristics of each object (e.g.
+ passwords, account restrictions, {internetwork addresses}).
+ Property data sets are the values assigned to an entity's
+ bindery properties.
+
+ [Netware Version 3.11 "Concepts" documentation (a glossary of
+ Netware-related terms)].
+
+ (1996-03-07)
+
+binding handle
+
+ <networking> An identifier representing the connection between
+ a {client} and {server}. An association between client/server
+ end-points and {protocols}.
+
+ (1997-03-18)
+
+binding-time analysis
+
+ <compiler> An analysis to identify sub-expressions which can
+ be evaluated at {compile-time} or where versions of a function
+ can be generated and called which are specialised to certain
+ values of one or more arguments.
+
+ See {partial evaluation}.
+
+ (1995-03-28)
+
+BinHex
+
+ <file format> A {Macintosh} format for representing a {binary
+ file} using only {printable characters}. The file is
+ converted to lines of letters, numbers and punctuation.
+ Because BinHex files are simply text they can be sent through
+ most {electronic mail} systems and stored on most computers.
+ However the conversion to text makes the file larger, so it
+ takes longer to transmit a file in BinHex format than if the
+ file was represented some other way.
+
+ {Filename extension}: .hqx.
+
+ See also {BinHex 4.0}, {uuencode}.
+
+ [Encoding algorithm?]
+
+ (1994-11-30)
+
+Binhex 4.0
+
+ <file format> A seven bit wide representation of a {Macintosh}
+ file with {CRC} error checking. Binhex 4.0 files are designed
+ for communication of Mac files over long distance, possibly
+ noisy, seven bit wide paths.
+
+ [Difference from other binhex formats?]
+
+ (1996-09-17)
+
+BinProlog
+
+ <language> Probably the fastest freely available {C}-emulated
+ {Prolog}. BinProlog features:
+
+ logical and permanent {global variables}; backtrackable
+ {destructive assignment}; circular term {unification};
+ extended {DCGs} (now built into the {engine} as "invisible
+ grammars"); {intuitionistic} and {linear implication} based
+ {hypothetical reasoning}; a {Tcl}/{Tk} interface.
+
+ Version 3.30 runs on {SPARC}/{Solaris} 2.x, {SunOS} 4.x; {DEC
+ Alpha} 64-bit version; {DEC} {MIPS}; {SGI} {MIPS}; {68k} -
+ {NeXT}, {Sun-3}; {IBM RS6000}; {HP PA-RISC} (two variants);
+ {Intel 80386}, {Intel 486}/{Linux}, {MS-DOS}, {Microsoft
+ Windows 3.1} (with DOS-extender {go32} v1.10).
+
+ {Multi-BinProlog} is a {multi-threaded} {Linda}-style parallel
+ extension to BinProlog for {Solaris} 2.3.
+
+ {(ftp://clement.info.umoncton.ca/BinProlog/)}.
+
+ E-mail: Paul Tarau <tarau@info.umoncton.ca>.
+
+ (1995-04-04)
+
+bioinformatics
+
+ <application> The field of science concerning the application
+ of {computer science} and {information technology} to biology;
+ using computers to handle biological information, especially
+ {computational molecular biology}.
+
+ (2005-01-07)
+
+BioMeDical Package
+
+ <language, library, statistics> (BMDP) A statistical language
+ and library of over forty statistical routines developed in
+ 1961 at {UCLA}, Health Sciences Computing Facility under
+ Dr. Wilford Dixon. BMDP was first implemented in {Fortran}
+ for the {IBM 7090}. Tapes of the original source were
+ distributed for free all over the world.
+
+ BMDP is the second iteration of the original {BIMED} programs.
+ It was developed at {UCLA} Health Sciences Computing facility,
+ with NIH funding. The "P" in BMDP originally stood for
+ "parameter" but was later changed to "package". BMDP used
+ keyword parameters to defined what was to be done rather than
+ the fixed card format used by original BIMED programs.
+
+ BMDP supports many statistical funtions: simple data
+ description, {survival analysis}, {ANOVA}, {multivariate
+ analyses}, {regression analysis}, and {time series} analysis.
+
+ BMDP Professional combines the full suite of BMDP Classic
+ (Dynamic) release 7.0 with the BMDP New System 2.0 {Windows}
+ front-end.
+
+ {BMDP from Statistical Solutions
+ (http://statsol.ie/bmdp/bmdp.htm)}.
+
+ (2004-01-14)
+
+biometric device
+
+ {biometrics}
+
+biometrics
+
+ <security, hardware> The use of special input devices to
+ analyse some physical parameter assumed to be unique to an
+ individual, in order to confirm their identity as part of an
+ {authentication} procedure.
+
+ Examples include {fingerprint scanning}, {iris recognition},
+ {facial recognition}, voice recognition ({speaker
+ recognition}), {signature}, {vascular pattern recognition}.
+
+ {(http://www.findbiometrics.com/Pages/guide2.html)}.
+
+ (2007-02-22)
+
+BIOR
+
+ An early system on {UNIVAC} I or II.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1995-04-01)
+
+BIOS
+
+ {Basic Input/Output System}
+
+BIP
+
+ An incorrect singular of {BIPS}. One billion instructions per
+ second is 1 BIPS, not 1 BIP.
+
+bipartite graph
+
+ {complete graph}
+
+BIPM
+
+ {Bureau International des Poids et Mesures}
+
+bipolar
+
+ 1. <electronics> See {bipolar transistor}.
+
+ 2. <communications> In digital transmission, an electrical
+ line signalling method where the mark value alternates between
+ positive and negative polarities.
+
+ See also {AMI}.
+
+ (1995-03-02)
+
+bipolar transistor
+
+ <electronics> A {transistor} made from a sandwich of n- and
+ p-type {semiconductor} material: either npn or pnp. The
+ middle section is known as the "base" and the other two as the
+ "collector" and "emitter". When used as an amplifying
+ element, the base to emitter junction is in a "forward-biased"
+ (conducting) condition, and the base to collector junction is
+ "reverse-biased" or non-conducting. Small changes in the base
+ to emitter current (the input signal) cause either {holes}
+ (for pnp devices) or free {electrons} (for npn) to enter the
+ base from the emitter. The attracting voltage of the
+ collector causes the majority of these charges to cross into
+ and be collected by the collector, resulting in amplification.
+
+ Contrast {field effect transistor}.
+
+ (1995-10-04)
+
+BIPS
+
+ Billion (10^9) instructions per second. Same as {GIPS}.
+
+Bird-Meertens Formalism
+
+ <theory, programming> (BMF) (Or "Squiggol") A calculus for
+ derivation of {functional programs} from a specification. It
+ consists of a set of {higher-order functions} that operate on
+ lists including {map}, {fold}, {scan}, {filter}, inits, tails,
+ {cross product} and {function composition}.
+
+ ["A Calculus of Functions for Program Derivation", R.S. Bird,
+ in Res Topics in Fnl Prog, D. Turner ed, A-W 1990].
+
+ ["The Squiggolist", ed Johan Jeuring, published irregularly by
+ CWI Amsterdam].
+
+ (1995-05-01)
+
+Birds Of a Feather
+
+ (BOF) (From the saying "Birds of a feather flock together") An
+ informal discussion group, scheduled on a conference program
+ or formed ad hoc, to consider a specific issue or subject. It
+ is not clear where or when this term originated, but it is now
+ associated with the {USENIX} conferences for {Unix} techies
+ and was already established there by 1984. It was used
+ earlier than that at {DECUS} conferences and is reported to
+ have been common at {SHARE} meetings as far back as the early
+ 1960s.
+
+ (1994-10-11)
+
+BISDN
+
+ Broadband {Integrated Services Digital Network}.
+
+Bison
+
+ <tool> {GNU}'s replacement for the {yacc} {parser generator}.
+ Bison runs under {Unix} and on {Atari} computers. It was
+ written by Robert Corbett.
+
+ Latest version: 1.28, as of 2000-05-22.
+
+ As of version 1.24, Bison will no longer apply the {GNU}
+ {General Public License} to your code. You can use the output
+ files without restriction.
+
+ {FTP GNU.org (ftp://ftp.gnu.org/gnu/bison/)} or your nearest
+ {GNU archive site}.
+
+ E-mail: <bug-bison@gnu.org>.
+
+ {Bison++} is a version which produces {C++} output.
+
+ (2000-07-05)
+
+Bison++
+
+ GNU's Yacc parser generator retargeted to C++ by Alain
+ Coetmeur <coetmeur@icdc.fr>. Version 1.04.
+
+ {(ftp://iecc.com/pub/file/bison++.tar.gz)}.
+ {(ftp://iecc.com/pub/file/misc++.tar.gz)}.
+ {(ftp://psuvax1.cs.psu.edu/pub/src/gnu/bison++-1.04.tar.Z)}.
+
+ (1993-07-08)
+
+BIST
+
+ {Built-in Self Test}
+
+bisync
+
+ {Binary Synchronous Transmission}
+
+bit
+
+ <unit> (b) {binary} digit.
+
+ The unit of information; the amount of information obtained by
+ asking a yes-or-no question; a computational quantity that can
+ take on one of two values, such as false and true or 0 and 1;
+ the smallest unit of storage - sufficient to hold one bit.
+
+ A bit is said to be "set" if its value is true or 1, and
+ "reset" or "clear" if its value is false or 0. One speaks of
+ setting and clearing bits. To {toggle} or "invert" a bit is
+ to change it, either from 0 to 1 or from 1 to 0.
+
+ The term "bit" first appeared in print in the computer-science
+ sense in 1949, and seems to have been coined by the eminent
+ statistician, {John Tukey}. Tukey records that it evolved
+ over a lunch table as a handier alternative to "bigit" or
+ "binit".
+
+ See also {flag}, {trit}, {mode bit}, {byte}, {word}.
+
+ [{Jargon File}]
+
+ (2002-01-22)
+
+bit bang
+
+ Transmission of data on a {serial line} accomplished by
+ rapidly changing a single output bit, in software, at the
+ appropriate times. The technique is a simple loop with eight
+ OUT and SHIFT instruction pairs for each byte. Input is more
+ interesting. And {full-duplex} (doing input and output at the
+ same time) is one way to separate the real hackers from the
+ {wannabees}.
+
+ Bit bang was used on certain early models of {Prime}
+ computers, presumably when {UARTs} were too expensive, and on
+ archaic {Zilog Z80} micros with a {Zilog} PIO but no SIO. In
+ an interesting instance of the {cycle of reincarnation}, this
+ technique is now (1991) coming back into use on some {RISC}
+ architectures because it consumes such an infinitesimal part
+ of the processor that it actually makes sense not to have a
+ {UART}.
+
+ [{Jargon File}]
+
+bit bashing
+
+ (Also "bit diddling" or {bit twiddling}). Any of several
+ kinds of low-level programming characterised by manipulation
+ of {bit}, {flag}, {nibble}, and other
+ smaller-than-character-sized pieces of data. These include
+ low-level device control, encryption algorithms, checksum and
+ error-correcting codes, hash functions, some flavours of
+ graphics programming (see {bitblt}), and assembler/compiler
+ code generation. May connote either tedium or a real
+ technical challenge (more usually the former). "The command
+ decoding for the new tape driver looks pretty solid but the
+ bit-bashing for the control registers still has bugs." See
+ also {bit bang}, {mode bit}.
+
+bitblt
+
+ /bit'blit/ [{BLT}] 1. Any of a family of closely related
+ algorithms for moving and copying rectangles of bits between
+ main and display memory on a {bit-mapped} device, or between
+ two areas of either main or display memory (the requirement to
+ do the {Right Thing} in the case of overlapping source and
+ destination rectangles is what makes BitBlt tricky).
+
+ 2. {blit}, {BLT}.
+
+ [{Jargon File}]
+
+bit bucket
+
+ <jargon> 1. (Or "{write-only memory}", "WOM") The universal
+ data sink (originally, the mythical receptacle used to catch
+ bits when they fall off the end of a {register} during a
+ {shift} instruction). Discarded, lost, or destroyed data is
+ said to have "gone to the bit bucket". On {Unix}, often used
+ for {/dev/null}. Sometimes amplified as "the Great Bit Bucket
+ in the Sky".
+
+ 2. The place where all lost mail and news messages eventually
+ go. The selection is performed according to {Finagle's Law};
+ important mail is much more likely to end up in the bit bucket
+ than junk mail, which has an almost 100% probability of
+ getting delivered. Routing to the bit bucket is automatically
+ performed by mail-transfer agents, news systems, and the lower
+ layers of the network.
+
+ 3. The ideal location for all unwanted mail responses: "Flames
+ about this article to the bit bucket." Such a request is
+ guaranteed to overflow one's mailbox with flames.
+
+ 4. Excuse for all mail that has not been sent. "I mailed you
+ those figures last week; they must have landed in the bit
+ bucket." Compare {black hole}.
+
+ This term is used purely in jest. It is based on the fanciful
+ notion that bits are objects that are not destroyed but only
+ misplaced. This appears to have been a mutation of an earlier
+ term "bit box", about which the same legend was current;
+ old-time hackers also report that trainees used to be told
+ that when the CPU stored bits into memory it was actually
+ pulling them "out of the bit box".
+
+ Another variant of this legend has it that, as a consequence
+ of the "parity preservation law", the number of 1 bits that go
+ to the bit bucket must equal the number of 0 bits. Any
+ imbalance results in bits filling up the bit bucket. A
+ qualified computer technician can empty a full bit bucket as
+ part of scheduled maintenance.
+
+ In contrast, a "{chad box}" is a real container used to catch
+ {chad}. This may be related to the origin of the term "bit
+ bucket" [Comments ?].
+
+ (1996-11-20)
+
+bit decay
+
+ {bit rot}
+
+bit diddling
+
+ {bit bashing}
+
+bite
+
+ {byte}
+
+Bit Error Rate
+
+ <data, communications> (BER) The fraction of a message or block of
+ {data} that is wrong.
+
+ (2003-03-25)
+
+bit field
+
+ <data> Part of an item of data, storage location or message,
+ identified as a certain number of contiguous {bits} starting
+ at a certain bit position within the data. Bit position zero
+ is usually the least significant bit.
+
+ For example, in an {ARM} {machine code} instruction the
+ four-bit field at bits 28 to 31 (the four most significant
+ bits in the 32-bit word) is the "condition code".
+
+ (2007-03-26)
+
+bitmap
+
+ <graphics, file format> A data file or structure which
+ corresponds {bit} for bit with an {image} displayed on a
+ screen, probably in the same format as it would be stored in
+ the display's {video memory} or maybe as a {device independent
+ bitmap}. A bitmap is characterised by the width and height of
+ the image in {pixels} and the number of bits per pixel which
+ determines the number of shades of grey or colours it can
+ represent. A bitmap representing a coloured image (a
+ "{pixmap}") will usually have pixels with between one and
+ eight bits for each of the red, green, and blue components,
+ though other colour encodings are also used. The green
+ component sometimes has more bits that the other two to cater
+ for the human eye's greater discrimination in this component.
+
+ See also {vector graphics}, {image formats}.
+
+ (1996-09-21)
+
+bitmap display
+
+ <hardware> A computer output device where each {pixel}
+ displayed on the {monitor} screen corresponds directly to one
+ or more {bits} in the computer's {video memory}. Such a
+ display can be updated extremely rapidly since changing a
+ pixel involves only a single processor write to memory
+ compared with a {terminal} or {VDU} connected via a serial
+ line where the speed of the serial line limits the speed at
+ which the display can be changed.
+
+ Most modern {personal computers} and {workstations} have
+ bitmap displays, allowing the efficient use of {graphical user
+ interfaces}, interactive graphics and a choice of on-screen
+ {fonts}. Some more expensive systems still delegate graphics
+ operations to dedicated hardware such as {graphics
+ accelerators}.
+
+ The bitmap display might be traced back to the earliest days
+ of computing when the Manchester University Mark I(?)
+ computer, developed by F.C. Williams and T. Kilburn shortly
+ after the Second World War. This used a {storage tube} as its
+ {working memory}. Phosphor dots were used to store single
+ bits of data which could be read by the user and interpreted
+ as binary numbers.
+
+ [Is this history correct? Was it ever used to display
+ "graphics"? What was the resolution?]
+
+ (2002-05-15)
+
+bitmap font
+
+ <text> A {font} where each character is stored as an {array}
+ of {pixels} (a {bitmap}). Such fonts are not easily scalable,
+ in contrast to {vectored fonts} (like those used in
+ {PostScript}).
+
+ [Examples?]
+
+ (1995-02-16)
+
+bitmapped display
+
+ {bitmap display}
+
+bit mask
+
+ <programming> A pattern of {binary} values which is combined
+ with some value using {bitwise} AND with the result that bits
+ in the value in positions where the mask is zero are also set
+ to zero. For example, if, in {C}, we want to test if bits 0
+ or 2 of x are set, we can write
+
+ int mask = 5; /* binary 101 */
+
+ if (x & mask) ...
+
+ A bit mask might also be used to set certain bits using
+ bitwise OR, or to invert them using bitwise {exclusive OR}.
+
+ (1995-05-12)
+
+BITNET
+
+ <networking> /bit'net/ (Because It's Time NETwork) An academic
+ and research computer network connecting approximately 2500
+ computers. BITNET provides interactive, {electronic mail} and
+ file transfer services, using a {store and forward}
+ {protocol}, based on {IBM} {Network Job Entry} protocols.
+
+ Bitnet-II encapsulates the Bitnet protocol within {IP}
+ {packets} and depends on the {Internet} to route them. BITNET
+ traffic and Internet traffic are exchanged via several
+ {gateway} hosts.
+
+ BITNET is now operated by {CREN}.
+
+ BITNET is everybody's least favourite piece of the network.
+ The BITNET hosts are a collection of {IBM} {dinosaurs},
+ {VAXen} (with lobotomised communications hardware), and {Prime
+ Computer} supermini computers. They communicate using
+ 80-character {EBCDIC} card images (see {eighty-column mind});
+ thus, they tend to mangle the {headers} and text of
+ third-party traffic from the rest of the {ASCII}/{RFC 822}
+ world with annoying regularity. BITNET is also notorious as
+ the apparent home of {BIFF}.
+
+ [{Jargon File}]
+
+ (2002-09-02)
+
+bitonal image
+
+ <graphics> An {image} consisting only of a foreground colour
+ and a background colour.
+
+ Compare {monochrome}.
+
+ (1998-03-14)
+
+bit-paired keyboard
+
+ <hardware> (Obsolete, or "bit-shift keyboard") A non-standard
+ keyboard layout that seems to have originated with the
+ {Teletype} {ASR-33} and remained common for several years on
+ early computer equipment. The ASR-33 was a mechanical device
+ (see {EOU}), so the only way to generate the character codes
+ from keystrokes was by some physical linkage. The design of
+ the ASR-33 assigned each character key a basic pattern that
+ could be modified by flipping bits if the SHIFT or the CTRL
+ key was pressed. In order to avoid making the thing more of a
+ Rube Goldberg {kluge} than it already was, the design had to
+ group characters that shared the same basic bit pattern on one
+ key.
+
+ Looking at the {ASCII} chart, we find:
+
+ high low bits
+ bits 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001
+ 010 ! " # $ % & ' ( )
+ 011 0 1 2 3 4 5 6 7 8 9
+
+ This is why the characters !"#$%&'() appear where they do on a
+ Teletype (thankfully, they didn't use shift-0 for space).
+ This was *not* the weirdest variant of the {QWERTY} layout
+ widely seen, by the way; that prize should probably go to one
+ of several (differing) arrangements on {IBM}'s even clunkier
+ 026 and 029 card punches.
+
+ When electronic {terminals} became popular, in the early
+ 1970s, there was no agreement in the industry over how the
+ keyboards should be laid out. Some vendors opted to emulate
+ the Teletype keyboard, while others used the flexibility of
+ electronic circuitry to make their product look like an office
+ typewriter. These alternatives became known as "bit-paired"
+ and "typewriter-paired" keyboards. To a hacker, the
+ bit-paired keyboard seemed far more logical - and because most
+ hackers in those days had never learned to touch-type, there
+ was little pressure from the pioneering users to adapt
+ keyboards to the typewriter standard.
+
+ The doom of the bit-paired keyboard was the large-scale
+ introduction of the computer terminal into the normal office
+ environment, where out-and-out technophobes were expected to
+ use the equipment. The "typewriter-paired" standard became
+ universal, "bit-paired" hardware was quickly junked or
+ relegated to dusty corners, and both terms passed into disuse.
+
+ [{Jargon File}]
+
+ (1995-02-20)
+
+bit pattern
+
+ <data> A sequence of {bits}, in a memory, a communications
+ channel or some other device. The term is used to contrast
+ this with some higher level interpretation of the bits such as
+ an integer or an {image}. A {bit string} is similar but
+ suggests an arbitrary, as opposed to predetermined, length.
+
+ (1998-09-27)
+
+bit plane
+
+ <graphics> (Or "bitplane") The memory in a graphic display
+ device which holds a complete one-bit-per-{pixel} image.
+ Several bit planes may be used in conjunction to give more
+ bits per pixel or to overlay several images or mask one with
+ another.
+
+ "Bit plane" may be used as a synonym for "{bitmap}", though
+ the latter suggests the data itself rather than the memory and
+ also suggests a graphics file format.
+
+ (1997-03-16)
+
+bit rate
+
+ <communications, digital signal processing> (Or "bitrate") A
+ {data rate} expressed in bits per second. This is a similar
+ to {baud} but the latter is more applicable to channels with
+ more than two states.
+
+ The common units of bit rate are {kilobits per second} (Kbps)
+ and {megabits per second} (Mbps). In data rates, the
+ multipliers "k", "M", etc. stand for powers of 1000 not powers
+ of 1024.
+
+ The term is also commonly used when discussing digital
+ {sampling} and {sample rates}. For example, the {MP3} audio
+ {compaction} algorithm is often set to ouput files with a
+ bitrate of 120 kbps. This means that the file contains an
+ average of 120 kilobits for each second of audio (900 KB per
+ minute). This compares with {CD audio} which is encoded at
+ 44100 16-bit stereo samples per second or 1408 kbps.
+
+ (2003-05-19)
+
+bit-robbing
+
+ {in-band signalling}
+
+bit rot
+
+ <jargon> A hypothetical disease the existence of which has
+ been deduced from the observation that unused programs or
+ features will often stop working after sufficient time has
+ passed, even if "nothing has changed". The theory explains
+ that bits decay as if they were radioactive. As time passes,
+ the contents of a file or the code in a program will become
+ increasingly garbled.
+
+ People with a physics background tend to prefer the variant
+ "bit decay" for the analogy with particle decay.
+
+ There actually are physical processes that produce such
+ effects (alpha particles generated by trace radionuclides in
+ ceramic chip packages, for example, can change the contents of
+ a computer memory unpredictably, and various kinds of subtle
+ media failures can corrupt files in mass storage), but they
+ are quite rare (and computers are built with {error detection}
+ circuitry to compensate for them). The notion long favoured
+ among hackers that {cosmic rays} are among the causes of such
+ events turns out to be a myth.
+
+ Bit rot is the notional cause of {software rot}.
+
+ See also {computron}, {quantum bogodynamics}.
+
+ [{Jargon File}]
+
+ (1998-03-15)
+
+bit slice
+
+ <architecture> A technique for constructing a {processor} from
+ modules, each of which processes one {bit-field} or "slice" of
+ an {operand}. Bit slice processors usually consist of an
+ {ALU} of 1, 2, 4 or 8 bits and control lines (including
+ {carry} or {overflow} signals usually internal to the {CPU}).
+ For example, two 4-bit ALUs could be arranged side by side,
+ with control lines between them, to form an 8-bit ALU. A
+ {sequencer} executes a program to provide data and control
+ signals.
+
+ The {AMD Am2901} is an example.
+
+ (1994-11-15)
+
+bits per inch
+
+ <unit> (BPI) A measure of the recording density of a {magnetic
+ tape} or {disk}.
+
+ (1995-04-13)
+
+bits per pixel
+
+ <hardware, graphics> (bpp) The number of {bits} of information
+ stored per {pixel} of an {image} or displayed by a {graphics
+ adapter}. The more bits there are, the more colours can be
+ represented, but the more memory is required to store or
+ display the image.
+
+ A colour can be described by the intensities of red, green and
+ blue ({RGB}) components. Allowing 8 {bits} (1 {byte}) per
+ component (24 bits per pixel) gives 256 levels for each
+ component and over 16 million different colours - more than
+ the human eye can distinguish. {Microsoft Windows} [and
+ others?] calls this {truecolour}. An image of 1024x768 with
+ 24 bpp requires over 2 MB of memory.
+
+ "High colour" uses 16 bpp (or 15 bpp), 5 bits for blue, 5 bits
+ for red and 6 bits for green. This reduced colour precision
+ gives a slight loss of image quality at a 1/3 saving on
+ memory.
+
+ Standard {VGA} uses a {palette} of 16 colours (4 bpp), each
+ colour in the palette is 24 bit. Standard {SVGA} uses a
+ {palette} of 256 colours (8 bpp).
+
+ Some graphics hardware and software support 32-bit colour
+ depths, including an 8-bit "{alpha channel}" for transparency
+ effects.
+
+ (1999-08-01)
+
+bits per second
+
+ <communications, unit> (bps, b/s) The unit in which {data
+ rate} is measured.
+
+ For example, a {modem}'s data rate is usually measured in
+ {kilobits} per second. In 1996, the maximum modem speed for
+ use on the {PSTN} was 33.6 kbps, rising to 56 kbps in 1997.
+
+ Note that kilo- (k), mega- (M), etc. in data rates denote
+ powers of 1000, not 1024.
+
+ (2002-03-23)
+
+bit string
+
+ <programming, data> An ordered sequence of {bits}. This is
+ very similar to a {bit pattern} except that the term "string"
+ suggests an arbitrary length sequence as opposed to a
+ pre-determined length "pattern".
+
+bit stuffing
+
+ <protocol> A {protocol} which guarantees the receiver of
+ {synchronous} data can recover the sender's clock. When the
+ data stream sent contains a large number of adjacent bits
+ which cause no transition of the signal, the receiver cannot
+ adjust its clock to maintain proper synchronised reception.
+ To eliminate the possibility of such a pathological case, when
+ a preset number of transitionless bits have been transmitted,
+ a bit which does cause a transition is "stuffed" (transmitted)
+ by the sender. The receiver follows the same protocol and
+ removes the stuffed bit after the specified number of
+ transitionless bits, but can use the stuffed bit to recover
+ the sender's clock.
+
+ The advantage of bit stuffing is that only a bit (not a
+ {byte}) is inserted in the data stream, and that only when the
+ content of the data stream fails to provide a timing signal to
+ the receiver. Thus very nearly 100% of the bits transported
+ are useful data. In contrast, {asynchronous} transmission of
+ data "throws away" a start bit and one or more stop bits for
+ each data byte sent.
+
+ (1996-04-23)
+
+BitTorrent
+
+ <networking> A popular, distributed form of {peer-to-peer}
+ {file sharing} that enables a {client} program to fetch
+ different parts of a file (a "torrent") from different sources
+ in parallel. The system is designed to encourage users to
+ make downloaded data available for others to upload. This is
+ aided by a scheme for exchanging unique identifiers, commonly
+ stored in ".torrent" files. A downloader who does not serve
+ data to others is called a "leech". A "seed" is a computer
+ that has a complete copy of a file, possibly the original.
+
+ The bittorrent.com site claims there are over 100 million
+ users as of 2007-03-24.
+
+ Most of the data is copyright material like films or
+ commercial software.
+
+ {(http://www.bittorrent.com/what-is-bittorrent)}.
+
+ (2007-03-27)
+
+bit twiddling
+
+ 1. (pejorative) An exercise in tuning (see {tune}) in which
+ incredible amounts of time and effort go to produce little
+ noticeable improvement, often with the result that the code
+ becomes incomprehensible.
+
+ 2. Aimless small modification to a program, especially for
+ some pointless goal.
+
+ 3. {bit bashing}, especially used for the act of frobbing the
+ device control register of a peripheral in an attempt to get
+ it back to a known state.
+
+ [{Jargon File}]
+
+bitty box
+
+ <abuse> (Or "calculator") /bit'ee boks/ A computer
+ sufficiently small, primitive, or incapable as to cause a
+ hacker acute claustrophobia at the thought of developing
+ software on or for it. The term is especially used of small,
+ obsolescent, {single-tasking}-only {personal computers} such
+ as the {Atari 800}, {Osborne}, {Sinclair}, {VIC-20}, {TRS-80}
+ or {IBM PC}, but the term is a general pejorative opposite of
+ "real computer" (see {Get a real computer!}).
+
+ See also {mess-dos}, {toaster}, {toy}.
+
+ (1994-11-29)
+
+bitwise
+
+ <programming> A bitwise operator treats its operands as a
+ {vector} of {bits} rather than a single number. {Boolean}
+ bitwise operators combine bit N of each operand using a
+ {Boolean} function ({NOT}, {AND}, {OR}, {XOR}) to produce bit
+ N of the result.
+
+ For example, a bitwise AND operator ("&" in {C}) would
+ evaluate 13 & 9 as (binary) 1101 & 1001 = 1001 = 9, whereas,
+ the logical AND, ({C} "&&") would evaluate 13 && 9 as TRUE &&
+ TRUE = TRUE = 1.
+
+ In some languages, e.g. {Acorn}'s {BASIC V}, the same operators
+ are used for both bitwise and logical operations. This
+ usually works except when applying NOT to a value x which is
+ neither 0 (false) nor -1 (true), in which case both x and (NOT
+ x) will be non-zero and thus treated as TRUE.
+
+ Other operations at the bit level, which are not normally
+ described as "bitwise" include shift and rotate.
+
+ (1995-05-12)
+
+bitwise complement
+
+ The bitwise complement of a {bit field} is a bit field of the
+ same length but with each zero changed to a one and vice
+ versa. This is the same as the {ones complement} of a binary
+ integer.
+
+ (1994-11-14)
+
+bixie
+
+ /bik'see/ Variant {emoticons} used on {Byte Information
+ eXchange}. The {smiley} bixie is <@_@>, apparently intending
+ to represent two cartoon eyes and a mouth. A few others have
+ been reported.
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+biz-core stability
+
+ <security> {Internet} security products which secure the
+ {business core}.
+
+ [Examples?]
+
+ (2003-03-09)
+
+bj
+
+ <networking> The {country code} for Benin.
+
+ (1999-01-27)
+
+Bjarne Stroustrup
+
+ <person> The father of {C++} and author of the C++ {bible}.
+
+ ["The C++ Programming Language", Bjarne Stroustrup,
+ Addison-Wesley, 1986].
+
+ [Details?]
+
+ (2000-05-12)
+
+BJC4000
+
+ A colour {bubble jet} printer from {Canon}. Released in
+ September 1994. It features 720 x 360 dots per inch in black
+ and white mode and 360 x 360 in colour. It has two
+ cartridges: one for black and one for the three primary
+ colours so it prints true black when printing in colour.
+
+ (1994-11-29)
+
+black art
+
+ A collection of arcane, unpublished, and (by implication)
+ mostly ad-hoc techniques developed for a particular
+ application or systems area (compare {black magic}). VLSI
+ design and compiler code optimisation were (in their
+ beginnings) considered classic examples of black art; as
+ theory developed they became {deep magic}, and once standard
+ textbooks had been written, became merely {heavy wizardry}.
+ The huge proliferation of formal and informal channels for
+ spreading around new computer-related technologies during the
+ last twenty years has made both the term "black art" and what
+ it describes less common than formerly. See also {voodoo
+ programming}.
+
+ [{Jargon File}]
+
+black box
+
+ <jargon> An {abstraction} of a device or system in which only
+ its externally visible behaviour is considered and not its
+ implementation or "inner workings".
+
+ See also {functional testing}.
+
+ (1997-07-03)
+
+black-box testing
+
+ {functional testing}
+
+Black Data Processing Associates
+
+ <body> (BDPA) A non-profit professional association, founded
+ in 1975 to promote positive influence in the {information
+ technology} (IT) industry and how it affects African
+ Americans. The BDPA facilitates African American professional
+ participation in local and national activities keeping up with
+ developing IT trends.
+
+ BDPA offers a forum for exchanging information and ideas about
+ the computer industry. It provides numerous networking
+ opportunities through monthly program meetings, seminars, and
+ workshops and the annual national conference. Membership is
+ open to anyone interested in IT.
+
+ The Foundation provides scholarships to students who compete
+ in an annual {Visual Basic} competition.
+
+ {(http://bdpa.org/conf96)}.
+
+ E-mail: <nbdpa@ix.netcom.com>.
+
+ Telephone: Ms. Pat Drumming, +1 (800) 727-BDPA.
+
+ (1996-04-07)
+
+black hole
+
+ 1. An expression which depends on its own value or a technique
+ to detect such expressions. In graph reduction, when the
+ reduction of an expression is begun, the root of the
+ expression can be overwritten with a black hole. If the
+ expression depends on its own value, e.g.
+
+ x = x + 1
+
+ then it will try to evaluate the black hole which will usually
+ print an error message and abort the program. A secondary
+ effect is that, once the root of the expression has been
+ black-holed, parts of the expression which are no longer
+ required may be freed for garbage collection.
+
+ Without black holes the usual result of attempting to evaluate
+ an expression which depends on itself would be a stack
+ overflow. If the expression is evaluated successfully then
+ the black hole will be updated with the value.
+
+ Expressions such as
+
+ ones = 1 : ones
+
+ are not black holes because the list constructor, : is lazy so
+ the reference to ones is not evaluated when evaluating ones to
+ WHNF.
+
+ 2. Where an {electronic mail} message or {news} aritcle has
+ gone if it disappears mysteriously between its origin and
+ destination sites without returning a {bounce message}.
+ Compare {bit bucket}.
+
+ [{Jargon File}]
+
+BlackIce
+
+ <software, security> A commercial {firewall} and {intrusion
+ detection} system.
+
+ {BlackIce Home (http://blackice.iss.net/)}.
+
+ (2003-09-13)
+
+black magic
+
+ <jargon> (Or "{FM}") A technique that works, though nobody
+ really understands why. More obscure than {voodoo
+ programming}, which may be done by {cookbook}.
+
+ Compare {black art}, {deep magic}, and {magic number}.
+
+ (2001-04-30)
+
+blargh
+
+ /blarg/ [MIT] The opposite of {ping}. An exclamation
+ indicating that one has absorbed or is emitting a quantum of
+ unhappiness. Less common than {ping}.
+
+ [{Jargon File}]
+
+blast
+
+ 1. {BLT}, used especially for large data sends over a network
+ or comm line. Opposite of {snarf}. Usage: uncommon. The
+ variant "blat" has been reported.
+
+ 2. [HP/Apollo] Synonymous with {nuke}. Sometimes the message
+ "Unable to kill all processes. Blast them (y/n)?" would
+ appear in the command window upon logout.
+
+blat
+
+ 1. {blast}.
+
+ 2. See {thud}.
+
+ [{Jargon File}]
+
+BLAZE
+
+ A {single assignment} language for {parallel processing}.
+
+ ["The BLAZE Language: A Parallel Language for Scientific
+ Programming", P. Mehrotra <mehrotra@csrd.uiuc.edu> et al, J
+ Parallel Comp 5(3):339-361 (Nov 1987)].
+
+BLAZE 2
+
+ An {object-oriented} successor to {BLAZE}.
+
+ ["Concurrent Object Access in BLAZE 2", P. Mehrotra et al,
+ SIGPLAN Notices 24(4):40-42 (Apr 1989)].
+
+bleam
+
+ <jargon> To transmit or send data.
+
+ "Bleam that binary to me in an e-mail".
+
+ [Origin? Used where?]
+
+ (1997-05-14)
+
+bleeper
+
+ {pager}
+
+bletcherous
+
+ /blech'*-r*s/ Disgusting in design or function; aesthetically
+ unappealing. This word is seldom used of people. "This
+ keyboard is bletcherous!" (Perhaps the keys don't work very
+ well, or are misplaced.) The term {bletcherous} applies to
+ the esthetics of the thing so described; similarly for
+ cretinous. By contrast, something that is "losing" or
+ "bagbiting" may be failing to meet objective criteria.
+
+ [{Jargon File}]
+
+Bletchley Park
+
+ <body, history> A country house and grounds some 50 miles
+ North of London, England, where highly secret work deciphering
+ intercepted German military radio messages was carried out
+ during World War Two. Thousands of people were working there
+ at the end of the war, including a number of early computer
+ pioneers such as {Alan Turing}.
+
+ The nature and scale of the work has only emerged recently,
+ with total secrecy having been observed by all the people
+ involved. Throughout the war, Bletchley Park produced highly
+ important strategic and tactical intelligence used by the
+ Allies, (Churchill's "golden eggs"), and it has been claimed
+ that the war in Europe was probably shortened by two years as
+ a result.
+
+ An exhibition of wartime code-breaking memorabilia, including
+ an entire working {Colossus}, restored by Tony Sale, can be
+ seen at Bletchley Park on alternate weekends.
+
+ The {Computer Conservation Society} (CCS), a specialist group
+ of the {British Computer Society} runs a museum on the site
+ that includes a working {Elliot} {mainframe} computer and many
+ early {minicomputers} and {microcomputers}. The CCS hope to
+ have substantial facilities for storage and restoration of old
+ artifacts, as well as archive, library and research
+ facilities.
+
+ Telephone: Bletchley Park Trust office +44 (908) 640 404
+ (office hours and open weekends).
+
+ (1998-12-18)
+
+Blind Carbon Copy
+
+ <messaging> (BCC) An {electronic mail} {header} which lists
+ addresses to which a message should be sent, but which will
+ not be seen by the recipients.
+
+ Bcc is defined in {RFC 822} and supported by most e-mail
+ systems. A normal, non-blind "CC" header would be visible to
+ all recipients, thus allowing them to reply to each other as
+ well as to the sender. According to RFC 822, the addresses
+ listed in a BCC header are not included in the copies of the
+ message sent to the recipients. RFC 822 says BCC addresses
+ may appear in the copy sent to "BCC" recipients themselves
+ (though this would be unusual).
+
+ (1998-03-14)
+
+B-LINE
+
+ An early {CAD} language.
+
+ ["B-LINE, Bell Line Drawing Language", A.J. Frank, Proc Fall
+ JCC 33 1968].
+
+ (1994-11-17)
+
+blinkenlights
+
+ /blink'*n-li:tz/ Front-panel diagnostic lights on a computer,
+ especially a {dinosaur}. Derives from the last word of the
+ famous blackletter-Gothic sign in mangled pseudo-German that
+ once graced about half the computer rooms in the
+ English-speaking world. One version ran in its entirety as
+ follows:
+
+ ACHTUNG! ALLES LOOKENSPEEPERS!
+
+ Das computermachine ist nicht fuer gefingerpoken und
+ mittengrabben. Ist easy schnappen der springenwerk,
+ blowenfusen und poppencorken mit spitzensparken. Ist nicht
+ fuer gewerken bei das dumpkopfen. Das rubbernecken
+ sichtseeren keepen das cotten-pickenen hans in das pockets
+ muss; relaxen und watchen das blinkenlichten.
+
+ This silliness dates back at least as far as 1959 at Stanford
+ University and had already gone international by the early
+ 1960s, when it was reported at London University's ATLAS
+ computing site. There are several variants of it in
+ circulation, some of which actually do end with the word
+ "blinkenlights".
+
+ In an amusing example of turnabout-is-fair-play, German
+ hackers have developed their own versions of the blinkenlights
+ poster in fractured English, one of which is reproduced here:
+
+ ATTENTION
+
+ This room is fullfilled mit special electronische
+ equippment. Fingergrabbing and pressing the cnoeppkes from
+ the computers is allowed for die experts only! So all the
+ "lefthanders" stay away and do not disturben the
+ brainstorming von here working intelligencies. Otherwise
+ you will be out thrown and kicked anderswhere! Also: please
+ keep still and only watchen astaunished the blinkenlights.
+
+ See also {geef}.
+
+ [{Jargon File}]
+
+BLISS
+
+ {Basic Language for Implementation of System Software}
+
+BLISS-10
+
+ <language> A version of {BLISS} from {CMU} for the {PDP-10}.
+
+ (2002-02-01)
+
+BLISS-11
+
+ <language> A {cross-compiler} for the {PDP-11} running on a
+ {PDP-10}. Written at {CMU} to support the {C.mmp}/{Hydra}
+ project.
+
+ (2002-02-01)
+
+BLISS-16C
+
+ <language> {DEC}'s {cross-compiler} equivalent of {BLISS-11}.
+
+ (2002-02-01)
+
+BLISS-32
+
+ <language> A version of {BLISS} from DEC for {VAX}/{VMS}.
+
+ (2002-02-01)
+
+BLISS-36
+
+ <language> {DEC}'s equivalent of {BLISS-10}.
+
+ (2002-02-01)
+
+blit
+
+ /blit/ 1. To copy a large array of bits from one part of a
+ computer's memory to another part, particularly when the
+ memory is being used to determine what is shown on a display
+ screen. "The storage allocator picks through the table and
+ copies the good parts up into high memory, and then blits it
+ all back down again." See {bitblt}, {BLT}, {dd}, {cat},
+ {blast}, {snarf}. More generally, to perform some operation
+ (such as toggling) on a large array of bits while moving them.
+
+ 2. Sometimes all-capitalised as "BLIT": an early experimental
+ {bit-mapped} {terminal} designed by Rob Pike at {Bell Labs},
+ later commercialised as the {AT&T 5620}. (The folk etymology
+ from "Bell Labs Intelligent Terminal" is incorrect. Its
+ creators liked to claim that "Blit" stood for the Bacon,
+ Lettuce, and Interactive Tomato).
+
+ [{Jargon File}]
+
+ (1994-11-16)
+
+blitter
+
+ <hardware, graphics> /blit'r/ (Or "{raster blaster}"). A
+ special-purpose {integrated circuit} or hardware system built
+ to perform {blit} (or "{bit bang}") operations, especially
+ used for fast implementation of {bit-mapped} graphics.
+
+ The {Commodore} {Amiga} and a few other {microcomputers} have
+ these, but in 1991 the trend is away from them (however, see
+ {cycle of reincarnation}).
+
+ [{Jargon File}]
+
+ (1996-04-30)
+
+blivet
+
+ /bliv'*t/ [allegedly from a World War II military term meaning
+ "ten pounds of manure in a five-pound bag"] 1. An intractable
+ problem.
+
+ 2. A crucial piece of hardware that can't be fixed or replaced
+ if it breaks.
+
+ 3. A tool that has been hacked over by so many incompetent
+ programmers that it has become an unmaintainable tissue of
+ hacks.
+
+ 4. An out-of-control but unkillable development effort.
+
+ 5. An embarrassing bug that pops up during a customer demo.
+
+ 6. In the subjargon of computer security specialists, a
+ denial-of-service attack performed by hogging limited
+ resources that have no access controls (for example, shared
+ spool space on a multi-user system).
+
+ This term has other meanings in other technical cultures;
+ among experimental physicists and hardware engineers of
+ various kinds it seems to mean any random object of unknown
+ purpose (similar to hackish use of {frob}). It has also been
+ used to describe an amusing trick-the-eye drawing resembling a
+ three-pronged fork that appears to depict a three-dimensional
+ object until one realises that the parts fit together in an
+ impossible way.
+
+ [{Jargon File}]
+
+bloat
+
+ {software bloat}
+
+bloatware
+
+ <jargon, abuse> {Software} suffering from {software bloat}.
+
+ (1995-10-14)
+
+BLOB
+
+ 1. {binary large object}.
+
+ 2. <architecture> {blitter object}.
+
+ [{Jargon File}]
+
+block
+
+ 1. <unit> A unit of data or memory, often, but not
+ exclusively, on a {magnetic disk} or {magnetic tape}.
+
+ Compare {record}, {sector}.
+
+ (2000-07-17)
+
+ 2. <operating system> To delay or sit idle while waiting for
+ something.
+
+ Compare {busy-wait}.
+
+ (2000-07-17)
+
+ 3. <programming> A delimited section of {source code} in a
+ {block-structured} language.
+
+ (2004-09-29)
+
+Block And List Manipulation
+
+ {BALM}
+
+Block Diagram Compiler
+
+ <simulation, language> (BDL) A {block diagram} simulation tool,
+ with associated language.
+
+ ["A Software Environment for Digital Signal-Processing
+ Simulations," D.H. Johnson & R.E. Vaughan, Circuits Systems
+ and Signal Processing 6(1):31-43, 1987].
+
+ (2000-07-17)
+
+blocked records
+
+ <storage> Several {records} written as a contiguous block on
+ {magnetic tape} so that they may be accessed in a single I/O
+ operation. Blocking increases the amount of data that may be
+ stored on a tape because there are fewer {inter-block gaps}.
+ It requires that the tape drive or processor have a
+ sufficiently large buffer to store the whole block.
+
+ (1995-04-13)
+
+Block Redundancy Check
+
+ {Longitudinal Redundancy Check}
+
+Block Started by Symbol
+
+ <memory> (BSS) The uninitialised data segment produced by
+ {Unix} {linkers}. Objects in the bss segment have only a name
+ and a size but no value.
+
+ Executable code is located in the {code segment} and
+ initialised data in the {data segment}.
+
+ (2004-02-24)
+
+block-structured
+
+ <language> Any programming language in which sections of
+ {source code} contained within pairs of matching {delimiters}
+ such as "{" and "}" (e.g. in {C}) or "begin" and "end"
+ (e.g. {Algol}) are executed as a single unit. A block of code
+ may be the body of a {subroutine} or {function}, or it may be
+ controlled by conditional execution ({if statement}) or
+ repeated execution ({while statement}, {for statement}, etc.).
+
+ In all but the most primitive block structured languages a
+ {variable}'s {scope} can be limited to the block in which it
+ is declared.
+
+ Block-structured languages support {structured programming}
+ where each block can be written without detailed knowledge of
+ the inner workings of other blocks, thus allowing a {top-down
+ design} approach.
+
+ See also {abstract data type}, {module}.
+
+ (2004-09-29)
+
+block transfer computations
+
+ <algorithm, humour> (From the UK television series "Dr. Who")
+ Computations so fiendishly subtle and complex that they could
+ not be performed by machines. Used to refer to any task that
+ should be expressible as an {algorithm} in theory, but isn't.
+
+ [{Jargon File}]
+
+ (2004-09-28)
+
+blog
+
+ <web> (From "web log") Any kind of diary published on
+ the {web}, usually written by an individual (a
+ "blogger") but also by corporate bodies.
+
+ Blogging is regarded by some as an important social phenomenon as
+ it contributes to the easy exchange of ideas among a large and
+ growing international community ("the blogosphere").
+
+ A blog is just a special kind of {website}. The {home page}
+ usually shows the most recent article and links to earlier
+ articles, the owner's profile and web logs written by the owner's
+ friends. There is usually a facility for readers to add comments
+ to the bottom of articles. Blogs usually provide an {RSS feed} of
+ current articles, allowing readers to subscribe by adding the feed
+ to their favourite RSS reader.
+
+ Many sites, e.g. {(http://blogger.com/)}, let you create a blog
+ for free. Many blogs consist almost entirely of links to other
+ web logs, some publish original content, a few are worth reading.
+
+ (2013-08-15)
+
+blog-driven development
+
+ {cut-and-waste code}
+
+Bloggs Family, the
+
+ An imaginary family consisting of Fred and Mary Bloggs and
+ their children. Used as a standard example in knowledge
+ representation to show the difference between extensional and
+ intensional objects. For example, every occurrence of "Fred
+ Bloggs" is the same unique person, whereas occurrences of
+ "person" may refer to different people. Members of the Bloggs
+ family have been known to pop up in bizarre places such as the
+ DEC Telephone Directory. Compare {Mbogo, Dr. Fred}.
+
+Bloombug
+
+ <humour> A {bug} that accidentally generates money.
+
+ [After "Bloomberg"?]
+
+ (2012-11-10)
+
+Blosim
+
+ Block-Diagram Simulator. A block-diagram simulator. "A Tool
+ for Structured Functional Simulation", D.G. Messerschmitt,
+ IEEE J on Selected Areas in Comm, SAC-2(1):137-147, 1984.
+
+blow an EPROM
+
+ /bloh *n ee'prom/ (Or "blast", "burn") To program a {read-only
+ memory}, e.g. for use with an {embedded system}. This term
+ arose because the programming process for the {Programmable
+ Read-Only Memory} (PROM) that preceded present-day {Erasable
+ Programmable Read-Only Memory} (EPROM) involved intentionally
+ blowing tiny electrical fuses on the chip. The usage lives on
+ (it's too vivid and expressive to discard) even though the
+ write process on EPROMs is nondestructive.
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+blow away
+
+ <operating system, jargon> To remove (files and directories)
+ from permanent storage, generally by accident. "He
+ reformatted the wrong partition and blew away last night's
+ netnews".
+
+ Compare: {nuke}.
+
+ [{Jargon File}]
+
+ (1996-01-05)
+
+blowing your buffer
+
+ <jargon> Losing your train of thought. A reference to {buffer
+ overflow}.
+
+ (1999-01-15)
+
+blow out
+
+ <jargon> (Probably from mining and tunnelling jargon) Of
+ {software}, to fail spectacularly; almost as serious as {crash
+ and burn}.
+
+ See {blow past}, {blow up}, {die horribly}.
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+blow past
+
+ To {blow out} despite a safeguard. "The server blew past the
+ 5K reserve buffer."
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+blow up
+
+ 1. Of a scientific computation: to become unstable. It
+ suggests that the computation is diverging so rapidly that it
+ will soon overflow or at least go {nonlinear}.
+
+ 2. {blow out}.
+
+ [{Jargon File}]
+
+BLOX
+
+ A {visual language}.
+
+BLT
+
+ 1. /B-L-T/, /bl*t/ or (rarely) /belt/ Synonym for {blit}.
+ This is the original form of {blit} and the ancestor of
+ {bitblt}. It refers to any large bit-field copy or move
+ operation (one resource-intensive memory-shuffling operation
+ done on pre-paged versions of {ITS}, {WAITS} and {TOPS-10} was
+ sardonically referred to as "The Big BLT"). The jargon usage
+ has outlasted the {PDP-10} BLock Transfer instruction from
+ which {BLT} derives; nowadays, the {assembly language}
+ {mnemonic} {BLT} almost always means "Branch if Less Than
+ zero".
+
+ 2. bacon, lettuce and tomato (sandwich).
+
+ [{Jargon File}]
+
+Blue
+
+ A language proposed by Softech to meet the {DoD} {Ironman}
+ requirements which led to {Ada}. ["On the BLUE Language
+ Submitted to the DoD", E.W. Dijkstra, SIGPLAN Notices
+ 13(10):10-15 (Oct 1978)].
+
+Blue Book
+
+ 1. <publication> Informal name for one of the four standard
+ references on the page-layout and graphics-control language
+ {PostScript}. The other three official guides are known as
+ the {Green Book}, the {Red Book}, and the {White Book}.
+
+ ["PostScript Language Tutorial and Cookbook", Adobe Systems,
+ Addison-Wesley 1985, (ISBN 0-201-10179-3)].
+
+ 2. <publication> Informal name for one of the three standard
+ references on Smalltalk. This book also has green and red
+ siblings.
+
+ ["Smalltalk-80: The Language and its Implementation", David
+ Robson, Addison-Wesley 1983, (ISBN 0-201-11371-63)].
+
+ 3. <publication> Any of the 1988 standards issued by the
+ {ITU-T}'s ninth plenary assembly. These include, among other
+ things, the {X.400} {electronic mail} specification and the
+ Group 1 through 4 fax standards.
+
+ See also {book titles}.
+
+ [{Jargon File}]
+
+ (1995-10-12)
+
+Blue Box
+
+ <operating system> The complete implementation of the {Mac OS}
+ run-time environment on the more modern {Rhapsody} operating
+ system. {Blue Box} is not an {emulation} layer; at any given
+ time it will be based on the same source code and ROM image as
+ the current version of Mac OS and will thus incorporate future
+ Mac OS improvements.
+
+ (1997-10-15)
+
+blue dot syndrome
+
+ <graphics, jargon> The inability to display an {image} {file}
+ or {text} embedded in an image file on your monitor.
+
+ [Why?]
+
+ (2002-05-28)
+
+Blue Glue
+
+ {Systems Network Architecture}
+
+Blue Screen of Death
+
+ <humour> (BSOD) The infamous white-on-blue text screen which
+ appears when {Microsoft Windows} crashes. BSOD is mostly seen
+ on the 16-bit systems such as {Windows 3.1}, but also on
+ {Windows 95} and apparently even under {Windows NT 4}. It is
+ most likely to be caused by a {GPF}, although Windows 95 can
+ do it if you've removed a required {CD-ROM} from the drive.
+ It is often impossible to recover cleanly from a BSOD.
+
+ The acronym BSOD is sometimes used as a verb, e.g. "{Windoze}
+ just keeps BSODing on me today".
+
+ (1998-09-08)
+
+Blue Screen of Life
+
+ <operating system> (BSOL, by analogy with "{Blue Screen of
+ Death}") The opening screen of {Microsoft} {Windows NT}.
+
+ This screen shows the {file system} loading, and any problems
+ such as conversions from {FAT} to {NTFS} or a scan of a {hard
+ drive}.
+
+ The Blue Screen of Life occurs in one way, as opposed to the
+ {Blue Screen of Death}, which can occur in many different ways
+ and times.
+
+ [Is this term ever used in connection with {Windows 3.x} or
+ {Windows 9x}?]
+
+ (1999-04-18)
+
+Blue Sky Software
+
+ {eHelp Corporation}
+
+Bluetooth
+
+ <protocol, standard> A specification for short-range radio
+ links between mobile computers, mobile phones, digital
+ cameras, and other portable devices.
+
+ {(http://bluetooth.com)}.
+
+ (2001-03-16)
+
+blue wire
+
+ (IBM) Patch wires added to circuit boards at the factory to
+ correct design or fabrication problems. These may be
+ necessary if there hasn't been time to design and qualify
+ another board version.
+
+ Compare {purple wire}, {red wire}, {yellow wire}.
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+blurgle
+
+ /bler'gl/ [Great Britain] Spoken {metasyntactic variable}, to
+ indicate some text that is obvious from context, or which is
+ already known. If several words are to be replaced, blurgle
+ may well be doubled or trebled. "To look for something in
+ several files use "{grep} string blurgle blurgle"." In each
+ case, "blurgle blurgle" would be understood to be replaced by
+ the file you wished to search. Compare {mumble}.
+
+ [{Jargon File}]
+
+bm
+
+ <networking> The {country code} for Bermuda.
+
+ (1999-01-27)
+
+BMAN
+
+ {Broadband Metropolitan Area Network}
+
+BMASF
+
+ Basic Module Algebra Specification Language? "Design of a
+ Specification Language by Abstract Syntax Engineering",
+ J.C.M. Baeten et al, in LNCS 490, pp.363-394.
+
+BMDP
+
+ {BioMeDical Package}
+
+B-Method
+
+ <programming, tool> A system for rigorous or formal
+ development of software using the notion of {Abstract
+ Machines} to specify and design software systems. The
+ B-Method is supported by the {B-Toolkit}.
+
+ Abstract Machines are specified using the Abstract Machine
+ Notation (AMN) which is in turn based on the mathematical
+ theory of {Generalised Substitutions}.
+
+ (1995-03-13)
+
+BMF
+
+ {Bird-Meertens Formalism}
+
+BMP
+
+ {Basic Multilingual Plane}
+
+bmp
+
+ <file format, graphics> {Microsoft Windows} {bitmap} format.
+ Bmp files may use {run-length encoding}.
+
+ This is the only graphics format where {compression} actually
+ enlarges the file. The format is widely used nonetheless.
+
+ [Format?]
+
+ (1998-03-14)
+
+BMWF
+
+ <body> The Austrian, German and Swiss(?) Ministries of
+ Science.
+
+ [Expansion?]
+
+ (1998-12-09)
+
+bn
+
+ <networking> The {country code} for Brunei Darussalam.
+
+ (1999-01-27)
+
+BNC
+
+ <hardware> A connector for {coaxial cable} such as that used
+ for some video connections and {RG58} "{cheapernet}"
+ connections. A BNC connector has a bayonet-type shell with
+ two small knobs on the female connector which lock into spiral
+ slots in the male connector when it is twisted on.
+
+ Different sources expand BNC as Bayonet Navy Connector,
+ British Naval Connector, Bayonet Neill Concelman, or Bayonet
+ Nut Connection.
+
+ (1995-09-18)
+
+BNF
+
+ {Backus-Naur Form}. Originally Backus Normal Form.
+
+ [{Jargon File}]
+
+BNR Pascal
+
+ ["Remote Rendezvous", N. Gammage et al, Soft Prac & Exp
+ 17(10):741-755 (Oct 1987)].
+
+ (1994-12-21)
+
+BNR Prolog
+
+ A {constraint logic} language.
+
+ [Details?]
+
+ (1994-12-21)
+
+bo
+
+ <networking> The {country code} for Bolivia.
+
+ (1999-01-27)
+
+BOA
+
+ {Basic Object Adapter}
+
+boa
+
+ [IBM] Any one of the fat cables that lurk under the floor in a
+ {dinosaur pen}. Possibly so called because they display a
+ ferocious life of their own when you try to lay them straight
+ and flat after they have been coiled for some time. It is
+ rumored within IBM that channel cables for the 370 are limited
+ to 200 feet because beyond that length the boas get dangerous
+ --- and it is worth noting that one of the major cable makers
+ uses the trademark "Anaconda".
+
+ [{Jargon File}]
+
+board
+
+ 1. In-context synonym for {bboard}; sometimes used even for
+ {Usenet} newsgroups.
+
+ 2. An electronic circuit board.
+
+boat anchor
+
+ 1. Like {doorstop} but more severe; implies that the offending
+ hardware is irreversibly dead or useless. "That was a working
+ motherboard once. One lightning strike later, instant boat
+ anchor!"
+
+ 2. A person who just takes up space.
+
+ 3. Obsolete but still working hardware, especially when used
+ of an old S100-bus hobbyist system; originally a term of
+ annoyance, but became more and more affectionate as the
+ hardware became more and more obsolete.
+
+ [{Jargon File}]
+
+Bob
+
+ David Betz. A tiny object-oriented language.
+
+ {(ftp://ftp.mv.com/pub/ddj/packages/bob15.arc)}.
+
+ [Dr Dobbs J, Sep 1991, p.26].
+
+Bobo the Webmonkey
+
+ <web> What {B1FF} was to {BITNET} users, Bobo the
+ Webmonkey is to {webmonkeys} - the mythical prototype of
+ incompetent web designers everywhere. In fact, Bobo may be
+ what B1FF became when he grew up.
+
+ Bobo knows about {HTML} only what he has learned from viewing
+ the source of other people's Web pages.
+
+ Bobo doesn't know what a {MIME type} is, even though someone
+ gave him a hardcopy of the {FOLDOC} entry for it.
+
+ Bobo may have used an HTML code validator
+ {(http://validator.w3.org/)} before, but isn't sure.
+
+ Bobo doesn't know what the difference between {GIF} and {JPEG}
+ is. He thinks {PNG} is a foreign country.
+
+ All the pages Bobo has designed say "Welcome to [organisation]
+ online!" at the top, and say "click here!" at least three
+ times per page.
+
+ Bobo has used {Photoshop} before; he doesn't understand why
+ people keep asking if he's ever been tested for
+ color-blindness.
+
+ Bobo never got that "its" / "it's" distinction real clear, as
+ you can tell from his pages.
+
+ Bobo likes <BLINK>.
+
+ (1998-04-04)
+
+BOCS
+
+ Berard Object and Class Specifier, an Object-oriented CASE
+ tool from Berard Software Engineering.
+
+Boehm B.
+
+ Proposed the COCOMO technique for evaluating the cost of a
+ software project.
+
+BOEING
+
+ <language> An early system on the {IBM 1130}.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (2004-09-14)
+
+BOF
+
+ /B-O-F/ or /bof/ 1. {Birds Of a Feather}.
+
+ 2. Boring Old Fart.
+
+ [{Jargon File}]
+
+BOFH
+
+ {Bastard Operator From Hell}
+
+bogometer
+
+ <humour> /boh-gom'-*t-er/ A notional instrument for measuring
+ {bogosity}.
+
+ Compare the "wankometer" described in the {wank} entry.
+
+ [{Jargon File}]
+
+ (1999-06-10)
+
+BogoMips
+
+ <unit> (From "bogus", "{MIPS}") The timing unit of the {Linux}
+ {kernel}.
+
+ A BogoMips is an unscientific measurement of {processor} speed
+ made by the {Linux} {kernel} when it {boots}, to calibrate an
+ internal {busy-loop}.
+
+ {BogoMips MiniHowto
+ (http://metalab.unc.edu/LDP/HOWTO/mini/BogoMips.html)}.
+
+ (1999-05-06)
+
+bogon
+
+ /boh'gon/ (By analogy with proton/electron/neutron, but
+ doubtless reinforced after 1980 by the similarity to Douglas
+ Adams's "Vogons")
+
+ 1. The elementary particle of bogosity (see {quantum
+ bogodynamics}). For instance, "the Ethernet is emitting
+ bogons again" means that it is broken or acting in an erratic
+ or bogus fashion.
+
+ 2. A query {packet} sent from a {TCP/IP} {domain resolver} to
+ a root server, having the reply bit set instead of the query
+ bit.
+
+ 3. Any bogus or incorrectly formed packet sent on a network.
+
+ 4. A person who is bogus or who says bogus things. This was
+ historically the original usage, but has been overtaken by its
+ derivative senses. See also {bogosity}; compare {psyton},
+ {fat electrons}, {magic smoke}.
+
+ The bogon has become the type case for a whole bestiary of
+ nonce particle names, including the "clutron" or "cluon"
+ (indivisible particle of cluefulness, obviously the
+ antiparticle of the bogon) and the futon (elementary particle
+ of {randomness}, or sometimes of lameness). These are not so
+ much live usages in themselves as examples of a live
+ meta-usage: that is, it has become a standard joke or
+ linguistic maneuver to "explain" otherwise mysterious
+ circumstances by inventing nonce particle names. And these
+ imply nonce particle theories, with all their dignity or lack
+ thereof (we might note parenthetically that this is a
+ generalisation from "(bogus particle) theories" to "bogus
+ (particle theories)"!). Perhaps such particles are the
+ modern-day equivalents of trolls and wood-nymphs as standard
+ starting-points around which to construct explanatory myths.
+ Of course, playing on an existing word (as in the "futon")
+ yields additional flavour.
+
+ [{Jargon File}]
+
+bogon filter
+
+ /boh'gon fil'tr/ Any device, software or hardware, that limits
+ or suppresses the flow and/or emission of bogons.
+ "Engineering hacked a bogon filter between the {Cray} and the
+ {VAXen}, and now we're getting fewer dropped packets." See
+ also {bogosity}.
+
+bogon flux
+
+ /boh'gon fluhks/ A measure of a supposed field of {bogosity}
+ emitted by a speaker, measured by a {bogometer}; as a speaker
+ starts to wander into increasing bogosity a listener might say
+ "Warning, warning, bogon flux is rising". See {quantum
+ bogodynamics}.
+
+ [{Jargon File}]
+
+bogosity
+
+ /boh-go's*-tee/ The degree to which something is "bogus" in
+ the hackish sense of "bad". At CMU, bogosity is measured with
+ a {bogometer}; in a seminar, when a speaker says something
+ bogus, a listener might raise his hand and say "My bogometer
+ just triggered". More extremely, "You just pinned my
+ bogometer" means you just said or did something so
+ outrageously bogus that it is off the scale, pinning the
+ bogometer needle at the highest possible reading (one might
+ also say "You just redlined my bogometer"). The agreed-upon
+ unit of bogosity is the {microLenat}.
+
+ Also, the potential field generated by a {bogon flux}; see
+ {quantum bogodynamics}. See also {bogon flux}, {bogon
+ filter}.
+
+ (2002-04-14)
+
+bogo-sort
+
+ <algorithm, humour> /boh"goh-sort"/ (Or "stupid-sort") The
+ archetypical perversely awful {algorithm} (as opposed to
+ {bubble sort}, which is merely the generic *bad* algorithm).
+ Bogo-sort is equivalent to repeatedly throwing a deck of cards
+ in the air, picking them up at random, and then testing
+ whether they are in order. It serves as a sort of canonical
+ example of awfulness. Looking at a program and seeing a dumb
+ algorithm, one might say "Oh, I see, this program uses
+ bogo-sort."
+
+ Also known as "monkey sort" after the {Infinite Monkey
+ Theorem}.
+
+ Compare {brute force}, {Lasherism}.
+
+ {An implementation (http://stdout.org/~adam/psort)}.
+
+ [{Jargon File}]
+
+ (2002-04-07)
+
+bogotify
+
+ <jargon> /boh-go't*-fi:/ To make or become bad. A program
+ that has been changed so many times as to become completely
+ disorganised has become bogotified. If you tighten a nut too
+ hard and strip the threads on the bolt, the bolt has become
+ bogotified.
+
+ See also {bogosity}.
+
+ (2003-01-25)
+
+bogue out
+
+ /bohg owt/ To become bogus, suddenly and unexpectedly. "His
+ talk was relatively sane until somebody asked him a trick
+ question; then he bogued out and did nothing but {flame}
+ afterward." See also {bogosity}.
+
+ [{Jargon File}]
+
+BOHICA
+
+ <humour> /bo-hee-ka/ {Bend Over, Here It Comes
+ Again}.
+
+Bohr bug
+
+ <jargon, programming> /bohr buhg/ (From Quantum physics) A
+ repeatable {bug}; one that manifests reliably under a possibly
+ unknown but well-defined set of conditions.
+
+ Compare {heisenbug}. See also {mandelbug}, {schroedinbug}.
+
+ [{Jargon File}]
+
+ (1995-02-28)
+
+boink
+
+ /boynk/ [{Usenet}: variously ascribed to the TV series
+ "Cheers" "Moonlighting", and "Soap"] 1. To have sex with;
+ compare {bounce}. (This is mainstream slang.) In Commonwealth
+ hackish the variant "bonk" is more common.
+
+ 2. After the original Peter Korn "Boinkon" {Usenet} parties,
+ used for almost any net social gathering, e.g. Miniboink, a
+ small boink held by Nancy Gillett in 1988; Minniboink, a
+ Boinkcon in Minnesota in 1989; Humpdayboinks, Wednesday
+ get-togethers held in the San Francisco Bay Area.
+
+ Compare {@-party}.
+
+ 3. Variant of "bonk"; see {bonk/oif}.
+
+ [{Jargon File}]
+
+BOLERO
+
+ <programming> {Software AG}'s {object-oriented} development
+ environment and {application server} for Electronic Business
+ applications.
+
+ (1999-03-06)
+
+Bolt, Beranek and Newman, Inc.
+
+ {BBN Technologies}
+
+bomb
+
+ 1. <software> General synonym for {crash} except that it is
+ not used as a noun. Especially used of software or {OS}
+ failures. "Don't run Empire with less than 32K stack, it'll
+ bomb".
+
+ 2. <operating system> {Atari ST} and {Macintosh} equivalents
+ of a {Unix} "{panic}" or {Amiga} {guru}, in which {icons} of
+ little black-powder bombs or mushroom clouds are displayed,
+ indicating that the system has died. On the {Macintosh}, this
+ may be accompanied by a decimal (or occasionally
+ {hexadecimal}) number indicating what went wrong, similar to
+ the {Amiga} {guru meditation} number. {MS-DOS} computers tend
+ to {lock up} in this situation.
+
+ 3. <software> A piece of code embedded in a program that
+ remains dormant until it is triggered. Logic bombs are
+ triggered by an event whereas time bombs are triggered either
+ after a set amount of time has elapsed, or when a specific
+ date is reached.
+
+ [{Jargon File}]
+
+ (1996-12-08)
+
+bon
+
+ <language> (From "Bonnie", {Ken Thompson}'s wife) A language
+ designed by {Ken Thompson} and later revised by him to produce
+ {B}.
+
+ [When? Features?]
+
+ (1997-02-04)
+
+bondage-and-discipline language
+
+ A language (such as {Pascal}, {Ada}, APL, or Prolog) that,
+ though ostensibly general-purpose, is designed so as to
+ enforce an author's theory of "right programming" even though
+ said theory is demonstrably inadequate for systems hacking or
+ even vanilla general-purpose programming. Often abbreviated
+ "B&D"; thus, one may speak of things "having the B&D nature".
+
+ See {Pascal}. Compare {languages of choice}.
+
+ [{Jargon File}]
+
+ (1996-01-05)
+
+bonk/oif
+
+ /bonk/, /oyf/ In the {MUD} community, it has become
+ traditional to express pique or censure by "bonking" the
+ offending person. Convention holds that one should
+ acknowledge a bonk by saying "oif!" and there is a myth to the
+ effect that failing to do so upsets the cosmic bonk/oif
+ balance, causing much trouble in the universe. Some MUDs have
+ implemented special commands for bonking and oifing.
+
+ [{Jargon File}]
+
+ (1998-01-18)
+
+Booch method
+
+ <programming> A widely used {object-oriented analysis} and
+ {object-oriented design} method.
+
+ {(http://hsr.ch/div/Booch/BoochReference/)}.
+
+ [Grady Booch, "Object-oriented Analysis and Design with
+ Applications", 2nd edition. Benjamin Cummings, Redwood City,
+ ISBN 0-8053-5340-2, 1993]
+
+ (2000-05-23)
+
+book
+
+ 1. <text> {e-book}.
+
+ 2. {book titles}.
+
+ 3. <computer> {MacBook}.
+
+ 4. {O'Reilly and Associates}.
+
+bookmark
+
+ <web> A user's reference to a document on the
+ {web} or other hypermedia system, usually in the
+ form of a {URL} and a title or comment string.
+
+ Most web and {Gopher} {browsers} can save and load
+ a file of bookmarks to allow you to quickly locate documents
+ to which you want to refer again.
+
+ (1997-06-09)
+
+Bookreader
+
+ {DEC}'s {CD-ROM}-based on-line documentation browser.
+
+book titles
+
+ <publication> There is a tradition in hackerdom of informally
+ tagging important textbooks and standards documents with the
+ dominant colour of their covers or with some other conspicuous
+ feature of the cover. Many of these are described in {this
+ dictionary} under their own entries. See {Aluminum Book},
+ {Blue Book}, {Cinderella Book}, {Devil Book}, {Dragon Book},
+ {Green Book}, {Orange Book}, {Pink-Shirt Book}, {Purple Book},
+ {Red Book}, {Silver Book}, {White Book}, {Wizard Book},
+ {Yellow Book}, {bible}, {rainbow series}.
+
+ [{Jargon File}]
+
+ (1996-12-03)
+
+Bookviewer
+
+ A hypertext documentation system from Oracle based on Oracle
+ Toolkit. It allows the user to create private links and
+ bookmarks, and to make multimedia annotations.
+
+bool
+
+ {Boolean}
+
+Boolean
+
+ <logic> 1. {Boolean algebra}.
+
+ <programming> 2. (bool) The type of an expression with two
+ possible values, "true" and "false". Also, a variable of
+ Boolean type or a function with Boolean arguments or result.
+ The most common Boolean functions are {AND}, {OR} and {NOT}.
+
+ (1997-12-01)
+
+Boolean algebra
+
+ <logic> (After the logician {George Boole})
+
+ 1. Commonly, and especially in computer science and digital
+ electronics, this term is used to mean {two-valued logic}.
+
+ 2. This is in stark contrast with the definition used by pure
+ mathematicians who in the 1960s introduced "Boolean-valued
+ {models}" into logic precisely because a "Boolean-valued
+ model" is an interpretation of a {theory} that allows more
+ than two possible truth values!
+
+ Strangely, a Boolean algebra (in the mathematical sense) is
+ not strictly an {algebra}, but is in fact a {lattice}. A
+ Boolean algebra is sometimes defined as a "complemented
+ {distributive lattice}".
+
+ Boole's work which inspired the mathematical definition
+ concerned {algebras} of {sets}, involving the operations of
+ intersection, union and complement on sets. Such algebras
+ obey the following identities where the operators ^, V, - and
+ constants 1 and 0 can be thought of either as set
+ intersection, union, complement, universal, empty; or as
+ two-valued logic AND, OR, NOT, TRUE, FALSE; or any other
+ conforming system.
+
+ a ^ b = b ^ a a V b = b V a (commutative laws)
+ (a ^ b) ^ c = a ^ (b ^ c)
+ (a V b) V c = a V (b V c) (associative laws)
+ a ^ (b V c) = (a ^ b) V (a ^ c)
+ a V (b ^ c) = (a V b) ^ (a V c) (distributive laws)
+ a ^ a = a a V a = a (idempotence laws)
+ --a = a
+ -(a ^ b) = (-a) V (-b)
+ -(a V b) = (-a) ^ (-b) (de Morgan's laws)
+ a ^ -a = 0 a V -a = 1
+ a ^ 1 = a a V 0 = a
+ a ^ 0 = 0 a V 1 = 1
+ -1 = 0 -0 = 1
+
+ There are several common alternative notations for the "-" or
+ {logical complement} operator.
+
+ If a and b are elements of a Boolean algebra, we define a <= b
+ to mean that a ^ b = a, or equivalently a V b = b. Thus, for
+ example, if ^, V and - denote set intersection, union and
+ complement then <= is the inclusive subset relation. The
+ relation <= is a {partial ordering}, though it is not
+ necessarily a {linear ordering} since some Boolean algebras
+ contain incomparable values.
+
+ Note that these laws only refer explicitly to the two
+ distinguished constants 1 and 0 (sometimes written as {LaTeX}
+ \top and \bot), and in {two-valued logic} there are no others,
+ but according to the more general mathematical definition, in
+ some systems variables a, b and c may take on other values as
+ well.
+
+ (1997-02-27)
+
+Boolean logic
+
+ <logic> A {logic} based on {Boolean algebra}.
+
+ (1995-03-25)
+
+Boolean search
+
+ <information science> (Or "Boolean query") A query using the
+ {Boolean} operators, {AND}, {OR}, and {NOT}, and parentheses
+ to construct a complex condition from simpler criteria. A
+ typical example is searching for combinatons of keywords on a
+ {web} {search engine}.
+
+ Examples:
+
+ car or automobile
+
+ "New York" and not "New York state"
+
+ The term is sometimes stretched to include searches using
+ other operators, e.g. "near".
+
+ Not to be confused with {binary search}.
+
+ See also: {weighted search}.
+
+ (1999-10-23)
+
+Boole, George
+
+ {George Boole}
+
+Booster
+
+ A {data-parallel} language.
+
+ "The Booster Language", E. Paalvast, TR PL 89-ITI-B-18, Inst
+ voor Toegepaste Informatica TNO, Delft, 1989.
+
+boot
+
+ {bootstrap}
+
+boot block
+
+ <operating system> A program on a {hard disk}, {floppy disk}
+ or other media, which is loaded when the computer is turned on
+ or rebooted and which controls the next phase of loading the
+ actual {operating system}. The loading and execution of the
+ boot block is usually controlled by {firmware} in {ROM} or
+ {PROM}. It may be at some fixed location possibly or may be
+ pointed to by the {master boot record}.
+
+ (2009-05-19)
+
+boot disk
+
+ <operating system> The {magnetic disk} (usually a {hard disk})
+ from which an {operating system} {kernel} is loaded (or
+ "bootstrapped"). This second phase in system start-up is
+ performed by a simple bootstrap loader program held in {ROM},
+ possibly configured by data stored in some form of writable
+ {non-volatile storage}.
+
+ {MS-DOS} and {Microsoft Windows} can be configured (in the
+ {BIOS}) to try to boot off either {floppy disk} or {hard
+ disk}, in either order. By default they first check for the
+ presence of a {floppy disk} in the drive at start-up and try
+ to use that as a boot disk if present. If no disk is in the
+ drive they then try to boot off the hard disk.
+
+ Some {operating systems}, notably {SunOS} and {Solaris}, can
+ be configured to boot from a network rather than from disk.
+ Such a system can thus run as a {diskless workstation}.
+
+ (1997-06-09)
+
+booting
+
+ {bootstrap}
+
+BOOTP
+
+ The Bootstrap Protocol.
+
+ A {protocol} described in {RFCs} 951 and 1084 and used for
+ booting {diskless workstations}.
+
+ See also {Reverse Address Resolution Protocol}.
+
+ (1995-02-16)
+
+bootstrap
+
+ <operating system, compiler> To load and initialise the
+ {operating system} on a computer. Normally abbreviated to
+ "{boot}". From the curious expression "to pull oneself up by
+ one's bootstraps", one of the legendary feats of Baron von
+ Munchhausen. The {bootstrap loader} is the program that runs
+ on the computer before any (normal) program can run. Derived
+ terms include {reboot}, {cold boot}, {warm boot}, {soft boot}
+ and {hard boot}.
+
+ The term also applies to the use of a {compiler} to compile
+ itself. The usual process is to write an {interpreter} for a
+ language, L, in some other existing language. The compiler is
+ then written in L and the interpreter is used to run it. This
+ produces an {executable} for compiling programs in L from the
+ source of the compiler in L. This technique is often used to
+ verify the correctness of a compiler. It was first used in
+ the {LISP} community.
+
+ See also {My Favourite Toy Language}.
+
+ [{Jargon File}]
+
+ (2005-04-12)
+
+bootstrap loader
+
+ <operating system> A short {program} loaded from {non-volatile
+ storage} and used to {bootstrap} a computer.
+
+ On early computers great efforts were expended on making the
+ bootstrap loader short, in order to make it easy to {toggle}
+ in via the {front panel} switches. It was just clever enough
+ to read in a slightly more complex {program} (usually from
+ {punched cards} or {paper tape}), to which it handed control.
+ This {program} in turn read the {application} or {operating
+ system} from a {magnetic tape} drive or {disk drive}. Thus,
+ in successive steps, the {computer} "pulled itself up by its
+ bootstraps" to a useful operating state.
+
+ Nowadays the bootstrap loader is usually found in {ROM} or
+ {EPROM}, and reads the first stage in from a fixed location on
+ the {disk}, called the "{boot block}". When this {program}
+ gains control, it is powerful enough to load the actual {OS}
+ and hand control over to it. A {diskless workstation} can use
+ {bootp} to load its OS from the network.
+
+ (2005-04-12)
+
+boot virus
+
+ An {MS-DOS} {virus} that infects the {boot record} program on
+ {hard disks} and {floppy disks} or the {master boot record} on
+ hard disks. The virus gets loaded into memory before {MS-DOS}
+ and takes control of the computer, infecting any floppy disks
+ subsequently accessed. An infected {boot disk} may stop the
+ computer starting up at all.
+
+ (1995-02-16)
+
+Border Gateway Protocol
+
+ (BGP) An {Exterior Gateway Protocol} defined in {RFC 1267} and
+ {RFC 1268}. Its design is based on experience gained with
+ {Exterior Gateway Protocol} (EGP), as defined in {STD} 18,
+ {RFC 904} and EGP usage in the {NSFNet} {backbone}, as
+ described in RFCs 1092 and 1093.
+
+ (1994-11-29)
+
+borf
+
+ <jargon> To uncerimoniously disconnect someone from a system
+ without prior warning. {BBS} {Sysops} routinely "borf" pest
+ users by turning off the modem or by hitting the "auto-borf"
+ key sequence.
+
+ You can also be "borfed" by software dropping {carrier} due to
+ a {bug}.
+
+ The origin of the term is unknown but it has been in use since
+ at least 1982.
+
+ (1997-03-21)
+
+Borland International, Inc.
+
+ {Borland Software Corporation}
+
+Borland Software Corporation
+
+ <company> A company that sells a variety of {PC} software
+ development and {database} systems. Borland was founded in
+ 1983 and initially became famous for their low-cost software,
+ particularly {Turbo Pascal}, {Turbo C}, and {Turbo Prolog}.
+
+ Current and past products include the {Borland C++} C++ and C
+ developement environment, the {Paradox} and {dBASE}
+ {databases}, {Delphi}, {JBuilder}, and {InterBase}.
+
+ Borland has approximately 1000 employees worldwide and has
+ operations in Australia, Canada, France, Germany, Japan,
+ Netherlands, and the United Kingdom.
+
+ Borland sold {Quattro} Pro to {Novell} in 1994 for $100M.
+ Novell later sold the product to {Corel Corporation}, who also
+ bought {Paradox}. dBASE was sold in March(?) 1999 to {dBase
+ Inc.}
+
+ In Febuary 1998 Borland bought {Visigenic Software, Inc.}.
+
+ The company changed its name to Inprise Corporation on
+ 1998-04-29 and then on 2000-11-14 they announced they were
+ changing it back to Borland from the first quarter of 2001.
+
+ Quarterly sales $69M, profits $61M (Aug 1994).
+ $56M, $6.4M (July 2001)
+
+ {(http://borland.com/)}.
+
+ Headquarters: 100 Borland Way, Scotts Valley, CA, 95066, USA.
+ Telephone: +1 (408) 431 1000.
+
+ (2002-03-16)
+
+BOS
+
+ 1. <operating system> {Basic Operating System}.
+
+ 2. <tool> A data management system written at {DESY} and used
+ in some high energy physics programs.
+
+ 3. <programming> The {Basic Object System}.
+
+ (1999-01-20)
+
+Bose-Chaudhuri-Hocquenghem Code
+
+ <data, communications> (BHC Code) An {error detection and
+ correction} technique based on {Cyclic Redundancy Code}, used
+ in telecommunications applications.
+
+ (1995-01-16)
+
+BOSS
+
+ Bridgport Operating System Software. A derivative of the {ISO
+ 1054} numerical machine control language for milling, etc.
+
+bot
+
+ <networking, chat, web> (From "{robot}") Any type
+ of autonomous {software} that operates as an {agent} for a
+ user or a {program} or simulates a human activity. On the
+ {Internet}, the most popular bots are programs (called
+ {spiders} or crawlers) used for searching. They access {web
+ sites}, retrieve documents and follow all the {hypertext
+ links} in them; then they generate catalogs that are accessed
+ by {search engines}.
+
+ A {chatbot} converses with humans (or other bots). A
+ {shopbot} searches the Web to find the best price for a
+ product. Other bots (such as {OpenSesame}) observe a user's
+ patterns in navigating a website and customises the site for
+ that user.
+
+ {Knowbots} collect specific information from {websites}.
+
+ (1999-05-20)
+
+botmaster
+
+ <chat> The owner of a {bot}.
+
+ (1997-04-07)
+
+bottom
+
+ <theory> The least defined element in a given {domain}.
+
+ Often used to represent a non-terminating computation.
+
+ (In {LaTeX}, bottom is written as {\perp}, sometimes with the
+ domain as a subscript).
+
+ (1997-01-07)
+
+BottomFeeder
+
+ <networking> An {RSS} {aggregator}.
+
+ {BottomFeeder Home
+ (http://cincomsmalltalk.com/BottomFeeder)}.
+
+ (2003-09-29)
+
+bottom feeder
+
+ {slopsucker}
+
+bottom-unique
+
+ In {domain theory}, a function f is bottom-unique if
+
+ f x = bottom <=> x = bottom
+
+ A bottom-unique function is also {strict}.
+
+bottom-up implementation
+
+ <programming> The opposite of {top-down design}. It is now
+ received wisdom in most programming cultures that it is best
+ to design from higher levels of abstraction down to lower,
+ specifying sequences of action in increasing detail until you
+ get to actual code. Hackers often find (especially in
+ exploratory designs that cannot be closely specified in
+ advance) that it works best to *build* things in the opposite
+ order, by writing and testing a clean set of primitive
+ operations and then knitting them together.
+
+ [{Jargon File}]
+
+ (1996-05-10)
+
+bottom-up model
+
+ <programming> A method for estimating the cost of a complete
+ software project by combining estimates for each component.
+
+ (1996-05-28)
+
+bottom-up testing
+
+ <programming> An integration testing technique that tests the
+ low-level components first using test drivers for those
+ components that have not yet been developed to call the
+ low-level components for test.
+
+ Compare {bottom-up implementation}.
+
+ (1996-05-10)
+
+botwar
+
+ <chat> The epic struggle of {bots} vying for dominance.
+
+ Botwars are generally (and quite inappropriately) carried out
+ on {talk} systems, typically {IRC}, where botwar crossfire
+ (such as {pingflood}ing) absorbs scarce server resources and
+ obstructs human conversation.
+
+ The wisdom of experience indicates that {Core Wars}, not
+ {talk} systems, are the appropriate venue for aggressive bots
+ and their {botmasters}.
+
+ Compare {penis war}.
+
+ (1997-04-08)
+
+bounce
+
+ 1. (Perhaps by analogy to a bouncing check) An {electronic
+ mail} message that is undeliverable and returns an error
+ notification (a "{bounce message}") to the sender is said to
+ "bounce".
+
+ 2. To play volleyball. The now-demolished {D. C. Power Lab}
+ building used by the {Stanford AI Lab} in the 1970s had a
+ volleyball court on the front lawn. From 5 PM to 7 PM was the
+ scheduled maintenance time for the computer, so every
+ afternoon at 5 would come over the intercom the cry: "Now hear
+ this: bounce, bounce!", followed by Brian McCune loudly
+ bouncing a volleyball on the floor outside the offices of
+ known volleyballers.
+
+ 3. To engage in sexual intercourse; probably from the
+ expression "bouncing the mattress", but influenced by Roo's
+ psychosexually loaded "Try bouncing me, Tigger!" from the
+ "Winnie-the-Pooh" books.
+
+ Compare {boink}.
+
+ 4. To casually reboot a system in order to clear up a
+ transient problem. Reported primarily among {VMS} users.
+
+ 5. (VM/CMS programmers) Automatic warm-start of a computer
+ after an error. "I logged on this morning and found it had
+ bounced 7 times during the night"
+
+ 6. (IBM) To {power cycle} a peripheral in order to reset it.
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+bounce message
+
+ A notification message returned to the sender by a site unable
+ to relay {e-mail} to the intended recipient or the next link
+ in a {bang path}. Reasons might include a nonexistent or
+ misspelled user name or a {down} relay site. Bounce messages
+ can themselves fail, with occasionally ugly results; see
+ {sorcerer's apprentice mode} and {software laser}. The terms
+ "bounce mail" and "barfmail" are also common.
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+boundary scan
+
+ The use of {scan registers} to capture state from device input
+ and output pins. {IEEE} Standard 1149.1-1990 describes the
+ international standard implementation (sometimes called JTAG
+ after the Joint Test Action Group which began the
+ standardisation work).
+
+ (1995-02-14)
+
+boundary value
+
+ {boundary value analysis}
+
+boundary value analysis
+
+ <programming> A test data selection technique in which values
+ are chosen to lie along data extremes. Boundary values
+ include maximum, minimum, just inside/outside boundaries,
+ typical values, and error values. The hope is that, if a
+ systems works correctly for these special values then it will
+ work correctly for all values in between.
+
+ (1996-05-10)
+
+bounded
+
+ <theory> In {domain theory}, a subset S of a {cpo} X is
+ bounded if there exists x in X such that for all s in S, s <=
+ x. In other words, there is some element above all of S. If
+ every bounded subset of X has a least upper bound then X is
+ boundedly {complete}.
+
+ ("<=" is written in {LaTeX} as {\subseteq}).
+
+ (1995-02-03)
+
+boundedly complete
+
+ <theory> (Or "consistently complete") In {domain theory}, a
+ {complete partial order} is boundedly complete if every {bounded}
+ {subset} has a {least upper bound}.
+
+ (2014-07-01)
+
+bound variable
+
+ 1. A bound variable or {formal argument} in a function
+ definition is replaced by the {actual argument} when the
+ function is applied. In the {lambda abstraction}
+
+ \ x . M
+
+ x is the bound variable. However, x is a {free variable} of
+ the term M when M is considered on its own. M is the {scope}
+ of the binding of x.
+
+ 2. In logic a bound variable is a quantified variable. See
+ {quantifier}.
+
+bournebasic
+
+ A {BASIC} {interpreter}.
+
+ comp.sources.misc archives volume 1.
+
+Bourne shell
+
+ (sh, Shellish). The original {command-line interpreter}
+ {shell} and script language for {Unix} written by S.R. Bourne
+ of {Bell Laboratories} in 1978. sh has been superseded for
+ interactive use by the {Berkeley} {C shell}, {csh} but still
+ widely used for writing {shell scripts}.
+
+ There were even earlier shells, see {glob}. [Details?]
+
+ {ash} is a Bourne Shell clone.
+
+ ["Unix {Time-Sharing} System: The Unix Shell", S.R. Bourne,
+ Bell Sys Tech J 57(6):1971-1990 (Jul 1978)].
+
+boustrophedonic
+
+ <hardware> (From the Greek "boustrophe-don": turning like oxen
+ in plowing; from "bous": ox, cow; "strephein": to turn) An
+ ancient method of writing using alternate left-to-right and
+ right-to-left lines. It used for an optimisation performed by
+ some computer typesetting software and moving-head printers to
+ reduce physical movement of the print head. The adverbial
+ form "boustrophedonically" is also found.
+
+ (1994-11-29)
+
+box
+
+ <computer> 1. A computer; especially in the construction "foo
+ box" where foo is some functional qualifier, like "graphics",
+ or the name of an {operating system} (thus, "{Unix} box",
+ "{MS-DOS} box", etc.) "We preprocess the data on Unix boxes
+ before handing it up to the {mainframe}." The plural
+ "{boxen}" is sometimes seen.
+
+ 2. Without qualification in an {IBM} {SNA} site, "box" refers
+ specifically to an {IBM} {front-end processor}.
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+boxed comments
+
+ <programming> {Comments} that occupy several lines by
+ themselves; so called because in {assembler} and {C} code they
+ are often surrounded by a box in a style similar to this:
+
+ /*************************************************
+ *
+ * This is a boxed comment in C style
+ *
+ *************************************************/
+
+ Common variants of this style omit the asterisks in column 2
+ or add a matching row of asterisks closing the right side of
+ the box. The sparest variant omits all but the comment
+ {delimiters} themselves; the "box" is implied.
+
+ Opposite of {winged comments}.
+
+ [{Jargon File}]
+
+ (1997-07-21)
+
+boxen
+
+ /bok'sn/ (By analogy with {VAXen}) A fanciful plural of {box}
+ often encountered in the phrase "Unix boxen", used to describe
+ commodity {Unix} hardware. The connotation is that any two
+ Unix boxen are interchangeable.
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+Boxer
+
+ 1. <language> A {visual language} by Hal Abelson and Andy
+ diSessa of Berkeley which claims to be the successor to
+ {Logo}. Boxes are used to represent {scope}.
+
+ 2. <tool> A {text editor} for {MS-DOS} and {Microsoft
+ Windows}.
+
+ {(http://boxersoftware.com/users/dhamel)}.
+
+ (2001-04-30)
+
+boxology
+
+ <graphics> /bok-sol'*-jee/ {ASCII art}.
+
+ This term implies a more restricted domain, that of
+ box-and-arrow drawings. "His report has a lot of boxology in
+ it."
+
+ Compare {macrology}.
+
+ [{Jargon File}]
+
+ (1994-12-02)
+
+Boycott Apple
+
+ Some time before 1989, {Apple Computer, Inc.} started a
+ lawsuit against {Hewlett-Packard} and {Microsoft}, claiming
+ they had breeched Apple's {copyright} on the {look and feel}
+ of the {Macintosh user interface}. In December 1989, {Xerox}
+ failed to sue {Apple Computer}, claiming that the software for
+ Apple's {Lisa} computer and {Macintosh} {Finder}, both
+ copyrighted in 1987, were derived from two {Xerox} programs:
+ {Smalltalk}, developed in the mid-1970s and {Star},
+ copyrighted in 1981.
+
+ Apple wanted to stop people from writing any program that
+ worked even vaguely like a {Macintosh}. If such {look and
+ feel} lawsuits succeed they could put an end to {free
+ software} that could substitute for commercial software.
+
+ In the weeks after the suit was filed, {Usenet} reverberated
+ with condemnation for Apple. {GNU} supporters {Richard
+ Stallman}, {John Gilmore}, and Paul Rubin decided to take
+ action against Apple. Apple's reputation as a force for
+ progress came from having made better computers; but The
+ {League for Programming Freedom} believed that Apple wanted to
+ make all non-Apple computers worse. They therefore campaigned
+ to discourage people from using Apple products or working for
+ Apple or any other company threatening similar obstructionist
+ tactics (e.g. {Lotus} and {Xerox}).
+
+ Because of this boycott the {Free Software Foundation} for a
+ long time didn't support {Macintosh} {Unix} in their software.
+ In 1995, the LPF and the FSF decided to end the boycott.
+
+ [Dates? Other events? Why did Xerox's case against Apple
+ fail?]
+
+ (1995-04-18)
+
+bozotic
+
+ <abuse> (From Bozo the Clown, a famous circus personality, via
+ "bozo" - a clod, idiot or generally silly person) any form of
+ clown-like or ludicrous behaviour. The word also has echoes
+ of "robotic", so bozotic behaviour is mindless, automaton-like
+ stupidity.
+
+ [{Jargon File}]
+
+ (1996-01-05)
+
+BPEL
+
+ {Web Services Business Process Execution Language}
+
+BPI
+
+ {bits per inch}
+
+bpmake
+
+ {Aspirin}
+
+bpp
+
+ {bits per pixel}
+
+BPR
+
+ {Business Process Re-engineering}
+
+BPS
+
+ {Basic Programming Support}
+
+bps
+
+ {bits per second}
+
+BQS
+
+ {Berkeley Quality Software}
+
+br
+
+ <networking> The {country code} for Brazil.
+
+ (1999-01-27)
+
+brace
+
+ <character> {left brace} or {right brace}.
+
+bracket
+
+ <character> (Or square bracket) A {left bracket} or {right
+ bracket}.
+
+ Often used loosely for {parentheses}, {square brackets},
+ {braces}, {angle brackets}, or any other kind of unequal
+ paired {delimiters}.
+
+ (1996-09-08)
+
+bracket abstraction
+
+ <compiler> An {algorithm} which turns a term into a function
+ of some variable. The result of using bracket abstraction on
+ T with respect to variable v, written as [v]T, is a term
+ containing no occurrences of v and denoting a function f such
+ that f v = T. This defines the function f = (\ v . T). Using
+ bracket abstraction and {currying} we can define a language
+ without {bound variables} in which the only operation is
+ {monadic} function application.
+
+ See {combinator}.
+
+ (1995-03-07)
+
+braille
+
+ <human language> /breyl/ (Often capitalised) A class of
+ {writing systems}, intended for use by blind and low-vision
+ users, which express {glyphs} as raised dots. Currently
+ employed braille standards use eight dots per cell, where a
+ cell is a glyph-space two dots across by four dots high; most
+ glyphs use only the top six dots.
+
+ Braille was developed by Louis Braille (pronounced /looy
+ bray/) in France in the 1820s. Braille systems for most
+ languages can be fairly trivially converted to and from the
+ usual script.
+
+ Braille has several totally coincidental parallels with
+ digital computing: it is {binary}, it is based on groups of
+ eight bits/dots and its development began in the 1820s, at the
+ same time {Charles Babbage} proposed the {Difference Engine}.
+
+ Computers output Braille on {braille displays} and {braille
+ printers} for hard copy.
+
+ {British Royal National Institute for the Blind
+ (http://rnib.org.uk/wesupply/fctsheet/braille.htm)}.
+
+ (1998-10-19)
+
+braille display
+
+ <hardware> (Or "refreshable braille display", "refreshable
+ display") An electromechanical device that renders {braille}
+ with tiny, independently controlled pins used to represent the
+ state of dots in braille cells. Each pin, in its "on" state,
+ raises above the top of its hole in the screen; in its "off"
+ state, it drops below the top of its hole. Older systems used
+ tiny solenoids to control the state of the pins; modern
+ systems are {piezoelectric}.
+
+ Typical dimensions of a braille display are 1 line of 40
+ cells, each cell of two-by-eight dots.
+
+ (1998-10-19)
+
+Braille embosser
+
+ {Braille printer}
+
+Braille printer
+
+ <printer> (Or "(Braille) embosser") A {printer}, necessarily
+ an {impact printer}, that renders text as {Braille}. Blind
+ users call other printers {ink printers}.
+
+ (1999-02-26)
+
+Brain Aid Prolog
+
+ <language> (BAP) A parallel {Prolog} environment for
+ {transputer} systems by Frank Bergmann <fraber@fraber.de>,
+ Martin Ostermann <ost@xan.dfv.rwth-aachen.de>, and Guido von
+ Walter <guido@parsytec.de> of {Brain Aid Systems} GbR. BAP is
+ based on a model of communicating sequential Prolog processes.
+ The {run-time system} consists of a multi-process {operating
+ system} with support for several applications running
+ concurrently.
+
+ {(http://fraber.de/bap/)}.
+
+ (2002-11-12)
+
+brain-damaged
+
+ 1. [generalisation of "Honeywell Brain Damage" (HBD), a
+ theoretical disease invented to explain certain utter
+ cretinisms in Honeywell {Multics}] Obviously wrong; cretinous;
+ {demented}.
+
+ There is an implication that the person responsible must have
+ suffered brain damage, because he should have known better.
+ Calling something brain-damaged is really bad; it also implies
+ it is unusable, and that its failure to work is due to poor
+ design rather than some accident. "Only six monocase
+ characters per file name? Now *that's* brain-damaged!"
+
+ 2. [especially in the Mac world] May refer to free
+ demonstration software that has been deliberately crippled in
+ some way so as not to compete with the commercial product it
+ is intended to sell. Synonym {crippleware}.
+
+ [{Jargon File}]
+
+ (2011-01-04)
+
+brain-dead
+
+ Brain-damaged in the extreme. It tends to imply terminal
+ design failure rather than malfunction or simple stupidity.
+
+brain dump
+
+ (The act of telling someone) everything one knows about a
+ particular topic. Typically used when someone is going to let
+ a new party maintain a piece of code. Conceptually analogous
+ to an operating system {core dump} in that it saves a lot of
+ useful {state} before an exit. "You'll have to give me a
+ brain dump on FOOBAR before you start your new job at
+ HackerCorp." At Sun, this is also known as "TOI" (transfer of
+ information).
+
+ [{Jargon File}]
+
+brain fart
+
+ <jargon, humour> 1. The actual result of a {braino}, as
+ opposed to the mental {glitch} that is the braino itself.
+ E.g. typing "dir" on a {Unix box} after a session with
+ {MS-DOS}.
+
+ 2. A biproduct of a bloated mind producing information
+ effortlessly. A burst of useful information. "I know you're
+ busy on the Microsoft story, but can you give us a brain fart
+ on the Mitnik bust?"
+
+ (1997-04-29)
+
+Brainfuck
+
+ <language> An eight-instruction programming language created
+ by Urban Müller. His goal was apparently to create a
+ {Turing-complete} language with the smallest {compiler} ever,
+ for the {Amiga OS} 2.0. He eventually reduced his compiler to
+ under 200 bytes.
+
+ A Brainfuck program has a pointer that moves within an array
+ of 30000 bytes, initially all set to zero. The pointer
+ initially points to the beginning of this array. The language
+ has eight commands, each of which is represented as a single
+ character, and which can be expressed in terms of {C} as
+ follows:
+
+ > ==> ++p;
+ < ==> --p;
+ + ==> ++*p;
+ - ==> --*p;
+ . ==> putchar(*p);
+ , ==> *p = getchar();
+ [ ==> while (*p) {
+ ] ==> }
+
+ {Brian Raiter's Brainfuck page
+ (http://muppetlabs.com/~breadbox/bf/)}.
+
+ (2003-11-18)
+
+braino
+
+ {thinko}
+
+branch
+
+ 1. <mathematics> An {edge} in a {tree}.
+
+ 2. <programming> A {jump}.
+
+Branch and Hang
+
+ <humour> (BRH) Originally a mythical instruction for the {IBM
+ 1130} at {Indiana University}.
+
+ Later some real examples were discovered. The {Texas
+ Instruments} {TI-980} allowed all {addressing modes} with all
+ instructions, including Store Immediate Extended (stores the
+ value into the extension word of the instruction) and Branch
+ and Link Immediate (makes a subroutine call to the same
+ instruction -- Branch and Hang).
+
+ Compare {HCF}.
+
+ (1997-02-12)
+
+branch coverage testing
+
+ <programming> A test method which aims to ensure that each
+ possible branch from each decision point (e.g. "if" statement)
+ is executed at least once, thus ensuring that all reachable
+ code is executed.
+
+ (1996-05-10)
+
+branch delay slot
+
+ {delayed control-transfer}
+
+Branch on Chip Box Full
+
+ <humour> (BCBF) A mythical {IBM 1130} instruction whose action
+ depended on the contents of the {chip box}. This was one of a
+ long list of fake {assembly language} instructions that went
+ around {Indiana University} in the 1970s.
+
+ (1997-02-12)
+
+branch prediction
+
+ <processor, algorithm> A technique used in some processors
+ with {instruction prefetch} to guess whether a {conditional
+ branch} will be taken or not and prefetch code from the
+ appropriate location.
+
+ When a branch instruction is executed, its address and that of
+ the next instruction executed (the chosen destination of the
+ branch) are stored in the {Branch Target Buffer}. This
+ information is used to predict which way the instruction will
+ branch the next time it is executed so that instruction
+ prefetch can continue. When the prediction is correct (and it
+ is over 90% of the time), executing a branch does not cause a
+ {pipeline break}.
+
+ Some later {CPUs} simply prefetch both paths instead of trying
+ to predict which way the branch will go.
+
+ An extension of the idea of branch prediction is {speculative
+ execution}.
+
+ (1998-03-14)
+
+Branch Target Buffer
+
+ <processor> (BTB) A {register} used to store the predicted
+ destination of a branch in a processor using {branch
+ prediction}?
+
+ [Is this correct? Examples?]
+
+ (1995-05-05)
+
+branch to Fishkill
+
+ (IBM: from the location of one of the corporation's
+ facilities) Any unexpected jump in a program that produces
+ catastrophic or just plain weird results.
+
+ See {jump off into never-never land}, {hyperspace}.
+
+ [{Jargon File}]
+
+Brazil
+
+ An {operating system} from {Acorn Computers} used on an {ARM}
+ card which could be fitted to an {IBM PC}. There was also an
+ {ARM} second processor for the {BBC Microcomputer} which used
+ Brazil. Never used on the {Archimedes}(?).
+
+ (1994-12-05)
+
+BRB
+
+ <chat> (I will) be right back.
+
+ (1998-01-18)
+
+breadcrumbs
+
+ (After the story "Hansel and Gretel" by the Brothers Grimm).
+
+ 1. <web> {Links} displayed across the top of a {web
+ page} listing the most recently visited pages so the reader
+ can quickly jump back to one. Since this function is provided
+ by the {web browser}, breadcrumbs are a waste of space.
+
+ A better use of the space is to display links to the page's
+ logical parent pages in the information hierarchy.
+
+ 2. <programming> Information output by statements inserted
+ into a program for {debugging by printf}.
+
+ [{Jargon File}]
+
+ (2007-03-07)
+
+breadth-first search
+
+ <algorithm> A {graph search algorithm} which tries all
+ one-step extensions of current paths before trying larger
+ extensions. This requires all current paths to be kept in
+ memory simultaneously, or at least their end points.
+
+ Opposite of {depth-first search}. See also {best first
+ search}.
+
+ (1996-01-05)
+
+break
+
+ 1. To cause to be {broken}. "Your latest patch
+ to the editor broke the paragraph commands."
+
+ 2. (Of a program) To stop temporarily, so that it may
+ debugged. The place where it stops is a "{breakpoint}".
+
+ 3. To send an {EIA-232} break (two character widths of line
+ high) over a {serial line}.
+
+ 4. [Unix] To strike whatever key currently causes the tty
+ driver to send SIGINT to the current process. Normally,
+ break, delete or {control-C} does this.
+
+ 5. "break break" may be said to interrupt a conversation (this
+ is an example of verb doubling). This usage comes from radio
+ communications, which in turn probably came from landline
+ telegraph/teleprinter usage, as badly abused in the Citizen's
+ Band craze.
+
+ 6. {pipeline break}.
+
+ 7. {break statement}.
+
+ [{Jargon File}]
+
+ (2004-03-24)
+
+break-even point
+
+ In the process of implementing a new computer language, the
+ point at which the language is sufficiently effective that one
+ can implement the language in itself. That is, for a new
+ language called, hypothetically, FOOGOL, one has reached
+ break-even when one can write a demonstration compiler for
+ FOOGOL in FOOGOL, discard the original implementation
+ language, and thereafter use working versions of FOOGOL to
+ develop newer ones. This is an important milestone. See {My
+ Favourite Toy Language}.
+
+ [There actually is a language called {Foogol}].
+
+breakpoint
+
+ <programming> A point in a {program} that, when reached, triggers
+ some special behavior useful to the process of {debugging};
+ generally, breakpoints are used to either pause program
+ {execution}, and/or {dump} the values of some or all of the
+ program {variables}. Breakpoints may be part of the program
+ itself; or they may be set by the programmer as part of an
+ {interactive} session with a {debugging tool} for scrutinizing the
+ program's execution.
+
+ (1999-06-07)
+
+break statement
+
+ <programming> A {statement} in the {C} programming language
+ that transfers control out of the innermost enclosing
+ {switch}, {while}, {do}, or {for} statement. The statement
+ also exists in languages derived from C, such as {C++} and
+ {Java}.
+
+ (2004-03-24)
+
+breath-of-life packet
+
+ ({XEROX PARC}) An {Ethernet} {packet} that contains
+ {bootstrap} code, periodically sent out from a working
+ computer to infuse the "breath of life" into any computer on
+ the network that has crashed. Computers depending on such
+ packets have sufficient hardware or firmware code to wait for
+ (or request) such a packet during the reboot process.
+
+ See also {dickless workstation}.
+
+ The notional "kiss-of-death packet", with a function
+ complementary to that of a breath-of-life packet, is
+ recommended for dealing with hosts that consume too many
+ network resources. Though "kiss-of-death packet" is usually
+ used in jest, there is at least one documented instance of an
+ {Internet} subnet with limited address-table slots in a
+ gateway computer in which such packets were routinely used to
+ compete for slots, rather like Christmas shoppers competing
+ for scarce parking spaces.
+
+ [{Jargon File}]
+
+ (1995-01-26)
+
+breedle
+
+ {feep}
+
+BRH
+
+ {Branch and Hang}
+
+BRI
+
+ {Basic Rate Interface}
+
+Brian Reid
+
+ <person> The person who cofounded {Usenet}'s anarchic alt.*
+ {newsgroup} {hierarchy} with {John Gilmore}.
+
+ (1997-04-12)
+
+BRIDGE
+
+ A component of {ICES} for civil engineers.
+
+ [Sammet 1969, p. 616].
+
+bridge
+
+ <networking, hardware> A device which forwards traffic between
+ {network segments} based on {data link layer} information.
+ These segments would have a common {network layer} address.
+
+ Every network should only have one {root bridge}.
+
+ See also {gateway}, {router}.
+
+ (2001-03-04)
+
+Bridgetalk
+
+ <language> A {visual language}.
+
+ (2001-03-04)
+
+briefcase
+
+ <tool> A {Win95}/{WinNT} utility for keeping files on two
+ computers without permanent connection in sync.
+
+ The scenario briefcase was designed for is the combination of
+ an office computer and a {portable} one. You connect the two
+ before leaving your office, create a briefcase on the portable
+ (if you don't already have one on it), then copy the files you
+ want to work on while away into the briefcase. You can at
+ this point disconnect the two computers, take the portable
+ with you and work on the files in the briefcase at home or on
+ the road. When you get back to your office the briefcase
+ utility can automatically update the files you changed on the
+ office computer.
+
+ (1998-05-18)
+
+brightness
+
+ <graphics> (Or "tone", "luminance", "value", "luminosity",
+ "lightness") The coordinate in the {HSB} {colour model} that
+ determines the total amount of light in the colour. Zero
+ brightness is black and 100% is white, intermediate values are
+ "light" or "dark" colours.
+
+ The other coordinates are {hue} and {saturation}.
+
+ (1999-07-05)
+
+Brilliant
+
+ One of five pedagogical languages based on {Markov}
+ {algorithms}, used in ["Nonpareil, a Machine Level Machine
+ Independent Language for the Study of Semantics", B. Higman,
+ ULICS Intl Report No ICSI 170, U London (1968)].
+
+ See also {Diamond}, {Nonpareil}, {Pearl}, {Ruby}.
+
+bring X to its knees
+
+ To present a computer, operating system, piece of software, or
+ algorithm with a load so extreme or {pathological} that it
+ grinds to a halt. "To bring a MicroVAX to its knees, try
+ twenty users running {vi} - or four running {Emacs}."
+ Compare {hog}.
+
+ [{Jargon File}]
+
+British Broadcasting Corporation
+
+ <company> (BBC) The non-commercial UK organisation that
+ commissions, produces and broadcasts television and radio
+ programmes.
+
+ The BBC commissioned the "{BBC Micro}" from {Acorn Computers}
+ for use in a television series about using computers. They
+ also have one of the world's most respected news websites (on
+ which I work!).
+
+ {BBC Home (http://bbc.co.uk/)}.
+
+ {BBC News (http://news.bbc.co.uk/)}.
+
+ (2003-07-02)
+
+British Library Method
+
+ <algorithm> {Brute force} searching.
+
+ According to legends circulating in the 1970s, in the British
+ Library books are searched for by examining each book
+ sequentially in the first shelf, then the next shelf,
+ continuing until the book is found or the entire library has
+ been searched.
+
+ The term was referred to in a Dutch coursebook, "Inleiding In
+ De Informatica" (Introduction to Informatics) from a course
+ given by C.H.A. Koster and Th.A. Zoethout. This was based on
+ a course given at the TU Berlin.
+
+ [Reference?]
+
+ (1999-04-14)
+
+British Standards Institute
+
+ <body, standard> (BSI) The British member of {ISO}.
+
+ (1996-06-12)
+
+British Telecom
+
+ <company> (BT) The largest telecommunications provider in the
+ UK.
+
+ Due to regulatory issues, BT had to sell off its interest in
+ McCaw Cellular. BT sold it to {AT&T} for something like 4B$.
+ BT then invested that in {MCI}. As a part of the deal, MCI
+ was given BT North America, which was the old {Tymnet}. MCI
+ laid off about 40% of the Tymnet staff.
+
+ {(http://intervid.co.uk/)}.
+
+ (1995-05-09)
+
+British Telecom Research Laboratories
+
+ <company> (BTRL) The laboratories where {British Telecom}
+ develops many of its new Network services.
+
+ {(http://labs.bt.com/)}.
+
+ Address: Martlesham Heath, near Ipswich, Suffolk, UK.
+
+ (1995-04-25)
+
+brittle
+
+ <jargon> Said of {software} that is functional but easily
+ broken by changes in operating environment or configuration,
+ or by any minor tweak to the software itself. Also, any
+ system that responds inappropriately and disastrously to
+ abnormal but expected external stimuli; e.g. a {file system}
+ that is usually totally scrambled by a power failure is said
+ to be brittle. This term is often used to describe the
+ results of a research effort that were never intended to be
+ robust, but it can be applied to commercially developed
+ software, which displays the quality far more often than it
+ ought to.
+
+ Opposite of {robust}.
+
+ [{Jargon File}]
+
+ (1995-05-09)
+
+broadband
+
+ <communications> A class of communication channel capable of
+ supporting a wide range of frequencies, typically from audio
+ up to video frequencies. A broadband channel can carry
+ multiple signals by dividing the total capacity into multiple,
+ independent bandwidth channels, where each channel operates
+ only on a specific range of frequencies.
+
+ The term has come to be used for any kind of {Internet}
+ connection with a {download} speed of more than 56 {kbps},
+ usually some kind of {Digital Subscriber Line}, e.g. {ADSL}.
+ A broadband connection is typically always connected, in
+ contrast to a {dial-up} connection, and a fixed monthly rate
+ is charged, often with a cap on the total amount of data that
+ can be transferred. Domestic broadband connections typically
+ share a telephone line with normal voice calls and the two
+ uses can occur simultaneously without interference.
+
+ See also {baseband}, {narrowband}.
+
+ (2006-03-30)
+
+broadcast
+
+ A transmission to multiple, unspecified recipients. On
+ Ethernet, a broadcast packet is a special type of multicast
+ packet which all nodes on the network are always willing to
+ receive.
+
+broadcast quality video
+
+ <communications, multimedia> Roughly, {video} with more than
+ 30 frames per second at a {resolution} of 800 x 640 {pixels}.
+
+ The quality of moving pictures and sound is determined by the
+ complete chain from camera to receiver. Relevant factors are
+ the colour temperature of the lighting, the balance of the
+ red, green and blue vision pick-up tubes to produce the
+ correct display colour temperature (which will be different)
+ and the {gamma} pre-correction to cancel the non-linear
+ characteristic of {cathode-ray tubes} in television receivers.
+ The {resolution} of the camera tube and video coding system
+ will determine the maximum number of {pixels} in the picture.
+
+ Different colour coding systems have different defects. The
+ NTSC system (National Television Systems Committee) can
+ produce {hue} errors. The PAL system (Phase Alternation by
+ Line) can produce {saturation} errors.
+
+ Television modulation systems are specified by ITU CCIR Report
+ 624. Low-resolution systems have {bandwidths} of 4.2 MHz with
+ 525 to 625 lines per frame as used in the Americas and Japan.
+ Medium resolution of 5 to 6.5 MHz with 625 lines is used in
+ Europe, Asia, Africa and Australasia. {High-Definition
+ Television} (HDTV) will require 8 MHz or more of bandwidth.
+
+ A medium resolution (5.5 MHz in UK) picture can be represented
+ by 572 lines of 402 pixels. Note the ratio of pixels to lines
+ is not the same as the {aspect ratio}. A {VGA} display (480n
+ lines of 640 pixels) could thus display 84% of the height of
+ one picture frame.
+
+ Most compression techniques reduce quality as they assume a
+ restricted range of detail and motion and discard details to
+ which the human eye is not sensitive.
+
+ Broadcast quality implies something better than amateur or
+ domestic video and therefore can't be retained on a domestic
+ video recorder. Broadcasts use quadriplex or U-matic
+ recorders.
+
+ The lowest frame rate used for commercial entertainment is the
+ 24Hz of the 35mm cinema camera. When broadcast on a 50Hz
+ television system, the pictures are screened at 25Hz reducing
+ the running times by 4%. On a 60Hz system every five movie
+ frames are screened as six TV frames, still at the 4%
+ increased rate. The six frames are made by mixing adjacent
+ frames, with some degradation of the picture.
+
+ A computer system to meet international standard reproduction
+ would at least VGA resolution, an interlaced frame rate of
+ 24Hz and 8 bits to represent the luminance (Y) component. For
+ a component display system using red, green and blue (RGB)
+ electron guns and phosphor dots each will require 7 bits.
+ Transmission and recording is different as various coding
+ schemes need less bits if other representations are used
+ instead of RGB. Broadcasts use YUV and compression can reduce
+ this to about 3.5 bits per pixel without perceptible
+ degradation. High-quality video and sound can be carried on a
+ 34 Mbaud channel after being compressed with {ADPCM} and
+ {variable length coding}, potentially in real time.
+
+ (1997-07-04)
+
+broadcast storm
+
+ <networking> A {broadcast} on a {network} that causes multiple
+ {hosts} to respond by broadcasting themselves, causing the
+ storm to grow exponentially in severity.
+
+ See {network meltdown}.
+
+ [{Jargon File}]
+
+ (1995-02-07)
+
+Broadway
+
+ <standard, operating system> A standard which the {X
+ Consortium} is currently (January 1997) developing and plans
+ to release soon as an {open standard}. A prime goal is to be
+ more {bandwidth}-efficient and easier to develop for (and to
+ {port}) than the {X Window System}, which has been widely
+ described as over-sized, over-featured, over-engineered and
+ incredibly over-complicated.
+
+ {(http://x.org/consortium/broadway.html)}.
+
+ (1997-05-15)
+
+brochureware
+
+ <jargon, business> A planned, but non-existent, product, like
+ {vaporware} but with the added implication that marketing is
+ actively selling and promoting it (they've printed brochures).
+ Brochureware is often deployed to con customers into not
+ committing to a competing existing product.
+
+ The term is now especially applicable to new {websites}, website
+ revisions, and ancillary services such as customer support and
+ product return.
+
+ Owing to the explosion of {database}-driven, {cookie}-using
+ {dot-coms} (of the sort that can now deduce that you are, in
+ fact, a dog), the term is now also used to describe sites made
+ up of {static HTML} pages that contain not much more than
+ contact info and mission statements. The term suggests that
+ the company is small, irrelevant to the web, local in scope,
+ clueless, broke, just starting out, or some combination
+ thereof.
+
+ Many new companies without product, funding, or even staff,
+ post brochureware with investor info and press releases to
+ help publicise their ventures. As of December 1999, examples
+ include pop.com and cdradio.com.
+
+ Small-timers that really have no business on the web such as
+ lawncare companies and divorce laywers inexplicably have
+ brochureware made that stays unchanged for years.
+
+ [{Jargon File}]
+
+ (2001-05-10)
+
+broken
+
+ Not working properly (of programs).
+
+broken arrow
+
+ <communications> The error code displayed on line 25 of a {IBM
+ 3270} {terminal} (or a {terminal emulator} emulating a 3270)
+ for various kinds of {protocol} violations and "unexpected"
+ error conditions (including connection to a {down} computer).
+ On a PC, simulated with "->/_", with the two centre characters
+ overstruck.
+
+ "Broken arrow" is also military jargon for an accident
+ involving nuclear weapons.
+
+ [{Jargon File}]
+
+ (1995-02-07)
+
+broker
+
+ {object request broker}
+
+broket
+
+ <character> /broh'k*t/ or /broh'ket/ (From broken bracket)
+ Either of the characters "<" or ">" when used as paired
+ enclosing {delimiters} ({angle brackets}).
+
+ [{Jargon File}]
+
+ (1997-07-21)
+
+brontobyte
+
+ <unit, data> A proposed unit of {data} equal to 10^27 {bytes}. A
+ brontobyte is 1000^9 bytes or 1000 {yottabytes}.
+
+ "Bronto-" is not an official prefix and the term brontobyte is
+ generally attributed to the IBM Dictionary of Computing.
+
+ One brontobyte would be enough data to store a three-dimensional
+ map of the Earth with one byte for each {voxel} of a
+ one-centimetre grid.
+
+ See {prefix}.
+
+ [Where did IBM get it from?]
+
+ (2013-11-04)
+
+Brooks's Law
+
+ <programming> "Adding manpower to a late software project
+ makes it later" - a result of the fact that the expected
+ advantage from splitting work among N programmers is O(N)
+ (that is, proportional to N), but the complexity and
+ communications cost associated with coordinating and then
+ merging their work is O(N^2) (that is, proportional to the
+ square of N).
+
+ The quote is from Fred Brooks, a manager of {IBM}'s {OS/360}
+ project and author of "{The Mythical Man-Month}".
+
+ The myth in question has been most tersely expressed as
+ "Programmer time is fungible" and Brooks established
+ conclusively that it is not. Hackers have never forgotten his
+ advice; too often, {management} still does.
+
+ See also {creationism}, {second-system effect}, {optimism}.
+
+ [{Jargon File}]
+
+ (1996-09-17)
+
+brouter
+
+ A device which bridges some {packets} (i.e. forwards based on
+ {data link layer} information) and routes other packets (i.e.
+ forwards based on {network layer} information). The
+ {bridge}/{route} decision is based on configuration
+ information.
+
+Brouwer Fixed-Point Theorem
+
+ <topology> A well-known result in {topology} stating that any
+ {continuous transformation} of an n-dimensional disk must have
+ at least one {fixed point}.
+
+ [Is this correct?]
+
+ (2001-03-29)
+
+Brown and Sharpe Wire Gauge
+
+ {American Wire Gauge}
+
+brown paper bag bug
+
+ <programming> A programming {bug} that is so stupid that it
+ makes the programmer want to put a brown paper bag over his
+ head.
+
+ (2001-01-16)
+
+browser
+
+ <hypertext> A program which allows a person to read
+ {hypertext}. The browser gives some means of viewing the
+ contents of {nodes} (or "pages") and of {navigating} from one
+ node to another.
+
+ {Netscape Navigator}, {NCSA} {Mosaic}, {Lynx}, and {W3} are
+ examples for browsers for the {web}. They act as
+ {clients} to remote {web servers}.
+
+ (1996-05-31)
+
+browserconfig.xml
+
+ <web> A {Microsoft} configuration file used to
+ customise the appearance and behaviour of {website} links
+ {pinned} to the {Windows} {start screen} or {desktop} {taskbar}.
+ browserconfig.xml allows the site owner to specify things like
+ {badges} and tile images.
+
+ {browserconfig.xml reference
+ (http://msdn.microsoft.com/en-us/library/ie/dn320426%28v=vs.85%29.aspx)}.
+
+ (2014-07-24)
+
+BRS
+
+ {Big Red Switch}
+
+BRUIN
+
+ Brown University Interactive Language.
+
+ A simple interactive language with {PL/I}-like {syntax}, for
+ {IBM 360}.
+
+ ["Meeting the Computational Requirements of the University,
+ Brown University Interactive Language", R.G. Munck, Proc 24th
+ ACM Conf, 1969].
+
+ (1995-02-14)
+
+brute force
+
+ <programming> A primitive programming style in which the
+ programmer relies on the computer's processing power instead
+ of using his own intelligence to simplify the problem, often
+ ignoring problems of scale and applying naive methods suited
+ to small problems directly to large ones. The term can also
+ be used in reference to programming style: brute-force
+ programs are written in a heavy-handed, tedious way, full of
+ repetition and devoid of any elegance or useful abstraction
+ (see also {brute force and ignorance}).
+
+ The {canonical} example of a brute-force algorithm is
+ associated with the "{travelling salesman problem}" (TSP), a
+ classical {NP-hard} problem:
+
+ Suppose a person is in, say, Boston, and wishes to drive to N
+ other cities. In what order should the cities be visited in
+ order to minimise the distance travelled?
+
+ The brute-force method is to simply generate all possible
+ routes and compare the distances; while guaranteed to work and
+ simple to implement, this algorithm is clearly very stupid in
+ that it considers even obviously absurd routes (like going
+ from Boston to Houston via San Francisco and New York, in that
+ order). For very small N it works well, but it rapidly
+ becomes absurdly inefficient when N increases (for N = 15,
+ there are already 1,307,674,368,000 possible routes to
+ consider, and for N = 1000 - well, see {bignum}). Sometimes,
+ unfortunately, there is no better general solution than brute
+ force. See also {NP-complete}.
+
+ A more simple-minded example of brute-force programming is
+ finding the smallest number in a large list by first using an
+ existing program to sort the list in ascending order, and then
+ picking the first number off the front.
+
+ Whether brute-force programming should actually be considered
+ stupid or not depends on the context; if the problem is not
+ terribly big, the extra CPU time spent on a brute-force
+ solution may cost less than the programmer time it would take
+ to develop a more "intelligent" algorithm. Additionally, a
+ more intelligent algorithm may imply more long-term complexity
+ cost and bug-chasing than are justified by the speed
+ improvement.
+
+ When applied to {cryptography}, it is usually known as {brute
+ force attack}.
+
+ {Ken Thompson}, co-inventor of {Unix}, is reported to have
+ uttered the epigram "When in doubt, use brute force". He
+ probably intended this as a {ha ha only serious}, but the
+ original {Unix} {kernel}'s preference for simple, robust and
+ portable {algorithms} over {brittle} "smart" ones does seem to
+ have been a significant factor in the success of that
+ {operating system}. Like so many other tradeoffs in software
+ design, the choice between brute force and complex,
+ finely-tuned cleverness is often a difficult one that requires
+ both engineering savvy and delicate aesthetic judgment.
+
+ [{Jargon File}]
+
+ (1995-02-14)
+
+brute force and ignorance
+
+ <jargon> (BFI) A popular design technique at many software
+ houses - {brute force} coding unrelieved by any knowledge of
+ how problems have been previously solved in elegant ways.
+ Dogmatic adherence to design methods tends to encourage this
+ sort of thing. Characteristic of early {larval stage}
+ programming; unfortunately, many never outgrow it.
+
+ Also encountered in the variants BFMI - brute force and
+ massive ignorance, and BFBI - brute force and bloody
+ ignorance.
+
+ "Gak, they used a {bubble sort}! That's strictly BFI."
+
+ Compare {bogosity}.
+
+ [{Jargon File}]
+
+ (1996-06-12)
+
+brute force attack
+
+ <cryptography> A method of breaking a cipher (that is, to
+ decrypt a specific encrypted text) by trying every possible
+ {key}. The quicker the brute force attack, the weaker the
+ cipher. Feasibility of brute force attack depends on the key
+ length of the cipher, and on the amount of computational power
+ available to the attacker. Brute force attack is impossible
+ against the ciphers with variable-size key, such as a
+ {one-time pad} cipher.
+
+ {Breaking ciphers with many workstations
+ (http://distributed.net/projects.html.en)}.
+
+ (2000-01-16)
+
+BS
+
+ {backspace}
+
+bs
+
+ <networking> The {country code} for the Bahamas.
+
+ (1999-01-27)
+
+BS2000
+
+ <operating system> An {operating system} from {SNI} for
+ {mainframes}.
+
+ {(http://mch.sni.de.public/bs2000/server.htm)}.
+
+ (1997-06-13)
+
+BSA
+
+ 1. {Business Software Alliance}.
+
+ 2. {Bidouilleurs Sans Argent}.
+
+BSD
+
+ {Berkeley Software Distribution}
+
+BSD386
+
+ {386BSD}
+
+BSDI
+
+ {Berkeley Software Design, Inc.}
+
+BSD/OS
+
+ <operating system> {BSDI}'s commercial version of {Berkeley
+ Standard Distribution} {Unix}. BSD/OS is a
+ {POSIX}-compatible, {Unix}-like system for the {80386}, {486},
+ and {Pentium}. It is based on the {BSD} software from {UCB},
+ a number of other sources, and components engineered by BSDI.
+ The initial production release of BSD/OS shipped in March,
+ 1993.
+
+ (1996-01-13)
+
+BSD Unix
+
+ {Berkeley Software Distribution}
+
+BSI
+
+ {British Standards Institute}
+
+BSL
+
+ <language> A variant of {IBM}'s {PL/S} systems language.
+ Versions: BSL1, BSL2.
+
+ (1998-06-15)
+
+BSOD
+
+ {Blue Screen of Death}
+
+BSOL
+
+ {Blue Screen of Life}
+
+BSOM
+
+ {Beats the shit outa me}
+
+BSP method
+
+ <programming> A {CASE} method from {IBM}.
+
+ (1998-02-24)
+
+BSRAM
+
+ {Burst Static Random Access Memory}
+
+BSS
+
+ 1. <programming> {Block Started by Symbol}.
+
+ 2. <networking> {Basic Service Set}
+
+BSS segment
+
+ {Block Started by Symbol}
+
+BST
+
+ <convention> British Summer Time. The name for
+ daylight-saving time in the UK {GMT} time zone.
+
+ (2000-03-28)
+
+bt
+
+ <networking> The {country code} for Bhutan.
+
+ (1999-01-27)
+
+BTB
+
+ {Branch Target Buffer}
+
+btoa
+
+ <tool, messaging, algorithm, file format> /B too A/ A {binary}
+ to {ASCII} conversion utility.
+
+ btoa is a {uuencode} or {base 64} equivalent which addresses
+ some of the problems with the uuencode standard but not as
+ many as the base 64 standard. It avoids problems that some
+ {hosts} have with spaces (e.g. conversion of groups of spaces
+ to tabs) by not including them in its character set, but may
+ still have problems on non-ASCII systems (e.g. {EBCDIC}).
+
+ btoa is primarily used to transfer {binary files} between
+ systems across connections which are not {eight-bit clean},
+ e.g. {electronic mail}.
+
+ btoa takes adjacent sets of four binary {octets} and encodes
+ them as five ASCII {octets} using ASCII characters '!' through
+ to 'u'. Special characters are also used: 'x' marks the
+ beginning or end of the archive; 'z' marks four consecutive
+ zeros and 'y' (version 5.2) four consecutive spaces.
+
+ Each group of four octets is processed as a 32-bit integer.
+ Call this 'I'. Let 'D' = 85^4. Divide I by D. Call this
+ result 'R'. Make I = I - (R * D) to avoid {overflow} on the
+ next step. Repeat, for values of D = 85^3, 85^2, 85 and 1.
+ At each step, to convert R to the output character add decimal
+ 33 (output octet = R + ASCII value for '!'). Five output
+ octets are produced.
+
+ btoa provides some {integrity checking} in the form of a line
+ {checksum}, and facilities for patching corrupted downloads.
+
+ The {algorithm} used by btoa is more efficient than uuencode
+ or base 64. ASCII files are encoded to about 120% the size of
+ their binary sources. This compares with 135% for uuencode or
+ base 64.
+
+ {C source (ftp://hpux.csc.liv.ac.uk/hpux/Misc/btoa-5.2/)}.
+ (version 5.2 - ~1994).
+
+ Pre-compiled {MS-DOS} versions are also available.
+
+ (1997-08-08)
+
+B-Toolkit
+
+ <tool, programming, product> A set of software tools designed
+ to support a rigorous or formal development of software
+ systems using the {B-Method}.
+
+ The Toolkit also provides a development environment automating
+ the management of all associated files, ensuring that the
+ entire development, including code and documentation, is
+ always in a consistent state.
+
+ The Toolkit includes: a specification, design and code
+ configuration management system, including integrity and
+ dependency management and source file editing facilities; a
+ set of software specification and design analysis tools, which
+ includes {syntax} checkers, type checkers and a specification
+ animator; a set of verification tools, which includes a
+ proof-obligation generator and automatic and interactive
+ provers; a set of coding tools, which includes a translator,
+ linker, rapid prototyping facilities and a reusable
+ specification/code module library; a documentation tool for
+ automatically producing fully cross-referenced and indexed
+ type-set documents from source files; a re-making tool for
+ automatically re-checking and re-generating specifications,
+ designs, code and documentation after modifications to source
+ files.
+
+ A normal licence costs 25,000 pounds, academic 6,250 pounds.
+
+ (1995-03-13)
+
+BTOS
+
+ {Convergent Technologies Operating System}
+
+B-tree
+
+ <algorithm> A multi-way {balanced tree}.
+
+ The "B" in B-tree has never been officially defined. It could
+ stand for "balanced" or "Bayer", after one of the original
+ designers of the algorithms and structure. A B-tree is _not_
+ (necessarily?) a "{binary tree}".
+
+ A B+-tree (as used by {IBM}'s {VSAM}) is a B-tree where the
+ leaves are also linked sequentially, thus allowing both fast
+ {random access} and sequential access to data.
+
+ [Knuth's Art of Computer Programming].
+
+ [Example algorithm?]
+
+ (2000-01-10)
+
+BTRIEVE
+
+ 1. <company> {BTRIEVE Technologies, Inc.}.
+
+ 2. <tool> A trademark of {BTRIEVE Technologies, Inc.} for
+ their {ISAM} {index file} manager for {IBM PCs}.
+
+ (1995-03-28)
+
+BTRIEVE Technologies, Inc.
+
+ <company, database> /bee-treev/ (BTI) A provider of
+ {client-server} {database engines}. BTI was founded by former
+ {Novell, Inc.} employees, including the original developers of
+ the Btrieve database engine. BTI acquired the database
+ product line from Novell in April, 1994.
+
+ {(http://btrieve.com/)}.
+
+ Address: Austin, Texas, USA.
+
+ (1995-12-14)
+
+BTRL
+
+ <company> {British Telecom Research Laboratories}.
+
+BTS
+
+ {Bug Tracking System}
+
+BTW
+
+ <chat> By the way.
+
+ (2002-06-12)
+
+BUAF
+
+ [alt.fan.warlord] Big Ugly ASCII Font. A special form of
+ {ASCII art}. Various programs exist for rendering text
+ strings into block, {bloob}, and pseudo-script fonts in cells
+ between four and six character cells on a side; this is
+ smaller than the letters generated by older {banner} programs.
+ These are sometimes used to render one's name in a {sig
+ block}, and are critically referred to as "BUAF"s. See
+ {warlording}.
+
+ [{Jargon File}]
+
+BUAG
+
+ [alt.fan.warlord] Big Ugly ASCII Graphic. Pejorative term for
+ ugly {ASCII ART}, especially as found in {sig blocks}. For
+ some reason, mutations of the head of Bart Simpson are
+ particularly common in the least imaginative {sig blocks}.
+
+ See {warlording}.
+
+bubble memory
+
+ A storage device built using materials such as gadolinium
+ gallium garnet which are can be magnetised easily in only one
+ direction. A film of these materials can be created so that
+ it is magnetisable in an up-down direction. The magnetic
+ fields tend to join together, some with the north pole facing
+ up, some with the south.
+
+ When a veritcal magnetic field is imposed on this, the areas
+ in opposite alignment to the field shrink to circles, or
+ 'bubbles'. A bubble can be formed by reversing the field in a
+ small spot, and can be destroyed by increasing the field.
+
+ Bubble memory is a kind of {non-volatile storage} but
+ {EEPROM}, {Flash Erasable Programmable Read-Only Memory} and
+ ferroelectric technologies, which are also non-volatile, are
+ faster.
+
+ ["Great Microprocessors of the Past and Present", V 4.0.0,
+ John Bayko <bayko@hercules.cs.uregina.ca>, Appendix C]
+
+ (1995-02-03)
+
+bubble sort
+
+ A sorting technique in which pairs of adjacent values in the
+ list to be sorted are compared and interchanged if they are
+ out of order; thus, list entries "bubble upward" in the list
+ until they bump into one with a lower sort value. Because it
+ is not very good relative to other methods and is the one
+ typically stumbled on by {naive} and untutored programmers,
+ hackers consider it the {canonical} example of a naive
+ algorithm. The canonical example of a really *bad* algorithm
+ is {bogo-sort}. A bubble sort might be used out of ignorance,
+ but any use of bogo-sort could issue only from brain damage or
+ willful perversity.
+
+ [{Jargon File}]
+
+bucky bits
+
+ /buh'kee bits/ 1. Obsolete. The bits produced by the CONTROL
+ and META shift keys on a SAIL keyboard ({octal} 200 and 400
+ respectively), resulting in a 9-bit keyboard character set.
+ The MIT AI TV (Knight) keyboards extended this with TOP and
+ separate left and right CONTROL and META keys, resulting in a
+ 12-bit character set; later, LISP Machines added such keys as
+ SUPER, HYPER, and GREEK (see {space-cadet keyboard}).
+
+ 2. By extension, bits associated with "extra" shift keys on
+ any keyboard, e.g. the ALT on an IBM PC or command and option
+ keys on a Macintosh.
+
+ It has long been rumored that "bucky bits" were named after
+ Buckminster Fuller during a period when he was consulting at
+ Stanford. Actually, bucky bits were invented by Niklaus Wirth
+ when *he* was at Stanford in 1964--65; he first suggested the
+ idea of an EDIT key to set the 8th bit of an otherwise 7 bit
+ ASCII character. It seems that, unknown to Wirth, certain
+ Stanford hackers had privately nicknamed him "Bucky" after a
+ prominent portion of his dental anatomy, and this nickname
+ transferred to the bit. Bucky-bit commands were used in a
+ number of editors written at Stanford, including most notably
+ TV-EDIT and NLS.
+
+ The term spread to MIT and CMU early and is now in general
+ use. Ironically, Wirth himself remained unaware of its
+ derivation for nearly 30 years, until {GLS} dug up this
+ history in early 1993! See {double bucky}, {quadruple bucky}.
+
+ (2001-06-22)
+
+buffer
+
+ 1. An area of memory used for storing messages. Typically, a
+ buffer will have other attributes such as an input pointer
+ (where new data will be written into the buffer), and output
+ pointer (where the next item will be read from) and/or a count
+ of the space used or free. Buffers are used to decouple
+ processes so that the reader and writer may operate at
+ different speeds or on different sized blocks of data.
+
+ There are many different algorithms for using buffers, e.g.
+ first-in first-out (FIFO or shelf), last-in first-out (LIFO or
+ stack), double buffering (allowing one buffer to be read while
+ the other is being written), cyclic buffer (reading or writing
+ past the end wraps around to the beginning).
+
+ 2. An electronic device to provide compatibility between two
+ signals, e.g. changing voltage levels or current capability.
+
+buffered write-through
+
+ <memory management> A variation of {write-through} where the
+ {cache} uses a "write buffer" to hold data being written back
+ to {main memory}. This frees the cache to service read
+ requests while the write is taking place. There is usually
+ only one stage of buffering so subsequent writes must wait
+ until the first is complete. Most accesses are reads so
+ buffered write-through is only useful for very slow main
+ memory.
+
+ (1998-04-24)
+
+buffer overflow
+
+ <programming> What happens when you try to store more data in
+ a {buffer} than it can handle. This may be due to a mismatch
+ in the processing rates of the producing and consuming
+ processes (see {overrun} and {firehose syndrome}), or because
+ the buffer is simply too small to hold all the data that must
+ accumulate before a piece of it can be processed. For
+ example, in a text-processing tool that {crunch}es a line at a
+ time, a short line buffer can result in {lossage} as input
+ from a long line overflows the buffer and overwrites data
+ beyond it. Good defensive programming would check for
+ overflow on each character and stop accepting data when the
+ buffer is full.
+
+ See also {spam}, {overrun screw}.
+
+ [{Jargon File}]
+
+ (1996-05-13)
+
+buffer overrun
+
+ {buffer overflow}
+
+bug
+
+ <programming> An unwanted and unintended property of a
+ {program} or piece of {hardware}, especially one that causes
+ it to malfunction. Antonym of {feature}. E.g. "There's a bug
+ in the editor: it writes things out backward." The
+ identification and removal of bugs in a program is called
+ "{debugging}".
+
+ Admiral {Grace Hopper} (an early computing pioneer better
+ known for inventing {COBOL}) liked to tell a story in which a
+ technician solved a {glitch} in the {Harvard Mark II machine}
+ by pulling an actual insect out from between the contacts of
+ one of its relays, and she subsequently promulgated {bug} in
+ its hackish sense as a joke about the incident (though, as she
+ was careful to admit, she was not there when it happened).
+ For many years the logbook associated with the incident and
+ the actual bug in question (a moth) sat in a display case at
+ the Naval Surface Warfare Center (NSWC). The entire story,
+ with a picture of the logbook and the moth taped into it, is
+ recorded in the "Annals of the History of Computing", Vol. 3,
+ No. 3 (July 1981), pp. 285--286.
+
+ The text of the log entry (from September 9, 1947), reads
+ "1545 Relay #70 Panel F (moth) in relay. First actual case of
+ bug being found". This wording establishes that the term was
+ already in use at the time in its current specific sense - and
+ Hopper herself reports that the term "bug" was regularly
+ applied to problems in radar electronics during WWII.
+
+ Indeed, the use of "bug" to mean an industrial defect was
+ already established in Thomas Edison's time, and a more
+ specific and rather modern use can be found in an electrical
+ handbook from 1896 ("Hawkin's New Catechism of Electricity",
+ Theo. Audel & Co.) which says: "The term "bug" is used to a
+ limited extent to designate any fault or trouble in the
+ connections or working of electric apparatus." It further
+ notes that the term is "said to have originated in
+ {quadruplex} telegraphy and have been transferred to all
+ electric apparatus."
+
+ The latter observation may explain a common folk etymology of
+ the term; that it came from telephone company usage, in which
+ "bugs in a telephone cable" were blamed for noisy lines.
+ Though this derivation seems to be mistaken, it may well be a
+ distorted memory of a joke first current among *telegraph*
+ operators more than a century ago!
+
+ Actually, use of "bug" in the general sense of a disruptive
+ event goes back to Shakespeare! In the first edition of
+ Samuel Johnson's dictionary one meaning of "bug" is "A
+ frightful object; a walking spectre"; this is traced to
+ "bugbear", a Welsh term for a variety of mythological monster
+ which (to complete the circle) has recently been reintroduced
+ into the popular lexicon through fantasy {role-playing games}.
+
+ In any case, in jargon the word almost never refers to
+ insects. Here is a plausible conversation that never actually
+ happened:
+
+ "There is a bug in this ant farm!"
+
+ "What do you mean? I don't see any ants in it."
+
+ "That's the bug."
+
+ [There has been a widespread myth that the original bug was
+ moved to the Smithsonian, and an earlier version of this entry
+ so asserted. A correspondent who thought to check discovered
+ that the bug was not there. While investigating this in late
+ 1990, your editor discovered that the NSWC still had the bug,
+ but had unsuccessfully tried to get the Smithsonian to accept
+ it - and that the present curator of their History of
+ American Technology Museum didn't know this and agreed that it
+ would make a worthwhile exhibit. It was moved to the
+ Smithsonian in mid-1991, but due to space and money
+ constraints has not yet been exhibited. Thus, the process of
+ investigating the original-computer-bug bug fixed it in an
+ entirely unexpected way, by making the myth true! - ESR]
+
+ [{Jargon File}]
+
+ (1999-06-29)
+
+bug-compatible
+
+ Said of a design or revision that has been badly compromised
+ by a requirement to be compatible with {fossils} or
+ {misfeatures} in other programs or (especially) previous
+ releases of itself. "{MS-DOS} 2.0 used \ as a path separator
+ to be bug-compatible with some cretin's choice of / as an
+ option character in 1.0."
+
+ [{Jargon File}]
+
+bug fix
+
+ <programming> A change to a program or system intended to
+ permanently cure a {bug}. Often a fix for one bug
+ inadvertantly introduces new bugs, hence the need for careful
+ forethought and testing.
+
+ Compare: {workaround}.
+
+ (1998-06-25)
+
+bug fix release
+
+ <programming> A {release} which introduces no new {features},
+ but which merely aims to fix bugs in previous releases. All
+ too commonly new bugs are introduced at the same time.
+
+ (1996-08-04)
+
+Bugfoot
+
+ {Loch Ness Monster Bug}
+
+bug-for-bug compatible
+
+ Same as {bug-compatible}, with the additional implication that
+ much tedious effort went into ensuring that each (known) bug
+ was replicated.
+
+ [{Jargon File}]
+
+buglix
+
+ /buhg'liks/ Pejorative term referring to {DEC}'s {ULTRIX}
+ {operating system} in its earlier *severely* buggy versions.
+ Still used to describe ULTRIX, but without nearly so much
+ venom. Compare {AIDX}, {HP-SUX}, {Nominal Semidestructor},
+ {Telerat}, {sun-stools}.
+
+bugs
+
+ {bug}
+
+BUGSYS
+
+ <programming> A programming system for {pattern recognition}
+ and preparing animated films, for {IBM 7094} and {IBM 360}.
+
+ ["BUGSYS: A Programming System for Picture Processing - Not
+ for Debugging", R.A. Ledley et al, CACM 9(2) (Feb 1966)].
+
+ (1995-02-14)
+
+bug tracking system
+
+ <programming> (BTS) A system for receiving and filing {bugs}
+ reported against a {software} project, and tracking those bugs
+ until they are fixed. Most major software projects have their
+ own BTS, the {source code} of which is often available for use
+ by other projects.
+
+ Well known BTSs include {GNATS}, {Bugzilla}, and {Debbugs}.
+
+ (2002-06-12)
+
+Bugzilla
+
+ <programming> The web-based {bug tracking system} used by the
+ {Mozilla} project.
+
+ {Bugzilla home (http://bugzilla.mozilla.org/)}.
+
+ (2002-06-12)
+
+build
+
+ <programming, systems> To process all of a project's {source
+ code} and other digital assets or resources in order to
+ produce a deployable product. In the simplest case this might
+ mean compiling one file of {C} source to produce an
+ {executable} file. More complex builds would typically
+ involve compiling multiple source files, building library
+ modules, packaging intermediate build products (e.g. {Java}
+ {class files} in a {jar file}), adding or updating version
+ information and other data about the product (e.g. intended
+ deployment {platform}), running tests and interacting with a
+ {source code control} system.
+
+ The build process is normally automated using tools such as
+ {Unix} {make}, {Apache} {ant} or as part of an {integrated
+ development environment}. This is taken one step further by
+ {continuous integration} set-ups which periodically build the
+ system while you are working on it.
+
+ (2011-12-16)
+
+built-in
+
+ (Or "primitive") A built-in function or operator is one
+ provided by the lowest level of a language implementation.
+ This usually means it is not possible (or efficient) to
+ express it in the language itself. Typical examples are the
+ basic arithmetic and {Boolean} operators (in {C} syntax: +, -,
+ *, /, %, !, &&, ||), bit manipulation operators (~, &, |, ^)
+ and I/O primitives. Other common functions may be provided in
+ libraries but are not built-in if they are written in the
+ language being implemented.
+
+ (1995-02-14)
+
+Built-in Self Test
+
+ (BIST) The technique of designing circuits with additional
+ logic which can be used to test proper operation of the
+ primary (functional) logic.
+
+ (1995-02-14)
+
+Bull
+
+ {Bull Information Systems}
+
+bulletin board
+
+ {bulletin board system}
+
+bulletin board system
+
+ <communications, application> (BBS, bboard /bee'bord/, message
+ board, forum; plural: BBSes) A computer and associated
+ software which typically provides an electronic message
+ database where people can log in and leave messages. Messages
+ are typically split into {topic groups} similar to the
+ {newsgroups} on {Usenet} (which is like a distributed BBS).
+ Any user may submit or read any message in these public areas.
+
+ The term comes from physical pieces of board on which people
+ can pin messages written on paper for general consumption - a
+ "physical bulletin board". {Ward Christensen}, the programmer
+ and operator of the first BBS (on-line 1978-02-16) called it a
+ CBBS for "computer bulletin board system". Since the rise of
+ the {World-Wide Web}, the term has become antiquated, though
+ the concept is more popular than ever, with many {websites}
+ featuring discussion areas where users can post messages for
+ public consumption.
+
+ Apart from public message areas, some BBSes provided archives
+ of files, personal {electronic mail} and other services of
+ interest to the system operator ({sysop}).
+
+ Thousands of BBSes around the world were run from amateurs'
+ homes on {MS-DOS} boxes with a single {modem} line each.
+ Although BBSes were traditionally the domain of hobbyists,
+ many connected directly to the {Internet} (accessed via
+ {telnet}), others were operated by government, educational,
+ and research institutions.
+
+ Fans of {Usenet} or the big commercial {time-sharing} bboards
+ such as {CompuServe}, {CIX} and {GEnie} tended to consider
+ local BBSes the low-rent district of the hacker culture, but
+ they helped connect hackers and users in the personal-{micro}
+ and let them exchange code.
+
+ Use of this term for a {Usenet} newsgroup generally marks one
+ either as a {newbie} fresh in from the BBS world or as a real
+ old-timer predating {Usenet}.
+
+ (2005-09-20)
+
+bulletproof
+
+ Used of an algorithm or implementation considered extremely
+ {robust}; lossage-resistant; capable of correctly recovering
+ from any imaginable exception condition - a rare and valued
+ quality. Synonym {armor-plated}.
+
+ [{Jargon File}]
+
+Bull Information Systems
+
+ <company> A multinational I.T. group based in Europe with
+ 21,000 people and operations in more than 85 countries. In
+ 1997, Bull earned revenues of over $4 billion, including over
+ 65% outside of France, its country of origin. The company is
+ ranked as the third largest {systems integrator} in Europe.
+
+ {(http://bull.com/)}.
+
+ (1998-07-02)
+
+bum
+
+ 1. To make highly efficient, either in time or space, often at
+ the expense of clarity. "I managed to bum three more
+ instructions out of that code." "I spent half the night
+ bumming the interrupt code." In {elder days}, {John McCarthy}
+ (inventor of {Lisp}) used to compare some efficiency-obsessed
+ hackers among his students to "ski bums"; thus, optimisation
+ became "program bumming", and eventually just "bumming".
+
+ 2. To squeeze out excess; to remove something in order to
+ improve whatever it was removed from (without changing
+ function; this distinguishes the process from a
+ {featurectomy}).
+
+ 3. A small change to an algorithm, program, or hardware
+ device to make it more efficient. "This hardware bum makes
+ the jump instruction faster."
+
+ Usage: now uncommon, largely superseded by v. {tune} (and
+ {tweak}, {hack}), though none of these exactly capture sense
+ 2. All these uses are rare in Commonwealth hackish, because
+ in the parent dialects of English "bum" is a rude synonym for
+ "buttocks".
+
+ [{Jargon File}]
+
+bump
+
+ Increment. E.g. {C}'s {++} operator. It is used especially of
+ counter variables, pointers and index dummies in "for",
+ "while", and "do-while" loops.
+
+ (1994-11-29)
+
+burble
+
+ [Lewis Carroll's "Jabberwocky"] Like {flame}, but connotes
+ that the source is truly clueless and ineffectual (mere
+ flamers can be competent). A term of deep contempt. "There's
+ some guy on the phone burbling about how he got a DISK FULL
+ error and it's all our comm software's fault." This is
+ mainstream slang in some parts of England.
+
+ [{Jargon File}]
+
+Bureau International des Poids et Mesures
+
+ <body, standard> (BIPM) The standards body that ensures
+ world-wide uniformity of measurements and their traceability
+ to the {International System of Units} (SI). The BIPM is
+ based in France and operates with the authority of the
+ Convention of the Metre, a diplomatic treaty between fifty-one
+ nations. It operates through a series of committees, whose
+ members are the national metrology laboratories of the member
+ states of the convention, and through its own laboratory work.
+
+ The BIPM carries out measurement-related research. It takes
+ part in, and organises, international comparisons of national
+ measurement standards, and it carries out calibrations for
+ member states.
+
+ {BIPM Home (http://www.bipm.org/)}.
+
+ (2014-07-08)
+
+Burge's Language
+
+ Unnamed functional language based on lambda-calculus.
+ Recursive Programming techniques", W.H. Burge, A-W 1975.
+
+buried treasure
+
+ A surprising piece of code found in some program. While
+ usually not wrong, it tends to vary from {crufty} to
+ bletcherous, and has lain undiscovered only because it was
+ functionally correct, however horrible it is. Used
+ sarcastically, because what is found is anything *but*
+ treasure. Buried treasure almost always needs to be dug up
+ and removed. "I just found that the scheduler sorts its queue
+ using {bubble sort}! Buried treasure!"
+
+ [{Jargon File}]
+
+burn-in
+
+ 1. <hardware> {screen saver}.
+
+ 2. <hardware, testing> {burn-in period}.
+
+burn-in period
+
+ 1. <testing> A factory {soak test} intended to increase the
+ chance that components that fail early due to {infant
+ mortality} will fail before the system leaves the factory.
+
+ 2. <jargon> When one is so intensely involved in a new project
+ that one forgets basic needs such as food, drink and sleep.
+ Excessive burn-in can lead to burn-out. See {hack mode},
+ {larval stage}.
+
+ [{Jargon File}]
+
+ (2007-01-17)
+
+Burroughs Corporation
+
+ <company> A company which merged with {Sperry Univac} to form
+ {Unisys Corporation}. They produced the {Datatron 200 series}
+ among other computers.
+
+ (2007-01-16)
+
+Burst EDO
+
+ {Burst Extended Data Out DRAM}
+
+Burst Extended Data Out DRAM
+
+ <storage> (Burst EDO, BEDO) A variant on {EDO DRAM} in which
+ read or write cycles are batched in bursts of four. The
+ bursts wrap around on a four byte boundary which means that
+ only the two least significant bits of the {CAS} address are
+ modified internally to produce each address of the burst
+ sequence. Consequently, burst EDO bus speeds will range from
+ 40MHz to 66MHz, well above the 33MHz bus speeds that can be
+ accomplished using {Fast Page Mode} or EDO DRAM.
+
+ Burst EDO was introduced sometime before May 1995.
+
+ (1996-06-25)
+
+burst page
+
+ {banner}
+
+Burst Static Random Access Memory
+
+ <storage> (BSRAM) A kind of {SRAM} used primarily for external
+ {Level 2 cache} memory.
+
+ [How does it work?]
+
+ (1998-02-24)
+
+bus
+
+ <architecture, networking> A set of electrical conductors
+ (wires, PCB tracks or connections in an {integrated circuit})
+ connecting various "stations", which can be {functional units}
+ in a computer or {nodes} in a {network}. A bus is a
+ {broadcast} channel, meaning that each station receives every
+ other station's transmissions and all stations have equal
+ access to the bus.
+
+ Various schemes have been invented to solve the problem of
+ collisions: multiple stations trying to transmit
+ at once, e.g. {CSMA/CD}, {bus master}.
+
+ The term is almost certainly derived from the electrical
+ engineering term "bus bar" - a substantial, rigid power supply
+ conductor to which several connections are made. This was
+ once written "'bus bar" as it was a contraction of "omnibus
+ bar" - a connection bar "for all", by analogy with the
+ passenger omnibus - a conveyance "for all".
+
+ {More on derivation (/pub/misc/omnibus.html)}.
+
+ There are busses both within the {CPU} and connecting it to
+ external {memory} and {peripheral} devices. The data bus,
+ address bus and control signals, despite their names, really
+ constitute a single bus since each is useless without the
+ others.
+
+ The width of the data bus is usually specified in {bits} and
+ is the number of parallel connectors. This and the {clock
+ rate} determine the bus's data rate (the number of {bytes} per
+ second which it can carry). This is one of the factors
+ limiting a computer's performance. Most current
+ {microprocessors} have 32-bit busses both internally and
+ externally. 100 or 133 {megahertz} bus clock rates are
+ common. The bus clock is typically slower than the processor
+ clock.
+
+ Some processors have internal busses which are wider than
+ their external busses (usually twice the width) since the
+ width of the internal bus affects the speed of all operations
+ and has less effect on the overall system cost than the width
+ of the external bus.
+
+ Various bus designs have been used in the {PC}, including
+ {ISA}, {EISA}, {Micro Channel}, {VL-bus} and {PCI}. Other
+ peripheral busses are NuBus, TURBOchannel, VMEbus, MULTIBUS and
+ STD bus.
+
+ See also {bus network}.
+
+ {Ukranian (http://open-taxi.com/mynews/~adrian/10)}.
+
+ (2010-07-10)
+
+bus error
+
+ <processor> A fatal failure in the execution of a {machine
+ language} instruction resulting from the {processor} detecting
+ an anomalous condition on its {bus}. Such conditions include
+ invalid address alignment (accessing a multi-byte number at an
+ odd address), accessing a {physical address} that does not
+ correspond to any device, or some other device-specific
+ hardware error. A bus error triggers a processor-level
+ {exception} which {Unix} translates into a "SIGBUS" {signal}
+ which, if not caught, will terminate the current process.
+
+ (2000-04-04)
+
+Bush, Vannevar
+
+ {Vannevar Bush}
+
+Business Analyst
+
+ <job> A person who analyses the operations of a department or
+ functional unit to develop a general systems solution to the
+ problem. The solution will typically involve a combination of
+ manual and automated processes. The business analyst can
+ provide insights into an operation for an {information systems
+ analyst}.
+
+ (2004-03-09)
+
+Business Application Programming Interface
+
+ <business, application, programming> (BAPI) /bap'ee/ A set of
+ {methods} provided by an {SAP} business {object}.
+
+ Release 4.0 of {SAP AG}'s {R/3} system supports
+ {object-oriented programming} via an interface defined in
+ terms of {objects} and {methods} called BAPIs. For example if
+ a material object provides a function to check availability,
+ the corresponding SAP business object type "Material" might
+ provide a BAPI called "Material.CheckAvailability".
+
+ The definitions of SAP business objects and their BAPIs are
+ kept in an SAP business object repository. SAP provide
+ {classes} and {libraries} to enable a programming team to
+ build SAP applications that use business objects and BAPIs.
+ Supported environments include {COM} and {Java}.
+
+ The {Open BAPI Network
+ (http://sap.com/solutions/technology/bapis/index.htm)}.
+ gives background information and lists objects and BAPIs.
+
+ (2002-08-30)
+
+Business Process Re-engineering
+
+ <business> (BPR) Any radical change in the way in which an
+ organisation performs its business activities. BPR involves a
+ fundamental re-think of the business processes followed by a
+ redesign of business activities to enhance all or most of its
+ critical measures - costs, quality of service, staff dynamics,
+ etc.
+
+ (1999-09-27)
+
+Business Software Alliance
+
+ <company> The BSA was created by {Microsoft} in 1988 in an
+ attempt to combat {software theft}. The alliance includes the
+ majority of leading software publishers including {Novell},
+ {Symantec}, and {Autodesk} and is actively campaigning in over
+ 65 countries.
+
+ The BSA operates a three-pronged approach: 1. Lobbying to
+ strengthen copyright laws and co-operation with law
+ enforcement agencies. 2. Educating the public through
+ marketing, roadshows, etc. 3. Bringing legal actions against
+ counterfeiters. BSA's aims are the same as the {Federation
+ Against Software Theft} but it is not limited to the UK.
+
+ In December 1990 the BSA obtained the first legal order in the
+ UK which allowed a surprise search on a company's offices for
+ suspected copyright infringement.
+
+ {(http://bsa.org/bsa)}.
+
+ UK Office: Business Software Alliance, 1st Floor, Leaconfield
+ House, Curzon Street, London W1Y 8AS, United Kingdom.
+
+ See also {software audit}.
+
+ (1996-05-19)
+
+Business Systems Analyst
+
+ <job> A person who works directly with management and users to
+ analyse, specify, and design {business applications}. The
+ Business Systems Analyst develops detailed functional, system,
+ and program specifications using {structured design
+ methodologies} and {CASE} tools. He must have strong business
+ sense and communications skills. He works with both the
+ {information systems} team and the strategic planning business
+ group.
+
+ (2004-03-09)
+
+business to business
+
+ <business> (B2B) {Electronic commerce} between businesses, as
+ opposed to between a consumer and a business (B2C).
+
+ While derived from "business to business", "B2B" is narrower
+ in meaning.
+
+ (2001-03-26)
+
+bus master
+
+ <architecture> The device in a computer which is driving the
+ {address bus} and bus control signals at some point in time.
+ In a simple architecture only the (single) {CPU} can be bus
+ master but this means that all communications between
+ ("slave") I/O devices must involve the CPU. More
+ sophisticated architectures allow other capable devices (or
+ multiple CPUs) to take turns at controling the bus. This
+ allows, for example, a {network controller} card to access a
+ {disk controller} directly while the CPU performs other tasks
+ which do not require the bus, e.g. fetching code from its
+ {cache}.
+
+ Note that any device can drive data onto the {data bus} when
+ the CPU reads from that device, but only the bus master drives
+ the {address bus} and control signals.
+
+ {Direct Memory Access} is a simple form of bus mastering where
+ the I/O device is set up by the CPU to read from or write to
+ one or more contiguous blocks of memory and then signal to the
+ CPU when it has done so. Full bus mastering (or "First Party
+ DMA", "bus mastering DMA") implies that the I/O device is
+ capable of performing more complex sequences of operations
+ without CPU intervention (e.g. servicing a complete {NFS}
+ request). This will normally mean that the I/O device
+ contains its own processor or {microcontroller}.
+
+ See also {distributed kernel}.
+
+ (1996-08-26)
+
+bus mastering
+
+ {bus master}
+
+bus network
+
+ <networking> A {network topology} in which all {nodes} are
+ connected to a single wire or set of wires (the bus). Bus
+ networks typically use {CSMA/CD} techniques to determine which
+ node should transmit data at any given time.
+
+ Some {networks} are implemented as a {bus}, e.g. {Ethernet} -
+ a one-bit bus operating at 10, 100, 1000 or 10,000 {megabits
+ per second}. Originally Ethernet was a {physical layer} bus
+ consisting of a wire (with {terminators} at each end) to which
+ each node was attached. {Switched Ethernet}, while no longer
+ physically a bus still acts as one at the logical layers.
+
+bus topology
+
+ {bus}
+
+Busy Beaver
+
+ <theory> (BB) One of a series of sets of {Turing Machine}
+ programs. The BBs in the Nth set are programs of N states
+ that produce a larger finite number of ones on an initially
+ blank tape than any other program of N states. There is no
+ program that, given input N, can deduce the productivity
+ (number of ones output) of the BB of size N.
+
+ The productivity of the BB of size 1 is 1. Some work has been
+ done to figure out productivities of bigger Busy Beavers - the
+ 7th is in the thousands.
+
+ (1994-10-24)
+
+busy-loop
+
+ {tight loop}
+
+busy-wait
+
+ <programming> To wait for an {event} by {spinning} through a
+ {tight loop} or timed-delay loop that {polls} for the event on
+ each pass, as opposed to setting up an {interrupt handler} and
+ continuing execution on another part of the task. This is a
+ wasteful technique, best avoided on {time-sharing} systems
+ where a busy-waiting program may {hog} the processor.
+
+ [{Jargon File}]
+
+ (1999-06-10)
+
+Butterfly Common LISP
+
+ A parallel version of {Common LISP} for the {BBN Butterfly}
+ computer.
+
+Butterfly Scheme
+
+ A parallel version of {Scheme} for the {BBN Butterfly}
+ computer.
+
+button
+
+ 1. <electronics> {push-button}.
+
+ 2. <operating system> A graphical representation of an
+ electrical {push-button} appearing as part of a {graphical
+ user interface}. Moving the {mouse pointer} over the
+ graphical button and pressing one of the physical mouse
+ buttons starts some software action such as closing a window
+ or deleting a file.
+
+ See also {radio button}.
+
+ (1997-07-07)
+
+buzz
+
+ 1. Of a program, to run with no indication of progress and
+ perhaps without guarantee of ever finishing; especially said
+ of programs thought to be executing a {tight loop} of code. A
+ program that is buzzing appears to be {catatonic}, but never
+ gets out of catatonia, while a buzzing loop may eventually end
+ of its own accord. "The program buzzes for about 10 seconds
+ trying to sort all the names into order." See {spin}; see
+ also {grovel}.
+
+ 2. [ETA Systems] To test a wire or printed circuit trace for
+ continuity by applying an AC rather than DC signal. Some wire
+ faults will pass DC tests but fail a buzz test.
+
+ 3. To process an {array} or list in sequence, doing the same
+ thing to each element. "This loop buzzes through the tz array
+ looking for a terminator type."
+
+ [{Jargon File}]
+
+bv
+
+ <networking> The {country code} for Bouvet Island.
+
+ (1999-01-27)
+
+bw
+
+ <networking> The {country code} for Botswana.
+
+ (1999-01-27)
+
+bwBASIC
+
+ Bywater BASIC interpreter.
+
+ A {BASIC} {interpreter} by Ted A. Campbell <tcamp@delphi.com>
+ which implements a large superset of the {ANSI Standard for
+ Minimal BASIC} (X3.60-1978) in {ANSI C}, and offers a simple
+ interactive environment including some {shell} program
+ facilities as an extension of BASIC. The interpreter source
+ has been compiled successfully on a range of {ANSI C}
+ {compilers} on varying {platforms} including {MS-DOS}, {Unix},
+ and {Acorn} {RISC OS}.
+
+ Version 2.10 was posted to {news:comp.sources.misc}, volume
+ 40.
+
+ (1993-10-29)
+
+BWQ
+
+ [IBM] Buzz Word Quotient. The percentage of buzzwords in a
+ speech or documents. Usually roughly proportional to
+ {bogosity}. See {TLA}.
+
+ [{Jargon File}]
+
+by
+
+ <networking> The {country code} for Belarus.
+
+ (1999-01-27)
+
+byacc
+
+ {Berkeley Yacc}
+
+by hand
+
+ 1. Said of an operation (especially a repetitive, trivial,
+ and/or tedious one) that ought to be performed automatically
+ by the computer, but which a hacker instead has to step
+ tediously through. "My mailer doesn't have a command to
+ include the text of the message I'm replying to, so I have to
+ do it by hand." This does not necessarily mean the speaker
+ has to retype a copy of the message; it might refer to, say,
+ dropping into a subshell from the mailer, making a copy of
+ one's mailbox file, reading that into an editor, locating the
+ top and bottom of the message in question, deleting the rest
+ of the file, inserting ">" characters on each line, writing
+ the file, leaving the editor, returning to the mailer, reading
+ the file in, and later remembering to delete the file.
+ Compare {eyeball search}.
+
+ 2. By extension, writing code which does something in an
+ explicit or low-level way for which a presupplied library
+ routine ought to have been available. "This cretinous
+ {B-tree} library doesn't supply a decent iterator, so I'm
+ having to walk the trees by hand."
+
+ [{Jargon File}]
+
+Byte
+
+ <publication> A popular computing magazine.
+
+ {(http://byte.com)}.
+
+ (1997-03-27)
+
+byte
+
+ <unit> /bi:t/ (B) A component in the machine {data hierarchy}
+ larger than a {bit} and usually smaller than a {word}; now
+ nearly always eight bits and the smallest addressable unit of
+ storage. A byte typically holds one {character}.
+
+ A byte may be 9 bits on 36-bit computers. Some older
+ architectures used "byte" for quantities of 6 or 7 bits, and
+ the PDP-10 and IBM 7030 supported "bytes" that were actually
+ {bit-fields} of 1 to 36 (or 64) bits! These usages are now
+ obsolete, and even 9-bit bytes have become rare in the general
+ trend toward power-of-2 word sizes.
+
+ The term was coined by Werner Buchholz in 1956 during the
+ early design phase for the {IBM} {Stretch} computer. It was a
+ mutation of the word "bite" intended to avoid confusion with
+ "bit". In 1962 he described it as "a group of bits used to
+ encode a character, or the number of bits transmitted in
+ parallel to and from input-output units". The move to an
+ 8-bit byte happened in late 1956, and this size was later
+ adopted and promulgated as a standard by the {System/360}
+ {operating system} (announced April 1964).
+
+ James S. Jones <jsjones@graceland.edu> adds:
+
+ I am sure I read in a mid-1970's brochure by IBM that outlined
+ the history of computers that BYTE was an acronym that stood
+ for "Bit asYnchronous Transmission E..?" which related to
+ width of the bus between the Stretch CPU and its CRT-memory
+ (prior to Core).
+
+ Terry Carr <bear@mich.com> says:
+
+ In the early days IBM taught that a series of bits transferred
+ together (like so many yoked oxen) formed a Binary Yoked
+ Transfer Element (BYTE).
+
+ [True origin? First 8-bit byte architecture?]
+
+ See also {nibble}, {octet}.
+
+ [{Jargon File}]
+
+ (2003-09-21)
+
+byte-code
+
+ <file format, software> A {binary} file containing an
+ {executable} program, consisting of a sequence of ({op code},
+ data) pairs.
+
+ Byte-code op codes are most often fixed size binary patterns,
+ but can be variable size. The data portion consists of zero
+ or more {bits} whose format typically depends on the op code.
+
+ A byte-code program is interpreted by a {byte-code
+ interpreter}. The advantage of this technique compared with
+ outputing {machine code} for some particular processor is that
+ the same byte-code can be executed on any processor on which
+ the byte-code interpreter runs. The byte-code may be compiled
+ to machine code ("native code") for speed of execution but
+ this usually requires significantly greater effort for each
+ new taraget architecture than simply porting the interpreter.
+
+ For example, {Java} is compiled to byte-code which runs on the
+ {Java Virtual Machine}.
+
+ (2006-05-29)
+
+byte-code compiler
+
+ <programming, tool> A {compiler} which outputs a program in
+ some kind of {byte-code}.
+
+ Compare: {byte-code interpreter}.
+
+ (1995-11-04)
+
+byte-code interpreter
+
+ <software> A program that {executes} a {byte code} program.
+
+ An example is the {Java Virtual Machine}.
+
+ (1999-11-28)
+
+byte compiler
+
+ {byte-code compiler}
+
+bytesexual
+
+ <jargon> /bi:t" sek"shu-*l/ An adjective used to describe
+ hardware, denotes willingness to compute or pass data in
+ either {big-endian} or {little-endian} format (depending,
+ presumably, on a {mode bit} somewhere). See also {NUXI
+ problem}.
+
+ [{Jargon File}]
+
+ (2009-05-28)
+
+Byzantine
+
+ <jargon, architecture> A term describing any system that has
+ so many labyrinthine internal interconnections that it would
+ be impossible to simplify by separation into loosely coupled
+ or linked components.
+
+ The city of Byzantium, later renamed Constantinople and then
+ Istanbul, and the Byzantine Empire were vitiated by a
+ bureaucratic overelaboration bordering on lunacy: quadruple
+ banked agencies, dozens or even scores of superfluous levels
+ and officials with high flown titles unrelated to their actual
+ function, if any.
+
+ Access to the Emperor and his council was controlled by
+ powerful and inscrutable eunuchs and by rival sports factions.
+
+ [Edward Gibbon, "Decline and Fall of the Roman Empire"].
+
+ (1999-01-15)
+
+bz
+
+ <networking> The {country code} for Belize.
+
+ (1999-01-27)
+
+bzzzt, wrong
+
+ <jargon> /bzt rong/ ({Usenet}, {Internet}) From the flim "Dead
+ Poets Society", spoofing quiz shows such as "Truth or
+ Consequences" where an incorrect answer earns a blast from the
+ buzzer.
+
+ An expression of mock-rude disagreement, often following a
+ quote from another poster in a {forum}. The less abbreviated
+ "*Bzzzzt*, wrong, but thank you for playing" is also common.
+
+ [{Jargon File}]
+
+ (2009-10-28)
+
+C
+
+ <language> A programming language designed by {Dennis Ritchie}
+ at {AT&T} {Bell Labs} ca. 1972 for systems programming on the
+ {PDP-11} and immediately used to reimplement {Unix}.
+
+ It was called "C" because many features derived from an
+ earlier compiler named "{B}". In fact, C was briefly named
+ "NB". B was itself strongly influenced by {BCPL}. Before
+ {Bjarne Stroustrup} settled the question by designing {C++},
+ there was a humorous debate over whether C's successor should
+ be named "D" or "P" (following B and C in "BCPL").
+
+ C is terse, low-level and permissive. It has a {macro
+ preprocessor}, {cpp}.
+
+ Partly due to its distribution with {Unix}, C became immensely
+ popular outside {Bell Labs} after about 1980 and is now the
+ dominant language in systems and {microcomputer} applications
+ programming. It has grown popular due to its simplicity,
+ efficiency, and flexibility. C programs are often easily
+ adapted to new environments.
+
+ C is often described, with a mixture of fondness and disdain,
+ as "a language that combines all the elegance and power of
+ {assembly language} with all the readability and
+ maintainability of assembly language".
+
+ Ritchie's original C, known as {K&R C} after Kernighan and
+ Ritchie's book, has been {standard}ised (and simultaneously
+ modified) as {ANSI C}.
+
+ See also {ACCU}, {ae}, {c68}, {c386}, {C-Interp}, {cxref},
+ {dbx}, {dsp56k-gcc}, {dsp56165-gcc}, {gc}, {GCT}, {GNU C},
+ {GNU superoptimiser}, {Harvest C}, {malloc}, {mpl},
+ {Pthreads}, {ups}.
+
+ [{Jargon File}]
+
+ (1996-06-01)
+
+C#
+
+ <language> /see sharp/ An {object-oriented} language devised
+ and promoted by {Microsoft}, intended to replace {Java}, which
+ it strongly resembles.
+
+ {(http://csharpindex.com/)}.
+
+ (2001-10-04)
+
+(c)
+
+ <character, legal> An {ASCII} rendition of the encircled "c"
+ {copyright} symbol. Unfortunately, this rendition is not
+ legally valid: the circle must be complete. The word
+ "copyright" in full is perfectly adequate though.
+
+ (In {LaTeX} the copyright symbol is written as \copyright).
+
+ [{Jargon File}]
+
+ (2004-08-20)
+
+C*
+
+ <language, parallel> An {object-oriented}, {data-parallel}
+ superset of {ANSI C} with synchronous {semantics}, for the
+ {Connection Machine}, designed by {Thinking Machines}, 1987.
+ C* adds a "domain" data type and a selection statement for
+ parallel execution in domains.
+
+ An unimplemented language called "{Parallel C}" [which one?]
+ influenced the design of {C*}. {Dataparallel-C} was based on
+ {C*}.
+
+ Latest version: 6.x, as of 1993-07-27.
+
+ ["C*: An Extended C Language for Data Parallel Programming",
+ J.R. Rose et al, Proc Second Intl Conf on Supercomputing,
+ L.P. Kartashev et al eds, May 1987, pp 2-16].
+
+ ["C* Programming Manual", Thinking Machines Corp, 1986].
+
+ [{Jargon File}]
+
+ (2000-11-14)
+
+C++
+
+ <language> One of the most used {object-oriented} languages, a
+ superset of {C} developed primarily by {Bjarne Stroustrup}
+ <bs@alice.att.com> at {AT&T} {Bell Laboratories} in 1986.
+
+ In C++ a {class} is a user-defined {type}, syntactically a
+ {struct} with {member functions}. {Constructors} and
+ {destructors} are member functions called to create or destroy
+ {instances}. A {friend} is a nonmember function that is
+ allowed to access the private portion of a class. C++ allows
+ {implicit type conversion}, {function inlining}, {overloading}
+ of operators and function names, and {default function
+ arguments}. It has {streams} for I/O and {references}.
+
+ C++ 2.0 (May 1989) introduced {multiple inheritance},
+ {type-safe linkage}, pointers to members, and {abstract
+ classes}.
+
+ C++ 2.1 was introduced in ["Annotated C++ Reference Manual",
+ B. Stroustrup et al, A-W 1990].
+
+ {MS-DOS
+ (ftp://grape.ecs.clarkson.edu/pub/msdos/djgpp/djgpp.zip)},
+ {Unix ANSI C++
+ (ftp://gnu.org/pub/gnu/g++-1.39.0.tar.Z)} - X3J16
+ committee. (They're workin' on it).
+
+ See also {cfront}, {LEDA}, {uC++}.
+
+ {Usenet} newsgroup: {news:comp.lang.c++}.
+
+ ["The C++ Programming Language", Bjarne Stroustrup, A-W,
+ 1986].
+
+ (1996-06-06)
+
+C+-
+
+ <language> (C More or Less) A subject-oriented language (SOL).
+ Each C+- {class} instance, known as a subject, holds hidden
+ {members}, known as prejudices, agendas or undeclared
+ preferences, which are impervious to outside messages; as well
+ as public members, known as boasts or claims.
+
+ The following {C} {operators} are overridden as shown:
+
+ > better than
+ < worse than
+ >> way better than
+ << forget it
+ ! not on your life
+ == comparable, other things being equal
+ !== get a life, guy!
+
+ C+- is {strongly typed}, based on stereotyping and
+ self-righteous logic. The {Boolean} {variables} TRUE and
+ FALSE (known as constants in other, less realistic languages)
+ are supplemented with CREDIBLE and DUBIOUS, which are fuzzier
+ than Zadeh's traditional fuzzy categories. All Booleans can
+ be declared with the modifiers strong and weak. Weak
+ implication is said to "preserve deniability" and was added at
+ the request of the DoD to ensure compatibility with future
+ versions of {Ada}. Well-formed falsehoods (WFFs) are
+ {assignment}-compatible with all Booleans. What-if and
+ why-not interactions are aided by the special conditional
+ EVENIFNOT X THEN Y.
+
+ C+- supports {information hiding} and, among {friend classes}
+ only, rumor sharing. Borrowing from the {Eiffel} lexicon,
+ non-friend classes can be killed by arranging contracts. Note
+ that friendships are {intransitive}, {volatile} and
+ non-{Abelian}.
+
+ {Operator precedence} rules can be suspended with the
+ directive #pragma dwim, known as the "{Do what I mean}"
+ {pragma}.
+
+ {ANSIfication} will be firmly resisted. C+-'s slogan is "Be
+ Your Own Standard."
+
+ [{Jargon File}]
+
+ (1999-06-15)
+
+C+@
+
+ <language> (Formerly "Calico"). An {object-oriented language}
+ from {Bell Laboratories} which uniformly represents all data
+ as pointers to self-described objects. C+@ provides {multiple
+ inheritance} with {delegation} and with control over which
+ {methods} come from which delegated object; and {default
+ methodologies}. It has a simple {syntax} with emphasis on
+ graphics. It was originally used for prototyping of
+ telecommunication services.
+
+ The language is patented by AT&T and {Unir Tech} has the
+ exclusive license from Bell Labs to distribute C+@.
+ Unfortunately Unir is owned and operated by well-known
+ anti-{IETF} ranter, Jim Fleming, which may have had something
+ to do with the language's rapid disappearence from the radar
+ screen.
+
+ It runs under {SunOS} and compiles to {Vcode}.
+
+ E-mail: Jim Vandendorpe <jimvan@iexist.att.com>.
+
+ ["A Dynamic C-Based Object-Oriented System for Unix", S.
+ Engelstad et al, IEEE Software 8(3):73-85 (May 1991)].
+
+ ["The C+@ Programming Language", J. Fleming, Dr Dobbs J, Oct
+ 1993, pp.24-32].
+
+ [{Jargon File}]
+
+ (2005-01-05)
+
+C-10
+
+ <language> An improved version of {COLINGO}.
+
+ [Sammet 1969, p.702].
+
+ (1994-10-28)
+
+C1 security
+
+ {Orange Book}
+
+c2man
+
+ <tool> An automatic {documentation} extraction tool by Graham
+ Stoney. c2man extracts comments from {C} source code to
+ generate functional interface documentation in the same format
+ as sections 2 and 3 of the {Unix} Programmer's Manual. It
+ looks for comments near the objects they document, rather than
+ imposing a rigid {syntax} or requiring the programmer to use a
+ typesetting language. Acceptable documentation can often be
+ generated from existing code with no modifications.
+
+ c2man supports both {K&R} and {ISO}/{ANSI C} coding styles.
+ Output can be in {nroff} -man, {Texinfo} or {LaTeX} format.
+ It {automagically} documents {enum} parameter and return
+ values, it handles both {C} (/* */) and {C++} (//) style
+ comments, but not C++ grammar (yet). It requires {yacc},
+ {byacc} or {bison} for syntax analysis; {lex} or {flex} for
+ {lexical analysis} and {nroff}, {groff}, {texinfo} or {LaTeX}
+ to format the output. It runs under {Unix}, {OS/2} and
+ {MS-DOS}.
+
+ Version 2.0 patchlevel 25 (1995-10-25).
+
+ {Washington FTP
+ (ftp://ftp.wustl.edu/usenet/comp.sources.reviewed/volume03/)}.
+ {Stuttgart FTP
+ (ftp://ftp.informatik.uni-stuttgart.de/pub/archive/comp.sources/reviewed/)}.
+ {Patches
+ (ftp://lth.se/pub/netnews/sources.bugs/volume93/sep/)}.
+
+ Patches posted to {Usenet} newsgroups {news:comp.sources.bugs}
+ and {news:comp.sources.reviewed}.
+
+ (2003-05-02)
+
+C2 security
+
+ {Orange Book}
+
+c386
+
+ <tool> A {compiler} for {K&R C} plus {prototypes} and other
+ {ANSI C} features by Matthew Brandt, Christoph van Wuellen,
+ Keith and Dave Walker. c386 is targetted to several {68000}
+ and {Intel 80386} {assemblers}, including {gas}.
+ {floating-point} support is by {inline code} or {emulation}.
+ It can produce lots of warnings and generates better code than
+ {ACK}.
+
+ {Version 4.2a
+ (ftp://bugs.nosc.mil/pub/Minix/common-pkgs/c386-4.2.tar.Z)}.
+
+ (2009-11-11)
+
+C5
+
+ <language> An {OPS5} implementation in {C}.
+
+ (2009-11-13)
+
+C64
+
+ {Commodore 64}
+
+c68
+
+ {c386}
+
+CA
+
+ 1. <theory, architecture> {cellular automaton}.
+
+ 2. <company> {Computer Associates}.
+
+ 3. <cryptography> {Certificate Authority}.
+
+ca
+
+ <networking> The {country code} for Canada.
+
+ (1995-04-19)
+
+cable modem
+
+ <communications, hardware> A type of {modem} that allows
+ people to access the {Internet} via their cable television
+ service.
+
+ A cable modem can transfer data at 500 {kbps} or higher,
+ compared with 28.8 kbps for common telephone line modems, but
+ the actual transfer rates may be lower depending on the number
+ of other simultaneous users on the same cable.
+
+ Industry pundits often point out that the cable system still
+ does not have the {bandwidth} or service level in many areas
+ to make this feasible. For example, it has to be capable of
+ two-way communication.
+
+ See also: {DOCSIS}.
+
+ (2000-12-19)
+
+cache
+
+ <memory management> /kash/ A small fast memory holding
+ recently accessed data, designed to speed up subsequent access
+ to the same data. Most often applied to processor-memory
+ access but also used for a local copy of data accessible over
+ a network etc.
+
+ When data is read from, or written to, {main memory} a copy is
+ also saved in the cache, along with the associated main memory
+ address. The cache monitors addresses of subsequent reads to
+ see if the required data is already in the cache. If it is (a
+ {cache hit}) then it is returned immediately and the main
+ memory read is aborted (or not started). If the data is not
+ cached (a {cache miss}) then it is fetched from main memory
+ and also saved in the cache.
+
+ The cache is built from faster memory chips than main memory
+ so a cache hit takes much less time to complete than a normal
+ memory access. The cache may be located on the same
+ {integrated circuit} as the {CPU}, in order to further reduce
+ the access time. In this case it is often known as {primary
+ cache} since there may be a larger, slower {secondary cache}
+ outside the CPU chip.
+
+ The most important characteristic of a cache is its {hit rate}
+ - the fraction of all memory accesses which are satisfied from
+ the cache. This in turn depends on the cache design but
+ mostly on its size relative to the main memory. The size is
+ limited by the cost of fast memory chips.
+
+ The hit rate also depends on the access pattern of the
+ particular program being run (the sequence of addresses being
+ read and written). Caches rely on two properties of the
+ access patterns of most programs: temporal locality - if
+ something is accessed once, it is likely to be accessed again
+ soon, and spatial locality - if one memory location is
+ accessed then nearby memory locations are also likely to be
+ accessed. In order to exploit spatial locality, caches often
+ operate on several words at a time, a "{cache line}" or "cache
+ block". Main memory reads and writes are whole {cache lines}.
+
+ When the processor wants to write to main memory, the data is
+ first written to the cache on the assumption that the
+ processor will probably read it again soon. Various different
+ policies are used. In a {write-through} cache, data is
+ written to main memory at the same time as it is cached. In a
+ {write-back} cache it is only written to main memory when it
+ is forced out of the cache.
+
+ If all accesses were writes then, with a write-through policy,
+ every write to the cache would necessitate a main memory
+ write, thus slowing the system down to main memory speed.
+ However, statistically, most accesses are reads and most of
+ these will be satisfied from the cache. Write-through is
+ simpler than write-back because an entry that is to be
+ replaced can just be overwritten in the cache as it will
+ already have been copied to main memory whereas write-back
+ requires the cache to initiate a main memory write of the
+ flushed entry followed (for a processor read) by a main memory
+ read. However, write-back is more efficient because an entry
+ may be written many times in the cache without a main memory
+ access.
+
+ When the cache is full and it is desired to cache another line
+ of data then a cache entry is selected to be written back to
+ main memory or "flushed". The new line is then put in its
+ place. Which entry is chosen to be flushed is determined by a
+ "{replacement algorithm}".
+
+ Some processors have separate instruction and data caches.
+ Both can be active at the same time, allowing an instruction
+ fetch to overlap with a data read or write. This separation
+ also avoids the possibility of bad {cache conflict} between
+ say the instructions in a loop and some data in an array which
+ is accessed by that loop.
+
+ See also {direct mapped cache}, {fully associative cache},
+ {sector mapping}, {set associative cache}.
+
+ (1997-06-25)
+
+cache block
+
+ {cache line}
+
+cache coherency
+
+ <storage> (Or "cache consistency") /kash koh-heer'n-see/ The
+ synchronisation of data in multiple {caches} such that reading
+ a memory location via any cache will return the most recent
+ data written to that location via any (other) cache.
+
+ Some {parallel processors} do not cache accesses to {shared
+ memory} to avoid the issue of cache coherency. If caches are
+ used with shared memory then some system is required to detect
+ when data in one processor's cache should be discarded or
+ replaced because another processor has updated that memory
+ location. Several such schemes have been devised.
+
+ (1998-11-10)
+
+cache conflict
+
+ <storage> A sequence of accesses to memory repeatedly
+ overwriting the same {cache} entry. This can happen if two
+ blocks of data, which are mapped to the same set of cache
+ locations, are needed simultaneously.
+
+ For example, in the case of a {direct mapped cache}, if
+ {arrays} A, B, and C map to the same range of cache locations,
+ thrashing will occur when the following loop is executed:
+
+ for (i=1; i<n; i++)
+ C[i] = A[i] + B[i];
+
+ Cache conflict can also occur between a program loop and the
+ data it is accessing.
+
+ See also {ping-pong}.
+
+ (1997-01-21)
+
+cache consistency
+
+ {cache coherency}
+
+cache hit
+
+ <storage> A request to read from memory which can satisfied
+ from the {cache} without using the {main memory}.
+
+ Opposite: {cache miss}.
+
+ (1997-01-21)
+
+cache line
+
+ <storage> (Or cache block) The smallest unit of memory than
+ can be transferred between the {main memory} and the {cache}.
+
+ Rather than reading a single word or byte from main memory at
+ a time, each cache entry is usually holds a certain number of
+ words, known as a "cache line" or "cache block" and a whole
+ line is read and cached at once. This takes advantage of the
+ principle of locality of reference: if one location is read
+ then nearby locations (particularly following locations) are
+ likely to be read soon afterward. It can also take advantage
+ of {page-mode} {DRAM} which allows faster access to
+ consecutive locations.
+
+ (1997-01-21)
+
+cache memory
+
+ {cache}
+
+cache miss
+
+ <storage> A request to read from memory which cannot be
+ satisfied from the {cache}, for which the {main memory} has to
+ be consulted.
+
+ Opposite: {cache hit}.
+
+ (1997-01-21)
+
+Cache On A STick
+
+ <architecture> (COAST) {Intel Corporation} attempt to's
+ standardise the modular {L2 cache} subsystem in
+ {Pentium}-based computers.
+
+ A COAST module should be about 4.35" wide by 1.14" high.
+ According to earlier specifications from {Motorola}, a module
+ between 4.33" and 4.36" wide, and between 1.12" and 1.16" high
+ is within the COAST standard. Some module vendors, including
+ some major motherboard suppliers, greatly violate the height
+ specification.
+
+ Another COAST specification violated by many suppliers
+ concerns clock distribution in synchronous modules. The
+ specification requires that the clock tree to each synchronous
+ chip be balanced, i.e. equal length from edge of the connector
+ to individual chips. An unbalanced clock tree increases
+ reflections and noise.
+
+ For a 256 {kilobyte} cache module the standard requires the
+ same clock be used for both chips but some vendors use
+ separate clocks to reduce loading on the clock driver and
+ hence increase the clock speed. However, this creates
+ unbalanced loading in other motherboard configurations, such
+ as motherboards with soldered caches in the system.
+
+ (1996-06-10)
+
+caching
+
+ {cache}
+
+CACI
+
+ <company> A company developing and marketing {SIMSCRIPT},
+ {MODSIM} and other {simulation} software products.
+
+ Telephone: +1 (619) 457-9681.
+
+ (1994-09-22)
+
+CACM
+
+ {Communications of the ACM}
+
+CAD
+
+ {Computer Aided Design}
+
+CAD/CAM
+
+ {Computer Aided Design}/Computer Aided Manufacturing.
+
+CADD
+
+ {Computer Aided Detector Design}
+
+Cadence Design Systems
+
+ <company> A company that sells {electronic design automation}
+ software and services.
+
+ {(http://cadence.com/)}.
+
+ See also {Verilog}.
+
+ (1999-04-16)
+
+CADET
+
+ Computer Aided Design Experimental Translator.
+
+ [Sammet 1969, p. 683].
+
+ (1994-11-29)
+
+CADRE
+
+ <company> The US {software engineering} vendor which merged
+ with {Bachman Information Systems} to form {Cayenne Software}
+ in July 1996.
+
+ (1998-02-08)
+
+CAE
+
+ 1. <operating system> {Common Applications Environment}.
+
+ 2. <application> {Computer Aided Engineering}.
+
+CAF
+
+ {constant applicative form}
+
+CAFE
+
+ ["Job Control Languages: MAXIMOP and CAFE", J. Brandon, Proc
+ BCS Symp on Job Control Languages--Past Present and Future,
+ NCC, Manchester, England 1974].
+
+ (1994-10-28)
+
+CAGE
+
+ Early system on IBM 704. Listed in CACM 2(5):16 (May 1959).
+
+CAI
+
+ {Computer-Aided Instruction}
+
+Cairo
+
+ {Windows NT 4}
+
+CAIS
+
+ {Common APSE Interface Specification}
+
+CAIS-A
+
+ Common APSE Interface Set A
+
+ DoD-STD-1838A.
+
+CAiSE
+
+ Conference on Advanced Information Systems Engineering.
+
+CAJOLE
+
+ <language> (Chris And John's Own LanguagE) A {dataflow}
+ language developed by Chris Hankin <clh@doc.ic.ac.uk> and John
+ Sharp at {Westfield College}.
+
+ ["The Data Flow Programming Language CAJOLE: An Informal
+ Introduction", C.L. Hankin et al, SIGPLAN Notices 16(7):35-44
+ (Jul 1981)].
+
+ (1994-11-08)
+
+CAL
+
+ 1. {Computer Assisted Learning}.
+
+ 2. {Course Author Language}.
+
+Calc
+
+ <tool, mathematics> An extensible, advanced desk calculator
+ and mathematical tool written in {Emacs Lisp} by Dave
+ Gillespie <daveg@synaptics.com>. Calc runs as part of {GNU
+ Emacs}. You can use Calc as only a simple four-function
+ calculator, but it also provides additional features including
+ choice of algebraic or {RPN} ({stack}-based) entry,
+ logarithms, trigonometric and financial functions, {arbitrary
+ precision}, complex numbers, vectors, matrices, dates, times,
+ infinities, sets, algebraic simplification, differentiation,
+ and integration.
+
+ Latest version: 2.02, as of 1994-11-08.
+
+ FTP calc-2.02.tar.z from your nearest {GNU archive site}.
+
+ (2000-10-20)
+
+calculator
+
+ {bitty box}
+
+Calculus of Communicating Systems
+
+ (CCS) A mathematical model (a formal language) for describing
+ processes, mostly used in the study of {parallelism}. A CCS
+ program, written in {behaviour expressions syntax} denotes a
+ process behaviour. Programs can be compared using the notion
+ of {observational equivalence}.
+
+ ["A Calculus of Communicating Systems", LNCS 92, Springer
+ 1980].
+
+ ["Communication and Concurrency", R. Milner, P-H 1989].
+
+ (1994-11-29)
+
+Calendar API
+
+ {Calendar Application Programming Interface}
+
+Calendar Application Programming Interface
+
+ (CAPI, Calendar API) An {API} for calendar {software}.
+
+ {Microsoft} has defined a CAPI for their {Schedule+}
+ application.
+
+ (1995-01-11)
+
+Caliban
+
+ A {declarative} annotation language for controlling the
+ partitioning and placement of the evaluation of expressions in
+ a distributed {functional language}. Designed by Paul Kelly
+ <phjk@doc.ic.ac.uk>, {Imperial College}.
+
+ ["Functional Programming for Loosely-coupled Multiprocessors",
+ P. Kelly, Pitman/MIT Press, 1989].
+
+ (1995-01-11)
+
+Calico
+
+ {C+@}
+
+California State University San Marcos
+
+ (CSUSM)
+
+ {(http://coyote.csusm.edu/)}.
+
+ (1994-12-21)
+
+callback
+
+ 1. <programming> A scheme used in {event-driven} programs
+ where the program registers a {subroutine} (a "callback
+ handler") to handle a certain {event}. The program does not
+ call the handler directly but when the event occurs, the
+ {run-time system} calls the handler, usually passing it
+ arguments to describe the event.
+
+ 2. <communications, security> A {user authentication} scheme
+ used by some computers running {dial-up} services. The user
+ dials in to the computer and gives his {user name} and
+ {password}. The computer then hangs up the connection and
+ uses an {auto-dial} {modem} to call back to the user's
+ registered telephone number. Thus, if an unauthorised person
+ discovers a user's password, the callback will go, not to him,
+ but to the owner of that login who will then know that his
+ account is under attack.
+
+ However, some {PABXs} can be fooled into thinking that the
+ caller has hung up by sending them a dial tone. When the
+ computer tries to call out on the same line it is not actually
+ dialing through to the authorised user but is still connected
+ to the original caller.
+
+ 3. <communications> {cost control callback}.
+
+ (2003-07-13)
+
+call-by-name
+
+ <reduction> (CBN) (Normal order reduction, leftmost, outermost
+ reduction). An {argument} passing convention (first provided
+ by {ALGOL 60}?) where argument expressions are passed
+ unevaluated. This is usually implemented by passing a pointer
+ to a {thunk} - some code which will return the value of the
+ argument and an environment giving the values of its {free
+ variables}.
+
+ This {evaluation strategy} is guaranteed to reach a {normal
+ form} if one exists.
+
+ When used to implement {functional programming} languages,
+ call-by-name is usually combined with {graph reduction} to
+ avoid repeated evaluation of the same expression. This is
+ then known as {call-by-need}.
+
+ The opposite of call-by-name is {call-by-value} where
+ arguments are evaluated before they are passed to a function.
+ This is more efficient but is less likely to terminate in the
+ presence of infinite data structures and {recursive}
+ functions.
+
+ Arguments to {macros} are usually passed using call-by-name.
+
+ (2006-05-27)
+
+call-by-need
+
+ <reduction> A {reduction strategy} which delays evaluation of
+ {function} {arguments} until their values are needed. A value
+ is needed if it is an argument to a {primitive} function or it
+ is the condition in a {conditional}. Call-by-need is one
+ aspect of {lazy evaluation}.
+
+ The term first appears in Chris Wadsworth's thesis "Semantics
+ and Pragmatics of the Lambda calculus" (Oxford, 1971, p. 183).
+ It was used later, by J. Vuillemin in his thesis (Stanford,
+ 1973).
+
+ (1995-05-27)
+
+call-by-reference
+
+ <programming> An {argument} passing convention where the
+ address of an argument {variable} is passed to a {function} or
+ {procedure}, as opposed to passing the value of the argument
+ expression. Execution of the function or procedure may have
+ {side-effects} on the actual argument as seen by the caller.
+ The {C} language's "&" (address of) and "*" (dereference)
+ operators allow the programmer to code explicit
+ call-by-reference. Other languages provide special syntax to
+ declare reference arguments (e.g. {ALGOL 60}).
+
+ See also {call-by-name}, {call-by-value},
+ {call-by-value-result}.
+
+ (2006-05-27)
+
+call-by-value
+
+ (CBV) An {evaluation strategy} where arguments are evaluated
+ before the function or procedure is entered. Only the values
+ of the arguments are passed and changes to the arguments
+ within the called procedure have no effect on the actual
+ arguments as seen by the caller. See {applicative order
+ reduction}, {call-by-value-result}, {strict evaluation},
+ {call-by-name}, {lazy evaluation}.
+
+call-by-value-result
+
+ An argument passing convention where the {actual argument} is
+ a variable V whose value is copied to a local variable L
+ inside the called function or procedure. If the procedure
+ modifies L, these changes will not affect V, which may also be
+ in scope inside the procedure, until the procedure returns
+ when the final value of L is copied to V. Under
+ {call-by-reference} changes to L would affect V immediately.
+ Used, for example, by {BBC BASIC V} on the {Acorn}
+ {Archimedes}.
+
+call/cc
+
+ {call-with-current-continuation}
+
+Call Data Record
+
+ <telecommunications> (CDR) A data record that contains
+ information related to a telephone call, including the
+ origination and destination addresses of the call, the time
+ the call started and ended, the duration of the call, the time
+ of day the call was made, toll charges that were added through
+ the network, or charges for operator services.
+
+ [Context?]
+
+ (2010-03-21)
+
+callee
+
+ <programming> The {function} or {subroutine} being called by
+ the {caller}.
+
+ (2001-05-09)
+
+Caller ID
+
+ <communications> (CID) A short piece of text transmitted by
+ some telephone systems describing the origin of a call,
+ e.g. the name of the caller. Some telephone handsets can
+ display this. A {computer telephony integration} system might
+ use it to trigger actions on the callee's computer such as
+ looking up the caller in a database and displaying their
+ details on screen.
+
+ There may also be a separate "caller id number" giving the
+ telephone number of the originator of the call.
+
+ (2008-04-30)
+
+calling convention
+
+ <programming> The arrangement of {arguments} for a procedure
+ or function call. Different programming languages may require
+ arguments to be pushed onto a {stack} or entered in
+ {registers} in left-to-right or right-to left order, and
+ either the caller or the callee can be responsible for
+ removing the arguments. The calling convention also
+ determines if a variable number of arguments is allowed.
+
+ (1995-11-11)
+
+Call-Level Interface
+
+ <database, standard> (SQL/CLI) A programming interface
+ designed to support {SQL} access to {databases} from
+ shrink-wrapped {application programs}.
+
+ CLI was originally created by a subcommittee of the {SQL
+ Access Group} (SAG). The SAG/CLI specification was published
+ as the {Microsoft} {Open DataBase Connectivity} (ODBC)
+ specification in 1992. In 1993, SAG submitted the CLI to the
+ {ANSI} and {ISO} SQL committees.
+
+ SQL/CLI provides an international standard
+ implementation-independent CLI to access SQL databases.
+ {Client-server} tools can easily access databases through
+ {dynamic link libraries}. It supports and encourages a rich
+ set of client-server tools.
+
+ SQL/CLI is an addendum to 1992 SQL standard (SQL-92). It was
+ completed as ISO standard ISO/IEC 9075-3:1995 Information
+ technology -- Database languages -- SQL -- Part 3: Call-Level
+ Interface (SQL/CLI). The current SQL/CLI effort is adding
+ support for {SQL3}.
+
+ {(http://jcc.com/sql_cli.html)}.
+
+ (1996-10-27)
+
+Call Unix
+
+ <communications, tool> (cu) The original {Unix} {virtual
+ terminal} utility. cu allows a user on one computer to log in
+ to another connected via {Ethernet}, direct {serial line} or
+ {modem}. It shares some configuration files with {UUCP} in
+ order to be able to use the same connections without conflict.
+
+ {Unix manual page}: cu(1).
+
+ (1997-12-01)
+
+Callware
+
+ <company> The developers of {Phonetastic}.
+
+ (1996-12-08)
+
+call-with-current-continuation
+
+ <Lisp, programming> (call/cc) A {Lisp} control function that
+ takes a function f as its argument and calls f, passing it the
+ current {continuation}, which is itself a function, k. k,
+ which represents the context of the call to call/cc, takes the
+ result of call/cc (which is the result of f) and returns the
+ final result of the whole program. Thus if, for example, the
+ final result is to print the value returned by call/cc then
+ anything passed to k will also be printed.
+
+ E.g, in {Scheme}:
+
+ (define (f k)
+ (k 1)
+ (k 2)
+ 3)
+
+ (display (call-with-current-continuation f))
+
+ Will display 1.
+
+ (2001-04-27)
+
+CALS
+
+ Computer-Aided Acquisition and Logistics Support: a DoD
+ standard for electronic exchange of data with commercial
+ suppliers.
+
+Caltech Intermediate Form
+
+ <language> (CIF) A geometry language for {VLSI} design, in
+ which the primitives are coloured rectangles.
+
+ ["Introduction to VLSI Systems", Mead & Conway, A-W 1980,
+ Section 4.5].
+
+ (1995-01-25)
+
+CAM
+
+ 1. <storage, architecture> {content addressable memory}.
+
+ 2. <application> {computer aided manufacturing}.
+
+CAM-6
+
+ Software for running {cellular automata}. CAM-6 has been
+ implemented in hardware as {CAM-PC}.
+
+ (1995-04-21)
+
+CAMAL
+
+ <tool> CAMbridge ALgebra system.
+
+ A {symbolic mathematics} system used in Celestial Mechanics
+ and General Relativity. CAMAL was implemented in {BCPL} on
+ {Titan}.
+
+ ["CAMAL User's Manual", John P. Fitch, Cambridge U, England
+ (1975)].
+
+ ["The Design of the Cambridge Algebra System", S.R. Bourne et
+ al, Proc 2nd Symp of Symb & Alg Manip, SIGSAM 1971].
+
+ (1995-02-16)
+
+Cambridge Lisp
+
+ A flavour of Lisp using BCPL. Sources owned by Fitznorman
+ partners.
+
+Camelot Library
+
+ <library>
+
+ ["The Camelot Library", J. Bloch, in "Guide to the Camelot
+ Distributed Transaction Facility: Release I", A.Z. Spector et
+ al eds, CMU 1988, pp. 29-62].
+
+ [What is it?]
+
+ (1995-04-19)
+
+camera ready
+
+ <publication> A final edition of a document or graphic (e.g. a
+ newspaper advertisement or a technical paper for a journal)
+ that is of suitable quality for mass reproduction by making
+ printing plates from the negatives by photoengraving.
+
+ (1996-11-15)
+
+CAMIL
+
+ Computer Assisted/Managed Instructional Language.
+
+ A language used for {CAI} at Lowry AFB, CO.
+
+ ["The CAMIL Programming Language", David Pflasterer, SIGPLAN
+ Notices 13(11):43 (Nov 1978)].
+
+ (1994-11-09)
+
+CAML
+
+ <language>
+
+ 1. A language for preparation of animated movies. 1976.
+
+ (1994-11-09)
+
+ 2. {Categorical Abstract Machine Language}.
+
+ (2000-07-06)
+
+Caml Light
+
+ A small portable implementation of a version of {CAML} by
+ Xavier Leroy <Xavier.Leroy@inria.fr> and Damien Doligez of
+ {INRIA}. Caml Light uses a {bytecode interpreter} written in
+ {C}. It adds a {Modula-2}-like {module} system, {separate
+ compilation}, {lazy streams} for parsing and printing,
+ graphics primitives and an interface with {C}.
+
+ Version 0.6 runs on {Unix}, {MS-DOS}, {Macintosh}, {Atari ST}
+ and {Amiga}. It includes an {interpreter}, {compiler},
+ {Emacs} mode, libraries, {scanner generator}, {parser
+ generator}, {run-time support} and an interactive development
+ environment.
+
+ The latest version, as of April 2003, is 0.75 and runs on
+ {Unix}, {Macintosh} and {Windows}.
+
+ The development of Caml Light has been stopped; current
+ development is on {Objective Caml}.
+
+ {(http://caml.inria.fr/distrib-caml-light-eng.html)}.
+ {(ftp://ftp.inria.fr/lang/caml-light/)}.
+
+ E-mail: <caml@inria.fr>.
+
+ Mailing list: <caml-list@inria.fr>.
+
+ {Usenet} newsgroup: {news:comp.lang.ml}.
+
+ (2003-04-12)
+
+CAM-PC
+
+ <hardware> A {cellular automata} circuit board which is a
+ hardware implementation from {Automatrix} of the {MIT} {CAM-6}
+ machine. It comes with dozens of experiments and
+ applications.
+
+ {(http://automatrix.com/campc/index.html)}.
+
+ (1995-04-21)
+
+Campus Wide Information System
+
+ (CWIS) Information and services made publicly available at
+ university sites via {kiosks} running interactive computing
+ systems, possibly via campus networks. Services routinely
+ include directory information, calendars, {bulletin boards}
+ and {databases}.
+
+ (1994-11-09)
+
+CAN
+
+ {Cancel}
+
+Canada
+
+ Country with {domain} "ca".
+
+ (1995-04-06)
+
+Cancel
+
+ <character> (CAN, Control-X) {ASCII} character 24.
+
+ (1996-06-28)
+
+Cancelbunny
+
+ {Cancelpoodle}
+
+Cancelm00se
+
+ {Cancelmoose}
+
+Cancelmoose
+
+ <messaging> A semi-mythical being that cancels {Usenet}
+ {articles} posted by others. (In general, an article can only
+ be cancelled by its original author.)
+
+ The Cancelmoose's usual target is {spam} or extremely
+ excessive {cross-post}ing.
+
+ Some believe that the Cancelmoose exists only in the same
+ mythic sense that {B1FF}, the {NSA line eater} and {Shub
+ Internet} exist; others consider Cancelmoose's historicity to
+ be closer to that of {Kibo}. The latter group assume that the
+ real Cancelmoose is not one person (or moose), but instead is
+ a cabal of {NNTP} wonks. However, the Cancelmoose is probably
+ real, seeing as how it has its own {website}.
+
+ {(http://nocem.org/)}.
+
+ (1999-01-14)
+
+Cancelpoodle
+
+ <messaging> (Or Cancelbunny) A manifestation of the
+ {Cancelmoose} in the form of a more selective (and probably
+ not automated) way to cancel {Usenet} articles.
+
+ The term became common during the alt.religion.scientology
+ wars of the mid-90s, during which Cancelpoodles were used.
+ The "poodle" part is an allusion to one of the parties
+ obliquely involved in the fray, who an earlier well-known
+ witticism had compared to "a psychotic poodle".
+
+ (1999-01-14)
+
+candidate key
+
+ <database> One of several possible attributes or combinations
+ of attributes which can be used to uniquely identify a body of
+ information (a "{record}"). The chosen candidate key is
+ called the {primary key}.
+
+ (2006-05-29)
+
+Candle
+
+ Part of the {Scorpion} environment development system.
+
+ (1994-11-09)
+
+candygrammar
+
+ <language> A programming-language grammar that is mostly
+ {syntactic sugar}; a play on "candygram". {COBOL}, {Apple
+ Computer}'s {Hypertalk} language, and many {4GLs} share this
+ property. The intent is to be as English-like as possible and
+ thus easier for unskilled people to program. However,
+ {syntax} isn't what makes programming hard; it's the mental
+ effort and organisation required to specify an {algorithm}
+ precisely. Thus "candygrammar" languages are just as
+ difficult to program in, and far more painful for the
+ experienced hacker.
+
+ {GLS} notes: The overtones from the 1977 Chevy Chase "Jaws"
+ parody on Saturday Night Live should not be overlooked.
+ Someone lurking outside an apartment door tries to get the
+ occupant to open up, while ominous music plays in the
+ background. The last attempt is a half-hearted "Candygram!"
+ When the door is opened, a shark bursts in and chomps the poor
+ occupant. There is a moral here for those attracted to
+ candygrammars.
+
+ [{Jargon File}]
+
+ (2004-09-23)
+
+canonical
+
+ (Historically, "according to religious law")
+
+ 1. <mathematics> A standard way of writing a formula. Two
+ formulas such as 9 + x and x + 9 are said to be equivalent
+ because they mean the same thing, but the second one is in
+ "canonical form" because it is written in the usual way, with
+ the highest power of x first. Usually there are fixed rules
+ you can use to decide whether something is in canonical form.
+ Things in canonical form are easier to compare.
+
+ 2. <jargon> The usual or standard state or manner of
+ something. The term acquired this meaning in computer-science
+ culture largely through its prominence in {Alonzo Church}'s
+ work in computation theory and {mathematical logic} (see
+ {Knights of the Lambda-Calculus}).
+
+ Compare {vanilla}.
+
+ This word has an interesting history. Non-technical academics
+ do not use the adjective "canonical" in any of the senses
+ defined above with any regularity; they do however use the
+ nouns "canon" and "canonicity" (not "canonicalness"* or
+ "canonicality"*). The "canon" of a given author is the
+ complete body of authentic works by that author (this usage is
+ familiar to Sherlock Holmes fans as well as to literary
+ scholars). "The canon" is the body of works in a given field
+ (e.g. works of literature, or of art, or of music) deemed
+ worthwhile for students to study and for scholars to
+ investigate.
+
+ The word "canon" derives ultimately from the Greek "kanon"
+ (akin to the English "cane") referring to a reed. Reeds were
+ used for measurement, and in Latin and later Greek the word
+ "canon" meant a rule or a standard. The establishment of a
+ canon of scriptures within Christianity was meant to define a
+ standard or a rule for the religion. The above non-technical
+ academic usages stem from this instance of a defined and
+ accepted body of work. Alongside this usage was the
+ promulgation of "canons" ("rules") for the government of the
+ Catholic Church. The usages relating to religious law derive
+ from this use of the Latin "canon". It may also be related to
+ arabic "qanun" (law).
+
+ Hackers invest this term with a playfulness that makes an
+ ironic contrast with its historical meaning. A true story:
+ One Bob Sjoberg, new at the {MIT AI Lab}, expressed some
+ annoyance at the incessant use of jargon. Over his loud
+ objections, {GLS} and {RMS} made a point of using as much of
+ it as possible in his presence, and eventually it began to
+ sink in. Finally, in one conversation, he used the word
+ "canonical" in jargon-like fashion without thinking. Steele:
+ "Aha! We've finally got you talking jargon too!" Stallman:
+ "What did he say?" Steele: "Bob just used "canonical" in the
+ canonical way."
+
+ Of course, canonicality depends on context, but it is
+ implicitly defined as the way *hackers* normally expect things
+ to be. Thus, a hacker may claim with a straight face that
+ "according to religious law" is *not* the canonical meaning of
+ "canonical".
+
+ (2002-02-06)
+
+Canonical Encoding Rules
+
+ <protocol, standard> (CER) A restricted variant of {BER} for
+ producing unequivocal {transfer syntax} for data structures
+ described by {ASN.1}.
+
+ Whereas {BER} gives choices as to how data values may be
+ encoded, CER and {DER} select just one encoding from those
+ allowed by the basic encoding rules, eliminating all of the
+ options. They are useful when the encodings must be
+ preserved, e.g. in security exchanges.
+
+ CER and {DER} differ in the set of restrictions that they
+ place on the encoder. The basic difference between CER and
+ {DER} is that {DER} uses definitive length form and CER uses
+ indefinite length form.
+
+ Documents: {ITU-T} X.690, {ISO} 8825-1.
+
+ See also {PER}.
+
+ (1998-05-19)
+
+canonical name
+
+ (CNAME) A host's official name as opposed to an alias. The
+ official name is the first hostname listed for its {Internet
+ address} in the hostname database, {/etc/hosts} or the
+ {Network Information Service} (NIS) map hosts.byaddr ("hosts"
+ for short). A host with multiple network interfaces may have
+ more than one Internet address, each with its own canonical
+ name (and zero or more aliases).
+
+ You can find a host's canonical name using {nslookup} if you
+ say
+
+ set querytype=CNAME
+
+ and then type a hostname.
+
+ (1994-11-29)
+
+canonicity
+
+ <theory, jargon> The extent to which something is {canonical}.
+
+ (1995-03-03)
+
+C (ANSI)
+
+ {ANSI C}
+
+can't happen
+
+ <programming> The traditional program comment for code
+ executed under a condition that should never be true, for
+ example a file size computed as negative. Often, such a
+ condition being true indicates data corruption or a faulty
+ {algorithm}; it is almost always handled by emitting a fatal
+ error message and terminating or crashing, since there is
+ little else that can be done.
+
+ Some case variant of "can't happen" is also often the text
+ emitted if the "impossible" error actually happens. Although
+ "can't happen" events are genuinely infrequent in production
+ code, programmers wise enough to check for them habitually are
+ often surprised at how frequently they are triggered during
+ development and how many headaches checking for them turns out
+ to head off.
+
+ See also {firewall code}, {professional programming}.
+
+ [{Jargon File}]
+
+ (1996-05-10)
+
+Cantor
+
+ 1. <person, mathematics> A mathematician.
+
+ Cantor devised the diagonal proof of the uncountability of the
+ {real numbers}:
+
+ Given a function, f, from the {natural numbers} to the {real
+ numbers}, consider the real number r whose binary expansion is
+ given as follows: for each natural number i, r's i-th digit is
+ the complement of the i-th digit of f(i).
+
+ Thus, since r and f(i) differ in their i-th digits, r differs
+ from any value taken by f. Therefore, f is not {surjective}
+ (there are values of its result type which it cannot return).
+
+ Consequently, no function from the natural numbers to the
+ reals is surjective. A further theorem dependent on the
+ {axiom of choice} turns this result into the statement that
+ the reals are uncountable.
+
+ This is just a special case of a diagonal proof that a
+ function from a set to its {power set} cannot be surjective:
+
+ Let f be a function from a set S to its power set, P(S) and
+ let U = { x in S: x not in f(x) }. Now, observe that any x in
+ U is not in f(x), so U != f(x); and any x not in U is in f(x),
+ so U != f(x): whence U is not in { f(x) : x in S }. But U is
+ in P(S). Therefore, no function from a set to its power-set
+ can be surjective.
+
+ 2. <language> An {object-oriented language} with {fine-grained
+ concurrency}.
+
+ [Athas, Caltech 1987. "Multicomputers: Message Passing
+ Concurrent Computers", W. Athas et al, Computer 21(8):9-24
+ (Aug 1988)].
+
+ (1997-03-14)
+
+CAP
+
+ 1. <networking> {Columbia AppleTalk Package}.
+
+ 2. <communications> {Carrierless Amplitude/Phase Modulation}.
+
+ 3. <networking> {Competitive Access Provider}
+
+Capabilities Maturity Model
+
+ {Capability Maturity Model}
+
+capability
+
+ <operating system, security> An {operating system} security or
+ access control model where specific types of access to a
+ specific object are granted by giving a process this data
+ structure or {token}.
+
+ The token may be unforgeable (typically by using {encryption}
+ or hardware "tagged" memory). Capabilities are used in OSes
+ such as {Hydra}, {KeyKOS}, {EROS}, {Chorus}/{Mix}, and the
+ {Stanford V system}. Similar to {Kerberos}, but in an OS
+ context.
+
+ Compare {access control list}.
+
+ (1998-03-08)
+
+Capability Maturity Model
+
+ <software> (CMM) The {Software Engineering Institute}'s model
+ of {software engineering} that specifies five levels of
+ maturity of the processes of a software organisation. CMM
+ offers a framework for evolutionary process improvement.
+ Originally applied to software development (SE-CMM), it has
+ been expanded to cover other areas including Human Resources
+ and Software Acquitition.
+
+ The levels - focii - and key process areas are:
+
+ Level 1 Initial - Heroes - None.
+
+ Level 2 Repeatable - Project Management - Software Project
+ Planning, Software Project Tracking and Oversight, Software
+ Subcontract Management, Software Quality Assurance, Software
+ Configuration Management, Requirements Management.
+
+ Level 3 Defined - Engineering Process - Organisation Process
+ Focus, Organisation Process Definition, Peer Reviews, Training
+ Program, Inter-group Coordination, Software Product
+ Engineering, Integrated Software Management.
+
+ Level 4 Managed - Product and Process Quality - Software
+ Quality Management, Quantitative Process Management.
+
+ Level 5 Optimising - Continuous Improvement - Process Change
+ Management, Technology Change Management, Defect Prevention.
+
+ {(http://www.sei.cmu.edu/cmm/cmm.html)}.
+
+ (2001-04-28)
+
+capacitor
+
+ <electronics> An electronic device that can store electrical
+ charge. The charge stored Q in Coulombs is related to the
+ capacitance C in Farads and the voltage V across the capacitor
+ in Volts by Q = CV.
+
+ The basis of a {dynamic RAM} cell is a capacitor. They are
+ also used for power-supply smoothing (or "decoupling"). This
+ is especially important in digital circuits where a digital
+ device switching between states causes a sudden demand for
+ current. Without sufficient local power supply decoupling,
+ this current "spike" cannot be supplied directly from the
+ power supply due to the inductance of the connectors and so
+ will cause a sharp drop in the power supply voltage near the
+ switching device. This can cause other devices to malfunction
+ resulting in hard to trace {glitch}es.
+
+ (1995-04-12)
+
+capacity
+
+ <communications> The maximum possible {data transfer rate} of
+ a communications channel under ideal conditions. The total
+ capacity of a channel may be shared between several
+ independent data streams using some kind of {multiplexing}, in
+ which case, each stream's data rate may be limited to a fixed
+ fraction of the total capacity.
+
+ (2001-05-22)
+
+CAPI
+
+ 1. {Calendar Application Programming Interface}.
+
+ 2. <cryptography> {Cryptographic Application Programming
+ Interface}.
+
+ 3. <networking> {Common ISDN Application Programming
+ Interface}.
+
+Cap'n Crunch
+
+ {Captain Crunch}
+
+Captain Abstraction
+
+ The champion of the principles of {abstraction} and
+ modularity, who protects unwary students on {MIT}'s course
+ {6.001} from the nefarious designs of Sergeant Spaghetticode
+ and his vile {concrete} programming practices.
+
+ See also {spaghetti code}.
+
+ (1994-11-22)
+
+Captain Crunch
+
+ 1. <person> ("Cap'n Crunch") An early 1970s
+ {hacker}/{phreaker}/{phacker} who used a free whistle included
+ with "Cap'n Crunch" breakfast cereal to fake pay phone system
+ tones and make large quantities of free phone calls. Also
+ alludes to "{crunch}".
+
+ {(http://well.com/user/crunch/)}.
+
+ 2. (After the above) {wardialer}.
+
+ 3. Reportedly, a program which {crash}es a computer by
+ overloading the {interrupt} {stack}.
+
+ (1998-08-25)
+
+CAPTCHA
+
+ <security> A type of test used to determine whether a request
+ to a {website} comes from a human or a computer program,
+ typically by asking the user to perform some kind of {image
+ recognition} task such as reading distorted text. The term
+ was coined in 2000 by Luis von Ahn, Manuel Blum, Nicholas
+ J. Hopper (all of {Carnegie Mellon University}) and John
+ Langford (of {IBM}) as a contrived acronym for "Completely
+ Automated Public Turing test to tell Computers and Humans
+ Apart". CAPTCHA aims to prevent software tools from
+ performing actions which might degrade the service, such as
+ registering user accounts or automating the playing of a game.
+
+ (2009-01-02)
+
+CAR
+
+ {Contents of Address Part of Register}
+
+card
+
+ 1. <hardware> A circuit board.
+
+ 2. <storage> {SD card}.
+
+ 3. <history> A {punched card}.
+
+ 4. <hypertext> An alternative term for a {node} in a system
+ (e.g. {HyperCard}, {Notecards}) in which the node size is
+ limited.
+
+Cardbox for Windows
+
+ <database> A database handling program, especially useful for
+ scholars and librarians.
+
+ [Details? Features? Developer? URL?]
+
+ (1997-05-14)
+
+Cardbus
+
+ <hardware> The 32-bit version of the {PCMCIA} (PC Card) {bus}.
+
+ [Spec?]
+
+ (1996-08-20)
+
+card creep
+
+ {chip creep}
+
+cardinality
+
+ <mathematics> The number of elements in a set. If two sets
+ have the same number of elements (i.e. there is a {bijection}
+ between them) then they have the same cardinality. A
+ cardinality is thus an {isomorphism class} in the {category}
+ of sets.
+
+ {aleph 0} is defined as the cardinality of the first
+ {infinite} {ordinal}, {omega} (the number of {natural
+ numbers}).
+
+ (1995-03-29)
+
+cardinal number
+
+ The {cardinality} of some set.
+
+CARDS
+
+ Central Archive for Reusable Defense Software of the DoD.
+
+card walloper
+
+ <jargon> An {EDP} programmer who grinds out {batch programs}
+ that do things like print people's paychecks. Compare {code
+ grinder}.
+
+ See also {punched card}, {eighty-column mind}.
+
+ [{Jargon File}]
+
+ (2003-09-20)
+
+Career Limiting Move
+
+ <jargon> (CLM, Sun) Any action endangering one's future
+ prospects of getting plum projects and raises, and possibly
+ one's job. E.g. "His Halloween costume was a parody of his
+ manager. He won the prize for "best CLM"." A severe bug
+ discovered by a customer might be a "CLM bug".
+
+ (2000-08-09)
+
+caret
+
+ ^
+
+ Common: hat; control; uparrow; caret; {ITU-T}: circumflex.
+ Rare: chevron; {INTERCAL}: shark (or shark-fin); to the ("to
+ the power of"); fang; pointer (in Pascal).
+
+careware
+
+ /keir'weir/ (Or "{charityware}") {Shareware} for which either
+ the author suggests that some payment be made to a nominated
+ charity or a levy directed to charity is included on top of
+ the distribution charge.
+
+ Compare {crippleware}.
+
+ [{Jargon File}]
+
+ (1994-12-16)
+
+cargo cult programming
+
+ <programming, humour> A style of (incompetent) programming
+ dominated by ritual inclusion of code or program structures
+ that serve no real purpose. A cargo cult programmer will
+ usually explain the extra code as a way of working around some
+ bug encountered in the past, but usually neither the bug nor
+ the reason the code apparently avoided the bug was ever fully
+ understood (compare {shotgun debugging}, {voodoo
+ programming}).
+
+ The term "cargo cult" is a reference to aboriginal religions
+ that grew up in the South Pacific after World War II. The
+ practices of these cults centre on building elaborate mockups
+ of aeroplanes and military style landing strips in the hope of
+ bringing the return of the god-like aeroplanes that brought
+ such marvelous cargo during the war. Hackish usage probably
+ derives from Richard Feynman's characterisation of certain
+ practices as "cargo cult science" in his book "Surely You're
+ Joking, Mr. Feynman" (W. W. Norton & Co, New York 1985, ISBN
+ 0-393-01921-7).
+
+ [{Jargon File}]
+
+ (2002-05-28)
+
+Caribou CodeWorks
+
+ <company> The company which sells {QTRADER}.
+
+ Director of Marketing: Norm Larsen <wwcoinc@winternet.com>.
+
+ (1995-11-05)
+
+Carl Friedrich Gauss
+
+ <person> A German mathematician (1777 - 1855), one of all time
+ greatest. Gauss discovered the {method of least squares} and
+ {Gaussian elimination}.
+
+ Gauss was something of a child prodigy; the most commonly told
+ story relates that when he was 10 his teacher, wanting a rest,
+ told his class to add up all the numbers from 1 to 100. Gauss
+ did it in seconds, having noticed that 1+...+100 = 100+...+1 =
+ (101+...+101)/2.
+
+ He did important work in almost every area of mathematics.
+ Such eclecticism is probably impossible today, since further
+ progress in most areas of mathematics requires much hard
+ background study.
+
+ Some idea of the range of his work can be obtained by noting
+ the many mathematical terms with "Gauss" in their names. E.g.
+ {Gaussian elimination} ({linear algebra}); {Gaussian primes}
+ (number theory); {Gaussian distribution} (statistics); {Gauss}
+ [unit] (electromagnetism); {Gaussian curvature} (differential
+ geometry); {Gaussian quadrature} (numerical analysis);
+ {Gauss-Bonnet formula} (differential geometry); {Gauss's
+ identity} ({hypergeometric functions}); {Gauss sums} ({number
+ theory}).
+
+ His favourite area of mathematics was {number theory}. He
+ conjectured the {Prime Number Theorem}, pioneered the {theory
+ of quadratic forms}, proved the {quadratic reciprocity
+ theorem}, and much more.
+
+ He was "the first mathematician to use {complex numbers} in a
+ really confident and scientific way" (Hardy & Wright, chapter
+ 12).
+
+ He nearly went into architecture rather than mathematics; what
+ decided him on mathematics was his proof, at age 18, of the
+ startling theorem that a regular N-sided polygon can be
+ constructed with ruler and compasses if and only if N is a
+ power of 2 times a product of distinct {Fermat primes}.
+
+ (1995-04-10)
+
+Carnegie Mellon University
+
+ <body, education> (CMU) A university in Pittsburgh,
+ Pennsylvania. {School of Computer Science
+ (http://cs.cmu.edu/Web/FrontDoor.html)}.
+
+ (1997-06-23)
+
+carpal tunnel syndrome
+
+ {overuse strain injury}
+
+Carriage Return
+
+ <character> (CR, Control-M, {ASCII} 13) The character which
+ causes the {cursor} to move to the left margin, often used
+ with {line feed} to start a new line of output.
+
+ Encoded in {C} and {Unix} as "\r".
+
+ (1996-06-24)
+
+Carrierless Amplitude/Phase Modulation
+
+ <communications> (CAP) A design of {Asymmetric Digital
+ Subscriber Line} {transceiver} developed by {Bell Labs}. CAP
+ was the first ADSL design to be commercially deployed and, as
+ of August 1996, was installed on more lines than any other.
+
+ CAP is a variation of {Quadrature Amplitude Modulation}, the
+ modulation used by most existing {modems} in 1997. With CAP,
+ the three channels ({POTS}, downstream data and upstream data)
+ are supported by splitting the frequency spectrum. Voice
+ occupies the standard 0-4 Khz frequency band, followed by the
+ upstream channel and the high-speed downstream channel.
+
+ (1997-10-08)
+
+carrier scanner
+
+ <security> (Or "wardialer") A program which uses a {modem} to
+ dial a series of phone numbers (say, from 770-0000 to
+ 770-9999), and keeps a log of what phone numbers answer with a
+ modem {carrier}. The results of such a search were generally
+ used by people looking to engage in {random} mischief in
+ {random} machines.
+
+ Since the 1980s, wardialers have generally fallen into disuse,
+ partly because of easily available "{caller ID}" technology,
+ partly because fax machines are now in wide use and would
+ often be logged as a {carrier} by a wardialer, and partly
+ because there are so many new and more interesting venues for
+ computerised mischief these days.
+
+ (1997-03-16)
+
+carrier signal
+
+ <communications> A continuous signal of a single frequency
+ capable of being modulated by a second, data-carrying signal.
+ In radio communication, the two common kinds of modulation are
+ {amplitude modulation} and {frequency modulation}.
+
+ (1995-03-01)
+
+Cartesian coordinates
+
+ <mathematics, graphics> (After Renee Descartes, French
+ philosopher and mathematician) A pair of numbers, (x, y),
+ defining the position of a point in a two-dimensional space by
+ its perpendicular projection onto two axes which are at right
+ angles to each other. x and y are also known as the
+ {abscissa} and {ordinate}.
+
+ The idea can be generalised to any number of independent axes.
+
+ Compare {polar coordinates}.
+
+ (1997-07-08)
+
+Cartesian product
+
+ <mathematics> (After Renee Descartes, French philosper and
+ mathematician) The Cartesian product of two sets A and B is
+ the set
+
+ A x B = {(a, b) | a in A, b in B}.
+
+ I.e. the product set contains all possible combinations of one
+ element from each set. The idea can be extended to products
+ of any number of sets.
+
+ If we consider the elements in sets A and B as points along
+ perpendicular axes in a two-dimensional space then the
+ elements of the product are the "{Cartesian coordinates}" of
+ points in that space.
+
+ See also {tuple}.
+
+ (1995-03-01)
+
+CAS
+
+ 1. <hardware> {Column Address Strobe}.
+
+ 2. <communications> (channel associated signaling) {in-band
+ signalling}.
+
+CAS 8051 Assembler
+
+ An experimental one-pass {assembler} for the 8051 with
+ {C}-like syntax by Mark Hopkins. Most features of a modern
+ assembler included except {macros} (soon to be added).
+ Requires an {ANSI-C} compiler. Ported to {MS-DOS}, {Ultrix},
+ {Sun-4}. (July 1993).
+
+ Version 1.2. Assembler/linker, disassembler, documentation,
+ examples.
+
+ {(ftp://lyman.pppl.gov/pub/8051/assem)},
+ {(ftp://nic.funet.fi/pub/microprocs/MCS-51/csd4-archive/assem)}.
+ {Other software tools and applications
+ (ftp://nic.funet.fi/pub/compilers/8051/)}.
+
+ (1995-01-26)
+
+cascade
+
+ 1. <compiler> A huge volume of spurious error-messages output
+ by a {compiler} with poor {error recovery}. Too frequently,
+ one trivial {syntax} error (such as a missing ")" or "}")
+ throws the {parser} out of synch so that much of the remaining
+ program text, whether correct or not, is interpreted as
+ garbaged or ill-formed.
+
+ 2. <messaging> A chain of {Usenet} followups, each adding some
+ trivial variation or riposte to the text of the previous one,
+ all of which is reproduced in the new message; an {include
+ war} in which the object is to create a sort of communal
+ graffito.
+
+ 3. <networking> A collection of interconneced networking
+ devices, typically {hubs}, that allows those devices to act
+ together as a {logical} {repeater}.
+
+ [{Jargon File}]
+
+ (1997-07-17)
+
+Cascading Style Sheets
+
+ <web> (CSS) An extension to {HTML} to allow styles,
+ e.g. colour, {font}, size to be specified for certain elements
+ of a {hypertext} document. Style information can be included
+ in-line in the HTML file or in a separate CSS file (which can
+ then be easily shared by multiple HTML files). Multiple
+ levels of CSS can be used to allow selective overriding of
+ styles.
+
+ {(http://w3.org/Style/CSS/)}.
+
+ (2000-07-26)
+
+CASE
+
+ 1. {Computer Aided Software Engineering}.
+
+ 2. {Common Application Service Element}.
+
+case
+
+ 1. <programming> {switch statement}.
+
+ 2. <character> Whether a character is a capital letter ("upper
+ case" - ABC..Z) or a small letter ("lower case" - abc..z).
+
+ The term case comes from the printing trade when the use of
+ moving type was invented in the early Middle Ages (Caxton or
+ Gutenberg?) and the letters for each {font} were stored in a
+ box with two sections (or "cases"), the upper case was for the
+ capital letters and the lower case was for the small letters.
+ The Oxford Universal Dictionary of Historical Principles (Feb
+ 1993, reprinted 1952) indicates that this usage of "case" (as
+ the box or frame used by a compositor in the printing trade)
+ was first used in 1588.
+
+ (1996-03-01)
+
+case and paste
+
+ <programming> (From "{cut and paste}") The addition of a new
+ {feature} to an existing system by selecting the code from an
+ existing feature and pasting it in with minor changes. This
+ usually results in gross violation of the fundamental
+ programming tenet, {Don't Repeat Yourself}.
+
+ Common in telephony circles because most operations in a
+ telephone switch are selected using "case" statements. Leads
+ to {software bloat}.
+
+ In some circles of {Emacs} users this is called "programming
+ by Meta-W", because Meta-W is the Emacs command for copying a
+ block of text to a {kill buffer} in preparation to pasting it
+ in elsewhere. The term is condescending, implying that the
+ programmer is acting mindlessly rather than thinking carefully
+ about what is required to integrate the code for two similar
+ cases.
+
+ At {DEC}, this is sometimes called "clone-and-hack" coding.
+
+ [{Jargon File}]
+
+ (1996-03-01)
+
+case based reasoning
+
+ <artificial intelligence> (CBR) A technique for problem
+ solving which looks for previous examples which are similar to
+ the current problem. This is useful where {heuristic}
+ {knowledge} is not available.
+
+ There are many situations where experts are not happy to be
+ questioned about their knowledge by people who want to write
+ the knowledge in rules, for use in {expert systems}. In most
+ of these situations, the natural way for an expert to describe
+ his or her knowledge is through examples, stories or cases
+ (which are all basically the same thing). Such an expert will
+ teach trainees about the expertise by apprenticeship, i.e. by
+ giving examples and by asking the trainees to remember them,
+ copy them and adapt them in solving new problems if they
+ describe situations that are similar to the new problems. CBR
+ aims to exploit such knowledge.
+
+ Some key research areas are efficient indexing, how to define
+ "similarity" between cases and how to use temporal
+ information.
+
+ (1996-05-28)
+
+CASE Data Interchange Format
+
+ (CDIF) An emerging standard for interchange of data between
+ {CASE} tools.
+
+ (1994-11-03)
+
+CASE framework
+
+ A set of products and conventions that allow CASE tools to be
+ integrated into a coherent environment.
+
+case insensitive
+
+ {case sensitivity}
+
+Case Integration Services
+
+ <standard, programming> (CIS) A committee formed to discuss
+ {CASE} tool integration standards related to {ATIS}.
+
+ (1994-10-25)
+
+CASE*Method
+
+ An analysis and design method from {Oracle} targeted at
+ information management applications.
+
+ (1994-10-28)
+
+case sensitive
+
+ {case sensitivity}
+
+case sensitivity
+
+ <text> Whether a text matching operation distinguishes
+ upper-{case} (capital) letters from lower case (is "case
+ sensitive") or not ("case insensitive").
+
+ Case in file names should be preserved (for readability) but
+ ignored when matching (so the user doesn't have to get it
+ right). {MS-DOS} does not preserve case in file names, {Unix}
+ preserves case and matches are case sensitive.
+
+ Any decent {text editor} will allow the user to specify
+ whether or not text searches should be {case sensitive}.
+
+ Case sensitivity is also relevant in programming (most
+ programming languages distiguish between case in the names of
+ {identifiers}), and addressing ({Internet} {domain names} are
+ case insensitive but {RFC 822} local {mailbox} names are case
+ sensitive).
+
+ Case insensitive operations are sometimes said to "fold case",
+ from the idea of folding the character code table so that
+ upper and lower case letters coincide. The alternative "smash
+ case" is more likely to be used by someone who considers this
+ behaviour a {misfeature} or in cases where one case is
+ actually permanently converted to the other.
+
+ "{MS-DOS} will automatically smash case in the names of all
+ the files you create".
+
+ (1997-07-09)
+
+CASE SOAP III
+
+ Version of SOAP assembly language for IBM 650. Listed in
+ CACM 2(5):16 (May 1959).
+
+case statement
+
+ {switch statement}
+
+CASE tools
+
+ Software tools to help in the application of CASE methods to a
+ software project.
+
+cashe
+
+ <spelling> It's spelled "{cache}".
+
+ (1996-12-13)
+
+CAST
+
+ {Computer Aided Software Testing}
+
+cast
+
+ {explicit type conversion}
+
+casters-up mode
+
+ [IBM, probably from slang belly up] Yet another synonym for
+ "broken" or "down". Usually connotes a major failure. A
+ system (hardware or software) which is "down" may be already
+ being restarted before the failure is noticed, whereas one
+ which is "casters up" is usually a good excuse to take the
+ rest of the day off (as long as you're not responsible for
+ fixing it).
+
+ [{Jargon File}]
+
+casting the runes
+
+ <jargon> What a {guru} does when you ask him or her to run a
+ particular program because it never works for anyone else;
+ especially used when nobody can ever see what the guru is
+ doing different from what J. Random Luser does.
+
+ Compare {incantation}, {runes}, {examining the entrails}; also
+ see the {AI koan} about Tom Knight.
+
+ (1997-12-26)
+
+CAT
+
+ Common Abstract Tree Language. R. Voeller & Uwe Schmidt, U
+ Kiel, Germany 1983. Universal intermediate language, used by
+ Norsk Data in their family of compilers. "A Multi-Language
+ Compiler System with Automatically Generated Codegenerators,
+ U. Schmidt et al, SIGPLAN Notices 19(6):202-2121 (June 1984).
+
+ [{Jargon File}]
+
+cat
+
+ <tool> (From "catenate") {Unix}'s command which copies one or
+ more entire files to the screen or some other output sink
+ without pause.
+
+ See also {dd}, {BLT}.
+
+ Among {Unix} fans, cat is considered an excellent example of
+ user-interface design, because it delivers the file contents
+ without such verbosity as spacing or headers between the files
+ (the {pr} command can be used to do this), and because it does
+ not require the files to consist of lines of text, but works
+ with any sort of data.
+
+ Among Unix haters, cat is considered the {canonical} example
+ of *bad* user-interface design, because of its woefully
+ unobvious name. It is far more often used to {blast} a file
+ to standard output than to concatenate files. The name "cat"
+ for the former operation is just as unintuitive as, say,
+ LISP's {cdr}.
+
+ Of such oppositions are {holy wars} made.
+
+ (1994-11-29)
+
+Cat 3
+
+ {Category 3}
+
+Cat 5
+
+ {Category 5}
+
+catatonic
+
+ <jargon> A description of a system that gives no indication
+ that it is still working. This might be because it has
+ crashed without being able to give any error message or
+ because it is busy but not designed to give any feedback.
+
+ Compare {buzz}.
+
+ [{Jargon File}]
+
+ (2004-08-19)
+
+CATE
+
+ {Computer Aided Test Engineering}.
+
+Categorical Abstract Machine Language
+
+ <language> (Originally "CAML" - Categorical Abstract Machine
+ Language) A version of {ML} by G. Huet, G. Cousineau, Ascander
+ Suarez, Pierre Weis, Michel Mauny and others of {INRIA} and
+ {ENS}. CAML is intermediate between {LCF ML} and {SML} [in
+ what sense?]. It has {first-class} functions, {static type
+ inference} with {polymorphic} types, user-defined {variant
+ types} and {product types}, and {pattern matching}. It is
+ built on a proprietary run-time system.
+
+ The CAML V3.1 implementation added {lazy} and {mutable} data
+ structures, a "{grammar}" mechanism for interfacing with the
+ {Yacc} {parser generator}, {pretty-printing} tools,
+ high-performance {arbitrary-precision} arithmetic, and a
+ complete library. CAML V3 is often nicknamed "heavy CAML",
+ because of its heavy memory and CPU requirements compared to
+ {Caml Light}.
+
+ in 1990 Xavier Leroy and Damien Doligez designed a new
+ implementation called {Caml Light}, freeing the previous
+ implementation from too many experimental high-level features,
+ and more importantly, from the old Le_Lisp back-end.
+
+ Following the addition of a {native-code} compiler and a
+ powerful {module} system in 1995 and of the {object} and
+ {class} layer in 1996, the project's name was changed to
+ {Objective Caml}.
+
+ ["The CAML Reference Manual", P. Weis et al, TR INRIA-ENS,
+ 1989].
+
+ (2003-04-12)
+
+category
+
+ <theory> A category K is a collection of objects, obj(K), and
+ a collection of {morphisms} (or "{arrows}"), mor(K) such that
+
+ 1. Each morphism f has a "typing" on a pair of objects A, B
+ written f:A->B. This is read 'f is a morphism from A to B'.
+ A is the "source" or "{domain}" of f and B is its "target" or
+ "{co-domain}".
+
+ 2. There is a {partial function} on morphisms called
+ {composition} and denoted by an {infix} ring symbol, o. We
+ may form the "composite" g o f : A -> C if we have g:B->C and
+ f:A->B.
+
+ 3. This composition is associative: h o (g o f) = (h o g) o f.
+
+ 4. Each object A has an identity morphism id_A:A->A associated
+ with it. This is the identity under composition, shown by the
+ equations
+
+ id__B o f = f = f o id__A.
+
+ In general, the morphisms between two objects need not form a
+ {set} (to avoid problems with {Russell's paradox}). An
+ example of a category is the collection of sets where the
+ objects are sets and the morphisms are functions.
+
+ Sometimes the composition ring is omitted. The use of
+ capitals for objects and lower case letters for morphisms is
+ widespread but not universal. Variables which refer to
+ categories themselves are usually written in a script font.
+
+ (1997-10-06)
+
+Category 3
+
+ <hardware> (Cat 3, or "voice grade") An American Standards
+ Institute standard for {UTP} cables. Used, e.g., for
+ {100BaseVG} network cabling.
+
+ (1998-06-30)
+
+Category 5
+
+ <hardware> (Cat 5) An American Standards Institute standard
+ for {UTP} cables. Used, e.g., for {100BaseTX} cabling.
+
+ (1998-06-30)
+
+CA-Telon
+
+ <application> A {Computer Aided Software Engineering} (CASE)
+ tool for designing, generating and maintaining {COBOL} and
+ {PL/I} {application programs}. Telon was developed by
+ {Pansophic} Systems who were bought by {Computer Associates}
+ in 1991, whereupon it was renamed CA-Telon.
+
+ It supports high-level, non-{prodedural} design and
+ prototyping, combined with automatic {code generation}. There
+ are {mainframe} and {PC} versions. The generated COBOL
+ applications can execute in {AIX}, {HP-UX}, {VSE}, {OS/400}
+ for the {AS/400}, {PC-DOS}, or {OS/2}.
+
+ (2000-01-19)
+
+cathode ray tube
+
+ <hardware> (CRT) An electrical device for displaying images by
+ exciting phosphor dots with a scanned electron beam. CRTs are
+ found in computer {VDUs} and {monitors}, televisions and
+ oscilloscopes. The first commercially practical CRT was
+ perfected on 29 January 1901 by Allen B DuMont.
+
+ A large glass envelope containing a negative electrode (the
+ cathode) emits electrons (formerly called "cathode rays") when
+ heated, as in a {vacuum tube}. The electrons are accelerated
+ across a large voltage gradient toward the flat surface of
+ the tube (the screen) which is covered with phosphor. When an
+ electron strikes the phosphor, light is emitted. The electron
+ beam is deflected by electromagnetic coils around the outside
+ of the tube so that it scans across the screen, usually in
+ horizontal stripes. This scan pattern is known as a {raster}.
+ By controlling the current in the beam, the brightness at any
+ particular point (roughly a "{pixel}") can be varied.
+
+ Different phosphors have different "{persistence}" - the
+ length of time for which they glow after being struck by
+ electrons. If the scanning is done fast enough, the eye sees
+ a steady image, due to both the persistence of the phospor and
+ of the eye itself. CRTs also differ in their {dot pitch},
+ which determines their spatial {resolution}, and in whether
+ they use {interlace} or not.
+
+ (1994-11-17)
+
+CATIA
+
+ <tool, product> A {CAD}/CAM system produced by Dassault
+ Systemes and sold by {IBM}. CATIA is used heavily in the car
+ and aerospace industries. It runs on various {Unix} platforms
+ and {Windows NT}.
+
+ {(http://catia.ibm.com/catmain.html)}.
+
+ (2002-06-12)
+
+cationic cocktail
+
+ <hardware> (Or "Downy cocktail") Diluted fabric softener
+ sprayed on computer room carpets to prevent static electricity
+ from being built up by feet shuffling on carpet.
+
+ The {canonical} cationic cocktail is one part unscented liquid
+ fabric softener (in the US, usually "Downy" brand) to five
+ parts water.
+
+ "Cationic" is the chemical term for the most common active
+ ingredient in fabric softeners. The use of the term
+ "cocktail" may be influenced by its use in other jargons,
+ especially pharmacological and chemical, to denote a mixture
+ which, like cationic cocktail, typically contains no alcohol
+ and would be unwise to drink.
+
+ (1998-04-04)
+
+C/ATLAS
+
+ <language> A DoD test language. It is a variant of {ATLAS}.
+
+ (1995-05-01)
+
+CATNIP
+
+ {Common Architecture for Next Generation Internet Protocol}
+
+CATO
+
+ Fortran-like CAI language for PLATO system on CDC 1604. "CSL
+ PLATO System Manual", L.A. Fillman, U Illinois, June 1966.
+
+Cauchy sequence
+
+ <mathematics> A sequence of elements from some {vector space}
+ that converge and stay arbitrarily close to each other (using
+ the {norm} definied for the space).
+
+ (2000-03-10)
+
+cause-effect graphing
+
+ <programming> A testing technique that aids in selecting, in a
+ systematic way, a high-yield set of test cases that logically
+ relates causes to effects to produce test cases. It has a
+ beneficial side effect in pointing out incompleteness and
+ ambiguities in specifications.
+
+ (1996-05-10)
+
+CAV
+
+ {Constant Angular Velocity}
+
+Cayenne Software
+
+ <company> The company formed when {CADRE} merged with {Bachman
+ Information Systems} in July 1996.
+
+ {(http://cayennesoft.com/)}.
+
+ [Details?]
+
+ (2001-04-30)
+
+CAYLEY
+
+ <symbolic mathematics, tool> A {symbolic mathematics} system
+ for {group theory} written by John Cannon of the {University
+ of Sydney}, Australia in 1976.
+
+ Cayley was used at about 100 sites but has been superseded by
+ a much more general system, {Magma}.
+
+ ["An Introduction to the Group Theory Language CAYLEY", J.
+ Cannon, Computational Group Theory, M.D. Atkinson ed, Academic
+ Press 1984, pp. 148-183].
+
+ Latest version: V3.7, for {Sun}, {Apollo}, {VAX}/{VMS}.
+
+ (2000-09-03)
+
+cb
+
+ {C Beautifier}
+
+CBASIC
+
+ A {BASIC} compiler by Gordon Eubanks, now at {Symantec}. It
+ evolved from/into {EBASIC}.
+
+ (1994-11-29)
+
+CBBS
+
+ {bulletin board system}
+
+C-BC
+
+ <language> A {strongly typed} version of {BC} by Mark Hopkins,
+ with expanded {C}-like {syntax}, more base types and the
+ ability to form {array} and {pointer} types of any dimension
+ and to allocate/free arrays at {run time}.
+
+ Most {POSIX-BC} features are supported, except that
+ {functions} must be declared consistently and declared before
+ first use. {String} handling is slightly different. It
+ requires an {ANSI-C} compiler and runs under {MS-DOS} or
+ {Unix}.
+
+ Version: 1.1.
+
+ Posted to {alt.sources} 1993-04-10.
+
+ (1993-08-23)
+
+CBD
+
+ {component based development}
+
+C Beautifier
+
+ (cb) A {Unix} tool for reformatting {C} {source} code.
+
+ {Unix manual page}: cb(1).
+
+CBIR
+
+ <image> {content-based information retrieval}.
+
+ (1995-11-23)
+
+CBN
+
+ {call-by-name}
+
+CBR
+
+ {case based reasoning}
+
+CBT
+
+ {Computer-Based Training}
+
+CBV
+
+ {call-by-value}
+
+cbw
+
+ {Crypt Breakers Workbench}
+
+cc
+
+ <networking> The {country code} for the Cocos (Keeling)
+ Islands.
+
+ (1999-01-27)
+
+CC++
+
+ {Compositional C++}
+
+C/C++
+
+ 1. {Borland C/C++}.
+
+ 2. {Watcom C/C++}.
+
+ 3. Either {C} or {C++}.
+
+CCalc
+
+ A {symbolic mathematics} system for {MS-DOS}, available from
+ {Simtel}.
+
+ (1995-04-12)
+
+CCD
+
+ {Charge-Coupled Device}
+
+CCIRN
+
+ Coordinating Committee for Intercontinental Research Networks.
+
+CCITT
+
+ Commite' Consultatif International de Telegraphique et
+ Telephonique. (International consultative committee on
+ telecommunications and Telegraphy).
+
+ CCITT changed its name to {ITU-T} on 1 March 1993.
+
+ (1994-11-03)
+
+CCITT HIgh-Level Language
+
+ <language> (CHILL) A {real-time} language widely used in
+ telecommunications. CHILL was developed in the 1970s and
+ improved in 1984, 1988, 1992, and 1996. It is used in several
+ countries including Germany, Norway, Brasil, and South Korea.
+
+ {Cygnus} are developing a compiler based on {gcc}.
+
+ {(http://www1.informatik.uni-jena.de/languages/chill/chill.htm)}.
+
+ ["An Analytical Description of CHILL, the CCITT High Level
+ Language", P. Branquart, LNCS 128, Springer 1982].
+
+ ["CHILL User's Manual", ITU, 1986, ISBN 92-61-02601-X.
+ ISO-9496 (1988?)].
+
+ (1997-01-20)
+
+CCL
+
+ 1. Coral Common LISP.
+
+ 2. Computer Control Language. English-like query language
+ based on COLINGO, for IBM 1401 and IBM 1410.
+
+CCLU
+
+ Cambridge CLU. {CLU} extended to support {concurrency},
+ distributed programming and {remote procedure call}, by
+ G. Hamilton et al at {CUCL}.
+
+ E-mail: Jean Bacon <jmb@cl.cam.ac.uk>.
+
+ (1994-10-13)
+
+ccmail
+
+ It's written {cc:mail}.
+
+cc:mail
+
+ <tool, product> Commercial {electronic mail} software by
+ {Lotus Corporation} for {Microsoft Windows}.
+
+ (1995-03-14)
+
+CCP
+
+ 1. <language> {Concurrent Constraint Programming}.
+
+ 2. {Command Control Processor}.
+
+CCR
+
+ 1. {condition code register}.
+
+ 2. (Database) {concurrency control and recovery}.
+
+CCS
+
+ 1. <networking> {Common Communication Services}.
+
+ 2. <language, parallel> {Calculus of Communicating Systems}.
+
+ 3. <history> {Computer Conservation Society}.
+
+ 4. <storage, standard> {Common Command Set}.
+
+ 5. <communications> {centum call second}.
+
+CCSP
+
+ {Contextually Communicating Sequential Processes}
+
+CCTA
+
+ The Government Centre for Information Systems.
+
+ (Originally "Central Computer and Telecommunications Agency").
+
+ CCTA is part of the Office of Public Service and Science,
+ which works to improve government's services to the public.
+ They are responsible for stimulating and promoting the
+ effective use of Information Systems in support of the
+ efficient delivery of business objectives and improved quality
+ of services by the public sector.
+
+ CCTA had to change its name as it was not an agency in the
+ "Next Steps" sense. The letters were retained as customers
+ were familiar with them.
+
+ {(http://open.gov.uk/)}.
+
+ E-mail: <info@open.gov.uk>.
+
+ Address: Norwich, UK.
+
+ (1995-01-18)
+
+CD
+
+ {Compact Disc}
+
+cd
+
+ 1. <operating system> {change directory}.
+
+ 2. <networking> The {country code} for the Democratic Republic
+ of the Congo (formerly Zaire, {zr}).
+
+ (1999-01-27)
+
+CDA
+
+ 1. <file format> {Compound Document Architecture}.
+
+ 2. <legal> {Communications Decency Act}.
+
+CD burner
+
+ {Compact Disc writer}
+
+CDC
+
+ {Control Data Corporation}
+
+CDC 6600
+
+ <computer> A {mainframe} computer from {Control Data
+ Corporation}, first delivered in 1964. It is generally
+ considered to be the first successful {supercomputer}, about
+ three times faster than {STRETCH}. Its successor was the {CDC
+ 7600}.
+
+ (2007-03-01)
+
+CDDI
+
+ {Copper Distributed Data Interface}
+
+CDD/Plus
+
+ {DEC}'s {CASE} {repository}.
+
+CDE
+
+ 1. C Development environment from {IDE}.
+
+ 2. {Common Desktop Environment}.
+
+ 3. {Co-operative Development Environment}.
+
+ (1996-07-11)
+
+CDF
+
+ Common Data Format. A library and toolkit for
+ multi-dimensional data sets.
+
+CD-i
+
+ {Compact Disc interactive}
+
+CDIF
+
+ {CASE Data Interchange Format}
+
+CDL
+
+ 1. Computer Definition [Design?] Language. A hardware
+ description language. "Computer Organisation and
+ Microprogramming", Yaohan Chu, P-H 1970.
+
+ 2. Command Definition Language. Portion of ICES used to
+ implement commands. Sammet 1969, p.618-620.
+
+ 3. Compiler Description Language. C.H.A. Koster, 1969.
+ Intended for implementation of the rules of an affix grammar
+ by recursive procedures. A procedure may be a set of
+ tree-structured alternatives, each alternative is executed
+ until one successfully exits. Used in a portable COBOL-74
+ compiler from MPB, mprolog system from SzKI, and the Mephisto
+ chess computer. "CDL: A Compiler Implementation Language", in
+ Methods of Algorithmic Language Implementation, C.H.A. Koster,
+ LNCS 47, Springer 1977, pp.341-351. "Using the CDL Compiler
+ Compiler", C.H.A. Koster, 1974. Versions: CDL2, CDLM used at
+ Manchester.
+
+ 4. Common Design Language. "Common Design Language", IBM,
+ Software Engineering Inst, Sept 1983.
+
+ 5. Control Definition Language. Ideas which contributed to
+ Smalltalk.
+
+ ["Control Structures for Programming Languges", David
+ A. Fisher, PhD Thesis, CMU 1970].
+
+CDM
+
+ 1. {Content Data Model}
+
+ 2. {Code Division Multiplexing}
+
+CDMA
+
+ {Code Division Multiple Access}
+
+CDP1802
+
+ {RCA 1802}
+
+CDPD
+
+ {Cellular Digital Packet Data}
+
+CDR
+
+ 1. <networking> {Committed Data Rate}.
+
+ 2. <programming> {Contents of Decrement part of Register}.
+
+ 3. <storage> {Compact Disc Recordable} (CD-R).
+
+ 4. <telecommunications> {Call Data Record}.
+
+CD-Read-Write
+
+ {Compact Disc Rewritable}
+
+CD-Rewritable
+
+ {Compact Disc Rewritable}
+
+CD-ROM
+
+ {Compact Disc Read-Only Memory}
+
+CD-ROM drive
+
+ {Compact Disc Read-Only Memory}
+
+CD-RW
+
+ {Compact Disc Rewritable}
+
+CDS
+
+ {Concrete Data Structure}
+
+cd tilde
+
+ /C-D til-d*/ To go home. From the {Unix} {C shell} and
+ Korn-shell command "cd ~", which takes one to one's "$HOME"
+ directory. "cd" with no arguments does the same thing.
+
+ [{Jargon File}]
+
+ (1994-10-28)
+
+CDW
+
+ {data warehouse}
+
+CE
+
+ {IBM Customer Engineer}
+
+Cecil
+
+ AN {object-oriented} language combining {multi-methods} with a
+ classless object model, object-based {encapsulation} and
+ optional {static type checking}. It distinguishes between
+ {subtyping} and {code inheritance}. Includes both explicit
+ and implicit parameterisation of objects, types, and methods.
+
+ {(ftp://cs.washington.edu/pub/chambers/cecil-spec.ps.Z)}.
+
+ ["The Cecil Language: Specification and Rationale",
+ C. Chambers, TR 93-03-05, U Wash (Mar 1993)].
+
+ (1994-10-28)
+
+Cedar
+
+ A superset of {Mesa}, from {Xerox PARC}, adding {garbage
+ collection}, {dynamic types} and a universal pointer type (REF
+ ANY). Cedar is a large complex language designed for custom
+ Xerox hardware and the Cedar {operating system}/environment.
+ Data types are {atoms}, lists, ropes ("industrial strength"
+ strings), conditions. Multi-processing features include
+ {threads}, {monitors}, {signals} and catch phrases. It was
+ used to develop the Cedar integrated programming environment.
+
+ ["A Description of the Cedar Language", Butler Lampson, Xerox
+ PARC, CSL-83-15 (Dec 1983)].
+
+ ["The Structure of Cedar", D. Swinehart et al, SIGPLAN Notices
+ 20(7):230-244 (July 1985)].
+
+ (1995-01-26)
+
+CEEMAC+
+
+ Graphics language for DOS 3.3 on {Apple II}.
+
+CEI-PACT
+
+ Central European Initiative on Parallel Computation.
+
+Celeron
+
+ <processor> {Intel Corporation}'s trade name for its family of
+ {Pentium II} {microprocessors} meant for use in low-end
+ computers.
+
+ The Celeron is constructed on the 0.25 micron Deschutes base.
+ {Clock rates} of 266, 300 and 333 {MHz} are supported. It is
+ built on the same {daughterboard} as the Pentium II without
+ the black plastic case and {heat sink}. Four Celeron models
+ are in production as of October 1998. The 266 and 300 MHz
+ models are essentially Pentium II {CPUs} without the Level 2
+ {cache} {RAM}. The 300A and 333 MHz Celerons include 128k of
+ Level 2 cache.
+
+ A special mounting bracket on the motherboard is used to
+ secure the Celeron in place in its standard 242-pin Slot 1
+ socket. Intel calls the caseless design SEPP (Single Edge
+ Processor Package) to differentiate it from the Pentium II SEC
+ (Single Edge Cartridge). Some believe that the real purpose
+ for the different mounting configurations is to prevent users
+ from placing lower cost processors onto Pentium II
+ motherboards.
+
+ A Celeron is about one third the cost of a similar speed
+ Pentium II. Hardware {hackers} claim that the Celeron 300
+ without Level 2 cache could be {overclocked} to perform as
+ well as a Pentium II at a fraction of the price.
+
+ {(http://intel.com/Celeron/)}.
+
+ {Tom's Hardware (http://www2.tomshardware.com/cpuslot1.html)}.
+
+ (1998-10-06)
+
+CELIP
+
+ A cellular language for {image processing}.
+
+ ["CELIP: A cellular Language for Image Processing",
+ W. Hasselbring <willi@informatik.uni-essen.de>, Parallel
+ Computing 14:99-109 (1990)].
+
+ (1994-12-05)
+
+cell
+
+ 1. <spreadsheet> In a {spreadsheet}, the intersection of a row
+ a column and a sheet, the smallest addressable unit of data.
+ A cell contains either a constant value or a {formula} that is
+ used to calculate a value. The cell has a {format} that
+ determines how to display the value. A cell can be part of a
+ {range}. A cell is usually referred to by its column
+ (labelled by one or more letters from the sequence A, B, ...,
+ Z, AA, AB, ..., AZ, BA, BB, ..., BZ, ... ) and its row number
+ counting up from one, e.g. cell B3 is in the second column
+ across and the third row down. A cell also belongs to a
+ particular sheet, e.g. "Sheet 1".
+
+ 2. <networking> {ATM}'s term for a {packet}.
+
+ (2007-10-22)
+
+Cellang
+
+ See {Cellular}.
+
+CELLAS
+
+ CELLular ASsemblies.
+
+ A {concurrent} {block-structured} language.
+
+ [Mentioned in "Attribute Grammars", LNCS 323, p.97].
+
+ (1994-12-05)
+
+Cello
+
+ <web> A {web browser} {client} for {IBM PCs}. Runs under
+ {Microsoft Windows}.
+
+ (2014-08-23)
+
+cell reference
+
+ <spreadsheet> A string identifying a particular {cell} in a
+ {spreadsheet}, possibly relative to the cell containing the
+ reference. A cell reference may be absolute (denoted by a "$"
+ prefix in {Excel}) or relative (no prefix) in each dimension,
+ thus, e.g. B$6 refers to the second cell across in the sixth
+ row. The distinction between absolute and relative is only
+ significant when the referring cell is copied, e.g. if cell
+ A1, which refers to B$6, is copied to cell B1, then B1 will
+ refer to C6.
+
+ If the reference is to a cell in a different sheet then it is
+ prefixed with the target sheet's name and an exclamation
+ mark. E.g. "Sheet 1!B3".
+
+ (2007-10-22)
+
+CELLSIM
+
+ <application> A program for modelling populations of
+ biological cells.
+
+ ["CELLSIM II User's Manual", C.E. Donaghey, U Houston. Sep
+ 1975].
+
+ (1994-12-05)
+
+CEll Space Simulation Language
+
+ <language> (CESSL) A language for simulating {cellular space
+ models}.
+
+ ["The CESSL Programming Language", D.R. Frantz, 012520-6-T, CS
+ Dept, U Michigan, Sept 1971].
+
+ (1994-12-14)
+
+Cellular
+
+ <language> A system for {cellular automaton} programming by J Dana
+ Eckart <dana@faculty.cs.runet.edu>. Cellular includes a
+ {byte-code compiler}, {run-time system}, and a viewer.
+
+ Latest version: 2.0, as of 1993-04-03.
+
+ Posted to comp.sources.unix, volume 26.
+
+ See also {Cellang}.
+
+ (2000-10-07)
+
+cellular automata
+
+ {cellular automaton}
+
+cellular automaton
+
+ <algorithm, parallel> (CA, plural "- automata") A regular
+ spatial lattice of "cells", each of which can have any one of
+ a finite number of states. The state of all cells in the
+ lattice are updated simultaneously and the state of the entire
+ lattice advances in discrete time steps. The state of each
+ cell in the lattice is updated according to a local rule which
+ may depend on the state of the cell and its neighbors at the
+ previous time step.
+
+ Each cell in a cellular automaton could be considered to be a
+ {finite state machine} which takes its neighbours' states as
+ input and outputs its own state.
+
+ The best known example is J.H. Conway's game of {Life}.
+
+ {FAQ
+ (http://alife.santafe.edu/alife/topics/cas/ca-faq/ca-faq.html)}.
+
+ {Usenet} newsgroups: {news:comp.theory.cell-automata},
+ {news:comp.theory.self-org-sys}.
+
+ (1995-03-03)
+
+Cellular Digital Packet Data
+
+ <communications, protocol> (CDPD) A wireless standard
+ providing two-way, 19.2 kbps {packet} data transmission over
+ exisiting {cellular telephone} channels.
+
+ [Reference?]
+
+ (1994-12-05)
+
+cellular multiprocessing
+
+ <architecture, parallel> (CMP) The partitioning of
+ {processors} into separate computing environments running
+ different {operating systems}.
+
+ The term cellular multiprocessing appears to have been coined
+ by {Unisys}, who are developing a system where computers
+ communicate as clustered machines through a high speed {bus},
+ rather than through communication {protocols} such as
+ {TCP/IP}.
+
+ The Unisys system is based on {Intel} processors, initially
+ the {Pentium II Xeon} and moving on to the 64-bit {Merced}
+ processors later in 1999. It will be scalable from four up to
+ 32 processors, which can be clustered or partitioned in
+ various ways. For example a sixteen processor system could be
+ configured as four {Windows NT} systems (each functioning as a
+ four-processor {symmetric multiprocessing} system), or an
+ 8-way NT and 8-way {Unix} system.
+
+ Supported operating systems will be {Windows NT}, {SCO}'s
+ {Unixware} 7.0, Unisys' {SVR4} {Unix} and possibly the OS2200
+ and MCP-AS {mainframe} operating systems (with the assistance
+ of Unisys' own dedicated {chipset}).
+
+ {(http://marketplace.unisys.com/ent/cmp.html)}.
+
+ (1998-09-09)
+
+Cellular Neural Network
+
+ <architecture> (CNN) The CNN Universal Machine is a low cost,
+ low power, extremely high speed {supercomputer} on a chip. It
+ is at least 1000 times faster than equivalent {DSP} solutions
+ of many complex {image processing} tasks. It is a stored
+ program supercomputer where a complex sequence of image
+ processing {algorithms} is programmed and downloaded into the
+ chip, just like any digital computer. Because the entire
+ computer is integrated into a chip, no signal leaves the chip
+ until the image processing task is completed.
+
+ Although the CNN universal chip is based on analogue and logic
+ operating principles, it has an on-chip analog-to-digital
+ input-output interface so that at the system design and
+ application perspective, it can be used as a digital
+ component, just like a DSP. In particular, a development
+ system is available for rapid design and prototyping.
+ Moreover, a {compiler}, an {operating system}, and a
+ {user-friendly} CNN {high-level language}, like the {C}
+ language, have been developed which makes it easy to implement
+ any image processing algorithm.
+
+ [Professor Leon Chua, University of California at Berkeley].
+
+ (1995-04-27)
+
+CELP
+
+ <language> Computationally Extended Logic
+ Programming.
+
+ ["Computationally Extended Logic Programming", M.C. Rubenstein
+ et al, Comp Langs 12(1):1-7 (1987)].
+
+ (1995-04-27)
+
+CEN
+
+ Conseil Européen pour la Normalisation.
+
+ A body coordinating {standard}isation activities in the EEC
+ and EFTA countries.
+
+ (1994-12-14)
+
+CENELEC
+
+ <body, standard> The European Committee for Electrotechnical
+ Standardization. A body developing electrotechnical standards for
+ the Single European Market / European Economic Area in order to
+ reduce internal frontiers and trade barriers for electrotechnical
+ products, systems and services. CENELEC's 19 member countries and
+ 11 affiliate countries aim to adopt and implement the required
+ standards, which are mostly identical to the {International
+ Electrotechnical Commission} (IEC) standards. CENELEC works in
+ co-operation with {Comité Européen de Normalisation} (CEN) and
+ {European Telecommunications Standards Institute} (ETSI).
+
+ (1999-09-28)
+
+centi-call second
+
+ <spelling> No, it's {centum call second}.
+
+ (2002-03-25)
+
+central office
+
+ <communications> The place where telephone companies terminate
+ customer lines and locate switching equipment to interconnect
+ those lines with other networks.
+
+ (1995-03-20)
+
+Central office exchange service
+
+ <communications> (Centrex) A {PBX} service providing
+ {switching} at the {central office} instead of at the company
+ premises. Typically, the telephone company owns and manages
+ all the communications equipment necessary to implement the
+ PBX and then sells various services to the company.
+
+ (1999-10-27)
+
+central processing unit
+
+ <architecture, processor> (CPU, processor) The part of a
+ computer which controls all the other parts. Designs vary
+ widely but the CPU generally consists of the {control unit},
+ the {arithmetic and logic unit} (ALU), {registers}, temporary
+ {buffers} and various other logic.
+
+ The control unit fetches {instructions} from memory and
+ decodes them to produce signals which control the other parts
+ of the computer. These signals cause it to transfer data
+ between memory and ALU or to activate {peripherals} to perform
+ input or output.
+
+ Various types of memory, including {cache}, {RAM} and {ROM},
+ are often considered to be part of the CPU, particularly in
+ modern {microprocessors} where a single {integrated circuit}
+ may contain one or more processors as well as any or all of
+ the above types of memory. The CPU, and any of these
+ components that are in separate chips, are usually all located
+ on the same {printed circuit board}, known as the
+ {motherboard}. This in turn is located in the {system unit}
+ (sometimes incorrectly referred to as the "CPU").
+
+ A {parallel computer} has several CPUs which may share other
+ resources such as memory and peripherals.
+
+ The term "processor" has to some extent replaced "CPU", though
+ RAM and ROM are not logically part of the processor.
+
+ {List of processors
+ (http://lldn.timesys.com/complete_list_of_processors)}.
+
+ (2007-04-02)
+
+Centrex
+
+ {Central office exchange service}
+
+Centronics
+
+ <company, hardware, printer> A company in Hudson N.H., USA,
+ best known for designing the {parallel interface} for printers
+ with the same name, found on many {microcomputers}.
+
+ [Pin-out?]
+
+ (1998-03-15)
+
+Centrum voor Wiskunde en Informatica
+
+ (CWI, Centre for Mathematics and Computer Science) An
+ independent research institute active in the fields of
+ mathematics and computer science. CWI also aims to transfer
+ new knowledge in these fields to society, trade and industry
+
+ CWI is funded for 70 percent by NWO, the National Organisation
+ for Scientific Research. The remaining 30 percent is obtained
+ through national and international programmes and contract
+ research commissioned by industry.
+
+ Address: Kruislaan 413, 1098 SJ Amsterdam, The Netherlands;
+ P.O.Box 94079, 1090 GB Amsterdam, The Netherlands.
+
+ Telephone: +31 (20) 5929 333.
+
+ {(http://cwi.nl/)}.
+
+ {(ftp://ftp.cwi.nl/pub/)}.
+
+centum call second
+
+ <unit> (CCS) A unit used (in North America) to quantify the
+ total traffic running in a network. 1 CCS is 100
+ call-seconds. That means 1 CCS could be 2 calls of 50 seconds
+ duration or 20 calls of 5 seconds duration.
+
+ (2002-03-25)
+
+century meltdown
+
+ {Year 2000}
+
+CEN/XFS
+
+ {Extensions for Financial Services}
+
+cepstra
+
+ {cepstrum}
+
+cepstrum
+
+ <mathematics> (Coined in a 1963 paper by Bogert, Healey, and
+ Tukey) The {Fourier transform} of the log-magnitude spectrum:
+
+ fFt(ln( | fFt(window . signal) | ))
+
+ This function is used in {speech recognition} and possibly
+ elsewhere. Note that the outer transform is NOT an inverse
+ Fourier transform (as reported in many respectable DSP texts).
+
+ [What's it for?]
+
+ (1997-01-07)
+
+CEPT
+
+ {Comite Europeen des Postes et Telecommunications}
+
+CER
+
+ {Canonical Encoding Rules}
+
+Ceramic Pin Grid Array
+
+ <hardware, processor> (CPGA) A form of {Pin Grid Array}
+ package used by {Cyrix III} {processors}.
+
+ Compare {PPGA} and {FC-PGA}.
+
+ [Other uses?]
+
+ (2000-08-26)
+
+Ceres workstation Oberon System
+
+ <language, tool> A complete {Oberon} {compiler} written in
+ {Oberon}. Source to most of the complete Ceres workstation
+ Oberon System, including the {National Semiconductor 32032}
+ {code generator} is available. Less of the low level system
+ specific code is available.
+
+ {(ftp://neptune.ethz.ch/Oberon/)}.
+
+ (1994-12-14)
+
+Cerf, Vint
+
+ {Vint Cerf}
+
+CERN
+
+ <body> The European Laboratory for Particle Physics in
+ Swizerland.
+
+ {Tim Berners-Lee} invented the {World-Wide Web} while working
+ at CERN.
+
+ Other notable computing developments at CERN include {ADAMO},
+ {Application Software Installation Server}, {CERNLIB},
+ {cfortran.h}, {CHEOPS}, {CICERO}, {Cortex}, {EMDIR}, {HBOOK},
+ {LIGHT}, {NFT}, {PATCHY}, {PL-11}, {Schoonschip}, {SHIFT},
+ and {ZEBRA}.
+
+ {CERN Home (http://cern.ch/)}.
+
+ (2004-10-24)
+
+CERNLIB
+
+ <library> The {CERN} Program Library.
+
+ (2004-09-01)
+
+CERT
+
+ {Computer Emergency Response Team}
+
+Certificate Authority
+
+ <cryptography, body> (CA or "Trusted Third Party") An entity
+ (typically a company) that issues {digital certificates} to
+ other entities (organisations or individuals) to allow them to
+ prove their identity to others. A Certificate Authority might
+ be an external company such as {VeriSign} that offers digital
+ certificate services or they might be an internal organisation
+ such as a corporate {MIS} department. The Certificate
+ Authority's chief function is to verify the identity of
+ entities and issue digital certificates attesting to that
+ identity.
+
+ The process uses {public key cryptography} to create a
+ "network of trust". If I want to prove my identity to you, I
+ ask a CA (who you trust to have verified my identity) to
+ encrypt a {hash} of my signed key with their {private key}.
+ Then you can use the CA's {public key} to decrypt the hash and
+ compare it with a hash you calculate yourself. Hashes are
+ used to decrease the amount of data that needs to be
+ transmitted. The hash function must be {cryptographically
+ strong}, e.g. {MD5}.
+
+ {(http://home.netscape.com/comprod/server_central/support/faq/certificate_faq.html#11)}.
+
+ (1998-03-30)
+
+CESP
+
+ {Common ESP}
+
+CESSL
+
+ {CEll Space Simulation Language}
+
+cextract
+
+ <programming, tool> A {C} {prototype} extractor by Adam Bryant
+ <adb@cs.bu.edu>. cextract can generate {header files} for
+ large multi-file C programs, and will automatically generate
+ prototypes for all of the functions in such a program. It can
+ also generate a sorted list of all functions and their
+ locations. cextract version 1.7 works with both {ANSI C} and
+ {K&R C} and runs under {Unix} and {VMS}.
+
+ Posted to comp.sources.reviewed.
+
+ (1992-11-03)
+
+cf
+
+ <networking> The {country code} for the Central African
+ Republic.
+
+ (1999-01-27)
+
+CFD
+
+ {Computational Fluid Dynamics}
+
+CFML
+
+ {ColdFusion Markup Language}
+
+cforth
+
+ A {Forth} {interpreter}.
+
+ Posted to comp.sources.unix volume 1.
+
+ (1994-11-29)
+
+cfortran.h
+
+ <library> A {transparent}, machine independent interface
+ between {C} and {Fortran} routines and {global data},
+ developed by Burkhard Burow at CERN. It provides {macros}
+ which allow the {C} {preprocessor} to translate a simple
+ description of a C (Fortran) routine or global data into a
+ Fortran (C) interface.
+
+ Version 2.6 runs on {VAX}/{VMS}/{Ultrix}, {DECstation},
+ {Silicon Graphics}, {IBM} {RS/6000}, {Sun}, {Cray}, {Apollo},
+ {HP9000}, {LynxOS}, {f2c}, {NAG f90}.
+
+ {(ftp://zebra.desy.de/cfortran/)}.
+
+ cfortran.h was reviewed in RS/Magazine November 1992 and a
+ user's experiences with cfortran.h are described in the Jan 93
+ issue of Computers in Physics.
+
+ (1992-04-12)
+
+CFP
+
+ 1. {Constraint Functional Programming}.
+
+ 2. {Communicating Functional Processes}.
+
+ 3. Call For Papers (for a conference).
+
+CFP92
+
+ {SPEC CFP92}
+
+cg
+
+ <networking> The {country code} for Congo.
+
+ (1999-01-27)
+
+CGA
+
+ {Color Graphics Adapter}
+
+CGGL
+
+ {Code-Generator Generator Language}
+
+CGI
+
+ 1. <web> {Common Gateway Interface}.
+
+ 2. <graphics> {computer-generated imagery}.
+
+ 3. <company> A French {software engineering} vendor in the US.
+
+ 4. <company> {Computer Generation Incorporated}.
+
+cgi-bin
+
+ {Common Gateway Interface}
+
+CGI Joe
+
+ <job, abuse> (From "GI Joe") A hard-core {CGI} script
+ programmer with all the social skills and charisma of a
+ plastic action figure.
+
+ (1997-03-30)
+
+CGI program
+
+ {Common Gateway Interface}
+
+CGI script
+
+ {Common Gateway Interface}
+
+CGM
+
+ {Computer Graphics Metafile}
+
+CGOL
+
+ <language> A package providing {ALGOL}-like {surface syntax}
+ for {MACLISP}, written by V.R. Pratt in 1977.
+
+ {(ftp://mc.lcs.mit.edu/its/ai/lisp/cgol.fasl)}.
+
+ ["CGOL - An Alternative Exetrnal Representation for LISP
+ Users", V. Pratt, MIT AI Lab, Working Paper 89, 1976].
+
+ (2005-01-07)
+
+cgram
+
+ <language> An {ANSI C} {LL1} or {LL2} {grammar} written in
+ {Scheme} by Mohd Hanafiah Abdullah <napi@cs.indiana.edu>. A
+ program (f-f-d.s) extracts the FIRST/FOLLOW/DIRECTOR sets.
+
+ {(ftp://primost.cs.wisc.edu/pub/comp.compilers/cgram-ll1.Z)}.
+
+ (2005-01-07)
+
+Ch
+
+ <language> An {interpreted} programming language sold by {Soft
+ Integration} and marketed for {scripting}, {shell programming}
+ and graph plotting, it is a superset of {C++}. Ch is also the
+ name of Soft Integration's {interpreter} for the language.
+ Currently the Ch interpreter is available for {Windows},
+ {Solaris}, {HP-UX}, {Linux} and {Mac} platforms.
+
+ {Soft Integration (http://softintegration.com/)}.
+
+ (2003-08-15)
+
+ch
+
+ <networking> The {country code} for Switzerland.
+
+ (1999-01-27)
+
+chad
+
+ <jargon, printer> /chad/ (Or "selvage" /sel'v*j/ (sewing and
+ weaving), "{perf}", "perfory", "snaf"). 1. The perforated
+ edge strips on paper for {sprocket feed} printers, after they
+ have been separated from the printed portion.
+
+ The term {perf} may also refer to the perforations themselves,
+ rather than the chad they produce when torn.
+
+ [Why "snaf"?]
+
+ 2. (Or "chaff", "computer confetti", "keypunch droppings") The
+ confetti-like bits punched out of {punched cards} or {paper
+ tape} which collected in the {chad box}.
+
+ One of the {Jargon File}'s correspondents believed that "chad"
+ derived from the {chadless keypunch}.
+
+ [{Jargon File}]
+
+ (1997-07-18)
+
+chad box
+
+ <hardware> ({IBM} called this a "chip box") A metal box about
+ the size of a lunchbox (or in some models a large
+ wastebasket), for collecting the {chad} that accumulated in
+ {Iron Age} {card punches}. You had to open the covers of the
+ card punch periodically and empty the chad box.
+
+ The {bit bucket} was notionally the equivalent device in the
+ {CPU} enclosure, which was typically across the room in
+ another great grey-and-blue box.
+
+ [{Jargon File}]
+
+ (1996-11-20)
+
+Chadless keypunch
+
+ <hardware> A {card punch} which cut little U-shapes in
+ {punched cards}, rather than punching out a circle or
+ rectangle. The U's made a hole when folded back.
+
+ One of the {Jargon File}'s correspondents believed that the
+ term "chad" derived from the {Chadless keypunch}. Obviously,
+ if the Chadless keypunch didn't make them, then the stuff that
+ other keypunches made had to be "{chad}". The assertion that
+ the keypunch was named after its inventor is not supported by
+ any record in US or UK patents or surname references.
+
+ (2000-11-22)
+
+chain
+
+ 1. <operating system> (From {BASIC}'s "CHAIN" statement) To
+ pass control to a child or successor without going through the
+ {operating system} {command interpreter} that invoked you.
+ The state of the parent program is lost and there is no
+ returning to it. Though this facility used to be common on
+ memory-limited {microcomputers} and is still widely supported
+ for {backward compatibility}, the jargon usage is
+ semi-obsolescent; in particular, {Unix} calls this {exec}.
+
+ Compare with the more modern "{subshell}".
+
+ 2. <programming> A series of linked data areas within an
+ {operating system} or {application program}. "Chain rattling"
+ is the process of repeatedly running through the linked data
+ areas searching for one which is of interest. The implication
+ is that there are many links in the chain.
+
+ 3. <theory> A possibly infinite, non-decreasing sequence of
+ elements of some {total ordering}, S
+
+ x0 <= x1 <= x2 ...
+
+ A chain satisfies:
+
+ for all x,y in S, x <= y \/ y <= x.
+
+ I.e. any two elements of a chain are related.
+
+ ("<=" is written in {LaTeX} as {\sqsubseteq}).
+
+ [{Jargon File}]
+
+ (1995-02-03)
+
+Challenge-Handshake Authentication Protocol
+
+ <networking, security, standard, protocol> (CHAP) An
+ {authentication} scheme used by {PPP} servers to validate the
+ identity of the originator of the connection upon connection
+ or any time later.
+
+ CHAP applies a three-way {handshaking} procedure. After the
+ link is established, the server sends a "challenge" message to
+ the originator. The originator responds with a value
+ calculated using a {one-way hash function}. The server checks
+ the response against its own calculation of the expected hash
+ value. If the values match, the authentication is
+ acknowledged; otherwise the connection is usually terminated.
+
+ CHAP provides protection against {playback} attack through the
+ use of an incrementally changing identifier and a variable
+ challenge value. The authentication can be repeated any time
+ while the connection is open limiting the time of exposure to
+ any single attack, and the server is in control of the
+ frequency and timing of the challenges. As a result, CHAP
+ provides greater security then {PAP}.
+
+ CHAP is defined in {RFC} 1334.
+
+ (1996-03-05)
+
+Chalmers University of Technology
+
+ <body, education> A Swedish university founded in 1829
+ offering master of science and doctoral degrees. Research is
+ carried out in the main engineering sciences as well as in
+ technology related mathematical and natural sciences. Five
+ hundred faculty members work in more than 100 departments
+ organised in nine schools. Chalmers collaborates with the
+ University of Göteborg.
+
+ Around 8500 people work and study on the Chalmers campus,
+ including around 500 faculty members and some 600 teachers and
+ doctoral students. About 4800 students follow the master
+ degree programs. Every year 700 Masters of Science in
+ Engineering and in Architecture graduate from Chalmers, and
+ about 190 PhDs and licentiates are awarded. Some 40% of
+ Sweden's engineers and architects are Chalmers graduates.
+
+ About a thousand research projects are in progress and more
+ than 1500 scientific articles and research reports are
+ published every year. Chalmers is a partner in 80 EC research
+ projects.
+
+ {(http://chalmers.se/Home-E.html)}.
+
+ Address: S-412 96 Göteborg, Sweden.
+
+ (1995-02-16)
+
+change management
+
+ <system management> Techniques that aid in evolution,
+ composition and policy management of the design and
+ implementation of an object or system.
+
+ (1995-02-16)
+
+changeover
+
+ <programming> The time when a new system has been tested
+ successfully and replaces the old system.
+
+ (2003-11-12)
+
+channel
+
+ <chat> (Or "chat room", "room", depending on the system in
+ question) The basic unit of group discussion in {chat} systems
+ like {IRC}. Once one joins a channel, everything one types is
+ read by others on that channel. Channels can either be named
+ with numbers or with strings that begin with a "#" sign and
+ can have topic descriptions (which are generally irrelevant to
+ the actual subject of discussion).
+
+ Some notable channels are "#initgame", "#hottub" and
+ "#report". At times of international crisis, "#report" has
+ hundreds of members, some of whom take turns listening to
+ various news services and typing in summaries of the news, or
+ in some cases, giving first-hand accounts of the action
+ (e.g. Scud missile attacks in Tel Aviv during the Gulf War in
+ 1991).
+
+ [{Jargon File}]
+
+ (1998-01-25)
+
+channel associated signaling
+
+ {in-band signalling}
+
+channel hopping
+
+ <chat> To rapidly switch channels on {IRC}, or a {GEnie} chat
+ board. This term may derive from the TV idiom, "channel
+ surfing".
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+channel op
+
+ <messaging> /chan'l op/ (Or "{op}", "chan op", "chop") Someone
+ who is endowed with privileges on a particular {IRC}
+ {channel}. These privileges include the right to {kick}
+ users, to change various status bits and to make others into
+ CHOPs.
+
+ The full form, "channel operator", is almost never used.
+
+ [{Jargon File}]
+
+ (1998-01-08)
+
+channel service unit
+
+ <communications> (CSU) A type of {interface} used to connect a
+ {terminal} or computer to a digital medium in the same way
+ that a {modem} is used for connection to an analogue medium.
+
+ A CSU is provided by the {communication carrier} to customers
+ who wish to use their own equipment to retime and regenerate
+ the incoming signals. The customer must supply all of the
+ transmit logic, receive logic and timing recovery in order to
+ use the CSU, whereas a {digital service unit} DSU performs
+ these functions.
+
+ (1995-01-30)
+
+channel service unit/data service unit
+
+ <communications, hardware> (CSU/DSU, or "..digital..") A
+ device that performs both the {channel service unit} (CSU) and
+ {data service unit} (DSU) functions. The Channel Service Unit
+ (CSU) is used to terminate a {DS1} or {DS0} (56/64 kb/s)
+ digital circuit. It peforms {line conditioning}, protection,
+ {loop-back} and timing functions. The Data Service Unit (DSU)
+ terminates the data circuit to the {Data Terminal Equipment}
+ (DTE) and converts the customer's data stream into a bi-polar
+ format for transmission.
+
+ (2001-10-19)
+
+chan op
+
+ {channel op}
+
+chaos
+
+ <mathematics> A property of some {non-linear dynamic systems}
+ which exhibit sensitive dependence on initial conditions.
+ This means that there are initial states which evolve within
+ some finite time to states whose separation in one or more
+ dimensions of {state space} depends, in an average sense,
+ exponentially on their initial separation.
+
+ Such systems may still be completely {deterministic} in that
+ any future state of the system depends only on the initial
+ conditions and the equations describing the change of the
+ system with time. It may, however, require arbitrarily high
+ precision to actually calculate a future state to within some
+ finite precision.
+
+ ["On defining chaos", R. Glynn Holt
+ <rgholt@voyager.jpl.nasa.gov> and D. Lynn Holt
+ <lholt@seraph1.sewanee.edu>.
+ {(ftp://mrcnext.cso.uiuc.edu/pub/etext/ippe/preprints/Phil_of_Science/Holt_and_Holt.On_Defining_Chaos)}]
+
+ Fixed precision {floating-point} arithmetic, as used by most
+ computers, may actually introduce chaotic dependence on
+ initial conditions due to the accumulation of rounding errors
+ (which constitutes a non-linear system).
+
+ (1995-02-07)
+
+CHAP
+
+ {Challenge-Handshake Authentication Protocol}
+
+char
+
+ <programming> /keir/ or /char/; rarely, /kar/ character.
+ Especially used by {C} programmers, as "char" is {C}'s
+ typename for character data.
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+character
+
+ <character> An {atom} in a {character repertoire}.
+
+ Compare with {glyph}.
+
+ (1998-10-18)
+
+character encoding
+
+ <character> (Or "character encoding scheme") A mapping of
+ {binary} values to {code positions} and back; generally a 1:1
+ ({bijective}) mapping.
+
+ In the case of {ASCII}, this is generally a f(x)=x mapping:
+ code point 65 maps to the byte value 65, and vice versa. This
+ is possible because ASCII uses only code positions
+ representable as single bytes, i.e., values between 0 and 255,
+ at most. ({US-ASCII} only uses values 0 to 127, in fact.)
+
+ {Unicode} and many {CJK} {coded character sets} use many more
+ than 255 positions, requiring more complex mappings: sometimes
+ the characters are mapped onto pairs of bytes (see {DBCS}).
+ In many cases, this breaks programs that assume a one-to-one
+ mapping of bytes to characters, and so, for example, treat any
+ occurrance of the byte value 13 as a {carriage return}. To
+ avoid this problem, character encodings such as {UTF-8} were
+ devised.
+
+ (1998-10-18)
+
+character encoding scheme
+
+ {character encoding}
+
+character graphics
+
+ {ASCII art}
+
+characteristic function
+
+ <mathematics> The characteristic function of set returns True
+ if its argument is an element of the set and False otherwise.
+
+ (1995-04-13)
+
+character key
+
+ {key}
+
+character repertoire
+
+ <character> The set of all {characters} onto which a {coded
+ character set} maps {integers} ({code positions}).
+
+ For example, consider these two simple coded character sets:
+
+ Coded Character Set One:
+ integer 0 -> the character "A"
+ integer 1 -> the character "B"
+
+ Coded Character Set Two:
+ integer 0 -> the character "B"
+ integer 1 -> the character "A"
+
+ Both of these coded character sets map to the characters "A"
+ and "B", so they have the same character repertoire. But
+ since the mapping is different (and obviously incompatible),
+ these are different coded character sets.
+
+ (1998-12-17)
+
+character set
+
+ <character> 1. A particular mapping between {characters} and
+ {byte strings}, i.e. the combination of a particular
+ {character encoding} (which maps between byte strings and
+ {integers}) and a particular {coded character set} (which maps
+ between integers and characters).
+
+ For example: {ASCII} (the ASCII coded character set, encoded
+ directly as single-byte values), or {UTF-8} (the Unicode coded
+ character set, encoded with an 8-bit transformation method).
+
+ 2. Occasionally: a {character repertoire}; or a {coded
+ character set}.
+
+ (1998-12-17)
+
+character set identifier
+
+ <character> (CSID) (IBM) A number that identifies a {character
+ set}.
+
+ (1995-03-21)
+
+charge-coupled device
+
+ <electronics> (CCD) A semiconductor technology used to build
+ light-sensitive electronic devices such as cameras and image
+ scanners. CCDs can be made to detect either colour or
+ black-and-white. Each CCD chip consists of an array of
+ light-sensitive photocells. The photocell is sensitised by
+ giving it an electrical charge prior to exposure.
+
+ (2006-04-29)
+
+CHARITY
+
+ <language> A {functional language} based purely on {category
+ theory} by Cockett, Spencer, and Fukushima, 1990-1991.
+
+ A version for {Sun-4} is available from Tom Fukushima
+ <fukushim@ucalgary.ca>.
+
+ ["About Charity", J.R.B. Cockett, U. Calgary, Canada, et al].
+
+ (2000-10-30)
+
+charityware
+
+ {careware}
+
+Charles Babbage
+
+ <person> The british inventor known to some as the "Father of
+ Computing" for his contributions to the basic design of the
+ computer through his {Analytical Engine}. His previous
+ {Difference Engine} was a special purpose device intended for
+ the production of mathematical tables.
+
+ Babbage was born on December 26, 1791 in Teignmouth,
+ Devonshire UK. He entered Trinity College, Cambridge in 1814
+ and graduated from Peterhouse. In 1817 he received an MA from
+ Cambridge and in 1823 started work on the Difference Engine
+ through funding from the British Government. In 1827 he
+ published a table of {logarithms} from 1 to 108000. In 1828
+ he was appointed to the Lucasian Chair of Mathematics at
+ Cambridge (though he never presented a lecture). In 1831 he
+ founded the British Association for the Advancement of Science
+ and in 1832 he published "Economy of Manufactures and
+ Machinery". In 1833 he began work on the Analytical
+ Engine. In 1834 he founded the Statistical Society of London.
+ He died in 1871 in London.
+
+ Babbage also invented the cowcatcher, the dynamometer,
+ standard railroad gauge, uniform postal rates, occulting
+ lights for lighthouses, Greenwich time signals, and the
+ heliograph opthalmoscope. He also had an interest in cyphers
+ and lock-picking.
+
+ [Adapted from the text by J. A. N. Lee, Copyright September
+ 1994].
+
+ Babbage, as (necessarily) the first person to work with
+ machines that can attack problems at arbitrary levels of
+ {abstraction}, fell into a trap familiar to {toolsmiths}
+ since, as described here by the English ethicist, Lord
+ Moulton:
+
+ "One of the sad memories of my life is a visit to the
+ celebrated mathematician and inventor, Mr Babbage. He was far
+ advanced in age, but his mind was still as vigorous as ever.
+ He took me through his work-rooms. In the first room I saw
+ parts of the original Calculating Machine, which had been
+ shown in an incomplete state many years before and had even
+ been put to some use. I asked him about its present form. 'I
+ have not finished it because in working at it I came on the
+ idea of my {Analytical Machine}, which would do all that it
+ was capable of doing and much more. Indeed, the idea was so
+ much simpler that it would have taken more work to complete
+ the Calculating Machine than to design and construct the other
+ in its entirety, so I turned my attention to the Analytical
+ Machine.'"
+
+ "After a few minutes' talk, we went into the next work-room,
+ where he showed and explained to me the working of the
+ elements of the Analytical Machine. I asked if I could see
+ it. 'I have never completed it,' he said, 'because I hit upon
+ an idea of doing the same thing by a different and far more
+ effective method, and this rendered it useless to proceed on
+ the old lines.' Then we went into the third room. There lay
+ scattered bits of mechanism, but I saw no trace of any working
+ machine. Very cautiously I approached the subject, and
+ received the dreaded answer, 'It is not constructed yet, but I
+ am working on it, and it will take less time to construct it
+ altogether than it would have token to complete the Analytical
+ Machine from the stage in which I left it.' I took leave of
+ the old man with a heavy heart."
+
+ "When he died a few years later, not only had he constructed
+ no machine, but the verdict of a jury of kind and sympathetic
+ scientific men who were deputed to pronounce upon what he had
+ left behind him, either in papers or in mechanism, was that
+ everything was too incomplete of be capable of being put to
+ any useful purpose."
+
+ [Lord Moulton, "The invention of algorithms, its genesis, and
+ growth", in G. C. Knott, ed., "Napier tercentenary memorial
+ volume" (London, 1915), p. 1-24; quoted in Charles Babbage
+ "Passage from the Life of a Philosopher", Martin
+ Campbell-Kelly, ed. (Rutgers U. Press and IEEE Press, 1994),
+ p. 34].
+
+ Compare: {uninteresting}, {Ninety-Ninety Rule}.
+
+ (1996-02-22)
+
+Charles Simonyi
+
+ <person> {Microsoft} {programmer}, most famously responsible
+ for {Hungarian Notation}.
+
+ Simonyi was born in Budapest in 1948, and for more than a
+ decade was senior {programmer} at {Microsoft} in Redmond.
+
+ (1999-05-25)
+
+CHARM
+
+ <language> An explicitly {parallel programming language} based
+ on {C}, for both shared and nonshared {MIMD} computers.
+
+ {(ftp://a.cs.uiuc.edu/pub/CHARM)}.
+
+ Mailing list: <charm@cs.uiuc.edu>.
+
+ ["The CHARM(3.2) Programming Language Manual", UIUC, Dec
+ 1992].
+
+ (2006-04-29)
+
+CHARM++
+
+ <language> An {object-oriented} {parallel programming} system,
+ similar to {CHARM} but based on {C++}.
+
+ {(ftp://a.cs.uiuc.edu/pub/CHARM/Charm++)}.
+
+ E-mail: Sanjeev Krishnan <sanjeev@cs.uiuc.edu>.
+
+ [TR 1796, UIUC].
+
+ (1994-11-29)
+
+Charme
+
+ <language, logic, nondeterminism> A language with {discrete
+ combinatorial constraint logic} aimed at industrial problems such
+ as planning and {scheduling}. Implemented in {C} at {Bull} in
+ 1989.
+
+ Charme is an outgrowth of ideas from {CHIP}. It is
+ semantically {nondeterministic}, with choice and
+ {backtracking}, similar to {Prolog}.
+
+ ["Charme Reference Manual", AI Development Centre, Bull,
+ France 1990].
+
+ (1994-11-15)
+
+CHARYBDIS
+
+ <mathematics, tool> A {Lisp} program to display
+ mathematical expressions. It is related to {MATHLAB}.
+
+ [Sammet 1969, p. 522].
+
+ (1994-11-15)
+
+chase pointers
+
+ <programming> To determine a chain of memory locations where
+ each location holds a pointer to the next, starting from some
+ initial pointer, e.g. traversing a {linked list} or other
+ {graph} structure. This may be performed by a computer
+ executing a program or by a programmer going through a {core
+ dump} or using a debugger.
+
+ [{Jargon File}]
+
+ (2006-05-06)
+
+CHASM
+
+ {CHeap ASseMbler}
+
+chat
+
+ <chat, messaging> Any system that allows any number of
+ logged-in users to have a typed, real-time, on-line
+ conversation via a {network}.
+
+ The medium of {chat} is descended from {talk}, but the terms
+ (and the media) have been distinct since at least the early
+ 1990s. {talk} is prototypically for a small number of people,
+ generally with no provision for {channels}. In {chat}
+ systems, however, there are many {channels} in which any
+ number of people can talk; and users may send private
+ (one-to-one) messages.
+
+ Some early chat systems (in use 1998) include {IRC}, {ICQ} and
+ {Palace}. More recent alternatives include {MSN Messenger}
+ and {Google Talk}.
+
+ Chat systems have given rise to a distinctive style combining
+ the immediacy of talking with all the precision (and
+ verbosity) that written language entails. It is difficult to
+ communicate inflection, though conventions have arisen to help
+ with this.
+
+ The conventions of chat systems include special items of
+ jargon, generally abbreviations meant to save typing, which
+ are not used orally. E.g. {BCNU}, {BBL}, {BTW}, {CUL},
+ {FWIW}, {FYA}, {FYI}, {IMHO}, {OT}, {OTT}, {TNX}, {WRT},
+ {WTF}, {WTH}, {<g>}, {<gr&d>}, {BBL}, {HHOK}, {NHOH}, {ROTFL},
+ {AFK}, {b4}, {TTFN}, {TTYL}, {OIC}, {re}.
+
+ Much of the chat style is identical to (and probably derived
+ from) {Morse code} jargon used by ham-radio amateurs since the
+ 1920s, and there is, not surprisingly, some overlap with {TDD}
+ jargon. Most of the jargon was in use in {talk} systems.
+ Many of these expressions are also common in {Usenet} {news}
+ and {electronic mail} and some have seeped into popular
+ culture, as with {emoticons}.
+
+ The {MUD} community uses a mixture of {emoticons}, a few of
+ the more natural of the old-style {talk mode} abbreviations,
+ and some of the "social" list above. In general, though,
+ MUDders express a preference for typing things out in full
+ rather than using abbreviations; this may be due to the
+ relative youth of the MUD cultures, which tend to include many
+ touch typists. Abbreviations specific to MUDs include:
+ {FOAD}, ppl (people), THX (thanks), UOK? (are you OK?).
+
+ Some {BIFF}isms (notably the variant spelling "d00d") and
+ aspects of {ASCIIbonics} appear to be passing into wider use
+ among some subgroups of MUDders and are already pandemic on
+ {chat} systems in general.
+
+ See also {hakspek}.
+
+ {Suck article "Screaming in a Vacuum"
+ (http://suck.com/daily/96/10/23/)}.
+
+ (2006-05-31)
+
+chatbot
+
+ <chat> (Or "chatterbot") A {bot} meant to be able to interact
+ conversationally with humans. A chatbot is either an exercise
+ in {AI} or merely an interface as in an {infobot}.
+
+ One of the first and most famous chatterbots (prior to the
+ Web) was {Eliza}.
+
+ (1999-06-19)
+
+chat room
+
+ {channel}
+
+chatterbot
+
+ {chatbot}
+
+CHeap ASseMbler
+
+ <tool> (CHASM) A {shareware} {assembler} for {MS-DOS}.
+
+ (1994-11-15)
+
+cheapernet
+
+ <networking> (Or "thinnet") A colloquial term for thin-wire
+ {Ethernet} ({10base2}) that uses {RG58} {coaxial cable}
+ instead of the full-spec "Yellow Cable".
+
+ (1995-03-28)
+
+checkdigit
+
+ <data> A one-digit {checksum}.
+
+Checkout Test language
+
+ <language> (CTL)
+
+ ["Checkout Test Language: An Interpretive Language Designed
+ for Aerospace Checkout Tasks", G.S. Metsker, Proc FJCC 33(2)
+ 1968].
+
+ (1994-11-14)
+
+checkpoint
+
+ <programming> Saving the current state of a program and its
+ data, including intermediate results, to disk or other
+ {non-volatile storage}, so that if interrupted the program
+ could be restarted at the point at which the last checkpoint
+ occurred.
+
+ This facility came into popular use in {mainframe} {operating
+ systemss} such as {OS/360} in which programs frequently ran
+ for longer than the mean time between system failures. If a
+ program run fails because of some event beyond the program's
+ control (e.g. hardware or {operating system} failure) then the
+ processor time invested before the checkpoint will not have
+ been wasted.
+
+ (1995-02-07)
+
+checksum
+
+ <storage, communications> A computed value which depends on
+ the contents of a block of data and which is transmitted or
+ stored along with the data in order to detect corruption of
+ the data. The receiving system recomputes the checksum based
+ upon the received data and compares this value with the one
+ sent with the data. If the two values are the same, the
+ receiver has some confidence that the data was received
+ correctly.
+
+ The checksum may be 8 bits (modulo 256 sum), 16, 32, or some
+ other size. It is computed by summing the bytes or words of
+ the data block ignoring {overflow}. The checksum may be
+ negated so that the total of the data words plus the checksum
+ is zero.
+
+ {Internet} {packets} use a 32-bit checksum.
+
+ See also {digital signature}, {cyclic redundancy check}.
+
+ (1996-03-01)
+
+chemist
+
+ <jargon> (Cambridge) Someone who wastes computer time on
+ {number crunching} when you'd far rather the computer were
+ working out anagrams of your name or printing Snoopy calendars
+ or running {life} patterns. May or may not refer to someone
+ who actually studies chemistry.
+
+ [{Jargon File}]
+
+ (1995-02-07)
+
+Chen
+
+ {Peter Chen}
+
+CHEOPS
+
+ <communications> A satellite-based batch data dissemination
+ project between {CERN} and member state institutes.
+
+ (2006-06-21)
+
+Chernobyl packet
+
+ <networking> /cher-noh'b*l pak'*t/ A {network} {packet} that
+ induces a {broadcast storm} and/or {network meltdown}, named
+ in memory of the April 1986 nuclear accident at Chernobyl in
+ Ukraine.
+
+ The typical scenario involves an {IP} {Ethernet} {datagram}
+ that passes through a {gateway} with both source and
+ destination {Ethernet address} and {IP address} set as the
+ respective broadcast addresses for the subnetworks being gated
+ between.
+
+ Compare {Christmas tree packet}.
+
+ [{Jargon File}]
+
+ (2004-02-17)
+
+chess
+
+ <games> A two-player {game} with {perfect information}.
+
+ {Usenet} newsgroup: {news:rec.games.chess}.
+
+ See also {Internet Chess Server}.
+
+ (1995-03-25)
+
+CHI
+
+ <language> A {wide spectrum language}, the forerunner of
+ {Refine}.
+
+ ["Research on Knowledge-Based Software Environments at Kestrel
+ Institute", D.R. Smith et al, IEEE Trans Soft Eng, SE-11(11)
+ 1985]
+
+ (2006-07-11)
+
+Chicago
+
+ {Windows 95}
+
+chicken head
+
+ <graphics, abuse> The {Commodore} Business Machines logo,
+ which strongly resembles a poultry part. Rendered in {ASCII}
+ as "C=".
+
+ With the arguable exception of the {Amiga}, Commodore's
+ computers are notoriously crocky little {bitty box}es (see
+ also {PETSCII}). Thus, this usage may owe something to Philip
+ K. Dick's novel "Do Androids Dream of Electric Sheep?" (the
+ basis for the movie "Blade Runner"; the novel is now sold
+ under that title), in which a "chickenhead" is a mutant with
+ below-average intelligence.
+
+ [{Jargon File}]
+
+ (2006-07-12)
+
+chicklet keyboard
+
+ <spelling> It's spelled "{chiclet keyboard}".
+
+ (1997-05-16)
+
+chiclet keyboard
+
+ <hardware, abuse> A {keyboard} with a small, flat rectangular
+ or lozenge-shaped rubber or plastic keys that look like pieces
+ of Chiclets chewing gum. Used especially to describe the
+ original {IBM PCjr} keyboard. Vendors unanimously liked these
+ because they were cheap, and a lot of early {portable} and
+ {laptop computers} were launched with them. Customers
+ rejected the idea with almost equal unanimity, and chiclets
+ are not often seen on anything larger than a digital watch any
+ more.
+
+ [{Jargon File}]
+
+ (1997-05-16)
+
+Chief Information Officer
+
+ <job> (CIO) The person who determines the overall strategic
+ direction and business contribution of the {information
+ systems} function in a business.
+
+ (2004-03-18)
+
+child
+
+ {daughter}
+
+child process
+
+ <operating system> A {process} created by another process (the
+ {parent process}). Each process may create many child
+ processes but will have only one parent process, except for
+ the very first process which has no parent. The first
+ process, called {init} in {Unix}, is started by the {kernel}
+ at {boot time} and never terminates. A child process inherits
+ most of its attributes, such as open files, from its parent.
+ In fact in Unix, a child process is created (using {fork}) as
+ a copy of the parent. The chid process can then overlay
+ itself with a different program (using {exec}) as required.
+
+ (1997-11-22)
+
+child record
+
+ <database> A {record} lower in the hierarchical tree than a
+ parent record; it is also directly liked to the parent and
+ hierarchical {databases}.
+
+ (1995-04-13)
+
+child version
+
+ <system management> In {change management}, a {configuration item}
+ derived by altering another item (its parent version).
+
+ (2006-07-12)
+
+CHILI
+
+ <language> D.L. Abt. A language for {systems programming},
+ based on {ALGOL 60} with extensions for {structures} and {type
+ declarations}.
+
+ ["CHILI, An Algorithmic Language for Systems Programming",
+ CHI-1014, Chi Corp, Sep 1975]
+
+ (2006-07-12)
+
+CHILL
+
+ {CCITT HIgh-Level Language}
+
+Chimera
+
+ <web> A modular, {X Window System}-based
+ {web browser} for {Unix}. Chimera uses the
+ {Athena} {widget} set so {Motif} is not needed. It supports
+ forms, inline images, {TERM}, {SOCKS}, {proxy servers},
+ {Gopher}, {FTP}, {HTTP} and local file accesses. Chimera can
+ be extended using external programs. New {protocols} can
+ easily be added and alternate image formats can be used for
+ inline images (e.g. {PostScript}).
+
+ Version 1.60 is available for
+ {(ftp://ftp.cs.unlv.edu/pub/chimera)}.
+
+ {(http://unlv.edu/chimera/)}.
+
+ Chimera runs on {Sun} {SPARC} {SunOS} 4.1.x, {IBM} {RS/6000}
+ {AIX} 3.2.5, {Linux} 1.1.x. It should run on anything with
+ {X11}R[3-6], {imake} and a {C} compiler.
+
+ (1994-11-08)
+
+chine nual
+
+ <documentation> /sheen'yu-*l/ (MIT) The {LISP Machine} Manual,
+ so called because the title was wrapped around the cover so
+ only those letters showed on the front.
+
+ [{Jargon File}]
+
+ (1994-12-02)
+
+Chinese Army technique
+
+ {Mongolian Hordes technique}
+
+CHIP
+
+ <language>
+
+ 1. An early system on the {IBM 1130}.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (2004-09-14)
+
+ 2. {Constraint Handling In Prolog}.
+
+chip
+
+ {integrated circuit}
+
+CHIP-48
+
+ A reimplementation of {CHIP-8} for the {HP-48} calculator by
+ Andreas Gustafson <gson@niksula.hut.fi>.
+
+ Posted to {news:comp.sys.handhelds} in Sep 1990.
+
+ {(ftp://vega.hut.fi/pub/misc/hp48sx/asap)}.
+
+ (1994-12-02)
+
+CHIP-8
+
+ <language, games> A low-level {interpretive language} (really
+ a high-level {machine code}) developed at {RCA} in the late
+ 1970s for {video games} on computers using {RCA}'s {CDP1802}
+ processor. It could also be used on the {DREAM 6800}.
+
+ {Amiga interpreter
+ (ftp://ftp.cso.uiuc.edu/pub/amiga/fish/f5/ff537/CHIP8.lzh)}.
+
+ (2002-04-09)
+
+chip art
+
+ {microchip art}
+
+chip box
+
+ {chad box}
+
+chip creep
+
+ <hardware> Gradual loosening of an {integrated circuit}
+ ("chip") in its {socket} as a result of expansion and
+ contraction during the normal heating and cooling cycles of an
+ electronic system, combined with vibration, e.g. due to
+ cooling fans. The chip can loosen to the point that poor
+ electrical contact between chip and socket reduces the signal
+ quality, causing failure. Pushing chips back into their
+ sockets can cure such symptoms temporarily. Permanent
+ solutions include soldering chips directly to the {PCB} and
+ clipping the component into the socket (as on some {in-line
+ memory modules}).
+
+ The same phenomenon can affect anything plugged into a socket
+ but not held securely in place, e.g. a {circuit board} plugged
+ into an {edge connector} on a {motherboard} or {backplane} can
+ suffer "card creep".
+
+ (2007-06-19)
+
+chip graffiti
+
+ {microchip art}
+
+Chip Jewelry
+
+ <jargon> A euphamism for old computers destined to be scrapped
+ or turned into decorative ornaments. "I paid three grand for
+ that {Mac SE}, and now it's nothing but chip jewelry."
+
+ (1997-03-30)
+
+Chip Scale Packaging
+
+ <hardware> (CSP) A type of {surface mount} {integrated
+ circuit} packaging that provides pre-speed-sorted, pre-tested
+ and pre-packaged {die} without requiring special testing. An
+ example is {Motorola}'s {Micro SMT} packaging.
+
+ See also: {chip-on-board}, {flip chip}, {multichip module},
+ {known good die}, {ball grid array}.
+
+ ["Chip scale packaging gains at SMI. (Surface Mount
+ International)", Bernard Levine, Electronic News (1991), Sept
+ 4, 1995 v41 n2081 p1(2)].
+
+ (2006-08-14)
+
+chip set
+
+ <hardware> A collection of {integrated circuits} that are
+ designed to be used together for some specific purpose.
+ E.g. control circuitry in an {IBM PC}.
+
+ (1995-03-27)
+
+Chips & Technologies
+
+ <company> A former leading distributor and supplier of
+ {integrated circuits} and {software} to {personal computer}
+ manufacturers. As well as semiconductors they also made {flat
+ panel displays}, {video controllers} and other computer
+ related products.
+
+ In 1998, {Intel Corporation} bought Chips and Technologies for
+ their flat panel controllers. In January 2000, {Asiliant
+ Technologies} licensed the rights from Intel to continue to
+ manufacturer and sell Chips and Technologies components.
+
+ Address: 2950 Zanker Road, San Jose, California 95134, USA.
+
+ (2006-09-19)
+
+CHISEL
+
+ <language> An extension of {C} for {VLSI} design, implemented
+ as a C {preprocessor}. It produces {CIF} as output.
+
+ ["CHISEL - An Extension to the Programming language C for VLSI
+ Layout", K. Karplus, PHD Thesis, Stanford U, 1982].
+
+ (2006-09-19)
+
+chm
+
+ {Compiled HTML}
+
+chmod
+
+ <file system> ("Change mode") The {Unix} command and {system
+ call} to change the access {permissions} of a named file.
+ Each file (directory, device, etc.) has nine kinds of access
+ which can be allowed or denied. Different permissions apply
+ to the owner of the file, the members of the group the file
+ belongs to, and all users. Each of these classes of user
+ (owner, group and other) can have permission to read, write or
+ execute the file. Chmod can also set various other mode bits
+ for a file or directory such as the {sticky bit} and the {set
+ user id} bit.
+
+ Unix {man} page: chmod
+
+ (1995-01-31)
+
+CHOCS
+
+ <language> A generalisation of {CCS}.
+
+ ["A Calculus of Higher-Order Communicating Systems",
+ B. Thomsen, 16th POPL pp. 143-154, 1989].
+
+ (2006-09-20)
+
+choke
+
+ <jargon> To fail to process input or, more generally, to fail
+ at any endeavor.
+
+ E.g. "NULs make System V's "lpr(1)" choke." See {barf},
+ {gag}.
+
+ [{Jargon File}]
+
+ (2006-09-20)
+
+chomp
+
+ <jargon> To fail.
+
+ (1996-06-01)
+
+CHOP
+
+ {channel op}
+
+Chop
+
+ <language, tool> A {code generator} by Alan L. Wendt
+ <wendt@CS.ColoState.EDU> for the {lcc} {C} compiler {front
+ end}. Version 0.6 is interfaced with Fraser and Hanson's
+ {lcc} {front end}. The result is a {C} compiler with good
+ code selection but no {global optimisation}. In 1993, Chop
+ could compile and run small test programs on the {VAX}. The
+ {National Semiconductor 32000} and {Motorola 68000} code
+ generators are being upgraded for {lcc} compatibility.
+
+ {(ftp://beethoven.cs.colostate.edu/pub/chop/0.6.tar.Z)}.
+
+ ["Fast Code Generation Using Automatically-Generated Decision
+ Trees", ACM SIGPLAN '90 PLDI].
+
+ (1993-04-28)
+
+Chorus
+
+ <operating system> A distributed {operating system} developed
+ at {INRIA}.
+
+ (2006-09-20)
+
+Christmas tree
+
+ <hardware, jargon> A kind of {EIA-232} {line tester} or
+ {breakout box} featuring rows of blinking red and green {LEDs}
+ suggestive of Christmas lights.
+
+ [{Jargon File}]
+
+ (2006-09-20)
+
+Christmas tree packet
+
+ <networking> (Or kamikaze packet) A {packet} with every single
+ option set for whatever {protocol} is in use. The term
+ doubtless derives from a fanciful image of each little option
+ bit being represented by a different-coloured light bulb, all
+ turned on.
+
+ {RFC 1025}, "TCP and IP Bake Off" says:
+
+ 10 points for correctly being able to process a "Kamikaze"
+ packet (AKA {nastygram}, Christmas tree packet, lamp test
+ segment, et al.). That is, correctly handle a segment with
+ the maximum combination of features at once (e.g. a SYN URG
+ PUSH FIN segment with options and data).
+
+ Compare: {Chernobyl packet}.
+
+ [{Jargon File}]
+
+ (1994-11-09)
+
+Christopher Strachey
+
+ <person> Professor of Computation at Oxford, England, born
+ 1916, died May 1975. He invented the term "{currying}".
+
+ See also: {General Purpose Macro-generator}.
+
+ (1998-06-29)
+
+chromatic number
+
+ <mathematics> The smallest number of colours necessary to
+ colour the nodes of a {graph} so that no two adjacent nodes
+ have the same colour.
+
+ See also: {four colour map theorem}.
+
+ {Graph Theory Lessons
+ (http://utc.edu/~cpmawata/petersen/lesson8.htm)}.
+
+ {Eric Weisstein's World Of Mathematics
+ (http://mathworld.wolfram.com/ChromaticNumber.html)}.
+
+ {The Geometry Center
+ (http://geom.umn.edu/~zarembe/grapht1.html)}.
+
+ (2000-03-18)
+
+chrome
+
+ <jargon> (From automotive slang via wargaming) Showy
+ {features} added to attract users but contributing little or
+ nothing to the power of a system.
+
+ "The 3D icons in {Motif} are just chrome, but they certainly
+ are *pretty* chrome!"
+
+ Chrome is distinguished from {bells and whistles} by the fact
+ that the latter are usually added to gratify developers' own
+ desires for featurefulness. Often used as a term of contempt
+ and sometimes used in conjunction with 'fluff', "all the fluff
+ and chrome that comes with Motif".
+
+ [{Jargon File}]
+
+ (1997-09-19)
+
+chroot
+
+ <operating system> The {UNIX} command to make the {root
+ directory} (/) become something other than its default for the
+ lifetime of the current process. It can only be run by
+ privileged users and is used to give a process (commonly a
+ network server such as {FTP} or {HTTP}) access to a restricted
+ portion of the {file system}.
+
+ The new root contains copies of all the essential files and
+ directories, e.g. /lib, /dev/tty, /tmp.
+
+ (1996-12-08)
+
+CHRP
+
+ {PowerPC Platform}
+
+chug
+
+ <jargon> To run slowly; to {grind} or {grovel}. "The disk is
+ chugging like crazy."
+
+ [{Jargon File}]
+
+ (1995-03-25)
+
+chug report
+
+ <humour> From "chug" - to drink heavily. A {bug report} whose
+ the submitter is thought to have had one too many. Not as bad
+ as a {drug report}.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2011-12-03)
+
+chunker
+
+ <programming> A program like {Unix}'s "split" which breaks an
+ input file into parts, usually of a pre-set size, e.g. the
+ maximum size that can fit on a {floppy}. The parts can then
+ be assembled with a {dechunker}, which is usually just the
+ chunker in a different mode.
+
+ (1998-12-15)
+
+Church, Alonzo
+
+ {Alonzo Church}
+
+Church integer
+
+ <theory> A representation of integers as functions invented by
+ {Alonzo Church}, inventor of {lambda-calculus}. The integer N
+ is represented as a {higher-order function} which applies a
+ given function N times to a given expression. In the {pure
+ lambda-calculus} there are no constants but numbers can be
+ represented by Church integers.
+
+ A {Haskell} function to return a given Church integer could be
+ written:
+
+ church n = c
+ where
+ c f x = if n == 0 then x else c' f (f x)
+ where
+ c' = church (n-1)
+
+ A function to turn a Church integer into an ordinary integer:
+
+ unchurch c = c (+1) 0
+
+ See also {von Neumann integer}.
+
+ (1994-11-29)
+
+Church of the SubGenius
+
+ <body, humour> A mutant offshoot of {Discordianism} launched
+ in 1981 as a spoof of fundamentalist Christianity by the
+ "Reverend" Ivan Stang, a brilliant satirist with a gift for
+ promotion. Popular among hackers as a rich source of bizarre
+ imagery and references such as "Bob" the divine
+ drilling-equipment salesman, the Benevolent Space Xists, and
+ the Stark Fist of Removal. Much SubGenius theory is concerned
+ with the acquisition of the mystical substance or quality of
+ {slack}.
+
+ {(http://sunsite.unc.edu/subgenius/slack.html)}.
+
+ (1996-01-02)
+
+Church-Rosser Theorem
+
+ <theory> A property of a {reduction} system that states that
+ if an expression can be reduced by zero or more reduction
+ steps to either expression M or expression N then there exists
+ some other expression to which both M and N can be reduced.
+ This implies that there is a unique {normal form} for any
+ expression since M and N cannot be different normal forms
+ because the theorem says they can be reduced to some other
+ expression and normal forms are irreducible by definition. It
+ does not imply that a normal form is reachable, only that if
+ reduction terminates it will reach a unique normal form.
+
+ (1995-01-25)
+
+ci
+
+ <networking> The {country code} for Cote d'Ivoire (the Ivory
+ Coast).
+
+ [{Jargon File}]
+
+ (1999-01-27)
+
+CI$
+
+ {CompuServe Information Service}
+
+CICERO
+
+ <project> Control Information system Concepts based on
+ Encapsulated Real-time Objects.
+
+ A {CERN} {DRDC} proposal.
+
+ (1995-01-25)
+
+Cichlid
+
+ <graphics, tool> A tool for rapidly visualising arbitrary data
+ in high-quality 3D, while allowing the viewer to explore and
+ interact with the data in {real time}. Cichlid was designed
+ with remote data generation and machine independence in mind;
+ data is transmitted via {TCP} from any number of sources (data
+ servers) to the visualisation code (the client), which
+ displays them concurrently.
+
+ [Who? URL?]
+
+ (2004-01-22)
+
+CICS
+
+ {Customer Information Control System}
+
+CID
+
+ {Caller ID}
+
+CIDR
+
+ {Classless Inter-Domain Routing}
+
+CIEL
+
+ <language> An {object-oriented} {Prolog}-like language.
+
+ ["CIEL: Classes et Instances En Logique", M. Gandriau, Thesis
+ ENSEEIHT, 1988].
+
+ (1995-01-25)
+
+CIF
+
+ {Caltech Intermediate Form}
+
+CIFS
+
+ {Common Internet File System}
+
+Cigale
+
+ <language, tool> A {parser generator} language with extensible
+ {syntax}.
+
+ ["CIGALE: A Tool for Interactive Grammar Construction and
+ Expression Parsing", F. Voisin, Sci Comp Prog 7:61-86, 1986].
+
+ (1999-01-14)
+
+CIL
+
+ 1. <project> {Component Integration Laboratories}.
+
+ 2. <language> {Common Intermediate Language}.
+
+CIM
+
+ 1. <application> {Computer Integrated Manufacturing}.
+
+ 2. <standard> {Common Information Model}.
+
+CIMS PL/I
+
+ <language> A {PL/I} subset from the Courant Institute of
+ Mathematical Sciences.
+
+ ["CIMS PL/I", P.W. Abrahams, Courant Inst].
+
+ (1997-12-15)
+
+Cinderella Book
+
+ <publication> "Introduction to Automata Theory, Languages, and
+ Computation", by John Hopcroft and Jeffrey Ullman,
+ (Addison-Wesley, 1979). So called because the cover depicts a
+ girl (putatively Cinderella) sitting in front of a Rube
+ Goldberg device and holding a rope coming out of it. On the
+ back cover, the device is in shambles after she has
+ (inevitably) pulled on the rope.
+
+ See also {book titles}.
+
+ [{Jargon File}]
+
+ (1996-12-03)
+
+CINT92
+
+ {SPEC CINT92}
+
+C-Interp
+
+ An {interpreter} for a small subset of {C}, originally part of
+ a communications package.
+
+ {(ftp://oac2.hsc.uth.tmc.edu/Mac/Misc/C_Interp.sit)}. E-mail:
+ Chuck Shotton <cshotton@oac.hsc.uth.tmc.edu>.
+
+ (1993-05-14)
+
+CIO
+
+ {Chief Information Officer}
+
+ciphertext
+
+ <cryptography> Text which has been encrypted by some
+ {encryption} system.
+
+ Opposite: {plaintext}.
+
+ (1994-10-27)
+
+CIP-L
+
+ {CIP Language}
+
+CIP Language
+
+ language> (CIP-L, Computer-aided Intuition-guided Programming
+ Language) A {wide-spectrum language} for incremental {program
+ transformation}. There are {ALGOL}- and {Pascal}-like
+ variants.
+
+ ["The Munich Project CIP, v.I: The Wide Spectrum Language
+ CIP-L", LNCS 183, Springer 1984. Version: CIP85].
+
+ (2006-09-20)
+
+CIR
+
+ {Committed Information Rate}
+
+CIRCAL
+
+ {CIRcuit CALculus}
+
+circuit
+
+ 1. <communications> A communications path in a {circuit
+ switching} network.
+
+ 2. <electronics> A complete path through which an electric
+ current can flow.
+
+ The term is used loosely for any device or subsystem using
+ electrical or electronic components. E.g. "That lightning
+ bolt fried the circuits in my GPS receiver". An {integrated
+ circuit} (IC) contains components built on a Silicon {die}.
+
+ (2002-07-15)
+
+CIRcuit CALculus
+
+ (CIRCAL) A {process algebra} used to model and verify the
+ design correctness of {concurrent} systems such as {digital
+ logic}.
+
+ ["CIRCAL and the Representation of Communication, Concurrency
+ and Time", G.J. Milne <milne@cis.unisa.edu.au>, ACM TOPLAS
+ 7(2):270-298, 1985].
+
+ (2001-03-25)
+
+circuit switch
+
+ {circuit switching}
+
+circuit switched
+
+ {circuit switching}
+
+circuit switching
+
+ <communications> Communication via a single dedicated path
+ between the sender and receiver. The telephone system is an
+ example of a circuit switched network.
+
+ The term {connection-oriented} is used in {packet}-based
+ networks in contrast to {connectionless} communication or
+ {packet switching}.
+
+ (2006-09-20)
+
+circular buffer
+
+ <programming> An area of {memory} used to store a continuous
+ stream of data by starting again at the beginning of the
+ buffer after reaching the end. A circular buffer is usually
+ written by one process and read by another. Separate read and
+ write {pointers} are maintained. These are not allowed to
+ pass each other otherwise either unread data would be
+ overwritten or invalid data would be read.
+
+ A circuit may implement a {hardware circular buffer}.
+
+ (2000-06-17)
+
+Cirrus Logic
+
+ <company> A manufacturer of {integrated circuits} including
+ the {Advanced RISC Machine} and display interface processors
+ and cards for use as {Windows accelerators} (requiring
+ dedicated driver software).
+
+ {(http://cirrus.com/)}.
+
+ [Other products?]
+
+ (1996-10-13)
+
+CIS
+
+ 1. <standard, programming> {Case Integration Services}.
+
+ 2. <networking> {Cooperative Information System}.
+
+ 3. <business> {Customer Interaction Software},
+ {Customer Information Systems}.
+
+CISC
+
+ {Complex Instruction Set Computer}
+
+Cisco Systems, Inc.
+
+ <company> {Ethernet} hardware manufacturers.
+
+ {(http://cisco.com/)}.
+
+ Address: 170 West Tasman Drive, San Jose, CA 95134-1706, USA.
+ Telephone: +1 408 526 4000, +1 800 553 6387. Fax: +1 408 526
+ 4100.
+
+ (1995-04-19)
+
+CISI
+
+ <company> A French software producer.
+
+ (2006-09-20)
+
+CITRAN
+
+ <language> {Caltech}'s answer to {MIT}'s {JOSS}.
+
+ [Sammet 1969, p. 217].
+
+ (2006-09-20)
+
+CityScape
+
+ <company> A re-seller of {Internet} connections to the {PIPEX}
+ {backbone}.
+
+ E-Mail: <sales@cityscape.co.uk>.
+
+ Address: CityScape Internet Services, 59 Wycliffe Rd.,
+ Cambridge, CB1 3JE, England. Telephone: +44 (1223) 566 950.
+
+ (1994-11-08)
+
+CIX
+
+ 1. <networking> {Commercial Internet Exchange}.
+
+ 2. <messaging> {Compulink Information eXchange}.
+
+CJK
+
+ <character> In {internationalisation}, a collective term for
+ Chinese, Japanese, and Korean.
+
+ The characters of these languages are all partly based on {Han
+ characters} (i.e., "hanzi" or "{kanji}"), which require 16-bit
+ {character encodings}. CJK character encodings should consist
+ minimally of {Han characters} plus language-specific phonetic
+ scripts such as pinyin, bopomofo, hiragana, hangul, etc.
+
+ {CJKV} is CJK plus {Vietnamese}.
+
+ {(ftp://ftp.ora.com/pub/examples/nutshell/ujip/doc/cjk.inf)}.
+
+ (2001-01-01)
+
+CJKV
+
+ <character> {CJK} plus {Vietnamese}. Vietnamese, like the
+ other three CJK languages, requires 16-bit {character
+ encodings} but it does not use {Han characters}.
+
+ ["CJKV Information Processing: Chinese, Japanese, Korean &
+ Vietnamese Computing", Ken Lunde, pub. O'Reilly 1998,
+ {(http://oreilly.com/catalog/cjkvinfo/)}].
+
+ (2001-03-18)
+
+ck
+
+ <networking> The {country code} for the Cook Islands.
+
+ (1999-01-27)
+
+CL
+
+ <language>
+
+ 1. {Control Language}.
+
+ 2. {Clausal Language}.
+
+cl
+
+ <networking> The {country code} for Chile.
+
+ (1999-01-27)
+
+CLAM
+
+ <mathematics, tool> A system for {symbolic mathematics},
+ especially General Relativity. It was first implemented in
+ {ATLAS} {assembly language} and later {Lisp}.
+
+ See also {ALAM}.
+
+ ["CLAM Programmer's Manual", Ray d'Inverno & Russell-Clark,
+ King's College London, 1971].
+
+ (1994-11-08)
+
+C Language Integrated Production System
+
+ <language> (CLIPS) A language produced by Gary Riley of NASA
+ {JSC} in Houston, Texas, for developing {expert systems}, with
+ the inferencing and representation capabilities of {OPS5} and
+ support for {forward chaining} rule-based, {object-oriented}
+ and {procedural} programming. CLIPS has a {Lisp}-like
+ {syntax}. It is available for {MS-DOS} and comes with source
+ code in {C}.
+
+ COSMIC, U Georgia, (404) 542-3265. Austin Code Works
+ <info@acw.com> (512) 258-0785.
+
+ Versions include CLIPS 5.1, CLIPS/Ada 4.3 and CLIPS6.0 (see
+ {PCLIPS}).
+
+ {(http://jsc.nasa.gov/~clips/CLIPS.html)}.
+
+ E-mail: <service@cossack.cosmic.uga.edu>.
+
+ Telnet: cosmic.uga.edu, user: cosline.
+
+ {U. Michigan
+ (ftp://earth.rs.itd.umich.edu/mac.bin/etc/compsci/Clips/)},
+ {ENSMP, France (ftp://ftp.ensmp.fr/pub/clips/)}.
+
+ ["Expert Systems: Principles and Programming", Joseph
+ Giarratano and Gary Riley, PWS Publ 1994, ISBN 0-534-93744-6].
+
+ (1994-12-16)
+
+Clarify
+
+ <company> A software vendor, specialising in {Customer
+ Relationship Management} software. {Nortel Networks} sold
+ Clarify to {Amdocs} in 2002.
+
+ {(http://amdocsclarify.com/)}.
+
+ (2003-06-20)
+
+Clarion
+
+ <language> A family of systems from {SoftVelocity, Inc.} for
+ building {database} applications on {Microsoft Windows}.
+ Clarion products include Clarion 4GL language with a {C++} and
+ {Modula-2} {compiler}. Clarion products support fast,
+ efficient database application development. Clarion was
+ originally developed by Clarion Software Corporation, later to
+ become TopSpeed Corporation. In 2000, the Clarion product
+ line was acquired by SoftVelocity Inc.
+
+ (2003-10-15)
+
+Claris
+
+ <company> A subsidiary company of {Apple Computer, Inc.}. In
+ January 1998, Apple restructured Claris to concentrate on
+ their {FileMaker} line of {database} {software} and changed
+ the company's name to {FileMaker, Inc.}.
+
+ (1998-02-18)
+
+CLASP
+
+ {Computer Language for AeronauticS and Programming}
+
+class
+
+ 1. <programming> The prototype for an {object} in an
+ {object-oriented language}; analogous to a {derived type} in a
+ {procedural language}. A class may also be considered to be a
+ set of objects which share a common structure and behaviour.
+ The structure of a class is determined by the {class
+ variables} which represent the {state} of an object of that
+ class and the behaviour is given by a set of {methods}
+ associated with the class.
+
+ Classes are related in a {class hierarchy}. One class may be
+ a specialisation (a "{subclass}") of another (one of its
+ "{superclasses}") or it may be composed of other classes or it
+ may use other classes in a {client-server} relationship. A
+ class may be an {abstract class} or a {concrete class}.
+
+ See also {signature}.
+
+ 2. <programming> See {type class}.
+
+ 3. <networking> One of three types of {Internet addresses}
+ distinguished by their most significant bits.
+
+ 3. <language> A language developed by the {Andrew Project}.
+ It was one of the first attempts to add {object-oriented}
+ features to {C}.
+
+ (1995-05-01)
+
+Class 5 switch
+
+ <communications> The lowest designation used in {AT&T}'s
+ hierarchical {General Toll Switching Plan}, developed in 1929.
+
+ (2013-09-14)
+
+class hierarchy
+
+ <programming> In {object-oriented programming}, a set of {classes}
+ related by {inheritance}. Each class is a "subclass" of another
+ class - its "superclass". The subclass contains all the features
+ of its superclass, but may add new features or redefine existing
+ features. The features of a class are the set of {attributes} (or
+ "properties") that an object of that class has and the {methods}
+ that can be invoked on it.
+
+ If each class has a just one superclass, this is called {single
+ inheritance}. The opposite is {multiple inheritance}, under which
+ a class may have multiple superclasses. Single inheritance gives
+ the class hierarchy a {tree} structure whereas multiple
+ inheritance gives a {directed graph}. Typically there is one
+ class at the top of the hierarchy which is the "object" class, the
+ most general class that is an ancestor of all others and which has
+ no superclass.
+
+ In computing, as in genealogy, trees grow downwards, which is why
+ subclasses are considered to be "below" their superclasses.
+
+ When {invoking a method} on an {object}, the method is first
+ looked for in the object's class, then the superclass of that
+ class, and so on up the hierarchy until it is found. Thus a class
+ need only define those methods which are specific to it and it
+ will inherit all other methods from all its superclasses. An
+ object of the subclass can do everything that an object of the
+ superclass can and possible more.
+
+ {C++} calls the superclass the "base class" and the subclass the
+ "derived class" (not to be confused with a {derived type}).
+
+ (2014-09-06)
+
+classic
+
+ <jargon> An adjective used before or after a noun to describe
+ the original version of something, especially if the original
+ is considered to be better.
+
+ Examples include "Star Trek Classic" - the original TV series
+ as opposed to the films, ST The Next Generation or any of the
+ other spin-offs and follow-ups; or "PC Classic" - {IBM}'s
+ {ISA}-bus computers as opposed to the {PS/2} series.
+
+ (1996-10-27)
+
+Classic-Ada
+
+ <language> An {object-oriented} extension to {Ada}, said to be
+ like {Smalltalk}. It is implemented as an {Ada}
+ {preprocessor}.
+
+ (1994-12-05)
+
+classical logic
+
+ <logic> Non-{intuitionistic logic}.
+
+ (1995-04-13)
+
+Classic C
+
+ {K&R C}
+
+Classless Inter-Domain Routing
+
+ <networking> (CIDR) /sid*r/ A technique that summarises a
+ block of {Internet addresses} in a {routing table} as an
+ address in {dotted decimal notation} followed by a {forward
+ slash} and a two-digit decimal number giving the number of
+ leading one bits in the subnet mask. For example,
+ 123.123.123.0/24 specifies a subnet mask of
+ 11111111.11111111.11111111.00000000 (binary), implying the
+ block of addresses 123.123.123.0 through 123.123.123.255.
+
+ CIDR is "classless" because it is not limited to the subnet
+ masks specified by {Internet address} classes A, B and C.
+
+ According to {RFC 1519}, CIDR was implemented to distribute
+ Internet address space more efficiently and to provide a
+ mechanism for {IP route aggregation}. This in turn reduces
+ the number of entries in IP routing tables, enabling faster,
+ more efficient routing, e.g. using {routing} {protocols} such
+ as {OSPF}. CIDR is supported by {BGP4}.
+
+ See also {RFC 1467}, {RFC 1518}, {RFC 1520}.
+
+ (2006-01-26)
+
+class library
+
+ <programming> A {library} of reusable {class}es for use with
+ an {object-oriented programming} system.
+
+ (1994-12-05)
+
+class method
+
+ <programming> 1. A {method} that operates on a {class object} (an
+ {object} of {class} "class"). A class method is really just an
+ ordinary {object method} that happens to operate on class objects.
+
+ A class method might, for example, return a list of objects
+ representing the methods and attributes of the given class.
+
+ 2. A {static method}.
+
+ (2014-09-06)
+
+class object
+
+ <programming> In {object-oriented programming}, an {object} of
+ {class} "class" that represents a {class} at {run time}. The
+ existence of class objects allows {introspection} - the ability
+ for a program to discover and modify attributes of its own code.
+ (See {self-modifying code}).
+
+ A class object may also be used for "housekeeping" tasks like
+ keeping count of how many objects of the class have been created,
+ though this may also be done by some kind of {collection} object.
+
+ A {class method} is a {method} that operates on class objects.
+
+ (2014-09-06)
+
+Class Oriented Ring Associated Language
+
+ <language> (CORAL) A language developed by L.G. Roberts at
+ {MIT} in 1964 for graphical display and systems programming on
+ the {TX-2}. It used "rings" (circular lists) from
+ {Sketchpad}.
+
+ ["Graphical Communication and Control Languages",
+ L.B. Roberts, Information System Sciences: Proc Second
+ Congress, 1965].
+
+ [Sammet 1969, p.462].
+
+ (1994-11-30)
+
+Class-Relation Method
+
+ <programming> A design technique based on the concepts of
+ {object-oriented programming} and the {Entity-Relationship
+ model} from the French company {Softeam}.
+
+ (1994-12-05)
+
+Clausal Language
+
+ <language> (CL) A programming language and {proof system}
+ developed by Paul Voda and a colleague since 1997, written in
+ {Trilogy} II.
+
+ {Paul Voda Home (http://fmph.uniba.sk/~voda)}.
+
+ (2002-05-28)
+
+clause
+
+ 1. <logic> A {logical formula} in {conjunctive normal form},
+ which has the {schema}
+
+ p1 ^ ...^ pm => q1 V ... V qn.
+
+ or, equivalently,
+
+ ~p1 V ... V ~pn V q1 V ... V qn,
+
+ where pi and qi are {atoms}.
+
+ The operators ~, ^, V, => are {connectives}, where ~ stands
+ for {negation}, ^ for {conjunction}, V for {disjunction} and
+ => for {implication}.
+
+ 2. <grammar> A part of a sentence (or programming language
+ statement) that does not constitute a full sentence, e.g. an
+ adjectival clause in human language or a WHERE clause in a
+ {SQL} statement.
+
+ (2004-05-28)
+
+Clean
+
+ <language> A {lazy} {higher-order} {purely functional
+ language} from the {University of Nijmegen}. Clean was
+ originally a subset of {Lean}, designed to be an experimental
+ {intermediate language} and used to study the {graph
+ rewriting} model. To help focus on the essential
+ implementation issues it deliberately lacked all {syntactic
+ sugar}, even {infix} expressions or {complex lists},
+
+ As it was used more and more to construct all kinds of
+ applications it was eventually turned into a general purpose
+ functional programming language, first released in May 1995.
+ The new language is {strongly typed} (Milner/Mycroft type
+ system), provides {modules} and {functional I/O} (including a
+ {WIMP} interface), and supports {parallel processing} and
+ {distributed processing} on {loosely coupled} parallel
+ architectures. Parallel execution was originally based on the
+ {PABC} {abstract machine}.
+
+ It is one of the fastest implementations of functional
+ languages available, partly aided by programmer {annotations}
+ to influence evaluation order.
+
+ Although the two variants of Clean are rather different, the
+ name Clean can be used to denote either of them. To
+ distinguish, the old version can be referred to as Clean 0.8,
+ and the new as Clean 1.0 or Concurrent Clean.
+
+ The current release of Clean (1.0) includes a compiler,
+ producing code for the {ABC} {abstract machine}, a {code
+ generator}, compiling the ABC code into either {object-code}
+ or {assembly language} (depending on the {platform}), I/O
+ libraries, a {development environment} (not all platforms),
+ and {documentation}. It is supported (or will soon be
+ supported) under {Mac OS}, {Linux}, {OS/2}, {Windows 95},
+ {SunOS}, and {Solaris}.
+
+ {(http://cs.kun.nl/~clean/)}. E-mail:
+ <clean@cs.kun.nl>. Mailing list: <clean-request@cs.kun.nl>.
+
+ ["Clean - A Language for Functional Graph Rewriting", T. Brus
+ et al, IR 95, U Nijmegen, Feb 1987].
+
+ ["Concurrent Clean", M.C. van Eekelen et al, TR 89-18, U
+ Nijmegen, Netherlands, 1989].
+
+ [{Jargon File}]
+
+ (1995-11-08)
+
+clean
+
+ <jargon>
+
+ 1. Used of hardware or software designs, implies "elegance in
+ the small", that is, a design or implementation that may not
+ hold any surprises but does things in a way that is reasonably
+ intuitive and relatively easy to comprehend from the outside.
+ The antonym is "grungy" or {crufty}.
+
+ 2. To remove unneeded or undesired files in a effort to reduce
+ clutter: "I'm cleaning up my account." "I cleaned up the
+ garbage and now have 100 Meg free on that partition."
+
+ [{Jargon File}]
+
+ (1994-12-12)
+
+cleanroom
+
+ <programming> A software development approach aimed at
+ producing software with the minimum number of {errors}.
+
+ (1994-12-12)
+
+CLEAR
+
+ <language> A {specification language} based on {initial
+ algebras}.
+
+ ["An Informal Introduction to Specification Using CLEAR",
+ R.M. Burstall in The Correctness Problem in Computer Science,
+ R.S. Boyer et al eds, Academic Press 1981, pp. 185-213].
+
+ (1994-11-03)
+
+clear box testing
+
+ {white box testing}
+
+Clear Language for Expressing Orders
+
+ <language> (CLEO) A language developed by {ICL} in the 1960s
+ and used until early 1972 on {Leo} III {mainframes}.
+
+ (1994-11-03)
+
+CLEO
+
+ {Clear Language for Expressing Orders}
+
+CLHEP
+
+ <library> A {C++} {class library} for high energy physics
+ {applications}.
+
+ (1994-12-12)
+
+CLI
+
+ 1. <operating system> {Command Line Interface}.
+
+ 2. <database, standard> {Call-Level Interface}.
+
+CLiCC
+
+ <language> A {Common Lisp} to {C} compiler by Heinz Knutzen
+ <hk@informatik.uni-kiel.de>, Ulrich Hoffman
+ <uho@informatik.uni-kiel.de> and Wolfgang Goerigk
+ <wg@informatik.uni-kiel.de>. CLiCC is meant to be used as a
+ supplement to existing {CLISP} systems for generating
+ {portable} {applications}. Target {C} code must be linked
+ with the CLiCC {run-time library} to produce an {executable}.
+
+ Version 0.6.2 conforms to a subset of {Common Lisp} and {CLOS}
+ called {CL_0} or {CommonLisp_0} and based on {CLtL1}. It runs
+ with {Lucid Lisp}, {AKCL} or {CLISP}. Work on {CLtL2} and
+ {ANSI-CL} conformance is in progress.
+
+ {(ftp://ftp.informatik.uni-kiel.de/pub/kiel/apply/)}.
+
+ (1994-01-04)
+
+click
+
+ <hardware> To press and release a {button} on a {mouse} or
+ other {pointing device}. This generates an {event}, also
+ specifying the screen position, which is processed by the
+ {window manager} or {application program}.
+
+ On a mouse with more than one button, the unqualified term
+ usually implies pressing the left-most button (with the right
+ index finger), other buttons would be qualified,
+ e.g. "{right-click}". Multiple clicks in quick succession,
+ e.g. a double-click, often have a different meaning from slow
+ single clicks. {Keyboard} modifiers may also be used,
+ e.g. "shift-click", meaning to hold down the shift key on the
+ keyboard while clicking the mouse button.
+
+ If the mouse moves while the button is pressed then this is a
+ {drag}.
+
+ (1995-03-14)
+
+client
+
+ <programming> A computer system or process that requests a
+ service of another computer system or process (a "{server}")
+ using some kind of {protocol} and accepts the server's
+ responses. A client is part of a {client-server} software
+ architecture.
+
+ For example, a {workstation} requesting the contents of a file
+ from a {file server} is a client of the file server.
+
+ (1997-10-27)
+
+client-server
+
+ <programming> A common form of {distributed system} in which
+ software is split between {server} tasks and {client} tasks.
+ A client sends requests to a server, according to some
+ {protocol}, asking for information or action, and the server
+ responds.
+
+ This is analogous to a customer (client) who sends an order
+ (request) on an order form to a supplier (server) who
+ despatches the goods and an invoice (response). The order
+ form and invoice are part of the "protocol" used to
+ communicate in this case.
+
+ There may be either one centralised server or several
+ distributed ones. This model allows clients and servers to be
+ placed independently on {nodes} in a {network}, possibly on
+ different {hardware} and {operating systems} appropriate to
+ their function, e.g. fast server/cheap client.
+
+ Examples are the name-server/name-resolver relationship in
+ {DNS}, the file-server/file-client relationship in {NFS} and
+ the screen server/client application split in the {X Window
+ System}.
+
+ {Usenet} newsgroup: {news:comp.client-server}.
+
+ ["The Essential Client/Server Survival Guide", 2nd edition,
+ 1996].
+
+ (1998-01-25)
+
+client/server
+
+ {client-server}
+
+Client-Server Analyst Programmer
+
+ <job> A person who analyses and designs {application programs}
+ for a {client-server architecture}. Typical skills include
+ {ODBC}, {Windows 95}, {Windows NT}, {Macintosh}, {Novell},
+ {OS/2}, {Unix}, and {RPC}.
+
+ (2004-03-09)
+
+client-server model
+
+ {client-server}
+
+Client To Client Protocol
+
+ <networking> (CTCP) A type of {protocol} created to allow
+ structured data such as {font} information to be exchanged
+ between users on {IRC}. It is also used to send a query to a
+ user. The available CTCP commands include VERSION, FINGER,
+ DCC CHAT, DCC SEND, TIME, PING, ECHO, CLIENTINFO. Some
+ commands are not available on some IRC {client} software.
+
+ (1995-04-12)
+
+C++Linda
+
+ <language>
+
+ ["The AUC C++Linda System", C. Callsen et al, U Aalborg, in
+ Linda-Like Systems and Their Implementation, G. Wilson ed, U
+ Edinburgh TR 91-13, 1991].
+
+ (1994-12-12)
+
+C-Linda
+
+ <language> The most widely used variant of {Linda}, with {C}
+ as the base language. It is available from Sci Comp Assocs
+ <linda@sca.com>.
+
+ (1994-12-12)
+
+CLIP
+
+ 1. {Compiler Language for Information Processing}.
+
+ 2. {Common LISP in Parallel}.
+
+CLiP
+
+ <programming, tool> A {documentation} extractor by Eric W. van
+ Ammers that recognises a particular style of {comments}. This
+ style can be adjusted to suit virtually any programming
+ language and target documentation language. CLiP was designed
+ to be compatible with {hypertext} systems.
+
+ Version 2.1 runs on {MS-DOS}, {VAX}/{VMS} and {Unix}
+
+ {(ftp://sun01.info.wau.nl/clip/)}.
+
+ (1993-11-18)
+
+clipboard
+
+ <operating system> A temporary memory area, used to transfer
+ information within a document being edited or between
+ documents or between programs. The fundamental operations are
+ "cut" which moves data from a document to the clipboard,
+ "copy" which copies it to the clipboard, and "paste" which
+ inserts the clipboard contents into the current document in
+ place of the current selection.
+
+ Different {Graphical User Interfaces} vary in how they handle
+ the different types of data which a user might want to
+ transfer via the clipboard, some (e.g. the {X Window System})
+ support only plain text, others (e.g. {NEXTSTEP}) support
+ arbitrarily typed data such as images.
+
+ (1996-08-23)
+
+Clipper
+
+ 1. <hardware, cryptography> An {integrated circuit} which
+ implements the {SkipJack} {algorithm}. The Clipper is
+ manufactured by the US government to encrypt telephone data.
+ It has the added feature that it can be decrypted by the US
+ government, which has tried to make the chip compulsory in the
+ United States. Phil Zimmerman (inventor of {PGP}) remarked,
+ "This doesn't even pass the sniff test" (i.e. it stinks).
+
+ {(http://wired.com/clipper/)}.
+
+ {news:alt.privacy.clipper}
+
+ 2. A compiled {dBASE} dialect from Nantucket Corp, LA.
+ Versions: Winter 85, Spring 86, Autumn 86, Summer 87, 4.5
+ (Japanese Kanji), 5.0. It uses the {Xbase} programming
+ language.
+
+ (2004-09-01)
+
+CLIPS
+
+ {C Language Integrated Production System}
+
+clique
+
+ <mathematics> A {maximal} {totally connected} {subgraph}.
+ Given a {graph} with {nodes} N, a clique C is a {subset} of N
+ where every node in C is directly connected to every other
+ node in C (i.e. C is totally connected), and C contains all
+ such nodes (C is maximal). In other words, a clique contains
+ all, and only, those nodes which are directly connected to all
+ other nodes in the clique.
+
+ [Is this correct?]
+
+ (1996-09-22)
+
+CLISP
+
+ <language>
+
+ 1. {Conversational LISP}.
+
+ 2. A {Common Lisp} implementation by {Bruno Haible
+ (http://haible.de/bruno/)} of {Karlsruhe University} and
+ {Michael Stoll (http://math.uni-duesseldorf.de/~stoll/)}.
+ of {Munich University}, both in Germany. CLISP includes an
+ {interpreter}, {bytecode compiler}, almost all of the {CLOS}
+ {object system}, a {foreign language interface} and a {socket
+ interface}. An {X11} interface is available through {CLX} and
+ {Garnet}. Command line editing is provided by the {GNU}
+ readline library. CLISP requires only 2 MB of {RAM}. The
+ {user interface} comes in German, English, French, Spanish,
+ Dutch, and Russian and can be changed at {run time}.
+
+ CLISP is {Free Software} and distributed under the {GPL}. It
+ runs on {microcomputers} ({OS/2}, {Microsoft Windows},
+ {Amiga}, {Acorn}) as well as on {Unix} workstations ({Linux},
+ {BSD}, {SVR4}, {Sun4}, {Alpha}, {HP-UX}, {NeXTstep}, {SGI},
+ {AIX}, {Sun3}, and others).
+
+ {Official web page (http://clisp.cons.org)}. {Mailing list
+ (http://lists.sourceforge.net/lists/listinfo/clisp-list)}.
+
+ (2003-08-04)
+
+Clive Sinclair
+
+ <person> Sir Clive Sinclair (1939- ) The British inventor who
+ pioneered the home {microcomputer} market in the early 1980s,
+ with the introduction of low-cost, easy to use, {8-bit}
+ computers produced by his company, {Sinclair Research}.
+
+ Sir Clive also invented and produced a variety of electronic
+ devices from the 1960s to 1990s, including pocket calculators
+ (he marketed the first pocket calculator in the world),
+ radios and televisions. Perhaps he is most famous (or some
+ might say notorious) for his range electric vehicles,
+ especially the Sinclair C5, introduced in 1985. He has been a
+ member of MENSA, the high IQ society, since 1962.
+
+ {Planet Sinclair (http://nvg.ntnu.no/sinclair/)}.
+
+ ["The Sinclair Story", Rodney Dale, pub. Duckworth 1985]
+
+ (1998-11-09)
+
+CLIX
+
+ <language> ["Overview of a Parallel Object-Oriented Language
+ CLIX", J. Hur et al, in ECOOP '87, LNCS 276, Springer 1987,
+ pp. 265-273].
+
+ (1994-12-16)
+
+CLM
+
+ {Career Limiting Move}
+
+CLNP
+
+ {ConnectionLess Network Protocol}
+
+clobber
+
+ <jargon> To overwrite, usually unintentionally: "I walked off
+ the end of the array and clobbered the stack."
+
+ Compare {mung}, {scribble}, {trash}, {smash the stack}.
+
+ [{Jargon File}]
+
+ (1994-12-16)
+
+clock
+
+ <processor> A circuit in a {processor} that generates a
+ regular sequence of electronic pulses used to synchronise
+ operations of the processor's components. The time between
+ pulses is the {cycle time} and the number of pulses per second
+ is the {clock rate} (or frequency).
+
+ The execution times of instructions on a computer are usually
+ measured by a number of clock cycles rather than seconds.
+ {Clock rates} for various models of the computer may increase
+ as technology improves, and it is usually the relative times
+ one is interested in when discussing the {instruction set}.
+
+ (1994-12-16)
+
+clock frequency
+
+ {clock rate}
+
+clock rate
+
+ <processor, benchmark> The fundamental rate in {cycles} per
+ second at which a computer performs its most basic operations
+ such as adding two numbers or transfering a value from one
+ {register} to another.
+
+ The clock rate of a computer is normally determined by the
+ frequency of a crystal. The original {IBM PC}, circa 1981,
+ had a clock rate of 4.77 MHz (almost five million
+ cycles/second). As of 1995, {Intel}'s Pentium chip runs at
+ 100 MHz (100 million cycles/second). The clock rate of a
+ computer is only useful for providing comparisons between
+ computer chips in the same {processor family}. An {IBM PC}
+ with an {Intel 486} {CPU} running at 50 MHz will be about
+ twice as fast as one with the same CPU, memory and display
+ running at 25 MHz. However, there are many other factors to
+ consider when comparing different computers. Clock rate
+ should not be used when comparing different computers or
+ different processor families. Rather, some {benchmark} should
+ be used. Clock rate can be very misleading, since the amount
+ of work different computer chips can do in one cycle varies.
+ For example, {RISC} CPUs tend to have simpler instructions
+ than {CISC} CPUs (but higher clock rates) and {pipelined}
+ processors execute more than one instruction per cycle.
+
+ (1995-01-12)
+
+clock speed
+
+ {clock rate}
+
+clone
+
+ <jargon> 1. An exact copy of a product, made legally or
+ illegally, from {documentation} or by {reverse engineering},
+ and usually cheaper.
+
+ E.g. "PC clone": a PC-BUS/{ISA}, {EISA}, {VESA}, or {PCI}
+ compatible {x86}-based {microcomputer} (this use is sometimes
+ misspelled "klone" or "PClone"). These invariably have much more
+ bang per buck than the {IB PCM} they resemble.
+
+ E.g. "Unix clone": An {operating system} designed to deliver a
+ {Unix}-like environment without Unix licence fees or with
+ additional "mission-critical" features such as support for
+ {real-time} programming.
+
+ 2. <chat> A {clonebot}.
+
+ [{Jargon File}]
+
+ (2000-06-15)
+
+clone-and-hack coding
+
+ {case and paste}
+
+clonebot
+
+ <chat> (Or "clone") A {bot} meant to replicate itself en masse
+ on a {talk} network (generally {IRC}). A bot appears on the
+ network as several {agents}, and then carries out some task,
+ typically that of {flood}ing another user.
+
+ Compare {ghost}.
+
+ (1997-04-07)
+
+CLOS
+
+ {Common LISP Object System}
+
+closed-box testing
+
+ {functional testing}
+
+closed set
+
+ <mathematics> A set S is closed under an operator * if x*y is
+ in S for all x, y in S.
+
+ (1994-12-16)
+
+closed term
+
+ <theory> A term with no {free variables}.
+
+ (1994-12-16)
+
+Clos network
+
+ <networking> A type of {network} topology that can connect N
+ inputs to N outputs with less that N^2 crosspoint switches.
+
+ (2006-10-07)
+
+closure
+
+ 1. <programming> In a {reduction system}, a closure is a data
+ structure that holds an expression and an environment of
+ variable bindings in which that expression is to be evaluated.
+ The variables may be local or global. Closures are used to
+ represent unevaluated expressions when implementing
+ {functional programming languages} with {lazy evaluation}. In
+ a real implementation, both expression and environment are
+ represented by pointers.
+
+ A {suspension} is a closure which includes a flag to say
+ whether or not it has been evaluated. The term "{thunk}" has
+ come to be synonymous with "closure" but originated outside
+ {functional programming}.
+
+ 2. <theory> In {domain theory}, given a {partially ordered
+ set}, D and a subset, X of D, the upward closure of X in D is
+ the union over all x in X of the sets of all d in D such that
+ x <= d. Thus the upward closure of X in D contains the
+ elements of X and any greater element of D. A set is "upward
+ closed" if it is the same as its upward closure, i.e. any d
+ greater than an element is also an element. The downward
+ closure (or "left closure") is similar but with d <= x. A
+ downward closed set is one for which any d less than an
+ element is also an element.
+
+ ("<=" is written in {LaTeX} as {\subseteq} and the upward
+ closure of X in D is written \uparrow_\{D} X).
+
+ (1994-12-16)
+
+closure conversion
+
+ <theory> The transformation of {continuation passing style}
+ code so that the only {free variables} of {functions} are
+ names of other functions.
+
+ See also {Lambda lifting}.
+
+ (1994-12-16)
+
+cloud
+
+ {cloud computing}
+
+cloud computing
+
+ <architecture> A loosely defined term for any system providing
+ access via the {Internet} to processing power, storage,
+ software or other computing services, often via a {web
+ browser}. Typically these services will be rented from an
+ external company that hosts and manages them.
+
+ (2009-04-21)
+
+Clover
+
+ <communications, protocol> A {protocoll} similar to {packet
+ radio} or {AMTOR}.
+
+ (1995-03-03)
+
+clover key
+
+ {feature key}
+
+CLP
+
+ 1. {Cornell List Processor}.
+
+ 2. {Constraint Logic Programming}.
+
+CLP*
+
+ <language, logic programming> A derivative of {Constraint
+ Logic Programming} (CLP).
+
+ ["CLP* and Constraint Abstraction", T. Hickey, 16th POPL,
+ pp. 125-133, 1989].
+
+ [Difference?]
+
+ (1994-11-01)
+
+CLP(R)
+
+ <language> Constraint Logic Programming (Real) A {constraint
+ logic programming} language with {real} arithmetic
+ {constraints} developed by Joxan Jaffar <joxan@watson.ibm.com>
+ of {IBM} {TJWRC} and S. Michaylov of {Monash University} in
+ 1986.
+
+ The implementation contains a {byte-code compiler} and a
+ built-in {constraint} solver which deals with {linear
+ arithmetic} and contains a mechanism for delaying {nonlinear}
+ constraints until they become linear. Since CLP(R) is a
+ superset of {PROLOG}, the system is also usable as a
+ general-purpose {logic programming} language. There are also
+ powerful facilities for {meta programming} with constraints.
+
+ Significant CLP(R) applications have been published in diverse
+ areas such as molecular biology, finance and physical
+ modelling.
+
+ Version 1.2 for {Unix}, {MS-DOS} and {OS/2} is available from
+ the authors. It is free for academic and research purposes.
+
+ E-mail: Roland Yap <roland@bruce.cs.monash.edu.au>.
+
+ ["The CLP(R) Language and System", J. Jaffar et al, IBM RR
+ RC16292 (#72336), Nov 1990].
+
+ (1992-10-14)
+
+CLP(sigma*)
+
+ <language> A {constraint logic programming} language with
+ {regular sets}.
+
+ ["CLP(sigma*): Constraint Logic Programming with Regular
+ Sets", C. Walinsky, Proc ICLP, 1989, pp.181-190].
+
+ (1994-12-16)
+
+CLR
+
+ {Consortium for Lexical Research}
+
+CLtL1
+
+ <publication> A report on {Common LISP}:
+
+ ["Common LISP: The Language", Guy L. Steele, Digital Press
+ 1984, ISBN 0-932376-41-X].
+
+ (1994-12-16)
+
+CLtL2
+
+ {Aluminum Book}
+
+CLU
+
+ <language> (CLUster) An {object-oriented} programming language
+ developed at {MIT} by {Liskov} et al in 1974-1975.
+
+ CLU is an {object-oriented} language of the {Pascal} family
+ designed to support {data abstraction}, similar to {Alphard}.
+ It introduced the {iterator}: a {coroutine} yielding the
+ elements of a data object, to be used as the sequence of
+ values in a {for loop}.
+
+ A CLU program consists of separately compilable {procedures},
+ {clusters} and iterators, no nesting. A cluster is a module
+ naming an {abstract type} and its operations, its internal
+ representation and implementation. Clusters and iterators may
+ be generic. Supplying actual constant values for the
+ {parameters} instantiates the {module}.
+
+ There are no {implicit type conversions}. In a cluster, the
+ explicit type conversions 'up' and 'down' change between the
+ abstract type and the representation. There is a universal
+ type 'any', and a procedure force[] to check that an object is
+ a certain type. Objects may be mutable or {immutable}.
+
+ {Exceptions} are raised using 'signal' and handled with
+ 'except'. {Assignment} is by sharing, similar to the sharing
+ of data objects in {Lisp}. Arguments are passed by
+ {call-by-sharing}, similar to {call-by-value}, except that the
+ arguments are objects and can be changed only if they are
+ mutable. CLU has {own variables} and multiple assignment.
+
+ CLU was one of {Kamin's interpreters}. {clu2c} compiled CLU to
+ {C}. {Concurrent CLU} was an extension designed to support
+ parallel proceses.
+
+ ["CLU Reference Manual", Barbara Liskov et al, LNCS 114,
+ Springer 1981].
+
+ E-mail: Paul R. Johnson <prj@pm-prj.lcs.mit.edu>.
+
+ {Versions for Sun and VAX/VMS
+ (ftp://pion.lcs.mit.edu/pub/clu/)}. {Portable version
+ (ftp://mintaka.lcs.mit.edu/pub/dcurtis/)}.
+
+ (1994-12-16)
+
+clu2c
+
+ <tool> A {CLU} to {C} {compiler}.
+
+ {(ftp://ftp.is.titech.ac.jp/pub/clu2c/)}.
+
+ (2000-08-06)
+
+cluster
+
+ 1. <architecture> Multiple {servers} providing the same
+ service. The term may imply {resilience} to failure and/or
+ some kind of {load balancing} between the servers. Compare
+ {RAIS}.
+
+ 2. <file system> An elementary unit of allocation of a {disk}
+ made up of one or more physical {blocks}.
+
+ A {file} is made up of a whole number of possibly
+ non-contiguous clusters. The cluster size is a tradeoff
+ between space efficiency (the bigger is the cluster, the
+ bigger is on the average the wasted space at the end of each
+ file) and the length of the {FAT}.
+
+ (1996-11-04)
+
+Cluster 86
+
+ <language> A {distributed} {object-oriented} language by
+ L. Shang <lshang@inf.ethz.ch> of {Nanjing University},
+ ca. 1986. A cluster is a {metatype}.
+
+ There are versions for {MS-DOS} and {Unix}.
+
+ ["Cluster: An Informal Report", L. Shang, SIGPLAN Notices
+ 26(1):57-76, Jan 1991].
+
+ (1994-12-21)
+
+clustergeeking
+
+ <jargon> /kluh'st*r-gee"king/ ({CMU}) Spending more time at a
+ computer cluster doing CS homework than most people spend
+ breathing.
+
+ [{Jargon File}]
+
+ (1994-12-21)
+
+clustering
+
+ {cluster}
+
+CLUT
+
+ {colour palette}
+
+CLV
+
+ {Constant Linear Velocity}
+
+CLX
+
+ <library, graphics> The {Common Lisp} library providing a
+ low-level interface to the {X Window System}, equivalent to
+ {Xlib}. {Graphics toolkits} can be built on top of CLX,
+ e.g. {McCLIM}, {Garnet}, {CLUE} and {CLIO}. Various LISP
+ implementors have independently ported CLX to their own
+ {platforms}, fixing {bugs} and, in some cases, adding features
+ in the process.
+
+ {CLX Wiki (http://cliki.net/CLX)}.
+
+ (2004-08-27)
+
+CM
+
+ {Configuration Management}
+
+cm
+
+ <networking> The {country code} for Cameroon.
+
+ (1999-01-27)
+
+CMA
+
+ {Concert Multithread Architecture} from {DEC}.
+
+CMAY
+
+ <operating system> A {microkernel}.
+
+ ["A Microkernel for Distributed Applications", R. Bagrodia et
+ al, Proc 5th Intl Conf Distrib Comp Sys IEEE 1985,
+ pp. 140-149].
+
+ (1994-12-21)
+
+CMC
+
+ 1. <messaging> {Computer Mediated Communication}.
+
+ 2. <hardware> {Common Mezzanine Card}.
+
+cmd
+
+ <operating system> The {command interpreter} of {Microsoft
+ Disk Operating System}. cmd.exe appears as the interactive
+ "Command Prompt" window in later versions of {Microsoft
+ Windows} and is also responsible for executing .bat {batch
+ files}.
+
+ (2009-11-30)
+
+CMGA
+
+ 1. <body> {Computer Management Group of Australia}
+
+ 2. <body> {Community of Massive Gaming Agency}.
+
+CMIP
+
+ {Common Management Information Protocol}
+
+CMIS
+
+ {Common Management Information Services}
+
+CML
+
+ 1. A {query language}.
+
+ ["Towards a Knowledge Description Language", A. Borgida et al,
+ in On Knowledge Base Management Systems, J. Mylopoulos et al
+ eds, Springer 1986].
+
+ 2. {Concurrent ML}.
+
+ (1994-12-21)
+
+CMM
+
+ {Capability Maturity Model}
+
+CMOS
+
+ {Complementary Metal Oxide Semiconductor}
+
+CMP
+
+ 1. {cellular multiprocessing}.
+
+ 2. {Container Managed Persistance}.
+
+ 3. {Configuration Management Plan}.
+
+CMS
+
+ <programming> A {code management} system from {DEC}.
+
+ (1994-12-21)
+
+CMS-2
+
+ <language> A general purpose language used for command and
+ control applications in the US Navy. Variants: CMS-2M and
+ CMS-2Y.
+
+ ["CMS-2Y Programmers Reference Manual", M-5049, PDCSSA, San
+ Diego CA, Oct 1976].
+
+ (1994-12-21)
+
+CMU
+
+ {Carnegie Mellon University}
+
+CMU CL
+
+ {CMU Common Lisp}
+
+CMU Common Lisp
+
+ <language> (CMU CL) A {public domain} "industrial strength"
+ {Common Lisp} programming environment. Many of the {X3J13}
+ changes have been incorporated into CMU CL. Wherever
+ possible, this has been done so as to transparently allow use
+ of either {CLtL1} or proposed {ANSI CL}. Probably the new
+ features most interesting to users are {SETF} functions,
+ {LOOP} and the {WITH-COMPILATION-UNIT} {macro}.
+
+ The new CMU CL compiler is called {Python}.
+
+ Version 17c includes an {incremental compiler}, profiler,
+ run-time support, documentation, an editor and a debugger. It
+ runs under {Mach} on {SPARC}, {MIPS} and {IBM PC RT} and under
+ {SunOS} on {SPARC}.
+
+ {(ftp://lisp-sun1.slisp.cs.cmu.edu/pub/)}.
+
+ E-mail: <slisp@cs.cmu.edu>.
+
+ (1993-11-18)
+
+CMVC
+
+ {Configuration Management Version Control} from {IBM}.
+
+CMYK
+
+ <graphics> cyan, magenta, yellow, key.
+
+ A {colour model} that describes each {colour} in terms of the
+ quantity of each secondary colour (cyan, magenta, yellow), and
+ "key" (black) it contains. The CMYK system is used for
+ printing. For mixing of pigments, it is better to use the
+ secondary colours, since they mix subtractively instead of
+ additively. The secondary colours of light are cyan, magenta
+ and yellow, which correspond to the primary colours of pigment
+ (blue, red and yellow). In addition, although black could be
+ obtained by mixing these three in equal proportions, in
+ four-colour printing it always has its own ink. This gives
+ the CMYK model. The K stands for "Key' or 'blacK,' so as not
+ to cause confusion with the B in {RGB}.
+
+ Alternative colour models are {RGB} and {HSB}.
+
+ (1994-12-22)
+
+CMZ
+
+ <programming> A {portable} {interactive} {code management}
+ system from {CodeME} S.A.R.L in use in the high-energy physics
+ community.
+
+ (1994-12-22)
+
+cn
+
+ <networking> The {country code} for China.
+
+ (1999-01-27)
+
+CNAME
+
+ <networking> The {canonical name} query type for {Domain Name
+ System}. This query asks a DNS {server} for a {host}'s
+ official {hostname}.
+
+ (1994-12-22)
+
+CNC
+
+ {Collaborative Networked Communication}
+
+CNET
+
+ <body> Centre national d'Etudes des Telecommunications. The
+ French national telecommunications research centre at Lannion.
+
+ (1994-12-22)
+
+CNI
+
+ {Coalition for Networked Information}
+
+CNN
+
+ <architecture> {Cellular Neural Network}.
+
+CNR
+
+ {Communication and Network Riser}
+
+CNRI
+
+ {Corporation for National Research Initiatives}
+
+co
+
+ <networking> The {country code} for Colombia.
+
+ (1999-01-27)
+
+CO2
+
+ <language, database> An {object-oriented} {database} language
+ combining {C} and {O2}, from GIP Altair, Versailles, France.
+
+ [Francois Bancilon et al, in Advances in Object-Oriented
+ Database Systems, K.R. Dittrich ed, LNCS 334, Springer 1988].
+
+ (1994-12-22)
+
+Coad/Yourdon
+
+ <programming> An {object-oriented analysis} and design
+ {methodology}, developed by {edward Yourdon} and Peter Coad.
+
+ (1995-04-07)
+
+COALA
+
+ <language>
+
+ ["COALA: The Object Code of the Compiler Producing System", S.
+ Kruszewski et al, MERA, Warsaw 1974].
+
+ (1994-12-22)
+
+coalesced sum
+
+ <theory> (Or "smash sum") In {domain theory}, the coalesced
+ sum of {domains} A and B, A (+) B, contains all the
+ non-{bottom} elements of both domains, tagged to show which
+ part of the sum they come from, and a new {bottom} element.
+
+ D (+) E = { bottom(D(+)E) }
+ U { (0,d) | d in D, d /= bottom(D) }
+ U { (1,e) | e in E, e /= bottom(E) }
+
+ The bottoms of the constituent domains are coalesced into a
+ single bottom in the sum. This may be generalised to any
+ number of domains.
+
+ The ordering is
+
+ bottom(D(+)E) <= v For all v in D(+)E
+
+ (i,v1) <= (j,v2) iff i = j & v1 <= v2
+
+ "<=" is usually written as {LaTeX} \sqsubseteq and "(+)" as
+ {LaTeX} \oplus - a "+" in a circle.
+
+ (1994-12-22)
+
+Coalition for Networked Information
+
+ <body> (CNI) A consortium formed by American Research
+ Libraries, {CAUSE} and {EDUCOM} to promote the creation of,
+ and access to, information resources in networked environments
+ in order to enrich scholarship and enhance intellectual
+ productivity.
+
+ (1994-12-22)
+
+coarse grain
+
+ {granularity}
+
+COAST
+
+ {Cache On A STick}
+
+coax
+
+ {coaxial cable}
+
+coaxial cable
+
+ <hardware> A kind of cable with a solid central conductor
+ surrounded by insulator, in turn surrounded by a cylindrical
+ shield woven from fine wires. It is used to carry high
+ frequency signals such as {video} or {radio}. The shield is
+ usually connected to electrical ground to reduce electrical
+ interference.
+
+ (1995-03-28)
+
+COBOL
+
+ {COmmon Business Oriented Language}
+
+COBOL-1961 Extended
+
+ <language> A short-lived separation of {COBOL} specifications.
+
+ [Sammet 1969, p. 339].
+
+ (1994-10-28)
+
+COBOL fingers
+
+ <jargon> /koh'bol fing'grz/ Reported from Sweden, a
+ hypothetical disease one might get from coding in {COBOL}.
+ The language requires code verbose beyond all reason (see
+ {candygrammar}); thus it is alleged that programming too much
+ in COBOL causes one's fingers to wear down to stubs by the
+ endless typing.
+
+ [{Jargon File}]
+
+ (1994-12-22)
+
+COBRA
+
+ <spelling> Do you mean {CORBA}? Or is there a COBRA?
+
+ (1996-05-10)
+
+cobwebsite
+
+ <jargon, web> A {website} that hasn't been updated for
+ a long time. A dead {web page}.
+
+ (1997-04-29)
+
+Cocktail
+
+ {GMD Toolbox for Compiler Construction}
+
+cocktail shaker sort
+
+ <algorithm> A bi-directional {bubble sort}. Passes alternate
+ between ascending through array indexes, pushing the largest
+ item to the bottom; and descending through array indexes,
+ pushing the smallest item to the top.
+
+ [Performace vs plain bubble?]
+
+ (2001-03-26)
+
+CoCo
+
+ <computer> The {Tandy} Color Computer with a Motorola
+ {MC6809E} {CPU}. The {Dragon} is a CoCo clone. The CoCo was
+ as powerful as the {IBM XT} at the time it was made, and could
+ run {OS-9}.
+
+ (1997-02-12)
+
+Cocol
+
+ {Coco Language}
+
+Coco Language
+
+ <language> (Cocol) A language for writing left-attributed {LL1
+ grammars}, used as the input language for the {Coco} LL1
+ {parser generator}, which produces {Modula-2 table-driven
+ parsers} as output.
+
+ Cocol-2 is a version for the Coco-2 generator. {Cocol/R} is
+ an improvement over the original Cocol and Cocol-2.
+
+ {(ftp://neptune.inf.ethz.ch/)}.
+
+ ["A Compiler Generator for Microcomputers", P. Rechenberg et
+ al, P-H 1989].
+
+ (1997-12-09)
+
+Cocol/R
+
+ <language> (Coco Language) A language for writing
+ left-attributed {LL1 grammars}, used as the input language for
+ the {Coco/R} LL1 {parser generators}, which produce {C++},
+ {Pascal}, {Modula-2}, {Java} or {Oberon} {recursive-descent
+ parsers} and associated {scanners} as output.
+
+ Cocol/R is an improvement over the original {Cocol} and
+ Cocol-2.
+
+ [Moessenboeck, H., "A Generator for Fast Compiler Front-Ends",
+ Report 127, Dept. Informatik, ETH Zurich, 1990].
+
+ (1997-12-09)
+
+COCOMO
+
+ {Constructive Cost Model}
+
+Coco/R
+
+ <tool> A program by Hanspeter Moessenboeck
+ <moessenboeck@ssw.uni-linz.ac.at> which generates {recursive
+ descent parsers} and their associated {scanners} from
+ {attributed grammars} (LL1). Coco/R can {bootstrap} itself to
+ generate its own driver, {parser}, scanner and {semantic
+ evaluator} from an attributed grammar included in the
+ distribution.
+
+ Versions exist for generating {Oberon}, {Modula-2}, {Pascal},
+ {C}, and {C++} source for {MS-DOS} and {Unix}. A {Java}
+ implementation was planned.
+
+ Latest version: 1.34, as gf 1994-10-13.
+
+ Coco/R was ported to {Modula-2} by Marc Brandis, Christof
+ Brass, and Pat Terry.
+
+ {(ftp://ftp.ssw.uni-linz.ac.at/pub/Coco)}.
+
+ Mail server: <server@ftp.psg.com> (Subject: send
+ pub/modula-2/coco/).
+
+ E-mail: Pat Terry <p.terry@ru.ac.za> (Modula/Pascal versions),
+ Hanspeter Moessenboeck <moessenboeck@ssw.uni-linz.ac.at>
+ (Oberon, Java versions), Frankie Arzu <farzu@uvg.edu.gt> (C,
+ C++ versions).
+
+ ["A compiler generator for microcomputers", by Rechenberg and
+ Mossenbock, Prentice Hall, 1989, 0-13-155136-1].
+
+ [Moessenboeck, H., "A Generator for Fast Compiler Front-Ends",
+ Report 127, Dept. Informatik, ETH Zurich, 1990].
+
+ [Terry, P.D., "Compilers and Compiler Generators: An
+ Introduction with C++", ITCP: ISBN 1-85032-298-8].
+
+ (1997-12-09)
+
+CODASYL
+
+ {Conference On DAta SYstems Languages}
+
+Codd's First Normal Form
+
+ {database normalisation}
+
+Codd's reduction algorithm
+
+ <database> An {algorithm} to convert an arbitrary expression
+ of the {relational calculus} to an equivalent expression of
+ the {relational algebra}. This can be used as the basis of an
+ implementation of the relational calculus.
+
+ (1998-10-05)
+
+code
+
+ 1. <software> Instructions for a computer in some programming
+ language, often {machine language} (machine code).
+
+ The word "code" is often used to distinguish instructions from
+ {data} (e.g. "The code is marked 'read-only'") whereas the
+ word "{software}" is used in contrast with "{hardware}" and
+ may consist of more than just code.
+
+ (2000-04-08)
+
+ 2. <cryptography> Some method of {encryption} or the resulting
+ encrypted message.
+
+ (2006-11-10)
+
+Code 2.0
+
+ <language> A {coarse-grain} {dataflow} language with a graphical
+ interface for users to draw communication structure.
+
+ {(http://cs.utexas.edu/users/code)}.
+
+ E-mail: Emery Berger <emery@cs.utexas.edu>.
+
+ ["The CODE 2.0 Parallel Programming Language", P. Newton et
+ al, Proc ACM Intl Conf on Supercomput, Jul 1992].
+
+ (1996-01-13)
+
+codebook
+
+ {data dictionary}
+
+CODEC
+
+ {coder/decoder}
+
+CodeCenter
+
+ <programming> (Formerly {Saber-C}) A proprietary {software
+ development environment} for {C} programs, offering an
+ integrated toolkit for developing, testing, debugging and
+ maintainance.
+
+ (1994-12-23)
+
+coded character set
+
+ <character, standard> A mapping, generally 1:1, from a set of
+ {integers}, known as {character codes} or {code positions}, to
+ a set of {characters} that may include letters, digits,
+ punctuation, {control codes}, mathematical and typographic
+ symbols.
+
+ There are several {standard} coded character sets, the most
+ widely used is {ASCII}, generally in its {Latin-1} dialect,
+ with {Unicode} becoming slowly more common; while {EBCDIC} and
+ {Baudot} are extinct except in {legacy systems}.
+
+ (2009-01-06)
+
+Code Division Multiple Access
+
+ <communications> (CDMA) (Or "spread spectrum") A form of
+ {multiplexing} where the transmitter encodes the signal using
+ a {pseudorandom} sequence which the receiver also knows and
+ can use to decode the received signal. Each different random
+ sequence corresponds to a different communication channel.
+
+ {Motorola} uses CDMA for digital cellular phones. Qualcomm
+ pioneered the introduction of CDMA into wireless telephone
+ services.
+
+ (2001-03-28)
+
+code division multiplexing
+
+ {Code Division Multiple Access}
+
+Code-Generator Generator Language
+
+ <language> ("seagull") (CGGL) A {machine description language}
+ based on modelling the computer as a {finite-state machine}.
+
+ ["A Code Generator Generator Language", M.K. Donegan et al,
+ SIGPLAN Notices 14(8):58-64, Aug 1979].
+
+ (1994-10-24)
+
+code grinder
+
+ <jargon, abuse> A {suit}-wearing minion of the sort hired in
+ legion strength by banks and insurance companies in the {Real
+ World} to implement payroll packages in {RPG} and other such
+ unspeakable horrors. In its native habitat, the code grinder
+ often removes the suit jacket to reveal an underplumage
+ consisting of button-down shirt (starch optional) and a tie.
+ In times of dire stress, the sleeves (if long) may be rolled
+ up and the tie loosened about half an inch. It seldom helps.
+ The {code grinder}'s milieu is about as far from hackerdom as
+ one can get and still touch a computer; the term connotes
+ pity.
+
+ Used of or to a {hacker}, this term is a really serious slur
+ on the person's creative ability; it connotes a design style
+ characterised by primitive technique, rule-boundedness, {brute
+ force} and utter lack of imagination.
+
+ Compare {card walloper}. Contrast {real programmer}.
+
+ [{Jargon File}]
+
+ (1994-11-11)
+
+code management
+
+ {source code management}
+
+code police
+
+ <humour> (By analogy with George Orwell's "Thought Police" in
+ "1984") A mythical team of Gestapo-like storm troopers that
+ enforce programming style rules. Used ironically, to suggest
+ that the practice under discussion is condemned mainly by
+ anal-retentive {weenies}. "Dike out that {goto} or the code
+ police will get you!" The ironic usage is perhaps more
+ common.
+
+ [{Jargon File}]
+
+ (1994-12-08)
+
+code position
+
+ <character> An {integer} that a {coded character set} maps to
+ a {character}. A code position is normally stored or
+ transmitted by applying a {character encoding} to turn it into
+ a {byte string}.
+
+ (2002-03-03)
+
+coder/decoder
+
+ <communications> (CODEC) An electronic device or component
+ combining the circuits needed to convert digital signals to
+ and from analog ({Pulse Code Modulation}) form.
+
+ (1997-07-22)
+
+codes
+
+ 1. <jargon> Programs. This usage is common among scientific
+ computing people who use {supercumputers} for heavy-duty
+ {number crunching}.
+
+ 2. <cryptography> Something to do with {cryptography}.
+
+ [{Jargon File}]
+
+ (1994-10-28)
+
+C-odeScript
+
+ <language> A {Liana} interpreter, embeddable in {C} and {C++}
+ programs.
+
+ (1995-03-09)
+
+code segment
+
+ <memory> ({Intel 8086} CS) The area of memory containing the
+ {machine code} instructions of a {program}. The code segment
+ of a program may be shared between multiple processes running
+ that code so long as none of them tries to modify it.
+
+ {Unix}, confusingly, calls this the "text segment" and the
+ area for uninitialied data, the {bss segment}.
+
+ Initialised data is located in the {data segment}.
+
+ (1996-12-21)
+
+code walk
+
+ <programming> Stepping through {source code} as part of a
+ {code review}.
+
+ Where a code walk probably only follows the potential {control
+ flow} of a program, a {dry run} is a more detailed manual
+ execution of a program that also keeps track of the value of
+ every {variable} involved.
+
+ (2006-11-27)
+
+codewalker
+
+ <programming, tool> A program component that analyses other
+ programs. {Compilers} have codewalkers in their front ends;
+ so do {cross-reference generators} and some database front
+ ends. Other utility programs that try to do too much with
+ source code may turn into codewalkers. As in "This new
+ 'vgrind' feature would require a codewalker to implement."
+
+ [{Jargon File}]
+
+ (1994-12-23)
+
+CODIL
+
+ {COntext Dependent Information Language}
+
+codomain
+
+ <theory> The set of values or {type} containing all possible
+ results of a {function}. The codomain of a function f of type
+ D -> C is C. A function's {image} is a subset of its
+ codomain.
+
+ (1994-12-23)
+
+coercion
+
+ {implicit type conversion}
+
+COFF
+
+ {Common Object File Format}
+
+COGENT
+
+ {COmpiler and GENeralized Translator}
+
+Cogent Prolog
+
+ <language> A full {Edinburgh standard Prolog} with {debugger},
+ {listener}, {DCG}, many {built-ins}, text windows, support for
+ {modules}, and support for both 16-bit and 32-bit {protected
+ mode}.
+
+ Contact: Dennis C. Merritt.
+
+ (1999-11-24)
+
+Cognitech
+
+ <company> A French software company specialising in
+ {artificial intelligence}.
+
+ (1995-01-04)
+
+cognitive architecture
+
+ <architecture> A computer architecure involving
+ {non-deterministic}, multiple {inference} processes, as found
+ in {neural networks}. Cognitive architectures model the human
+ brain and contrast with single processor computers.
+
+ The term might also refer to software architectures,
+ e.g. {fuzzy logic}.
+
+ [Origin? Better definition? Reference?]
+
+ (1995-11-29)
+
+COGO
+
+ <application> A subsystem of {ICES} aimed at {coordinate geometry}
+ problems in civil engineering.
+
+ ["Engineer's Guide to ICES COGO I", R67-46, CE Dept MIT, Aug
+ 1967].
+
+ (1995-01-04)
+
+Coherent Parallel C
+
+ <language> A {data parallel} version of {C}.
+
+ ["Coherent Parallel C", E. Felten et al in Third Conf on
+ Hypercube Concurrent Computers and Appls, ACM, 1988,
+ pp. 440-450].
+
+ (1995-01-04)
+
+COHESION
+
+ <programming> {DEC}'s {CASE} environment.
+
+ [Details?].
+
+ (1995-01-04)
+
+COIF
+
+ <language> {Fortran} with {interactive} graphic extensions for
+ {circuit design}, on {UNIVAC 1108}.
+
+ ["An Interactive Software System for Computer-Aided Design: An
+ Application to Circuit Projects", CACM 9(13), Sep 1970].
+
+ (1995-01-04)
+
+CoIP
+
+ {Conferencing over IP}
+
+cokebottle
+
+ <character, humour> /kohk'bot-l/ Any unusual character,
+ particularly one you can't type because it isn't on your
+ keyboard. {MIT} people used to complain about the
+ "control-meta-cokebottle" commands at {SAIL}, and {SAIL}
+ people complained about the "{altmode}-altmode-cokebottle"
+ commands at {MIT}. After the demise of the {space-cadet
+ keyboard}, "cokebottle" was used less, but was often used to
+ describe weird or non-intuitive keystrokes.
+
+ The {OSF}/{Motif} {window manager}, "{mwm}" keystroke for
+ switching to the default keybindings and behaviour is
+ control-meta-{bang}. Since {exclamation mark} might be
+ thought to look like a Coke bottle, {Motif} hackers referred
+ to this keystroke as "cokebottle".
+
+ See also {quadruple bucky}.
+
+ [{Jargon File}]
+
+ (1995-01-04)
+
+COLASL
+
+ <mathematics, application> An early system for numerical
+ problems on the {IBM 7030}. It used a special {character set}
+ for input of natural mathematical expressions.
+
+ [Sammet 1969, pp. 265-271].
+
+ (1995-01-04)
+
+COLD
+
+ 1. <language> A {sugar}ed version of {COLD-K}.
+
+ 2. <storage> Computer Output to Laser Disk - see {Enterprise
+ Report Management}.
+
+ (2007-07-24)
+
+cold boot
+
+ <operating system> A {boot} from {power off}.
+
+ Contrast {warm boot}.
+
+ [{Jargon File}]
+
+ (1995-11-27)
+
+ColdFusion
+
+ <web, database, tool> {Allaire Corporation}'s commercial
+ {database} application development tool that allows {databases} to
+ have a {web interface}, so a database can be queried and updated
+ using a {web browser}.
+
+ The ColdFusion Server application runs on the {web server} and
+ has access to a {database}. ColdFusion files on the web
+ server are {HTML} pages with additional ColdFusion commands to
+ {query} or {update} the database, written in {CFML}. When the
+ page is requested by the user, the {web server} passes the
+ page to the Cold Fusion application, which executes the {CFML}
+ commands, places the results of the {CFML} commands in the
+ {HTML} file, and returns the page to the {web server}. The
+ page returned to the {web server} is now an ordinary {HTML}
+ file, and it is sent to the user.
+
+ Examples of ColdFusion applications include order entry, event
+ registration, catalogue search, directories, calendars, and
+ interactive training. ColdFusion applications are robust
+ because all database interactions are encapsulated in a single
+ industrial-strength {CGI} script. The formatting and
+ presentation can be modified and revised at any time (as
+ opposed to having to edit and recompile {source code}).
+
+ ColdFusion Server can connect with any database that supports
+ {ODBC} or {OLE DB} or one that has a native database driver.
+ Native database drivers are available for {Oracle} and
+ {Sybase} databases.
+
+ ColdFusion is available for {Windows}, {Solaris}, and {HP-UX}.
+ A {development environment} for creating ColdFusion files,
+ called ColdFusion Studio, is also available for {Windows}.
+
+ Latest version: MX(6), as of 2003-07-11.
+
+ The {filename extension} for ColdFusion files is .cfm
+
+ {(http://coldfusion.com/)}.
+
+ (2003-07-27)
+
+ColdFusion Markup Language
+
+ <language, web> (CFML) A {tag} based {markup}
+ language used to create {ColdFusion} {web applications} by
+ embedding ColdFusion commands in {HTML} files.
+
+ (1999-08-01)
+
+COLD-K
+
+ <language> A formal design {kernel language} for describing
+ (sequential) software systems in intermediate stages of their
+ design.
+
+ ["An Introduction to COLD-K", H.B.M. Jonkers in Algebraic
+ Methods: Theory, Tools and Applications, M. Wirsing et al eds,
+ LNCS 394, Springer 1989, pp. 139-205].
+
+ (1995-01-04)
+
+COLINGO
+
+ <language> Compile On-LINe and GO. An english-like {query}
+ system from {MITRE Corporation} for the {IBM 1401}.
+
+ ["The COLINGO System Design Philosophy", Information System
+ Sciences, Proc Second Congress, 1965].
+
+ [Sammet 1969, p. 664].
+
+ (1995-01-04)
+
+collision
+
+ 1. <networking> When two {hosts} transmit on a {network} at
+ once causing their {packets} to corrupt each other.
+
+ See {collision detection}.
+
+ 2. <programming> {hash collision}.
+
+ (1995-01-06)
+
+collision detection
+
+ <networking> A class of methods for sharing a data
+ transmission medium in which {hosts} transmit as soon as they
+ have data to send and then check to see whether their
+ transmission has suffered a {collision} with another host's.
+
+ If a collision is detected then the data must be resent. The
+ resending algorithm should try to minimise the chance that two
+ hosts's data will repeatedly collide. For example, the
+ {CSMA/CD} protocol used on {Ethernet} specifies that they
+ should then wait for a random time before re-transmitting.
+
+ See also {backoff}.
+
+ This contrasts with {slotted protocols} and {token passing}.
+
+ (1997-03-18)
+
+collocation
+
+ {co-location}
+
+co-location
+
+ <networking> /koh'loh-kay`sh*n/ or /koh`loh-kay'sh*n/ (Or
+ "colocation") Providing network connections such as {Internet}
+ {leased lines} to several {servers} housed together in a
+ {server room}. This is typically provided as a commercial
+ service.
+
+ The hyphenated form is correct and the most common on the web,
+ followed by "colocation". "collocation" (/ko`loh-kay'sh*n/,
+ not /koh'-/), is an old word with a similar meaning. It is
+ common in dictionaries and follows the pattern of other
+ Latin-derived words like collect, college, and collate, but is
+ least common on the web.
+
+ The verbal form is "to colocate" or "co-locate" (commonly
+ /koh'loh`kayt/, also (US) /koh`loh'kayt/).
+
+ (2000-10-03)
+
+colon
+
+ <character> ":" {ASCII} character 58. Common names: {ITU-T}:
+ colon. Rare: dots; {INTERCAL}: two-spot.
+
+ (1995-09-25)
+
+color
+
+ {colour}
+
+Color Graphics Adapter
+
+ <hardware, graphics> (CGA) One of {IBM}'s earliest hardware
+ video {display standards} for use in {IBM PCs}. CGA can
+ display 80*25 or 40*25 text in 16 colors, 640*200 {pixels} of
+ graphics in two colors or 320*200 in four colors (IBM PC video
+ modes 0-6). It is now obsolete.
+
+ (1995-11-11)
+
+color model
+
+ {colour model}
+
+Colossus
+
+ (A huge and ancient statue on the Greek island of Rhodes).
+
+ 1. <computer> The Colossus and Colossus Mark II computers used
+ by {Alan Turing} at {Bletchley Park}, UK during the Second
+ World War to crack the "Tunny" cipher produced by the Lorenz
+ SZ 40 and SZ 42 machines. Colossus was a semi-fixed-program
+ {vacuum tube} calculator (unlike its near-contemporary, the
+ freely programmable {Z3}).
+
+ ["Breaking the enemy's code", Glenn Zorpette, IEEE Spectrum,
+ September 1987, pp. 47-51.]
+
+ 2. The computer in the 1970 film, "Colossus: The Forbin
+ Project". Forbin is the designer of a computer that will run
+ all of America's nuclear defences. Shortly after being turned
+ on, it detects the existence of Goliath, the Soviet
+ counterpart, previously unknown to US Planners. Both
+ computers insist that they be linked, whereupon the two become
+ a new super computer and threaten the world with the immediate
+ launch of nuclear weapons if they are detached. Colossus
+ begins to give its plans for the management of the world under
+ its guidance. Forbin and the other scientists form a
+ technological resistance to Colossus which must operate
+ underground.
+
+ {The Internet Movie Database
+ (http://www.imdb.com/title/tt0064177)}.
+
+ (2007-01-04)
+
+colour
+
+ <graphics> (US "color") Colours are usually represented as
+ {RGB} triples in a {digital} {image} because this corresponds
+ most closely to the electronic signals needed to drive a
+ {CRT}. Several equivalent systems ("{colour models}") exist,
+ e.g. {HSB}. A colour {image} may be stored as three separate
+ images, one for each of red, green, and blue, or each {pixel}
+ may encode the colour using separate {bit-fields} for each
+ colour component, or each pixel may store a logical colour
+ number which is looked up in a hardware {colour palette} to
+ find the colour to display.
+
+ Printers may use the {CMYK} or {Pantone} representations of
+ colours as well as RGB.
+
+ (1999-08-02)
+
+colour depth
+
+ {bits per pixel}
+
+colour look-up table
+
+ {colour palette}
+
+colour model
+
+ <graphics> Any system for representing {colours} as {ordered
+ sets} of numbers. The most common colour models are {RGB},
+ {CMYK}, and {HSB}. There are several others, e.g. {CMY}, and
+ the "Lab" system(?).
+
+ See also: {Pantone}.
+
+ (1999-10-21)
+
+colour palette
+
+ <graphics, hardware> (colour look-up table, CLUT) A device
+ which converts the {logical} colour numbers stored in each
+ {pixel} of {video} memory into {physical} colours, normally
+ represented as {RGB} triplets, that can be displayed on the
+ {monitor}. The palette is simply a block of fast {RAM} which
+ is addressed by the logical colour and whose output is split
+ into the red, green and blue levels which drive the actual
+ display (e.g. {CRT}).
+
+ The number of entries (logical colours) in the palette is the
+ total number of colours which can appear on screen
+ simultaneously. The width of each entry determines the number
+ of colours which the palette can be set to produce.
+
+ A common example would be a palette of 256 colours
+ (i.e. addressed by eight-bit pixel values) where each colour
+ can be chosen from a total of 16.7 million colours (i.e. eight
+ bits output for each of red, green and blue).
+
+ Changes to the palette affect the whole screen at once and can
+ be used to produce special effects which would be much slower
+ to produce by updating pixels.
+
+ (1997-06-03)
+
+Columbia AppleTalk Package
+
+ <networking> (CAP) An implementation of {Apple Computer}'s
+ {AppleTalk} {protocols} for {Unix} {4.2BSD} and its
+ derivatives, from {Columbia University}. There are two
+ different {LAP} delivery mechanisms for: {IPTalk} and
+ {Ethertalk} (possibly using {UAB}).
+
+ CAP supports the following {AppleTalk} {protocols}: {AppleTalk
+ Transaction Protocol} (ATP), {Name Binding Protocol} (NBP),
+ {Printer Access Protocol} (PAP), {AppleTalk Session Protocol}
+ (ASP), {AppleTalk Filing Protocol} (AFP) client side. In
+ addition, the {Datagram Delivery Protocol} (DDP) and {Zone
+ Information Protocol} (ZIP) are partially available. The
+ structure of the {Internet Appletalk Bridge} software makes it
+ impossible to provide full DDP service. Only the Get Zone
+ List ATP ZIP command is implemented for ZIP.
+
+ (1995-01-10)
+
+column
+
+ 1. <database> A named slice through a {database} {table} that
+ includes the same field of each {row}. For example, a
+ telephone directory table might have a row for each person
+ with a name column and a telephone number column.
+
+ 2. <storage> A line of memory cells in a {dynamic
+ random-access memory}, that is selected by a particular column
+ address.
+
+ (2007-10-12)
+
+Column Address Strobe
+
+ <hardware> (CAS) A signal sent from a processor (or {memory
+ controller}) to a {dynamic random-access memory} (DRAM) (qv)
+ circuit to indicate that the column {address lines} are valid.
+
+ (1996-10-17)
+
+COM
+
+ 1. <programming> {Component Object Model}.
+
+ 2. <storage> Computer Output on Microfilm - see {Enterprise
+ Report Management}.
+
+com
+
+ <networking> (.com, "commercial") The {top-level domain}
+ originally for American companies but, since the explosion of
+ the {web}, used by most companies and for {vanity
+ domains} of all types, whether in the US or not, often in
+ addition to {country code} domains like amazon.co.uk.
+
+ The term "dot com" is now widely used to refer to any Internet
+ business as in "My dot com turned into a dot bomb".
+
+ (2007-02-18)
+
+.com
+
+ {com}
+
+COMAL
+
+ {COMmon Algorithmic Language}
+
+combination
+
+ 1. <mathematics> A {set} containing a certain number of
+ objects selected from another set.
+
+ The number of combinations of r objects chosen from a set of n
+ is
+
+ n C r = n! / ((n-r)! r!)
+
+ where "n C r" is normally with n and r as subscripts or as n
+ above r in parentheses.
+
+ See also {permutation}.
+
+ 2. <reduction> In the theory of {combinators}, a combination
+ denotes an expression in which {function application} is the
+ only operation.
+
+ (1995-04-10)
+
+combinator
+
+ <theory> A function with no {free variables}. A term is
+ either a constant, a variable or of the form A B denoting the
+ {application} of term A (a function of one argument) to term
+ B. {Juxtaposition} associates to the left in the absence of
+ parentheses. All combinators can be defined from two basic
+ combinators - S and K. These two and a third, I, are defined
+ thus:
+
+ S f g x = f x (g x)
+ K x y = x
+ I x = x = S K K x
+
+ There is a simple translation between {combinatory logic} and
+ {lambda-calculus}. The size of equivalent expressions in the
+ two languages are of the same order.
+
+ Other combinators were added by {David Turner} in 1979 when he
+ used combinators to implement {SASL}:
+
+ B f g x = f (g x)
+ C f g x = f x g
+ S' c f g x = c (f x) (g x)
+ B* c f g x = c (f (g x))
+ C' c f g x = c (f x) g
+
+ See {fixed point combinator}, {curried function},
+ {supercombinators}.
+
+ (2002-11-03)
+
+combinatory logic
+
+ <logic> A system for reducing the operational notation of
+ {logic}, mathematics or a {functional language} to a sequence
+ of modifications to the input data structure. First
+ introduced in the 1920's by {Schoenfinkel}. Re-introduced
+ independently by {Haskell Curry} in the late 1920's (who
+ quickly learned of Schoenfinkel's work after he had the idea).
+ Curry is really responsible for most of the development, at
+ least up until work with Feys in 1958.
+
+ See {combinator}.
+
+ (1995-01-05)
+
+Comdex
+
+ <business> A computer show that is held twice yearly, once in
+ the spring (in Atlanta) and once in autumn (in Las Vegas).
+ Comdex is a major show during which new releases of software
+ and hardware are made. {Microsoft}, for example, often
+ annouces its products at Comdex.
+
+ (1995-01-11)
+
+COME FROM
+
+ <programming, humour> A semi-mythical language construct dual
+ to the "go to"; "COME FROM" <label> would cause the referenced
+ label to act as a sort of {trapdoor}, so that if the program
+ ever reached it, control would quietly and {automagically} be
+ transferred to the statement following the "COME FROM".
+
+ "COME FROM" was first proposed in R.L. Clark's "A Linguistic
+ Contribution to GOTO-less programming", which appeared in a
+ 1973 {Datamation} issue (and was reprinted in the April 1984
+ issue of "{Communications of the ACM}"). This parodied the
+ then-raging "{structured programming}" {holy wars} (see
+ {considered harmful}).
+
+ Mythically, some variants are the "assigned COME FROM" and the
+ "computed COME FROM" (parodying some nasty control constructs
+ in {Fortran} and some extended {BASICs}). Of course,
+ {multitasking} (or {nondeterminism}) could be implemented by
+ having more than one "COME FROM" statement coming from the
+ same label.
+
+ In some ways the {Fortran} "DO" looks like a "COME FROM"
+ statement. After the terminating statement number/"CONTINUE"
+ is reached, control continues at the statement following the
+ DO. Some generous Fortrans would allow arbitrary statements
+ (other than "CONTINUE") for the statement, leading to examples
+ like:
+
+ DO 10 I=1,LIMIT
+ C imagine many lines of code here, leaving the
+ C original DO statement lost in the spaghetti...
+ WRITE(6,10) I,FROB(I)
+ 10 FORMAT(1X,I5,G10.4)
+
+ in which the trapdoor is just after the statement labelled 10.
+ (This is particularly surprising because the label doesn't
+ appear to have anything to do with the flow of control at
+ all!)
+
+ While sufficiently astonishing to the unsuspecting reader,
+ this form of "COME FROM" statement isn't completely general.
+ After all, control will eventually pass to the following
+ statement. The implementation of the general form was left to
+ {Univac Fortran}, ca. 1975 (though a roughly similar feature
+ existed on the {IBM 7040} ten years earlier). The statement
+ "AT 100" would perform a "COME FROM 100". It was intended
+ strictly as a debugging aid, with dire consequences promised
+ to anyone so deranged as to use it in production code. More
+ horrible things had already been perpetrated in production
+ languages, however; doubters need only contemplate the
+ "{ALTER}" verb in {COBOL}.
+
+ {SCL} on {VME} {mainframes} has a similar language construct
+ called "whenever", used like this:
+
+ whenever x=123345 then S;
+
+ Meaning whenever variable x reached the value 123345 then
+ execute statement S.
+
+ "COME FROM" was supported under its own name for the first
+ time 15 years later, in {C-INTERCAL} (see {INTERCAL},
+ {retrocomputing}); knowledgeable observers are still reeling
+ from the shock.
+
+ [{Jargon File}]
+
+ (1998-04-19)
+
+COMIS
+
+ <language> A COMpilation and Interpretation System.
+
+ A {Fortran} {interpreter} use by the {PAW} system.
+
+ (1994-11-30)
+
+COMIT
+
+ <language> The first string-handling and {pattern-matching}
+ language, designed in 1957-8 for applications in {natural
+ language} translation. The user has a workspace organised
+ into shelves. Strings are made of constituents (words),
+ accessed by {subscript}. A program is a set of rules, each of
+ which has a pattern, a replacement and goto another rule.
+
+ ["COMIT Programmer's Reference Manual", V.H. Yngve, MIT Press
+ 1961].
+
+ [Sammet 1969, pp. 416-436].
+
+ (1994-11-30)
+
+Comite Europeen des Postes et Telecommunications
+
+ <body> (CEPT, European Conference of Post and
+ Telecommunications) The committee that defined the CEPT speech
+ {compression} scheme.
+
+ [Details of compression scheme?]
+
+ (1998-03-16)
+
+COMIT II
+
+ <language> ["Computer Programming with COMIT II", Victor
+ H. Yngve, MIT Press, 1963].
+
+ (1995-01-11)
+
+Comma
+
+ <project> COMputable MAthematics.
+
+ An {ESPRIT} project at KU {Nijmegen}.
+
+ (1994-11-30)
+
+comma
+
+ <character> "," {ASCII} character 44. Common names: {ITU-T}:
+ comma. Rare: {ITU-T}: cedilla; {INTERCAL}: tail.
+
+ In the {C} programming language, "," is an operator which
+ evaluates its first argument (which presumably has
+ {side-effects}) and then returns the value of its second
+ argument. This is useful in "for" statements and {macros}.
+
+ (1995-03-10)
+
+command
+
+ <operating system> A character string which tells a program to
+ perform a specific action. Most commands take {arguments}
+ which either modify the action performed or supply it with
+ input. Commands may be typed by the user or read from a file
+ by a {command interpreter}. It is also common to refer to
+ menu items as commands.
+
+ (1997-06-21)
+
+Command Control Processor
+
+ <operating system> (CCP) {CP/M}'s {command-line interpreter}.
+
+ (2001-11-01)
+
+command interpreter
+
+ <operating system> A program which reads textual commands from
+ the user or from a file and executes them. Some commands may
+ be executed directly within the interpreter itself
+ (e.g. setting variables or control constructs), others may
+ cause it to load and execute other files.
+
+ {Unix}'s command interpreters are known as {shells}.
+
+ When an {IBM PC} is {boot}ed {BIOS} loads and runs the
+ {MS-DOS} command interpreter into memory from file COMMAND.COM
+ found on a {floppy disk} or {hard disk} drive. The commands
+ that COMMAND.COM recognizes (e.g. COPY, DIR, PRN) are called
+ internal commands, in contrast to external commands which are
+ executable files.
+
+ (1995-03-16)
+
+command key
+
+ {feature key}
+
+command line interface
+
+ <operating system> A means of communication between a
+ {program} and its {user}, based solely on textual input and
+ output. Commands are input with the help of a {keyboard} or
+ similar device and are interpreted and executed by the
+ program. Results are output as text or graphics to the
+ {terminal}.
+
+ Command line interfaces usually provide greater flexibility
+ than {graphical user interfaces}, at the cost of being harder
+ for the novice to use. Consequently, some {hackers} look down
+ on GUIs as designed {For The Rest Of Them}.
+
+ (1996-01-12)
+
+command-line interpreter
+
+ {command interpreter}
+
+command line option
+
+ <software> (Or "option", "flag", "switch", "option switch") An
+ argument to a command that modifies its function rather than
+ providing data. Options generally start with "-" in {Unix} or
+ "/" in {MS-DOS}. This is usually followed by a single letter
+ or occasionally a digit. More recently, {GNU} software
+ adopted the --longoptionname style, usually in addition to
+ traditional, single-character, -x style equivalents.
+
+ Some commands require each option to be a separate argument,
+ introduced by a new "-" or "/", others allow multiple option
+ letters to be concatenated into a single argument with a
+ single "-" or "/", e.g. "ls -al". A few Unix commands
+ (e.g. {ar}, {tar}) allow the "-" to be omitted. Some options
+ may or must be followed by a value, e.g. "cc prog.c -o prog",
+ sometimes with and sometimes without an intervening space.
+
+ {getopt} and {getopts} are commands for parsing command line
+ options. There is also a {C} library routine called getopt
+ for the same purpose.
+
+ (2007-02-18)
+
+comma separated values
+
+ <file format> (CSV) A {file format} used as a portable
+ representation of a {database}. Each line is one entry or
+ record and the fields in a record are separated by {commas}.
+ Commas may be followed by arbitrary space and/or tab
+ characters which are ignored. If field includes a comma, the
+ whole field must be surrounded with {double quotes}.
+
+ (1995-05-06)
+
+COMMEN
+
+ [L.J. Cohen. Proc SJCC 30:671-676, AFIPS (Spring 1967)].
+
+ (1994-11-30)
+
+comment
+
+ <programming> (Or "remark") Explanatory text embedded in
+ program {source} (or less often data) intended to help human
+ readers understand it.
+
+ Code completely without comments is often hard to read, but
+ code with too many comments is also bad, especially if the
+ comments are not kept up-to-date with changes to the code.
+ Too much commenting may mean that the code is
+ over-complicated. A good rule is to comment everything that
+ needs it but write code that doesn't need much of it.
+ Comments that explain __why__ something is done and how the code
+ relates to its environment are useful.
+
+ A particularly irksome form of over-commenting explains
+ exactly what each statement does, even when it is obvious to
+ any reasonably competant programmer, e.g.
+
+ /* Open the input file */
+ infd = open(input_file, O_RDONLY);
+
+ (2007-02-19)
+
+commented out
+
+ {comment out}
+
+comment out
+
+ <programming> To surround a section of code with {comment}
+ {delimiters} or to prefix every line in the section with a
+ comment marker. This prevents it from being compiled or
+ interpreted. It is often done to temporarily disable the
+ code, e.g. during {debugging} or when the code is redundant or
+ obsolete, but is being left in the source to make the intent
+ of the active code clearer.
+
+ The word "comment" is sometimes replaced with whatever
+ {syntax} is used to mark comments in the language in question,
+ e.g. "hash out" ({shell script}, {Perl}), "REM out" ({BASIC}),
+ etc.
+
+ Compare {condition out}.
+
+ [{Jargon File}]
+
+ (1998-04-28)
+
+commercial at
+
+ <character> "@". {ASCII} code 64. Common names: at sign, at,
+ strudel. Rare: each, vortex, whorl, {INTERCAL}: whirlpool,
+ cyclone, snail, ape, cat, rose, cabbage, amphora. {ITU-T}:
+ commercial at.
+
+ The @ sign is used in an {electronic mail address} to separate
+ the local part from the {hostname}. This dates back to July
+ 1972 when {Ray Tomlinson} was designing the first[?] {e-mail}
+ program.
+
+ It is ironic that @ has become a trendy mark of Internet
+ awareness since it is a very old symbol, derived from the
+ latin preposition "ad" (at).
+
+ Giorgio Stabile, a professor of history in Rome, has traced
+ the symbol back to the Italian Renaissance in a Roman
+ mercantile document signed by Francesco Lapi on 1536-05-04.
+
+ In Dutch it is called "apestaartje" (little ape-tail), in
+ German "affenschwanz" (ape tail). The French name is
+ "arobase". In Spain and Portugal it denotes a weight of about
+ 25 pounds, the weight and the symbol are called "arroba".
+ Italians call it "chiocciola" (snail).
+
+ See {@-party}.
+
+ (2003-04-28)
+
+Commercial Internet eXchange
+
+ <networking, body> (CIX) The CIX is a non-profit, 501(c)6,
+ trade association coordinating {Internet} services. Its
+ member organisations provide {TCP/IP} or {OSI} data
+ {internetwork} services to the general public. The CIX gives
+ them unrestricted access to other worldwide networks. It also
+ takes an interest in the development and future direction of
+ the {Internet}.
+
+ The CIX provides a neutral forum to exchange ideas,
+ information, and experimental projects among suppliers of
+ internetworking services. The CIX broadens the base of
+ national and international cooperation and coordination among
+ member networks. Together, the membership may develop
+ consensus positions on legislative and policy issues of mutual
+ interest.
+
+ The CIX encourages technical research and development for the
+ mutual benefit of suppliers and customers of data
+ communications internetworking services. It assists its
+ member networks in the establishment of, and adherence to,
+ operational, technical, and administrative policies and
+ standards necessary to ensure fair, open, and competitive
+ operations and communication among member networks. CIX
+ policies are formulated by a member-elected board of
+ directors.
+
+ {(http://cix.org/)}.
+
+ (1995-01-13)
+
+commercial off-the-shelf software
+
+ {commercial software}
+
+commercial software
+
+ <software> (Or "commercial off-the-shelf software", COTS)
+ {Software} that is produced for sale. This contrasts with
+ {free software}, which is produced for free distribution,
+ meaning without charge and/or without restriction on further
+ distribution.
+
+ Some companies that sell software distribute some (versions)
+ of products free of charge (but usually with restricted
+ distribution rights), this would probably still be called
+ commercial software. Conversely, software that an individual
+ distributes for free, but for which he accepts donations,
+ would still be called free software.
+
+ (2007-02-07)
+
+Commercial Translator
+
+ <language> An English-like pre-{COBOL} language for business
+ {data processing}.
+
+ [Sammet 1969, p. 378].
+
+ (1994-11-08)
+
+Committed Data Rate
+
+ <communications> (CDR) The data transfer rate that an {ISP}
+ guarantees a {virtual circuit} will carry. The CDR is the
+ data portion of {Committed Information Rate} (CIR).
+
+ (2007-02-28)
+
+Committed Information Rate
+
+ <networking> (CIR) The guaranteed average {data rate} of a
+ {virtual circuit} in a {frame relay} network. The CIR plus
+ the Excess Information Rate (EIR, burst rate) is equal to or
+ less than the speed of the access port into the network.
+
+ The term CIR includes voice and non-data packets that are not
+ included in the {Committed Data Rate} (CDR). CIR is generally
+ used in reference to {leased lines} and similar classes of
+ network services, not {dial-up}.
+
+ (2010-05-07)
+
+comm mode
+
+ <chat> (Or "com mode") An {ITS} feature supporting interactive
+ on-line {chat}.
+
+ [{Jargon File}]
+
+ (1998-01-18)
+
+Commodore
+
+ <company, computer> {Commodore Business Machines} or one of
+ their computers such as the {Commodore 64}.
+
+ (2010-09-14)
+
+Commodore 1010
+
+ <storage> A 3.5-inch floppy {disk drive} for the {Amiga}.
+
+ (1998-12-23)
+
+Commodore 128
+
+ <computer> (C128) An expanded {Commodore 64}, {Commodore
+ Business Machines}' last commercially released 8-bit computer.
+ However, they did prototype the {Commodore 65} and {Commodore
+ SX64}.
+
+ (1996-06-05)
+
+Commodore 1541
+
+ <storage> The best known {floppy disk} drive for the
+ {Commodore 64}. The 1541 was a single-sided 160 Kb drive but
+ converting to {flippy disks} would give another 160 Kb.
+
+ The disk drive used {Group Code Recording} and contained a
+ {6502} processor as a {disk controller}. Some people wrote
+ code for it to vibrate the head at different frequencies to
+ play tunes.
+
+ The transfer rate was about 300 bytes per second. The 1541
+ used a {bit-serial} version of the {IEEE 488} parallel
+ protocol. Some third-party speed-ups could transfer about 4
+ kilobytes per second over the interface, and some "fast
+ loaders" managed up to 10 kbps.
+
+ The {Commodore 1570} was an upgraded 1541 for use with the
+ {Commodore 128}.
+
+ (2000-03-07)
+
+Commodore 1570
+
+ <storage> {Commodore Business Machines}'s allegedly "advanced"
+ disk drive for use with the {C128}. It is basically a {1541}
+ with the capability to use "burst loading" (like the
+ {Commodore 1571}), and lots of new {bugs}.
+
+ The {Commodore 1571} was a double-sided version of the 1570.
+
+ (1996-04-07)
+
+Commodore 1571
+
+ <storage> {Commodore Business Machines}'s "advanced" {disk
+ drive} for the {C128}. It was the double-sided version of the
+ {Commodore 1570} disk drive but, unlike the 1570, worked quite
+ well.
+
+ The 1571 supported "{burst mode}" loading when used on a C128
+ in native mode, which increased the transfer speed from 1541
+ speed to about three kilobytes per second (about a 10-fold
+ increase). The 1571 could be told to emulate a {1541} for use
+ with a {C64} or 1541 disks.
+
+ Bugs in early releases of the 1571 {ROM} affected access to
+ the second side of the disk.
+
+ (1996-04-07)
+
+Commodore 1581
+
+ <storage> {Commodore Business Machines}'s 3.5 inch {disk
+ drive} for the {Commodore 64} and {Commodore 128}. The drive
+ stores 800 {kilobytes} using an {MFM} format which is
+ different from both {messy-dos} 720 kb, and the {Amiga} 880 kb
+ formats.
+
+ The 1581 supports a poor imitation of {directories} which are
+ really just {partitions} and largely unused. It also supports
+ burst loading like the {Commodore 1571}, but is actually
+ faster as it is better designed. It has 3160 {blocks} free
+ when formatted.
+
+ The 1581 is the highest density C64 serial bus drive made by
+ Commodore. However Creative Micro Designs (CMD) make the
+ {FD2000} (1.6MB) and (until recently) the {FD4000} (3.2MB)
+ 3.5" disk drives. {GEOS} users like 1581s as they are very
+ fast when used with GEOS.
+
+ See also {Commodore 1541}, {Commodore 1571}.
+
+ (1998-12-23)
+
+Commodore 64
+
+ <computer> (C64) An 8-bit {Commodore Business Machines}
+ {personal computer} released around September 1981.
+ Prototypes were (apparently) made before Christmas 1980 (and
+ shown at some computer fair).
+
+ The {CPU} was a {6510} from {MOS Technology} (who were a
+ wholly owned subsiduary of Commodore at this time(?)). The
+ C64 had 64 {kilobytes} of {RAM} as standard and a 40-column
+ text, 320x200 {pixel} display generating {composite video},
+ usually connected to a television.
+
+ {DMA}-based memory expanders for the C64 (and C128) allowed
+ 128, 256, and 512 kb of RAM. Several third party
+ manufacturers produce accelerators and RAM expanders for the
+ C64 and C128. (Some, risking a {holy war}, compare this to
+ putting a brick on roller-skates). Such accelerators come in
+ speeds up to 20MHz (20 times the original) and RAM expanders
+ to 16MB.
+
+ The C64's {1541} 5.25 {floppy disk} drive had a {6502}
+ processor as a {disk controller}.
+
+ See also {Commodore 65}.
+
+ ["Assembly language programming with the Commodore 64", Marvin
+ L. De Jong].
+
+ (1996-06-05)
+
+Commodore 64DX
+
+ {Commodore 65}
+
+Commodore 65
+
+ <computer> (Or Commodore 64DX, C65, C64DX) The last 8-bit
+ computer designed by {Commodore Business Machines}, about
+ 1989-1991. The C65 boasts an {ugly} collection of {custom}
+ {integrated circuits} which makes even the {Amiga} hardware
+ look standard.
+
+ The core of the C65 {chipset} is the {CSG 4510} and {CSG
+ 4569}. The 4510 is a {65CE02} with two {6526} {CIAs}. The
+ 4569 is equivalent to a combination of the {6569} VIC-II and
+ the {MMU} of the {Commodore 64}. The C65 also has a {DMA
+ controller} (Commodore's purpose built {DMAgic}) which also
+ functions as a simple {blitter}, and a {floppy controller} for
+ the internal {Commodore 1581}-like disk drive. The floppy
+ controller, known as the {F011}, supports seven drives (though
+ the {DOS} only supports 2). The {4510} supports all the {C64}
+ {video modes}, plus an 80 column text mode, and {bitplane}
+ modes. The bitplane modes can use up to eight bitplanes, and
+ {resolutions} of up to 1280 x 400. The {palette} is 12-bit
+ like the {Amiga 500}. It also has two SID's (MOS 8580/6581)
+ for stereo audio.
+
+ The C65 has two busses, D and E, with 64 {kilobytes} of {RAM}
+ on each. The VIC-III can access the D-bus while the CPU
+ accesses the E-bus, and then they can swap around. This
+ effectively makes the whole 8MB {address space} both {chip
+ ram} and {fast ram}. {RAM} expansion is accomplished through
+ a {trap door} slot in the bottom which uses a {grock} of a
+ connector. The C65 has a {C128}-like native mode, where all
+ of the new features are enabled, and the CPU runs at 3.5
+ megahertz with its {pipeline} enabled. It also has a C64
+ {incompatibility mode} which offers approx 50-80%
+ compatibility with C64 software by turning off all its {bells
+ and whistles}. The {bells and whistles} can still be accessed
+ from the C64 mode, which is dissimilar to the C128's
+ inescapable C64 mode.
+
+ Production of the C65 was dropped only a few weeks before it
+ moved from the Alpha stage, possibly due to Commodore's cash
+ shortage. Commodore estimate that "between 50 and 10000"
+ exist. There are at least three in Australia, about 30 in
+ Germany and "some" in the USA and Canada.
+
+ (1996-04-07)
+
+Commodore Business Machines
+
+ <company> (CBM) Makers of the {PET}, {Commodore 64},
+ {Commodore 16}, {Commodore 128}, and {Amiga} {personal
+ computers}. Their logo is a {chicken head}.
+
+ The Commodore name is controlled by Commodore Licensing BV,
+ now a subsidiary of Asiarim. Commodore USA signed an
+ agreement with Commodore Licensing BV.
+
+ On 1994-04-29, Commodore International announced that it had
+ been unable to renegotiate terms of outstanding loans and was
+ closing down the business. Commodore US was expected to go
+ into liquidation. Commodore US, France, Spain, and Belgium
+ were liquidated for various reasons. The names Commodore and
+ Amiga were maintained after the liquidation.
+
+ After 1994, the rights to the Commodore name bounced across
+ several European companies.
+
+ On 1995-04-21, German retailer {Escom AG} bought Commodore
+ International for $14m and production of the Amiga resumed.
+ Netherlands-based {Tulip Computers} took over the brand.
+
+ Production of the 8-bit range alledgedly never stopped during
+ the time in liquidation because a Chinese company were
+ producing the {C64} in large numbers for the local market
+ there.
+
+ In 2004, Tulip sold the Commodore name to another Dutch firm,
+ Yeahronimo, that eventually changed its name to Commodore
+ International.
+
+ In April 2008 three creditors took the company to court
+ demanding a bankruptcy ruling.
+
+ On 2010-03-17, Commodore USA announced that it was to release
+ a new PC in June 2010 which looks very similar to the old
+ Commodore 64 but comes with a {Core 2 Duo}, {Core 2 Quad},
+ {Pentium D} or {Celeron D} processor and with {Ubuntu} {Linux}
+ or {Windows 7} installed. {PC World article
+ (http://pcworld.com/article/192415)}.
+
+ (2010-09-14)
+
+Commodore SX64
+
+ <computer> A "portable" {Commodore 64}. Shaped vaguely like a
+ seat cushion, this cumbersome experiment in transportable
+ computers had a detachable keyboard on one end which, when
+ removed, revealed a 6" {monitor} and a 5 1/4" {floppy disk}
+ drive. The curious combination of a bulky design and
+ microscopic display are the most likely cause for the SX64's
+ discontinuation.
+
+ [Processor? RAM? Dates?]
+
+ (1997-10-25)
+
+COMmon Algorithmic Language
+
+ <language> (COMAL) A language for beginners developed by
+ Benedict Loefstedt and Borge Christensen in 1973 and popular
+ in Europe and Scandinavia. It has a {Pascal}-like structure
+ added to {BASIC}. COMAL-80 has been adopted as an
+ introductory language in Denmark.
+
+ There is a version for the {Amiga} and a well-supported
+ version for the {PC}, running under {MS-DOS} and {Microsoft
+ Windows}, called UniCOMAL. Recently, it has been developed as
+ a web-scripting language called WebCOMAL.
+
+ {macharsoft (http://macharsoft.demon.co.uk/)}.
+
+ There is a COMAL User's Group at 5501 Groveland Terr, Madison
+ WI 53716, USA.
+
+ ["Beginning COMAL", B. Christensen, Ellis Harwood 1982].
+
+ (2000-11-14)
+
+Common Applications Environment
+
+ <operating system> (CAE) Part of {X/Open}, based on {POSIX}
+ and {C}.
+
+ [Details?]
+
+ (2007-03-01)
+
+Common Applications Service Element
+
+ {Common Application Service Element}
+
+Common Architecture for Next Generation Internet Protocol
+
+ <networking> (CATNIP, originally Common Architecture
+ Technology for Next-generation Internet Protocol)
+
+ A network architecture designed to provide a compressed form
+ of the existing {network layer} {protocols} and to integrate
+ {CLNP}, {IP}, and {IPX}. It provides for any of the
+ {transport layer} {protocols} in use, including {TP4}, {CLTP},
+ {TCP}, {UDP}, {IPX}, and {SPX}, to run over any of the network
+ layer protocol formats: CLNP, IP (version 4), IPX and CATNIP.
+
+ CATNIP was originally proposed by Robert L. Ullmann of {Lotus
+ Development Corporation} on 1993-12-22. It was published as
+ {RFC 1707} in October 1994 but it is not an {Internet}
+ standard of any kind.
+
+ (1996-03-23)
+
+COmmon Business Oriented Language
+
+ <language, business> /koh'bol/ (COBOL) A programming language
+ for simple computations on large amounts of data, designed by
+ the {CODASYL} Committee in April 1960. COBOL's {natural
+ language} style is intended to be largely self-documenting.
+ It introduced the {record} structure.
+
+ COBOL was probably the most widely used programming language
+ during the 1960s and 1970s. Many of the major programs that
+ required repair or replacement due to {Year 2000} {software
+ rot} issues were originally written in COBOL, and this was
+ responsible for a short-lived increased demand for COBOL
+ programmers. Even in 2002 though, new COBOL programs are
+ still being written in some organisations and many old COBOL
+ programs are still running in {dinosaur} shops.
+
+ Major revisions in 1968 (ANS X3.23-1968), 1974 (ANS
+ X3.23-1974) and 1985.
+
+ {Usenet} newsgroup: {news:comp.lang.cobol}.
+
+ ["Initial Specifications for a Common Business Oriented
+ Language" DoD, US GPO, Apr 1960].
+
+ (2002-02-21)
+
+common carrier
+
+ <communications, company> (Or "phone company") A private
+ company that offers telecommunications services to the public.
+
+ (1995-03-20)
+
+Common Command Set
+
+ <storage, standard> (CCS) Additional requirements and features
+ for direct-access {SCSI} devices.
+
+ In 1985 when the first {SCSI} standard was being finalised as
+ an {American National Standard}, the {X3T9.2} Task Group was
+ approached by some manufacturers who wanted changes. Rather
+ than delay the SCSI standard, X3T9.2 formed an ad hoc group to
+ define CCS.
+
+ [Spec? Status? "direct-access"?]
+
+ (1997-03-23)
+
+Common Communication Services
+
+ <networking, IBM> (CCS) The standard program interface to
+ networks in {IBM}'s {SAA}.
+
+ (2007-05-14)
+
+Common Desktop Environment
+
+ <graphics, operating system> (CDE) A {desktop manager} from
+ {COSE}.
+
+ (1994-10-31)
+
+Common ESP
+
+ <language> (CESP) A {Unix}-based version of ESP ({Extended
+ Self-containing Prolog}) from {Mitsubishi}'s {AI Language
+ Institute}.
+
+ (2000-07-11)
+
+Common Gateway Interface
+
+ <web> (CGI) A {standard} for running external
+ {programs} from a {web} {HTTP} {server}. CGI
+ specifies how to pass {arguments} to the program as part of
+ the HTTP request. It also defines a set of {environment
+ variables} that are made available to the program. The
+ program generates output, typically {HTML}, which the web
+ server processes and passes back to the {browser}.
+ Alternatively, the program can request {URL redirection}. CGI
+ allows the returned output to depend in any arbitrary way on
+ the request.
+
+ The CGI program can, for example, access information in a
+ {database} and format the results as HTML. The program can
+ access any data that a normal application program can, however
+ the facilities available to CGI programs are usually limited
+ for security reasons.
+
+ Although CGI programs can be compiled programs, they are more
+ often written in a (semi) {interpreted language} such as
+ {Perl}, or as {Unix} {shell scripts}, hence the common name
+ "CGI script".
+
+ Here is a trivial CGI script written in Perl. (It requires
+ the "CGI" module available from {CPAN}).
+
+ #!/usr/bin/perl
+ use CGI qw(:standard);
+
+ print header, start_html,
+ h1("CGI Test"),
+ "Your IP address is: ", remote_host(),
+ end_html;
+
+ When run it produces an {HTTP} header and then a simple HTML
+ page containing the {IP address} or {hostname} of the machine
+ that generated the initial request. If run from a command
+ prompt it outputs:
+
+ Content-Type: text/html; charset=ISO-8859-1
+
+ <!DOCTYPE html
+ PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
+ "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
+ <html xmlns="http://www.w3.org/1999/xhtml"
+ lang="en-US" xml:lang="en-US">
+ <head>
+ <title>Untitled Document</title>
+ <meta http-equiv="Content-Type"
+ content="text/html; charset=iso-8859-1" />
+ </head>
+ <body>
+ <h1>CGI Test</h1>Your IP address is: localhost
+ </body>
+ </html>
+
+ The CGI program might be saved as the file "test.pl" in the
+ appropriate directory on a web server,
+ e.g. "/home/httpd/test".
+
+ Accessing the appropriate {URL}, e.g.
+ http://acme.com/test/test.pl, would cause the program to
+ run and a custom page produced and returned.
+
+ Early web servers required all CGI programs to be installed in
+ one directory called cgi-bin but it is better to keep them
+ with the HTML files to which they relate unless they are truly
+ global to the site. Similarly, it is neither necessary nor
+ desirable for all CGI programs to have the extension ".cgi".
+
+ Each CGI request is handled by a new process. If the process
+ fails to terminate for some reason, or if requests are
+ received faster than the server can respond to them, the
+ server may become swamped with processes. In order to improve
+ performance, {Netscape} devised {NSAPI} and {Microsoft}
+ developed the {ISAPI} standard which allow CGI-like tasks to
+ run as part of the main server process, thus avoiding the
+ overhead of creating a new process to handle each CGI
+ invocation. Other solutions include {mod_perl} and {FastCGI}.
+
+ Latest version: CGI/1.1.
+
+ {(http://hoohoo.ncsa.uiuc.edu/cgi)}.
+
+ (2007-05-22)
+
+Common Hardware Reference Platform
+
+ {PowerPC Platform}
+
+Common Information Model
+
+ <standard> (CIM) An {open systems} management {standard}
+ driven by the {Distributed Management Task Force} (DMTF).
+
+ (2003-06-07)
+
+Common Intermediate Format
+
+ <communications, standard> (CIF) A {video} format used in
+ {videoconferencing} systems, which supports both {NTSC} and
+ {PAL} signals, with a {data rate} of 30 {frames per second}
+ (fps), with each {frame} containing 288 lines and 352
+ {luminance} {pixels} per line. CIF is part of the {ITU}
+ {H.261} videoconferencing standard.
+
+ CIF is also known as Full CIF (FCIF) to distinguish it from
+ {Quarter CIF} (QCIF), a related video format standard that
+ transfers one fourth as much data as CIF.
+
+ (2007-05-14)
+
+Common Intermediate Language
+
+ <language> (CIL)
+
+ [Details?]
+
+ ["Construction of a Transportable, Milti-Pass Compiler for
+ Extended Pascal", G.J. Hansen et al, SIGPLAN Notices
+ 14(8):117-126, Aug 1979].
+
+ (1994-10-24)
+
+Common Internet File System
+
+ <protocol> (CIFS) An {Internet} {file system} {protocol},
+ based on {Microsoft}'s {SMB}. Microsoft has given CIFS to the
+ {Internet Engineering Task Force} (IETF) as an Internet Draft.
+ CIFS is intended to complement existing protocols such as
+ {HTTP}, {FTP}, and {NFS}.
+
+ CIFS runs on top of {TCP/IP} and uses the Internet's {Domain
+ Name Service} (DNS). It is optimised to support the slower
+ speed {dial-up} connections common on the Internet.
+
+ CIFS is more flexible than FTP. FTP operations are carried
+ out on entire files whereas CIFS is aimed at routine data
+ access and incorporates high-performance multi-user read and
+ write operations, {locking}, and file-sharing semantics.
+
+ CIFS is probably closest in functionality to NFS. NFS gives
+ random access to files and directories, but is {stateless}.
+ With CIFS, once a file is open, state about the current access
+ to that file is stored on both the client and the server.
+ This allows changes on the server side to be notified to the
+ clients that are interested.
+
+ {Microsoft Overview
+ (http://msdn.microsoft.com/library/en-us/fileio/base/cifs_smb_protocol_overview.asp)}.
+
+ {SNIA page (http://snia.org/tech_activities/CIFS/)}.
+
+ {CIFS: A Common Internet File System, Paul Leach and Dan Perry
+ (http://microsoft.com/Mind/1196/CIFS.htm)}.
+
+ {IETF Specification. CIFS version 1
+ (ftp://ietf.org/internet-drafts/draft-leach-cifs-v1-spec-01.txt)}.
+
+ (2003-03-12)
+
+Common-ISDN-API
+
+ {Common ISDN Application Programming Interface}
+
+Common ISDN Application Programming Interface
+
+ <networking> (CAPI, Common-ISDN-API) A programming interface
+ standard for an application program to communicate with an
+ {ISDN} card.
+
+ Work on CAPI began in 1989, focussing on the German ISDN
+ protocol, and was finished in 1990 by a CAPI working group
+ consisting of application providers, ISDN equipment
+ manufacturers, large customers, user groups and DBP Telekom,
+ resulting in COMMON-ISDN-API Version 1.1. Following
+ completion of the international protocol specification, almost
+ every telecommunication provider offers {BRI} and {PRI} with
+ {protocols} based on {Q.931} / ETS 3009 102. Common-ISDN-API
+ Version 2.0 was developed to support all Q.931 protocols.
+
+ Latest version: 2.0, as of 1998-09-07.
+
+ {(http://capi.org/)}.
+
+ [Why not CIAPI?]
+
+ (1998-09-07)
+
+Common Lisp
+
+ <language> A dialect of {Lisp} defined by a consortium of
+ companies brought together in 1981 by the {Defence Advanced
+ Research Projects Agency} (DARPA). Companies included
+ {Symbolics}, {Lisp Machines, Inc.}, {Digital Equipment
+ Corporation}, {Bell Labs}., {Xerox}, {Hewlett-Packard},
+ {Lawrence Livermore Labs}., {Carnegie-Mellon University},
+ {Stanford University}, {Yale}, {MIT} and {USC Berkeley}.
+ Common Lisp is {lexically scoped} by default but can be
+ {dynamically scoped}.
+
+ Common Lisp is a large and complex language, fairly close to a
+ superset of {MacLisp}. It features {lexical binding}, data
+ structures using defstruct and setf, {closures}, multiple
+ values, types using declare and a variety of numerical types.
+ Function calls allow "&optional", keyword and "&rest"
+ arguments. Generic sequence can either be a list or an
+ {array}. It provides formatted printing using escape
+ characters. Common LISP now includes {CLOS}, an extended LOOP
+ {macro}, condition system, {pretty printing} and logical
+ pathnames.
+
+ Implementations include {AKCL}, {CCL}, {CLiCC}, {CLISP},
+ {CLX}, {CMU Common Lisp}, {DCL}, {KCL}, {MCL} and {WCL}.
+
+ Mailing list: <common-lisp@ai.sri.com>.
+
+ {ANSI Common Lisp draft proposal
+ (ftp://ftp.think.com/public/think/lisp:public-review.text)}.
+
+ ["Common LISP: The Language", Guy L. Steele, Digital Press
+ 1984, ISBN 0-932376-41-X].
+
+ ["Common LISP: The Language, 2nd Edition", Guy L. Steele,
+ Digital Press 1990, ISBN 1-55558-041-6].
+
+ (1994-09-29)
+
+Common LISP in Parallel
+
+ <language, parallel> (CLIP) A version of {Common LISP} from
+ {Allegro} for the {Sequent Symmetry}.
+
+ (1994-12-12)
+
+Common LISP Object System
+
+ <language> (CLOS) An {object-oriented} extension to {Common
+ LISP}, based on {generic functions}, {multiple inheritance},
+ {declarative method combination} and a {meta-object protocol}.
+ A descendant of {CommonLoops} and based on {Symbolics}
+ {FLAVORS} and {Xerox} {LOOPS}, among others.
+
+ See also {PCL}.
+
+ ["Common LISP Object System Specification X3J13 Document
+ 88-002R", D.G. Bobrow et al, SIGPLAN Notices 23, Sep 1988].
+
+ (1994-11-30)
+
+CommonLoops
+
+ <language> {Xerox}'s {object-oriented} {Lisp} which led to
+ {CLOS}.
+
+ See also {Portable CommonLoops}.
+
+ {(ftp://arisia.xerox.com/pub/pcl/September-16-92-PCL-c.tar.Z)}.
+
+ ["CommonLoops: Merging Lisp and Object-Oriented Programming",
+ D.G. Bobrow et al, SIGPLAN Notices 21(11):17-29, Nov 1986].
+
+ (1999-07-02)
+
+Common Management Information Protocol
+
+ <protocol> (CMIP) Part of the {OSI} body of {standards}
+ specifying {protocol} elements that may be used to provide the
+ operation and notification services described in the related
+ standard, CMIS ({Common Management Information Services}).
+
+ Document: {ISO}/{IEC} 9596, or equivalent {ITU} X.711.
+
+ (1997-12-07)
+
+Common Management Information Services
+
+ <networking> (CMIS) Part of the {OSI} body of network
+ {standards}.
+
+ Network management information services are used by {peer
+ process}es to exchange information and commands for the
+ purpose of {network management}. CMIS defines a message set
+ (GET, CANCEL-GET, SET, CREATE, DELETE, EVENT-REPORT and
+ ACTION), and the structure and content of the messages such
+ that they might be used by "open" systems. In concept, it is
+ similar to {SNMP}, but more powerful (and hence more complex).
+
+ {ISO}/{IEC} 9595.
+
+ (2007-08-07)
+
+Common Object File Format
+
+ <file format> (COFF) The {executable file} and {object file}
+ format used by {Unix System V} Release 3 and later.
+
+ {Unix manual page}: coff(5).
+
+ (2007-08-15)
+
+Common Object Model
+
+ {Component Object Model}
+
+Common Object Request Broker Architecture
+
+ <standard, programming> (CORBA) An {Object Management Group}
+ specification which provides a standard messaging interface
+ between distributed {objects}.
+
+ The original CORBA specification (1.1) has been revised
+ through version 2 (CORBA 2) with the latest specification
+ being version 3 (CORBA 3). In its most basic form CORBA
+ consists of the {Interface Definition Language} (IDL) and the
+ Dynamic Invocation Interface (DII).
+
+ The IDL definition is complied into a Stub (client) and
+ Skeleton (server) component that communicate through an
+ {Object Request Broker} (ORB). When an ORB determines that a
+ request is to a remote object, it may execute the request by
+ communicating with the remote ORB.
+
+ The Corba IDL can be mapped to a number of languages including
+ {C}, {C++}, {Java}, {COBOL}, {Smalltalk}, {Ada}, {Lisp},
+ {Python}, and {IDLscript}. CORBA ORBs are widely available
+ for a number of platforms. The OMG standard for inter-ORB
+ communication is {IIOP}, this ensures that all CORBA 2
+ compliant ORBS are able to interoperate.
+
+ Latest version: Corba 3.0.3 2004-03-12, as of 2007-09-04.
+
+ See also {COSS}, {Component Object Model}, {RMI}.
+
+ {OMG CORBA specs
+ (http://www.omg.org/technology/documents/corba_spec_catalog.htm)}.
+
+ (2007-09-04)
+
+Common Objects
+
+ <language> An {object-oriented} {Lisp} from {Hewlett-Packard}.
+
+ ["Inheritance and the Development of Encapsulated Software
+ Components", A. Snyder, Proc 20th Hawaii Conf on Sys Sci,
+ pp. 227-238, 1987].
+
+ (1995-01-18)
+
+Common Program Interface
+
+ <programming> (CPI) The {API} of {SAA}.
+
+ (1997-12-01)
+
+Common User Access
+
+ <programming> (CUA) The {user interface} standard of {SAA}.
+
+ (1997-12-01)
+
+Commonwealth Hackish
+
+ <jargon> Hacker jargon as spoken outside the US, especially in
+ the British Commonwealth. It is reported that Commonwealth
+ speakers are more likely to pronounce truncations like "char"
+ and "soc", etc., as spelled (/char/, /sok/), as opposed to
+ American /keir/ and /sohsh/. Dots in {newsgroup} names
+ (especially two-component names) tend to be pronounced more
+ often (so soc.wibble is /sok dot wib'l/ rather than /sohsh
+ wib'l/). The prefix {meta} may be pronounced /mee't*/;
+ similarly, Greek letter beta is usually /bee't*/, zeta is
+ usually /zee't*/, and so forth. Preferred {metasyntactic
+ variables} include {blurgle}, "eek", "ook", "frodo", and
+ "bilbo"; "wibble", "wobble", and in emergencies "wubble";
+ "banana", "tom", "dick", "harry", "wombat", "frog", {fish},
+ and so on and on (see {foo}).
+
+ Alternatives to verb doubling include suffixes "-o-rama",
+ "frenzy" (as in feeding frenzy), and "city" (examples: "barf
+ city!" "hack-o-rama!" "core dump frenzy!"). Finally, note
+ that the American terms "parens", "brackets", and "braces" for
+ (), [], and {} are uncommon; Commonwealth hackish prefers
+ "brackets", "square brackets", and "curly brackets". Also,
+ the use of "pling" for {bang} is common outside the United
+ States.
+
+ See also {attoparsec}, {calculator}, {chemist}, {console
+ jockey}, {fish}, {go-faster stripes}, {grunge}, {hakspek},
+ {heavy metal}, {leaky heap}, {lord high fixer}, {loose bytes},
+ {muddie}, {nadger}, {noddy}, {psychedelicware}, {plingnet},
+ {raster blaster}, {RTBM}, {seggie}, {spod}, {sun lounge},
+ {terminal junkie}, {tick-list features}, {weeble}, {weasel},
+ {YABA}, and notes or definitions under {Bad Thing}, {barf},
+ {bum}, {chase pointers}, {cosmic rays}, {crippleware},
+ {crunch}, {dodgy}, {gonk}, {hamster}, {hardwarily},
+ {mess-dos}, {nibble}, {proglet}, {root}, {SEX}, {tweak} and
+ {xyzzy}.
+
+ [{Jargon File}]
+
+ (1995-01-18)
+
+Communicating Functional Processes
+
+ <language> (CFP) A parallel {functional programming} language.
+
+ ["Communicating Functional Processes", M.C. van Eekelen et al,
+ TR 89-3, U Nijmegen, Netherlands, 1989].
+
+ (1994-11-30)
+
+Communicating Sequential Processes
+
+ <language, parallel> (CSP) A notation for {concurrency} based
+ on {synchronous message passing} and selective communications
+ designed by {Anthony Hoare} in 1978. It features {cobegin}
+ and coend and was a precursor to {occam}.
+
+ See also {Contextually Communicating Sequential Processes}.
+
+ ["Communicating Sequential Processes", A.R. Hoare, P-H 1985].
+
+ (1994-11-01)
+
+Communication and Network Riser
+
+ <hardware, standard> (CNR) A specification for {audio},
+ {modem}, {USB} and {Local Area Networking} interfaces of core
+ computer logic {chip sets}. {Intel} introduced CNR on
+ 2000-02-07. It was mainly developed by hardware and software
+ developers who helped release AMR ({Audio/Modem Riser}) and is
+ used by several computer manufacturers.
+
+ {(http://www.computerhope.com/jargon/c/cnr.htm)}.
+
+ (2007-03-15)
+
+Communications Decency Act
+
+ <legal> (CDA) An amendment to the U.S. 1996 Telecommunications
+ Bill that went into effect on 1996-02-08. The law, originally
+ proposed by Senator James Exon to protect children from
+ obscenity on the Internet, ended up making it punishable by
+ fines of up to $250,000 to post indecent language on the
+ Internet anywhere that a minor could read it.
+
+ Thousands of outraged {Internet} users turned their {web
+ pages} black in protest or displayed the {Electronic Frontier
+ Foundation}'s special {icons}.
+
+ On 1996-06-12, a three-judge panel in Philadelphia ruled the
+ CDA unconstitutional and issued an injunction against the
+ United States Justice Department forbidding them to enforce
+ the "indecency" provisions of the law. Internet users
+ celebrated by displaying an animated "Free Speech" fireworks
+ icon to their web pages, courtesy of the {Voters
+ Telecommunications Watch}. The Justice Department appealed
+ the decision to the U.S. Supreme Court.
+
+ (1996-11-03)
+
+Communications of the ACM
+
+ <publication> (CACM) A monthly publication by the {Association
+ for Computing Machinery} sent to all members. CACM is an
+ influential publication that keeps computer science
+ professionals up to date on developments. Each issue includes
+ articles, case studies, practitioner oriented pieces, regular
+ columns, commentary, departments, the ACM Forum, technical
+ correspondence and advertisements.
+
+ {(http://acm.org/cacm/)}.
+
+ (1995-01-18)
+
+communications port
+
+ <hardware, communications> A connector for a communications
+ interface, usually, a {serial port}.
+
+ (1996-08-04)
+
+Communications Server
+
+ <operating system> {IBM}'s rebranding of {ACF}.
+
+ (1999-01-20)
+
+communications software
+
+ <communications, software> {Application programs}, {operating
+ system} components, and probably {firmware}, forming part of a
+ {communication system}. These different software components
+ might be classified according to the functions within the
+ {Open Systems Interconnect} model which they provide.
+
+ Typical applications include a {web browser}, {Mail User
+ Agent}, {chat} and {telnet}.
+
+ (2001-03-18)
+
+communication system
+
+ <communications> A system or facility for transfering data
+ between persons and equipment. The system usually consists of
+ a collection of individual communication {networks},
+ transmission systems, relay stations, tributary stations and
+ {terminal} equipment capable of interconnection and
+ interoperation so as to form an integrated whole. These
+ individual components must serve a common purpose, be
+ technically compatible, employ common procedures, respond to
+ some form of control and generally operate in unison.
+
+ ["Communications Standard Dictionary", 2nd Edition, Martin
+ H. Weik].
+
+ (1995-02-06)
+
+Community of Massive Gaming Agency
+
+ <body> (CMGA) An online {gaming portal} introduced by German Telekom.
+
+ (2003-06-15)
+
+COMNET
+
+ <simulation, networking> A {simulation} tool from {CACI} for
+ analysing wide-area voice or data networks, based on
+ {SIMSCRIPT}.
+
+ (2008-10-13)
+
+compact
+
+ 1. <theory> (Or "finite", "isolated") In {domain theory}, an
+ element d of a {cpo} D is compact if and only if, for any
+ {chain} S, a subset of D,
+
+ d <= lub S => there exists s in S such that d <= s.
+
+ I.e. you always reach d (or better) after a finite number of
+ steps up the chain.
+
+ ("<=" is written in {LaTeX} as {\sqsubseteq}).
+
+ [{Jargon File}]
+
+ (1995-01-13)
+
+ 2. <jargon> Of a design, describes the valuable property that
+ it can all be apprehended at once in one's head. This
+ generally means the thing created from the design can be used
+ with greater facility and fewer errors than an equivalent tool
+ that is not compact. Compactness does not imply triviality or
+ lack of power; for example, {C} is compact and {Fortran} is
+ not, but C is more powerful than Fortran. Designs become
+ non-compact through accreting {features} and {cruft} that
+ don't merge cleanly into the overall design scheme (thus, some
+ fans of {Classic C} maintain that {ANSI C} is no longer
+ compact).
+
+ (2008-10-13)
+
+Compact COBOL
+
+ <language> A subset of {COBOL} defined, but not published,
+ ca. 1961.
+
+ [Sammet 1969, p. 339].
+
+ (2008-10-13)
+
+Compact Disc
+
+ <storage> (CD) (Not "disk", this spelling is part of the
+ standard).
+
+ A 4.72 inch disc developed by {Sony} and {Philips} that can
+ store, on the same disc, still and/or moving images in
+ monochrome and/or color; stereo or two separate sound tracks
+ integrated with and/or separate from the images; and digital
+ program and information files.
+
+ The same fabrication process is used to make both audio CDs
+ and {CD-ROMs} for storing computer data, the only difference
+ is in the device used to read the CD (the player or drive).
+
+ {CD Information Center
+ (http://cd-info.com/cd-info/CDInfoCenter.html)}.
+
+ (1999-06-23)
+
+Compact Disc interactive
+
+ <storage> (CD-i) An embedded application of {CD-ROM} allowing
+ the user limited interaction with films, games and educational
+ applications via a special {controller}.
+
+ (1994-11-02)
+
+Compact Disc Read-Only Memory
+
+ <storage> (CD-ROM) A {non-volatile} optical data storage
+ medium using the same physical format as audio {compact
+ discs}, readable by a computer with a CD-ROM drive.
+
+ CD-ROM is popular for distribution of large databases,
+ software and especially {multimedia} {applications}. The
+ maximum capacity is about 600 megabytes. A CD can store
+ around 640 {megabytes} of data - about 12 billion bytes per
+ pound weight.
+
+ CD-ROM drives are rated with a speed factor relative to music
+ CDs (1x or 1-speed which gives a data transfer rate of 150
+ {kilobytes} per second). 12x drives were common in April
+ 1997. Above 12x speed, there are problems with vibration and
+ heat. {Constant angular velocity} (CAV) drives give speeds up
+ to 20x but due to the nature of CAV the actual throughput
+ increase over 12x is less than 20/12.
+
+ 20x was thought to be the maximum speed due to mechanical
+ constraints but on 1998-02-24, {Samsung Electronics}
+ introduced the SCR-3230, a 32x CD-ROM drive which uses a ball
+ bearing system to balance the spinning CD-ROM in the drive to
+ reduce noise.
+
+ CD-ROM drives may connect to an {IDE} interface, a {SCSI}
+ interface or a propritary interface, of which there are three
+ - Sony, Panasonic, and Mitsumi. Most CD-ROM drives can also
+ play audio CDs.
+
+ There are several formats used for CD-ROM data, including
+ {Green Book CD-ROM}, {White Book CD-ROM} and {Yellow Book
+ CD-ROM}. {ISO 9660} defines a standard {file system}, later
+ extended by {Joliet}.
+
+ See also {Compact Disc Recordable}, {Digital Versatile Disc}.
+
+ {Byte, February 1997
+ (http://byte.com/art/9702/sec17/art5.htm)}.
+
+ (2006-09-25)
+
+Compact Disc Read-Write
+
+ {Compact Disc Rewritable}
+
+Compact Disc Recordable
+
+ <storage> (CD-R) A write-once version of {CD-ROM}. CD-Rs can
+ hold about 650 {megabytes} of data. They are very durable and
+ can be read by normal CD-ROM drives, but once data has been
+ written it cannot be altered.
+
+ Standard prerecorded CDs have their information permanently
+ stamped into an aluminium reflecting layer. CD-R discs have a
+ dye-based recording layer and an additional golden reflecting
+ layer.
+
+ Digital information is written to the disc by burning
+ (forming) pits in the recording layer in a pattern
+ corresponding to that of a conventional CD.
+
+ The laser beam heats the substrate and recording layer to
+ approximately 250 C. The recording layer melts and the
+ substrate expands into the space that becomes available.
+
+ {Phillips: New Technologies
+ (http://www-us.sv.philips.com/newtech/cdrewritable.html)}.
+
+ See also {CD-RW} and {DVD-RAM}.
+
+ (1999-08-01)
+
+Compact Disc Rewritable
+
+ <storage> (CD-RW) A rewritable version of {CD-ROM}. A CD-RW
+ drive can write about 650 {megabytes} of data to CD-RW media
+ an unlimited number of times. Most CD-RW drives can also
+ write once to {CD-R} media.
+
+ CD-RW media cannot be read by CD-ROM drives built prior to
+ 1997 due to the reduced reflectivity (15% compared to 70%) of
+ CD-RW media.
+
+ CD-RW drives and media are currently (1999) more expensive
+ than {CD-R} drives and media. CD-R is sometimes considered a
+ better technology for archival purposes as the data cannot be
+ accidentally modified or tampered with, and encourages better
+ archival practices.
+
+ Standard prerecorded CDs have their information permanently
+ stamped into an aluminium reflecting layer. CD-WR discs have
+ a phase-change recording layer and an additional silver
+ (aluminium) reflecting layer.
+
+ A laser beam can melt crystals in the recording layer into a
+ non-crystalline amorphous phase or anneal them slowly at a
+ lower temperature back to the crystalline state. The different
+ reflectance of the areas make them appear as the 'pits' and
+ 'lands' of a standard CD.
+
+ {Phillips: New Technologies
+ (http://www-us.sv.philips.com/newtech/cdrewritable.html)}.
+
+ See also {CD-R} and {DVD-RAM}.
+
+ (1999-08-01)
+
+Compact Disc writer
+
+ <storage> (CD burner) A device that can write data to {Compact
+ Disc Recordable} (CD-R) or {Compact Disc Rewritable} (CD-RW)
+ discs. Now both these CD formats are often combined with a
+ {DVD writer}.
+
+ (2008-09-16)
+
+compaction
+
+ {compression}
+
+compactness preserving
+
+ <theory> In {domain theory}, a {function} f is compactness
+ preserving if f c is {compact} whenever c is.
+
+ (1995-01-13)
+
+Compaq Computer Corporation
+
+ <company> A US manufacturer and vendor of {IBM PC compatible}
+ {personal computers} and servers. Compaq was started in 1982
+ by three ex-{Texas Instruments} employees and by 1995 had
+ become the largest PC manufacturer.
+
+ Quarterly sales $2499M, profits $210M (Aug 1994).
+
+ Compaq was acquired by {Hewlett-Packard} in 2004.
+
+ {(http://compaq.com/)}.
+
+ (1995-10-24)
+
+Compas Pascal
+
+ The predecessor of {Turbo Pascal}, sol by {POLY Data} of
+ Denmark. It was later renamed POLY Pascal, and afterward
+ sold to {Borland}.
+
+ (1995-01-19)
+
+COMPASS
+
+ COMPrehensive ASSembler.
+
+ The {assembly language} on {CDC} computers.
+
+ (1995-01-19)
+
+compatibility
+
+ {compatible}
+
+compatible
+
+ <jargon> Different systems (e.g., {programs}, {file formats},
+ {protocols}, even {programming languages}) that can work
+ together or exchange data are said to be compatible.
+
+ See also {backward compatible}, {forward compatible}.
+
+ (1998-01-15)
+
+Compatible Timesharing System
+
+ <operating system> (CTSS) One of the earliest (1963)
+ experiments in the design of interactive {time-sharing}
+ {operating systems}. CTSS was ancestral to {Multics}, {Unix},
+ and {ITS}. It was developed at the {MIT} Computation Center
+ by a team led by Fernando J. Corbato. CTSS ran on a modified
+ {IBM 7094} with a second 32K-word bank of memory, using two
+ {2301 drums} for swapping. {Remote access} was provided to up
+ to 30 users via an {IBM 7750} {communications controller}
+ connected to {dial-up} {modems}.
+
+ The name {ITS} (Incompatible {time-sharing} System) was a hack
+ on CTSS, meant both as a joke and to express some basic
+ differences in philosophy about the way I/O services should be
+ presented to user programs.
+
+ (1997-01-29)
+
+Compel
+
+ {COMpute ParallEL}
+
+Competitive Access Provider
+
+ <networking> (CAP, or "Bypass Carrier") A company which
+ provides network links between the customer and the
+ {IntereXchange Carrier} or even directly to the {Internet
+ Service Provider}. CAPs operate private networks independent
+ of {Local Exchange Carriers}.
+
+ ["Getting Connected The Internet at 56k and Up", Kevin Dowd,
+ First Edition, p. 49, O'Reilly & Associates, Inc., June 1996,
+ ISBN 1-56592-154-2 (US), ISBN 1-56592-203-4 (international)].
+
+ (1997-07-23)
+
+Compiled HTML
+
+ <filename extension> A {Microsoft} file format for
+ distributing a collection of {HTML} files, along with their
+ associated images, sounds, etc., as a single compressed
+ archive file.
+
+ Microsoft use this format for {Windows} {HTML Help} files.
+ Most chms include a project (.hhp) file listing the included
+ files and basic settings, a contents (.hhc) file, an index
+ (.hhk) file, html files, and, optionally, image files.
+
+ Users view chms with hh.exe, the HTML Help viewer installed
+ with {Internet Explorer}.
+
+ Filename extension: .chm.
+
+ {(http://msdn.microsoft.com/library/en-us/htmlhelp/html/vsconHH1Start.asp)}.
+
+ (2003-05-17)
+
+compiler
+
+ <programming, tool> A program that converts another program
+ from some {source language} (or {programming language}) to
+ {machine language} (object code). Some compilers output
+ {assembly language} which is then converted to {machine
+ language} by a separate {assembler}.
+
+ A compiler is distinguished from an assembler by the fact that
+ each input statement does not, in general, correspond to a
+ single machine instruction or fixed sequence of instructions.
+ A compiler may support such features as automatic allocation
+ of variables, arbitrary arithmetic expressions, control
+ structures such as FOR and WHILE loops, variable {scope},
+ input/ouput operations, {higher-order functions} and
+ {portability} of source code.
+
+ {AUTOCODER}, written in 1952, was possibly the first primitive
+ compiler. {Laning and Zierler}'s compiler, written in
+ 1953-1954, was possibly the first true working algebraic
+ compiler.
+
+ See also {byte-code compiler}, {native compiler}, {optimising
+ compiler}.
+
+ (1994-11-07)
+
+COmpiler and GENeralized Translator
+
+ <language> (COGENT) A {compiler} writing language with
+ pattern-directed string and list processing features, for {CDC
+ 3600} and {CDC} 3800. A COGENT program consists of
+ {productions} defining a {context-free} language, plus
+ analysis and synthesis function generators.
+
+ ["COGENT Programming Manual", J.C. Reynolds, ANL-7022, Argonne,
+ Mar 1965].
+
+ [Sammet 1969, p.638].
+
+ ["An Introduction to the COGENT System", J.C. Reynolds, Proc
+ ACM 20th Natl Conf, 1965].
+
+ (1994-12-23)
+
+compiler compiler
+
+ {compiler-compiler}
+
+Compiler-Compiler
+
+ An early {compiler generator} for the {Atlas}, with its own
+ distinctive input language.
+
+ ["The Compiler-Compiler", R.A. Brooker et al, Ann Rev
+ Automatic Programming 3:229-275, Pergamon 1963].
+
+ (1994-10-24)
+
+compiler-compiler
+
+ A utility to generate the {source code} of a {parser},
+ {interpreter} or {compiler} from an annotated language
+ description (usually in {BNF}). Most so called
+ compiler-compilers are really just {parser generators}.
+
+ Examples are {Bison}, {Eli}, {FSL}, {META 5}, {MUG2},
+ {Parsley}, {Pre-cc}, {Yacc}.
+
+ (1995-01-23)
+
+compiler jock
+
+ A programmer who specialises in writing {compilers}.
+
+ [{Jargon File}]
+
+ (1995-01-19)
+
+Compiler Language for Information Processing
+
+ (CLIP) A language written in 1958-1959, based on {IAL}, which
+ led to {JOVIAL}. CLIP was one of the first languages used to
+ write its own {compiler}.
+
+ [Sammet 1969, p. 635].
+
+ (1994-12-12)
+
+Compiler Target Language
+
+ (CTL) The intermediate language used by the {ALICE} parallel
+ machine.
+
+ ["The Design and Implementation of ALICE: A Parallel Graph
+ Reduction Machine", M.D. Cripps et al, Proc Workshop on Graph
+ Reduction, Springer 1987].
+
+ (1994-11-14)
+
+compile time
+
+ <programming> The period of time during which a program's
+ {source code} is being translated into {machine code}, as
+ opposed to {run time} when the program is being executed. As
+ well as the work done by the {compiler}, this may include
+ macro preprocessing as done by {cpp} for example. The final
+ stage of program construction, performed by the {linker},
+ would generally also be classed as compile time but might be
+ distinguished as {link time}.
+
+ For example, {static data} in a {C} program is allocated at
+ compile time whereas non-static data is allocated at {run
+ time}, typically on the {stack}.
+
+ (2004-09-28)
+
+COMPL
+
+ <language, operating system>
+
+ ["The COMPL Language and Operating System", A.G. Fraser et al,
+ Computer J 9(2):144-156, 1966].
+
+ (1995-01-24)
+
+complement
+
+ <logic> The other value or values in the set of possible
+ values.
+
+ See {logical complement}, {bitwise complement}, {set
+ complement}.
+
+ (1995-01-24)
+
+Complementary Metal Oxide Semiconductor
+
+ <integrated circuit> (CMOS) A {semiconductor} fabrication
+ technology using a combination of n- and p-doped semiconductor
+ material to achieve low {power dissipation}. Any path through
+ a {gate} through which {current} can flow includes both n and
+ p type {transistors}. Only one type is turned on in any
+ {stable state} so there is no {static power dissipation} and
+ current only flows when a gate switches in order to charge the
+ {parasitic capacitance}.
+
+ (1999-06-04)
+
+complementary nondeterministic polynomial
+
+ <complexity> (Co-NP) The set (or property) of problems with a
+ yes/no answer where the complementary no/yes problem takes
+ {nondeterministic polynomial time} ({NP}).
+
+ For example, "Is n prime" is Co-NP and "Is n not prime" is NP,
+ since it is only necessary to find one {factor} to prove that
+ n is not {prime} whereas to prove that it is prime all possible
+ factors must be eliminated.
+
+ (2009-05-21)
+
+complete
+
+ See also {complete graph}, {complete inference system},
+ {complete lattice}, {complete metric space}, {complete partial
+ ordering}, {complete theory}.
+
+ [1. or 2. or both?]
+
+ (1996-04-24)
+
+complete graph
+
+ A {graph} which has a link between every pair of nodes. A
+ complete {bipartite graph} can be partitioned into two subsets
+ of nodes such that each node is joined to every node in the
+ other subset.
+
+ (1995-01-24)
+
+complete inference system
+
+ <logic> An {inference} system A is complete with respect to
+ another system B if A can reach every conclusion which is true
+ in B. The dual to completeness is {soundness}.
+
+ (1998-07-05)
+
+complete lattice
+
+ A {lattice} is a {partial ordering} of a set under a relation
+ where all finite subsets have a {least upper bound} and a
+ {greatest lower bound}. A complete lattice also has these for
+ infinite subsets. Every finite lattice is complete. Some
+ authors drop the requirement for {greatest lower bounds}.
+
+ (1994-12-02)
+
+complete metric space
+
+ <theory> A {metric space} in which every sequence that
+ converges in itself has a limit. For example, the space of
+ {real numbers} is complete by {Dedekind's axiom}, whereas the
+ space of {rational numbers} is not - e.g. the sequence a[0]=1;
+ a[n_+1]:=a[n]/2+1/a[n].
+
+ (1998-07-05)
+
+completeness
+
+ {complete}
+
+complete partial ordering
+
+ <theory> (cpo) A {partial ordering} of a {set} under a
+ {relation}, where all {directed} {subsets} have a {least upper
+ bound}. A cpo is usually defined to include a least element,
+ {bottom} (David Schmidt calls this a {pointed cpo}). A cpo
+ which is {algebraic} and {boundedly complete} is a (Scott)
+ {domain}.
+
+ (1994-11-30)
+
+complete theory
+
+ <logic> An abstract logical {theory} in which all true
+ statements have formal {proofs} within the theory.
+
+ (1998-07-05)
+
+complete unification
+
+ <programming> W.P. Weijland's name for {unification} without
+ {occur check}.
+
+ (1996-01-11)
+
+Complex Instruction Set Computer
+
+ (CISC) A processor where each instruction can perform several
+ low-level operations such as memory access, arithmetic
+ operations or address calculations. The term was coined in
+ contrast to {Reduced Instruction Set Computer}.
+
+ Before the first RISC processors were designed, many computer
+ architects were trying to bridge the "{semantic gap}" - to
+ design {instruction sets} to support {high-level languages} by
+ providing "high-level" instructions such as procedure call and
+ return, loop instructions such as "decrement and branch if
+ non-zero" and complex {addressing modes} to allow data
+ structure and {array} accesses to be compiled into single
+ instructions.
+
+ While these architectures achieved their aim of allowing
+ high-level language constructs to be expressed in fewer
+ instructions, it was observed that they did not always result
+ in improved performance. For example, on one processor it was
+ discovered that it was possible to improve the performance by
+ NOT using the procedure call instruction but using a sequence
+ of simpler instructions instead. Furthermore, the more
+ complex the instruction set, the greater the overhead of
+ decoding an instruction, both in execution time and silicon
+ area. This is particularly true for processors which used
+ {microcode} to decode the (macro) instruction. It is easier
+ to debug a complex instruction set implemented in microcode
+ than one whose decoding is "{hard-wired}" in silicon.
+
+ Examples of CISC processors are the {Motorola} {680x0} family
+ and the {Intel 80186} through {Intel 486} and {Pentium}.
+
+ (1994-10-10)
+
+complexity
+
+ <algorithm> The level in difficulty in solving mathematically
+ posed problems as measured by the time, number of steps or
+ arithmetic operations, or memory space required (called time
+ complexity, computational complexity, and space complexity,
+ respectively).
+
+ The interesting aspect is usually how complexity scales with
+ the size of the input (the "{scalability}"), where the size of
+ the input is described by some number N. Thus an {algorithm}
+ may have computational complexity O(N^2) (of the order of the
+ square of the size of the input), in which case if the input
+ doubles in size, the computation will take four times as many
+ steps. The ideal is a constant time algorithm (O(1)) or
+ failing that, O(N).
+
+ See also {NP-complete}.
+
+ (1994-10-20)
+
+complexity analysis
+
+ In sructured program design, a quality-control operation that
+ counts the number of "compares" in the logic implementing a
+ function; a value of less than 10 is considered acceptable.
+
+complexity class
+
+ <algorithm> A collection of {algorithms} or {computable
+ functions} with the same {complexity}.
+
+ (1996-04-24)
+
+complexity measure
+
+ <algorithm> A quantity describing the {complexity} of a
+ computation.
+
+ (1996-04-24)
+
+complex number
+
+ <mathematics> A number of the form x+iy where i is the square
+ root of -1, and x and y are {real numbers}, known as the
+ "real" and "imaginary" part. Complex numbers can be plotted
+ as points on a two-dimensional plane, known as an {Argand
+ diagram}, where x and y are the {Cartesian coordinates}.
+
+ An alternative, {polar} notation, expresses a complex number
+ as (r e^it) where e is the base of {natural logarithms}, and r
+ and t are real numbers, known as the magnitude and phase. The
+ two forms are related:
+
+ r e^it = r cos(t) + i r sin(t)
+ = x + i y
+ where
+ x = r cos(t)
+ y = r sin(t)
+
+ All solutions of any {polynomial equation} can be expressed as
+ complex numbers. This is the so-called {Fundamental Theorem
+ of Algebra}, first proved by Cauchy.
+
+ Complex numbers are useful in many fields of physics, such as
+ electromagnetism because they are a useful way of representing
+ a magnitude and phase as a single quantity.
+
+ (1995-04-10)
+
+complex programmable logic device
+
+ <hardware> (CPLD) A programmable circuit similar to an {FPGA},
+ but generally on a smaller scale, invented by {Xilinx, Inc}.
+
+ (1998-09-26)
+
+component
+
+ <programming> An {object} adhering to a {component
+ architecture}.
+
+ (1997-11-20)
+
+component architecture
+
+ <programming> A notion in {object-oriented} programming where
+ "components" of a program are completely generic. Instead of
+ having a specialised set of {methods} and {fields} they have
+ generic methods through which the component can advertise the
+ functionality it supports to the system into which it is
+ loaded. This enables completely {dynamic loading} of
+ {objects}. {JavaBeans} is an example of a component
+ architecture.
+
+ See also {design pattern}.
+
+ (1997-11-20)
+
+component based development
+
+ <programming> (CBD) The creation, integration, and {re-use} of
+ {components} of program code, each of which has a common
+ interface for use by multiple systems.
+
+ (1999-08-23)
+
+Component Integration Laboratories
+
+ <project> (CIL) An effort to create a common framework for
+ interoperability between {application programs} on {desktop}
+ {platforms}, formed by {Apple Computer, Inc.}, {IBM},
+ {Novell}, {Oracle}, {Taligent}, {WordPerfect} and {Xerox}.
+
+ [When? What happened?]
+
+ (1994-10-24)
+
+Component Object Model
+
+ <programming> (COM) An open software architecture from {DEC}
+ and {Microsoft}, allowing interoperation between
+ {ObjectBroker} and {OLE}. Microsoft evolved COM into {DCOM}.
+
+ On page XV of Box's book in the foreword by Charlie Kindel he
+ says, "It is Mark Ryland's fault that some people call COM the
+ 'Common Object Model.' He deeply regrets it and apologizes
+ profusely."
+
+ ["Essential COM", Don Box].
+
+ [Details? URL?]
+
+ (1999-06-12)
+
+com port
+
+ {communications port}
+
+composite
+
+ {aggregate}
+
+composition
+
+ 1. {function composition}.
+
+ 2. {typesetting}.
+
+Compositional C++
+
+ <language, parallel> (CC++) Extensions to {C++} for
+ {compositional parallel programming}.
+
+ {FTP Caltech (ftp://csvax.cs.caltech.edu/pub/comp)}.
+
+ [Did Carl Kesselman at Cal Tech develop it?]
+
+ (2000-08-16)
+
+Compound Document Architecture
+
+ <file format> (CDA) {DEC}'s set of {standards} for compound
+ document creation, storage, retrieval, interchange and
+ manipulation.
+
+ (1996-11-03)
+
+compound key
+
+ <database> (Or "multi-part key", "concatenated key") A {key}
+ which consists of more than one {attribute} of the body of
+ information (e.g. database "{record}") it identifies.
+
+ (1997-04-26)
+
+COMPREHENSIVE
+
+ An early system on {MIT}'s {Whirlwind}.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (2002-06-03)
+
+Comprehensive Perl Archive Network
+
+ <tool> (CPAN) A collection of {Internet} {archives} containing
+ material related to the {Perl} programming language.
+
+ {(http://perl.com/CPAN)}.
+
+ (1999-12-04)
+
+Comprehensive TeX Archive Network
+
+ <text> (CTAN) An {archive site} for the {TeX} text formatting
+ package.
+
+ {(http://tex.ac.uk)}. {Gopher
+ (gopher://gopher.tex.ac.uk/)}. {(ftp://ftp.tex.ac.uk/)}.
+ NFS: nfs.tex.ac.uk.
+
+ (1995-01-18)
+
+compress
+
+ 1. To feed data through any {compression} {algorithm}.
+
+ 2. <tool> The {Unix} program "compress", now largely
+ supplanted by {gzip}.
+
+ Unix compress was written in {C} by Joseph M. Orost, James
+ A. Woods et al., and was widely circulated via {Usenet}. It
+ uses the {Lempel-Ziv Welch} {algorithm} and normally produces
+ files with the suffix ".Z".
+
+ Compress uses variable length codes. Initially, nine-bit
+ codes are output until they are all used. When this occurs,
+ ten-bit codes are used and so on, until an
+ implementation-dependent maximum is reached.
+
+ After every 10 {kilobytes} of input the compression ratio is
+ checked. If it is decreasing then the entire string table is
+ discarded and information is collected from scratch.
+
+Compressed SLIP
+
+ <networking> (CSLIP) {VanJacobsen TCP header compression}. A
+ version of {SLIP} using {compression}. CSLIP has no effect on
+ the data portion of the {packet} and has nothing to do with
+ compression by {modem}. It does reduce the {TCP} header from
+ 40 bytes to 7 bytes, a noticeable difference when doing
+ {telnet} with lots of little packets. CSLIP has no effect on
+ UDP, only TCP.
+
+ (1995-05-28)
+
+compressed video
+
+ {video compression}
+
+compression
+
+ 1. <application> (Or "compaction") The coding of data to save
+ storage space or transmission time. Although data is already
+ coded in digital form for computer processing, it can often be
+ coded more efficiently (using fewer bits). For example,
+ {run-length encoding} replaces strings of repeated characters
+ (or other units of data) with a single character and a count.
+ There are many compression {algorithms} and utilities.
+ Compressed data must be decompressed before it can be used.
+
+ The standard {Unix} compression utilty is called {compress}
+ though {GNU}'s superior {gzip} has largely replaced it. Other
+ compression utilties include {pack}, {zip} and {PKZIP}.
+
+ When compressing several similar files, it is usually better
+ to join the files together into an {archive} of some kind
+ (using {tar} for example) and then compress them, rather than
+ to join together individually compressed files. This is
+ because some common compression {algorithms} build up tables
+ based on the data from their current input which they have
+ already compressed. They then use this table to compress
+ subsequent data more efficiently.
+
+ See also {TIFF}, {JPEG}, {MPEG}, {Lempel-Ziv Welch},
+ "{lossy}", "{lossless}".
+
+ {Compression FAQ
+ (ftp://rtfm.mit.edu/pub/usenet/news.answers/compression-faq/)}.
+
+ {Web Content Compression FAQ
+ (http://perl.apache.org/docs/tutorials/client/compression/compression.html)}.
+
+ {Usenet} newsgroups: {news:comp.compression},
+ {news:comp.compression.research}.
+
+ 2. <multimedia> Reducing the dynamic range of an audio signal,
+ making quiet sounds louder and loud sounds quieter. Thus,
+ when discussing digital audio, the preferred term for reducing
+ the total amount of data is "compaction". Some advocate this
+ term in all contexts.
+
+ (2004-04-26)
+
+COMPROSL
+
+ COMpound PROcedural Scientific Language.
+
+ A language for scientists and engineers.
+
+ [Sammet 1969, pp. 299-300].
+
+Compu$erve
+
+ (Or "CompuSpend", "Compu$pend") A pejorative name for
+ {CompuServe Information Service} ({CI$}) drawing attention to
+ perceived high charges.
+
+ [{Jargon File}]
+
+ (1994-11-08)
+
+Compulink Information eXchange
+
+ (CIX) A London-based conferencing system, also providing
+ {electronic mail}, {FTP}, {telnet}, {IRC}, {Gopher} and
+ {web}. Includes conferences "archimedes" or "bbc"
+ for users of {Acorn} computers.
+
+ E-mail: <cixadmin@cix.compulink.co.uk>.
+
+ Telephone: +44 (181) 390 8446.
+
+ (1994-11-08)
+
+CompuServe
+
+ {CompuServe Information Service}
+
+CompuServe Corporation
+
+ <company> The parent organisation of {CompuServe Information
+ Service}, CompuServe Network Services and CompuServe Remote
+ Computing Services. CompuServe was owned by H.R. Block but is
+ now (1999) owned by {America On-Line}.
+
+ {(http://compuserve.com/)}.
+
+ (1995-09-12)
+
+CompuServe Information Service
+
+ <company> (CIS, CompuServe Interactive Services). An ISP and
+ on-line service {portal} based in Columbus, Ohio, USA; part of
+ {AOL} since February 1998.
+
+ CIS was founded in 1969 as a computer {time-sharing service}.
+ Along with {AOL} and {Prodigy}, CIS was one of the first
+ pre-Internet, on-line services for consumers, providing
+ {bulletin boards}, on-line conferencing, business news, sports
+ and weather, financial transactions, {electronic mail},
+ {Usenet} news, travel and entertainment data and on-line
+ editions of computer publications. CIS was originally run by
+ {CompuServe Corporation}.
+
+ In 1979, CompuServe was the first service to offer {electronic
+ mail} and technical support to personal computer users. In
+ 1980 they were the first to offer {real-time} {chat} with its
+ CB Simulator. By 1982, the company had formed its Network
+ Services Division to provide wide-area networking to corporate
+ clients.
+
+ Initially mostly serving the USA, in 1986 they developed a
+ Japanese version called NIFTYSERVE. In 1989, they expanded
+ into Europe and became a leading {Internet service provider}.
+
+ In 2001 they released version 7.0 of their client program.
+
+ {CompuServe home (http://compuserve.com/)}.
+
+ (2009-04-02)
+
+CompuServe Interactive Services
+
+ {CompuServe Information Service}
+
+Compusult Ltd.
+
+ A computer consulting firm (in Newfoundland, Canada?) that
+ provides a public access {Unix}.
+
+ (1994-10-20)
+
+computability theory
+
+ <mathematics> The area of theoretical computer science
+ concerning what problems can be solved by any computer.
+
+ A function is computable if an {algorithm} can be implemented
+ which will give the correct output for any valid input.
+
+ Since computer programs are {countable} but {real numbers} are
+ not, it follows that there must exist real numbers that
+ cannot be calculated by any program. Unfortunately, by
+ definition, there isn't an easy way of describing any of them!
+
+ In fact, there are many tasks (not just calculating real
+ numbers) that computers cannot perform. The most well-known
+ is the {halting problem}, the {busy beaver} problem is less
+ famous but just as fascinating.
+
+ ["Computability", N.J. Cutland. (A well written
+ undergraduate-level introduction to the subject)].
+
+ ["The Turing Omnibus", A.K. Dewdeney].
+
+ (1995-01-13)
+
+computable
+
+ {computability theory}
+
+Computational Adequacy Theorem
+
+ This states that for any program (a non-function typed term in
+ the {typed lambda-calculus} with constants) {normal order
+ reduction} (outermost first) fails to terminate if and only if
+ the {standard semantics} of the term is {bottom}. Moreover,
+ if the reduction of program e1 terminates with some {head
+ normal form} e2 then the standard semantics of e1 and e2 will
+ be equal. This theorem is significant because it relates the
+ operational notion of a reduction sequence and the
+ {denotational semantics} of the input and output of a
+ reduction sequence.
+
+computational complexity
+
+ <algorithm> The number of steps or arithmetic operations
+ required to solve a computational problem. One of the three
+ kinds of {complexity}.
+
+ (1996-04-24)
+
+Computational Fluid Dynamics
+
+ <language> (CFD) A {Fortran}-based parallel language for the
+ {Illiac IV}.
+
+ (1994-11-29)
+
+computational geometry
+
+ <mathematics> The study of {algorithms} for combinatorial,
+ topological, and metric problems concerning sets of points,
+ typically in {Euclidean space}. Representative areas of
+ research include geometric search, convexity, proximity,
+ intersection, and {linear programming}.
+
+ (1997-08-03)
+
+computational learning
+
+ {grammatical inference}
+
+computational molecular biology
+
+ <application> The area of {bioinformatics} concerning the use
+ of computers to characterise the molecular components of
+ living things.
+
+ (2005-01-07)
+
+COMpute ParallEL
+
+ <language> (Compel) The first {single-assignment} language.
+
+ ["A Language Design for Concurrent Processes", L.G. Tesler et
+ al, Proc SJCC 32:403-408, AFIPS (Spring 1968)].
+
+ (1995-01-19)
+
+Computer
+
+ <publication> A journal of the {IEEE Computer Society}.
+
+ (1995-03-10)
+
+computer
+
+ <computer> A machine that can be programmed to manipulate
+ symbols. Computers can perform complex and repetitive
+ procedures quickly, precisely and reliably and can quickly
+ store and retrieve large amounts of data.
+
+ The physical components from which a computer is constructed
+ (electronic circuits and input/output devices) are known as
+ "{hardware}". Most computers have four types of hardware
+ component: CPU, input, output and memory. The CPU ({central
+ processing unit}) executes programs ("{software}") which tell
+ the computer what to do. Input and output (I/O) devices allow
+ the computer to communicate with the user and the outside
+ world. There are several kinds of memory - fast, expensive,
+ short term memory (e.g. {RAM}) to hold intermediate results,
+ and slower, cheaper, long-term memory (e.g. {magnetic disk} and
+ {magnetic tape}) to hold programs and data between jobs.
+
+ See also {analogue computer}.
+
+ (1995-03-10)
+
+Computer Aided Design
+
+ <application> (CAD) The part of {CAE} concerning the drawing
+ or physical layout steps of engineering design. Often found
+ in the phrase "CAD/CAM" for ".. manufacturing".
+
+ (1994-11-30)
+
+Computer Aided Detector Design
+
+ <project, standard> (CADD) A project to standardise {HEP}
+ detector designer.
+
+ (2011-02-18)
+
+Computer Aided Engineering
+
+ <application> (CAE) The use of {software} to help with all
+ phases of engineering design work. Like {computer aided
+ design}, but also involving the conceptual and analytical
+ design steps and extending into {Computer-Integrated
+ Manufacturing} (CIM).
+
+ (1994-10-28)
+
+Computer-Aided Instruction
+
+ <application, education> (CAI, or "- assisted", "- learning",
+ CAL, Computer-Based Training CBT, "e-learning") The use of
+ computers for education and training.
+
+ The programs and data used in CAI, known as "courseware", may
+ be supplied on media such as {CD-ROM} or delivered via a
+ {network} which also enables centralised logging of student
+ progress. CAI may constitute the whole or part of a course,
+ may be done individually or in groups ("Computer Supported
+ Collaborative Learning", CSCL), with or without human
+ guidance.
+
+ (2011-11-25)
+
+Computer-Aided Learning
+
+ {Computer-Aided Instruction}
+
+Computer Aided Software Engineering
+
+ <programming> (CASE, or "- assisted -") A technique for using
+ computers to help with one or more phases of the {software
+ life-cycle}, including the systematic analysis, design,
+ implementation and maintenance of software. Adopting the CASE
+ approach to building and maintaining systems involves software
+ tools and training for the developers who will use them.
+
+ (1996-05-10)
+
+Computer-Aided Software Testing
+
+ <programming> (CAST) Automated software testing in one or more
+ phases of the {software life-cycle}.
+
+ (1996-05-10)
+
+Computer Aided Test Engineering
+
+ <testing, electronics> (CATE) {CASE} methods applied to
+ electronics testing and linked to {CAE}.
+
+ (2007-05-03)
+
+Computer Animation Movie Language
+
+ <language> A programming language for generating {animation}.
+
+ ["A Computer Animation Movie Language for Educational Motion
+ Pictures", D.D. Weiner et al, Proc FJCC 33(2), AFIPS, Fall
+ 1968].
+
+ (2012-01-30)
+
+Computer-Assisted Learning
+
+ {Computer-Aided Instruction}
+
+Computer-Assisted Software Engineering
+
+ {Computer-Aided Software Engineering}
+
+Computer Associates International, Inc.
+
+ <company> (CA) A US software development company, founded in
+ 1976. CA have purchased many other software companies,
+ including {Spectrum Software, Inc.}, {Cheyenne Software},
+ {Platinum Technology, Inc.}, {ASK Corporation}. They produce
+ a number of popular software packages, including {Unicenter
+ TNG} and {Ingres}.
+
+ They had an {Initial Public Offering} in 1981 valued at more
+ than US$3.2M, had more than US$6B in revenue in 2000, and
+ employ more than 17,000 people.
+
+ {(http://ca.com/)}.
+
+ (20002-04-20)
+
+Computer-Based Training
+
+ {Computer-Aided Instruction}
+
+computer bus
+
+ {bus}
+
+Computer Compiler
+
+ 1. <language> A proposed language for {compiler} design.
+
+ [Sammet 1969, p. 695].
+
+ 2. A discussion of various applications of computers to the
+ design and production of computers.
+
+ {ACM
+ (http://dl.acm.org/citation.cfm?id=1464213&CFID=83216609&CFTOKEN=42516197)}.
+
+ ["A proposal for a computer compiler", Gernot Metze
+ (University of Illinois), Sundaram Seshu (University of
+ Illinois), AFIPS '66 (Spring) Proceedings of the 1966-04-26 -
+ 28, Spring joint computer conference].
+
+ (2007-02-13)
+
+computer confetti
+
+ <jargon> (Or "{chad}") A common term for {punched-card}
+ {chad}, which, however, does not make good confetti, as the
+ pieces are stiff and have sharp corners that could injure the
+ eyes.
+
+ {GLS} reports that he once attended a wedding at {MIT} during
+ which he and a few other guests enthusiastically threw chad
+ instead of rice. The groom later grumbled that he and his
+ bride had spent most of the evening trying to get the stuff
+ out of their hair.
+
+ [{Jargon File}]
+
+ (2001-06-22)
+
+Computer Conservation Society
+
+ <body> (CCS) A british group that aims to promote the
+ conservation and study of historic computers, past and future.
+ The CCS is a co-operative venture between the {British
+ Computer Society}, the Science Museum of London and the Museum
+ of Science and Industry in Manchester. The CCS was
+ constituted in September 1989 as a Specialist Group of the
+ BCS.
+
+ A number of active projects and working groups focus on
+ specific computer restorations, early computer technologies
+ and software. Membership is open to anyone interested.
+
+ {Home (http://computerconservationsociety.org)}.
+
+ See also {Bletchley Park}.
+
+ (2012-03-22)
+
+computer cookie
+
+ {HTTP cookie}
+
+computer crime
+
+ <legal> Breaking the criminal law by use of a computer.
+
+ See also {computer ethics}, {software law}.
+
+ (1997-07-09)
+
+Computer Design Language
+
+ <language> An {ALGOL}-like language for computer design.
+
+ ["An ALGOL-like Computer Design Language", Y. Chu, CACM 8(10)
+ (Oct 1965)].
+
+ (1994-11-17)
+
+computer dictionary
+
+ {Free On-line Dictionary of Computing}
+
+Computer Emergency Response Team
+
+ <security, body> (CERT) An organisation formed by {DARPA} in
+ November 1988 in response to the {Internet worm} incident.
+ The CERT charter is to work with the {Internet} community to
+ help it responf to computer security events involving Internet
+ {hosts}, to raise awareness of computer security issues and to
+ conduct research targeted at improving the security of
+ existing systems. CERT products and services include 24-hour
+ technical assistance for responding to computer security
+ incidents, product vulnerability assistance, technical
+ documents and tutorials.
+
+ {CERT Home (http://cert.org/)}.
+
+ E-mail: <cert@cert.org> (incident reports).
+
+ Telephone +1 (412) 268 7090 (24-hour hotline).
+
+ (2012-05-18)
+
+computer ethics
+
+ <philosophy> Ethics is the field of study that is concerned
+ with questions of value, that is, judgments about what human
+ behaviour is "good" or "bad". Ethical judgments are no
+ different in the area of computing from those in any other
+ area. Computers raise problems of privacy, ownership, theft,
+ and power, to name but a few.
+
+ Computer ethics can be grounded in one of four basic
+ world-views: Idealism, Realism, Pragmatism, or Existentialism.
+ Idealists believe that reality is basically ideas and that
+ ethics therefore involves conforming to ideals. Realists
+ believe that reality is basically nature and that ethics
+ therefore involves acting according to what is natural.
+ Pragmatists believe that reality is not fixed but is in
+ process and that ethics therefore is practical (that is,
+ concerned with what will produce socially-desired results).
+ Existentialists believe reality is self-defined and that
+ ethics therefore is individual (that is, concerned only with
+ one's own conscience). Idealism and Realism can be considered
+ ABSOLUTIST worldviews because they are based on something
+ fixed (that is, ideas or nature, respectively). Pragmatism
+ and Existentialism can be considered RELATIVIST worldviews
+ because they are based or something relational (that is,
+ society or the individual, respectively).
+
+ Thus ethical judgments will vary, depending on the judge's
+ world-view. Some examples:
+
+ First consider theft. Suppose a university's computer is used
+ for sending an e-mail message to a friend or for conducting a
+ full-blown private business (billing, payroll, inventory,
+ etc.). The absolutist would say that both activities are
+ unethical (while recognising a difference in the amount of
+ wrong being done). A relativist might say that the latter
+ activities were wrong because they tied up too much memory and
+ slowed down the machine, but the e-mail message wasn't wrong
+ because it had no significant effect on operations.
+
+ Next consider privacy. An instructor uses her account to
+ acquire the cumulative grade point average of a student who is
+ in a class which she instructs. She obtained the password for
+ this restricted information from someone in the Records Office
+ who erroneously thought that she was the student's advisor.
+ The absolutist would probably say that the instructor acted
+ wrongly, since the only person who is entitled to this
+ information is the student and his or her advisor. The
+ relativist would probably ask why the instructor wanted the
+ information. If she replied that she wanted it to be sure
+ that her grading of the student was consistent with the
+ student's overall academic performance record, the relativist
+ might agree that such use was acceptable.
+
+ Finally, consider power. At a particular university, if a
+ professor wants a computer account, all she or he need do is
+ request one but a student must obtain faculty sponsorship in
+ order to receive an account. An absolutist (because of a
+ proclivity for hierarchical thinking) might not have a problem
+ with this divergence in procedure. A relativist, on the other
+ hand, might question what makes the two situations essentially
+ different (e.g. are faculty assumed to have more need for
+ computers than students? Are students more likely to cause
+ problems than faculty? Is this a hold-over from the days of
+ "in loco parentis"?).
+
+ {"Philosophical Bases of Computer Ethics", Professor Robert
+ N. Barger (http://nd.edu/~rbarger/metaethics.html)}.
+
+ {Usenet} newsgroups: {news:bit.listserv.ethics-l},
+ {news:alt.soc.ethics}.
+
+ (1995-10-25)
+
+computer file
+
+ {file}
+
+computer geek
+
+ <jargon> (Or "turbo nerd", "turbo geek") One who eats
+ (computer) {bugs} for a living. One who fulfils all the
+ dreariest negative stereotypes about {hackers}: an asocial,
+ malodourous, pasty-faced monomaniac with all the personality
+ of a cheese grater. The term cannot be used by outsiders
+ without implied insult to all {hackers}; compare
+ black-on-black usage of "nigger". A computer geek may be
+ either a fundamentally clueless individual or a proto-hacker
+ in {larval stage}.
+
+ See also {Alpha Geek}, {propeller head}, {clustergeeking},
+ {geek out}, {wannabee}, {terminal junkie}, {spod}, {weenie}.
+
+ [{Jargon File}]
+
+ (1997-06-26)
+
+computer-generated imagery
+
+ <graphics> (CGI) Animatied graphics produced by computer and
+ used in film or television.
+
+ (1998-10-13)
+
+Computer Generation Incorporated
+
+ <company> (CGI) A US software development company and systems
+ integrator.
+
+ {(http://compgen.com/)}.
+
+ E-mail: Paul G. Smith <pauls@compgen.com>
+
+ Telephone: +1 (404) 705 2800
+
+ Address: Bldg. G, 4th Floor, 5775 Peachtree-Dunwoody Rd.,
+ Atlanta, GA 30342, USA.
+
+ (1997-02-11)
+
+Computer Graphics Metafile
+
+ <graphics, file format> (CGM) A standard file format for
+ storage and communication of graphical information, widely
+ used on {personal computers} and accepted by {desktop
+ publishing} and technical illustration systems.
+
+ {MIME type}: image/cgm.
+
+ {ANSI}/{ISO} 8632-1987. Worked on by the {ISO}/{IEC} group
+ {JTC1/SC24}.
+
+ {CGM Open Consortium (http://cgmopen.org/)}.
+
+ See also: {WebCGM}.
+
+ (1999-02-16)
+
+Computer Integrated Manufacturing
+
+ <application> (CIM) Use of computers to control multiple
+ aspects of a production process in a factory. A CIM system
+ may control and/or monitor areas such as design, analysis,
+ planning, purchasing, cost accounting, inventory control,
+ distribution, materials handling and management.
+
+ (2003-06-07)
+
+computer language
+
+ {programming language}
+
+Computer Language for AeronauticS and Programming
+
+ <language> (CLASP) A {real-time} language from NASA, focussing
+ on {fixed-point} mathematics. CLASP is a near subset of
+ {SPL}, with some ideas from {PL/I}.
+
+ ["Flight Computer and Language Processor Study", Raymond
+ J. Rubey, Management Information Services, Detroit, 1971].
+
+ (1994-10-13)
+
+computer law
+
+ <legal> Legal aspects of the production, sale and use of
+ computers; including areas such as {software law},
+ {copyright}, patents, sale of goods, communication law and
+ general media issues such as free speech.
+
+ (2012-08-30)
+
+computer literacy
+
+ <education> Basic skill in use of computers, from the
+ perspective of such skill being a necessary societal skill.
+
+ The term was coined by Andrew Molnar, while director of the
+ Office of Computing Activities at the {National Science
+ Foundation}.
+
+ "We started computer literacy in '72 [...] We coined that
+ phrase. It's sort of ironic. Nobody knows what computer
+ literacy is. Nobody can define it. And the reason we
+ selected [it] was because nobody could define it, and [...] it
+ was a broad enough term that you could get all of these
+ programs together under one roof" (cited in Aspray, W.,
+ (September 25, 1991) "Interview with Andrew Molnar," OH 234.
+ Center for the History of Information Processing, Charles
+ Babbage Institute, University of Minnesota).
+
+ The term, as a coinage, is similar to earlier coinages, such
+ as "visual literacy", which {Merriam-Webster
+ (http://m-w.com/)} dates to 1971, and the more recent
+ "media literacy".
+
+ A more useful definition from
+ {(http://www.computerliteracyusa.com/)} is:
+
+ Computer literacy is an understanding of the concepts,
+ terminology and operations that relate to general computer
+ use. It is the essential knowledge needed to function
+ independently with a computer. This functionality includes
+ being able to solve and avoid problems, adapt to new
+ situations, keep information organized and communicate
+ effectively with other computer literate people.
+
+ (2007-03-23)
+
+Computer Management Group of Australia
+
+ <body> (CMGA) An Australian group that organises conferences,
+ exhibitions, meetings and seminars about IT management for its
+ corporate and individual members.
+
+ {CMGA Home (http://cmga.org.au/)}.
+
+ (2012-10-25)
+
+Computer Mediated Communication
+
+ <messaging> (CMC) Communication that takes place through, or
+ is facilitated by, computers. Examples include {e-mail}, the
+ {web}, real-time {chat} tools like {IRC}, {Windows
+ Live Messenger} and {video conferencing}.
+
+ (2012-10-25)
+
+computer nerd
+
+ {computer geek}
+
+computer network
+
+ {network}
+
+Computer Output on Microfilm
+
+ {Enterprise Report Management}
+
+Computer Output to Laser Disc
+
+ {Enterprise Report Management}
+
+Computer Output to Laser Disk
+
+ {Enterprise Report Management}
+
+Computer Professionals for Social Responsibility
+
+ <body> (CPSR) A non-profit organisation whose mission is to
+ provide the public and policymakers with realistic assessments of
+ the power, promise and problems of {Information Technology} and
+ the effects of computers on society.
+
+ CPSR was founded in the USA in 1981 but has spread to many other
+ countries. CPSR is supported by its membership. CPSR sponsors
+ conferences such as their Annual Meeting, Directions and
+ Implications in Advanced Computing (DIAC), the Participatory
+ Design Conference (PDC) and the Computers, Freedom and Privacy
+ (CFP) conference.
+
+ {CPSR Home (http://cpsr.org/)}.
+
+ (2012-11-04)
+
+computer program
+
+ {software}
+
+Computer + Science NETwork
+
+ <body> (CSNET) The networking organisation which combined with
+ {BITNET} to form {CREN}.
+
+ (1994-11-30)
+
+computer security
+
+ {security}
+
+computer sex
+
+ <jargon> Two computers interfaced with each other.
+
+ (1996-02-22)
+
+Computer Software Configuration Item
+
+ <jargon, software> (CSCI) A {configuration item} consisting of
+ {software}.
+
+ (2012-11-07)
+
+Computer-Supported Collaborative Learning
+
+ <education> (CSCL) Any form of {Computer-Aided Instruction}
+ that emphasises group learning as opposed to working alone.
+
+ (2011-11-25)
+
+Computer Supported Cooperative Work
+
+ <tool> (CSCW) (Or "groupware") Software tools and technology
+ to support groups of people working together on a project,
+ often at different sites.
+
+ See also {Lotus Notes}.
+
+ (1994-11-30)
+
+Computer Telephone Integration
+
+ <communications> (CTI or "- Telephony -") Enabling computers to
+ know about and control telephony functions such as making and
+ receiving voice, {fax} and data calls, telephone directory
+ services and {caller identification}.
+
+ CTI is used in call centres to link incoming calls to computer
+ software functions such as database look-up of the caller's
+ number, supported by services such as {Automatic Number
+ Identification} and {Dialled Number Identification Service}.
+
+ Application software ({middleware}) can link {personal computers}
+ and servers with telephones and/or a {PBX}. Telephony and
+ {software} vendors such as {AT&T}, {British Telecom}, {IBM},
+ {Novell}, {Microsoft} and {Intel} have developed CTI services.
+
+ The main {CTI} functions are integrating {messaging} with
+ {databases}, {word processors} etc.; controlling voice, {fax},
+ and {e-mail} messaging systems from a single {application
+ program}; graphical call control - using a {graphical user
+ interface} to perform functions such as making and receiving
+ calls, forwarding and conferencing; call and {data}
+ association - provision of information about the caller from
+ databases or other applications automatically before the call
+ is answered or transferred; {speech synthesis} and {speech
+ recognition}; automatic logging of call related information
+ for invoicing purposes or callback.
+
+ CTI can improve customer service, increase productivity, reduce
+ costs and enhance workflow automation.
+
+ IBM were one of the first with workable CTI, now sold as
+ "CallPath". {Callware}'s {Phonetastic} is another {middleware}
+ product.
+
+ CTI came out of the 1980s call centre boom, where it linked
+ central servers and {IVRs} with {PBX}es to provide call
+ transfer and {screen popping}. In the 1990s, efforts were
+ made by several vendors, such as IBM, Novell {TSAPI} and
+ Microsoft {TAPI}, to provide a version for {desktop computers}
+ that would allow control of a desktop telephone and assist in
+ {hot desking}.
+
+ See also {Telephony Application Programming Interface}.
+
+ (2012-11-18)
+
+Computer Telephony
+
+ {Computer Telephone Integration}
+
+Computer Telephony Integration
+
+ {Computer Telephone Integration}
+
+computer virus
+
+ {virus}
+
+computer vision
+
+ <application> A branch of {artificial intelligence} and {image
+ processing} concerned with computer processing of images from the
+ real world. Computer vision typically requires a combination of
+ low level {image processing} to enhance the image quality
+ (e.g. remove noise, increase contrast), {pattern recognition} to
+ recognise features such as lines, areas and colours and {image
+ understanding} to translate these features into knowledge about
+ the objects in the scene.
+
+ {Usenet} newsgroup: {news:comp.ai.vision}.
+
+ (2012-12-25)
+
+compute server
+
+ <computer, parallel> A kind of {parallel processor} where the
+ parallel processors have no I/O except via a bus or other
+ connection to a {front-end processor} which handles all I/O to
+ disks, {terminals} and network.
+
+ In some antiquated {IBM} {mainframes}, a second CPU was
+ provided that could not access I/O devices, known as the slave
+ or attached processor, while the CPU having access to all
+ devices was known as the master processor.
+
+ (1995-03-19)
+
+computing
+
+ {computer}
+
+Computing Devices Canada Ltd.
+
+ {General Dynamics Canada Ltd.}
+
+computing dictionary
+
+ {Free On-line Dictionary of Computing}
+
+computron
+
+ <jargon> /kom'pyoo-tron"/ 1. A notional unit of computing power
+ combining execution speed and storage capacity. E.g. "That
+ machine can't run GNU Emacs, it doesn't have enough computrons!"
+
+ 2. A mythical subatomic particle that carries computation or
+ information, in much the same way that an electron carries
+ electric charge (see also {bogon}).
+
+ [{Jargon File}]
+
+ (2013-03-02)
+
+Compuware Corporation
+
+ <company> A US {software} and service company established in 1973.
+ Since 1973, Compuware focused on optimising business software
+ development, testing and operation. In 1999 the company had grown
+ to over 15,000 employees worldwide and revenues of more than
+ $1.6B. By 2013 it had shrunk to less than 5000.
+
+ Current (2013) products and services include performance
+ optimisation, availability and quality of web, non-web, mobile,
+ streaming and cloud applications; project portfolio management,
+ professional services automation; mainframe applications and
+ developer tools; rapid application development and professional
+ services.
+
+ {(http://compuware.com/)}.
+
+ (2013-03-08)
+
+COMSL
+
+ <language> ["COMSL - A Communication System Simulation Language",
+ R.L. Granger, Proc FJCC 37 (1970)].
+
+ (2013-03-08)
+
+COMTRAN
+
+ ["Communications Computer Language COMTRAN", D.W. Clark et al,
+ RADC-TR-69-190, Rose Air Development Center, Griffiss AFB, NY,
+ July 1969].
+
+ [Sammet 1969, p.324, 331].
+
+ConC
+
+ <language> A {concurrent} extension of {C} based on {decomposed
+ Petri nets}. It uses the 'handshake' and 'unit' constructs.
+
+ ["ConC: A Language for Distributed Real-Time Programming",
+ V.K. Garg et al, Computer Langs 16(1):5-18 (1991)].
+
+ (1995-03-02)
+
+concatenate
+
+ <programming> To join together two or more files or lists to form
+ one big one.
+
+ The {Unix} {cat} command can be used to concatenate files.
+
+ (1995-12-22)
+
+concatenated key
+
+ {compound key}
+
+concentrator
+
+ <communications> A device that combines the data streams from
+ many simultaneously active inputs into one shared channel in
+ such a way that the streams can be separated after
+ transmission. The concentrator's output bandwidth must be at
+ least as great as the total bandwidth of all simultaneously
+ active inputs. A concentrator is one kind of {multiplexing}
+ device.
+
+ For example, a concentrator may be used to connect 24 2400 bps
+ TTYs to a host via a 57600 bps channel.
+
+ (2000-03-01)
+
+conceptualisation
+
+ <artificial intelligence> The process or result of listing the
+ types of objects, concepts and other entities that are assumed to
+ exist in some area of interest and the relationships that hold
+ among them. A conceptualisation is an {abstract}, simplified view
+ of the world that we wish to represent. For example, we may
+ conceptualise a family as the set of names, sexes and the
+ relationships of the family members. Choosing a
+ conceptualisation is the first stage of {knowledge
+ representation}. A conceptualisation is a high-level {data model}.
+
+ Every {knowledge base}, {knowledge-based system}, or
+ {knowledge-level agent} is committed to some
+ conceptualisation, explicitly or implicitly.
+
+ (2013-04-17)
+
+Concert/C
+
+ <language, parallel> A {parallel} extension of {ANSI C} with
+ {asynchronous} {message passing}, developed at the {IBM} {TJWRC}
+ in July 1993. Concert/C provides {primitives} to create and
+ terminate {processes} and communicate between them. The programmer
+ explicitly expresses parallelization and distribution.
+
+ {1994 Announcement
+ (http://www.cs.bu.edu/~best/courses/cs551/projects/concert.txt)}.
+
+ (2013-05-05)
+
+ConCoord
+
+ <programming, parallel> An environment for programming networks of
+ {sequential} and {parallel} computers. ConCoord supports
+ {explicit parallelism} with different {granularity}.
+
+ (2013-05-22)
+
+concrete class
+
+ <programming> In {object-oriented programming}, a {class}
+ suitable to be instantiated, as opposed to an {abstract
+ class}.
+
+ (1995-05-01)
+
+Concrete Data Structure
+
+ <theory> (CDS) A model of programming language terms developed in
+ the context of constructing fully {abstract semantics} for
+ {sequential} languages. A CDS is a 4-tuple (C,V,E,|-) where C is
+ a cell, V is a value, E is an event and |- is an "enabling
+ relation". An event is a cell and a value. A cell C is "enabled"
+ by a set of events S if S |- C. A state is a set of events which
+ are consistent in that the values they give for any cell are all
+ equal. Every cell in a state is enabled.
+
+ [G. Berry, P.-L. Curien, "Theory and practice of sequential
+ algorithms: the kernel of applicative language CDS", Algebraic
+ methods in semantics, CUP 1985].
+
+ (1994-11-30)
+
+concrete syntax
+
+ <language, data> The {syntax} of a language including all the
+ features visible in the {source code} such as {parentheses}
+ and {delimiters}. The concrete syntax is used when {parsing}
+ the program or other input, during which it is usually
+ converted into some kind of {abstract syntax tree} (conforming
+ to an {abstract syntax}).
+
+ In communications, concrete syntax is called {transfer
+ syntax}.
+
+ (1997-07-21)
+
+CONCUR
+
+ <language> A proposal for a language for programming with
+ {concurrent} processes. CONCUR was inspired by {Modula} but
+ removes Modula's restrictions on the placement of process
+ declarations and invocations in order to study the implications of
+ process support more fully. Anderson presents a {compiler} which
+ translates CONCUR into the {object language} for a hypothetical
+ machine.
+
+ ["CONCUR, A Language for Continuous Concurrent
+ Processes", R.M. Salter et al, Comp Langs 5(3):163-189, 1981].
+
+ {["Concur: a High-Level Language for Concurrent Programming",
+ Karen Anderson Thesis, B. Thomas Golisano College of Computing and
+ Information Sciences, 1979]
+ (https://ritdml.rit.edu/handle/1850/15968?show=full)}
+
+ (2013-06-05)
+
+concurrency
+
+ {multitasking}
+
+Concurrent C
+
+ 1. <language> An extension of {C} with {rendezvous}-based
+ {concurrency}. Versions for most {Unix} systems were available
+ commercially from {AT&T}.
+
+ ["Concurrent C", N.H. Gehani et al, Soft Prac & Exp
+ 16(9):821-844 (1986)].
+
+ ["The Concurrent C Programming Language", N. Gehani et al,
+ Silicon Press 1989].
+
+ (1994-11-11)
+
+ 2. <language> An extension of {C} with {asynchronous} {message
+ passing}.
+
+ ["Concurrent C: A Language for Distributed Systems",
+ Y. Tsujino et al, Soft Prac & Exp 14(11):1061-1078 (Nov
+ 1984)].
+
+ (1994-11-11)
+
+Concurrent C++
+
+ <language> A {programming language} developed by Gehani and Roome
+ at {Bell Labs} by merging their earlier {Concurrent C} language
+ with {C++}.
+
+ ["Concurrent C++: Concurrent Programming with Class(es)",
+ N. Gehani, W.D. Roome, Bell Labs, 1986].
+
+ (2013-06-26)
+
+Concurrent Clean
+
+ <language> An alternative name for {Clean} 1.0.
+
+ (1995-11-08)
+
+Concurrent CLU
+
+ <language> A {programming language} extending {CLU} for
+ {concurrent} processes, developed by by Hamilton in 1984.
+
+ ["Preserving Abstraction in Concurrent
+ Programming", R.C.B. Cooper, K.G. Hamilton, IEEE
+ Trans Soft Eng SE-14(2):258-263, Feb 1988].1
+
+ (2013-09-28)
+
+Concurrent Constraint Programming
+
+ <language> (CCP) Not a language, but a general approach.
+
+ [Details?]
+
+ (2001-11-01)
+
+Concurrent Euclid
+
+ <language, parallel> A {concurrent} extension of a subset of
+ {Euclid} ("{Simple Euclid}") developed by J.R. Cordy and
+ R.C. Holt of the {University of Toronto} in 1980.
+
+ Concurrent Euclid features {separate compilation}, {modules},
+ processes and {monitors}, {signal} and {wait} on {condition
+ variables}, 'converters' to defeat {strong type checking},
+ absolute addresses. All procedures and functions are
+ {re-entrant}. {TUNIS} (a {Unix}-like {operating system}) is
+ written in Concurrent Euclid.
+
+ ["Specification of Concurrent Euclid", J.R. Cordy & R.C. Holt,
+ Reports CSRI-115 & CSRI-133, CSRI, U Toronto, Jul 1980,
+ rev. Aug 1981].
+
+ ["Concurrent Euclid, The Unix System, and Tunis," R.C. Holt,
+ A-W, 1983].
+
+ (2005-02-19)
+
+Concurrent LISP
+
+ <language> A {concurrent} version of {Lisp}. Sugimoto et al
+ implemented an {interpreter} on a "large scale computer" and were
+ planning to implement it on multiple {microprocessors}.
+
+ ["A Multi-Processor System for Concurrent Lisp", S. Sugimoto et
+ al, Proc 1983 Intl Conf parallel Proc, 1983 pp.135-143].
+
+ (2013-10-18)
+
+Concurrent Massey Hope
+
+ <language, functional programming> An extension of {Massey
+ Hope}, by Peter Burgess, Robert Pointon, and Nigel Perry
+ <N.Perry@massey.ac.nz> of {Massey University}, NZ, that
+ provides {multithreading} and {type}d inter-{thread}
+ communication. It uses {C} for {intermediate code} rather
+ than {assembly language}.
+
+ (1999-08-04)
+
+Concurrent ML
+
+ <language> (CML) A {concurrent} extension of {SML/NJ} written
+ by J. Reppy at {Cornell University} in 1990. CML supports
+ dynamic {thread} creation and synchronous {message passing} on
+ typed channels. Threads are implemented using first-class
+ {continuations}. First-class synchronous operations allow
+ users to tailor their synchronisation abstractions for their
+ application. CML also supports both {stream I/O} and
+ low-level I/O in an integrated fashion.
+
+ Latest version 0.9.8, as of 1994-12-21, requires SML/NJ 0.75
+ or later.
+
+ {(ftp://ftp.cs.cornell.edu/pub/)}.
+
+ E-mail: <sml-bugs@research.att.com> (bugs).
+
+ ["CML: A Higher-Order Concurrent Language", John H. Reppy,
+ SIGPLAN Notices 26(6):293-305, June 1991].
+
+ (2000-08-09)
+
+Concurrent Oberon
+
+ <language> A {concurrent} version of {Oberon}. There is an
+ implementation the {Ceres} {workstation}.
+
+ ["Adding Concurrency to the Oberon System", S. Lalis et al,
+ ETH Zurich, 1993].
+
+ (1994-11-11)
+
+Concurrent Object-Oriented C
+
+ <language> (cooC) A language with {concurrent} {object} execution
+ from {Toshiba}. It has {synchronous} and {asynchronous} {message
+ passing}. It has been implemented for {SunOS}.
+
+ {(ftp://tsbgw.isl.rdc.toshiba.co.jp/pub/toshiba/cooc-beta.1.1.tar.Z)}.
+
+ [SIGPLAN Notices 28(2)].
+
+ (2000-08-13)
+
+Concurrent Object-Oriented Language
+
+ <language> (COOL) An extension of {C++} with {task-level
+ parallelism} for {shared-memory} {multi-processors}.
+
+ ["COOL: A Language for Parallel Programming", R. Chandra
+ <rohit@seagull.stanford.edu> et al in Languages and Compilers
+ for Parallel Computing, D. Gelernter et al eds, MIT Press
+ 1990, pp. 126-148].
+
+ E-mail: Rohit Chandra <rohit@cool.stanford.edu>.
+
+ (1994-11-30)
+
+Concurrent Pascal
+
+ <language> An extension of a {Pascal} subset, {Sequential Pascal},
+ developed by Brinch Hansen in 1972-75. Concurrent Pascal was the
+ first language to support {monitors}. It provided access to
+ hardware devices through monitor calls and also supported
+ processes and {class}es.
+
+ ["The Programming Language Concurrent Pascal", Per Brinch
+ Hansen, IEEE Trans Soft Eng 1(2):199-207 (Jun 1975)].
+
+ (1994-11-30)
+
+concurrent processing
+
+ {multitasking}
+
+Concurrent Prolog
+
+ <language> A {Prolog} variant with {guarded clauses} and
+ {committed-choice nondeterminism} ({don't-care nondeterminism}) by
+ Ehud "Udi" Shapiro, Yale <shapiro-ehud@yale.edu>. A subset has
+ been implemented, but not the full language.
+
+ See also {Mandala}.
+
+ ["Concurrent Prolog: Collected Papers", E. Shapiro, V.1-2, MIT
+ Press 1987].
+
+ (1994-11-30)
+
+Concurrent Scheme
+
+ <language> A parallel {Lisp}, for the {Mayfly} by M. Swanson
+ <swanson%teewinot@cs.utah.edu>.
+
+ ["Concurrent Scheme", R.R. Kessler et al, in Parallel Lisp:
+ Languages and Systems, T. Ito et al eds, LNCS 441, Springer
+ 1989].
+
+ (1994-11-30)
+
+ConcurrentSmalltalk
+
+ <language> A {concurrent} variant of {Smalltalk}.
+
+ ["Concurrent Programming in ConcurrentSmalltalk", Y. Yokote et
+ al in Object-Oriented Concurrent Programming, A. Yonezawa et
+ al eds, MIT Press 1987, pp. 129-158].
+
+ (1994-11-30)
+
+Concurrent SP/k
+
+ <language> (CSP/k) A {PL/I}-like {concurrent} language.
+
+ ["Structured Concurrent Programming with Operating System
+ Applications", R.C. Holt et al, A-W 1978].
+
+ (1997-12-15)
+
+Concurrent Versions System
+
+ <programming> (CVS) A {cross-platform} {code management
+ system} originally based on {RCS}.
+
+ CVS tracks all revisions to a file in an associated file with
+ the same name as the original file but with the string ",v"
+ (for version) appended to the filename. These files are
+ stored in a (possibly centralised) repository.
+
+ Changes are checked in or "committed" along with a comment (which
+ appears in the the "commit log"). CVS has the notions of
+ projects, {branches}, file locking and many others needed to
+ provide a full-functioned repository.
+
+ It is commonly accessed over over its own "anonCVS" {protocol} for
+ read-only access (many {open source} projects are available by
+ anonymous CVS) and over the {SSH} protocol by those with commit
+ privileges ("committers").
+
+ CVS has been rewritten several times and does not depend on
+ RCS. However, files are still largely compatible; one can
+ easily migrate a project from RCS to CVS by copying the
+ history files into a CVS repository. A sub-project of the
+ {OpenBSD} project is building a complete new implementation of
+ CVS, to be called OpenCVS.
+
+ {CVS Home (http://cvshome.org/)}. {OpenCVS
+ (http://opencvs.org/)}.
+
+ (2005-01-17)
+
+condela
+
+ {Connection Definition Language}
+
+condition out
+
+ <programming> A programming technique that prevents a section of
+ {code} from being executed by putting it in an {if statement}
+ whose condition is always false.
+
+ It is often easier to do this than to {comment out} the code
+ because you don't need to modify the code itself (as you would if
+ commenting out each line individually) or worry about {nested
+ comments} within the code (as you would if putting nesting comment
+ delimiters around it).
+
+ For example, in {Perl} you could write:
+
+ if (0) {
+ ...code to be ignored...
+ }
+
+ In a compiled language, the {compiler} could simply generate no
+ code for the whole if statement. Some compiled languages such as
+ C provide {compile-time directives} that achieve the same effect,
+ e.g.:
+
+ #if 0
+ ...code to be ignored...
+ #endif
+
+ (or "#ifdef notdef").
+
+ [{Jargon File}]
+
+ (2013-12-08)
+
+condom
+
+ <jargon> 1. The protective plastic bag that accompanies {3.5-inch
+ microfloppy diskettes}. Rarely, also used of (paper) disk
+ envelopes. Unlike the {write protect tab}, the condom (when left
+ on) not only impedes the practice of {SEX} but has also been shown
+ to have a high failure rate as drive mechanisms attempt to access
+ the disk - and can even fatally frustrate insertion.
+
+ 2. The protective cladding on a {light pipe}.
+
+ 3. "keyboard condom": A flexible, transparent plastic cover
+ for a keyboard, designed to provide some protection against
+ dust and {programming fluid} without impeding typing.
+
+ 4. "elephant condom": the plastic shipping bags used inside
+ cardboard boxes to protect hardware in transit.
+
+ [{Jargon File}]
+
+ (1995-03-14)
+
+Conference On DAta SYstems Languages
+
+ <body> (CODASYL) A consortium that developed {database models} and
+ standard {database} extensions for {COBOL}.
+
+ CODASYL was formed in 1959 to guide the development of a
+ {standard} {programming language} that could be used on many
+ computers. Members came from industry and government data
+ processing departments. Its goal was to promote more effective
+ data {systems analysis}, design and implementation. It published
+ specifications for various languages over the years, handing these
+ over to official standards bodies ({ISO}, {ANSI} or their
+ predecessors) for formal standardisation.
+
+ The 1965 List Processing Task Force worked on the {IDS/I} database
+ extension. It later renamed itself to the Data Base Task Group
+ (DBTG) and publishing the Codasyl Data Model, the first to allow
+ one-to-many {relations}. This work also introduced {data
+ definition languages} (DDLs) to define the {database schema} and a
+ {data manipulation language} (DML) to be embedded in COBOL
+ programs to request and update data in the database.
+
+ Interest in CODASYL declined with the rise of {relational
+ databases} beginning in the early 1980s.
+
+ (2013-12-29)
+
+Conferencing over IP
+
+ <communications, standard> (CoIP) Standards for the transmission
+ of {multimedia} over the {Internet}. CoIP extends {VoIP} (voice
+ over Internet Protocol) with {text}, {images}, {video}. The main
+ CoIP standard is based on {H.323}.
+
+ The VoIP forum of the {IMTC} merged with the {H.323} Activity
+ Group in January 1999 to form the Conferencing over IP (CoIP)
+ Activity Group.
+
+ VoIP uses "VoIP Devices" as {gateways} to {route} voice data
+ {packets} over the Internet or {PSTN}. {Protocols} such as {SGCP}
+ and its successor {MGCP} extend VoIP to handle media other than
+ voice data.
+
+ (2013-12-29)
+
+confidence test
+
+ <testing> Tests to confirm that the results of a program lie
+ within certain ranges according to the expected probability
+ distribution.
+
+ (1997-10-27)
+
+CONFIG.SYS
+
+ <operating system> A {text file} containing special system
+ configuration commands, found in the {root directory} on an
+ {MS-DOS} computer, typically on {drive} C (the {hard disk}). It
+ is read by {MS-DOS} at {boot time}, after the setup has been read
+ from {CMOS RAM} and before running {AUTOEXEC.BAT}. It can be
+ modified by the user.
+
+ Some example commands which CONFIG.SYS might contain are:
+
+ DEVICE=C:\DOS\HIMEM.SYS /testmem:off
+
+ Load the {extended memory} manager.
+
+ DEVICE=C:\DOS\EMM386.EXE RAM
+
+ Load the {expanded memory} manager.
+
+ BUFFERS=10,0
+
+ Specify memory for {disk buffers}.
+
+ FILES=70
+
+ Set the number of files that can be open at once.
+
+ DOS=UMB
+
+ DOS is located in {UppeMemoryBlock}.
+
+ LASTDRIVE=Z
+
+ Disk drives are A: to Z:.
+
+ FCBS=16,0
+
+ Set the number of {file control blocks}.
+
+ DEVICEHIGH /L:1,12048 =C:\DOS\SETVER.EXE
+
+ Report the DOS version to older programs.
+
+ DOS=HIGH
+
+ DOS should maintain a link to {UMB}.
+
+ COUNTRY=358,437 C:\DOS\COUNTRY.SYS
+
+ Set the {country code} for some programs.
+
+ STACKS=9,256
+
+ Set {dynamic stacks} for hardware control.
+
+ SHELL=C:\DOS\COMMAND.COM C:\DOS\ /E:1024 /p
+
+ Set the location of the {command interpreter}.
+
+ (1995-03-16)
+
+configuraholic
+
+ <jargon> A {luser} who twiddles with computer settings until
+ it no longer works and must be fixed by the {system
+ administror}.
+
+ (2007-03-20)
+
+configuration item
+
+ <jargon> Hardware or software, or an aggregate of both, which
+ is designated by the project configuration manager (or
+ contracting agency) for {configuration management}.
+
+ (1996-05-29)
+
+configuration management
+
+ <job, system management> A discipline applying technical and
+ administrative controls to identifying, documentating and
+ reporting on {configuration items}, their physical and functional
+ characteristics and changes to characteristics of those
+ configuration items.
+
+ {Change management} is one aspect of configuration management but
+ may also refer to the softer, human side of getting people to
+ adapt to changing processes and organisation.
+
+ {Source code management} or "code management" is configuration
+ management applied to {code} through the various stages of the
+ {software life-cycle}.
+
+ (2014-01-21)
+
+configuration programming
+
+ <programming> An approach that advocates the use of a separate
+ configuration language to specify the {coarse-grain} structure
+ of programs. Configuration programming is particularly
+ attractive for {concurrent}, parallel and distributed systems
+ that have inherently complex program structures.
+
+ {Darwin} is an example of a configuration language.
+
+ (1995-03-14)
+
+configure
+
+ <software> A program by {Richard Stallman} to discover
+ properties of the current {platform} and to set up {make} to
+ compile and install {gcc}.
+
+ {Cygnus configure} was a similar system developed by
+ K. Richard Pixley in collaboration with Richard Stallman.
+ In 1994, David MacKenzie and others modified {autoconf} to
+ incorporate all the features of Cygnus configure and many
+ {GNU} programs, including gcc now use autoconf.
+
+ {Metaconfig} is a similar program used in building {Perl}.
+
+ {(http://airs.com/ian/configure)}.
+
+ (2005-04-15)
+
+conflation
+
+ <database> Combining or blending of two or more versions of a
+ text; confusion or mixing up. Conflation {algorithms} are
+ used in {databases}.
+
+ [Any specific technical meaning?]
+
+ (1996-04-14)
+
+congestion
+
+ <communications> The condition that arises when the amount of data
+ senders want to send down a communication path exceeds its
+ {capacity}. Typically this will result in some {packets} being
+ delayed, thus increasing the average {latency}.
+
+ (2014-05-04)
+
+CONIC
+
+ <systems> A {distributed system} language and {operating system}
+ developed at {Imperial College} to support {dynamic
+ configuration}.
+
+ {Paper (http://spiral.imperial.ac.uk/bitstream/10044/1/452/1/Dynamic%20Configuration%20for%20Distributed.pdf)}.
+
+ ["Dynamic Configuration for Distributed Systems", J. Kramer et
+ al, IEEE Trans Soft Eng SE-11(4):424-436, Apr 1985].
+
+ (2014-05-04)
+
+conjunction
+
+ {AND}
+
+Conjunctive Normal Form
+
+ <logic> (CNF) A {logical formula} consisting of a
+ {conjunction} of {disjunctions} of terms where no disjunction
+ contains a conjunction. Such a formula might also be
+ described as a product of sums. E.g. the CNF of
+
+ (A and B) or C
+ is
+ (A or C) and (B or C).
+
+ Contrast {Disjunctive Normal Form}.
+
+ (1995-12-10)
+
+connect
+
+ <library, networking> {Unix} socket library routine to connect
+ a socket that has been created on the local hosts to one at a
+ specified socket address on the remote host.
+
+ {Unix manual pages}: connect(2), accept(2).
+
+ (1995-03-21)
+
+connected graph
+
+ <mathematics> A {graph} such that there is a path between any
+ pair of nodes (via zero or more other nodes).
+
+ Thus if we start from any node and visit all nodes connected
+ to it by a single edge, then all nodes connected to any of
+ them, and so on, then we will eventually have visited every
+ node in the connected graph.
+
+ (1996-09-22)
+
+connected subgraph
+
+ <mathematics> A {connected graph} consisting of a {subset} of
+ the {nodes} and {edges} of some other graph.
+
+ (1996-09-22)
+
+Connection Definition Language
+
+ <language> (condela) A {procedural}, parallel language for
+ defining {neural networks}.
+
+ {(ftp://tut.cis.ohio-state.edu/pub/condela)}.
+
+ (1994-11-30)
+
+connectionless protocol
+
+ <protocol> The data communication method in which communication
+ occurs between {hosts} with no previous setup. {Packets} sent
+ between two hosts may take different routes.
+
+ {UDP} is a connectionless protocol. Also called {packet
+ switching}. Contrast {circuit switching}, {connection-oriented}.
+
+ (2014-05-04)
+
+Connection Machine LISP
+
+ <language> {Lisp} with a parallel data structure, the
+ 'xapping', an array of values assigned to an {array} of sites.
+
+ [G.L. Steele et al, "Connection Machine LISP: Fine-Grained
+ Parallel Symbolic Processing", in Proc 1986 ACM Conf on LISP
+ and Functional Prog, Aug 1986, pp.279-297].
+
+ ["Connection Machine LISP Reference Manual", Thinking Machines
+ Corp, Feb 1987].
+
+ (1995-02-28)
+
+connection-oriented
+
+ <networking> (Or connection-based, stream-oriented). A type
+ of {transport layer} data communication service that allows a
+ {host} to send data in a continuous stream to another host.
+ The transport service will guarantee that all data will be
+ delivered to the other end in the same order as sent and
+ without duplication. Communication proceeds through three
+ well-defined phases: connection establishment, data transfer,
+ connection release. The most common example is {Transmission
+ Control Protocol} (TCP).
+
+ Opposite of {connectionless}, {datagram}. See also {circuit
+ switching}, {packet switching}, {virtual circuit}.
+
+connection-oriented network service
+
+ <networking> (CONS) Because of the relatively long transit
+ delays and inferior bit error rate of {WANs}, a more
+ sophisticated {connection-oriented} {protocol} is normally
+ used.
+
+ (1997-11-08)
+
+connective
+
+ <logic> An operator used in {first order logic} to combine two
+ logical formulas.
+
+ (2014-05-04)
+
+connector conspiracy
+
+ <business, standard> The tendency of manufacturers (or, by
+ extension, other designers) to come up with products that
+ don't fit with the old stuff, thereby making you buy either
+ all new stuff or expensive interface devices.
+
+ The term probably came into prominence with the appearance of
+ the DEC {KL-10}, none of whose connectors matched anything
+ else. The KL-10 {Massbus} connector was actually *patented*
+ by {DEC}, who reputedly refused to licence the design, thus
+ effectively locking out competition for the lucrative Massbus
+ peripherals market. This policy was a source of frustration
+ for the owners of dying, obsolescent disk and tape drives.
+
+ A related phenomenon is the invention of new screw heads so
+ that only Designated Persons, possessing the magic
+ screwdrivers, can remove covers and make repairs or install
+ options. Older Apple {Macintosh}es took this one step
+ further, requiring not only a hex wrench but a specialised
+ case-cracking tool to open the box.
+
+ With the advent of more open-systems computing this term has
+ fallen somewhat into disuse.
+
+ Compare {backward combatability}.
+
+ [{Jargon File}]
+
+ (2010-02-04)
+
+CONNIVER
+
+ <language> An {artificial intelligence} {programming language} for
+ {automatic theorem proving} from {MIT}. CONNIVER grew out of
+ {PLANNER} and was based on {coroutines} rather than
+ {backtracking}. It allowed multiple database contexts with
+ hypothetical assertions.
+
+ ["The CONNIVER Reference Manual", D. McDermott & G.J. Sussman
+ <gjs@zurich.ai.mit.edu>, AI Memo 259, MIT AI Lab, 1973].
+
+ (1995-01-10)
+
+Co-NP
+
+ {complementary nondeterministic polynomial}
+
+CONS
+
+ {connection-oriented network service}
+
+cons
+
+ <programming> /konz/ or /kons/ A {Lisp} function which takes an
+ element H and a {list} T and returns a new list whose {head} is H
+ and whose {tail} is T.
+
+ In {Lisp}, "cons" (short for "construct") is the fundamental
+ operation for building structures. It actually takes any two
+ objects and returns them in a "cons cell" or pair object. This is
+ sometimes called a {dotted-pair} because an application of cons:
+
+ (cons H T)
+
+ can also be input and output using an {infix} dot operator:
+
+ (H . T)
+
+ (with suitable quoting of arguments).
+
+ A cons cell can also be used as two-branched tree node object with
+ one object hanging from each branch. Because the result of a cons
+ is itself an object, it can be used to build {binary trees} of any
+ shape and complexity.
+
+ Typically, a cons would be represented in memory as a two
+ consecutive {pointers}.
+
+ For historical reasons, the functions to return the objects in a
+ cons are called {car} and {cdr}.
+
+ [{Jargon File}]
+
+ (2014-06-11)
+
+conservative evaluation
+
+ <programming> Under this {parallel evaluation strategy}, no
+ evaluation is started unless it is known to be needed. The
+ opposite of conservative evaluation is {speculative evaluation}.
+
+ (2014-06-21)
+
+considered harmful
+
+ <programming, humour> A type of phrase based on the title of
+ {Edsger W. Dijkstra}'s famous note in the March 1968
+ {Communications of the ACM}, "Goto Statement Considered Harmful",
+ which fired the first salvo in the {structured programming wars}.
+
+ Amusingly, the {ACM} considered the resulting acrimony
+ sufficiently harmful that it will (by policy) no longer print
+ articles taking so assertive a position against a coding practice.
+
+ In the ensuing decades, a large number of both serious papers and
+ parodies bore titles of the form "X considered Y". The
+ structured-programming wars eventually blew over with the
+ realisation that both sides were wrong, but use of such titles has
+ remained as a persistent minor in-joke.
+
+ [{Jargon File}]
+
+ (2014-06-21)
+
+consistently complete
+
+ {boundedly complete}
+
+console
+
+ 1. <hardware, operating system, history> The {operator}'s station
+ of a {mainframe} as opposed to an ordinary user's {terminal}. In
+ times past, the console was a privileged location that conveyed
+ godlike powers to anyone with fingers on its keys. Under {Unix}
+ and other modern {time-sharing} {operating systems}, such
+ privileges are guarded by {passwords} instead, and the console is
+ just the {tty} the system was booted from. On Unix the device is
+ called /dev/console.
+
+ On a {microcomputer} {Unix} box, the console is the main screen
+ and keyboard. Other, character-only, terminals may be connected
+ to {serial ports}. Typically only the console can do real
+ {graphics} or run {X}. See also {CTY}.
+
+ 2. <games> A self-contained {microcomputer} optimised for gaming,
+ with powerful graphical output designed to be displayed on a
+ television; equipped with one or more {joystick} controllers for
+ input and an {optical drive} to load software. Later generations
+ also feature {Internet} connection via {wireless} or wired
+ {Ethernet} for downloading games and multiplayer networked play.
+ Typically such devices have no keyboard so text must be input
+ using the controller to operate an on-screen keyboard, e.g. to
+ enter player names.
+
+ The most successful recent examples are the {Sony Playstation} and
+ {Microsoft Xbox} families.
+
+ [{Jargon File}]
+
+ (2014-07-01)
+
+console jockey
+
+ {terminal junkie}
+
+consortium
+
+ <body> A group of two or more companies, educational
+ institutions, governments or other bodies with some shared
+ purpose.
+
+ Examples from computing include the {World Wide Web
+ Consortium} (W3C), {Apache Software Foundation}, {The Open
+ Group}, {X Consortium}.
+
+ (2009-06-05)
+
+Consortium for Lexical Research
+
+ <body> (CLR) A repository for {natural language processing}
+ software, {lexical} data, tools and resources; set up in July 1991
+ in the Computing Research Laboratory of {New Mexico State
+ University}, Las Cruces, New Mexico, USA.
+
+ CLR maintained a public {FTP} {archive site} and a separate
+ members-only library. As of 1994-02-01, CLR had about 60 members,
+ mostly academic institutions, including most US natural language
+ processing centres. Materials could be contributed in exchange
+ for membership.
+
+ In 2006, the CRL closed down due to lack of funding. The CLR
+ FTP server and e-mail address seems to have disappeared with it.
+
+ [{The Consortium for Lexical Research, Y. Wilks, Principal
+ Investigator, Computing Research Laboratory, New Mexico State
+ University
+ (http://clair.eecs.umich.edu/aan/paper.php?paper_id=H92-1114)}].
+
+ (2014-07-06)
+
+constant angular velocity
+
+ <storage> (CAV) One of the two schemes for controlling the rate of
+ rotation of the disk in a {disk drive}. Constant {angular
+ velocity} keeps the rate of rotation constant. This means that
+ the {linear velocity} of the disk under the head is larger when
+ reading or writing the outer {tracks}. This in turn implies
+ either a variation in the data rate to and from the heads or the
+ bits per unit length along the track.
+
+ The alternative, {constant linear velocity}, requires the rate of
+ rotation of the disk to accelerate and decelerate according to the
+ radial postion of the heads, increasing the energy use and
+ vibration.
+
+ (2014-07-16)
+
+constant applicative form
+
+ <functional programming> (CAF) A {supercombinator} which is
+ not a {lambda abstraction}. This includes truly constant
+ expressions such as 12, (+ 1 2), [1, 2, 3] as well as partially
+ applied functions such as (+ 4). Note that this last example
+ is equivalent under {eta abstraction} to \ x . + 4 x which is
+ not a CAF.
+
+ Since a CAF is a supercombinator, it contains no free
+ variables. Moreover, since it is not a lambda abstraction it
+ contains no variables at all. It may however contain
+ identifiers which refer to other CAFs, e.g.
+
+ c 3 where c = (* 2).
+
+ A CAF can always be lifted to the top level of the program.
+ It can either be compiled to a piece of graph which will be
+ shared by all uses or to some shared code which will overwrite
+ itself with some graph the first time it is evaluated. A CAF
+ such as
+
+ ints = from 1 where from n = n : from (n+1)
+
+ can grow without bound but may only be accessible from within
+ the code of one or more functions. In order for the {garbage
+ collector} to be able to reclaim such structures, we associate
+ with each function a list of the CAFs to which it refers.
+ When garbage collecting a reference to the function we collect
+ the CAFs on its list.
+
+ [{The Implementation of Functional Programming Languages, Simon
+ Peyton Jones (http://research.microsoft.com/%7Esimonpj/papers/slpj-book-1987/PAGES/224.HTM)}].
+
+ (2006-10-12)
+
+constant folding
+
+ <compiler> A {compiler} {optimisation} technique where
+ constant subexpressions are evaluated at {compile time}. This
+ is usually only applied to built-in numerical and {boolean}
+ operators whereas {partial evaluation} is more general in that
+ expressions involving user-defined functions may also be
+ evaluated at compile time.
+
+ (1997-02-20)
+
+Constantine/Yourdon
+
+ {Yourdon/Constantine}
+
+constant linear velocity
+
+ <storage> (CLV) A way of controlling the rotation of the {disks}
+ in a {disk drive} in which the {linear velocity} of the disk
+ surface relative to the {read/write heads} is kept constant.
+
+ In order to achieve constant linear velocity, the disk must rotate
+ faster (at a higher {angular velocity}) when reading or writing
+ tracks closer to the centre.
+
+ Having a constant linear read/write speed along the track means
+ that the electrical signal to and from the heads has a constant
+ {data rate} (bits per second), thus simplifying the timing of the
+ drive electronics somewhat. However, rotating at less than the
+ maximum possible rate sacrifices some potential performance
+ compared to the alternative, {constant angular velocity}. Also,
+ varying the rate causes more vibration and consumes more energy.
+
+ (2014-07-27)
+
+constant mapping
+
+ <networking> A precursor to {ARP} used by some {TCP} software in
+ which the destination {Ethernet address} is constructed from the
+ top 24 {bits} of the source Ethernet address followed by the low
+ 24 bits of the (class A) destination {Internet address}. For this
+ scheme the top 24 bits of the Ethernet address must be the same on
+ all hosts on the network.
+
+ (2014-08-06)
+
+constraint
+
+ <programming, mathematics> A {Boolean} {relation}, often an
+ equality or {ineqality} relation, between the values of one or
+ more mathematical {variables}. E.g. x>3 is a constraint on x.
+ The process of {constraint satisfaction} attempts to assign values
+ to variables so that all constraints are true.
+
+ {Usenet} newsgroup: {news:comp.constraints}. {FAQ
+ (http://cs.unh.edu/ccc/archive/)}.
+
+ (2002-06-08)
+
+constraint functional programming
+
+ <programming> (CFP) {functional programming} plus {constraints}.
+
+ (2002-06-08)
+
+Constraint Handling In Prolog
+
+ <language> (CHIP) A {constraint logic programming} language
+ developed by M. Dincbas at {ECRC}, Munich, Germany in 1985 which
+ includes {Boolean unification} and a symbolic {simplex}-like
+ {algorithm}. CHIP introduced the {domain-variable model}.
+
+ ["The Constraint Logic Programming Language CHIP", M. Dincbas
+ et al, Proc 2nd Intl Conf on Fifth Generation Computer Sys,
+ Tokyo (Nov 1988), pp.249-264].
+
+ ["Constraint Satisfaction in Logic Programming", Van
+ Hentenryck. Available from COSYTEC, 4 rue Jean Rostand,
+ F91893 Orsay, France].
+
+ (1994-11-15)
+
+ConstraintLisp
+
+ <language> An {object-oriented} {constraint} language based on
+ {CSP}. An extension of {Common Lisp} and {CLOS}.
+
+ ["ConstraintLisp: An Object-Oriented Constraint Programming
+ Language", Bing Liu (ex bing@iti.gov.sg) et al, SIGPLAN
+ Notices 27(11):17-26, Nov 1992].
+
+ (2000-04-02)
+
+Constraint Logic Programming
+
+ <programming> (CLP) A programming framework based (like {Prolog})
+ on {LUSH} (or {SLD}) {resolution}, but in which {unification} has
+ been replaced by a {constraint solver}. A CLP {interpreter}
+ contains a Prolog-like {inference engine} and an {incremental
+ constraint solver}. The engine sends constraints to the solver
+ one at a time. If the new constraint is consistent with the
+ collected constraints it will be added to the set. If it is
+ inconsistent, it will cause the engine to {backtrack}.
+
+ {CLP*} is a variant.
+
+ ["Constraint Logic Programming", J. Jaffar et al, 14th POPL,
+ ACM 1987].
+
+ (1994-11-01)
+
+CONSTRAINTS
+
+ <programming> A {programming language} for solving {constraints}
+ using {value inference}.
+
+ ["CONSTRAINTS: A Language for Expressing Almost-Hierarchical
+ Descriptions", G.J. Sussman et al, Artif Intell 14(1):1-39, Aug
+ 1980].
+
+ (1994-11-01)
+
+constraint satisfaction
+
+ <application> The process of assigning values to {variables} while
+ meeting certain requirements or "{constraints}". For example, in
+ {graph colouring}, a node is a variable, the colour assigned to it
+ is its value and a link between two nodes represents the
+ constraint that those two nodes must not be assigned the same
+ colour. In {scheduling}, constraints apply to such variables as
+ the starting and ending times for tasks.
+
+ The {Simplex} method is one well known technique for solving
+ numerical constraints.
+
+ The search difficulty of constraint satisfaction problems can be
+ determined on average from knowledge of easily computed structural
+ properties of the problems. In fact, hard instances of
+ {NP-complete} problems are concentrated near an abrupt transition
+ between under- and over-constrained problems. This transition is
+ analogous to phase transitions in physical systems and offers a
+ way to estimate the likely difficulty of a constraint problem
+ before attempting to solve it with search.
+
+ {Phase transitions in search
+ (ftp://parcftp.xerox.com/pub/dynamics/constraints.html)} (Tad
+ Hogg, {XEROX PARC}).
+
+ (1995-02-15)
+
+constructed type
+
+ <types> A {type} formed by applying some {type constructor
+ function} to one or more other types. The usual constructions are
+ functions: t1 -> t2, products: (t1, t2), sums: t1 + t2 and
+ lifting: lift(t1).
+
+ (In {LaTeX}, the lifted type is written with a subscript
+ {\perp}).
+
+ See also {algebraic data type}, {primitive type}.
+
+ (1995-02-03)
+
+Constructive Cost Model
+
+ <programming> (COCOMO) A method for estimating the cost of a
+ {software} package, proposed by Dr Barry Boehm.
+
+ The Basic COCOMO Model estimates the effort required to develop
+ software in three modes of development ({Organic Mode},
+ {Semidetached Mode}, or {Embedded Mode}) using only {DSIs} as an
+ input. The Basic model is good for quick estimates.
+
+ The Intermediate Model extends the Basic Model with an {Effort
+ Adjustment Factor} (EAF) and different coefficients for the effort
+ equation. The user supplies settings for cost drivers that
+ determine the effort and duration of the software projects. It
+ also allows DSI values and cost drivers to be chosen for
+ individual components instead of for the system as a whole.
+
+ The Detailed COCOMO Model uses effort multipliers for each phase
+ of the project and provides a three-level product hierarchy and
+ has some other capabilities such as a procedure for adjusting the
+ phase distribution of the development schedule.
+
+ ["Software Engineering Economics", B. Boehm, Prentice-Hall,
+ 1981].
+
+ (1996-05-29)
+
+constructive proof
+
+ <mathematics> A proof that something exists that provides an
+ example or a method for actually constructing it.
+
+ For example, for any pair of finite real numbers n < 0 and p > 0,
+ there exists a real number 0 < k < 1 such that
+
+ f(k) = (1-k)*n + k*p = 0.
+
+ A constructive proof would proceed by rearranging the above to
+ derive an equation for k:
+
+ k = 1/(1-n/p)
+
+ From this and the constraints on n and p, we can show that 0 < k <
+ 1.
+
+ A few mathematicians actually reject *all* non-constructive
+ arguments as invalid; this means, for instance, that the law of
+ the {excluded middle} (either P or not-P must hold, whatever P is)
+ has to go; this makes {proof by contradiction} invalid. See
+ {intuitionistic logic}.
+
+ Constructive proofs are popular in theoretical computer science,
+ both because computer scientists are less given to abstraction
+ than mathematicians and because {intuitionistic logic} turns out
+ to be an appropriate theoretical treatment of the foundations of
+ computer science.
+
+ (2014-08-24)
+
+constructive solid geometry
+
+ <graphics> (CSG) A method for describing the geometry of
+ complex scenes by applying set operations to primitive
+ objects.
+
+ See also {CSG-tree}.
+
+ [What operations? What objects?]
+
+ (1998-06-09)
+
+constructor
+
+ <programming> 1. In {functional programming} and {type
+ theory}, one of the symbols used to create an object with an
+ {algebraic data type}.
+
+ 2. A function provided by a {class} in {C++} and some other
+ {object-oriented languages} to {instantiate} an object,
+ i.e. to name it and initialise it. The constructor function
+ has the same name as the class. A class may also have a
+ {destructor} function to destroy objects of that class.
+
+ (1994-10-20)
+
+Consul
+
+ <language> A {constraint}-based [{future}-based?] language
+ with {Lisp}-like {syntax}.
+
+ ["Consul: A Parallel Constraint Language", D. Baldwin, IEEE
+ Software 6(4):62-71].
+
+ (1994-11-30)
+
+consultant
+
+ <job> A person who facilitates organisational change and/or
+ provides subject matter expertise on technical, functional and
+ business topics during development or implementation.
+ Consultants perform {business requirements analysis},
+ recommends selection of packaged software, develop proposals
+ for consulting services and manage implementation projects at
+ client sites. They provides expert knowledge of products such
+ as {SAP R/3}, {PeopleSoft}, {HRMS/Financials}, and
+ {SmartStream}.
+
+ (2004-03-09)
+
+container class
+
+ A {class} whose instances are collections of other objects.
+ Examples include {stacks}, {queues}, {lists} and {arrays}.
+
+content addressable memory
+
+ (CAM, or "associative memory") A kind of storage device which
+ includes comparison logic with each bit of storage. A data
+ value is broadcast to all words of storage and compared with
+ the values there. Words which match are flagged in some way.
+ Subsequent operations can then work on flagged words, e.g. read
+ them out one at a time or write to certain bit positions in
+ all of them. A CAM can thus operate as a {data parallel}
+ ({SIMD}) processor.
+
+ CAMs are often used in {caches} and {memory management units}.
+
+ (1995-02-16)
+
+content-based information retrieval
+
+ <image, algorithm> (CBIR) A general term for methods for using
+ information stored in image archives.
+
+ [Details?]
+
+ [IEEE Computer, September 1995].
+
+ (1995-11-23)
+
+Content Data Model
+
+ (CDM) An {SGML}-based {DoD} specification for interactive
+ manuals.
+
+ (1995-02-15)
+
+content-free
+
+ 1. (By analogy with "context-free") Used of a message that
+ adds nothing to the recipient's knowledge. Though this
+ adjective is sometimes applied to {flamage}, it more usually
+ connotes derision for communication styles that exalt form
+ over substance or are centred on concerns irrelevant to the
+ subject ostensibly at hand. Perhaps most used with reference
+ to speeches by company presidents and other professional
+ manipulators.
+
+ See also {four-colour glossies}.
+
+ 2. Within British schools the term refers to general-purpose
+ software such as a {word processor}, a {spreadsheet} or a
+ program that tests spelling of words supplied by the teacher.
+ This is in contrast to software designed to teach a particular
+ topic, e.g. a plant growth simulation, an interactive periodic
+ table or a program that tests spelling of a predetermined list
+ of words. Content-free software can be more cost-effective as
+ it can be reused for many lessons throughout the syllabus.
+
+ [{Jargon File}]
+
+ (1998-08-26)
+
+contention slot
+
+ (Or contention period). Minimum time a {host} must transmit
+ for before it can be sure that no other host's {packet} has
+ collided with its transmission. If the maximum propagation
+ delay from one host to any other is T, then a host that starts
+ to transmit at time t0 may collide with a host that starts
+ just before t0 + T. The first host will not detect the
+ collision until time t0 + 2T.
+
+Contents of Decrement part of Register
+
+ <programming> (cdr) /ku'dr/ or /kuh'dr/ The {LISP} operation
+ that returns the right-hand node of a {binary tree} structure.
+ In the typical case where the tree is used to store a list,
+ the cdr is the tail of the list, i.e. all but the first
+ element.
+
+ The instruction format of the {IBM 7090} that hosted the
+ original LISP implementation featured two 15-bit fields called
+ the "address" and "decrement" parts. The term "cdr" was
+ originally "Contents of Decrement part of Register".
+ Similarly, "car" stood for "Contents of Address part of
+ Register".
+
+ [{Jargon File}]
+
+ (2007-02-28)
+
+context
+
+ That which surrounds, and gives meaning to, something else.
+
+ <grammar> In a {grammar} it refers to the symbols before and
+ after the symbol under consideration. If the syntax of a
+ symbol is independent of its context, the grammar is said to
+ be {context-free}.
+
+context clash
+
+ <grammar> When a {parser} cannot tell which alternative
+ {production} of a {syntax} applies by looking at the next
+ input {token} ("lexeme").
+
+ E.g. given syntax
+
+ C -> A | b c
+
+ A -> d | b e
+
+ If you're parsing non-terminal C and the next token is 'b',
+ you don't know whether it's the first or second alternative of
+ C since they both can start with b.
+
+ To discover whether a grammar has a context clash:
+
+ For each non-terminal, N, with multiple alternatives, look at
+ the first symbol of each alternative's right-hand side, call
+ it s. If s is the empty string, then find the set FOLLOWER(N)
+ otherwise find the set FIRST*(s). If any of the sets for N's
+ alternatives intersect then there will be a context clash when
+ parsing N. If the next input symbol is one of those in the
+ intersection of two sets then you won't know which of the
+ alternatives applies.
+
+ FIRST(s) is the set of symbols with which s can start,
+ including s itself. If s is a non-terminal then FIRST(s) also
+ includes the first symbol of each alternative right-hand side
+ of s. The '*' in FIRST*(s) means the "{transitive closure}"
+ of FIRST which means keep applying FIRST to each element of
+ the result until the result doesn't change. I.e. start with
+ just the set R = {s}, then for each non-terminal x in R, add
+ FIRST(x) to R. Keep doing this until nothing new is added.
+ (We are really only interested in the terminals in FIRST*(s)
+ but some definitions include the non-terminals).
+
+ FOLLOWER(N) is the set of symbols which can come after N in a
+ sentence. Find each occurrence of N on the right-hand side of
+ a rule, e.g.
+
+ M -> ... | ... N ... | ...
+
+ If there is a symbol s immediately following N then add
+ FIRST*(s) to the result (again, we're only interested in the
+ terminal symbols in FIRST*(s)) if there is no symbol after N
+ in the alternative then add FOLLOWER(M) to the result (i.e. if
+ N can be the last symbol in an M then anything that can follow
+ M can also follow N).
+
+ If a grammar can generate the same sentence in multiple
+ different ways (with different parse tress) then it is
+ ambiguous. An ambiguity must start with a context clash (but
+ not all context clashes imply ambiguity). The context clash
+ occurs when trying to parse the first token of the phrase with
+ multiple parses - you will not be able to tell which
+ alternative to take. To see if a context clash is also a case
+ of ambiguity you would need to follow the alternatives
+ involved in each context clash to see if they can generate the
+ same complete sequence of tokens.
+
+ (1995-04-05)
+
+COntext Dependent Information Language
+
+ <language> (CODIL) An early language for non-numerical
+ business problems.
+
+ ["CODIL, Part1. The Importance of Flexibility", C.F. Reynolds
+ et al, Computer J 14(3):217-220, May 1971].
+
+ (1994-12-23)
+
+context-free
+
+ Said of a {grammar} where the syntax of each constituent is
+ independent of the symbols occuring before and after it in a
+ sentence. {Parsers} for such grammars are simpler than those
+ for context-dependent grammars because the parser need only
+ know the current symbol.
+
+context-sensitive menu
+
+ <operating system> A {menu} which appears in response to a
+ user action (typically a {mouse} click) and whose contents are
+ determined by which {application window} was clicked or has
+ the {input focus}.
+
+ Most {GUIs} use a secondary mouse button (right or middle) to
+ call up a context-sensitive menu as the {primary mouse button}
+ is normally used to interact with objects which are already
+ visible.
+
+ The context-sensitive menu often contains functions that are
+ also available in a {menu bar} but the context-sensitive menu
+ provides quick access to a subset of functions that are
+ particularly relevant to the window area clicked on.
+
+ The {RISC OS} {WIMP} uses only context-sensitive menus (always
+ invoked using the middle mouse button). This saves screen
+ space and reduces mouse movement compared to a {menu bar}.
+
+ (1999-09-22)
+
+context switch
+
+ <operating system> When a {multitasking} {operating system}
+ stops running one {process} and starts running another. Many
+ operating systems implement concurrency by maintaining
+ separate environments or "contexts" for each process. The
+ amount of separation between processes, and the amount of
+ information in a context, depends on the operating system but
+ generally the OS should prevent processes interfering with each
+ other, e.g. by modifying each other's memory.
+
+ A context switch can be as simple as changing the value of the
+ {program counter} and {stack pointer} or it might involve
+ resetting the {MMU} to make a different set of memory {pages}
+ available.
+
+ In order to present the user with an impression of parallism,
+ and to allow processes to respond quickly to external events,
+ many systems will context switch tens or hundreds of times per
+ second.
+
+ (1996-12-18)
+
+Contextually Communicating Sequential Processes
+
+ (CCSP) A notation based on {CSP}.
+
+ ["Contextually Communicating Sequential Processes - A Software
+ Engineering Approach", M. Hull et al, Software Prac & Exp
+ 16(9):845-864 (Sept 1986)].
+
+ (1994-11-01)
+
+continental drift
+
+ In 1980 {David Turner} remarked that {KRC} ran "at the speed
+ of the continental drift".
+
+ (1994-12-06)
+
+continuation
+
+ {continuation passing style}
+
+Continuation Passing Style
+
+ (CPS) A semantically clean language with continuations used as
+ an intermediate language for {Scheme} and the {SML/NJ}
+ {compiler}.
+
+ ["Rabbit: A Compiler for Scheme", G.L. Steele, AI-TR-474, MIT
+ (May 1978)].
+
+ ["Compiling With Continuations", A. Appel, Cambridge U Press
+ 1992].
+
+continuation passing style
+
+ <programming> (CPS) A style of programming in which every user
+ function f takes an extra argument c known as a continuation.
+ Whenever f would normally return a result r to its caller, it
+ instead returns the result of applying the continuation to r.
+ The continuation thus represents the whole of the rest of the
+ computation. Some examples:
+
+ normal (direct style) --> continuation passing
+
+ square x = x * x square x k = k (x*x)
+
+ g (square 23) square 23 g
+
+ (square 3) + 1 square 3 ( \ s . s+1 )
+
+ (1995-04-04)
+
+continuations
+
+ {continuation passing style}
+
+continuous function
+
+ A function f : D -> E, where D and E are {cpos}, is continuous
+ if it is {monotonic} and
+
+ f (lub Z) = lub { f z | z in Z }
+
+ for all {directed} sets Z in D. In other words, the image of
+ the lub is the lub of any directed image.
+
+ All {additive} functions (functions which preserve all lubs)
+ are continuous. A continuous function has a {least fixed
+ point} if its {domain} has a least element, {bottom} (i.e. it
+ is a cpo or a "pointed cpo" depending on your definition of a
+ cpo). The {least fixed point} is
+
+ fix f = lub {f^n bottom | n = 0..infinity}
+
+ (1994-11-30)
+
+Continuous System Modeling Program
+
+ <simulation> (CSMP) A program for {simulation} of dynamics of
+ {continuous systems}. CSMP is similar to {CSSL}.
+
+ ["A Guide to Using CSMP - The Continuous System Modeling
+ Program", Frank H. Speckhart et al, P-H 1976].
+
+ (1995-02-23)
+
+Continuous System Simulation Language
+
+ <simulation> (CSSL) Versions include {ACSL}, {HYTRAN}, {SL-I},
+ {S/360} and {CSMP}.
+
+ CSSL(Continuous System Simulation Language) versions I, II,
+ III, IV and V have been commercially available since 1968.
+ CSSL-I was developed for {Jet Propulsion Labs} in 1968.
+ CSSL-III was widely distributed from 1969-1975. CSSL-IV
+ (interactive version) was developed by R. Nilsen and ran on
+ over 30 different computers. Currently CSSL-V is marketed by
+ {Simulation Services International} and available on {PCs} and
+ {workstations}.
+
+ ["The SCi Continuous System Simulation Language (CSSL)",
+ Simulation, 9(6), Dec 1967].
+
+ [URL?]
+
+ (2003-04-15)
+
+continuous wave
+
+ <communications, history> (CW) A term from early radio history
+ for a transmitter using an {electron tube} (valve) oscillator
+ to constantly add energy to a tuned circuit connected to an
+ antenna.
+
+ The term is used in contrast with the use of a {spark gap} to
+ initiate a damped {sinusoidal wave} in a {tuned circuit}
+ consisting of an {inductor} and {capacitor}. The energy in
+ this circuit constantly changes between the capacitor's
+ electrostatic field and the inductor's magnetic field. The
+ energy is then coupled to the radiating antenna, loosely (so
+ as not to dampen the wave too quickly).
+
+ Some radio amateurs understand "CW" to mean transmission by
+ means a single frequency signal which is either on or off
+ (e.g. {Morse code}), as opposed to a carrier which varies
+ continuously in amplitude, frequency or phase. Some would
+ even call the former "unmodulated" even though turning on and
+ off is actually the most extreme form of amplitude modulation.
+
+ (2009-11-24)
+
+contraction
+
+ {reduction}
+
+contract programmer
+
+ <job> A programmer who works on a fixed-length/temporary
+ contract, and is often specialised in writing certain types of
+ code.
+
+ A contract programmer may be independent or they may work in a
+ supplier's {professional services} department, providing
+ consultancy and programming services for the supplier's
+ products.
+
+ (2004-03-09)
+
+control
+
+ <character> (Or "ctrl", "^") One (or a pair) of {modifier
+ keys} found on all modern {keyboards}. If the control key is
+ held down while pressing and releasing certain other keys then
+ a "{control character}" is generated, e.g. holding control and
+ hitting "A" generates control-A ({ASCII} code 1). The ASCII
+ code for the control character is generally 64 less than that
+ for the unmodified character.
+
+ The control key does not generate any character on its own but
+ most modern keyboards and {operating systems} allow a program
+ to tell whether each of the individual keys on the keyboard
+ (including modifier keys) is pressed at any time.
+
+ Control characters mostly have some kind of "non-printing"
+ effect on the output such as ringing the bell (Control-G) or
+ advancing to the next line (Control-J). Most have alternative
+ names suggesting these functions (Bell, Line Feed, etc.).
+
+ See {ASCII character table}.
+
+ (1997-07-10)
+
+Control and Status Register
+
+ <hardware> (CSR) A {register} in most {CPUs} which stores
+ additional information about the results of machine
+ instructions, e.g. comparisons. It usually consists of
+ several independent flags such as {carry}, {overflow} and
+ zero. The CSR is chiefly used to determine the outcome of
+ {conditional branch} instructions or other forms of
+ conditional execution.
+
+ (1998-06-26)
+
+control bus
+
+ <architecture> In a {digital computer}, the signal paths that
+ carry commands from the {instruction decode} logic to various
+ different functional units such as the {ALU}, {memory address
+ register}, {memory data register} and other {buffers}.
+
+ Named by analogy with the {address bus} and {data bus}, each
+ of which carries a set of related signals, the signals carried
+ by the control bus are more independant.
+
+ Some might include other signals such as timing ({clock}) and
+ status under the term, further reducing its similarity to
+ other busses.
+
+ (2007-07-25)
+
+control-C
+
+ <character> (Or ETX, End of Text) The {ASCII} character with
+ code 3.
+
+ Control-C is the interrupt character used on many {operating
+ systems}, including {Unix} and {MS-DOS} to abort a running
+ program.
+
+ Among {BSD} {Unix} hackers, the canonical humorous response
+ to "Give me a break!" is "Control C".
+
+ [{Jargon File}]
+
+ (1995-03-16)
+
+control code
+
+ <character> A character which is input or output to cause some
+ special action rather than to appear as part of the data.
+
+ Most control characters are input by holding down (either of)
+ the "Control" key(s) on the keyboard and simultaneously
+ pressing another key which may be a letter or (depending on
+ the keyboard and {operating system}) certain punctuation
+ characters. Some control codes usually have their own special
+ keys: {escape}, {tab}, {delete}, {backspace}, {return} and can
+ thus be entered with a single keypress.
+
+ Different {operating systems} and programs have different
+ conventions for what effect typing certain control codes will
+ have, such as interrupting the current process or suspending
+ output.
+
+ Control codes may be output for their effect on the output
+ device, e.g. moving the cursor or print head to the start of a
+ new line.
+
+ See {control-O}, {control-Q}, {control-S}.
+
+ (1995-03-23)
+
+control flow
+
+ <programming> (Or "flow of control") The sequence of execution
+ of instructions in a program. This is determined at run time
+ by the input data and by the {control structures} (e.g. "if"
+ statements) used in the program.
+
+ Not to be confused with "{flow control}".
+
+ (1997-09-14)
+
+control-G
+
+ {bell}
+
+Control Language
+
+ <language> (CL) The {batch} language for {IBM RPG}/38, used in
+ conjunction with {RPG III}.
+
+ See also {OCL}.
+
+ (2000-04-08)
+
+controller
+
+ <hardware> Part of a computer, typically a separate circuit
+ board, which allows the computer to use certain kinds of
+ {peripheral} devices. A {disk controller} is used to connect
+ {hard disks} and {floppy disks}, a {network controller} is
+ used for {Ethernet}. Other controllers are: {keyboard
+ controller}, {interrupt controller} and {graphics controller}.
+
+ (1998-03-16)
+
+control-O
+
+ <character> {ASCII} character 15 (SI).
+
+ The character used on some {operating systems} to abort output
+ but allow the program to keep on running. The name "SI" comes
+ from its use on some terminals to "shift in" an alternative
+ character set. "SO" is {Control-N}.
+
+ Compare {control-S}.
+
+ [{Jargon File}]
+
+ (1995-03-16)
+
+Control Program
+
+ <operating system> (CP) The component of {IBM}'s {Virtual
+ Machine} (VM) that provides "guest support" for {operating
+ systems} that run on IBM {mainframe} compatible processors.
+ Cp does this by providing a seamless {emulation} of privileged
+ functions in the problem program environment.
+
+ (1999-01-19)
+
+Control Program for Microcomputers
+
+ <operating system> (CP/M) An early {microcomputer} {operating
+ system} written by Gary Kildall of {Digital Research} for
+ {8080} and {Zilog Z80}-based 8-bit computers. CP/M was very
+ popular in the late 1970s but was virtually wiped out by
+ {MS-DOS} after the release of the {IBM PC} in 1981.
+
+ Many of CP/M's features and conventions strongly resemble
+ those of early {DEC} operating systems such as {TOPS-10},
+ {OS/8}, {RSTS} and {RSX-11}.
+
+ CP/M might have been the {OS} for the {IBM PC} instead of
+ {MS-DOS} but Kildall wanted to keep control of his creation
+ and only license it to IBM. Big Blue however wanted to own
+ and control it completely. Kildall spent the day IBM's reps
+ wanted to meet him enjoying the perfect flying weather in his
+ private plane.
+
+ [Did CP/M use the same {FAT} file system as MS-DOS?]
+
+ (1996-01-07)
+
+control-Q
+
+ <character> (Or XON, DC1, {Device Control} 1) The character
+ with {ASCII} code 17, used in {software handshaking} to resume
+ output after a previous {control-S}.
+
+ [{Jargon File}]
+
+ (1996-06-28)
+
+control-S
+
+ <character> (Or XOFF, DC3, {Device Control} 3) The character
+ with {ASCII} code 19, used in {software handshaking} to
+ temporarily suspend output until a {control-Q} is received.
+
+ [{Jargon File}]
+
+ (1996-06-28)
+
+control structure
+
+ <programming> One of the instructions, statements or groups of
+ statements in a programming language which determines the
+ sequence of execution of other instructions or statements (the
+ {control flow}).
+
+ In {assembly language} this typically consists of {jumps} and
+ {conditional jumps} along with {procedure} call and return
+ though some architectures include other constructs such as an
+ instruction which skips the following instruction depending on
+ some condition ({PDP}?), various kinds of {loop} instructions
+ (later {Motorola 680x0}) or conditional execution of all
+ instructions (Advanced RISC Machine).
+
+ Basic control structures (whatever their names in particular
+ languages) include "if CONDITION then EXPRESSION else
+ EXPRESSION", the {switch statement}, "while CONDITION do
+ EXPRESSION", "gosub", the suspect "{goto}" and the much-feared
+ "{come from}". Other constructs handle errors and
+ {exceptions} such as {traps} and {interrupts}.
+
+ (1997-09-14)
+
+control tty
+
+ (/dev/ptyp*) The network side of a {pseudo-tty}.
+
+control unit
+
+ 1. <processor> The part of a {CPU} that sends control signals
+ to other components to cause them to execute the {machine
+ cycle} - fetch, decode, execute, store.
+
+ 2. <architecture> Any device that controls the I/O operations
+ of one or more {peripheral} devices, e.g. a {disk controller}.
+
+ (2008-05-21)
+
+conventional memory
+
+ <storage> The first 640 {kilobytes} of an {IBM PC}'s memory.
+ Prior to {EMS}, {XMS}, and {HMA}, {real mode} application
+ could use only this part of the memory.
+
+ (1996-01-10)
+
+converged network
+
+ <networking> A single {network} that can carry {voice},
+ {video} and {data}.
+
+ (2007-06-07)
+
+Convergent Technologies
+
+ <company> A company formed by a small group of people who left
+ {Intel Corporation} in 1979. Convergent Technologies' first
+ product was the IWS (Integrated Workstation) based on the
+ {Intel 8086}, which ran {Convergent Technologies Operating
+ System} - their first {operating system}.
+
+ Unisys bought {Convergent Technologies} in 1988.
+
+ [Who bought/merged with who and when?]
+
+ (1998-04-03)
+
+Convergent Technologies Operating System
+
+ <operating system> (CTOS, BTOS, STARSYS) /see-toss/ A modular,
+ {message-passing}, {multi-process} based {operating system}.
+
+ {Convergent Technologies}' first product was the IWS
+ (Integrated Workstation) based on the {Intel 8086}, which had
+ CTOS as its operating system. It is a modular operating
+ system with built in {local area networking}. CTOS supports
+ multiple processes or {threads}, and message-based
+ {inter-process communication}.
+
+ Companies which have licensed CTOS include {Burroughs} (BTOS)
+ and {Bull} (STARSYS). The largest customer was {Unisys}, with
+ whom Convergent Technologies merged to become one company in
+ 1988. CTOS now has over 800,000 users worldwide.
+
+ CTOS runs on Intel {Pentium} computers, and can run
+ concurrently with {Microsoft} {Windows NT}.
+
+ For some reason, CTOS is no longer marketted to new customers,
+ although there is a support comittment for existing customers
+ until 2001. Major customers include Police Forces, Banks, and
+ Airlines.
+
+ Latest version: CTOS III 1.3.2.
+
+ ["Exploring CTOS", Miller E., Crook J., Loy J. - Prentice
+ Hall, ISBN 0-13-297342-1, 1991].
+
+ (1996-09-24)
+
+Conversational LISP
+
+ <language> (CLISP) A mixed English-like, {ALGOL}-like surface
+ {syntax} for {Interlisp}.
+
+ ["CLISP: Conversational LISP", W. Teitelman, in Proc Third
+ Intl Joint Conf on AI, Stanford, Aug 1973, pp.686-690].
+
+ (1994-11-01)
+
+Conversational Monitor System
+
+ {Virtual Machine/Conversational Monitor System}
+
+converse
+
+ <logic> The truth of a {proposition} of the form A => B and
+ its converse B => A are shown in the following truth table:
+
+ A B | A => B B => A
+ ------+----------------
+ f f | t t
+ f t | t f
+ t f | f t
+ t t | t t
+
+ (2002-07-12)
+
+conversion to iteration
+
+ A transformation applied to functional programs to replace
+ recursion with iteration. A tail-recursive function can be
+ compiled to an iterative loop where the recursive call becomes
+ a jump back to the start and the parameters are held in
+ registers which are updated with new values each time around
+ the loop. See Iteration, Tail recursion optimisation.
+
+CONVERT
+
+ <language> 1. (Or "REC", "Regular Expression Converter") A
+ {string processing} language that combined the {pattern
+ matching} and transformation operations of {COMIT} with the
+ {recursive data structures} of {Lisp}.
+
+ ["Convert", A. Guzman et al, CACM 9(8):604-615, Aug 1966].
+
+ 2. An early language to convert programs and data from one
+ language to another.
+
+ ["CONVERT Manual", OLI Systems Inc, Oct 1976].
+
+ (2007-02-05)
+
+convert.f90
+
+ A {Fortran77} to {Fortran90} translator by Michael Metcalf
+ <metcalf@cernvm.cern.ch>. The significant differences between
+ the two Fortrans make this package useful.
+
+ {(ftp://jkr.cc.rl.ac.uk/pub/MandR/convert.f90)}.
+
+ (1993-07-17)
+
+Convex Computer Corporation
+
+ <company> A mini-super-computer manufacturer.
+
+ Address: Richardson, Texas, USA.
+
+ (1995-03-01)
+
+convex hull
+
+ <mathematics, graphics> For a {set} S in space, the smallest
+ {convex set} containing S. In the plane, the convex hull can
+ be visualized as the shape assumed by a rubber band that has
+ been stretched around the set S and released to conform as
+ closely as possible to S.
+
+ (1997-08-03)
+
+Conway, John Horton
+
+ {John Horton Conway}
+
+Conway's Law
+
+ <project, humour> The rule that the organisation of the
+ software and the organisation of the software team will be
+ congruent; originally stated as "If you have four groups
+ working on a compiler, you'll get a 4-pass compiler".
+
+ Melvin Conway, an early proto-hacker, wrote an {assembler} for
+ the {Burroughs 220} called SAVE. The name "SAVE" didn't stand
+ for anything; it was just that you lost fewer card decks and
+ listings because they all had SAVE written on them.
+
+ [{Jargon File}]
+
+Conway's Life
+
+ {Life}
+
+cooC
+
+ {Concurrent Object-Oriented C}.
+
+cooccurrence matrix
+
+ <mathematics> Given a position operator P(i,j), let A be a nxn
+ matrix whose element A[i][j] is the number of times that
+ points with grey level (intensity) g[i] occur, in the position
+ specified by P, relative to points with grey level g[j]. Let
+ C be the nxn matrix that is produced by dividing A with the
+ total number of point pairs that satisfy P. C[i][j] is a
+ measure of the joint probability that a pair of points
+ satisfying P will have values g[i], g[j]. C is called a
+ cooccurrence matrix defined by P. Examples for the operator P
+ are: "i above j", "i one position to the right and two below
+ j", etc.
+
+ (1995-05-11)
+
+cookbook
+
+ <programming> (From amateur electronics and radio) A book of
+ small code segments that the reader can use to do various
+ {magic} things in programs.
+
+ One current example is the "{PostScript} Language Tutorial and
+ Cookbook" by Adobe Systems, Inc (Addison-Wesley, ISBN
+ 0-201-10179-3), also known as the {Blue Book} which has
+ recipes for things like wrapping text around arbitrary curves
+ and making 3D fonts.
+
+ Cookbooks, slavishly followed, can lead one into {voodoo
+ programming}, but are useful for hackers trying to {monkey up}
+ small programs in unknown languages. This function is
+ analogous to the role of phrasebooks in human languages.
+
+ [{Jargon File}]
+
+ (1994-11-04)
+
+cooked mode
+
+ The normal{Unix} character-input mode, with interrupts enabled
+ and with erase, kill and other special-character
+ interpretations performed directly by the tty driver.
+ Opposite of {raw mode}. See also {rare mode}. Other
+ operating systems often have similar mode distinctions, and
+ the raw/rare/cooked way of describing them has spread widely
+ along with the {C} language and other Unix exports. Most
+ generally, "cooked mode" may refer to any mode of a system
+ that does extensive preprocessing before presenting data to a
+ program.
+
+ [{Jargon File}]
+
+cookie
+
+ 1. <web> {HTTP cookie}.
+
+ 2. <protocol> A handle, transaction ID, or other token of
+ agreement between cooperating programs. "I give him a packet,
+ he gives me back a cookie".
+
+ The ticket you get from a dry-cleaning shop is an example of a
+ cookie; the only thing it's useful for is to relate a later
+ transaction to this one (so you get the same clothes back).
+
+ Compare {magic cookie}; see also {fortune cookie}.
+
+ 3. <security, jargon> A {cracker} term for the {password} list
+ on a {multi-user} computer.
+
+ 4. <jargon> An adjective describing a computer that just
+ became {toast}.
+
+ (1997-04-14)
+
+cookie bear
+
+ {cookie monster}
+
+cookie file
+
+ <operating system> A collection of {fortune cookies} in a
+ format that facilitates retrieval by a {fortune} program.
+ There are many cookie files in public distribution, and site
+ admins often assemble their own from various sources.
+
+ [{Jargon File}]
+
+ (1997-01-07)
+
+cookie jar
+
+ 1. <programming> An area of memory set aside for storing
+ {cookies}. Most commonly heard in the {Atari ST} community;
+ many useful ST programs record their presence by storing a
+ distinctive {magic number} in the jar. Programs can inquire
+ after the presence or otherwise of other programs by searching
+ the contents of the jar.
+
+ 2. <security> A {cracker} term for the password file of a
+ multi-user computer.
+
+ [{Jargon File}]
+
+ (1997-02-12)
+
+cookie monster
+
+ <recreation> (From the children's TV program "Sesame Street")
+ Any of a family of early (1970s) hacks reported on {TOPS-10},
+ {ITS}, {Multics} and elsewhere that would lock up either the
+ victim's terminal (on a {time-sharing} machine) or the
+ {console} (on a batch {mainframe}), repeatedly demanding "I
+ WANT A COOKIE". The required responses ranged in complexity
+ from "COOKIE" through "HAVE A COOKIE" and upward.
+
+ See also {wabbit}.
+
+ [{Jargon File}]
+
+ (1997-02-12)
+
+cooky
+
+ {cookie}
+
+COOL
+
+ 1. {Concurrent Object-Oriented Language}.
+
+ 2. CLIPS Object-Oriented Language?
+
+ 3. A C++ class library developed at {Texas Instruments} that
+ defines {containers} like {Vectors}, {List}, {Hash_Table},
+ etc. It uses a shallow hierarchy with no common {base class}.
+ The functionality is close to {Common Lisp} data structures
+ (like {libg++}). The {template} {syntax} is very close to
+ {Cfront} 3.x and {g++} 2.x.
+
+ JCOOL's main difference from COOL and GECOOL is that it uses
+ real C++ templates instead of a similar syntax that is
+ preprocessed by a special 'cpp' distributed with COOL and
+ GECOOL.
+
+ {(ftp://csc.ti.com/pub/COOL.tar.Z)}.
+
+ GECOOL, JCOOL: {(ftp://cs.utexas.edu/pub/COOL/)}.
+
+ E-mail: Van-Duc Nguyen <nguyen@crd.ge.com>
+
+ (1992-08-05)
+
+CooL
+
+ <language> Combined object-oriented Language.
+
+ An {object-oriented} language from the {ITHACA} {Esprit}
+ project, which combines {C}-based languages with {database}
+ technology.
+
+ (1995-03-15)
+
+COOL:Gen
+
+ {Advantage Gen}
+
+Co-operative Development Environment
+
+ <tool, product> (CDE) A set of tools from {Oracle} for
+ enterprise-wide, {client/server} {application} development.
+
+ (1995-03-15)
+
+Cooperative Information System
+
+ <networking> (CIS) Networked computers which support
+ individual or collaborative human work, and manage access to
+ information and computing services. Computation is done
+ {concurrent}ly over the network by cooperative {database}
+ systems, {expert systems}, multi-agent planning systems, and
+ other software application systems ranging from the
+ conventional to the advanced.
+
+ (1995-05-11)
+
+cooperative multitasking
+
+ <parallel, operating system> A form of {multitasking} where it
+ is the responsibility of the currently running task to give up
+ the processor to allow other tasks to run. This contrasts
+ with {pre-emptive multitasking} where the task {scheduler}
+ periodically suspends the running task and restarts another.
+
+ Cooperative multitasking requires the programmer to place
+ calls at suitable points in his code to allow his task to be
+ {deschedule}d which is not always easy if there is no obvious
+ top-level {main loop} or some routines run for a long time.
+ If a task does not allow itself to be descheduled all other
+ tasks on the system will appear to "freeze" and will not
+ respond to user action.
+
+ The advantage of cooperative multitasking is that the
+ programmer knows where the program will be descheduled and can
+ make sure that this will not cause unwanted interaction with
+ other processes. Under {pre-emptive multitasking}, the
+ scheduler must ensure that sufficient state for each process
+ is saved and restored that they will not interfere. Thus
+ cooperative multitasking can have lower {overheads} than
+ pre-emptive multitasking because of the greater control it
+ offers over when a task may be descheduled.
+
+ Cooperative multitasking is used in {RISC OS}, {Microsoft
+ Windows} and {Macintosh} {System 7}.
+
+ (1995-03-20)
+
+coordinate
+
+ <mathematics> One member of a {tuple} of numbers which defines
+ the position of a point in some space. Commonly used
+ coordinate systems have as many coordinates as their are
+ dimensions in the space, e.g. a pair for two dimensions. The
+ most common coordinate system is {Cartesian coordinates},
+ probably followed by {polar coordinates}.
+
+ (1997-07-09)
+
+Coordinated Universal Time
+
+ <time, standard> (UTC, World Time) The standard time common to
+ every place in the world. UTC is derived from {International
+ Atomic Time} (TAI) by the addition of a whole number of "leap
+ seconds" to synchronise it with {Universal Time} 1 (UT1), thus
+ allowing for the eccentricity of the Earth's orbit, the
+ rotational axis tilt (23.5 degrees), but still showing the
+ Earth's irregular rotation, on which UT1 is based.
+
+ Coordinated Universal Time is expressed using a 24-hour clock
+ and uses the {Gregorian calendar}. It is used in aeroplane
+ and ship navigation, where it also sometimes known by the
+ military name, "Zulu time". "Zulu" in the phonetic alphabet
+ stands for "Z" which stands for longitude zero.
+
+ UTC was defined by the International Radio Consultative
+ Committee ({CCIR}), a predecessor of the {ITU-T}. CCIR
+ Recommendation 460-4, or ITU-T Recommendation X.680 (7/94),
+ contains the full definition.
+
+ The language-independent international abbreviation, UTC, is
+ neither English nor French. It means both "Coordinated
+ Universal Time" and "Temps Universel Coordonné".
+
+ {BIPM
+ (http://www.bipm.org/enus/5_Scientific/c_time/time_1.html)}.
+
+ {The Royal Observatory Greenwich
+ (http://rog.nmm.ac.uk/leaflets/time/time.html)}.
+
+ {History of UTC and GMT
+ (http://ecco.bsee.swin.edu.au/chronos/GMT-explained.html)}.
+
+ {U.S. National Institute of Standards & Technology
+ (http://its.bldrdoc.gov/fs-1037/dir-009/_1277.htm)}.
+
+ {UK National Physical Laboratory
+ (http://npl.co.uk/npl/ctm/time_scales.html)}.
+
+ {US Naval Observatory
+ (http://tycho.usno.navy.mil/systime.html)}.
+
+ {International Telecommunications Union
+ (http://itu.int/radioclub/rr/arts02.htm)}.
+
+ {Earth's irregular rotation (/pub/misc/earth_rotation)}.
+
+ (2001-08-30)
+
+Coordinating Committee for Intercontinental Research Networks
+
+ (CCIRN) A committee that includes the United States FNC and
+ its counterparts in North America and Europe. Co-chaired by
+ the executive directors of the Federal Networking Council and
+ the European Association of Research Networks (RARE), the
+ CCIRN provides a forum for cooperative planning among the
+ principal North American and European research networking
+ bodies.
+
+ (1994-11-30)
+
+coordination language
+
+ <networking, protocol> A language defined specifically to
+ allow two or more parties ({components}) to communicate in
+ order to accomplish some shared goal.
+
+ Examples of coordination languages are {Linda} and {Xerox}'s
+ {CLF} ({STITCH}).
+
+ (2004-04-18)
+
+copious free time
+
+ <jargon> (Apple; originally from the introduction to Tom
+ Lehrer's song "It Makes A Fellow Proud To Be A Soldier") Used
+ ironically to indicate the speaker's lack of the quantity in
+ question; a mythical schedule slot for accomplishing tasks
+ held to be unlikely or impossible. Sometimes used to indicate
+ that the speaker is interested in accomplishing the task, but
+ believes that the opportunity will not arise. "I'll implement
+ the automatic layout stuff in my copious free time."
+
+ The phrase is also used for time reserved for bogus or
+ otherwise idiotic tasks, such as implementation of bad
+ {chrome}, or the stroking of {suits}. "I'll get back to him
+ on that feature in my copious free time."
+
+ [{Jargon File}]
+
+ (1994-11-30)
+
+copper
+
+ Conventional electrical network cable with a core conductor of
+ copper (or aluminium!)
+
+ Opposed to {light pipe} or, say, a short-range microwave link.
+
+ [{Jargon File}]
+
+ (1994-11-30)
+
+Copper Distributed Data Interface
+
+ (CDDI) {FDDI} running over conventional copper cables. A
+ {Cisco}/{Crescendo} copyright term(?). All {FDDI}
+ connections, {single-attached} or {dual-attached}, can be
+ either {optical fibre} or copper.
+
+ (1994-12-14)
+
+coprocessor
+
+ Any computer processor which assists the main processor (the
+ "{CPU}") by performing certain special functions, usually much
+ faster than the main processor could perform them in software.
+ The coprocessor often decodes instructions in parallel with
+ the main processor and executes only those instructions
+ intended for it.
+
+ The most common example is a {floating point} coprocessor (or
+ "{FPU}"), others are graphics and networking.
+
+ (1995-01-05)
+
+copy and paste
+
+ <text> (Or "cut and paste", after the paper, scissors and glue
+ method of document production) The system supported by most
+ document editing applications (e.g. {text editors}) and most
+ {operating systems} that allows you to select a part of the
+ document and then save it in a temporary buffer (known
+ variously as the "clipboard", "cut buffer", "kill ring"). A
+ "copy" leaves the document unchanged whereas a "cut" deletes
+ the selected part.
+
+ A "paste" inserts the data from the clipboard at the current
+ position in the document (usually replacing any currently
+ selected data). This may be done more than once, in more than
+ one position and in different documents.
+
+ More sophisticated {operating systems} support copy and paste
+ of different data types between different applications,
+ possibly with automatic format conversion, e.g from {rich
+ text} to plain {ASCII}.
+
+ {GNU Emacs} uses the terms "kill" instead of "cut" and "yank"
+ instead of "paste" and data is stored in the "kill ring".
+
+ [Origin? Macintosh? Xerox?]
+
+ (1998-07-01)
+
+copybook
+
+ <programming, library> (Or "copy member", "copy module") A
+ common piece of {source code} designed to be copied into many
+ source programs, used mainly in {IBM} {DOS} {mainframe}
+ programming.
+
+ In {mainframe} {DOS} (DOS/VS, DOS/{VSE}, etc.), the copybook
+ was stored as a "book" in a {source} library. A library was
+ comprised of "books", prefixed with a letter designating the
+ language, e.g., A.name for Assembler, C.name for Cobol, etc.,
+ because {DOS} didn't support multiple libraries, private
+ libraries, or anything. This term is commonly used by {COBOL}
+ programmers but is supported by most {mainframe} languages.
+ The {IBM} {OS} series did not use the term "copybook", instead
+ it referred to such files as "libraries" implemented as
+ "partitioned data sets" or {PDS}.
+
+ Copybooks are functionally equivalent to {C} and {C++}
+ {include} files.
+
+ (1997-07-31)
+
+copybroke
+
+ <security> /kop'ee-brohk/ (Or "copywronged" - a play on
+ "{copyright}") 1. Used to describe an instance of a
+ {copy-protected} program that has been "broken"; that is, a
+ copy with the copy-protection scheme disabled or removed.
+
+ 2. Copy-protected software which is unusable because of some
+ {bit-rot} or {bug} that has confused the {copy protection}.
+
+ 3. Used to describe data damaged because of a side effect of a
+ copy protection system.
+
+ [{Jargon File}]
+
+ (1997-03-16)
+
+copying garbage collection
+
+ A {garbage collection} method where memory is divided into two
+ equal halves, known as the "from space" and "to space".
+ Garbage collection copies active cells from the from space to
+ the to space and leaves behind an invisible pointer (an
+ "indirection") from the old position to the new copy. Once
+ all active cells have been copied in one direction, the spaces
+ are swapped and the process repeated in the opposite
+ direction.
+
+copyleft
+
+ <legal> /kop'ee-left/ (A play on "copyright") The {copyright}
+ notice and {General Public License} applying to the works of
+ the {Free Software Foundation}, granting reuse and
+ reproduction rights to everyone.
+
+ Typically copyrights take away freedoms; copyleft preserves
+ them. It is a legal instrument that requires those who pass
+ on a program to include the rights to use, modify, and
+ redistribute the code; the code and the freedoms become
+ legally inseparable.
+
+ The copyleft used by the GNU Project combines a regular
+ copyright notice and the "GNU General Public License" (GPL).
+ The GPL is a copying license which basically says that you
+ have the aforementioned freedoms. The license is included in
+ each GNU source code distribution and manual.
+
+ See also {General Public Virus}.
+
+ [{Jargon File}]
+
+ (1995-04-18)
+
+copy member
+
+ {copybook}
+
+copy module
+
+ {copybook}
+
+copy protection
+
+ <security> Any technique designed to prevent unauthorised
+ copying of software. Such techniques will only hinder the
+ most incompetant attempts at {software theft} but often
+ prevent legitimate customers from using products they have
+ paid for in the way they want. Considered silly.
+
+ [{Jargon File}]
+
+ (2010-02-03)
+
+copyright
+
+ <legal> The exclusive rights of the owner of the copyright on
+ a work to make and distribute copies, prepare derivative
+ works, and perform and display the work in public (these last
+ two mainly apply to plays, films, dances and the like, but
+ could also apply to software).
+
+ A work, including a piece of software, is under copyright by
+ default in most coutries, whether of not it displays a
+ copyright notice. However, a copyright notice may make it
+ easier to assert ownership. The copyright owner is the person
+ or company whose name appears in the copyright notice on the
+ box, or the disk or the screen or wherever. Most countries
+ have agreed to uphold each others' copyrights.
+
+ A copyright notice has three parts. The first can be either the
+ {copyright symbol} (a letter C in a circle), the word "Copyright"
+ or the abbreviation "Copr". Only the first of these is recognised
+ internationally and the common {ASCII} rendering "(C)" is not
+ valid anywhere. This is followed by the name of the copyright
+ holder and the year of publication. The year should be the year
+ of _first_ publication, it is not necessary as some believe to
+ update this every year to the current year. Copyright protection
+ in most countries extends for 50 years after the author's death.
+
+ Originally, most of the computer industry assumed that only
+ the program's underlying instructions were protected under
+ copyright law but, beginning in the early 1980s, a series of
+ lawsuits involving the video screens of game programs extended
+ protections to the appearance of programs.
+
+ Use of copyright to restrict redistribution is immoral,
+ unethical and illegitimate. It is a result of brainwashing by
+ monopolists and corporate interests and it violates everyone's
+ rights. Such use of copyrights and patents hamper
+ technological progress by making a naturally abundant resource
+ scarce. Many, from communists to right wing libertarians, are
+ trying to abolish intellectual property myths.
+
+ See also {public domain}, {copyleft}, {software law}.
+
+ {Universal Copyright Convention
+ (http://www.unesco.org/new/en/culture/themes/creativity/creative-industries/copyright/)}.
+
+ {US Copyright Office (http://copyright.gov/)}.
+
+ {Usenet} newsgroup: {news:misc.legal.computing}.
+
+ [Is this definition correct in the UK? In the US? Anywhere?]
+
+ (2014-01-08)
+
+copyright symbol
+
+ <character, legal> "&copy;" The internationally recognised
+ symbol required to introduce a {copyright} notice, a letter C
+ with a circle around it. This can be encoded in {ISO 8859-1}
+ as character code decimal 169, hexadecimal A9, in {HTML} as
+ &amp;copy;, &amp;#169; or &amp;#xA9;.
+
+ A "c" in parentheses: "(c)" is sometimes used in documents
+ stored in a {coded character set} such as {ASCII} that does
+ not include the C in a circle, but this has no legal meaning.
+
+ (2009-01-06)
+
+copywronged
+
+ {copybroke}
+
+CORAL
+
+ 1. {Class Oriented Ring Associated Language}.
+
+ 2. A {deductive database} and {logic programming} system based
+ on {Horn-clause} rules with extensions like {SQL}'s {group-by}
+ and {aggregation} operators. CORAL was developed at the
+ University of Wisconsin-Madison. It is implemented in C++ and
+ has a {Prolog}-like {syntax}.
+
+ Many evaluation techniques are supported, including {bottom-up
+ fixpoint evaluation} and top-down {backtracking}. {Modules}
+ are separately compiled; different evaluation methods can be
+ used in different modules within a single program.
+ Disk-resident data is supported via an interface to the
+ {Exodus} storage manager. There is an on-line help facility.
+ It requires {AT&T} {C++} 2.0 (or {G++} soon) and runs on
+ {Decstation} and {Sun-4}.
+
+ {(ftp://ftp.cs.wisc.edu/)}.
+
+ (1993-01-29)
+
+CORAL 66
+
+ A real-time system programming language derived from {JOVIAL}
+ and {ALGOL 60}. It was adopted as the British military
+ standard from 1970 until the arrival of {Ada}.
+
+ ["Official Definition of CORAL 66", P.M. Woodward et al, HMSO,
+ London, 1970].
+
+CORBA
+
+ {Common Object Request Broker Architecture}
+
+CORBIE
+
+ <language> An early system on the {IBM 704}.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (1996-05-10)
+
+CORC
+
+ CORnell Compiler. Simple language for student math problems.
+
+ ["The Cornell Computing Language", R.W. Conway et al, CACM
+ 6(6):317-320 (Jun 1963) Sammet 1969, p.294-296].
+
+core
+
+ 1. <storage> {Main memory} or {RAM}. This term dates from the
+ days of {ferrite core memory} and, like the technology, is now
+ archaic.
+
+ Some derived idioms outlived the hardware: for example, "in
+ core" (meaning {paged in}), {core dump}, "core image", "core
+ file". Some varieties of Commonwealth hackish prefer {store}.
+
+ [{Jargon File}]
+
+ (2009-11-06)
+
+ 2. <processor> An {integrated circuit} design, usually for a
+ {microprocessor}, which includes only the {CPU} and which is
+ intended to be incorporated on a chiip with other circuits
+ such as {cache}, {memory management unit}, I/O ports and
+ timers. The trend in 2009 is to have multiple cores per chip.
+
+ The {ARM6}, {ARM7} and {ARM8} are early examples, the {Intel}
+ {Core i9} more recent.
+
+ 3. <language> A varient on {kernel} as used to describe
+ features built into a language as opposed to those provided by
+ {libraries}.
+
+ (2009-11-06)
+
+core cancer
+
+ <jargon> A process that exhibits a slow but inexorable
+ {resource leak} - like a cancer, it kills by crowding out
+ productive "tissue".
+
+ [{Jargon File}]
+
+ (1997-11-10)
+
+core dump
+
+ <programming, operating system, jargon> Common {Iron Age}
+ jargon, preserved by {Unix} for a {memory dump}.
+
+ The term is also used for a complete account of a human's
+ knowledge on some subject (also {brain dump}), especially in a
+ lecture or answer to an exam question.
+
+ [{Jargon File}]
+
+ (2007-05-09)
+
+core gateway
+
+ Historically, one of a set of gateways ({routers}) operated by
+ the {Internet Network Operations Center} at Bolt, Beranek and
+ Newman (BBN). The core gateway system formed a central part
+ of {Internet} routing in that all groups must advertise paths
+ to their networks from a core gateway.
+
+Corel Corporation
+
+ <company> A software publisher best known for the {CorelDraw}
+ {application}. Founded in June 1985 by Dr. Michael Cowpland,
+ Corel Corporation was originally a {systems integration}
+ company. In January 1989, however they entered the software
+ publishing market with the introduction of CorelDraw. Corel
+ became the second largest maker of personal {productivity
+ software} in January 1996 when they purchased the
+ {WordPerfect} family of software from {Novell, Inc.}.
+
+ {(http://corel.com/)}.
+
+ (1997-03-12)
+
+core leak
+
+ {memory leak}
+
+Corel VENTURA
+
+ <text, graphics> (Previously "Ventura Publisher") The first
+ full-featured {desktop publishing} program available for the
+ {IBM personal computer} and compatibles. Ventura Publisher
+ was originally distributed by {Ventura}, a wholy owned
+ subsiduary of {Xerox Corporation} but was acquired by {Corel
+ Corporation} in September 1993.
+
+ Latest version: Corel VENTURA 8, as of 1999-04-05.
+
+ {Home
+ (http://corelnet.com/products/graphicsandpublishing/ventura8/index.htm)}.
+
+ (1999-04-05)
+
+Core Protocol Stack
+
+ <architecture>
+
+ 1. A portion of the {Web Services} {architecture} for
+ defining and describing various {Web Services}.
+
+ 2. The architectural {protocol} layers of a {Bluetooth}
+ {wireless} {communication} system, comprising the {Host
+ Control Interface} (HCI), {Logical Link Control and Adaptation
+ Protocol} (L2CAP), {RS232 Serial Cable Emulation Profile}
+ (RFCOMM), {Service Discovery Protocol} (SDP), and {Object
+ Exchange} (OBEX).
+
+ (2002-06-28)
+
+Core War
+
+ <games> (Or more recently, "Core Wars") A game played between
+ {assembly code} programs running in the {core} of a simulated
+ machine (and vicariously by their authors). The objective is
+ to kill your opponents' programs by overwriting them.
+
+ The programs are written using an {instruction set} called
+ "{Redcode}" and run on a {virtual machine} called "{MARS}"
+ (Memory Array Redcode Simulator).
+
+ Core War was devised by Victor Vyssotsky, Robert Morris Sr.,
+ and {Dennis Ritchie} in the early 1960s (their original game
+ was called "{Darwin}" and ran on a {PDP-1} at {Bell Labs}).
+ It was first described in the "Core War Guidelines" of March,
+ 1984 by D. G. Jones and A. K. Dewdney of the Department of
+ Computer Science at The University of Western Ontario
+ (Canada).
+
+ Dewdney wrote several "Computer Recreations" articles in
+ "Scientific American" which discussed Core War, starting with
+ the May 1984 article. Those articles are contained in the two
+ anthologies cited below. A.K. Dewdney's articles are still
+ the most readable introduction to Core War, even though the
+ {Redcode} dialect described in there is no longer current.
+
+ The International Core War Society (ICWS) creates and
+ maintains Core War standards and the runs Core War
+ tournaments. There have been six annual tournaments and two
+ standards (ICWS'86 and ICWS'88).
+
+ ["The Armchair Universe: An Exploration of Computer Worlds",
+ A. K. Dewdney, W. H. Freeman, New York, 1988, ISBN
+ 0-7167-1939-8, LCCN QA76.6 .D517 1988]
+
+ ["The Magic Machine: A Handbook of Computer Sorcery",
+ A. K. Dewdney, W. H. Freeman, New York, 1990, ISBN
+ 0-7167-2125-2 (Hardcover), 0-7167-2144-9 (Paperback), LCCN
+ QA76.6 .D5173 1990].
+
+ (1998-10-30)
+
+corge
+
+ /korj/ Yet another {metasyntactic variable}, named after a cat
+ invented by Mike Gallaher and propagated by the {GOSMACS}
+ documentation.
+
+ See {grault}.
+
+ [{Jargon File}]
+
+ (1994-12-08)
+
+Cornell List Processor
+
+ (CLP) A list processing language, an extension of {CORC}, used
+ for {simulation}.
+
+ [Sammet 1969, p. 461].
+
+ (1994-11-01)
+
+Cornell Theory Center
+
+ (CTC) One of four supercomputing centers funded by the US
+ {National Science Foundation}. The CTC also receives funding
+ from the {Advanced Research Projects Agency}, the National
+ Institutes of Health, New York State, {IBM} Corporation, and
+ other members of the center's Corporate Research Institute.
+
+ {(http://tc.cornell.edu/)}.
+
+ (1994-12-08)
+
+Cornell University
+
+ <body, education> A US Ivy League University founded in 1868
+ by businessman Ezra Cornell and respected scholar Andrew
+ Dickson White. Cornell includes thirteen colleges and
+ schools. On the Ithaca campus are the seven undergraduate
+ units and four graduate and professional units. The Medical
+ College and the Graduate School of Medical Sciences are in New
+ York City. Cornell has 13,300 undergraduates and 6,200
+ graduate and professional students.
+
+ See also {Concurrent ML}, {Cornell Theory Center}, {Cornell
+ University Programming Language}, {CU-SeeMe}, {ISIS}.
+
+ {(http://cornell.edu/)}.
+
+ (1996-12-01)
+
+Coroutine Pascal
+
+ ["Control Separation in Programming languages", Lemon et al,
+ ACM Ann Conf 1977].
+
+ (1994-12-08)
+
+Corporation for National Research Initiatives
+
+ <body> (CNRI) A US research and development organisation that
+ leads and funds research and development of network-based
+ information technology including the {National Information
+ Infrastructure}.
+
+ Address: Reston, VA, USA.
+
+ {CNRI Home (http://cnri.reston.va.us/)}.
+
+ (2004-08-27)
+
+Corporation for Open Systems
+
+ (COS) An international consortium of computer users and
+ vendors set up to provide ways of testing {OSI}
+ implementations.
+
+ (1994-11-30)
+
+Corporation for Research and Educational Networking
+
+ <body> (CREN) The organisation responsible for providing
+ networking service to {BITNET} and {CSNET} users. CREN was
+ formed in October 1989, when {BITNET} and {CSNET} were
+ combined under one authority. {CSNET} is no longer
+ operational, but CREN still runs {BITNET}.
+
+ [Still true?]
+
+ (1996-05-17)
+
+CORREGATE
+
+ Based on {Internal Translator} (IT).
+
+ [Sammet 1969, p. 139].
+
+ (1994-11-30)
+
+Correlatives and Conversions
+
+ The {data description language} used in the {Pick} {operating
+ system}.
+
+ ["Exploring the Pick Operating System", J.E. Sisk et al,
+ Hayden 1986].
+
+ (1994-11-30)
+
+Cortex
+
+ An experimental slow controls project at {CERN}.
+
+ (1994-11-30)
+
+CORTL
+
+ An intermediate language, a form of {RTL}, by Carl McConnell
+ <mcconnell@cs.uiuc.edu>.
+
+ (1994-11-30)
+
+COS
+
+ 1. {Cray Operating System}.
+
+ 2. {Corporation for Open Systems}.
+
+COSE
+
+ Common Open Software Environment. An initiative by
+ Hewlett-Packard, Sun, IBM, Novell, Univel and SCO to move
+ toward consistency and interoperability between Unix
+ suppliers.
+
+COSINE
+
+ Cooperation for Open Systems Interconnection Networking in
+ Europe. A EUREKA project.
+
+cosmic rays
+
+ Notionally, the cause of {bit rot}. However, this is a
+ semi-independent usage that may be invoked as a humorous way
+ to {handwave} away any minor {randomness} that doesn't seem
+ worth the bother of investigating. "Hey, Eric - I just got
+ a burst of garbage on my {tube}, where did that come from?"
+ "Cosmic rays, I guess." Compare {sunspots}, {phase of the
+ moon}. The British seem to prefer the usage "cosmic showers";
+ "alpha particles" is also heard, because stray alpha particles
+ passing through a memory chip can cause single bit errors
+ (this becomes increasingly more likely as memory sizes and
+ densities increase).
+
+ Factual note: Alpha particles cause bit rot, cosmic rays do
+ not (except occasionally in spaceborne computers). Intel
+ could not explain random bit drops in their early chips, and
+ one hypothesis was cosmic rays. So they created the World's
+ Largest Lead Safe, using 25 tons of the stuff, and used two
+ identical boards for testing. One was placed in the safe, one
+ outside. The hypothesis was that if cosmic rays were causing
+ the bit drops, they should see a statistically significant
+ difference between the error rates on the two boards. They
+ did not observe such a difference. Further investigation
+ demonstrated conclusively that the bit drops were due to alpha
+ particle emissions from thorium (and to a much lesser degree
+ uranium) in the encapsulation material. Since it is
+ impossible to eliminate these radioactives (they are uniformly
+ distributed through the earth's crust, with the statistically
+ insignificant exception of uranium lodes) it became obvious
+ that one has to design memories to withstand these hits.
+
+ [{Jargon File}]
+
+COSS
+
+ {Common Object Services Specification} in {CORBA}.
+
+cost control callback
+
+ <communications> A system where a computer automatically
+ rejects incoming {dial-up} calls from certain telephone
+ numbers and calls them back, with the result that the caller
+ pays nothing for the connection. This differs from security
+ {callback} in that it applies to certain phone numbers instead
+ of to certain user names.
+
+ (2003-07-13)
+
+Cost Driver Attribute
+
+ <programming> Factors affecting the productivity of software
+ development. These include attributes of the software,
+ computers, personnel, and project.
+
+ (1996-05-28)
+
+Cost/Schedule Control System Criteria
+
+ <project> (C/SCSC) A set of criteria specified by the Federal
+ Government for reporting project schedule and financial
+ information.
+
+ (1996-05-29)
+
+COTS
+
+ <software> commercial off-the-shelf. See {commercial software}.
+
+ (2007-02-08)
+
+Cougar
+
+ <web, standard> A former (development) name for the
+ {W3C}'s {HTML} 4 standard.
+
+ (2001-02-06)
+
+cough and die
+
+ <jargon> {barf}. Connotes that the program is throwing its
+ hands up by design rather than because of a bug or oversight.
+ "The parser saw a control-A in its input where it was looking
+ for a printable, so it coughed and died."
+
+ Compare {die}, {die horribly}, {scream and die}.
+
+ [{Jargon File}]
+
+ (1995-03-07)
+
+count
+
+ <programming> One of the built-in {aggregate functions} in
+ {relational database} systems, that returns the number of rows
+ in a result. The argument to the function is nearly always
+ "*", e.g.
+
+ SELECT COUNT(*) FROM books
+
+ which returns the number of rows in the "books" table. If,
+ instead, we say
+
+ SELECT COUNT(publisher) FROM books
+
+ then only rows with a non-{null} value in the "publisher"
+ column will be counted.
+
+ (2010-09-26)
+
+countable
+
+ <mathematics> A term describing a {set} which is {isomorphic}
+ to a subet of the {natural numbers}. A countable set has
+ "countably many" elements. If the isomorphism is stated
+ explicitly then the set is called "a counted set" or "an
+ {enumeration}".
+
+ Examples of countable sets are any {finite} set, the {natural
+ numbers}, {integers}, and {rational numbers}. The {real
+ numbers} and {complex numbers} are not [proof?].
+
+ (1999-08-29)
+
+countably many
+
+ {countable}
+
+counted
+
+ <mathematics> A term describing a {set} with an explicit
+ {isomorphism} to the {natural numbers}.
+
+ Compare: {countable}.
+
+ (1995-04-13)
+
+counterbug
+
+ <humour> A {bug} used as a relpy to refute another person's
+ bug report, as in "counterargument".
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2012-10-24)
+
+country code
+
+ <networking, standard> Originally, a two-letter abbreviation
+ for a particular country (or geographical region), generally
+ used as a {top-level domain}.
+
+ Originally country codes were just for countries; but country
+ codes have been allocated for many areas (mostly islands) that
+ aren't countries, such as Antarctica (aq), Christmas Island
+ (cx) and Saint Pierre et Miquelon (pm).
+
+ Country codes are defined in {ISO 3166} and are used as the
+ top level domain for {Internet} {hostnames} in most countries
+ but hardly ever in the USA (code "us"). ISO 3166 defines
+ short and full english and french names, two- and three-letter
+ codes and a three-digit code for each country.
+
+ There are also {language codes}.
+
+ {Latest list (http://www.iso.org/iso/en/prods-services/iso3166ma/02iso-3166-code-lists/list-en1.html)}.
+
+ (2006-12-11)
+
+coupling
+
+ <programming, hardware> The degree to which components depend
+ on one another. There are two types of coupling, "tight" and
+ "loose". Loose coupling is desirable for good {software
+ engineering} but tight coupling may be necessary for maximum
+ performance. Coupling is increased when the data exchanged
+ between components becomes larger or more complex.
+
+ (1996-08-01)
+
+Course Author Language
+
+ <language> (CAL) The {CAI} language for the {IBM 360}.
+
+ ["Design of a Programming Language for Computer Assisted
+ Learning", F.M. Tonge, Proc IFIP Congress 1968, v2].
+
+ (1994-11-08)
+
+courseware
+
+ <application> Programs and data used in {Computer-Based
+ Training}.
+
+ (1995-03-13)
+
+Coursewriter III
+
+ <language, education> A simple {CAI} language, developed
+ around 1976.
+
+ ["Coursewriter III, Version 3 Author's Guide", SH20-1009,
+ IBM].
+
+ (1995-03-13)
+
+cowboy
+
+ [Sun, from William Gibson's {cyberpunk} SF] Synonym
+ for {hacker}. It is reported that at Sun this word is often
+ said with reverence.
+
+ [{Jargon File}]
+
+COWSEL
+
+ COntrolled Working SpacE Language. Burstall and Popplestone,
+ U Edinburgh, 1964-66. LISP-like semantics with FORTH-like
+ stack, and reverse Polish syntax. Forerunner of POP.
+ EPU-R-12, U Edinburgh (Apr 1966).
+
+CP
+
+ A concurrent Prolog.
+
+ "The Concurrent Logic Programming Language CP": Definition and
+ Operational Semantics", V. Saraswat, 14th POPL, ACM 1987,
+ pp.49-62.
+
+CPAN
+
+ {Comprehensive Perl Archive Network}
+
+CParaOps5
+
+ <language> A {parallel} version of {OPS5} written at CMU, in
+ {C} and compiling to C. CParaOps5 is available for {Unix},
+ {Mach}, {Encore Multimaxen}, and {Sequent}.
+
+ Latest version: 5.4, as of 1999-08-30.
+
+ {(http://cs.ucsb.edu/~acha/software.html)}.
+
+ (1999-08-30)
+
+CPE
+
+ {Customer Premises Equipment}
+
+CPGA
+
+ {Ceramic Pin Grid Array}
+
+CPI
+
+ {Common Program Interface}
+
+CPL
+
+ Combined Programming Language. U Cambridge and U London. A
+ very complex language, syntactically based on ALGOL 60, with a
+ pure functional subset. Provides the ..where.. form of local
+ definitions. Strongly typed but has a "general" type enabling
+ a weak form of polymorphism. Functions may be defined as
+ either normal or applicative order. Typed array and
+ polymorphic list structures. List selection is through
+ structure matching. Partially implemented on the Titan (Atlas
+ 2) computer at Cambridge. Led to the much simpler BCPL. "The
+ Main Features of CPL", D.W. Barron et al, Computer J
+ 6(2):134-143 (Jul 1963).
+
+CPLD
+
+ {complex programmable logic device}
+
+CPM
+
+ {Control Program for Microcomputers}
+
+CP/M
+
+ {Control Program for Microcomputers}
+
+cpo
+
+ {complete partial ordering}
+
+cpp
+
+ {C preprocessor}.
+
+cppp
+
+ <tool> A compiler {front-end} for {C++} by Tony Davis
+ <ted@cs.brown.edu> with complete semantic processing. cppp is
+ based on {Yacc} and outputs an {abstract syntax graph}.
+ Version: 1.14.
+
+ {(ftp://wilma.cs.brown.edu/pub/cppp.tar.Z)}.
+
+ (1993-05-26)
+
+C preprocessor
+
+ <tool, programming> (cpp) The standard {Unix}
+ {macro}-expansion utility run as the first phase of the {C}
+ compiler, {cc}. Cpp interprets lines beginning with "#" such
+ as
+
+ #define BUFFER_SIZE 256
+
+ as a textual {assignment} giving the symbol BUFFER_SIZE a
+ value "256". Symbols defined with cpp are traditionally given
+ upper case names to distinguish them from C identifiers. This
+ symbol can be used later in the input, as in
+
+ char input_buffer[BUFFER_SIZE];
+
+ This use of cpp to name constants, rather than writing these
+ {magic numbers} inline, makes a program easier to read and
+ maintain, especially if there is more than one occurrence of
+ BUFFER_SIZE all of which must all have the same value.
+
+ Cpp macros can have parameters:
+
+ #define BIT(n) (1<<(n))
+
+ This can be used with any appropriate actual argument:
+
+ msb = BIT(nbits-1);
+
+ Note the parentheses around the "n" in the definition of BIT.
+ Without these, operator precedence might mean that the
+ expression substituted in place of n might not be interpreted
+ correctly (though the example above would be OK).
+
+ Cpp also supports conditional compilation with the use of
+
+ #ifdef SYMBOL
+ ...
+ #else
+ ...
+ #endif
+ and
+ #if EXPR
+ ...
+ #else
+ ...
+ #endif
+
+ constructs, where SYMBOL is a Cpp symbol which may or may not
+ be defined and EXPR is an arithmetic expression involving only
+ Cpp symbols, constants and C operators which Cpp can evaluate
+ to a constant at {compile time}.
+
+ {Decus cpp} is a free implementation for {VMS}.
+
+ The most widely used C preprocessor today is the {GNU} CPP,
+ distributed as part of {GCC}.
+
+ (2001-12-31)
+
+C Programmer's Disease
+
+ <programming> The tendency of the undisciplined {C} programmer
+ to set arbitrary but supposedly generous static limits on
+ table sizes (defined, if you're lucky, by constants in header
+ files) rather than taking the trouble to do proper dynamic
+ storage allocation. If an application user later needs to put
+ 68 elements into a table of size 50, the afflicted programmer
+ reasons that he or she can easily reset the table size to 68
+ (or even as much as 70, to allow for future expansion) and
+ recompile. This gives the programmer the comfortable feeling
+ of having made the effort to satisfy the user's (unreasonable)
+ demands, and often affords the user multiple opportunities to
+ explore the marvellous consequences of {fandango on core}. In
+ severe cases of the disease, the programmer cannot comprehend
+ why each fix of this kind seems only to further disgruntle the
+ user.
+
+ [{Jargon File}]
+
+ (2001-12-31)
+
+C-Prolog
+
+ <language, Prolog> An implementation of {Prolog} in {C},
+ developed by F. Pereira <pereira@research.att.com> et al in
+ July 1982. It had no {garbage collection}.
+
+ It is not in the {public domain}.
+
+ (1994-10-13)
+
+cproto
+
+ <programming, tool> A translator , written by Chin Huang at
+ canrem.com, that generates {ANSI C} {function prototypes} from
+ {K&R} {C} function definitions. It can also translate
+ function definition heads between {K&R} style and {ANSI C}
+ style.
+
+ Posted to {comp.sources}.misc, volume 29. Runs under {Unix},
+ {MS-DOS}.
+
+ (1992-07-18)
+
+CPS
+
+ 1. Conversational Programming System. An interactive extended
+ subset of {PL/I} from {Allen-Babcock} Corp in 1965.
+
+ ["Conversational Programming System under TSO (PBPO), Terminal
+ User's Manual", SH20-1197, IBM].
+
+ [Sammet 1969, p. 232-240].
+
+ 2. {Continuation Passing Style}.
+
+CPSR
+
+ {Computer Professionals for Social Responsibility}
+
+CPU
+
+ {central processing unit}
+
+CPU Info Center
+
+ <processor> An old {website} at the {University of
+ California at Berkeley} describing many different computers
+ and their performance.
+
+ {(http://bwrc.eecs.berkeley.edu/CIC/)}.
+
+ (2000-01-12)
+
+CPU time
+
+ {processor time}
+
+CPU Wars
+
+ /C-P-U worz/ A 1979 large-format comic by Chas Andres
+ chronicling the attempts of the brainwashed androids of IPM
+ (Impossible to Program Machines) to conquer and destroy the
+ peaceful denizens of HEC (Human Engineered Computers). This
+ rather transparent allegory featured many references to
+ {ADVENT} and the immortal line "Eat flaming death,
+ minicomputer mongrels!" (uttered, of course, by an IPM
+ stormtrooper). It is alleged that the author subsequently
+ received a letter of appreciation on IBM company stationery
+ from the head of IBM's Thomas J. Watson Research Laboratories
+ (then, as now, one of the few islands of true hackerdom in the
+ IBM archipelago). The lower loop of the B in the IBM logo, it
+ is said, had been carefully whited out. See {eat flaming
+ death}.
+
+ [{Jargon File}]
+
+CR
+
+ {Carriage Return}
+
+cr
+
+ <networking> The {country code} for Costa Rica.
+
+ (1999-01-27)
+
+cracker
+
+ <jargon> An individual who attempts to gain unauthorised
+ access to a computer system. These individuals are often
+ malicious and have many means at their disposal for breaking
+ into a system. The term was coined ca. 1985 by hackers in
+ defence against journalistic misuse of "{hacker}". An earlier
+ attempt to establish "worm" in this sense around 1981--82 on
+ {Usenet} was largely a failure.
+
+ Use of both these neologisms reflects a strong revulsion
+ against the theft and vandalism perpetrated by cracking rings.
+ The neologism "cracker" in this sense may have been influenced
+ not so much by the term "safe-cracker" as by the non-jargon
+ term "cracker", which in Middle English meant an obnoxious
+ person (e.g., "What cracker is this same that deafs our ears /
+ With this abundance of superfluous breath?" -- Shakespeare's
+ King John, Act II, Scene I) and in modern colloquial American
+ English survives as a barely gentler synonym for "white
+ trash".
+
+ While it is expected that any real hacker will have done some
+ playful cracking and knows many of the basic techniques,
+ anyone past {larval stage} is expected to have outgrown the
+ desire to do so except for immediate practical reasons (for
+ example, if it's necessary to get around some security in
+ order to get some work done).
+
+ Contrary to widespread myth, cracking does not usually involve
+ some mysterious leap of hackerly brilliance, but rather
+ persistence and the dogged repetition of a handful of fairly
+ well-known tricks that exploit common weaknesses in the
+ security of target systems. Accordingly, most crackers are
+ only mediocre hackers.
+
+ Thus, there is far less overlap between hackerdom and
+ crackerdom than the {mundane} reader misled by
+ sensationalistic journalism might expect. Crackers tend to
+ gather in small, tight-knit, very secretive groups that have
+ little overlap with the huge, open hacker poly-culture; though
+ crackers often like to describe *themselves* as hackers, most
+ true hackers consider them a separate and lower form of life,
+ little better than {virus} writers. Ethical considerations
+ aside, hackers figure that anyone who can't imagine a more
+ interesting way to play with their computers than breaking
+ into someone else's has to be pretty {losing}.
+
+ See also {Computer Emergency Response Team}, {dark-side
+ hacker}, {hacker ethic}, {phreaking}, {samurai}, {Trojan
+ horse}.
+
+ [{Jargon File}]
+
+ (1998-06-29)
+
+cracking
+
+ {cracker}
+
+crack root
+
+ <security, jargon> To defeat the security system of a {Unix}
+ machine and gain {root} privileges thereby. The sort of thing
+ a {cracker} wants to do.
+
+ [{Jargon File}]
+
+ (2010-02-04)
+
+crank
+
+ (Automotive slang) Verb used to describe the performance of a
+ machine, especially sustained performance. "This box cranks
+ (or, cranks at) about 6 megaflops, with a burst mode of twice
+ that on vectorised operations."
+
+ [{Jargon File}]
+
+ (1994-12-01)
+
+crapplet
+
+ <web, abuse> A badly written or profoundly useless
+ {Java} {applet}. "I just wasted 30 minutes downloading this
+ stinkin' crapplet!"
+
+ (1997-03-30)
+
+CrApTeX
+
+ /krap'tekh/ (University of York, England) Term of abuse used
+ to describe {TeX} and {LaTeX} when they don't work (when used
+ by TeXhackers), or all the time (by everyone else). The
+ non-TeX enthusiasts generally dislike it because it is more
+ verbose than other formatters (e.g. {troff}) and because
+ (particularly if the standard Computer Modern fonts are used)
+ it generates vast output files.
+
+ See {religious issues}.
+
+ [{Jargon File}]
+
+ (1994-12-01)
+
+crash
+
+ 1. A sudden, usually drastic failure. Most often said of the
+ {system}, especially of magnetic disk drives (the term
+ originally described what happened when the air gap of a hard
+ disk collapses). "Three {lusers} lost their files in last
+ night's disk crash." A disk crash that involves the
+ read/write heads dropping onto the surface of the disks and
+ scraping off the oxide may also be referred to as a "head
+ crash", whereas the term "system crash" usually, though not
+ always, implies that the operating system or other software
+ was at fault.
+
+ 2. To fail suddenly. "Has the system just crashed?"
+ "Something crashed the OS!" See {down}. Also used
+ transitively to indicate the cause of the crash (usually a
+ person or a program, or both). "Those idiots playing
+ {SPACEWAR} crashed the system."
+
+ [{Jargon File}]
+
+ (1994-12-01)
+
+crash and burn
+
+ <jargon> A spectacular crash, in the mode of the conclusion of
+ the car-chase scene in the movie "Bullitt" and many subsequent
+ imitators (compare {die horribly}). A {Sun-3} {display
+ screen} losing the flyback transformer and lightning strikes
+ on {VAX-11/780} backplanes are notable crash and burn
+ generators.
+
+ The construction "crash-and-burn machine" is reported for a
+ computer used exclusively for alpha or {beta} testing, or
+ reproducing bugs (i.e. not for development). The implication
+ is that it wouldn't be such a disaster if that machine
+ crashed, since only the testers would be inconvenienced.
+
+ [{Jargon File}]
+
+ (1996-02-22)
+
+crawler
+
+ {robot}
+
+crawling horror
+
+ <jargon> Ancient {crufty} hardware or software that is kept
+ obstinately alive by forces beyond the control of the hackers
+ at a site. Like {dusty deck} or {gonkulator}, but connotes
+ that the thing described is not just an irritation but an
+ active menace to health and sanity. "Mostly we code new stuff
+ in C, but they pay us to maintain one big Fortran II
+ application from nineteen-sixty-X that's a real crawling
+ horror."
+
+ Compare {WOMBAT}.
+
+ [{Jargon File}]
+
+ (1994-12-01)
+
+Cray instability
+
+ A shortcoming of a program or {algorithm} that manifests
+ itself only when a large problem is being run on a powerful
+ machine such as a {Cray}. Generally more subtle than {bugs}
+ that can be detected in smaller problems running on a
+ {workstation} or {minicomputer}.
+
+ [{Jargon File}]
+
+ (1994-10-13)
+
+crayola
+
+ /kray-oh'l*/ A {super-minicomputer} or {super-microcomputer}
+ that provides some reasonable percentage of {supercomputer}
+ performance for an unreasonably low price. A crayola might
+ also be a {killer micro}.
+
+ [{Jargon File}]
+
+ (1994-10-13)
+
+crayola books
+
+ <publication> A humorous and/or disparaging term for the
+ {rainbow series} of National Computer Security Center (NCSC)
+ computer security standards.
+
+ See also {Orange Book}.
+
+ [{Jargon File}]
+
+ (1996-12-03)
+
+crayon
+
+ 1. Someone who works on {Cray} {supercomputers}. More
+ specifically, it implies a programmer, probably of the {CDC}
+ ilk, probably male, and almost certainly wearing a tie
+ (irrespective of gender). Systems types who have a {Unix}
+ background tend not to be described as crayons.
+
+ 2. A {computron} that participates only in {number crunching}.
+
+ 3. A unit of computational power equal to that of a single
+ {Cray-1}. There is a standard joke about this usage that
+ derives from an old Crayola crayon promotional gimmick: When
+ you buy 64 crayons you get a free sharpener.
+
+ [{Jargon File}]
+
+ (1994-10-13)
+
+Cray Research, Inc.
+
+ <company> US manufacturer of large powerful {mainframe}
+ {supercomputers}, co-founded by noted computer architect,
+ {Seymour Cray}.
+
+ Quarterly sales $216M, profits $8M (Aug 1994).
+
+ Cray were bought by {Silicon Graphics, Inc.}.
+
+ [More details?]
+
+ (1999-10-19)
+
+CRC
+
+ {cyclic redundancy check}
+
+creationism
+
+ The (false) belief that large, innovative software designs can
+ be completely specified in advance and then painlessly
+ magicked out of the void by the normal efforts of a team of
+ normally talented programmers. In fact, experience has shown
+ repeatedly that good designs arise only from evolutionary,
+ exploratory interaction between one (or at most a small
+ handful of) exceptionally able designer(s) and an active user
+ population - and that the first try at a big new idea is
+ always wrong. Unfortunately, because these truths don't fit
+ the planning models beloved of {management}, they are
+ generally ignored.
+
+ [{Jargon File}]
+
+creeping elegance
+
+ Describes a tendency for parts of a design to become {elegant}
+ past the point of diminishing return, something which often
+ happens at the expense of the less interesting parts of the
+ design, the schedule, and other things deemed important in the
+ {Real World}. See also {creeping featurism}, {second-system
+ effect}, {tense}.
+
+creeping featurism
+
+ <jargon> /kree'ping fee'chr-izm/ (Or "feature creep") A
+ systematic tendency to load more {chrome} and {features} onto
+ systems at the expense of whatever elegance they may have
+ possessed when originally designed. "The main problem with
+ {BSD} Unix has always been creeping featurism."
+
+ More generally, creeping featurism is the tendency for
+ anything to become more complicated because people keep saying
+ "Gee, it would be even better if it had this feature too".
+ The result is usually a patchwork because it grew one ad-hoc
+ step at a time, rather than being planned. Planning is a lot
+ of work, but it's easy to add just one extra little feature to
+ help someone, and then another, and another, .... When
+ creeping featurism gets out of hand, it's like a cancer.
+
+ Usually this term is used to describe computer programs, but
+ it could also be said of the federal government, the IRS 1040
+ form, and new cars. A similar phenomenon sometimes afflicts
+ conscious redesigns; see {second-system effect}. See also
+ {creeping elegance}.
+
+ [{Jargon File}]
+
+ (1997-08-03)
+
+creeping featuritis
+
+ <jargon> /kree'ping fee'-chr-i:`t*s/ A variant of {creeping
+ featurism}, with its own spoonerism: "feeping creaturitis".
+ Some people like to reserve this form for the disease as it
+ actually manifests in {software} or {hardware}, as opposed to
+ the lurking general tendency in designers' minds. -ism means
+ "condition" or "pursuit of", whereas -itis usually means
+ "inflammation of".
+
+ [{Jargon File}]
+
+ (1997-08-03)
+
+C-Refine
+
+ A {preprocessor} for {C} and languages with similar syntax by
+ Lutz Prechelt <prechelt@ira.uka.de>. C-Refine allows symbolic
+ naming of code fragments so as to redistribute complexity and
+ provide running commentary.
+
+ Version 3.0 is available from comp.sources.reviewed archives.
+ It is highly portable and has been ported to {Unix}, {MS-DOS},
+ {Atari}, {Amiga}.
+
+ {(ftp://ftp.uu.net/usenet/comp.sources.reviewed/volume02/crefine)}.
+
+ (1992-07-16)
+
+CREN
+
+ {Corporation for Research and Educational Networking}
+
+CREW PRAM
+
+ concurrent read, exclusive write {PRAM}.
+
+crippleware
+
+ 1. Software that has some important functionality deliberately
+ removed, so as to entice potential users to pay for a working
+ version.
+
+ 2. (Cambridge) {Guiltware} that exhorts you to donate to some
+ charity.
+
+ Compare {careware}, {nagware}.
+
+ 3. Hardware deliberately crippled, which can be upgraded to a
+ more expensive model by a trivial change (e.g. removing a
+ jumper). A correspondant gave the following example:
+
+ In 1982-5, a friend had a {Sharp} {scientific calculator}
+ which was on the list of those permitted in exams. No
+ programmable calculators were allowed.
+
+ A very similar, more expensive, programmable model had two
+ extra keys for programming where the cheaper version just had
+ blank metal.
+
+ My friend took his calculator apart (as you would) and lo and
+ behold, the rubber switches of the program keys were there on
+ the circuit board. So all he had to do was cut a hole in the
+ face. For exams he would pre-load the calculator with any
+ useful routines, put a sticker with his name on it over the
+ hole, and press the buttons through the sticker with a pen.
+
+ [{Jargon File}]
+
+ (2001-05-12)
+
+criptography
+
+ <spelling> It's spelled "{cryptography}".
+
+ (1996-12-13)
+
+Crisis Software
+
+ A small UK company producing {software} for the {Acorn}
+ {Archimedes} range of computers.
+
+ {(http://dcs.warwick.ac.uk/~phid/Crisis/)}.
+
+ (1994-11-10)
+
+CRISP
+
+ A {Lisp}-like language and {compiler} for the {IBM 370}
+ written by Jeff Barnett of SDC, Santa Monica, CA, USA in the
+ early 1970s. It generalised {Lisp}'s two-part {cons nodes} to
+ n-part nodes.
+
+ (1994-11-10)
+
+crisp
+
+ (Or "discrete") The opposite of "{fuzzy}".
+
+ (1994-12-23)
+
+Crispy Critters
+
+ <jargon> (Or "Crispy Crittered". From the "Post" breakfast
+ cereal of the same name) {hardware} which is {fried} or
+ {toast}.
+
+ (1995-01-31)
+
+critical mass
+
+ In physics, the minimum amount of fissionable material
+ required to sustain a chain reaction. Of a software product,
+ describes a condition of the software such that fixing one bug
+ introduces one plus {epsilon} bugs. (This malady has many
+ causes: {creeping featurism}, ports to too many disparate
+ environments, poor initial design, etc.) When software
+ achieves critical mass, it can never be fixed; it can only be
+ discarded and rewritten.
+
+ [{Jargon File}]
+
+ (1994-12-23)
+
+critical section
+
+ A non-{re-entrant} piece of code that can only be executed by
+ one process at a time. It will usually terminate in bounded
+ time and a process will only have to wait a bounded time to
+ enter it. Some synchronisation mechanism is required at the
+ entry and exit of the critical section to ensure exclusive
+ use.
+
+CRL
+
+ Carnegie Representation Language.
+
+ {Carnegie Group, Inc.} Frame language derived from SRL.
+ Written in Common LISP. Used in the product Knowledge Craft.
+
+CRLF
+
+ <character> /ker'l*f/, sometimes /kru'l*f/ or /C-R-L-F/ A
+ {carriage return} (CR, {ASCII} 13) followed by a {line feed}
+ (LF, {ASCII} 10). Under {Unix} influence this usage has
+ become less common because Unix uses just line feed as its
+ line terminator.
+
+ See {newline}, {terpri}.
+
+ [{Jargon File}]
+
+ (1995-03-27)
+
+CRM
+
+ 1. <business> {Customer Relationship Management}.
+
+ 2. <networking> {Cisco Resource Manager}.
+
+crock
+
+ [American scatologism "crock of shit"] 1. An awkward feature
+ or programming technique that ought to be made cleaner. For
+ example, using small integers to represent error codes without
+ the program interpreting them to the user (as in, for example,
+ Unix "make(1)", which returns code 139 for a process that dies
+ due to {segfault}).
+
+ 2. A technique that works acceptably, but which is quite prone
+ to failure if disturbed in the least. For example, a
+ too-clever programmer might write an assembler which mapped
+ {instruction mnemonics} to numeric {opcodes}
+ {algorithm}ically, a trick which depends far too intimately on
+ the particular bit patterns of the opcodes. (For another
+ example of programming with a dependence on actual opcode
+ values, see {The Story of Mel}.) Many crocks have a tightly
+ woven, almost completely unmodifiable structure. See {kluge},
+ {brittle}. The adjectives "crockish" and "crocky", and the
+ nouns "crockishness" and "crockitude", are also used.
+
+ [{Jargon File}]
+
+cron
+
+ <operating system> The Unix clock {daemon} that executes
+ commands at specified dates and times according to
+ instructions in a "crontab" file.
+
+ {Unix manual page}: cron(8).
+
+ (1997-04-10)
+
+cross-assembler
+
+ An {assembler} which runs on one type of processor and
+ produces {machine code} for another.
+
+ There is a set of {6502}, 68xx and {Zilog Z80} and {8085}
+ cross-assemblers in {C} by <msmakela@cc.helsinki.fi> and Alan
+ R. Baldwin. They run under {MS-DOS} and could be compiled to
+ run under {Unix} and on the {Amiga} and {Atari ST}.
+
+ See also {fas}.
+
+ {(ftp://ccosun.caltech.edu/)}.
+
+ (1993-03-10)
+
+cross-compiler
+
+ <programming> A {compiler} which runs on one {platform} and
+ produces code for another, as opposed to a {native} code
+ compiler which produces code for the platform on which it
+ runs.
+
+ (1998-02-24)
+
+cross-platform
+
+ <software, hardware> A term that describes a language,
+ software application or hardware device that works on more
+ than one system {platform} (e.g. {Unix}, {Microsoft Windows},
+ {Macintosh}). E.g. {Netscape Navigator}, {Java}.
+
+ (1998-02-24)
+
+cross-post
+
+ [{Usenet}] To post a single article simultaneously to several
+ {newsgroups}. Distinguished from posting the article
+ repeatedly, once to each newsgroup, which causes people to see
+ it multiple times (which is very bad form). Gratuitous
+ cross-posting without a Followup-To line directing responses
+ to a single followup group is frowned upon, as it tends to
+ cause {followup} articles to go to inappropriate newsgroups
+ when people respond to only one part of the original posting.
+
+ [{Jargon File}]
+
+cross software
+
+ Software developed on one kind of computer for use on another
+ (usually because the other computer does not have itself
+ adequate facilities for software development).
+
+CROSSTABS
+
+ Simple language for statistical analysis of tabular data.
+ "User's Manual for the CROSSTABS System", Cambridge Computer
+ Assoc (Feb 1977).
+
+crosstalk
+
+ <electronics> Interference caused by two signals becoming
+ partially superimposed on each other due to electromagnetic
+ (inductive) or electrostatic (capacitive) coupling between the
+ conductors carrying the signals. A common example of
+ crosstalk is where the magnetic field from changing current
+ flow in one wire induces current in another wire running
+ parallel to the other, as in a transformer. Crosstalk can be
+ reduced by using shielded cables and increasing the distance
+ between conductors.
+
+ (1995-12-20)
+
+CROW PRAM
+
+ concurrent read, owner write {PRAM}.
+
+CRT
+
+ {cathode ray tube}
+
+CRUD
+
+ <programming, testing> A mnemonic for the four most important
+ kinds of activity that almost any system of any type needs to
+ support: create, read, update, delete. The absence or failure of
+ any one of these is often a sign of a bad design or poor testing.
+
+ (2014-08-06)
+
+crudware
+
+ /kruhd'weir/ Pejorative term for the hundreds of megabytes of
+ low-quality {freeware} circulated by user's groups and {BBSs}
+ in the micro-hobbyist world.
+
+ [{Jargon File}]
+
+cruft
+
+ <jargon> (back-formation from "crufty") Anything unpleasant
+ that accumulates over time. Also used as a verb, as in {cruft
+ together}, {hand cruft}.
+
+ [{Jargon File}]
+
+ (2006-01-19)
+
+crufted
+
+ {cruft}
+
+cruft together
+
+ <jargon> To {hack together} though with the suggestion that
+ the result may be {cruft}.
+
+ [{Jargon File}]
+
+ (2006-01-19)
+
+crumb
+
+ <data, jargon> (Or tayste /tayst/) Silly suggested term for
+ two {binary digits}.
+
+ The term "quarter" has also been suggested, referring to the
+ US 25-cent coin. This was once equal in value to two of the
+ eight "bits" - pie-slice-shaped "pieces of eight" - into which
+ Spanish silver crowns were cut to make change.
+
+ [{Jargon File}]
+
+ (2007-05-31)
+
+crunch
+
+ 1. <jargon> To process, usually in a time-consuming or
+ complicated way. Connotes an essentially trivial operation
+ that is nonetheless painful to perform. The pain may be due
+ to the triviality's being embedded in a loop from 1 to
+ 1,000,000,000. "Fortran programs do mostly {number
+ crunching}."
+
+ 2. <compression> To reduce the size of a file without losing
+ information by a scheme such as {Huffman coding}. Since such
+ {lossless compression} usually takes more computations than
+ simpler methods such as {run-length encoding}, the term is
+ doubly appropriate.
+
+ 3. The {hash character}. Used at {XEROX} and {CMU}, among
+ other places.
+
+ 4. To squeeze program source to the minimum size that will
+ still compile or execute. The term came from a {BBC
+ Microcomputer} program that crunched {BBC BASIC} {source} in
+ order to make it run more quickly (apart from storing
+ {keywords} as byte codes, the language was wholly interpreted,
+ so the number of characters mattered). {Obfuscated C Contest}
+ entries are often crunched; see the first example under that
+ entry.
+
+ [{Jargon File}]
+
+ (2007-11-12)
+
+cruncha cruncha cruncha
+
+ <jargon> /kruhn'ch* kruhn'ch* kruhn'ch*/ An encouragement
+ sometimes muttered to a machine bogged down in a serious
+ {grovel}. Also describes a notional sound made by grovelling
+ hardware.
+
+ See {grind} (sense 3).
+
+ (2003-06-02)
+
+crunchy
+
+ {floppy disk}
+
+cryppie
+
+ <job, cryptography> /krip'ee/ A cryptographer. One who hacks
+ or implements software or hardware for {cryptography}.
+
+ [{Jargon File}]
+
+ (1996-08-23)
+
+crypt
+
+ {Unix} command to perform {encryption} and {decryption}.
+
+cryptanalysis
+
+ The branch of {cryptography} concerned with decoding encrypted
+ messages when you're not supposed to be able to.
+
+ (1994-12-06)
+
+Crypt Breakers Workbench
+
+ (cbw) A freely distributable multi-window integrated workbench
+ of tools for {cryptanalysis} of files encrypted with the
+ {4.2BSD} {Unix} {crypt} command. It was originally written by
+ Robert W. Baldwin at {MIT}.
+
+ {(ftp://black.ox.ac.uk/src/security)},
+ {(ftp://scitsc.wlv.ac.uk/pub/infomagic/usenet.cdrom/sources/unix/volume10)},
+ {(ftp://ftp.sunet.se/pub/usenet/comp.sources.unix/volume10)}.
+
+ (1994-12-06)
+
+cryptography
+
+ <cryptography> The practise and study of {encryption} and
+ {decryption} - encoding data so that it can only be decoded by
+ specific individuals. A system for encrypting and decrypting
+ data is a cryptosystem. These usually involve an {algorithm}
+ for combining the original data ("{plaintext}") with one or
+ more "keys" - numbers or strings of characters known only to
+ the sender and/or recipient. The resulting output is known as
+ "{ciphertext}".
+
+ The security of a cryptosystem usually depends on the secrecy
+ of (some of) the keys rather than with the supposed secrecy of
+ the {algorithm}. A strong cryptosystem has a large range of
+ possible keys so that it is not possible to just try all
+ possible keys (a "{brute force}" approach). A strong
+ cryptosystem will produce ciphertext which appears random to
+ all standard statistical tests. A strong cryptosystem will
+ resist all known previous methods for breaking codes
+ ("{cryptanalysis}").
+
+ See also {cryptology}, {public-key encryption}, {RSA}.
+
+ {Usenet} newsgroups: {news:sci.crypt},
+ {news:sci.crypt.research}.
+
+ {FAQ} {MIT
+ (ftp://rtfm.mit.edu/pub/usenet/news.answers/cryptography-faq/)}.
+
+ {Cryptography glossary
+ (http://io.com/~ritter/GLOSSARY.HTM#BruteForceAttack)}.
+
+ {RSA cryptography glossary
+ (http://rsasecurity.com/rsalabs/faq/glossary.html)}.
+
+ {Cryptography, PGP, and Your Privacy
+ (http://draco.centerline.com:8080/~franl/crypto.html)}.
+
+ (2000-01-16)
+
+cryptology
+
+ The study of {cryptography} and {cryptanalysis}.
+
+ (1994-12-06)
+
+Crystal
+
+ Concurrent Representation of Your Space-Time ALgorithms.
+
+ A {recursion equation} parallel language.
+
+ ["A Parallel Language and its Compilation to Multiprocessor
+ Machines or VLSI", M.C. Chen, 13th POPL, ACM 1986 pp.131-139].
+
+ (1994-12-06)
+
+CS-4
+
+ ["CS-4 Language Reference Manual and Operating System
+ Interface", Ben M. Brosgol et al, Report IR-130-2,
+ Intermetrics, Cambridge MA, Oct 1975].
+
+ (1995-01-19)
+
+C-Scheme
+
+ {MIT Scheme}
+
+CSCI
+
+ {Computer Software Configuration Item}
+
+C/SCSC
+
+ {Cost/Schedule Control System Criteria}
+
+CSCW
+
+ {Computer Supported Cooperative Work}
+
+CSG
+
+ {constructive solid geometry}
+
+CSG-tree
+
+ <graphics> (Or "status tree"?) An approach used in {ray
+ tracing} to evaluate {constructive solid geometry} structures.
+
+ [Better explanation? "Evaluate"?]
+
+ (1998-06-09)
+
+csh
+
+ {C shell}
+
+C sharp
+
+ {C#}
+
+C shell
+
+ <operating system> (csh) The {Unix} {command-line interpreter}
+ {shell} and {script language} by {William Joy}, originating
+ from {Berkeley} {Unix}.
+
+ {Unix} systems up to around {Unix Version 7} only had one
+ shell - the {Bourne shell}, sh. Csh had better {interactive}
+ features, notably command input {history}, allowing earlier
+ commands to be recalled and edited (though it was still not as
+ good as the {VMS} equivalent of the time).
+
+ Presumably, csh's {C}-like {syntax} was intended to endear it
+ to programmers but sadly it lacks some {sh} features which are
+ useful for writing {shell scripts} so you need to know two
+ different syntaxes for every shell construct.
+
+ A plethora of different shells followed csh, e.g. {tcsh},
+ {ksh}, {bash}, {rc}, but sh and csh are the only ones which
+ are provided with most versions of Unix.
+
+ (1998-04-04)
+
+.cshrc
+
+ <operating system> (C Shell run commands) A {C Shell} startup
+ configuration file. This file is found in a user's {home
+ directory} and can contain shell and other commands to set
+ variables, define aliases, and perform any other
+ initialisation which should happen for every shell (as opposed
+ to {.login} which is only run for a {login shell}).
+
+ Compare {AUTOEXEC.BAT} on {MS-DOS}.
+
+ See also {rc}.
+
+ (1996-04-09)
+
+CSID
+
+ {character set identifier}
+
+C++SIM
+
+ A {class} library like the {simulation} class libraries of
+ {SIMULA}, by Mark Little <M.C.Little@newcastle.ac.uk>.
+ Version: 1.0.
+
+ {(ftp://arjuna.ncl.ac.uk/)}.
+
+ (1993-06-04)
+
+CSK Corporation
+
+ <company> The japanese company that owns {CSK Software} and
+ {Sega}. CSK Corp. is the largest independent japanese
+ software company.
+
+ (2003-05-13)
+
+CSK Software
+
+ <company> An international software company formed by the
+ merger of {Quay Financial Software} and {Micrognosis}, and
+ fully owned by {CSK Corporation}, Japan.
+
+ CSK Software is based in Frankfurt/Main (Germany) with offices
+ in London (UK), Zurich (Switzerland), Madrid (Spain), and
+ Singapore. Products segments are RDD: Real-time data
+ delivery, main product is {Slingshot} for delivering real-time
+ data over the Internet (real push technology). ETS:
+ Electronic Trading Systems, price calculation and automatic
+ trading (with connections to {XONTRO} and {XETRA}). EAI:
+ {Enterprise Application Integration}, main product is {XGen},
+ a universal message converter with {GUI} and connections also
+ to {SWIFT}.
+
+ {(http://csksoftware.com/)}.
+
+ E-mail: <info@csksoftware.com>.
+
+ Address: CSK Software AG, Opernplatz 2, D-60313 Frankfurt,
+ Germany.
+
+ Tel: +49 (69) 509 520. Fax: +49 (69) 5095 2333.
+
+ (2003-05-13)
+
+CSL
+
+ 1. Computer Structure Language. A computer {hardware
+ description language}, written in {BCPL}.
+
+ ["Computer Structure Language (CSL)", Proc 1975 Symp on Comp
+ Hardware Description Languages and their Appl, ACM (Sep
+ 1975)].
+
+ 2. Control and Simulation Language. A language for industrial
+ simulation from Esso and {IBM}.
+
+ ["Control and Simulation Language", J.N. Buxton et al,
+ Computer J 5(3):194-199 (Oct 1962). Version: CSL 2 (1966 for
+ IBM 7094)].
+
+CSLIP
+
+ {Compressed SLIP}
+
+CSM
+
+ ["CSM - A Distributed Programming Language", S. Zhongxiu et
+ al, IEEE Trans Soft Eng SE-13(4):497-500 (Apr 1987)].
+
+CSMA/CD
+
+ Carrier Sense Multiple Access / Collision Detect.
+
+ The low level network arbitration {protocol} used on
+ {Ethernet}. Nodes wait for quiet on the net before starting
+ to transmit and listen while they are transmitting. If two
+ nodes transmit at once the data gets corrupted. The nodes
+ detect this and continue to transmit for a certain length of
+ time to ensure that all nodes detect the collision. The
+ transmitting nodes then wait for a random time before
+ attempting to transmit again thus minimising the chance of
+ another collision. The ability to detect collision during
+ transmission reduces the amount of {bandwidth} wasted on
+ collisions compared with simple {ALOHA} broadcasting.
+
+ (1995-02-23)
+
+CSMP
+
+ {Continuous System Modeling Program}
+
+CSNET
+
+ Computers and Science Network, operated by {CREN} for US
+ computer science institutes. It provides {electronic mail}
+ service via {dial-up} lines, {X.25} and {Internet} services.
+
+CSO
+
+ Campus Phone Book software developed for, and originally used
+ at, the Computer Services Office of the University of Illinois
+ at Urbana-Champaign. The server software is known as "qi" and
+ the client is "ph". Recent versions of the software refer to
+ CCSO (Computing & Communications Service Office).
+
+ {(ftp://uxc.cso.uiuc.edu/)}.
+
+CSP
+
+ 1. <language> {Communicating Sequential Processes}.
+
+ 2. <hardware> {Chip Scale Packaging}.
+
+CSP/80
+
+ Based on CSP.
+
+ "CSP/80: A Language for Communicating Processes", M. Jazayeri
+ et al, Proc Fall COMPCON80, IEEE pp.736-740 (Sept 1980).
+
+CS/PCode
+
+ Used at {Microsoft}.
+
+CSP/k
+
+ {Concurrent SP/k}
+
+CS-Prolog
+
+ Distributed logic language.
+
+ "CS-Prolog on Multi-Transputer Systems", I. Futo et al,
+ Microprocessors & Microsystems, March 1989.
+
+CSPS
+
+ ["Toward Comprehensive Specification of Distributed Systems",
+ G. Roman et al, Proc 7th Intl Conf on Distrib Comp Sys, IEEE
+ 1987, pp. 282-289].
+
+CSP-S
+
+ ["Implementation of CSP-S for Description of Distributed
+ Algorithms", L. Patniak et al, Comput Lang 9(3):193-202
+ (1984)].
+
+CS/QCode
+
+ Used at {Microsoft}.
+
+ [More detail?]
+
+CSR
+
+ {Control and Status Register}
+
+CSS
+
+ {Cascading Style Sheets}
+
+CSSA
+
+ An {object-oriented} language.
+
+ ["Key Concepts in the INCAS Multicomputer Project", J. Nehmer
+ et al, IEEE Trans Soft Eng SE-13(8):913-923 (Aug 1987)].
+
+CSS/II
+
+ Computer System Simulator II. Like {GPSS}, for {IBM 360}.
+
+ ["Computer System Simulator II (CSS II) Program Description
+ and Operations Manual", SH20-0875, IBM].
+
+CSSL
+
+ {Continuous System Simulation Language}
+
+CSTools
+
+ {Concurrency} through {message-passing} to named message
+ queues.
+
+CSU
+
+ 1. {California State University}.
+
+ 2. {Cleveland State University}.
+
+ 3. {Channel Service Unit}.
+
+CSU/DSU
+
+ {channel service unit/digital service unit}
+
+CSV
+
+ {comma separated values}
+
+CT
+
+ {Computer Telephone Integration}
+
+CTC
+
+ {Cornell Theory Center}
+
+CTC++
+
+ <testing> A {test coverage} analysis tool from {Testwell} for
+ {C} and {C++} that checks for function, decision, condition
+ and multicondtion coverage in host, target and kernel.
+
+ {CTC++ Home (http://testwell.fi/)}.
+
+ (2004-10-20)
+
+CTCP
+
+ <networking> {Client To Client Protocol}
+
+CTI
+
+ 1. <communications> {Computer Telephone Integration}.
+
+ 2. <education> Computers in Teaching Initiative. A UK
+ government scheme.
+
+ (1996-12-08)
+
+CTL
+
+ 1. {Checkout Test language}.
+
+ 2. {Compiler Target Language}.
+
+ 3. {Computational Tree Logic}
+
+CTOS
+
+ 1. <operating system> {Computerised Tomography Operating
+ System}.
+
+ 2. <operating system> {Convergent Technologies Operating
+ System}.
+
+ctrl
+
+ {control}
+
+CTS
+
+ 1. <communications> {clear to send}.
+
+ 2. <medical> {overuse strain injury}.
+
+CTSS
+
+ {Compatible Timesharing System}
+
+CTY
+
+ /sit'ee/ or /C-T-Y/ [MIT] The terminal physically associated
+ with a computer's system {console}. The term is a contraction
+ of "Console {tty}", that is, "Console TeleTYpe". This {ITS}-
+ and {TOPS-10}-associated term has become less common, as most
+ Unix hackers simply refer to the CTY as "the console".
+
+ [{Jargon File}]
+
+CU
+
+ <chat> "see you".
+
+ (1997-12-01)
+
+cu
+
+ 1. <communications> {Call Unix}.
+
+ 2. <networking> The {country code} for Cuba.
+
+CUA
+
+ {Common User Access}
+
+Cube
+
+ Three-dimensional visual language for higher-order logic.
+
+ "The Cube Language", M. Najork et al, 1991 IEEE Workshop on
+ Visual Langs, Oct 1991, pp.218-224.
+
+ [{Jargon File}]
+
+cube
+
+ 1. [short for "cubicle"] A module in the open-plan offices
+ used at many programming shops. "I've got the manuals in my
+ cube."
+
+ 2. A NeXT machine (which resembles a matte-black cube).
+
+cubing
+
+ <jargon> By analogy with "tubing", hacking on an IPSC ({Intel
+ Personal SuperComputer}) hypercube. "Louella's gone cubing
+ *again*!!"
+
+ [{Jargon File}]
+
+ (2003-10-09)
+
+CUCH
+
+ CUrry-CHurch.
+
+ {Lambda-calculus}
+
+ ["A Type-Theoretical Alternative to CUCH, ISWIM, OWHY", Dana
+ Scott, Oxford U 1969].
+
+ ["Introduction to the CUCH", C. Bohm et al, in Automata
+ Theory, E.R. Caianiello ed, A-P 1966, pp.35-65].
+
+ (1994-12-02)
+
+Cuckoo's Egg
+
+ {The Cuckoo's Egg}
+
+CUL
+
+ <chat> "See you later".
+
+ (1997-12-01)
+
+Culler-Fried System
+
+ A system for interactive mathematics.
+
+ [Sammet 1969, p. 253-255].
+
+ (1994-11-15)
+
+CUPID
+
+ A graphic {query language}.
+
+ ["CUPID: A Graphic Oriented Facility for Support of
+ Nonprogrammer Interactions with a Database", N. McDonald, PhD
+ Thesis, CS Dept, UC Berkeley 1975].
+
+CUPL
+
+ Cornell University Programming Language.
+
+ A language for simple mathematics problems, based on {CORC},
+ with {PL/I}-like {syntax}.
+
+ ["An Instruction Language for CUPL", R.J. Walker, Cornell U,
+ Jul 1967].
+
+ (1994-11-15)
+
+curly bracket
+
+ brace
+
+current
+
+ <electronics> The quantity of {charge} per unit time, measured
+ in Amperes (Amps, A). By historical convention, the sign of
+ current is positive for currents flowing from positive to
+ negative {potential}, but experience indicates that electrons
+ are negatively charged and flow in the opposite direction.
+
+ (1995-10-05)
+
+curried function
+
+ <mathematics, programming> A {function} of N {arguments} that
+ is considered as a function of one argument which returns
+ another function of N-1 arguments. E.g. in {Haskell} we can
+ define:
+
+ average :: Int -> (Int -> Int)
+
+ (The parentheses are optional). A {partial application} of
+ average, to one Int, e.g. (average 4), returns a function of
+ type (Int -> Int) which averages its argument with 4. In
+ uncurried languages a function must always be applied to all
+ its arguments but a {partial application} can be represented
+ using a {lambda abstraction}:
+
+ \ x -> average(4,x)
+
+ Currying is necessary if {full laziness} is to be applied to
+ functional sub-expressions.
+
+ It was named after the logician {Haskell Curry} but the
+ 19th-century logician, {Gottlob Frege} was the first to
+ propose it and it was first referred to in ["Uber die
+ Bausteine der mathematischen Logik", M. Schoenfinkel,
+ Mathematische Annalen. Vol 92 (1924)].
+
+ {David Turner} said he got the term from {Christopher
+ Strachey} who invented the term "currying" and used it in his
+ lecture notes on programming languages written circa 1967.
+ Strachey also remarked that it ought really to be called
+ "Schoenfinkeling".
+
+ Stefan Kahrs <smk@dcs.ed.ac.uk> reported hearing somebody in
+ Germany trying to introduce "scho"nen" for currying and
+ "finkeln" for "uncurrying". The verb "scho"nen" means "to
+ beautify"; "finkeln" isn't a German word, but it suggests "to
+ fiddle".
+
+ ["Some philosophical aspects of combinatory logic",
+ H. B. Curry, The Kleene Symposium, Eds. J. Barwise,
+ J. Keisler, K. Kunen, North Holland, 1980, pp. 85-101]
+
+ (2002-07-24)
+
+currying
+
+ Turning an uncurried function into a {curried function}.
+
+curseperl
+
+ A {curses} library for {Perl} by the author of Perl, Larry
+ Wall <lwall@netlabs.com>. It comes with Perl.
+
+ (1994-12-06)
+
+curses
+
+ A set of subroutines in {Unix} for handling navigation on a
+ terminal screen using the cursor.
+
+cursor
+
+ 1. <hardware> A visually distinct mark on a display indicating
+ where newly typed text will be inserted. The cursor moves as
+ text is typed and, in most modern editors, can be moved around
+ within a document by the user to change the insertion point.
+
+ 2. <database> In {SQL}, a named control structure used by an
+ {application program} to point to a row of data. The position
+ of the {row} is within a {table} or {view}, and the cursor is
+ used interactively so select rows from columns.
+
+ (1996-12-27)
+
+cursor dipped in X
+
+ <jargon> The metaphorical source of the electronic equivalent
+ of a poisoned-pen letter. Derived from English metaphors of
+ the form "pen dipped in X" (where X = e.g. "acid", "bile",
+ "vitriol"). These map over neatly to this hackish usage (the
+ cursor being what moves, leaving letters behind, when one is
+ composing on-line).
+
+ "Talk about a {nastygram}! He must've had his cursor dipped
+ in acid when he wrote that one!"
+
+ [{Jargon File}]
+
+ (1996-12-27)
+
+CU-SeeMe
+
+ <communications> /see`-yoo-see'-mee/ ("CU" from {Cornell
+ University}) A {shareware} {personal computer}-based
+ {videoconferencing} program for use over the {Internet},
+ developed at {Cornell University}, starting in 1992.
+
+ CU-SeeMe allows for direct {audiovisual} connections between
+ {clients}, or, like {irc}, it can support multi-user
+ converencing via {servers} (here called "reflectors") to
+ distribute the video and audio signals between multiple
+ clients.
+
+ CU-SeeMe was the first videoconferencing tool available at a
+ reasonable price (in this case, free) to users of personal
+ computers.
+
+ {(http://cu-seeme.cornell.edu/)}.
+
+ {(http://home.stlnet.com/~hubble/cuseeme/index.html)}.
+
+ Compare with {multicast backbone}.
+
+ (1996-12-01)
+
+CUSI
+
+ A collection of indices to various {web} and other
+ {Internet} documents. It is located at {Nexor} in the UK.
+
+ {(http://web.nexor.co.uk/public/cusi/cusi.html)}.
+
+ (1994-11-29)
+
+cuspy
+
+ /kuhs'pee/ [WPI: from the {DEC} abbreviation CUSP, for
+ "Commonly Used System Program", i.e. a utility program used by
+ many people] 1. (of a program) Well-written.
+
+ 2. Functionally excellent. A program that performs well and
+ interfaces well to users is cuspy. See {rude}.
+
+ [{Jargon File}]
+
+custom
+
+ (Or "bespoke") An adjective describing any product that is
+ special in some way, individually created for a specific user
+ or system, as opposed to generic or off-the-shelf.
+
+ (2008-06-25)
+
+Customer Information Control System
+
+ <communications, database> (CICS) An {IBM} communications
+ system that was converted for {database} handling.
+
+ [Huh?]
+
+ (1994-11-29)
+
+Customer Information Systems
+
+ {Customer Relationship Management}
+
+Customer Interaction Software
+
+ {Customer Relationship Management}
+
+Customer Relationship Management
+
+ <business> (CRM, CIS, Customer Information Systems, Customer
+ Interaction Software, TERM, Technology Enabled Relationship
+ Manager) Enterprise-wide software applications that allow
+ companies to manage every aspect of their relationship with a
+ customer. The aim of these systems is to assist in building
+ lasting customer relationships - to turn customer satisfaction
+ into customer loyalty.
+
+ Customer information acquired from sales, marketing, customer
+ service, and support is captured and stored in a centralised
+ {database}. The system may provide {data-mining} facilities
+ that support an {opportunity management system}. It may also
+ be integrated with other systems such as accounting and
+ manufacturing for a truly enterprise-wide system with
+ thousands of users.
+
+ (1999-08-20)
+
+CUT
+
+ {Coordinated Universal Time}
+
+cut and paste
+
+ {copy and paste}
+
+cut-and-waste code
+
+ <humour, programming> Code that someone found online (e.g. in a
+ {blog}) and copied and pasted into a product. The result is
+ usually a lot of wasted time trying to track down obscure bugs
+ from code that may have made sense in the original context but not
+ in the new one. Also known as blog-driven development.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2014-07-03)
+
+cut a tape
+
+ To write a software or document distribution on magnetic tape
+ for shipment. Has nothing to do with physically cutting the
+ medium! "Cutting a disk" has also been reported as live
+ usage. Related slang usages are mainstream business's "cut a
+ check", the recording industry's "cut a record", and the
+ military's "cut an order".
+
+ All of these usages reflect physical processes in obsolete
+ recording and duplication technologies. The first stage in
+ manufacturing an old-style vinyl record involved cutting
+ grooves in a stamping die with a precision lathe. More
+ mundanely, the dominant technology for mass duplication of
+ paper documents in pre-photocopying days involved "cutting a
+ stencil", punching away portions of the wax overlay on a silk
+ screen. More directly, paper tape with holes punched in it
+ was an important early storage medium.
+
+ [{Jargon File}]
+
+cutover
+
+ <communications, networking> /cut-ov*/ Switching from an old
+ ({hardware} and/or {software}) system to a replacement system,
+ covering the overlap from when the new system is {live} until
+ the old system has been {shut down}.
+
+ (1997-07-09)
+
+cut-through switching
+
+ <networking> The application of {wormhole routing} to
+ {packets} in a {packet switching} system so that forwarding of
+ a packet starts as soon as its destination is known, before
+ the whole packet has arrived.
+
+ Compare {store and forward}.
+
+ (2006-12-06)
+
+cv
+
+ <networking> The {country code} for Cape Verde.
+
+ (1999-01-27)
+
+CVS
+
+ {Concurrent Versions System}
+
+CW
+
+ {continuous wave}
+
+CWeb
+
+ <language> An {ANSI C} implementation of the {Web} {literate
+ programming} language. Version 3.1 by Levy, Knuth, and Marc
+ van Leeuwen is writen in, and outputs, {ANSI C} and {C++}.
+
+ {(ftp://ftp.cwi.nl/pub/cweb/)}.
+
+ (1993-12-16)
+
+CWI
+
+ {Centrum voor Wiskunde en Informatica}
+
+CWIC
+
+ Compiler for Writing and Implementing Compilers. Val Schorre.
+ One of the early metacompilers. Compare {Meta-II}.
+
+CWIS
+
+ {Campus-Wide Information System}
+
+C with Classes
+
+ Short-lived predecessor to C++.
+
+ ["Classes: An Abstract Data Type Facility for the C Language",
+ B. Stroustrup, CSTR-84 Bell Labs, Apr 1980]. Also in [SIGPLAN
+ Notices (Jan 1982)].
+
+cx
+
+ <networking> The {country code} for Christmas Island.
+
+ (1999-01-27)
+
+cxref
+
+ <tool> A cross-reference generator by Arnold Robbins from
+ {Georgia Institute of Technology}.
+
+ (2000-02-29)
+
+cy
+
+ <networking> The {country code} for Cyprus.
+
+ (1999-01-27)
+
+Cy486SLC
+
+ A version of the {Intel 486} made by {Cyrix}. It has a
+ {486SX} {instruction set}, a 1 kilobyte {cache}, and an {Intel
+ 80386SX}-compatible pinout and thus, 16-bit data bus.
+
+ (1994-11-30)
+
+cyber
+
+ <chat> To have {cybersex}.
+
+ (1997-06-21)
+
+cyberbunny
+
+ <abuse> Someone who knows absolutely nothing about computers
+ and advises people who know absolutely nothing about
+ computers. The term is used mostly on {AOL}, {Prodigy},
+ {Compuserve}, etc.
+
+ (1996-02-18)
+
+cyberchondriac
+
+ <jargon, humour> (After "hypochondriac") 1. A user who always
+ thinks there is something wrong with his computer.
+
+ 2. Someone who uses the {web} to indulge their
+ hyperchondria.
+
+ (2001-03-10)
+
+cybercrud
+
+ <jargon> /si:'ber-kruhd/ 1. (Coined by Ted Nelson) Obfuscatory
+ tech-talk. Verbiage with a high {MEGO} factor. The computer
+ equivalent of bureaucratese.
+
+ 2. Incomprehensible stuff embedded in e-mail. First there
+ were the "Received" headers that show how mail flows through
+ systems, then MIME ({Multi-purpose Internet Mail Extensions})
+ headers and part boundaries, and now huge blocks of {hex} for
+ PEM ({Privacy Enhanced Mail}) or PGP ({Pretty Good Privacy})
+ {digital signatures} and certificates of authenticity. This
+ stuff all has a purpose and good user interfaces should hide
+ it, but all too often users are forced to wade through it.
+
+ [{Jargon File}]
+
+ (1995-04-04)
+
+CyberGlove
+
+ <hardware, virtual reality> A {data glove} sold by {Virtual
+ Technologies}. The spandex-like glove houses 18 sensors to
+ track accurately just about every move your hand is capable of
+ making. The accompanying software includes a
+ three-dimensional hand model that can he added to any {virtual
+ reality} application. The glove includes a mount for Polhemus
+ and Ascension sensors.
+
+ (2003-06-17)
+
+cybernetics
+
+ <robotics> /si:`b*-net'iks/ The study of control and
+ communication in living and man-made systems.
+
+ The term was first proposed by {Norbert Wiener} in the book
+ referenced below. Originally, cybernetics drew upon
+ electrical engineering, mathematics, biology, neurophysiology,
+ anthropology, and psychology to study and describe actions,
+ feedback, and response in systems of all kinds. It aims to
+ understand the similarities and differences in internal
+ workings of organic and machine processes and, by formulating
+ abstract concepts common to all systems, to understand their
+ behaviour.
+
+ Modern "second-order cybernetics" places emphasis on how the
+ process of constructing models of the systems is influenced by
+ those very systems, hence an elegant definition - "applied
+ epistemology".
+
+ Related recent developments (often referred to as {sciences of
+ complexity}) that are distinguished as separate disciplines
+ are {artificial intelligence}, {neural networks}, {systems
+ theory}, and {chaos theory}, but the boundaries between those
+ and cybernetics proper are not precise.
+
+ See also {robot}.
+
+ {The Cybernetics Society (http://cybsoc.org)} of the UK.
+
+ {American Society for Cybernetics
+ (http://asc-cybernetics.org/)}.
+
+ {IEEE Systems, Man and Cybernetics Society
+ (http://isye.gatech.edu/ieee-smc/)}.
+
+ {International project "Principia Cybernetica"
+ (http://pespmc1.vub.ac.be/DEFAULT.html)}.
+
+ {Usenet} newsgroup: {sci.systems (news:sci.systems)}.
+
+ ["Cybernetics, or control and communication in the animal and the
+ machine", N. Wiener, New York: John Wiley & Sons, Inc., 1948]
+
+ (2002-01-01)
+
+cyberpunk
+
+ /si:'ber-puhnk/ (Originally coined by SF writer Bruce Bethke
+ and/or editor Gardner Dozois) A subgenre of SF launched in
+ 1982 by William Gibson's epoch-making novel "Neuromancer"
+ (though its roots go back through Vernor Vinge's "True Names"
+ to John Brunner's 1975 novel "The Shockwave Rider"). Gibson's
+ near-total ignorance of computers and the present-day hacker
+ culture enabled him to speculate about the role of computers
+ and hackers in the future in ways hackers have since found
+ both irritatingly na"ive and tremendously stimulating.
+ Gibson's work was widely imitated, in particular by the
+ short-lived but innovative "Max Headroom" TV series. See
+ {cyberspace}, {ice}, {jack in}, {go flatline}.
+
+ Since 1990 or so, popular culture has included a movement or
+ fashion trend that calls itself "cyberpunk", associated
+ especially with the rave/techno subculture. Hackers have
+ mixed feelings about this. On the one hand, self-described
+ cyberpunks too often seem to be shallow trendoids in black
+ leather who have substituted enthusiastic blathering about
+ technology for actually learning and *doing* it. Attitude is
+ no substitute for competence. On the other hand, at least
+ cyberpunks are excited about the right things and properly
+ respectful of hacking talent in those who have it. The
+ general consensus is to tolerate them politely in hopes that
+ they'll attract people who grow into being true hackers.
+
+ [{Jargon File}]
+
+cyberrhea
+
+ <humour, jargon> /si:'ber-eer/ An affliction of some {word
+ processor} users; excessive frequency and looseness of
+ productivity. Particularly virulent among those who have not
+ discovered the fortifying virtues of revision.
+
+ ["Right Words, Right Places" Scott Rice, Wadsworth, 1993, A5.]
+
+ (1997-02-25)
+
+cybersex
+
+ <networking> Sex performed in {real time} via a digital
+ medium.
+
+ Compare {teledildonics}.
+
+ [Details?]
+
+ (1998-02-10)
+
+cyberspace
+
+ <jargon> /si:'ber-spays/ 1. (Coined by {William Gibson})
+ Notional "information-space" loaded with visual cues and
+ navigable with brain-computer interfaces called "cyberspace
+ decks"; a characteristic prop of {cyberpunk} SF. In 1991
+ serious efforts to construct {virtual reality} interfaces
+ modelled explicitly on Gibsonian cyberspace were already under
+ way, using more conventional devices such as glove sensors and
+ binocular TV headsets. Few hackers are prepared to deny
+ outright the possibility of a cyberspace someday evolving out
+ of the network (see {network, the}).
+
+ 2. Occasionally, the metaphoric location of the mind of a
+ person in {hack mode}. Some hackers report experiencing
+ strong eidetic imagery when in hack mode; interestingly,
+ independent reports from multiple sources suggest that there
+ are common features to the experience. In particular, the
+ dominant colours of this subjective "cyberspace" are often
+ grey and silver, and the imagery often involves constellations
+ of marching dots, elaborate shifting patterns of lines and
+ angles, or moire patterns.
+
+ [{Jargon File}]
+
+ (1999-02-01)
+
+cyberspastic
+
+ <humour> A person suffering from information overload while
+ browsing the {Internet} or {web}.
+
+ Compare {webhead}.
+
+ (1995-11-09)
+
+cyber-squatting
+
+ <jargon, networking> The practice of registering famous brand
+ names as {Internet} {domain names}, e.g. harrods.com, ibm.firm
+ or sears.shop, in the hope of later selling them to the
+ appropriate owner at a profit.
+
+ (1998-01-22)
+
+CyberWand
+
+ <hardware, virtual reality> A {virtual reality} {controller}.
+ The CyberWand costs $99, or $765 with optional Polhemus
+ sensor. It is basically the handle of a flight control system
+ without the base. The controller's four buttons and 2-D hat
+ sensor track six degrees of movement.
+
+ (1995-04-04)
+
+CyberZine
+
+ <publication> A combination paper and {web} on-line
+ {Cyberspace} guide. Upon payment you will be given a user name
+ and password to access CyberZine on-line and the paper version
+ will be posted first class. Subscribers can also use the
+ CyberZine help desk.
+
+ {(http://cyberzine.org/)}.
+
+ (1994-09-22)
+
+CYBIL
+
+ Control Data's system programming language in the 80's. Major
+ parts of CDC systems written in this.
+
+Cyc
+
+ <artificial intelligence> A large {knowledge-based system}.
+
+ Cyc is a very large, multi-contextual {knowledge base} and
+ {inference engine}, the development of which started at the
+ {Microelectronics and Computer Technology Corporation} (MCC)
+ in Austin, Texas during the early 1980s.
+
+ Over the past eleven years the members of the Cyc team, lead
+ by {Doug Lenat}, have added to the knowledge base a huge
+ amount of fundamental human knowledge: {facts}, rules of
+ thumb, and {heuristics} for reasoning about the objects and
+ events of modern everyday life.
+
+ Cyc is an attempt to do symbolic {AI} on a massive scale. It
+ is not based on numerical methods such as statistical
+ probabilities, nor is it based on {neural networks} or {fuzzy
+ logic}. All of the knowledge in Cyc is represented
+ {declaratively} in the form of logical {assertions}. Cyc
+ presently contains approximately 400,000 significant
+ assertions, which include simple statements of fact, rules
+ about what conclusions to draw if certain statements of fact
+ are satisfied, and rules about how to reason with certain
+ types of facts and rules. The {inference engine} derives new
+ conclusions using {deductive reasoning}.
+
+ To date, Cyc has made possible ground-breaking pilot
+ applications in the areas of {heterogeneous} database browsing
+ and integration, {captioned image retrieval}, and {natural
+ language processing}.
+
+ In January of 1995, a new independent company named Cycorp was
+ created to continue the Cyc project. Cycorp is still in
+ Austin, Texas. The president of Cycorp is {Doug Lenat}.
+
+ The development of Cyc has been supported by several
+ organisations, including {Apple}, {Bellcore}, {DEC}, {DoD},
+ {Interval}, {Kodak}, and {Microsoft}.
+
+ {(http://cyc.com/)}.
+
+ {Unofficial FAQ (http://robotwisdom.com/ai/cycfaq.html)}.
+
+ (1999-09-07)
+
+CYCL
+
+ A {frame language}.
+
+ ["Building Large Knowledge-Based Systems", Doug B. Lenat et
+ al, A-W 1990].
+
+cycle
+
+ <unit> A basic unit of computation, one period of a computer
+ {clock}.
+
+ Each {instruction} takes a number of clock cycles. Often the
+ computer can access its memory once on every clock cycle, and
+ so one speaks also of "memory cycles".
+
+ Every {hacker} wants more cycles (noted hacker {Bill Gosper}
+ describes himself as a "cycle junkie"). There are only so
+ many cycles per second, and when you are sharing a computer
+ the cycles get divided up among the users. The more cycles
+ the computer spends working on your program rather than
+ someone else's, the faster your program will run. That's why
+ every hacker wants more cycles: so he can spend less time
+ waiting for the computer to respond.
+
+ The use of the term "cycle" for a computer clock period can
+ probably be traced back to the rotation of a generator
+ generating alternating current though computers generally use
+ a clock signal which is more like a {square wave}.
+ Interestingly, the earliest mechanical calculators,
+ e.g. Babbage's {Difference Engine}, really did have parts
+ which rotated in true cycles.
+
+ [{Jargon File}]
+
+ (1997-09-30)
+
+cyclebabble
+
+ <jargon> Advertising raw {clock speed}, instead of {bus
+ speed}.
+
+ {IBM} uses raw clock speed as the speed of the computer. In
+ the {IBM PC} and {IBM PC XT}, the clock is divided by 4 to
+ produce the 4-phase bus clocks. Thus a 4 MHz IBM XT really
+ runs at 0.895 MHz, because that 4 MHz was really 3.58 MHz
+ which gets divided by four.
+
+ A {Tandy} {Color Computer} ran at exactly the same speed, but
+ clock speed was specified as bus speed, 0.895 MHz, leaving the
+ impression that it was 4 times slower. Actually it ran a
+ little faster with a more efficient {instruction set}. If the
+ actual {clock rate} had been specified on a {CoCo 3}, it would
+ have been 14.32 MHz, although the bus speed was still 0.895
+ MHz. That high speed also generated video, color, and {hidden
+ refresh} timing.
+
+ 100 MHz computers are running at bus speeds of around 25 MHz.
+
+ (1997-02-13)
+
+cycle crunch
+
+ <jargon> A situation wherein the number of people trying to
+ use a computer simultaneously has reached the point where no
+ one can get enough {cycles} because they are spread too thin
+ and the system has probably begun to {thrash}.
+
+ This scenario is an inevitable result of Parkinson's Law
+ applied to {time-sharing}. Usually the only solution is to
+ buy more computer. Happily, this has rapidly become easier
+ since the mid-1980s, so much so that the very term "cycle
+ crunch" now has a faintly archaic flavour; most hackers now
+ use {workstations} or {personal computers} as opposed to
+ traditional {time-sharing} systems.
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+cycle drought
+
+ A scarcity of {cycles}. It may be due to a {cycle crunch},
+ but it could also occur because part of the computer is
+ temporarily not working, leaving fewer cycles to go around.
+ "The {high moby} is {down}, so we're running with only half
+ the usual amount of memory. There will be a cycle drought
+ until it's fixed."
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+cycle of reincarnation
+
+ A term coined by {Ivan Sutherland} ca. 1970 to refer to a
+ well-known effect whereby function in a computing system
+ family is migrated out to special-purpose {peripheral}
+ hardware for speed, then the peripheral evolves toward more
+ computing power as it does its job, then somebody notices that
+ it is inefficient to support two asymmetrical processors in
+ the architecture and folds the function back into the main
+ {CPU}, at which point the cycle begins again.
+
+ Several iterations of this cycle have been observed in
+ {graphics-processor} ({blitter}) design, and at least one or
+ two in communications and {floating-point} processors. Also
+ known as "the Wheel of Life", "the Wheel of Samsara" and other
+ variations of the basic Hindu/Buddhist theological idea.
+
+ [{Jargon File}]
+
+ (1994-11-16)
+
+cycle server
+
+ <jargon> A powerful computer that exists primarily for running
+ large {batch} jobs. The term implies that {interactive} tasks
+ such as editing are done on other machines on the network,
+ such as {workstations}.
+
+ [{Jargon File}]
+
+ (1998-03-13)
+
+cyclic redundancy check
+
+ <algorithm> (CRC or "cyclic redundancy code") A number derived
+ from, and stored or transmitted with, a block of data in order
+ to detect corruption. By recalculating the CRC and comparing
+ it to the value originally transmitted, the receiver can
+ detect some types of transmission errors.
+
+ A CRC is more complicated than a {checksum}. It is calculated
+ using division either using {shifts} and {exclusive ORs} or
+ {table lookup} ({modulo} 256 or 65536).
+
+ The CRC is "redundant" in that it adds no information. A
+ single corrupted {bit} in the data will result in a one bit
+ change in the calculated CRC but multiple corrupted bits may
+ cancel each other out.
+
+ CRCs treat blocks of input bits as coefficient-sets for
+ {polynomials}. E.g., binary 10100000 implies the polynomial:
+ 1*x^7 + 0*x^6 + 1*x^5 + 0*x^4 + 0*x^3 + 0*x^2 + 0*x^1 + 0*x^0.
+ This is the "message polynomial". A second polynomial, with
+ constant coefficients, is called the "generator polynomial".
+ This is divided into the message polynomial, giving a quotient
+ and remainder. The coefficients of the remainder form the
+ bits of the final CRC. So, an order-33 generator polynomial
+ is necessary to generate a 32-bit CRC. The exact bit-set used
+ for the generator polynomial will naturally affect the CRC
+ that is computed.
+
+ Most CRC implementations seem to operate 8 bits at a time by
+ building a table of 256 entries, representing all 256 possible
+ 8-bit byte combinations, and determining the effect that each
+ byte will have. CRCs are then computed using an input byte to
+ select a 16- or 32-bit value from the table. This value is
+ then used to update the CRC.
+
+ {Ethernet} {packets} have a 32-bit CRC. Many disk formats
+ include a CRC at some level.
+
+ (1997-08-02)
+
+cyclic redundancy code
+
+ {cyclic redundancy check}
+
+Cyclo
+
+ <programming, tool> (Cyclomatic complexity tool) A {C} and
+ {C++} code analysis tool by Roger D. Binns. It measures
+ {cyclomatic complexity}, shows function calls, and can draw
+ {flowgraphs} of {ANSI C} and {C++} code. It requires {Lex}
+ and {C++}.
+
+ Posted to {alt.sources}, 1993-06-28.
+
+ (1993-06-28)
+
+cyclomatic complexity
+
+ <programming, testing> A measure of the number of linearly
+ independent paths through a program {module}. Cyclomatic
+ complexity is a measure for the complexity of code related to
+ the number of ways there are to traverse a piece of code.
+ This determines the minimum number of inputs you need to test
+ all ways to execute the program.
+
+ (1998-03-17)
+
+Cygnus Tcl Tools
+
+ <tool> A rebundling of {Tcl} and {Tk} into the {Cygnus} {GNU}
+ build framework with "{configure}" by david d 'zoo' zuhn
+ <zoo@cygnus.com>.
+
+ Latest version: Release-930124, as of 1993-01-24.
+
+ {(ftp://cygnus.com/pub/)}.
+
+ (2000-09-25)
+
+cylinder
+
+ <storage> The set of {tracks} on a multi-headed {disk} that
+ may be accessed without head movement. That is, the
+ collection of disk tracks which are the same distance from the
+ spindle about which the disks rotate. Each such group forms
+ the shape of a cylinder. Placing data that are likely to be
+ accessed together in cylinders reduces the access
+ significantly as head movement ({seeking}) is slow compared to
+ disk rotation and switching between heads.
+
+ (1997-07-15)
+
+CypherText
+
+ <language> An interactive language for text formatting and
+ typesetting.
+
+ ["CypherText: An Extensible Composing and Typesetting
+ Language", C.G. Moore et al, Proc FJCC 37, AFIPS (Fall 1970)].
+
+ (1995-05-10)
+
+Cyrix
+
+ <company> A {microprocessor} manufacturer. They produce an
+ {Intel 486} equivalent - the {Cy486SLC} and a {Pentium}
+ equivalent - the {Cyrix 6x86}.
+
+ {(http://cyrix.com/)}.
+
+ (1996-03-23)
+
+Cyrix 6x86
+
+ <processor> (6x86) {IBM} and {Cyrix}'s {sixth-generation},
+ 64-bit {80x86}-compatible {microprocessor}. The 6x86 combines
+ aspects of both {RISC} and {CISC}. It has a {superscalar},
+ {superpipelined} {core}, and performs {register renaming},
+ {speculative execution}, {out-of-order completion}, and {data
+ dependency removal}. It has a 16-kilobyte {primary cache} and
+ is socket-compatible with the {Pentium} P54C. It has four
+ performance levels: PR 120+, PR 150+, PR 166+ and PR 200+.
+
+ The chip was designed by Cyrix and is manufactured by IBM.
+
+ The architecture of the 6x86 is more advanced than that of the
+ Pentium, incorporating some of the features of Intel's
+ {Pentium Pro}. At a given {clock rate} it executes most code
+ more quickly than a Pentium would. However, its {FPU} is
+ considerably less efficient than Intel's.
+
+ {IBM FAQ
+ (http://chips.ibm.com/products/x86/6x86/faqs/6x86_faqs.html)},
+ {Cyrix FAQ
+ (http://cyrix.com/process/prodinfo/6x86/faq-6x86.htm)}.
+
+ (1997-05-26)
+
+cz
+
+ <networking> The {country code} for the Czech Republic.
+
+ (1999-01-27)
+
+D
+
+ 1. "The Data Language." {MS-DOS} 4GL.
+
+ 2. A {Haskell}-like language, with {type class}es.
+
+ E-mail: <polar@cs.syr.edu>.
+
+D-1000
+
+ <computer> {Datamatic Corporation}'s first computer,
+ which weighed 25 tons, took up 6,000 square feet and
+ cost $1.5 million, produced some time after 1955.
+
+ (2009-01-14)
+
+DAA
+
+ Distributed Application Architecture: under design by
+ Hewlett-Packard and Sun. A distributed object management
+ environment that will allow applications to be developed
+ independent of operating system, network or windowing system.
+
+DAC
+
+ {Digital to Analog Converter}
+
+DACAPO
+
+ Broad-range hardware specification language. "Mixed Level
+ Modelling and Simulation of VLSI Systems", F.J. Rammig in
+ Logic Design and Simulation, E. Horbst ed, N-H 1986.
+
+DACNOS
+
+ A prototype network operating system for multi-vendor
+ environments, from IBM European Networking Centre Heidelberg
+ and University of Karlsruhe.
+
+ (1995-01-16)
+
+D/A converter
+
+ {Digital to Analog Converter}
+
+DACTL
+
+ Declarative Alvey Compiler Target Language.
+
+ An intermediate language from the {University of East Anglia},
+ used in the {Flagship} project. DACTL is based on a form of
+ {graph rewriting} which can be used to implement {functional
+ languages}, {logic languages} and {imperative languages}. The
+ current version is Dactl0.
+
+ ["DACTL - A Computational Model and Compiler Target Language
+ Based on Graph Reduction", J.R.W. Glauert et al, ICL Tech J
+ 5(3) (1987)].
+
+ (1994-09-22)
+
+DADS
+
+ {Dictionary of Algorithms and Data Structures}
+
+daemon
+
+ <operating system> /day'mn/ or /dee'mn/ (From the mythological
+ meaning, later rationalised as the acronym "Disk And Execution
+ MONitor") A program that is not invoked explicitly, but lies
+ dormant waiting for some condition(s) to occur. The idea is
+ that the perpetrator of the condition need not be aware that a
+ daemon is lurking (though often a program will commit an
+ action only because it knows that it will implicitly invoke a
+ daemon).
+
+ For example, under {ITS} writing a file on the {LPT} spooler's
+ directory would invoke the spooling daemon, which would then
+ print the file. The advantage is that programs wanting files
+ printed need neither compete for access to, nor understand any
+ idiosyncrasies of, the {LPT}. They simply enter their
+ implicit requests and let the daemon decide what to do with
+ them. Daemons are usually spawned automatically by the
+ system, and may either live forever or be regenerated at
+ intervals.
+
+ {Unix} systems run many daemons, chiefly to handle requests
+ for services from other {hosts} on a {network}. Most of these
+ are now started as required by a single real daemon, {inetd},
+ rather than running continuously. Examples are {cron} (local
+ timed command execution), {rshd} (remote command execution),
+ {rlogind} and {telnetd} (remote login), {ftpd}, {nfsd} (file
+ transfer), {lpd} (printing).
+
+ Daemon and {demon} are often used interchangeably, but seem to
+ have distinct connotations (see {demon}). The term "daemon"
+ was introduced to computing by {CTSS} people (who pronounced
+ it /dee'mon/) and used it to refer to what {ITS} called a
+ {dragon}.
+
+ [{Jargon File}]
+
+ (1995-05-11)
+
+DAG
+
+ 1. <architecture> {Data Address Generator}.
+
+ 2. <mathematics> {directed acyclic graph}.
+
+ (1997-08-30)
+
+Daisy
+
+ A {functional language}.
+
+ ["Daisy Programming Manual", S.D. Johnson, CS Dept TR, Indiana
+ U, 1988].
+
+DAISY 201
+
+ An early system on {G-15}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+daisy chain
+
+ <networking> A {bus} wiring scheme in which, for example,
+ device A is wired to device B, device B is wired to device C,
+ etc. The last device is normally wired to a resistor or
+ {terminator}. All devices may receive identical signals or,
+ in contrast to a simple bus, each device in the chain may
+ modify one or more signals before passing them on.
+
+ Characteristic of {RS-485}, of {Apple}'s {LocalTalk}, and of
+ various industrial control networks; also often used to
+ describe {Thinwire} {Ethernet} ({10base2}).
+
+ (1997-01-07)
+
+daisywheel printer
+
+ <printer> A kind of {impact printer} where the characters are
+ arranged on the ends of the spokes of a wheel (resembling the
+ petals on a daisy).
+
+ The wheel (usually made of plastic) is rotated to select the
+ character to print and then an electrically operated hammer
+ mechanism bends the selected spoke forward slightly,
+ sandwiching an ink ribbon between the character and the paper,
+ as in a typewriter.
+
+ One advantage of this arrangement over that of a typewriter is
+ that different wheels may be inserted to produce different
+ {typefaces}.
+
+ (1998-04-28)
+
+dancing frog
+
+ <programming, humour> A {bug} or {glitch} that only occurs for
+ a particular user; never when the user tries to show it to
+ anyone else.
+
+ The term is derived from a Warner Brothers cartoon in which a
+ man discovers a frog which can sing and dance; he believes
+ this will make his fortune but the frog never performs in
+ front of anyone else.
+
+ (2004-10-16)
+
+dangling pointer
+
+ <programming> A reference that doesn't actually lead anywhere.
+ In {C} and some other languages, a pointer that doesn't
+ actually point at anything valid. Usually this happens
+ because it formerly pointed to something that has moved or
+ disappeared, e.g. a {heap}-allocated block which has been freed
+ and reused.
+
+ Used as jargon in a generalisation of its technical meaning;
+ for example, a local phone number for a person who has since
+ moved is a dangling pointer.
+
+ {This dictionary} contains many dangling pointers -
+ cross-references to non-existent entries, as explained in {the
+ Help page (help.html)}.
+
+ [{Jargon File}]
+
+ (2014-09-20)
+
+DANTE
+
+ A company established by the national research networks in
+ Europe to provide international network services.
+
+DAP Fortran
+
+ ["Efficient High Speed Computing with the Distributed Array
+ Processor", P.M. Flanders et al, pp.113-127 (1977)].
+
+ [Same as Fortran- Plus?]
+
+DAPLEX
+
+ ["The Functional Data Model and the Data Language DAPLEX",
+ D.W. Shipman, ACM Trans Database Sys, 6(1):140-173 (Mar
+ 1981)].
+
+DARE
+
+ Differential Analyzer REplacement. A family of simulation
+ languages for continuous systems.
+
+ ["Digital Continuous System Simulation", G.A. Korn et al, P-H
+ 1978].
+
+dark-side hacker
+
+ <jargon, legal> A criminal or malicious hacker; a {cracker}.
+ From George Lucas's Darth Vader, "seduced by the dark side of
+ the Force". The implication that hackers form a sort of elite
+ of technological Jedi Knights is intended.
+
+ Opposite: {samurai}.
+
+ [{Jargon File}]
+
+ (1997-04-28)
+
+Darms
+
+ <language, music> A music language.
+
+ ["The Darms Project: A Status Report", R.F. Erickson,
+ Computers and the Humanities 9(6):291-298 (June 1975)].
+
+ (1995-05-12)
+
+DARPA
+
+ {Defense Advanced Research Projects Agency}
+
+Dartmouth BASIC
+
+ <language> The original {BASIC} language, designed by John
+ G. Kemeny and Thomas E. Kurtz at Dartmouth College in 1963.
+ Dartmouth BASIC first ran on a {GE 235} [date?] and on an {IBM
+ 704} on 1964-05-01. It was designed for quick and easy
+ programming by students and beginners using Dartmouth's
+ experimental {time-sharing} system. Unlike most later BASIC
+ dialects, Dartmouth BASIC was compiled.
+
+ (2003-07-02)
+
+Darwin
+
+ 1. <operating system> An {operating system} based on the
+ {FreeBSD} version of {Unix}, running on top of a {microkernel}
+ ({Mach} 3.0 with darwin 1.02) that offers advanced networking,
+ services such as the {Apache} {web server}, and support for
+ both {Macintosh} and Unix {file systems}. Darwin was
+ originally released in March 1999. It currently runs on
+ {PowerPC} based Macintosh computers, and, in October 2000, was
+ being ported to {Intel} processor-based computers and
+ compatible systems by the Darwin community.
+
+ 2. <programming, tool> A general purpose structuring tool of
+ use in building complex {distributed systems} from diverse
+ components and diverse component interaction mechanisms.
+ Darwin is being developed by the Distributed Software
+ Engineering Section of the Department of Computing at
+ {Imperial College}. It is in essence a {declarative} binding
+ language which can be used to define hierarchic compositions
+ of interconnected components. Distribution is dealt with
+ orthogonally to system structuring. The language allows the
+ specification of both static structures and dynamic structures
+ which evolve during execution. The central abstractions
+ managed by Darwin are components and services. Bindings are
+ formed by manipulating references to services.
+
+ The {operational semantics} of Darwin is described in terms of
+ the {Pi-calculus}, {Milner}'s calculus of mobile processes.
+ The correspondence between the treatment of names in the
+ Pi-calculus and the management of service references in Darwin
+ leads to an elegant and concise Pi-calculus model of Darwin's
+ {operational semantics}. The model has proved useful in
+ arguing the correctness of Darwin implementations and in
+ designing extensions to Darwin and reasoning about their
+ behaviour.
+
+ {Distributed Software Engineering Section
+ (http://www-dse.doc.ic.ac.uk/)}. {Darwin publications
+ (http://scorch.doc.ic.ac.uk/dse-papers/darwin/)}.
+
+ E-mail: Jeff Magee <jnm@doc.ic.ac.uk>, Naranker Dulay
+ <nd@doc.ic.ac.uk>.
+
+ 3. {Core War}.
+
+ (2003-08-08)
+
+DAS
+
+ Digital Analog Simulator.
+
+ Represents {analog computer} design.
+
+ (1994-11-08)
+
+DASD
+
+ {Direct-Access Storage Device}
+
+DASE
+
+ {Distributed Application Support Environment}
+
+DASL
+
+ Datapoint's Advanced System Language.
+
+ A cross between {C} and {Pascal} by Gene Hughes with custom
+ features for {Datapoint} hardware (no {stack}). It is used
+ internally by Datapoint.
+
+ (1994-11-08)
+
+DAT
+
+ 1. {Digital Audio Tape}.
+
+ 2. {Dynamic Address Translation}.
+
+data
+
+ <data, data processing, jargon> /day't*/ (Or "raw data")
+ Numbers, {characters}, {images}, or other method of recording,
+ in a form which can be assessed by a human or (especially)
+ input into a {computer}, stored and {processed} there, or
+ transmitted on some {digital channel}. Computers nearly
+ always represent data in {binary}.
+
+ Data on its own has no meaning, only when interpreted by some
+ kind of {data processing system} does it take on meaning and
+ become {information}.
+
+ For example, the binary data 01110101 might represent the integer
+ 117 or the {ASCII} lower case U character or the blue component of
+ a pixel in some {video}. Which of these it represents is
+ determined by the way it is processed (added, printed, displayed,
+ etc.). Even these numbers, characters or pixels however are still
+ not really information until their context is known, e.g. my bank
+ balance is £117, there are two Us in "vacuum", you have blue eyes.
+
+ (2007-09-10)
+
+data abstraction
+
+ <data> Any representation of data in which the implementation
+ details are hidden (abstracted). {Abstract data types} and
+ {objects} are the two primary forms of data abstraction.
+
+ [Other forms?].
+
+ (2003-07-03)
+
+data acquisition
+
+ {data logging}
+
+Data Address Generator
+
+ <architecture> (DAG) The mechanism which generates temporary
+ memory addresses for data that is transferred between memory
+ and {registers} in a {Digital Signal Processor}.
+
+ Certain {DSP} architectures incorporate more than one DAG to
+ simplify the programming needed to move blocks of data between
+ buffers.
+
+ For instance, certain {Fast Fourier Transform} {algorithms}
+ requiring {bit reversing}, can use the DAG for that purpose,
+ or they can use two DAGS, one for Program Memory Data (PMD),
+ and the other for Data Memory Data (DMD).
+
+ (1997-08-12)
+
+database
+
+ 1. <database> One or more large structured sets of persistent
+ data, usually associated with software to update and {query}
+ the data. A simple database might be a single file containing
+ many {records}, each of which contains the same set of
+ {fields} where each field is a certain fixed width.
+
+ A database is one component of a {database management system}.
+
+ See also {ANSI/SPARC Architecture}, {atomic}, {blob}, {data
+ definition language}, {deductive database}, {distributed
+ database}, {fourth generation language}, {functional
+ database}, {object-oriented database}, {relational database}.
+
+ {Carol E. Brown's tutorial
+ (http://accounting.rutgers.edu/raw/aies/www.bus.orst.edu/faculty/brownc/lectures/db_tutor/db_tutor.htm)}.
+
+ 2. <hypertext> A collection of {nodes} managed and stored in
+ one place and all accessible via the same {server}. {Links}
+ outside this are "external", and those inside are "internal".
+
+ On the {World-Wide Web} this is called a {website}.
+
+ 3. All the facts and rules comprising a {logic programming}
+ program.
+
+ (2005-11-17)
+
+database administrator
+
+ <job> A person responsible for the design and management of
+ one or more {databases} and for the evaluation, selection and
+ implementation of {database management systems}. In smaller
+ organisations, the data administrator and database
+ administrator are often one in the same; however, when they
+ are different, the database administrator's function is more
+ technical. The database administrator would implement the
+ database software that meets the requirements outlined by the
+ organisation's data administrator and {systems analysts}.
+
+ Tasks might include controling an organisation's data
+ resources, using {data dictionary} software to ensure {data
+ integrity} and security, recovering corrupted data and
+ eliminating data redundancy and uses tuning tools to improve
+ database performance.
+
+ (2004-03-11)
+
+database analyst
+
+ <job> A person who uses {data modeling} to analyse and specify
+ data use within an application area. A database analyst
+ defines both {logical views} and physical data structures. In
+ a {client/server} environment, he defines the database part of
+ the back end system.
+
+ (2004-03-11)
+
+database machine
+
+ <hardware> A {computer} or special hardware that stores and
+ retrieves data from a {database}. It is specially designed
+ for database access and is coupled to the main ({front-end})
+ computer(s) by a high-speed channel. This contrasts with a
+ {database server}, which is a computer in a {local area
+ network} that holds a database. The database machine is
+ tightly coupled to the main {CPU}, whereas the database server
+ is loosely coupled via the network.
+
+ [Example?]
+
+ (2004-03-11)
+
+database management system
+
+ <database> (DBMS) A suite of programs which typically manage
+ large structured sets of persistent data, offering ad hoc
+ query facilities to many users. They are widely used in
+ business applications.
+
+ A database management system (DBMS) can be an extremely
+ complex set of software programs that controls the
+ organisation, storage and retrieval of data (fields, records
+ and files) in a database. It also controls the security and
+ integrity of the database. The DBMS accepts requests for data
+ from the application program and instructs the operating
+ system to transfer the appropriate data.
+
+ When a DBMS is used, information systems can be changed much
+ more easily as the organisation's information requirements
+ change. New categories of data can be added to the database
+ without disruption to the existing system.
+
+ Data security prevents unauthorised users from viewing or
+ updating the database. Using passwords, users are allowed
+ access to the entire database or subsets of the database,
+ called subschemas (pronounced "sub-skeema"). For example, an
+ employee database can contain all the data about an individual
+ employee, but one group of users may be authorised to view
+ only payroll data, while others are allowed access to only
+ work history and medical data.
+
+ The DBMS can maintain the integrity of the database by not
+ allowing more than one user to update the same record at the
+ same time. The DBMS can keep duplicate records out of the
+ database; for example, no two customers with the same customer
+ numbers (key fields) can be entered into the database.
+
+ {Query languages} and {report writers} allow users to
+ interactively interrogate the database and analyse its data.
+
+ If the DBMS provides a way to interactively enter and update
+ the database, as well as interrogate it, this capability
+ allows for managing personal databases. However, it may not
+ leave an audit trail of actions or provide the kinds of
+ controls necessary in a multi-user organisation. These
+ controls are only available when a set of application programs
+ are customised for each data entry and updating function.
+
+ A business information system is made up of subjects
+ (customers, employees, vendors, etc.) and activities (orders,
+ payments, purchases, etc.). Database design is the process of
+ deciding how to organize this data into record types and how
+ the record types will relate to each other. The DBMS should
+ mirror the organisation's data structure and process
+ transactions efficiently.
+
+ Organisations may use one kind of DBMS for daily transaction
+ processing and then move the detail onto another computer that
+ uses another DBMS better suited for random inquiries and
+ analysis. Overall systems design decisions are performed by
+ data administrators and systems analysts. Detailed database
+ design is performed by database administrators.
+
+ The three most common organisations are the {hierarchical
+ database}, {network database} and {relational database}. A
+ database management system may provide one, two or all three
+ methods. Inverted lists and other methods are also used. The
+ most suitable structure depends on the application and on the
+ transaction rate and the number of inquiries that will be
+ made.
+
+ Database machines are specially designed computers that hold
+ the actual databases and run only the DBMS and related
+ software. Connected to one or more mainframes via a
+ high-speed channel, database machines are used in large volume
+ transaction processing environments. Database machines have a
+ large number of DBMS functions built into the hardware and
+ also provide special techniques for accessing the disks
+ containing the databases, such as using multiple processors
+ concurrently for high-speed searches.
+
+ The world of information is made up of data, text, pictures
+ and voice. Many DBMSs manage text as well as data, but very
+ few manage both with equal proficiency. Throughout the 1990s,
+ as storage capacities continue to increase, DBMSs will begin
+ to integrate all forms of information. Eventually, it will be
+ common for a database to handle data, text, graphics, voice
+ and video with the same ease as today's systems handle data.
+
+ See also: {intelligent database}.
+
+ (1998-10-07)
+
+database manager
+
+ The part of the database management system (DBMS) that handles
+ the organisation, storage and retrieval of the data. A
+ database manager may work with traditional programming
+ languages, such as COBOL and BASIC, or may work only with its
+ proprietary programming language. The terms database manager
+ and database management system are used interchangeably.
+
+ A database manager links two or more files together and is the
+ foundation for developing routine business systems. Contrast
+ with file manager, which works with only one file at a time
+ and is typically used interactively on a personal computer for
+ managing personal, independent files, such as name and address
+ lists.
+
+database normalisation
+
+ <database> A series of steps followed to obtain a {database}
+ design that allows for efficient access and {storage} of data
+ in a {relational database}. These steps reduce data
+ redundancy and the chances of data becoming inconsistent.
+
+ A {table} in a {relational database} is said to be in normal
+ form if it satisfies certain {constraints}. {Codd}'s original
+ work defined three such forms but there are now five generally
+ accepted steps of normalisation. The output of the first step
+ is called First Normal Form (1NF), the output of the second
+ step is Second Normal Form (2NF), etc.
+
+ First Normal Form eliminates {repeating groups} by putting
+ each value of a multi-valued attribute into a new row.
+
+ Second Normal Form eliminates {functional dependencies} on a
+ {partial key} by putting the fields in a separate table from
+ those that are dependent on the whole {key}.
+
+ Third Normal Form eliminates functional dependencies on
+ non-key fields by putting them in a separate table. At this
+ stage, all non-key fields are dependent on the key, the whole
+ key and nothing but the key.
+
+ Fourth Normal Form separates independent multi-valued facts
+ stored in one table into separate tables.
+
+ Fifth Normal Form breaks out data redundancy that is not
+ covered by any of the previous normal forms.
+
+ {(http://bkent.net/Doc/simple5.htm)}.
+
+ [What about non-relational databases?]
+
+ (2005-07-28)
+
+database query language
+
+ <database> A language in which users of a {database} can
+ (interactively) formulate requests and generate reports. The
+ best known is {SQL}.
+
+ (1998-04-15)
+
+database server
+
+ A stand-alone computer in a local area network that holds and
+ manages the database. It implies that database management
+ functions, such as locating the actual record being requested,
+ is performed in the server computer. Contrast with file
+ server, which acts as a remote disk drive and requires that
+ large parts of the database, for example, entire indexes, be
+ transmitted to the user's computer where the real database
+ management tasks are performed.
+
+ First-generation personal computer database software was not
+ designed for a network; thus, modified versions of the
+ software released by the vendors employed the file server
+ concept. Second-generation products, designed for local area
+ networks, perform the management tasks in the server where
+ they should be done, and consequently are turning the file
+ server into a database server.
+
+database transaction
+
+ <database> A set of related changes applied to a {database}. The
+ term typically implies that either all of the changes should be
+ applied or, in the event of an error, none of them, i.e. the
+ transaction should be {atomic}. Atomicity is one of the {ACID}
+ properties a transaction can have, another is {isolation} -
+ preventing interference between processes trying to access the
+ database {cocurrently}. This is usually achieved by some form of
+ {locking} - where one process takes exclusive control of a
+ database {table} or {row} for the duration of the transaction,
+ preventing other processes from accessing the locked data.
+
+ The canonical example of a transaction is transferring money
+ between two bank accounts by subtracting it from one and adding it
+ to the other.
+
+ Some {relational database management systems} require the user to
+ explicitly start a transaction and then either commit it (if all
+ the individual steps are successful) or roll it back (if there are
+ any errors).
+
+ (2013-06-03)
+
+Data/BASIC
+
+ <language> (Or "Pick BASIC") A {BASIC}-like language with
+ {database} capabilities, the main programming language on the
+ {Pick OS}.
+
+ ["The Data/BASIC Language - A Data Processing Language for
+ Non-Professional Programmers", P.C. Dressen, Proc SJCC 36,
+ AFIPS, Spring 1970].
+
+ (2001-04-30)
+
+DATABUS
+
+ DATApoint BUSiness Language.
+
+ A language like an interpreted {assembly language}, used for
+ custom applications on {Datapoint} computers.
+
+ (1995-01-16)
+
+data bus
+
+ <architecture> The bus (connections between and within the
+ {CPU}, memory, and peripherals) used to carry {data}. Other
+ connections are the {address bus} and control signals.
+
+ The width and {clock rate} of the data bus determine its data
+ rate (the number of {bytes} per second it can carry), which is
+ one of the main factors determining the processing power of a
+ computer. Most current processor designs use a 32-bit bus,
+ meaning that 32 bits of data can be transferred at once. Some
+ processors have an internal data bus which is wider than their
+ external bus in order to make external connections cheaper
+ while retaining some of the benefits in processing power of a
+ wider bus.
+
+ See also {data path}.
+
+ (1995-01-16)
+
+datacenter manager
+
+ <job> A person who plans and directs all computer and
+ {peripheral} operations, {data entry}, data control scheduling
+ and quality control.
+
+ (2004-03-11)
+
+data channel
+
+ <communications> A channel (on a {BRI} or {PRI} line) used to
+ carry control information, to set up connections on the
+ associated {bearer channels}. The name wasn't too bad back
+ when users were sending voice (not data) over the {bearer
+ channels}, but in 1997 it's quite a misnomer.
+
+ (1997-03-10)
+
+DATACODE I
+
+ <language> An early system used on the {Datatron 200} series.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (1994-12-06)
+
+Datacom
+
+ A {DBMS} from {Computer Associates International}.
+
+ (1994-12-06)
+
+Data Communication Equipment
+
+ <communications, hardware> (DCE) The devices and connections
+ of a communications network that connect the communication
+ circuit between the data source and destination (the {Data
+ Terminal Equipment} or DTE). A {modem} is the most common
+ kind of DCE.
+
+ Before data can be transmited over a modem, the DTR (Data
+ Terminal Ready) signal must be active. DTR tells the DCE that
+ the DTE is ready to transmit and receive data.
+
+ DCE and DTE are usually connected by an {EIA-232} {serial
+ line}. It is necessary to distinguish these two types of
+ device because their connectors must be wired differently if a
+ "straight-through" cable (pin 1 to pin 1, pin 2 to pin 2 etc.)
+ is to be used. DCE should have a female connector and should
+ transmit on pin two and receive on pin three. It is a curious
+ fact that many {modems} are "DTE" according to the original
+ standard.
+
+ (1995-02-28)
+
+data communications analyst
+
+ <job> A person who installs, maintains, and troubleshoots
+ {data networks}. A data communications analyst may have
+ knowledge of {T1} lines, {TCP/IP}, {fiber optics}, {SNA},
+ {frame relay}. He assists users with problems related to
+ connectivity, analyses data flow, configures {modems}, {DSUs},
+ {multiplexors}, and {routers}, and uses network tools such as
+ {NetView} or {Netspy}.
+
+ (2004-03-11)
+
+Data Communications Equipment
+
+ {Data Communication Equipment}
+
+data compression
+
+ <algorithm> {compression}. Probably to distinguish it from
+ (electronic) {signal compression}.
+
+ (1995-04-02)
+
+Data definition language
+
+ <language, database> (DDL)
+
+ 1. A language enabling the structure and instances of a
+ {database} to be defined in a human-, and machine-readable
+ form.
+
+ {SQL} contains DDL commands that can be used either
+ interactively, or within programming language {source code},
+ to define databases and their components, e.g. CREATE and
+ DROP.
+
+ See also {Data manipulation language} (DML).
+
+ 2. A specification language for databases, based on the
+ {entity-relationship model}. It is used in the {Eli}
+ {compiler-compiler} to manage type definitions.
+
+ ["DDL Reference Manual", ECE Dept U Colorado, 1991].
+
+ (1999-04-26)
+
+data dictionary
+
+ <database> A data structure that stores {metadata}, i.e. data
+ about {data}. The term "data dictionary" has several uses.
+
+ Most generally it is a set of {data descriptions} that
+ can be shared by several applications.
+
+ Usually it means a {table} in a {database} that stores the
+ names, {field} {types}, length, and other characteristics of
+ the fields in the database tables.
+
+ An active data dictionary is automatically updated as changes
+ occur in the database. A passive data dictionary must be
+ manually updated.
+
+ In a {DBMS}, this functionality is performed by the {system
+ catalog}. The data dictionary is a more general software
+ utility used by designers, users, and administrators for
+ {information resource management}.
+
+ The data dictionary may maintain information on system
+ hardware, software, documentation, users, and other aspects.
+
+ Data dictionaries are also used to document the database
+ design process itself and can accumulate metadata
+ ready to feed into the system catalog.
+
+ [Does anybody call them "codebooks"?]
+
+ (2001-04-24)
+
+data dictionary file
+
+ <database> (DDF) A set of files describing the structure of a
+ {database} file. DDFs define {database tables} and include
+ information about file locations, field layouts and
+ indexes. DDFs are the standard method for defining field and
+ index characteristics for {Btrieve} files.
+
+ (1997-06-03)
+
+data driven
+
+ A data driven architecture/language performs computations in
+ an order dictated by data dependencies. Two kinds of data
+ driven computation are {dataflow} and {demand driven}.
+
+ From about 1970 research in parallel {data driven} computation
+ increased. Centres of excellence emerged at {MIT},
+ {CERT-ONERA} in France, {NTT} and {ETL} in Japan and
+ {Manchester University}.
+
+Data Driven Machine
+
+ <language> (DDM) A {dataflow} language.
+
+ ["The Architecture and System Method of DDM-1: A Recursively
+ Structured Data Driven Machine", A. Davis, Proc 5th Ann Symp
+ Comp Arch, IEEE 1978].
+
+ (1999-04-26)
+
+Data Encryption Algorithm
+
+ (DEA) An {ANSI} {standard} defined in ANSI X3.92-1981. It is
+ identical to the {Data Encryption Standard} (DES).
+
+ (1994-12-06)
+
+Data Encryption Key
+
+ (DEK) Used for the {encryption} of message text and for the
+ computation of message integrity checks (signatures).
+
+ See {cryptography}.
+
+ (1994-12-06)
+
+Data Encryption Standard
+
+ (DES) The {NBS}'s popular, standard {encryption} algorithm.
+ It is a {product cipher} that operates on 64-bit blocks of
+ data, using a 56-bit key. It is defined in {FIPS} 46-1 (1988)
+ (which supersedes FIPS 46 (1977)). DES is identical to the
+ {ANSI} standard {Data Encryption Algorithm} (DEA) defined in
+ ANSI X3.92-1981.
+
+ DES has been implemented in {VLSI}. {SunOS} provides a des
+ command which can make use of DES hardware if fitted. Neither
+ the software nor the hardware are supposed to be distributed
+ outside the USA.
+
+ {Unix manual pages}: des(1), des(3), des(4).
+
+ (1994-12-06)
+
+data feed
+
+ <data, architecture> Some process for transferring {data} from
+ one system to another in a predetermined form.
+
+ (2009-05-17)
+
+data flow
+
+ <architecture> A data flow architecture or language performs a
+ computation when all the {operands} are available. Data flow is
+ one kind of {data driven} architecture, the other is {demand
+ driven}. It is a technique for specifying {fine-grain
+ concurrency}, usually in the form of two-dimensional graphs in
+ which instructions that are available for concurrent execution are
+ written alongside each other while those that must be executed in
+ sequence are written one under the other. Data dependencies
+ between instructions are indicated by directed arcs. Instructions
+ do not reference memory since the data dependence arcs allow data
+ to be transmitted directly from the producing instruction to the
+ consuming one.
+
+ Data flow schemes differ chiefly in the way that they handle
+ {re-entrant} code. Static schemes disallow it, dynamic
+ schemes use either "code copying" or "tagging" at every point
+ of reentry.
+
+ An example of a data flow architecture is {MIT}'s {VAL}
+ machine.
+
+data flow analysis
+
+ <programming> A process to discover the dependencies between
+ different data items manipulated by a program. The order of
+ execution in a {data driven} language is determined solely by
+ the data dependencies. For example, given the equations
+
+ 1. X = A + B
+ 2. B = 2 + 2
+ 3. A = 3 + 4
+
+ a data-flow analysis would find that 2 and 3 must be evaluated
+ before 1. Since there are no data dependencies between 2 and
+ 3, they may be evaluated in any order, including in parallel.
+
+ This technique is implemented in {hardware} in some
+ {pipelined} processors with multiple {functional units}. It
+ allows instructions to be executed as soon as their inputs are
+ available, independent of the original program order.
+
+ (1996-05-13)
+
+Data Flow Diagram
+
+ <programming> A graphical notation used to describe how {data}
+ flows between {processes} in a system. Data flow diagrams are
+ an important tool of most {structured analysis} techniques.
+
+ {(http://smartdraw.com/resources/centers/software/dfd.htm)}.
+
+ (2003-05-17)
+
+data fork
+
+ {Macintosh file system}
+
+data frame
+
+ {activation record}
+
+Data General
+
+ <company> A US computer manufacturer. Responsible for the
+ {Nova} {minicomputer}.
+
+ Quarterly sales $284M, profits -$12M (Aug 1994).
+
+ (1994-09-26)
+
+Data General mN601
+
+ {Data General MicroNova 601}
+
+data glove
+
+ <hardware, virtual reality> An input device for {virtual
+ reality} in the form of a glove which measures the movements
+ of the wearer's fingers and transmits them to the computer.
+ Sophisticated data gloves also measure movement of the wrist
+ and elbow. A data glove may also contain control buttons or
+ act as an output device, e.g. vibrating under control of the
+ computer. The user usually sees a virtual image of the
+ data glove and can point or grip and push objects.
+
+ Examples are {Fifth Dimension Technologies} (5DT)'s {5th
+ Glove}, and {Virtual Technologies}' {CyberGlove}. A cheaper
+ alternative is {InWorld VR}'s {CyberWand}.
+
+ ["Full freedom plus input", PC Magazine, Mar 14 1995,
+ pp. 168-190].
+
+ [Inventor?]
+
+ (1995-04-04)
+
+datagram
+
+ A self-contained, independent entity of data carrying
+ sufficient information to be {route}d from the source to the
+ destination computer without reliance on earlier exchanges
+ between this source and destination computer and the
+ transporting {network}.
+
+ See also {connectionless}, {frame}, {packet}.
+
+data hierarchy
+
+ The system of data objects which provide the {methods} for
+ {information} storage and retrieval. Broadly, a data
+ hierarchy may be considered to be either natural, which arises
+ from the alphabet or syntax of the language in which the
+ information is expressed, or machine, which reflects the
+ facilities of the computer, both hardware and software.
+
+ A natural data hierarchy might consist of {bits},
+ {characters}, words, phrases, sentences, paragraphs, and
+ chapters. One might use components bound to an application,
+ such as field, record, and file, and these would ordinarily be
+ further specified by having {data descriptors} such as name
+ field, address field, etc. On the other hand, a machine or
+ software system might use {bit}, {byte}, {word}, {block},
+ {partition}, {channel}, and {port}.
+
+ Programming languages often provide {types} or {objects} which
+ can create data hierarchies of arbitrary complexity, thus
+ allowing software system designers to model language
+ structures described by the linguist to greater or lesser
+ degree.
+
+ The distinction between the natural form of data and the
+ facilities provided by the machine may be obscure, because
+ users force their needs into the molds provided, and
+ programmers change machine designs. As an example, the
+ natural data type "character" and the machine type "byte" are
+ often used interchangeably, because the latter has evolved to
+ meet the need of representing the former.
+
+ (1995-11-03)
+
+data integrity
+
+ <data> The absence of unintended changes or errors in some
+ data. Integrity implies that the data is an exact copy of
+ some original version, e.g. that it has not been corrupted in
+ the process of being written to, and read back from, a {hard
+ disk} or during transmission via some communications channel.
+
+ Integrity may further imply that the {information} represented
+ by the data has been {validated}, i.e. verified to conform to
+ certain constraints, e.g. a date's year, month and day parts
+ are within the appropriate ranges and the date actually
+ exists.
+
+ (2009-06-03)
+
+Data Interchange Standards Association
+
+ <standard> (DISA) A not-for-profit corporation that acts as
+ the secretariat for {ANSI}'s {EDI} standards committee, ASC
+ X12 that works on {ANSI X12}. DISA manages ASC X12's
+ membership, balloting, standards development and maintenance,
+ publications, and communications with ANSI.
+
+ (1999-09-18)
+
+Data Jack
+
+ <hardware> A wall-mounted or desk-mounted connector
+ (frequently a wide telephone-style 8-pin {RJ-45}) for
+ connecting to data cabling in a building.
+
+ (1997-01-07)
+
+Datakit
+
+ <networking> A {circuit-switched} digital network, similar to
+ {X.25}. Datakit supports {host-to-host} connections and
+ {EIA-232} connections for {terminals}, {printers}, and {hosts}.
+
+ Most of {Bell Laboratories} is {trunk}ed together on Datakit.
+ On top of DK transport service, people run {UUCP} for
+ {electronic mail} and {dkcu} for {remote login}.
+
+ ISN is the version of Datakit supported by {AT&T} Information
+ Systems. Bell Laboratories in Holmdel, New Jersey, uses ISN
+ for internal data communication.
+
+ {(http://fc.net:80/phrack/files/p18/p18-9.html)}.
+
+ ["Towards a universal data transport system", A. G. Fraser,
+ IEEE Journal on Selected Areas in Communications, SAC-1(5)
+ pp. 803-16, 1983].
+
+ (1996-10-20)
+
+Dataless Management Services
+
+ <operating system> (DMS)
+
+ {(http://cs.arizona.edu/computer.help/policy/DIGITAL_unix/AA-PS3LE-TE_html/sharing10.html)}.
+
+ (2005-09-15)
+
+dataless management utility
+
+ <operating system> (DMU) A {Dataless Management Services}
+ (DMS) utility for managing the sharing of installed operating
+ software between DMS servers and clients. It allows users to
+ install, configure, show and delete DMS environments and add,
+ list, modify and remove DMS clients.
+
+ (2005-09-15)
+
+Data Link Connection Identifier
+
+ <networking> (DLCI) A channel number which is attached to
+ {data frames} to tell a {Frame Relay} network how to route the
+ data. In Frame Relay, multiple logical channels are
+ {multiplexed} over a single physical channel. The DLCI says
+ which of these logical channels a particular data frame
+ belongs to.
+
+ {(http://etinc.com/frmain.htm#whatsadlci)}.
+
+ (2000-02-13)
+
+data link layer
+
+ <networking> Layer two, the second lowest layer in the {OSI}
+ seven layer model. The data link layer splits data into
+ {frames} (see {fragmentation}) for sending on the {physical
+ layer} and receives acknowledgement frames. It performs error
+ checking and re-transmits frames not received correctly. It
+ provides an error-free virtual channel to the {network layer}.
+ The data link layer is split into an upper sublayer, {Logical
+ Link Control} (LLC), and a lower sublayer, {Media Access
+ Control} (MAC).
+
+ Example {protocols} at this layer are {ABP}, {Go Back N},
+ {SRP}.
+
+ (1995-02-14)
+
+data link level
+
+ {data link layer}
+
+Data Link Provider Interface
+
+ <networking> (DLPI) The interface that a {network driver}
+ presents to the (higher level) {logical link layer} for
+ driving the network at the {datagram} level in a {Unix}
+ {STREAMS} environment and possibly elsewhere.
+
+ DLPI corresponds to {ISO 8802}/2 ({LLC}) which covers both
+ {connection-oriented} and {connectionless} {protocols}.
+
+ [Is this correct? Better explanation?]
+
+ (1996-01-29)
+
+Data Link Switching
+
+ <networking> (DLSw) A standard for transporting {IBM} {Systems
+ Network Architecture} (SNA) and {network basic input/output
+ system} (NetBIOS) traffic over an {Internet protocol} network.
+
+ Initially, in 1992, DLSw was proprietary to IBM. It was
+ submitted to the {IETF} as {RFC 1434} in 1993, later updated
+ by {RFC 1795}.
+
+ {(http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/dlsw.htm)}.
+
+ (2008-01-11)
+
+data logger
+
+ {data logging}
+
+data logging
+
+ <data> (data acquisition) Storing a series of measurements
+ over time, usually from a sensor that converts a physical
+ quantity such as temperature, pressure, relative humidity,
+ light, resistance, current, power, speed, vibration into a
+ voltage that is then converted by a {digital to analog
+ converter} (DAC) into a binary number. Data logging hardware
+ may have several DACs for multiple simultaneous measurements.
+ The hardware usually connects to a {parallel port}, {serial
+ port} or {USB} port on a {PC}.
+
+ (2004-11-15)
+
+Data Management Language
+
+ <language> (DML)
+
+ 1. Any language for manipulating data or files,
+ e.g. {IBM}'s {Distributed Data Management} (DDM).
+
+ 2. An early {ALGOL}-like language with lists and graphics,
+ that ran on the {Honeywell 635}.
+
+ ["DML: A Data Management Language", D.W. Bray et al, GE,
+ Syracuse NY].
+
+ (1999-06-07)
+
+Data Manipulation Language
+
+ <language, database> (DML, or {Data Management Language}) A
+ language for the manipulation of data in a {database} by
+ applications and/or directly by end-users.
+
+ {SQL} contains DML commands such as INSERT, UPDATE, and
+ DELETE.
+
+ See also {Data Definition Language} (DDL).
+
+ (1999-04-26)
+
+data mart
+
+ <database> A type of {data warehouse} designed primarily to
+ address a specific function or department's needs, as opposed
+ to a data warehouse which is traditionally meant to address
+ the needs of the organisation from an enterprise perspective.
+ In addition, a data mart often uses {aggregation} or
+ summarisation of the data to enhance query performance.
+ However, it is important to maintain the ability to access the
+ underlying base data to enable {drill-down analysis} as
+ necessary.
+
+ (1998-04-24)
+
+Datamatic Corporation
+
+ {Honeywell}
+
+Datamation
+
+ /day"t*-may"sh*n/ A magazine that many hackers assume all
+ {suits} read. Used to question an unbelieved quote, as in
+ "Did you read that in "Datamation?"" It used to publish
+ something hackishly funny every once in a while, like the
+ original paper on {COME FROM} in 1973, and Ed Post's "Real
+ Programmers Don't Use Pascal" ten years later, but it has
+ since become much more exclusively {suit}-oriented and boring.
+
+ [{Jargon File}]
+
+data mining
+
+ <database> Analysis of data in a {database} using tools which
+ look for trends or anomalies without knowledge of the meaning
+ of the data. Data mining was invented by {IBM} who hold some
+ related patents.
+
+ Data mining may well be done on a {data warehouse}.
+
+ {ShowCase STRATEGY (http://showcasecorp.com/)} is an
+ example of a data mining tool.
+
+ (2001-02-08)
+
+data model
+
+ <database> The product of the {database} design process which
+ aims to identify and organize the required data logically and
+ physically.
+
+ A data model says what information is to be contained in a
+ database, how the information will be used, and how the items
+ in the database will be related to each other.
+
+ For example, a data model might specify that a customer is
+ represented by a customer name and credit card number and a
+ product as a product code and price, and that there is a
+ one-to-many relation between a customer and a product.
+
+ It can be difficult to change a database layout once code has
+ been written and data inserted. A well thought-out data model
+ reduces the need for such changes. Data modelling enhances
+ application maintainability and future systems may re-use
+ parts of existing models, which should lower development
+ costs.
+
+ A data modelling language is a mathematical formalism with a
+ notation for describing data structures and a set of
+ operations used to manipulate and validate that data.
+
+ One of the most widely used methods for developing data models
+ is the {entity-relationship model}. The {relational model} is
+ the most widely used type of data model. Another example is
+ {NIAM}.
+
+ ["Principles of Database and Knowledge-Base Systems",
+ J.D. Ullman, Volume I, Computer Science Press, 1988, p. 32].
+
+ (2000-06-24)
+
+data modeling
+
+ <spelling> US spelling of "{data model}ling".
+
+ (2000-06-24)
+
+data modelling
+
+ {data model}
+
+Data Over Cable Service Interface Specification
+
+ <communications, networking> (DOCSIS) {ITU}-approved interface
+ requirements for {cable modems} involved in high-speed data
+ distribution over a {cable television} network. DOCSIS
+ compatible equipment uses a 6 MHz {carrier} band for
+ {downstream}, using 64 and 256 {QAM} (ITU Annex B), and {QPSK}
+ and 16 QAM for {upstream}, allowing up to 36 and 10 Mb/s,
+ respectively for downstream and upstream channels.
+
+ {CableLabs FAQ (http://cablemodem.com/FAQs.html)}.
+
+ (2001-07-10)
+
+Data Over Cable Systems Interface Specifications
+
+ {Data Over Cable Service Interface Specification}
+
+data packet
+
+ {packet}
+
+Dataparallel-C
+
+ <language, parallel> {C} with {parallel} extensions by Hatcher
+ and Quinn of the University of New Hampshire. Dataparallel-C
+ was based on an early version of {C*} and runs on the {Intel}
+ {iPSC-2} and {nCube}.
+
+Data Parallel Haskell
+
+ <language, parallel> Adds Parallel Objects with arbitrary
+ Dimension (PODs) and POD comprehensions to Haskell.
+
+ {(ftp://redstar.dcs.qmw.ac.uk/cpc/jon_hill/dpGlue.ps.Z)}.
+
+ ["Data Parallel Haskell: Mixing Old and New Glue", J. Hill].
+
+ (1995-03-30)
+
+data path
+
+ <architecture> A {CPU}'s internal {data bus} and {functional
+ units}. The width of the data path in bits is a major
+ determiner of the processor's performance.
+
+ (1997-07-09)
+
+Dataphone Digital Service
+
+ <communications, product> (DDS) The first private-line digital
+ service offered by {AT&T}, with data rates typically at 2.4,
+ 4.8, 9.6 and 56 kilobits per second. DDS is now part of
+ AT&T's {Accunet} family of services. Most LEC (local exchange
+ carriers) and IXC (IntereXchange Carriers) offer similar
+ services.
+
+ (1995-02-28)
+
+DataPoint
+
+ <company> An early {minicomputer} manufacturer which also
+ developed {ARCnet}.
+
+ (2004-08-25)
+
+data processing
+
+ <application> The input, verification, organisation, storage,
+ retrieval, transformation, and extraction of {information}
+ from {data}. The term is normally associated with commercial
+ applications such as stock control or payroll.
+
+ (1995-03-30)
+
+Data Protection Act
+
+ <legal> (DPA) A UK law guaranteeing rights to individuals in
+ relation to personal data that others hold on them. For
+ example, under the DPA, you have the right to see what data a
+ company holds on you.
+
+ (2007-06-17)
+
+data rate
+
+ {data transfer rate}
+
+data redundancy
+
+ <data, communications, storage> Any technique that stores or
+ transmits extra, derived data that can be used to detect or
+ repair errors, either in hardware or software. Examples are
+ {parity bits} and the {cyclic redundancy check}.
+
+ If the cost of errors is high enough, e.g. in a
+ {safety-critical system}, redundancy may be used in both
+ hardware AND software with three separate computers programmed
+ by three separate teams ("triple redundancy") and some system
+ to check that they all produce the same answer, or some kind
+ of majority voting system.
+
+ The term is not typically used for other, less beneficial,
+ duplication of data.
+
+ 2. <communications> The proportion of a message's gross
+ information content that can be eliminated without losing
+ essential information.
+
+ Technically, redundancy is one minus the ratio of the actual
+ uncertainty to the maximum uncertainty. This is the fraction
+ of the structure of the message which is determined not by the
+ choice of the sender, but rather by the accepted statistical
+ rules governing the choice of the symbols in question.
+
+ [Shannon and Weaver, 1948, p. l3]
+
+ (2010-02-04)
+
+data segment
+
+ <memory> The range of memory locations where the {initialised
+ data} of a program produced by a {Unix} {linker} is located.
+
+ Executable code is located in the {code segment} and
+ uninitialised data in the {bss segment}.
+
+ (2004-02-24)
+
+data service unit
+
+ <communications> (DSU or "data service unit") A device used in
+ digital transmission for connecting a CSU (Channel Service
+ Unit) to {Data Terminal Equipment} (a terminal or computer),
+ in the same way that a {modem} is used for connection to an
+ analogue medium.
+
+ A DSU provides a standard interface to a user's terminal which
+ is compatible with {modems} and handles such functions as
+ signal translation, regeneration, reformatting, and timing.
+ The transmitting portion of the DSU processeses the customers'
+ signal into bipolar pulses suitable for transmission over the
+ digital facility. The receiving portion of the DSU is used
+ both to extract timing information and to regenerate mark and
+ space information from the received {bipolar} signal.
+
+ (1995-01-30)
+
+data set
+
+ <operating system, storage> An {IBM} term for a {file}.
+
+ (1997-04-15)
+
+data set organization
+
+ <operating system, storage> (DSORG) An {IBM} term for {file}
+ structure. These include PS {physical sequential}, DA {direct
+ access}, IS {indexed sequential}, PO {partitioned} (a
+ library). This system dates from {OS/360}, and breaks down
+ beginning with {VSAM} and {VTAM}, where it is no longer
+ applied.
+
+ Sequential and indexed data sets can be accessed using either
+ a "basic" or a "queued" "access method." For example a
+ DSORG=PS file can use either BSAM (basic sequential access
+ method) or QSAM (queued sequential access method). It can
+ also be processed as a {direct file} using BDAM. Likewise a
+ library can be processed using BPAM (basic partitioned access
+ method), BSAM, QSAM, or BDAM. DSORG and access method are
+ somewhat, but not completely, orthogonal.
+
+ The "basic" access method deals with {physical blocks} rather
+ than {records}, and usually provides more control over the
+ specific {device}. Each I/O operation using the "basic"
+ access method reads or writes a single block. A "basic" read
+ or write starts an {asynchronous} I/O operation, and the
+ programmer is responsible for waiting for completion and
+ checking for errors.
+
+ The "queued" access method deals with {logical records} and
+ provides blocking and deblocking services. It is "queued"
+ because it provides {read-ahead} and {write-behind} services.
+ While a program is processing records in one input block, for
+ example, QSAM may be reading one or more blocks ahead. Queued
+ "get" or "put" operations are synchronous as far as the
+ programmer is concerned. The operation is complete when the
+ next logical record has been successfully processed.
+
+ EXCP ({Execute Channel Program}) is a lower-level method of
+ accessing data.
+
+ IBM manuals usually named "Data Administration Guide",
+ e.g. SC26-4505-1 for MVS/ESA DFP 3.1, provide more detail
+ about data set organizations and access methods.
+
+ (2005-08-08)
+
+DataStage
+
+ <database, tool> A tool set for designing, developing, and
+ running {applications} that populate one or more {tables} in a
+ {data warehouse} or {data mart}.
+
+ [Reference]?
+
+ (2004-06-23)
+
+Datastorm Technologies, Inc.
+
+ <company> The original suppliers of {Procomm}.
+
+ Address: Columbia MO, USA.
+
+ (2004-06-29)
+
+data striping
+
+ <storage> Segmentation of logically {sequential} data, such as
+ a single file, so that segments can be written to multiple
+ physical devices (usually {disk drives}) in a {round-robin}
+ fashion. This technique is useful if the processor is capable
+ of reading or writing data faster than a single disk can
+ supply or accept it. While data is being transferred from the
+ first disk, the second disk can locate the next segment.
+
+ Data striping is used in some modern {databases}, such as
+ {Sybase}, and in certain {RAID} devices under hardware
+ control, such as {IBM}'s {RAMAC} array subsystem (9304/9395).
+
+ Data striping is different from, and may be used in
+ conjunction with, {mirroring}.
+
+ (1996-10-17)
+
+data structure
+
+ <data, programming> Any method of organising a collection of
+ {data} to allow it to be manipulated effectively. It may
+ include {meta} data to describe the properties of the
+ structure.
+
+ Examples data structures are: {array}, {dictionary}, {graph},
+ {hash}, {heap}, {linked list}, {matrix}, {object}, {queue},
+ {ring}, {stack}, {tree}, {vector}.
+
+ (2003-09-11)
+
+Data Structures Language
+
+ <language> A dialect of {MAD} with extensions for lists and
+ graphics, on {Philco 212}.
+
+ ["A Compiler Language for Data Structures", N. Laurance, Proc
+ ACM 23rd Natl Conf 36 (1968)].
+
+ (1995-02-28)
+
+Data Terminal Equipment
+
+ <communications, hardware> (DTE) A device which acts as the
+ source and/or destination of data and which controls the
+ communication channel. DTE includes terminals, computers,
+ {protocol converters}, and {multiplexors}.
+
+ DTE is usually connected via an {EIA-232} {serial line} to
+ {Data Communication Equipment} (DCE), typically a {modem}. It
+ is necessary to distinguish these two types of device because
+ their connectors must be wired differently if a
+ "straight-through" cable (pin 1 to pin 1, pin 2 to pin 2 etc.)
+ is to be used. DTE should have a male connector and should
+ transmit on pin three and receive on pin two. It is a curious
+ fact that many {modems} are actually "DTE" according to the
+ original standard.
+
+ (1995-02-28)
+
+Data Terminal Ready
+
+ <communications> (DTR) The wire in a full {RS-232} connection
+ that tells the {Data Communication Equipment} (DCE, typically
+ a {modem}) that the {Data Terminal Equipment} (DTE, typically
+ a computer or {terminal}) is ready to transmit and receive
+ data.
+
+ (2000-04-05)
+
+DATA-TEXT
+
+ <tool> A system from {Harvard} for numerical computations in
+ the Social Sciences.
+
+ ["DATA-TEXT Primer", D.J. Armor, Free Press 1972].
+
+ (1994-12-06)
+
+data transfer
+
+ <data> Copying or moving {data} from one place to another,
+ typically via some kind of {network} (e.g. {Asynchronous
+ Transfer Mode}, {File Transfer Protocol}) or local data
+ connection ({bus}, {SCSI}, {IDE}, {SATA}).
+
+ (2009-06-09)
+
+data transfer rate
+
+ <communications> (Or "throughput, data rate", "transmission
+ rate") The amount of {data} transferred in one direction over
+ a link divided by the time taken to transfer it, usually
+ expressed in bits per second (bps), bytes per second (Bps) or
+ {baud}. The link may be anything from an interface to a {hard
+ disk} to a radio transmission from a satellite.
+
+ Where data transfer is not continuous throughout the given
+ time interval, the data transfer rate is thus an average rate
+ that will be lower than the peak rate. The peak or maximum
+ possible rate may itself be lower than the {capacity} of the
+ communication channel if the channel is shared, or part of the
+ signal is not considered as data, e.g. {checksum} or {routing}
+ information.
+
+ When applied to data rate, the multiplier {prefixes} "kilo-",
+ "mega-", "giga-", etc. (and their abbreviations, "k", "M",
+ "G", etc.) always denote powers of 1000. For example, 64 kbps
+ is 64,000 bits per second. This contrasts with units of
+ {storage} where they stand for powers of 1024, e.g. 1 KB =
+ 1024 bytes.
+
+ The other important characteristic of a channel is its
+ {latency}.
+
+ The {bandwidth} of a channel determines the data transfer rate
+ but is a different characteristic, measured in {Hertz}.
+ [Relationship?]
+
+ (2008-02-08)
+
+DATATRIEVE
+
+ <database, language> A query and report system for use with
+ {DEC}'s {VMS} ({RMS}, {VAX Rdb}/VMS or {VAX DBMS}).
+
+ (2007-01-16)
+
+Datatron 200 series
+
+ <computer> A family of computers produced by {Burroughs} that
+ included the {Datatron 204} and {Datatron 220}.
+
+ (2007-01-16)
+
+data type
+
+ {type}
+
+DataViews
+
+ {Graphical user interface} development software from
+ {V.I.Corporation}, aimed at constructing
+ {platform}-independent interactive views of dynamic data.
+
+ (1994-12-07)
+
+DataVis
+
+ A {dataflow} language for scientific {visualisation}.
+
+ ["Data Flow Visual Programming Languages", D. Hils, J Vis
+ Langs and Comput, Dec 1991].
+
+ (1994-12-06)
+
+data warehouse
+
+ <database> (Or corporate data warehouse, CDW) Any system for
+ storing, retrieving and managing large amounts of data. Data
+ warehouse software often includes sophisticated {compression}
+ and {hashing} techniques for fast searches, as well as
+ advanced filtering. A data warehouse is often a {relational
+ database} containing a recent snapshot of corporate data and
+ optimised for searching. Planners and researchers can use
+ this database without worrying about slowing down day-to-day
+ operations of the production database. The latter can be
+ optimised for transaction processing (inserts and updates).
+
+ Compare {data mart}.
+
+ (2007-05-16)
+
+data warehousing
+
+ {data warehouse}
+
+date
+
+ <convention, data> A string unique to a time duration of 24
+ hours between 2 successive midnights defined by the local time
+ zone. The specific representation of a date will depend on
+ which calendar convention is in force; e.g., Gregorian,
+ Islamic, Japanese, Chinese, Hebrew etc. as well as local
+ ordering conventions such as UK: day/month/year, US:
+ month/day/year.
+
+ Inputting and outputting dates on computers is greatly
+ complicated by these {localisation} issues which is why they
+ tend to operate on dates internally in some unified form such
+ as seconds past midnight at the start of the first of January
+ 1970.
+
+ Many software and hardware representations of dates allow only
+ two digits for the year, leading to the {year 2000} problem.
+
+ {Unix manual page}: date(1), ctime(3).
+
+ (1997-07-11)
+
+DAU
+
+ /dow/ [German Fidonet] D"ummster Anzunehmender User. A German
+ acronym for stupidest imaginable user. From the
+ engineering-slang GAU for Gr"osster Anzunehmender Unfall
+ (worst foreseeable accident), especially of a LNG tank farm
+ plant or something with similarly disastrous consequences. In
+ popular German, GAU is used only to refer to worst-case
+ nuclear accidents such as a core meltdown.
+
+ See {cretin}, {loser} and {weasel}.
+
+ [{Jargon File}]
+
+ (1994-12-06)
+
+daughter
+
+ <mathematics, data> (Or "child", "successor") In a {tree}, a
+ {node} pointed to by a {parent}, i.e. another node closer to
+ the {root node}.
+
+ (1998-11-14)
+
+daughterboard
+
+ <hardware> (Or "daughter board", "daughtercard", "daughter
+ card") A {printed circuit board} that connects to the
+ {motherboard}. The daughterboard is typically smaller than
+ the motherboard.
+
+ A daughterdboard often adds to or supports the main functions
+ of the {motherboard}, unlike an {expansion card} which
+ provides some new function. For example, a post-release
+ hardware modification might be released as a daughterboard for
+ soldering onto the {motherboard}.
+
+ (2004-09-28)
+
+daughtercard
+
+ {daughterboard}
+
+David Turner
+
+ <person> Professor David A Turner. One of the pioneers of
+ {functional languages}. He designed several languages,
+ including, {SASL} (1976), {KRC} (1981), and {Miranda}, many of
+ which were implemented using {combinators} and the {S-K
+ reduction machine} which he defined.
+
+ He coined the name "{ZF expression}" for the {list
+ comprehension}.
+
+ He worked at UKC and set up a company, {Research Software
+ Limited} to market {Miranda}.
+
+ (1994-12-06)
+
+day mode
+
+ {phase}
+
+DAZIX
+
+ Daisy/Cadnetix Corporation.
+
+ A supplier of digital electronic {CAE} systems.
+
+ (1994-12-06)
+
+DB
+
+ {database}
+
+DB2
+
+ <database> A {relational database} from {IBM}.
+
+ When running under IBM's MVS ({Multiple Virtual Storage})
+ {operating system}, DB2 is implemented on top of {VSAM} and
+ uses its underlying data structures.
+
+ DB2, later called "DB2 Universal DataBase", also runs under
+ {windows NT}, {AIX}, {Solaris} and, most recently, {Linux}.
+
+ [Details? Was there a "DB1"?]
+
+ (1999-02-01)
+
+DB-25
+
+ <hardware> The standard 25-pin {D-shell connector} used for
+ {EIA-232} serial communication.
+
+ {DE-9} is a common alternative.
+
+ (1996-12-08)
+
+DB2 catalog
+
+ <database> An {IBM} {DB2} {system table} listing all objects in a
+ database installation including hosts, servers, databases, tables
+ and many more. Commands are provided to manage the catalog, e.g.
+
+ db2 catalog database mydatabase on /databases/mydatabase
+
+ to add a database reference.
+
+ {Catalog documentation
+ (http://www-01.ibm.com/support/knowledgecenter/SSEPGG_9.7.0/com.ibm.db2.luw.sql.ref.doc/doc/r0011297.html)}.
+
+ (2014-08-16)
+
+DBA
+
+ {database administrator}
+
+dBASE
+
+ <tool, product, language> An interactive {DBMS}, originally
+ from {Ashton-Tate Corporation}, and the language used by it.
+
+ dBASE evolved from {Vulcan} by Wayne Ratliffe, which came out
+ in around 1980 and ran on CP/M. It was called dBaseII when
+ sold to {Ashton-Tate Corporation}.
+
+ The first release was dBASE II, ca 1980. There never was a
+ "dBASE I". Later versions included: {dBASE III}, dBASE III+,
+ and dBASE IV.
+
+ Ashton-Tate was taken over in the early 1990s by what became
+ {Borland Software Corporation} who sold dBase in March(?)
+ 1999 to the newly formed dBase Inc. dBase Inc's first release
+ was {Visual dBASE} 5.7, a Y2K upgrade to Visual dBASE 5.x.
+
+ Current version, as of 2003-11-24: dBASE PLUS 2.0x build 1703.
+
+ {dBase Home (http://dbase.com/)}.
+
+ (2003-11-24)
+
+DBC
+
+ <language, parallel> A {data-parallel} {bit-serial} {C} based
+ on {MPL}. SRC, Bowie MD.
+
+ E-mail: <maya@super.org>.
+
+ (1995-05-01)
+
+DBCS
+
+ <character> (IBM) double-byte character set.
+
+ A {character set} that uses 16 bits to represent a character.
+
+ (1995-03-21)
+
+dBFAST
+
+ {dBASE} dialect for {MS-DOS} and {MS-Windows}.
+
+DBH
+
+ {Denis Howe}
+
+DBMS
+
+ {database management system}
+
+DBPL
+
+ <language, database> A {procedural language} with {relational
+ database} constructs. A successor to {Pascal/R} and
+ {Modula/R}.
+
+ ["DBPL Report", J.W. Schmidt et al, DBPL-Memo 111-88,
+ Fachbereich Informatik, Johann Wolfgang Goethe-Universitaet,
+ Frankfurt, Germany, 1988].
+
+ (1994-12-07)
+
+DBRI
+
+ {Dual Basic Rate Interface}
+
+dbx
+
+ <programming> A {source-level debugger} originating from {BSD
+ Unix} but now available for many other {Unix} distributions.
+
+ {Sun documentation
+ (http://developers.sun.com/sunstudio/documentation/ss12/mr/man1/dbx.1.html)}.
+
+ (2009-04-27)
+
+dBXL
+
+ A {dBASE}-like {interpreter}/language for {MS-DOS} from
+ {WordTech}, Orinda, CA.
+
+ (1994-12-07)
+
+DC
+
+ <language, tool> The {Unix} {arbitrary precision} {postfix}
+ calculator and its language.
+
+ Here is an example program which prints out {factorials}:
+
+ echo "[la1+dsa*pla2220>y]sy0sa1lyx" | dc
+
+ {Unix manual page}: dc(1).
+
+ {bc} provides a somewhat more readable syntax which is
+ compiled into dc. There is also a {GNU DC}.
+
+ (1995-03-17)
+
+DC1
+
+ {control-Q}
+
+DC2
+
+ {Device Control 2}
+
+DC3
+
+ {Control-S}
+
+DC4
+
+ {Device Control 4}
+
+DCA
+
+ 1. Defense Communications Agency. See {DISA}.
+
+ 2. {Document Content Architecture} from {IBM}.
+
+DCAC
+
+ {Domestic Communications Assistance Center}
+
+DCALGOL
+
+ Data Communications ALGOL. A superset of {Burroughs Extended
+ ALGOL} used for writing Message Control Systems.
+
+DCC
+
+ 1. <audio> {Digital Compact Cassette}.
+
+ 2. <networking> {Direct Client to Client Protocol}.
+
+ (2001-12-02)
+
+DCDL
+
+ Digital Control Design Language. A language for simulating
+ computer systems.
+
+ ["DCDS Digital Simulating System", H. Potash et al, Proc FJCC
+ 35, AFIPS (Fall 1969)].
+
+DCE
+
+ 1. {Data Communication Equipment}.
+
+ 2. Data Circuit-terminating Equipment.
+
+ 3. {Distributed Computing Environment} from {OSF}.
+
+DCG
+
+ {Definite Clause Grammar}
+
+DCI
+
+ {Display Control Interface}
+
+DCL
+
+ 1. DIGITAL Command Language. The interactive command and
+ scripting language for VAX/VMS.
+
+ 2. Delphi Common LISP. An implementation of Common LISP that
+ has been used as a basis for CLOS.
+
+DCOM
+
+ {Distributed Component Object Model}
+
+DCP
+
+ {definitional constraint programming}
+
+D. C. Power Lab
+
+ The former site of {SAIL}. This name was very funny because
+ the obvious connection to electrical engineering was
+ nonexistent - the lab was named after a Donald C. Power.
+ Compare {Marginal Hacks}.
+
+ [But did DCP's parents realise the joke?]
+
+ [{Jargon File}]
+
+DCS
+
+ 1. {Digital Cellular System}.
+
+ 2. {Digital Control System}.
+
+DCT
+
+ {Discrete Cosine Transform}
+
+DD
+
+ 1. <storage> {double density}.
+
+ 2. <database> {data dictionary}.
+
+ 3. <programming> {Deployment Descriptor}.
+
+ (2005-01-26)
+
+dd
+
+ A {Unix} copy command with special options suitable for
+ block-oriented devices; it was often used in heavy-handed
+ system maintenance, as in "Let's "dd" the {root partition}
+ onto a tape, then use the {boot PROM} to load it back on to a
+ new disk".
+
+ dd had a distinctly non-Unixy keyword option syntax
+ reminiscent of {IBM} {System/360} JCL (which had an elaborate
+ DD "Dataset Definition" specification for I/O devices).
+ Though the command filled a need, the interface design was
+ clearly a prank.
+
+ [{Jargon File}]
+
+ (2005-08-08)
+
+DDB
+
+ {device independent bitmap}
+
+DDCMP
+
+ {Digital Data Communications Message Protocol} ({DEC}).
+
+DDE
+
+ {Dynamic Data Exchange}
+
+DDE Manager
+
+ An {Oracle} product that lets {Microsoft Windows}
+ applications that support the {Dynamic Data Exchange} (DDE)
+ {protocol} act as front end tools for Oracle. It allows
+ applications like {Excel}, {Word}, {Ami Professional}, {WingZ}
+ and {ToolBook} to query, update, graph and report information
+ stored in Oracle.
+
+DDIF
+
+ Digital Document Interchange Format. A CDA specification for
+ representing compound documents in revisable format; a DEC
+ standard for document encoding.
+
+DDL
+
+ 1. ["A Digital System Design Language (DDL)", J.R. Duley, IEEE
+ Trans on Computers c-17(9), pp. 850-861, Sep 1968].
+
+ 2. <language, games> An {adventure} language developed by
+ M. Urban, C. Kostanick et al of the {UCLA} Computer Club. DDL
+ was the forerunner of {ADL}.
+
+ 3. {Data Definition Language}.
+
+ 4. {Document Description Language}.
+
+ 5. {Dynamic Data Exchange}. (Originally "Linking").
+
+ (1997-06-05)
+
+DDM
+
+ 1. <protocol, database> {Distributed Data Management}.
+
+ 2. <language> {Data Driven Machine}.
+
+ (1999-06-07)
+
+DDN
+
+ {Defense Data Network}
+
+DDO
+
+ {Dynamic Drive Overlay}
+
+DDP
+
+ {Distributed Data Processing}
+
+DDR
+
+ {Double Data Rate Random Access Memory}
+
+DDR-RAM
+
+ {Double Data Rate Random Access Memory}
+
+DDR-SDRAM
+
+ {Double Data Rate Random Access Memory}
+
+DDS
+
+ 1. {Digital Data Service}.
+
+ 2. {Digital Data System}.
+
+ 3. {Dataphone Digital Service}.
+
+DDT
+
+ 1. Generic term for a program that assists in debugging other
+ programs by showing individual {machine instructions} in a
+ readable symbolic form and letting the user change them. In
+ this sense the term DDT is now archaic, having been widely
+ displaced by "debugger" or names of individual programs like
+ "{adb}", "{sdb}", "{dbx}", or "{gdb}".
+
+ 2. Under {MIT}'s fabled {ITS} {operating system}, DDT (running
+ under the alias HACTRN) was also used as the {shell} or top
+ level command language used to execute other programs.
+
+ 3. Any one of several specific debuggers supported on early
+ {DEC} hardware. The {DEC} {PDP-10} Reference Handbook (1969)
+ contained a footnote on the first page of the documentation
+ for DDT that illuminates the origin of the term:
+
+ Historical footnote: DDT was developed at {MIT} for the
+ {PDP-1} computer in 1961. At that time DDT stood for "DEC
+ Debugging Tape". Since then, the idea of an on-line debugging
+ program has propagated throughout the computer industry. DDT
+ programs are now available for all DEC computers. Since media
+ other than tape are now frequently used, the more descriptive
+ name "Dynamic Debugging Technique" has been adopted, retaining
+ the DDT abbreviation. Confusion between DDT-10 and another
+ well known pesticide, dichloro-diphenyl-trichloroethane
+ (C14-H9-Cl5) should be minimal since each attacks a different,
+ and apparently mutually exclusive, class of bugs.
+
+ (The "tape" referred to was, incidentally, not magnetic but
+ paper.) Sadly, this quotation was removed from later editions
+ of the handbook after the {suits} took over and DEC became
+ much more "businesslike".
+
+ The history above is known to many old-time hackers. But
+ there's more: Peter Samson, compiler of the original {TMRC}
+ lexicon, reports that he named "DDT" after a similar tool on
+ the {TX-0} computer, the direct ancestor of the PDP-1 built at
+ {MIT}'s Lincoln Lab in 1957. The debugger on that
+ ground-breaking machine (the first transistorised computer)
+ rejoiced in the name FLIT (FLexowriter Interrogation Tape).
+
+ [{Jargon File}]
+
+DDW
+
+ {distributed data warehouse}
+
+de
+
+ <networking> The {country code} for Germany.
+
+ (1999-01-27)
+
+DE-9
+
+ <hardware> The standard 9-pin {D-shell connector} used for
+ {EIA-232} serial communication. DE-9 is a common alternative
+ to {DB-25}, especially on {personal computers}.
+
+ (1999-12-08)
+
+DEA
+
+ {Data Encryption Algorithm}
+
+DEACON
+
+ Direct English Access and CONtrol. English-like query system.
+ Sammet 1969, p.668.
+
+dead
+
+ 1. Non-functional; {down}; {crash}ed. Especially used of
+ {hardware}.
+
+ 2. At {XEROX PARC}, software that is working but not
+ undergoing continued development and support.
+
+ [{Jargon File}]
+
+DEADBEEF
+
+ <convention, storage> /ded-beef/ The {hexadecimal} pattern
+ used to fill words of freshly allocated memory under a number
+ of {IBM} environments including the {RS/6000}; equal to
+ decimal 3,735,928,559 (unsigned) or -559,038,737 (32-bit
+ signed). As in "Your program is DEADBEEF" (meaning gone,
+ aborted, flushed from memory).
+
+ (1998-06-29)
+
+dead code
+
+ <programming> (Or "infeasible path", "{grunge}") Any part of a
+ program that can never be accessed because all calls to it
+ have been removed, or because it is guarded by a control
+ structure that provably must always transfer control somewhere
+ else. The presence of dead code may reveal either logical
+ errors due to alterations in the program or significant
+ changes in the assumptions and environment of the program (see
+ also {software rot}); a good compiler should report dead code
+ so a maintainer can think about what it means. Sometimes it
+ simply means that an *extremely* defensive programmer has
+ inserted {can't happen} tests which really can't happen - yet.
+
+ Synonym {grunge}.
+
+ [{Jargon File}]
+
+ (1996-05-22)
+
+deadlock
+
+ <parallel, programming> A situation where two or more
+ {processes} are unable to proceed because each is waiting for
+ one of the others to do something.
+
+ A common example is a program waiting for output from a server
+ while the server is waiting for more input from the
+ controlling program before outputting anything. It is
+ reported that this particular flavour of deadlock is sometimes
+ called a "starvation deadlock", though the term "starvation"
+ is more properly used for situations where a program can never
+ run simply because it never gets high enough priority.
+
+ Another common flavour is "constipation", in which each
+ process is trying to send stuff to the other but all buffers
+ are full because nobody is reading anything). See {deadly
+ embrace}.
+
+ Another example, common in {database} programming, is two
+ processes that are sharing some resource (e.g. read access to
+ a {table}) but then both decide to wait for exclusive
+ (e.g. write) access.
+
+ The term "deadly embrace" is mostly synonymous, though usually
+ used only when exactly two processes are involved. This is
+ the more popular term in Europe, while {deadlock} predominates
+ in the United States.
+
+ Compare: {livelock}. See also {safety property}, {liveness
+ property}.
+
+ [{Jargon File}]
+
+ (2000-07-26)
+
+deadly embrace
+
+ {deadlock}
+
+dead tree
+
+ <publication, jargon> Paper.
+
+ Use of this term emphasises the waste of natural resources and
+ limited features available from the printed form of a document
+ compared with an electronic rendition.
+
+ E.g. "I read the dead tree edition of the {Guardian
+ (http://guardian.co.uk/)} on the train".
+
+ See also {tree-killer}.
+
+ (1999-11-03)
+
+dead tree edition
+
+ {dead tree}
+
+deamon
+
+ <spelling> It's spelled "{daemon}".
+
+ (1996-12-13)
+
+death code
+
+ A routine whose job is to set everything in the computer -
+ {registers}, memory, flags - to zero, including that portion
+ of memory where it is running; its last act is to stomp on its
+ own "store zero" instruction. Death code isn't very useful,
+ but writing it is an interesting hacking challenge on
+ architectures where the instruction set makes it possible,
+ such as the {PDP-8} or the {Data General} {Nova}.
+
+ Perhaps the ultimate death code is on the {TI 990} series,
+ where all {registers} are actually in {RAM}, and the
+ instruction "store immediate 0" has the {opcode} 0. The
+ {program counter} will immediately wrap around core as many
+ times as it can until a user hits HALT. Any empty memory
+ location is death code. Worse, the manufacturer recommended
+ use of this instruction in startup code (which would be in
+ {ROM} and therefore survive).
+
+ [{Jargon File}]
+
+Death Star
+
+ ["Star Wars" film] 1. The AT&T corporate logo, which appears
+ on computers sold by AT&T and bears an uncanny resemblance to
+ the Death Star in the movie. This usage is particularly
+ common among partisans of {BSD} Unix, who tend to regard the
+ AT&T versions as inferior and AT&T as a bad guy. Copies still
+ circulate of a poster printed by Mt. Xinu showing a starscape
+ with a space fighter labelled {4.2BSD} streaking away from a
+ broken AT&T logo wreathed in flames.
+
+ 2. AT&T's internal magazine, "Focus", uses "death star" to
+ describe an incorrectly done AT&T logo in which the inner
+ circle in the top left is dark instead of light - a frequent
+ result of dark-on-light logo images.
+
+deb
+
+ <filename extension, Debian> The {filename extension} for a
+ {Debian} {binary package}.
+
+ (2001-01-27)
+
+Debbugs
+
+ <programming> The {bug tracking system} used by the {Debian}
+ Project. Each bug is given a number, and is kept on file
+ until it is marked as having been dealt with. The system is
+ mainly controlled by {electronic mail}, but the bug reports
+ can be viewed via the {web}.
+
+ {Debbugs home (http://debian.org/Bugs/)}.
+
+ (2002-06-12)
+
+Debian
+
+ <operating system> /deb'ee`n/, *not* /deeb'ee`n/ The
+ non-profit volunteer organisation responsible for Debian
+ {GNU}/{Linux} and Debian {GNU}/{Hurd}. Debian's {Linux}
+ distribution is dedicated to free and {open source} software;
+ the main goal of the distribution is to ensure that one can
+ download and install a fully-functional {operating system}
+ that is completely adherent to the Debian Free Software
+ Guidelines (DFSG).
+
+ Debian was begun in August 1993 by Ian Murdock, and was
+ sponsored by the {Free Software Foundation} from November 1994
+ to November 1995. The name Debian is a contraction of DEB(ra)
+ and IAN Murdock.
+
+ Debian's packaging system (dpkg) is similar to other popular
+ packaging systems like {RPM}. There are over 2200 packages of
+ precompiled software available in the main (free) section of
+ the Debian 2.1 distribution alone -- this is what sets Debian
+ apart from many other Linux distributions. The high quality
+ and huge number of official packages (most Debian systems'
+ /usr/local/ remains empty -- almost everything most Linux
+ users want is officially packaged) are what draw many people
+ to use Debian.
+
+ Another unique aspect to the Debian project is the open
+ development; pre-releases are made available from Day 1 and if
+ anyone wishes to become a Debian developer, all that is needed
+ is proof of identification and a signed {PGP} or {GPG} key.
+ There are over 400 Debian developers all around the world --
+ many developers have never met face-to-face, and most
+ development talks take place on the many {mailing lists} and
+ the {IRC} network.
+
+ {(http://debian.org/)}.
+
+ {Debian Linux archives (ftp://ftp.debian.org/debian)}.
+
+ (1999-02-23)
+
+Debian GNU/Hurd
+
+ <operating system> A {GNU} distribution based on the {Hurd}
+ {kernel} instead of the more well known {Linux} kernel.
+
+ [Reference?]
+
+ (2001-12-02)
+
+Debian GNU/Linux
+
+ {Debian}
+
+debianize
+
+ <Debian> To take a {source package} and make the necessary
+ modifications to allow it to be built as a policy compliant
+ {Debian} package.
+
+ (2000-05-31)
+
+deboursification
+
+ <jargon> Removal of irrelevant {newsgroups} from the
+ Newsgroups header of a {followup}. The term applies
+ particularly to the removal of frivolous groups added by one
+ of the Kooks.
+
+ See also: {sneck}.
+
+ [Sam Spade anti-{spam} software].
+
+ (1999-09-15)
+
+De Bruijn graph
+
+ <mathematics> A class of {graphs} with elegant properties.
+
+ De Bruijn graphs are especially easy to use for {routing},
+ with shifting of source and destination addresses.
+
+ [What properties? How are they used in routing?]
+
+ (1998-04-28)
+
+De Bruijn notation
+
+ <language> A variation of {lambda notation} for specifying
+ {functions} using numbers instead of names to refer to {formal
+ parameters}. A reference to a formal parameter is a number
+ which gives the number of lambdas (written as \ here) between
+ the reference and the lambda which binds the parameter.
+ E.g. the function \ f . \ x . f x would be written \ . \ . 1
+ 0. The 0 refers to the innermost lambda, the 1 to the next
+ etc. The chief advantage of this notation is that it avoids
+ the possibility of {name capture} and removes the need for {alpha
+ conversion}.
+
+ [N.G. De Bruijn, "Lambda Calculus Notation with Nameless
+ Dummies: A Tool for Automatic Formula Manipulation, with
+ Application to the Church-Rosser Theorem", Indag Math. 34, pp
+ 381-392].
+
+ (2003-06-15)
+
+DEBUG
+
+ <software, tool> The bundled {compiler}/{assembler} for
+ {DOS}/{Windows} after {CP/M}.
+
+ [Did CP/M have "DEBUG"?]
+
+ ["DOS Power Tools, Techniques, Tricks, and Utilities, PC
+ Magazine, Paul Somerson Executive Editor, Bantam Books, 1988].
+
+ (2003-06-17)
+
+debugger
+
+ <tool, programming> A {tool} used by a {programmer} to monitor
+ and control a program he is trying to fix. The most important
+ functions of a debugger are {tracing}, stepping, {breakpoints} and
+ {watches}.
+
+ Tracing displays a step-by-step report on what {statement} the
+ program is currently executing, allowing the programmer to follow
+ the {flow of control} through {if statements}, {loops},
+ {subroutine} calls, etc.
+
+ {Breakpoints} and {watches} both pause execution of the program
+ and return control to the debugger under certain conditions. A
+ {breakpoint} triggers when execution reaches a particular
+ {statement} in the program and a {watch} triggers whenever a
+ specific variable is modified. Stepping is like a breakpoint on
+ every statement, often with the option to step "into" or "over" a
+ {subroutine}, i.e. continue stepping through the statements of the
+ subroutine or just execute it without pausing and resume stepping
+ when it returns.
+
+ Whenever control returns to the debugger it lets the programmer
+ ask to see the values of {variables}, and possibly modify them,
+ before resuming execution. Some debuggers can be set to
+ automatically perform some action like display a variable value
+ and resume.
+
+ A debugger can interact with the target program in different ways.
+ Some debuggers require the program to be loaded into the debugger
+ which may then modify or "instrument" the program for debugging.
+ Others can "attach" to a program that is already running. Some
+ are built into the normal program execution environment (e.g. an
+ {interpreter}) and can be set to run under certain conditions,
+ e.g. errors.
+
+ Early debuggers such as {Unix}'s {adb} only knew about the
+ compiled executable code so sometimes debugging had to be done at
+ the level of {machine code} instructions and numerical memory
+ locations. If you were lucky, the debugger could access the
+ program's {symbol table} and display the original names of
+ subroutines and variables. Sometimes this required the program to
+ be "compiled for debugging". Since compiling every program for
+ debugging would add significantly to the size of a {distribution}
+ of a whole {operating system}, it is common for programs to be
+ distributed without debugging support but for individual programs
+ to be made available with it.
+
+ A major advance in debuggers was source-level debugging. This
+ gives the programmer a view of their {source code} annotated with
+ breakpoints and a pointer to the statement currently being
+ executed. Such a view is commonly part of an {integrated
+ development environment} like {Visual Basic}.
+
+ (2014-08-23)
+
+debugging
+
+ <programming> The process of attempting to determine the cause of
+ the symptoms of malfunctions in a program or other system. These
+ symptoms may be detected during {testing} or use by {real users}.
+
+ Symptoms are often caused by factors outside the program, such as
+ misconfiguration of the user's {operating system},
+ misunderstanding by the user (see {PEBCAK}) or failures in other
+ external systems on which the program relies. Some of these are
+ more in the realm of {technical support} but need to be
+ eliminated. Debugging really starts when it has been established
+ that the program is not behaving according to its specification
+ (which may be formal or informal). It can be done by visual
+ inspection of the {source code}, {debugging by printf} or using a
+ {debugger}. The result may be that the program is actually
+ behaving as specified but that the spec is wrong or the
+ requirements on which it was based were deficient in some way (see
+ {BAD}).
+
+ Once a bug has been identified and a fix applied, the program must
+ be tested to determine whether the bug is really fixed and what
+ effects the changes have had on other aspects of the program's
+ operation (see {regression testing}).
+
+ The term is said to have been coined by {Grace Hopper}, based on
+ the term "{bug}".
+
+ (2006-11-27)
+
+debugging an empty file
+
+ <programming, humour> A humourous definition of {programming}
+ that considers a complete absence of any code as a {bug} to be
+ fixed.
+
+ {test-driven development} proceeds by the programmer writing
+ tests for code that doesn't exist yet, which could be
+ described as testing an empty file.
+
+ (2012-05-01)
+
+debugging by printf
+
+ <programming> The {debugging} technique where the programmer
+ inserts print statements into a program so that when run the
+ program leaves a "trail of {breadcrumbs}" allowing him to see
+ which parts were executed. The information output may just be
+ a short string to indicate that a particular point in the code
+ has been reached or it might be a complete {stack trace}. The
+ output typically just goes to the window or terminal in which
+ the program is running or may be written to a log file.
+
+ {printf} is the standard {C} print function, other languages
+ would use different names.
+
+ (2007-03-08)
+
+debugging tool
+
+ {debugger}
+
+DEC
+
+ {Digital Equipment Corporation}
+
+dec
+
+ <programming> /dek/ decrement, decrease by one. Especially
+ used by {assembly language} programmers, as many assembly
+ languages have a "dec" {mnemonic}.
+
+ Opposite: {inc}.
+
+ [{Jargon File}]
+
+DEC Alpha
+
+ <processor> A {RISC} {microprocessor} from {DEC}. In November
+ 1995, the Alpha was purportedly the fastest non-research chip
+ used in commonly available {workstations}. It is
+ {superpipelined} and {superscalar}. In February 1996 it was
+ clocked at 200 MHz and in March 1998 at 666 MHz.
+
+ (1998-03-17)
+
+decay
+
+ [Nuclear physics] An automatic conversion which is applied to
+ most array-valued expressions in {C}; they "decay into"
+ pointer-valued expressions pointing to the array's first
+ element. This term is not used in the official standard for
+ the language.
+
+ [{Jargon File}]
+
+DECdesign
+
+ A software analysis and design tool from {DEC} supporting
+ several methodologies. Now replaced by {Teamwork}.
+
+ (1994-09-05)
+
+DECdns
+
+ Distributed Naming Service.
+
+ Adopted by {OSF} as the naming service for {DCE}.
+
+DEChead
+
+ /dek'hed/ 1. A {DEC} {field servoid}. Not flattering.
+
+ 2. ["deadhead"] A Grateful Dead fan working at {DEC}.
+
+ [{Jargon File}]
+
+dechunker
+
+ {chunker}
+
+decidability
+
+ <mathematics> A property of sets for which one can determine
+ whether something is a member or not in a {finite} number of
+ computational steps.
+
+ Decidability is an important concept in {computability
+ theory}. A set (e.g. "all numbers with a 5 in them") is said
+ to be "decidable" if I can write a program (usually for a
+ {Turing Machine}) to determine whether a number is in the set
+ and the program will always terminate with an answer YES or NO
+ after a finite number of steps.
+
+ Most sets you can describe easily are decidable, but there are
+ infinitely many sets so most sets are undecidable, assuming
+ any finite limit on the size (number of instructions or number
+ of states) of our programs. I.e. how ever big you allow your
+ program to be there will always be sets which need a bigger
+ program to decide membership.
+
+ One example of an undecidable set comes from the {halting
+ problem}. It turns out that you can encode every program as a
+ number: encode every symbol in the program as a number (001,
+ 002, ...) and then string all the symbol codes together. Then
+ you can create an undecidable set by defining it as the set of
+ all numbers that represent a program that terminates in a
+ finite number of steps.
+
+ A set can also be "semi-decidable" - there is an {algorithm}
+ that is guaranteed to return YES if the number is in the set,
+ but if the number is not in the set, it may either return NO
+ or run for ever.
+
+ The {halting problem}'s set described above is semi-decidable.
+ You decode the given number and run the resulting program. If
+ it terminates the answer is YES. If it never terminates, then
+ neither will the decision algorithm.
+
+ (1995-01-13)
+
+decidable
+
+ {decidability}
+
+decimal point
+
+ <character> "." {ASCII} character 46. Common names are:
+ point; {dot}; {ITU-T}, USA: period; {ITU-T}: decimal point.
+ Rare: radix point; UK: full stop; {INTERCAL}: spot.
+
+ (1995-03-14)
+
+decision problem
+
+ <theory> A problem with a yes/no answer. Determining whether
+ some potential solution to a question is actually a solution
+ or not. E.g. "Is 43669" a {prime number}?". This is in
+ contrast to a "{search problem}" which must find a solution
+ from scratch, e.g. "What is the millionth prime number?".
+
+ See {decidability}.
+
+ (1996-05-03)
+
+decision support
+
+ Software used to aid management decision making, typically
+ relying on a {decision support database}.
+
+ [Examples?]
+
+ (1995-02-14)
+
+decision support database
+
+ A {database} from which data is extracted and analysed
+ statistically (but not modified) in order to inform business
+ or other decisions. This is in contrast to an {operational
+ database} which is being continuously updated.
+
+ For example, a decision support database might provide data to
+ determine the average salary of different types of workers,
+ whereas an operational database containing the same data would
+ be used to calculate pay check amounts.
+
+ Often, decision support data is extracted from operation
+ databases.
+
+ (1995-02-14)
+
+Decision Support Systems
+
+ <application, tool> (DSS) Software tools to help with
+ {decision support}.
+
+ (1995-02-14)
+
+decision theory
+
+ <probability> A branch of statistics concerning strategies for
+ decision making in non-{deterministic} systems. Decision
+ theory seeks to find strategies that maximise the expected
+ value of a {utility function} measuring the desirability of
+ possible outcomes.
+
+ (1995-09-22)
+
+deckle
+
+ /dek'l/ (From "dec-" and "{nibble}"; the original spelling
+ seems to have been "decle") Two {nickles}; 10 {bits}.
+ Reported among developers for {Mattel}'s {GI 1600} (the
+ {Intellivision} games processor), a chip with 16-bit wide
+ {RAM} but 10-bit wide {ROM}.
+
+ [{Jargon File}]
+
+ (1994-11-23)
+
+declarative language
+
+ <language> Any {relational language} or {functional language}.
+ These kinds of {programming language} describe relationships
+ between variables in terms of {functions} or {inference
+ rules}, and the language executor ({interpreter} or
+ {compiler}) applies some fixed {algorithm} to these relations
+ to produce a result.
+
+ Declarative languages contrast with {imperative languages}
+ which specify explicit manipulation of the computer's internal
+ state; or {procedural languages} which specify an explicit
+ sequence of steps to follow.
+
+ The most common examples of declarative languages are {logic
+ programming} languages such as {Prolog} and {functional
+ languages} like {Haskell}.
+
+ See also {production system}.
+
+ (2004-05-17)
+
+DECmate I
+
+ <computer> The first in {DEC}'s series of miniaturised {PDP-8}
+ computers based on the {Intersil 6120} [Harris 6120?]
+ {microprocessor} and dedicated to {wordprocessing}. The
+ DECmate was DEC's original competition for the {IBM PC}.
+
+ The DECmate I was introduced in 1980 as the successor to the
+ {WT78}. The processor ran at 10 MHz, and was housed in a
+ {VT100} {CRT} terminal. It was a very limted model, no {EAE}
+ option was available, memory was 32 Kwords. It used the RX02
+ 8" dual floppy drive. Options were the DP278-A and -B
+ communication ports and RL278: 1 to 4 {RL02} {cartridge disk}
+ drives.
+
+ {(http://telnet.hu/hamster/dr/decmate.html)}.
+
+ [Processor manufacturer?]
+
+ (2003-05-29)
+
+DECnet
+
+ A proprietary network protocol designed by Digital Equipment
+ Corporation. The functionality of each Phase of the
+ implementation, such as Phase IV and Phase V, is different.
+
+decode
+
+ <cryptography> To apply {decryption}.
+
+ (2004-05-22)
+
+Decomposed Petri Net
+
+ <parallel> (DPN) A {Petri net} that has been split into
+ multiple, interconnected nets. This makes it easier to
+ analyse or run the net.
+
+ DPNs are the basis of {concurrency} in {ConC}.
+
+ (2006-11-27)
+
+decompress
+
+ <compression, data> To reverse the effects of data
+ {compression}.
+
+ (2001-01-30)
+
+decryption
+
+ <cryptography> Any procedure used in {cryptography} to convert
+ {ciphertext} (encrypted data) into {plaintext}.
+
+ (1995-05-10)
+
+DECstation
+
+ <computer> A range of {RISC} based {workstations} manufactured
+ by {DEC}.
+
+ [Details?]
+
+ (1997-04-29)
+
+DECT
+
+ {Digital Enhanced Cordless Telecommunications}
+
+DECtape
+
+ <hardware, storage> A reel of {magnetic tape} about 4 inches
+ in diameter and one inch wide. Unlike today's {macrotapes},
+ microtape drivers allowed {random access} to the data, and
+ therefore could be used to support {file systems} and even for
+ {swapping} (this was generally done purely for {hack value},
+ as they were far too slow for practical use). DECtape was a
+ variant on {LINCtape}.
+
+ In their heyday DECtapes were used in pretty much the same
+ ways one would now use a {floppy disk}: as a small, portable
+ way to save and transport files and programs.
+
+ (1995-03-16)
+
+DECUS
+
+ {Digital Equipment Computer Users Society}
+
+Decus cpp
+
+ An almost-{ANSI C} {preprocessor} by Martin Minow. It is
+ shipped with {X11R5} (contrib/util/cpp) because some systems
+ don't have a working {cpp}.
+
+ It runs on {VMS} ({Vax C}, {Decus C}), {RSX-11M}, {RSTS/E},
+ {P/OS}, {RT11}, {A/UX} and {Apollo Domain}/IX 9.6 and is
+ highly portable.
+
+ (1994-11-03)
+
+DEC Wars
+
+ A 1983 {Usenet} posting by Alan Hastings and Steve Tarr
+ spoofing the "Star Wars" movies in hackish terms. Some years
+ later, ESR (disappointed by Hastings and Tarr's failure to
+ exploit a great premise more thoroughly) posted a
+ 3-times-longer complete rewrite called "Unix WARS"; the two
+ are often confused.
+
+ [{Jargon File}]
+
+DECwindows
+
+ DEC's windowing environment based on the {X Window System}.
+
+DECwrite
+
+ {DEC}'s {CDA}-based, {WYSIWYG} document processing
+ application. It can generate and import {SGML} marked-up
+ documents.
+
+DED
+
+ Dark-Emitting Diode (that is, a burned-out LED). Compare
+ {SED}, {LER}, {write-only memory}. In the early 1970s both
+ Signetics and Texas instruments released DED spec sheets as
+ {AFJs} (suggested uses included "as a power-off indicator").
+
+ [{Jargon File}]
+
+dedicated line
+
+ <communications> A telephone line leased expressly for the
+ purpose of connecting two users more-or-less permenantly..
+ Such lines may be "voice grade" which provides the {bandwidth}
+ and {signal to noise ratio} of ordinary {public switched
+ telephone network} circuits, or specified in ways which allow
+ transport of suitably encoded digital signals at faster rates.
+
+ In some cases, lines may be physical wires between the
+ communicating parties. Over longer distances, it is common
+ for the connection to be virtual, which means that although
+ the two users can communicate only with each other, their
+ signals and others are multiplexed, amplified, switched,
+ scrambled, demultiplexed and so on in complex ways between the
+ end points.
+
+ This contrasts with a {dial-up} connection which is only
+ opened when one end requires it.
+
+ (1996-08-10)
+
+deductive database
+
+ <database> A combination of a conventional {database}
+ containing {facts}, a {knowledge base} containing {rules}, and
+ an {inference engine} which allows the derivation of
+ {information} implied by the facts and rules.
+
+ Commonly, the knowledge base is expressed in a subset of
+ {first-order logic} and either a {SLDNF} or {Datalog}
+ inference engine is used.
+
+ (1995-04-27)
+
+deductive tableau
+
+ <tool> A theorem proof system consisting of a table whose rows
+ contain assertions or goals. Variables in assertions are
+ implicitly universally quantified and variables in goals are
+ implicitly existentially quantified. The declarative meaning
+ of a tableau is that if every instance of every assertion is
+ true then some instance of at least one of the goals is true.
+
+ (1994-12-07)
+
+Deep Blue
+
+ <computer> A super computer developed by researchers at {IBM}
+ to explore the use of {parallel processing} to solve complex
+ computing problems. It is known as the first computer to beat
+ the current chess World Grand Master.
+
+ Deep Blue started it's life as a PhD project at {Carnegie
+ Mellon University} by PhD students Feng-hsiung Hsu and Murray
+ Campbell. Chiptest, as it was known then, consisted of a
+ custom designed chip hosted in a {Sun} 3/160 computer.
+
+ The project moved over to IBM in 1989 when Hsu and Campbell
+ joined IBM. {Deep Thought}, as it was known by then, played
+ for the first time against Garry Kasparov in the same year.
+ The game of two matches was easily won by Kasparov.
+
+ The next match against Kasparov took place in February 1996.
+ By then the machine was again renamed, at that time it was
+ known as Deep Blue. It was also heavily re-engineered: it was
+ by then running on a 32-node {RS/6000} cluster, each
+ containing 8 custom designed chips. Alas, Kasparov won again.
+
+ The breakthrough finally happened in February 1997: with both
+ the algorithm and the raw speed significantly improved, Deep
+ Blue beat Kasparov 3.5:2.5.
+
+ {HOME (http://chess.ibm.com)}.
+
+ (1997-06-16)
+
+deep hack mode
+
+ {hack mode}
+
+deep magic
+
+ [possibly from C. S. Lewis's "Narnia" books] An awesomely
+ arcane technique central to a program or system, especially
+ one neither generally published nor available to hackers at
+ large (compare {black art}); one that could only have been
+ composed by a true {wizard}. Compiler optimisation techniques
+ and many aspects of {OS} design used to be {deep magic}; many
+ techniques in cryptography, signal processing, graphics, and
+ AI still are. Compare {heavy wizardry}. Especially found in
+ comments of the form "Deep magic begins here.". Compare
+ {voodoo programming}.
+
+deep space
+
+ 1. The notional location of any program that has gone {off the
+ trolley}. Especially used of programs that just sit there
+ silently grinding long after either failure or some output is
+ expected. "Uh oh. I should have had a prompt ten seconds
+ ago. The program's in deep space somewhere." Compare {buzz},
+ {catatonic}, {hyperspace}.
+
+ 2. The metaphorical location of a human so dazed and/or
+ confused or caught up in some esoteric form of {bogosity} that
+ he or she no longer responds coherently to normal
+ communication.
+
+ [{Jargon File}]
+
+de facto standard
+
+ A widespread consensus on a particular product or {protocol}
+ which has not been ratified by any official {standards} body,
+ such as {ISO}, but which nevertheless has a large market
+ share.
+
+ The archetypal example of a de facto standard is the {IBM PC}
+ which, despite is many glaring technical deficiencies, has
+ gained such a large share of the {personal computer} market
+ that it is now popular simply because it is popular and
+ therefore enjoys fierce competition in pricing and software
+ development.
+
+ (1994-10-27)
+
+default
+
+ <data> A value or thing to use when none is specified by the
+ user. Defaults are important for making systems behave in a
+ predictable way without the user having to give lots of
+ "obvious" details.
+
+ For example: the default {TCP/IP port} for the {HTTP}
+ {protocol} is 80, the {Unix} {ls} command does not list files
+ whose names begin with ".", the default {number base} in most
+ contexts is 10 (decimal), the default {filename extension} for
+ {Microsoft Word} documents is ".doc".
+
+ (2009-02-20)
+
+default.htm
+
+ {index.html}
+
+default route
+
+ <networking> A {routing table} entry which is used to direct
+ {packets} addressed to {hosts} or {networks} not explicitly
+ listed in the routing table.
+
+ (1996-05-13)
+
+defect
+
+ {bug}
+
+defect analysis
+
+ <programming> Using defects as data for continuous quality
+ improvement. Defect analysis generally seeks to classify
+ defects into categories and identify possible causes in order
+ to direct process improvement efforts.
+
+ (1996-05-13)
+
+defect density
+
+ <programming> The ratio of the number of {defects} to program
+ length.
+
+ (1996-05-13)
+
+Defense Advanced Research Project Agency
+
+ {Defense Advanced Research Projects Agency}
+
+Defense Advanced Research Projects Agency
+
+ <body> (DARPA, ARPA) An agency of the US Department of Defense
+ responsible for the development of new technology for use by
+ the military. DARPA was established in 1958 in response to
+ the Soviet launching of Sputnik, with the mission of keeping
+ the US's military technology ahead of its enemies. DARPA is
+ independent from other more conventional military R&D and
+ reports directly to senior DoD management. DARPA has around
+ 240 personnel (about 140 technical) directly managing a $2
+ billion budget. These figures are "on average" since DARPA
+ focusses on short (two to four-year) projects run by small,
+ purpose-built teams.
+
+ ARPA was its original name, then it was renamed DARPA (for
+ Defense) in 1972, then back to ARPA [When?], and then,
+ incredibly, back to DARPA again on 1996-03-11!
+
+ ARPA was responsible for funding development of {ARPANET}
+ (which grew into the {Internet}), as well as the {Berkeley}
+ version of {Unix} and {TCP/IP}.
+
+ {(http://darpa.mil/)}.
+
+ {History (/pub/misc/darpa)}.
+
+ (1999-07-17)
+
+Defense Calculator
+
+ {IBM 701}
+
+Defense Communications Agency
+
+ (DCA) Now called Defense Information Systems Agency (DISA).
+
+Defense Data Network
+
+ (DDN) A global communications network serving the US
+ Department of Defense. Composed of {MILNET}, other portions
+ of the {Internet}, and classified networks which are not part
+ of the {Internet}. The DDN is used to connect military
+ installations and is managed by the {Defense Information
+ Systems Agency}.
+
+ (1994-12-01)
+
+Defense Data Network Network Information Center
+
+ (DDN NIC or just "The NIC") The {DDN} {NIC}'s primary
+ responsibility is the assignment of {Internet address}es and
+ {Autonomous System numbers}, the administration of the root
+ domain, and providing information and support services to the
+ {DDN}. It is also a primary repository for {RFCs}.
+
+ See also {Internet Registry}.
+
+ (1994-12-07)
+
+Defense Information Systems Agency
+
+ (DISA) Formerly called the Defense Communications Agency
+ (DCA), this is the government agency responsible for managing
+ the {Defense Data Network} (DDN) portion of the {Internet},
+ including the {MILNET}. Currently, DISA administers the
+ {DDN}, and supports the user assistance services of the DDN
+ {NIC}.
+
+ {(http://disa.mil/)}.
+
+ (1994-12-01)
+
+Defense Trade Regulations
+
+ <legal> The U.S. law governening munitions export and defense
+ technology (F-16s, TOW missiles and {cryptology}). According
+ to the U.S. (and Canada) cryptography is a munition and people
+ who export it can be charged as though they were exporting
+ bombs or state secrets. People have been.
+
+ See also {EFF}.
+
+ (1995-06-19)
+
+deferral
+
+ Waiting for quiet on the {Ethernet}.
+
+definite clause
+
+ <logic> A {Horn clause} that has exactly one {positive
+ literal}.
+
+ (2000-01-24)
+
+definite sentence
+
+ <logic> A collection of {definite clauses}.
+
+ (2003-12-04)
+
+definitional constraint programming
+
+ <language> (DCP) A declarative, programming paradigm which
+ integrates {concurrent constraint programming}, {constraint
+ logic programming} and {functional programming}. In this
+ setting a concurrent constraint language becomes a
+ coordination system that organises the concurrent interaction
+ of parallel functional computations. The language is also a
+ generalisation of parallel {functional programming} languages,
+ such as {Id}, where {constraints} and constraint abstractions
+ are reused to define new constraints, as the means of
+ programming logical variables for parallel coordination.
+
+ {Goffin} is a DCP language.
+
+ (1995-03-28)
+
+deflate
+
+ <file format, compression> A {compression} {standard} derived
+ from {LZ77}; it is reportedly used in {zip}, {gzip}, {PKZIP},
+ and {png}, among others.
+
+ Unlike {LZW}, deflate compression does not use patented
+ compression {algorithms}.
+
+ Used as a verb to mean to compress (not decompress!) a file
+ which has been compressed using deflate compression. The
+ opposite, {inflate}, means to decompress data which has been
+ deflated.
+
+ Deflate is described in {RFC 1951}.
+
+ (1997-06-21)
+
+deflate compression
+
+ {deflate}
+
+deflate/inflate compression
+
+ {deflate}
+
+deforestation
+
+ <programming> A technique invented by {Phil Wadler} for
+ eliminating intermediate data structures built and passed
+ between composed functions in {function languages}.
+
+ (1997-06-21)
+
+defrag
+
+ {defragment}
+
+defragment
+
+ <tool, file system> /dee-frag(-ment)'/ (Or "defrag") To
+ coalesce files and free space on a {file system}; to reduce
+ {fragmentation}.
+
+ (2004-08-19)
+
+defunct process
+
+ {zombie process}
+
+degree
+
+ The degree (or valency) of a node in a graph is the number of
+ edges joined to it.
+
+degrees of freedom
+
+ <robotics> The number of independent parameters required to
+ specify the position and orientation of an object. Often used
+ to classify {robot} arms. For example, an arm with six
+ degrees of freedom could reach any position close enough and
+ could orient it's end effector (grip or tool etc.) at any
+ angle about the three perpendicular axes.
+
+dehose
+
+ /dee-hohz/ To clear a {hosed} condition.
+
+ [{Jargon File}]
+
+DEK
+
+ {Data Encryption Key}
+
+Delaunay triangulation
+
+ <mathematics, graphics> (After B. Delaunay) For a {set} S of
+ points in the {Euclidean plane}, the unique {triangulation}
+ DT(S) of S such that no point in S is inside the circumcircle
+ of any triangle in DT(S). DT(S) is the dual of the {voronoi
+ diagram} of S.
+
+delayed control-transfer
+
+ <architecture> A technique used on the {SPARC} processor to reduce
+ the effect of {pipeline breaks} by executing the instruction after
+ a branch instruction (the "delay instruction" in the "delay
+ slot"). If there is no useful instruction which can be placed in
+ the delay slot then the "annul bit" on the control transfer
+ instruction can be set, preventing execution of the delay
+ instruction (unless the control transfer is conditional and is
+ taken).
+
+ Annulled branches are indicated in SPARC assembler language by
+ appending ",A" to the {operation code}. For example,
+
+ LOOP: ...
+ CMP %L0,10
+ BLE,A LOOP
+ ADD %L2, %L3, #L4
+
+ If the delay instruction is also a control transfer instruction
+ then it gets more complicated. Both control transfer instructions
+ are executed (but not the following instruction) and, assuming
+ they are both taken, control is transferred briefly to the
+ destination of the first and then immediately to the destination
+ of the second.
+
+ (2001-06-26)
+
+delay instruction
+
+ {delayed control-transfer}
+
+delay slot
+
+ {delayed control-transfer}
+
+delete
+
+ 1. <operating system> (Or "erase") To make a file
+ inaccessible.
+
+ Usually this operation only deletes information from the
+ tables the {file system} uses to locate named files; the
+ file's contents still exist on {disk} and can sometimes be
+ recovered by scanning the whole disk for strings which are
+ known to have been in the file. Files created subsequently on
+ the same disk are quite likely to reuse the same blocks and
+ thus overwrite the deleted file's data permanently.
+
+ 2. <character> The {control character} with {ASCII} code 127.
+ Usually entering this character from the keyboard deletes the
+ last character typed from the {input buffer}. Sadly there is
+ great confusion between {operating systems} and keyboard
+ manufacturers as to whether this function should be assigned
+ to the delete or {backspace} key/character.
+
+ The choice of code 127 (binary 1111111) is not arbitrary but
+ dates back to the use of {paper tape} for input. The delete
+ key rewound the tape by one character and punched out all
+ seven holes, thus obliterating whatever character was there
+ before. The tape reading software ignored any delete
+ characters in the input.
+
+ (1996-12-01)
+
+delimiter
+
+ <character> A {character} or {string} used to separate, or
+ mark the start and end of, items of data in, e.g., a
+ {database}, {source code}, or {text file}.
+
+ See also: {record}.
+
+ (2001-03-16)
+
+delint
+
+ /dee-lint/ To modify code to remove problems detected when
+ {lint}ing. Confusingly, this process is also referred to as
+ "linting" code.
+
+ [{Jargon File}]
+
+Delirium
+
+ An embedding coordinate language for parallel programming,
+ implemented on {Sequent Symmetry}, {Cray}, {BBN Butterfly}.
+
+ ["Parallel Programming with Coordination Structures", S. Lucco
+ et al, 18th POPL, pp.197-208 (1991)].
+
+Delivered Source Instruction
+
+ <programming, unit> (DSI) One line of source code (LOC)
+ developed by a project.
+
+ DSI is the primary input to many tools for estimating software
+ cost. The term "delivered" is generally meant to exclude
+ non-delivered support software such as test drivers. However,
+ if these are developed with the same care as delivered
+ software, with their own reviews, test plans, documentation,
+ etc., then they should be counted. The "source instructions"
+ include all program instructions created by project personnel
+ and processed into {machine code} by some combination of
+ preprocessors, compilers, and assemblers. It excludes
+ comments and unmodified utility software. It includes {job
+ control language}, format statements, and data declarations.
+
+ (1996-05-29)
+
+Dell Computer Corporation
+
+ <company> One of the biggest US manufacturers of {IBM PC}
+ compatibles.
+
+ "From notebooks to networks", their slogan says.
+
+ {(http://us.dell.com)}.
+
+ (1996-05-29)
+
+Delphi
+
+ 1. <company, communications> A US {Internet service provider}.
+
+ [Addresses?]
+
+ (1995-04-06)
+
+ 2. <language> {Borland}'s {Object Oriented Pascal} (OOPascal)
+ {Rapid Application Development} package for {Microsoft
+ Windows}. Delphi combines visual, component-based design with
+ an optimising {native code compiler} and scalable database
+ access.
+
+ (1996-05-27)
+
+Delphi Technique
+
+ <programming, tool> A group forecasting technique, generally
+ used for future events such as technological developments,
+ that uses estimates from experts and feedback summaries of
+ these estimates for additional estimates by these experts
+ until reasonable consensus occurs. It has been used in
+ various software cost-estimating activities, including
+ estimation of factors influencing software costs.
+
+ (1996-05-29)
+
+Delta
+
+ <language>
+
+ 1. An expression-based language developed by J.C. Cleaveland
+ in 1978.
+
+ 2. A string-processing language with single-character commands
+ from {Tandem Computers}.
+
+ 3. A language for system specification of simulation
+ execution.
+
+ ["System Description and the DELTA Language",
+ E. Holback-Hansen et al, DELTA Proj Rep 4, Norweg Comput Ctr,
+ Feb 1977].
+
+ 4. A {COBOL} generating language produced by {Delta Software
+ Entwicklung GmbH (http://delta-software.de/)}.
+
+ (2000-08-02)
+
+delta
+
+ 1. A quantitative change, especially a small or incremental
+ one (this use is general in physics and engineering). "I just
+ doubled the speed of my program!" "What was the delta on
+ program size?" "About 30 percent." (He doubled the speed of
+ his program, but increased its size by only 30 percent.)
+
+ 2. [Unix] A {diff}, especially a {diff} stored under the set
+ of version-control tools called SCCS (Source Code Control
+ System) or RCS (Revision Control System). See {change
+ management}.
+
+ 3. A small quantity, but not as small as {epsilon}. The
+ jargon usage of {delta} and {epsilon} stems from the
+ traditional use of these letters in mathematics for very small
+ numerical quantities, particularly in "epsilon-delta" proofs
+ in limit theory (as in the differential calculus). The term
+ {delta} is often used, once {epsilon} has been mentioned, to
+ mean a quantity that is slightly bigger than {epsilon} but
+ still very small. "The cost isn't epsilon, but it's delta"
+ means that the cost isn't totally negligible, but it is
+ nevertheless very small. Common constructions include "within
+ delta of ---", "within epsilon of ---": that is, "close to"
+ and "even closer to".
+
+ [{Jargon File}]
+
+ (2000-08-02)
+
+Delta-4
+
+ Definition and Design of an open Dependable Distributed system
+ architecture. An Esprit project investigating the achievement
+ of dependability in open distributed systems, including
+ real-time systems.
+
+delta conversion
+
+ {delta reduction}
+
+Delta-Prolog
+
+ A {Prolog} extension with {AND-parallelism}, {don't-know
+ nondeterminism} and interprocess communication using
+ {synchronous event goals} and {distributed backtracking}.
+
+ ["Delta-Prolog: A Distributed Logic Programming Language",
+ L.M. Pereira et al, Intl Conf 5th Gen Comp Sys, Nov 1984].
+
+delta reduction
+
+ <theory> In {lambda-calculus} extended with constants, delta
+ reduction replaces a function applied to the required number
+ of arguments (a {redex}) by a result. E.g. plus 2 3 --> 5.
+ In contrast with {beta reduction} (the only kind of reduction
+ in the {pure lambda-calculus}) the result is not formed simply
+ by textual substitution of arguments into the body of a
+ function. Instead, a delta redex is matched against the left
+ hand side of all delta rules and is replaced by the right hand
+ side of the (first) matching rule. There is notionally one
+ delta rule for each possible combination of function and
+ arguments. Where this implies an infinite number of rules,
+ the result is usually defined by reference to some external
+ system such as mathematical addition or the hardware
+ operations of some computer. For other types, all rules can
+ be given explicitly, for example {Boolean} negation:
+
+ not True = False
+ not False = True
+
+ (1997-02-20)
+
+DELTASE
+
+ A distributed processing environment concerned with
+ fault-tolerant and process-control applications from the
+ Esprit Delta-4 project.
+
+demand driven
+
+ A demand driven architecture/language performs computations
+ when the result is required by some other computation.
+ E.g. {Imperial College}'s {ALICE} running {HOPE}.
+
+ See also {data flow}, {lazy evaluation}, {reduction}.
+
+ (1995-02-16)
+
+demand paged
+
+ {demand paging}
+
+demand paging
+
+ <memory management> A kind of {virtual memory} where a {page}
+ of memory will be {paged in} if an attempt is made to access
+ it and it is not already present in main memory. This
+ normally involves a {memory management unit} which looks up
+ the {virtual address} in a {page map} to see if it is paged
+ in. If it is not then the {operating system} will page it in,
+ update the page map and restart the failed access. This
+ implies that the processor must be able to recover from and
+ restart a failed memory access or must be suspended while some
+ other mechanism is used to perform the paging.
+
+ Paging in a page may first require some other page to be moved
+ from main memory to disk ("paged out") to make room. If this
+ page has not been modified since it was paged in, it can
+ simply be reused without writing it back to disk. This is
+ determined from the "modified" or "dirty" flag bit in the
+ {page map}. A {replacement algorithm} or policy is used to
+ select the page to be paged out, often this is the {least
+ recently used} (LRU) {algorithm}.
+
+ {Prepaging} is generally more efficient than demand paging.
+
+ (1998-04-24)
+
+DeMarco
+
+ Tom DeMarco proposed a form of {structured analysis}.
+
+ (1995-02-16)
+
+DeMarco/Yourdon
+
+ {Yourdon/Demarco}
+
+demented
+
+ Yet another term of disgust used to describe a program. The
+ connotation in this case is that the program works as
+ designed, but the design is bad. Said, for example, of a
+ program that generates large numbers of meaningless error
+ messages, implying that it is on the brink of imminent
+ collapse.
+
+ [{Jargon File}]
+
+ (1994-12-07)
+
+Demeter
+
+ A {CASE} tool developed mainly by Karl Lieberherr.
+
+ ["Contributions to Teaching Object-Oriented Design and
+ Programming" Aug/Sep 1988 issue of JOOP, OOPSLA '89
+ Proceedings].
+
+ (1994-12-07)
+
+demigod
+
+ <person> A hacker with years of experience, a national
+ reputation, and a major role in the development of at least
+ one design, tool, or game used by or known to more than half
+ of the hacker community. To qualify as a genuine demigod, the
+ person must recognisably identify with the hacker community
+ and have helped shape it. Major demigods include {Ken
+ Thompson} and {Dennis Ritchie} (co-inventors of {Unix} and
+ {C}) and {Richard Stallman} (inventor of {Emacs}). In their
+ hearts of hearts, most hackers dream of someday becoming
+ demigods themselves, and more than one major software project
+ has been driven to completion by the author's veiled hopes of
+ apotheosis.
+
+ See also {net.god}, {true-hacker}.
+
+ [{Jargon File}]
+
+ (1994-10-27)
+
+De-Militarised Zone
+
+ <networking> (DMZ) (From the military term for an area between
+ two opponents where fighting is prevented) DMZ {Ethernets}
+ connect networks and computers controlled by different bodies.
+ They may be external or internal. External DMZ Ethernets link
+ regional networks with {routers} to internal networks.
+ Internal DMZ Ethernets link local nodes with routers to the
+ regional networks.
+
+ Compare {red zone}.
+
+ (1995-02-23)
+
+demo
+
+ /de'moh/ 1. A demonstration of a product, often of an early
+ version or prototype. A demo is a far more effective way of
+ inducing bugs to manifest themselves than any number of {test}
+ runs, especially when important people are watching.
+
+ 2. {demo version}.
+
+ 3. A program written to demonstrate the programmer's coding
+ ability and/or the power of the computer it runs on. Such
+ demos are nearly always written in {machine code} and
+ traditionally feature scrolling text about the author, his
+ friends, his code and anything else he fancies and animated
+ graphics.
+
+ [{Jargon File}]
+
+ (1994-11-04)
+
+demodulate
+
+ {demodulation}
+
+demodulation
+
+ <communications> To recover the {signal} from the {carrier}.
+ For example, in a radio broadcast using {amplitude modulation}
+ the audio signal is transmitted as the mean amplitude of a
+ radio-frequency carrier so demodulation requires a circuit
+ which measures the amplitude and filters out the carrier.
+ There are many other kinds of {modulation} and corresponding
+ demodulation.
+
+ (1998-07-29)
+
+demo mode
+
+ ({Sun}) 1. The state of being {heads down} in order to finish
+ code in time for a {demo}, usually due yesterday.
+
+ 2. <games> (Or "attract mode") A mode in which video games sit
+ by themselves running through a portion of the game. Some
+ serious {apps} have a demo mode they use as a screen saver, or
+ may go through a demo mode on startup (for example, the
+ {Microsoft Windows} opening screen - which lets you impress
+ your neighbors without actually having to put up with
+ {Microsloth Windows}).
+
+ [{Jargon File}]
+
+ (1995-02-22)
+
+demon
+
+ 1. <operating system> (Often used equivalently to {daemon},
+ especially in the {Unix} world, where the latter spelling and
+ pronunciation is considered mildly archaic). A program or
+ part of a program which is not invoked explicitly, but that
+ lies dormant waiting for some condition(s) to occur.
+
+ At {MIT} they use "demon" for part of a program and "daemon"
+ for an {operating system} process.
+
+ Demons (parts of programs) are particularly common in {AI}
+ programs. For example, a {knowledge}-manipulation program
+ might implement {inference rules} as demons. Whenever a new
+ piece of knowledge was added, various demons would activate
+ (which demons depends on the particular piece of data) and
+ would create additional pieces of knowledge by applying their
+ respective inference rules to the original piece. These new
+ pieces could in turn activate more demons as the inferences
+ filtered down through chains of logic. Meanwhile, the main
+ program could continue with whatever its primary task was.
+ This is similar to the {triggers} used in {relational
+ databases}.
+
+ The use of this term may derive from "Maxwell's Demons" -
+ minute beings which can reverse the normal flow of heat from a
+ hot body to a cold body by only allowing fast moving molecules
+ to go from the cold body to the hot one and slow molecules
+ from hot to cold. The solution to this apparent thermodynamic
+ paradox is that the demons would require an external supply of
+ energy to do their work and it is only in the absence of such
+ a supply that heat must necessarily flow from hot to cold.
+
+ Walt Bunch believes the term comes from the demons in Oliver
+ Selfridge's paper "Pandemonium", MIT 1958, which was named
+ after the capital of Hell in Milton's "Paradise Lost".
+ Selfridge likened neural cells firing in response to input
+ patterns to the chaos of millions of demons shrieking in
+ Pandemonium.
+
+ 2. <company> {Demon Internet} Ltd.
+
+ 3. A {program generator} for {differential equation} problems.
+
+ [N.W. Bennett, Australian AEC Research Establishment,
+ AAEC/E142, Aug 1965].
+
+ [{Jargon File}]
+
+ (1998-09-04)
+
+Demon Internet Ltd.
+
+ <company> One of the first company to provide public
+ {Internet} access in the UK.
+
+ The staff of Demon Systems Ltd., an established software
+ house, started Demon Internet on 1992-06-01 and it was the
+ first system in the United Kingdom to offer low cost full
+ {Internet} access. It was started with the support of about
+ 100 founder members who discussed the idea on {Compulink
+ Information Exchange}, and were brave enough to pay a year's
+ subscription in advance. They aimed to have 200 members in
+ the first year to cover costs, ignoring any time spent. After
+ about two weeks they realised they needed nearer 400. By
+ November 1993 they had over 2000 subscribers and by August
+ 1994 they had about 11000 with 20% per month growth. All
+ revenues have been reinvested in resources and expansion of
+ service.
+
+ Demon link to {Sprintlink} in the United States making them
+ totally independent. They peer with {EUNet} and {PIPEX} to
+ ensure good connectivity in Great Britain as well as having
+ links to the {JANET}/{JIPS} UK academic network. A direct
+ line into the {Department of Computing, Imperial College,
+ London (http://sunsite.doc.ic.ac.uk)} from their Central
+ London {Point of Presence} (PoP) (styx.demon.co.uk) gives
+ access to the biggest {FTP} and {Archie} site in Europe.
+
+ Demon provide local call access to a large proportion of the
+ UK. The central London {PoP} provides {leased line}
+ connections at a cheaper rate for those customers in the
+ central 0171 area. Further lines and {PoPs} are being added
+ continuously.
+
+ Subscribers get allocated an {Internet Address} and can choose
+ a {hostname} within the demon.co.uk {domain}. They can have
+ any number of e-mail address at that host.
+
+ In October 1994 Demon confirmed a large contract with the
+ major telecommunications provider {Energis}. They will supply
+ guaranteed bandwidth to Demon's 10Mb/s {backbone} from several
+ cities and towns. Several {PoPs} will be phased out and
+ replaced with others during 1995.
+
+ E-mail: <internet@demon.net>.
+
+ {(ftp://ftp.demon.co.uk/)}.
+
+ {(http://demon.co.uk/)}.
+
+ {Usenet} newsgroup: {news:demon.announce}.
+
+ Telephone: +44 (181) 349 0063.
+
+ Address: Demon Internet Ltd., 42 Hendon Lane, Finchley, London
+ N3 1TT, UK.
+
+ (1994-11-08)
+
+DeMorgan's theorem
+
+ <logic> A logical {theorem} which states that the {complement}
+ of a {conjunction} is the {disjunction} of the complements or
+ vice versa. In symbols:
+
+ not (x and y) = (not x) or (not y)
+ not (x or y) = (not x) and (not y)
+
+ E.g. if it is not the case that I am tall and thin then I am
+ either short or fat (or both). The theorem can be extended to
+ combinations of more than two terms in the obvious way.
+
+ The same laws also apply to sets, replacing logical complement
+ with set complement, conjunction ("and") with set
+ intersection, and disjunction ("or") with set union.
+
+ A ({C}) programmer might use this to re-write
+
+ if (!foo && !bar) ...
+ as
+ if (!(foo || bar)) ...
+
+ thus saving one operator application (though an {optimising
+ compiler} should do the same, leaving the programmer free to
+ use whichever form seemed clearest).
+
+ (1995-12-14)
+
+demo version
+
+ 1. An early, barely-functional version of a program which
+ can be used for demonstration purposes as long as the operator
+ uses *exactly* the right commands and skirts its numerous
+ bugs, deficiencies, and unimplemented portions.
+
+ 2. A special version of a finished program (frequently with
+ some features crippled) which is distributed at little or no
+ cost to the user for enticement purposes. See {crippleware}.
+
+ (1994-11-04)
+
+Denis Howe
+
+ <person> Denis B. Howe (1960 -) Editor of the {Free On-line
+ Dictionary of Computing}.
+
+ (2008-03-26)
+
+Dennis Ritchie
+
+ <person> Dennis M. Ritchie, co-author of the {Unix} {operating
+ system}, inventor of the {C} programming language and
+ {demigod}.
+
+ See also {K&R}, {Core War}, {If you want X, you know where to
+ find it}.
+
+ (2008-03-26)
+
+denotational semantics
+
+ <theory> A technique for describing the meaning of programs in
+ terms of mathematical {functions} on programs and program
+ components. Programs are translated into functions about
+ which properties can be proved using the standard mathematical
+ theory of functions, and especially {domain theory}.
+
+ Compare {axiomatic semantics}, {operational semantics},
+ {standard semantics}.
+
+ (1996-08-21)
+
+Denotational Semantics Language
+
+ <specification, language> (DSL) The {specification language}
+ used by the {SIS} {compiler generator}.
+
+ ["SIS - Semantics Implementation System", P.D. Mosses, TR
+ DAIMI MD-30, Aarhus U, Denmark].
+
+ (1996-10-13)
+
+Department of Defense
+
+ <body> (DoD) The US military body responsible for sponsoring
+ many software engineering standards.
+
+ (1996-05-29)
+
+Department of Defense Network
+
+ <networking> (DDN) A military subset of the {Internet}, which
+ includes {ARPAnet}.
+
+ (1994-12-07)
+
+depeditate
+
+ /dee-ped'*-tayt/ [by (faulty) analogy with "decapitate"]
+ Humorously, to cut off the feet of. When one is using some
+ computer-aided typesetting tools, careless placement of text
+ blocks within a page or above a rule can result in chopped-off
+ letter descenders. Such letters are said to have been
+ depeditated.
+
+ [{Jargon File}]
+
+dependability
+
+ {software reliability}
+
+dependable software
+
+ {software reliability}
+
+Deployment Descriptor
+
+ <programming> (DD) A {J2EE} configuration file.
+
+ (2005-01-26)
+
+deprecated
+
+ Said of a program or feature that is considered obsolescent
+ and in the process of being phased out, usually in favour of a
+ specified replacement. Deprecated features can,
+ unfortunately, linger on for many years. This term appears
+ with distressing frequency in standards documents when the
+ committees writing the documents realise that large amounts of
+ extant (and presumably happily working) code depend on the
+ feature(s) that have passed out of favour.
+
+ See also {dusty deck}.
+
+ [{Jargon File}]
+
+ (1995-04-19)
+
+depth-first search
+
+ <algorithm> A graph search {algorithm} which extends the
+ current path as far as possible before {backtracking} to the
+ last {choice point} and trying the next alternative path.
+ Depth-first search may fail to find a solution if it enters a
+ cycle in the graph. This can be avoided if we never extend a
+ path to a node which it already contains.
+
+ Opposite of {breadth first search}. See also {iterative
+ deepening}.
+
+ (1995-04-19)
+
+deque
+
+ {double-ended queue}
+
+dequeue
+
+ {queue}
+
+DER
+
+ {Distinguished Encoding Rules}
+
+dereference
+
+ <programming> To access the thing to which a pointer points,
+ i.e. to follow the pointer. E.g. in {C}, the declarations
+
+ int i;
+ int *p = &i;
+
+ declare i as an integer and p as a pointer to integer. p is
+ initialised to point at i ("&i" is the address of i - the
+ inverse of "*"). The expression *p dereferences p to yield i
+ as an {lvalue}, i.e. something which can appear either on the
+ left of an {assignment} or anywhere an integer expression is
+ valid. Thus
+
+ *p = 17;
+
+ would set i to 17. *p++ is not the same as i++ however since
+ it is parsed as *(p++), i.e. increment p (which would be an
+ invalid thing to do if it was pointing to a single int, as in
+ this example) then dereference p's old value.
+
+ The {C} operator "->" also dereferences its left hand argument
+ which is assumed to point to a {structure} or {union} of which
+ the right hand argument is a {member}.
+
+ At first sight the word "dereference" might be thought to mean
+ "to cause to stop referring" but its meaning is well
+ established in jargon.
+
+ (1998-12-15)
+
+de-rezz
+
+ <jargon> /dee-rez'/ (Or "derez") "de-resolve" via the film
+ "Tron". 1. To disappear or dissolve; the image that goes with
+ it is of an object breaking up into raster lines and static
+ and then dissolving. Occasionally used of a person who seems
+ to have suddenly "fuzzed out" mentally rather than physically.
+ Usage: extremely silly, also rare. This verb was actually
+ invented as *fictional* hacker jargon, and adopted in a spirit
+ of irony by real hackers years after the fact.
+
+ 2. The Macintosh resource decompiler. On a Macintosh, many
+ program structures (including the code itself) are managed in
+ small segments of the program file known as "resources"; "Rez"
+ and "DeRez" are a pair of utilities for compiling and
+ decompiling resource files. Thus, decompiling a resource is
+ "derezzing". Usage: very common.
+
+ [{Jargon File}]
+
+derived class
+
+ {subclass}
+
+derived type
+
+ <programming> A {type} constructed from {primitive types} or
+ other derived types using a {type constructor function}. This
+ term is usually applied to {procedural languages} such as {C}
+ or {Ada}. C's derived types are the {array}, {function},
+ {pointer}, {structure}, and {union}.
+
+ Compare {derived class}.
+
+ (2001-09-14)
+
+DES
+
+ {Data Encryption Standard}
+
+descender
+
+ <text> A lowercase letter that extends below the base line,
+ such as "g", "j", or "p". Also used to denote the part of the
+ letter extending below the base line. Compare {ascender}.
+
+ (1998-03-27)
+
+descent function
+
+ If a {recursive} function is of the form
+
+ f x = ... f (d x) ...
+
+ then d is known as the descent function.
+
+Descriptive Intermediate Attributed Notation for Ada
+
+ <language> (DIANA) A formerly {de facto standard}
+ {intermediate language} for {Ada} programs, developed by Goos
+ and Wulf at {CMU} in January 1981. DIANA is an {attributed
+ tree} representation, with an abstract interface defined in
+ {Interface Description Language} (Nestor, Lamb and Wulf, CMU,
+ 1981; Snodgrass(?), 1989(?)). DIANA resulted from a merger of
+ {AIDA} and {TCOL.Ada}. At the present (2001) it is no longer
+ used by the major ADA compilers
+
+ ["DIANA - An Intermediate Language for Ada", G.T. Goos et al,
+ LNCS 161, Springer 1983].
+
+ (2001-09-15)
+
+Descriptive Top-Level Specification
+
+ (DTLS) A language used in {POSIX} and {TRUSIX}.
+
+ (1994-11-11)
+
+descriptor
+
+ <operating system> An integer, string or other small data
+ value which refers to one of several objects allocated to a
+ program by the {operating system}, usually the {kernel}. A
+ common example is a {Unix} {file descriptor} which is a small
+ integer that identifies an I/O channel. Another example is a
+ reference to an area of memory (e.g. {shared memory}).
+
+ Compare {capability}.
+
+ (1998-02-06)
+
+design
+
+ <process> The approach that engineering (and some other)
+ disciplines use to specify how to create or do something. A
+ successful design must satisfies a (perhaps informal)
+ {functional specification} (do what it was designed to do);
+ conforms to the limitations of the target medium (it is
+ possible to implement); meets implicit or explicit
+ requirements on performance and resource usage (it is
+ efficient enough).
+
+ A design may also have to satisfy restrictions on the design
+ process itself, such as its length or cost, or the tools
+ available for doing the design.
+
+ In the {software life-cycle}, design follows {requirements
+ analysis} and is followed by implementation.
+
+ ["Object-Oriented Analysis and Design with Applications", 2nd
+ ed., Grady Booch].
+
+ (1996-12-08)
+
+Design In Real Time
+
+ <programming> (Dirt) A user {interface builder} for the {X
+ Window System} by R. Hesketh.
+
+ (1994-12-07)
+
+design pattern
+
+ <programming> A description of an {object-oriented design}
+ technique which names, abstracts and identifies aspects of a
+ design structure that are useful for creating an
+ object-oriented design. The design pattern identifies
+ {classes} and {instances}, their roles, collaborations and
+ responsibilities. Each design pattern focuses on a particular
+ object-oriented design problem or issue. It describes when it
+ applies, whether it can be applied in the presence of other
+ design constraints, and the consequences and trade-offs of its
+ use.
+
+ {Home
+ (http://st-www.cs.uiuc.edu/users/patterns/patterns.html)}.
+
+ ["Design Patterns: Elements of Reusable Object-Oriented
+ Software", Erich Gamma, Richard Helm, Ralph Johnson, and John
+ Vlissides].
+
+ (1997-07-21)
+
+design recovery
+
+ <process> A subtask of {reverse engineering} in which domain
+ knowledge, external information, and deduction of fuzzy
+ reasoning are added to the observations of the subject system
+ to identify meaningful higher level abstractions beyond those
+ obtained directly by examining the system itself.
+
+ In other words, design recovery aims to work out what a system
+ or component was designed to do rather than just examining its
+ subcomponents and their interrelationships.
+
+ (1996-12-08)
+
+Design System language
+
+ J. Gaffney, Evans & Sutherland 1976. Interpretive FORTH-like
+ language for 3d graphics databases. Earliest forerunner of
+ both Interpress and PostScript. Mentioned in PostScript
+ Language Reference Manual, Adobe Systems, A-W 1985.
+
+desk check
+
+ <programming> To {grovel} over hardcopy of {source code},
+ mentally simulating the {control flow}; a method of catching
+ bugs. No longer common practice in this age of on-screen
+ editing, fast compiles, and sophisticated debuggers - though
+ some maintain stoutly that it ought to be.
+
+ Compare {dry run}, {eyeball search}, {vdiff}, {vgrep}.
+
+ [{Jargon File}]
+
+ (1996-05-13)
+
+desktop
+
+ 1. <operating system> In a {WIMP} {graphical user interface},
+ the visual representation of a real desktop (the top surface
+ of a piece of furniture) with documents, folders and a rubbish
+ bin arranged on it. The user manipulates files on the
+ computer by using a {mouse} to {click} and {drag} their
+ representations ({icons}) on the desktop.
+
+ The WIMP interface and desktop metaphor was invented at {Xerox
+ PARC} and popularised by the {Apple Macintosh}.
+
+ 2. <computer> {desktop computer}.
+
+ (2007-09-12)
+
+desktop database
+
+ {Macintosh file system}
+
+Desktop Management Interface
+
+ <standard, operating system> (DMI) A {specification} from the
+ {Desktop Management Task Force} (DMTF) that establishes a
+ standard {framework} for managing networked computers. DMI
+ covers {hardware} and {software}, {desktop} systems and
+ {servers}, and defines a model for filtering events and
+ describing {interfaces}.
+
+ DMI provides a common path for technical support, IT managers,
+ and individual users to access information about all aspects
+ of a computer - including {processor} type, installation date,
+ attached {printers} and other {peripherals}, power sources,
+ and maintenance history. It provides a common format for
+ describing products to aid vendors, systems integrators, and
+ end users in enterprise desktop management.
+
+ DMI is not tied to any specific hardware, operating system, or
+ management protocols. It is easy for vendors to adopt,
+ mappable to existing management protocols such as {Simple
+ Network Management Protocol} (SNMP), and can be used on
+ non-network computers.
+
+ DMI's four components are:
+
+ Management Information Format (MIF) - a text file containing
+ information about the hardware and software on a computer.
+ Manufacturers can create their own MIFs specific to a
+ component.
+
+ Service layer - an OS add-on that connects the management
+ interface and the component interface and allows management
+ and component software to access MIF files. The service layer
+ also includes a common interface called the local agent, which
+ is used to manage individual components.
+
+ Component interface (CI) - an {application program interface}
+ (API) that sends status information to the appropriate MIF
+ file via the service layer. Commands include Get, Set, and
+ Event.
+
+ Management interface (MI) - the management software's
+ interface to the service layer. Commands are Get, Set, and
+ List.
+
+ CI, MI, and service layer drivers are available on the
+ Internet. {Intel}'s {LANDesk Client Manager} (LDCM) is based
+ on DMI.
+
+ Version: 2.0s (as of 2000-01-19).
+
+ {(http://dmtf.org/spec/dmis.html)}.
+
+ {Sun overview
+ (http://sun.com/solstice/products/ent.agents/presentations/sld014.html)}.
+
+ (2000-01-19)
+
+Desktop Management Task Force
+
+ <body> (DMTF) The industry consortium that develops, supports,
+ and maintains standards for systems management of {PC} systems
+ and products, to reduce total cost of ownership. These
+ include the {Desktop Management Interface} (DMI), the
+ most-widely used management standard today.
+
+ The DMTF is participating in an industry effort to create a
+ standard for management over the {Internet}. They are
+ defining an {object-oriented} {Common Information Model}
+ (CIM).
+
+ {(http://dmtf.org/)}.
+
+ (2000-01-19)
+
+desktop manager
+
+ A {user interface} to system services, usually {icon} and
+ {menu} based like the {Macintosh} {Finder}, enabling the user
+ to run {application programs} and use a {file system}
+ without directly using the command language of the {operating
+ system}.
+
+ (1994-12-07)
+
+desktop publisher
+
+ {desktop publishing}
+
+desktop publishing
+
+ <text, application> (DTP) Using computers to lay out text and
+ graphics for printing in magazines, newsletters, brochures,
+ etc. A good DTP system provides precise control over
+ templates, styles, fonts, sizes, colour, paragraph formatting,
+ images and fitting text into irregular shapes.
+
+ Example programs include {FrameMaker}, {PageMaker}, {InDesign}
+ and {GeoPublish}.
+
+ {(http://cs.purdue.edu/homes/gwp/dtp/dtp.html)}.
+
+ {Usenet} newsgroup: {news:comp.text.desktop}.
+
+ (2005-03-14)
+
+DESQview
+
+ A system from {Quarterdeck Office Systems} implementing
+ {multitasking} under {MS-DOS}.
+
+destructor
+
+ <programming> A {function} provided by a {class} in {C++} and
+ some other {object-oriented languages} to delete an object,
+ the inverse of a {constructor}.
+
+ (1998-04-28)
+
+DESY
+
+ Deutsches Electronen Synchrotron Laboratory, Hamburg, Germany.
+
+DETAB
+
+ DEcision TABle.
+
+ A {decision table} {COBOL} preprocessor written by A. Chapman
+ in 1964.
+
+ Versions: DETAB 65, DETAB X.
+
+ [Sammet 1969, p. 315].
+
+ (1994-12-07)
+
+deterministic
+
+ 1. <probability> Describes a system whose time evolution can
+ be predicted exactly.
+
+ Contrast {probabilistic}.
+
+ 2. <algorithm> Describes an {algorithm} in which the correct
+ next step depends only on the current state. This contrasts
+ with an algorithm involving {backtracking} where at each point
+ there may be several possible actions and no way to chose
+ between them except by trying each one and backtracking if it
+ fails.
+
+ (1995-09-22)
+
+deterministic automaton
+
+ <theory> A {finite-state automaton} in which the overall
+ course of the computation is completely determined by the
+ program, the starting state, and the initial inputs. The
+ class of problems solvable by such automata is the class P
+ (see {polynomial-time algorithm}).
+
+ (1996-05-03)
+
+DETOL
+
+ <language> {Directly Executable Test Oriented
+ Language}.
+
+ (1995-09-29)
+
+developer
+
+ {programmer}
+
+development
+
+ The process of analysis, design, coding and testing software.
+
+Developmental Test and Evaluation
+
+ <programming> (DT&E) Activity which focuses on the
+ technological and engineering aspects of a system or piece of
+ equipment.
+
+ (1996-05-13)
+
+development environment
+
+ <programming, tool> An integrated suite of {tools} to aid the
+ {development} of {software} in a particular {language} or for
+ a particular {application}. Usually, this consists of a
+ {compiler} and {editor} and may also include one or more of a
+ {debugger}, {profiler}, and {source code} manager.
+
+ See also: {IDE}.
+
+ (1999-08-01)
+
+device
+
+ {peripheral}
+
+Device Control
+
+ <character> One of the four {ASCII} characters, {DC1}, {DC2},
+ {DC3}, and {DC4}, once used to remotely control equipment
+ (e.g. a {paper tape} reader) via electromagnetic switches.
+ The characters were usually paired, DC1/DC3 turning one device
+ on/off, and DC2/DC4 another.
+
+ [Other examples of equipment?]
+
+ (1996-08-20)
+
+Device Control 1
+
+ {Control-Q}
+
+Device Control 2
+
+ <character> (DC2) The {mnemonic} for {ASCII} character 18, one
+ of the four {Device Control} characters.
+
+ (1996-06-28)
+
+Device Control 3
+
+ {Control-S}
+
+Device Control 4
+
+ <character> (DC4) The {mnemonic} for {ASCII} character 20, one
+ of the four {Device Control} characters.
+
+ (1996-06-28)
+
+device driver
+
+ <operating system> {Software} to control a hardware component
+ or {peripheral} device of a computer such as a {magnetic
+ disk}, {magnetic tape} or printer.
+
+ A device driver is responsible for accessing the hardware
+ {registers} of the device and often includes an {interrupt
+ handler} to service interrupts generated by the device.
+
+ Device drivers often form part of the lowest level of the
+ {operating system} {kernel}, with which they are linked when
+ the kernel is built. Some more recent systems have loadable
+ device drivers which can be installed from files after the
+ {operating system} is running.
+
+ (1994-10-27)
+
+device independent bitmap
+
+ <graphics, file format> (DIB) An {image} format in which the
+ sequence and depth of {pixels} in the file is not specifically
+ related to their layout in any particular device. This allows
+ any device dependent bitmap (DDB) image to be converted to or
+ DIB format without loss of information, and this can then
+ later be converted to other DDB formats for, e.g., printing or
+ display. Rather than requiring converters from each DDB
+ format to all other formats, only converters to and from DIB
+ are needed.
+
+ DIB images are normally transferred in {metafiles}, {bmp}
+ files, and the {clipboard}.
+
+ Transferring colour bitmaps from one device to another was not
+ possible in versions of {Microsoft Windows} earlier than 3.0.
+ {Application programs} can build DIB images without any
+ interaction with Windows. If Windows lacks a drawing
+ primitive, the application can simulate it directly into the
+ DIB instead of using the existing {graphics device interface}
+ (GDI) primitives. Unfortunately, under Windows versions 3.0
+ and 3.1, {GDI} cannot perform output operations directly to a
+ DIB.
+
+ Conversion between DIB and DDB is performed by the {device
+ driver}. Where the driver does not have this facility, the
+ conversion is performed by GDI but only in monochrome. DIBs
+ are slower to use than device dependent bitmaps due to the
+ conversions required.
+
+ (1996-09-20)
+
+Device Manager
+
+ <operating system> The {Microsoft Windows} {control panel}
+ {applet} used to enable, disable and configure the hardware on
+ which Windows is running. You can launch Device Manager via
+ the Control Panel/System or directly with:
+
+ rundll32.exe devmgr.dll DeviceManager_Execute
+
+ (2008-04-16)
+
+Devil Book
+
+ <publication> "The Design and Implementation of the {4.3BSD}
+ Unix Operating System", by Samuel J. Leffler, Marshall Kirk
+ McKusick, Michael J. Karels, and John S. Quarterman
+ (Addison-Wesley Publishers, 1989, ISBN 0-201-06196-1).
+
+ The standard reference book on the internals of {BSD} {Unix}.
+ So called because the cover has a picture depicting a little
+ devil (a visual play on {daemon}) in sneakers, holding a
+ pitchfork (referring to one of the characteristic features of
+ Unix, the "{fork}(2)" {system call}).
+
+ [{Jargon File}]
+
+ (1996-12-03)
+
+/dev/null
+
+ /dev-nuhl/ [The Unix null device, used as a {data sink}] A
+ notional "black hole" in any information space being
+ discussed, used, or referred to. A controversial posting, for
+ example, might end "Kudos to rasputin@kremlin.org, flames to
+ /dev/null". See {bit bucket}.
+
+ [{Jargon File}]
+
+devo
+
+ /dee'voh/ (In-house jargon at {Symbolics}) A person in a
+ development group. See also {doco} and {mango}.
+
+ (1994-11-04)
+
+DEX
+
+ A cross between {Modula-2} and {C} by W. van Oortmerssen.
+
+ {Amiga version 1.2
+ (ftp://ftp.cso.uiuc.edu/pub/amiga/fish/f7/ff743/TurboDEX.lzh)}.
+
+DFA
+
+ Deterministic Finite-state Automaton. See {Finite State
+ Machine}.
+
+DFC
+
+ A {dataflow} language.
+
+ ["Data Flow Language DFC: Design and Implementation",
+ S. Toshio et al, Systems and Computers in Japan, 20(6):1- 10
+ (Jun 1989)].
+
+DFD
+
+ {Data Flow Diagram}
+
+DFS
+
+ 1. <algorithm> {Depth-First Search}.
+
+ 2. <file system> {Distributed File System}.
+
+DFT
+
+ {discrete Fourier transform}
+
+DGL
+
+ 1. Data Generation Language. A tool for generating test data
+ for hardware or software systems.
+
+ 2. Distributed {GL}.
+
+DG/L
+
+ 1. Descriptive Geometry Language. Early CAD/CAE language,
+ used light pen. "Interactive Graphic Consoles - Environment
+ and Software", R.L. Beckermeyer, Proc FJCC 37 (1970).
+
+ 2. Data General ca 1973-1974. Derivative of ALGOL 60,
+ developed from DG's ALGOL-5, used as the systems language
+ under {AOS} and {RDOS} for the DG Eclipse family of computers.
+ Replaced by PL/I in the early 80's. Data General manual
+ 093-000229-01.
+
+DHCP
+
+ {Dynamic Host Configuration Protocol}
+
+Dhrystone
+
+ <benchmark> A short {synthetic benchmark} program by Reinhold
+ Weicker <weicker.muc@sni.de>, <weicker.muc@sni-usa.com>,
+ intended to be representative of system (integer) programming.
+ It is available in {ADA}, {Pascal} and {C}.
+
+ The current version is Dhrystone 2.1. The author says,
+ "Relying on MIPS V1.1 (the result of V1.1) numbers can be
+ hazardous to your professional health."
+
+ Due to its small size, the memory system outside the {cache}
+ is not tested. Compilers can too easily optimise for
+ Dhrystone. String operations are somewhat over-represented.
+
+ {Sources (ftp://ftp.nosc.mil/pub/aburto/)}.
+
+ {Results
+ (http://performance.netlib.org/performance/html/dhrystone.data.col0.html)}.
+
+ (2002-03-26)
+
+DHSD
+
+ {Duplex High Speed Data}
+
+DHTML
+
+ {Dynamic HTML}
+
+Dialled Number Identification Service
+
+ <communications> (DNIS) A service that tells the recipient of
+ a telephone call the telephone number dialled by the person
+ making the call. It is used by call centres hosting multiple
+ numbers, voicemail systems and ISPs offering shared dial-in
+ services.
+
+ Compare {ANI}, {Caller ID}.
+
+ (2005-02-09)
+
+DIALOG
+
+ 1. A commercial bibliographic database and retrieval service
+ from DIALOG Information Services.
+
+ 2. Interactive mathematics using a {graphics tablet} by
+ Illinois Inst Tech, 1966.
+
+ ["DIALOG: A Conversational Programming System with a Graphical
+ Orientation", S.H. Cameron et al, CACM 10:349-357 (1967).
+ Sammet 1969, p.255-258].
+
+dialup
+
+ A temporary, as opposed to dedicated, connection between
+ machines established over a telephone line using {modems}.
+
+DIAMAG
+
+ An interactive extension of {ALGOL}.
+
+ [Sammet 1969, p.195].
+
+diameter
+
+ The diameter of a {graph} is the maximum value of the minimum
+ distance between any two nodes.
+
+Diamond
+
+ One of five pedagogical languages based on Markov algorithms,
+ used in "Nonpareil, a Machine Level Machine Independent
+ Language for the Study of Semantics", B. Higman, ULICS Intl
+ Report No ICSI 170, U London (1968). (cf. Brilliant,
+ Nonpareil, Pearl[3], Ruby[2]).
+
+DIANA
+
+ {Descriptive Intermediate Attributed Notation for Ada}
+
+DIB
+
+ {device independent bitmap}
+
+DIBOL
+
+ Digital Interactive Business Oriented Language.
+
+ DEC, 1970.
+
+ Fortran syntax with BCD arithmetic.
+
+ Versions for PDP-8 and RT-11.
+
+ ANSI X3.165-1988.
+
+dickless workstation
+
+ <abuse> Extremely pejorative hackerism for "{diskless
+ workstation}".
+
+ [{Jargon File}]
+
+ (1995-03-28)
+
+Dick Size War
+
+ {penis war}
+
+DICOM
+
+ <medical, standard> (From Digital Imaging and COmmunications
+ in Medicine) A {standard} developed by ACR-NEMA (American
+ College of Radiology - National Electrical Manufacturer's
+ Association) for communications between medical imaging
+ devices. It conforms to the {ISO reference model} for network
+ communications and incorporates {object-oriented} design
+ concepts.
+
+ (1995-03-29)
+
+dictionary
+
+ 1. {data dictionary}.
+
+ 2. {associative array}.
+
+ 3. {Free On-line Dictionary of Computing}.
+
+Dictionary APL
+
+ {Sharp APL}
+
+dictionary flame
+
+ [{Usenet}] An attempt to sidetrack a debate away from issues
+ by insisting on meanings for key terms that presuppose a
+ desired conclusion or smuggle in an implicit premise. A
+ common tactic of people who prefer argument over definitions
+ to disputes about reality. Compare {spelling flame}.
+
+ [{Jargon File}]
+
+Dictionary of Algorithms and Data Structures
+
+ <algorithm> (DADS) A dictionary by Paul Black.
+
+ {(http://www.aprendelo.com/rec/dictionary-algorithms-and-data-structures.html)}.
+
+ (2001-03-26)
+
+Dictionary of Computing
+
+ {Free On-line Dictionary of Computing}
+
+DID
+
+ {Direct Inward Dialing}
+
+diddle
+
+ <jargon> (US) To work in a casual manner, or the result of such
+ work. (In the UK "to diddle someone" means to cheat them).
+
+ "I diddled a copy of {ADVENT} so it didn't double-space all the
+ time." "Let's diddle this piece of code and see if the problem
+ goes away."
+
+ Similar to {twiddle}, less purposeful than {tweak}.
+
+ [{Jargon File}]
+
+ (2013-08-18)
+
+Didot point
+
+ <unit, text> A variant of the {point}, equal to 0.3759 mm, or
+ 1/72 of a French Royal inch (27.07 mm), or about 1/68 inch.
+ Didot points are used in Europe. This unit is named after the
+ French printer François Ambroise Didot (1730 - 1804) who
+ defined the "point-based" typographical measurement system.
+
+ (2002-03-11)
+
+die
+
+ 1. <jargon> {crash}. Unlike {crash}, which is used primarily
+ of hardware, this verb is used of both hardware and software.
+
+ See also {go flatline}, {casters-up mode}.
+
+ 2. <electronics> Plural: dies. An unpackaged {integrated
+ circuit}.
+
+ [{Jargon File}]
+
+ (2002-12-09)
+
+die horribly
+
+ <jargon> The software equivalent of {crash and burn}, and the
+ preferred emphatic form of {die}. "The converter choked on an
+ FF in its input and died horribly".
+
+ [{Jargon File}]
+
+ (1996-05-28)
+
+diff
+
+ /dif/ 1. A change listing, especially giving differences
+ between (and additions to) different versions of a piece of
+ source code or documentation (the term is often used in the
+ plural "diffs"). "Send me your diffs for the Jargon File!"
+
+ Compare {vdiff}.
+
+ 2. Specifically, such a listing produced by the diff {Unix}
+ command, especially when used as input to the {patch} utility
+ (which actually performs the modifications). This is a common
+ method of distributing patches and source updates.
+
+ 3. To compare (whether or not by use of automated tools on
+ machine-readable files).
+
+ See also {vdiff}, {mod}.
+
+ [{Jargon File}]
+
+ (1995-02-10)
+
+Difference Engine
+
+ <computer, history> {Charles Babbage}'s design for the first
+ automatic mechanical calculator. The Difference Engine was a
+ special purpose device intended for the production of
+ mathematical tables. Babbage started work on the Difference
+ Engine in 1823 with funding from the British Government. Only
+ one-seventh of the complete engine, about 2000 parts, was
+ built in 1832 by Babbage's engineer, Joseph Clement. This was
+ demonstrated successfully by Babbage and still works
+ perfectly. The engine was never completed and most of the
+ 12,000 parts manufactured were later melted for scrap.
+
+ It was left to Georg and Edvard Schuetz to construct the first
+ working devices to the same design which were successful in
+ limited applications. The Difference Engine No. 2 was finally
+ completed in 1991 at the Science Museum, London, UK and is on
+ display there.
+
+ The engine used gears to compute cumulative sums in a series
+ of {registers}: r[i] := r[i] + r[i+1]. However, the addition
+ had the {side effect} of zeroing r[i+1]. Babbage overcame
+ this by simultaneously copying r[i+1] to a temporary register
+ during the addition and then copying it back to r[i+1] at the
+ end of each cycle (each turn of a handle).
+
+ {Difference Engine at the Science Museum
+ (http://nmsi.ac.uk/on-line/treasure/plan/2ndcomp.htm#babbage)}.
+
+ (1997-09-29)
+
+difference equation
+
+ <mathematics> A {relation} between consecutive elements of a
+ {sequence}. The first difference is
+
+ D u(n) = u(n+1) - u(n)
+
+ where u(n) is the nth element of sequence u. The second
+ difference is
+
+ D2 u(n) = D (D u(n))
+ = (u(n+2) - u(n+1)) - (u(n+1) - u(n))
+ = u(n+2) - 2u(n+1) + u(n)
+
+ And so on. A {recurrence relation} such as
+
+ u(n+2) + a u(n+1) + b u(n) = 0
+
+ can be converted to a difference equation (in this case, a
+ second order linear difference equation):
+
+ D2 u(n) + p D u(n) + q u(n) = 0
+
+ and vice versa. a, b, p, q are constants.
+
+ (1995-02-10)
+
+differential backup
+
+ <operating system> A kind of {backup} that copies all {files}
+ that have changed since the last {full backup}. Each
+ differential backup will include all files in previous
+ differential backups since the full backup so to restore a
+ version of a file, you only need to search the full backup and
+ the relevant differential backup.
+
+ Some systems support differential backup by associating an
+ "Archive" flag with each file and setting this flag whenever
+ the file is modified to indicate that it should be included in
+ the next backup. A differential backup does not change this
+ flag, whereas an {incremental backup} resets it.
+
+ (2004-03-05)
+
+differential driver
+
+ <hardware> An electronic device (commonly an {integrated
+ circuit}), containing two amplifiers, used to drive a
+ {differential line}.
+
+ (1995-03-14)
+
+differential line
+
+ <hardware> A kind of electrical connection using two wires,
+ one of which carries the normal signal (V) and the other
+ carries an inverted version the signal (-V). A differential
+ amplifier at the receiver subtracts the inverted signal from
+ the normal signal to yield a signal proportional to V. This
+ subtraction is intended to cancel out any noise induced in the
+ wires, on the assmption that the same level of noise will have
+ been induced in both wires. {Twisted pair} wiring is often
+ used to try to ensure that this is the case.
+
+ The two wires might be connected at the receiver to separate
+ {analogue to digital converters} and the subtraction performed
+ digitally.
+
+ The {RS-422} {serial line} {standard} specifies differential
+ drivers and receivers, whereas the earlier {RS-232} standard
+ does not.
+
+ Opposite: {single ended}.
+
+ (1995-03-08)
+
+Diffie-Hellman
+
+ <cryptography> A {public-key encryption} {key exchange
+ algorithm}.
+
+ {FAQ (http://rsa.com/rsalabs/faq/html/3-6-1.html)}.
+
+ (1999-03-15)
+
+digerati
+
+ <jargon> (Or "digirati". By analogy with "literati" - people
+ knowledgeable about literature) People knowledgeable about
+ computers, "computer literate".
+
+ [Newsweek, March 1995?].
+
+ (1995-05-07)
+
+digest
+
+ A periodical collection of messages which have been posted to
+ a {newsgroup} or {mailing list}. A digest is prepared by a
+ {moderator} who selects articles from the group or list,
+ formats them and adds a contents list. The digest is then
+ either mailed to an alternative {mailing list} or posted to an
+ alternative newsgroup.
+
+ Some {news readers} and {electronic mail} programs provide
+ commands to "undigestify" a digest, i.e. to split it up into
+ individual articles which may then be read and saved or
+ discarded separately.
+
+Digex
+
+ {Digital Express Group, Inc.}
+
+DigiCash
+
+ <company> A company, started in April 1990, which aims to
+ develop and license products to support electronic payment
+ methods including {chip card}, software only, and hybrid.
+
+ {Ecash} is their trial form of software-only electronic money.
+
+ {(http://digicash.com/home.html)}.
+
+ (1995-04-10)
+
+Digicom
+
+ {(ftp://ftp.whnet.com/pub/wolfgang)},
+ {(ftp://softmodem.whnet.com/pub/wolfgang)},
+ {(ftp://ftp.netcom.com/pub/wolfgang)}.
+ {(http://ftp.whnet.com/wolfgang/)}.
+
+ [Description?]
+
+digirati
+
+ {digerati}
+
+digit
+
+ An employee of Digital Equipment Corporation. See also
+ {VAX}, {VMS}, {PDP-10}, {TOPS-10}, {DEChead}, {double
+ DECkers}, {field circus}.
+
+ [{Jargon File}]
+
+Digital
+
+ <company> Common abbreviation for {Digital Equipment
+ Corporation}.
+
+ (1995-12-18)
+
+digital
+
+ <data> A description of {data} which is stored or transmitted
+ as a sequence of discrete symbols from a finite set, most
+ commonly this means {binary} data represented using electronic
+ or electromagnetic signals.
+
+ The opposite is {analogue}.
+
+ (1998-10-28)
+
+digital audio
+
+ <multimedia, file format> A sequence of discrete samples taken
+ from a continuous sound ({audio}) waveform. Tens of thousands
+ of samples are taken each second. Each sample represents the
+ intensity of the sound pressure wave at that instant. Apart
+ from the sampling frequency, the other parameter is the
+ digital encoding of each sample including the number of {bits}
+ used. The encoding may be linear, logarithmic or {mu-law}.
+
+ Digital audio is typically created by taking 16-bit samples
+ over a spectrum of 44.1 thousand cycles per second (kHz), this
+ means that CD quality sound requires 1.4 million bits of data
+ per second. Digital telephone systems use lower sample rates.
+
+ {Filename extension}: .au ({Unix}), .snd ({MS-DOS}, {MS
+ Windows}).
+
+ See also {Audio IFF}, {MP3}, {wav}.
+
+ {Usenet} newsgroups: alt.binaries.sounds.*.
+
+ A {FAQ} on audio file formats is available. {Part 1
+ (ftp://ftp.cwi.nl/pub/audio/AudioFormats.part1)}, {Part 2
+ (ftp://ftp.cwi.nl/pub/audio/AudioFormats.part2)}.
+
+ (1999-07-30)
+
+Digital Audio Tape
+
+ <storage, music> (DAT) A format for storing music on magnetic
+ tape, developed in the mid-1980s by {Sony} and {Philips}. As
+ digital music was popularized by {compact discs}, the need for
+ a digital recording format for the consumer existed. The
+ problem is that digital music contains over 5 megabytes of
+ data per minute before error correction and supplementary
+ information. Before DAT, the only way to record digitally was
+ to use a video or a reel-to-reel recorder.
+
+ DAT uses a rotary-head (or "helical scan") format, where the
+ read/write head spins diagonally across the tape like a video
+ cassette recorder. Thus the proper name is "R-DAT", where "R"
+ for rotary distinguishes it from "S-DAT", a stationary design
+ that did not make it out of the laboratories. Studio
+ reel-to-reel decks are able to use stationary heads because
+ they can have wider tape and faster tape speeds, but for the
+ desired small medium of DAT the rotary-head compromise was
+ made despite the potential problems with more moving parts.
+
+ Most DAT recorders appear to be a cross between a typical
+ analog cassette deck and a {compact disc} player. In addition
+ to the music, one can record subcode information such as the
+ number of the track (so one can jump between songs in a
+ certain order) or absolute time (counted from the beginning of
+ the tape). The tape speed is much faster than a regular deck
+ (one can rewind 30 minutes of music in 10-25 seconds), though
+ not quite as fast as a compact disc player. DAT decks have
+ both analog and digital inputs and outputs.
+
+ DAT tapes have only one recordable side and can be as long 120
+ minutes.
+
+ DAT defines the following recording modes with the following
+ performance specifications...
+
+ 2 channel 48KHz Sample rate, 16-bit linear encoding
+ 120 min max.
+ Frequency Response 2-22KHz (+-0.5dB)
+ SN = 93 dB DR = 93 dB
+
+ 2 channel 44.1Khz Sample rate, 16-bit linear encoding
+ 120 min max
+ Frequency Response 2-22KHz (+-0.5dB)
+ SN = 93 dB DR = 93 dB
+
+ 2 channel 32KHz Sample Rate, 12-bit non-linear encoding
+ 240 min max
+ Frequency Response 2-14.5KHz (+-0.5dB)
+ SN = 92 dB DR = 92 dB
+
+ 4 channel 32KHz (not supported by any deck)
+
+ DAT is also used for recording computer data. Most computer
+ DAT recorders use DDS format which is the same as audio DAT
+ but they usually have completely different connectors and it
+ is not always possible to read tapes from one system on the
+ other. Computer tapes can be used in audio machines but are
+ usually more expensive. You can record for two minutes on
+ each metre of tape.
+
+ (1995-02-09)
+
+digital camera
+
+ <graphics, hardware> A camera that captures and stores still
+ images as {digital} data instead of on photographic film.
+
+ The first digital cameras became available in the early
+ 1990s[?].
+
+ [Which and when was the first?]
+
+ (2000-08-10)
+
+digital carrier
+
+ <hardware, communications> A medium which can carry {digital}
+ signals; broadly equivalent to the {physical layer} of the
+ {OSI} seven layer model of networks. Carriers can be
+ described as {baseband} or {broadband}. A baseband carrier
+ can include direct current (DC), whereas broadband carriers
+ are modulated by various methods into frequency bands which do
+ not include DC.
+
+ Sometimes a {modem} (modulator/demodulator) or {codec}
+ (coder/decoder) combines several channels on one transmission
+ path. The combining of channels is called {multiplexing}, and
+ their separation is called demultiplexing, independent of
+ whether a modem or codec bank is used. Modems can be
+ associated with {frequency division multiplexing} (FDM) and
+ codecs with {time division multiplexing} (TDM) though this
+ grouping of concepts is somewhat arbitrary.
+
+ If the medium of a carrier is copper telephone wire, the
+ circuit may be called {T1}, {T3}, etc. as these designations
+ originally described such.
+
+ T1 carriers used a restored polar line coding scheme which
+ allowed a baseband signal to be transported as broadband and
+ restored to baseband at the receiver. T1 is not used in this
+ sense today, and indeed it is often confused with the {DS1}
+ signal carried.
+
+ (1996-03-31)
+
+digital certificate
+
+ <communications, security> An {attachment} to an {electronic
+ mail} message used for security purposes, e.g. to verify that
+ a user sending a message is who he or she claims to be, and to
+ provide the receiver with the means to encode a reply.
+
+ An individual wishing to send an encrypted message applies for
+ a digital certificate from a {certificate authority} (CA).
+ The CA issues an encrypted digital certificate containing the
+ applicant's {public key} and a variety of other identification
+ information. The CA makes its own public key readily
+ available on the {Internet}.
+
+ The recipient of an encrypted message uses the CA's public key
+ to decode the digital certificate attached to the message,
+ verifies it as issued by the CA and then obtains the sender's
+ public key and identification information held within the
+ certificate.
+
+ (2006-05-27)
+
+digital computer
+
+ <computer> A {computer} that represents numbers and other data
+ using discrete internal states, in contrast to the
+ continuously varying quantities used in an {analog computer}.
+
+ Some of the fundamental ideas behind the digital computer were
+ proposed by {Alan Turing} between 1936 and 1938. The design
+ of the {Atanasoff-Berry Computer} (1937-1942) included some of
+ the important implementation details but the first digital
+ computer to successfully run real programs was the {Z3}
+ (1941). {ENIAC} (1943-1946) was the first electronic digital
+ computer but was only programmable by manual rewiring or
+ switches.
+
+ (2003-10-01)
+
+Digital Control System
+
+ <systems> (DCS) A {digital computer} used for {real-time} control
+ of a {dynamic system}, usually in an industrial environment,
+ possibly as part of a {Supervisory Control and Data Acquisition}
+ (SCADA) system.
+
+ A DCS samples {feedback} from the system under control and
+ modifies the control signals in an attempt to achieve some
+ desired behaviour.
+
+ Analysis of such digital-analogue feedback systems can involve
+ mathematical methods such as {difference equations}, {Laplace
+ transforms}, {z transfer functions}, {state space models} and
+ {state transition matrices}.
+
+ (2004-08-22)
+
+digital dashboard
+
+ <software> A personalised desktop {portal} that focuses on
+ {business intelligence} and {knowledge management}.
+
+ {Microsoft}'s version has a launch screen including stock
+ quotes, voice mail and e-mail messages, a calendar, a weather
+ forecast, traffic information, access to news feeds, customer
+ and sales data, and Internet conferences. A digital dashboard
+ might previously have been thought of as an executive
+ information system. In the future, digital dashboards could
+ be available on {personal digital assistants} and cellular
+ phones.
+
+ ["Gates pitches 'digital dashboards' to bevy of top CEOs", Bob
+ Trott, pub. InfoWorld Electric, 1999-05-19].
+
+ (1999-09-14)
+
+Digital Data Service
+
+ <communications> (DDS) The class of service offered by
+ telecommunications companies for transmitting digital data as
+ opposed to voice.
+
+ (1995-02-28)
+
+digital electronics
+
+ <electronics> The implementation of {two-valued logic} using
+ electronic {logic gates} such as {and gates}, {or gates} and
+ {flip-flops}. In such circuits the logical values true and
+ false are represented by two different {voltages}, e.g. 0V for
+ false and +5V for true. Similarly, numbers are normally
+ represented in {binary} using two different voltages to
+ represented zero and one.
+
+ Digital electronics contrasts with {analogue} electronics
+ which represents continuously varying quantities like sound
+ pressure using continuously varying voltages.
+
+ Digital electronics is the foundation of modern computers and
+ {digital communications}. Massively complex digital logic
+ circuits with millions of gates can now be built onto a single
+ {integrated circuit} such as a {microprocessor} and these
+ circuits can perform millions of operations per second.
+
+ (2006-01-14)
+
+Digital Enhanced Cordless Telecommunications
+
+ <communications, standard> (DECT, formerly ".. European ..") A
+ {standard} developed by the {European Telecommunication
+ Standard Institute} from 1988, governing pan-European {digital
+ mobile telephony}. DECT covers wireless {PBXs}, {telepoint},
+ residential {cordless telephones}, wireless access to the
+ {public switched telephone network}, Closed User Groups
+ (CUGs), {Local Area Networks}, and wireless {local loop}.
+
+ DECT defines only the radio connection between two points and
+ can be used for remote access to public and private networks.
+ Other mobility standards, such as {GSM}, {TACS}, and {DCS
+ 1800} add the necessary switching, signaling, and management
+ functions that are not specified by DECT.
+
+ The DECT Common Interface radio standard is a {multicarrier}
+ {time division multiple access}, {time division duplex}
+ (MC-TDMA-TDD) radio transmission technique using ten {radio
+ frequency} channels from 1880 to 1930 MHz, each divided into
+ 24 time slots of 10ms, and twelve {full-duplex} accesses per
+ {carrier}, for a total of 120 possible combinations.
+
+ A DECT base station (an RFP, Radio Fixed Part) can transmit
+ all 12 possible accesses (time slots) simultaneously by using
+ different frequencies or using only one frequency. All
+ signaling information is transmitted from the RFP within a
+ multiframe (16 frames). {Voice} signals are digitally encoded
+ into a 32 kbit/s signal using {Adaptive Differential Pulse
+ Code Modulation}.
+
+ The {handover} process is requested autonomously by the
+ portable terminal and the Radio Fixed Parts, according to the
+ carrier signal levels. A "Generic Access Profile" defines a
+ minimum set of requirements for the support of speech
+ telephony.
+
+ {(http://italtel.it/catalog/data/inglese/capc_5.htm)}.
+
+ (1999-04-13)
+
+digital envelope
+
+ <cryptography>
+
+ {(http://rsa.com/rsalabs/faq/html/2-2-4.html)}.
+
+ [Summary?]
+
+ (1999-03-16)
+
+Digital Equipment Computer Users Society
+
+ <body> (DECUS) A world-wide organisation of {Information
+ Technology} professionals interested in the products, services,
+ and technologies of {Digital Equipment Corporation} and related
+ vendors. Membership in the US chapter is free and provides
+ participants with the means to enhance their professional
+ development, forums for technical training, mechanisms for
+ obtaining up-to-date information, advocacy programs and
+ opportunities for informal disclosure and interaction with
+ professional colleagues of like interest.
+
+ {DECUS Home (http://www.decus.org/)}.
+
+ (2014-08-26)
+
+Digital Equipment Corporation
+
+ <company, hardware> (DEC) A computer manufacturer and software
+ vendor.
+
+ Before the {killer micro} revolution of the late 1980s,
+ hackerdom was closely symbiotic with DEC's pioneering
+ {time-sharing} machines. The first of the group of hacker
+ cultures nucleated around the {PDP-1} (see {TMRC}).
+ Subsequently, the {PDP-6}, {PDP-10}, {PDP-20}, {PDP-11} and
+ {VAX} were all foci of large and important hackerdoms and DEC
+ machines long dominated the {ARPANET} and {Internet} machine
+ population.
+
+ The first PC from DEC was a {CP/M} computer called {Rainbow},
+ announced in 1981-82.
+
+ DEC was the technological leader of the minicomputer era
+ (roughly 1967 to 1987), but its failure to embrace
+ {microcomputers} and {Unix} early cost it heavily in profits
+ and prestige after {silicon} got cheap. However, the
+ {microprocessor} design tradition owes a heavy debt to the
+ {PDP-11} {instruction set}, and every one of the major
+ general-purpose microcomputer {operating systems} so far
+ (CP/M, {MS-DOS}, {Unix}, {OS/2}) were either genetically
+ descended from a DEC OS, or incubated on DEC {hardware} or
+ both. Accordingly, DEC is still regarded with a certain wry
+ affection even among many hackers too young to have grown up
+ on DEC machines. The contrast with {IBM} is instructive.
+
+ Quarterly sales $3923M, profits -$1746M (Aug 1994).
+
+ DEC was taken over by {Compaq Computer Corporation} in 1998.
+ In 2002 Compaq was in turn acquired by {Hewlett-Packard} who
+ sold off parts of Digital Equipment Corporation to {Intel} and
+ absorbed the rest. The Digital logo is no longer used.
+
+ (2012-07-29)
+
+Digital Equipment Corporation Network
+
+ <networking> (DECNET) {Ethernet} software used on {DEC}
+ computers such as the {Vax}.
+
+ [More details?]
+
+ (1999-06-03)
+
+Digital European Cordless Telecommunications
+
+ {Digital Enhanced Cordless Telecommunications}
+
+Digital Express Group, Inc.
+
+ (Digex) The largest {Internet provider} in the Washington
+ metropolitan area with {POPs} in Maryland, Virginia, New
+ Jersey, New York and California.
+
+ {(http://digex.net)}.
+
+ (1994-10-25)
+
+Digital Lempel Ziv 1
+
+ <algorithm> (DLZ1) A {Lempel-Ziv compression} {algorithm}
+ which maps variable length input strings to variable length
+ output symbols. During compression, the algorithm builds a
+ dictionary of strings which is accessed by means of a {hash
+ table}. Compression occurs when input data matches a string
+ in the table and is replaced with the output symbol.
+
+ DLZ1 is used on {Digital Linear Tape}.
+
+ (1997-04-05)
+
+Digital Library Initiative
+
+ A project to research digital libraries which aims to provide
+ real collections to real users (high school students,
+ University researchers and students, users in public
+ libraries). The project is sponsored jointly by three US
+ federal funding agencies, led by the National Science
+ Foundation.
+
+ The {University of Michigan}, one of the six sites selected in
+ 1994 to collaborate, will provide collections on earth and
+ space sciences. The project, known there as the University of
+ Michigan Digital Library Project (UMDL), is a large,
+ multi-year project headed by Daniel Atkins, Dean of the School
+ of Information and Library Studies.
+
+ {UMDL (http://http2.sils.umich.edu/UMDL/HomePage.html)}.
+
+ (1995-02-23)
+
+Digital Linear Tape
+
+ <storage> (DLT) A kind of {magnetic tape} drive
+ originally developed by {DEC} and now marketed by {Quantum}.
+
+ DLT drives implement the {Digital Lempel Ziv 1} (DLZ1)
+ {compression} {algorithm} in a combination of {hardware} and
+ {firmware}. They use a popular chip by {Stac} (now {hi/fn})
+ to do the string searching. Counting, sorting and {Huffman
+ coding} are done in firmware (with hardware support for the
+ Huffman algorithm?).
+
+ In April 1997 DLT drives can transfer 5 {megabytes} per second
+ and can store 35 {gigabytes} on a single cartridge.
+ Compression might roughly double these figures.
+
+ (1997-04-05)
+
+digital logic
+
+ {two-valued logic}
+
+Digital Multimeter
+
+ <electronics> (DMM) A peice of test equipment used for
+ measuring voltage, current, resistance, and possibly other
+ electircal quantities and displaying the value in number form.
+
+ (1997-02-12)
+
+Digital Radio Mondiale
+
+ <communications> (DRM) A form of {monaural} digital broadcast
+ using {carrier} frequencies below 30 MHz. DRM uses {MPEG-4
+ AAC Main Profile} and {SBR} at data rates of 16-25 kbps.
+
+ {(http://drm.org/)}.
+
+ (2001-12-20)
+
+Digital Research
+
+ <company> The company which developed {CP/M}, the {operating
+ system} used on many of the first generation 8-bit
+ {microprocessor}-based {personal computers}. Digital Research
+ also produced {DR-DOS}.
+
+ Address: Santa Cruz, CA, USA.
+
+ (1998-03-17)
+
+Digital Rights Management
+
+ <legal> (DRM) Any technology used to limit the use of
+ {software}, music, movies or other digital data. This
+ generally relies on some interaction between the media and the
+ system that plays it. For example, video {DVDs} usually
+ include a {region code}. If this does not match the player's
+ region code, the player will refuse to play the disc.
+
+ (2006-02-02)
+
+digital service unit
+
+ {data service unit}
+
+Digital Signal Processing
+
+ (DSP) Computer manipulation of analog signals (commonly sound
+ or {image}) which have been converted to digital form
+ (sampled).
+
+ (1994-12-07)
+
+Digital Signal Processing Language
+
+ <language> (DSPL) A {C}-derived {DSP} language.
+
+ ["The Programming Language DSPL", A. Schwarte & H. Hanselmann,
+ Proc PCIM 90, 1990].
+
+ (1994-12-01)
+
+digital signature
+
+ <cryptography> Extra data appended to a message which
+ identifies and authenticates the sender and message data using
+ {public-key encryption}.
+
+ The sender uses a {one-way hash function} to generate a
+ hash-code of about 32 bits from the message data. He then
+ encrypts the hash-code with his private key. The receiver
+ recomputes the hash-code from the data and decrypts the
+ received hash with the sender's public key. If the two
+ hash-codes are equal, the receiver can be sure that data has
+ not been corrupted and that it came from the given sender.
+
+ (1995-02-07)
+
+digital signatures
+
+ {digital signature}
+
+Digital Signature Standard
+
+ <cryptography, standard> The {NIST}'s {standard} for {digital
+ signatures} (authenticating both a message and the signer)
+ that was first announced in 1991. It is based on an
+ {algorithm} using {discrete logarithms}, which is a variant of
+ the {Elgamal algorithm} with Schnorr's improvements. DSS's
+ security is currently considered very strong - comparable to
+ {RSA}. It is estimated that DSS's 1024-bit keys would take
+ 1.4E16 {MIPS}-years to crack.
+
+ (1995-11-16)
+
+Digital Simulation Language
+
+ <language> (DSL) Extensions to {Fortran} to simulate {analog
+ computer} functions. Version DSL/90 ran on the {IBM 7090}.
+
+ ["DSL/90 - A Digital Simulation Program for Continuous System
+ Modelling", Proc SJCC 28, AFIPS, Spring 1966].
+
+ [Sammet 1969, p 632].
+
+ (1996-10-13)
+
+Digital Simultaneous Voice and Data
+
+ <communications> (DSVD) A technique supported by some {modems}
+ for multiplexing compressed speech with digital data for
+ transmission over a normal telephone line.
+
+ DSVD isn't standardised yet, so generally you have to have the
+ same make of modem at both ends for it to work.
+
+ [How does it work? Which modems? References?]
+
+ (1997-06-05)
+
+DIGITAL Standard MUMPS
+
+ (DSM) {DEC}'s version of {MUMPS}.
+
+ (1995-01-10)
+
+Digital Subscriber Line
+
+ <communications, protocol> (DSL, or Digital Subscriber Loop,
+ xDSL - see below) A family of {digital} {telecommunications}
+ {protocols} designed to allow high speed data communication
+ over the existing {copper} telephone lines between end-users
+ and telephone companies.
+
+ When two conventional {modems} are connected through the
+ telephone system ({PSTN}), it treats the communication the
+ same as voice conversations. This has the advantage that
+ there is no investment required from the telephone company
+ (telco) but the disadvantage is that the {bandwidth} available
+ for the communication is the same as that available for voice
+ conversations, usually 64 kb/s ({DS0}) at most. The
+ {twisted-pair} copper cables into individual homes or offices
+ can usually carry significantly more than 64 kb/s but the
+ telco needs to handle the signal as digital rather than
+ analog.
+
+ There are many implementation of the basic scheme, differing
+ in the communication {protocol} used and providing varying
+ {service levels}. The {throughput} of the communication can
+ be anything from about 128 kb/s to over 8 Mb/s, the
+ communication can be either symmetric or asymmetric (i.e. the
+ available bandwidth may or may not be the same {upstream} and
+ {downstream}). Equipment prices and service fees also vary
+ considerably.
+
+ The first technology based on DSL was {ISDN}, although ISDN is
+ not often recognised as such nowadays. Since then a large
+ number of other protocols have been developed, collectively
+ referred to as xDSL, including {HDSL}, {SDSL}, {ADSL}, and
+ {VDSL}. As yet none of these have reached very wide
+ deployment but wider deployment is expected for 1998-1999.
+
+ {(http://cyberventure.com/~cedpa/databus-issues/v38n1/xdsl.html)}.
+
+ {2Wire DSL provider lookup (http://2Wire.com/)}.
+
+ ["Data Cooks, But Will Vendors Get Burned?", "Supercomm
+ Spotlight On ADSL" & "Lucent Sells Paradine", Wilson & Carol,
+ Inter@ctive Week Vol. 3 #13, p1 & 6, June 24 1996].
+
+ (2001-04-30)
+
+Digital Subscriber Line Access Module
+
+ <networking, hardware> (DSLAM, or Digital Subscriber Line
+ Access Multiplexer) The generic term for the {Central Office}
+ (CO) equipment where x{DSL} lines are terminated. The
+ multiple {DSL} signals may be {multiplexed} onto a {wideband}
+ channel such as {ATM}.
+
+ (2000-04-05)
+
+Digital Subscriber Loop
+
+ {Digital Subscriber Line}
+
+Digital Switched Network
+
+ <communications> (DSN) The completely digital version of the
+ {PSTN}.
+
+ (1997-07-18)
+
+Digital to Analog Converter
+
+ <electronics> (DAC) A device which takes a digital value and
+ outputs a voltage which is proportional to the input value.
+
+ Typical uses include digital generation of audio signals or
+ conversion of a {bitmap image} to a signal to drive a {CRT}.
+
+ (1998-02-15)
+
+Digital Versatile Disc
+
+ <storage> (DVD, formerly "Digital Video Disc") An optical
+ storage medium with improved capacity and bandwidth compared
+ with the {Compact Disc}. DVD, like CD, was initally marketed
+ for entertainment and later for computer users. [When was it
+ first available?]
+
+ A DVD can hold a full-length film with up to 133 minutes of
+ high quality video, in {MPEG-2} format, and audio.
+
+ The first DVD drives for computers were read-only drives
+ ("DVD-ROM"). These can store 4.7 GBytes - over seven times
+ the storage capacity of CD-ROM. DVD-ROM drives read existing
+ {CD-ROMs} and music CDs and are compatible with installed
+ sound and video boards. Additionally, the DVD-ROM drive can
+ read DVD films and modern computers can decode them in
+ software in {real-time}.
+
+ The DVD video standard was announced in November 1995.
+ Matshusita did much of the early development but Philips made
+ the first DVD player, which appeared in Japan in November
+ 1996. In May 2004, Sony released the first dual-layer drive,
+ which increased the disc capacity to 8.5 GB. Double-sided,
+ dual-layer discs will eventually increase the capacity to 17
+ GB.
+
+ Write-once DVD-R ("recordable") drives record a 3.9GB DVD-R
+ disc that can be read on a DVD-ROM drive. Pioneer released
+ the first DVD-R drive on 1997-09-29.
+
+ By March 1997, {Hitachi} had released a rewritable DVD-RAM
+ drive (by false analogy with {random-access memory}). DVD-RAM
+ drives read and write to a 2.6 GB DVD-RAM disc, read and
+ write-once to a 3.9GB DVD-R disc, and read a 4.7 GB or 8.5 GB
+ DVD-ROM. Later, DVD-RAM discs could be read on DVD-R and
+ DVD-ROM drives.
+
+ {Background (http://tacmar.com/dvd_background.htm)}. {RCA
+ home (http://imagematrix.com/DVD/home.html)}.
+
+ (2006-01-07)
+
+Digital Versatile Disk Random Access Memory
+
+ <storage> (DVD-RAM) Rewritable {DVD} media that is recordable
+ on both sides, giving up to 9.6{GB} of storage. A drive can
+ record to disk and read from it at the same time, so the term
+ {full duplex} is often used. There are two general types of
+ media: traditional discrete disk in DVD or Jewel case, and one
+ in a permanent case like a large floppy; the disk remains in
+ the case, and the case goes into the drive. The former can
+ sometimes be read by regular DVD drives; the latter obviously
+ cannot.
+
+ {Technical details, somewhat dated, at burnworld.com
+ (http://burnworld.com/dvd/primer/dvdram.htm)}.
+
+ (2005-01-26)
+
+Digital Video Disc
+
+ {Digital Versatile Disc}
+
+Dijkstra's guarded command language
+
+ <language> A language invented by {Edsger Dijkstra} ca. 1974.
+ It introduced the concept of {guards} and {committed choice
+ nondeterminism} ({don't care nondeterminism}). Described and
+ used in ["A Discipline of Programming", E. Dijkstra, P-H
+ 1976].
+
+ (1994-12-07)
+
+dike
+
+ To remove or disable a portion of something, as a wire from a
+ computer or a subroutine from a program. A standard slogan is
+ "When in doubt, dike it out". (The implication is that it is
+ usually more effective to attack software problems by reducing
+ complexity than by increasing it.) The word "dikes" is widely
+ used among mechanics and engineers to mean "diagonal cutters",
+ especially the heavy-duty metal-cutting version, but may also
+ refer to a kind of wire-cutters used by electronics
+ technicians. To "dike something out" means to use such
+ cutters to remove something. Indeed, the TMRC Dictionary
+ defined dike as "to attack with dikes". Among hackers this
+ term has been metaphorically extended to informational objects
+ such as sections of code.
+
+ [{Jargon File}]
+
+DIL
+
+ {Dual In-Line Package}
+
+Dilbert
+
+ <humour> A cartoon computer worker drawn by Scott Adams
+ <scottadams@aol.com>, who works in Silicon Valley. The
+ cartoon became so popular he left his day job. The cartoon
+ satirises typical corporate life, especially that which
+ revolves around computers.
+
+ See also: {BOFH}.
+
+ {(http://unitedmedia.com/comics/dilbert/)}.
+
+ (1996-10-11)
+
+Dilberted
+
+ <jargon> To be exploited and oppressed by your boss. Derived
+ from the experiences of {Dilbert}, the geek-in-hell comic
+ strip character. "I've been dilberted again. The old man
+ revised the specs for the fourth time this week."
+
+ (1997-03-29)
+
+DIM
+
+ {DIM statement}
+
+DIMATE
+
+ <language> Depot Installed Maintenance Automatic Test
+ Equipment. A language for programming {automatic test
+ equipment}. It Runs on the {RCA 301}.
+
+ ["A Simple User-Oriented Source Language for Programming
+ Automatic Test Equipment", B.H. Scheff, CACM 9(4) (Apr 1966)].
+
+ [Sammet 1969, p. 647].
+
+ (1996-01-07)
+
+DIMM
+
+ {Dual In-Line Memory Module}
+
+DIM statement
+
+ <programming> (From "dimension") A {keyword} in most versions
+ of the {BASIC} programming language that declares the size of
+ an {array}. E.g.
+
+ DIM A(100)
+
+ declares a one-dimensional array with 101 numeric elements
+ (including A(0)).
+
+ {Visual Basic} uses the DIM (or "Dim") statement for any
+ variable declaration, even {scalars}, e.g.
+
+ Dim DepartmentNumber As Integer
+
+ which declares a single (scalar) variable of type Integer.
+
+ (1999-03-26)
+
+DIN
+
+ Deutsche Institut fuer Normung. The German standardisation
+ body, a member of {ISO}.
+
+DIN-8
+
+ <hardware> An 8-pin round connector, sometimes used for
+ {EIA-232} serial communication when space is restricted, such
+ as on {laptop computers}.
+
+ (1996-12-08)
+
+ding
+
+ 1. Synonym for {feep}. Usage: rare among hackers, but
+ commoner in the {Real World}.
+
+ 2. "dinged": What happens when someone in authority gives you
+ a minor bitching about something, especially something
+ trivial. "I was dinged for having a messy desk."
+
+ [{Jargon File}]
+
+Dining Philosophers Problem
+
+ <parallel> (DPP) A problem introduced by {Dijkstra} concerning
+ resource allocation between processes. The DPP is a model and
+ universal method for testing and comparing theories on
+ resource allocation. Dijkstra hoped to use it to help create
+ a layered {operating system}, by creating a machine which
+ could be consider to be an entirely {deterministic}
+ {automaton}.
+
+ The problem consists of a finite set of processes which share
+ a finite set of resources, each of which can be used by only
+ one process at a time, thus leading to potential {deadlock}.
+
+ The DPP visualises this as a number of philosophers sitting
+ round a dining table with a fork between each adjacent pair.
+ Each philosopher may arbitrarily decide to use either the fork
+ to his left or the one to his right but each fork may only be
+ used by one philosopher at a time.
+
+ Several potential solutions have been considered.
+
+ Semaphores - a simple, but unfair solution where each
+ resources is a {binary semaphore} and additional semaphores
+ are used to avoid deadlock and/or {starvation}.
+
+ Critical Regions - each processor is protected from
+ interference while it exclusively uses a resource.
+
+ Monitors - the process waits until all required resources are
+ available then grabs all of them for use.
+
+ The best solution allows the maximum parallelism for any
+ number of processes (philosophers), by using an array to track
+ the process' current state (i.e. hungry, eating, thinking).
+ This solution maintains an array of semaphores, so hungry
+ philosophers trying to acquire resources can block if the
+ needed forks are busy.
+
+ (1998-08-09)
+
+dink
+
+ /dink/ Said of a machine that has the {bitty box} nature; a
+ machine too small to be worth bothering with - sometimes the
+ system you're currently forced to work on. First heard from
+ an {MIT} hacker working on a {CP/M} system with 64K, in
+ reference to any {6502} system, then from fans of 32 bit
+ architectures about 16-bit machines. "GNUMACS will never work
+ on that dink machine." Probably derived from mainstream
+ "dinky", which isn't sufficiently pejorative.
+
+ See {macdink}.
+
+ [{Jargon File}]
+
+ (1994-10-31)
+
+DinnerBell
+
+ An {object-oriented} {dataflow} language with {single
+ assignment}.
+
+ ["Object-Oriented Load Distribution in DinnerBell", S. Kono
+ <kono@csl.sony.co.jp> et al, in TOOLS Pacific 90].
+
+ (1994-10-31)
+
+DINO
+
+ {Data parallel} superset of {C}.
+
+ {(ftp://ftp.cs.colorado.edu/pub/cs/distribs/dino/)}.
+
+ ["The DINO Parallel Programming Language", M. Rosing et al, J
+ Parallel Dist Comp 13(9):30-42 (Sep 1991)].
+
+ ["DINO Parallel Programming Language", M. Rosing et al,
+ CU-CS-457-90, U Colorado, April 1990].
+
+dinosaur
+
+ 1. Any hardware requiring raised flooring and special power.
+ Used especially of old {minicomputers} and {mainframes}, in
+ contrast with newer {microprocessor}-based machines.
+
+ In a famous quote from the 1988 Unix EXPO, {Bill Joy} compared
+ the liquid-cooled mainframe in the massive {IBM} display with
+ a grazing dinosaur "with a truck outside pumping its bodily
+ fluids through it". IBM was not amused.
+
+ Compare {big iron}; see also {dinosaurs mating}.
+
+ 2. [IBM] A very conservative user; a {zipperhead}.
+
+ [{Jargon File}]
+
+dinosaur pen
+
+ A traditional {mainframe} computer room complete with raised
+ flooring, special power, its own ultra-heavy-duty air
+ conditioning, and a side order of Halon fire extinguishers.
+
+ See {boa}.
+
+ (1995-11-17)
+
+dinosaurs mating
+
+ <humour> The activity said to occur when yet another {big
+ iron} merger or buy-out occurs; reflects a perception by
+ hackers that these signal another stage in the long, slow
+ dying of the {mainframe} industry. Also described as
+ "elephants mating": lots of noise and action at a high level,
+ with an eventual outcome in the somewhat distant future.
+
+ In its glory days of the 1960s, it was "{IBM} and the Seven
+ Dwarves": {Burroughs}, {Control Data}, {General Electric},
+ {Honeywell}, {NCR}, {RCA}, and {Univac}. Early on, RCA sold
+ out to Univac and GE also sold out, and it was "IBM and the
+ BUNCH" (an acronym for Burroughs, Univac, NCR, Control Data,
+ and Honeywell) for a while. Honeywell was bought out by Bull.
+
+ Univac in turn merged with {Sperry} to form Sperry/Univac,
+ which was later merged (although the employees of Sperry
+ called it a hostile takeover) with Burroughs to form {Unisys}
+ in 1986 (this was when the phrase "dinosaurs mating" was
+ coined). In 1991 {AT&T} absorbed NCR, only to spit it out
+ again in 1996. Unisys bought {Convergent Technologies} in
+ 1988 and later others.
+
+ More such earth-shaking unions of doomed giants seem
+ inevitable.
+
+ [More dates?]
+
+ [{Jargon File}]
+
+ (1998-07-10)
+
+diode
+
+ <hardware, electronics> A {semiconductor} device which
+ conducts electric current run in one direction only. This is
+ the simplest kind of semiconductor device, it has two
+ terminals and a single PN junction. One diode can be used as
+ a {half-wave rectifier} or four as a {full-wave rectifier}.
+
+ (1995-03-14)
+
+Diophantine equation
+
+ <mathematics> Equations with {integer} coefficients to which
+ integer solutions are sought. Because the results are
+ restricted to integers, different {algorithms} must be used
+ from those which find {real} solutions.
+
+ [More details?]
+
+ (1998-08-27)
+
+DIP
+
+ 1. {Dual In-line Package}.
+
+ 2. {Document Image Processing}.
+
+diplex
+
+ <communications> (From {telegraphy}) Two simultaneous
+ transmissions in one direction.
+
+ Compare: {duplex}.
+
+ (2000-03-30)
+
+DIPP
+
+ {Dual Inline Pin Package}
+
+Direct-Access Storage Device
+
+ <hardware> (DASD) {IBM} {mainframe} terminology for a {disk
+ drive}, in contrast with a tape drive which is a sequential
+ access device.
+
+ (1995-03-01)
+
+Direct Client to Client Protocol
+
+ <networking> (DCC) An {IRC} {protocol} created to allow users
+ to chat privately and to send and receive files directly
+ instead of having to go thorugh the IRC servers. DCC protects
+ users from being monitored by IRC Server operators that have
+ enabled conversation logging. It also allows much more
+ efficient use of available {bandwidth} as the data does not
+ need to be {broadcast} all over the world just to reach a
+ specific user.
+
+ The available DCC commands include DCC CHAT (direct user to
+ user chat), DCC SEND (direct user to user file send) and DCC
+ GET (file acknowledgement from a receiver).
+
+ (1995-04-12)
+
+Direct Connection
+
+ A re-seller of {Internet} connections to the {PIPEX}
+ {backbone}.
+
+directed acyclic graph
+
+ (DAG) A {directed graph} containing no cycles. This means
+ that if there is a route from node A to node B then there is
+ no way back.
+
+ (1994-12-07)
+
+directed graph
+
+ (digraph) A graph with one-way edges.
+
+ See also {directed acyclic graph}.
+
+ (1994-11-11)
+
+Directed Oc
+
+ <language> (Doc) A language related to {Oc}.
+
+ ["Programming Language Doc and Its Self-Description, or 'X=X
+ Is Considered Harmful'", M. Hirata, Proc 3rd Conf Japan Soc
+ Soft Sci Tech, pp. 69-72, 1986].
+
+ (1999-10-08)
+
+directed set
+
+ <theory> A {set} X is directed under some {relation}, <= (less
+ than or equal), if it is non-empty and if for any two elements
+ x and y there exists an element z such that x <= z and y <= z.
+ I.e. all pairs have an {upper bound}.
+
+ (1994-11-11)
+
+Direct Inward Dialing
+
+ <communications> (DID) A service offered by telephone
+ companies which allows the last 3 or 4 digits of a phone
+ number to be transmitted to the destination {exchange}.
+
+ For example, a company could have 10 incoming lines, all with
+ the number 234 000. If a caller dials 234 697, the call is
+ sent to 234 000 (the company's exchange), and the digits 697
+ are transmitted. The company's exchange then routes the call
+ to extension 697. This gives the impression of 1000 direct
+ dial lines, whereas in fact there are only 10. Obviously,
+ only 10 at a time can be used.
+
+ This system is also used by {fax servers}. Instead of an
+ exchange at the end of the 234 000 line, a computer running
+ fax server software and {fax modem} cards uses the last three
+ digits to identify the recipient of the fax. This allows 1000
+ people to have their own individual fax numbers, even though
+ there is only one 'fax machine'.
+
+ {Dictionary of PC Hardware and Data Communications Terms
+ (http://ora.com/reference/dictionary/terms/D/Direct_Inward_Dialing.htm)}.
+
+ (1997-06-29)
+
+directional coupler
+
+ <communications> (tap) A {passive} device used in {cable}
+ systems to divide and combine {radio frequency} signals. A
+ directional coupler has at least three ports: line in, line
+ out, and the tap. The signal passes between line in and line
+ out ports with loss referred to as the {insertion loss}. A
+ small portion of the signal power applied to the line in port
+ passes to the tap port. A signal applied to the tap port is
+ passed to the line in port less the tap attenuation value.
+ The tap signals are isolated from the line out port to prevent
+ reflections. A signal applied to the line out port passes to
+ the line in port and is isolated from the tap port. Some
+ devices provide more than one tap output line (multi-taps).
+
+ (1995-12-23)
+
+Directly Executable Test Oriented Language
+
+ <language> (DETOL) A simple language to control a specific
+ type of test equipment.
+
+ ["Improved DETOL Programming Manual for the Series 5500
+ Automatic Test System", Pub. 5500-31-0-1, AAI Corporation Sep
+ 1973].
+
+ (1995-09-29)
+
+direct mapped cache
+
+ <architecture> A {cache} where the cache location for a given
+ address is determined from the middle address bits. If the
+ {cache line} size is 2^n then the bottom n address bits
+ correspond to an offset within a cache entry. If the cache
+ can hold 2^m entries then the next m address bits give the
+ cache location. The remaining top address bits are stored as
+ a "tag" along with the entry.
+
+ In this scheme, there is no choice of which block to flush on
+ a cache miss since there is only one place for any block to
+ go. This simple scheme has the disadvantage that if the
+ program alternately accesses different addresses which map to
+ the same cache location then it will suffer a cache miss on
+ every access to these locations. This kind of {cache
+ conflict} is quite likely on a multi-processor. See also
+ {fully associative cache}, {set associative cache}.
+
+Direct Memory Access
+
+ <architecture> (DMA) A facility of some architectures which
+ allows a peripheral to read and write memory without
+ intervention by the CPU. DMA is a limited form of {bus
+ master}ing.
+
+ (1996-08-23)
+
+directories
+
+ {directory}
+
+directory
+
+ <file system> A node in a hierarchical {file system} which
+ contains zero or more other nodes - generally, {files} or
+ other directories.
+
+ The term "folder" is sometimes used in systems such as the
+ {Macintosh} or {Microsoft Windows} in which directories are
+ traditionally depicted as folders (like small briefcases).
+
+ (2007-02-21)
+
+Directory Access Protocol
+
+ X.500 protocol used for communication between a Directory User
+ Agent and a Directory System Agent.
+
+directory service
+
+ <database, networking> A structured repository of information
+ on people and resources within an organisation, facilitating
+ management and communication.
+
+ On a {LAN} or {WAN} the directory service identifies all
+ aspects of the {network} including users, software, hardware,
+ and the various rights and policies assigned to each. As a
+ result applications can access information without knowing
+ where a particular resource is physically located, and users
+ interact oblivious to the network {topology} and {protocols}.
+
+ To allow {heterogeneous networks} to share directory
+ information the {ITU} proposed a common structure called
+ {X.500}. However, its complexity and lack of seamless
+ {Internet} support led to the development of {Lightweight
+ Directory Access Protocol} (LDAP) which has continued to
+ evolve under the aegis of the {IETF}. Despite its name {LDAP}
+ is too closely linked to {X.500} to be "lightweight".
+
+ {LDAP} was adopted by several companies such as {Netscape
+ Communications Corporation} (Netscape Directory Server) and
+ has become a {de facto standard} for directory services.
+ Other LDAP compatible offerings include {Novell, Inc.}'s
+ {Novell Directory Services} (NDS) and {Microsoft
+ Corporation}'s {Active Directory}. The Netscape and Novell
+ products are available for {Windows NT} and {Unix}
+ {platforms}. {Novell Directory Services} also run on Novell
+ platforms. {Microsoft Corporation}'s {Active Directory} is an
+ integral part of {Microsoft's Windows 2000} and although it
+ can interface with directory services running on other systems
+ it is not available for other platforms.
+
+ (2001-01-02)
+
+Directory System Agent
+
+ (DSA) The software that provides the {X.500} Directory Service
+ for a portion of the directory information base. Generally,
+ each DSA is responsible for the directory information for a
+ single organisation or organisational unit.
+
+ (1994-12-07)
+
+Directory User Agent
+
+ (DUA) The software that accesses the {X.500} Directory Service
+ on behalf of the directory user. The directory user may be a
+ person or another software element.
+
+ (1994-12-07)
+
+DirectX
+
+ <programming, hardware> A {Microsoft} programming interface
+ {standard}, first included with {Windows 95}. DirectX gives
+ (games) programmers a standard way to gain direct access to
+ enhanced hardware features under Windows 95 instead of going
+ via the Windows 95 {GDI}. Some DirectX code runs faster than
+ the equivalent under {MS DOS}.
+
+ DirectX promises performance improvements for graphics, sound,
+ video, 3D, and network capabilites of games, but only where
+ both hardware and software support DirectX.
+
+ DirectX 2 introduced the Direct3D interface. Version 5 was
+ current at 1998-02-01. Version 8.1 is included in {Windows
+ XP}.
+
+ Latest version: 8.1 (as of 2001-12-31).
+
+ {(http://microsoft.com/directx/)}.
+
+ (2001-12-31)
+
+DIRFT
+
+ {Do It Right the First Time}
+
+Dirt
+
+ {Design In Real Time}
+
+dirtball
+
+ ({XEROX PARC}) A small, perhaps struggling outsider; not in
+ the major or even the minor leagues. For example, "Xerox is
+ not a dirtball company".
+
+ Outsiders often observe in the PARC culture an institutional
+ arrogance which usage of this term exemplifies. The
+ brilliance and scope of PARC's contributions to computer
+ science have been such that this superior attitude is not much
+ resented. - ESR
+
+ [{Jargon File}]
+
+ (1994-12-07)
+
+dirty power
+
+ Electrical mains voltage that is unfriendly to the delicate
+ innards of computers. Spikes, {drop-outs}, average voltage
+ significantly higher or lower than nominal, or just plain
+ noise can all cause problems of varying subtlety and severity
+ (these are collectively known as {power hits}).
+
+ [{Jargon File}]
+
+dis
+
+ <programming> A {CPython} {bytecode} {disassembler}.
+
+ {dis home (https://docs.python.org/2/library/dis.html)}.
+
+ (2014-06-08)
+
+DISA
+
+ 1. <body> {Defense Information Systems Agency}.
+
+ 2. <standard> {Data Interchange Standards Association}.
+
+ (1999-09-18)
+
+disaster planning
+
+ {disaster recovery}
+
+disaster recovery
+
+ <business> (DR) Planning and implementation of procedures and
+ facilities for use when essential systems are not available
+ for a period long enough to have a significant impact on the
+ business, e.g. when the head office is blown up.
+
+ Disasters include natural: fire, flood, lightning, hurricane;
+ hardware: power failure, component failure, {head crash};
+ software failure: {bugs}, resources; vandalism: arson,
+ bombing, {cracking}, theft; data corruption or loss: human
+ error, media failure; communications: computer network
+ equipment, {network storm}, telephones; security: passwords
+ compromised, {computer virus}; legal: change in legislation;
+ personnel: unavailability of essential staff, industrial
+ action.
+
+ Companies need to plan for disaster: before: {risk analysis},
+ preventive measures, training; during: how should staff and
+ systems respond; after: recovery measures, post mortem
+ analysis.
+
+ Hardware can usually be replaced and is usually insured.
+ Software and data needs to be backed up off site. Alternative
+ communication systems should be arranged in case of network
+ failure or inaccessible premises, e.g. emergency telephone
+ number, home working, alternative data center.
+
+ (2007-06-20)
+
+disc
+
+ <storage, spelling> British spelling of "{disk}", normally
+ only used for "{compact disc}".
+
+ (1995-07-30)
+
+disc drive
+
+ {disc}
+
+disclaimer
+
+ <networking> Statement ritually appended to many {Usenet}
+ postings (sometimes automatically, by the posting software)
+ reiterating the fact (which should be obvious, but is easily
+ forgotten) that the article reflects its author's opinions and
+ not necessarily those of the organisation running the computer
+ through which the article entered the network.
+
+ [{Jargon File}]
+
+ (1995-07-30)
+
+disconnect
+
+ {SCSI reconnect}
+
+Discordianism
+
+ <recreation> /dis-kor'di-*n-ism/ The veneration of {Eris},
+ also known as Discordia; widely popular among hackers.
+ Discordianism was popularised by Robert Shea and Robert Anton
+ Wilson's novel "Illuminatus!" as a sort of self-subverting
+ Dada-Zen for Westerners - it should on no account be taken
+ seriously but is far more serious than most jokes. Consider,
+ for example, the Fifth Commandment of the Pentabarf, from
+ "Principia Discordia": "A Discordian is Prohibited of
+ Believing What he Reads." Discordianism is usually connected
+ with an elaborate conspiracy theory/joke involving
+ millennia-long warfare between the anarcho-surrealist
+ partisans of Eris and a malevolent, authoritarian secret
+ society called the Illuminati.
+
+ See {Religion}, {Church of the SubGenius}, and {ha ha only
+ serious}.
+
+ [{Jargon File}]
+
+ (1997-04-12)
+
+discrete
+
+ <mathematics> A description of a quantity whose value is one
+ of a fixed set of values, as opposed to a {continuous} - a
+ value capable of infinitessimal variation. For example,
+ {integers} are discrete values whereas {real numbers} are
+ continuous; {digital sound} has discrete {amplitude} leves
+ whereas {analog sound} is continuous.
+
+ (2009-10-08)
+
+discrete cosine transform
+
+ <mathematics> (DCT) A technique for expressing a waveform as a
+ weighted sum of cosines.
+
+ The DCT is central to many kinds of {signal processing},
+ especially video {compression}.
+
+ Given data A(i), where i is an integer in the range 0 to N-1,
+ the forward DCT (which would be used e.g. by an encoder) is:
+
+ B(k) = sum A(i) cos((pi k/N) (2 i + 1)/2)
+ i=0 to N-1
+
+ B(k) is defined for all values of the frequency-space variable
+ k, but we only care about integer k in the range 0 to N-1.
+ The inverse DCT (which would be used e.g. by a decoder) is:
+
+ AA(i)= sum B(k) (2-delta(k-0)) cos((pi k/N)(2 i + 1)/2)
+ k=0 to N-1
+
+ where delta(k) is the {Kronecker delta}.
+
+ The main difference between this and a {discrete Fourier
+ transform} (DFT) is that the DFT traditionally assumes that
+ the data A(i) is periodically continued with a period of N,
+ whereas the DCT assumes that the data is continued with its
+ mirror image, then periodically continued with a period of 2N.
+
+ Mathematically, this transform pair is exact, i.e. AA(i) ==
+ A(i), resulting in {lossless coding}; only when some of the
+ coefficients are approximated does compression occur.
+
+ There exist fast DCT {algorithms} in analogy to the {Fast
+ Fourier Transform}.
+
+ (1997-03-10)
+
+discrete Fourier transform
+
+ <mathematics> (DFT) A {Fourier transform}, specialized to the
+ case where the {abscissas} are integers.
+
+ The DFT is central to many kinds of {signal processing},
+ including the analysis and {compression} of video and {sound}
+ information.
+
+ A common implementation of the DFT is the {Fast Fourier
+ Transform} (FFT).
+
+ See also {discrete cosine transform}.
+
+ (1997-03-10)
+
+discrete preorder
+
+ <mathematics> A {preorder} is said to be discrete if any two
+ of its elements are {incomparable}.
+
+ (1995-09-21)
+
+discriminated union
+
+ <theory> The discriminated union of two sets A and B is
+
+ A + B = {(inA, a) | a in A} U {(inB, b)| b in B}
+
+ where inA and inB are arbitrary tags which specify which
+ summand an element originates from.
+
+ A {type} (especially an {algebraic data type}) might be
+ described as a discriminated union if it is a {sum type} whose
+ objects consist of a tag to say which part of the union they
+ belong to and a value of the corresponding type.
+
+ (1995-04-25)
+
+discussion group
+
+ <messaging> Any system that supports group messaging, e.g. a
+ shared {mailbox}, {Usenet}, {bulletin board system}, or
+ possibly a {mailing list}, used to publish messages on some
+ particular topic.
+
+ (2000-11-16)
+
+Disiple
+
+ <language, DSP> A {DSP} language.
+
+ ["A Compiler that Easily Retargets High Level Language
+ Programs for Different Signal Processing Architectures", J.E.
+ Peters & S.M. Dunn, Proc ICASSP 89, pp. 1103-1106, May 1989].
+
+ (2000-11-16)
+
+disjoint union
+
+ In {domain theory}, a union (or sum) which results in a domain
+ without a least element.
+
+Disjunctive Normal Form
+
+ (DNF) A logical formula consisting of a {disjunction} of
+ {conjunctions} where no conjunction contains a disjunction.
+ E.g. the DNF of (A or B) and C is (A and C) or (B and C).
+
+ (1994-12-07)
+
+disk
+
+ <storage> 1. {magnetic disk}.
+
+ 2. {compact disc}.
+
+ 3. {optical disk}.
+
+ Note: the american spelling, "disk", is normal for most
+ computer disks whereas "compact disc", having come to
+ computers via the audio world, is correctly spelled with a
+ "c", indeed, this spelling is part of the CD standard.
+
+ (1995-07-30)
+
+disk controller
+
+ <hardware, storage> (Or "hard disk controller", HDC) The
+ circuit which allows the {CPU} to communicate with a {hard
+ disk}, {floppy disk} or other kind of {disk drive}.
+
+ The most common disk controllers in use are {IDE} and {SCSI}
+ controllers. Most home {personal computers} use IDE
+ controllers. High end PCs, {workstations} and network {file
+ servers} mostly have {SCSI adaptors}.
+
+ (1998-03-16)
+
+disk drive
+
+ <hardware, storage> (Or "hard disk drive", "hard drive",
+ "floppy disk drive", "floppy drive") A {peripheral} device
+ that reads and writes {hard disks} or {floppy disks}. The
+ drive contains a motor to rotate the disk at a constant rate
+ and one or more read/write heads which are positioned over the
+ desired {track} by a servo mechanism. It also contains the
+ electronics to amplify the signals from the heads to normal
+ digital logic levels and vice versa.
+
+ In order for a disk drive to start to read or write a given
+ location a read/write head must be positioned radially over
+ the right track and rotationally over the start of the right
+ sector.
+
+ Radial motion is known as "{seek}ing" and it is this which
+ causes most of the intermittent noise heard during disk
+ activity. There is usually one head for each disk surface and
+ all heads move together. The set of locations which are
+ accessible with the heads in a given radial position are known
+ as a "{cylinder}". The "{seek time}" is the time taken to
+ seek to a different cylinder.
+
+ The disk is constantly rotating (except for some {floppy disk}
+ drives where the motor is switched off between accesses to
+ reduce wear and power consumption) so positioning the heads
+ over the right sector is simply a matter of waiting until it
+ arrives under the head. With a single set of heads this
+ "{rotational latency}" will be on average half a revolution
+ but some big drives have multiple sets of heads spaced at
+ equal angles around the disk.
+
+ If seeking and rotation are independent, access time is seek
+ time + rotational latency. When accessing multiple tracks
+ sequentially, data is sometimes arranged so that by the time
+ the seek from one track to the next has finished, the disk has
+ rotated just enough to begin accessing the next track.
+
+ See also {sector interleave}.
+
+ Early disk drives had a capacity of a few {megabytes} and were
+ housed inside a separate cabinet the size of a washing
+ machine. Over a few decades they shrunk to fit a {terabyte}
+ or more in a box the size of a paperback book.
+
+ The disks may be {removable disks}; floppy disks always are,
+ removable hard disks were common on {mainframes} and
+ {minicomputers} but less so on {microcomputers} until the mid
+ 1990s(?) with products like the {Zip Drive}.
+
+ A {CD-ROM} drive is not usually referred to as a disk drive.
+
+ Two common interfaces for disk drives (and other devices) are
+ {SCSI} and {IDE}. {ST-506} used to be common in
+ microcomputers (in the 1980s?).
+
+ (1997-04-15)
+
+disk duplexing
+
+ <hardware, storage> A variation on {disk mirroring} where, as
+ well as redundant {disk drives}, a second {disk controller} or
+ {host adapter} is also present.
+
+ (1996-02-22)
+
+diskette
+
+ {floppy disk}
+
+disk farm
+
+ <jargon> (Or "{laundromat}") A large room or rooms filled with
+ {disk drives} (especially {washing machines}).
+
+ [{Jargon File}]
+
+ (1995-03-27)
+
+diskless workstation
+
+ <computer, networking> A {personal computer} or {workstation}
+ which has neither a {hard disk} nor {floppy disk} drive and
+ which performs all file access via a {local area network}
+ connection to a {file server}. The lowest level {bootstrap}
+ code is stored in {non-volatile storage}. This uses a simple
+ {protocol} such as {BOOTP} to request and {download} more
+ sophisticated boot code and eventually, the {operating
+ system}.
+
+ The archtypal product was the {3Station} developed by Bob
+ Metcalfe at {3Com}. Another example was the {Sun} 3/50.
+
+ Diskless workstations are ideal when many users are running
+ the same application. They are small, quiet, more reliable
+ than products with disks, and help prevent both the theft of
+ data and the introduction of viruses since the software and
+ data available on them is controlled by the network
+ administrator or system administrator. They do however rely
+ on a server which becomes a disadvantage if it is heavily
+ loaded or {down}.
+
+ See also {breath-of-life packet}.
+
+ (1995-03-28)
+
+disk mirroring
+
+ <hardware, storage> Use of one or more {mirrors} of a {hard
+ disk}.
+
+ (1996-02-17)
+
+Disk Operating System
+
+ <operating system> (DOS) The original {disk operating system}
+ from {IBM}.
+
+ DOS was the low-end OS of choice on the {IBM 360}, the
+ high-end system was called just "{OS}". DOS had a smaller
+ {kernel} and less functionality than OS and could run on the
+ typical 32K 360/30 and 64K 360/40 class machines.
+
+ DOS was a successor to {TOS}.
+
+ (1999-01-20)
+
+disk operating system
+
+ <operating system> (DOS) The name of a number of {operating
+ systems} which include facilities for storing files on disk,
+ often used to refer to {Microsoft DOS}. Such a system must
+ handle physical disk I/O, the mapping of file names to disk
+ addresses and protection of files from unauthorised access (in
+ a {multi-user} system).
+
+ A DOS should present a uniform interface to different storage
+ device such as {floppy disks}, {hard disks} and {magnetic
+ tape} drives. It may also provide some kind of locking to
+ prevent unintentional simultaneous access by two processes to
+ the same file (or {record}).
+
+ (1998-07-08)
+
+disks
+
+ {disk}
+
+disk striping
+
+ {data striping}
+
+Dislang
+
+ <language>
+
+ ["Dislang: A Distributed Programming Language/System", C. Li
+ et al, Proc 2nd Intl Conf Distrib Comp Sys, IEEE 1981,
+ pp. 162-172].
+
+ (1995-05-10)
+
+disman
+
+ {Distributed Management}
+
+display
+
+ 1. <hardware> {monitor}.
+
+ 2. <language> A vector of pointers to {activation records}.
+ The Nth element points to the activation record containing
+ variables declared at {lexical depth} N. This allows faster
+ access to variables from outer {scopes} than the alternative
+ of linked activation records (but most variable accesses are
+ either local or global or occasionally to the immediately
+ enclosing scope). Displays were used in some {ALGOL}
+ implementations.
+
+ (1996-02-22)
+
+display hack
+
+ <graphics> A program with the same approximate purpose as a
+ kaleidoscope: to make pretty pictures. Famous display hacks
+ include {munching squares}, {smoking clover}, the {BSD Unix}
+ "rain(6)" program, "worms(6)" on miscellaneous Unixes, and the
+ {X} "kaleid(1)" program. Display hacks can also be
+ implemented without programming by creating text files
+ containing numerous escape sequences for interpretation by a
+ video terminal; one notable example displayed, on any VT100, a
+ Christmas tree with twinkling lights and a toy train circling
+ its base. The {hack value} of a display hack is proportional
+ to the aesthetic value of the images times the cleverness of
+ the algorithm divided by the size of the code. Synonym
+ {psychedelicware}.
+
+ [{Jargon File}]
+
+ (1995-05-10)
+
+Display PostScript
+
+ An extended form of {PostScript} permitting its interactive
+ use with {bitmap displays}.
+
+Display Screen Equipment
+
+ {Visual Display Unit}
+
+display standard
+
+ <hardware, standard> {IBM} and others have introduced a
+ bewildering plethora of graphics and text display {standards}
+ for {IBM PC}s. The standards are mostly implemented by
+ plugging in a video display board (or "{graphics adaptor}")
+ and connecting the appropriate monitor to it. Each new
+ standard subsumes its predecessors. For example, an {EGA}
+ board can also do {CGA} and {MDA}.
+
+ With the {PS/2}, IBM introduced the {VGA} standard and built
+ it into the main system board {motherboard}. VGA is also
+ available as a plug-in board for PCs from third-party vendors.
+ Also with the PS/2, IBM introduced the {8514} high-resolution
+ graphics standard. An 8514 adaptor board plugs into the PS/2,
+ providing a dual-monitor capability.
+
+ Graphics software had to support the major IBM graphics
+ standards and many non-IBM, proprietary standards for
+ displays. Either software vendors provided {display drivers}
+ or display vendors provided drivers for the software package.
+ In either case, switching software or switching display
+ systems was fraught with compatibility problems.
+
+ Display Resolution Colours Sponsor Systems
+
+ MDA 720x350 T 2 IBM PC
+ CGA 320x200 4 IBM PC
+ EGA 640x350 16 IBM PC
+ PGA 640x480 256 IBM PC
+
+ Hercules 729x348 2 non-IBM PC
+
+ MCGA 720x400 T
+ 320x200 G 256 PS/2
+
+ VGA 720x400 T
+ 640x480 G 16
+
+ SVGA 800x600 16 VESA
+
+ XVGA 1024x768 256 (IBM name: 8514)
+
+ T: text, G: graphics.
+
+ More colours are available from third-party vendors for some
+ display types.
+
+ See also {MDA}, {CGA}, {EGA}, {PGA}, {Hercules}, {MCGA},
+ {VGA}, {SVGA}, {8514}, {VESA}.
+
+ [What were the corresponding "mode" numbers"?]
+
+ (2011-03-20)
+
+display standards
+
+ {display standard}
+
+display terminal
+
+ {visual display unit}
+
+Dissociated Press
+
+ [Play on "Associated Press"; perhaps inspired by a reference
+ in the 1949 Bugs Bunny cartoon "What's Up, Doc?"] An
+ algorithm for transforming any text into potentially humorous
+ garbage even more efficiently than by passing it through a
+ {marketroid}. The algorithm starts by printing any N
+ consecutive words (or letters) in the text. Then at every
+ step it searches for any random occurrence in the original
+ text of the last N words (or letters) already printed and then
+ prints the next word or letter. {Emacs} has a handy command
+ for this. Here is a short example of word-based Dissociated
+ Press applied to an earlier version of the {Jargon File}:
+
+ wart: A small, crocky {feature} that sticks out of
+ an array (C has no checks for this). This is relatively
+ benign and easy to spot if the phrase is bent so as to be
+ not worth paying attention to the medium in question.
+
+ Here is a short example of letter-based Dissociated Press
+ applied to the same source:
+
+ window sysIWYG: A bit was named aften /bee't*/ prefer
+ to use the other guy's re, especially in every cast a
+ chuckle on neithout getting into useful informash speech
+ makes removing a featuring a move or usage actual
+ abstractionsidered interj. Indeed spectace logic or problem!
+
+ A hackish idle pastime is to apply letter-based Dissociated
+ Press to a random body of text and {vgrep} the output in hopes
+ of finding an interesting new word. (In the preceding
+ example, "window sysIWYG" and "informash" show some promise.)
+ Iterated applications of Dissociated Press usually yield
+ better results. Similar techniques called "travesty
+ generators" have been employed with considerable satirical
+ effect to the utterances of {Usenet} flamers; see {pseudo}.
+
+ [{Jargon File}]
+
+distfix
+
+ <programming> ("distributed {fixity}"?) A description of an
+ {operator} represented by multiple symbols before, between,
+ and/or after the arguments.
+
+ The classical example is the {C} conditional operator, "?:"
+ which is written
+
+ E1 ? E2 : E3
+
+ If E1 is true it returns E2 otherwise it returns E3. Several
+ {functional programming languages}, e.g. {Hope}, {Haskell},
+ have similar operators ("if E1 then E2 else E3").
+
+ {Objective C} {messages} are effectively distfix operator
+ applications:
+
+ getRow:row andColumn:col ofCell:cell
+
+ is a message with three arguments, row, col, and cell.
+
+ (1997-01-21)
+
+Distributed Component Object Model
+
+ <programming> (DCOM) {Microsoft}'s extension of their
+ {Component Object Model} (COM) to support objects distributed
+ across a {network}. DCOM has been submitted to the {IETF} as
+ a draft standard. Since 1996, it has been part of {Windows
+ NT} and is also available for {Windows 95}.
+
+ Unlike {CORBA}, which runs on many {operating systems}, DCOM
+ is currently (Dec 1997) only implemented by {Microsoft} for
+ {Microsoft Windows} and by {Software AG}, under the name
+ "{EntireX}", for {Unix} and {IBM} {mainframes}. DCOM serves
+ the same purpose as {IBM}'s {DSOM} {protocol}.
+
+ DCOM is broken because it's an {object model} that has no
+ provisions for {inheritance}, one of the major reasons for
+ {object oriented programming} in the first place.
+
+ {(http://microsoft.com/com/tech/DCOM.asp)}.
+
+ [Details?]
+
+ (2000-08-02)
+
+Distributed Computing Environment
+
+ (DCE) An architecture consisting of {standard} programming
+ interfaces, conventions and {server} functionalities
+ (e.g. naming, distributed file system, {remote procedure call})
+ for distributing applications transparently across networks of
+ {heterogeneous} computers. DCE is promoted and controlled by
+ the {Open Software Foundation} (OSF).
+
+ {Usenet} newsgroup: {news:comp.soft-sys.dce}.
+
+ {(http://dstc.edu.au/AU/research_news/dce/dce.html)}.
+
+ (1994-12-07)
+
+distributed database
+
+ A collection of several different {databases} that looks like
+ a single {database} to the user. An example is the {Internet}
+ {Domain Name System} (DNS).
+
+ (1994-12-07)
+
+Distributed Data Management
+
+ <protocol, database> (DDM) An {IBM} {data} {protocol}
+ architecture for data management services across {distributed}
+ systems in an {SNA} environment.
+
+ DDM provides a common {data management language} for data
+ interchange among different IBM system platforms.
+
+ Products supporting DDM include {AS/400}, {System/36},
+ {System/38} and {CICS/DDM}.
+
+ On the AS/400, DDM controls remote file processing.
+ DDM enables application programs running on one AS/400
+ system to access data files stored on another system
+ supporting DDM. Similarly, other systems that have DDM can
+ access files in the database of the local AS/400 system.
+ DDM makes it easier to distribute file processing between two
+ or more systems.
+
+ {OS/400 Distributed Data Management V3R6 Reference
+ (http://as400bks.rochester.ibm.com/cgi-bin/bookmgr/bookmgr.cmd/BOOKS/QBJALH00/CCONTENTS)}.
+
+ (1999-04-26)
+
+distributed data warehouse
+
+ <database> (DDW) Data shared across multiple data
+ repositories, for the purpose of {OLAP}. Each data warehouse
+ may belong to one or many organisations. The sharing im;plies
+ a common format or definition of data elements (e.g. using
+ XML).
+
+ (2008-03-15)
+
+Distributed Eiffel
+
+ ["Distributed Eiffel: A Language for Programming
+ Multi-Granular Distributed Objects on the Clouds Operating
+ System", L. Gunaseelan et al, IEEE Conf Comp Langs, 1992].
+
+ (1994-12-07)
+
+Distributed Logic Programming
+
+ <language> (DLP) A {logic programming} language similar to
+ {Prolog}, combined with parallel {object orientation} similar
+ to {POOL}. DLP supports distributed {backtracking} over the
+ results of a {rendezvous} between {objects}. {Multi-threaded}
+ objects have autonomous activity and may simultaneously
+ evaluate {method} calls.
+
+ ["DLP: A Language for Distributed Logic Programming",
+ A. Eliens, Wiley 1992].
+
+ (1996-01-07)
+
+Distributed Management Environment
+
+ (DME) An {OSF} {standard}. It had reached the {RFT} stage.
+
+ (1995-02-22)
+
+distributed memory
+
+ <architecture> The kind of memory in a {parallel processor}
+ where each processor has fast access to its own local memory
+ and where to access another processor's memory it must send a
+ message via the inter-processor network.
+
+ Opposite: {shared memory}.
+
+ (1995-03-22)
+
+Distributed Network Operating System
+
+ <operating system> (DNOS) A proprietary {operating system} for
+ {Texas Instruments} {990}-series {minicomputers}.
+
+ (1996-04-01)
+
+Distributed Operating Multi Access Interactive Network
+
+ (DOMAIN) The proprietary network {protocol} used by {Apollo}
+ {workstations}.
+
+ (1995-02-16)
+
+Distributed Processes
+
+ (DP) The first {concurrent} language based on {remote
+ procedure calls}.
+
+ ["Distributed Processes: A Concurrent Programming Concept",
+ Per Brinch Hansen CACM 21(11):934-940 (Nov 1978)].
+
+ (1994-12-02)
+
+Distributed Queue Dual Bus
+
+ <networking, standard> (DQDB) An {IEEE} {standard} for
+ {metropolitan area networks}.
+
+ {(http://ece.wpi.edu/~vlad/ee535/hw5/page1.html)}.
+
+ [Details?]
+
+ (2000-08-02)
+
+Distributed Smalltalk
+
+ ["The Design and Implementation of Distributed Smalltalk",
+ J. Bennett, SIGPLAN Notices 22(12):318-330 (Dec 1980)].
+
+ (1994-12-02)
+
+distributed system
+
+ A collection of (probably heterogeneous) automata whose
+ distribution is transparent to the user so that the system
+ appears as one local machine. This is in contrast to a
+ network, where the user is aware that there are several
+ machines, and their location, storage replication, load
+ balancing and functionality is not transparent. Distributed
+ systems usually use some kind of {client-server} organisation.
+
+ Distributed systems are considered by some to be the "next
+ wave" of computing.
+
+ {Distributed Computing Environment} is the {Open Software
+ Foundation}'s software architecture for distributed systems.
+
+ {(http://dstc.edu.au/AU/research_news/dist-env.html)}.
+
+ (1994-12-06)
+
+distributed systems
+
+ {distributed system}
+
+distribution
+
+ 1. <software> A software source tree packaged for
+ distribution; but see {kit}.
+
+ 2. <messaging> A vague term encompassing {mailing lists} and
+ {Usenet} {newsgroups} (but not {BBS} {fora}); any
+ topic-oriented message channel with multiple recipients.
+
+ 3. <messaging> An information-space domain (usually loosely
+ correlated with geography) to which propagation of a {Usenet}
+ message is restricted; a much-underused feature.
+
+ [{Jargon File}]
+
+distributive lattice
+
+ <theory> A {lattice} for which the {least upper bound} (lub)
+ and {greatest lower bound} (glb) operators distribute over one
+ another so that
+
+ a lub (b glb c) == (a lub c) glb (a lub b)
+
+ and vice versa.
+
+ ("lub" and "glb" are written in {LateX} as {\sqcup} and
+ {\sqcap}).
+
+ (1998-11-09)
+
+disusered
+
+ <jargon> ({Usenet}) Said of a person whose account on a
+ computer has been removed to prevent access. Setting the
+ DISUSER account status flag on {VMS} disables the account.
+
+ "He got disusered when they found out he'd been {cracking}
+ through the school's {Internet} access."
+
+ [{Jargon File}]
+
+ (1994-12-08)
+
+dithering
+
+ <data, algorithm> A technique used in {quantisation} processes
+ such as {graphics} and {audio} to reduce or remove the
+ correlation between noise and signal.
+
+ Dithering is used in {computer graphics} to create additional
+ colors and shades from an existing {palette} by interspersing
+ {pixels} of different colours. On a {monochrome} display,
+ areas of grey are created by varying the proportion of black
+ and white pixels. In colour displays and printers, colours
+ and textures are created by varying the proportions of
+ existing colours. The different colours can either be
+ distributed randomly or regularly. The higher the
+ {resolution} of the display, the smoother the dithered colour
+ will appear to the eye.
+
+ Dithering doesn't reduce resolution. There are three types:
+ regular dithering which uses a very regular predefined
+ pattern; random dither where the pattern is a random noise;
+ and pseudo random dither which uses a very large, very
+ regular, predefined pattern.
+
+ Dithering is used to create patterns for use as backgrounds,
+ fills and shading, as well as for creating {halftones} for
+ printing. When used for printing is it very sensitive to
+ paper properties. Dithering can be combined with
+ {rasterising}. It is not related to {anti-aliasing}.
+
+ (2003-07-20)
+
+Ditto Drive
+
+ <hardware, storage> The Ditto {tape drives} range in capacity
+ from 120 {megabytes} to 1.6 {gigabytes} ({data compression}
+ can roughly double these figures). The newer devices are
+ designed for special tapes, though they will read standard
+ tape types.
+
+ The largest of tape stores up 3.2 {GB}. Using an enhanced
+ {floppy drive} card the transfer rate approaches the claimed
+ 19 {MB}/minute. External {parallel} port versions are also
+ available.
+
+ {Compatibility details
+ (http://iomega.com/support/techs/ditto/3040.html)}.
+
+ (1997-03-26)
+
+diverge
+
+ If a series of approximations to some value get progressively
+ further from it then the series is said to diverge.
+
+ The {reduction} of some term under some {evaluation strategy}
+ diverges if it does not reach a {normal form} after a finite
+ number of reductions.
+
+ (1994-12-08)
+
+divisor
+
+ A quantity that evenly divides another quantity.
+
+ Unless otherwise stated, use of this term implies that the
+ quantities involved are integers. (For non-integers, the more
+ general term {factor} may be more appropriate.)
+
+ Example: 3 is a divisor of 15.
+ Example: 3 is not a divisor of 14.
+
+ (1997-03-07)
+
+dj
+
+ <networking> The {country code} for Djibouti.
+
+ (1999-01-27)
+
+DJGPP
+
+ <tool> A 32-bit {GNU} {C}/{C++}/etc development system for
+ {MS-DOS}.
+
+ {(http://delorie.com/djgpp/)}.
+
+ Address: DJ Delorie, Rochester, NH, USA.
+
+ (1995-04-10)
+
+DjVu
+
+ <application, compression, file format, graphics, web> (pronounced
+ like "deja vu") An {image compression} {algorithm} and program
+ developed by {Yann LeCun}'s research group at {AT&T Labs}. DjVu
+ provides high {resolution} {digital images} for distribution over
+ the {Internet}. DjVu is five to 20 times more efficient than
+ {JPEG} or {GIF}. A free {web browser} {plug-in} allows users to
+ display DjVu images.
+
+ {(http://djvu.research.att.com/)}.
+
+ (1999-10-07)
+
+DK
+
+ {Datakit}
+
+dk
+
+ <networking> The {country code} for Denmark.
+
+ (1999-01-27)
+
+DL/1
+
+ Query language, linear keyword.
+
+DLC
+
+ {Data Link Control}
+
+DLCI
+
+ {Data Link Connection Identifier}
+
+ [Is this correct?]
+
+ (1997-03-01)
+
+DLE
+
+ <character> Data Link Escape, the {mnemonic} for {ASCII} 16.
+
+ (1996-06-24)
+
+DLG
+
+ (DFA-based Lexical analyser Generator) The {lexical analyser}
+ generator in the {Purdue Compiler-Construction Tool Set}.
+
+DL/I
+
+ The data manipulation language of IMS.
+
+DLL
+
+ 1. <networking> {Data Link Layer}.
+
+ 2. <library> {Dynamically Linked Library}.
+
+ 3. {Dial Long Line} equipment.
+
+ (2000-04-05)
+
+DLM
+
+ Distributed Lock Manager on distributed VMS systems.
+
+DLP
+
+ <language> {Distributed Logic Programming}.
+
+ (1996-01-07)
+
+DLPI
+
+ {Data Link Provider Interface}
+
+DLSw
+
+ {Data Link Switching}
+
+DLT
+
+ {Digital Linear Tape}
+
+DLUR/DLUS
+
+ <networking> Dependent Logical Unit Requester/Server. The
+ DLUR function is an {APPN} enhancement for an end node or
+ network node that supports dependent {LUs}. The DLUS function
+ is a product feature of an {interchange node} or a {T5}
+ network node supporting {session services} extensions.
+
+ {(http://booksrv2.raleigh.ibm.com/cgi-bin/bookmgr/bookmgr.cmd/BOOKS/DLUR7/)}.
+
+ (1997-05-08)
+
+DLZ1
+
+ {Digital Lempel Ziv 1}
+
+dm
+
+ <networking> The {country code} for Dominica.
+
+ (1999-01-27)
+
+DMA
+
+ {Direct Memory Access}
+
+DMAD
+
+ Diagnostic Machine Aid-Digital. A system for functional
+ testing of digital devices.
+
+ ["DMAD M/MM Manual", BR-8392, Raytheon Co. (Oct 1973)]
+
+ (1994-11-02)
+
+dmake
+
+ Required by {uC++}.
+
+ {(ftp://plg.uwaterloo.ca/pub/dmake/dmake38.tar.Z)}.
+
+ [What is it?]
+
+ (1994-11-02)
+
+DMALGOL
+
+ {ALGOL} with extensions to interface to {DMS II}, the
+ {Burroughs} {database}.
+
+ (1995-02-22)
+
+DME
+
+ {Distributed Management Environment}
+
+DMI
+
+ {Desktop Management Interface}
+
+DML
+
+ <language>
+
+ 1. {Data Manipulation Language}.
+
+ 2. {Data Management Language}.
+
+ 3. ["DML: A Meta-language and System for the Generation of
+ Practical and Efficient Compilers from Denotational
+ Specifications", M. Pettersson et al, IEEE Conf Comp Langs,
+ 1992].
+
+ (1999-04-27)
+
+DMM
+
+ {Digital Multimeter}
+
+DMS
+
+ {Dataless Management Services}
+
+DMTF
+
+ {Desktop Management Task Force}
+
+DMU
+
+ {Data Management Unit}
+
+ {Data Manipulation Unit}
+
+ {Data Multiplexer Unit}
+
+ {dataless management utility}
+
+DMZ
+
+ {De-Militarised Zone}
+
+DNA computing
+
+ <architecture> The use of DNA molecules to encode
+ computational problems. Standard operations of molecular
+ biology can then be used to solve some {NP-hard} {search
+ problems} in parallel using a very large number of molecules.
+ The exponential scaling of NP-hard problems still remains, so
+ this method will require a huge amount of DNA to solve large
+ problems.
+
+ [L. M. Adleman, "Molecular Computation of Solutions to
+ Combinatorial Problems", Science 266:1021-1024, 1994].
+
+ (1997-02-11)
+
+DNF
+
+ {disjunctive normal form}
+
+DNIS
+
+ {Dialled Number Identification Service}
+
+DNIX
+
+ <operating system> A flavor of {Unix} that is proprietary to
+ {Olivetti} and {Wang Global}.
+
+ [Details? Reference?]
+
+ (2000-12-16)
+
+DNOS
+
+ {Distributed Network Operating System}
+
+DNS
+
+ 1. {Domain Name System}.
+
+ 2. Distributed Name Service. See {DECdns}.
+
+do
+
+ 1. <programming> {repeat loop}.
+
+ 2. <networking> The {country code} for Dominican Republic.
+
+ (1999-06-10)
+
+DOA
+
+ <jargon> Dead on arrival. A piece of {hardware} that has
+ never worked.
+
+ (2000-12-19)
+
+Doc
+
+ {Directed Oc}
+
+doc
+
+ /dok/ Common spoken and written shorthand for "documentation".
+ Often used in the plural "docs" and in the construction "doc
+ file" (i.e. documentation available on-line).
+
+ [{Jargon File}]
+
+docking station
+
+ <hardware> A {desktop} mains powered unit into which a
+ {laptop} or other portable computer can be connected via fixed
+ connectors at the rear of the computer to provide quick and
+ convenient connection of {peripherals} not normally used with
+ a laptop. These can include power supply, {expansion cards},
+ additional {storage}, an external {monitor}, {network card},
+ {CD-ROM}, full-size {keyboard}, {printer}, and {mouse}. The
+ alternative would require each of the above to be connected to
+ the laptop individually.
+
+ (2000-04-10)
+
+DOCMaker
+
+ <text, tool, product> An application for the {Apple}
+ {Macintosh} which creates stand-alone, self-running document
+ {files}. It features scrollable and re-sizable windows,
+ graphics, varied text styles and {fonts}, full printing
+ capability, and links to other {software} and {information}.
+
+ Companies such as Federal Express, GTE, {Hewlett-Packard},
+ {Iomega}, {Adobe Systems, Inc.}, {Apple Computer} and
+ {Aladdin} use DOCMaker to distribute disk-based
+ {documentation} with their products.
+
+ {(http://hsv.tis.net/~greenmtn/docm1.html)}.
+
+ (1998-01-27)
+
+doco
+
+ <jargon> /do'koh/ 1. (In-house jargon at Symbolics) A
+ documentation writer.
+
+ See also {devo} and {mango}.
+
+ 2. (UK) A short technical document. A "doco" is often not the
+ documentation passed to management.
+
+ Compare {doc}.
+
+ [{Jargon File}]
+
+ (1999-10-08)
+
+DOCSIS
+
+ {Data Over Cable Service Interface Specification}
+
+doctype decoration
+
+ <humour> When a {web author} adds a {doctype declaration} but
+ doesn't bother to write valid {HTML}.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2013-05-30)
+
+document
+
+ 1. <application> Any specific type of {file} produced or
+ edited by a specific {application}; usually capable of being
+ printed. E.g. "Word document", "Photoshop document", etc.
+
+ 2. <hypertext> A term used on some systems (e.g. {Intermedia})
+ for a {hypertext} {node}. It is sometimes used for a
+ collection of nodes on related topics, possibly stored or
+ distributed as one.
+
+ 3. <programming> To write {documentation} on a certain piece
+ of code.
+
+ (2003-10-25)
+
+documentation
+
+ <programming> The multiple kilograms of macerated, pounded,
+ steamed, bleached, and pressed trees that accompany most
+ modern software or hardware products (see also {tree-killer}).
+ Hackers seldom read paper documentation and (too) often resist
+ writing it; they prefer theirs to be terse and {on-line}. A
+ common comment on this predilection is "You can't {grep} dead
+ trees".
+
+ See {drool-proof paper}, {verbiage}, {treeware}.
+
+ [{Jargon File}]
+
+ (2003-10-25)
+
+Document Examiner
+
+ <hypertext, tool> A high-performance {hypertext} system by
+ {Symbolics} that provides on-line access to their user
+ documentation.
+
+ (1995-04-16)
+
+Document Image Processing
+
+ (DIP) Storage, management and retrieval of {images}.
+
+ (1994-11-11)
+
+Document Object Model
+
+ <hypertext, language, web> A {W3C} specification
+ for {application program interfaces} for accessing the content
+ of {HTML} and {XML} documents.
+
+ {(http://w3.org/DOM/)}.
+
+ (1999-12-14)
+
+Document Style Semantics and Specification Language
+
+ (DSSSL) An {ISO} {standard} under preparation, addressing the
+ {semantics} of high-quality composition in a manner
+ independent of particular formatting systems or processes.
+ DSSSL is intended as a complementary standard to {SGML} for
+ the specification of semantics.
+
+Document Type Definition
+
+ <text, standard> (DTD) The definition of a document type in
+ {SGML} or {XML}, consisting of a set of {mark-up} tags and
+ their interpretation.
+
+ {Docbook DTD home (http://oasis-open.org/docbook/)}.
+
+ {XML DTD Tutorial (http://xml101.com/dtd)}.
+
+ (2001-04-30)
+
+DOCUS
+
+ Display Oriented Computer Usage System. Interactive system
+ using push buttons. Sammet 1969, p.678
+
+DoD
+
+ 1. <body> {Department of Defense}.
+
+ 2. {Dial on Demand}.
+
+ (2000-03-25)
+
+DoD-1
+
+ Unofficial name of the language that became Ada.
+
+dodgy
+
+ Synonym with {flaky}. Preferred outside the US
+
+ [{Jargon File}]
+
+DOD-STD-2167A
+
+ <standard> A {DoD} {standard} specifying the overall process
+ for the development and documentation of mission-critical
+ software systems.
+
+ (1996-05-28)
+
+DoD-STD-2168
+
+ <standard> A {DoD} {standard} for software quality assurance
+ procedures.
+
+ (1996-05-29)
+
+DOE
+
+ Distributed Object Environment: a distributed object-oriented
+ application framework from SunSoft.
+
+DOF
+
+ {degrees of freedom}
+
+dog
+
+ <tool> An enhanced version of the {Unix} {cat} command that,
+ in addition to outputting the contents of files, can output
+ the data obtained by fetching {URLs}. It also offers various
+ output options such as line numbering.
+
+ {Unix manual page}:
+ {(http://www.penguin-soft.com/penguin/man/1/dog.html)}.
+
+ (2009-06-12)
+
+dogcow
+
+ /dog'kow/ See {Moof}.
+
+ [{Jargon File}]
+
+dogfood
+
+ {eating one's own dogfood}
+
+dogfooding
+
+ {eating one's own dogfood}
+
+dogpile
+
+ ({Usenet}, probably from mainstream "puppy pile") When many
+ people post unfriendly responses in short order to a single
+ posting, they are sometimes said to "dogpile" or "dogpile on"
+ the person to whom they're responding. For example, when a
+ religious missionary posts a simplistic appeal to alt.atheism,
+ he can expect to be dogpiled.
+
+ (1994-12-08)
+
+dogwash
+
+ /dog'wosh/ (A quip in the "urgency" field of a very optional
+ software change request, ca. 1982. It was something like
+ "Urgency: Wash your dog first") A project of minimal priority,
+ undertaken as an escape from more serious work. Many games
+ and much {freeware} get written this way, including {this
+ dictionary}.
+
+ [{Jargon File}]
+
+ (1994-12-08)
+
+Do It Right the First Time
+
+ <chat> (DIRFT) A programming approach that aims to avoid the
+ overheads of debugging and testing incomplete or incorrect code by
+ careful specification, design and implementation. DIRFT contrasts
+ with {rapid prototyping} which emphasises the benefits of having
+ running code as soon as possible, even if it is not perfect.
+ DIRFT is appropriate in the rare cases where the requirements are
+ well understood and unlikely to change, e.g. reimplementing
+ exactly the same function in a different language.
+
+ (2012-11-17)
+
+Dojo
+
+ {The Dojo Toolkit}
+
+DOL
+
+ Display Oriented Language. Subsystem of DOCUS. Sammet 1969,
+ p.678.
+
+dollar
+
+ <character> "$" Common names: {ITU-T}: dollar sign. Rare:
+ currency symbol; buck; cash; string; escape (when used as the
+ echo of ASCII ESC); ding; cache; {INTERCAL}: big money.
+
+ Well-known uses of the dollar symbol in computing include as a
+ prefix on the names of {string} {variables} in {BASIC},
+ {shell} and related languages like {Perl}. In shell languages
+ it is also used in {positional parameters} so "$1" is the
+ first parameter to a shell script, "$2" the second, etc.
+
+ (2006-09-10)
+
+do loop
+
+ {repeat loop}
+
+DOM
+
+ {Document Object Model}
+
+domain
+
+ 1. <networking> A group of computers whose {fully qualified
+ domain names} (FQDN) share a common suffix, the "domain name".
+
+ The {Domain Name System} maps {hostnames} to {Internet
+ address} using a hierarchical {namespace} where each level in
+ the hierarchy contributes one component to the FQDN. For
+ example, the computer foldoc.doc.ic.ac.uk is in the
+ doc.ic.ac.uk domain, which is in the ic.ac.uk domain, which is
+ in the ac.uk domain, which is in the uk {top-level domain}.
+
+ A domain name can contain up to 67 characters including the
+ dots that separate components. These can be letters, numbers
+ and hyphens.
+
+ 2. An {administrative domain} is something to do with {routing}.
+
+ 3. {Distributed Operating Multi Access Interactive Network}.
+
+ 4. <mathematics> In the theory of functions, the set of
+ argument values for which a {function} is defined.
+
+ See {domain theory}.
+
+ 5. <programming> A specific phase of the {software life cycle}
+ in which a developer works. Domains define developers' and
+ users' areas of responsibility and the scope of possible
+ relationships between products.
+
+ 6. The subject or market in which a piece of software is
+ designed to work.
+
+ (2007-10-01)
+
+domain address
+
+ <networking> The name of a {host} on the {Internet} belonging
+ to the {hierarchy} of Internet {domains}.
+
+ (1994-10-27)
+
+Domain Analysis
+
+ <systems analysis> 1. Determining the operations, data
+ objects, properties and {abstractions} appropriate for
+ designing solutions to problems in a given {domain}.
+
+ 2. The {domain engineering} activity in which domain knowledge
+ is studied and formalised as a domain definition and a domain
+ specification. A {software reuse} approach that involves
+ combining software components, subsystems, etc., into a single
+ application system.
+
+ 3. The process of identifying, collecting organising,
+ analysing and representing a {domain model} and software
+ architecture from the study of existing systems, underlying
+ theory, emerging technology and development histories within
+ the domain of interest.
+
+ 4. The analysis of systems within a domain to discover
+ commonalities and differences among them.
+
+ (1997-12-26)
+
+domain architecture
+
+ <systems analysis> A generic, organisational structure or
+ design for software systems in a {domain}. The domain
+ architecture contains the designs that are intended to satisfy
+ requirements specified in the {domain model}. A domain
+ architecture can be adapted to create designs for software
+ systems within a domain and also provides a framework for
+ configuring {assets} within individual software systems.
+
+ (1997-12-26)
+
+Domain Architecture Model
+
+ <systems analysis> A set of software architectures generic to
+ a {domain} that define organising frameworks for constructing
+ new application designs and implementations within the domain,
+ consistent with the domain requirements model.
+
+ (1997-12-26)
+
+domain calculus
+
+ <database> A form of {relational calculus} in which {scalar}
+ variables take values drawn from a given {domain}.
+
+ Examples of the domain calculus are {ILL}, {FQL}, {DEDUCE} and
+ the well known {Query By Example} (QBE). {INGRES} is a
+ {relational DBMS} whose {DML} is based on the relational
+ calculus.
+
+domain engineering
+
+ <systems analysis> 1. The development and evolution of
+ {domain} specific knowledge and artifacts to support the
+ development and evolution of systems in the domain. Domain
+ engineering includes engineering of {domain models},
+ components, methods and tools and may also include {asset
+ management}.
+
+ 2. The engineering process of analysing and modelling a
+ domain, designing and modelling a generic solution
+ architecture for a product line within that domain,
+ implementing and using reusable components of that
+ architecture and maintaining and evolving the domain,
+ architecture and implementation models.
+
+ 3. A reuse-based approach to defining the scope ({domain
+ definition}), specifying the structure ({domain architecture})
+ and building the Assets (requirements, designs, software code,
+ documentation) for a class of systems, subsystems or
+ applications. Domain engineering can include domain
+ definition, domain analysis, developing the domain
+ architecture domain implementation.
+
+domain handle
+
+ <networking> Information held by a {domain name} registrar
+ about a registrant (the person or organisation that owns the
+ name). Typically the registrar stores one copy of this
+ information and refers to that copy for each additional domain
+ registered by the same person. The information would include
+ basic contact details: name, e-mail address, etc. and billing
+ information. Some of this information would be used to
+ populate the {whois} database entry for a domain.
+
+ {(http://www.easyname.eu/support/domains/20-what-is-a-domain-handle)}.
+
+ (2009-09-17)
+
+domainist
+
+ <jargon> /doh-mayn'ist/ 1. Said of a domain address (as
+ opposed to a {bang path}) because the part to the right of the
+ "@" specifies a nested series of "domains"; for example,
+ esr@snark.thyrsus.com specifies the machine called snark in
+ the subdomain called thyrsus within the top-level domain
+ called com. See also {big-endian}.
+
+ 2. Said of a site, mailer or routing program which knows how
+ to handle domainist addresses.
+
+ 3. Said of a person (especially a site admin) who prefers
+ domain addressing, supports a domainist mailer, or
+ proselytises for domainist addressing and disdains {bang
+ paths}. This term is now (1993) semi-obsolete, as most sites
+ have converted.
+
+ [{Jargon File}]
+
+ (1995-04-21)
+
+domain maturity
+
+ <systems analysis> The level of stability and depth of
+ understanding that has been achieved in an area for which
+ {applications} are developed.
+
+ (1997-12-26)
+
+domain model
+
+ <systems analysis> 1. A definition of the functions, objects,
+ data, requirements, relationships and variations in a
+ particular {domain}.
+
+ 2. A product of {domain analysis} which provides a
+ representation of the requirements of the domain. The domain
+ model identifies and describes the structure of data, flow of
+ information, functions, constraints and controls within the
+ Domain that are included in software systems in the domain.
+ The Domain Model describes commonalities and variabilities
+ among requirements for software systems in the domain.
+
+ (1997-12-26)
+
+domain name
+
+ {fully qualified domain name}
+
+Domain Name Server
+
+ <spelling> {Domain Name System}.
+
+ (1997-12-15)
+
+Domain Name System
+
+ <networking> (DNS) A general-purpose distributed, replicated,
+ data query service chiefly used on {Internet} for translating
+ {hostnames} into {Internet addresses}. Also, the style of
+ {hostname} used on the Internet, though such a name is
+ properly called a {fully qualified domain name}. DNS can be
+ configured to use a sequence of name servers, based on the
+ domains in the name being looked for, until a match is found.
+
+ The name resolution client (e.g. Unix's gethostbyname()
+ library function) can be configured to search for host
+ information in the following order: first in the local {hosts
+ file}, second in {NIS} and third in DNS. This sequencing of
+ Naming Services is sometimes called "name service switching".
+ Under {Solaris} is configured in the file /etc/nsswitch.conf.
+
+ DNS can be queried interactively using the command {nslookup}.
+ It is defined in {STD 13}, {RFC 1034}, {RFC 1035}, {RFC 1591}.
+
+ {BIND} is a common DNS server.
+
+ {Info from Virtual Office, Inc.
+ (http://virtual.office.com/domains.html)}.
+
+ (2001-05-14)
+
+domain selection
+
+ <systems analysis> The prioritisation and selection of one or
+ more {domains} for which specific {software reuse} engineering
+ projects are to be initiated.
+
+ (1997-12-26)
+
+Domain Software Engineering Environment
+
+ <programming> (DSEE) A proprietary {CASE} framework and
+ {configuration management} system from {Apollo}.
+
+ (1996-05-29)
+
+domain-specific language
+
+ <language> A machine-processable language whose terms are
+ derived from a {domain model} and that is used for the
+ definition of components or software architectures supporting
+ that domain. A domain-specific language is often used as
+ input to an application generator.
+
+ (1997-12-26)
+
+domain squatter
+
+ <web> An unscrupulous person who registers a
+ {domain name} in the hope of selling it to the rightful,
+ expected owner at a profit. E.g. {(http://foldoc.com/)}.
+
+ (2007-07-15)
+
+domain theory
+
+ <theory> A branch of mathematics introduced by Dana Scott in
+ 1970 as a mathematical theory of programming languages, and
+ for nearly a quarter of a century developed almost exclusively
+ in connection with {denotational semantics} in computer
+ science.
+
+ In {denotational semantics} of programming languages, the
+ meaning of a program is taken to be an element of a domain. A
+ domain is a mathematical structure consisting of a set of
+ values (or "points") and an ordering relation, <= on those
+ values. Domain theory is the study of such structures.
+
+ ("<=" is written in {LaTeX} as {\subseteq})
+
+ Different domains correspond to the different types of object
+ with which a program deals. In a language containing
+ functions, we might have a domain X -> Y which is the set of
+ functions from domain X to domain Y with the ordering f <= g
+ iff for all x in X, f x <= g x. In the {pure lambda-calculus}
+ all objects are functions or {applications} of functions to
+ other functions. To represent the meaning of such programs,
+ we must solve the {recursive} equation over domains,
+
+ D = D -> D
+
+ which states that domain D is ({isomorphic} to) some {function
+ space} from D to itself. I.e. it is a {fixed point} D = F(D)
+ for some operator F that takes a domain D to D -> D. The
+ equivalent equation has no non-trivial solution in {set
+ theory}.
+
+ There are many definitions of domains, with different
+ properties and suitable for different purposes. One commonly
+ used definition is that of Scott domains, often simply called
+ domains, which are {omega-algebraic}, {consistently complete}
+ {CPOs}.
+
+ There are domain-theoretic computational models in other
+ branches of mathematics including {dynamical systems},
+ {fractals}, {measure theory}, {integration theory},
+ {probability theory}, and {stochastic processes}.
+
+ See also {abstract interpretation}, {bottom}, {pointed
+ domain}.
+
+ (1999-12-09)
+
+Domestic Communications Assistance Center
+
+ <body> (DCAC) A joint effort between the U.S. Marshals
+ Service, FBI and Drug Enforcement Agency. The DCAC is charged
+ with developing customised hardware for intercepting
+ {Internet} and wireless communications. The DCAC is under the
+ control and budget of the FBI.
+
+ {CNET article
+ (http://news.cnet.com/8301-1009_3-57439734-83/fbi-quietly-forms-secretive-net-surveillance-unit/)}.
+
+ (2012-06-24)
+
+DOMF
+
+ Distributed Object Management Facility.
+
+ An {OMG}-compliant object management system; part of {DOE}.
+ Produced by {SunSoft}.
+
+ (1994-11-04)
+
+Donald Knuth
+
+ <person> Donald E. Knuth, the author of the {TeX} document
+ formatting system, {Metafont} its {font}-design program and
+ the 3 volume computer science "Bible" of {algorithms}, "The
+ Art of Computer Programming".
+
+ Knuth suggested the name "{Backus-Naur Form}" and was also
+ involved in the {SOL} simulation language, and developed the
+ {WEB} {literate programming} system.
+
+ See also {MIX}, {Turingol}.
+
+ (1994-11-04)
+
+dongle
+
+ <hardware> /dong'gl/ (From "dangle" - because it dangles off
+ the computer?)
+
+ 1. <security> A security or {copy protection} device for
+ commercial {microcomputer} programs that must be connected to
+ an {I/O port} of the computer while the program is run.
+ Programs that use a dongle query the port at start-up and at
+ programmed intervals thereafter, and terminate if it does not
+ respond with the expected validation code.
+
+ One common form consisted of a serialised {EPROM} and some
+ drivers in a {D-25} connector shell.
+
+ Dongles attempt to combat {software theft} by ensuring that,
+ while users can still make copies of the program (e.g. for
+ {backup}), they must buy one dongle for each simultaneous use
+ of the program.
+
+ The idea was clever, but initially unpopular with users who
+ disliked tying up a port this way. By 1993 almost all dongles
+ passed data through transparently while monitoring for their
+ particular {magic} codes (and combinations of status lines)
+ with minimal if any interference with devices further down the
+ line. This innovation was necessary to allow {daisy-chained}
+ dongles for multiple pieces of software.
+
+ In 1998, dongles and other copy protection systems are fairly
+ uncommon for {Microsoft Windows} software but one engineer in
+ a print and {CADD} bureau reports that their {Macintosh}
+ computers typically run seven dongles: After Effects, Electric
+ Image, two for Media 100, Ultimatte, Elastic Reality and CADD.
+ These dongles are made for the Mac's daisy-chainable {ADB}
+ port.
+
+ The term is used, by extension, for any physical electronic
+ key or transferable ID required for a program to function.
+ Common variations on this theme have used the {parallel port}
+ or even the {joystick} port or a {dongle-disk}.
+
+ An early 1992 advertisment from Rainbow Technologies (a
+ manufacturer of dongles) claimed that the word derived from
+ "Don Gall", the alleged inventor of the device. The company's
+ receptionist however said that the story was a myth invented
+ for the ad.
+
+ [{Jargon File}]
+
+ (1998-12-13)
+
+ 2. A small adaptor cable that connects, e.g. a {PCMCIA}
+ {modem} to a telephone socket or a PCMCIA {network card} to an
+ {RJ45} {network cable}.
+
+ (2002-09-29)
+
+dongle cracker
+
+ <security> Someone who enables software that has been written
+ to require a {dongle} to run without it.
+
+ (2007-06-11)
+
+dongle-disk
+
+ /don'gl disk/ (Or "key disk") A kind of {dongle} consisting of
+ a special {floppy disk} that is required in order to perform
+ some task. Some contain special coding that allows an
+ application to identify it uniquely, others *are* special code
+ that does something that normally-resident programs don't or
+ can't.
+
+ For example, {AT&T}'s "Unix PC" would only come up in {root
+ mode} with a special boot disk.
+
+ [{Jargon File}]
+
+ (1998-12-13)
+
+Don't do that then!
+
+ <humour> (From an old doctor's office joke about a patient
+ with a trivial complaint) A stock response to a user
+ complaint. "When I type control-S, the whole system comes to
+ a halt for thirty seconds." "Well don't do that then!"
+
+ [{Jargon File}]
+
+ (1998-12-13)
+
+donuts
+
+ (Obsolete) A collective noun for any set of memory bits. This
+ usage is extremely archaic and may no longer be live jargon;
+ it dates from the days of {ferrite core memories} in which
+ each bit was implemented by a doughnut-shaped magnetic
+ {flip-flop}.
+
+ [{Jargon File}]
+
+Dooced
+
+ <jargon> Losing your job because of something posted on a
+ personal website. After {(http://dooce.com/)} where Heather
+ Armstrong posted details about her job.
+
+ (2012-04-13)
+
+DOOM
+
+ <games> A simulated 3D moster-hunting action game for {IBM
+ PCs}, created and published by {id Software}. The original
+ press release was dated January 1993. A cut-down shareware
+ version v1.0 was released on 10 December 1993 and again with
+ some bug-fixes, as v1.4 in June 1994.
+
+ DOOM is similar to Wolfenstein 3d (id Software, Apogee) but
+ has better {texture mapping}; walls can be at any angle, of
+ any thickness and have windows; lighting can fade into the
+ distance or come from point sources; floors and ceilings can
+ be of any height; many surfaces are animated; up to four
+ players can play over a network or two by serial link; it has
+ a high {frame rate} (comparable to TV on a {486}/33); DOOM
+ isn't just a collection of connected closed rooms like
+ Wolfenstein but sounds can travel anywhere and alert monsters
+ of your approach.
+
+ The shareware version is available from these sites:
+ {Cactus (ftp://cactus.org/pub/IHHD/multi-player/)},
+ {Manitoba (ftp://ftp.cc.umanitoba.ca/pub/doom/)},
+ {UK (ftp://ftp.demon.co.uk/pub/ibmpc/games/id/)},
+ {South Africa (ftp://ftp.sun.ac.za/pub/msdos/games/id/)},
+ {UWP ftp (ftp://archive.uwp.edu/pub/msdos/games/id/)},
+ {UWP http (http://archive.uwp.edu/pub/msdos/games/id/)},
+ {Finland (ftp://ftp.funet.fi/pub/msdos/games/id)},
+ {Washington (ftp://wuarchive.wustl.edu/pub/MSDOS_UPLOADS/games/doom)}.
+
+ A {FAQ} by Hank Leukart: {UWP
+ (ftp://ftp.uwp.edu/pub/msdos/games/id/home-brew/doom)},
+ {Washington
+ (ftp://wuarchive.wustl.edu/pub/MSDOS_UPLOADS/games/doomstuff)}.
+ {FAQ on WWW (http://venom.st.hmc.edu/~tkelly/doomfaq/intro.html)}.
+ {Other links (http://gamesdomain.co.uk/descript/doom.html)}.
+
+ {Usenet} newsgroups: {news:rec.games.computer.doom.announce},
+ {news:rec.games.computer.doom.editing},
+ {news:rec.games.computer.doom.help},
+ {news:rec.games.computer.doom.misc},
+ {news:rec.games.computer.doom.playing}, {news:alt.games.doom},
+ {news:comp.sys.ibm.pc.games.action},
+ {news:comp.sys.ibm.pc.games.announce},
+ {news:comp.sys.ibm.pc.games.misc}.
+
+ Mailing List: <listserv@cedar.univie.ac.at> ("sub DOOML" in
+ the message body, no subject).
+
+ Telephone: +44 (1222) 362 361 - the UK's first multi-player
+ DOOM and games server.
+
+ (1994-12-14)
+
+DOORS
+
+ {Dynamic Object Oriented Requirements System}
+
+doorstop
+
+ Used to describe equipment that is non-functional and halfway
+ expected to remain so, especially obsolete equipment kept
+ around for political reasons or ostensibly as a backup. "When
+ we get another Wyse-50 in here, that ADM 3 will turn into a
+ doorstop."
+
+ Compare {boat anchor}.
+
+ [{Jargon File}]
+
+Dorito Syndrome
+
+ <humour> Feelings of emptiness and dissatisfaction triggered
+ by addictive substances that lack nutritional content. "I
+ just spent six hours surfing the Web, and now I've got a bad
+ case of Dorito Syndrome."
+
+ (1997-03-30)
+
+DORUM
+
+ {Draft Once ReUse Many}
+
+DOS
+
+ <operating system> 1. The common abbreviation for {MS-DOS}.
+
+ 2. {IBM}'s {Disk Operating System}.
+
+ 3. Any {disk operating system}.
+
+ (2001-03-16)
+
+DOS/360
+
+ <operating system> The {operating system} announced by {IBM}
+ at the low end for the {System/360} in 1964 and delivered in
+ 1965 or 1966.
+
+ Following the failure of {OS}, IBM designed DOS for the low
+ end machines, able to run in 16KB(?) and 64KB memory.
+
+ DOS/360 used three {memory partitions}, but it had no serious
+ {memory protection}. The three partitions were not
+ specialised, but frequently one was used for {spooling}
+ {punched cards} to {disk}, another one for {batch job}
+ execution and another for spooling disk to printers.
+
+ With DOS/VS, introduced in 1970, the number of partitions was
+ increased, {virtual memory} was introduced and the minimum
+ memory requirements increased.
+
+ Later they released DOS/VSE and ESA/VSE. DOS/360 successors
+ are still alive today (1997) though not as popular as in the
+ late 1960s.
+
+ Contrary to the Hacker's {Jargon File}, {GECOS} was not copied
+ from DOS/360.
+
+ (1997-09-22)
+
+DOS Protected Mode Interface
+
+ (DPMI) The method which {Microsoft} prescribes for a {DOS}
+ program to access {extended memory} under a {multitasking}
+ environment, e.g. {Microsoft Windows}. This service is
+ provided by the HIMEM.SYS driver on {IBM PCs}.
+
+ The DPMI specification was finalized in 1990. The
+ specification itself is available from {Intel Literature
+ Sales}.
+
+ VCPI (Virtual Control Program Interface), which was an
+ alternative, and incompatible method for doing the same thing.
+
+ ["Windows 3.1 Secrets", Brian Livingston, 1992, ISBN
+ 1-878058-43-6, pages 280-281 and 302].
+
+ (1995-01-12)
+
+DOS requester
+
+ <networking> An {MS-DOS} {client} that provides transparent
+ redirection of printing and file accesses to a network
+ {server}. It handles levels 3, 4 and 5 of the {Open Systems
+ Interconnect} seven layer model.
+
+ A DOS requester under {Novell NetWare} will interface to a
+ {network card} driver with an {ODI} interface, and will be
+ either a single executable (netx.exe) or a set of {VLMs} that
+ are loaded on demand.
+
+ In the {IBM}/{Microsoft} {LAN Manager}/{SMB} world, where
+ the name {DOS redirector} is more common, there will be an
+ {NDIS} interface driver and a net.exe executable.
+
+ {NetWare Client 32 for DOS/Windows
+ (http://developer.novell.com/research/appnotes/1996/may/01/)}.
+
+ {(http://cad.strath.ac.uk/~davidm/projects/guide/requester.html)}.
+
+ (1998-01-05)
+
+dot
+
+ <character> {decimal point}.
+
+ See also {dot file}, {dot notation}.
+
+ (1995-03-14)
+
+dot address
+
+ An {Internet address} in {dot notation}.
+
+dot com
+
+ {com}
+
+dot file
+
+ <operating system, convention> A {Unix} {application program}
+ configuration file. On {Unix}, files named with a leading dot
+ are not normally shown in directory listings. Many programs
+ define one or more dot files in which startup or configuration
+ information may be optionally recorded; a user can customise
+ the program's behaviour by creating the appropriate file in
+ the current or {home directory}.
+
+ Dot files tend to proliferate - with every nontrivial
+ application program defining at least one, a user's home
+ directory can be filled with scores of dot files, without the
+ user really being aware of it. Common examples are .profile,
+ .cshrc, .login, .emacs, .mailrc, .forward, .newsrc, .plan,
+ .rhosts, .sig, .xsession.
+
+ See also {profile}, {rc file}.
+
+ [{Jargon File}]
+
+ (1994-12-07)
+
+dot leaders
+
+ <text> A row of {full stops} intended to guide the reader's
+ eye across the page from a column of variable length items on
+ the left to the corresponding items in a column on the right.
+ Used, for example, in the contents page of a book to tie a
+ heading on the left to its page number on the right.
+
+ (2010-07-25)
+
+dot matrix printer
+
+ <hardware, printer> A kind of printer with a vertical column
+ of up to 48 small closely packed needles or "pins" each of
+ which can be individually forced forward to press an ink
+ ribbon against the paper. The print head is repeatedly
+ scanned across the page and different combinations of needles
+ activated at each point.
+
+ Dot matrix printers are noisy compared to {non-impact
+ printers}.
+
+ [Other pin arrangements?]
+
+ (1995-03-14)
+
+dot notation
+
+ <networking> {Berkeley Unix} notation for an {Internet
+ address}, consisting of one to four numbers (a "dotted quad")
+ in {hexadecimal} (leading 0x), {octal} (leading 0), or
+ (usually) decimal. It represents a 32-bit address. Each
+ leading number represents eight bits of the address (high byte
+ first) and the last number represents the rest. E.g. address
+ 0x25.32.0xab represents 0x252000ab. By far the most common
+ form is four decimal numbers, e.g. 146.169.22.42.
+
+ Many programs accept an address in dot notation in place of a
+ {hostname}.
+
+ (2000-08-10)
+
+dot pitch
+
+ <hardware> The distance between a dot and the closest dot of
+ the same colour (red, green or blue) on a color {CRT}. Dot
+ pitch is typically from 0.28 to 0.51 mm but large presentation
+ monitors may go up to 1.0 mm. The smaller the dot pitch, the
+ crisper the image, 0.31 or less provides a sharp image,
+ especially when displaying text.
+
+ Dot pitch measurements between conventional tubes and {Sony}'s
+ {Trinitron} tubes are roughly, but not exactly comparable.
+ Sony's {CRTs} use vertical stripes, not dots, and its
+ measurement is the distance between stripes, not the diagonal
+ distance between dots.
+
+ ["The Computer Glossary", Alan Freedman].
+
+ (1995-12-14)
+
+dotted quad
+
+ dot notation
+
+double bucky
+
+ Using both the CTRL and META keys. "The command to burn all
+ LEDs is double bucky F."
+
+ This term originated on the Stanford extended-ASCII keyboard,
+ and was later taken up by users of the {space-cadet keyboard}
+ at MIT. A typical MIT comment was that the Stanford {bucky
+ bits} (control and meta shifting keys) were nice, but there
+ weren't enough of them; you could type only 512 different
+ characters on a Stanford keyboard. An obvious way to address
+ this was simply to add more shifting keys, and this was
+ eventually done; but a keyboard with that many shifting keys
+ is hard on touch-typists, who don't like to move their hands
+ away from the home position on the keyboard. It was
+ half-seriously suggested that the extra shifting keys be
+ implemented as pedals; typing on such a keyboard would be very
+ much like playing a full pipe organ. This idea is mentioned
+ in a parody of a very fine song by Jeffrey Moss called "Rubber
+ Duckie", which was published in "The Sesame Street Songbook"
+ (Simon and Schuster 1971, ISBN 0-671-21036-X). These lyrics
+ were written on May 27, 1978, in celebration of the Stanford
+ keyboard:
+
+ Double Bucky
+
+ Double bucky, you're the one!
+ You make my keyboard lots of fun.
+ Double bucky, an additional bit or two:
+ (Vo-vo-de-o!)
+ Control and meta, side by side,
+ Augmented ASCII, nine bits wide!
+ Double bucky! Half a thousand glyphs, plus a few!
+ Oh,
+ I sure wish that I
+ Had a couple of
+ Bits more!
+ Perhaps a
+ Set of pedals to
+ Make the number of
+ Bits four:
+ Double double bucky!
+ Double bucky, left and right
+ OR'd together, outta sight!
+ Double bucky, I'd like a whole word of
+ Double bucky, I'm happy I heard of
+ Double bucky, I'd like a whole word of you!
+
+ - The Great Quux
+
+ (With apologies to Jeffrey Moss. This, by the way, is an
+ excellent example of computer {filk} --- ESR).
+
+ See also {meta bit}, {cokebottle}, and {quadruple bucky}.
+
+ [{Jargon File}]
+
+ (1994-12-07)
+
+double-click
+
+ <operating system> Two clicks of a {mouse} button made in
+ rapid succession without moving the mouse. A double-click
+ often combines the actions of selecting, and then activating
+ an object in a {GUI}, e.g. selecting and opening a document.
+ Some {text editors} use double-click to select the word under
+ the {mouse pointer}.
+
+ When used as a verb it is often written as two words with a
+ space instead of a hyphen.
+
+ (2006-07-09)
+
+Double Data Rate Random Access Memory
+
+ <storage> (DDR-RAM, DDR-SDRAM ...Synchronous...) {RAM} that
+ transfers data on both 0-1 and 1-0 {clock} transitions,
+ theoretically yielding twice the data transfer rate of normal
+ RAM or {SDRAM}.
+
+ {DDR-RAM Article
+ (http://pcreview.co.uk/Article.php?aid=9)}.
+
+ {DDR-SDRAM Article
+ (http://www4.tomshardware.com/mainboard/00q4/001030/)}.
+
+ (2001-05-24)
+
+Double Data Rate Synchronous Random Access Memory
+
+ {Double Data Rate Random Access Memory}
+
+double DECkers
+
+ <jargon> Married couples in which both partners work for
+ {Digital Equipment Corporation}.
+
+ [{Jargon File}]
+
+ (1994-12-07)
+
+double density
+
+ {floppy disk}
+
+doubled sig
+
+ A {sig block} that has been included twice in a {Usenet}
+ article or, less commonly, in an {electronic mail} message.
+ An article or message with a doubled sig can be caused by
+ improperly configured software. More often, however, it
+ reveals the author's lack of experience in electronic
+ communication.
+
+ See {BIFF}, {pseudo}.
+
+ [{Jargon File}]
+
+ (1994-12-07)
+
+double-duplex
+
+ <communications> (From {telegraphy}) A {full-duplex} link with
+ two telegraphers (a sender and a receiver) at each end, to
+ simultaneously transmit in both directions.
+
+ Compare: {single-duplex}.
+
+ (2000-03-30)
+
+double-ended queue
+
+ <algorithm> /dek/ (deque) A {queue} which can have items added
+ or removed from either end[?].
+
+ The Knuth reference below reports that the name was coined by
+ E. J. Schweppe.
+
+ [D. E. Knuth, "The Art of Computer Programming. Volume 1:
+ Fundamental Algorithms", second edition, Sections 2.2.1, 2.6,
+ Addison-Wesley, 1973].
+
+ {Silicon Graphics (http://sgi.com/tech/stl/Deque.html)}.
+
+ [Correct definition? Example use?]
+
+ (2003-12-17)
+
+double quote
+
+ <character> '"' {ASCII} character 34. Often used in
+ programming languages to delimit strings. In {Unix} {shells}
+ and {Perl} it delimits a string inside which variable
+ substitution may occur.
+
+ Common names: quote. Rare: literal mark; double-glitch;
+ {ITU-T}: quotation marks; {ITU-T}: dieresis; dirk; {INTERCAL}:
+ rabbit-ears; double prime.
+
+ (1995-03-28)
+
+doubly linked list
+
+ <programming> A data structure in which each element contains
+ pointers to the next and previous elements in the list, thus
+ forming a bidirectional linear list.
+
+ (1995-03-28)
+
+DOUGLAS
+
+ <language> An early system on the {IBM 701}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1994-12-07)
+
+Douglas Engelbart
+
+ <person> Douglas C. Engelbart, the inventor of the {mouse}.
+
+ On 1968-12-09, Douglas C. Engelbart and the group of 17
+ researchers working with him in the {Augmentation Research
+ Center} at {Stanford Research Institute} in Menlo Park,
+ California, USA, presented a 90-minute live public
+ demonstration of the on live system, {NLS}, they had been
+ working on since 1962. The presentation was a session in the
+ of the Fall Joint Computer Conference held at the Convention
+ Center in San Francisco, and it was attended by about 1000
+ computer professionals. This was the public debut of the
+ computer {mouse}, {hypertext}, object addressing, dynamic file
+ linking and shared-screen collaboration involving two persons
+ at different sites communicating over a network with audio and
+ video interface.
+
+ The original 90-minute video: {Hyperlinks
+ (http://vodreal.stanford.edu/engel/08engel200.ram)}, {Mouse
+ (http://vodreal.stanford.edu/engel/12engel200.ram)},
+ {Web-board
+ (http://vodreal.stanford.edu/engel/23engel200.ram)}.
+
+ {Biography (http://www2.bootstrap.org/dce-bio.htm)}.
+
+ {Tia O'Brien, "The Mouse", Silicon Valley News
+ (http://mercurycenter.com/svtech/news/special/engelbart/)}.
+
+ {(http://inventors.about.com/library/weekly/aa081898.htm)}.
+
+ (2003-08-06)
+
+Doug Lenat
+
+ <person> One of the world's leading computer scientists
+ specialising in {Artificial Intelligence}. He is currently
+ (1999) head of the {Cyc} Project at {MCC}, and President of
+ Cycorp. He has been a Professor of Computer Science at
+ {Carnegie-Mellon University} and {Stanford University}.
+
+ See also {microLenat}.
+
+ (1999-08-24)
+
+DOW COMPILER
+
+ An early system on the {Datatron 200} series.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1994-12-07)
+
+Do What the Fuck You Want to Public License
+
+ <legal> (WTFPL) An obscenely permissive {license} for {software}
+ and other scientific or artistic works. As the name suggests, the
+ WTFPL does not restrict what you can do with the licenced work at
+ all. The only restriction on the use of the license itself is
+ that if you change it you also change the name.
+
+ The WTFPL aims to expose and remove the problems of the popular
+ but competing {GPL} and {BSD} licences.
+
+ Since, according to its own terms, the license can be completely
+ ignored, it can be little more than an amusing paradox.
+
+ {Unlicense} is a more serious template for dedicating {software}
+ to the {public domain}.
+
+ {WTFPL Home (http://www.wtfpl.net/)}.
+
+ (2013-11-05)
+
+down
+
+ 1. Not operating. "The up escalator is down" is considered a
+ humorous thing to say, and "The elevator is down" always
+ means "The elevator isn't working" and never refers to what
+ floor the elevator is on. With respect to computers, this
+ term has passed into the mainstream; the extension to other
+ kinds of machine is still hackish.
+
+ 2. "go down" To stop functioning; usually said of the
+ {system}. The message from the {console} that every hacker
+ hates to hear from the operator is "System going down in 5
+ minutes".
+
+ 3. "take down", "bring down" To deactivate purposely, usually
+ for repair work or {PM}. "I'm taking the system down to work
+ on that bug in the tape drive." Occasionally one hears the
+ word "down" by itself used as a verb in this sense.
+
+ See {crash}; opposite: {up}.
+
+ [{Jargon File}]
+
+ (1994-12-07)
+
+download
+
+ <jargon> To transfer data from one computer to another.
+ Downloading usually refers to transfer from a larger "host"
+ system (especially a {server} or {mainframe}) to a smaller
+ "client" system, especially a {microcomputer} or specialised
+ peripheral, and "{upload}" usually means from small to large.
+
+ Others hold that, technically, download means "receive" and
+ upload means "send", irrespective of the size of the systems
+ involved.
+
+ Note that in communications between ground and space,
+ space-to-earth transmission is always "down" and the reverse
+ "up", regardless of size. So far the in-space machines have
+ invariably been smaller; thus the upload/download distinction
+ has been reversed from its usual sense.
+
+ [{Jargon File}]
+
+ (2003-11-04)
+
+downloading
+
+ {download}
+
+downsizing
+
+ <jargon> The process of moving an {application program} from a
+ {mainframe} to a cheaper system, typically a {client-server}
+ system.
+
+ (1995-03-27)
+
+downstream
+
+ {upstream}
+
+down-time
+
+ <jargon> A period of time during which a (computer) system is
+ not operational, due to a malfunction or maintenance.
+
+ (1997-06-08)
+
+downward closed
+
+ {closure}
+
+Downy cocktail
+
+ {cationic cocktail}
+
+DP
+
+ 1. {data processing}.
+
+ According to hackers, use of the term marks one immediately as
+ a {suit}.
+
+ See {DPer}.
+
+ 2. {dot pitch}.
+
+ 3. {Dissociated Press}.
+
+ [{Jargon File}]
+
+ (1996-07-22)
+
+DPA
+
+ {Data Protection Act}
+
+DPB
+
+ /d*-pib'/ The {PDP-10} instruction "DePosit Byte" that inserts
+ some bits into the middle of some other bits. Hackish usage
+ has been kept alive by the {Common LISP} function of the same
+ name.
+
+ [{Jargon File}]
+
+ (1994-12-07)
+
+DPer
+
+ /dee-pee-er/ Data Processor. Hackers are absolutely amazed
+ that {suits} use this term self-referentially. *Computers*
+ process data, not people!
+
+ See {DP}.
+
+ [{Jargon File}]
+
+ (1994-12-07)
+
+dpi
+
+ Dots per inch.
+
+ A measure of resolution for printers, scanners and displays.
+
+ {Laser printers} typically reach 300 DPI, though 600 DPI is
+ becoming more common. Commercial typesetters are usually
+ around 1200 DPI.
+
+ (1995-01-05)
+
+DPL
+
+ DECmmp Parallel Language.
+
+ A {C}-like parallel language for the {DECmpp} machine.
+
+ (1994-12-07)
+
+DPL-82
+
+ ["DPL-82: A Language for Distributed Processing", L. Ericson,
+ Proc 3rd Intl Conf Distrib Comp Sys, IEEE 1982, pp.526-531].
+
+ (1994-12-07)
+
+DPLL
+
+ {Digital Phase-Locked Loop}
+
+DPMI
+
+ {DOS Protected Mode Interface}
+
+DPMS
+
+ <hardware> {Display Power Management Signaling}.
+
+ (1995-12-11)
+
+DPN
+
+ {Decomposed Petri Net}
+
+DPP
+
+ {Dining Philosophers Problem}
+
+d-Prolog
+
+ <language> A version of {Prolog} extended with {defeasible
+ reasoning}.
+
+ {(ftp://aisun1.ai.uga.edu/ai.prolog/)} for {MS-DOS} and {Unix}.
+
+ (1994-12-07)
+
+DPS
+
+ 1. <language, text> {Display PostScript}.
+
+ 2. <language> A {real-time} language with direct
+ expression of timing requests.
+
+ ["Language Constructs for Distributed Real-Time PRogramming",
+ I. Lee et al Proc IEEE Real-Time Sys Symp pp.57-66 (Dec
+ 1985)].
+
+ [What does it stand for?]
+
+ (1995-03-28)
+
+DPS-6
+
+ <computer> A {Honeywell} {minicomputer} from the 1980s-1990s.
+ It originally ran the {GCOS-6} {operating system}.
+
+ (2004-08-24)
+
+dpSather
+
+ {Data-parallel} {Sather}. {deterministic} {fine-grained
+ parallelism}.
+
+ E-mail: <hws@csis.dit.csiro.au>.
+ {(ftp://lynx.csis.dit.csiro.au/p/pub/ather/dpsather.papers)}.
+
+DPSK
+
+ <communications> {Differential Phase-Shift Keying}.
+
+DQDB
+
+ {Distributed Queue Dual Bus}
+
+draco
+
+ A blend of {Pascal}, {C} and {ALGOL 68} developed by Chris
+ Gray in 1987. It has been implemented for {CP/M-80} and
+ {Amiga}.
+
+ (1994-11-04)
+
+Draft Once ReUse Many
+
+ <jargon> (DORUM) Reusing parts of a document to produce parts
+ of an entirely new document. The term normally refers to text
+ documents but the practise is equally common in programming.
+
+ (1998-05-09)
+
+drag
+
+ {drag and drop}
+
+drag and drop
+
+ A common method for manipulating files (and sometimes text)
+ under a {graphical user interface} or {WIMP} environment. The
+ user moves the pointer over an icon representing a file and
+ presses a mouse button. He holds the button down while moving
+ the pointer (dragging the file) to another place, usually a
+ directory viewer or an icon for some {application program},
+ and then releases the button (dropping the file). The meaning
+ of this action can often be modified by holding certain keys
+ on the keyboard at the same time.
+
+ Some systems also use this technique for objects other than
+ files, e.g. portions of text in a {word processor}.
+
+ The biggest problem with drag and drop is does it mean "copy"
+ or "move"? The answer to this question is not intuitively
+ evident, and there is no consensus for which is the right
+ answer. The same vendor even makes it move in some cases and
+ copy in others. Not being sure whether an operation is copy
+ or move will cause you to check very often, perhaps every time
+ if you need to be certain. Mistakes can be costly. People
+ make mistakes all the time with drag and drop. {Human
+ computer interaction} studies show a higher failure rate for
+ such operations, but also a higher "forgiveness rate" (users
+ think "silly me") than failures with commands (users think
+ "stupid machine"). Overall, drag and drop took some 40 times
+ longer to do than single-key commands.
+
+ [Erik Naggum <erik@naggum.no>]
+
+ (2007-06-15)
+
+dragging
+
+ {drag}
+
+drag-n-drop
+
+ <spelling> Stupid spelling of {drag and drop}.
+
+ (1996-12-13)
+
+DRAGON
+
+ 1. An {Esprit} project aimed at providing effective support to
+ {reuse} in {real-time} distributed {Ada} {application
+ programs}.
+
+ 2. An implementation language used by {BTI Computer Systems}.
+
+ E-mail: Pat Helland <helland@hal.com>.
+
+ [{Jargon File}]
+
+ (1994-12-08)
+
+dragon
+
+ [MIT] A program similar to a {daemon}, except that it is not
+ invoked at all, but is instead used by the system to perform
+ various secondary tasks. A typical example would be an
+ accounting program, which keeps track of who is logged in,
+ accumulates load-average statistics, etc. Under ITS, many
+ terminals displayed a list of people logged in, where they
+ were, what they were running, etc., along with some random
+ picture (such as a unicorn, Snoopy or the Enterprise), which
+ was generated by the "name dragon". Use is rare outside
+ {MIT}, under {Unix} and most other {operating systems} this
+ would be called a "background {demon}" or {daemon}. The
+ best-known Unix example of a dragon is {cron}. At {SAIL},
+ they called this sort of thing a "phantom".
+
+ [{Jargon File}]
+
+Dragon Book
+
+ <publication> The classic text "Compilers: Principles,
+ Techniques and Tools", by Alfred V. Aho, Ravi Sethi, and
+ Jeffrey D. Ullman (Addison-Wesley 1986; ISBN 0-201-10088-6).
+ So called because of the cover design featuring a dragon
+ labelled "complexity of compiler design" and a knight bearing
+ the lance "LALR parser generator" among his other trappings.
+ This one is more specifically known as the "Red Dragon Book"
+ (1986); an earlier edition, sans Sethi and titled "Principles
+ Of Compiler Design" (Alfred V. Aho and Jeffrey D. Ullman;
+ Addison-Wesley, 1977; ISBN 0-201-00022-9), was the "Green
+ Dragon Book" (1977). (Also "New Dragon Book", "Old Dragon
+ Book".) The horsed knight and the Green Dragon were warily
+ eying each other at a distance; now the knight is typing
+ (wearing gauntlets!) at a terminal showing a video-game
+ representation of the Red Dragon's head while the rest of the
+ beast extends back in normal space.
+
+ See also {book titles}.
+
+ (1996-12-03)
+
+DRAGOON
+
+ <language> A {distributed}, {concurrent}, {object-oriented}
+ {Ada}-based language developed in the {Esprit} {DRAGON}
+ project by Colin Atkinson at {Imperial College} in 1989 (Now
+ at University of Houston, Clear Lake). DRAGOON supports
+ object-oriented programming for {embeddable systems} and is
+ presently implemented as an Ada {preprocessor}.
+
+ ["Object-Oriented Reuse, Concurrency and Distribution: An
+ Ada-Based Approach", C. Atkinson, A-W 1991, ISBN
+ 0-2015-6-5277].
+
+ (1999-11-22)
+
+drain
+
+ <jargon> (IBM) To allow a system to complete the processing of
+ its current work before the system becomes unavailable.
+ E.g. draining a device before taking it {off-line} or telling
+ a {web server} in a {server farm} not to accept any new
+ requests but to finish processing any requests it has already
+ accepted.
+
+ [{Jargon File}]
+
+ (2005-07-18)
+
+DRAM
+
+ {dynamic random-access memory}
+
+DRAM refresh
+
+ <storage> The operation which cycles through a {DRAM} reading
+ each row and writing it back again to compensate for the
+ gradual leakage of charge from the {capacitors} which store
+ the data. This may be done by the {CPU} but is often done by
+ a dedicated {memory controller}.
+
+ (1997-02-23)
+
+Drawing eXchange Format
+
+ (DXF) A file format for graphical information, similar to
+ {IGES}. Commonly used by {CAD} systems like {AutoCAD}.
+
+ (1994-12-08)
+
+dread high bit disease
+
+ <character> A condition endemic to {PRIME} (also known as
+ "PR1ME") {minicomputers} that results in all the characters
+ having their high bit (0x80, see {meta bit}) ON rather than
+ OFF. This complicates transporting files to other systems and
+ talking to true 8-bit devices. Folklore had it that PRIME
+ adopted the convention in order to save 25 cents per {serial
+ line} per machine; PRIME old-timers, on the other hand, claim
+ they inherited the disease from {Honeywell} via customer
+ NASA's compatibility requirements and struggled heroically to
+ cure it. Whoever was responsible, this probably qualifies as
+ one of the most cretinous design tradeoffs ever made. A few
+ other machines have exhibited similar brain damage.
+
+ [{Jargon File}]
+
+ (2002-04-09)
+
+DREAM 6800
+
+ <computer> A computer based on the {Motorola 6800}
+ {microprocessor}.
+
+ The DREAM 6800 could be programmed in {CHIP-8}.
+
+ (2002-04-09)
+
+DRECNET
+
+ /drek'net/ [Yiddish/German "dreck", meaning filth] Deliberate
+ distortion of DECNET, a networking protocol used in the {VMS}
+ community. So called because DEC helped write the Ethernet
+ specification and then (either stupidly or as a malignant
+ customer-control tactic) violated that spec in the design of
+ DRECNET in a way that made it incompatible. See also
+ {connector conspiracy}.
+
+drill down
+
+ <database> (Or "drill-down analysis") To examine data in
+ greater detail, especially, in {reporting}, to interactively
+ select some item from a summary and display the data that
+ contributed to that item, broken down by some extra parameter.
+
+ For example, when viewing your company's total worldwide sales
+ for each month of this year, you might drill down to see
+ October's sales by country, then again to see October's sales
+ in Afghanistan by product and so on.
+
+ This kind of analysis is often supported by some kind of {data
+ warehouse}.
+
+ (2007-06-04)
+
+drill-down analysis
+
+ {drill down}
+
+drive
+
+ <storage> A {peripheral} device that allows a computer to read
+ or/or write some storage medium such as a {hard disk}, {floppy
+ disk}, {magnetic tape}, {compact disc} or {DVD}. These would
+ be called a {disk drive}, {magnetic tape drive}, etc. CD and
+ DVD drives are known collectively as {optical drives}. When
+ unqualified the term probably refers to a hard disk drive.
+
+ The term "drive" refers particularly to the electrical
+ components such as electric motors and head positioning
+ system, read-write heads and associated electronics.
+
+ Of the above storage media, typically only hard disks are
+ fixed, the rest being removable. Most PCs in 2009 include one
+ disk drive and one optical drive housed in the main PC
+ enclosure. Extra drives can be connected externally via
+ {USB}, {SCSI} or {Firewire}. Magnetic tape is always
+ removable and tape drives are typically external.
+
+ Not to be confused with a "driver" meaning {device driver} -
+ software used to access a peripheral device.
+
+ (2009-12-01)
+
+driver
+
+ 1. <operating system> {device driver}.
+
+ 2. <programming> The {main loop} of an event-processing
+ program; the code that gets commands and dispatches them for
+ execution.
+
+ 3. <tool> In the {TeX} world and the computerised typesetting
+ world in general, a program that translates some
+ device-independent or other common format to something a real
+ device can actually understand.
+
+ [{Jargon File}]
+
+drivers
+
+ {driver}
+
+Dr. James H. Clark
+
+ <person> The founder of {Silicon Graphics, Inc.} and
+ co-founder of {Netscape Communications Corporation}.
+
+ (1998-05-21)
+
+DRM
+
+ 1. {Digital Rights Management}
+
+ 2. {Digital Radio Mondiale}
+
+ (2006-02-02)
+
+droid
+
+ <robotics> (From "android") The robots of the Star Wars
+ universe. While androids look somewhat human-like, Star Wars'
+ droids are typically fashioned in the likeness of their
+ creators or in a utilitarian design that stresses function
+ over appearance. Droids are equipped with artificial
+ intelligence, though some are naturally created smarter than
+ others depending on the function they are designed to serve.
+
+ "Droid" is a Lucasfilm Ltd. trademark.
+
+ {starwars.com (http://starwars.com/databank/droid/)}.
+
+ ["A Guide to the Star Wars Universe", Bill Slavicsek, 1994,
+ Lucasfilm Ltd.]
+
+ [Was George Lucas really the first to use the abbreviation (in
+ 1977)?]
+
+ (2006-07-21)
+
+DROOL
+
+ <games> Dave's Recycled Object-Oriented Language. Language
+ for writing adventure games. An updated implementation of
+ AdvSys. {multiple inheritance}, garbage collection.
+
+ ["Dave's Recycled OO Language", David Betz, Dr. Dobbs J, Oct
+ 1993, pp.74-78].
+
+drool-proof paper
+
+ <jargon> Documentation that has been obsessively {dumbed
+ down}, to the point where only a {cretin} could bear to read
+ it, is said to have succumbed to the "drool-proof paper
+ syndrome" or to have been "written on drool-proof paper". For
+ example, this is an actual quote from {Apple Computer}'s
+ LaserWriter manual: "Do not expose your LaserWriter to open
+ fire or flame."
+
+ [{Jargon File}]
+
+ (1997-06-23)
+
+drop cable
+
+ Wiring between a computer and its {Ethernet transceiver}.
+ Maximum length if full-spec is 47m.
+
+drop-down list
+
+ {pull-down list}
+
+drop-down menu
+
+ {pull-down menu}
+
+drop-ins
+
+ [analogy with {drop-outs}] Spurious characters appearing on a
+ terminal or console as a result of {line noise} or a system
+ malfunction of some sort. Especially used when these are
+ interspersed with one's own typed input.
+
+ [{Jargon File}]
+
+drop on the floor
+
+ To react to an error condition by silently discarding messages
+ or other valuable data. "The gateway ran out of memory, so it
+ just started dropping packets on the floor." Also frequently
+ used of faulty mail and netnews relay sites that lose
+ messages. See also {black hole}, {bit bucket}.
+
+drop-outs
+
+ 1. A variety of "power glitch" (see {glitch}); momentary zero
+ voltage on the electrical mains.
+
+ 2. Missing characters in typed input due to software
+ malfunction or system overload (one cause of such behaviour
+ under {Unix} when a bad connection to a modem swamps the
+ processor with spurious character interrupts; see {screaming
+ tty}).
+
+ 3. Mental glitches; used as a way of describing those
+ occasions when the mind just seems to shut down for a couple
+ of beats. See {glitch}, {fried}.
+
+ [{Jargon File}]
+
+ (2001-02-22)
+
+DrScheme
+
+ <Scheme> A popular {Scheme} implementation from the {PLT} team
+ at {Rice University}.
+
+ {(http://cs.rice.edu/CS/PLT/packages/drscheme/)}.
+
+ (2001-02-22)
+
+DRUCO I
+
+ Early system on IBM 650. Listed in CACM 2(5):16 (May 1959).
+
+drugged
+
+ (Or "on drugs") 1. Conspicuously stupid, heading toward
+ {brain-damaged}. Often accompanied by a pantomime of toking a
+ joint.
+
+ 2. Of hardware, very slow relative to normal performance.
+
+ [{Jargon File}]
+
+ (2011-12-03)
+
+drug report
+
+ <humour> A {bug report} so utterly incomprehensible that
+ whoever submitted it must have been smoking crack. Even
+ worse than a {chug report}.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2011-12-03)
+
+drum
+
+ Ancient slow, cylindrical magnetic media that were once
+ state-of-the-art storage devices. Under {BSD} {Unix} the disk
+ partition used for swapping is still called "/dev/drum"; this
+ has led to considerable humour and not a few straight-faced
+ but utterly bogus "explanations" getting foisted on {newbies}.
+
+ See also "{The Story of Mel}".
+
+ (1994-12-22)
+
+drunk mouse syndrome
+
+ (Also "mouse on drugs") A malady exhibited by the mouse
+ pointing device of some computers. The typical symptom is for
+ the mouse cursor on the screen to move in random directions
+ and not in sync with the motion of the actual mouse. Can
+ usually be corrected by unplugging the mouse and plugging it
+ back again. Another recommended fix for optical mice is to
+ rotate your {mouse mat} 90 degrees.
+
+ At {Xerox PARC} in the 1970s, most people kept a can of copier
+ cleaner (isopropyl alcohol) at their desks. When the steel
+ ball on the mouse had picked up enough {cruft} to be
+ unreliable, the mouse was doused in cleaner, which restored it
+ for a while. However, this operation left a fine residue that
+ accelerated the accumulation of cruft, so the dousings became
+ more and more frequent. Finally, the mouse was declared
+ "alcoholic" and sent to the clinic to be dried out in a CFC
+ ultrasonic bath.
+
+ [{Jargon File}]
+
+dry run
+
+ <programming> To execute a program by hand, writing values of
+ variables and other run-time data on paper, in order to check
+ its operation and {control flow} or to track down a {bug} (as
+ part of {debugging}). A dry run is an extreme form of {desk
+ check} or {code review} and is practical only for fairly
+ simple programs, small amounts of data and simple external
+ interfaces. It was often performed {off-line} using a
+ {hardcopy} of the {source code}.
+
+ Dry runs were common practice in the days when access to
+ computers was limited but the availability of {screen editors}
+ and fast {compilers} makes {debugging by printf} a more
+ productive method in most cases. Sophisticated {debuggers}
+ that allow you to get the computer to step through your source
+ code line by line and show values of variables make even this
+ unnecessary.
+
+ (2006-11-27)
+
+DS0
+
+ <communications> The zeroth {DS level}, having a transmission
+ rate of 64,000 bits per second (64 kb/s), intended to carry
+ one {voice channel} (a phone call).
+
+ (2001-03-18)
+
+DS1
+
+ <communications> A {DS level} and {framing specification} for
+ synchronous digital streams, over circuits in the North
+ American {digital transmission hierarchy}, at the {T1}
+ transmission rate of 1,544,000 bits per second ({baud}).
+
+ DS1 is commonly used to multiplex 24 {DS0} channels. Each DS0
+ channel, originally a digitised voice-grade telephone signal,
+ carries 8000 bytes per second (64,000 bits per second). A DS1
+ frame includes one byte from each of the 24 DS0 channels and
+ adds one {framing bit}, making a total of 193 bits per frame
+ at 8000 frames per second. The result is 193*8000 = 1,544,000
+ bits per second.
+
+ In the original standard, the successive framing bits
+ continuously repeated the 12-bit sequence 110111001000, and
+ such a 12-frame unit is called a super-frame. In voice
+ telephony, errors are acceptable (early standards allowed as
+ much as one frame in six to be missing entirely), so the least
+ significant bit in two of the 24 streams was used for
+ signaling between network equipments. This is called
+ {robbed-bit signaling}.
+
+ To promote error-free transmission, an alternative called the
+ extended super-frame (ESF) of 24 frames was developed. In
+ this standard, six of the 24 framing bits provide a six bit
+ {cyclic redundancy check} (CRC-6), and six provide the actual
+ framing. The other 12 form a virtual circuit of 4000 bits per
+ second for use by the transmission equipment, for {call
+ progress signals} such as busy, idle and ringing. DS1 signals
+ using ESF equipment are nearly error-free, because the CRC
+ detects errors and allows automatic re-routing of connections.
+
+ Compare {T-carrier systems}.
+
+ [Kenneth Sherman, "Data Communications : a user's guide",
+ third edition (1990), Reston/Prentice-Hall/Simon & Schuster].
+
+ (1996-03-30)
+
+DS1C
+
+ <communications> A {DS level} and {framing specification} for
+ digital signals in the North American digital transmission
+ hierarchy. A DS1C signal uses 48 {PCM} channels and has a
+ transmission rate of 3.15 Megabits per second, twice that of
+ {DS1}.
+
+ DS1C uses two {DS1} signals combined and sent on a 3.152
+ megabit per second {carrier} which allows 64 kilobits per
+ second for synchronisation and {framing} using "{pulse
+ stuffing}". The channel 2 signal is logically inverted, and a
+ framing bit is stuffed in two out of three code words,
+ resulting in 26-bit information units. The channels are
+ interleaved and then scrambled by the addition {modulo} 2 of
+ the signal with the previous bit. Finally the bit stream is
+ combined with a control bit sequence that permits the
+ {demultiplexor} to function by preceding each 52 bits with one
+ DS1C framing bit. A series of 24 such 53-bit frames forms a
+ 1272-bit "M-frame".
+
+ (1995-02-07)
+
+DS2
+
+ <communications> A {DS level} and {framing specification} for
+ digital signals in the North American digital transmission
+ hierarchy. A DS2 signal uses 96 {PCM} channels and has a
+ transmission rate of 6.31 Megabits per second, twice that of
+ {DS1C}.
+
+ (1995-02-07)
+
+DS3
+
+ <communications> The third {DS level}, a {framing
+ specification} for digital signals in the North American
+ digital transmission hierarchy. A DS3 signal has a
+ transmission rate of 44.736 Megabits per second.
+
+ DS3 is used, for example, on {T3} synchronous {Integrated
+ Services Digital Network} lines.
+
+ (1995-01-12)
+
+DSA
+
+ {Directory System Agent}
+
+DSDM
+
+ {Dynamic Systems Development Method}
+
+DSE
+
+ 1. Display Screen Equipment. See {Visual Display Unit}.
+
+ 2. {Data Structure Editor}.
+
+ (2002-11-09)
+
+DSEE
+
+ {Domain Software Engineering Environment}
+
+D-shell connector
+
+ <hardware> One of the family of connectors: DA-15, {DB-25},
+ DC-37, DD-50, {DE-9}, and DEH-15 [VGA]. The "D" is the shape
+ of the shell, the next letter determines connector size, and
+ the number is the maximum pin count.
+
+ (1999-12-08)
+
+DSI
+
+ {Delivered Source Instruction}
+
+DSL
+
+ 1. <communications> {Digital Subscriber Line}.
+
+ 2. <language> {Digital Simulation Language}.
+
+ 3. <language> {Denotational Semantics Language}.
+
+ (1996-10-13)
+
+DSLAM
+
+ {Digital Subscriber Line Access Module}
+
+DS level
+
+ <communications> (Digital Signal or Data Service level)
+ Originally an {AT&T} classification of transmitting one or
+ more voice conversations in one digital data stream. The best
+ known DS levels are {DS0} (a single conversation), {DS1} (24
+ conversations multiplexed), {DS1C}, {DS2}, and {DS3}.
+
+ By extension, the DS level can refer to the raw data rate
+ necessary for transmission:
+
+ DS0 64 Kb/s
+ DS1 1.544 Mb/s
+ DS1C 3.15 Mb/s
+ DS2 6.31 Mb/s
+ DS3 44.736 Mb/s
+ DS4 274.1 Mb/s
+
+ (where K and M signify multiplication by 1000 and 1000000,
+ rather than powers of two). In this sense it can be used to
+ measure of data service rates classifying the user access
+ rates for various point-to-point {WAN} technologies or
+ standards (e.g. {X.25}, {SMDS}, {ISDN}, {ATM}, {PDH}).
+
+ Japan uses the US standards for DS0 through DS2 but Japanese
+ DS5 has roughly the circuit capacity of US DS4, while the
+ European standards are rather different (see {E1}). In
+ the US all of the transmission rates are integral multiples of
+ 8000 bits per second but rates above DS1 are not necessarily
+ integral multiples of 1,544 kb/s.
+
+ (1998-05-18)
+
+DSM
+
+ 1. Data Structure Manager.
+
+ An {object-oriented} language by J.E. Rumbaugh and M.E. Loomis
+ of {GE}, similar to {C++}. It is used in implementation of
+ {CAD}/{CAE} software. DSM is written in DSM and {C} and
+ produces {C} as output.
+
+ ["DSM: An Object-Relationship Modeling Language", A. Shah et
+ al, SIGPLAN Notices 24(10):191-202 (OOPSLA '89) (Oct 1989)].
+
+ 2. {DIGITAL Standard MUMPS}.
+
+ (1995-01-10)
+
+DSN
+
+ {Digital Switched Network}
+
+DSO
+
+ {dynamic shared object}
+
+DSORG
+
+ {data set organization}
+
+DSP
+
+ {digital signal processing}
+
+DSP32 Assembly Language
+
+ A high-level assembly language for the DSP32
+ Programmable DSP Chip.
+
+DSP56000
+
+ A {digital signal processing} chip from {Motorola}.
+
+ An assembler called {a56} and a port of {gcc} called
+ {dsp56k-gcc} are available.
+
+DSP56001
+
+ A {digital signal processing} chip from {Motorola}.
+
+ An assembler called {a56} is available.
+
+dsp56165-gcc
+
+ A port of {gcc} version 1.40 to the {Motorola} {DSP56156} and
+ {DSP56000} by Andrew Sterian <asterian@eecs.umich.edu>.
+
+ {alt.sources}
+
+dsp56k-gcc
+
+ {Motorola}'s port of {gcc} version 1.37.1 to the {Motorola}
+ {DSP56000}.
+
+ {Finland
+ (ftp://nic.funet.fi/pub/ham/dsp/dsp56k-tools/dsp56k-gcc.tar.Z)}.
+ {Australia
+ (ftp://evans.ee.adfa.oz.au/pub/micros/56k/g56k.tar.Z)}.
+
+DSP/C
+
+ Numerical extension to C, for DSP applications.
+
+ ["DSP/C: A Standard High Level Language for DSP and Numeric
+ Processing", K. Leary & W. Waddington, Proc ICASSP 90, Apr
+ 1990, pp.1065-1068].
+
+DSPL
+
+ {Digital Signal Processing Language}
+
+DSR
+
+ {Dynamic Service Register}
+
+DSS
+
+ 1. {Decision Support Systems}.
+
+ 2. {Digital Signature Standard}.
+
+ (1995-11-16)
+
+DSSSL
+
+ {Document Style Semantics and Specification Language}
+
+DST
+
+ Daylight-Saving Time.
+
+DSU
+
+ 1. <communications> {Data Service Unit}.
+
+ 2. {Disk Subsystem Unit} ({Artecon}).
+
+ 3. <humour> {Dwarf Storage Unit}.
+
+ (1996-12-01)
+
+DSVD
+
+ {Digital Simultaneous Voice and Data}
+
+DSW
+
+ {penis war}
+
+DTALGOL
+
+ Decision Table ALGOL.
+
+ An {ALGOL} superset from {Victoria University}, Wellington
+ that added {decision tables} and runs on {Burroughs Large
+ System}.
+
+ (1995-02-02)
+
+DTD
+
+ {Document Type Definition}
+
+DTE
+
+ {Data Terminal Equipment}
+
+DT&E
+
+ {Developmental Test and Evaluation}
+
+DTLS
+
+ {Descriptive Top-Level Specification}
+
+DTMF
+
+ {Dual Tone Multi Frequency}
+
+DTP
+
+ {desktop publishing}
+
+DTR
+
+ {Data Terminal Ready}
+
+DTS
+
+ 1. {Distributed Time Service}.
+
+ 2. <audio> {Digital Theatre Sound}.
+
+ (2001-12-24)
+
+DTSS
+
+ <operating system> The first commercial {time-sharing} system,
+ created by {Dartmouth College} and sold by {General Electric}
+ around 1967.
+
+ GE's Information Service Divsion (ISD) marketed DTSS which was
+ running on a system called {GE-265} (a combination of the
+ {front-end processor} the {Datanet-30} and the {GE-235}).
+
+ DTSS was ported (and significantly improved by GE ISD around
+ 1965-1966 on a combination of DN-30 and {GE-635}). This
+ proprietary system, called Mk-II, later improved by GE and
+ renamed Mk-III, is still working today (1997) as part of the
+ GE service bureau that also includes {IBM} and {Unix}
+ computers.
+
+ (1997-09-16)
+
+D-type
+
+ 1. <hardware> A type of computer peripheral connector so named
+ because one side is shorter (with one less pin) than the other
+ giving a (squarish) "D" shape. The connectors have two rows
+ of pins (or holes). Common types are 25-way (13+12 pins) and
+ 9-way (5+4 pins). They are often used for serial lines,
+ especially {EIA-232}.
+
+ (1995-01-05)
+
+ 2. {D-type flip-flop}.
+
+D-type flip-flop
+
+ <hardware> A digital logic device that stores the status of
+ its "D" input whenever its clock input makes a certain
+ transition (low to high or high to low). The output, "Q",
+ shows the currently stored value.
+
+ Compare {J-K flip-flop}.
+
+ (1995-03-28)
+
+du
+
+ <tool, storage> ("disk usage") The {Unix} command to list the
+ amount of disk space consumed by a directory and its
+ subdirectories.
+
+ {Unix manual page}: du(1).
+
+ (2004-04-01)
+
+DUA
+
+ {Directory User Agent}
+
+dual
+
+ <mathematics> Every field of mathematics has a different
+ meaning of dual. Loosely, where there is some binary symmetry
+ of a theory, the image of what you look at normally under this
+ symmetry is referred to as the dual of your normal things.
+
+ In linear algebra for example, for any {vector space} V, over
+ a {field}, F, the vector space of {linear maps} from V to F is
+ known as the dual of V. It can be shown that if V is
+ finite-dimensional, V and its dual are {isomorphic} (though no
+ isomorphism between them is any more natural than any other).
+
+ There is a natural {embedding} of any vector space in the dual
+ of its dual:
+
+ V -> V'': v -> (V': w -> wv : F)
+
+ (x' is normally written as x with a horizontal bar above it).
+ I.e. v'' is the linear map, from V' to F, which maps any w to
+ the scalar obtained by applying w to v. In short, this
+ double-dual mapping simply exchanges the roles of function and
+ argument.
+
+ It is conventional, when talking about vectors in V, to refer
+ to the members of V' as covectors.
+
+ (1997-03-16)
+
+DUAL-607
+
+ <language> An early system on the {IBM 701}.
+
+ [CACM 2(5):16 (May 1959)].
+
+ (1994-12-13)
+
+dual-attached
+
+ The form of {FDDI} interface where a device is connected to
+ both FDDI token-passing rings, so that uninterrupted operation
+ continues in the event of a failure of either of the rings.
+ All connections to the main {FDDI} rings are dual-attached.
+ Typically, a small number of critical infrastructure devices
+ such as {routers} and {concentrators} are dual-attached,
+ whereas {host} computers are normally single-attached or
+ {dual-homed} to a router or concentrator.
+
+ For example, a ring could be formed between a single router
+ and two concentrators (all dual-attached) then all other
+ components that need to be fault-tolerant (typically file
+ servers) can be {dual-homed} to both concentrators.
+
+ (1994-12-13)
+
+dual boot
+
+ <operating system> Any system offering the user the choice of
+ two {operation systems} (OSes) under which to start a
+ computer. A dual boot system allows the user to run programs
+ for both operating systems on a single computer (though not
+ simultaneously). The term "multiple boot" or "multiboot"
+ extends the idea to more than two OSes.
+
+ The OSes are generally unaware of each other's existence.
+ They are installed on separate {hard disk} {partitions} or on
+ separate disks. They may be able to access each other's
+ files, possibly via some extra {driver} software if they use
+ different {file systems}.
+
+ The OSes need not be completely different - they might be
+ different versions of {Microsoft Windows} (e.g. {Windows XP}
+ and {Windows NT}) or {Linux} (e.g. {Debian} and {Fedora}).
+
+ A dual boot system differs from an {emulator} such as
+ {vmware}, which runs one or more OSes "on top" of the primary
+ OS, using its resources.
+
+ (2005-02-01)
+
+dual-homed
+
+ <networking> A kind of connection to a {FDDI} network where a
+ {host} is simultaneously connected to two separate devices in
+ the same FDDI ring. One of the connections becomes active
+ while the other one is automatically blocked. If the first
+ connection fails, the backup link takes over with no
+ perceptible delay.
+
+ A dual-homed device can tolerate a fault in one of its "homes"
+ whereas a {dual-attached} device can tolerate a fault in one
+ of the rings.
+
+ (1994-12-13)
+
+Dual In-Line
+
+ <hardware> {Dual In-Line Package}.
+
+Dual In-line Memory Module
+
+ <storage> Small circuit boards carrying memory {integrated
+ circuits}, with signal and power pins on both sides of the
+ board, in contrast to {single-in-line memory modules} (SIMM).
+
+ The individual gold or lead connectors (pins) on SIMMs,
+ although they are on both sides of the chip, are connected to
+ the same memory chip, while on a DIMM, the connections on each
+ side of the module connect to different chips. This allows
+ for a wider data path, as more modules can be accessed at
+ once. DIMM pins are arranged in a zigzag design to allow PCB
+ tracks to pass between them.
+
+ The 8-byte DIMM format with dual-sided contacts can
+ accommodate 4- and 16-megabit {dynamic RAM} chips, and is
+ predicted to handle 64- and 256-Mbit devices. The 8-byte DIMM
+ will hold up to 32 megabytes of memory using 16-Mbit DRAMs,
+ but with the 256-Mbit future-generation DRAM, it will be able
+ to hold a 64-Mx64 configuration. Another variation, the
+ 72-pin {SO-DIMM}, is designed to connect directly to 32 bit
+ data buses, and is intended for use in memory-expansion
+ applications in {notebook computers}.
+
+ A Dual in-line memory module (DIMM), as opposed to SIMMs (used
+ by the majority of the PC industry) allows for a 128-bit data
+ path by interleaving memory on alternating memory access
+ cycles. SIMMs on the other hand, have a 64-bit data path.
+ Suppliers are unanimous in their belief that the DIMM will
+ eventually replace the SIMM as the market's preferred memory
+ module.
+
+ (1996-01-28)
+
+Dual In-Line Package
+
+ <hardware> (DIL, DIP) The most common type of package for
+ small and medium scale {integrated circuits}, with up to about
+ 48 pins. The pins hang vertically from the two long edges of
+ the rectangular package, spaced at intervals of 0.1 inch. The
+ pins fit through holes in the circuit board to which they are
+ soldered or into a socket.
+
+ [More than 48 pins?]
+
+ (1995-02-06)
+
+dual ported
+
+ A term used to describe memory {integrated circuits} which can
+ be accessed simultaneously via two independent address and
+ data busses.
+
+ Dual ported memory is often used in {video display} hardware,
+ especially in conjunction with {Video Random Access Memory}
+ (VRAM). The two ports allow the video display hardware to
+ read memory to display the contents on screen at the same time
+ as the CPU writes data to other areas of the same memory. In
+ single-ported memory these two processes cannot occur
+ simultanteously, the CPU must wait, thus resulting in slower
+ access times. {Cycle stealing} is one technique used to avoid
+ this in single-ported {video memory}.
+
+ (1995-01-12)
+
+dual-stack
+
+ <networking> A term used to describe a network {node} running both
+ {IPv4} and {IPv6} {protocol stacks} (or possibly others) at the
+ same time. Such a machine can act as a {protocol converter}
+ between the two networks.
+
+ A node without dual-stack support can relay traffic in a protocol
+ it does not support natively by use of {tunnelling}.
+
+ {RFC 4213 (http://tools.ietf.org/html/rfc4213)}
+
+ (2013-10-08)
+
+Dual Tone Multi Frequency
+
+ <communications> (DTMF, or "touch-tone") A method used by the
+ telephone system to communicate the keys pressed when
+ dialling. Pressing a key on the phone's keypad generates two
+ simultaneous tones, one for the row and one for the column.
+ These are decoded by the exchange to determine which key was
+ pressed.
+
+ (1995-03-28)
+
+duck typing
+
+ <programming> A term coined by Dave Thomas for a kind of
+ {dynamic typing} typical of some programming languages, such
+ as {Smalltalk}, {Ruby} or {Visual FoxPro}, where a
+ {variable}'s {run-time} value determines the operations that
+ can be performed on it.
+
+ The term comes from the "duck test": if it walks like a duck
+ and quacks like a duck, it must be a duck.
+
+ Duck typing considers the {methods} to which a value responds
+ and the {attributes} it posesses rather than its relationship
+ to a type hierarchy. This encourages greater {polymorphism}
+ because types are enforced as late as possible.
+
+ {(http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/100511)}.
+
+ (2006-09-13)
+
+DUEL
+
+ <programming> A {front end} to {gdb} by Michael Golan
+ <mg@cs.princeton.edu>. DUEL implements a language designed
+ for {debugging} {C} programs. It features efficient ways to
+ select and display data items. It is normally linked into the
+ gdb executable, but could stand alone. It interprets a subset
+ of {C} in addition to its own language.
+
+ Version 1.10.
+
+ {(ftp://ftp.cs.princeton.edu/duel/)}.
+
+ (1993-03-20)
+
+duff
+
+ 1. <programming> {Duff's device}.
+
+ 2. <person> {Tom Duff}.
+
+Duff's device
+
+ The most dramatic use yet seen of {fall through} in {C},
+ invented by Tom Duff when he was at Lucasfilm. Trying to
+ {bum} all the instructions he could out of an inner loop that
+ copied data serially onto an output port, he decided to unroll
+ it. He then realised that the unrolled version could be
+ implemented by *interlacing* the structures of a switch and a
+ loop:
+
+ register n = (count + 7) / 8; /* count > 0 assumed */
+
+ switch (count % 8)
+ {
+ case 0: do { *to = *from++;
+ case 7: *to = *from++;
+ case 6: *to = *from++;
+ case 5: *to = *from++;
+ case 4: *to = *from++;
+ case 3: *to = *from++;
+ case 2: *to = *from++;
+ case 1: *to = *from++;
+ } while (--n > 0);
+ }
+
+ Shocking though it appears to all who encounter it for the
+ first time, the device is actually perfectly valid, legal C.
+ C's default {fall through} in case statements has long been
+ its most controversial single feature; Duff observed that
+ "This code forms some sort of argument in that debate, but I'm
+ not sure whether it's for or against."
+
+ [For maximal obscurity, the outermost pair of braces above
+ could be actually be removed - {GLS}]
+
+ [{Jargon File}]
+
+ (2001-06-22)
+
+dumbed down
+
+ <jargon> Simplified, with a strong connotation of
+ *over*simplified. Often, a {marketroid} will insist that the
+ interfaces and documentation of software be dumbed down after
+ the designer has burned untold gallons of midnight oil making
+ it smart. This creates friction.
+
+ See {user-friendly}.
+
+ (1995-04-14)
+
+dumb terminal
+
+ <hardware> A type of {terminal} that consists of a keyboard
+ and a display screen that can be used to enter and transmit
+ data to, or display data from, a computer to which it is
+ connected. A dumb terminal, in contrast to an {intelligent
+ terminal}, has no independent processing capability or
+ {auxiliary storage} and thus cannot function as a stand-alone
+ device.
+
+ The dumbest kind of terminal is a {glass tty}. The next step
+ up has a minimally {addressable cursor} but no on-screen
+ editing or other features normally supported by an
+ {intelligent terminal}.
+
+ Once upon a time, when glass ttys were common and addressable
+ cursors were something special, what is now called a dumb
+ terminal could pass for a smart terminal.
+
+ [Examples?]
+
+ [{Jargon File}]
+
+ (1995-04-14)
+
+dump
+
+ <operating system> 1. An undigested and voluminous mass of
+ information about a problem or the state of a system,
+ especially one routed to the slowest available output device
+ (compare {core dump}), and most especially one consisting of
+ {hexadecimal} or {octal} {runes} describing the byte-by-byte
+ state of memory, mass storage, or some file. In {elder days},
+ debugging was generally done by "groveling over" a dump (see
+ {grovel}); increasing use of high-level languages and
+ interactive debuggers has made such tedium uncommon, and the
+ term "dump" now has a faintly archaic flavour.
+
+ 2. A {backup}. This usage is typical only at large
+ {time-sharing} installations.
+
+ {Unix manual page}: dump(1).
+
+ [{Jargon File}]
+
+ (1994-12-01)
+
+dumpster diving
+
+ /dump'-ster di:'-ving/ 1. The practice of sifting refuse from
+ an office or technical installation to extract confidential
+ data, especially security-compromising information ("dumpster"
+ is an Americanism for what is elsewhere called a "skip").
+ Back in AT&T's monopoly days, before paper shredders became
+ common office equipment, phone phreaks (see {phreaking}) used
+ to organise regular dumpster runs against phone company plants
+ and offices. Discarded and damaged copies of AT&T internal
+ manuals taught them much. The technique is still rumored to
+ be a favourite of crackers operating against careless targets.
+
+ 2. The practice of raiding the dumpsters behind buildings
+ where producers and/or consumers of high-tech equipment are
+ located, with the expectation (usually justified) of finding
+ discarded but still-valuable equipment to be nursed back to
+ health in some hacker's den. Experienced dumpster-divers not
+ infrequently accumulate basements full of moldering (but still
+ potentially useful) {cruft}.
+
+ [{Jargon File}]
+
+Dungeon
+
+ {Zork}
+
+dup killer
+
+ /d[y]oop kill'r/ Software that is supposed to detect and
+ delete duplicates of a message that may have reached the
+ {FidoNet} system via different routes.
+
+ See also {dup loop}.
+
+ [{Jargon File}]
+
+ (1995-02-02)
+
+duplex
+
+ <communications> Used to describe a communications channel
+ that can carry signals in both directions, in contrast to a
+ {simplex} channel which only ever carries a signal in one
+ direction.
+
+ If signals can only flow in one direction at a time the
+ communications is "{half-duplex}", like a single-lane road with
+ traffic lights at each end. Walkie-talkies with a
+ "press-to-talk" button provide half-duplex communications.
+
+ If signals can flow in both directions simultaneously the
+ communications is "{full-duplex}", like a normal two-lane
+ road. Telephones provide full-duplex communications.
+
+ The term "duplex" was first used in wireless, telegraph, and
+ telephone communications. Nearly all communications circuits
+ used by computers are two-way, so the term is seldom used.
+
+ {(http://cit.ac.nz/smac/dc100www/dc_014.htm)}.
+
+ (2001-07-21)
+
+Duplex High Speed Data
+
+ (DHSD) A term which describes a {full-duplex} channel that can
+ carry 64 kilobits per second.
+
+ This is the kind of service provided by an Inmarsat-B type
+ portable earth station or a {leased line} (not {ISDN}).
+
+ (1995-02-02)
+
+dup loop
+
+ <messaging> /d[y]oop loop/ (also "dupe loop") [FidoNet] An
+ infinite stream of duplicated, near-identical messages on a
+ FidoNet {echo}, the only difference being unique or mangled
+ identification information applied by a faulty or incorrectly
+ configured system or network gateway, thus rendering {dup
+ killers} ineffective. If such a duplicate message eventually
+ reaches a system through which it has already passed (with the
+ original identification information), all systems passed on
+ the way back to that system are said to be involved in a {dup
+ loop}.
+
+ [{Jargon File}]
+
+ (2003-12-15)
+
+Durra
+
+ Description language for {coarse-grained concurrency} on
+ heterogeneous processors. "Durra: A Task-level Description
+ Language", M.R. Barbacci et al, CMU/SEI-86-TR-3, CMU 1986.
+
+dusty deck
+
+ Old software (especially applications) which one is obliged to
+ remain compatible with, or to maintain. {DP} types call this
+ "legacy code", a term hackers consider smarmy and excessively
+ reverent. The term implies that the software in question is a
+ holdover from card-punch days. Used especially when referring
+ to old scientific and {number crunching} software, much of
+ which was written in Fortran and very poorly documented but is
+ believed to be too expensive to replace. See {fossil};
+ compare {crawling horror}.
+
+ [{Jargon File}]
+
+DV cartridge
+
+ <games> (Digital Video?) A plug-in circuit cartridge required
+ by some games consoles in order to play {MPEG} video material.
+
+ (1994-11-02)
+
+DVD
+
+ {Digital Versatile Disc}
+
+DVD-R
+
+ {Digital Versatile Disc}
+
+DVD-RAM
+
+ {Digital Versatile Disk Random Access Memory}
+
+DVD-ROM
+
+ {Digital Versatile Disc}
+
+DVI
+
+ 1. <file format> (device independent) The usual output format
+ of {TeX}, giving a description of a formatted document that is
+ not related to any specific hardware or other standard
+ document format. Utilities exist to view and print DVI files
+ on various systems and devices.
+
+ 2. {Digital Video Input}.
+
+ (2003-09-11)
+
+Dvorak
+
+ <hardware> A configuration of (computer) keyboard keys
+ arranged to increase the speed and ease of typing over the
+ normal {qwerty} layout; the most common characters (for
+ English) have been put on the home row.
+
+ The standard Dvorak International layout is:
+
+ `~ 1! 2@ 3# 4% 5^ 6^ 7& 8* 9( 0) [\{ ]\} \\|
+ '" ,< .> p y f g c r l /? +=
+ a o e u i d h t n s -_
+ ;: q j k x b m w v z
+
+ [Do other Dvorak-like layout standards exist for other
+ languages?]
+
+ (2002-03-14)
+
+Dwarf Storage Unit
+
+ <humour> (DSU) An {IBM} term for a cupboard.
+
+ (1996-06-24)
+
+DWDM
+
+ {wavelength division multiplexing}
+
+dweeb
+
+ An even lower form of life than the {spod}, found in much the
+ same habitat as the former. though more prevailent on {talker
+ systems}. Unlike spods, upon receiving the desired response
+ to the question "Are you male or female?", dweebs will then
+ engage upon a detailed description of themselves and how
+ wonderful they are, often in the hopes of truly impressing the
+ other with their "charm" and "wit". Nearly all dweebs are
+ male, but very few actually live up to the image that they
+ present. Dweebs, unfortunately, are often the cause of
+ ill-will, and may well bring a bad reputation to the system in
+ question. They are often, however, easy to wind up and can be
+ the source of great mirth to the seasoned user.
+
+dwg
+
+ <filename extension> The {filename extension} for {Autodesk}
+ {drawing} files.
+
+ {(http://faqs.org/faqs/graphics/fileformats-faq/part3/)}.
+
+ (2000-08-02)
+
+DWIM
+
+ /dwim/ [acronym, "Do What I Mean" (not what I say)] 1. Able to
+ guess, sometimes even correctly, the result intended when
+ bogus input was provided.
+
+ 2. The BBNLISP/INTERLISP function that attempted to accomplish
+ this feat by correcting many of the more common errors. See
+ {hairy}.
+
+ 3. Occasionally, an interjection hurled at a balky computer,
+ especially when one senses one might be tripping over
+ legalisms (see {legalese}).
+
+ Warren Teitelman originally wrote DWIM to fix his typos and
+ spelling errors, so it was somewhat idiosyncratic to his
+ style, and would often make hash of anyone else's typos if
+ they were stylistically different. Some victims of DWIM thus
+ claimed that the acronym stood for "Damn Warren's Infernal
+ Machine!'.
+
+ In one notorious incident, Warren added a DWIM feature to the
+ command interpreter used at {Xerox PARC}. One day another
+ hacker there typed "delete *$" to free up some disk space.
+ (The editor there named backup files by appending "$" to the
+ original file name, so he was trying to delete any backup
+ files left over from old editing sessions.) It happened that
+ there weren't any editor backup files, so DWIM helpfully
+ reported "*$ not found, assuming you meant 'delete *'". It
+ then started to delete all the files on the disk! The hacker
+ managed to stop it with a {Vulcan nerve pinch} after only a
+ half dozen or so files were lost.
+
+ The disgruntled victim later said he had been sorely tempted
+ to go to Warren's office, tie Warren down in his chair in
+ front of his workstation, and then type "delete *$" twice.
+
+ DWIM is often suggested in jest as a desired feature for a
+ complex program; it is also occasionally described as the
+ single instruction the ideal computer would have. Back when
+ proofs of program correctness were in vogue, there were also
+ jokes about "DWIMC" (Do What I Mean, Correctly). A related
+ term, more often seen as a verb, is DTRT (Do The Right Thing);
+ see {Right Thing}.
+
+ [{Jargon File}]
+
+DX4
+
+ {Intel DX4}
+
+DXF
+
+ {Drawing Exchange Format}
+
+dyadic
+
+ <programming> {binary} (describing an {operator}).
+
+ Compare {monadic}.
+
+ (1998-07-24)
+
+Dyadic Systems Limited
+
+ {Dyalog Limited}
+
+Dyalog APL
+
+ <language> Arguably the current (2001) market-leading
+ implementation of {APL}, from {Dyalog Limited}. Dyalog APL
+ runs under {Windows 95}, {Windows 98}, {Windows NT}, and
+ {Windows 2000}; and several popular {UNIX} systems including
+ {Linux}.
+
+ Dyalog APL complies with {ISO 8485} and has many features that
+ make it good for complex {GUI} applications.
+
+ Dyalog APL was introduced in 1983 and is currently (2002) in
+ active development.
+
+ (2003-11-17)
+
+Dyalog Limited
+
+ <company> The company that distributes {Dyalog APL}.
+ Previously known as Dyadic Systems Limited.
+
+ {Dyalog Home (http://dyalog.com)}.
+
+ (2003-11-17)
+
+DYANA
+
+ {DYnamics ANAlyzer}
+
+Dylan
+
+ {DYnamic LANguage}
+
+Dylperl
+
+ A {dynamic linking} package for {Perl} by Roberto Salama
+ <rs@fi.gs.com>. Dynamically loaded functions are accessed as
+ if they were user-defined functions. This code is based on
+ Oliver Sharp's May 1993 article in Dr. Dobbs Journal ("Dynamic
+ Linking under Berkeley Unix").
+
+ Posted to {news:comp.lang.perl} on 1993-08-11.
+
+ (1993-08-11)
+
+dynamic adaptive routing
+
+ Automatic re{routing} of traffic based on analysis of current
+ {network} conditions. This does not include routing decisions
+ based on predefined information.
+
+ (1995-01-30)
+
+Dynamic Address Translation
+
+ <architecture> (DAT) Conversion of a {virtual address} into a
+ {physical address}, as performed by a {memory management unit}
+ and an {operating system} which supports {virtual memory}.
+
+ (1995-01-30)
+
+Dynamically Linked Library
+
+ <library> (DLL) A {library} which is linked to {application
+ programs} when they are loaded or run rather than as the final
+ phase of {compilation}. This means that the same block of
+ library code can be shared between several {tasks} rather than
+ each task containing copies of the routines it uses. The
+ executable is compiled with a library of "{stubs}" which allow
+ {link errors} to be detected at {compile-time}. Then, at {run
+ time}, either the system {loader} or the task's entry code
+ must arrange for library calls to be patched with the
+ addresses of the real shared library routines, possibly via a
+ {jump table}.
+
+ The alternative is to make library calls part of the
+ {operating system} {kernel} and enter them via some kind of
+ {trap} instruction. This is generally less efficient than an
+ ordinary {subroutine} call.
+
+ It is important to ensure that the version of a dynamically
+ linked library is compatible with what the executable expects.
+
+ Examples of operating systems using dynamic linking are
+ {SunOS} (.so - shared object files), {Microsoft Windows}
+ (.dll) and {RISC OS} on the {Acorn} {Archimedes} (relocatable
+ modules).
+
+ (1995-12-12)
+
+dynamically scoped
+
+ {dynamic scope}
+
+dynamically typed
+
+ {dynamic typing}
+
+dynamic analysis
+
+ <programming> Evaluation of a program based on its execution.
+ Dynamic analysis relies on executing a piece of software with
+ selected test data.
+
+ (1996-05-13)
+
+dynamic binding
+
+ The property of {object-oriented programming} languages where
+ the code executed to perform a given operation is determined
+ at {run time} from the {class} of the operand(s) (the receiver
+ of the message). There may be several different classes of
+ objects which can receive a given message. An expression may
+ denote an object which may have more than one possible class
+ and that class can only be determined at run time. New
+ classes may be created that can receive a particular message,
+ without changing (or recompiling) the code which sends the
+ message. An class may be created that can receive any set of
+ existing messages.
+
+ {C++} implements dynamic binding using "{virtual member
+ functions}".
+
+ One important reason for having dynamic binding is that it
+ provides a mechanism for selecting between alternatives which
+ is arguably more robust than explicit selection by
+ conditionals or {pattern matching}. When a new {subclass} is
+ added, or an existing subclass changes, the necessary
+ modifications are localised: you don't have incomplete
+ conditionals and broken patterns scattered all over the
+ program.
+
+ See {overloading}.
+
+dynamic database management system
+
+ <database> (dynamic DBMS) A {database} with "value-based"
+ relationships where typically the relationship is specified at
+ retrieval time and the locations of related records are
+ discovered during retrieval. Both {Independent Logical File}
+ (ILF) databases and {relational databases} are value-based.
+
+ The opposite is a {static database management system}.
+
+ (1998-10-07)
+
+Dynamic Data Exchange
+
+ <language> (DDE, originally Dynamic Data Linking, DDL) A
+ {Microsoft Windows} 3 {hotlink} {protocol} that allows
+ {application programs} to communicate using a {client-server}
+ model. Whenever the server (or "publisher") modifies part of
+ a document which is being shared via DDE, one or more clients
+ ("subscribers") are informed and include the modification in
+ the copy of the data on which they are working.
+
+ (1997-06-05)
+
+Dynamic Data Linking
+
+ {Dynamic Data Exchange}
+
+dynamic DBMS
+
+ {dynamic database management system}
+
+Dynamic Drive Overlay
+
+ <storage, software> (DDO) Software to allow a {system BIOS}
+ that does not support {Logical Block Addressing} to access
+ drives larger than 528 MB.
+
+ The alternatives are to update the system BIOS or install an
+ {EIDE controller} card with a suitable on-board BIOS.
+
+ {Seagate
+ (http://seagate.com/support/disc/drivers/discfile.shtml)}.
+
+ (2001-03-18)
+
+Dynamic Execution
+
+ <processor> A combination of techniques - {multiple branch
+ prediction}, {data flow analysis} and {speculative execution}.
+ {Intel} implemented Dynamic Execution in the {P6} after
+ analysing the execution of billions of lines of code.
+
+ (1995-05-05)
+
+Dynamic Host Configuration Protocol
+
+ <protocol> (DHCP) A {protocol} that provides a means to
+ dynamically allocate {IP address}es to computers on a {local
+ area network}. The {system administrator} assigns a range of
+ IP addresses to DHCP and each client computer on the LAN has
+ its {TCP/IP} software configured to request an IP address from
+ the DHCP server. The request and grant process uses a lease
+ concept with a controllable time period.
+
+ DHCP is defined in {RFC 2131}.
+
+ {Microsoft} introduced DHCP on their {NT server} with version
+ 3.5 in late 1994.
+
+ {(http://dhcp.org/)}.
+
+ (1998-11-22)
+
+Dynamic HTML
+
+ <language, web> (DHTML) The addition of
+ {JavaScript} to {HTML} to allow web pages to change and
+ interact with the user without having to communicate with the
+ server. JavaScript allows the behaviour of the page to be
+ controlled by code that is downloaded with the HTML. It does
+ this by manipulating the {Document Object Model} (DOM).
+
+ The term DHTML is often also taken to include the use of
+ "style" information to give finer control of HTML layout. The
+ style information can be supplied as {Cascading Style Sheets}
+ (CSS) or as "style" attributes (which can be manipulated by
+ JavaScript). Layers are often also used with DHTML.
+
+ Both the JavaScript and style data can be included in the HTML
+ file or in a separate file referred to from the HTML. Some
+ web browsers allow other languages (e.g. {VBScript} or {Perl})
+ to be used instead of JavaScript but this is less common.
+
+ DHTML can be viewed in {Internet Explorer} 4+, {Firefox} and
+ {Netscape} Communicator 4+ but, as usual, Microsoft disagree
+ on how DHTML should be implemented. The {Document Object
+ Model} Group of the {World Wide Web Consortium} is developing
+ standards for DHTML.
+
+ {(http://w3c.org/DOM/)}.
+
+ (2005-10-17)
+
+DYnamic LANguage
+
+ <language> (Dylan) A simple {object-oriented} {Lisp} dialect,
+ most closely resembling {CLOS} and {Scheme}, developed by
+ Advanced Technology Group East at {Apple Computer}.
+
+ {Thomas} is a Dylan {compiler} implemented in {Scheme}.
+
+ See also {Marlais}.
+
+ ["Dylan(TM) an Object-Oriented Dynamic Language", {Apple
+ Computer}, Eastern Research and Technology, April 1992].
+
+ (1995-04-19)
+
+dynamic link
+
+ <compiler> A pointer from an {activation record} to the
+ {activation record} for the {scope} from which the current
+ scope was called at {run time}. This is used in a {statically
+ scoped} language to restore the {environment pointer} on exit
+ from a scope. To access a {non-local variable} in a
+ {dynamically scoped} language, dynamic links are followed
+ until a binding for the given variable name is found.
+
+ (1995-03-07)
+
+dynamic link library
+
+ {Dynamically Linked Library}
+
+Dynamic Object-Oriented Requirements System
+
+ <programming, tool, product> (DOORS) A tool from {Quality
+ Systems & Software Ltd.} for handling all kinds of
+ {requirements} (in fact, any information at all) as modules
+ containing trees of text objects, qualified by an arbitrary
+ number of user-defined attributes, and cross-linked by
+ directional links.
+
+dynamic RAM
+
+ {dynamic random-access memory}
+
+dynamic random-access memory
+
+ <storage> (DRAM) A type of {semiconductor} memory in which the
+ information is stored in {capacitors} on a {MOS} {integrated
+ circuit}. Typically each {bit} is stored as an amount of
+ electrical charge in a storage cell consisting of a capacitor
+ and a {transistor}. Due to leakage the capacitor discharges
+ gradually and the memory cell loses the information.
+ Therefore, to preserve the information, the memory has to be
+ refreshed periodically. Despite this inconvenience, the DRAM
+ is a very popular memory technology because of its high
+ density and consequent low price.
+
+ The first commercially available DRAM chip was the {Intel
+ 1103}, introduced in 1970.
+
+ Early DRAM chips, containing up to a 16k x 1 (16384 locations
+ of one bit each), needed 3 supply voltages (+5V, -5V and
+ +12V). Beginning with the 64 kilobit chips, {charge pumps}
+ were included on-chip to create the necessary supply voltages
+ out of a single +5V supply. This was necessary to fit the
+ device into a 16-pin {DIL} package, which was the preferred
+ package at the time, and also made them easier to use.
+
+ To reduce the pin count, thereby helping miniaturisation,
+ DRAMs generally had a single data line which meant that a
+ computer with an N bit wide {data bus} needed a "bank" of (at
+ least) N DRAM chips. In a bank, the address and control
+ signals of all chips were common and the data line of each
+ chip was connected to one of the data bus lines.
+
+ Beginning with the 256 kilobit DRAM, a tendency toward
+ {surface mount} packaging arose and DRAMs with more than one
+ data line appeared (e.g. 64k x 4), reducing the number of
+ chips per bank. This trend has continued and DRAM chips with
+ up to 36 data lines are available today. Furthermore,
+ together with surface mount packages, memory manufacturers
+ began to offer memory modules, where a bank of memory chips
+ was preassembled on a little {printed circuit} board (SIP =
+ Single Inline Pin Module, SIMM = Single Inline Memory Module,
+ DIMM = Dual Inline Memory Module). Today, this is the
+ preferred way to buy memory for {workstations} and {personal
+ computers}.
+
+ DRAM bit cells are arranged on a chip in a grid of rows and
+ columns where the number of rows and columns are usually a
+ power of two. Often, but not always, the number of rows and
+ columns is the same. A one megabit device would then have
+ 1024 x 1024 memory cells. A single memory cell can be
+ selected by a 10-bit row address and a 10-bit column address.
+
+ To access a memory cell, one entire row of cells is selected
+ and its contents are transferred into an on-chip buffer. This
+ discharges the storage capacitors in the bit cells. The
+ desired bits are then read or written in the buffer. The
+ (possibly altered) information is finally written back into
+ the selected row, thereby refreshing all bits (recharging the
+ capacitors) in the row.
+
+ To prevent data loss, all bit cells in the memory need to be
+ refreshed periodically. This can be done by reading all rows
+ in regular intervals. Most DRAMs since 1970 have been
+ specified such that one of the rows needs to be refreshed at
+ least every 15.625 microseconds. For a device with 1024 rows,
+ a complete refresh of all rows would then take up to 16 ms; in
+ other words, each cell is guaranteed to hold the data for 16
+ ms without refresh. Devices with more rows have accordingly
+ longer retention times.
+
+ Many varieties of DRAM exist today. They differ in the way
+ they are interfaced to the system - the structure of the
+ memory cell itself is essentially the same.
+
+ "Traditional" DRAMs have multiplexed address lines and
+ separate data inputs and outputs. There are three control
+ signals: RAS\ (row address strobe), CAS\ (column address
+ strobe), and WE\ (write enable) (the backslash indicates an
+ {active low} signal). Memory access procedes as follows:
+ 1. The control signals initially all being inactive (high), a
+ memory cycle is started with the row address applied to the
+ address inputs and a falling edge of RAS\ . This latches the
+ row address and "opens" the row, transferring the data in the
+ row to the buffer. The row address can then be removed from
+ the address inputs since it is latched on-chip. 2. With RAS\
+ still active, the column address is applied to the address
+ pins and CAS\ is made active as well. This selects the
+ desired bit or bits in the row which subsequently appear at
+ the data output(s). By additionally activating WE\ the data
+ applied to the data inputs can be written into the selected
+ location in the buffer. 3. Deactivating CAS\ disables the
+ data input and output again. 4. Deactivating RAS\ causes the
+ data in the buffer to be written back into the memory array.
+
+ Certain timing rules must be obeyed to guarantee reliable
+ operation. 1. RAS\ must remain inactivate for a while before
+ the next memory cycle is started to provide sufficient time
+ for the storage capacitors to charge (Precharge Time). 2. It
+ takes some time from the falling edge of the RAS\ or CAS\
+ signals until the data appears at the data output. This is
+ specified as the Row Access Time and the Column Access Time.
+ Current DRAM's have Row Access Times of 50-100 ns and Column
+ Access Times of 15-40 ns. Speed grades usually refer to the
+ former, more important figure.
+
+ Note that the Memory Cycle Time, which is the minimum time
+ from the beginning of one access to the beginning of the next,
+ is longer than the Row Access Time (because of the Precharge
+ Time).
+
+ Multiplexing the address pins saves pins on the chip, but
+ usually requires additional logic in the system to properly
+ generate the address and control signals, not to mention
+ further logic for refresh. Therefore, DRAM chips are usually
+ preferred when (because of the required memory size) the
+ additional cost for the control logic is outweighed by the
+ lower price.
+
+ Based on these principles, chip designers have developed many
+ varieties to improve performance or ease system integration of
+ DRAMs:
+
+ PSRAMs (Pseudo Static Random Access Memory) are essentially
+ DRAMs with a built-in address {multiplexor} and refresh
+ controller. This saves some system logic and makes the device
+ look like a normal {SRAM}. This has been popular as a lower
+ cost alternative for SRAM in {embedded systems}. It is not a
+ complete SRAM substitute because it is sometimes busy when
+ doing self-refresh, which can be tedious.
+
+ {Nibble Mode DRAM} can supply four successive bits on one data
+ line by clocking the CAS\ line.
+
+ {Page Mode DRAM} is a standard DRAM where any number of
+ accesses to the currently open row can be made while the RAS
+ signal is kept active.
+
+ Static Column DRAM is similar to Page Mode DRAM, but to access
+ different bits in the open row, only the column address needs
+ to be changed while the CAS\ signal stays active. The row
+ buffer essentially behaves like SRAM.
+
+ {Extended Data Out DRAM} (EDO DRAM) can continue to output
+ data from one address while setting up a new address, for use
+ in {pipelined} systems.
+
+ DRAM used for Video RAM ({VRAM}) has an additional long
+ shift register that can be loaded from the row buffer. The
+ shift register can be regarded as a second interface to the
+ memory that can be operated in parallel to the normal
+ interface. This is especially useful in {frame buffers} for
+ {CRT} displays. These frame buffers generate a serial data
+ stream that is sent to the CRT to modulate the electron beam.
+ By using the shift register in the VRAM to generate this
+ stream, the memory is available to the computer through the
+ normal interface most of the time for updating the display
+ data, thereby speeding up display data manipulations.
+
+ SDRAM (Synchronous DRAM) adds a separate clock signal to the
+ control signals. It allows more complex {state machines} on
+ the chip and high speed "burst" accesses that clock a series
+ of successive bits out (similar to the nibble mode).
+
+ CDRAM (Cached DRAM) adds a separate static RAM array used for
+ caching. It essentially combines main memory and {cache}
+ memory in a single chip. The cache memory controller needs to
+ be added externally.
+
+ RDRAM (Rambus DRAM) changes the system interface of DRAM
+ completely. A byte-wide bus is used for address, data and
+ command transfers. The bus operates at very high speed: 500
+ million transfers per second. The chip operates synchronously
+ with a 250MHz clock. Data is transferred at both rising and
+ falling edges of the clock. A system with signals at such
+ frequencies must be very carefully designed, and the signals
+ on the Rambus Channel use nonstandard signal levels, making it
+ incompatible with standard system logic. These disadvantages
+ are compensated by a very fast data transfer, especially for
+ burst accesses to a block of successive locations.
+
+ A number of different refresh modes can be included in some of
+ the above device varieties:
+
+ RAS\ only refresh: a row is refreshed by an ordinary read
+ access without asserting CAS\. The data output remains
+ disabled.
+
+ CAS\ before RAS\ refresh: the device has a built-in counter
+ for the refresh row address. By activating CAS\ before
+ activating RAS\, this counter is selected to supply the row
+ address instead of the address inputs.
+
+ Self-Refresh: The device is able to generate refresh cycles
+ internally. No external control signal transitions other than
+ those for bringing the device into self-refresh mode are
+ needed to maintain data integrity.
+
+ (1996-07-11)
+
+dynamic routing
+
+ <networking> (Or "adaptive routing") {Routing} that adjusts
+ automatically to network topology or traffic changes.
+
+ (1997-05-08)
+
+DYnamics ANAlyzer
+
+ <language> (DYANA) An early language specialised for
+ vibrational and other dynamic physical systems.
+
+ [Sammet 1969, p. 628].
+
+ (1997-07-20)
+
+dynamic scope
+
+ <language> In a dynamically scoped language, e.g. most
+ versions of {Lisp}, an {identifier} can be referred to, not
+ only in the block where it is declared, but also in any
+ function or procedure called from within that block, even if
+ the called procedure is declared outside the block.
+
+ This can be implemented as a simple stack of (identifier,
+ value) pairs, accessed by searching down from the top of stack
+ for the most recent instance of a given identifier.
+
+ The opposite is {lexical scope}. A common implementation of
+ dynamic scope is {shallow binding}.
+
+ (1996-07-11)
+
+dynamic scoping
+
+ {dynamic scope}
+
+Dynamic Systems Development Method
+
+ <programming> (DSDM) An independent software development
+ framework.
+
+ {DSDM.org Home (http://dsdm.org/)}.
+
+ [What is it?]
+
+ (2002-02-14)
+
+dynamic translation
+
+ <architecture> A {virtual machine} implementation approach,
+ used to speed up execution of {byte-code} programs. To
+ execute a program unit such as a {method} or a {function}, the
+ virtual machine compiles its bytecodes into (hardware) machine
+ code. The translated code is also placed in a cache, so that
+ next time that unit's machine code can be executed
+ immediately, without repeating the translation.
+
+ This technique was pioneered by the commercial {Smalltalk}
+ implementation currently known as {VisualWorks}, in the early
+ 1980s. Currently it is also used by some implementations of
+ the {Java Virtual Machine} under the name {JIT} (Just In Time
+ compilation).
+
+ [Peter L. Deutsch and Alan Schiffman. "Efficient
+ Implementation of the Smalltalk-80 System", 11th Annual
+ Symposium on Principles of Programming Languages, Jan 1984,
+ pp. 297-302].
+
+ (2002-04-15)
+
+dynamic typing
+
+ <programming> Enforcement of type rules at {run time} as
+ opposed to {compile time}. Dynamic typing catches more errors
+ as run-time exceptions than {static typing}.
+
+ {Tcl}, {Perl}, {PHP}, {Python} and {Visual Basic} are examples
+ of dynamically typed languages. A dynamically typed language
+ may have {strong typing} or {weak typing}.
+
+ (2004-07-20)
+
+DYNAMO
+
+ DYNamic MOdels. A language for continuous {simulation}
+ including economic, industrial and social systems, developed
+ by Phyllis Fox and A.L. Pugh in 1959.
+
+ Versions include DYNAMO II, DYNAMO II/370, DYNAMO II/F, DYNAMO
+ III and Gaming DYNAMO.
+
+ ["DYNAMO User's Manual", A.L. Pugh, MIT Press 1976].
+
+Dynix
+
+ <library> A {host-based} library automation system from {Dynix
+ Automated Library Systems}. First installed in 1993, it is
+ now used in over 2000 libraries worldwide.
+
+ Dynix runs on {Unix} using the {UniVerse} post relational
+ database. The software is configurable using tables of
+ parameters. It includes modules for cataloguing, circulation,
+ OPAC, acquisitions, serials, reserve book room, advance
+ bookings, homebound, BiblioBus, Pac Plus for Windows, Kids
+ Catalog, Dynix Online Catalog, media bookings, and community
+ information.
+
+ {(http://uk.dynix.com/classic.html)}.
+
+ (1995-04-28)
+
+Dynix Automated Library Systems
+
+ <company> The world's largest supplier of library automation
+ systems with European offices in France, Germany, Ireland, the
+ Netherlands and the UK.
+
+ Dynix sell two library management systems - Horizon
+ ({client/server}) and, Dynix ({host-based}). Both have {GUI}
+ or {terminal interfaces}. Dynix also sell other products and
+ services for {database} enrichment, interconnectivity, and
+ on-line and {CD-ROM} databases.
+
+ {(http://uk.dynix.com/dynix.html)}.
+
+ (1995-04-28)
+
+dynner
+
+ <data, jargon> /din'r/ 32 {bits}, by analogy with {byte}.
+ Usage: rare and extremely silly.
+
+ See also {playte}, {tayste}, {crumb}.
+
+ [{Jargon File}]
+
+ (1997-12-03)
+
+DYSAC
+
+ Digital Simulated Analog Computer.
+
+ [Sammet 1969, p. 629].
+
+DYSTAL
+
+ DYnamic STorage ALlocation.
+
+ Adds lists, strings, sorting, statistics and matrix operations
+ to Fortran. Sammet 1969, p.388. "DYSTAL: Dynamic Storage
+ Allocation Language in FORTRAN", J.M. Sakoda, in Symbol
+ Manipulation Languages and Techniques, D.G. Bobrow ed, N-H
+ 1971, pp.302- 311.
+
+ (1995-03-17)
+
+dz
+
+ <networking> The {country code} for Algeria.
+
+ (1999-01-27)
+
+E
+
+ 1. An extension of {C++} with {database} types and
+ {persistent} {objects}. E is a powerful and flexible
+ {procedural} programming language. It is used in the {Exodus}
+ database system.
+
+ See also {GNU E}.
+
+ {(ftp://ftp.cs.wisc.edu/exodus/E/)}.
+
+ ["Persistence in the E Language: Issues and Implementation",
+ J.E. Richardson et al, Soft Prac & Exp 19(12):1115-1150 (Dec
+ 1989)].
+
+ 2. <language> A {procedural language} by Wouter van
+ Oortmerssen with {semantics} similar to {C}. E features
+ lists, low-level {polymorphism}, {exception} handling, quoted
+ expressions, {pattern matching} and {object} {inheritance}.
+ {Amiga E} is a version for the {Amiga}.
+
+ (1999-10-05)
+
+E1
+
+ <communications> A European {framing specification} for the
+ transmission of 32 {DS0} (64 kb/s) data streams. By
+ extension, it can also denote the transmission rate required
+ (2.048 Mb/s = 2048 kb/s). Unlike {DS1} it is free of
+ {bit-robbing}.
+
+ (2002-03-22)
+
+E2
+
+ <communications> A European {framing specification} for the
+ transmission of four multiplexed {E1} data streams, resulting
+ in a transmission rate of 8.448 Mb/s (= 8448 kb/s).
+
+ (2002-03-22)
+
+E2ES
+
+ {end-to-end solution}
+
+E3
+
+ <communications> A European {framing specification} for the
+ transmission of 16 multiplexed {E1} data streams, resulting in
+ a transmission rate of 34.368 Mb/s (= 34,368 kb/s).
+
+ (2002-03-22)
+
+E4
+
+ <communications> A European {framing specification} for the
+ transmission of 64 multiplexed {E1} data streams, resulting in
+ a transmission rate of 139.264 Mb/s (= 139,264 kb/s).
+
+ (2002-03-22)
+
+E5
+
+ <communications> A European {framing specification} for the
+ transmission of 256 multiplexed {E1} data streams, resulting
+ in a transmission rate of 565.148 Mbps (= 565,148 kb/s).
+
+ (2002-03-22)
+
+E-acute
+
+ <character> "É" - a capital "E" with an acute accent. Character
+ code 201, 0xC9. Entity reference: &amp;Eacute;.
+
+ (2013-01-13)
+
+EAF
+
+ {Effort Adjustment Factor}
+
+EAG
+
+ {Extended Affix Grammar}
+
+eager evaluation
+
+ Any {evaluation strategy} where evaluation of some or all
+ function arguments is started before their value is required.
+ A typical example is {call-by-value}, where all arguments are
+ passed evaluated. The opposite of eager evaluation is
+ {call-by-need} where evaluation of an argument is only started
+ when it is required.
+
+ The term "{speculative evaluation}" is very close in meaning
+ to eager evaluation but is applied mostly to parallel
+ architectures whereas eager evaluation is used of both
+ sequential and parallel evaluators.
+
+ Eager evaluation does not specify exactly when argument
+ evaluation takes place - it might be done fully speculatively
+ (all {redex}es in the program reduced in parallel) or may be
+ done by the caller just before the function is entered.
+
+ The term "eager evaluation" was invented by Carl Hewitt and
+ Henry Baker <hbaker@netcom.com> and used in their paper ["The
+ Incremental Garbage Collection of Processes", Sigplan Notices,
+ Aug 1977.
+ {(ftp://ftp.netcom.com/pub/hb/hbaker/Futures.html)}]. It was
+ named after their "eager beaver" evaluator.
+
+ See also {conservative evaluation}, {lenient evaluation},
+ {strict evaluation}.
+
+ (1994-12-22)
+
+Eagle
+
+ A {dBASE}-like dialect bundled with {Emerald Bay}, sold by
+ {Migent} from 1986-1988, later renamed {Vulcan} when {Wayne
+ Ratliff} reacquired the product.
+
+EAI
+
+ {Enterprise Application Integration}
+
+EAPROM
+
+ {Electrically Alterable Programmable Read-Only Memory}
+
+earliest deadline first
+
+ <operating system, algorithm> (EDF) A strategy for {CPU} or
+ disk access {scheduling}. With EDF, the task with the
+ earliest deadline is always executed first.
+
+ {Scan-EDF} is an example.
+
+ (1995-11-15)
+
+Early PL/I
+
+ <language> (EPL) A {PL/I} subset dialect by McIlroy, Morris et
+ al, the first running PL/I {compiler}. It was used by {Bell
+ Labs} and {MIT} to write {Multics}. EPL had extensions to
+ handle the segment/offset nature of {Multics} pointers.
+
+ See also {REPL}, {TMG}.
+
+ ["EPL Reference Manual", Project MAC, April 1966].
+
+ [Sammet 1969, p. 542].
+
+ (1995-11-15)
+
+EARN
+
+ <networking> {European Academic and Research
+ Network}.
+
+ (1995-11-15)
+
+EAROM
+
+ Electrically Alterable Read-Only Memory.
+
+ {EEPROM}
+
+earthquake
+
+ (IBM) The ultimate real-world shock test for computer
+ hardware. Hackish sources at {IBM} deny the rumor that the
+ San Francisco Bay Area quake of 1989 was initiated by the
+ company to test quality-assurance procedures at its California
+ plants.
+
+ [{Jargon File}]
+
+ (1995-04-22)
+
+Ease
+
+ General purpose parallel programming language, combining the
+ process constructs of CSP and the distributed data structures
+ of Linda. "Programming with Ease: Semiotic Definition of the
+ Language", S.E. Zenith, <zenith-steven@yale.edu> Yale U
+ TR-809, Jul 1990.
+
+EASE II
+
+ Early system on IBM 650. Listed in CACM 2(5):16 (May 1959).
+
+EASIAC
+
+ Early system on Midac computer. Listed in CACM 2(5):16 (May
+ 1959).
+
+EAST
+
+ A {Eureka} project developing a {software engineering}
+ {platform}.
+
+ (1994-12-07)
+
+easter egg
+
+ <jargon> (From the custom of the Easter Egg hunt observed in
+ the US and many parts of Europe)
+
+ 1. A message hidden in the {object code} of a program as a
+ joke, intended to be found by persons disassembling or
+ browsing the code.
+
+ 2. A message, graphic, sound effect, or other behaviour
+ emitted by a program (or, on an {IBM PC}, the {BIOS} {ROM}) in
+ response to some undocumented set of commands or keystrokes,
+ intended as a joke or to display program credits.
+
+ One well-known early Easter egg found in a couple of
+ {operating systems} caused them to respond to the command
+ "make love" with "not war?". Many {personal computers}, and
+ even satellite control computers, have much more elaborate
+ eggs hidden in {ROM}, including lists of the developers' names
+ (e.g. {Microsoft Windows} 3.1x), political exhortations and
+ snatches of music. The {Tandy} Color Computer 3 ({CoCo}) had
+ images of the entire development team. Microsoft {Excel} 97
+ includes a flight simulator!
+
+ {(http://eeggs.com/)}.
+
+ [{Jargon File}]
+
+ (2003-06-23)
+
+Easter egging
+
+ <jargon> ({IBM}, From the custom of the Easter Egg hunt
+ observed in the US and many parts of Europe) The act of
+ replacing unrelated components more or less at random in the
+ hope that a malfunction will go away. Hackers consider this
+ the normal operating mode of {field circus} techs and do not
+ love them for it.
+
+ Compare {Easter egg}, {shotgun debugging}.
+
+ [{Jargon File}]
+
+ (1998-03-18)
+
+Eastern Washington University
+
+ A university 20 miles southwest of Spokane, WA on the edge of
+ the rolling Palouse Prairie.
+
+ {(http://ewu.edu/)}.
+
+ Address: Cheney, Washington, USA.
+
+ (1995-02-28)
+
+EASY FOX
+
+ An early system on the {JOHNNIAC} computer.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+eat flaming death
+
+ <humour, abuse> A construction popularised among hackers by
+ the infamous {CPU Wars} comic; supposedly derive from a
+ famously turgid line in a WWII-era anti-Nazi propaganda comic
+ that ran "Eat flaming death, non-Aryan mongrels!" or something
+ of the sort (however, it is also reported that the Firesign
+ Theater's 1975 album "In The Next World, You're On Your Own"
+ included the phrase "Eat flaming death, fascist media pigs";
+ this may have been an influence). Used in humorously
+ overblown expressions of hostility. "Eat flaming death,
+ {EBCDIC} users!"
+
+ [{Jargon File}]
+
+ (2006-12-12)
+
+eating one's own dogfood
+
+ <programming> When a developer uses their own code for their
+ own daily needs. Being a user as well as a developer creates
+ the user empathy that is the hallmark of good software.
+
+ The term seems to have originated at {Microsoft}.
+
+ {(http://www.joelonsoftware.com/items/2004/04/16.html)}
+
+ (2006-12-12)
+
+eating your own dogfood
+
+ {eating one's own dogfood}
+
+EAX
+
+ {Environmental Audio eXtensions}
+
+EBASIC
+
+ <language> A {BASIC} by Gordon Eubanks, now at {Symantec},
+ that led to {CBASIC}.
+
+ (2006-12-12)
+
+EBCDIC
+
+ {Extended Binary Coded Decimal Interchange Code}
+
+EBCIDIC
+
+ <spelling> It's spelled "{EBCDIC}".
+
+ (1996-12-13)
+
+EBNF
+
+ <language> {Extended Backus-Naur Form}.
+
+Ebone
+
+ A pan-European {backbone} network service.
+
+ec
+
+ <networking> The {country code} for Ecuador.
+
+ (1999-01-27)
+
+EC++
+
+ A preprocessor
+ by Glauco Masotti <masotti@lipari.usc.edu>
+ that translates Extended C++ into C++.
+
+ {(ftp://ftp.uu.net/languages/c++/EC++.tar.Z)}.
+
+ (1989-10-10)
+
+ECAP II
+
+ Electronic Circuit Analysis Program. Simple language for
+ analysing electrical networks. "Introduction to Computer
+ Analysis: ECAP for Electronics Technicians and Engineers",
+ H. Levin, P-H 1970.
+
+E-carrier system
+
+ <communications> A series of {digital} transmission formats
+ promulgated by the {ITU} and used outside of North America and
+ Japan.
+
+ The basic unit of the E-carrier system is the {DS0}, which has
+ a transmission rate of 64 Kbps, and is commonly used for one
+ {voice circuit}. The {E1} format consists of 32 DS0 channels,
+ for a total capacity of 2.048 Mbps. {E2}, {E3}, {E4}, and
+ {E5} circuits carry multiple E1 channels multiplexed,
+ resulting in transmission rates of up to 565.148 Mbps.
+
+ The E-carrier system is similar to, and compatible with, the
+ {T-carrier system} used in North America, but has higher
+ capacity since it uses {out-of-band signaling} in contrast to
+ the {in-band signaling} or {bit-robbing} used in the T-system.
+
+ (2000-03-10)
+
+Ecash
+
+ <application> A trial form of {electronic funds transfer} over
+ the {Internet} (and soon by {electronic mail}).
+
+ The ecash software stores digital money, signed by a bank, on
+ the user's local computer. The user can spend the digital
+ money at any shop accepting ecash, without the trouble of
+ having to open an account there first, or having to transmit
+ credit card numbers. The shop just has to accept the money,
+ and deposit it at the bank. The security is provided by a
+ {public-key} {digital signature}.
+
+ There process involves the issuing banks who exchange real
+ money for ecash, users who have and spend ecash, shops who
+ accept ecash payments, and clearing banks who clear payments
+ received by shops.
+
+ At the moment, all users and shops must have an account at
+ {DigiCash}'s own bank, the "First Digital Bank" at
+ bank.digicash.com. They can withdraw money from the bank, and
+ convert it to ecash. Shops can be started by any ecash user.
+
+ {(http://digicash.com/ecash/ecash-home.html)}.
+
+ (1995-04-10)
+
+ECC
+
+ {error detection and correction}
+
+Eccles-Jordan circuit
+
+ {flip-flop}
+
+Echidna
+
+ {Constraint logic programming} embedded in an
+ {object-oriented} language. The {syntax} is an extension of
+ {Edinburgh Prolog}.
+
+ ["Hierarchical Arc Consistency Applied to Numeric Processing
+ in Constraint Logic Programming", G. Sidebottom et al,
+ TR-91-06, CSS-IS, Simon Fraser U, and Comp Intell 8(4)
+ (1992)].
+
+ {(ftp://cs.sfu.edu/pub/ecl/papers)}.
+
+ E-mail: <expert@cs.sfu.edu>.
+
+ (1994-12-08)
+
+echo
+
+ 1. A {topic group} on {FidoNet}'s {echomail} system.
+
+ Compare {newsgroup}.
+
+ 2. A {Unix} command that just prints its arguments.
+
+ [{Jargon File}]
+
+echo cancellation
+
+ A process which removes unwanted echoes from the signal on a
+ telephone line. Echoes are usually caused by impedance
+ mismatches along an analogue line.
+
+ECHT
+
+ European Conference on {Hypertext}.
+
+ECIP2
+
+ An {Esprit} project on the definition of a specification
+ language at the requirement level.
+
+ECIS
+
+ {European Committee for Interoperable Systems}
+
+Eckert-Mauchly Computer Corporation
+
+ <company> The company which designed and built {Univac}
+ computers.
+
+ (1995-03-01)
+
+ECL
+
+ 1. <hardware> {Emitter Coupled Logic}.
+
+ 2. <language> Extensible {CL}.
+
+ Wegbreit, ca 1970.
+
+ ["The ECL Programming System", B. Wegbreit, Proc FJCC
+ 39:253-261, AFIPS (Fall 1971)].
+
+ ["ECL Programmer's Manual", B. Wegbreit, TR 23-74, Harvard U
+ (Dec 1974)].
+
+ (1994-11-09)
+
+ECLIPSE
+
+ A {Prolog} + {CLP} compiler from {ECRC}.
+
+ECM
+
+ <storage> {error correcting memory}.
+
+ (1995-10-10)
+
+ECMA
+
+ 1. {European Computer Manufacturers Association},
+ now {ECMA International}.
+
+ 2. A subset of {ALGOL}. [Sammet 1969, p.180].
+
+ (1998-09-07)
+
+ECMA International
+
+ <body> (Formerly European Computer Manufacturers Association)
+ An industry association founded in 1961 and dedicated to the
+ standardisation of information and communication systems.
+
+ ECMA edits {standards} and technical reports. All ECMA
+ publications are available free of charge.
+
+ The best known ECMA standard is ECMA 262, defining the
+ {scripting language} {ECMAScript}.
+
+ (2003-06-23)
+
+ECMAScript
+
+ <language> ({ECMA} standard 262, {ISO} standard 16262) The
+ standardised version of the core {JavaScript} language.
+
+ (2005-07-28)
+
+Ecole Normale Superieure
+
+ <body> (ENS) A higher education and research institution in
+ Paris, France.
+
+e-commerce
+
+ {electronic commerce}
+
+Econet
+
+ 1. One of the IGC networks. EcoNet serves individuals and
+ organisations working for environmental preservation and
+ sustainability. Important issues covered include: global
+ warming, energy policy, rainforest preservation, legislative
+ activities, water quality, toxics and environmental education.
+
+ EcoNet users can send and receive private messages, including
+ fax and telex, to and from more than 18,000 international
+ users on the APC networks or to millions on other networks.
+ EcoNet seeks to build coalitions and partnerships with
+ activist and non-profit organisations to develop the use of
+ the electronic communications medium. EcoNet provides
+ subsidies and financial incentives to environmental
+ organisations and committed individuals who foster the
+ effectiveness of organisations through the use of electronic
+ networking. FTP/Telnet: igc.apc.org.
+
+ 2. A network produced by {Acorn Computers} Ltd. for the {BBC
+ Microcomputer} and its successors.
+
+ECOOP
+
+ European Conference on Object-oriented Programming.
+
+ECP
+
+ 1. {Engineering Change Proposal}.
+
+ 2. {Enhanced Capabilities Port}.
+
+ 3. {Extended Capabilities Port}.
+
+ 4. {Extended Concurrent Prolog}.
+
+ (1997-12-01)
+
+ECRC
+
+ {European Computer-Industry Research Centre GmbH}
+
+ECRC-Prolog
+
+ Evidently {Prolog} with {coroutine} extensions.
+
+ See also {SEPIA}.
+
+ ["ECRC-Prolog User's Manual Version 1.0", K. Estenfeld,
+ TR-LP-08 ECRC, Feb 1986].
+
+ (1994-12-01)
+
+ECSL
+
+ Extended CSL.
+
+ A {discrete simulation} language, the successor to {CSL}.
+
+ ["Extended Control and Simulation Language", A.T. Clementson,
+ Comp J 9(3):215-220 (1966)].
+
+ (1994-12-08)
+
+ECSP
+
+ An extension to {CSP}, supporting dynamic communication
+ channels and nested processes.
+
+ ["Static Type Checking of Interprocess Communication in ECSP",
+ F. Baiardi et al, SIGPLAN Notices 19(6):290-299 (June 1984)].
+
+ (1994-12-08)
+
+ECSS II
+
+ Extendable Computer System Simulator.
+
+ An extension of {SIMSCRIPT II}.
+
+ ["The ECSS II Language for Simulating Computer Systems",
+ D.W. Kosy, R-1895-GSA, Rand Corp].
+
+ (1994-12-08)
+
+ECSSL
+
+ Formerly APSE. An equation-oriented specification language
+ for {continuous simulations}. The {compiler} outputs
+ {HYTRAN}, which must be run on an analog processor.
+
+ (1994-12-08)
+
+ed
+
+ <tool, text> (editor) {Unix}'s {line editor}. Ed is rarely
+ used by humans since even {vi} is better.
+
+ {Unix manual page}: ed(1).
+
+ (1999-03-01)
+
+EDA
+
+ 1. {Electronic Design Automation}.
+
+ 2. {Exploratory Data Analysis}.
+
+ 3. A product line from {Dazix}.
+
+ (1995-10-02)
+
+EDAC
+
+ {error detection and correction}
+
+e-ddress
+
+ {electronic mail address}
+
+Eden
+
+ <language, operating system> A {concurrent},
+ {object-oriented}, distributed {operating system} and
+ language, {Eden Programming Language} (EPL), based on {remote
+ procedure call}. It has both {synchronous} and {asynchronous}
+ {message passing}.
+
+ ["The Eden System: A Technical Review", G. Almes et al, IEEE
+ Trans Soft Eng SE-11(1):43-59, Jan 1985].
+
+ (2009-05-26)
+
+Eden Programming Language
+
+ <language> (EPL) A language developed at the {University of
+ Washington}, based on {Concurrent Euclid} and used with the
+ {Eden} distributed operating system.
+
+ EPL influenced {Emerald} and {Distributed Smalltalk}.
+
+ ["EPL Programmer's Guide", A. Black et al, U Washington June
+ 1984].
+
+ {Eden}
+
+EDF
+
+ {earliest deadline first}
+
+EDI
+
+ {Electronic Data Interchange}
+
+EDI analyst
+
+ <job> A person who introduces {EDI} {standards} and
+ technology. An EDI analyst makes decisions for information
+ construction and selects resources for EDI processing and
+ application expansion. He coordinates processing and
+ transmission schedules and mapping of standard data formats.
+ He generally serves as a key contact for trading partners and
+ value-added network consultants.
+
+ (2004-03-11)
+
+EDIF
+
+ Electronic Design Interchange Format.
+
+ Not a programming language, but a format to simplify data
+ transfer between CAD/CAE systems. LISP-like syntax. See also
+ {Berkeley EDIF200}.
+
+ E-mail: <edif-support@cs.man.ac.uk>
+ {(ftp://edif.cs.man.ac.uk/pub/edif)}.
+
+ ["Designer's Guide to EDIF", E. Marx et al, EDN 1987."EDIF
+ Electronic Design Interchange Format Version 200", ANSI/EIA
+ Standard 548].
+
+ (1995-03-10)
+
+EDIFACT
+
+ {ISO 9735}:1988
+
+Edinburgh Multi Access System
+
+ <operating system> (EMAS) One of the first {operating systems}
+ written in a {high-level language} ({IMProved Mercury
+ autocode}), apparently predating {Unix}.
+
+ [Papers in J. {British Computer Society}].
+
+ [More info? Dates?]
+
+ (1996-04-07)
+
+Edinburgh Prolog
+
+ Prolog dialect which eventually developed into the standard,
+ as opposed to Marseille Prolog. (The difference is largely
+ syntax.) Clocksin & Mellish describe Edinburgh Prolog.
+ Version: C-Prolog.
+
+ (1995-03-10)
+
+Edinburgh SML
+
+ (EdML) Implementation of the {Core} language of {SML}.
+ {Byte-code interpreter} in {C}. Ported to {Amiga}, {Atari},
+ {Archimedes} and {IBM PC}.
+
+ Version: 0.44.
+
+ {(ftp://ftp.dcs.ed.ac.uk/pub/edml/EDML4)}.
+
+ E-mail: <lfcs@ed.ac.uk>.
+
+ (1994-12-08)
+
+Edison
+
+ 1. (Named after the American inventor Thomas Edison
+ (1847-1931))
+
+ A simplified Pascal by Per Brinch Hansen with {modules} and
+ {concurrency} (cobegin/coend).
+
+ ["Edison - A Multiprocessor Language", P. Brinch Hansen, CS
+ Dept, USC, Sep 1980].
+
+ ["Programming a Personal Computer", Brinch Hansen, P-H 1977].
+
+ 2. A language which adds an {OPS5}-like {rete}-based
+ {production system} system to {C}. It is implemented as a {C}
+ {preprocessor}.
+
+ ["Edison, A Unix and C Friendly Rete Based Production System",
+ B. Thirion, SIGPLAN Notices 27(1):75-84 (Jan 1992)].
+
+ (1994-12-08)
+
+edit
+
+ <application> Use of some kind of {editor} program to modify a
+ {document}. Also used to refer to the modification itself,
+ e.g. "my last edit only made things worse".
+
+ To edit something usually implies that the changes will
+ persist for some time, usually by saving the edited document
+ to a {file}, though one might open an editor, create a new
+ document in memory, print it and exit without saving it to
+ disk.
+
+ Editing is normally done by a human but see, e.g., {sed}.
+
+ (2007-07-11)
+
+editor
+
+ <application> A program used to {edit} a {document}.
+
+ Different types of document have different editors, e.g. a
+ {text editor} for {text files}, an {image editor} for
+ {images}, an {HTML editor} for {web pages}, etc. The term can
+ be used for pretty much any kind of data modification, e.g. a
+ {disk sector editor} which operates directly on the {hard
+ disk}, bypassing the {filesystem}.
+
+ (2007-07-11)
+
+EDL
+
+ <language>
+
+ 1. {Experiment Description Language}.
+
+ 2. {Event Description Language}.
+
+EDM
+
+ {Electronic Data Management}
+
+EdML
+
+ {Edinburgh SML}
+
+EDMS
+
+ {Electronic Document Management System}
+
+EDO DRAM
+
+ {Extended Data Out Dynamic Random Access Memory}
+
+EDO memory
+
+ {Extended Data Out Dynamic Random Access Memory}
+
+EDO RAM
+
+ {Extended Data Out Dynamic Random Access Memory}
+
+EDP
+
+ {Electronic Data Processing}
+
+EDP auditor
+
+ <job> A person who analyses system functions and operations to
+ determine adequate security and controls. An EDP analyst
+ evaluates systems and operational procedures and reports
+ findings to senior management. He writes ad hoc report
+ programs using {4GLs} and specialised audit software.
+
+ (2004-03-11)
+
+EDRAM
+
+ {Enhanced Dynamic Random Access Memory}
+
+EDS
+
+ {Enhanced Directory Service}
+
+EDS+
+
+ <database, hardware> A {database accelerator} built by {ICL}
+ as part of the {EDS} project. The machine has up to 64 nodes,
+ each node having 64Mb of memory, 2 {SPARC} processors and a
+ 1Gb of disk.
+
+ See also {PARADE}.
+
+ (1994-11-02)
+
+EDSAC
+
+ {Electronic Discrete Sequential Automatic Computer}
+
+edu
+
+ <networking> ("education") The {top-level domain} for
+ educational establishments in the USA (and some other
+ countries). E.g. "mit.edu". The UK equivalent is "ac.uk".
+
+ (1999-01-26)
+
+education contact
+
+ <job> The person at a company who should receive educational
+ material.
+
+ (2004-03-11)
+
+edutainment
+
+ <application> Interactive education and entertainment services
+ or software, usually supplied commercially via a cable network
+ or on {CD-ROM}.
+
+ (1995-03-30)
+
+Edward Lorenz
+
+ <person> A mathematical meteorologist who discovered the
+ {Lorenz attractor} in the 1960s.
+
+ (1996-01-13)
+
+Edward Yourdon
+
+ <person> A {software engineering} consultant, widely known as
+ the developer of the "{Yourdon method}" of structured systems
+ analysis and design, as well as the co-developer of the
+ Coad/Yourdon method of {object-oriented analysis} and design.
+ He is also the editor of three software journals - American
+ Programmer, Guerrilla Programmer, and Application Development
+ Strategies - that analyse software technology trends and
+ products in the United States and several other countries
+ around the world.
+
+ Ed Yourdon received a B.S. in Applied Mathematics from {MIT},
+ and has done graduate work at MIT and at the Polytechnic
+ Institute of New York. He has been appointed an Honorary
+ Professor of {Information Technology} at Universidad CAECE in
+ Buenos Aires, Argentina and has received numerous honors and
+ awards from other universities and professional societies
+ around the world.
+
+ He has worked in the computer industry for 30 years, including
+ positions with {DEC} and {General Electric}. Earlier in his
+ career, he worked on over 25 different {mainframe} computers,
+ and was involved in a number of pioneering computer projects
+ involving {time-sharing} and {virtual memory}.
+
+ In 1974, he founded the consulting firm, {Yourdon, Inc.}. He
+ is currently immersed in research in new developments in
+ software engineering, such as object-oriented software
+ development and {system dynamics} modelling.
+
+ Ed Yourdon is the author of over 200 technical articles; he
+ has also written 19 computer books, including a novel on
+ {computer crime} and a book for the general public entitled
+ Nations At Risk. His most recent books are Object-Oriented
+ Systems Development (1994), Decline and Fall of the American
+ Programmer (1992), Object-Oriented Design (1991), and
+ Object-Oriented Analysis (1990). Several of his books have
+ been translated into Japanese, Russian, Chinese, Spanish,
+ Portugese, Dutch, French, German, and other languages, and his
+ articles have appeared in virtually all of the major computer
+ journals.
+
+ He is a regular keynote speaker at major computer conferences
+ around the world, and serves as the conference Chairman for
+ Digital Consulting's SOFTWARE WORLD conference. He was an
+ advisor to Technology Transfer's research project on software
+ industry opportunities in the former Soviet Union, and a
+ member of the expert advisory panel on CASE acquisition for
+ the U.S. Department of Defense.
+
+ Mr. Yourdon was born on a small planet at the edge of one of
+ the distant red-shifted galaxies. He now lives in the Center
+ of the Universe (New York City) with his wife, three children,
+ and nine Macintosh computers, all of which are linked together
+ through an Appletalk network.
+
+ (1995-04-16)
+
+Edwin
+
+ {MIT Scheme}
+
+ee
+
+ <networking> The {country code} for Estonia.
+
+ (1999-01-27)
+
+EEMA
+
+ {European Electronic Messaging Association}
+
+EEPROM
+
+ {Electrically Erasable Programmable Read-Only Memory}
+
+ See also {EAPROM}.
+
+EER
+
+ An extended {entity-relationship model}.
+
+E. F. Codd
+
+ <person> The inventor of the {relational data model} of
+ {databases}.
+
+ [Name? More?]
+
+ (1995-11-29)
+
+EFF
+
+ {Electronic Frontier Foundation}
+
+effective computable
+
+ <theory> A term describing a {function} for which there is an
+ {effective algorithm} that correctly calculates the function.
+ The algorithm must consist of a {finite} sequence of
+ instructions.
+
+ (1996-05-03)
+
+effective number of bits
+
+ <hardware> (ENOB) An indication of the quality of an {analog
+ to digital converter}. The measurement is related to the test
+ frequency and the {signal-to-noise ratio}.
+
+ [Better definition?]
+
+ (1998-06-15)
+
+Effort Adjustment Factor
+
+ <programming> (EAF) A term used in {COCOMO} to calculate a
+ {cost driver attribute}'s effect on a project. It is the
+ product of the effort multipliers corresponding to each of the
+ cost drivers for the project.
+
+ (1996-05-29)
+
+EFI
+
+ {Extensible Firmware Interface}
+
+EFL
+
+ {Extended Fortran Language}
+
+EFNet
+
+ <networking> (From "Eris-free Net", eris being
+ eris.berkeley.edu).
+
+ The dominant {Internet Relay Chat} network.
+
+ See also {Undernet}.
+
+ (1995-11-09)
+
+Eforth
+
+ <language> A system produced by Ting to help implementers
+ produce Forths for different targets, using {assemblers}.
+
+ (1996-07-28)
+
+E-Forth
+
+ <language> A {Forth} {interpreter} written in {Motorla 6809}
+ assembly code by Lennart Benschop
+ <lennart@blade.stack.urc.tue.nl>. Posted to {Usenet}
+ newsgroup {alt.sources} on 1993-11-03 with a {Motorola 6809}
+ {assembler}.
+
+ (1993-11-03)
+
+EFT
+
+ {electronic funds transfer}
+
+EFTPOS
+
+ {Electronic Funds Transfer Point of Sale}
+
+EFTS
+
+ {electronic funds transfer}
+
+eg
+
+ <networking> The {country code} for Egypt.
+
+ (1999-01-27)
+
+EGA
+
+ {Enhanced Graphics Adapter}
+
+Eggdrop
+
+ <communications> The world's most popular {open source IRC
+ bot}, designed for flexibility and ease of use. Eggdrop is
+ freely distributable under the {GPL}. It was originally
+ developed by Robey Pointer but he no longer works on it.
+
+ Eggdrop is designed to run on {Linux}, {*BSD}, {SunOs},
+ {Windows}, {Mac OS X} and other platforms. It is extendable
+ with {Tcl} scripts and/or {C} modules. It supports
+ {Undernet}, {DALnet}, {EFnet}, {IRCnet}, and {QuakeNet}. It
+ can form {botnets} and share {partylines} and userfiles
+ between bots.
+
+ (2005-07-07)
+
+egosurfing
+
+ <jargon> Scanning the {web}, databases, print media
+ or research papers looking for the mention of your name.
+
+ (1997-04-17)
+
+EGP
+
+ {Exterior Gateway Protocol}
+
+egrep
+
+ <tool> An extended version of the {Unix} {grep} command.
+ Egrep accepts extended {regular expressions} (REs) including
+ "*" following multi-character REs; "+" (one or more matches);
+ "?" (zero or one matches); "|" separating two REs matches
+ either. REs may be bracketed with (). Despite its additional
+ complexity, egrep is usually faster than {fgrep} or {grep}.
+
+ (2004-07-20)
+
+Egyptian brackets
+
+ <programming, humour> A humourous term for {K&R} {indent style},
+ referring to the "one hand up in front, one down behind" pose
+ which popular culture inexplicably associates with Egypt.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2011-11-30)
+
+Eh
+
+ /A/. Software Portability Group, U Waterloo. A typeless
+ language derived from (and similar to) B. Provides guaranteed
+ order of evaluation for side effects in expressions. Also
+ character indexing operators.
+
+ See also {Zed}.
+
+ ["Eh Reference Manual", R.S.C. Braga, RR CS-76-45, U Waterloo,
+ Nov 1976].
+
+eh
+
+ <networking> The {country code} for Western Sahara.
+
+ (1999-01-27)
+
+eHelp Corporation
+
+ <company> A vendor of {Microsoft} {Windows} application
+ development tools such as {RoboHELP} and {RoboDemo}.
+
+ EHelp were formerly (around 1997) Blue Sky Software.
+
+ {eHelp Home (http://ehelp.com/)}.
+
+ Address: 7777 Fay Avenue, Suite 201, La Jolla, CA 92037, USA.
+ Telephone: +1-800-793-0364, +1 (619) 459 6365. Fax: +1 (619)
+ 459 6366.
+
+ (2003-07-24)
+
+EHTS
+
+ Emacs HyperText System.
+
+ An experimental multi-user {hypertext} system from the
+ {University of Aalborg}. It consists of a text editor (based
+ on {Epoch} and {GNU Emacs} and written in {elisp}) and a
+ graphical {browser} (based on {XView} and written in {C})
+ running under the {X Window System} and {OpenWindows}. Both
+ tools use {HyperBase} as their {database}.
+
+ (1995-01-05)
+
+EIA
+
+ {Electronics Industry Association}
+
+EIA-232
+
+ <communications, standard> (Formerly "RS-232") The most common
+ {asynchronous} {serial line} {standard}. EIA-232 is the {EIA}
+ equivalent of {ITU-T} {V.24}, and {V.28}.
+
+ EIA-232 specifies the {gender} and pin use of connectors, but
+ not their physical type. {RS-423} specifies the electrical
+ signals. 25-way {D-type} connectors are common but often only
+ three wires are connected - one ground (pin 7) and one for
+ data in each direction. The other pins are primarily related
+ to {hardware handshaking} between sender and receiver and to
+ {carrier detection} on {modems}, inoperative circuits, busy
+ conditions etc.
+
+ The standard classifies equipment as either {Data
+ Communications Equipment} (DCE) or {Data Terminal Equipment}
+ (DTE). DTE receives data on pin 3 and transmits on pin 2
+ (TD). A DCE EIA-232 interface has a female connector. DCE
+ receives data from DTE on pin 2 (TD) and sends that data out
+ the analog line. Data received from the analog line is sent
+ by the DCE on pin 3(RD).
+
+ Originally DCE was a modem and DTE was a computer or terminal.
+ The terminal or computer was connected (via EIA-232) to two
+ modems, which were connected via a telephone line.
+
+ The above arrangement allows a computer or terminal to be
+ connected to a modem with a straight-through (2-2, 3-3) cable.
+ It is common, however, to find equipment with the wrong sex
+ connector or with pins two and three reversed, requiring the
+ insertion of a cable or adaptor wired as a {gender mender} or
+ {null modem}. Such an adaptor is also required when
+ connecting a computer directly to a terminal or to another
+ computer without the use of modems.
+
+ (1999-12-28)
+
+EIA-232C
+
+ <communications, standard> The {EIA} equivalent of {ITU-T}
+ {standard} {V.24}.
+
+ The {EIA} EIA-232C electrical signal is unbalanced +/- 5 to +/-
+ 12V, {polar} {non return to zero} and handles data speeds up
+ to 19.2 kilobits per second.
+
+ [Correct name? Relationship to RS-232C? Difference from
+ EIA-232?]
+
+ (2004-08-02)
+
+EIA-422
+
+ <communications, standard> (Formerly "RS-422") An {EIA}
+ {serial line} {standard} which specifies 4-wire,
+ {full-duplex}, {differential line}, {multi-drop}
+ communications. The mechanical connections for this interface
+ are specified by {EIA-449}. The maximum cable length is
+ 1200m. Maximum data rates are 10Mbps at 1.2m or 100Kbps at
+ 1200m. EIA-422 cannot implement a truly multi-point
+ communications network (such as with {EIA-485}), although only
+ one driver can be connected to up to ten receivers. The best
+ use of EIA-422 is probably in {EIA-232} extension cords.
+
+ {Comparing EIA-422, 423, 449 to RS-232-C
+ (http://rad.com/networks/1995/rs232/rs449.htm)}. {Details
+ on RS-232, 422, 423 and 485
+ (http://rs485.com/rs485spec.html)}.
+
+ (2002-10-05)
+
+EIA-423
+
+ <communications, standard> (Formerly "RS-423") An {EIA}
+ {serial line} {standard} which specifies {single ended}
+ communication. The mechanical connections for this interface
+ are specified by {EIA-449}. Although it was originally
+ intented as a successor of {EIA-232} it is not widely used.
+ The {EIA-232} standard has its limits at 20kbps and 1.5m.
+ EIA-423 can have a cable lenght of 1200m, and achieve a data
+ rate of 100Kbps. When no data is being transmitted, the
+ serial line is at a logical zero (+3 to +15 Volts). A logical
+ one is represented as a signal level of -15 to -3 Volts. In
+ practise, one often finds signals which switch between
+ nominally +4.5 and +0.5 Volts. Such signals are large by
+ modern standards, and because the impedance of the circuits is
+ relatively high, the allowable bit rate is modest. The data
+ is preceded by a start bit which is always a logical
+ one. There may be seven or eight bits of data, possibly
+ followed by an even or odd parity bit and one or two stop
+ bits. A "break" condition is a continuous logical one on the
+ line which is what would be observed if nothing was connected.
+
+ {Comparing EIA-422, 423, 449 to RS-232-C
+ (http://rad.com/networks/1995/rs232/rs449.htm)}. {Details
+ on RS-232, 422, 423 and 485
+ (http://rs485.com/rs485spec.html)}.
+
+ (2002-10-05)
+
+EIA-449
+
+ <communications, standard> (Formerly "RS-449") An EIA
+ {standard} for a 37-pin or 9-pin {D-type} connector
+ (functional- and mechanical characteristics), usually used
+ with {EIA-422} or {EIA-423} electrical specifications.
+
+ (2002-10-05)
+
+EIA-485
+
+ <communications, standard> (Formerly "RS-485") An {EIA}
+ {serial line} {standard} which specifies 2-wire,
+ {half-duplex}, {differential line}, {multi-point}
+ communications. Maximum cable length is 1200m. Maximum data
+ rates are 10Mbps at 1.2m or 100Kbps at 1200m. EIA-485 can
+ implement a truly multi-point communications network, and
+ specifies up to 32 drivers and 32 receivers on a single
+ (2-wire) bus.
+
+ {Differential SCSI} uses EIA-485.
+
+ {Details on RS-232, 422, 423, and 485
+ (http://rs485.com/rs485spec.html)}.
+
+ (2003-04-18)
+
+EIA-530
+
+ <communications, standard> (Formerly "RS-530") An {EIA}
+ {serial line} {standard} which specifies {differential line}
+ and {singe ended} communications. Combining {EIA-422} and
+ {EIA-423}, and defining a 25-pin connector for mechanical
+ connections, this standard serves as a complement to {EIA-232}
+ for high(er) speed data transmissions.
+
+ (2002-10-05)
+
+EIDE
+
+ {Advanced Technology Attachment Interface with Extensions}
+
+Eiffel
+
+ <language> An {object-oriented} language produced by {Bertrand
+ Meyer} in 1985. Eiffel has {classes} with {multiple
+ inheritance} and {repeated inheritance}, {deferred class}es
+ (like {Smalltalk}'s {abstract class}), and {clusters} of
+ classes. Objects can have both {static types} and {dynamic
+ types}. The dynamic type must be a descendant of the static
+ (declared) type. {Dynamic binding} resolves {multiple
+ inheritance} clashes. It has flattened forms of classes, in
+ which all of the inherited features are added at the same
+ level and {generic class}es parametrised by type.
+
+ Other features are {persistent objects}, {garbage collection},
+ {exception} handling, {foreign language interface}. Classes
+ may be equipped with {assertions} (routine preconditions and
+ postconditions, class {invariants}) implementing the theory of
+ "{Design by Contract}" and helping produce more reliable
+ software.
+
+ Eiffel is compiled to {C}. It comes with libraries containing
+ several hundred classes: data structures and {algorithms}
+ (EiffelBase), graphics and user interfaces (EiffelVision) and
+ language analysis (EiffelLex, EiffelParse).
+
+ The first release of Eiffel was release 1.4, introduced at the
+ first {OOPSLA} in October 1986. The language proper was first
+ described in a University of California, Santa Barbara report
+ dated September 1985.
+
+ Eiffel is available, with different libraries, from several
+ sources including {Interactive Software Engineering}, USA (ISE
+ Eiffel version 3.3); Sig Computer GmbH, Germany (Eiffel/S);
+ and {Tower, Inc.}, Austin (Tower Eiffel).
+
+ The language definition is administered by an open
+ organisation, the Nonprofit International Consortium for
+ Eiffel (NICE). There is a standard kernel library.
+
+ An {Eiffel source checker} and compiler {front-end} is
+ available.
+
+ Latest version: 4.2, as of 1998-10-28.
+
+ Latest version: ISE Eiffel version 3.3.
+
+ See also {Sather}, {Distributed Eiffel}, {Lace}, {shelf}.
+
+ E-mail: <queries@eiffel.com>.
+
+ ["Eiffel: The Language", Bertrand Meyer, P-H 1992].
+
+ (1998-11-15)
+
+Eiffel source checker
+
+ A compiler {front-end} for {Eiffel} 3 by Olaf Langmack
+ <langmack@inf.fu-berlin.de> and Burghardt Groeber. It was
+ generated automatically with the {Karlsruhe toolbox} for
+ compiler construction according to the most recent public
+ language definition. The {parser} derives an easy-to-use
+ {abstract syntax tree}, supports elementary error recovery and
+ provides a precise source code indication of errors. It
+ performs a strict syntax check and analyses 4000 lines of
+ source code per second on a {Sun} {SPARC} {workstation}.
+
+ {(ftp://ftp.fu-berlin.de/pub/heron/ep.tar.Z)}.
+
+ (1992-12-14)
+
+eigenvalue
+
+ <mathematics> The factor by which a {linear transformation}
+ multiplies one of its {eigenvectors}.
+
+ (1995-04-10)
+
+eigenvector
+
+ <mathematics> A {vector} which, when acted on by a particular
+ {linear transformation}, produces a scalar multiple of the
+ original vector. The scalar in question is called the
+ {eigenvalue} corresponding to this eigenvector.
+
+ It should be noted that "vector" here means "element of a
+ vector space" which can include many mathematical entities.
+ Ordinary vectors are elements of a vector space, and
+ multiplication by a matrix is a {linear transformation} on
+ them; {smooth functions} "are vectors", and many partial
+ differential operators are linear transformations on the space
+ of such functions; quantum-mechanical states "are vectors",
+ and {observables} are linear transformations on the state
+ space.
+
+ An important theorem says, roughly, that certain linear
+ transformations have enough eigenvectors that they form a
+ {basis} of the whole vector states. This is why {Fourier
+ analysis} works, and why in quantum mechanics every state is a
+ superposition of eigenstates of observables.
+
+ An eigenvector is a (representative member of a) {fixed point}
+ of the map on the {projective plane} induced by a {linear
+ map}.
+
+ (1996-09-27)
+
+eight-bit clean
+
+ <software> A term which describes a system that deals
+ correctly with extended {character sets} which (unlike ASCII)
+ use all eight {bits} of a {byte}. Many programs and
+ communications systems assume that all characters have codes
+ in the range 0 to 127. This leaves the top bit of each byte
+ free for use as a {parity} bit or some kind of {flag bit}.
+ These assumptions break down when the program is used in some
+ non-english-speaking countries with larger alphabets.
+
+ If a binary file is transmitted via a communications link
+ which is not eight-bit clean, it will be corrupted. To combat
+ this you can encode it with {uuencode} which uses only {ASCII}
+ characters. There are some links however which are not even
+ "seven-bit clean" and cause problems even for uuencoded data.
+
+ (1995-01-05)
+
+eight queens problem
+
+ {eight queens puzzle}
+
+eight queens puzzle
+
+ <algorithm> A puzzle in which one has to place eight queens on
+ a chessboard such that no queen is attacking any other,
+ i.e. no two queens occupy the same row, column or diagonal.
+ One may have to produce all possible such configurations or
+ just one.
+
+ It is a common students assignment to devise a program to
+ solve the eight queens puzzle. The {brute force} {algorithm}
+ tries all 64*63*62*61*60*59*58*57 = 178,462,987,637,760
+ possible layouts of eight pieces on a chessboard to see which
+ ones meet the criterion. More intelligent algorithms use the
+ fact that there are only ten positions for the first queen
+ that are not reflections of each other, and that the first
+ queen leaves at most 42 safe squares, giving only
+ 10*42*41*40*39*38*37*36 = 1,359,707,731,200 layouts to try,
+ and so on.
+
+ The puzzle may be varied with different number of pieces and
+ different size boards.
+
+ [Best algorithm?]
+
+ (1999-07-28)
+
+eighty-column mind
+
+ <abuse> The sort said to be possessed by persons for whom the
+ transition from {punched card} to {paper tape} was traumatic
+ (nobody has dared tell them about disks yet). It is said that
+ these people, including (according to an old joke) the founder
+ of {IBM}, will be buried "face down, 9-edge first" (the 9-edge
+ being the bottom of the card). This directive is inscribed on
+ IBM's 1402 and 1622 card readers and is referenced in a famous
+ bit of doggerel called "The Last Bug", the climactic lines of
+ which are as follows:
+
+ He died at the console
+ Of hunger and thirst.
+ Next day he was buried,
+ Face down, 9-edge first.
+
+ The eighty-column mind is thought by most {hackers} to
+ dominate IBM's customer base and its thinking.
+
+ See {fear and loathing}, {card walloper}.
+
+ [{Jargon File}]
+
+ (1996-08-16)
+
+eighty-twenty rule
+
+ <programming> The program-design version of the law of
+ diminishing returns. The 80/20 rule says that roughly 80% of
+ the problem can be solved with 20% of the effort that it would
+ take to solve the whole problem.
+
+ For example, parsing {e-mail addresses} in "From:" lines in
+ e-mail messages is notoriously difficult if you follow the RFC
+ 2822 specification. However, about 60% of actual "From:"
+ lines are in the format "From: Their Name <user@host>", with a
+ far more constrained idea of what can be in "user" or "host"
+ than in RFC 2822. Another 25% just add double-quotes around
+ "Their Name". Matching just those two patterns would thus
+ cover 85% of "From:" lines, with a tiny portion of the code
+ required to fully implement RFC2822.
+
+ (Adding support for "From: user@host" and "From: user@host
+ (Their Name) " brings coverage to almost 100%, leaving only
+ really baroque things that RFC-2822 permits, like "From:
+ Pete(A wonderful \) chap) <pete(his account)@silly.test(his
+ host)" or the like.)
+
+ It is an eternal question whether too much attention is paid
+ to the 80/20 rule (leading to systems that are irrevocably
+ broken for "unusual" cases), or too little (leading to systems
+ that sacrifice usability in the typical case, just so that
+ rare cases can work properly).
+
+ Compare: {KISS Principle}
+
+ (2003-11-17)
+
+EIRP
+
+ {equivalent isotropically radiated power}
+
+EISA
+
+ {Extended Industry-Standard Architecture}
+
+EJB
+
+ {Enterprise JavaBeans}
+
+Eksi Sozluk
+
+ <web> ("Sour Dictionary") An online, Turkish,
+ colaborative, hypertext dictionary.
+
+ {Eksi Sozluk Home (http://sourtimes.org/)}.
+
+ (2006-11-02)
+
+EL1
+
+ Extensible Language One. An extensible language by
+ B. Wegbreit of Harvard ca 1974. EL1 is internally somewhat
+ {Lisp}-like, but fully typed with {records} and pointers. The
+ external {syntax} is {ALGOL}-like and extensible, supporting
+ user-defined {data structures}, control structures and
+ operations. The {parser} is table-driven, with a modifiable
+ set of productions. Used as the basis for the {ECL}
+ {operating system}.
+
+ ["Studies in Extensible Programming Languages", B. Wegbreit,
+ Garland. Pub 1980].
+
+el(alpha)
+
+ Aims to be a high-level language that knows about real
+ hardware, for systems programming. "Essential Language
+ el(alpha) - A Reduced Expression Set Language for Systems
+ Programming", T. Watanabe et al, SIGPLAN Notices 26(1):85-98.
+
+Elan
+
+ ["Top-down Programming with Elan", C.H.A. Koster, Ellis
+ Horwood 1987].
+
+El Camino Bignum
+
+ <humour> /el' k*-mee'noh big'nuhm/ The road mundanely called
+ El Camino Real, a road through the San Francisco peninsula
+ that originally extended all the way down to Mexico City and
+ many portions of which are still intact. Navigation on the
+ San Francisco peninsula is usually done relative to El Camino
+ Real, which defines {logical} north and south even though it
+ isn't really north-south many places. El Camino Real runs
+ right past {Stanford University}.
+
+ The Spanish word "real" (which has two syllables: /ray-al'/)
+ means "royal"; El Camino Real is "the royal road". In the
+ {Fortran} language, a "{real}" quantity is a number typically
+ precise to seven significant digits, and a "{double
+ precision}" quantity is a larger {floating-point} number,
+ precise to perhaps fourteen significant digits (other
+ languages have similar "real" types).
+
+ When a {hacker} from {MIT} visited Stanford in 1976, he
+ remarked what a long road El Camino Real was. Making a pun on
+ "real", he started calling it "El Camino Double Precision" -
+ but when the hacker was told that the road was hundreds of
+ miles long, he renamed it "El Camino Bignum", and that name
+ has stuck. (See {bignum}).
+
+ [{Jargon File}]
+
+ (1996-07-16)
+
+elder days
+
+ The heroic age of hackerdom (roughly, pre-1980); the era of
+ the {PDP-10}, {TECO}, {ITS} and the {ARPANET}. This term has
+ been rather consciously adopted from J. R. R. Tolkien's
+ fantasy epic "The Lord of the Rings".
+
+ Compare {Iron Age}. See also {elvish} and {Great Worm}.
+
+ [{Jargon File}]
+
+e-learning
+
+ {Computer-Aided Instruction}
+
+Electing a Pope
+
+ <electronics, humour> (From the smoke signals given out when
+ the guys in funny hats choose a new Pope) Causing an
+ {integrated circuit} or other electronic component to emit
+ smoke by passing too much current through it.
+
+ See {magic smoke}.
+
+ (1995-08-18)
+
+Electrically Alterable Programmable Read-Only Memory
+
+ <storage> (EAPROM) A {PROM} whose contents can be changed.
+
+ [What's the difference between EAPROM and {EEPROM}?]
+
+ (1995-11-12)
+
+Electrically Erasable Programmable Read-Only Memory
+
+ <storage> (EEPROM) A {non-volatile storage} device using a
+ technique similar to the floating gates in {EPROMs} but with
+ the capability to discharge the floating gate electrically.
+ Usually bytes or words can be erased and reprogrammed
+ individually during system operation.
+
+ In contrast to {RAM}, writing takes much longer than reading
+ and EEPROM is more expensive and less dense than RAM. It is
+ appropriate for storing small amounts of data which is changed
+ infrequently, e.g. the hardware configuration of an {Acorn}
+ {Archimedes}.
+
+ [Difference from {EAPROM}?]
+
+ (1995-04-22)
+
+Electromagnetic Compatibility
+
+ <hardware, testing> (EMC) The extent to which a piece of
+ hardware will tolerate electrical interference from other
+ equipment, and will interfere with other equipment.
+
+ There are strict legal EMC requirements for the sale of any
+ electrical or electronic hardware in most countries, although
+ the actual standards differ. See, for example, {EMCNet
+ (http://emcnet.com/)}.
+
+ See also {Electrostatic Discharge}, {Radio Frequency
+ Interference}.
+
+ (1997-12-19)
+
+electromigration
+
+ <electronics> Mass transport due to momentum exchange between
+ conducting electrons and diffusing metal atoms.
+ Electromigration causes progressive damage to the metal
+ conductors in an {integrated circuit}. It is characteristic
+ of metals at very high current density and temperatures of
+ 100C or more.
+
+ The term was coined by Professor Hilbert Huntington in the
+ late 1950s because he didn't like the German use of the word
+ "electrotransport".
+
+ Mass transoport occurs via the Einstein relation J=DFC/kT
+ where F is the driving force for the transoport. For
+ electromigraiton F is z*epj and z* is an electromigration
+ parameter relating the momentum exchange and z is the charge
+ of the "diffusing" species.
+
+ (1999-02-25)
+
+electron
+
+ <electronics> A sub-atomic particle with a negative quantised
+ {charge}. A flow of electrical {current} consists of the
+ unidirectional (on average) movement of many electrons. The
+ more mobile electrons are in a given material, the greater it
+ electrical conductance (or equivalently, the lower its
+ resistance).
+
+ (1995-10-06)
+
+electronic commerce
+
+ <application, communications> (EC) The conducting of business
+ communication and transactions over networks and through
+ computers. As most restrictively defined, electronic commerce
+ is the buying and selling of goods and services, and the
+ transfer of funds, through digital communications. However EC
+ also includes all inter-company and intra-company functions
+ (such as marketing, finance, manufacturing, selling, and
+ negotiation) that enable commerce and use {electronic mail},
+ {EDI}, file transfer, fax, {video conferencing}, {workflow},
+ or interaction with a remote computer.
+
+ Electronic commerce also includes buying and selling over the
+ {web} and the {Internet}, {electronic funds
+ transfer}, {smart cards}, {digital cash} (e.g. Mondex), and all
+ other ways of doing business over digital networks.
+
+ [{Electronic Commerce Dictionary}].
+
+ (1995-10-08)
+
+Electronic Commerce Dictionary
+
+ <publication> A lexicon of {electronic commerce} terms. It
+ includes over 900 terms and acronyms, and over 200 {website}
+ addresses. It has entries on commerce over the {World-Wide
+ Web}, {Internet} payment systems, The {National Information
+ Infrastructure}, {Electronic Data Interchange}, {Electronic
+ Funds Transfer}, {Public Key Cryptography}, {smart cards} and
+ {digital cash}, computer and network security for commerce,
+ marketing through electronic media.
+
+ {(http://tedhaynes.com/haynes1/intro.html)}.
+
+ (1999-03-24)
+
+electronic data interchange
+
+ <application, communications> (EDI) The exchange of
+ standardised document forms between computer systems for
+ business use. EDI is part of {electronic commerce}.
+
+ EDI is most often used between different companies ("trading
+ partners") and uses some variation of the {ANSI X12}
+ {standard} (USA) or {EDIFACT} (UN sponsored global standard).
+
+ [{Electronic Commerce Dictionary}].
+
+ (1995-10-06)
+
+Electronic Data Processing
+
+ 1. <application> (EDP) {data processing} by computers.
+
+ 2. <company> The name of {Honeywell}'s computer business
+ between 1960, when it gained complete ownership of {Datamatic
+ Corporation}, and 1963, when it was officially renamed
+ Honeywell Inc.
+
+ (1995-03-30)
+
+Electronic Design Automation
+
+ <application> (EDA) Software tools for the development of
+ {integrated circuits} and systems.
+
+ Companies selling EDA tools include {Cadence}, {Intergraph},
+ {Mentor}, {Synopsys}, {Viewlogic}. {Zuken-Redac Dazix} has
+ been acquired by Intergraph.
+
+ (1995-10-09)
+
+Electronic Discrete Sequential Automatic Computer
+
+ <computer, history> (EDSAC, often "Electronic Delay Storage
+ Automatic Computer") Based upon the {EDVAC} (Electronic
+ Discrete Variable Automatic Computer) designed in 1945, the
+ EDSAC was completed in 1949 at the University of Cambridge
+ Mathematical Laboratory in England. The EDSAC performed its
+ first calculation on 1949-05-06. EDSAC was considered to be
+ the first computer to store programs. It ceased to exist in
+ about 1951.
+
+ [What happened to it?]
+
+ (2010-01-07)
+
+Electronic Frontier Foundation
+
+ <body> (EFF) A group established to address social and legal
+ issues arising from the impact on society of the increasingly
+ pervasive use of computers as a means of communication and
+ information distribution. EFF is a non-profit civil liberties
+ public interest organisation working to protect freedom of
+ expression, privacy, and access to on-line resources and
+ information.
+
+ {(http://eff.org/)}.
+
+ (1994-12-08)
+
+electronic funds transfer
+
+ <application, communications> (EFT, EFTS, - system) Transfer
+ of money initiated through electronic terminal, automated
+ teller machine, computer, telephone, or {magnetic tape}. In
+ the late 1990s, this increasingly includes transfer initiated
+ via the {web}. The term also applies to credit
+ card and automated bill payments.
+
+ {Glossary (http://fms.treas.gov/eft/glossary.html)}.
+
+ (1999-12-08)
+
+Electronic Funds Transfer Point of Sale
+
+ <business, real-time> A method of electronic payment which
+ allows money to be transferred from the account of the shopper
+ to the merchant in close-to real-time. Generally the shopper
+ will give the merchant a credit or debit card, which will be
+ swiped to obtain the account information. The shopper will
+ then be required to either sign a receipt or enter a {PIN} via
+ a keypad to authorise the transaction.
+
+ (2003-06-22)
+
+electronic funds transfer system
+
+ {electronic funds transfer}
+
+electronic magazine
+
+ <messaging, publication, web> (e-zine) A regular
+ publication on some particular topic distributed in digital
+ form, chiefly now via the {web} but also by
+ {electronic mail} or {floppy disk}. E-zines are often
+ distributed for free by enthusiasts.
+
+ (1996-08-04)
+
+electronic mail
+
+ <messaging> (e-mail) Messages automatically passed from one
+ computer user to another, often through computer {networks}
+ and/or via {modems} over telephone lines.
+
+ A message, especially one following the common {RFC 822}
+ {standard}, begins with several lines of {headers}, followed
+ by a blank line, and the body of the message. Most e-mail
+ systems now support the {MIME} {standard} which allows the
+ message body to contain "{attachments}" of different kinds
+ rather than just one block of plain {ASCII} text. It is
+ conventional for the body to end with a {signature}.
+
+ Headers give the name and {electronic mail address} of the
+ sender and recipient(s), the time and date when it was sent
+ and a subject. There are many other headers which may get
+ added by different {message handling systems} during delivery.
+
+ The message is "composed" by the sender, usually using a
+ special program - a "{Mail User Agent}" (MUA). It is then
+ passed to some kind of "{Message Transfer Agent}" (MTA) - a
+ program which is responsible for either delivering the message
+ locally or passing it to another MTA, often on another {host}.
+ MTAs on different hosts on a network often communicate using
+ {SMTP}. The message is eventually delivered to the
+ recipient's {mailbox} - normally a file on his computer - from
+ where he can read it using a mail reading program (which may
+ or may not be the same {MUA} as used by the sender).
+
+ Contrast {snail-mail}, {paper-net}, {voice-net}.
+
+ The form "email" is also common, but is less suggestive of the
+ correct pronunciation and derivation than "e-mail". The word
+ is used as a noun for the concept ("Isn't e-mail great?", "Are
+ you on e-mail?"), a collection of (unread) messages ("I spent
+ all night reading my e-mail"), and as a verb meaning "to send
+ (something in) an e-mail message" ("I'll e-mail you (my
+ report)"). The use of "an e-mail" as a count noun for an
+ e-mail message, and plural "e-mails", is now (2000) also well
+ established despite the fact that "mail" is definitely a mass
+ noun.
+
+ Oddly enough, the word "emailed" is actually listed in the
+ Oxford English Dictionary. It means "embossed (with a raised
+ pattern) or arranged in a net work". A use from 1480 is
+ given. The word is derived from French "emmailleure",
+ network. Also, "email" is German for enamel.
+
+ {The story of the first e-mail message
+ (http://pretext.com/mar98/features/story2.htm)}.
+
+ (2002-07-14)
+
+electronic mail address
+
+ <messaging> (Usually "e-mail address") The string used to
+ specify the source or destination of an {electronic mail}
+ message. E.g. "john@doc.acme.ac.uk".
+
+ The {RFC 822} standard is probably the most widely used on the
+ {Internet}. {X.400} was once used in Europe and Canada.
+ {UUCP}-style ({bang path}) addresses or other kinds of {source
+ route} became virtually extinct in the 1990s.
+
+ In the example above, "john" is the {local part} which is the
+ name of a {mailbox} on the destination computer. If the
+ sender and recipient use the same computer, or the same {LAN},
+ for electronic mail then the local part is usually all that is
+ required.
+
+ If they use different computers, e.g. they work at different
+ companies or use different {Internet service providers}, then
+ the "host part", e.g. "sales.acme.com" must be appended after
+ an "@". This usually takes the form of a {fully qualified
+ domain name} or, within a large organisation, it may be just
+ the {hostname} part, e.g. "sales". The destination computer
+ named by the host part is usually a {server} of some kind
+ rather than an individual's {workstation} or {PC}. The user's
+ mail is stored on the server and read later via {client} mail
+ software running on the user's computer.
+
+ Large organisations, such as universities will often set up a
+ global {alias} directory which maps a simple user name such as
+ "jsmith" to an address which contains more information such as
+ "jsmith@london.bigcomp.co.uk". This hides the detailed
+ knowledge of where the message will be delivered from the
+ sender, making it much easier to redirect mail if a user
+ leaves or moves to a different department for example.
+
+ (2006-10-18)
+
+electronic mail client
+
+ {Mail User Agent}
+
+electronic meeting
+
+ <messaging, meeting> The use of a {network} of {personal
+ computers} to improve communication that takes place in a meeting.
+ Electronic meetings are effective with as few as two participants
+ and with over 100 participants. Participants can be face-to-face
+ in a meeting room or distributed around the world. They may all
+ be participating at the same time or different times.
+
+ {Getting Results from Electronic Meetings
+ (http://emsl.co.uk/)}.
+
+ (2014-09-20)
+
+Electronic Numerical Integrator and Computer
+
+ <computer> (ENIAC) The first electronic {digital computer} and
+ an ancestor of most computers in use today. ENIAC was
+ developed by Dr. {John Mauchly} and {J. Presper Eckert} during
+ World War II at the Moore School of the {University of
+ Pennsylvania}.
+
+ In 1940 Dr. {John Vincent Atanasoff} attended a lecture by
+ Mauchly and subsequently agreed to show him his binary
+ calculator, the {Atanasoff-Berry Computer} (ABC), which was
+ partially built between 1937-1942. Mauchly used ideas from
+ the ABC in the design of ENIAC, which was started in June 1943
+ and released publicly in 1946.
+
+ ENIAC was not the first digital computer, {Konrad Zuse}'s {Z3}
+ was released in 1941. Though, like the ABC, the Z3 was
+ {electromechanical} rather than electronic, it was freely
+ programmable via paper tape whereas ENIAC was only
+ programmable by manual rewiring or switches. Z3 used binary
+ representation like modern computers whereas ENIAC used
+ decimal like mechanical calculators.
+
+ ENIAC was underwritten and its development overseen by
+ Lieutenant Herman Goldstine of the U.S. Army Ballistic
+ Research Laboratory (BRL). While the prime motivation for
+ constructing the machine was to automate the wartime
+ production of firing and bombing tables, the very first
+ program run on ENIAC was a highly classified computation
+ for Los Alamos. Later applications included weather
+ prediction, cosmic ray studies, wind tunnel design,
+ petroleum exploration, and optics.
+
+ ENIAC had 20 {registers} made entirely from {vacuum tubes}.
+ It had no other no memory as we currently understand it. The
+ machine performed an addition in 200 {microseconds}, a
+ multiplication in about three {milliseconds}, and a division
+ in about 30 milliseconds.
+
+ {John von Neumann}, a world-renowned mathematician serving on
+ the BRL Scientific Advisory Committee, soon joined the
+ developers of ENIAC and made some critical contributions.
+ While Mauchly, Eckert and the Penn team continued on the
+ technological problems, he, Goldstine, and others took up the
+ logical problems.
+
+ In 1947, while working on the design for the successor
+ machine, EDVAC, von Neumann realized that ENIAC's lack of a
+ central control unit could be overcome to obtain a rudimentary
+ stored program computer (see the Clippinger reference below).
+ Modifications were undertaken that eventually led to an
+ {instruction set} of 92 "orders". {Von Neumann} also proposed
+ the {fetch-execute cycle}.
+
+ [R. F. Clippinger, "A Logical Coding System Applied to the
+ ENIAC", Ballistic Research Laboratory Report No. 673, Aberdeen
+ Proving Ground, MD, September 1948.
+ {(http://ftp.arl.mil/~mike/comphist/48eniac-coding)}].
+
+ [H. H. Goldstine, "The Computer from Pascal to von Neumann",
+ Princeton University Press, 1972].
+
+ [K. Kempf, "Electronic Computers within the Ordnance Corps",
+ Aberdeen Proving Ground, MD, 1961.
+ {(http://ftp.arl.mil/~mike/comphist/61ordnance)}].
+
+ [M. H. Weik, "The ENIAC Story", J. American Ordnance Assoc.,
+ 1961. {(http://ftp.arl.mil/~mike/comphist/eniac-story.html)}].
+
+ [How "general purpose" was ENIAC, compared to Zuse's {Z3}?]
+
+ (2003-10-01)
+
+Electronic Performance Support System
+
+ <tool> (EPSS) A system that provides electronic task guidance
+ and support to the user at the moment of need. EPSS can
+ provide {application} help, reference information, guided
+ instructions and/or tutorials, subject matter expert advice
+ and hints on how to perform a task more efficiently. An EPSS
+ can combine various technologies to present the desired
+ information. The information can be in the form of text,
+ {graphical displays}, sound, and {video} presentations.
+
+ ["Electronic Performance Support Systems: How and Why to
+ Remake the Workplace Through the Strategic Application of
+ Technology", Gloria Gerry, Weingarten Press].
+
+ (1997-10-24)
+
+Electronic Piece Of Cheese
+
+ {EPOC}
+
+Electronic Report Management
+
+ <storage> (ERM, Enterprise Report Management) The capture,
+ archiving and publishing, in digital form, of (typically
+ {mainframe} generated) documents such as accounting and
+ financial reports. ERM often replaces systems based on paper
+ or {microfilm}.
+
+ ERM usually captures data from {print streams} and stores it
+ on {hard drives}, {storage area networks} or {optical disk}
+ drives. The data is indexed and can be retreived at the
+ desktop with a {web browser} or a {fat client}. ERM systems
+ are part of {enterprise content management} or {electronic
+ document management}.
+
+ An example application is {PearlDoc QuickFile Information
+ Management System (http://pearldoc.com/)} (IMS).
+
+ An early replacement for {greenbar} printed reports was
+ Computer Output on Microfilm (COM, not to be confused with
+ {Microsoft}'s {Component Object Model}). This was superseded
+ by Computer Output to Laser Disk (or Disc - COLD) which used
+ optical media.
+
+ In 1999 the {AIIM} renamed COLD to ERM/COLD to reflect the
+ variety of media in use. This was promoted, in 2002, by Mason
+ Grigsby - widely reputed as "The Father of COLD" for his
+ seminal work with {INSCI} in the late 1980s. Judging from
+ their website, AIIM don't seem too sure whether ERM is
+ "Electronic", "Enterprise" or both.
+
+ (2007-07-25)
+
+Electronics Industry Association
+
+ <body, standard> (EIA) A body which publishes "Recommended
+ Standards" (RS) for physical devices and their means of
+ interfacing. {EIA-232} is their standard that defines a
+ computer's {serial port}, connector pin-outs, and electrical
+ signaling.
+
+ (1995-03-02)
+
+electronic whiteboarding
+
+ {Audiographic Teleconferencing}
+
+electron model
+
+ <electronics> A {model} of {semiconductor} behaviour in which
+ {donors} contribute the {charge} of an {electron}, and
+ {acceptors} contribute a space for same, in effect
+ contributing a fictional positive charge of similiar
+ magnitude. Physicists use the {electron model}. Some
+ language theorists consider language and the {electron} to be
+ {models} in themselves.
+
+ Contrast {hole model}.
+
+ (1995-10-06)
+
+electron tube
+
+ <electronics> (Or tube, vacuum tube, UK: valve, electron
+ valve, thermionic valve, firebottle, glassfet) An electronic
+ component consisting of a space exhausted of gas to such an
+ extent that {electrons} may move about freely, and two or more
+ electrodes with external connections. Nearly all tubes are of
+ the thermionic type where one electrode, called the cathode,
+ is heated, and electrons are emitted from its surface with a
+ small energy (typically a Volt or less). A second electrode,
+ called the anode (plate) will attract the electrons when it is
+ positive with respect to the cathode, allowing current in one
+ direction but not the other.
+
+ In types which are used for amplification of signals,
+ additional electrodes, called grids, beam-forming electrodes,
+ focussing electrodes and so on according to their purpose, are
+ introduced between cathode and plate and modify the flow of
+ electrons by electrostatic attraction or (usually) repulsion.
+ A voltage change on a grid can control a substantially greater
+ change in that between cathode and anode.
+
+ Unlike {semiconductors}, except perhaps for {FETs}, the
+ movement of electrons is simply a function of electrostatic
+ field within the active region of the tube, and as a
+ consequence of the very low mass of the electron, the currents
+ can be changed quickly. Moreover, there is no limit to the
+ current density in the space, and the electrodes which do
+ dissapate power are usually metal and can be cooled with
+ forced air, water, or other refrigerants. Today these
+ features cause tubes to be the active device of choice when
+ the signals to be amplified are a power levels of more than
+ about 500 watts.
+
+ The first electronic digital computers used hundreds of vacuum
+ tubes as their active components which, given the reliability
+ of these devices, meant the computers needed frequent repairs
+ to keep them operating. The chief causes of unreliability are
+ the heater used to heat the cathode and the connector into
+ which the tube was plugged.
+
+ Vacuum tube manufacturers in the US are nearly a thing of the
+ past, with the exception of the special purpose types used in
+ broadcast and image sensing and displays. Eimac, GE, RCA, and
+ the like would probably refer to specific types such as "Beam
+ Power Tetrode" and the like, and rarely use the generic terms.
+
+ The {cathode ray tube} is a special purpose type based on
+ these principles which is used for the visual display in
+ television and computers. X-ray tubes are diodes (two element
+ tubes) used at high voltage; a tungsten anode emits the
+ energetic photons when the energetic electrons hit it.
+ Magnetrons use magnetic fields to constrain the electrons;
+ they provide very simple, high power, ultra-high frequency
+ signals for radar, microwave ovens, and the like. Klystrons
+ amplify signals at high power and microwave frequencies.
+
+ (1996-02-05)
+
+Electrostatic Discharge
+
+ <hardware, testing> (ESD) One kind of test that hardware
+ usually has to pass to prove it is suitable for sale and use.
+ The hardware must still work after is has been subjected to
+ some level of electrostatic discharge. Some organisations
+ have their own ESD requirements which hardware must meet
+ before it will be considered for purchase.
+
+ Different countries have different legal regulations about
+ levels of ESD.
+
+ See also {Radio Frequency Interference}, {Electromagnetic
+ Compatibility}.
+
+ (1997-12-19)
+
+elegant
+
+ (From Mathematics) Combining simplicity, power, and a certain
+ ineffable grace of design. Higher praise than "clever",
+ "winning" or even {cuspy}.
+
+ The French aviator, adventurer, and author Antoine de
+ Saint-Exup'ery, probably best known for his classic children's
+ book "The Little Prince", was also an aircraft designer. He
+ gave us perhaps the best definition of engineering elegance
+ when he said "A designer knows he has achieved perfection not
+ when there is nothing left to add, but when there is nothing
+ left to take away."
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+element
+
+ 1. <data, programming> One of the items of data in an {array}.
+
+ 2. <language, text> One kind of node in an {SGML}, {HTML}, or
+ {XML} {document} {tree}. An SGML element is typically
+ represented by a start {tag} ("<p>") and an end tag ("</p>").
+ In some SGML implementations, some tags are omissible, as with
+ "</p>" in {HTML}.
+
+ The start tag can contain {attributes} ("<p lang="en-UK"
+ class='stuff'>"), which are an unordered set of key-value
+ bindings for that element. Both the start tag and end tag for
+ an element typically contain the "tag name" (also called the
+ "{GI}" or generic identifier) for that element.
+
+ In {XML}, an element is always represented either by an
+ explicit start tag and end tag, or by an empty element tag
+ ("<img src='thing.{png}' alt='a dodad' />").
+
+ Other kinds of SGML node are: a section of character data
+ ("foo"), a comment ("<!-- bar -->"), a markup declaration
+ ("<!ENTITY reg CDATA '&#174'>"), or a processing instruction
+ ("<?xml-stylesheet href="shop-english.xsl" type="text/xsl"
+ ?>").
+
+ (2001-01-30)
+
+elephant
+
+ Large, grey, four-legged mammal.
+
+elephantine
+
+ Used of programs or systems that are both conspicuous {hogs}
+ (owing perhaps to poor design founded on {brute force and
+ ignorance}) and exceedingly {hairy} in source form. An
+ elephantine program may be functional and even friendly, but
+ (as in the old joke about being in bed with an elephant) it's
+ tough to have around all the same (and, like a pachyderm,
+ difficult to maintain). In extreme cases, hackers have been
+ known to make trumpeting sounds or perform expressive
+ proboscatory mime at the mention of the offending program.
+ Usage: semi-humorous. Compare "has the elephant nature" and
+ the somewhat more pejorative monstrosity. See also
+ {second-system effect} and {baroque}.
+
+ [{Jargon File}]
+
+elevator controller
+
+ An archetypal dumb embedded-systems application, like
+ {toaster} (which superseded it). During one period (1983--84)
+ in the deliberations of ANSI X3J11 (the C standardisation
+ committee) this was the canonical example of a really stupid,
+ memory-limited computation environment. "You can't require
+ "printf(3)" to be part of the default run-time library - what
+ if you're targeting an elevator controller?" Elevator
+ controllers became important rhetorical weapons on both sides
+ of several {holy wars}.
+
+ELF
+
+ Binary format used by System V Release 4 Unix.
+
+ELI
+
+ 1. <language> An early system on the {IBM 705} and {IBM 650}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ 2. {Embedded Lisp Interpreter}.
+
+Eli Compiler Construction System
+
+ <tool> A compiler generation package which integrates
+ off-the-shelf tools and libraries with specialised language
+ processors to generate complete compilers quickly and
+ reliably. It simplifies the development of new
+ special-purpose languages, implementation of existing
+ languages on new hardware and extension of the constructs and
+ features of existing languages.
+
+ It runs on {Sun-4} {SunOS} 4, 5, {Ultrix}/{MIPS}, {RS/6000},
+ {HP-UX}, {SGI}, {Linux}.
+
+ Latest version 4.3.1, as of 2000-08-07
+
+ {Colorado U (ftp://ftp.cs.colorado.edu/pub/cs/distribs/eli/)}.
+ {Europe (ftp://ftp.upb.de/unix/eli)}.
+
+ Mailing list: <eli-request@cs.colorado.edu>.
+
+ E-mail: <compiler@uni-paderborn.de>, Developers
+ <elibugs@cs.colorado.edu>, Users <eli@cs.colorado.edu>.
+
+ (2000-08-12)
+
+ELISP
+
+ 1. <language> A {Lisp} variant originally implemented for
+ {DEC-20s} by Chuck Hedrick of Rutgers.
+
+ 2. <language> A common abbreviation for {Emacs Lisp}. Use of
+ this abbreviation is discouraged because "Elisp" is or was a
+ trademark.
+
+ [Still a trademark? Whose?]
+
+ (1995-04-04)
+
+elite
+
+ 1. <security> A term used to describe skilled {crackers} or
+ {hackers}, or their deeds. In the last sense, compare to
+ {elegant}.
+
+ The term is also used to describe exclusive forums ({ftp}
+ sites, {BBSs}) used for trading pirated software, {crack}ing
+ tools, or {phreaking} codes.
+
+ (1997-01-31)
+
+ELIZA
+
+ <artificial intelligence> A famous program by {Joseph
+ Weizenbaum}, which simulated a Rogerian psychoanalyst by
+ rephrasing many of the patient's statements as questions and
+ posing them to the patient. It worked by simple {pattern
+ recognition} and substitution of key words into canned
+ phrases. It was so convincing, however, that there are many
+ anecdotes about people becoming very emotionally caught up in
+ dealing with ELIZA. All this was due to people's tendency to
+ attach to words meanings which the computer never put there.
+
+ See also {ELIZA effect}.
+
+ (1997-09-13)
+
+ELIZA effect
+
+ <jargon> /e-li:'z* *-fekt'/ (From {ELIZA}) The tendency of
+ humans to attach associations to terms from prior experience.
+ For example, there is nothing magic about the symbol "+" that
+ makes it well-suited to indicate addition; it's just that
+ people associate it with addition. Using "+" or "plus" to
+ mean addition in a computer language is taking advantage of
+ the ELIZA effect.
+
+ The ELIZA effect is a {Good Thing} when writing a programming
+ language, but it can blind you to serious shortcomings when
+ analysing an {Artificial Intelligence} system.
+
+ Compare {ad-hockery}; see also {AI-complete}.
+
+ [{Jargon File}]
+
+ (1997-09-13)
+
+Elk
+
+ {Extension Language Kit}
+
+ELLA
+
+ A hardware design language from DRA Malvern. Implemented in
+ {ALGOL68-RS}.
+
+ E-mail: <ella@dra.hmg.gb>. {SPARC version
+ (ftp://src.doc.ic.ac.uk/packages/ELLA)}.
+
+ ["ELLA 2000: A Language for Electronic System Design",
+ J.D. Morison and A.S. Clarke, McGraw-Hill 1993].
+
+Ellemtel
+
+ A {C++} style-guide originated by {Ellemtel Telecom Systems},
+ Stockholm.
+
+Ellie
+
+ <language> An {object-oriented} language with {fine-grained
+ parallelism} for {distributed computing}. Ellie is based on
+ {BETA}, {Smalltalk}, and others. Parallelism is supported by
+ {unbounded RPC} and "{future}" {objects}. Synchronisation is
+ by {dynamic interfaces}. {Classes}, {methods}, {blocks}, and
+ {objects} are all modelled by {first-class} "Ellie objects".
+ It supports {genericity}, {polymorphism}, and
+ {delegation}/{inheritance}.
+
+ {(http://diku.dk/ellie/papers/)}?
+
+ ["Ellie Language Definition Report", Birger Andersen
+ <birger.andersen@acm.org>, SIGPLAN Notices 25(11):45-65, Nov
+ 1990].
+
+ (2000-04-02)
+
+ELLIS
+
+ EuLisp LInda System. An object-oriented Linda system written
+ for EuLisp. "Using Object-Oriented Mechanisms to Describe
+ Linda", P. Broadbery <pab@maths.bath.ac.uk> et al, in
+ Linda-Like Systems and Their Implementation, G. Wilson ed, U
+ Edinburgh TR 91-13, 1991.
+
+elm
+
+ <messaging> A {full-screen} {MUA} for {Unix}, {MS-DOS}, {MS
+ Windows}, and {OS/2}.
+
+ {Usenet} newsgroup: {news:comp.mail.elm}.
+
+ {FAQ
+ (http://cis.ohio-state.edu/hypertext/faq/usenet/elm/FAQ/faq.html)}.
+
+ (1996-03-20)
+
+ELMAGUIDE
+
+ <language> The {metalanguage} used for interpretation of user
+ actions in the {ELMA} compiler writer developed at Tallinn
+ Poly Institute in 1978.
+
+ (1996-03-20)
+
+ELMAMETA
+
+ A Fortran extension, written at the {Tallinn Poly Inst} in
+ 1978, used for lexical, syntactic and semantic sepecification
+ in the {ELMA} {compiler} writer. This system was widely used
+ in the Soviet Union, and produced an {Ada} to {Diana}
+ {compiler}.
+
+ (1994-12-08)
+
+ELP
+
+ 1. English Language Programs. Language for testing avionics
+ equipment, on Varian 620/i.
+
+ "Multiband Automatic test Equipment - A Computer Controlled
+ Checkout System", T. Kuroda et al, Proc SJCC, 38 (1971).
+
+ 2. Equational Logic Programming. A semantically pure, fully
+ {lazy} language by M.J. O'Donnell <odonnell@cs.uchicago.edu>.
+ Latest version: 4.2.
+
+ {Sun and DEC versions
+ (ftp://gargoyle.uchicago.edu/pub/equations/eq4.2.tar.Z)}.
+
+ ["Equational Logic as a Programming Language", M.J. O'Donnell,
+ MIT Press 1985].
+
+ELSIE
+
+ <language> A distributed version of {ELLIS}.
+
+ ["Using Object-Oriented Mechanisms to Describe Linda",
+ P. Broadbery <pab@maths.bath.ac.uk> et al, in "Linda-Like
+ Systems and Their Implementati"on, G. Wilson ed, U Edinburgh
+ TR 91-13, 1991].
+
+ (1995-11-16)
+
+Elvis
+
+ <tool> A {vi} lookalike which supports nearly all of the vi/ex
+ commands, in both visual mode and colon mode.
+
+ Like vi/ex, elvis stores most of the text in a temporary file
+ instead of RAM. This allows it to edit files that are too
+ large to fit in a single process' data space.
+
+ Elvis runs under {BSD} UNIX, AT&T {SysV} UNIX, {MINIX},
+ {MS-DOS}, {Atari TOS}, {Coherent}, {OS9}/68000, {VMS},
+ {Windows 95} and {Windows NT}.
+
+ Elvis is just as awful to use as vi, so someone will like it.
+
+ Version 1.8pl14 (1995-09-04).
+
+ {FTP Delft (ftp://dutepp0.et.tudelft.nl/pub/Unix/Editors/)},
+ {FTP PDX (ftp://ftp.cs.pdx.edu/pub/elvis/)}.
+
+ E-mail: Steve Kirkendall <kirkenda@cs.pdx.edu>.
+
+ (1995-11-16)
+
+elvish
+
+ <character> 1. The Tengwar of Feanor, a table of letterforms
+ resembling the beautiful Celtic half-uncial hand of the "Book
+ of Kells". Invented and described by J.R.R. Tolkien in "The
+ Lord of The Rings" as an orthography for his fictional
+ "elvish" languages, this system (which is both visually and
+ phonetically {elegant}) has long fascinated hackers (who tend
+ to be intrigued by artificial languages in general). It is
+ traditional for graphics printers, plotters, window systems,
+ and the like to support a Feanorian typeface as one of their
+ demo items. By extension, the term might be used for any odd
+ or unreadable typeface produced by a graphics device.
+
+ 2. The typeface mundanely called "B"ocklin", an art-decoish
+ {display font}. [Why?]
+
+ [{Jargon File}]
+
+ (1998-04-28)
+
+EM
+
+ {End of Medium}
+
+EM-1
+
+ <language> A {stack}-oriented intermediate language from
+ {Vrije University Amsterdam}, used by the {Amsterdam Compiler
+ Kit}.
+
+ E-mail: Andrew Tanenbaum <ast@cs.vu.nl>.
+
+ (1996-04-07)
+
+EMA
+
+ Extended Mercury Autocode.
+
+ See {Autocode}.
+
+ (1995-01-24)
+
+Emacs
+
+ <text, tool> /ee'maks/ (Editing MACroS, or Extensible MACro
+ System, GNU Emacs) A popular {screen editor} for {Unix} and
+ most other {operating systems}.
+
+ Emacs is distributed by the {Free Software Foundation} and was
+ {Richard Stallman}'s first step in the {GNU} project. Emacs
+ is extensible - it is easy to add new functions; customisable
+ - you can rebind keys, and modify the behaviour of existing
+ functions; self-documenting - there is extensive on-line,
+ context-sensitive help; and has a real-time "what you see is
+ what you get" display. Emacs is writen in {C} and the higher
+ levels are programmed in {Emacs Lisp}.
+
+ Emacs has an entire {Lisp} system inside it. It was
+ originally written in {TECO} under {ITS} at the {MIT} {AI
+ lab}. AI Memo 554 described it as "an advanced,
+ self-documenting, customisable, extensible real-time display
+ editor".
+
+ It includes facilities to view directories, run compilation
+ subprocesses and send and receive {electronic mail} and
+ {Usenet} {news} ({GNUS}). {W3} is a {web browser}, the
+ ange-ftp package provides transparent access to files on
+ remote {FTP} {servers}. {Calc} is a calculator and {symbolic
+ mathematics} package. There are "modes" provided to assist in
+ editing most well-known programming languages. Most of these
+ extra functions are configured to load automatically on first
+ use, reducing start-up time and memory consumption. Many
+ hackers (including {Denis Howe}) spend more than 80% of their
+ {tube time} inside Emacs.
+
+ GNU Emacs is available for {Unix}, {VMS}, {GNU}/{Linux},
+ {FreeBSD}, {NetBSD}, {OpenBSD}, {MS Windows}, {MS-DOS}, and
+ other systems. Emacs has been re-implemented more than 30
+ times. Other variants include {GOSMACS}, CCA Emacs, UniPress
+ Emacs, Montgomery Emacs, and {XEmacs}. {Jove}, {epsilon}, and
+ {MicroEmacs} are limited look-alikes.
+
+ Some Emacs versions running under {window managers} iconify as
+ an overflowing kitchen sink, perhaps to suggest the one
+ feature the editor does not (yet) include. Indeed, some
+ hackers find Emacs too {heavyweight} and {baroque} for their
+ taste, and expand the name as "Escape Meta Alt Control Shift"
+ to spoof its heavy reliance on keystrokes decorated with
+ {bucky bits}. Other spoof expansions include "Eight Megabytes
+ And Constantly Swapping", "Eventually "malloc()'s All Computer
+ Storage", and "Emacs Makes A Computer Slow" (see {recursive
+ acronym}). See also {vi}.
+
+ Latest version: 20.6, as of 2000-05-11. 21.1 ({RSN}) adds a
+ new redisplay engine with support for {proportional text},
+ images, {toolbars}, {tool tips}, toolkit scroll bars, and a
+ mouse-sensitive mode line.
+
+ {FTP} from your nearest {GNU archive site}.
+
+ E-mail: (bug reports only) <bug-gnu-emacs@gnu.org>.
+
+ {Usenet} newsgroups: {news:gnu.emacs.help},
+ {news:gnu.emacs.bug}, {news:alt.religion.emacs},
+ {news:gnu.emacs.sources}, {news:gnu.emacs.announce}.
+
+ [{Jargon File}]
+
+ (1997-02-04)
+
+Emacs Lisp
+
+ <language> A dialect of {Lisp} used to implement the higher
+ layers of the {Free Software Foundation}'s editor, {GNU}
+ {Emacs}. Sometimes abbreviated to "{elisp}". An enormous
+ number of Emacs Lisp packages have been written including
+ modes for editing many programming languages and interfaces to
+ many {Unix} programs.
+
+e-mail
+
+ {electronic mail}
+
+e-mail address
+
+ {electronic mail address}
+
+e-mail client
+
+ {Mail User Agent}
+
+EMAS
+
+ {Edinburgh Multi Access System}
+
+Embedded Lisp Interpreter
+
+ <language> (ELI) A small {Common Lisp}-like {interpreter}
+ embedded in the {Andrew mail system}, written by Bob
+ Glickstein at {CMU}.
+
+ (2000-04-05)
+
+Embedded Mode
+
+ <programming> A term used by {COCOMO} to describe a project
+ development that is characterised by tight, inflexible
+ constraints and interface requirements. The product must
+ operate within (is embedded in) a strongly coupled complex of
+ hardware, software, regulations and operational procedures.
+ An embedded mode project will require a great deal of
+ innovation. An example would be a {real-time system} with
+ timing constraints and customised hardware.
+
+ (1996-05-29)
+
+embedded system
+
+ <computer> Hardware and software which forms a component of
+ some larger system and which is expected to function without
+ human intervention.
+
+ A typical embedded system consists of a single-board
+ {microcomputer} with software in {ROM}, which starts running
+ some special purpose {application program} as soon as it is
+ turned on and will not stop until it is turned off (if ever).
+
+ An embedded system may include some kind of {operating system}
+ but often it will be simple enough to be written as a single
+ program. It will not usually have any of the normal
+ {peripherals} such as a keyboard, monitor, serial connections,
+ mass storage, etc. or any kind of user interface software
+ unless these are required by the overall system of which it is
+ a part. Often it must provide {real-time} response.
+
+ {Usenet} newsgroup: {news:comp.arch.embedded}.
+
+ (1995-04-12)
+
+embedding
+
+ 1. <mathematics> One instance of some mathematical object
+ contained with in another instance, e.g. a {group} which is a
+ subgroup.
+
+ 2. <theory> ({domain theory}) A {complete partial order} F in
+ [X -> Y] is an embedding if
+
+ (1) For all x1, x2 in X, x1 <= x2 <=> F x1 <= F x2 and
+
+ (2) For all y in Y, {x | F x <= y} is {directed}.
+
+ ("<=" is written in {LaTeX} as {\sqsubseteq}).
+
+ (1995-03-27)
+
+EMBLA Pro
+
+ <messaging, tool> An {IMAP}-compliant {electronic mail}
+ {client} from {WinSoft Products Ltd}. EMBLA Pro allows you to
+ use an IMAP mail server in a true client/server network
+ manner, once you've connected to the IMAP server, you can
+ organise messages into folders on the server and you can view
+ messages and any attached files at the server before deciding
+ whether or not to download them to your local system. IMAP
+ allows the user to select individual message attachments to be
+ viewed and/or downloaded. You can delete files and messages
+ from the server, move or copy them to the local computer or
+ leave them for future retrieval. EMBLA Pro also supports the
+ standard {POP3} protocol. Both POP3 and IMAP2 run over
+ {E-SMTP}.
+
+ The IMAP {Unix} {daemons} can support specific environments,
+ for example, Sun MailTool attachments. All flavours of Unix
+ are catered for with a suite of binary mail daemons, eg:
+ {SunSoft} {Solaris}, {HP}, {IBM} and {SCO}.
+
+ EMBLA conforms to the SMTP, E-SMTP, {MIME} and IMAP {Internet}
+ standards - RFC1590 (RFC1521), RFC1522, RFC1426, RFC1425,
+ RFC1176, RFC0822, RFC0821 and the draft update of RFC1176.
+
+ {(http://ftech.co.uk/~winsoft/embla.htm)}.
+
+ (1996-03-11)
+
+embosser
+
+ {Braille printer}
+
+EMC
+
+ {Electromagnetic Compatibility}
+
+EMD Enterprises, Inc.
+
+ <company> A software development and consulting firm
+ specialising in {database} and {client-server} applications.
+
+ {(http://emdent.com/)}.
+
+ (1994-12-12)
+
+EMDIR
+
+ The CERN {Electronic Mail DIRectory} utility.
+
+ [Details?]
+
+ (1995-02-23)
+
+Emerald
+
+ An {object-oriented} distributed programming language and
+ environment developed at the {University of Washington} in the
+ early 1980s. Emeral was the successor to {EPL}. It is
+ {strongly typed} and uses {signatures} and {prototypes} rather
+ than {inheritance}.
+
+ ["Distribution and Abstract Types in Emerald", A. Black et al,
+ IEEE Trans Soft Eng SE-13(1):65-76 (Jan 1987)].
+
+ (1994-11-09)
+
+EMI
+
+ {External Machine Interface}
+
+Emitter Coupled Logic
+
+ (ECL) (Or "Current Mode Logic") A technology for building
+ logic gates where the emitter of a {transistor} is used as the
+ output rather than its collector. ECL has a propagation time
+ of 0.5 - 2 ns (faster than {TTL}) and a power dissipation 3 -
+ 10 times higher than {TTL}.
+
+ (1994-11-09)
+
+EML
+
+ Extended ML. A language for formally specifying {SML}
+ programs.
+
+ ["Formal Program Development in Extended ML for the Working
+ Programmer", D. Sannella, Proc 3rd BCS/FACS Workshop on
+ Refinement", Springer 1990].
+
+EMM
+
+ <storage> {Expanded Memory Manager}.
+
+ (1996-01-12)
+
+EMM386
+
+ <software, storage> An {expanded memory manager} for {IBM PCs}
+ with an {Intel 80386} or higher processor, part of {MS-DOS}
+ version 5.00 or higher. EMM386 uses {extended memory} to
+ simulate {expanded memory} and also provides {upper memory
+ blocks}. It must be loaded by a DEVICE= command in your
+ {CONFIG.SYS} file.
+
+ (1996-01-13)
+
+emote
+
+ <chat> (emotion) A command used on {talk} systems and {MUDs}
+ to indicate the performance of an action, usually a facial
+ expression of emotional state.
+
+ (1996-11-28)
+
+emoticon
+
+ <messaging> /ee-moh'ti-kon/ (Or "smiley") An {ASCII} {glyph}
+ used to indicate an emotional state in text-only {electronic
+ messaging} systems such as {chat}, {electronic mail}, {SMS} or
+ {news}. Although originally intended mostly as jokes,
+ emoticons are widely recognised if not expected; the lack of
+ verbal and visual cues can otherwise cause non-serious
+ comments to be misinterpreted, resulting in offence, arguments
+ and {flame wars}.
+
+ Hundreds of emoticons have been proposed, but only a few are
+ in common use. These include:
+
+ :-) "smiley face" (for humour, laughter,
+ friendliness, occasionally sarcasm)
+
+ :-( "frowney face" (for sadness, anger, or upset)
+
+ ;-) "half-smiley" (ha ha only serious); also
+ known as "semi-smiley" or "winkey face".
+
+ :-/ "wry face"
+
+ These are more recognisable if you tilt your head to the left.
+ The first two are by far the most frequently encountered.
+ Hyphenless forms of them are also common. The acronym "{lol}"
+ is also often used in the same context for the same effect
+ (and is easier to type).
+
+ The emoticon was invented by one Scott Fahlman on the {CMU}
+ {bboard} systems on 1982-09-19. He later wrote: "I had no
+ idea that I was starting something that would soon pollute all
+ the world's communication channels." {GLS} confirms that he
+ remembers this original posting, which has subsequently been
+ {retrieved from a backup
+ (http://research.microsoft.com/~mbj/Smiley/BBoard_Contents.html)}.
+
+ As with exclamation marks, overuse of the smiley is a mark of
+ loserhood! More than one per paragraph is a fairly sure sign
+ that you've gone over the line.
+
+ [{Jargon File}]
+
+ (2010-05-16)
+
+empeg
+
+ <hardware> An in-car audio product that plays {MP3} files from
+ a {hard disk}. It is based around a {DEC}/{Intel} {StrongARM}
+ {S-1100} processor and runs a version of {Linux}. The {user
+ interface} is written in {Python}.
+
+ {(http://empeg.com/)}.
+
+ See also {MPEG}.
+
+ (1999-09-14)
+
+empire
+
+ <games> Any of a family of military simulations derived from a
+ game written by Peter Langston many years ago. Five or six
+ multi-player variants of varying degrees of sophistication
+ exist, and one single-player version implemented for both
+ {Unix} and {VMS}; the latter is even available as {MS-DOS}
+ {freeware}. All are notoriously addictive.
+
+ [{Jargon File}]
+
+ (1995-08-06)
+
+empty element tag
+
+ {tag}
+
+EMS
+
+ {Expanded Memory Specification}
+
+emTeX
+
+ <language, text, tool> (Eberhard Mattes TeX) Eberhard Mattes
+ <mattes@azu.informatik.uni-stuttgart.de>'s version of the
+ {LaTeX} document preparation system designed for {DOS} and
+ {OS/2}.
+
+ (2001-05-24)
+
+EMU8000
+
+ <multimedia, hardware, music> The "{Advanced WavEffect}" music
+ synthesizer {integrated circuit} used on the {SB AWE32} card.
+
+ The EMU8000 is a sub-system offering high quality music
+ synthesis and an "effect {engine}" which provides musical
+ effects like reverb and chorus to {MIDI} playback. The
+ EMU8000 supports up to 32 voices, and the effect amount for
+ each voice can be controlled via MIDI.
+
+ (1996-12-15)
+
+emulation
+
+ <architecture> When one system performs in exactly the same
+ way as another, though perhaps not at the same speed. A
+ typical example would be emulation of one computer by (a
+ program running on) another. You might use an emulation as a
+ replacement for a system whereas you would use a simulation if
+ you just wanted to analyse it and make predictions about it.
+
+ (2003-05-22)
+
+emulator
+
+ {Hardware} or {software} that performs {emulation}.
+
+ (1995-05-12)
+
+Emulator program
+
+ <networking> (EP) {IBM} software that emulates a 2701/2/3
+ hard-wired {IBM 360} communications controller and resides in
+ a 370x/372x/374x comms controller.
+
+ See also {Partitioned Emulation Program} (PEP).
+
+ (1999-01-29)
+
+EMX
+
+ A programming environment for {OS/2} by Eberhard Mattes
+ <mattes@azu.informatik.uni-stuttgart.de>. EMX supports
+ programming in {C}, {C++} and {Objective C}. It works with
+ {gcc}, {g++}, {gdb}, {libg++}, .obj linkage, {DLL} and
+ {headers}. Version 0.8g.
+
+ {Europe (ftp://ftp.uni-stuttgart.de/soft/os2/emx-0.8g)}. {US
+ (ftp://ftp-os2.cdrom.com/os2/2_x/Unix/gnu/emx0.8g)}.
+
+ Mailing list: <listserv@ludd.luth.se> ("subscribe to
+ emx-list").
+
+ (1992-09-21)
+
+enabling
+
+ {software enabling}
+
+Encapsulated PostScript
+
+ (EPS) An extension of the {PostScript} graphics file format
+ developed by {Adobe Systems}. EPS is used for {PostScript}
+ graphics files that are to be incorporated into other
+ documents. An EPS file includes {pragmas} (special PostScript
+ comments) giving information such as the bounding box, page
+ number and fonts used.
+
+ On some computers, EPS files include a low resolution version
+ of the PostScript image. On the {Macintosh} this is in {PICT}
+ format, while on the {IBM PC} it is in {TIFF} or {Microsoft
+ Windows} {metafile} format.
+
+ [Spec?]
+
+ (1995-01-04)
+
+encapsulation
+
+ 1. The technique used by layered protocols in which a layer
+ adds header information to the protocol data unit (PDU) from
+ the layer above. As an example, in Internet terminology, a
+ packet would contain a header from the physical layer,
+ followed by a header from the network layer (IP), followed by
+ a header from the transport layer (TCP), followed by the
+ application protocol data.
+
+ 2. The ability to provide users with a well-defined interface
+ to a set of functions in a way which hides their internal
+ workings. In {object-oriented programming}, the technique of
+ keeping together data structures and the methods (procedures)
+ which act on them.
+
+ (1998-09-07)
+
+encode
+
+ 1. <algorithm, hardware> To convert {data} or some physical
+ quantity into a given format. E.g. {uuencode}.
+
+ See also {encoder}.
+
+ 2. <cryptography> To encrypt, to perform {encryption}.
+
+ (1999-07-06)
+
+encoder
+
+ 1. <algorithm, hardware> Any program, circuit or {algorithm}
+ which {encodes}.
+
+ Example usages: "{MPEG} encoder", "{NTSC} encoder",
+ "{RealAudio} encoder".
+
+ 2. <hardware> A sensor or transducer for converting rotary
+ motion or position to a series of electronic pulses.
+
+ (1997-03-04)
+
+encryption
+
+ <algorithm, cryptography> Any procedure used in {cryptography}
+ to convert {plaintext} into {ciphertext} (encrypted message)
+ in order to prevent any but the intended recipient from
+ reading that data.
+
+ Schematically, there are two classes of encryption primitives:
+ {public-key cryptography} and {private-key cryptography}; they
+ are generally used complementarily.
+ Public-key encryption algorithms include {RSA};
+ private-key algorithms include the obsolescent {Data Encryption
+ Standard}, the {Advanced Encryption Standard}, as well as
+ {RC4}.
+
+ The {Unix} command {crypt} performs a weak form of encryption.
+ Stronger encryption programs include {Pretty Good Privacy} and
+ the {GNU Privacy Guard}.
+
+ Other closely related aspects of {cryptograph} include
+ {message digests}.
+
+ (2003-04-12)
+
+endian
+
+ <data, architecture> Suffix used in the terms {big-endian} and
+ {little-endian} that describe the ordering of {bytes} in a
+ multi-byte number.
+
+ The term comes from Swift's "Gulliver's Travels" via the
+ famous paper "On Holy Wars and a Plea for Peace" by Danny
+ Cohen, USC/ISI IEN 137, 1980-04-01.
+
+ The Lilliputians, being very small, had correspondingly small
+ political problems. The Big-Endian and Little-Endian parties
+ debated over whether soft-boiled eggs should be opened at the
+ big end or the little end.
+
+ See also {middle-endian}, {holy wars}, {NUXI problem}, {swab}.
+
+ (2007-08-14)
+
+endless loop
+
+ {infinite loop}
+
+End Of Line
+
+ <character> (EOL) Synonym for {newline}, derived perhaps from
+ the original {CDC 6600} {Pascal}. The abbreviation "EOL" is
+ now rare, but widely recognised and occasionally used for
+ brevity. Used in the example entry under {BNF}.
+
+ Out of context this would probably be (deliberately) ambiguous
+ because different systems used different (combinations of)
+ characters to mark the end of a line. {Unix} uses a {line
+ feed}; DOS uses {carriage return}, line feed ({CRLF}) and the
+ {Macintosh} uses carriage return.
+
+ See also {EOF}.
+
+ (2002-03-22)
+
+End of Medium
+
+ <character> (EM) {ASCII} character 25.
+
+ (1996-06-28)
+
+End Of Text
+
+ {control-C}
+
+End Of Transmission
+
+ <character> (EOT) The {mnemonic} for {ASCII} character 4.
+
+end tag
+
+ {tag}
+
+end-to-end solution
+
+ <jargon> (E2ES) A term that suggests that the supplier of an
+ {application program} or system will provide all the hardware
+ and/or software components and resouces to meet the customer's
+ requirement and no other supplier need be involved.
+
+ Compare: {turn-key} solution.
+
+ (2006-03-30)
+
+End Transmission Block
+
+ <character> (ETB) The {mnemonic} for {ASCII} character 23.
+
+ (1996-06-28)
+
+end-user
+
+ <job> The person who uses a computer application, as opposed
+ to those who developed or support it. The end-user may or may
+ not know anything about computers, how they work, or what to
+ do if something goes wrong. End-users do not usually have
+ administrative responsibilities or privileges.
+
+ End users are certain to have a different set of assumptions
+ than the developers who created the application.
+
+ (1997-03-29)
+
+engage
+
+ <spelling> Do you mean {Nokia N-Gage}?
+
+ (2005-01-18)
+
+Engelbart, Douglas
+
+ {Douglas Engelbart}
+
+engine
+
+ <jargon> 1. A piece of {hardware} that encapsulates some
+ function but can't be used without some kind of {front end}.
+ Today we have, especially, "{print engine}": the guts of a
+ {laser printer}.
+
+ 2. An analogous piece of software; notionally, one that does a
+ lot of noisy {crunching}, such as a "database engine", or
+ "{search engine}".
+
+ The hackish senses of "engine" are actually close to its
+ original, pre-Industrial-Revolution sense of a skill, clever
+ device, or instrument (the word is cognate to "ingenuity").
+ This sense had not been completely eclipsed by the modern
+ connotation of power-transducing machinery in {Charles
+ Babbage}'s time, which explains why he named the
+ stored-program computer that he designed in 1844 the
+ "{Analytical Engine}".
+
+ [{Jargon File}]
+
+ (1996-05-31)
+
+English
+
+ <database> The official name of the {database} language used by
+ the {Pick} {operating system}, actually a sort of {crufty},
+ brain-damaged {SQL} with delusions of grandeur. The name permits
+ {marketroids} to say "Yes, and you can program our computers in
+ English!" to ignorant {suits} without quite running afoul of the
+ truth-in-advertising laws.
+
+ ["Exploring the Pick Operating System", J.E. Sisk et al,
+ Hayden 1986].
+
+ [{Jargon File}]
+
+ (2014-06-27)
+
+English shellcode
+
+ <security> A kind of {malware} that is embedded in ordinary
+ English sentences. English shellcode attempts to avoid
+ detection by {antivirus software} by making the code resemble,
+ e.g. {e-mail} text or {Wikipedia} entries. It was first
+ revealed by researchers at {Johns Hopkins}.
+
+ (2010-03-02)
+
+Enhanced Capabilities Port
+
+ <hardware> (ECP) The most common {parallel printer interface}
+ on current (1997) {IBM PC} compatibles.
+
+ Enhanced Capabilities Port is defined in standard IEEE 1284.
+ It is bi-directional and faster than earlier parallel ports.
+
+ Not to be confused with {Extended Capabilities Port}.
+
+ (1997-12-01)
+
+Enhanced Directory Service
+
+ <operating system> (EDS) A common, distributed, integrated,
+ {directory service} with centralized and/or replicated
+ administration.
+
+ [Reference?]
+
+ (2003-06-18)
+
+Enhanced Dynamic Random Access Memory
+
+ (EDRAM)
+ {(http://ruralnet.net/~prairie)}.
+
+ [Summary?]
+
+ (1995-11-23)
+
+Enhanced Graphics Adapter
+
+ <graphics, hardware> (EGA) An {IBM PC} {display standard} with
+ a {resolution} of 640 x 350 {pixels} of 16 colours.
+
+ (1995-06-28)
+
+Enhanced IDE
+
+ {Advanced Technology Attachment Interface with Extensions}
+
+Enhanced Integrated Drive Electronics
+
+ {Advanced Technology Attachment Interface with Extensions}
+
+enhanced parallel port
+
+ <hardware> (EPP) A {parallel port} that confirms to the
+ {IEEE}'s EPP {standard}. An EPP is actually an expansion bus
+ that can handle 64 {disk drives} and other {peripherals}.
+
+ ["PC Magazine", 1996-01-09, p. 262].
+
+ [Details? Manufacturers?]
+
+ (1996-04-07)
+
+Enhanced Small Disk Interface
+
+ <storage, hardware> (ESDI) An obsolete {hard disk}
+ {controller} {standard}, first introduced by {Maxtor} in 1983,
+ and intended to be the successor to the original
+ {ST-506}/{ST-412}. ESDI was faster and more reliable, but
+ still could not compete with {IDE} and {SCSI}.
+
+ EDSI used two cables: a 20-pin data cable to each drive and a
+ single 34-pin control cable {daisy chain} with the controller
+ at one end and a terminator at the other. In PCs, it
+ supported up to two drives at 1-2MB/s with drives up to 2GB.
+
+ {PC Guide
+ (http://pcguide.com/ref/hdd/if/obsoESDI-c.html)}.
+
+ (2003-08-01)
+
+enhancement
+
+ 1. A change to a product which is intended to make it better
+ in some way, e.g. new functions, faster, or occasionally more
+ compatible with other systems. Enhancements to {hardware}
+ components, especially {integrated circuits} often mean they
+ are smaller and less demanding of resources. Sadly, this is
+ almost never true of {software} enhancements.
+
+ 2. {Marketroid}-speak for a {bug fix}. This abuse of language
+ is a popular and time-tested way to turn incompetence into
+ increased revenue. A hacker being ironic would instead call
+ the fix a {feature}, or perhaps save some effort by declaring
+ "{That's not a bug, that's a feature!}".
+
+ [{Jargon File}]
+
+ (1998-04-04)
+
+ENIAC
+
+ {Electronic Numerical Integrator and Computer}
+
+Enigma
+
+ <hardware, cryptography> The electro-mechanical {cipher}
+ engine used by the Germans in World War II to encrypt and
+ decrypt field orders. Many of their messages were deciphered
+ at {Bletchley Park}, by {Alan Turing} and others.
+
+ See also: {Tunny Emulator}.
+
+ (2012-03-25)
+
+ENOB
+
+ {effective number of bits}
+
+ENQ
+
+ 1. <character> /enkw/ or /enk/ ENQuire. The {mnemonic} for
+ {ASCII} character 5.
+
+ 2. <chat> An on-line convention for querying someone's
+ availability. After opening a {chat} connection to someone
+ apparently in heavy hack mode, one might type "SYN SYN ENQ?"
+ (the SYNs representing notional synchronisation bytes), and
+ expect a return of {ACK} or {NAK} depending on whether or not
+ the person felt interruptible.
+
+ Compare {ping}, {finger}.
+
+ [{Jargon File}]
+
+ (1998-01-18)
+
+enqueue
+
+ {queue}
+
+ENS
+
+ <body> See {Ecole Normale Superieure}
+
+Ente Nazionale Italiano di Unificazione
+
+ (UNI) The Italian national standards body, a member of {ISO}.
+
+enterprise
+
+ <body> A business, generally a large one.
+
+ (1994-11-22)
+
+Enterprise Application Integration
+
+ <software> (EAI) The use of {middleware} to integrate the
+ {application programs}, {databases}, and {legacy systems}
+ involved in an organisation's critical business processes.
+
+ [Example?]
+
+ (1999-09-28)
+
+Enterprise JavaBeans
+
+ <specification, business, programming> (EJB) A {server}-side
+ {component architecture} for writing reusable {business logic}
+ and {portable} {enterprise} applications. EJB is the basis of
+ {Sun}'s {Java 2 Platform, Enterprise Edition} (J2EE).
+
+ Enterprise JavaBean components are written entirely in {Java}
+ and run on any EJB compliant server. They are {operating
+ system}, {platform}, and {middleware} independent, preventing
+ vendor {lock-in}.
+
+ EJB servers provide system-level services (the "plumbing")
+ such as {transactions}, security, {threading}, and
+ {persistence}.
+
+ The EJB architecture is inherently transactional,
+ {distributed}, {multi-tier}, {scalable}, secure, and {wire
+ protocol} neutral - any {protocol} can be used: {IIOP},
+ {JRMP}, {HTTP}, {DCOM} etc. EJB 1.1 requires {RMI} for
+ communication with components. EJB 2.0 is expected to require
+ support for RMI/IIOP.
+
+ EJB applications can serve assorted clients: {browsers}, Java,
+ {ActiveX}, {CORBA} etc. EJB can be used to wrap {legacy
+ systems}.
+
+ EJB 1.1 was released in December 1999. EJB 2.0 is in
+ development.
+
+ Sun claims broad industry adoption. 30 vendors are shipping
+ server products implementing EJB. Supporting vendors include
+ {IBM}, {Fujitsu}, {Sybase}, {Borland}, {Oracle}, and
+ {Symantec}.
+
+ An alternative is Microsoft's MTS ({Microsoft Transaction
+ Server}).
+
+ {(http://java.sun.com/products/ejb/)}.
+
+ {FAQ (http://java.sun.com/products/ejb/faq.html)}.
+
+ (2000-04-20)
+
+Enterprise Report Management
+
+ {Electronic Report Management}
+
+Enterprise Resource Planning
+
+ <application, business> (ERP) Any {software} system designed
+ to support and automate the business processes of medium and
+ large businesses. This may include manufacturing,
+ distribution, personnel, project management, payroll, and
+ financials.
+
+ ERP systems are accounting-oriented information systems for
+ identifying and planning the {enterprise}-wide resources
+ needed to take, make, distribute, and account for customer
+ orders. ERP systems were originally extensions of {MRP II}
+ systems, but have since widened their scope. An ERP system
+ also differs from the typical MRP II system in technical
+ requirements such as {relational database}, use of {object
+ oriented programming} language, {computer aided software
+ engineering} tools in development, {client/server}
+ {architecture}, and {open system} {portability}.
+
+ {JBOPS} are the major producers of ERP software.
+
+ {"ERP Systems - Using IT to gain a competitive advantage",
+ Shankarnarayanan S.
+ (http://expressindia.com/newads/bsl/advant.htm)}.
+
+ (1999-07-27)
+
+Enterprise Systems CONnectivity
+
+ <networking> (ESCON) {Optical fibre} connections between a
+ {mainframe} and its {peripherals}. Also an {IBM} registered
+ trademark.
+
+ (1997-03-31)
+
+EntireX
+
+ <operating system> The German company {Software AG}'s
+ implementation of {DCOM} under {Unix} and on {IBM}
+ {mainframes}, released at the end of 1997. EntireX enables
+ users to exchange their {DCOM} components between {Windows
+ 95}, {Windows NT}, {Unix} and {OS/390} and to build
+ {application programs} with components running on any of those
+ {platforms}.
+
+ {Home
+ (http://softwareag.com/corporat/solutions/entirex/entirex.htm)}.
+
+ (1999-02-05)
+
+entity
+
+ <database> In an {entity-relationship model}, an entity is a
+ type of thing being modeled such as "person" or "product".
+ Different entities have different sets of attributes such as
+ "name" or "price" and are connected via relationships like
+ "bought". Entities are closely related to {classes (class)}.
+
+ (2009-11-22)
+
+entity-relationship diagram
+
+ {entity-relationship model}
+
+entity-relationship model
+
+ <database, specification> An approach to {data modelling}
+ proposed by P. Chen in 1976. The model says that you divide
+ your database in two logical parts, entities (e.g. "customer",
+ "product") and relations ("buys", "pays for").
+
+ One of the first activities in specifying an application is
+ defining the entities involved and their relationships,
+ e.g. using an entity-relationship diagram to represent a
+ model.
+
+ ["The entity-relationship model: toward a unified view of
+ data", P.P. Chen, ACM Transactions on Database Systems 1:1 pp
+ 9-36, 1976].
+
+ (2009-11-21)
+
+entropy
+
+ <theory> A measure of the disorder of a system. Systems tend
+ to go from a state of order (low entropy) to a state of
+ maximum disorder (high entropy).
+
+ The entropy of a system is related to the amount of
+ {information} it contains. A highly ordered system can be
+ described using fewer {bits} of information than a disordered
+ one. For example, a string containing one million "0"s can be
+ described using {run-length encoding} as [("0", 1000000)]
+ whereas a string of random symbols (e.g. bits, or characters)
+ will be much harder, if not impossible, to compress in this
+ way.
+
+ {Shannon}'s formula gives the entropy H(M) of a message M in
+ bits:
+
+ H(M) = -log2 p(M)
+
+ Where p(M) is the probability of message M.
+
+ (1998-11-23)
+
+Entry Sequenced Data Set
+
+ <database> (ESDS) An {IBM} straight sequential flat file (like
+ {QSAM}) but externally managed via {IDCAMS}. ESDS is used in
+ {VSAM}.
+
+ (1999-01-11)
+
+enumerated type
+
+ <programming> (Or "enumeration") A {type} which includes in
+ its definition an exhaustive list of possible values for
+ variables of that type. Common examples include {Boolean},
+ which takes values from the list [true, false], and
+ day-of-week which takes values [Sunday, Monday, Tuesday,
+ Wednesday, Thursday, Friday, Saturday]. Enumerated types are
+ a feature of {strongly typed languages}, including {C} and
+ {Ada}.
+
+ Characters, (fixed-size) integers and even {floating-point}
+ types could be (but are not usually) considered to be (large)
+ enumerated types.
+
+ (1996-11-28)
+
+enumeration
+
+ 1. <mathematics> A {bijection} with the {natural numbers}; a
+ {counted set}.
+
+ Compare {well-ordered}.
+
+ 2. <programming> {enumerated type}.
+
+ (1996-11-28)
+
+environment
+
+ {environment variable}
+
+Environmental Audio eXtensions
+
+ <audio> (EAX) Something from {Creative Labs} for generating
+ sound effects.
+
+ EAX is a competitor to {Aureal}'s {A3D}.
+
+ [Hardware or software?]
+
+ (2008-02-17)
+
+environment variable
+
+ <programming, operating system> A {variable} that is bound in
+ the current environment. When evaluating an expression in
+ some environment, the evaluation of a variable consists of
+ looking up its name in the environment and substituting its
+ value.
+
+ Most programming languages have some concept of an environment
+ but in {Unix} {shell scripts} it has a specific meaning
+ slightly different from other contexts. In shell scripts,
+ environment variables are one kind of {shell variable}. They
+ differ from {local variables} and {command line arguments} in
+ that they are inheritted by a {child process}. Examples are
+ the PATH variable that tells the shell the {file system}
+ {paths} to search to find command {executables} and the TZ
+ variable which contains the local time zone. The variable
+ called "SHELL" specifies the type of shell being used.
+
+ These variables are used by commands or {shell scripts} to
+ discover things about the environment they are operating in.
+ Environment variables can be changed or created by the {user}
+ or a program.
+
+ To see a list of environment variables type "setenv" at the
+ {csh} or {tcsh} {prompt} or "set" at the {sh}, {bash}, {jsh}
+ or {ksh} prompt.
+
+ In other programming languages, e.g. {functional programming}
+ languages, the environment is extended with new bindings when
+ a {function}'s {parameters} are bound to its {actual
+ arguments} or when new variables are declared. In a
+ {block-structured} {procedural} language, the environment
+ usually consists of a {linked list} of {activation records}.
+
+ (1999-01-26)
+
+Envoy
+
+ {Motorola}'s integrated personal wireless communicator. Envoy
+ is a {personal digital assistant} which incorporates two-way
+ wireless and wireline communication. It was announced on 7
+ March 1994 and released in the third quarter of 1994. It runs
+ {Genral Magic}'s {Magic Cap} {operating system} and
+ Telescript(TM) communications language on Motorola's {Dragon}
+ chip set. This includes the highly integrated {Motorola
+ 68349} processor and a special purpose {application specific
+ integrated circuit} (ASIC) referred to as Astro. This chip
+ set was designed specifically for {Magic Cap} and
+ {Telescript}.
+
+ A user can write on the Envoy communicator with the
+ accompanying stylus or a finger, to type and select or move
+ objects on its screen. An on-screen keyboard can be used to
+ input information, draw or write personal notations, or send
+ handwritten messages and faxes.
+
+ Envoy can send a wireless message to another Envoy, {PC} or
+ fax; broadcast a message to a group, with each member of that
+ group receiving the message in their preferred format; gather
+ information based on your requirements; schedule a meeting and
+ automatically invite attendees; screen, route and organise
+ messages; send a business card to another Envoy across a
+ conference room table; access real-time scheduling and pricing
+ information for US airline flights, then order tickets via fax
+ or {electronic mail}; keep track of contacts through an
+ address book; receive daily news summaries and stock
+ information; capture, organize and review business and
+ personal expenses on-the-go; gather, edit and analyze
+ information in spreadsheets and graphs compatible with {Lotus
+ 1-2-3} and {Excel}; shop in an electronic mall.
+
+ {(http://motorola.com/MIMS/WDG/Technology/Envoy/)}.
+
+ [Was it released in Q3 '94?]
+
+ (1995-01-18)
+
+EOF
+
+ End Of File
+
+ 1. The {out-of-band} value returned by {C}'s sequential
+ character-input functions (and their equivalents in other
+ environments) when end of file has been reached. This value
+ is -1 under {C} libraries postdating V6 Unix, but was
+ originally 0.
+
+ 2. The keyboard character (usually control-D, the ASCII EOT
+ (End Of Transmission) character) that is mapped by the {Unix}
+ terminal driver into an end-of-file condition.
+
+ [{Jargon File}]
+
+ (1995-01-18)
+
+EOL
+
+ 1. {End Of Line}.
+
+ 2. Expression Oriented Language. A low-level language for
+ strings. Versions: EOL-1, EOL-2, EOL-3. ["EOL - A Symbol
+ Manipulation Language", L. Lukaszewicz, Computer J 10(1):53
+ (May 1967)].
+
+ [{Jargon File}]
+
+EOR
+
+ {exclusive or}
+
+EOT
+
+ 1. <character> {End Of Transmission}
+
+ 2. <storage> End Of Tape. A marker used on {magnetic tapes}.
+
+ (1996-06-24)
+
+EOU
+
+ <character, humour> The mnemonic of a mythical {ASCII} control
+ character (End Of User) that would make an {ASR-33} {Teletype}
+ explode on receipt. This construction parodies the numerous
+ obscure {delimiter} and control characters left in ASCII from
+ the days when it was associated more with wire-service
+ teletypes than computers (e.g. {FS}, {GS}, {RS}, {US}, {EM},
+ {SUB}, {ETX}, and especially {EOT}). It is worth remembering
+ that ASR-33s were big, noisy mechanical beasts with a lot of
+ clattering parts; the notion that one might explode was
+ nowhere near as ridiculous as it might seem to someone sitting
+ in front of a {tube} or flatscreen today.
+
+ [{Jargon File}]
+
+ (1996-06-29)
+
+EOUG
+
+ European {ORACLE} Users Group.
+
+EP
+
+ {Emulator program}
+
+EPCS
+
+ {Experimental Physics Control Systems}
+
+ephemeral port
+
+ <networking> A {TCP} or {UDP} {port} number that is
+ automatically allocated from a predefined range by the {TCP/IP
+ stack} software, typically to provide the port for the client
+ end of a {client-server} communication.
+
+ {BSD} used ports 1024 through 4999 as ephemeral ports, though
+ it is often desirable to increase this allocation.
+
+ {(http://ncftpd.com/ncftpd/doc/misc/ephemeral_ports.html)}.
+
+ (2002-10-06)
+
+EPILOG
+
+ 1. Extended Programming In LOGic. {PROLOG} with several AND's
+ having different time constraints.
+
+ ["Epilog: A Language for Extended Programming in Logic",
+ A. Porto in Implementations of Prolog, J.A. Campbell ed, Ellis
+ Horwood 1984].
+
+ 2. A {data-driven} {PROLOG}, with both {AND parallelism} and
+ {OR parallelism}. ["EPILOG = PROLOG + Data Flow", M.J. Wise,
+ SIGPLAN Noices 17:80-86 (1982)].
+
+EPIM
+
+ {Enterprise Product Information Management}
+
+EPL
+
+ 1. {Early PL/I}.
+
+ 2. {Experimental Programming Language}.
+
+ 3. {Eden Programming Language}.
+
+ 4. {Equational Programming Language}
+
+ 5. {Ethernet Private Line}
+
+EPOC
+
+ <operating system> A family of graphical {operating systems}
+ developed by {Psion} for portable devices, primarily {PDA}s.
+ The name EPOC came from epoch, the beginning of an era, but was
+ backfitted by the engineers to "Electronic Piece Of Cheese".
+ The first version, later known as EPOC16, was developed in the
+ late 1980s and early 1990s for Psion's "{SIBO}" (SIxteen Bit
+ Organisers) devices. All EPOC16 devices feature an
+ {8086}-family processor and a 16-bit architecture. EPOC16 is
+ a single-user {pre-emptive multitasking} operating system,
+ written in Intel 8086 {assembler language} and {C} and
+ designed to be delivered in {ROM}. It supported a simple
+ programming language called {OPL} and an {IDE} called {OVAL}.
+
+ EPOC16 was followed by {EPOC32} in 1997.
+
+ (2009-05-26)
+
+epoch
+
+ 1. <operating system> (Probably from astronomical timekeeping)
+ A term used originally in {Unix} documentation for the time
+ and date corresponding to zero in an {operating system}'s
+ {clock} and {timestamp} values.
+
+ Under most Unix versions the epoch is 1970-01-01 00:00:00 GMT;
+ under {VMS}, it's 1858-11-17 00:00:00 (the base date of the US
+ Naval Observatory's ephemerides); on a {Macintosh}, it's
+ 1904-01-01 00:00:00.
+
+ System time is measured in seconds or {ticks} past the epoch.
+ Weird problems may ensue when the clock wraps around (see
+ {wrap around}), which is not necessarily a rare event; on
+ systems counting 10 ticks per second, a signed 32-bit count of
+ ticks is good only for 0.1 * 2**31-1 seconds, or 6.8 years.
+ The one-tick-per-second clock of Unix is good only until
+ 2038-01-18, assuming at least some software continues to
+ consider it signed and that word lengths don't increase by
+ then. See also {wall time}.
+
+ 2. <editor> (Epoch) A version of {GNU Emacs} for the {X Window
+ System} from {NCSA}.
+
+ [{Jargon File}]
+
+ (2004-06-10)
+
+EPP
+
+ {Enhanced Parallel Port}
+
+EPROM
+
+ {Erasable Programmable Read-Only Memory}
+
+EPROM OTP
+
+ {Erasable Programmable Read-Only Memory One Time Programmable}
+
+EPROS
+
+ A specification/prototyping language. Implemented in {Franz
+ Lisp}.
+
+ {(ftp://utsun.s.u-tokyo.jp/lang/epros)}.
+
+ ["Software Prototyping, Formal Methods and VDM", Sharam
+ Hekmatpour et al, A-W 1988].
+
+EPS
+
+ {Encapsulated PostScript}
+
+EPSILON
+
+ <language> A {macro} language with high level features
+ including strings and lists, developed by A.P. Ershov at
+ Novosibirsk in 1967. EPSILON was used to implement {ALGOL 68}
+ on the {M-220}.
+
+ ["Application of the Machine-Oriented Language Epsilon to
+ Software Development", I.V. Pottosin et al, in Machine
+ Oriented Higher Level Languages, W. van der Poel, N-H 1974,
+ pp. 417-434].
+
+ [{Jargon File}]
+
+ (1995-05-10)
+
+epsilon
+
+ 1. <character> The fifth letter of the Greek alphabet.
+
+ 2. <mathematics> (From the Hungarian mathematician {Paul
+ Erdos}) A very small, insignificant, or negligible quantity of
+ something.
+
+ The use of epsilon is from the {epsilon-delta method} of
+ {proof} in {differential calculus}.
+
+ (2001-07-06)
+
+epsilon squared
+
+ <jargon> A quantity even smaller than {epsilon}, as small in
+ comparison to epsilon as epsilon is to something normal;
+ completely negligible. If you buy a supercomputer for a
+ million dollars, the cost of the thousand-dollar terminal to
+ go with it is {epsilon}, and the cost of the ten-dollar cable
+ to connect them is epsilon squared.
+
+ Compare {lost in the underflow}, {lost in the noise}.
+
+ (1997-09-05)
+
+EPSIMONE
+
+ Concurrent simulation language derived from Simone. "EPSIMONE
+ Manual", J. Beziin et al, Pub Int No 90, IRISA, Sept 1978.
+
+EPSS
+
+ {Electronic Performance Support System}
+
+EqL
+
+ An equational language. Bharat Jayaraman
+ <bharat@cs.buffalo.edu>. "EqL: The Language and its
+ Implementation", B. Jayaraman et al, IEEE Trans Soft Eng
+ SE-15(6):771-780 (June 1989).
+
+EQLOG
+
+ Equality, types and generic modules for logic programming.
+ A language using Horn clauses. J.A. Goguen, J. Meseguer.
+
+EQLog
+
+ OBJ2 plus logic programming based on Horn logic with equality.
+
+ "EQLog: Equality, Types and Generic Modules for Logic
+ Programming", J. Goguen et al in Functional and Logic
+ Programming, D. DeGroot et al eds, pp.295-363, P-H 1986.
+
+Eqn
+
+ Language for typesetting mathematics.
+
+ "A System for Typesetting Mathematics", B.W. Kernighan and
+ L.L. Cherry, CACM 18(3):151-157 (Mar 1975).
+
+equals
+
+ <character> "=", {ASCII} character 61.
+
+ Common names: {ITU-T}: equals; gets; takes. Rare:
+ quadrathorpe; {INTERCAL}: half-mesh.
+
+ Equals is used in many languages as the {assignment} operator
+ though earlier languages used ":=" ("becomes equal to") to
+ avoid upsetting mathematicians with statements such as "x =
+ x+1". It is also used in compounds such as "<=", ">=", "==",
+ "/=", "!=" for various comparison operators and in {C}'s "+=",
+ "*=" etc. which mimic the {primitive} operations of
+ {two-address code}.
+
+ (1995-03-29)
+
+equational logic
+
+ <logic> First-order equational logic consists of
+ {quantifier}-free terms of ordinary {first-order logic}, with
+ equality as the only {predicate} symbol. The {model theory}
+ of this logic was developed into {Universal algebra} by
+ Birkhoff et al. [Birkhoff, Gratzer, Cohn]. It was later made
+ into a branch of {category theory} by Lawvere ("algebraic
+ theories").
+
+ (1995-02-21)
+
+Equational Programming Language
+
+ <language> (EPL) An {equational language} for {parallel}
+ scientific applications, developed by RPI. Szymanski.
+
+ ["EPL - Parallel Programming with Recurrent Equations",
+ B. Szymanski in Parallel Functional Languages and Compilers,
+ B. Szymanski et al, A-W 1991].
+
+ (2010-09-21)
+
+Equel
+
+ Embedded Quel. {INGRES, Inc.} Combines QUEL theories with C
+ code.
+
+equivalence class
+
+ <mathematics> An equivalence class is a subset whose elements
+ are related to each other by an {equivalence relation}. The
+ equivalence classes of a set under some relation form a
+ {partition} of that set (i.e. any two are either equal or
+ {disjoint} and every element of the set is in some class).
+
+ (1996-05-13)
+
+equivalence class partitioning
+
+ <testing> A software testing technique that involves
+ identifying a small set of representative input values that
+ invoke as many different input conditions as possible.
+
+ For example, for {binary search} the following partitions
+ exist: inputs that do or do not conform to pre-conditions,
+ Inputs where the key element is or is not a member of the
+ array. One can combine these into finer partitions. One can
+ also pick specific conditions of the array, e.g. a single
+ value, even or odd number of elements. One should look at
+ {boundary conditions}, e.g. inputs where the key element is
+ the first or last element in the array.
+
+ (2004-01-18)
+
+equivalence partitioning
+
+ {equivalence class partitioning}
+
+equivalence relation
+
+ <mathematics> A relation R on a set including elements a, b,
+ c, which is reflexive (a R a), symmetric (a R b => b R a) and
+ transitive (a R b R c => a R c). An equivalence relation
+ defines an {equivalence} class.
+
+ See also {partial equivalence relation}.
+
+ (1996-05-13)
+
+equivalent isotropically radiated power
+
+ <communications> (EIRP) The power radiated by a radio antenna
+ calculated as the power output of the {intentional radiator}
+ multiplied by the gain of the antenna (due to its shape).
+
+ Limits are defined by the {FCC} and other national regulators.
+
+ (2008-02-11)
+
+ER
+
+ {Entity-Relationship}
+
+er
+
+ <networking> The {country code} for Eritrea.
+
+ (1999-01-27)
+
+ERA
+
+ {Entity-Relationship-Attribute}
+
+era
+
+ Synonym {epoch}. Webster's Unabridged makes these words
+ almost synonymous, but "era" usually connotes a span of time
+ rather than a point in time.
+
+Erasable Programmable Read-Only Memory
+
+ <storage> (EPROM) A type of storage device in which the data
+ is determined by electrical charge stored in an isolated
+ ("floating") {MOS} {transistor} {gate}. The isolation is good
+ enough to retain the charge almost indefinitely (more than ten
+ years) without an external power supply. The EPROM is
+ programmed by "injecting" charge into the floating gate, using
+ a technique based on the tunnel effect. This requires higher
+ voltage than in normal operation (usually 12V - 25V). The
+ floating gate can be discharged by applying ultraviolet light
+ to the chip's surface through a quartz window in the package,
+ erasing the memory contents and allowing the chip to be
+ reprogrammed.
+
+ (1995-04-22)
+
+erase
+
+ {delete}
+
+eraser stains code
+
+ <humour, programming> {Code} that has been {refactored} many
+ times, leaving swaths of {legacy code} and design; like paper that
+ has been written on and erased so many times that the pencil marks
+ are no longer the problem - the large greasy stain is.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2014-07-22)
+
+ERC
+
+ <database> An extended {entity-relationship model}.
+
+ [Details? What does it stand for?]
+
+ (1997-12-23)
+
+ERCIM
+
+ European Research Consortium on Informatics and Mathematics.
+ An association of European research organisations promoting
+ cooperative research on key issues in {Information
+ Technology}.
+
+ (2000-12-30)
+
+ERD
+
+ {entity-relationship diagram}
+
+EREW PRAM
+
+ exclusive read, exclusive write {PRAM}.
+
+ERFPI
+
+ An early system on the {LGP-30} computer.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1994-12-08)
+
+ergonomic
+
+ Concerning {ergonomics} or exhibitting good ergonimics.
+
+ (1995-04-14)
+
+ergonomics
+
+ The study of the design and arrangement of equipment so that
+ people will interact with the equipment in healthy,
+ comfortable, and efficient manner. As related to computer
+ equipment, ergonomics is concerned with such factors as the
+ physical design of the keyboard, screens, and related
+ hardware, and the manner in which people interact with these
+ hardware devices.
+
+ (1995-04-14)
+
+ERGO-Shell
+
+ <operating system, tool> An ergonomic {X Window System} {Unix}
+ {shell} for software engineers by Regine Freitag
+ <freitag@gmd.de>. ERGO-Shell is now obsolete.
+
+ Version: 2.1.
+
+ {(ftp://ftp.gmd.de/gmd/ergo/)}.
+
+ E-mail: Dr. Wolfgang Dzida, GMD <dzida@gmd.de> or the author.
+
+ (2000-12-19)
+
+Eric Conspiracy
+
+ <person, humour> A shadowy group of moustachioed hackers named
+ Eric first pinpointed as a sinister conspiracy by an infamous
+ talk.bizarre posting ca. 1986. This was doubtless influenced
+ by the numerous "Eric" jokes in the Monty Python oeuvre.
+ There do indeed seem to be considerably more moustachioed
+ Erics in hackerdom than the frequency of these three traits
+ can account for unless they are correlated in some arcane way.
+ Well-known examples include {Eric Allman} (of the "Allman
+ style" described under {indent style}), {Erik Fair} (co-author
+ of NNTP), {Eric S. Raymond} and about fifteen others. The
+ organisation line "Eric Conspiracy Secret Laboratories" now
+ emanates regularly from more than one site.
+
+ [{Jargon File}]
+
+ (1998-10-20)
+
+Eric S. Raymond
+
+ <person> One of the authors of the Hacker's {Jargon File}.
+ Eric was involved in the {JOLT} project and {GNU Emacs} as
+ well as maintaining several {FAQ} lists. He is a keen
+ advocate of {open source}.
+
+ {(http://ccil.org/~esr)}.
+
+ E-mail: <esr@snark.thyrsus.com>
+
+ (1998-10-20)
+
+Eris
+
+ /e'ris/ The Greek goddess of Chaos, Discord, Confusion, and
+ Things You Know Not Of; her name was latinised to Discordia
+ and she was worshiped by that name in Rome. Not a very
+ friendly deity in the Classical original, she was reinvented
+ as a more benign personification of creative anarchy starting
+ in 1959 by the adherents of {Discordianism} and has since been
+ a semi-serious subject of veneration in several "fringe"
+ cultures, including hackerdom.
+
+ See {Church of the SubGenius}.
+
+ [{Jargon File}]
+
+ (1994-12-08)
+
+Erlang
+
+ 1. <person> {Agner Krarup Erlang}. (The other senses were
+ named after him).
+
+ 2. <language> A concurrent {functional language} for large
+ industrial {real-time} systems by Armstrong, Williams and
+ Virding of Ellemtel, Sweden.
+
+ Erlang is untyped. It has {pattern matching} syntax,
+ {recursion equations}, explicit {concurrency}, {asynchronous
+ message passing} and is relatively free from {side-effects}.
+ It supports transparent cross-{platform} distribution. It has
+ primitives for detecting run-time errors, real-time {garbage
+ collection}, {modules}, {dynamic code replacement} (change
+ code in a continuously running real-time system) and a
+ {foreign language interface}.
+
+ An unsupported free version is available (subject to a
+ non-commercial licence). Commercial versions with support are
+ available from {Erlang Systems AB}. An {interpreter} in
+ {SICStus Prolog} and compilers in {C} and Erlang are available
+ for several {Unix} {platforms}.
+
+ {Open Telecom Platform} (OTP) is a set of {libraries} and
+ tools.
+
+ {Commercial version (http://erlang.se/)} - sales, support,
+ training, consultants. {Open-source version
+ (http://erlang.org/)} - downloads, user-contributed
+ software, mailing lists.
+
+ {Training and consulting (http://erlang-consulting.com/)}.
+
+ E-mail: <erlang@erix.ericsson.se>.
+
+ [Erlang - "Concurrent Programming in Erlang", J. Armstrong, M.
+ & Williams R. Virding, Prentice Hall, 1993. ISBN 13-285792-8.]
+
+ 3. <unit> 36 {CCS} per hour, or 1 call-second per second.
+
+ Erlang is a unit without dimension, accepted internationally
+ for measuring the traffic intensity. This unit is defined as
+ the aggregate of continuous occupation of a channel for one
+ hour (3600 seconds). An intensity of one Erlang means the
+ channel is continuously occupied.
+
+ (2003-03-25)
+
+ERM
+
+ {Electronic Report Management}
+
+erotica
+
+ {pornography}
+
+ERP
+
+ {Enterprise Resource Planning}
+
+error
+
+ 1. A discrepancy between a computed, observed, or measured
+ value or condition and the true, specified, or theoretically
+ correct value or condition.
+
+ 2. <programming> A mental mistake made by a programmer that
+ may result in a program {fault}.
+
+ 3. (verb) What a program does when it stops as result of a
+ programming error.
+
+ (2000-03-28)
+
+error-based testing
+
+ <programming> Testing where information about programming
+ style, error-prone language constructs, and other programming
+ knowledge is applied to select test data capable of detecting
+ faults, either a specified class of faults or all possible
+ faults.
+
+ (1996-05-13)
+
+error correcting memory
+
+ <storage> (ECM) {RAM} using some kind of {error detection and
+ correction} (EDAC) scheme. The two types of memory errors in
+ RAM (especially {DRAM}) are "soft" errors due to
+ radiation-induced bit switching, and "hard" errors due to the
+ unexpected deterioration of a memory chip. Soft errors do not
+ indicate lasting damage to the memory board, but they do
+ corrupt programs or data. Hard errors demand physical
+ repairs. Single bit memory failures are the most common. A
+ hard single bit failure, such as that caused by a completely
+ dead chip can be corrected by EDAC if each chip supplies only
+ one bit of each word. EDAC memory is the most common level of
+ protection for {minicomputers} and {mainframes} whereas the
+ cheaper parity protection is more common in {microcomputers}.
+
+ [Clearpoint, "The Designer's Guide to Add-In Memory", Third
+ Addition].
+
+ (1995-10-10)
+
+error detection and correction
+
+ <algorithm, storage> (EDAC, or "error checking and
+ correction", ECC) A collection of methods to detect errors in
+ transmitted or stored data and to correct them. This is done
+ in many ways, all of them involving some form of coding. The
+ simplest form of error detection is a single added {parity
+ bit} or a {cyclic redundancy check}. Multiple parity bits can
+ not only detect that an error has occurred, but also which
+ bits have been inverted, and should therefore be re-inverted
+ to restore the original data. The more extra bits are added,
+ the greater the chance that multiple errors will be detectable
+ and correctable.
+
+ Several codes can perform Single Error Correction, Double
+ Error Detection (SECDEC). One of the most commonly used is
+ the {Hamming code}.
+
+ At the other technological extreme, cuniform texts from about
+ 1500 B.C. which recorded the dates when Venus was visible,
+ were examined on the basis of contained redundancies (the
+ dates of appearance and disappearance were suplemented by the
+ length of time of visibility) and "the worst data set ever
+ seen" by [Huber, Zurich] was corrected.
+
+ {RAM} which includes EDAC circuits is known as {error
+ correcting memory} (ECM).
+
+ [Wakerly, "Error Detecting Codes", North Holland 1978].
+
+ [Hamming, "Coding and Information Theory", 2nd Ed, Prentice
+ Hall 1986].
+
+ (1995-03-14)
+
+es
+
+ 1. <networking> The {country code} for Spain.
+
+ 2. <operating system> {Extensible Shell}.
+
+ 3. (Expert System) An {expert system} for the {IBM PC}
+ featuring {forward chaining}, {backward chaining} and {fuzzy
+ set} relations.
+
+ {(ftp://ftp.uu.net/pub/ai/expert-sys/summers.tar.Z)}.
+
+ [BYTE Oct 1990].
+
+ (1999-02-01)
+
+ES-1
+
+ <text, tool> An early text editing {interpreter}.
+
+ [Sammet 1969, p. 684].
+
+ (1999-02-01)
+
+ESA
+
+ 1. <architecture> {Enterprise Systems Architecture}.
+
+ 2. <body> European Space Agency.
+
+ (1999-10-31)
+
+ESC
+
+ {escape}
+
+ESCAPE
+
+ <language> An early system on the {IBM 650}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1995-01-05)
+
+escape
+
+ <character> (ESC) {ASCII} character 27.
+
+ When sent by the user, escape is often used to abort execution
+ or data entry. When sent by the computer it often starts an
+ {escape sequence}.
+
+ (1997-11-27)
+
+escape sequence
+
+ <character> (Or "escape code") A series of characters starting
+ with the {escape} character (ASCII 27). Escape sequences are
+ often used to control display devices such as {VDUs}. An
+ escape sequence might change the colour of subsequent text,
+ reassign keys on the keyboard, change printer settings or
+ reposition the cursor. The escape sequences of the {DEC}
+ {vt100} {video terminal} have become a {de facto standard} for
+ this purpose.
+
+ The term is also used for any sequence of characters that
+ temporarily suspends normal processing of a stream of
+ characters to perform some special function. For example, the
+ {Hayes} {modem} uses the sequence "+++" to escape to command
+ mode in which characters are interpreted as commands to the
+ modem itself rather than as data to pass through.
+
+ [Was the character named after this use or vice versa?]
+
+ (1997-11-27)
+
+ESCD
+
+ {Extended System Configuration Data}
+
+ESCON
+
+ {Enterprise Systems CONnectivity}
+
+escrow
+
+ <security> An arrangement where something (generally money or
+ documents) is held in trust ("in escrow") by a trusted third
+ party until certain agreed conditions are met. In computing
+ the term is used for {key escrow} and also for {source code
+ escrow}.
+
+ (1999-12-14)
+
+ESD
+
+ {Electrostatic Discharge}
+
+ESDI
+
+ {Enhanced Small Disk Interface}
+
+ESF
+
+ Eureka Software Factory.
+
+ESI
+
+ 1. {European Software Institute}.
+
+ 2. A dialect of {JOSS}.
+
+ [Sammet 1969, p. 217].
+
+esim
+
+ A language for {simulation} of {VLSI} at the {switch level}.
+ The {primitives} are nodes and {transistors}.
+
+ [C.M. Baker et al, "Tools for Verifying Integrated CIrcuit
+ Design", Lambda 1(3):22-30 (1980)].
+
+ (1994-10-20)
+
+ESL
+
+ {Expert Systems} Ltd.
+
+ESLPDPRO
+
+ {ESL} public domain version of Edinburgh {Prolog} for
+ {MS-DOS}. The code is totally compatible with C-Prolog.
+
+ {(ftp://aisun1.ai.uga.edu/ai.prolog/eslpdpro.zip)}.
+
+ESML
+
+ {Extended Systems Modelling Language}
+
+ESMTP
+
+ <messaging, protocol> Extended {SMTP}. Initially defined in
+ {RFC 1869} and extended thereafter.
+
+ See also {ETRN}.
+
+ (1997-11-21)
+
+ESP
+
+ 1. Extra Simple Pascal. Subset of Pascal.
+
+ 2. Econometric Software Package. Statistical analysis of time
+ series. "Econometric Software Package, User's Manual",
+ J.P. Cooper, Graduate School of Business, U Chicago. Sammet
+ 1978.
+
+ 3. {Extended Self-containing Prolog}.
+
+ 4. An early {symbolic mathematics} system.
+
+ [A. Rom, Celest Mech 3:331-345 (1971)].
+
+ (1994-12-08)
+
+ESPOL
+
+ {Executive Systems Programming Oriented Language}
+
+ESPRIT
+
+ {European Strategic Programme for Research in Information Technology}
+
+ESR
+
+ {Eric S. Raymond}
+
+essential complexity
+
+ <programming> A measure of the "structuredness" of a program.
+
+ (1996-05-13)
+
+Estelle
+
+ A {Pascal} extension for formal specification of computer
+ {network} {protocols}. Protocols are described by {modules}
+ which are communicating {NFAs}. Modules are arranged in a
+ dynamic hierarchy and communicate at named interaction points.
+
+ {EstPC (ftp:osi.ncsl.nist.gov/pub/osikit/estpc)} Compiles
+ Estelle into C. {petdingo} Translates Estelle into C++
+
+ Adopted by {ITU-T}. ISO 9074 (1989).
+
+ ["The Formal Description Technique Estelle", M. Diaz et al
+ eds, N-H 1989].
+
+Esterel
+
+ A distributed language for synchronous interaction of
+ {real-time} systems with their environment. Uses explicit
+ timing requests. Esterel programs are compiled into finite
+ {automata}.
+
+ ["The ESTEREL Programming Language and its Mathematical
+ Semantics", G. Berry & L. Cosserat, TR 327, INRIA, 1984].
+
+EstPC
+
+ A {compiler} from {Estelle} to {C}.
+
+ {(ftp:osi.ncsl.nist.gov/pub/osikit/estpc)}.
+
+ (1994-09-19)
+
+ET
+
+ Bernd Gersdorf, U Bremen. An integration of functional and
+ logic programming.
+
+et
+
+ <networking> The {country code} for Ethiopia.
+
+ (1999-01-27)
+
+ET++
+
+ A {Smalltalk}-like system for {Suns}, built on {C++} by
+ Weinand of UBILAB Zurich. Version 3.0-alpha includes {class}
+ libraries and documentation.
+
+ {(ftp://iamsun.unibe.ch/C++/ET++/et2.2.tar.Z)}.
+
+ E-mail: Erich Gamma <gamma@ifi.unizh.ch>.
+
+ (1992-10-26)
+
+eta abstraction
+
+ {eta conversion}
+
+eta conversion
+
+ <theory> In {lambda-calculus}, the eta conversion rule states
+
+ \ x . f x <--> f
+
+ provided x does not occur as a {free variable} in f and f is a
+ function. Left to right is eta reduction, right to left is
+ eta abstraction (or eta expansion).
+
+ This conversion is only valid if {bottom} and \ x . bottom are
+ equivalent in all contexts. They are certainly equivalent
+ when applied to some argument - they both fail to terminate.
+ If we are allowed to force the evaluation of an expression in
+ any other way, e.g. using {seq} in {Miranda} or returning a
+ function as the overall result of a program, then bottom and
+ \ x . bottom will not be equivalent.
+
+ See also {observational equivalence}, {reduction}.
+
+eta expansion
+
+ {eta conversion}
+
+eta reduction
+
+ {eta conversion}
+
+ETB
+
+ {End Transmission Block}
+
+ETC
+
+ {ExTendible Compiler}
+
+e-text
+
+ {electronic text}
+
+ETHER
+
+ <language> A {concurrent} {object-oriented} language?
+
+ (1997-03-18)
+
+EtherGate
+
+ Multi-protocol Ethernet gateway made by LRT.
+ See Computer Systems, October 1985.
+
+Ethernet
+
+ <networking> A {local area network} first described by
+ Metcalfe & Boggs of {Xerox PARC} in 1976. Specified by {DEC},
+ {Intel} and {XEROX} (DIX) as {IEEE 802.3} and now recognised
+ as the industry standard.
+
+ Data is broken into {packets} and each one is transmitted
+ using the {CSMA/CD} {algorithm} until it arrives at the
+ destination without colliding with any other packet. The
+ first {contention slot} after a transmission is reserved for
+ an {acknowledge} packet. A {node} is either transmitting or
+ receiving at any instant. The {bandwidth} is about 10 Mbit/s.
+ Disk-Ethernet-Disk transfer rate with {TCP/IP} is typically 30
+ kilobyte per second.
+
+ Version 2 specifies that {collision} detect of the transceiver
+ must be activated during the {inter-packet gap} and that when
+ transmission finishes, the differential transmit lines are
+ driven to 0V (half step). It also specifies some {network
+ management} functions such as reporting {collisions}, retries
+ and {deferrals}.
+
+ Ethernet cables are classified as "XbaseY", e.g. 10base5,
+ where X is the data rate in {Mbps}, "base" means "{baseband}"
+ (as opposed to {radio frequency}) and Y is the category of
+ cabling. The original cable was {10base5} ("full spec"),
+ others are {10base2} ("thinnet") and {10baseT} ("twisted
+ pair") which is now (1998) very common. {100baseT} ("{Fast
+ Ethernet}") is also increasingly common.
+
+ {Usenet} newsgroup: {news:comp.dcom.lans.ethernet}.
+
+ {(http://wwwhost.ots.utexas.edu/ethernet/ethernet-home.html)}.
+
+ (1997-04-16)
+
+Ethernet address
+
+ <networking> (Or "{MAC} address") The physical address
+ identifying an individual {Ethernet controller} board. An
+ Ethernet addess is a 48-bit number aabbccddeeff where a-f are
+ {hexadecimal} digits. The first 24 bits, aabbcc, identify the
+ manufacturer of the controller. The Ethernet address is
+ hard-wired on some controllers, stored in a {ROM} on some, and
+ others allow it to be changed from software. It is usually
+ written as six hexadecimal numbers, e.g. 08:00:20:03:72:DC.
+
+ See also {ARP}, {Internet address}.
+
+ (1996-02-21)
+
+Ethernet meltdown
+
+ A {network meltdown} on {Ethernet}.
+
+ (1994-11-29)
+
+Ethernet Private Line
+
+ <networking> (EPL) A data service defined by the {Metro
+ Ethernet Forum}, providing a point-to-point Ethernet
+ connection between a pair of dedicated User-Network Interfaces
+ (UNIs), with a high degree of transparency.
+
+ (2010-09-21)
+
+EtherTalk
+
+ <networking> An {Apple Computer} {network} {standard} used to
+ extend an {AppleTalk} network across an {Ethernet} network.
+
+ Compare {LocalTalk}.
+
+ (1994-11-29)
+
+ethics
+
+ {computer ethics}
+
+ETL
+
+ <database> The processes of Extracting, Transforming (or
+ Transporting), and Loading data from {source systems} into a
+ {data warehouse}.
+
+ (2003-12-31)
+
+ETM
+
+ <database> An {active DBMS} from the {University of
+ Karlsruhe}.
+
+ [Expansion? Features?]
+
+ (1997-06-23)
+
+ETRN
+
+ <messaging, protocol> ("Extended {TURN}") An {ESMTP} command
+ (first defined in {RFC 1985}) with which a {client} asks the
+ {server} to deliver queued mail to the client via a new ESMTP
+ connection.
+
+ ETRN supersedes the {SMTP} "TURN" command in the same way that
+ ESMTP's "{EHLO}" supersedes SMTP's "{HELO}".
+
+ (1997-11-21)
+
+ETSI
+
+ {European Telecommunications Standards Institute}
+
+ETX
+
+ {End Of Text}
+
+Euclid
+
+ <language> (Named after the Greek geometer, fl ca 300 BC.) A
+ {Pascal} descendant for development of verifiable system
+ software. No {goto}, no {side effects}, no global
+ assignments, no functional arguments, no nested procedures, no
+ floats, no {enumeration types}. Pointers are treated as
+ indices of special arrays called collections. To prevent
+ {aliasing}, Euclid forbids any overlap in the list of actual
+ parameters of a procedure. Each procedure gives an imports
+ list, and the compiler determines the identifiers that are
+ implicitly imported. Iterators.
+
+ Ottawa Euclid is a variant.
+
+ ["Report on the Programming Language Euclid", B.W. Lampson et
+ al, SIGPLAN Notices 12(2):1-79, Feb 1977].
+
+ (1998-11-23)
+
+Euclidean Algorithm
+
+ {Euclid's Algorithm}
+
+Euclidean norm
+
+ <mathematics> The most common {norm}, calculated by summing
+ the squares of all coordinates and taking the square root.
+ This is the essence of {Pythagoras's theorem}. In the
+ infinite-dimensional case, the sum is infinite or is replaced
+ with an integral when the number of dimensions is
+ {uncountable}.
+
+ (2004-02-15)
+
+Euclid's Algorithm
+
+ <algorithm> (Or "Euclidean Algorithm") An {algorithm} for
+ finding the {greatest common divisor} (GCD) of two numbers.
+ It relies on the identity
+
+ gcd(a, b) = gcd(a-b, b)
+
+ To find the GCD of two numbers by this algorithm, repeatedly
+ replace the larger by subtracting the smaller from it until
+ the two numbers are equal. E.g. 132, 168 -> 132, 36 -> 96, 36
+ -> 60, 36 -> 24, 36 -> 24, 12 -> 12, 12 so the GCD of 132 and
+ 168 is 12.
+
+ This algorithm requires only subtraction and comparison
+ operations but can take a number of steps proportional to the
+ difference between the initial numbers (e.g. gcd(1, 1001) will
+ take 1000 steps).
+
+ (1997-06-30)
+
+Eudora
+
+ {Electronic mail} software for communicating over {TCP/IP}
+ from {Macintosh}, {Microsoft Windows}, {Windows NT}, and {IBM}
+ {OS/2} computers. Both commercial and free versions are
+ produced by {QUALCOMM, Inc.}
+
+EULA
+
+ {end-user license agreement}
+
+EULER
+
+ [Named after the Swiss mathematician Leonhard Euler
+ (1707-1783)] A revision of {ALGOL} by {Niklaus Wirth}. A
+ small predecessor of {Pascal}.
+
+ ["EULER: A Generalisation of ALGOL and Its Formal Definition",
+ N. Wirth, CACM 9(1) (Jan 1966) and 9(2) (Feb 1966)].
+
+EuLisp
+
+ 1985-present. A {Lisp} dialect intended to be a common
+ European {standard}, with influences from {Common LISP}, {Le
+ LISP}, {Scheme} and {T}. {First-class functions}, {class}es
+ and {continuations}, both {static scope} and {dynamic scope},
+ {modules}, support for {parallelism}. The class system
+ ({TELOS}) incorporates ideas from {CLOS}, {ObjVLisp} and
+ {Oaklisp}.
+
+ See also {Feel}.
+
+ E-mail: <eudist@maths.bath.ac.uk>.
+
+EUnet Ltd.
+
+ EUnet Ltd. is jointly owned by the EUnet national service
+ providers and {EurOpen}, the European Forum for Open Systems.
+
+ EUnet services include {electronic mail} ({Internet}-style
+ {RFC 822} as well as {X.400}), {InterEUnet} ({Internet
+ Protocol}) connectivity and services such as {remote login}
+ and {file transfer} over {leased lines}, {dial-up lines},
+ {X.25} and {Integrated Services Digital Network}. EUnet is
+ the primary European region provider of {network news} and the
+ top-level European distributor of {Internet Talk Radio}.
+
+ EUnet operates its own infrastructure across Europe and is the
+ largest European component of the {Internet}. EUnet is a
+ member of {Commercial Internet Exchange} and {Ebone93}, a
+ research network consortium.
+
+ E-mail: <info@EU.net>. {(http://eu.net/)}.
+
+Euphoria
+
+ End User Programming with Hierarchical Objects for Robust
+ Interpreted Applications. Interpreted language with dynamic
+ storage and dynamic typing. Rapid Deployment Software.
+
+ E-mail: <robert.craig@canrem.com>.
+
+Eureka
+
+ A European technological development programme.
+
+Eureka step
+
+ In {program transformation}, a transformation which is not
+ obvious or easy to define as an {algorithm}.
+
+ (1994-12-08)
+
+Eurisko
+
+ <artificial intelligence> A language for "{opportunistic
+ programming}" written by {Doug Lenat} in 1978. Eurisko
+ constructs its own methods and modifies its strategies as it
+ tries to solve a problem.
+
+ {(http://homepages.enterprise.net/hibou/aicourse/lenat.txt)}.
+
+ [Mentioned by Alan Kay, SIGPLAN Notices 28(3), March 1993,
+ p. 88].
+
+ (1994-12-08)
+
+Eurocard
+
+ A range of standard circuit board sizes.
+
+ Normal double Eurocard = 233.4 x 160 mm
+ Extended double Eurocard = 233.4 x 220 mm
+ Super extended double Eurocard = 233.4 x 250 mm
+ Hyper extended double Eurocard = 233.4 x 280 mm
+
+Euro-ISDN
+
+ European Integrated Services Digital Network.
+
+ An {ETSI} standard for {Integrated Services Digital Network}
+ being phased in in March 1994. Euro-ISDN will allow full
+ transparent interworking between all European countries
+ (members of the {CEPT}). It is available on a commercial
+ basis in most European countries.
+
+ (1994-12-08)
+
+EuroNet
+
+ <company> An {IAP} from Amsterdam, The Netherlands operating
+ since 1994-08-01 and owned by {France Telecom} since
+ 1998-11-06.
+
+ {(http://euronet.nl/)}.
+
+ E-mail: <info@euro.net>.
+
+ Telephone: +31 (020) 535 5555.
+
+ Fax: +31 (020) 535 5400.
+
+ Address: Herengracht 208-214, 1016 BS Amsterdam, The
+ Netherlands.
+
+ (1999-01-17)
+
+EuropaNET
+
+ A combination of pan-European backbone services run by DANTE.
+
+European Academic and Research Network
+
+ <networking> (EARN) A self-managing network in the research
+ community originally sponsored by {IBM}. It uses {BITNET}
+ {protocols} and connects to BITNET in the USA.
+
+ (1995-11-15)
+
+European Computer-Industry Research Centre GmbH
+
+ <body> (ECRC) A joint research organisation founded in 1984 on
+ the initiative of three major European manufacturers: {Bull}
+ (France), {ICL} (UK) and {Siemens} (Germany). Its activities
+ were intended to enhance the future competitive ability of the
+ European {Information Technology} industry and thus complement
+ the work of national and international bodies.
+
+ The Centre is intended to be the breeding ground for those
+ ideas, techniques and products which are essential for the
+ future use of electronic information processing. The work of
+ the Centre will focus on advanced information processing
+ technology for the next generation of computers.
+
+ ECRC is an independent company, owned equally by its
+ shareholders. The formal interface between ECRC and its
+ shareholders consists of two bodies: The Shareholders'
+ Council, which approves the Centre's programmes and budgets
+ and supervises their execution and the Scientific Advisory
+ Board, which advises the Shareholders' Council in determining
+ future research directions.
+
+ There are many collaborations between ECRC and its
+ shareholders' companies on specific projects (Technology
+ Transfer, prospective studies etc). The Centre is staffed by
+ highly qualified scientists drawn from different countries.
+ Research staff are hired directly by ECRC, as well as some who
+ come on assignment from the member companies, and others
+ seconded from public research agencies and universities.
+
+ Seminars are held which bring together specialists from the
+ Centre and the member companies.
+
+ ECRC's mission is to pursue research in fundamental areas of
+ computer science. The aim is to develop the theory,
+ methodologies and tools needed to build innovative computer
+ applications. ECRC contributes actively to the international
+ effort that is expanding the frontiers of knowledge in
+ computer science. It plays an important role in bridging the
+ gap between research and industry by striving to work at the
+ highest academic level with a strong industrial focus. ECRC
+ constitutes an opportunity in Europe for the best scientists
+ and offers young researchers the possibility to mature in an
+ environment which exposes them to both fundamental research
+ and the process of delivering the results to industry.
+
+ ECRC plays an important role in Europe and is involved in
+ several European Community initiatives. It is regularly
+ consulted by the Commission of the European Communities on
+ strategic issues, such as the definition of future research
+ plans, international co-operation and relationships between
+ academia and industry.
+
+ Address: ECRC GmbH, Arabellastrasse 17, D-81925 Munich,
+ Germany.
+
+ {(http://ecrc.de/)}.
+
+ Telephone: +49 (89) 926 99 0. Fax: +49 (89) 926 99 170.
+
+ (1994-12-01)
+
+European Computer Manufacturers Association
+
+ <body> (ECMA) The former name of {ECMA International}
+
+European Strategic Programme for Research in Information Technology
+
+ <project> (ESPRIT) A funding programme to develop Information
+ Technology in the European Economic Communities. Superseded
+ by {Framework 4}.
+
+ (1996-05-13)
+
+European Telecommunications Standards Institute
+
+ <body> (ETSI) A European version of the {ITU-T}(?).
+
+ (1996-05-13)
+
+EUUG
+
+ {European Unix User Group}
+
+EV6
+
+ <hardware, protocol> (Alpha EV6) {Compaq}'s {bus protocol} for
+ {Slot A} {motherboards}. The Alpha EV6 bus protocol is
+ capable of bus speeds from 40 to 400 MHz and uses a
+ {point-to-point} {topology} with {clock forwarding}.
+
+ (1999-08-05)
+
+Eva
+
+ 1. A toy ALGOL-like language used in "Formal Specification of
+ Programming Languages: A Panoramic Primer", F.G. Pagan, P-H
+ 1981.
+
+ 2. Explicit Vector Language.
+
+EVALUATE
+
+ <programming> The {COBOL85} {keyword} for a {switch
+ statement}.
+
+ (1997-06-10)
+
+evaluation
+
+ <programming> 1. Converting an expression into a value using
+ some {reduction strategy}.
+
+ 2. The process of examining a system or system component to
+ determine the extent to which specified properties are
+ present.
+
+ (1996-05-13)
+
+evaluation strategy
+
+ {reduction strategy}
+
+evaluator
+
+ <theory> Geoff Burn defines evaluators E0, E1, E2 and E3 which
+ when applied to an expression, reduce it to varying degrees.
+ E0 does no evaluation, E1 it evaluates to {weak head normal
+ form} (WHNF), E2 evaluates the structure of a list, i.e. it
+ evaluates it either to NIL or evaluates it to a CONS and then
+ applies E2 to the second argument of the CONS. E3 evaluates
+ the structure of a list and evaluates each element of the list
+ to {WHNF}. This concept can be extended to data structures
+ other than lists and forms the basis of the {evaluation
+ transformer} style of {strictness analysis}.
+
+ (1994-12-12)
+
+EVE
+
+ {Extensible VAX Editor}
+
+event
+
+ 1. <software> An occurrence or happening of significance to a
+ task or program, such as the completion of an asynchronous
+ input/output operation. A task may wait for an event or any
+ of a set of events or it may (request to) receive asynchronous
+ notification (a {signal} or {interrupt}) that the event has
+ occurred.
+
+ See also {event-driven}.
+
+ 2. <data> A transaction or other activity that affects the
+ records in a file.
+
+ (2000-02-09)
+
+Event Description Language
+
+ <language> (EDL)
+
+ ["EDL: A Basis for Distributed System Debugging Tools",
+ P.C. Bates et al, in Proc Hawaii Intl Conf on Sys Sci, Jan
+ 1982, pp.86-93].
+
+ (2007-07-11)
+
+event-driven
+
+ <programming> A kind of program, such as a {graphical user
+ interface}, with a main loop which just waits for {events} to
+ occur. Each event has an associated handler which is passed
+ the details of the event, e.g. mouse button 3 pressed at
+ position (355, 990).
+
+ For example, {X window system} and most {Visual Basic}
+ {application programs} are event-driven.
+
+ See also {callback}.
+
+ (2000-02-09)
+
+EVGA
+
+ {Extended Video Graphics Array}
+
+evolutionary algorithm
+
+ (EA) An {algorithm} which incorporates aspects of natural
+ selection or survival of the fittest. An evolutionary
+ algorithm maintains a population of structures (usually
+ randomly generated initially), that evolves according to rules
+ of selection, recombination, mutation and survival, referred
+ to as genetic operators. A shared "environment" determines
+ the fitness or performance of each individual in the
+ population. The fittest individuals are more likely to be
+ selected for reproduction (retention or duplication), while
+ recombination and mutation modify those individuals, yielding
+ potentially superior ones.
+
+ EAs are one kind of {evolutionary computation} and differ from
+ {genetic algorithms}. A GA generates each individual from
+ some encoded form known as a "chromosome" and it is these
+ which are combined or mutated to breed new individuals.
+
+ EAs are useful for optimisation when other techniques such as
+ {gradient descent} or direct, analytical discovery are not
+ possible. Combinatoric and real-valued function optimisation
+ in which the optimisation surface or fitness landscape is
+ "rugged", possessing many {locally optimal} solutions, are
+ well suited for evolutionary algorithms.
+
+ (1995-02-03)
+
+evolutionary computation
+
+ Computer-based problem solving systems that use computational
+ models of evolutionary processes as the key elements in design
+ and implementation.
+
+ A number of evolutionary computational models have been
+ proposed, including {evolutionary algorithms}, {genetic
+ algorithms}, the {evolution strategy}, {evolutionary
+ programming}, and {artificial life}.
+
+ {The Hitchhiker's Guide to Evolutionary Computation
+ (http://cis.ohio-state.edu/hypertext/faq/bngusenet/comp/ai/genetic/top.html)}.
+
+ {Bibliography
+ (http://liinwww.ira.uka.de/bibliography/Ai/EC-ref.html)}.
+
+ {Usenet} newsgroup: {news:comp.ai.genetic}.
+
+ (1995-03-02)
+
+evolutionary programming
+
+ (EP) A {stochastic} optimisation strategy originally conceived
+ by Lawrence J. Fogel in 1960.
+
+ An initially random population of individuals (trial
+ solutions) is created. Mutations are then applied to each
+ individual to create new individuals. Mutations vary in the
+ severity of their effect on the behaviour of the individual.
+ The new individuals are then compared in a "tournament" to
+ select which should survive to form the new population.
+
+ EP is similar to a {genetic algorithm}, but models only the
+ behavioural linkage between parents and their offspring, rather
+ than seeking to emulate specific genetic operators from nature
+ such as the encoding of behaviour in a genome and
+ recombination by genetic crossover.
+
+ EP is also similar to an {evolution strategy} (ES) although
+ the two approaches developed independently. In EP, selection
+ is by comparison with a randomly chosen set of other
+ individuals whereas ES typically uses {deterministic}
+ selection in which the worst individuals are purged from the
+ population.
+
+ (1995-02-03)
+
+evolution strategy
+
+ (ES) A kind of {evolutionary algorithm} where individuals
+ (potential solutions) are encoded by a set of real-valued
+ "object variables" (the individual's "genome"). For each
+ object variable an individual also has a "strategy variable"
+ which determines the degree of mutation to be applied to the
+ corresponding object variable. The strategy variables also
+ mutate, allowing the rate of mutation of the object variables
+ to vary.
+
+ An ES is characterised by the population size, the
+ number of offspring produced in each generation and whether
+ the new population is selected from parents and offspring or
+ only from the offspring.
+
+ ES were invented in 1963 by Ingo Rechenberg, Hans-Paul
+ Schwefel at the {Technical University of Berlin} (TUB) while
+ searching for the optimal shapes of bodies in a flow.
+
+ (1995-02-03)
+
+EWOS
+
+ {European Workshop for Open Systems}
+
+exa-
+
+ {prefix}
+
+Exabyte
+
+ <company, storage> A company and, by extension, a tape format for
+ computer data backup and transfer. The tape is a data quality 8mm
+ video cassette recorder tape. Exabyte units can store between
+ five and fourteen {gigabytes} of data per tape. Exabytes are
+ usually attached to {Unix} {workstations}.
+
+ [What different tape capacities exist? Compare with DAT?]
+
+ (1995-07-06)
+
+exabyte
+
+ <unit, data> (EB) A unit of {data} equal to 10^18 {bytes} but see
+ {binary prefix} for other definitions. An exabyte is exactly
+ 1000^6 bytes or 1000 {petabytes}.
+
+ 1000 exabytes are one {zettabyte}.
+
+ See {prefix}.
+
+ (2013-11-04)
+
+examining the entrails
+
+ The process of {grovel}ling through a {core dump} or {hex}
+ image in an attempt to discover the bug that brought a program
+ or system down. The reference is to divination from the
+ entrails of a sacrified animal.
+
+ Compare {runes}, {incantation}, {black art}, {desk check}.
+
+ [{Jargon File}]
+
+ (1994-12-12)
+
+EXAPT
+
+ EXtended {APT}.
+
+Excalibur bug
+
+ <humour, programming> The legendary bug that, despite repeated
+ valliant attempts, none but the true king of all programmers
+ can fix. Named after the sword in the stone in the legend of King
+ Arthur.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2013-03-20)
+
+Exceed
+
+ <interface> A tool to display remote {X Window System}
+ applications on {Microsoft Windows}. Exceed is not an X
+ server.
+
+ (2001-04-29)
+
+Excel
+
+ {Microsoft Excel}
+
+Excelan
+
+ Manufacturers of intelligent {Ethernet} cards. Software and
+ addresses are down-loadable. The cards have their own {RAM}
+ for buffers.
+
+Excelerator
+
+ A set of {CASE} tools from {Index Technology Corporation}.
+
+exception
+
+ An error condition that changes the normal {flow of control}
+ in a program. An exception may be generated ("raised") by
+ {hardware} or {software}. Hardware exceptions include
+ {reset}, {interrupt} or a signal from a {memory management
+ unit}. Exceptions may be generated by the {arithmetic logic
+ unit} or {floating-point unit} for numerical errors such as
+ divide by zero, {overflow} or {underflow} or {instruction
+ decoding} errors such as privileged, reserved, {trap} or
+ undefined instructions. Software exceptions are even more
+ varied and the term could be applied to any kind of error
+ checking which alters the normal behaviour of the program.
+
+ (1994-10-31)
+
+exception handler
+
+ Special code which is called when an {exception} occurs during
+ the execution of a program. If the programmer does not
+ provide a handler for a given exception, a built-in system
+ exception handler will usually be called resulting in abortion
+ of the program run and some kind of error indication being
+ returned to the user.
+
+ Examples of exception handler mechanisms are {Unix}'s signal
+ calls and {Lisp}'s {catch} and {throw}.
+
+ (1994-10-31)
+
+EXCH
+
+ <jargon> /eks'ch*/ or /eksch/ To exchange two things, each for
+ the other; to swap places. If you point to two people sitting
+ down and say "Exch!", you are asking them to trade places.
+ EXCH, meaning EXCHange, was originally the name of a {PDP-10}
+ instruction that exchanged the contents of a {register} and a
+ memory location.
+
+ Many newer hackers are probably thinking instead of the
+ {PostScript} exchange operator (which is usually written in
+ lowercase).
+
+ [{Jargon File}]
+
+ (1999-09-17)
+
+Exchange Server
+
+ {Microsoft Exchange}
+
+excl
+
+ {exclamation mark}
+
+exclamation mark
+
+ <character> The character "!" with {ASCII} code 33.
+
+ Common names: {bang}; pling; excl (/eks'kl/); shriek; {ITU-T}:
+ exclamation mark, exclamation point (US). Rare: {factorial};
+ exclam; smash; cuss; boing; yell; wow; hey; wham; eureka;
+ soldier; {INTERCAL}: spark-spot.
+
+ The {Commonwealth Hackish}, "pling", is common among {Acorn
+ Archimedes} owners. {Bang} is more common in the USA.
+
+ The occasional {CMU} usage, "shriek", is also used by {APL}
+ fans and mathematicians, especially {category} theorists.
+
+ Exclamation mark is used in {C} and elsewhere as the logical
+ negation {operation} ({NOT}).
+
+ (1998-09-17)
+
+exclamation point
+
+ {exclamation mark}
+
+exclusive or
+
+ <logic> (XOR, EOR) /X or, E or/ A two-input {Boolean logic}
+ {function} whose result is true if one input is true and the
+ other is false. The {truth table} is
+
+ A | B | A xor B
+ --+---+--------
+ F | F | F
+ F | T | T
+ T | F | T
+ T | T | F
+
+ The output is thus true if the inputs are not equal. If one
+ input is false, the other is passed unchanged whereas if one
+ input is true, the other is inverted.
+
+ In Boolean algebra, exclusive or is often written as a plus in
+ a circle: "&oplus;". The circle may be omitted suggesting
+ addition {modulo} two.
+
+ In {digital logic}, an exclusive or {logic gate} is drawn like
+ a normal {inclusive or} gate but with a curved line across
+ both inputs:
+ {exclusive or gate (img:http://upload.wikimedia.org/wikipedia/commons/e/e0/XOR.jpg)}.
+
+ (2006-12-13)
+
+EXCP
+
+ {Execute Channel Program}
+
+EXE
+
+ /eks'ee/ or /eek'see/ or /E-X-E/ An executable binary file.
+ Some operating systems (notably {MS-DOS}, VMS, and TWENEX) use
+ the extension .EXE to mark such files. This usage is also
+ occasionally found among Unix programmers even though Unix
+ executables don't have any required suffix.
+
+ [{Jargon File}]
+
+EXEC
+
+ <language> An early {batch} language for the {IBM} {VM/CMS}
+ systems.
+
+ [SC19-6209 Virtual Machine/ System Product CMS Command and
+ Macro Reference, Appendix F. CMS EXEC Control Statements].
+
+ [Was {EXEC 2} was a later version?]
+
+ (2000-08-06)
+
+exec
+
+ /eg-zek'/ <operating system> 1. execute.
+
+ A synonym for {chain} derived from the {Unix} "exec" {system
+ call}.
+
+ {Unix manual page}: execve(2).
+
+ 2. (Obsolete) {executive}.
+
+ The mainstream "exec" as an abbreviation for (human) executive
+ is *not* used. To a hacker, an "exec" is a always a program,
+ never a person.
+
+ 3. At {IBM} and {VM}/{CMS} shops, the equivalent of a {shell}
+ command file.
+
+ 4. <operating system> The innermost {kernel} of the {Amiga}
+ {operating system} which provides shared-library support,
+ device interface, {memory management}, {CPU} management, basic
+ {IPC}, and the basic structures for OS extension. The rest of
+ the Amiga OS (windowing, file system, third-party extensions,
+ etc.) is built using these structures.
+
+ [{Jargon File}]
+
+ (1997-08-01)
+
+EXEC 2
+
+ 1. <language> A {scripting language} produced by {IBM} in the
+ late 1970s.
+
+ Superseded by {REXX}.
+
+ [SC24-5219, "Virtual Machine/System Product EXEC 2
+ Reference"].
+
+ [Successor to {EXEC 1}? With or without a space?]
+
+ 2. <operating system> An archaic {operating system} from
+ {UNIVAC}. By about 1980 it had been replaced by {EXEC 8}.
+
+ [Dates? Did EXEC 3 to EXEC 7 exist?]
+
+ (2000-08-06)
+
+EXEC 8
+
+ <operating system> {Unisys}'s {operating system} from about
+ 1980 to 2000, by which time it was a dying breed with Unisys
+ moving to {Windows NT} and {Unix}.
+
+ [Was 8 the successor to {EXEC 2}?]
+
+ (2000-08-06)
+
+executable
+
+ <operating system> A {binary} file containing a program in
+ {machine language} which is ready to be {execute}d (run).
+
+ The term might also be, but generally isn't, applied to
+ {scripts} which are interpreted by a {command line
+ interpreter}. Executables are distinguished in {Unix} by
+ having the execute permission bits set, at least for the
+ owner. {MS-DOS} uses the {filename extension} ".exe".
+
+ (1997-06-21)
+
+executable content
+
+ <operating system> Executable programs sent by one computer to
+ another via a network. For example a {Java} {applet} is
+ executable content. Usage: rare.
+
+ (1998-03-23)
+
+execute
+
+ {execution}
+
+Execute Channel Program
+
+ <operating system> (EXCP) An {IBM} system for low-level file
+ access, where the programmer is completely responsible for
+ providing a list of device-specific "channel comands" to be
+ executed by {I/O channels}, {control units} and/or {devices}.
+ The {operating system} will simply check the "{CCW}" chains
+ for security purposes (access invalid memory or outside of
+ {file extents}) and then schedule them for execution.
+
+ (2005-08-08)
+
+execution
+
+ <operating system, programming> The process of carrying out
+ the {instructions} in a computer program by a computer.
+
+ See also {dry run}.
+
+ (1996-05-13)
+
+executive
+
+ <operating system> The {command interpreter} or {shell} for an
+ {operating system}. The term is used especially around
+ {mainframes} and probably derived from {UNIVAC}'s archaic
+ {EXEC 2} and current (in 2000) {EXEC 8} {operating systems}.
+
+ (2000-08-06)
+
+Executive Systems Programming Oriented Language
+
+ <language> An {ALGOL} superset with high level instructions
+ for low level actions, e.g. interrupting another processor on
+ a multiprocessor system. Its single pass compiler was very
+ fast: over 250 lines/s on a 10MHz processor.
+
+ ESPOL was used to write the MCP (Master Control Program) on
+ the {Burroughs 6700}. It was superseded by {NEWP}.
+
+ ["The B6700 ESPOL Reference Manual", Burroughs, 1970].
+
+ (2001-06-14)
+
+exercise, left as an
+
+ Used to complete a proof in technical books when one doesn't
+ mind a {handwave}, or to avoid one entirely. The complete
+ phrase is: "The proof [or "the rest"] is left as an exercise
+ for the reader." This comment *has* occasionally been
+ attached to unsolved research problems by authors possessed of
+ either an evil sense of humour or a vast faith in the
+ capabilities of their audiences.
+
+ [{Jargon File}]
+
+ (1995-02-20)
+
+exhaustive testing
+
+ <programming> Executing a program with all possible
+ combinations of inputs or values for program variables.
+
+ (1996-05-13)
+
+existence proof
+
+ {non-constructive proof}
+
+existential quantifier
+
+ {quantifier}
+
+exit
+
+ 1. <programming> A {library function} in the {C} and {Unix}
+ {run-time library} that causes the program to terminate and
+ return control to the {shell}. The alternative to calling
+ "exit" is simply to "fall off the end" of the program or its
+ top-level, {main}, routine.
+
+ Equivalent functions, possibly with different names, exist in
+ pretty much every programming language, e.g. "exit" in
+ {Microsoft DOS} or "END" in {BASIC}.
+
+ On exit, the {run-time system} closes open files and releases
+ other resources. An {exit status} code (a small integer, with
+ zero meaning OK and other values typically indicating some
+ kind of error) can be passed as the only argument to "exit";
+ this will be made available to the shell. Some languages
+ allow the programmer to set up exit handler code which will be
+ called before the standard system clean-up actions.
+
+ 2. Any point in a piece of code where control is returned to
+ the caller, possibly activating one or more user-provided exit
+ handlers. This might be a {return} statement, exit call (in
+ sense 1 above) or code that raises an error condition (either
+ intentionally or unintentionally). If the exit is from the
+ top-level routine then such a point would typically terminate
+ the whole program, as in sense 1.
+
+ (2008-05-15)
+
+EXODUS
+
+ <database> An extensible {database} project developed at the
+ University of Wisconsin.
+
+ (1996-05-13)
+
+eXodus
+
+ A package from White Pines allowing the Macintosh to be used
+ as an X server.
+
+EXOS
+
+ A brand of {Ethernet controller} card and Ethernet software
+ for {Unix}.
+
+ (1995-01-12)
+
+expanded memory
+
+ <storage> Memory used through {EMS}. In systems based on
+ {Intel 80386} or later processor expanded memory is part of
+ the {extended memory} that is mapped into the {expanded memory
+ page frame} by the processor. The mapping is controlled by
+ the {EMM}. In earlier systems, a dedicated {EMS} hardware
+ adaptor is needed to map memory into the page frame. In both
+ cases, an appropriate {device driver} is needed for the proper
+ communication between hardware and {EMM}.
+
+ (1996-01-10)
+
+expanded memory manager
+
+ <software, storage> (EMM) {IBM PC} memory manager software
+ implementing {Expanded Memory Specification}, such as {EMM386}
+ or {QEMM386}. EMMs can usually provide {UMB} as well.
+
+ (1996-01-10)
+
+expanded memory page frame
+
+ <storage> The part of the {IBM PC} {reserved memory} address
+ space used by {EMS}.
+
+ (1996-01-10)
+
+Expanded Memory Specification
+
+ <storage> (EMS) An {IBM PC} memory {paging} scheme enabling
+ access to memory other than {conventional memory} in {real
+ mode}.
+
+ {Expanded memory} is provided through a {page frame} of at
+ least 64 {kilobytes} in the {reserved memory} address region.
+ Access to this memory is provided by an {expanded memory
+ manager} (EMM) software. The EMM functions are accessible
+ through {interrupt} 67H.
+
+ In {8086} or {8088} based systems this is the only way to use
+ memory beyond conventional memory. In systems based on
+ {80286} or later, {XMS} and {HMA} provide alternative methods.
+
+ EMS was developed jointly by {Lotus}, {Intel}, and {Microsoft}
+ prior to 1988. Accordingly, this specification is sometimes
+ referred to as LIM EMS.
+
+ A complete discussion of EMS and programming examples can be
+ found in ["PC System Programming for developers", 1989, ISBN
+ 1-55755-035-2 (Book only) and ISBN 1-55755-036-0 (Book and
+ diskette)].
+
+ {EEMS}, a competing expanded memory management standard, was
+ developed by {AST Research}, {Quadram} and {Ashton-Tate}.
+
+ See also {upper memory block}.
+
+ (1996-01-10)
+
+expansion card
+
+ <hardware> A circuit board which can be plugged into one of a
+ computer's {expansion slots} to provide some optional extra
+ facility such as additional {RAM}, {disk controller},
+ {coprocessor}, {graphics accelerator}, communication device or
+ some special-purpose interface.
+
+ Different computers have different standards for the cards
+ they accept, e.g. {PCI}.
+
+ (1998-06-26)
+
+expansion slot
+
+ <hardware> A connector in a computer into which an {expansion
+ card} can be plugged. The connector supplies power to the
+ card and connects it to the {data bus}, {address bus} and
+ control signals of the {motherboard}.
+
+ (1998-06-26)
+
+expect
+
+ <language, tool> A {Unix} tool written in {Tcl} and a {script
+ language} for automating the operation of {interactive}
+ applications such as {telnet}, {FTP}, {passwd}, {fsck},
+ {rlogin}, {tip}, etc.. Expect can feed input to other
+ programs and perform {pattern matching} on their output. It
+ is also useful for testing these applications. By adding
+ {Tk}, you can also wrap interactive applications in {X11}
+ {GUIs}.
+
+ {(http://expect.nist.gov/)}.
+
+ ["expect: Scripts for Controlling Interactive Tasks", Don
+ Libes, Comp Sys 4(2), U Cal Press Journals, Nov 1991].
+
+ (1997-06-09)
+
+eXperimental LISP
+
+ <language> (xlisp) An experimental programming language
+ combining a subset of {Common Lisp} with an {object-oriented}
+ extension capability (Class and Object types). It was
+ implemented by David Micheal Betz at Apple to allow
+ experimentation with {object-oriented programming} on small
+ computers. The {C} {source code} has been ported to {Unix},
+ {Microsoft Windows}, {Macintosh}, {Amiga}, {Atari}, and
+ {MS-DOS}.
+
+ Version 2.1 of the {interpreter}, by Tom Almy is closer to
+ Common Lisp.
+
+ Latest version: 2.1, as of 1992-05-26.
+
+ {(ftp://wasp.eng.ufl.edu/)}, {(ftp://cs.orst.edu/)},
+ {(ftp://glia.biostr.washington.edu/)}.
+
+ E-mail: Tom Almy <toma@sail.labs.tek.com>.
+
+ {Microsoft Windows version
+ (ftp://ftp.cica.indiana.edu/util/wxlslib.zip)}.
+
+ {Macintosh version (ftp://netcom.com/pub/bskendig/)}.
+
+ {Usenet} newsgroup: {news:comp.lang.lisp.x}.
+
+ (2000-08-14)
+
+Experimental Physics Control Systems
+
+ <body> (EPCS) A group of the European Physical Society,
+ focussing on all aspects of controls, especially
+ {informatics}, in experimental physics, including accelerators
+ and experiments.
+
+ (1994-12-12)
+
+Experimental Programming Language
+
+ <language> (EPL) A language by {David May} which influenced
+ {occam}.
+
+ ["EPL: An Experimental Language for Distributed Computing",
+ D.C. May, in Trends and Applications 1978: Distributed
+ Processing, NBS, pp.69-71].
+
+ (1994-11-18)
+
+Experiment Description Language
+
+ <language> (EDL) J.S. Jenkins.
+
+ ["A Programmable System for Acquisition and Reduction of
+ Respiratory Physiological Data", J.S. Jenkins et al, Ann
+ Biomed Eng, 17:93-108 1989].
+
+ (2007-07-11)
+
+Expert Judgement Models
+
+ <programming> A method of software estimation that is based on
+ consultation with one or more experts that have experience
+ with similar projects. An expert-consensus mechanism such as
+ the {Delphi Technique} may be used to produce the estimate.
+
+ (1996-05-29)
+
+expert system
+
+ <artificial intelligence> A computer program that contains a
+ {knowledge base} and a set of {algorithms} or rules that infer
+ new facts from knowledge and from incoming data.
+
+ An expert system is an {artificial intelligence} application
+ that uses a knowledge base of human expertise to aid in
+ solving problems. The degree of problem solving is based on
+ the quality of the data and rules obtained from the human
+ expert. Expert systems are designed to perform at a human
+ expert level. In practice, they will perform both well below
+ and well above that of an individual expert.
+
+ The expert system derives its answers by running the knowledge
+ base through an {inference engine}, a software program that
+ interacts with the user and processes the results from the
+ rules and data in the knowledge base.
+
+ Expert systems are used in applications such as medical
+ diagnosis, equipment repair, investment analysis, financial,
+ estate and insurance planning, route scheduling for delivery
+ vehicles, contract bidding, counseling for self-service
+ customers, production control and training.
+
+ [Difference from "{knowledge-based system}"?]
+
+ (1996-05-29)
+
+Expert Systems Ltd.
+
+ <company> (ESL) Distributors of {ESLPDPRO}.
+
+ Adderss: Magdalen Centre, Oxford Science Park, Oxford, OX4
+ 4GA. Telephone +44 (865) 784474.
+
+ (1996-05-29)
+
+explicit parallelism
+
+ A feature of a programming language for a {parallel
+ processing} system which allows or forces the programmer to
+ annotate his program to indicate which parts should be
+ executed as independent parallel tasks. This is obviously
+ more work for the programmer than a system with {implicit
+ parallelism} (where the system decides automatically which
+ parts to run in parallel) but may allow higher performance.
+
+explicit type conversion
+
+ <programming> (Or "cast" in {C} and elsewhere). A programming
+ construct ({syntax}) to specify that an expression's value
+ should be converted to a different type.
+
+ For example, in {C}, to convert an {integer} (usually 32 bits)
+ to a {char} (usually 8 bits) we might write:
+
+ int i = 42;
+ char *p = &buf;
+ *p = (char) i;
+
+ The expression "(char)" (called a "cast") converts i's value
+ to char type. Casts (including this one) are often not
+ strictly necessary, due to automatic {coercions} performed by
+ the compiler, but can be used to make the conversion obvious
+ and to avoid warning messages.
+
+ (1999-09-19)
+
+exploit
+
+ <security> A security hole or an instance of taking advantage
+ of a security hole.
+
+ "[...] {hackers} say exploit. {sysadmins} say hole"
+ -- {Mike Emke (http://emke.com/)}.
+
+ Emke reports that the stress is on the second syllable. If
+ this is true, this may be a case of hackerly zero-deriving
+ verbs (especially instantials) from nouns, akin to "write" as
+ a noun to describe an instance of a disk drive writing to a
+ disk.
+
+ (2001-11-24)
+
+Exploratory Data Analysis
+
+ (EDA)
+
+ [J.W.Tukey, "Exploratory Data Analysis", 1977, Addisson
+ Wesley].
+
+exponent
+
+ <programming> (Or "characteristic") The part of a
+ {floating-point} number specifying the power of ten by which
+ the {mantissa} should be multiplied. In the common notation,
+ e.g. 3.1E8, the exponent is 8.
+
+ (1995-02-27)
+
+exponential
+
+ 1. <mathematics> A function which raises some given constant
+ (the "base") to the power of its argument. I.e.
+
+ f x = b^x
+
+ If no base is specified, {e}, the base of {natural
+ logarthims}, is assumed.
+
+ 2. <complexity> {exponential-time algorithm}.
+
+ (1995-04-27)
+
+exponential-time
+
+ <complexity> The set or property of problems which can be
+ solved by an {exponential-time algorithm} but for which no
+ {polynomial-time algorithm} is known.
+
+ (1995-04-27)
+
+exponential-time algorithm
+
+ <complexity> An {algorithm} (or {Turing Machine}) that is
+ guaranteed to terminate within a number of steps which is a
+ {exponential} function of the size of the problem.
+
+ For example, if you have to check every number of n digits to
+ find a solution, the {complexity} is O(10^n), and if you add
+ an extra digit, you must check ten times as many numbers.
+
+ Even if such an algorithm is practical for some given value of
+ n, it is likely to become impractical for larger values. This
+ is in contrast to a {polynomial-time algorithm} which grows
+ more slowly.
+
+ See also {computational complexity}, {polynomial-time},
+ {NP-complete}.
+
+ (1995-04-27)
+
+Express
+
+ 1. A language supporting {concurrency} through {message
+ passing} to named message queues from {ParaSoft} Corporation
+
+ {(ftp://ftp.parasoft.com/express/docs)}.
+
+ 2. Data definition language, meant to become an ISO standard
+ for product data representation and exchange. TC 184/SC4 N83,
+ ISO, 1991-05-31. E-mail: <smith@cme.nist.gov>.
+
+ 3. A data modelling language adopted by the {ISO} working
+ group on {STEP}.
+
+expression
+
+ <programming> Any piece of program code in a {high-level
+ language} which, when (if) its execution terminates, returns a
+ value. In most programming languages, expressions consist of
+ constants, variables, operators, functions, and {parentheses}.
+ The operators and functions may be built-in or user defined.
+ Languages differ on how expressions of different {types} may
+ be combined - with some combination of explicit {casts} and
+ implicit {coercions}.
+
+ The {syntax} of expressions generally follows conventional
+ mathematical notation, though some languages such as {Lisp} or
+ {Forth} have their own idiosyncratic syntax.
+
+ (2001-05-14)
+
+expression tree
+
+ <mathematics, grammar> The {syntax tree} of an {expression}.
+
+ (1998-11-14)
+
+extend
+
+ <programming> To add {features} to a program, especially
+ through the use of {hooks}.
+
+ "Extend" is very often used in the phrase "extend the
+ {functionality} of a program."
+
+ {Plug-ins} are one form of extension.
+
+ (1997-06-21)
+
+Extended Affix Grammar
+
+ <language, grammar> (EAG) A formalism for describing both the
+ {context free syntax} and the {context sensitive syntax} of
+ languages.
+
+ EAGs belong to the family of {two-level grammars}. They are
+ very closely related to two-level {van Wijngaarden grammars}.
+
+ EAG can be used as a specification formalism, specifying in
+ {relations} rather than {functions}, or as a {relational
+ programming language} like {PROLOG}.
+
+ {(http://www.cs.ru.nl/~kees/eag/)}
+
+ (2009-02-06)
+
+Extended ALGOL
+
+ <language> An extension of {ALGOL 60}, used to write the
+ {ESPOL} compiler on the {Burroughs B5500}, {Burroughs B6500},
+ and {Burroughs B6700}.
+
+ ["Burroughs B6700 Extended ALGOL Language Information Manual",
+ No. 5000128 (Jul 1971)].
+
+ [Sammet 1969, p. 196].
+
+ (1995-05-09)
+
+Extended Architecture
+
+ <storage> (XA) A {CD-ROM} drive specification required by
+ {Green Book CD-ROM} and {White Book CD-ROM} formats. Drives
+ labelled "XA ready" may require a {firmware} upgrade.
+
+ (1994-11-02)
+
+Extended Backus-Naur Form
+
+ <language> Any variation on the basic {Backus-Naur Form} (BNF)
+ {meta-syntax} notation with (some of) the following additional
+ constructs: {square brackets} "[..]" surrounding optional
+ items, suffix "*" for {Kleene closure} (a sequence of zero or
+ more of an item), suffix "+" for one or more of an item,
+ {curly brackets} enclosing a list of alternatives, and
+ super/subscripts indicating between n and m occurrences.
+
+ All these constructs can be expressed in plain BNF using extra
+ {productions} and have been added for readability and
+ succinctness.
+
+ (1995-04-28)
+
+Extended Binary Coded Decimal Interchange Code
+
+ <character, standard> /eb's*-dik/, /eb'see`dik/, /eb'k*-dik/,
+ /ee`bik'dik`/, /*-bik'dik`/ (EBCDIC) A proprietary 8-bit
+ {character set} used on {IBM} {dinosaurs}, the {AS/400}, and
+ {e-Server}.
+
+ EBCDIC is an extension to 8 bits of BCDIC (Binary Coded
+ Decimal Interchange Code), an earlier 6-bit character set used
+ on IBM computers. EBCDIC was [first?] used on the successful
+ {System/360}, anounced on 1964-04-07, and survived for many
+ years despite the almost universal adoption of {ASCII}
+ elsewhere. Was this concern for {backward compatibility} or,
+ as many believe, a marketing strategy to lock in IBM
+ customers?
+
+ IBM created 57 national EBCDIC character sets and an
+ International Reference Version (IRV) based on {ISO 646} (and
+ hence ASCII compatible). Documentation on these was not
+ easily accessible making international exchange of data even
+ between IBM mainframes a tricky task.
+
+ US EBCDIC uses more or less the same characters as {ASCII},
+ but different {code points}. It has non-contiguous letter
+ sequences, some ASCII characters do not exist in EBCDIC
+ (e.g. {square brackets}), and EBCDIC has some ({cent sign},
+ {not sign}) not in ASCII. As a consequence, the translation
+ between ASCII and EBCDIC was never officially completely
+ defined. Users defined one translation which resulted in a
+ so-called de-facto EBCDIC containing all the characters of
+ ASCII, that all ASCII-related programs use.
+
+ Some printers, telex machines, and even electronic cash
+ registers can speak EBCDIC, but only so they can converse with
+ IBM mainframes.
+
+ For an in-depth discussion of character code sets, and full
+ translation tables, see {Guidelines on 8-bit character codes
+ (ftp://ftp.ulg.ac.be/pub/docs/iso8859/iso8859.networking)}.
+
+ {A history of character codes
+ (http://tronweb.super-nova.co.jp/characcodehist.html)}.
+
+ (2002-03-03)
+
+Extended BNF
+
+ {Extended Backus-Naur Form}
+
+Extended C++
+
+ <language> {EC++} extended by G. Masotti
+ <masotti@lipari.usc.edu> with preconditions, postconditions
+ and {class invariants}, {parameterised classes}, {exception
+ handling} and {garbage collection}. {EC++} translates
+ Extended C++ into C++.
+
+ (1989-10-10)
+
+Extended Capabilities Port
+
+ <hardware> (ECP) A {parallel printer interface} for {IBM PC}
+ compatibles, supported by several, mainly US, manufacturers.
+
+ Not to be confused with the more common {Enhanced Capabilities
+ Port}.
+
+ (1997-12-01)
+
+Extended Concurrent Prolog
+
+ <language> (ECP) {Concurrent Prolog} with {OR parallelism},
+ {set abstraction} and {meta-inference} features.
+
+ ["AND-OR Queuing in Extended Concurrent Prolog", J. Tanaka et
+ al, Proc Logic Prog Conf '85, LNCS 193, Springer 1985].
+
+ (1994-12-01)
+
+Extended Data Out Dynamic Random Access Memory
+
+ <storage> (EDO DRAM, EDO RAM) A type of {DRAM} designed to
+ access nearby memory locations faster than {FPM DRAM}.
+
+ Extended Data Out DRAM (EDO-DRAM) allows the data outputs to
+ be kept active after the CAS\ signal goes inactive, using an
+ additional signal OE\ to control the data outputs. This can
+ be used in {pipelined} systems for overlapping accesses where
+ the next cycle is started before the data from the last cycle
+ is removed from the bus.
+
+ EDO DRAM is primarily used with {Intel}'s {Pentium} processors
+ since with slower processors there is no significant
+ performance gain. To make use of the advanced features of EDO
+ an appropriate {chipset}, such as {Triton}, must be used. In
+ early 1995, EDO DRAM was available for computers from
+ {Micron}, {Gateway 2000}, and {Intel Corporation}; since then
+ other manufactures followed suit.
+
+ Note that in comparison to {Burst EDO} EDO is sometimes
+ referred to as "Standard EDO".
+
+ (1996-06-25)
+
+Extended Data Out Random Access Memory
+
+ {Extended Data Out Dynamic Random Access Memory}
+
+Extended Fortran Language
+
+ (EFL) A {Fortran} {preprocessor} to provide {structured
+ programming} constructs much like {C}. EFL is a descendant of
+ {RATFOR}. It is written in C.
+
+ ["An Informal Description of EFL", S.I. Feldman].
+
+eXtended Graphics Array
+
+ <hardware> (XGA) An {IBM} {display standard} introduced in
+ 1990.
+
+ XGA supports a {resolution} of 1024 x 768 {pixels} with a
+ {palette} of 256 colours, or 640 x 480 with {high colour} (16
+ {bits per pixel}).
+
+ XGA-2 added 1024 x 768 support for high colour and higher
+ refresh rates, improved performance, and supports 1360 x 1024
+ in 16 colours.
+
+ XGA is probably not the same as {8514-A}.
+
+ See also {VESA}'s {EVGA} released at a similar time.
+
+ (1999-08-01)
+
+Extended Industry-Standard Architecture
+
+ <architecture, standard> (EISA) /eesa/ A {bus} standard for
+ {IBM compatibles} that extends the {ISA} bus architecture to
+ 32 bits and allows more than one {CPU} to share the bus. The
+ {bus mastering} support is also enhanced to provide access to
+ 4 GB of memory. Unlike {MCA}, EISA can accept older {XT bus
+ architecture} and {ISA} boards.
+
+ EISA was announced in late 1988 by compatible vendors as a
+ counter to {IBM}'s MCA in its {PS/2} series. Although
+ somewhat inferior to the MCA it became much more popular due
+ to the proprietary nature of MCA.
+
+ [Main sponsors? Open standard?]
+
+ (1996-06-25)
+
+extended memory
+
+ <storage> Memory above the first {megabyte} of {address space}
+ in an {IBM PC} with an {80286} or later processor.
+
+ Extended memory is not directly available in {real mode}, only
+ through {EMS}, {UMB}, {XMS}, or {HMA}; only applications
+ executing in {protected mode} can use extended memory
+ directly. In this case, the extended memory is provided by a
+ supervising {protected-mode} {operating system} such as
+ {Microsoft Windows}. The processor makes this memory
+ available through a system of {global descriptor tables} and
+ {local descriptor tables}. The memory is "protected" in the
+ sense that memory assigned a local descriptor cannot be
+ accessed by another program without causing a hardware {trap}.
+ This prevents programs running in protected mode from
+ interfering with each other's memory.
+
+ A {protected-mode} {operating system} such as Windows can also
+ run {real-mode} programs and provide {expanded memory} to
+ them. {DOS Protected Mode Interface} is {Microsoft}'s
+ prescribed method for an {MS-DOS} program to access extended
+ memory under a {multitasking} environment.
+
+ Having extended memory does not necessarily mean that you have
+ more than one megabyte of memory since the reserved memory
+ area may be partially empty. In fact, if your 386 or higher
+ uses extended memory as expanded memory then that part is not
+ in excess of 1Mb.
+
+ See also {conventional memory}.
+
+ (1996-01-10)
+
+extended memory manager
+
+ <software, storage> (XMM) The memory manager software
+ implementing {Extended Memory Specification}, such as {HIMEM}
+ or {QEMM386}. XMM's can usually also act as {A20 handlers}.
+
+ (1996-01-10)
+
+Extended Memory Specification
+
+ <storage> (XMS) The specification describing the use of {IBM
+ PC} {extended memory} in {real mode} for storing data (but not
+ executable code). Memory is made available by {extended
+ memory manager} (XMM) software. The XMM functions are
+ accessible through {interrupt} 2FH.
+
+ (1996-01-10)
+
+Extended ML
+
+ A language by Don Sannella of the {University of Edinburgh}
+ combining {algebraic specification} and {functional
+ programming}.
+
+ ["Program Specification and Development in Standard ML",
+ D. Sannella et al, 12th POPL, ACM 1985].
+
+ (1994-12-12)
+
+Extended Pascal
+
+ A superset of {ANSI} and {ISO Pascal} with many enhancements,
+ including {modules}, {separate compilation}, {type schema}ta,
+ variable-length strings, direct-access files, complex numbers,
+ initial values, constant expressions. ANSI/IEEE770X3.160-1989
+ and ISO 10206.
+
+ (1994-12-12)
+
+Extended Self-containing Prolog
+
+ <language> (ESP) An {object-oriented} extension of {KL0} by
+ Chikayama. ESP has {backtracking}-based control,
+ {unification}-based parameter passing and {object-oriented}
+ calling. An {object} in ESP is an {axiom} set. A {class}
+ definition consists of nature definitions ({inheritance}),
+ slot definitions ({class variables}) and {clause} definitions.
+ ESP has {multiple inheritance} similar to {Flavors}. It has
+ been implemented for {ICOT}'s {PSI} Sequential Inference
+ machine.
+
+ See also {CESP}.
+
+ E-mail: <k-hata@air.co.jp>.
+
+ ["Unique Features of ESP", T. Chikayama, Proc Intl Conf 5th
+ Gen Comp Sys, ICOT 1984].
+
+ (1994-12-08)
+
+Extended System Configuration Data
+
+ <operating system> (ESCD) An area of memory, not exceeding 32
+ kilobytes in size, used by {MS-DOS}(?) as {NVRAM} for {PNP
+ BIOS} and {PNP OS}. It must be writeable at {run time}.
+
+ Intel's {ICU} also uses ESCD to store information for PNP
+ {ISA} cards and {legacy} ISA cards.
+
+ (1999-11-22)
+
+Extended Systems Modelling Language
+
+ <language> (ESML) A {real-time} software engineering
+ methodology based on {RTSA}.
+
+ (2009-05-11)
+
+Extended Tcl
+
+ <language> (TclX) {Tcl} extended by Mark Diekhans
+ <markd@NeoSoft.com> and Karl Lehenbauer from 1989 on with
+ statements to provide high-level access {Unix} system
+ primitives.
+
+ Latest version: 7.6p2, as of 2003-02-12.
+
+ {TclX Home (http://neosoft.com/tclx/)}.
+
+ E-mail: <tcl-project@NeoSoft.com>.
+
+ (2003-02-12)
+
+Extended Tiny
+
+ A research/educational tool for experimenting with {array}
+ data dependence tests and reordering transformations. It
+ works with a language {tiny}, which does not have procedures,
+ {goto}'s, pointers, or other features that complicate
+ dependence testing.
+
+ Michael Wolfe's original {tiny} has been extended
+ substantially by William Pugh <pugh@cs.umd.edu> et al. at the
+ {University of Maryland}.
+
+ Version 3.0 (Dec 12th, 1992) includes a programming
+ environment, dependence tester, tests translator
+ ({Fortran}->tiny), documentation, and technical reports. It
+ should run on any {Unix} system.
+
+ {(ftp://cs.umd.edu/pub/omega)}.
+
+ E-mail: Omega test research group <omega@cs.umd.edu>.
+
+ (1992-12-12)
+
+Extended Video Graphics Array
+
+ <hardware, graphics> (EVGA) A {display standard} introduced by
+ {VESA} in 1991.
+
+ It offers a maximum {resolution} of 1024 x 768 {pixels}
+ ({non-interlaced}) and a 70 Hz {refresh rate}.
+
+ EVGA should not be confused with the older {EGA} (Enhanced
+ Graphics Array) or {XGA} (eXtended Graphics Array).
+
+ [Same as "{eXtended Video Graphics Array}" (XVGA)?]
+
+ (1999-08-01)
+
+eXtended Video Graphics Array
+
+ <hardware> (XVGA) A {display standard} with a {resolution} of
+ 1024 by 768 {pixels} of 256 colours. {IBM} call this mode
+ "{8514}".
+
+ [Same as "{Extended Video Graphics Array}" (EVGA)?]
+
+ (1997-12-11)
+
+ExTendible Compiler
+
+ <language> (ETC) A {Fortran}-like compiler that can be
+ extended with {macros}.
+
+ ["ETC - An Extendible Macro-Based Compiler", B.N. Dickman,
+ Proc SJCC 38 1971].
+
+ (2010-01-28)
+
+extensible
+
+ <programming> Said of a system (e.g., {program}, {file
+ format}, {programming language}, {protocol}, etc.) designed to
+ easily allow the addition of new {features} at a later date,
+ e.g. through the use of {hooks}, an {API} or {plug-ins}.
+
+ See also {extend}, {forward compatible}.
+
+ (1998-01-15)
+
+extensible database
+
+ <database> A {DBMS} that allows access to data from remote
+ sources as if the remote data were part of the {database}.
+
+ [Example?]
+
+ (1997-11-20)
+
+Extensible Firmware Interface
+
+ <specification> (EFI) A specification originating from {Intel
+ Corporation}, defining the {interface} between an {operating
+ system} and {platform} {firmware}, and aiming to reduce OS
+ dependence on details of the firmware implementation.
+
+ {EFI Home (http://intel.com/technology/efi/)}.
+
+ (2004-10-23)
+
+Extensible HyperText Markup Language
+
+ <hypertext, standard, web> (XHTML) A reformulation
+ of {HTML} 4.01 in {XML}. Being XML means that XHTML can be
+ viewed, edited, and validated with standard XML tools. At the
+ same time, it operates as well as or better than HTML 4 in
+ existing HTML 4 conforming user agents.
+
+ The most important change is that all elements must be
+ terminated, either with a closing tag or using the <tag.../>
+ shorthand. So, instead of
+
+ <input type=submit>
+
+ you would write
+
+ <input type="submit" />
+
+ The space before the "/" is required by some older browsers.
+ Other differences are that tag and attribute names should be
+ lower case and all attributes should be quoted.
+
+ {XHTML Home (http://w3.org/TR/xhtml1/)}.
+
+ {Quick Summary
+ (http://technorealm.co.uk/design/html-to-xhtml-conversions.html)}
+
+ Latest version: 1.0 Second Edition 2002-08-01, as of 2004-03-16.
+
+ (2006-01-19)
+
+Extensible Markup Language
+
+ <language, text> (XML) An initiative from the {W3C} defining
+ an "extremely simple" dialect of {SGML} suitable for use on
+ the {web}.
+
+ {(http://w3.org/XML/)}.
+
+ [Relationship to the {XSL} forthcoming subset of {DSSSL}?]
+
+ (1997-11-20)
+
+Extensible Shell
+
+ <operating system> (es) A {Unix} {shell} written by Byron
+ Rakitzis <byron@netapp.com> and Paul Haahr <haahr@adobe.com>,
+ derived from {rc}. Es has real {functions}, {closures},
+ {exceptions} and lets you redefine most internal shell
+ operations.
+
+ Version: 0.84.
+
+ {(ftp://ftp.sys.utoronto.ca/pub/es/)}.
+
+ ["Es - A Shell with Higher Order Functions", P. Haahr et al,
+ Proc Winter 1993 Usenix Technical Conference].
+
+ (1993-04-30)
+
+Extensible Stylesheet Language
+
+ <web> (XSL) A {standard} developed by the {World
+ Wide Web Consortium} defining a language for transforming and
+ formatting {XML (eXtensible Markup Language)} documents.
+
+ An XSL {stylesheet} is written in {XML} and consists of
+ instructions for tree transformation and formatting. The tree
+ transformations describe how each XML {tag} relates to other
+ data and the formatting instructions describe how to output
+ the various types of data.
+
+ {(http://w3.org/Style/XSL/)}.
+
+ See also {Extensible Stylesheet Language Transformations}.
+
+ (2005-09-30)
+
+Extensible Stylesheet Language Transformations
+
+ <web> (XSLT) A {W3C} standard for transforming
+ {XML} documents into other XML documents or other formats.
+ This was conceived as part of {XSL} but has been found to have
+ wider applications.
+
+ {(http://w3.org/TR/xslt)}.
+
+ (2001-10-04)
+
+Extensible VAX Editor
+
+ <text, tool> (EVE) A {DEC} product implemented using DEC's
+ {Text Processing Utility} (TPU).
+
+ [Details?]
+
+ (2000-05-08)
+
+extension
+
+ 1. <filename extension> {filename extension}.
+
+ 2. <programming> A {feature} or piece of {code} which
+ {extends} a program's {functionality}, e.g. a {plug-in}.
+
+ (1997-06-21)
+
+extensional
+
+ Extensional properties, e.g. extensional equality, relate to
+ the "black-box" behaviour of an object, i.e. how its output
+ depends on its input. The opposite is intensional which
+ concerns how the object is implemented.
+
+extensional equality
+
+ (Or extensionality). Functions, f and g are extensionally
+ equal if and only if
+
+ f x = g x for all x.
+
+ where "=" means both expressions fail to terminate (under some
+ given {reduction strategy}) or they both terminate with the
+ same basic value.
+
+ Two functions may be extensionally equal but not
+ inter-convertible (neither is reducible to the other). E.g.
+ \ x . x+x and \ x . 2*x. See also {observational
+ equivalence}, {referential transparency}.
+
+extensionality
+
+ {extensional equality}
+
+Extension Language Kit
+
+ <language> (Elk) A {Scheme} {interpreter} by Oliver Laumann
+ <net@cs.tu-berlin.de> and Carsten Bormann
+ <cabo@cs.tu-berlin.de> of the {Technical University of
+ Berlin}. Elk was designed to be used as a general extension
+ language. New {types} and {primitive} procedures can easily
+ be added. It has {first-class environments}, {dynamic-wind},
+ {fluid-let}, {macros}, {autoload}ing and a {dump}. It
+ provides interfaces to {Xlib}, {Xt} and various {widget} sets;
+ {dynamic loading} of extensions and {object files}; almost all
+ artificial limitations removed; {generational}/{incremental
+ garbage collector}; {Unix} {system call} extensions; {Records}
+ (structures) and {bit strings}.
+
+ Version: 2.2 is mostly {R3RS} compatible and runs on {Unix},
+ {Ultrix}, {VAX}, {Sun-3}, {Sun-4}, {68000}, {i386}, {MIPS}, {IBM
+ PC RT}, {RS/6000}, {HP700}, {SGI}, {Sony}, {MS-DOS}
+ ({gcc}+{DJGPP} or {go32}).
+
+ {Germany
+ (ftp://ftp.fu-berlin.de/pub/Unix/languages/scheme/elk-2.2.tar.gz)}.
+ {US (ftp://ftp.x.org/contrib/elk-2.2.tar.gz)}. {US
+ (ftp://gatekeeper.dec.com/pub/comp.sources.misc/volume8/elk)}.
+
+ (1994-12-15)
+
+Exterior Gateway Protocol
+
+ (EGP) A protocol which distributes routing information to the
+ {routers} which connect {autonomous systems}. The term
+ "{gateway}" is historical, and "router" is currently the
+ preferred term. There is also a routing protocol called {EGP}
+ defined in STD 18, RFC 904. See also {Border Gateway
+ Protocol}, {Interior Gateway Protocol}.
+
+eXternal Data Representation
+
+ (XDR) A {standard} for machine independent data structures
+ developed by {Sun Microsystems} for use in {remote procedure
+ call} systems. It is defined in {RFC 1014} and is similar to
+ {ASN.1}.
+
+ (1994-12-13)
+
+External Machine Interface
+
+ <protocol> (EMI) A {protocol} primarily used to connect to
+ {short message service} centres for {mobile telephones}. EMI
+ is an extension to Universal Computer Protocol (UCP). EMI was
+ was developed by CMG, now a part of {LogicaCMG}, the current
+ {SMSC} market leader.
+
+ Each byte of the message is encoded as two {hexadecimal}
+ characters using an encoding not quite like {ASCII}.
+
+ {EMI specification
+ (http://www.netfunitalia.it/downloads/SMSC_EMI_Specification.PDF)}
+
+ (2007-09-10)
+
+external memory
+
+ <storage> A vague term for slower, {non-volatile storage},
+ usually {magnetic disk}, in contrast to {main memory} which is
+ usually volatile {semiconductor} {RAM}.
+
+ [{Jargon File}]
+
+ (1997-02-17)
+
+EXTRA
+
+ Object-oriented, Pascal style, handles sets. "A Data Model
+ and Query Language for EXODUS", M.J. Carey et al, SIGMOD 88
+ Conf Proc, pp.413- 423, ACM SIGMOD Record 17:3 (Sept 1988).
+
+extranet
+
+ <web> The extension of a company's {intranet} out
+ onto the {Internet}, e.g. to allow selected customers,
+ suppliers and mobile workers to access the company's private
+ data and applications via the {web}. This is in
+ contrast to, and usually in addition to, the company's public
+ {website} which is accessible to everyone. The difference
+ can be somewhat blurred but generally an extranet implies
+ real-time access through a {firewall} of some kind.
+
+ Such facilities require very careful attention to security but
+ are becoming an increasingly important means of delivering
+ services and communicating efficiently.
+
+ [Did {Marc Andreessen} invent the term in September 1996?]
+
+ (1997-12-17)
+
+extrapolate
+
+ {extrapolation}
+
+extrapolation
+
+ <mathematics, algorithm> A mathematical procedure which
+ estimates values of a {function} for certain desired inputs
+ given values for known inputs.
+
+ If the desired input is outside the range of the known values
+ this is called extrapolation, if it is inside then it is
+ called interpolation.
+
+ The method works by fitting a "curve" (i.e. a function) to two
+ or more given points and then applying this function to the
+ required input. Example uses are calculating {trigonometric
+ functions} from tables and audio waveform sythesis.
+
+ The simplest form of interpolation is where a function, f(x),
+ is estimated by drawing a straight line ("linear
+ interpolation") between the nearest given points on either
+ side of the required input value:
+
+ f(x) ~ f(x1) + (f(x2) - f(x1))(x-x1)/(x2 - x1)
+
+ There are many variations using more than two points or higher
+ degree {polynomial} functions. The technique can also be
+ extended to functions of more than one input.
+
+ (2007-06-29)
+
+EXUG
+
+ {European X User Group}
+
+eyeball search
+
+ <jargon> (Or vgrep) To look for something in a mass of code or
+ data with one's own native optical sensors, as opposed to
+ using some sort of pattern matching software like {grep} or
+ any other automated search tool.
+
+ Compare {vdiff}, {desk check}.
+
+ [{Jargon File}]
+
+ (1997-12-17)
+
+EZ
+
+ High-level string-processing language derived from SNOBOL4,
+ SL5 and Icon.
+
+ ["The EZ Reference Manual", C.W. Fraser et al, CS TR 84-1, U
+ Arizona, 1984].
+
+ezd
+
+ <graphics, tool> (Easy drawing) A graphics {server} that sits
+ between an {application program} and an {X} server and allows
+ both existing and new programs easy access to structured
+ graphics. Ezd users have been able to have their programs
+ produce interactive drawings within hours of reading the
+ manual page. Ezd supports structured graphics - application
+ defined graphical objects are ordered into drawings by the
+ application. Unlike most X tools, ezd does not require any
+ event handling by the application. The ezd server maintains
+ the window contents. When an event occurs an application
+ supplied {Scheme} expression is evaluated.
+
+ Latest version: 15mar93 (as of 1993-03-10).
+
+ {(ftp://gatekeeper.dec.com/pub/DEC/ezd/)}.
+
+ Contact: Joel Bartlett.
+
+ (2000-03-25)
+
+e-zine
+
+ {electronic magazine}
+
+F100-L
+
+ {Ferranti F100-L}
+
+f2c
+
+ A {Fortran 77} to {C} translator by S. I. Feldman, D. M. Gay,
+ M. W. Maimone and N. L. Schryer. Produces {ANSI C} or {C++}.
+
+ {(ftp://netlib.bell-labs.com/netlib/f2c)}.
+
+ E-mail: <dmg@bell-labs.com>.
+
+ Latest version: 1997.07.24.
+
+ (1997-08-01)
+
+F2F
+
+ {face-to-face}
+
+F68K
+
+ A portable {Forth} system for {Motorola} {680x0} computers by
+ Joerg Plewe <joerg.plewe@mpi-dortmund.mpg.de>. Ported to
+ {Atari ST}, {Atari TT}, {Amiga}, {Sinclair QL} and {OS9}.
+ Easily ported to {Motorola} {68000} based systems.
+
+ {(ftp://archive.umich.edu/atari/Languages/)}.
+
+ (1992-12-14)
+
+FAC
+
+ Functional Array Calculator. An {APL}-like language, but
+ {purely functional} and {lazy}. It allows infinite {arrays}.
+
+ ["FAC: A Functional APL Language", H.-C. Tu and A.J. Perlis,
+ IEEE Trans Soft Eng 3(1):36-45 (Jan 1986)].
+
+facebook.com
+
+ <web> One of the most popular {social networking}
+ websites.
+
+ {FaceBook home (http://facebook.com/)}.
+
+ (2007-11-16)
+
+face time
+
+ <jargon> Time spent interacting with somebody face-to-face (as
+ opposed to via electronic links). "Oh, yeah, I spent some
+ face time with him at the last Usenix."
+
+ [{Jargon File}]
+
+face-to-face
+
+ <jargon, chat> (F2F, {IRL}) Used to describe personal
+ interaction in real life as opposed to via some digital or
+ electronic communications medium.
+
+ (1997-01-31)
+
+Facile
+
+ <language> A {concurrent} extension of {ML} from {ECRC}.
+
+ {(http://ecrc.de/facile/facile_home.html)}.
+
+ ["Facile: A Symmetric Integration of Concurrent and Functional
+ Programming", A. Giacalone et al, Intl J Parallel Prog
+ 18(2):121-160, Apr 1989].
+
+ (1994-12-01)
+
+facsimile
+
+ <communications> ("fax") A process by which fixed graphic
+ material including pictures, text, or images is scanned and
+ the information converted into electrical signals which are
+ transmitted via telephone to produce a paper copy of the
+ graphics on the receiving fax machine.
+
+ Some {modems} can be used to send and receive fax data. {V.27
+ ter} and {V.29} {protocols} are used.
+
+ [Details? Standards?]
+
+ (2004-07-26)
+
+FACT
+
+ {Fully Automated Compiling Technique}
+
+fact
+
+ <artificial intelligence, programming> The kind of {clause}
+ used in {logic programming} which has no {subgoals} and so is
+ always true (always succeeds). E.g.
+
+ wet(water).
+ male(denis).
+
+ This is in contrast to a {rule} which only succeeds if all its
+ subgoals do. Rules usually contain {logic variables}, facts
+ rarely do, except for oddities like "equal(X,X).".
+
+ (1996-10-20)
+
+factor
+
+ A quantity which is multiplied by another quantity.
+
+ See also {divisor}.
+
+ [{Jargon File}]
+
+factorial
+
+ <mathematics> The mathematical {function} that takes a
+ {natural number}, N, and returns the product of N and all
+ smaller positive integers. This is written
+
+ N! = N * (N-1) * (N-2) * ... * 1.
+
+ The factorial of zero is one because it is an {empty
+ product}.
+
+ Factorial can be defined {recursively} as
+
+ 0! = 1
+ N! = N * (N-1)! , N > 0
+
+ The {gamma function} is the equivalent for {real numbers}.
+
+ For example, the number of ways of shuffling 52 playing cards is
+ 52! or nearly 10^68. {52 Factorial
+ (http://czep.net/weblog/52cards.html)}.
+
+ (2012-11-23)
+
+FAD
+
+ ["FAD, A Simple and Powerful Database Language", F. Bancilon
+ et al, Proc 13th Intl Conf on VLDB, Brighton, England, Sep
+ 1987].
+
+failback
+
+ {failover}
+
+failover
+
+ <systems> Automatically switching to a different, {redundant}
+ system upon {failure} or {abnormal termination} of the currently
+ active system. Failover can be applied to a {cluster} of
+ {servers}, to {network} or storage components or any other set of
+ redundant devices that must provide {high availability} because
+ down-time would be expensive or inconvenient. It may be
+ implemented in hardware, software or a combination.
+
+ A "{hot standby}" is continuously active at the same time as
+ the failed system, using some kind of {load balancing} to
+ share the work, whereas a "{warm standby}" is ready to become
+ active at short notice.
+
+ When the failed system is operational again it may "failback",
+ i.e. become (one of) the active system(s) or it may become a
+ warm standby.
+
+ (2008-01-15)
+
+failure
+
+ The inability of a system or system component to perform a
+ required function within specified limits. A failure may be
+ produced when a {fault} is encountered.
+
+ (1996-05-13)
+
+failure-directed testing
+
+ <programming> (Or "heuristics testing") Software testing based
+ on the knowledge of the types of {errors} made in the past
+ that are likely for the system under test.
+
+ (1996-05-16)
+
+FAIR
+
+ <language> An early system on the {IBM 705}.
+
+ [Listed in CACM 2(5):1959-05-16].
+
+ (1996-05-13)
+
+Fairchild F8
+
+ <processor> An 8-bit {microprocessor}. The processor itself
+ had no {address bus} - program and data memory access were
+ contained in separate units, which reduced the number of pins
+ and the associated cost. It also featured 64 {registers},
+ accessed by the ISAR register in cells ({register windows}) of
+ eight, which meant external {RAM} wasn't always needed for
+ small applications. In addition, the 2-chip processor didn't
+ need support chips, unlike others which needed seven or more.
+
+ The F8 inspired other similar {CPUs}, such as the {Intel
+ 8048}. The use of the ISAR register allowed a subroutine to
+ be entered without saving a bunch of registers, speeding
+ execution - the ISAR would just be changed. Special purpose
+ registers were stored in the second cell (regs 9-15), and the
+ first eight registers were accessed directly. The windowing
+ concept was useful, but only the register pointed to by the
+ ISAR could be accessed - to access other registers the ISAR
+ was incremented or decremented through the window.
+
+ (1994-11-16)
+
+fall back
+
+ <communications> A feature of a {modem} {protocol} where two
+ modems which experience data corruption, e.g. due to line
+ noise, can renegotiate to use a lower speed connection,
+ possibly applying {fall forward} if the channel improves.
+
+ (2004-07-30)
+
+fall forward
+
+ <communications> A feature of a {modem} {protocol} where two
+ modems which {fall back} to a lower speed because of data
+ corruption can later return to the higher speed if the
+ connection improves.
+
+ (2004-07-30)
+
+fall over
+
+ [IBM] Yet another synonym for {crash} or {lose}. "Fall over
+ hard" equates to {crash and burn}.
+
+ [{Jargon File}]
+
+fall through
+
+ <programming> (The American misspelling "fall thru" is
+ also common)
+
+ 1. To exit a loop by exhaustion, i.e. by having fulfilled its
+ exit condition rather than via a break or exception condition
+ that exits from the middle of it. This usage appears to be
+ *really* old, dating from the 1940s and 1950s.
+
+ 2. To fail a test that would have passed control to a
+ subroutine or some other distant portion of code.
+
+ 3. In C, "fall-through" occurs when the flow of execution in a
+ {switch statement} reaches a "case" label other than by
+ jumping there from the switch header, passing a point where
+ one would normally expect to find a "break". A trivial
+ example:
+
+ switch (colour)
+ {
+ case GREEN:
+ do_green();
+ break;
+ case PINK:
+ do_pink();
+ /* FALL THROUGH */
+ case RED:
+ do_red();
+ break;
+ default:
+ do_blue();
+ break;
+ }
+
+ The effect of the above code is to "do_green()" when colour is
+ "GREEN", "do_red()" when colour is "RED", "do_blue()" on any
+ other colour other than "PINK", and (and this is the important
+ part) "do_pink()" __and then__ "do_red()" when colour is "PINK".
+ Fall-through is {considered harmful} by some, though there are
+ contexts (such as the coding of state machines) in which it is
+ natural; it is generally considered good practice to include a
+ comment highlighting the fall-through where one would normally
+ expect a break. See also {Duff's Device}.
+
+fall thru
+
+ {fall through}
+
+FALSE
+
+ A small, compiled extensible language with {lambda
+ abstractions} by W. van Oortmerssen.
+
+ {For Amiga (ftp://ftp.cso.uiuc.edu/pub/amiga/fish/ff885)}.
+
+fandango on core
+
+ <jargon, programming> (Unix/C, from the Mexican dance) In {C},
+ a wild pointer that runs out of bounds, causing a {core dump},
+ or corrupts the {malloc} {arena} in such a way as to cause
+ mysterious failures later on, is sometimes said to have "done
+ a fandango on core". On low-end personal machines without an
+ {MMU}, this can corrupt the {operating system} itself, causing
+ massive lossage. Other frenetic dances such as the rhumba,
+ cha-cha, or watusi, may be substituted.
+
+ See {aliasing bug}, {precedence lossage}, {smash the stack},
+ {memory leak}, {memory smash}, {overrun screw}, {core}.
+
+ [{Jargon File}]
+
+ (1994-12-16)
+
+fan-out
+
+ <electronics> The number of {logic gate} inputs that can be
+ driven from a single gate output of the same type. Circuit
+ designers need to add extra {buffers} if a signal goes to more
+ inputs than the fan-out of the gate that produces it allows.
+
+ (2007-05-16)
+
+FAP
+
+ <language> The {assembly language} for {Sperry-Rand 1103} and
+ 1103A.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1994-12-16)
+
+FAQ
+
+ {frequently asked question}
+
+FAQL
+
+ {frequently asked question}
+
+FAQ list
+
+ {frequently asked question}
+
+faradise
+
+ /far'*-di:z/ [US Geological Survey] To start any
+ hyper-addictive process or trend, or to continue adding
+ current to such a trend. Telling one user about a new
+ octo-tetris game you compiled would be a faradising act - in
+ two weeks you might find your entire department playing the
+ faradic game.
+
+farkled
+
+ <jargon> /far'kld/ (From DeVry Institute of Technology,
+ Atlanta) A synonym for {hosed}. Possibly related to Yiddish
+ "farblondjet" and/or the "Farkle Family" skits on Rowan &
+ Martin's Laugh-In.
+
+ [{Jargon File}]
+
+ (1998-09-07)
+
+farm
+
+ {processor farm}
+
+farming
+
+ <jargon> (From Adelaide University, Australia) What the
+ {heads} of a {disk drive} are said to do when they plow little
+ furrows in the magnetic media during a {head crash}.
+ Typically used as follows: "Oh no, the machine has just
+ crashed; I hope the hard drive hasn't gone {farming} again."
+
+ [{Jargon File}]
+
+ (2001-03-26)
+
+FARNET
+
+ A non-profit corporation, established in 1987, whose mission
+ is to advance the use of computer networks to improve research
+ and education.
+
+fas
+
+ 1. Frankenstein Cross Assemblers. A reconfigurable assembler
+ package, especially suited for 8-bit processors, consisting of
+ a base assembler module and a {yacc} parser, for each
+ {microprocessor}, to handle {mnemonics} and addressing.
+ Second party parser modules available from many sites.
+
+ Base assembler and yacc parser modules by Mark Zenier. FTP:
+ ftp.njit.edu/pub/msdos/frankasm/frankasm.zoo.
+
+ 2. FAS. A general purpose language sponsored by the Finnish
+ government in the 70's and 80's.
+
+FASBOL
+
+ ["FASBOL. A SNOBOL4 Compiler", P.J. Santos, Memo ERL-M134, UC
+ Berkeley 1971].
+
+fascist
+
+ <jargon> Said of a computer system with excessive or annoying
+ security barriers, usage limits, or access policies. The
+ implication is that said policies are preventing hackers from
+ getting interesting work done. The variant "fascistic" seems
+ to have been preferred at {MIT}.
+
+ In the design of languages and other software tools, "the
+ fascist alternative" is the most restrictive and structured
+ way of capturing a particular function; the implication is
+ that this may be desirable in order to simplify the
+ implementation or provide tighter error checking. Compare
+ {bondage-and-discipline language}, although that term is
+ global rather than local.
+
+ [{Jargon File}]
+
+ (2003-07-29)
+
+FASE
+
+ Fundamentally Analyzable Simplified English.
+
+ L.E. McMahon, Bell Labs.
+
+ [Sammet 1969, p.720].
+
+ (1994-11-09)
+
+FAST
+
+ 1. <body> {Federation Against Software Theft}.
+
+ 2. <language> {Fortran Automatic Symbol Translator}.
+
+ (1996-05-19)
+
+Fast ATA
+
+ {Advanced Technology Attachment Interface with Extensions}
+
+Fast ATA-2
+
+ {Advanced Technology Attachment Interface with Extensions}
+
+Faster LEX
+
+ <language> (FLEX) A reimplementation of the {Lex} {scanner
+ generator}, by Vern Paxson <vern@ee.lbl.gov>.
+
+ {Flex++} produces {C++} and {aflex} produces {Ada}.
+
+ FTP flex-2.3.8.tar.Z from a {GNU archive site} or
+ {(ftp://ftp.ee.lbl.gov/pub/flex-2.4.3.tar.Z)}.
+
+ ["The FLEX Scanner Generator", Vern Paxson <vern@ee.lbl.gov>,
+ Systems Engineering, LBL, CA].
+
+ [Home? Current version?]
+
+ (2003-12-16)
+
+Fast Ethernet
+
+ <networking> A version of {Ethernet} developed in the 1990s(?)
+ which can carry 100 {Mbps} compared with standard Ethernet's
+ 10 Mbps. It requires upgraded {network cards} and {hubs}.
+
+ The relevant standards are {100BaseT}, {100BaseFX} and
+ {100BaseVG}.
+
+ (1998-03-23)
+
+Fast Fourier Transform
+
+ <algorithm> (FFT) An {algorithm} for computing the {Fourier
+ transform} of a set of discrete data values. Given a finite
+ set of data points, for example a periodic sampling taken from
+ a real-world signal, the FFT expresses the data in terms of
+ its component frequencies. It also solves the essentially
+ identical inverse problem of reconstructing a signal from the
+ frequency data.
+
+ The FFT is a mainstay of {numerical analysis}. Gilbert Strang
+ described it as "the most important algorithm of our
+ generation". The FFT also provides the asymptotically fastest
+ known algorithm for multiplying two {polynomials}.
+
+ Versions of the algorithm (in {C} and {Fortran}) can be found
+ on-line from the {GAMS} server {here
+ (http://gams.nist.gov/cgi-bin/gams-serve/class/J1.html)}.
+
+ ["Numerical Methods and Analysis", Buchanan and Turner].
+
+ (1994-11-09)
+
+Fast Packet
+
+ {Asynchronous Transfer Mode}
+
+Fast Page Mode Dynamic Random Access Memory
+
+ <hardware, storage> Is this the same as {Page Mode Dynamic
+ Random Access Memory}?
+
+ (1996-10-06)
+
+Fast SCSI
+
+ <hardware> A variant on the {SCSI-2} bus. It uses the same
+ 8-bit bus as the original {SCSI}-1 but runs at up to 10MB/s -
+ double the speed of SCSI-1.
+
+ (1994-11-24)
+
+FAT
+
+ {File Allocation Table}
+
+FAT32
+
+ {File Allocation Table}
+
+fatal
+
+ <programming> Resulting in termination of the program.
+
+ (1997-08-03)
+
+fatal error
+
+ <programming, operating system> Any {error} which causes
+ abrupt {termination} of the program. The program may be
+ terminated either by itself or by the {operating system} (a
+ "{fatal exception}"). In the former instance, the program
+ contains code which catches the error and, as a result,
+ returns to the operating system or calls an operating system
+ service to terminate the program.
+
+ (1997-08-03)
+
+fatal exception
+
+ <programming, operating system> A program execution error
+ which is trapped by the {operating system} and which results
+ in abrupt termination of the program.
+
+ It may be possible for the program to catch some such errors,
+ e.g. a {floating point} {underflow}; others, such as an
+ invalid memory access (an attempt to write to read-only memory
+ or an attempt to read memory outside of the program's {address
+ space}), may always cause control to pass to the operating
+ system without allowing the program an opportunity to handle
+ the error. The details depend on the language's {run-time
+ system} and the operating system.
+
+ See also: {fatal error}.
+
+ (1997-08-03)
+
+fat binary
+
+ <operating system> An executable file containing code for more
+ than one {CPU}. The correct code is selected automatically at
+ run time. This is convenient for distributing {software} and
+ sharing it between multiple {platforms}.
+
+ {NEXTSTEP} supports fat binaries, e.g. for {Motorola 68000},
+ {Intel 80486} and {SPARC} ("triple fat"). {Mac OS} supports
+ fat binaries for both {680x0} and {PowerPC} native code.
+
+ [Other OSes?]
+
+ (1995-09-23)
+
+fat client
+
+ <networking> Opposite of "{thin client}".
+
+ (1996-12-08)
+
+fat electrons
+
+ <electronics, humour> Old-time hacker David Cargill's theory
+ on the cause of computer glitches. Your typical electricity
+ company draws its line current out of the big generators with
+ a pair of coil taps located near the top of the dynamo. When
+ the normal tap brushes get dirty, they take them off line to
+ clean them up, and use special auxiliary taps on the *bottom*
+ of the coil. Now, this is a problem, because when they do
+ that they get not ordinary or "thin" electrons, but the fat
+ sloppy electrons that are heavier and so settle to the bottom
+ of the generator. These flow down ordinary wires just fine,
+ but when they have to turn a sharp corner (as in an
+ integrated-circuit via), they're apt to get stuck. This is
+ what causes computer glitches.
+
+ [Obviously, fat electrons must gain mass by {bogon} absorption
+ - ESR]
+
+ Compare {bogon}, {magic smoke}.
+
+ [{Jargon File}]
+
+ (1996-12-08)
+
+fault
+
+ 1. <programming> A manifestation of an {error} in {software}.
+ A fault, if encountered, may cause a {failure}.
+
+ 2. <architecture> {page fault}.
+
+ (1996-05-14)
+
+fault-based testing
+
+ <testing> Software testing using test data designed to
+ demonstrate the absence of a set of pre-specified {faults};
+ typically, frequently occurring faults. For example, to
+ demonstrate that the software handles or avoids {divide by
+ zero} correctly, the test data would include zero.
+
+ (1996-05-15)
+
+fault tolerance
+
+ <architecture> 1. The ability of a system or component to
+ continue normal operation despite the presence of hardware or
+ software faults. This often involves some degree of
+ {redundancy}.
+
+ 2. The number of faults a system or component can withstand
+ before normal operation is impaired.
+
+ (1995-04-06)
+
+fault tolerant
+
+ {fault tolerance}
+
+fault tree analysis
+
+ <programming> A form of safety analysis that assesses hardware
+ safety to provide failure statistics and sensitivity analyses
+ that indicate the possible effect of critical failures.
+
+ (1996-05-15)
+
+fax
+
+ {facsimile}
+
+Fax over IP
+
+ <communications> (FoIP) Transmission of a {facsimile} over an
+ {IP} networking instead of {PSTN}, analogous to {Voice over
+ IP}.
+
+ (1999-04-26)
+
+FC
+
+ <language> A {functional language}.
+
+ ["FC Manual", L. Augustsson, Memo 13, Programming Methodology
+ Group, Chalmers U, Sweden 1982].
+
+ (1995-03-22)
+
+FC-AL
+
+ {Fibre Channel-Arbitrated Loop}.
+
+FCB
+
+ <operating system> {file control block}.
+
+F-code
+
+ The code for the {FP/M} {abstract machine}.
+
+ ["FP/M Abstract Syntax Description", Roger Bailey, Dept
+ Computing, Imperial College, U London, 1985]1w.
+
+ (1994-12-01)
+
+FCP
+
+ Flat Concurrent Prolog.
+
+ ["Design and Implementation of Flat Concurrent Prolog",
+ C. Mierowsky, TR CS84-21 Weizmann Inst, Dec 1984].
+
+ (1994-10-20)
+
+FC-PGA
+
+ {Flip Chip Pin Grid Array}
+
+FCS
+
+ {Frame Check Sequence}
+
+FDC
+
+ {floppy disk controller}
+
+FDD
+
+ {disk drive}
+
+FDDI
+
+ {Fiber Distributed Data Interface}
+
+FDISK
+
+ <operating system, tool> (Fixed disk utility) An {MS-DOS}
+ utility program which prepares a {hard disk} so that it can be
+ used as a {boot disk} and {file systems} can be created on it.
+ {OS/2}, {NT}, {Windows 95}, {Linux}, and other {Unix} versions
+ all have this command or something similar.
+
+ (1996-12-23)
+
+fd leak
+
+ {file descriptor leak}
+
+fdlibm
+
+ A new version of the {C} maths library, libm, by Dr. K-C Ng.
+ It is the basis for the bundled /usr/lib/libm.so in Solaris
+ 2.3 for SPARC and for future Solaris 2 releases for x86 and
+ PowerPC. It provides the standard functions necessary to pass
+ the usual test suites. This new libm can be configured to
+ handle exceptions in accordance with various language
+ standards or in the spirit of {IEEE 754}. The C source code
+ should be portable to any IEEE 754 system.
+
+ E-mail: <netlib@research.att.com> ("send all from fdlibm"),
+ <fdlibm-comments@sunpro.eng.sun.com> (comments and bug
+ reports).
+
+ {(ftp://netlib.att.com/netlib)}.
+
+ (1993-12-18).
+
+FDMA
+
+ {frequency division multiple access}
+
+FDSE
+
+ {full-duplex Switched Ethernet}
+
+FDSP
+
+ {full-duplex speaker phone}
+
+FDT
+
+ {Formal Description Technique}
+
+fdx
+
+ {full-duplex}
+
+FEA
+
+ {finite element analysis}
+
+fear and loathing
+
+ (Hunter S. Thompson) A state inspired by the prospect of
+ dealing with certain real-world systems and standards that are
+ totally {brain-damaged} but ubiquitous - {Intel 8086s},
+ {COBOL}, {EBCDIC}, or any {IBM} machine except the {Rios}
+ (also known as the {RS/6000}).
+
+ [{Jargon File}]
+
+ (1994-12-06)
+
+fear-driven development
+
+ <jargon, humour> When project management adds more pressure (fires
+ someone or something). A play on {test-driven development}.
+
+ [arnis-l, {Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2014-09-04)
+
+feasibility study
+
+ <systems analysis> Part of the {systems develpment life cycle}
+ which aims to determine whether it is sensible to develop some
+ system. The most popular model of feasibility study is
+ "TELOS", standing for Technical, Economic, Legal, Operational,
+ Schedule.
+
+ Technical Feasibility: does the technology exist to implement
+ the proposed system? Is it a practical proposition?
+
+ Economic Feasibility: is the system cost-effective? Do
+ benefits outweigh costs?
+
+ Legal Feasibility: is there any conflict between the proposed
+ system and legal requirements, e.g. the {Data Protection Act}?
+
+ Operational Feasibility: are the current work practices and
+ procedures adequate to support the new system?
+
+ Schedule Feasibility: can the system be developed in time?
+
+ After the feasibility study, the {requirements analysis}
+ should be carried out.
+
+ (2006-07-11)
+
+feasible
+
+ <algorithm> A description of an {algorithm} that takes
+ {polynomial} time (that is, for a problem set of size N, the
+ resources required to solve the problem can be expressed as
+ some polynomial involving N).
+
+ Problems that are "feasible" are said to be "in P" where P is
+ polynomial time. Problems that are "possible" but not
+ "feasible" are said to be "in NP".
+
+ (2001-04-12)
+
+ <systems analysis> A description of a project or system for
+ which a {feasibility study} gives a positive answer.
+
+ (2006-07-11)
+
+feature
+
+ <jargon> 1. A good property or behaviour (as of a program).
+ Whether it was intended or not is immaterial.
+
+ 2. An intended property or behaviour (as of a program).
+ Whether it is good or not is immaterial (but if bad, it is
+ also a {misfeature}).
+
+ 3. A surprising property or behaviour; in particular, one that
+ is purposely inconsistent because it works better that way -
+ such an inconsistency is therefore a {feature} and not a
+ {bug}. This kind of feature is sometimes called a {miswart}.
+
+ 4. A property or behaviour that is gratuitous or unnecessary,
+ though perhaps also impressive or cute. For example, one
+ feature of {Common LISP}'s "format" function is the ability to
+ print numbers in two different Roman-numeral formats (see
+ {bells, whistles, and gongs}).
+
+ 5. A property or behaviour that was put in to help someone
+ else but that happens to be in your way.
+
+ 6. A bug that has been documented. To call something a
+ feature sometimes means the author of the program did not
+ consider the particular case, and that the program responded
+ in a way that was unexpected but not strictly incorrect. A
+ standard joke is that a bug can be turned into a {feature}
+ simply by documenting it (then theoretically no one can
+ complain about it because it's in the manual), or even by
+ simply declaring it to be good. "That's not a bug, that's a
+ feature!" is a common catch-phrase. Apparently there is a
+ Volkswagen Beetle in San Francisco whose license plate reads
+ "FEATURE".
+
+ See also {feetch feetch}, {creeping featurism}, {wart}, {green
+ lightning}.
+
+ The relationship among bugs, features, misfeatures, warts and
+ miswarts might be clarified by the following hypothetical
+ exchange between two hackers on an airliner:
+
+ A: "This seat doesn't recline."
+
+ B: "That's not a bug, that's a feature. There is an emergency
+ exit door built around the window behind you, and the route
+ has to be kept clear."
+
+ A: "Oh. Then it's a misfeature; they should have increased
+ the spacing between rows here."
+
+ B: "Yes. But if they'd increased spacing in only one section
+ it would have been a wart - they would've had to make
+ nonstandard-length ceiling panels to fit over the displaced
+ seats."
+
+ A: "A miswart, actually. If they increased spacing throughout
+ they'd lose several rows and a chunk out of the profit margin.
+ So unequal spacing would actually be the Right Thing."
+
+ B: "Indeed."
+
+ "Undocumented feature" is a common euphemism for a {bug}.
+
+ 7. An attribute or function of a {class} in {Eiffel}.
+
+ [{Jargon File}]
+
+ (1995-10-22)
+
+feature creature
+
+ [Possibly from slang "creature feature" for a horror movie]
+ 1. One who loves to add features to designs or programs,
+ perhaps at the expense of coherence, concision or {taste}.
+
+ 2. Alternately, a mythical being that induces otherwise
+ rational programmers to perpetrate such crocks. See also
+ {feeping creaturism}, {creeping featurism}.
+
+ [{Jargon File}]
+
+feature creep
+
+ {creeping featurism}
+
+featurectomy
+
+ /fee"ch*r-ek"t*-mee/ The act of removing a {feature} from a
+ program. Featurectomies come in two flavours, the "righteous"
+ and the "reluctant". Righteous featurectomies are performed
+ because the remover believes the program would be more elegant
+ without the feature, or there is already an equivalent and
+ better way to achieve the same end. (Doing so is not quite
+ the same thing as removing a {misfeature}.) Reluctant
+ featurectomies are performed to satisfy some external
+ constraint such as code size or execution speed.
+
+ [{Jargon File}]
+
+ (1994-10-20)
+
+feature key
+
+ <hardware> (Or "flower", "pretzel", "clover", "propeller",
+ "beanie" (from propeller beanie), {splat}, "command key") The
+ {Macintosh} {modifier key} with the four-leaf clover graphic
+ on its keytop.
+
+ The feature key is the Mac's equivalent of a {control key}
+ (and so labelled on some Mac II keyboards). The proliferation
+ of terms for this creature may illustrate one subtle peril of
+ iconic interfaces. Macs also have an "Option" {modifier key},
+ equivalent to Alt.
+
+ The cloverleaf-like symbol's oldest name is "cross of
+ St. Hannes", but it occurs in pre-Christian Viking art as a
+ decorative motif. In Scandinavia it marks sites of historical
+ interest. An early {Macintosh} developer who happened to be
+ Swedish introduced it to Apple. Apple documentation gives the
+ translation "interesting feature".
+
+ The symbol has a {Unicode} character called "PLACE OF INTEREST
+ SIGN" (U+2318), previously known as "command key".
+
+ The Swedish name of this symbol stands for the word
+ "sev"ardhet" (interesting feature), many of which are old
+ churches. Some Swedes report as an idiom for it the word
+ "kyrka", cognate to English "church" and Scots-dialect "kirk"
+ but pronounced /shir'k*/ in modern Swedish. Others say this
+ is nonsense.
+
+ {(http://fileformat.info/info/unicode/char/2318/index.htm)}.
+
+ [{Jargon File}]
+
+ (2005-09-15)
+
+feature shock
+
+ <jargon> (From Alvin Toffler's "Future Shock") A user's
+ confusion when confronted with a package that has too many
+ features and poor introductory material.
+
+ [{Jargon File}]
+
+ (2005-09-15)
+
+FEC
+
+ {Forward Error Correction}
+
+FED
+
+ {field emission display}
+
+Federal Geographic Data Committee
+
+ (FGDC)
+
+ {(ftp://fgdc.er.usgs.gov/gdc/html/fgdc.html)}.
+
+ [Summary?]
+
+ (1995-03-06)
+
+Federal Information Exchange
+
+ <networking> (FIX) One of the connection points between the
+ American governmental {internets} and the {Internet}.
+
+ (2001-05-14)
+
+Federal Information Processing Standards
+
+ <standard> (FIPS) United States Government technical
+ {standards} published by the {National Institute of Standards
+ and Technology} (NIST). NIST develops FIPS when there are
+ compelling Federal government requirements such as for
+ security and {interoperability} but no acceptable industry
+ standards or solutions.
+
+ Computer-related products bought by the US Government must
+ conform to FIPS.
+
+ (2003-06-04)
+
+Federal Networking Council
+
+ (FNC) The coordinating group of representatives from federal
+ agencies involved in the development and use of federal
+ networking, especially those networks using {TCP/IP} and the
+ {Internet}. Current members include representatives from DOD,
+ DOE, {DARPA}, {NSF}, NASA, and HHS.
+
+ (1994-11-17)
+
+federation
+
+ <security> The establishment of some or all of business
+ agreements, {cryptographic} trust and user identifiers or
+ attributes across security and policy domains to enable more
+ seamless business interaction.
+
+ As {web services} promise to enable integration between
+ business partners through {loose coupling} at the application
+ and messaging layer, federation does so at the identity
+ management layer, insulating each domain from the details of
+ the others' authentication and authorization. Key to this
+ loose coupling at the identity management layer are
+ standardized mechanisms and formats for the communication of
+ identity information between the domains. {SAML} is one such
+ standard.
+
+ (2011-05-12)
+
+Federation Against Software Theft Limited
+
+ <body, legal> (FAST) A non-profitmaking organisation, formed
+ in 1984 by the software industry with the aim of eradicating
+ {software theft} in the UK. FAST was the world's first
+ anti-piracy organisation to work to protect the intellectual
+ property rights of software publishers. Initially
+ concentrating on lobbying parliament to revise Copyright law,
+ FAST also prosecutes organisations and individuals for
+ software theft on behalf of its members and publicises the
+ legal penalties and security risks.
+
+ FAST Corporate Services Limited runs the FAST Standard for
+ Software Compliance (FSSC-1:2004). This was developed in
+ collaboration with the {British Standards Institution} as an
+ independent standard of excellence in {software compliance}.
+
+ In 1995 FAST proposed to merge with the {Business Software
+ Alliance} created by {Microsoft} and which has a world-wide
+ influence. However, the talks fell through and in 1996,
+ {Novell} and {Adobe Systems, Inc.} defected to BSA.
+
+ {FAST Home (http://fast.org.uk/)}.
+
+ E-mail: <fast@fast.org>.
+
+ Address: York House, 18 York Road, Maidenhead, Berkshire SL6
+ 1SF.
+
+ Telephone: +44 (1628) 622 121
+
+ (2005-12-27)
+
+Fedora
+
+ <operating system, project> An open source project, sponsored
+ by {Red Hat, Inc.}, and potentially feeding into their
+ products.
+
+ {Fedora Home (http://fedora.redhat.com/)}.
+
+ (2005-12-27)
+
+feed
+
+ 1. <data> {data feed}.
+
+ 2. {Rich Site Summary}.
+
+feedback
+
+ <electronics> Part of a system output presented at its input.
+ Feedback may be unintended. When used as a design feature,
+ the output is usually transformed by passive components which
+ attenuate it in some manner; the result is then presented at
+ the system input.
+
+ Feedback is positive or negative, depending on the sign with
+ which a positive change in the original input reappears after
+ transformation. Negative feedback was invented by Black to
+ stabilise {vacuum tube} amplifiers. The behaviour becomes
+ largely a function of the feedback transformation and only
+ minimally a function of factors such as transistor gain which
+ are imperfectly known.
+
+ Positive feedback can lead to instability; it finds wide
+ application in the construction of oscillators.
+
+ Feedback can be used to control a system, as in {feedback
+ control}.
+
+ (1996-01-02)
+
+feedback control
+
+ <electronics> A control system which monitors its effect on
+ the system it is controlling and modifies its output
+ accordingly. For example, a thermostat has two inputs: the
+ desired temperature and the current temperature (the latter is
+ the feedback). The output of the thermostat changes so as to
+ try to equalise the two inputs.
+
+ Computer {disk drives} use feedback control to position the
+ read/write heads accurately on a recording track. Complex
+ systems such as the human body contain many feedback systems
+ that interact with each other; the homeostasis mechanisms that
+ control body temperature and acidity are good examples.
+
+ (1996-01-02)
+
+feed-forward
+
+ A {multi-layer perceptron} network in which the outputs from
+ all neurons (see {McCulloch-Pitts}) go to following but not
+ preceding layers, so there are no feedback loops.
+
+Feel
+
+ (Free and Eventually Eulisp) An initial implementation of an
+ {EuLisp} {interpreter} by Pete Broadbery
+ <pab@maths.bath.ac.uk>. Version 0.75 features an integrated
+ {object} system, {modules}, {parallelism}, interfaces to {PVM}
+ library, {TCP/IP} {sockets}, {futures}, {Linda} and {CSP}.
+ Portable to most {Unix} systems. Can use {shared memory} and
+ {threads} if available.
+
+ {(ftp://ftp.bath.ac.uk/pub/eulisp/)}.
+
+ (1992-09-14)
+
+feep
+
+ /feep/ 1. The soft electronic "bell" sound of a display
+ terminal (except for a VT-52); a beep (in fact, the
+ microcomputer world seems to prefer {beep}).
+
+ 2. To cause the display to make a feep sound. ASR-33s (the
+ original TTYs) do not feep; they have mechanical bells that
+ ring. Alternate forms: {beep}, "bleep", or just about
+ anything suitably onomatopoeic. (Jeff MacNelly, in his comic
+ strip "Shoe", uses the word "eep" for sounds made by computer
+ terminals and video games; this is perhaps the closest written
+ approximation yet.) The term "breedle" was sometimes heard at
+ SAIL, where the terminal bleepers are not particularly soft
+ (they sound more like the musical equivalent of a raspberry or
+ Bronx cheer; for a close approximation, imagine the sound of a
+ Star Trek communicator's beep lasting for five seconds). The
+ "feeper" on a VT-52 has been compared to the sound of a '52
+ Chevy stripping its gears. See also {ding}.
+
+ [{Jargon File}]
+
+feeper
+
+ /fee'pr/ The device in a terminal or workstation (usually
+ a loudspeaker of some kind) that makes the {feep} sound.
+
+feeping creature
+
+ [{feeping creaturism}] An unnecessary feature; a bit of
+ {chrome} that, in the speaker's judgment, is the camel's nose
+ for a whole horde of new features.
+
+ [{Jargon File}]
+
+feeping creaturism
+
+ /fee'ping kree"ch*r-izm/ A deliberate spoonerism for {creeping
+ featurism}, meant to imply that the system or program in
+ question has become a misshapen creature of hacks. This term
+ isn"t really well defined, but it sounds so neat that most
+ hackers have said or heard it. It is probably reinforced by
+ an image of terminals prowling about in the dark making their
+ customary noises.
+
+FEL
+
+ Function Equation Language. Programs are sets of definitions.
+ Sequences are lists stored in consecutive memory. "FEL
+ Programmer's Guide", R. M. Keller, AMPS TR 7, U Utah, March
+ 1982.
+
+femto-
+
+ {prefix}
+
+fence
+
+ 1. A sequence of one or more distinguished ({out-of-band})
+ characters (or other data items), used to delimit a piece of
+ data intended to be treated as a unit (the computer-science
+ literature calls this a "sentinel"). The NUL (ASCII 0000000)
+ character that terminates strings in C is a fence. {Hex} FF
+ is also (though slightly less frequently) used this way. See
+ {zigamorph}.
+
+ 2. An extra data value inserted in an array or other data
+ structure in order to allow some normal test on the array's
+ contents also to function as a termination test. For example,
+ a highly optimised routine for finding a value in an array
+ might artificially place a copy of the value to be searched
+ for after the last slot of the array, thus allowing the main
+ search loop to search for the value without having to check at
+ each pass whether the end of the array had been reached.
+
+ 3. [among users of optimising compilers] Any technique,
+ usually exploiting knowledge about the compiler, that blocks
+ certain optimisations. Used when explicit mechanisms are not
+ available or are overkill. Typically a hack: "I call a dummy
+ procedure there to force a flush of the optimiser's
+ register-colouring info" can be expressed by the shorter
+ "That's a fence procedure".
+
+ [{Jargon File}]
+
+ (1999-01-08)
+
+fencepost error
+
+ 1. (Rarely "lamp-post error") A problem with the discrete
+ equivalent of a {boundary condition}, often exhibited in
+ programs by iterative loops. From the following problem: "If
+ you build a fence 100 feet long with posts 10 feet apart, how
+ many posts do you need?" (Either 9 or 11 is a better answer
+ than the obvious 10).
+
+ For example, suppose you have a long list or array of items,
+ and want to process items m through n; how many items are
+ there? The obvious answer is n - m, but that is off by one;
+ the right answer is n - m + 1. The "obvious" formula exhibits
+ a fencepost error.
+
+ See also {zeroth} and note that not all {off-by-one errors}
+ are fencepost errors. The game of Musical Chairs involves a
+ catastrophic off-by-one error where N people try to sit in N -
+ 1 chairs, but it's not a fencepost error. Fencepost errors
+ come from counting things rather than the spaces between them,
+ or vice versa, or by neglecting to consider whether one should
+ count one or both ends of a row.
+
+ 2. (Rare) An error induced by unexpected regularities in input
+ values, which can (for instance) completely thwart a
+ theoretically efficient {binary tree} or {hash coding}
+ implementation. The error here involves the difference
+ between expected and worst case behaviours of an {algorithm}.
+
+ [{Jargon File}]
+
+ (1994-12-01)
+
+fepped out
+
+ <jargon> /fept owt/ The {Symbolics 3600} {LISP Machine} has a
+ {Front-End Processor} (FEP). When the main processor gets
+ {wedged}, the FEP takes control of the keyboard and screen.
+ Such a machine is said to have "fepped out" or "dropped into
+ the fep".
+
+ [{Jargon File}]
+
+ (1994-12-01)
+
+FEPROM
+
+ {Flash Erasable Programmable Read-Only Memory}
+
+Fermat prime
+
+ <mathematics> A {prime number} of the form 2^2^n + 1. Any
+ prime number of the form 2^n+1 must be a Fermat prime.
+ {Fermat} conjectured in a letter to someone or other that all
+ numbers 2^2^n+1 are prime, having noticed that this is true
+ for n=0,1,2,3,4.
+
+ {Euler} proved that 641 is a factor of 2^2^5+1. Of course
+ nowadays we would just ask a computer, but at the time it was
+ an impressive achievement (and his proof is very elegant).
+
+ No further Fermat primes are known; several have been
+ factorised, and several more have been proved composite
+ without finding explicit factorisations.
+
+ {Gauss} proved that a regular N-sided {polygon} can be
+ constructed with ruler and compasses if and only if N is a
+ power of 2 times a product of distinct Fermat primes.
+
+ (1995-04-10)
+
+Fermat's Last Post
+
+ <humour> A post to a {bug tracker}, {mailing list} or {forum}
+ in which the author claims to have found a simple fix or
+ workaround for a bug, but never says what it is and never
+ shows up again to explain it (even after others have been
+ puzzling over the bug for years).
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2012-02-19)
+
+Ferranti F100-L
+
+ <processor> A {processor}, with 16-bit addressing, {registers}
+ and data paths and a 1-bit serial {ALU}. The F100-L could
+ only access 32K of memory (one address bit was used for
+ {indirection}). It was designed by a British company for the
+ British Military.
+
+ The unique feature of the F100-L was that it had a complete
+ control bus available for a {coprocessor}. Any instruction
+ the F100-L couldn't decode was sent directly to the
+ coprocessor for processing. Applications for coprocessors at
+ the time were limited, but the design is still used in modern
+ processors, such as the {National Semiconductor 32000} series.
+
+ The {disk operating system} was written by Alec Cawley.
+
+ (2007-05-19)
+
+ferrite core memory
+
+ <storage> (Or "core") An early form of {non-volatile storage}
+ built (by hand) from tiny rings of magnetisable material
+ threaded onto very fine wire to form large (e.g. 13"x13" or
+ more) rectangluar arrays. Each core stored one {bit} of data.
+ These were sandwiched between {printed circuit boards}(?).
+ Sets of wires ran horizontally and vertically and where a
+ vertical and horizontal wire crossed, a core had both wires
+ threaded through it.
+
+ A single core could be selected and magnetised by passing
+ sufficient current through its horizontal and vertical wires.
+ A core would retain its magnetisation until it was
+ re-magnetised. The two possible polarities of magnetisation
+ were used to represent the binary values zero and one.
+
+ A third "sense" wire, passed through the core and, if the
+ magnetisation of the core was changed, a small pulse would be
+ induced in the sense wire which could be detected and used to
+ deduce the core's original state.
+
+ Some core memory was immersed in a bath of heated oil to
+ improve its performance.
+
+ Core memory was rendered obsolete by {semiconductor} memory.
+
+ For example, the 1970s-era {NCR 499} had two boards, each with
+ 16 {kilobytes} of core memory.
+
+ (1996-03-04)
+
+Ferroelectric RAM
+
+ {Ferroelectric Random Access Memory}
+
+Ferroelectric Random Access Memory
+
+ <storage> (FRAM) A type of {non-volatile} read/write {random
+ access} {semiconductor} memory. FRAM combines the advantages
+ of {SRAM} - writing is roughly as fast as reading, and {EPROM}
+ - non-volatility and in-circuit programmability. Current (Feb
+ 1997) disadvantages are high cost and low density, but that
+ may change in the future. Density is currently at most 32KB
+ on a chip, compared with 512KB for SRAM, 1MB for EPROM and 8MB
+ for DRAM.
+
+ A ferroelectric memory cell consists of a ferroelectric
+ {capacitor} and a {MOS} {transistor}. Its construction is
+ similar to the storage cell of a {DRAM}. The difference is in
+ the dielectric properties of the material between the
+ capacitor's electrodes. This material has a high dielectric
+ constant and can be polarized by an electric field. The
+ polarisation remains until it gets reversed by an opposite
+ electrical field. This makes the memory non-volatile. Note
+ that ferroelectric material, despite its name, does not
+ necessarily contain iron. The most well-known ferroelectric
+ substance is BaTiO3, which does not contain iron.
+
+ Data is read by applying an electric field to the capacitor.
+ If this switches the cell into the opposite state (flipping
+ over the electrical dipoles in the ferroelectric material)
+ then more charge is moved than if the cell was not flipped.
+ This can be detected and amplified by sense amplifiers.
+ Reading destroys the contents of a cell which must therefore
+ be written back after a read. This is similar to the
+ {precharge} operation in DRAM, though it only needs to be done
+ after a read rather than periodically as with DRAM {refresh}.
+ In fact it is most like the operation of {ferrite core
+ memory}.
+
+ FRAM has similar applications to EEPROM, but can be written
+ much faster. The simplicity of the memory cell promises high
+ density devices which can compete with DRAM.
+
+ {RAMTRON} is the company behind FRAM.
+
+ (1997-02-17)
+
+Fetch
+
+ A {Macintosh} program by Jim Matthews <Fetch@Dartmouth.edu>
+ for transferring files using {File Transfer Protocol} (FTP).
+ Fetch requires a Mac 512KE, System 4.1, and either {KSP} 1.03
+ or {MacTCP}.
+
+ Latest version: 2.1.2.
+
+ Fetch is Copyright 1992, Trustees of Dartmouth College.
+
+ {(ftp://ftp.Dartmouth.edu/pub/mac/Fetch_2.1.2.sit.hqx)}.
+ {(ftp://src.doc.ic.ac.uk/computing/systems/mac/info-mac/comm/tcp)}.
+
+ (1994-11-30)
+
+fetch-execute cycle
+
+ <architecture, processor> The sequence of actions that a
+ {central processing unit} performs to execute each {machine
+ code} instruction in a program.
+
+ At the beginning of each cycle the CPU presents the value of
+ the {program counter} on the {address bus}. The CPU then
+ fetches the instruction from {main memory} (possibly via a
+ {cache} and/or a {pipeline}) via the {data bus} into the
+ {instruction register}.
+
+ From the instruction register, the data forming the
+ instruction is decoded and passed to the {control unit} which
+ sends a sequence of control signals to the relevant {function
+ units} of the CPU to perform the actions required by the
+ instruction such as reading values from {registers}, passing
+ them to the {ALU} to add them together and writing the result
+ back to a register.
+
+ The program counter is then incremented to address the next
+ instruction and the cycle is repeated.
+
+ The fetch-execute cycle was first proposed by {John von
+ Neumann}.
+
+ (1998-06-25)
+
+Feynman, Richard P.
+
+ {Richard P. Feynman}
+
+FF
+
+ {form feed}
+
+ffccc
+
+ {Floppy} {Fortran} coding convention checker.
+
+FFP
+
+ Formal FP. A language similar to FP, but with regular
+ sugarless {syntax}, for machine execution.
+
+ See also {FL}.
+
+ ["Can Programming be Liberated From the von Neumann Style? A
+ Functional Style and Its Algebra of Programs", John Backus,
+ 1977 Turing Award Lecture, CACM 21(8):165-180 (Aug 1978)].
+
+ (1994-10-24)
+
+FFT
+
+ {Fast Fourier Transform}
+
+FGDC
+
+ {Federal Geographic Data Committee}
+
+FGHC
+
+ Flat GHC. A {flat} variant of {GHC} in which {guard} calls
+ can be only to {primitives}.
+
+ See also {KL1}.
+
+ (1994-10-24)
+
+FGL
+
+ 1. Flow Graph Lisp. A distributed dataflow language for AMPS
+ (Applicative Multi-Processing System). "A Loosely-Coupled
+ Applicative Multi-Processing System", R. Keller et al, NCC,
+ AFIPS June 1979, pp.613- 622.
+
+ 2. Function Graph Language. Related to FEL.
+
+FGL+LV
+
+ ["Functional Programming and the Logical Variable",
+ G. Lindstrom, POPL 1985, pp. 266-280].
+
+ (1994-11-30)
+
+FGRAAL
+
+ Fortran extended GRAph Algorithmic Language. A Fortran
+ extension for handling sets and graphs. "On a Programming
+ Language for Graph Algorithms", W.C. Rheinboldt et al, BIT
+ 12(2) 1972.
+
+fgrep
+
+ <tool> A variant of the {Unix} {grep} command which searches
+ for fixed (uninterpreted) strings rather than {regular
+ expressions}. Surprisingly, this is not always faster.
+
+ (1996-10-27)
+
+FhG
+
+ {Fraunhofer Gesellschaft}
+
+FHS
+
+ {Filesystem Hierarchy Standard}
+
+FHSS
+
+ {Frequency-Hopping Spread Spectrum}
+
+fi
+
+ <networking> The {country code} for Finland.
+
+ (1999-01-27)
+
+Fiber Distributed Data Interface
+
+ (FDDI) A 100 Mbit/s {ANSI} {standard} {local area network}
+ architecture, defined in X3T9.5. The underlying medium is
+ {optical fibre} (though it can be copper cable, in which case
+ it may be called {CDDI}) and the topology is a
+ {dual-attached}, counter-rotating {token ring}.
+
+ FDDI rings are normally constructed in the form of a "dual
+ ring of trees". A small number of devices, typically
+ infrastructure devices such as {routers} and {concentrators}
+ rather than {host} computers, are connected to both rings -
+ these are referred to as "{dual-attached}". Host computers
+ are then connected as {single-attached} devices to the
+ {routers} or {concentrators}. The dual ring in its most
+ degenerate form is simply collapsed into a single device. In
+ any case, the whole dual ring is typically contained within a
+ computer room.
+
+ This network topology is required because the dual ring
+ actually passes through each connected device and requires
+ each such device to remain continuously operational (the
+ standard actually allows for optical bypasses but these are
+ considered to be unreliable and error-prone). Devices such as
+ {workstations} and {minicomputers} that may not be under the
+ control of the {network managers} are not suitable for
+ connection to the dual ring.
+
+ As an alternative to a dual-attached connection, the same
+ degree of resilience is available to a {workstation} through a
+ {dual-homed} connection which is made simultaneously to two
+ separate devices in the same FDDI ring. One of the
+ connections becomes active while the other one is
+ automatically blocked. If the first connection fails, the
+ backup link takes over with no perceptible delay.
+
+ {Usenet} newsgroup: {news:comp.dcom.lans.fddi}.
+
+ (1994-12-13)
+
+Fiber Optic InterRepeater Link
+
+ <networking> (FOIRL) An older standard of {fiber optic} guides
+ used for carrying 10 MBps {Ethernet}. The maximum length of a
+ {segment} is 1 km. A FOIRL {multiport repeater} and
+ transceivers are necessary to carry the signal to multiple
+ devices.
+
+ The more recent version of Ethernet over fiber optic cables is
+ {10baseFL} with a maximum segment length of 2 km.
+
+ (1998-06-28)
+
+fiber optics
+
+ <spelling> US spelling of "fibre optics". See {optical
+ fibre}.
+
+ (1997-03-31)
+
+Fibonacci sequence
+
+ <mathematics> The {infinite} sequence of numbers beginning
+
+ 1, 1, 2, 3, 5, 8, 13, ...
+
+ in which each term is the sum of the two terms preceding it.
+
+ The ratio of successive Fibonacci terms tends to the {golden
+ ratio}, namely (1 + sqrt 5)/2.
+
+ [Why not "Fibonacci {series}"?]
+
+ (2002-10-15)
+
+Fibre Channel
+
+ <storage, networking, communications> An {ANSI} {standard}
+ originally intended for high-speed {SANs} connecting
+ {servers}, {disc arrays}, and {backup} devices, also later
+ adapted to form the {physical layer} of {Gigabit Ethernet}.
+
+ Development work on Fibre channel started in 1988 and it was
+ approved by the ANSI standards committee in 1994, running at
+ 100Mb/s. More recent innovations have seen the speed of Fibre
+ Channel SANs increase to 10Gb/s. Several topologies are
+ possible with Fibre Channel, the most popular being a number
+ of devices attached to one (or two, for redundancy) central
+ Fibre Channel switches, creating a reliable infrastructure
+ that allows servers to share storage arrays or tape libraries.
+
+ One common use of Fibre Channel SANs is for high availability
+ databaseq clusters where two servers are connected to one
+ highly reliable {RAID} array. Should one server fail, the
+ other server can mount the array itself and continue
+ operations with minimal {downtime} and loss of data.
+
+ Other advanced features include the ability to have servers
+ and {hard drives} seperated by hundreds of miles or to rapidly
+ {mirror} data between servers and hard drives, perhaps in
+ seperate geographic locations.
+
+ {Fibre Channel Industry Association
+ (http://fibrechannel.org)} (FCIA).
+
+ (2003-09-27)
+
+Fibre Channel-Arbitrated Loop
+
+ <hardware, standard> (FC-AL) A fast serial bus interface
+ standard intended to replace {SCSI} on high-end {servers}.
+
+ FC-AL has a number of advantages over SCSI. It offers higher
+ speed: the base speed is 100 {megabytes} per second, with 200,
+ 400, and 800 planned. Many devices are dual ported, i.e., can
+ be accessed through two independent ports, which doubles speed
+ and increases fault tolerance. Cables can be as long as 30 m
+ (coaxial) or 10 km (optical). FC-AL enables
+ {self-configuring} and {hot swapping} and the maximum number
+ of devices on a single port is 126. Finally, it provides
+ software compatibility with SCSI.
+
+ Despite all these features FC-AL is unlikely to appear on
+ desktops anytime soon, partly because its price, partly
+ because typical {desktop computers} would not take advantage
+ of many of the advanced features. On these systems {FireWire}
+ has more potential.
+
+ [Current status? Reference?]
+
+ (1999-09-12)
+
+fibre optics
+
+ {optical fibre}
+
+FIDIL
+
+ Based on "maps", generalised arrays whose index sets
+ ("domains") are arbitrary D-dimensional sets. Domains are
+ first-class objects and may be constructed by union,
+ intersection, etc.
+
+ ["Fidil: A Language for Scientific Programming",
+ P.N. Hilfinger et al, TR UCRL-98057, LLNL Jan 1988].
+
+FIDO
+
+ FInite DOmains. A constraint language implemented on top of
+ Prolog.
+
+ {(ftp://ftp.uni-kl.de/pub1/Unix/languages/fido/)}.
+
+FidoNet
+
+ A worldwide hobbyist network of personal computers which
+ exchanges {e-mail}, discussion groups, and files. Founded in
+ 1984 and originally consisting only of {IBM PCs} and
+ compatibles, FidoNet now includes such diverse machines as
+ {Apple IIs}, {Ataris}, {Amigas}, and {Unix} systems. Though
+ it is much younger than {Usenet}, FidoNet is already (in early
+ 1991) a significant fraction of {Usenet}'s size at some 8000
+ systems.
+
+ [{Jargon File}]
+
+field
+
+ <data, database> An area of a {database} {record}, or
+ {graphical user interface} {form}, into which a particular
+ item of data is entered.
+
+ Example usage: "The telephone number field is not really a
+ numerical field", "Why do we need a four-digit field for the
+ year?".
+
+ A {database} {column} is the set of all instances of a given
+ field from all records in a {table}.
+
+ (1999-04-26)
+
+field circus
+
+ A derogatory pun on "field service". The field service
+ organisation of any hardware manufacturer, but especially
+ {DEC}. There is an entire genre of jokes about DEC field
+ circus engineers:
+
+ Q: How can you recognise a DEC field circus engineer with a
+ flat tire?
+
+ A: He's changing one tire at a time to see which one is flat.
+
+ Q: How can you recognise a DEC field circus engineer who is
+ out of gas?
+
+ A: He's changing one tire at a time to see which one is flat.
+
+ See {Easter egging} for additional insight on these jokes.
+
+ There is also the "Field Circus Cheer" (from the {plan file}
+ for {DEC} on MIT-AI):
+
+ Maynard! Maynard!
+ Don't mess with us!
+ We're mean and we're tough!
+ If you get us confused
+ We'll screw up your stuff.
+
+ (DEC's service HQ is located in Maynard, Massachusetts).
+
+ [{Jargon File}]
+
+ (1994-12-01)
+
+field effect transistor
+
+ <electronics> (FET) A {transistor} with a region of {donor}
+ material with two terminals called the "source" and the
+ "drain", and an adjoining region of {acceptor} material
+ between, called the "gate". The voltage between the gate and
+ the {substrate} controls the current flow between source and
+ drain by depleting the donor region of its charge carriers to
+ greater or lesser extent.
+
+ There are two kinds of FET's, {Junction FETs} and {MOSFETs}.
+
+ Because no current (except a minute leakage current) flows
+ through the gate, FETs can be used to make circuits with very
+ low power consumption.
+
+ Contrast {bipolar transistor}.
+
+ (1995-10-05)
+
+field emission display
+
+ <hardware> (FED) A type of {flat panel display} in which field
+ emitting cathodes bombard a phosphor coating causing it to
+ emit light.
+
+ A field emission display is similar to a {cathode ray tube}
+ but only a few millimeters thick. They use a large array of
+ fine metal tips or carbon nanotubes (which are the most
+ efficient electron emitters known), to emit electrons through
+ a process known as field emission. Many of these are behind
+ each phosphor dot so FEDs do not display dead pixels like LCDs
+ even if 20% of the emitters fail. {Sony} is researching FED
+ because it is the flat-panel technology that comes closest to
+ matching the picture of a CRT.
+
+ (2007-10-10)
+
+field mouse
+
+ {wireless mouse}
+
+field-programmable gate array
+
+ <hardware> (FPGA) A {gate array} where the logic network can
+ be programmed into the device after its manufacture. An FPGA
+ consists of an array of logic elements, either gates or lookup
+ table {RAMs}, {flip-flops} and programmable interconnect
+ wiring.
+
+ Most FPGAs are reprogrammable, since their logic functions and
+ interconnect are defined by RAM cells. The {Xilinx} LCA,
+ {Altera} FLEX and {AT&T} ORCA devices are examples. Others
+ can only be programmed once, by closing "antifuses". These
+ retain their programming permanently. The {Actel} FPGAs are
+ the leading example of such devices. Atmel FPGAs are
+ currently (July 1997) the only ones in which part of the array
+ can be reprogrammed while other parts are active.
+
+ As of 1994, FPGAs have logic capacity up to 10K to 20K
+ 2-input-NAND-equivalent gates, up to about 200 I/O pins and
+ can run at {clock rates} of 50 MHz or more. FPGA designs must
+ be prepared using {CAD} software tools, usually provided by
+ the chip vendor, to do technology mapping, partitioning and
+ placement, routing, and binary output. The resulting binary
+ can be programmed into a {ROM} connected to the FPGA or
+ {downloaded} to the FPGA from a connected computer.
+
+ In addition to ordinary logic applications, FPGAs have enabled
+ the development of {logic emulators}. There is also research
+ on using FPGAs as computing devices, taking direct advantage
+ of their reconfigurability into problem-specific hardware
+ processors.
+
+ {Usenet} newsgroup: {news:comp.arch.fpga}.
+
+ (1997-07-11)
+
+field servoid
+
+ <jargon, abuse> /fee'ld ser'voyd/ A play on "android", a
+ derogatory term for a representative of a field service
+ organisation (see {field circus}), suggesting an unintelligent
+ rule-driven approach to servicing computer hardware.
+
+ [{Jargon File}]
+
+ (2003-02-03)
+
+FIFO
+
+ {first-in first-out}
+
+Fifth
+
+ An enhanced version of FORTH. M.S. Dissertation, Cliff Click
+ <cliff@cs.rice.edu>, Texas A&M, 1985. Available from the
+ Software Construction Co, (409)696-5432.
+
+Fifth Dimension Technologies
+
+ <company, virtual reality> (5DT) Manufacturers of the {5th
+ Glove}.
+
+ (1995-04-04)
+
+fifth generation language
+
+ <language, artificial intelligence> A myth the Japanese spent
+ a lot of money on. In about 1982, {MITI} decided it would
+ spend ten years and a lot of money applying {artificial
+ intelligence} to programming, thus solving the {software
+ crisis}. The project spent its money and its ten years and in
+ 1992 closed down with a wimper.
+
+ (1996-11-06)
+
+fifth normal form
+
+ {database normalisation}
+
+Fight-o-net
+
+ <messaging> A distortion of {FidoNet}, often applied after a
+ flurry of {flamage} in a particular {echo}, especially the
+ SYSOP echo or Fidonews (see {'Snooze}).
+
+ [{Jargon File}]
+
+ (1996-11-04)
+
+file
+
+ <file system> An element of data storage in a {file system}.
+
+ The history of computing is rich in varied kinds of files and
+ {file systems}, whether ornate like the {Macintosh file
+ system} or deficient like many simple pre-1980s file systems
+ that didn't have {directories}. However, a typical file has
+ these characteristics:
+
+ * It is a single sequence of bytes (but consider {Macintosh}
+ {resource forks}).
+
+ * It has a finite length, unlike, e.g., a {Unix} {device}.
+
+ * It is stored in a {non-volatile storage} medium (but see
+ {ramdrive}).
+
+ * It exists (nominally) in a {directory}.
+
+ * It has a name that it can be referred to by in file
+ operations, possibly in combination with its {path}.
+
+ Additionally, a file system may support other {file
+ attributes}, such as {permissions}; timestamps for creation,
+ last modification, and last access and revision numbers (a` la
+ {VMS}).
+
+ Compare: {document}.
+
+ (2007-01-04)
+
+File Allocation Table
+
+ <file system> (FAT) The component of an {MS-DOS} or {Windows
+ 95} {file system} which describes the {files}, {directories},
+ and free space on a {hard disk} or {floppy disk}.
+
+ A disk is divided into {partitions}. Under the FAT {file
+ system} each partition is divided into {clusters}, each of
+ which can be one or more {sectors}, depending on the size of
+ the partition. Each cluster is either allocated to a file or
+ directory or it is free (unused). A directory lists the name,
+ size, modification time and starting cluster of each file or
+ subdirectory it contains.
+
+ At the start of the partition is a table (the FAT) with one
+ entry for each cluster. Each entry gives the number of the
+ next cluster in the same file or a special value for "not
+ allocated" or a special value for "this is the last cluster in
+ the chain". The first few clusters after the FAT contain the
+ {root directory}.
+
+ The FAT file system was originally created for the {CP/M}[?]
+ {operating system} where files were catalogued using 8-bit
+ addressing. {MS DOS}'s FAT allows only {8.3} filenames.
+
+ With the introduction of MS-DOS 4 an incompatible 16-bit FAT
+ (FAT16) with 32-kilobyte {clusters} was introduced that
+ allowed {partitions} of up to 2 gigabytes.
+
+ Microsoft later created {FAT32} to support partitions larger
+ than two gigabytes and {pathnames} greater that 256
+ characters. It also allows more efficient use of disk space
+ since {clusters} are four kilobytes rather than 32 kilobytes.
+ FAT32 was first available in {OEM} Service Release 2 of
+ {Windows 95} in 1996. It is not fully {backward compatible}
+ with the 16-bit and 8-bit FATs.
+
+ {IDG article
+ (http://idg.net/idgframes/english/content.cgi?vc=docid_9-62525.html)}.
+ {(http://home.c2i.net/tkjoerne/os/fat.htm)}.
+ {(http://teleport.com/~brainy/)}.
+ {(http://209.67.75.168/hardware/fatgen.htm)}.
+ {(http://support.microsoft.com/support/kb/articles/q154/9/97.asp)}.
+
+ Compare: {NTFS}.
+
+ [How big is a FAT? Is the term used outside MS DOS? How long
+ is a FAT16 filename?]
+
+ (2000-02-05)
+
+File Attach
+
+ [FidoNet] 1. A file sent along with a mail message from one
+ BBS to another.
+
+ 2. Sending someone a file by using the File Attach option in a
+ BBS mailer.
+
+ [{Jargon File}]
+
+File Composition
+
+ A typesetting language.
+
+ ["File Composition System Reference Manual", No. 90388,
+ Information Intl].
+
+file compression
+
+ <algorithm> The {compression} of data in a file, usually to
+ reduce storage requirements.
+
+ (1995-04-06)
+
+file control block
+
+ <operating system> (FCB) An {MS-DOS} data structure that
+ stores information about an open file. The number of FCBs is
+ configured in {CONFIG.SYS} with a command
+
+ FCBS=x,y
+
+ where x (between 1 and 255 inclusive, default 4) specifies the
+ number of file control blocks to allocate and therefore the
+ number of files that MS-DOS can have open at one time. y (not
+ needed from DOS 5.0 onward) specifies the number of files to
+ be closed automatically if all x are in use.
+
+ (1995-03-21)
+
+file descriptor
+
+ <programming, operating system> An integer that identifies an
+ open {file} within a {process}. This number is obtained as a
+ result of opening a file. Operations which read, write, or
+ close a file would take the file descriptor as an input
+ parameter.
+
+ In many {operating system} implementations, file descriptors
+ are small integers which index a table of open files. In
+ {Unix}, file descriptors 0, 1 and 2 correspond to the
+ {standard input}, {standard output} and {standard error} files
+ respectively.
+
+ See {file descriptor leak}.
+
+ (1998-02-06)
+
+file descriptor leak
+
+ <programming> (Or "fd leak" /F D leek/) A kind of programming
+ {bug} analogous to a {core leak}, in which a program fails to
+ close {file descriptors} ("fd"s) after file operations are
+ completed, and thus eventually runs out of them.
+
+ See {leak}.
+
+ (1994-11-30)
+
+file extension
+
+ {filename extension}
+
+FileMaker
+
+ <software> A {database} application developed by {Claris}. It
+ is currently the leading database application for the
+ {Macintosh} and is the second most popular standalone package
+ for {Windows}.
+
+ (1998-02-18)
+
+FileMaker, Inc.
+
+ <company> The company that distributes the {FileMaker}
+ {database}. FileMaker, Inc. was previously known as {Claris}
+ and was renamed after a restructuring in January 1998.
+
+ {(http://filemaker.com/)}.
+
+ (1998-02-18)
+
+filename extension
+
+ <filename extension> The portion of a filename, following the
+ final point, which indicates the kind of data stored in the
+ file - the {file type}.
+
+ Many {operating systems} use filename extensions, e.g. {Unix},
+ {VMS}, {MS-DOS}, {Microsoft Windows}. They are usually from
+ one to three letters (some sad old OSes support no more than
+ three). Examples include "c" for {C} {source code}, "ps" for
+ {PostScript}, "txt" for arbitrary text.
+
+ {NEXTSTEP} and its descendants also use extensions on
+ directories for a similar purpose.
+
+ Apart from informing the user what type of content the file
+ holds, filename extensions are typically used to decide which
+ program to launch when a file is "run", e.g. by
+ double-clicking it in a {GUI} {file browser}. They are also
+ used by {Unix}'s {make} to determine how to build one kind of
+ file from another.
+
+ Compare: {MIME type}.
+
+ {Tony Warr's comprehensive list
+ (http://camalott.com/~rebma/filex.html)}.
+
+ {FAQS.org Graphics formats
+ (http://faqs.org/faqs/graphics/fileformats-faq/)}.
+
+ (2002-04-19)
+
+FileNet
+
+ <storage> A system for storage of {images} on laser disk using
+ {COLD}.
+
+ (1995-11-09)
+
+File Request
+
+ 1. The {FidoNet} equivalent of {FTP}, in which one {BBS}
+ system automatically dials another and {snarfs} one or more
+ files. Often abbreviated "FReq"; files are often announced as
+ being "available for FReq" in the same way that files are
+ announced as being "available for/by {anonymous FTP}" on the
+ {Internet}.
+
+ 2. The act of getting a copy of a file by using the File
+ Request option of the {BBS} mailer.
+
+ [{Jargon File}]
+
+ (1995-01-05)
+
+File Separator
+
+ <character> (FS) {ASCII} character 28.
+
+ (1996-06-28)
+
+file server
+
+ Hardware and software that together provide file-handling and
+ storage functions for multiple users on a {local area
+ network}. The most common choices for file server software
+ are {Sun Microsystems}' {Network File System} for {Unix} and
+ {Novell Netware} for {IBM PC} compatibles. There is also a
+ version of NFS for PCs called {PC-NFS}. Storing files on a
+ file server saves having multiple copies stored on individual
+ computers, thus economising on disk space and also makes
+ administrating and updating the files easier.
+
+File Service Protocol
+
+ <protocol> (FSP) A {protocol}, similar to {FTP}, for copying
+ {files} between computers. It's designed for {anonymous
+ archives}, and has protection against {server} and {network}
+ overloading. It doesn't use connections so it can survive
+ interruptions in service.
+
+ Until 1993-08-12, FSP didn't stand for anything. Wen-King
+ was responsible for the initials and Michael Grubb
+ <mg@ac.duke.edu> for their eventual expansion. Other
+ suggestions were "File Slurping Protocol", "Flaky Stream
+ Protocol" and "FTP's Sexier Partner".
+
+ {FAQ
+ (ftp://ftp.germany.eu.net/pub/networking/inet/fsp/fsp-faq/)}.
+
+ [fsp-faq, 1993-08-12].
+
+ (1997-12-07)
+
+file signature
+
+ A {magic number}.
+
+ [{Jargon File}]
+
+file system
+
+ <operating system> (FS, or "filesystem") 1. A system for
+ organizing {directories} and {files}, generally in terms of
+ how it is implemented in the {disk operating system}. E.g.,
+ "The {Macintosh file system} is just dandy as long as you
+ don't have to interface it with any other file systems".
+
+ 2. The collection of files and directories stored on a given
+ drive (floppy drive, hard drive, disk {partition}, {logical}
+ drive, {RAM drive}, etc.). E.g., "mount attaches a named file
+ system to the file system hierarchy at the pathname location
+ directory [...]" -- {Unix manual page} for "mount(8)".
+
+ As an extension of this sense, "file system" is sometimes used
+ to refer to the representatation of the file system's
+ organisation (e.g. its {file allocation table}) as opposed the
+ actual content of the files in the file system.
+
+ {Unix manual page}: fs(5), mount(8).
+
+ (1997-04-10)
+
+Filesystem Hierarchy Standard
+
+ <storage, standard> (FHS) A {standard} designed to be used by
+ {Unix} {distribution} developers, {package} developers, and
+ system implementors.
+
+ FHS consists of a set of {requirements} and guidelines for
+ file and directory placement under {UNIX}-like {operating
+ systems}.
+
+ The {guidelines} are intended to support interoperability of
+ applications, system administration tools, development tools,
+ and scripts. These systems should also be supported with
+ greater documentation uniformity.
+
+ The standard is primarily intended to be a reference and is
+ not a tutorial on how to manage a Unix filesystem or directory
+ hierarchy.
+
+ {(http://pathname.com/fhs/)}.
+
+ {RedHat deviation (http://redhat.com/corp/support/manuals/RHL-6.0-Manual/install-guide/manual/doc084.html)}.
+
+ (2001-05-24)
+
+file transfer
+
+ <networking> Copying a {file} from one computer to another
+ over a computer {network}.
+
+ See also {File Transfer Protocol}, {Kermit}, {Network File
+ System}, {rcp}, {uucp}, {XMODEM}, {ZMODEM}.
+
+ (1997-04-10)
+
+File Transfer Protocol
+
+ (FTP) A {client-server} protocol which allows a user on one
+ computer to transfer files to and from another computer over a
+ {TCP/IP} network. Also the client program the user executes
+ to transfer files. It is defined in {STD 9}, {RFC 959}.
+
+ See also {anonymous FTP}, {FSP}, {TFTP}.
+
+ {Unix manual page}: ftp(1).
+
+ (1994-12-01)
+
+file type
+
+ <file format> The kind of data stored in a file. Most modern
+ {operating systems} use the {filename extension} to determine
+ the file type though others store this information elsewhere
+ in the {file system}. The file type is used to choose an
+ appropriate icon to represent the file in a {GUI} and the
+ correct {application} with which to view, edit, run, or print
+ the file.
+
+ Different operating systems support different sets of file
+ types though most agree on a large common set and allow
+ arbitrary new types to be defined.
+
+ See also {MIME}.
+
+ {FileInfo.com - The File Extensions Resource
+ (http://fileinfo.com/)}
+
+ (2009-03-27)
+
+filing system
+
+ {file system}
+
+filk
+
+ /filk/ [SF fandom, where a typo for "folk" was adopted as a
+ new word] A popular or folk song with lyrics revised or
+ completely new lyrics, intended for humorous effect when
+ read, and/or to be sung late at night at SF conventions.
+ There is a flourishing subgenre of these called "computer
+ filks", written by hackers and often containing rather
+ sophisticated technical humour. See {double bucky} for an
+ example. Compare {grilf}, {hing} and {newsfroup}.
+
+ [{Jargon File}]
+
+fill-out form
+
+ <programming> A type of {user interface} used, for example, on
+ the {web}, to organise a set of questions or
+ options for the user so that it resembles a traditional paper
+ form that is filled out. Typical query types are:
+ fill-in-the-blank (text), menu of options, select zero or
+ more, or select exactly one ("{radio buttons}").
+
+ Most {web browsers} support fill-out forms.
+ {Overview
+ (http://ncsa.uiuc.edu/SDG/Software/Mosaic/Docs/fill-out-forms/overview.html)}.
+
+ (1998-03-24)
+
+film at 11
+
+ <jargon> (MIT, in parody of US TV newscasters) 1. Used in
+ conversation to announce ordinary events, with a sarcastic
+ implication that these events are earth-shattering. "{ITS}
+ crashes; film at 11." "Bug found in scheduler; film at 11."
+
+ 2. Also widely used outside MIT to indicate that additional
+ information will be available at some future time, *without*
+ the implication of anything particularly ordinary about the
+ referenced event. For example, "The mail file server died
+ this morning; we found garbage all over the root directory.
+ Film at 11." would indicate that a major failure had occurred
+ but that the people working on it have no additional
+ information about it as yet; use of the phrase in this way
+ suggests gently that the problem is liable to be fixed more
+ quickly if the people doing the fixing can spend time doing
+ the fixing rather than responding to questions, the answers to
+ which will appear on the normal "11:00 news", if people will
+ just be patient.
+
+ [{Jargon File}]
+
+ (1998-03-24)
+
+FILO
+
+ {stack}
+
+Filtabyte
+
+ <networking, hardware> An {Ethernet controller} card made by
+ {LRT} based on the {LANCE} and {SIA}. It uses {DMA}. Its
+ {Ethernet address} can be changed by software.
+
+ (1994-12-01)
+
+filter
+
+ 1. (Originally {Unix}, now also {MS-DOS}) A program that
+ processes an input data stream into an output data stream in
+ some well-defined way, and does no I/O to anywhere else except
+ possibly on error conditions; one designed to be used as a
+ stage in a {pipeline} (see {plumbing}). Compare {sponge}.
+
+ 2. ({functional programming}) A {higher-order function} which
+ takes a {predicate} and a list and returns those elements of
+ the list for which the predicate is true. In {Haskell}:
+
+ filter p [] = []
+ filter p (x:xs) = if p x then x : rest else rest
+ where
+ rest = filter p xs
+
+ See also {filter promotion}.
+
+ [{Jargon File}]
+
+filter promotion
+
+ <algorithm> In a {generate and test} algorithm, combining part
+ of the filter with the generator in order to reduce the number
+ of potential solutions generated. A trivial example:
+
+ filter (< 100) [1..1000] ==> [1..99]
+
+ where [1..n] generates the list of integers from 1 to n. Here
+ the filter has been combined completely with the generator.
+ This is an example of {fusion}.
+
+ (2005-03-18)
+
+FIMS
+
+ {Form Interface Management System}
+
+Finagle's Law
+
+ <humour> The generalised or "folk" version of {Murphy's Law},
+ fully named "Finagle's Law of Dynamic Negatives" and usually
+ rendered "Anything that can go wrong, will". One variant
+ favoured among hackers is "The perversity of the Universe
+ tends toward a maximum".
+
+ The label "Finagle's Law" was popularised by SF author Larry
+ Niven in several stories depicting a frontier culture of
+ asteroid miners; this "Belter" culture professed a religion
+ and/or running joke involving the worship of the dread god
+ Finagle and his mad prophet Murphy.
+
+ [{Jargon File}]
+
+ (1995-12-14)
+
+Financial Information eXchange
+
+ <business, protocol> (FIX) A {standard} messaging {protocol}
+ for the {real-time} electronic exchange of securities
+ transactions.
+
+ [Reference?]
+
+ (2001-05-14)
+
+Finder
+
+ <operating system> The part of the {Macintosh Operating
+ System} and {GUI} that simulates the {desktop}. The
+ {multitasking} version of Finder was called "{MultiFinder}"
+ until {multitasking} was integrated into the core of the OS
+ with the introduction of System 7.0 in 1990.
+
+ (2005-03-18)
+
+fine adjuster
+
+ <jargon, tool, humour> A tool used for {percussive
+ maintenance}, also known as a "hammer".
+
+ (1999-01-15)
+
+fine grain
+
+ {granularity}
+
+finger
+
+ <tool> A {Unix} program that displays information about a
+ particular user or all users logged on the system, or a remote
+ system. Finger typically shows full name, last login time,
+ idle time, terminal line, and terminal location (where
+ applicable). It may also display a {plan file} left by the
+ user (see also {Hacking X for Y}). Some versions take a "-l"
+ (long) argument which yields more information.
+
+ [{Jargon File}]
+
+ (2002-10-06)
+
+finger-pointing syndrome
+
+ <programming> All-too-frequent result of {bugs}, especially in
+ new or experimental configurations. The hardware vendor
+ points a finger at the software. The software vendor points a
+ finger at the hardware. All the poor users get is the finger.
+
+ [{Jargon File}]
+
+ (1995-12-14)
+
+finite
+
+ {compact}
+
+Finite Automata
+
+ {Finite State Machine}
+
+Finite Automaton
+
+ {Finite State Machine}
+
+finite differencing
+
+ {strength reduction}
+
+Finite Impulse Response
+
+ <electronics, DSP> (FIR) A type of {digital signal} {filter},
+ in which every {sample} of output is the weighted sum of past
+ and current samples of input, using only some finite number of
+ past samples.
+
+ (2001-06-06)
+
+Finite State Automata
+
+ {Finite State Machine}
+
+Finite State Automaton
+
+ {Finite State Machine}
+
+Finite State Machine
+
+ <mathematics, algorithm, theory> (FSM or "Finite State
+ Automaton", "transducer") An {abstract machine} consisting of
+ a set of {states} (including the initial state), a set of
+ input events, a set of output events, and a state transition
+ function. The function takes the current state and an input
+ event and returns the new set of output events and the next
+ state. Some states may be designated as "terminal states".
+ The state machine can also be viewed as a function which maps
+ an ordered sequence of input events into a corresponding
+ sequence of (sets of) output events.
+
+ A {deterministic} FSM (DFA) is one where the next state is
+ uniquely determinied by a single input event. The next state
+ of a {nondeterministic} FSM (NFA) depends not only on the
+ current input event, but also on an arbitrary number of
+ subsequent input events. Until these subsequent events occur
+ it is not possible to determine which state the machine is in.
+
+ It is possible to automatically translate any nondeterministic
+ FSM into a deterministic one which will produce the same
+ output given the same input. Each state in the DFA represents
+ the set of states the NFA might be in at a given time.
+
+ In a probabilistic FSM [proper name?], there is a
+ predetermined {probability} of each next state given the
+ current state and input (compare {Markov chain}).
+
+ The terms "acceptor" and "transducer" are used particularly in
+ language theory where automata are often considered as
+ {abstract machines} capable of recognising a language (certain
+ sequences of input events). An acceptor has a single
+ {Boolean} output and accepts or rejects the input sequence by
+ outputting true or false respectively, whereas a transducer
+ translates the input into a sequence of output events.
+
+ FSMs are used in {computability theory} and in some practical
+ applications such as {regular expressions} and digital logic
+ design.
+
+ See also {state transition diagram}, {Turing Machine}.
+
+ [J.H. Conway, "regular algebra and finite machines", 1971, Eds
+ Chapman & Hall].
+
+ [S.C. Kleene, "Representation of events in nerve nets and
+ finite automata", 1956, Automata Studies. Princeton].
+
+ [Hopcroft & Ullman, 1979, "Introduction to automata theory,
+ languages and computations", Addison-Wesley].
+
+ [M. Crochemore "tranducters and repetitions",
+ Theoritical. Comp. Sc. 46, 1986].
+
+ (2001-09-22)
+
+finn
+
+ <jargon, chat> To pull rank on somebody based on the amount of
+ time one has spent on {IRC}. The term derives from the fact
+ that IRC was originally written in Finland in 1987.
+
+ [{Jargon File}]
+
+ (2000-08-05)
+
+FIPS
+
+ {Federal Information Processing Standards}
+
+FIR
+
+ 1. <electronics> {Finite Impulse Response} (filter).
+
+ 2. <standard> Fast Infrared. {Infrared} standard from {IrDA},
+ part of {IrDA Data}. FIR supports {synchronous}
+ communications at 4 Mbps (and 1.115 Mbps?), at a distance of
+ up to 1 metre.
+
+ (1999-10-14)
+
+firebottle
+
+ {electron tube}
+
+firefighting
+
+ 1. What sysadmins have to do to correct sudden operational
+ problems. An opposite of hacking. "Been hacking your new
+ newsreader?" "No, a power glitch hosed the network and I
+ spent the whole afternoon fighting fires."
+
+ 2. The act of throwing lots of manpower and late nights at a
+ project, especially to get it out before deadline. See also
+ {gang bang}, {Mongolian Hordes technique}; however, the term
+ "firefighting" connotes that the effort is going into chasing
+ bugs rather than adding features.
+
+ (1994-12-01)
+
+Firefox
+
+ <web> A complete {free}, {open-source} {web
+ browser} from the {Mozilla Foundation} and therefore a true
+ code descendent of {Netscape Navigator}. The first non-{beta
+ release} was in late 2004.
+
+ {Firefox Home (http://mozilla.org/products/firefox)}.
+
+ (2005-01-26)
+
+firehose syndrome
+
+ <networking, jargon> An absence, failure or inadequacy of flow
+ control mechanisms causing the sender to overwhelm the
+ receiver. The implication is that, like trying to drink from
+ a firehose, the consequenses are worse than just loss of data,
+ e.g. the receiver may {crash}.
+
+ See {ping-flood}.
+
+ [{Jargon File}]
+
+ (2007-03-12)
+
+firewall
+
+ 1. {firewall code}.
+
+ 2. {firewall machine}.
+
+firewall code
+
+ 1. The code you put in a system (say, a telephone switch) to
+ make sure that the users can't do any damage. Since users
+ always want to be able to do everything but never want to
+ suffer for any mistakes, the construction of a firewall is a
+ question not only of defensive coding but also of interface
+ presentation, so that users don't even get curious about those
+ corners of a system where they can burn themselves.
+
+ 2. Any sanity check inserted to catch a {can't happen} error.
+ Wise programmers often change code to fix a bug twice: once to
+ fix the bug, and once to insert a firewall which would have
+ arrested the bug before it did quite as much damage.
+
+ [{Jargon File}]
+
+firewall machine
+
+ <networking, security> A dedicated {gateway} {server} with special
+ security precautions on it, used to service external connections
+ (typically from the {public Internet}). The firewall machine
+ protects servers and networks hidden behind it from {crackers}.
+
+ The typical firewall is an inexpensive {microprocessor}-based
+ {Unix} machine with no critical data, with public network ports on
+ it, but just one carefully watched connection back to the rest of
+ the cluster. The special precautions may include threat
+ monitoring, {call-back}, and even a complete {iron box} keyable to
+ particular incoming IDs or activity patterns.
+
+ The type of network and security environment of a firewall machine
+ is often called a {De-Militarised Zone} (DMZ). It may contain
+ other servers such as e-mail servers or {proxy gateways} -
+ machines that need to be publicly accessible but also need some
+ access to internal systems.
+
+ Also known as a (Venus) flytrap after the insect-eating plant.
+
+ (2014-07-15)
+
+FireWire
+
+ {High Performance Serial Bus}
+
+fireworks mode
+
+ The mode a machine is sometimes said to be in when
+ it is performing a {crash and burn} operation.
+
+ [{Jargon File}]
+
+Firmware
+
+ Software stored in read-only memory (ROM) or programmable ROM
+ (PROM). Easier to change than hardware but harder than
+ software stored on disk. Firmware is often responsible for
+ the behaviour of a system when it is first switched on. A
+ typical example would be a "monitor" program in a
+ microcomputer which loads the full operating system from disk
+ or from a network and then passes control to it.
+
+firmy
+
+ {stiffy}
+
+first class module
+
+ <programming> A {module} that is a {first class data object}
+ of the {programming language}, e.g. a {record} containing
+ {functions}. In a {functional language}, it is standard to
+ have first class programs, so program building blocks can have
+ the same status.
+
+ {Claus Reinke's Virtual Bookshelf
+ (http://informatik.uni-kiel.de/~cr/bib/bookshelf/Modules.html)}.
+
+ (2004-01-26)
+
+First Fit
+
+ <algorithm> A {resource} allocation scheme (usually for
+ {memory}). First Fit fits data into memory by scanning from
+ the beginning of available memory to the end, until the first
+ free space which is at least big enough to accept the data is
+ found. This space is then allocated to the data. Any left
+ over becomes a smaller, separate free space.
+
+ If the data to be allocated is bigger than the biggest free
+ space, the request cannot be met, and an error is generated.
+
+ Compare {Best Fit}.
+
+ (1997-06-02)
+
+first generation
+
+ 1. <architecture> {first generation computer}.
+
+ 2. <language> {first generation language}.
+
+first generation computer
+
+ <architecture> A prototype computer based on {vacuum tubes}
+ and other esoteric technologies. Chronologically, any
+ computer designed before the mid-1950s. Examples include
+ {Howard Aiken}'s {Mark 1} (1944), Maunchly and Eckert's
+ {ENIAC} (1946), and the {IAS} computer.
+
+ (1996-11-22)
+
+first generation language
+
+ Raw {machine code}. When computers were first "programmed"
+ from an input device, rather than by being rewired, they were
+ fed input in the form of numbers, which they then interpreted
+ as commands. This was really low level, and a program
+ fragment might look like "010307 010307". Almost no one
+ programs in machine language anymore, because translators are
+ nearly trivial to write.
+
+ (1994-12-01)
+
+first-in first-out
+
+ <algorithm> (FIFO, or "queue") A data structure or hardware
+ buffer from which items are taken out in the same order they
+ were put in. Also known as a "shelf" from the analogy with
+ pushing items onto one end of a shelf so that they fall off
+ the other. A FIFO is useful for buffering a stream of data
+ between a sender and receiver which are not synchronised -
+ i.e. not sending and receiving at exactly the same rate.
+ Obviously if the rates differ by too much in one direction for
+ too long then the FIFO will become either full ({block}ing the
+ sender) or empty ({block}ing the receiver). A {Unix} {pipe}
+ is a common example of a FIFO.
+
+ A FIFO might be (but isn't ever?) called a LILO - last-in
+ last-out. The opposite of a FIFO is a LIFO (last-in
+ first-out) or "{stack}".
+
+ (1999-12-06)
+
+first normal form
+
+ {database normalisation}
+
+first-order
+
+ Not {higher-order}.
+
+ (1995-03-06)
+
+first-order logic
+
+ <language, logic> The language describing the truth of
+ mathematical {formulas}. Formulas describe properties of
+ terms and have a truth value. The following are atomic
+ formulas:
+
+ True
+ False
+ p(t1,..tn) where t1,..,tn are terms and p is a predicate.
+
+ If F1, F2 and F3 are formulas and v is a variable then the
+ following are compound formulas:
+
+ F1 ^ F2 conjunction - true if both F1 and F2 are true,
+
+ F1 V F2 disjunction - true if either or both are true,
+
+ F1 => F2 implication - true if F1 is false or F2 is
+ true, F1 is the antecedent, F2 is the
+ consequent (sometimes written with a thin
+ arrow),
+
+ F1 <= F2 true if F1 is true or F2 is false,
+
+ F1 == F2 true if F1 and F2 are both true or both false
+ (normally written with a three line
+ equivalence symbol)
+
+ ~F1 negation - true if f1 is false (normally
+ written as a dash '-' with a shorter vertical
+ line hanging from its right hand end).
+
+ For all v . F universal quantification - true if F is true
+ for all values of v (normally written with an
+ inverted A).
+
+ Exists v . F existential quantification - true if there
+ exists some value of v for which F is true.
+ (Normally written with a reversed E).
+
+ The operators ^ V => <= == ~ are called connectives. "For
+ all" and "Exists" are {quantifiers} whose {scope} is F. A
+ term is a mathematical expression involving numbers,
+ operators, functions and variables.
+
+ The "order" of a logic specifies what entities "For all" and
+ "Exists" may quantify over. First-order logic can only
+ quantify over sets of {atomic} {propositions}. (E.g. For all p
+ . p => p). Second-order logic can quantify over functions on
+ propositions, and higher-order logic can quantify over any
+ type of entity. The sets over which quantifiers operate are
+ usually implicit but can be deduced from well-formedness
+ constraints.
+
+ In first-order logic quantifiers always range over ALL the
+ elements of the domain of discourse. By contrast,
+ second-order logic allows one to quantify over subsets.
+
+ ["The Realm of First-Order Logic", Jon Barwise, Handbook of
+ Mathematical Logic (Barwise, ed., North Holland, NYC, 1977)].
+
+ (2005-12-27)
+
+First Party DMA
+
+ {bus mastering}
+
+fish
+
+ (Adelaide University, Australia) 1. Another {metasyntactic
+ variable}. See {foo}. Derived originally from the Monty
+ Python skit in the middle of "The Meaning of Life" entitled
+ "Find the Fish".
+
+ 2. <storage> microfiche. A microfiche file cabinet may be
+ referred to as a "fish tank".
+
+ [{Jargon File}]
+
+ (1994-12-01)
+
+FISH queue
+
+ <humour> (By analogy with {FIFO} - first-in, first-out) first
+ in, still here.
+
+ A joking way of pointing out that processing of a particular
+ sequence of events or requests has stopped dead. Also "FISH
+ mode" and "FISHnet"; the latter may be applied to any network
+ that is running really slowly or exhibiting extreme flakiness.
+
+ [{Jargon File}]
+
+ (1994-12-01)
+
+FITNR
+
+ ({Thinking Machines, Inc.}) Fixed In the Next Release.
+
+ A written-only notation attached to bug reports. Often
+ wishful thinking.
+
+ [{Jargon File}]
+
+ (1994-12-01)
+
+FITS
+
+ Flexible Image Transport System. The standard data
+ interchange and archive format of the astronomy community.
+
+ (1994-12-01)
+
+FIX
+
+ 1. <networking> {Federal Information Exchange}.
+
+ 2. <business, protocol> {Financial Information eXchange}.
+
+ (2001-05-14)
+
+fix
+
+ 1. <mathematics> The {fixed point} {combinator}. Called Y in
+ {combinatory logic}. Fix is a {higher-order function} which
+ returns a fixed point of its argument (which is a function).
+
+ fix :: (a -> a) -> a
+ fix f = f (fix f)
+
+ Which satisfies the equation
+
+ fix f = x such that f x = x.
+
+ Somewhat surprisingly, fix can be defined as the non-recursive
+ {lambda abstraction}:
+
+ fix = \ h . (\ x . h (x x)) (\ x . h (x x))
+
+ Since this involves self-application, it has an {infinite
+ type}. A function defined by
+
+ f x1 .. xN = E
+
+ can be expressed as
+
+ f = fix (\ f . \ x1 ... \ xN . E)
+ = (\ f . \ x1 ... \xN . E)
+ (fix (\ f . \ x1 ... \ xN . E))
+ = let f = (fix (\ f . \ x1 ... \ xN . E))
+ in \ x1 ... \xN . E
+
+ If f does not occur {free} in E (i.e. it is not {recursive})
+ then this reduces to simply
+
+ f = \ x1 ... \ xN . E
+
+ In the case where N = 0 and f is free in E, this defines an
+ infinite data object, e.g.
+
+ ones = fix (\ ones . 1 : ones)
+ = (\ ones . 1 : ones) (fix (\ ones . 1 : ones))
+ = 1 : (fix (\ ones . 1 : ones))
+ = 1 : 1 : ...
+
+ Fix f is also sometimes written as mu f where mu is the Greek
+ letter or alternatively, if f = \ x . E, written as mu x . E.
+
+ Compare {quine}.
+
+ [{Jargon File}]
+
+ (1995-04-13)
+
+ 2. {bug fix}.
+
+ (1998-06-25)
+
+fixed disk
+
+ <storage> A {hard disk} which is not a {removable disk}.
+
+fixed point
+
+ <mathematics> The fixed point of a function, f is any value, x
+ for which f x = x. A function may have any number of fixed
+ points from none (e.g. f x = x+1) to infinitely many (e.g. f x
+ = x). The {fixed point combinator}, written as either "fix"
+ or "Y" will return the fixed point of a function.
+
+ See also {least fixed point}.
+
+ (1995-04-13)
+
+fixed-point
+
+ <programming> A {number representation} scheme where a number,
+ F is represented by an {integer} I such that F=I*R^-P, where R is
+ the (assumed) {radix} of the representation and P is the (fixed)
+ number of digits after the radix point.
+
+ On computers with no {floating-point unit}, fixed-point
+ calculations are significantly faster than floating-point as
+ all the operations are basically integer operations.
+ Fixed-point representation also has the advantage of having
+ uniform density, i.e., the smallest resolvable difference of
+ the representation is R^-P throughout the representable range,
+ in contrast to {floating-point} representations.
+
+ For example, in {PL/I}, FIXED data has both a {precision} and
+ a scale-factor (P above). So a number declared as 'FIXED
+ DECIMAL(7,2)' has a precision of seven and a scale-factor of
+ two, indicating five integer and two fractional decimal
+ digits. The smallest difference between numbers will be 0.01.
+
+ (2006-11-15)
+
+fixed point combinator
+
+ <mathematics> (Y) The name used in {combinatory logic} for the
+ {fixed point} function, also written as "{fix}".
+
+ (1994-10-20)
+
+fixed-radio access
+
+ {Wireless Local Loop}
+
+fixed-width
+
+ {record}
+
+FIXME
+
+ <programming> A standard tag often put in {comments} near a
+ piece of code that needs work. The point of doing so is that
+ a {grep} or a similar pattern-matching tool can find all such
+ places quickly. This is common in {GNU} code. Compare {XXX}.
+
+ [{Jargon File}]
+
+ (2001-03-16)
+
+fixpoint
+
+ {fixed point}
+
+fj
+
+ <networking> The {country code} for Fiji.
+
+ (1999-01-27)
+
+Fjolnir
+
+ <language> An Icelandic programming language for the {IBM PC}
+ from the {University of Iceland}.
+
+ [Pall Haraldsson <pallha@rhi.hi.is>].
+
+ (1995-03-17)
+
+fk
+
+ <networking> The {country code} for the Falkland Islands
+ (Malvinas).
+
+ (1999-01-27)
+
+FL
+
+ <language> Function Level.
+
+ John Backus's successor to {FP}, developed ca. 1985. FL is
+ {dynamically typed} and adds {higher-order functions},
+ {exceptions}, {user-defined types} and other features.
+
+ ["FL Language Manual, Parts 1 & 2", J. Backus et al, IBM
+ Research Report RJ 7100 (1989)].
+
+ (1994-10-20)
+
+F+L
+
+ <language> Functions plus Logic. Equational clauses within
+ function definitions to solve for {logic variable} bindings.
+
+ ["Functions plus Logic in Theory and Practice", R.B.
+ Kieburtz, Feb 1987, unpublished].
+
+ (1994-10-20)
+
+flag
+
+ 1. <programming> A variable or quantity that can take on one
+ of two values; a bit, particularly one that is used to
+ indicate one of two outcomes or is used to control which of
+ two things is to be done. "This flag controls whether to
+ clear the screen before printing the message." "The program
+ status word contains several flag bits." See also {hidden
+ flag}, {mode bit}.
+
+ 2. {command line option}.
+
+ [{Jargon File}]
+
+ (1998-05-02)
+
+flag day
+
+ <jargon> A software change that is neither forward- nor
+ backward-compatible, and which is costly to make and costly to
+ reverse. E.g. "Can we install that without causing a flag day
+ for all users?"
+
+ This term has nothing to do with the use of the word {flag} to
+ mean a variable that has two values. It came into use when a
+ massive change was made to the {Multics} {time-sharing} system
+ to convert from the old {ASCII} code to the new one; this was
+ scheduled for Flag Day (a US holiday), June 14, 1966.
+
+ See also {backward combatability}, {lock-in}.
+
+ [{Jargon File}]
+
+ (1998-01-15)
+
+FLAIR
+
+ <language> An early system on the {IBM 650}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1995-03-17)
+
+flaky
+
+ (Or "flakey") Subject to frequent {lossage}. This use is of
+ course related to the common slang use of the word to describe
+ a person as eccentric, crazy, or just unreliable. A system
+ that is flaky is working, sort of - enough that you are
+ tempted to try to use it - but fails frequently enough that
+ the odds in favour of finishing what you start are low.
+ Commonwealth hackish prefers {dodgy}.
+
+ [{Jargon File}]
+
+ (1996-01-05)
+
+flamage
+
+ {flame}
+
+flame
+
+ <messaging> To rant, to speak or write incessantly and/or
+ rabidly on some relatively uninteresting subject or with a
+ patently ridiculous attitude or with hostility toward a
+ particular person or group of people. "Flame" is used as a
+ verb ("Don't flame me for this, but..."), a flame is a single
+ flaming message, and "flamage" /flay'm*j/ the content.
+
+ Flamage may occur in any medium (e.g. spoken, {electronic
+ mail}, {Usenet} news, {web}). Sometimes a flame
+ will be delimited in text by marks such as "<flame
+ on>...<flame off>".
+
+ The term was probably independently invented at several
+ different places.
+
+ Mark L. Levinson says, "When I joined the Harvard student
+ radio station (WHRB) in 1966, the terms flame and flamer were
+ already well established there to refer to impolite ranting
+ and to those who performed it. Communication among the
+ students who worked at the station was by means of what today
+ you might call a paper-based Usenet group. Everyone wrote
+ comments to one another in a large ledger. Documentary
+ evidence for the early use of flame/flamer is probably still
+ there for anyone fanatical enough to research it."
+
+ It is reported that "flaming" was in use to mean something
+ like "interminably drawn-out semi-serious discussions"
+ (late-night bull sessions) at Carleton College during
+ 1968-1971.
+
+ {Usenetter} Marc Ramsey, who was at {WPI} from 1972 to 1976,
+ says: "I am 99% certain that the use of "flame" originated at
+ WPI. Those who made a nuisance of themselves insisting that
+ they needed to use a {TTY} for "real work" came to be known as
+ "flaming asshole lusers". Other particularly annoying people
+ became "flaming asshole ravers", which shortened to "flaming
+ ravers", and ultimately "flamers". I remember someone picking
+ up on the Human Torch pun, but I don't think "flame on/off"
+ was ever much used at WPI." See also {asbestos}.
+
+ It is possible that the hackish sense of "flame" is much older
+ than that. The poet Chaucer was also what passed for a wizard
+ hacker in his time; he wrote a treatise on the astrolabe, the
+ most advanced computing device of the day. In Chaucer's
+ "Troilus and Cressida", Cressida laments her inability to
+ grasp the proof of a particular mathematical theorem; her
+ uncle Pandarus then observes that it's called "the fleminge of
+ wrecches." This phrase seems to have been intended in context
+ as "that which puts the wretches to flight" but was probably
+ just as ambiguous in Middle English as "the flaming of
+ wretches" would be today. One suspects that Chaucer would
+ feel right at home on {Usenet}.
+
+ [{Jargon File}]
+
+ (2001-03-11)
+
+flame bait
+
+ <messaging> A {Usenet} posting or other message intended to
+ trigger a {flame war}, or one that invites {flames} in reply.
+
+ [{Jargon File}]
+
+ (1998-05-27)
+
+flame off
+
+ {flame on}
+
+flame on
+
+ <messaging, jargon> To begin or continue to {flame}. The
+ punning reference to Marvel Comics's Human Torch is no longer
+ widely recognised.
+
+ The phrase "flame on" may actually precede the flame, in which
+ case "flame off" will follow it.
+
+ See {rave}, {burble}.
+
+ [{Jargon File}]
+
+ (1996-10-29)
+
+flamer
+
+ <jargon, person> (Or "pain in the net") One who habitually
+ {flames}. Said especially of obnoxious {Usenet}
+ personalities.
+
+ [{Jargon File}]
+
+ (1996-08-26)
+
+flame war
+
+ <messaging, jargon> An acrimonious dispute conducted on a
+ public electronic forum such as {Usenet}. See {flame}.
+
+ [{Jargon File}]
+
+ (1998-05-27)
+
+flaming
+
+ {flame}
+
+FLAP
+
+ A {symbolic mathematics} package for {IBM 360}.
+
+ ["FLAP Programmer's Manual", A.H. Morris Jr., TR-2558 (1971)
+ US Naval Weapons Lab].
+
+ [Sammet 1969, p. 506].
+
+ [{Jargon File}]
+
+ (1994-10-17)
+
+flap
+
+ 1. <storage, jargon> To unload a {DECtape} (so it goes flap,
+ flap, flap). Old-time {hackers} at {MIT} tell of the days
+ when the disk was device 0 and {microtapes} were 1, 2,
+ etc. and attempting to flap device 0 would instead start a
+ motor banging inside a cabinet near the disk.
+
+ The term is used, by extension, for unloading any magnetic
+ tape. See also {macrotape}. Modern {cartridge tapes} no
+ longer actually flap, but the usage has remained.
+
+ The term could well be re-applied to {DEC}'s {TK50} cartridge
+ tape drive, a spectacularly misengineered contraption which
+ makes a loud flapping sound, almost like an old reel-type
+ lawnmower, in one of its many tape-eating failure modes.
+
+ 2. <networking> See {flapping router}.
+
+ [{Jargon File}]
+
+ (1997-06-17)
+
+flapping router
+
+ <networking> A {router} that transmits routing updates
+ alternately advertising a destination network first via one
+ route, then via a different route.
+
+ Flapping routers are identified on more advanced {protocol
+ analysers} such as the Network General (TM) Sniffer.
+
+ (1999-08-24)
+
+flarp
+
+ /flarp/ [Rutgers University] Yet another {metasyntactic
+ variable} (see {foo}). Among those who use it, it is
+ associated with a legend that any program not containing the
+ word "flarp" somewhere will not work. The legend is
+ discreetly silent on the reliability of programs which *do*
+ contain the magic word.
+
+ [{Jargon File}]
+
+Flash
+
+ <file format, web> (Or "Shockwave Flash") A file
+ format for delivering {interactive} {vector graphics} and
+ animation on the {web}, developed by {Macromedia}.
+
+ {(http://macromedia.com/software/flash/)}.
+
+ (1998-07-07)
+
+flash
+
+ 1. <file format> {Adobe} {Flash}.
+
+ 2. <storage> {flash memory}.
+
+ 2. <chat> A program to flood a {Unix} user's {terminal} with
+ {garbage} by exploiting a {security hole} in the {talk}
+ {daemon}.
+
+ (1996-09-08)
+
+flash drive
+
+ <storage> Any of various kinds of device using {sold-state
+ memory} ("flash memory") with an interface like a {hard disk
+ drive}, often a {USB} interface.
+
+ (2009-07-28)
+
+Flash EPROM
+
+ {Flash Erasable Programmable Read-Only Memory}
+
+Flash Erasable Programmable Read-Only Memory
+
+ <storage> (FEPROM, "flash memory") A kind of {non-volatile
+ storage} device similar to {EEPROM}, but where erasing can
+ only be done in blocks or the entire chip.
+
+ In 1995 this relatively new technology started to replace
+ {EPROMs} because reprogramming could be done with the chip
+ installed. At that time FEPROMs could be rewritten about 1000
+ times.
+
+ Like {EAPROM} and ferro-magnetic material, FEPROMs rely on {FN
+ tunnelling}. Some flash memory supports block erase.
+
+ (1995-04-22)
+
+Flash Lights Impressively
+
+ <programming, humour> (FLI) /FLY/ A joke {assembly language}
+ instruction first documented in the late 1970s in "The Hackers
+ Dictionary".
+
+ The FLI instruction was frequently referred to by engineers
+ when {minicomputers} such as the DEC {PDP-8}, {PDP-11} and
+ some early {microcomputers} such as the {IMSAI} and {Altair}
+ had dozens of front panel lights.
+
+ "When the computer is about to do some long I/O operation,
+ stick in a FLI so the accountants won't think the machine has
+ hung again."
+
+ (2004-08-23)
+
+flash memory
+
+ <storage> Originally, {Flash Erasable Programmable Read-Only
+ Memory} but commonly used for various kinds of {solid-state
+ memory}.
+
+ (2009-07-28)
+
+Flash ROM
+
+ {Flash Erasable Programmable Read-Only Memory}
+
+flat
+
+ 1. Lacking any complex internal structure. "That {bitty box}
+ has only a flat file system, not a hierarchical one." The verb
+ form is {flatten}. Usually used pejoratively (at least with
+ respect to file systems).
+
+ 2. Said of a memory architecture like that of the {VAX} or
+ {Motorola} {680x0} that is one big linear address space
+ (typically with each possible value of a processor register
+ corresponding to a unique address). This is a {Good Thing}.
+ The opposite is a "{segmented}" architecture like that of the
+ {Intel 80x86} in which addresses are composed from a
+ base-register/offset pair. Segmented designs are generally
+ considered cretinous.
+
+ 3. A flat {domain} is one where all elements except {bottom}
+ are incomparable (equally well defined). E.g. the integers.
+
+ [{Jargon File}]
+
+flat address space
+
+ <architecture> The memory architecture in which any memory
+ location can be selected from a single contiguous block by a
+ single integer offset.
+
+ Almost all popular {processors} have a flat address space, but
+ the {Intel x86} family has a {segmented address space}. A
+ flat address space greatly simplifies programming because of
+ the simple correspondence between addresses (pointers) and
+ integers.
+
+ (1996-09-10)
+
+flat ASCII
+
+ <text> (Or "plain ASCII") Said of a text file that contains
+ only 7-bit {ASCII} characters and uses only ASCII-standard
+ {control characters} (that is, has no embedded codes specific
+ to a particular text formatter {markup} language, or output
+ device, and no {meta}-characters).
+
+ Compare {flat file}.
+
+ [{Jargon File}]
+
+ (1996-01-26)
+
+flat file
+
+ <operating system, storage> A single file containing {flat
+ ASCII} representing or encoding some structure, e.g. a
+ {database}, tree or network.
+
+ Flat files can be processed with general purpose tools such as
+ {Perl} and {text editors} but are less efficient than {binary
+ files} if they must be {parsed} repeatedly by a program. Flat
+ files are more portable between different {operating systems}
+ and {application programs} than binary files, and are more
+ easily transmitted in {electronic mail}.
+
+ See also {flatten}, {sharchive}.
+
+ [{Jargon File}]
+
+ (1996-01-26)
+
+flat file database
+
+ <database> A {database} containing a single {table}, stored in
+ a single {flat file}, often in a human-readable format such as
+ {comma-separated values} or fixed-width columns.
+
+ (2008-06-16)
+
+flatten
+
+ To remove structural information, especially to filter
+ something with an implicit tree structure into a simple
+ sequence of leaves; also tends to imply mapping to
+ {flat ASCII}. "This code flattens an expression with
+ parentheses into an equivalent {canonical} form."
+
+ [{Jargon File}]
+
+flat thunk
+
+ <programming> A software mechanism that allows a {Win32}
+ application to load and call a 16-bit {DLL}, or a 16-bit
+ application to load and call a Win32 DLL.
+
+ See also {generic thunk}, {universal thunk}.
+
+ (1999-04-05)
+
+Flavors
+
+ <language> A {Lisp} variant for the {LISP Machine}, with
+ {object-oriented} features, developed by D. Weinreb and D.A. Moon
+ <moon@cambridge.apple.com> in 1980. "{Classes}" were called
+ Flavors in the language.
+
+ Though the Flavors design was superseded (notably by the {Common
+ LISP} {CLOS} facility), the term "flavor" persisted as a general
+ synonym for "class".
+
+ ["Object-Oriented Programming with Flavors", D.A. Moon, SIGPLAN
+ Notices 21(11):1-8 (OOPSLA '86), Nov 1986].
+
+ (1994-12-01)
+
+Fleng
+
+ A parallel logic language.
+
+ ["Massively Parallel Implementation of Flat GHC on the
+ Connection Machine", M. Nilsson, Proc Intl Conf on 5th Gen
+ Comp Sys, 1988, pp.1031-1040].
+
+FLEX
+
+ <language> 1. {Faster LEX}.
+
+ 2. A {real-time} language for dynamic environments.
+
+ ["FLEX: Towards Flexible Real-Time Programs", K. Lin et al,
+ Computer Langs 16(1):65-79, Jan 1991].
+
+ 3. An early {object-oriented} language developed for the
+ {FLEX} machine by {Alan Kay} in about 1967. The FLEX language
+ was a simplification of {Simula} and a predecessor of
+ {Smalltalk}.
+
+ (1995-03-29)
+
+Flex
+
+ <software, hardware> A system developed by Ian Currie (Iain?)
+ at the (then) {Royal Signals and Radar Establishment} at
+ Malvern in the late 1970s. The hardware was custom and
+ {microprogrammable}, with an {operating system}, (modular)
+ {compiler}, editor, {garbage collector} and {filing system}
+ all written in {Algol-68}. Flex was also re-implemented on
+ the {Perq}(?).
+
+ [I. F. Currie and others, "Flex Firmware", Technical Report,
+ RSRE, Number 81009, 1981].
+
+ [I. F. Currie, "In Praise of Procedures", RSRE, 1982].
+
+ (1997-11-17)
+
+Flex++
+
+ {GNU}'s {Flex} {scanner generator} retargeted to {C++} by
+ Alain Coetmeur <coetmeur@icdc.fr>. Version 3.0.
+
+ {(ftp://iecc.com/pub/file/flex++.tar.gz)}.
+ {(ftp://iecc.com/pub/file/misc++.tar.gz)}.
+ {(ftp://ftp.th-darmstadt.de/pub/programming/languages/C++/tools/flex++-3.0.tar.gz)}.
+
+ (1993-07-08)
+
+Flex 2
+
+ <language> A {preprocessor} designed to make {Fortran} look
+ more like {Pascal}, developed in about 1980.
+
+ [DECUS?]
+
+ (2004-08-23)
+
+FLI
+
+ {Flash Lights Impressively}.
+
+flib
+
+ /flib/ ({WPI}) A meta-number, said to be an integer between 3
+ and 4.
+
+ See {grix}, {N}.
+
+ (1995-01-31)
+
+FLIC
+
+ Functional Language Intermediate Code.
+
+ An {intermediate language} used in the {Chalmers} {LML}
+ compiler.
+
+ ["FLIC - A Functional Language Intermediate Code", S. Peyton
+ Jones <simonpj@dcs.gla.ac.uk> et al, RR 148, U Warwick, Sep
+ 1989].
+
+ (1995-01-31)
+
+FLIP
+
+ 1. An early {assembly language} on the {G-15}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ 2. ["FLIP User's Manual", G. Kahn, TR 5, INRIA 1981].
+
+ 3. Formal LIst Processor.
+
+ An early language for {pattern-matching} on {Lisp} structures,
+ similar to {CONVERT}.
+
+ ["FLIP, A Format List Processor", W. Teitelman, Memo
+ MAC-M-263, MIT 1966].
+
+ (1995-01-31)
+
+Flip Chip Pin Grid Array
+
+ <hardware, processor> (FC-PGA) The package of certain {Intel}
+ {Celeron} and {Pentium III} processors. FC-PGA processors fit
+ into {Socket 370} {motherboard} sockets.
+
+ The Flip Chip {Pin Grid Array} is similar to {PPGA}, except
+ that the {silicon} {core} is facing up and the {heat slug} is
+ exposed.
+
+ FC-PGA packaging is used by Pentium III processors, and
+ Celeron 566 processors onward. Earlier Celeron processors
+ used {PPGA} packaging.
+
+ Celeron processors are also available in {Slot 1} {SEPP}
+ packaging and Pentium III processors in Slot 1 {SECC2}
+ packaging.
+
+ Adapters are available to allow a PPGA Celeron to plug into
+ a Slot 1 connector.
+
+ (2000-08-26)
+
+flip-flop
+
+ <hardware> A digital logic circuit that can be in one of two
+ states which it switches (or "{toggles}") between under
+ control of its inputs. It can thus be considered as a one bit
+ memory. Three types of flip-flop are common: the {SR
+ flip-flop}, the {JK flip-flop} and the {D-type flip-flop} (or
+ {latch}).
+
+ Early literature refers to the "Eccles-Jordan circuit" and the
+ "Eccles-Jordan binary counter", using two {vacuum tubes} as
+ the active (amplifying) elements for each {bit} of information
+ storage. Later implementations using {bipolar transistors}
+ could operate at up to 20 million state transitions per second
+ as early as 1963.
+
+ (1995-11-11)
+
+flippy
+
+ <storage> /flip'ee/ A single-sided {floppy disk} altered for
+ double-sided use by addition of a second write-notch, so
+ called because it must be flipped over for the second side
+ (the "flip side") to be accessible. Used in the {Commodore
+ 1541} and elsewhere. No longer common.
+
+ [{Jargon File}]
+
+ (2000-03-07)
+
+FLIP-SPUR
+
+ <language> An early system on the {IBM 1130}.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (2004-09-14)
+
+float
+
+ <programming> The usual {keyword} for the {floating-point}
+ {data type}, e.g. in the {C} programming language. The
+ keyword "double" usually also introduces a floating-point
+ type, but with twice the {precession} of a float.
+
+ (2008-06-13)
+
+floater
+
+ <programming> A report in a {bug tracking} system that
+ "floats" at the top of the queue but never gets assigned to a
+ developer, maybe because there is a {workaround}.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2012-04-25)
+
+floating-point
+
+ <programming, mathematics> A number representation consisting
+ of a {mantissa}, M, an {exponent}, E, and a {radix} (or
+ "base"). The number represented is M*R^E where R is the
+ radix.
+
+ In science and engineering, {exponential notation} or
+ {scientific notation} uses a radix of ten so, for example, the
+ number 93,000,000 might be written 9.3 x 10^7 (where ^7 is
+ superscript 7).
+
+ In computer hardware, floating point numbers are usually
+ represented with a radix of two since the mantissa and
+ exponent are stored in binary, though many different
+ representations could be used. The {IEEE} specify a
+ {standard} representation which is used by many hardware
+ floating-point systems. Non-zero numbers are {normalised} so
+ that the {binary point} is immediately before the most
+ significant bit of the mantissa. Since the number is
+ non-zero, this bit must be a one so it need not be stored. A
+ fixed "bias" is added to the exponent so that positive and
+ negative exponents can be represented without a sign bit.
+ Finally, extreme values of exponent (all zeros and all ones)
+ are used to represent special numbers like zero and positive
+ and negative {infinity}.
+
+ In programming languages with {explicit typing},
+ floating-point types are introduced with the keyword "float"
+ or sometimes "double" for a higher precision type.
+
+ See also {floating-point accelerator}, {floating-point unit}.
+
+ Opposite: {fixed-point}.
+
+ (2008-06-13)
+
+floating-point accelerator
+
+ <hardware> (FPA) Additional hardware to perform functions on
+ {floating point} numbers such as addition, multiplication,
+ {logarithms}, {exponentials}, {trigonometric functions} and
+ various kinds of {rounding} and error detection. A floating
+ point accelerator often functions as a {co-processor} to the
+ {CPU}.
+
+ The term "floating-point accelerator" suggests a physically
+ larger system, often an extra circuit board, whereas a
+ "floating-point unit" is probably a single chip or even part
+ of a chip.
+
+ (1994-12-01)
+
+Floating-Point SPECbaserate
+
+ {SPECrate_base_fp92}
+
+Floating-Point SPECbaseratio
+
+ {SPECbase_fp92}
+
+Floating-Point SPECrate
+
+ {SPECrate_fp92}
+
+Floating-Point SPECratio
+
+ {SPECfp92}
+
+floating point underflow
+
+ {underflow}
+
+Floating-Point Unit
+
+ <hardware> (FPU) A {floating-point accelerator}, usually in a
+ single {integrated circuit}, possible on the same IC as the
+ {central processing unit}.
+
+ (1994-10-27)
+
+floating underflow
+
+ {underflow}
+
+F-Logic
+
+ An {object-oriented} language and {deductive database} system.
+
+ ["F-Logic: A Higher-Order Language for Reasoning about
+ Objects, Inheritance and Scheme", ACM SIGMOD May 1989,
+ pp. 134-146].
+
+ (1994-10-20)
+flood
+
+ <chat> On a real-time network (whether at the level of
+ {TCP/IP}, or at the level of, say, {IRC}), to send a huge
+ amount of data to another user (or a group of users, in a
+ channel) in an attempt to annoy him, lock his terminal, or to
+ overflow his network buffer and thus lose his network
+ connection.
+
+ The basic principles of flooding are that you should have
+ better network {bandwidth} than the person you're trying to
+ flood, and that what you do to flood them (e.g., generate ping
+ requests) should be *less* resource-expensive for your machine
+ to produce than for the victim's machine to deal with. There
+ is also the corrolary that you should avoid being caught.
+
+ Failure to follow these principles regularly produces
+ hilarious results, e.g., an IRC user flooding himself off the
+ network while his intended victim is unharmed, the attacker's
+ flood attempt being detected, and him being banned from the
+ network in semi-perpetuity.
+
+ See also {pingflood}, {clonebot} and {botwar}.
+
+ [{Jargon File}]
+
+ (1997-04-07)
+
+FLOP
+
+ 1. An early system on the {IBM 701}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1994-11-14)
+
+ 2. Erroneous singular of {FLOPS}.
+
+ (2005-06-17)
+
+Floppy
+
+ <programming, tool> A {Fortran} coding convention checker.
+ A later version can generate {HTML}.
+
+ See also {Flow}.
+
+ ffccc posted to comp.sources.misc volume 12.
+
+ (1996-08-23)
+
+floppy
+
+ {floppy disk}
+
+floppy disc
+
+ <spelling> It's "{floppy disk}", not like "{compact disc}".
+
+ (2004-11-08)
+
+floppy disk
+
+ <hardware, storage> (Or "floppy", "diskette") A small,
+ portable plastic disk coated in a magnetisable substance used
+ for storing computer data, readable by a computer with a
+ floppy disk drive. The physical size of disks has shrunk from
+ the early 8 inch, to 5 1/4 inch ("minifloppy") to 3 1/2 inch
+ ("microfloppy") while the data capacity has risen.
+
+ These disks are known as "floppy" disks (or diskettes) because
+ the disk is flexible and the read/write head is in physical
+ contact with the surface of the disk in contrast to "{hard
+ disks}" (or winchesters) which are rigid and rely on a small
+ fixed gap between the disk surface and the heads. Floppies
+ may be either single-sided or double-sided.
+
+ 3.5 inch floppies are less floppy than the larger disks
+ because they come in a stiff plastic "envelope" or case, hence
+ the alternative names "stiffy" or "crunchy" sometimes used to
+ distinguish them from the floppier kind.
+
+ The following formats are used on {IBM PCs} and elsewhere:
+
+ Capacity Density Width
+ 360K double 5.25"
+ 720K double 3.5"
+ 1.2M high 5.25"
+ 1.44M high 3.5"
+
+ Double denisty and high density are usually abbreviated DD and
+ HD. HD 3.5 inch disks have a second hole in the envelope and
+ an overlapping "HD" logo.
+
+ (1996-08-23)
+
+floppy disk drive
+
+ {disk drive}
+
+floppy drive
+
+ {disk drive}
+
+FLOPS
+
+ {Floating-point} operations per second.
+
+Flops
+
+ <benchmark> The {MFLOPS} {benchmark}.
+
+floptical
+
+ <hardware, storage> (From "floppy disk" and "optical") A
+ {floppy disk} which uses an optical tracking mechanism to
+ improve the positioning accuracy of an ordinary magnetic head,
+ thereby allowing more tracks and greater density.
+
+ {Storage media FAQ
+ (http://cis.ohio-state.edu/hypertext/faq/usenet/arch-storage/part1/faq.html)}.
+
+ (1995-03-15)
+
+Flow
+
+ <tool> A companion utility to {Floppy} by Julian James Bunn
+ <julian@vxcrna.cxern.ch>. Flow allows the user to produce
+ various reports on the structure of {Fortran 77} code, such as
+ {flow diagrams} and common block tables. It runs under {VMS},
+ {Unix}, {CMS}.
+
+ Posted to comp.sources.misc volume 31.
+
+ (1995-03-14)
+
+flow chart
+
+ <programming> An archaic form of visual control-flow
+ specification employing arrows and "speech balloons" of
+ various shapes.
+
+ Hackers never use flow charts, consider them extremely silly,
+ and associate them with {COBOL} programmers, {card wallopers},
+ and other lower forms of life. This attitude follows from the
+ observations that flow charts (at least from a hacker's point
+ of view) are no easier to read than code, are less precise,
+ and tend to fall out of sync with the code (so that they
+ either obfuscate it rather than explaining it, or require
+ extra maintenance effort that doesn't improve the code).
+
+ See also {Program Design Language}.
+
+ [{Jargon File}]
+
+ (1994-12-01)
+
+flow control
+
+ <communications, protocol> The collection of techniques used
+ in serial communications to stop the sender sending data until
+ the receiver can accept it. This may be either {software flow
+ control} or {hardware flow control}. The receiver typically
+ has a fixed size {buffer} into which received data is written
+ as soon as it is received. When the amount of buffered data
+ exceeds a "high water mark", the receiver will signal to the
+ transmitter to stop transmitting until the process reading the
+ data has read sufficient data from the buffer that it has
+ reached its "low water mark", at which point the receiver
+ signals to the transmitter to resume transmission.
+
+ (1995-03-22)
+
+flower key
+
+ {feature key}
+
+FLOW-MATIC or FLOWMATIC
+
+ (Originally B-0) Possibly the first English-like {DP}
+ language. Developed at Remington Rand in 1958 for the
+ {UNIVAC} I.
+
+ [Sammet 1969, pp. 316-324].
+
+ (1994-10-24)
+
+flow of control
+
+ {control flow}
+
+FLPL
+
+ Fortran List Processing Language. A package of {Fortran}
+ subroutines for handling lists by H. Gelernter et al, ca 1960.
+
+ [Sammet 1969, p. 388].
+
+ (1994-10-24)
+
+FLUB
+
+ <language> The {abstract machine} for {bootstrapping}
+ {STAGE2}.
+
+ [Mentioned in Machine Oriented Higher Level Languages, W. van
+ der Poel, N-H 1974, p. 271].
+
+ (1995-03-13)
+
+Fluegelman, Andrew
+
+ {Andrew Fluegelman}
+
+flush
+
+ <data> To delete something, usually superfluous, or to abort
+ an operation.
+
+ "Flush" was standard {ITS} terminology for aborting an output
+ operation. One spoke of the text that would have been
+ printed, but was not, as having been flushed. It is
+ speculated that this term arose from a vivid image of flushing
+ unwanted characters by hosing down the internal output buffer,
+ washing the characters away before they could be printed.
+
+ Compare {drain}.
+
+ 2. To force temporarily buffered data to be written to more
+ permanent memory. E.g. flushing buffered disk writes to disk,
+ as with {C}'s {standard I/O} library "fflush(3)" call. This
+ sense was in use among {BLISS} programmers at {DEC} and on
+ {Honeywell} and {IBM} machines as far back as 1965. Another
+ example of this usage is flushing a {cache} on a {context
+ switch} where modified data stored in the cace which belongs
+ to one processes must be written out to main memory so that
+ the cache can be used by another process.
+
+ [{Jargon File}]
+
+ (2005-07-18)
+
+Flynn's taxonomy
+
+ <architecture> A classification of computer architectures
+ based on the number of streams of instructions and data:
+
+ {Single instruction/single data} stream (SISD) - a sequential
+ computer.
+
+ Multiple instruction/single data stream (MISD) - unusual.
+
+ {Single instruction/multiple data} streams (SIMD) - e.g. an
+ {array processor}.
+
+ {Multiple instruction/multiple data} streams (MIMD) - multiple
+ autonomous processors simultaneously executing different
+ instructions on different data.
+
+ [Flynn, M. J., "Some Computer Organizations and Their
+ Effectiveness", IEEE Transactions on Computing C-21, No. 9,
+ Sep 1972, pp 948-960].
+
+ ["A Survey of Parallel Computer Architectures", Duncan, Ralph,
+ IEEE Computer, Feb 1990, pp 5-16].
+
+ (2003-05-29)
+
+fly page
+
+ {banner}
+
+Flyspeck 3
+
+ <humour> A standard name for any {font} that is so tiny as to
+ be unreadable, by analogy with names like "Helvetica 10" for
+ 10-point Helvetica. Legal boilerplate is usually printed in
+ Flyspeck 3.
+
+ (1994-11-08)
+
+flytrap
+
+ {firewall machine}
+
+FM
+
+ 1. <communications> {Frequency Modulation}.
+
+ 2. <jargon> Fucking Manual, a back-formation from {RTFM}.
+ Used to refer to the manual itself.
+
+ 3. <jargon> Fucking Magic, in the sense of {black magic}.
+
+ (2001-04-30)
+
+fm
+
+ <networking> The {country code} for the Federated States of
+ Micronesia.
+
+ Heavily used for {vanity domains} by FM radio stations.
+
+ (1999-01-27)
+
+FMPL
+
+ {Frobozz Magic Programming Language}
+
+FMQ
+
+ A {BNF}-based {paser generator} with an error corrector
+ generator, by Jon Mauney.
+
+ {(ftp://csczar.ncsu.edu/)}.
+
+ (1990-03-31)
+
+FMS
+
+ {Flexible Manufacturing System} (factory automation).
+
+FMV
+
+ {video}
+
+FNAL
+
+ Fermi National Accelerator Laboratory (Illinois, USA).
+
+FNC
+
+ {Federal Networking Council}
+
+fnord
+
+ 1. <convention> A word used in {electronic mail} and {news}
+ messages to tag utterances as surrealist mind-play or humour,
+ especially in connection with {Discordianism} and elaborate
+ conspiracy theories. "I heard that David Koresh is sharing an
+ apartment in Argentina with Hitler. (Fnord.)" "Where can I
+ fnord get the Principia Discordia from?"
+
+ 2. <programming> A {metasyntactic variable}, commonly used by
+ hackers with ties to {Discordianism} or the {Church of the
+ SubGenius}.
+
+ The word "fnord" was invented in the "Illuminatus!" trilogy by
+ Robert Shea and Robert Anton Wilson.
+
+ [{Jargon File}]
+
+ (1995-02-28)
+
+FN tunnelling
+
+ {Fowler-Nordheim tunnelling}
+
+fo
+
+ <networking> The {country code} for the Faroe Islands.
+
+ (1999-01-27)
+
+FOAD
+
+ <chat> fuck off and die.
+
+ (1998-01-18)
+
+FOAF
+
+ [{Usenet}] Friend Of A Friend. The source of an unverified,
+ possibly untrue story. This term was not originated by
+ hackers (it is used in Jan Brunvand's books on urban
+ folklore), but is much better recognised on {Usenet} and
+ elsewhere than in mainstream English.
+
+ [{Jargon File}]
+
+FOCAL
+
+ 1. FOrmula CALculator.
+
+ An interactive system written by Rick Merrill of {DEC} in 1969
+ for {PDP-5} and {PDP-8}. It was a descendant of {AID}/{JOSS}.
+
+ Versions: FOCAL-69, FOCAL-1971, FOCAL-11 (for {PDP-11} under
+ {RT-11}).
+
+ (1994-12-21)
+
+ 2. Forty-One CAlculator Language.
+
+ The programming language of the HP-41 calculator line.
+
+ (1994-12-21)
+
+FOCL
+
+ An {expert system shell} and {backward chaining} rule
+ {interpreter} for the {Macintosh}.
+
+ {(ftp://ics.uci.edu/pub/machine-learning-programs/KR-FOCL-ES.cpt.hqx)}.
+
+ E-mail: <pazzani@ics.uci.edu>.
+
+ (1994-12-21)
+
+FOCUS
+
+ <database, language> A hierarchical {database} language from
+ {Information Builders, Inc.}
+
+ (1994-12-21)
+
+focus group
+
+ <product> An event where market researchers meet (potential)
+ users of a product to try to plan how to improve it.
+
+ (1999-02-24)
+
+FOD
+
+ /fod/ [Abbreviation for "Finger of Death", originally a
+ spell-name from fantasy gaming] To terminate with extreme
+ prejudice and with no regard for other people. From {MUDs}
+ where the wizard command "FOD <player>" results in the
+ immediate and total death of <player>, usually as punishment
+ for obnoxious behaviour. This usage migrated to other
+ circumstances, such as "I'm going to fod the process that is
+ burning all the cycles." Compare {gun}.
+
+ In aviation, FOD means Foreign Object Damage, e.g. what happens
+ when a jet engine sucks up a rock on the runway or a bird in
+ flight. Finger of Death is a distressingly apt description of
+ what this generally does to the engine.
+
+ [{Jargon File}]
+
+FOIL
+
+ File Oriented Interpretive Language. CAI language.
+
+ ["FOIL - A File Oriented Interpretive Language",
+ J.C. Hesselbart, Proc ACM 23rd National Conf (1968)].
+
+FoIP
+
+ {Fax over IP}
+
+FOIRL
+
+ {Fiber Optic InterRepeater Link}
+
+fold case
+
+ {case sensitivity}
+
+folder
+
+ {directory}
+
+FOLDOC
+
+ {Free On-line Dictionary of Computing}
+
+followup
+
+ On {Usenet}, a {posting} generated in response to another
+ posting (as opposed to a {reply}, which goes by e-mail rather
+ than being broadcast). Followups include the ID of the
+ {parent message} in their headers; smart news-readers can use
+ this information to present {Usenet} news in "conversation"
+ sequence rather than order-of-arrival. See {thread}.
+
+ [{Jargon File}]
+
+font
+
+ <text> A set of {glyphs} ({images}) representing the
+ {characters} from some particular {character set} in a
+ particular size and {typeface}. The image of each character
+ may be encoded either as a {bitmap} (in a {bitmap font}) or by
+ a higher-level description in terms of lines and areas (an
+ {outline font}).
+
+ There are several different computer representations for
+ fonts, the most widely known are {Adobe Systems, Inc.}'s
+ {PostScript} font definitions and {Apple}'s {TrueType}.
+ {Window systems} can display different fonts on the screen and
+ print them.
+
+ [Other types of font?]
+
+ (2001-04-27)
+
+fontology
+
+ ({XEROX PARC}) The body of knowledge dealing with the
+ construction and use of new {fonts} (e.g. for window systems
+ and typesetting software). It has been said that fontology
+ recapitulates file-ogeny.
+
+ Unfortunately, this reference to the embryological dictum
+ that "Ontogeny recapitulates phylogeny" is not merely a joke.
+ On the Macintosh, for example, System 7 has to go through
+ contortions to compensate for an earlier design error that
+ created a whole different set of abstractions for fonts
+ parallel to "files" and "folders" - ESR
+
+ [{Jargon File}]
+
+ (1994-12-01)
+
+foo
+
+ <jargon> /foo/ A sample name for absolutely anything,
+ especially programs and files (especially {scratch files}).
+ First on the standard list of {metasyntactic variables} used
+ in {syntax} examples. See also {bar}, {baz}, {qux}, {quux},
+ {corge}, {grault}, {garply}, {waldo}, {fred}, {plugh},
+ {xyzzy}, {thud}.
+
+ The etymology of "foo" is obscure. When used in connection
+ with "bar" it is generally traced to the WWII-era Army slang
+ acronym {FUBAR}, later bowdlerised to {foobar}.
+
+ However, the use of the word "foo" itself has more complicated
+ antecedents, including a long history in comic strips and
+ cartoons.
+
+ "FOO" often appeared in the "Smokey Stover" comic strip by
+ Bill Holman. This surrealist strip about a fireman appeared
+ in various American comics including "Everybody's" between
+ about 1930 and 1952. FOO was often included on licence plates
+ of cars and in nonsense sayings in the background of some
+ frames such as "He who foos last foos best" or "Many smoke but
+ foo men chew".
+
+ Allegedly, "FOO" and "BAR" also occurred in Walt Kelly's
+ "Pogo" strips. In the 1938 cartoon "The Daffy Doc", a very
+ early version of Daffy Duck holds up a sign saying "SILENCE IS
+ FOO!". Oddly, this seems to refer to some approving or
+ positive affirmative use of foo. It has been suggested that
+ this might be related to the Chinese word "fu" (sometimes
+ transliterated "foo"), which can mean "happiness" when spoken
+ with the proper tone (the lion-dog guardians flanking the
+ steps of many Chinese restaurants are properly called "fu
+ dogs").
+
+ Earlier versions of this entry suggested the possibility that
+ hacker usage actually sprang from "FOO, Lampoons and Parody",
+ the title of a comic book first issued in September 1958, a
+ joint project of Charles and Robert Crumb. Though Robert
+ Crumb (then in his mid-teens) later became one of the most
+ important and influential artists in underground comics, this
+ venture was hardly a success; indeed, the brothers later
+ burned most of the existing copies in disgust. The title FOO
+ was featured in large letters on the front cover. However,
+ very few copies of this comic actually circulated, and
+ students of Crumb's "oeuvre" have established that this title
+ was a reference to the earlier Smokey Stover comics.
+
+ An old-time member reports that in the 1959 "Dictionary of the
+ TMRC Language", compiled at {TMRC} there was an entry that
+ went something like this:
+
+ FOO: The first syllable of the sacred chant phrase "FOO MANE
+ PADME HUM." Our first obligation is to keep the foo counters
+ turning.
+
+ For more about the legendary foo counters, see {TMRC}. Almost
+ the entire staff of what became the {MIT} {AI LAB} was
+ involved with TMRC, and probably picked the word up there.
+
+ Another correspondant cites the nautical construction
+ "foo-foo" (or "poo-poo"), used to refer to something
+ effeminate or some technical thing whose name has been
+ forgotten, e.g. "foo-foo box", "foo-foo valve". This was
+ common on ships by the early nineteenth century.
+
+ Very probably, hackish "foo" had no single origin and derives
+ through all these channels from Yiddish "feh" and/or English
+ "fooey".
+
+ [{Jargon File}]
+
+ (1998-04-16)
+
+foobar
+
+ <jargon> Another common {metasyntactic variable}; see {foo}.
+ Hackers do *not* generally use this to mean {FUBAR} in either
+ the slang or jargon sense.
+
+ According to a german correspondent, the term was coined
+ during WW2 by allied troops who could not pronounce the german
+ word "furchtbar" (horrible, terrible, awful).
+
+ [{Jargon File}]
+
+ (2003-07-03)
+
+foogol
+
+ A tiny {ALGOL}-like language by Per Lindberg, based on the
+ {VALGOL} I compiler, G.A. Edgar, DDJ May 1985. Runs on
+ {vaxen}. Posted to comp.sources.Unix archive volume 8.
+
+ {(ftp://ftp.wustl.edu/systems/amiga/fish/fish/ff066)}.
+
+FOOL
+
+ Fool's Lisp. A small {Scheme} {interpreter}.
+
+ {(ftp://scam.berkeley.edu/src/local/fools.tar.Z)}.
+
+ (1994-10-04)
+
+fool file
+
+ <jargon> A term found on {Usenet} for a notional repository of
+ all the most dramatically and abysmally stupid utterances
+ ever. An entire subgenre of {sig blocks} consists of the
+ header "From the fool file:" followed by some quote the poster
+ wishes to represent as an immortal gem of dimwittery; for this
+ usage to be really effective, the quote has to be so obviously
+ wrong as to be laughable. More than one {Usenetter} has
+ achieved an unwanted notoriety by being quoted in this way.
+
+ (2001-01-05)
+
+Fools' Lisp
+
+ A small {Scheme} {interpreter} by Jonathan Lee
+ <jonathan@scam.berkeley.edu>. Version 1.3.2 is R4RS
+ conformant. It runs on {Sun-3}, {Sun-4}, {Decstation}, {VAX}
+ ({Ultrix}), {Sequent}, {Apollo}.
+
+ {(ftp://scam.berkeley.edu/src/local/fools.tar.Z)}.
+
+ (1991-10-31)
+
+Foonly
+
+ 1. The {PDP-10} successor that was to have been built by the
+ Super Foonly project at the {Stanford Artificial Intelligence
+ Laboratory} along with a new operating system. The intention
+ was to leapfrog from the old DEC {time-sharing} system SAIL
+ was then running to a new generation, bypassing TENEX which at
+ that time was the {ARPANET} {standard}. {ARPA} funding for
+ both the Super Foonly and the new operating system was cut in
+ 1974. Most of the design team went to DEC and contributed
+ greatly to the design of the PDP-10 model KL10.
+
+ 2. The name of the company formed by Dave Poole, one of the
+ principal Super Foonly designers, and one of hackerdom's more
+ colourful personalities. Many people remember the parrot
+ which sat on Poole's shoulder and was a regular companion.
+
+ 3. Any of the machines built by Poole's company. The first
+ was the F-1 (a.k.a. Super Foonly), which was the
+ computational engine used to create the graphics in the movie
+ "TRON". The F-1 was the fastest PDP-10 ever built, but only
+ one was ever made. The effort drained Foonly of its financial
+ resources, and the company turned toward building smaller,
+ slower, and much less expensive machines. Unfortunately,
+ these ran not the popular {TOPS-20} but a TENEX variant called
+ Foonex; this seriously limited their market. Also, the
+ machines shipped were actually wire-wrapped engineering
+ prototypes requiring individual attention from more than
+ usually competent site personnel, and thus had significant
+ reliability problems. Poole's legendary temper and
+ unwillingness to suffer fools gladly did not help matters. By
+ the time of the Jupiter project cancellation in 1983, Foonly's
+ proposal to build another F-1 was eclipsed by the {Mars}, and
+ the company never quite recovered. See the {Mars} entry for
+ the continuation and moral of this story.
+
+ [{Jargon File}]
+
+FOOP
+
+ OBJ2 plus object-orientation. "Extensions and Foundations for
+ Object-Oriented Programming", J. Goguen et al, in Research
+ Directions in Object-Oriented Programming, B. Shriver et al
+ eds, MIT Press 1987.
+
+foot-net
+
+ {sneakernet}
+
+footprint
+
+ 1. <jargon, hardware> The floor or desk area taken up by a
+ piece of hardware.
+
+ 2. <jargon, storage> The amount of {disk} or {RAM} taken up by
+ a program or file.
+
+ 3. ({IBM}) The {audit trail} left by a crashed program (often
+ "footprints").
+
+ See also {toeprint}.
+
+ [{Jargon File}]
+
+ (1995-04-25)
+
+for
+
+ {for loop}
+
+fora
+
+ {forum}
+
+FORC
+
+ Early system on IBM 704. Listed in CACM 2(5):16 (May 1959).
+
+Force
+
+ A {dBASE} dialect for {MS-DOS}.
+
+ForceOne
+
+ A programming language by Andrew K. Wright.
+
+ ["Polymorphism in the Compiled Language ForceOne",
+ G.V. Cormack et al, Proc 20th Annual Hawaii Intl Conf on
+ System Sciences, 1987, pp.284-292].
+
+ ["Design of the Programming Language ForceOne", A.K. Wright,
+ MS Thesis, U Waterloo 1987].
+
+ (1994-10-24)
+
+ForceTwo
+
+ An unofficial successor to {ForceOne} by Andrew K. Wright.
+
+foreground
+
+ (Unix) On a {time-sharing} system, a task executing in
+ foreground is one able to accept input from and return output
+ to the user in contrast to one running in the {background}.
+ Nowadays this term is primarily associated with {Unix}, but it
+ appears first to have been used in this sense on {OS/360}.
+ Normally, there is only one foreground task per terminal (or
+ terminal window). Having multiple processes simultaneously
+ reading the keyboard is confusing.
+
+ [{Jargon File}]
+
+ (1994-10-24)
+
+Foreign eXchange Office
+
+ <communications> (FXO) An analog telephone plug on a handset
+ that receives {POTS} service from the telephone exchange
+ ("central office") via a {Foreign eXchange Subscriber} socket
+ and provides on-hook/off-hook indication to the exchange.
+
+ (2008-01-17)
+
+Foreign eXchange Subscriber
+
+ <communications> (FXS) A socket that provides analog telephone
+ service ({POTS}) from the telephone exchange ("central
+ office") to a handset with an {Foreign eXchange Office} plug.
+ The socket provides {dial tone}, power and a ring signal.
+
+ (2008-01-17)
+
+foreign key
+
+ <database> A {column} in a database {table} containing values
+ that are also found in some {primary key} column (of a
+ different table). By extension, any reference to entities of
+ a different type.
+
+ Some {RDBMSs} allow a column to be explicitly labelled as a
+ foreign key and only allow values to be inserted if they
+ already exist in the relevant primary key column.
+
+ [Is it still a foreign key if the primary key is in a different
+ column in the __same__ table?]
+
+ (2005-01-14)
+
+Foresight
+
+ <graphics, tool> A software product from {Nu Thena} providing
+ graphical modelling tools for high level system design and
+ {simulation}.
+
+ (1994-10-24)
+
+for free
+
+ Said of a capability of a programming language or hardware
+ equipment that is available by its design without needing
+ cleverness to implement: "In APL, we get the matrix operations
+ for free." "And owing to the way revisions are stored in this
+ system, you get revision trees for free." The term usually
+ refers to a serendipitous feature of doing things a certain
+ way (compare {big win}), but it may refer to an intentional
+ but secondary feature.
+
+ [{Jargon File}]
+
+ (1994-12-14)
+
+fork
+
+ <operating system> A {Unix} {system call} used by a {process}
+ (the "parent") to make a copy (the "child") of itself. The
+ child process is identical to the parent except it has a
+ different {process identifier} and a zero return value from
+ the fork call. It is assumed to have used no resources.
+
+ A fork followed by an {exec} can be used to start a different
+ process but this can be inefficient and some later Unix
+ variants provide {vfork} as an alternative mechanism for this.
+
+ See also {fork bomb}.
+
+ (1996-12-08)
+
+fork bomb
+
+ <programming> A particular species of {wabbit} that can be
+ written in one line of {C}:
+
+ main() {for(;;)fork();}
+
+ or {shell}:
+
+ $0 & $0 &
+
+ on any {Unix} system, or occasionally created by an egregious
+ coding bug. A fork bomb process "explodes" by {recursive}ly
+ spawning copies of itself using the {Unix} {system call}
+ "{fork}(2)". Eventually it eats all the process table entries
+ and effectively wedges the system. Fortunately, fork bombs
+ are relatively easy to spot and kill, so creating one
+ deliberately seldom accomplishes more than to bring the just
+ wrath of the {gods} down upon the perpetrator.
+
+ See also {logic bomb}.
+
+ [{Jargon File}]
+
+ (1994-12-14)
+
+forked
+
+ <jargon> (Unix; probably after "fucked") Terminally slow, or
+ dead. Originated when one system was slowed to a snail's pace
+ by an inadvertent {fork bomb}.
+
+ [{Jargon File}]
+
+ (1994-12-14)
+
+for loop
+
+ <programming> A {loop} construct found in many {procedural
+ languages} which repeatedly executes some instructions while a
+ condition is true.
+
+ In {C}, the for loop is written in the form;
+
+ for (INITIALISATION; CONDITION; AFTER)
+ STATEMENT;
+
+ where INITIALISATION is an expression that is evaluated once
+ before the loop, CONDITION is evaluated before each iteration
+ and the loop exits if it is false, AFTER is evaluated after
+ each iteration, and STATEMENT is any statement, including a
+ {compound statement} within braces "{..}", that is executed if
+ CONDITION is true.
+
+ For example:
+
+ int i;
+ for (i = 0; i < 10; i++)
+ {
+ printf("Hello\n");
+ }
+
+ prints "Hello" 10 times.
+
+ Other languages provide a more succinct form of "for"
+ statement specifically for iterating over {arrays} or {lists}.
+ E.g., the {Perl} code,
+
+ for my $task (@tasks)
+ {
+ postpone($task);
+ }
+
+ calls function "postpone()" repeatedly, setting $task to each
+ element of the "@tasks" array in turn. This avoids
+ introducing temporary index variables like "i" in the previous
+ example.
+
+ The for loop is an alternative way of writing a {while loop}
+ that is convenient because the loop control logic is collected
+ in a single place. It is also closely related to the {repeat
+ loop}.
+
+ (2009-10-07)
+
+FORM
+
+ <mathematics, tool> A system written by Jos Vermaseren
+ <t68@nikhefh.nikhef.nl> in 1989 for fast handling of very
+ large-scale {symbolic mathematics} problems. FORM is a
+ descendant of {Schoonschip} and is available for many
+ {personal computers} and {workstations}.
+
+ {(ftp://acm.princeton.edu/)}, {(ftp://nikhefh.nikhef.nl/)}.
+
+ Mailing list: <form@can.nl>.
+
+ (1995-04-12)
+
+FORMAC
+
+ FORmula MAnipulation Compiler. J. Sammet & Tobey, IBM Boston
+ APD, 1962. An extension of {Fortran} for {symbolic
+ mathematics}. Versions: PL/I-FORMAC and FORMAC73.
+
+ ["Introduction to FORMAC", J.E. Sammet et al, IEEE Trans Elec
+ Comp (Aug 1964)].
+
+ [Sammet 1969, pp. 474-491].
+
+FORMAL
+
+ 1. FORmula MAnipulation Language.
+
+ An early {Fortran} extension for {symbolic mathematics}.
+
+ ["FORMAL, A Formula Manipulation Language", C.K. Mesztenyi,
+ Computer Note CN-1, CS Dept, U Maryland (Jan 1971)].
+
+ 2. A data manipulation language for nonprogrammers from {IBM}
+ {LASC}.
+
+ ["FORMAL: A Forms-Oriented and Visual-Directed Application
+ System", N.C. Shu, IEEE Computer 18(8):38-49 (1985)].
+
+ (1994-12-06)
+
+formal argument
+
+ <programming> (Or "parameter") A name in a {function} or
+ {subroutine} definition that is replaced by, or bound to, the
+ corresponding {actual argument} when the function or
+ subroutine is called. In many languages formal arguments
+ behave like {local variables} which get initialised on entry.
+
+ See: {argument}.
+
+ (2002-07-02)
+
+Formal Description Technique
+
+ <specification, protocol> (FDT) A {formal method} for
+ developing telecomunications services and {protocols}. FDTs
+ range from abstract to implementation-oriented descriptions.
+ All FDTs offer the means for producing unambiguous
+ descriptions of {OSI} services and {protocols} in a more
+ precise and comprehensive way than {natural language}
+ descriptions. They provide a foundation for analysis and
+ verification of a description. The target of analysis and
+ verification may vary from abstract properties to concrete
+ properties. Natural language descriptions remain an essential
+ adjunct to formal description, enabling an unfarmiliar reader
+ to gain rapid insight into the structure and function of
+ services and protocols.
+
+ Examples of FDTs are {LOTOS}, {Z}, {SDL}, and {Estelle}.
+
+ [ISO/IEC DTR10167: "Guidelines for the application of
+ {Estelle}, {LOTOS} and {SDL}"].
+
+ (1994-12-06)
+
+formal methods
+
+ <mathematics, specification> Mathematically based techniques
+ for the {specification}, development and verification of
+ software and hardware systems.
+
+ {Referentially transparent} languages are amenable to symbolic
+ manipulation allowing {program transformation} (e.g. changing
+ a clear inefficient specification into an obscure but
+ efficient program) and proof of correctness.
+
+ {Oxford FM archive
+ (http://comlab.ox.ac.uk/archive/formal-methods.html)}.
+
+ (1996-05-15)
+
+Formal Object Role Modeling Language
+
+ <language> (FORML) A {CASE} language?
+
+ (1997-04-12)
+
+formal review
+
+ <project> A technical review conducted with the customer
+ including the types of reviews called for in DOD-STD-2167A
+ (Preliminary Design Review, Critical Design Review, etc.)
+
+ (1996-05-15)
+
+format
+
+ 1. <storage> {disk format} - to prepare a new, blank disk for
+ writing.
+
+ 2. <operating system> {file format} - how data is arranged in
+ a specific type of file.
+
+ (2007-09-04)
+
+FORMAT-Fortran
+
+ {Fortran Matrix Abstraction Technique Fortran}
+
+Formatting Output Specification Instance
+
+ <text, standard> (FOSI) An old {SGML} {DTD} {standard} for
+ {document management} in the US military, to be replaced (soon
+ after Oct 1996?) by the {ISO} standard {DSSSL}.
+
+ (1996-10-07)
+
+Formes
+
+ <language, music> An {object-oriented} language for music
+ composition and synthesis, written in {VLISP}.
+
+ ["Formes: Composition and Scheduling of Processes", X. Rodet &
+ P. Cointe, Computer Music J 8(3):32-50 (Fall 1984)].
+
+ (1996-06-24)
+
+form factor
+
+ <hardware> The type of packaging of a processor {integrated
+ circuit}, e.g. {PPGA}, {FC-PGA}.
+
+ More generally, a term popular among {marketroids} in 1998,
+ denoting the shape of something designed.
+
+ (2000-08-26)
+
+form feed
+
+ <character> (FF, Control-L, {ASCII} 12) The character used to
+ start a new page on a printer. This is done by "feeding" a
+ new page (or "form") through the printer.
+
+ (1996-06-24)
+
+form function
+
+ <jargon> The shape of something designed. This term is
+ currently (Feb 1998) in vogue among {marketroids}.
+
+ (1998-02-11)
+
+FORML
+
+ 1. <language> {Formal Object Role Modeling Language}.
+
+ 2. <event> {Forth Modification Lab}.
+
+ (1997-04-12)
+
+forms
+
+ 1. <programming> {fill-out form}.
+
+ 2. <library> (Xforms) A {GUI} component library for {X11}.
+
+ (1998-03-24)
+
+formula
+
+ 1. In logic, a sequence of symbols representing terms,
+ {predicates}, {connectives} and {quantifiers} which is either
+ true or false.
+
+ 2. <language, music> FORTH Music Language. An extension of
+ {FORTH} with concurrent note-playing processes. Runs on
+ {Macintosh} and {Atari ST} with {MIDI} output.
+
+ ["Formula: A Programming Language for Expressive Computer
+ Music", D.P. Anderson et al Computer 24(7):12 (Jul 1991)].
+
+ 3. Preprocessor language for the {Acorn Archimedes}, allowing
+ inline high-level statements to be entered in an assembly
+ program. Written in {nawk}.
+
+Formula ALGOL
+
+ An {ALGOL} extension for {symbolic mathematics}, strings and
+ lists, developed by A.J. Perlis and R. Iturriaga at {Carnegie}
+ for the {CDC G-20} in 1962.
+
+ ["An Extension of ALGOL for Manipulating Formulae",
+ A.J. Perlis et al, CACM 7(2):127-130 (Feb 1964)].
+
+ [Sammet 1969, p. 583].
+
+ (1995-02-15)
+
+Forsythe
+
+ A descendent of {Algol 60}, intended to be as uniform and
+ general as possible, while retaining the basic character of
+ its progenitor. Forsythe features {higher-order procedures}
+ and {intersection types}.
+
+ {(ftp://e.ergo.cs.cmu.edu/)}.
+
+ ["Preliminary Design of the Programming Language Forsythe",
+ J.C. Reynolds, CMU-CS-88-159, 1988].
+
+FORTH
+
+ 1. <language> An interactive extensible language using
+ {postfix syntax} and a data stack, developed by Charles
+ H. Moore in the 1960s. FORTH is highly user-configurable and
+ there are many different implementations, the following
+ description is of a typical default configuration.
+
+ Forth programs are structured as lists of "words" - FORTH's
+ term which encompasses language keywords, primitives and
+ user-defined {subroutines}. Forth takes the idea of
+ subroutines to an extreme - nearly everything is a subroutine.
+ A word is any string of characters except the separator which
+ defaults to space. Numbers are treated specially. Words are
+ read one at a time from the input stream and either executed
+ immediately ("interpretive execution") or compiled as part of
+ the definition of a new word.
+
+ The sequential nature of list execution and the implicit use
+ of the data stack (numbers appearing in the lists are pushed
+ to the stack as they are encountered) imply postfix syntax.
+ Although postfix notation is initially difficult, experienced
+ users find it simple and efficient.
+
+ Words appearing in executable lists may be "{primitives}"
+ (simple {assembly language} operations), names of previously
+ compiled procedures or other special words. A procedure
+ definition is introduced by ":" and ended with ";" and is
+ compiled as it is read.
+
+ Most Forth dialects include the source language structures
+ BEGIN-AGAIN, BEGIN-WHILE-REPEAT, BEGIN-UNTIL, DO-LOOP, and
+ IF-ELSE-THEN, and others can be added by the user. These are
+ "compiling structures" which may only occur in a procedure
+ definition.
+
+ FORTH can include in-line {assembly language} between "CODE"
+ and "ENDCODE" or similar constructs. Forth primitives are
+ written entirely in {assembly language}, secondaries contain a
+ mixture. In fact code in-lining is the basis of compilation
+ in some implementations.
+
+ Once assembled, primitives are used exactly like other words.
+ A significant difference in behaviour can arise, however, from
+ the fact that primitives end with a jump to "NEXT", the entry
+ point of some code called the sequencer, whereas
+ non-primitives end with the address of the "EXIT" primitive.
+ The EXIT code includes the scheduler in some {multi-tasking}
+ systems so a process can be {deschedule}d after executing a
+ non-primitive, but not after a primitive.
+
+ Forth implementations differ widely. Implementation
+ techniques include {threaded code}, dedicated Forth
+ processors, {macros} at various levels, or interpreters
+ written in another language such as {C}. Some implementations
+ provide {real-time} response, user-defined data structures,
+ {multitasking}, {floating-point} arithmetic, and/or {virtual
+ memory}.
+
+ Some Forth systems support virtual memory without specific
+ hardware support like {MMUs}. However, Forth virtual memory
+ is usually only a sort of extended data space and does not
+ usually support executable code.
+
+ FORTH does not distinguish between {operating system} calls
+ and the language. Commands relating to I/O, {file systems}
+ and {virtual memory} are part of the same language as the
+ words for arithmetic, memory access, loops, IF statements, and
+ the user's application.
+
+ Many Forth systems provide user-declared "vocabularies" which
+ allow the same word to have different meanings in different
+ contexts. Within one vocabulary, re-defining a word causes
+ the previous definition to be hidden from the interpreter (and
+ therefore the compiler), but not from previous definitions.
+
+ FORTH was first used to guide the telescope at NRAO, Kitt
+ Peak. Moore considered it to be a {fourth-generation
+ language} but his {operating system} wouldn't let him use six
+ letters in a program name, so FOURTH became FORTH.
+
+ Versions include fig-FORTH, FORTH 79 and FORTH 83.
+
+ {FAQs
+ (http://complang.tuwien.ac.at/forth/faq/faq-general-2.html)}.
+ {ANS Forth standard, dpANS6
+ (http://taygeta.com/forth/dpans.html)}.
+
+ FORTH Interest Group, Box 1105, San Carlos CA 94070.
+
+ See also {51forth}, {F68K}, {cforth}, {E-Forth}, {FORML},
+ {TILE Forth}.
+
+ [Leo Brodie, "Starting Forth"].
+
+ [Leo Brodie, "Thinking Forth"].
+
+ [Jack Woehr, "Forth, the New Model"].
+
+ [R.G. Loeliger, "Threaded Interpretive Languages"].
+
+ 2. {FOundation for Research and Technology - Hellas}.
+
+ (1997-04-16)
+
+for The Rest Of Them
+
+ {for The Rest Of Us}
+
+for The Rest Of Us
+
+ <abuse> (From the {Macintosh} slogan "The computer for the
+ rest of us") 1. Used to describe a {spiffy} product whose
+ affordability shames other comparable products, or (more
+ often) used sarcastically to describe {spiffy} but very
+ overpriced products.
+
+ 2. Describes a program with a limited interface, deliberately
+ limited capabilities, non-{orthogonal}ity, inability to
+ compose primitives, or any other limitation designed to not
+ "confuse" a naïve user. This places an upper bound on how far
+ that user can go before the program begins to get in the way
+ of the task instead of helping accomplish it.
+
+ Used in reference to {Macintosh} software which doesn't
+ provide obvious capabilities because it is thought that the
+ poor {luser} might not be able to handle them. Becomes "the
+ rest of *them*" when used in third-party reference; thus,
+ "Yes, it is an attractive program, but it's designed for The
+ Rest Of Them" means a program that superficially looks neat
+ but has no depth beyond the surface flash.
+
+ See also {point-and-drool interface}, {user-friendly}.
+
+ [{Jargon File}]
+
+ (2000-08-08)
+
+Forth Modification Lab
+
+ <event> (FORML) A {Forth} conference held every November on
+ the West coast of the USA ().
+
+ (1997-04-12)
+
+Fortran
+
+ <language> (Formula Translation) The first and, for a long
+ time, the most widely used programming language for numerical
+ and scientific applications. The original versions lacked
+ {recursive} procedures and {block structure} and had a
+ line-oriented {syntax} in which certain columns had special
+ significance.
+
+ There have been a great many versions.
+
+ The name is often written "FORTRAN", harking back to the days
+ before computers were taught about lower case, but {ANSI}
+ decreed, in about 1985 via the ANSI {FORTRAN} Technical
+ Committee {TC}, that it should be "Fortran".
+
+ See also: {Fortrash}.
+
+ [Was {Fortran I} the first version?]
+
+ (2000-07-07)
+
+Fortran 66
+
+ Fortran IV standardised. ASA X3.9-1966.
+
+Fortran 77
+
+ A popular version of {Fortran} with Block IF, PARAMETER and
+ SAVE statements added, but still no WHILE. It has
+ fixed-length character strings, format-free I/O, and {arrays}
+ with lower bounds.
+
+ [ANSI X3.9-1978].
+
+ {GNU version (ftp://gnu.org/pub/gnu/g77)}.
+
+ {Amiga version (ftp://ftp.cso.uiuc.edu/amiga/fish/ff470/BCF)}.
+
+ (1994-12-16)
+
+Fortran 90
+
+ (Previously "Fortran 8x" and "Fortran Extended") An extensive
+ enlargement of {Fortran 77}. Fortran 90 has {derived types},
+ {assumed shape arrays}, {array sections}, functions returning
+ arrays, case statement, {module} subprograms and internal
+ subprograms, optional and keyword subprogram arguments,
+ {recursion}, and {dynamic allocation}. It is defined in ISO
+ 1539:1991, soon to be adopted by {ANSI}.
+
+ ["Fortran 90 Explained", M. Metcalf et al, Oxford University
+ Press 1990].
+
+ (1994-12-16)
+
+Fortran Automatic Symbol Translator
+
+ <language> (FAST) An {assembly language} for the {IBM 650} by
+ {MITRE Corporation}.
+
+ [CACM 2(5):16 (May 1959)].
+
+ [Sammet 1969, p.526].
+
+ (1994-11-09)
+
+Fortran D
+
+ A {data-parallel} {Fortran} developed by {Ken Kennedy} at
+ {Rice University}.
+
+ ["Fortran D Language Specification", G. Fox et al, TR 90079,
+ Rice U, March 1991].
+
+ E-mail: Theresa Chapman <tlc@cs.rice.edu>.
+
+ (1994-12-16)
+
+Fortran I
+
+ An early version of {Fortran} designed by {John Backus} at
+ {IBM} for the {IBM 704}. The design was begun in 1954 and a
+ {compiler} released in April 1957.
+
+ [Was this the first Fortran?]
+
+ (1995-02-15)
+
+Fortran II
+
+ 1958. Added subroutines.
+
+Fortran III
+
+ This was only distributed to ca. 20 sites. See Wexelblat.
+
+Fortran IV
+
+ IBM 1962. For the IBM 7090/94. Many implementations went
+ well beyond the original definition.
+
+Fortran-Linda
+
+ Scientific Computer Assocs <linda@sca.com>.
+
+Fortran M
+
+ Parallel extensions to Fortran with processes and channels by
+ Ian Foster <fortran-m@mcs.anl.gov>.
+
+ ["Fortran M: A Language for Modular Parallel Programming",
+ I. Foster et al, MCS-P327-0992, ANL, 1992].
+
+ (1994-10-26)
+
+Fortran Matrix Abstraction Technique Fortran
+
+ <language> (FORMAT-Fortran) A language for manipulation,
+ printing and plotting of large matrices.
+
+ ["FORMAT-FORTRAN Matrix Abstraction Technique (Vol. V)"
+ AFFDL-TR-66-207, Douglas Aircraft Co. Oct 1968].
+
+ (1996-09-29)
+
+Fortran-Plus
+
+ Fortran for the DAP parallel machine, implements many
+ Fortran 90 features.
+
+FORTRANSIT
+
+ <language> Fortran Internal Translator.
+
+ A subset of {Fortran} translated into {IT} on the {IBM 650}.
+ It was in use in the late 1950s and early 1960s.
+
+ Compilation took place in several steps (using {punched cards}
+ as the only input/output media). FORTRANSIT was converted to
+ IT {Internal Translator} which was converted into {SOAP} and
+ thence to {machine code}.
+
+ In the SOAP -> machine code step, the user had to include card
+ decks for all the subroutines used in his FORTRANSIT program
+ (including e.g. square root, sine, and even basic {floating
+ point} routines).
+
+ [Sammet 1969, p. 141].
+
+ (1995-03-30)
+
+Fortran V
+
+ Preliminary work on adding character handling to {Fortran} by
+ {IBM} ca. 1962. This name as never really used.
+
+ (1994-10-26)
+
+Fortran VI
+
+ {IBM}'s internal name for early {PL/I} work ca. 1963.
+
+ [Sammet 1969, p. 540].
+
+ (1994-10-25)
+
+Fortrash
+
+ <abuse, language> /for'trash/ Hackerism for the {Fortran}
+ language, referring to its primitive design, gross and
+ irregular {syntax}, limited {control constructs}, and
+ slippery, exception-filled {semantics}.
+
+ [{Jargon File}]
+
+ (1994-10-26)
+
+FORTRUNCIBLE
+
+ A cross between Fortran and RUNCIBLE for the IBM 650.
+ Listed in CACM 2(5):16 (May 1959).
+
+fortune cookie
+
+ ({WAITS}, via the {Unix} "fortune" program) A quotation, item
+ of trivia, joke, or maxim selected at random from a collection
+ (the "{cookie file}") and printed to the user's tty at login
+ time or (less commonly) at logout time.
+
+ There was a fortune program on {TOPS-20}.
+
+ [First program?]
+
+ [{Jargon File}]
+
+ (1995-02-14)
+
+forum
+
+ <messaging> (Plural "fora" or "forums") Any discussion group
+ accessible through a dial-in {BBS} (e.g. {GEnie}, {CI$}), a
+ {mailing list}, or a {Usenet} {newsgroup} (see {network,
+ the}). A forum functions much like a {bulletin board}; users
+ submit {postings} for all to read and discussion ensues.
+
+ Contrast real-time {chat} or point-to-point personal {e-mail}.
+
+ [{Jargon File}]
+
+ (1998-01-18)
+
+for values of
+
+ <jargon> A common rhetorical maneuver at {MIT} is to use any
+ of the canonical {random numbers} as placeholders for
+ variables. "The max function takes 42 arguments, for
+ arbitrary values of 42". "There are 69 ways to leave your
+ lover, for 69 = 50". This is especially likely when the
+ speaker has uttered a random number and realises that it was
+ not recognised as such, but even "non-random" numbers are
+ occasionally used in this fashion. A related joke is that pi
+ equals 3 - for small values of pi and large values of 3.
+
+ This usage probably derives from the programming language MAD
+ ({Michigan Algorithm Decoder}), an {ALGOL}-like language that
+ was the most common choice among mainstream (non-hacker) users
+ at {MIT} in the mid-1960s. It had a {control structure} FOR
+ VALUES OF X = 3, 7, 99 DO ... that would repeat the indicated
+ instructions for each value in the list (unlike the usual FOR
+ that generates an {arithmetic sequence} of values). MAD is
+ long extinct, but similar for-constructs still flourish
+ (e.g. in {Unix}'s {shell} languages).
+
+ [{Jargon File}]
+
+ (1994-12-16)
+
+forward
+
+ <messaging> (verb) To send (a copy of) an {electronic mail}
+ message that you have received on to one or more other
+ {addressees}. Most e-mail systems can be configured to do
+ this automatically to all or certain messages, e.g. {Unix}
+ {sendmail} looks for a ".forward" file in the recipient's
+ {home directory}.
+
+ A {mailing list} server (or "{mail exploder}") is designed to
+ forward messages automatically to lists of people.
+
+ {Unix manual page}: aliases(5).
+
+ (2000-03-22)
+
+forward analysis
+
+ An analysis which determines properties of the output of a
+ program from properties of the inputs.
+
+forward chaining
+
+ A data-driven technique used in constructing {goals} or
+ reaching {inferences} derived from a set of {facts}. Forward
+ chaining is the basis of {production systems}. Oppose
+ {backward chaining}.
+
+ (1994-10-28)
+
+forward compatibility
+
+ <jargon> The ability to accept input from later versions of
+ itself.
+
+ Forward compatibility is harder to achieve than {backward
+ compatibility}, since, in the backward case, the input format
+ is know whereas a forward compatible system needs to cope
+ gracefully with unknown future features. An example of future
+ compatibility is the stipulation that a {web browser} should
+ ignore {HTML tags} it does not recognise.
+
+ See also {extensible}.
+
+ (2003-06-23)
+
+forward compatible
+
+ {forward compatibility}
+
+forward delta
+
+ The delta which, when combined with a version, creates a child
+ version. See change management
+
+forward engineering
+
+ <process> The traditional process of moving from high-level
+ abstractions and logical, implementation-independent designs
+ to the physical implementation of a system.
+
+ Contrast {reverse engineering}.
+
+ (1996-10-02)
+
+Forward Error Correction
+
+ <algorithm> (FEC) A class of methods for controling errors in
+ a one-way {communication} system. FEC sends extra information
+ along with the data, which can be used by the receiver to
+ check and correct the data.
+
+ A {CPU} writing data to {RAM} is a kind of one-way
+ communication - see {error correcting memory} and {error
+ checking and correction}.
+
+ (1996-10-02)
+
+forwards compatibility
+
+ {forward compatible}
+
+forwards compatible
+
+ {forward compatible}
+
+FORWISS
+
+ Bayerische Forschungszentrum fuer Wissensbasierte Systeme
+ (Bavarian research centre for knowledge-based systems) in
+ Passau.
+
+For Your Information
+
+ (FYI) A subseries of {RFCs} that are not technical {standards}
+ or descriptions of {protocols}. FYIs convey general
+ information about topics related to {TCP/IP} or the
+ {Internet}.
+
+ See also {STD}.
+
+ (1994-10-26)
+
+FOSI
+
+ {Formatting Output Specification Instance}
+
+FOSIL
+
+ {Fredette's Operating System Interface Language}
+
+FOSS
+
+ {free open-source software}
+
+fossil
+
+ 1. In software, a misfeature that becomes understandable only
+ in historical context, as a remnant of times past retained so
+ as not to break compatibility. Example: the retention of
+ {octal} as default base for string escapes in {C}, in spite of
+ the better match of {hexadecimal} to ASCII and modern
+ byte-addressable architectures. See {dusty deck}.
+
+ 2. More restrictively, a feature with past but no present
+ utility. Example: the force-all-caps (LCASE) bits in the V7
+ and {BSD} Unix tty driver, designed for use with monocase
+ terminals. (In a perversion of the usual
+ backward-compatibility goal, this functionality has actually
+ been expanded and renamed in some later {USG Unix} releases as
+ the IUCLC and OLCUC bits.)
+
+ 3. The FOSSIL (Fido/Opus/Seadog Standard Interface Level)
+ driver specification for serial-port access to replace the
+ {brain-dead} routines in the IBM PC ROMs. Fossils are used by
+ most {MS-DOS} {BBS} software in preference to the "supported"
+ ROM routines, which do not support interrupt-driven operation
+ or setting speeds above 9600; the use of a semistandard FOSSIL
+ library is preferable to the {bare metal} serial port
+ programming otherwise required. Since the FOSSIL
+ specification allows additional functionality to be hooked in,
+ drivers that use the {hook} but do not provide serial-port
+ access themselves are named with a modifier, as in "video
+ fossil".
+
+ [{Jargon File}]
+
+foundation
+
+ The axiom of foundation states that the membership relation is
+ well founded, i.e. that any non-empty collection Y of sets has
+ a member y which is disjoint from Y. This rules out sets
+ which contain themselves (directly or indirectly).
+
+FOundation for Research and Technology - Hellas
+
+ <company> (FORTH) A small Greek software and research company
+ associated with the Institute of Computer Science,
+
+ Address: Science and Technology Park of Crete, Vassilika
+ Vouton, P.O.Box 1385 GR 711 10 Heraklion, Crete, Greece.
+
+ Telephone: +30 (81) 39 16 00, Fax: +30 (81) 39 16 01.
+
+ (1997-04-12)
+
+four-colour glossies
+
+ 1. Literature created by {marketroids} that allegedly contains
+ technical specs but which is in fact as superficial as
+ possible without being totally {content-free}. "Forget the
+ four-colour glossies, give me the tech ref manuals." Often
+ applied as an indication of superficiality even when the
+ material is printed on ordinary paper in black and white.
+ Four-colour-glossy manuals are *never* useful for finding a
+ problem.
+
+ 2. [rare] Applied by extension to manual pages that don't
+ contain enough information to diagnose why the program doesn't
+ produce the expected or desired output.
+
+four colour map theorem
+
+ <mathematics, application> (Or "four colour theorem") The
+ theorem stating that if the plane is divided into connected
+ regions which are to be coloured so that no two adjacent
+ regions have the same colour (as when colouring countries on a
+ map of the world), it is never necessary to use more than four
+ colours.
+
+ The proof, due to Appel and Haken, attained notoriety by using
+ a computer to check tens of thousands of cases and is thus not
+ humanly checkable, even in principle. Some thought that this
+ brought the philosophical status of the proof into doubt.
+
+ There are now rumours of a simpler proof, not requiring the
+ use of a computer.
+
+ See also {chromatic number}
+
+ (1995-03-25)
+
+four colour theorem
+
+ {four colour map theorem}
+
+Fourier transform
+
+ <mathematics> A technique for expressing a waveform as a
+ weighted sum of sines and cosines.
+
+ Computers generally rely on the version known as {discrete
+ Fourier transform}.
+
+ Named after J. B. Joseph Fourier (1768 -- 1830).
+
+ See also {wavelet}, {discrete cosine transform}.
+
+ (1997-03-9)
+
+fourth generation computer
+
+ <architecture> A computer built using {Very Large Scale
+ Integration} (VLSI) {integrated circuits}, especially a
+ {microcomputer} based on a {microprocesseor}, or a {parallel
+ processor} containing two to thousands of {CPUs}.
+
+ VLSI made it routine to fabricate an entire CPU, main memory,
+ or similar device with a single integrated circuit that can be
+ mass produced at very low cost. This has resulted in new
+ classes of machines such as {personal computers}, and high
+ performance parallel processors that contains thousands of
+ CPUs.
+
+ (1996-11-22)
+
+fourth generation language
+
+ <language> (4GL, or "report generator language") An
+ "application specific" language, one with built-in knowledge
+ of an {application domain}, in the way that {SQL} has built-in
+ knowledge of the {relational} database domain.
+
+ The term was invented by Jim Martin to refer to
+ {non-procedural} {high level languages} built around
+ {database} systems.
+
+ Fourth generation languages are close to {natural language}
+ and were built with the concept that certain applications
+ could be generalised by adding limited programming ability to
+ them.
+
+ When given a description of the data format and the report to
+ generate, a 4GL system produces {COBOL} (or other 3GL) code,
+ that actually reads and processes the data and formats the
+ results.
+
+ Some examples of 4GL are: {database query language} e.g.{SQL};
+ {Focus}, {Metafont}, {PostScript}, {S}, {IDL-PV}, {WAVE},
+ {Gauss}, {Mathematica}, and {data-stream languages} such as
+ {AVS}, {APE}, {Iris Explorer}.
+
+ (2004-04-01)
+
+fourth normal form
+
+ {database normalisation}
+
+Fowler-Nordheim tunnelling
+
+ <electronics> (US: "tunneling") The quantum mechanical effect
+ exploited in {EAPROM} and {Flash Erasable Programmable Read
+ Only Memory}. It differs from {Frenkel-Pool Tunnelling} in
+ that it does not rely on defects in the {semiconductor}.
+
+ [More detail?]
+
+ (2001-09-27)
+
+Fox
+
+ {Free Objects for Crystallography}
+
+FoxBASE+
+
+ <database> {Fox Software}'s {dBASE} III+-like product which
+ later became {FoxPRO}. It used the {Xbase} programming
+ language.
+
+ [Features? Dates? Status?]
+
+ (2004-09-01)
+
+FoxPRO
+
+ <database> A {dBASE} IV-like product originally from {Fox
+ Software} which (well before 2000) mutated into {Microsoft}
+ {Visual FoxPro}.
+
+ [Features? Dates?]
+
+ (2000-08-06)
+
+Fox Software
+
+ <company> Developers of {FoxBASE+} and {FoxPRO}. Fox Software
+ merged with {Microsoft} around 1992.
+
+ Addresss: Perrysburg, OH, USA.
+
+ [More details?]
+
+ (1997-11-18)
+
+Fox Wiki
+
+ <application> A {wiki} for the {Fox} (Free Objects for
+ Crystallography) {software}.
+
+ {Fox Wiki (http://vincefn.net/Fox/)}.
+
+ (2014-01-20)
+
+FP
+
+ 1. {functional programming}.
+
+ 2. {floating-point}.
+
+ 3. Functional Programming. A {combinator}-based {functional
+ language} by John Backus stressing the use of {higher-order
+ functions}.
+
+ Implementation by Andy Valencia.
+ {(ftp://apple.com/comp.sources.Unix/volume13)}.
+
+ See also {FFP}, {FL}, {IFP}, {Berkeley FP}.
+
+ ["Can Programming be Liberated From the von Neumann Style? A
+ Functional Style and Its Algebra of Programs", John Backus,
+ 1977 Turing Award Lecture, CACM 21(8):165-180 (Aug 1978)].
+
+ 4. <programming> {Function Point}.
+
+ (1995-03-12)
+
+FP2
+
+ Functional Parallel Programming. A {term rewriting} language
+ which unifies {functional programming} and {parallel
+ programming}. Every object is a term and every computation is
+ done by rewriting. Rewrite rules are used to specify
+ {algebraic data types} and parallel processes.
+
+ ["Term Rewriting as a Basis for the Design of a Functional and
+ Parallel Programming Language. A Case Study: The Language
+ FP2", Ph. Jorrand in Fundamentals of Artificial Intelligence,
+ LNCS 258, Springer 1986, pp. 221-276].
+
+ (1994-10-20)
+
+FPA
+
+ 1. <hardware> {floating-point accelerator}.
+
+ 2. <programming> {Function Point Analysis}.
+
+fpc
+
+ A translator from {Backus}'s {FP} to {C}.
+
+ {(ftp://apple.com/comp.sources.Unix/Volume20)}.
+
+FPGA
+
+ {Field-Programmable Gate Array}
+
+FPLMTS
+
+ <communications> {Future Public Land Mobile
+ Telecommunications System}.
+
+FPM
+
+ {Fast Page Mode Dynamic Random Access Memory}
+
+FP/M
+
+ <programming> An {abstract machine} and intermediate language
+ for {functional languages}, used to implement {Hope}. FP/M is
+ an optimisation of the {SECD machine}.
+
+ ["The Compilation of FP/M Programs into Conventional Machine
+ Code", A.J. Field, Imperial College, London, 1985].
+
+ ["Functional Programming", A.J. Field & P.G. Harrison, A-W
+ 1988].
+
+ (1994-10-20)
+
+FPM DRAM
+
+ {Fast Page Mode Dynamic Random Access Memory}
+
+fprintf
+
+ <library> Variant of the {C} library routine {printf} which
+ prints to a given {stream}. E.g.
+
+ fprintf(stderr, "%s: can't open file \"%s\".",
+ argv[0], argv[1]);
+
+ which prints to the "{standard error}" output stream.
+
+ (1995-04-25)
+
+fps
+
+ {frames per second}
+
+FPU
+
+ {floating-point unit}
+
+FQDN
+
+ {fully qualified domain name}
+
+FQL
+
+ <language> A {functional database} language.
+
+ ["An Implementation Technique for Database Query Languages",
+ O.P. Buneman et al, ACM Trans Database Sys 7(2):164-186 (June
+ 1982)].
+
+ (1995-04-27)
+
+fr
+
+ <networking> The {country code} for France.
+
+ (1999-01-27)
+
+FRA
+
+ {Wireless Local Loop}
+
+fractal
+
+ <mathematics, graphics> A fractal is a rough or fragmented
+ geometric shape that can be subdivided in parts, each of which
+ is (at least approximately) a smaller copy of the whole.
+ Fractals are generally self-similar (bits look like the whole)
+ and independent of scale (they look similar, no matter how
+ close you zoom in).
+
+ Many mathematical structures are fractals; e.g. {Sierpinski
+ triangle}, {Koch snowflake}, {Peano curve}, {Mandelbrot set}
+ and {Lorenz attractor}. Fractals also describe many
+ real-world objects that do not have simple geometric shapes,
+ such as clouds, mountains, turbulence, and coastlines.
+
+ {Benoit Mandelbrot}, the discoverer of the {Mandelbrot set},
+ coined the term "fractal" in 1975 from the Latin fractus or
+ "to break". He defines a fractal as a set for which the
+ {Hausdorff Besicovich dimension} strictly exceeds the
+ {topological dimension}. However, he is not satisfied with
+ this definition as it excludes sets one would consider
+ fractals.
+
+ {sci.fractals FAQ
+ (ftp://src.doc.ic.ac.uk/usenet/usenet-by-group/sci.fractals/)}.
+
+ See also {fractal compression}, {fractal dimension}, {Iterated
+ Function System}.
+
+ {Usenet} newsgroups: {news:sci.fractals},
+ {news:alt.binaries.pictures.fractals}, {news:comp.graphics}.
+
+ ["The Fractal Geometry of Nature", Benoit Mandelbrot].
+
+ [Are there non-self-similar fractals?]
+
+ (1997-07-02)
+
+fractal compression
+
+ <algorithm> A technique for encoding {images} using
+ {fractals}.
+
+ {Yuval Fisher's fractal image compression site
+ (http://inls.ucsd.edu/y/Fractals/)}.
+
+ [Summary?]
+
+ (1998-03-27)
+
+fractal dimension
+
+ <mathematics> A common type of fractal dimension is the
+ Hausdorff-Besicovich Dimension, but there are several
+ different ways of computing fractal dimension. Fractal
+ dimension can be calculated by taking the limit of the
+ quotient of the log change in object size and the log change
+ in measurement scale, as the measurement scale approaches
+ zero. The differences come in what is exactly meant by
+ "object size" and what is meant by "measurement scale" and how
+ to get an average number out of many different parts of a
+ geometrical object. Fractal dimensions quantify the static
+ *geometry* of an object.
+
+ For example, consider a straight line. Now blow up the line
+ by a factor of two. The line is now twice as long as before.
+ Log 2 / Log 2 = 1, corresponding to dimension 1. Consider a
+ square. Now blow up the square by a factor of two. The
+ square is now 4 times as large as before (i.e. 4 original
+ squares can be placed on the original square). Log 4 / log 2
+ = 2, corresponding to dimension 2 for the square. Consider a
+ snowflake curve formed by repeatedly replacing ___ with _/\_,
+ where each of the 4 new lines is 1/3 the length of the old
+ line. Blowing up the snowflake curve by a factor of 3 results
+ in a snowflake curve 4 times as large (one of the old
+ snowflake curves can be placed on each of the 4 segments
+ _/\_). Log 4 / log 3 = 1.261... Since the dimension 1.261 is
+ larger than the dimension 1 of the lines making up the curve,
+ the snowflake curve is a fractal. [sci.fractals FAQ].
+
+FRAD
+
+ <communications> {Frame Relay Access Device}.
+
+fragile
+
+ {brittle}
+
+fragment
+
+ {fragmentation}
+
+fragmentation
+
+ 1. <networking> {segmentation}.
+
+ 2. The process, or result, of splitting a large area of free
+ memory (on disk or in main memory) into smaller non-contiguous
+ blocks. This happens after many blocks have been allocated
+ and freed. For example, if there is 3 kilobytes of free space
+ and two 1k blocks are allocated and then the first one (at the
+ lowest address) is freed, then there will be 2k of free space
+ split between the two 1k blocks. The maximum size block that
+ could then be allocated would be 1k, even though there was 2k
+ free. The solution is to "compact" the free space by moving
+ the allocated blocks to one end (and thus the free space to
+ the other).
+
+ As modern file systems are used and files are deleted and
+ created, the total free space becomes split into smaller
+ non-contiguous blocks (composed of "{clusters}" or "{sectors}"
+ or some other unit of allocation). Eventually new files being
+ created, and old files being extended, cannot be stored each
+ in a single contiguous block but become scattered across the
+ file system. This degrades performance as multiple {seek}
+ operations are required to access a single fragmented file.
+
+ Defragmenting consolidates each existing file and the free
+ space into a continuous group of sectors. Access speed will
+ be improved due to reduced seeking.
+
+ The rate of fragmentation depends on the {algorithm} used to
+ allocate space and the number and position of free sectors. A
+ nearly-full file system will fragment more quickly.
+
+ {MS-DOS} and {Microsoft Windows} use the simplest algorithm to
+ allocate free clusters and so fragmentation occurs quickly. A
+ disk should be defragmented before fragmentation reaches 10%.
+
+ See {garbage collection}.
+
+ (1997-08-29)
+
+FRAM
+
+ {Ferroelectric Random Access Memory}
+
+frame
+
+ 1. <networking> A {data link layer} "packet" which contains the
+ header and trailer information required by the physical
+ medium. That is, {network layer} {packets} are encapsulated
+ to become frames.
+
+ See also {datagram}, {encapsulation}, {packet}, {Maximum
+ Transmission Unit}.
+
+ 2. <programming> (language implementation) See {activation
+ record}.
+
+ 3. <hardware> One complete scan of the active area of a
+ {display screen}. Each frame consists of a number N of
+ horizontal {scan lines}, each of which, on a computer display,
+ consists of a number M of {pixels}. N is the {vertical
+ resolution} of the display and M is the {horizontal
+ resolution}. The rate at which the displayed image is updated
+ is the {refresh rate} in frames per second.
+
+ (2000-10-07)
+
+frame buffer
+
+ <hardware> Part of a video system in which an {image} is
+ stored, {pixel} by pixel and which is used to refresh a
+ {raster} image. The term "{video memory}" suggests a fairly
+ static display whereas a frame buffer holds one frame from a
+ sequence of frames forming a moving image.
+
+ Frame buffers are found in {frame grabbers} and {time base
+ correction} systems, for example.
+
+ (1997-10-03)
+
+Frame Check Sequence
+
+ <communications> (FCS) The extra characters added to a {frame}
+ for {error detection and correction}(?). FCS is used in
+ {X.25}, {HDLC}, {Frame Relay}, and other {data link layer}
+ {protocols}.
+
+ (1998-02-27)
+
+frame grabber
+
+ <hardware> A device that captures a single {frame} from an
+ {analog} {video} signal (from a video camera or {VCR}) and
+ stores it as a digital {image} under computer control.
+
+ (1997-07-11)
+
+FrameKit
+
+ <language> A {frame language}.
+
+ ["The FrameKit User's Guide", E. Nyberg, TR CMU- CMT-88-MEMO,
+ CMU 1988].
+
+ (1994-10-20)
+
+FrameMaker
+
+ <text> A commercial document preparation program produced by
+ {Frame Technology Corporation} who were taken over by {Adobe
+ Systems, Inc.} in 1995/6. FrameMaker is available for a wide
+ variety of {workstations} and is designed for technical and
+ scientific documents. It uses a powerful system of templates
+ and paragraph styles to control {WYSIWYG} formatting. It
+ supports graphics, tables, and contents pages among other
+ things.
+
+ Version: FrameMaker 6, due April 2000.
+
+ See also {Maker Interchange Format}.
+
+ (2000-04-04)
+
+frame pointer
+
+ A pointer to the current {activation record} in an
+ implementation of a {block structured} language.
+
+ (1994-10-20)
+
+frame rate
+
+ <graphics> The number of {frames} of an {animation} which are
+ displayed every second, measured in frames per second (fps).
+ The higher the frame rate, the smoother the animation will
+ appear but the more processing power and system {bandwidth} is
+ required.
+
+ At less than 30 fps, the human eye can see the new pictures
+ coming onto the screen.
+
+ (2000-02-02)
+
+Frame Relay
+
+ <communications> A {DTE}-{DCE} interface specification based
+ on {LAPD} (Q.921), the {Integrated Services Digital Network}
+ version of {LAPB} ({X.25} {data link layer}). A common
+ specification was produced by a consortium of {StrataCom},
+ {Cisco}, {Digital}, and Northern Telecom.
+
+ Frame Relay is the result of {wide area network}ing
+ requirements for speed; {LAN}-{WAN} and LAN-LAN
+ {internetworking}; "bursty" data communications; multiplicity
+ of {protocols} and {protocol transparency}. These
+ requirements can be met with technology such as {optical
+ fibre} lines, allowing higher speeds and fewer transmission
+ errors; intelligent network end devices ({personal computers},
+ {workstations}, and {servers}); standardisation and adoption
+ of ISDN protocols. Frame Relay could connect dedicated lines
+ and {X.25} to {ATM}, {SMDS}, {BISDN} and other "{fast packet}"
+ technologies.
+
+ Frame Relay uses the same basic {data link layer} {framing} and
+ {Frame Check Sequence} so current {X.25} hardware still works.
+ It adds addressing (a 10-bit {Data Link Connection Identifier}
+ (DLCI)) and a few control bits but does not include
+ retransmissions, link establishment, windows or error
+ recovery. It has none of X.25's {session layer} but adds some
+ simple interface management. Any {network layer} protocol can
+ be used over the data link layer Frames.
+
+ {Frame Relay Resource Center
+ (http://alliancedatacom.com/framerelay.asp)}.
+
+ (2000-07-14)
+
+Frame Relay Access Device
+
+ <communications> (FRAD) Hardware and software that turns
+ {packets} from {TCP}, {SNA}, {IPX}, etc into {frames} that can
+ be sent over a {Frame Relay} {wide area network}.
+
+ FRADs are a hot topic in data comms because companies like
+ {Netlink}, {Motorola}, {Stratacom} are making lots of money
+ out of them.
+
+ (1995-11-17)
+
+frames per second
+
+ <unit> (fps) The unit of measurement of the {frame rate} of a
+ moving image.
+
+ (2000-02-02)
+
+Frame Technology Corporation
+
+ <company> The company which developed {FrameMaker}, taken over
+ by {Adobe Systems, Inc.} in late 1995/early 1996.
+
+ (1995-01-30)
+
+framework
+
+ In {object-oriented} systems, a set of {class}es that embodies
+ an abstract design for solutions to a number of related
+ problems.
+
+ (1995-01-30)
+
+Framework 4
+
+ A European Union funding programme, the {information
+ technology} portion of which replaced {ESPRIT}.
+
+ (1994-09-19)
+
+framing specification
+
+ A specification of the "{protocol} bits" that surround the
+ "data bits" on a communications channel to allow the data to
+ be "framed" into chunks, like start and {stop bits} in
+ {EIA-232}. It allows a receiver to synchronize at points along
+ the data stream.
+
+ (1995-01-13)
+
+FRANK
+
+ ["Using BINS for Interprocess Communication", P.C.J. Graham,
+ SIGPLAN Notices 20(2):32-41 (Feb 1985)].
+
+ (1995-01-13)
+
+Franz Lisp
+
+ <language> A {MacLisp}-like dialect of {Lisp}, developed
+ primarily for work in {symbolic algebra} by R. Fateman et al
+ at {Ucb} in about 1980. It was named after the Hungarian
+ composer Franz Liszt (1811-1886). Franz Lisp was written in
+ {C} and includes a compiler called "{Liszt}".
+
+ ["The FRANZ LISP Manual", J.K. Foderaro et al. UC Berkeley
+ 1980].
+
+ Version: Opus 38.22. Liszt 8.08.
+
+ {(ftp://ted.cs.uidaho.edu/pub/hol/franz.tar.Z)}.
+
+ (2001-12-04)
+
+Fraps
+
+ <application, video> A {Windows} application that can be used
+ with games using {DirectX} or {OpenGL} to display the current
+ screen redraw rate in frames per second (FPS). Fraps can also
+ measure the frame rate between any two points and can capture
+ stills, audio and video to disk.
+
+ Latest version: 2.7.4 (2006-06-18), as of 2006-07-12.
+
+ {Fraps Home (http://fraps.com/)}.
+
+ (2006-07-12)
+
+Fraunhofer Gesellschaft
+
+ <company> (FhG, FhG IIS, Institut für Integrierte Schaltungen) A
+ german company, named after the physicist. IIS is Integrated
+ Circuit Institute.
+
+ FhG are known for their research on {audio compression},
+ especially {MPEG-1 Layer-3} (MP3).
+
+ (2001-12-04)
+
+FRED
+
+ Robert Carr. Language used by Framework, Ashton-Tate.
+
+ [{Jargon File}]
+
+fred
+
+ 1. The personal name most frequently used as a {metasyntactic
+ variable} (see {foo}). Allegedly popular because it's easy
+ for a non-touch-typist to type on a standard QWERTY keyboard.
+ Unlike {J. Random Hacker} or "J. Random Loser", this name has
+ no positive or negative loading (but see {Mbogo, Dr. Fred}).
+ See also {barney}.
+
+ 2. An acronym for "Flipping Ridiculous Electronic Device";
+ other F-verbs may be substituted for "flipping".
+
+Fredette's Operating System Interface Language
+
+ <language, operating system> (FOSIL) A portable {job control
+ language} for {IBM} {OS360}, {UNIVAC} {EXEC 8} and {Honeywell}
+ {GCOS}.
+
+ ["Fredette's Operating System Interface Language (FOSIL)",
+ G.N. Baird in Command Languages, C. Unger ed, N-H 1973].
+
+ (2000-08-06)
+
+frednet
+
+ /fred'net/ Used to refer to some {random} and uncommon
+ {protocol} encountered on a {network}. "We're implementing
+ bridging in our {router} to solve the frednet problem."
+
+ [{Jargon File}]
+
+free
+
+ See {free software}, {free variable}.
+
+FreeBSD
+
+ <operating system> A free {operating system} based on the {BSD
+ 4.4-lite} release from {Computer Systems Research Group} at
+ the {University of California at Berkeley}.
+
+ FreeBSD requires an {ISA}, {EISA}, {VESA}, or {PCI} based
+ computer with an {Intel 80386SX} to {Pentium} CPU (or
+ compatible {AMD} or {Cyrix} CPU) with 4 megabytes of {RAM} and
+ 60MB of disk space.
+
+ Some of FreeBSD's features are: {preemptive multitasking} with
+ dynamic priority adjustment to ensure smooth and fair sharing
+ of the computer between applications and users. Multiuser
+ access - {peripherals} such as printers and tape drives can be
+ shared between all users. Complete {TCP/IP} networking
+ including {SLIP}, {PPP}, {NFS} and {NIS}. {Memory
+ protection}, {demand-paged virtual memory} with a merged
+ {VM}/{buffer cache} design. FreeBSD was designed as a {32 bit
+ operating system}. {X Window System} (X11R6) provides a
+ {graphical user interface}. {Binary compatibility} with many
+ programs built for {SCO}, {BSDI}, {NetBSD}, {386BSD}, and
+ {Linux}. Hundreds of ready-to-run applications in the FreeBSD
+ ports collection. FreeBSD is {source code compatible} with
+ most popular commercial {Unix} systems and thus most
+ applications require few, if any, changes to compile. {Shared
+ libraries}. A full compliment of {C}, {C++}, {Fortran} and
+ {Perl} development tools and many other languages. {Source
+ code} for the entire system is available. Extensive on-line
+ documentation.
+
+ {(http://freebsd.org/)}.
+
+ {(ftp://ftp.freebsd.org/pub/FreeBSD)} or try your nearest
+ {mirror site} listed at the home site or buy the {CD-ROM} from
+ {Walnut Creek}.
+
+ (1998-11-24)
+
+FreeHEP
+
+ An organisation offering a repository of software and related
+ information for high energy physics applications.
+
+Freenet
+
+ Community-based bulletin board system with e-mail, information
+ services, interactive communications, and conferencing.
+ Freenets are funded and operated by individuals and volunteers
+ - in one sense, like public television. They are part of the
+ National Public Telecomputing Network (NPTN), an organisation
+ based in Cleveland, Ohio, devoted to making computer
+ telecommunication and networking services as freely available
+ as public libraries.
+
+Free Objects for Crystallography
+
+ <application> (Fox) A free, {open-source} program for ab
+ initio structure determination from powder diffraction.
+
+ {Fox Wiki (http://vincefn.net/Fox/)}.
+
+ (2014-01-21)
+
+Free On-line Dictionary
+
+ {Free On-line Dictionary of Computing}
+
+free open-source software
+
+ {free software}
+
+FreePPP
+
+ <networking> The latest incarnation of {MacPPP}. FreePPP
+ continues to be used by many MacOS users as an alternative to
+ {Apple}'s {TCP/IP} stack.
+
+ {(http://rockstar.com/ppp.shtml)}.
+
+ (2000-11-25)
+
+freerexx
+
+ {REXX} {interpreters} for {Unix} in {C++}.
+
+ {(ftp://rexx.uwaterloo.ca/pub/freerexx/rx102.tar.Z)}.
+
+free software
+
+ <software> Software that everyone is free to copy,
+ redistribute and modify. That implies free software must be
+ available as {source code}, hence "free open source software"
+ - "FOSS". It is usually also free of charge, though anyone
+ can sell free software so long as they don't impose any new
+ restrictions on its redistribution or use. The widespread
+ acceptance of this definition and free software itself owes a
+ great deal to {Richard Stallman} and the {Free Software
+ Foundation}.
+
+ There are many other kinds of "free software" in the sense of
+ "free of charge". See "{-ware}".
+
+ {This dictionary} is free in both senses, though since it is
+ documentation not {software} it is distributed under the
+ {GFDL}.
+
+ (2007-02-09)
+
+Free Software Foundation
+
+ <body> (FSF) An organisation devoted to the creation and
+ dissemination of {free software}, i.e. software that is free
+ from licensing fees or restrictions on use. The Foundation's
+ main work is supporting the {GNU} project, started by {Richard
+ Stallman} (RMS), partly to proselytise for his position that
+ information is community property and all software source
+ should be shared.
+
+ The GNU project has developed the GNU {Emacs} editor and a {C}
+ compiler, {gcc}, replacements for many Unix utilities and many
+ other tools. A complete {Unix}-like operating system ({HURD})
+ is in the works (April 1994).
+
+ Software is distributed under the terms of the {GNU General
+ Public License}, which also provides a good summary of the
+ Foundation's goals and principles. The Free Software
+ Foundation raises most of its funds from distributing its
+ software, although it is a charity rather than a company.
+ Although the software is freely available (e.g. by {FTP} - see
+ below) users are encouraged to support the work of the FSF by
+ paying for their distribution service or by making donations.
+
+ One of the slogans of the FSF is "Help stamp out software
+ hoarding!" This remains controversial because authors want to
+ own, assign and sell the results of their labour. However,
+ many hackers who disagree with RMS have nevertheless
+ cooperated to produce large amounts of high-quality software
+ for free redistribution under the Free Software Foundation's
+ imprimatur.
+
+ See {copyleft}, {General Public Virus}, {GNU archive site}.
+
+ {(ftp://ftp.gnu.ai.mit.edu)}.
+
+ Unofficial WWW pages: {PDX
+ (http://cs.pdx.edu/~trent/gnu/)}, {DeLorie
+ (http://delorie.com/gnu/)}.
+
+ E-mail: <gnu@gnu.org>.
+
+ Address: Free Software Foundation, Inc., 675 Massachusetts
+ Avenue, Cambridge, MA 02139, USA.
+
+ Telephone: +1 (617) 876 3296.
+
+ (1995-12-10)
+
+free variable
+
+ 1. A variable referred to in a function, which is not an
+ argument of the function. In {lambda-calculus}, x is a {bound
+ variable} in the term M = \ x . T, and a free variable of T.
+ We say x is bound in M and free in T. If T contains a subterm
+ \ x . U then x is rebound in this term. This nested, inner
+ binding of x is said to "shadow" the outer binding.
+ Occurrences of x in U are free occurrences of the new x.
+
+ Variables bound at the top level of a program are technically
+ free variables within the terms to which they are bound but
+ are often treated specially because they can be compiled as
+ fixed addresses. Similarly, an identifier bound to a
+ recursive function is also technically a free variable within
+ its own body but is treated specially.
+
+ A {closed term} is one containing no free variables.
+
+ See also {closure}, {lambda lifting}, {scope}.
+
+ 2. In {logic}, a variable which is not quantified (see
+ {quantifier}).
+
+freeware
+
+ <legal> {Software}, often written by enthusiasts and
+ distributed at no charge by users' groups, or via the
+ {web}, {electronic mail}, {bulletin boards},
+ {Usenet}, or other electronic media.
+
+ At one time, "freeware" was a trademark of {Andrew
+ Fluegelman}. It wasn't enforced after his death.
+
+ "Freeware" should not be confused with "{free software}"
+ (roughly, software with unrestricted redistribution) or
+ "{shareware}" (software distributed without charge for which
+ users can pay voluntarily).
+
+ {Jim Knopf's story (http://freewarehof.org/sstory.html)}.
+
+ [{Jargon File}]
+
+ (2003-07-26)
+
+freeze
+
+ To lock an evolving software distribution or document against
+ changes so it can be released with some hope of stability.
+ Carries the strong implication that the item in question will
+ "unfreeze" at some future date.
+
+ There are more specific constructions on this term. A
+ "feature freeze", for example, locks out modifications
+ intended to introduce new features but still allows bugfixes
+ and completion of existing features; a "code freeze" connotes
+ no more changes at all. At {Sun Microsystems} and elsewhere,
+ one may also hear references to "code slush" - that is, an
+ almost-but-not-quite frozen state.
+
+ [{Jargon File}]
+
+Frege, Gottlob
+
+ {Gottlob Frege}
+
+frequency division multiple access
+
+ {frequency division multiplexing}
+
+frequency division multiplexing
+
+ <communications> (FDM) The simultaneous transmission of
+ multiple separate signals through a shared medium (such as a
+ wire, {optical fibre}, or light beam) by modulating, at the
+ transmitter, the separate signals into separable frequency
+ bands, and adding those results linearly either before
+ transmission or within the medium. While thus combined, all
+ the signals may be amplified, conducted, translated in
+ frequency and routed toward a destination as a single signal,
+ resulting in economies which are the motivation for
+ multiplexing. Apparatus at the receiver separates the
+ multiplexed signals by means of frequency passing or rejecting
+ filters, and demodulates the results individually, each in the
+ manner appropriate for the modulation scheme used for that
+ band or group.
+
+ Bands are joined to form groups, and groups may then be joined
+ into larger groups; this process may be considered
+ recursively, but such technique is common only in large and
+ sophisticated systems and is not a necessary part of FDM.
+
+ Neither the transmitters nor the receivers need be close to
+ each other; ordinary radio, television, and cable service are
+ examples of FDM. It was once the mainstay of the long
+ distance telephone system. The more recently developed {time
+ division multiplexing} in its several forms lends itself to
+ the handling of digital data, but the low cost and high
+ quality of available FDM equipment, especially that intended
+ for television signals, make it a reasonable choice for many
+ purposes.
+
+ Compare {wavelength division multiplexing}, {time division
+ multiplexing}, {code division multiplexing}.
+
+ (2001-06-28)
+
+Frequency-Hopping Spread Spectrum
+
+ <communications> (FH, FHSS) A variation of {spread spectrum
+ communications} in which a sequence of {pseudo random numbers}
+ control a {frequency synthesizer}, generating different
+ carrier frequencies that "hop around" in the desired frequency
+ range. The receiver tunes to the same sequence of carrier
+ frequencies in synchronisation with the transmitter.
+
+ Frequency hopping spread spectrum was invented by Hedy Lamarr
+ ("the most beautiful girl in the world", Samson and Delilah
+ etc.) and the composer George Antheil. They held a patent
+ filed in 1942.
+
+ (2009-07-01)
+
+Frequency Modulation
+
+ <communications> (FM) A method of encoding data by varying the
+ frequency of a constant amplitude {carrier signal}.
+
+ Contrast {Amplitude Modulation}.
+
+ (2001-04-02)
+
+Frequency Shift Keying
+
+ <communications> (FSK) The use of {frequency modulation} to
+ transmit digital data, i.e. two different {carrier}
+ frequencies are used to represent zero and one.
+
+ FSK was originally used to transmit {teleprinter} messages by
+ radio ({RTTY}) but can be used for most other types of radio
+ and land-line digital telegraphy. More than two frequencies
+ can be used to increase transmission rates.
+
+ (1997-07-14)
+
+frequently asked question
+
+ <convention> (FAQ, or rarely FAQL, FAQ list) A document
+ provided for many {Usenet} {newsgroups} (and, more recently,
+ {web} services) which attempts to answer questions
+ which new readers often ask. These are maintained by
+ volunteers and posted regularly to the newsgroup. You should
+ always consult the FAQ list for a group before posting to it
+ in case your question or point is common knowledge.
+
+ The collection of all FAQ lists is one of the most precious
+ and remarkable resources on the {Internet}. It contains a
+ huge wealth of up-to-date expert knowledge on many subjects of
+ common interest. Accuracy of the information is greatly
+ assisted by its frequent exposure to criticism by an
+ interested, and occasionally well-informed, audience (the
+ readers of the relevant newsgroup).
+
+ The main {FTP archive} for FAQs is on a computer called {RTFM}
+ at {MIT}, where they can be accessed either {by group
+ (ftp://rtfm.mit.edu/pub/usenet-by-group/comp.answers/)} or {by
+ hierarchy (ftp://rtfm.mit.edu/pub/usenet-by-hierarchy/)}.
+ There is another archive at {Imperial College
+ (ftp://src.doc.ic.ac.uk/usenet/news-info/)}, London, UK and a
+ {web} archive in {Ohio
+ (http://cis.ohio-state.edu/hypertext/faq/usenet/top.html)},
+ USA.
+
+ The FAQs are also posted to {Usenet} newsgroups:
+ {news:comp.answers}, {news:news.answers} and
+ {news:alt.answers}.
+
+ (1997-12-08)
+
+Fresco
+
+ 1. <standard, programming> An {object-oriented} {API} for
+ {graphical user interfaces}, under development by the {X
+ Consortium} as an open, multi-vendor {standard}.
+
+ 2. <language, specification> An {object-oriented}
+ {specification language}.
+
+ ["Refinement in Fresco", in Object Oriented Specification Case
+ Studies, K. Lano et al eds, P-H 1993].
+
+ (1996-04-28)
+
+Fresh
+
+ <language>
+
+ ["Fresh: A Higher-Order Language Based on Unification",
+ G. Smolka, in Logic Programming: Functions, Relations and
+ Equations", D. DeGroot et al, P-H 1986, pp. 469-524].
+
+ (1996-04-28)
+
+friction feed
+
+ <printer> A method some {printers} and {plotters} use to move
+ paper by rotating one or both of a pair of spring-loaded
+ rubber-coated rollers with the paper sandwiched between them.
+
+ Friction feed printers are notorious for slipping when the
+ rollers wear out, but can take standard typing paper.
+
+ For printers with a {sheet feeder}, friction feed is more
+ appropriate than {sprocket feed} which requires the holes in
+ the paper to engage with the sprockets of the feed mechanism.
+
+ (1997-07-09)
+
+fried
+
+ 1. <hardware> Non-working due to hardware failure; burnt out.
+ Especially used of hardware brought down by a "power glitch"
+ (see {glitch}), {drop-outs}, a short, or some other electrical
+ event. (Sometimes this literally happens to electronic
+ circuits! In particular, resistors can burn out and
+ transformers can melt down, emitting noxious smoke - see
+ {friode}, {SED} and {LER}. However, this term is also used
+ metaphorically.) Compare {frotzed}.
+
+ 2. <jargon> Of people, exhausted. Said particularly of those
+ who continue to work in such a state. Often used as an
+ explanation or excuse. "Yeah, I know that fix destroyed the
+ file system, but I was fried when I put it in." Especially
+ common in conjunction with "brain": "My brain is fried today,
+ I'm very short on sleep."
+
+ [{Jargon File}]
+
+ (1996-04-28)
+
+Friend
+
+ Relationship between classes in the language C++.
+
+FRINGE
+
+ C. Katz, GE, 1961. Subcomponent of GE-255 GECOM system.
+ Sorting and merging of data, reports and file maintenance.
+
+frink
+
+ /frink/ The unknown ur-verb, fill in your own meaning. Found
+ especially on the {Usenet} newsgroup {news:alt.fan.lemurs},
+ where it is said that the lemurs know what "frink" means, but
+ they aren't telling.
+
+ Compare {gorets}.
+
+ [{Jargon File}]
+
+ (1994-12-16)
+
+friode
+
+ <humour, electronics> /fri:'ohd/ (TMRC) A reversible (that is,
+ fused, blown, or {fried}) {diode}. A friode may have been a
+ {SED} at some time.
+
+ See also {LER}.
+
+ [{Jargon File}]
+
+ (1996-04-28)
+
+fritterware
+
+ An excess of capability that serves no productive end. The
+ canonical example is font-diddling software on the Mac (see
+ {macdink}); the term describes anything that eats huge amounts
+ of time for quite marginal gains in function but seduces
+ people into using it anyway. See also {window shopping}.
+
+ [{Jargon File}]
+
+FRL
+
+ Frame Representation Language.
+
+ MIT.
+
+ ["The FRL Manual", R. Roberts et al, AI Memo 409, MIT AI Lab,
+ 1977].
+
+ (1994-12-16)
+
+FRMT-FTRN
+
+ Scientific language. 1976.
+
+frob
+
+ /frob/ 1. [MIT] The {TMRC} definition was "FROB = a
+ protruding arm or trunnion"; by metaphoric extension, a "frob"
+ is any random small thing; an object that you can comfortably
+ hold in one hand; something you can frob (sense 2). See
+ {frobnitz}.
+
+ 2. Abbreviated form of {frobnicate}.
+
+ 3. [{MUD}] A command on some {MUDs} that changes a player's
+ experience level (this can be used to make wizards); also, to
+ request {wizard} privileges on the "professional courtesy"
+ grounds that one is a wizard elsewhere. The command is
+ actually "frobnicate" but is universally abbreviated to the
+ shorter form.
+
+ [{Jargon File}]
+
+frobnicate
+
+ /frob'ni-kayt/ (Possibly from {frobnitz}, and usually
+ abbreviated to {frob}, but "frobnicate" is recognised as the
+ official full form). To manipulate or adjust, to {tweak}.
+ One frequently frobs bits or other 2-state devices. Thus:
+ "Please frob the light switch" (that is, flip it), but also
+ "Stop frobbing that clasp; you'll break it". One also sees
+ the construction "to frob a frob".
+
+ Usage: frob, {twiddle}, and {tweak} sometimes connote points
+ along a continuum. "Frob" connotes aimless manipulation;
+ "twiddle" connotes gross manipulation, often a coarse search
+ for a proper setting; "tweak" connotes fine-tuning. If
+ someone is turning a knob on an oscilloscope, then if he's
+ carefully adjusting it, he is probably tweaking it; if he is
+ just turning it but looking at the screen, he is probably
+ twiddling it; but if he's just doing it because turning a knob
+ is fun, he's frobbing it. The variant "frobnosticate" has
+ also been reported.
+
+ (1994-12-16)
+
+frobnitz
+
+ /frob'nits/, plural "frobnitzem" /frob'nit-zm/ or "frobni"
+ /frob'ni:/ (TMRC) An unspecified physical object, a widget.
+ Also refers to electronic {black boxes}. This rare form is
+ usually abbreviated to "frotz", or more commonly to {frob}.
+ Also used are "frobnule" (/frob'n[y]ool/) and "frobule"
+ (/frob'yool/). Starting perhaps in 1979, "frobozz" /fr*-boz'/
+ (plural: "frobbotzim" /fr*-bot'zm/) has also become very
+ popular, largely through its exposure as a name via {Zork}.
+ These variants can also be applied to nonphysical objects,
+ such as data structures.
+
+ Pete Samson, compiler of the original {TMRC} lexicon, adds,q
+ "Under the TMRC (railway) layout were many storage boxes,
+ managed (in 1958) by David R. Sawyer. Several had fanciful
+ designations written on them, such as "Frobnitz Coil Oil".
+ Perhaps DRS intended Frobnitz to be a proper name, but the
+ name was quickly taken for the thing". This was almost
+ certainly the origin of the term.
+
+ [{Jargon File}]
+
+ (1994-12-16)
+
+Frobozz Magic Programming Language
+
+ <language> (FMPL of Accardi). A {prototype-based},
+ {object-oriented}, {event-driven} (mainly I/O events) interpreted
+ language with {functional} features. Developed at the
+ {Experimental Computing Facility}, {University of California,
+ Berkeley}.
+
+ There is an {interpreter} by Jon Blow
+ <blojo@xcf.berkeley.edu>.
+
+ Latest version: 1, as of 1992-06-02.
+
+ {(ftp://xcf.berkeley.edu/src/local/fmpl)}.
+
+ Mailing list: <fmpl@xcf.berkeley.edu>.
+
+ E-mail: Jack Hsu <tcl-archive@barkley.berkeley.edu>.
+
+ (1992-06-02)
+
+frogging
+
+ ({University of Waterloo}) 1. Partial corruption of a text
+ file or input stream by some bug or consistent glitch, as
+ opposed to random events like line noise or media failures.
+ Might occur, for example, if one bit of each incoming
+ character on a tty were stuck, so that some characters were
+ correct and others were not.
+
+ See {terminak} for a historical example.
+
+ 2. By extension, accidental display of text in a mode where
+ the output device emits special symbols or {mnemonics} rather
+ than conventional ASCII. This often happens, for example,
+ when using a terminal or comm program on a device like an {IBM
+ PC} with a special "high-half" character set and with the
+ bit-parity assumption wrong. A hacker sufficiently familiar
+ with ASCII bit patterns might be able to read the display
+ anyway.
+
+ [{Jargon File}]
+
+Frolic
+
+ A {Prolog} system in {Common Lisp}.
+
+ {(ftp://ftp.cs.utah.edu/pub/frolic.tar.Z)}.
+
+ (1991-11-23)
+
+front end
+
+ 1. An intermediary computer that does set-up and filtering for
+ another (usually more powerful but less friendly) machine (a
+ "back end").
+
+ 2. Software that provides an interface to another program
+ "behind" it, which may not be as {user-friendly}. Probably
+ from analogy with hardware front-ends that interfaced with
+ {mainframes}.
+
+ [{Jargon File}]
+
+front-end processor
+
+ (FEP) 1. A small computer necessary to enable an {IBM}
+ {mainframe} using {SNA} to communicate beyond the limits of
+ the {dinosaur pen}.
+
+ 2. A small computer controlling the screen and keyboard of a
+ {Symbolics 3600} {LISP Machine}.
+
+front side bus
+
+ <hardware> (FSB) The {bus} via which a {processor}
+ communicates with its {RAM} and {chipset}; one half of the
+ {Dual Independent Bus} (the other half being the {backside
+ bus}). The {L2 cache} is usually on the FSB, unless it is on
+ the same chip as the processor [example?].
+
+ In {PCI} systems, the PCI bus runs at half the FSB speed.
+
+ {Intel}'s {Pentium 60} ran the bus and processor at 60 {MHz}.
+ All later processors have used multipliers to increase the
+ internal {clock} speed while maintaining the same external
+ clock speed, e.g. the {Pentium 90} used a 1.5x multiplier.
+ Modern {Socket 370} {motherboards} support multipliers from
+ 4.5x to 8.0x, and FSB speeds from 50 MHz to a proposed 83 MHz
+ standard. These higher speeds may cause problems with some
+ PCI hardware.
+
+ Altering the FSB speed and the multiplier ratio are the two
+ main ways of {overclocking} processors.
+
+ {Toms Hardware - The Bus Speed Guide
+ (http://www.tomshardware.com/reviews/bus-speed-guide,49.html)}.
+
+ {Toms Hardware - The Overclocking Guide
+ (http://www.tomshardware.com/reviews/overclocking-guide,15.html)}.
+
+ (2002-02-21)
+
+frotzed
+
+ <jargon> /frotst/ {down} because of hardware problems.
+ Compare {fried}. A machine that is merely frotzed may be
+ fixable without replacing parts, but a fried machine is more
+ seriously damaged.
+
+ (2010-05-16)
+
+frowney
+
+ <chat> (Or "frowney face") See {emoticon}.
+
+ [{Jargon File}]
+
+fry
+
+ 1. To fail. Said especially of smoke-producing hardware
+ failures. More generally, to become non-working. Usage:
+ never said of software, only of hardware and humans. See
+ {fried}, {magic smoke}.
+
+ 2. To cause to fail; to {roach}, {toast}, or {hose} a piece of
+ hardware. Never used of software or humans, but compare
+ {fried}.
+
+FS
+
+ 1. <file system> {file system}.
+
+ 2. <character> {File Separator}.
+
+FSB
+
+ {front side bus}
+
+fsck
+
+ 1. <operating system> file system check. The {Unix} program
+ that checks a {file system} for internal consistency and bad
+ blocks etc. and can repair some faults.
+
+ fsck is often used after a {crash} when the file system has
+ been left in an inconsistent state, e.g. due to incomplete
+ flushing of {buffers}.
+
+ (1998-03-06)
+
+ 2. <jargon> Used on {Usenet} {newsgroup} alt.sysadmin.recovery
+ as substitute for "fuck" and became more main-stream after the
+ {Communications Decency Act}.
+
+ (1998-03-06)
+
+FSF
+
+ {Free Software Foundation}
+
+FSK
+
+ {Frequency Shift Keying}
+
+FSL
+
+ Formal Semantics Language.
+
+ A language for {compiler} writing.
+
+ ["A Formal Semantics for Computer Languages and its Application
+ in a Compiler-Compiler", J.A. Feldman, CACM 9(1) (Jan 1966)].
+
+ [Sammet 1969, p. 641].
+
+ (1995-01-23)
+
+FSM
+
+ 1. <mathematics, algorithm, theory> {Finite State Machine}.
+
+ 2. <networking> {FDDI Switching Module}.
+
+ ({3Com} implements this device on its {LAN} switches).
+
+ [What is it?]
+
+ (1997-05-16)
+
+FSP
+
+ {File Service Protocol}
+
+fsplit
+
+ A tool to split up monolithic {Fortran} programs.
+
+FT
+
+ {fault tolerant}
+
+FTAM
+
+ File Transfer, Access, and Management: an application layer
+ protocol for file transfer and remote manipulation (ISO 8571).
+
+FTP
+
+ {File Transfer Protocol}
+
+FTP archive
+
+ {archive site}
+
+FTP by mail
+
+ A service offered by {DEC} to allow people without {Internet}
+ access to get copies of files which are available by
+ {anonymous FTP}. Send a message with just the word "help" in
+ the body to <ftpmail@decwrl.dec.com>.
+
+FTP server
+
+ <networking> A network {server} program or computer which
+ responds to requests for files via {FTP}.
+
+ A busy {Internet} {archive site} may have one or more
+ computers dedicated to running FTP server software. These
+ will typically have {hostnames} beginning with "ftp.",
+ e.g. ftp.denet.dk.
+
+ (1998-07-02)
+
+FTP Software, Inc.
+
+ <company> Developers of the original {PC/TCP} {Packet Driver}
+ specification.
+
+ Address: 26 Princess St. Wakefield, MA 01880-3004. Telephone:
+ +1 (617) 246 0900.
+
+ (1994-12-05)
+
+FTTP
+
+ Do you mean {FTP} or {HTTP}?
+
+FTW
+
+ <chat> An ambiguous acronym which might stand for any of "For
+ The Win" (the thing just referred to will help you succeed),
+ "Forever Two Wheels" (biker slang), {WTF} backwards, "Fuck The
+ World", "Fuck This War", "Fun To Watch" or something else.
+
+ (2008-09-12)
+
+FTX
+
+ <operating system> {Stratus}' {Unix operating system}.
+
+ (1998-07-06)
+
+FUBAR
+
+ 1. (WWII military slang) Fucked up beyond all
+ recognition (or repair).
+
+ See {foobar}.
+
+ 2. <hardware> The Failed UniBus Address Register in a
+ {VAX}. A good example of how jargon can occasionally be snuck
+ past the {suits}.
+
+ Larry Robinson <lrobins@indiana.edu> reports the following
+ nonstandard use for FUBAR:
+
+ One day somebody got mad at the {card reader} (or card eater
+ that day) on our {Univac 3200}. He taped a sign, "This thing
+ is FUBAR", on the metal weight that sits on the stack of
+ unread cards. The sign stayed there for over a year. One
+ day, somebody said, "Don't forget to put the fubar on top of
+ the stack". It stuck! We called that weight the fubar until
+ they took away the machine. The replacement card reader had
+ two spring loaded card clamps, one for the feed and one for
+ the return, and we called THOSE fubars until we dumped punch
+ cards.
+
+ Incidently, the way he taped the sign on the weight made up
+ for the lack of a little nylon piece that was missing from it,
+ and fixed the card reader. That's why the sign stayed there.
+
+ [{Jargon File}]
+
+ (1997-03-18)
+
+FUD
+
+ <jargon> /fuhd/ An acronym invented by {Gene Amdahl}
+ after he left {IBM} to found his own company: "FUD is the
+ fear, uncertainty, and doubt that {IBM} sales people instill
+ in the minds of potential customers who might be considering
+ [Amdahl] products." The idea, of course, was to persuade them
+ to go with safe IBM gear rather than with competitors'
+ equipment. This implicit coercion was traditionally
+ accomplished by promising that Good Things would happen to
+ people who stuck with IBM, but Dark Shadows loomed over the
+ future of competitors' equipment or software.
+
+ [{Jargon File}]
+
+ (1995-05-23)
+
+fudge
+
+ 1. To perform in an incomplete but marginally acceptable way,
+ particularly with respect to the writing of a program. "I
+ didn't feel like going through that pain and suffering, so I
+ fudged it - I'll fix it later."
+
+ 2. The resulting code.
+
+ [{Jargon File}]
+
+fudge factor
+
+ A value or parameter that is varied in an ad hoc way to
+ produce the desired result. The terms "tolerance" and {slop}
+ are also used, though these usually indicate a one-sided
+ leeway, such as a buffer that is made larger than necessary
+ because one isn't sure exactly how large it needs to be, and
+ it is better to waste a little space than to lose completely
+ for not having enough. A fudge factor, on the other hand, can
+ often be tweaked in more than one direction. A good example
+ is the "fuzz" typically allowed in {floating-point}
+ calculations: two numbers being compared for equality must be
+ allowed to differ by a small amount; if that amount is too
+ small, a computation may never terminate, while if it is too
+ large, results will be needlessly inaccurate. Fudge factors
+ are frequently adjusted incorrectly by programmers who don't
+ fully understand their import.
+
+Fudgets
+
+ <programming> (From "functional widgets") {Graphical user
+ interface} {widgets} available as The Fudget library - a
+ toolkit for concurrent programming of graphical user
+ interfaces, {client/servers} and more written in {Haskell} by
+ Thomas Hallgren <hallgren@cs.chalmers.se> and Magnus Carlsson
+ <magnus@cs.chalmers.se>.
+
+ Version: h9 1995-07-04 (Baastad Spring School Release).
+
+ {(http://cs.chalmers.se/Fudgets/)}.
+
+ {(ftp://ftp.cs.chalmers.se/pub/haskell/chalmers)}.
+
+ (1996-03-17)
+
+FUDGIT
+
+ A double-precision multi-purpose fitting program by Thomas
+ Koenig <ig25@rz.uni-karlsruhe.de>. It can manipulate complete
+ columns of numbers in the form of vector arithmetic. FUDGIT
+ is also an expression language {interpreter} understanding
+ most of {C} {grammar} except pointers. Morever, FUDGIT is a
+ front end for any plotting program supporting commands from
+ stdin, e.g. {Gnuplot}.
+
+ Version 2.27 runs on {AIX}, {HP-UX}, {Linux}, {IRIX}, {NeXT},
+ {SunOS}, {Ultrix}.
+
+ {(ftp://tsx-11.mit.edu/pub/linux/sources/usr.bin/)}.
+
+ (1993-03-22)
+
+FUD wars
+
+ /fuhd worz/ Political posturing, intended to create {FUD},
+ engaged in by hardware and software vendors ostensibly
+ committed to standardisation but actually willing to fragment
+ the market to protect their own shares. The {Unix
+ International} vs. {OSF} conflict is but one outstanding
+ example.
+
+ [{Jargon File}]
+
+ (1994-12-01)
+
+Fuel-can
+
+ A derogatory term for the {Atari Falcon}.
+
+ (1994-12-22)
+
+Fugue
+
+ <language, music> A music language implemented in {Xlisp}.
+
+ ["Fugue: A Functional Language for Sound Synthesis",
+ R.B. Dannenberg et al, Computer 24(7):36-41 (Jul 1991)].
+
+ (1994-12-01)
+
+Fujitsu
+
+ <company> A Japanese elecronics corporation. Fujitsu owns
+ {ICL}, {Amdahl Corporation}, and {DMR}.
+
+ Home {USA (http://fujitsu.com/)}, {Japan
+ (http://fujitsu.co.jp/index-e.html)}.
+
+ (2000-04-03)
+
+full-custom
+
+ Design of {integrated circuits} at the transistor or polygon
+ level. This is in contrast to the use of libraries of
+ components. Full-custom design requires considerable skill
+ and experience and is usually only feasible for simple
+ circuits, especially ones with much repetition, such as memory
+ device, where a small saving in the size and power consumption
+ of a component will yield a large overall saving.
+
+ (1994-12-01)
+
+full-duplex
+
+ <communications> (fdx, from {telegraphy}) 1. A type of
+ {duplex} communications channel which carries data in both
+ directions at once.
+
+ On purely {digital} connections, full-duplex communication
+ requires two pairs of wires. On {analog} networks or in
+ digital networks using carriers, it is achieved by dividing
+ the {bandwidth} of the line into two frequencies, one for
+ sending, and the other for receiving.
+
+ 2. An obsolete term for {remote echo}.
+
+ Compare {simplex}, {half-duplex}, {double-duplex}.
+
+ (2001-07-21)
+
+full-duplex Switched Ethernet
+
+ <networking> (FDSE) A {Switched Ethernet} link which can carry
+ data in both directions simultaneously, doubling transmission
+ capacity from the usual 10 to 20 megabits per second.
+
+ (1996-06-20)
+
+full laziness
+
+ <functional programming> A transformation, described by
+ Wadsworth in 1971, which ensures that subexpressions in a
+ function body which do not depend on the function's arguments
+ are only evaluated once. E.g. each time the function
+
+ f x = x + sqrt 4
+
+ is applied, (sqrt 4) will be evaluated. Since (sqrt 4) does
+ not depend on x, we could transform this to:
+
+ f x = x + sqrt4
+ sqrt4 = sqrt 4
+
+ We have replaced the dynamically created (sqrt 4) with a
+ single shared constant which, in a {graph reduction} system,
+ will be evaluated the first time it is needed and then updated
+ with its value.
+
+ See also {fully lazy lambda lifting}, {let floating}.
+
+ (1994-11-09)
+
+full-motion video
+
+ <video> (FMV) Any kind of {video} that is theoretically
+ capable of changing the entire content on the screen fast
+ enough that the transitions are not obvious to the human eye,
+ i.e. about 24 times a second or more. In practise most {video
+ encoding} relies on the fact that in most video there is
+ relatively little change from one {frame} to the next. This
+ allows for {compression} of the video data.
+
+ The term is used, chiefly in {computer games}, in contrast to
+ techniques such as the use of {sprites} that move against a
+ more-or-less fixed background.
+
+ (2011-01-04)
+
+full outer join
+
+ {outer join}
+
+fully associative cache
+
+ <memory management> A type of {cache} in which data from any
+ address can be stored in any cache location. The whole address
+ must be used as the tag (the value that identifies a block of data
+ in the cache). All tags must be compared simultaneously
+ (associatively) with the requested address and if one matches then
+ its associated data is accessed. This requires an {associative
+ memory} to hold the tags which makes this form of cache more
+ expensive. It does however solve the problem of contention for
+ cache locations ({cache conflict}) since a block need only be
+ flushed when the whole cache is full and then the block to flush
+ can be selected in a more efficient way.
+
+ The alternatives are {direct mapped cache} or {set associative
+ cache}.
+
+ (2013-08-09)
+
+Fully Automated Compiling Technique
+
+ <language> (FACT, "Honeywell-800 Business Compiler") A
+ pre-{COBOL} English-like business data processing language for
+ the {Honeywell 800}, developed ca. 1959.
+
+ [Sammet 1969, p. 327].
+
+ (1994-12-01)
+
+fully lazy lambda lifting
+
+ John Hughes's optimisation of {lambda lifting} to give {full
+ laziness}. {Maximal free expressions} are shared to minimise
+ the amount of recalculation. Each inner sub-expression is
+ replaced by a function of its maximal free expressions
+ (expressions not containing any {bound variable}) applied to
+ those expressions. E.g.
+
+ f = \ x . (\ y . (+) (sqrt x) y)
+
+ ((+) (sqrt x)) is a maximal free expression in
+ (\ y . (+) (sqrt x) y) so this inner {abstraction} is replaced
+ with
+
+ (\ g . \ y . g y) ((+) (sqrt x))
+
+ Now, if a {partial application} of f is shared, the result of
+ evaluating (sqrt x) will also be shared rather than
+ re-evaluated on each application of f. As Chin notes, the
+ same benefit could be achieved without introducing the new
+ {higher-order function}, g, if we just extracted out (sqrt x).
+
+ This is similar to the {code motion} optimisation in
+ {procedural languages} where constant expressions are moved
+ outside a loop or procedure.
+
+ (1994-12-01)
+
+fully qualified domain name
+
+ <networking> (FQDN) The full name of a system, consisting of
+ its local {hostname} and its {domain} name, including a
+ {top-level domain} (tld). For example, "venera" is a hostname
+ and "venera.isi.edu" is an FQDN. An FQDN should be sufficient
+ to determine a unique {Internet address} for any host on the
+ {Internet}. This process, called "name resolution", uses the
+ {Domain Name System} (DNS).
+
+ With the explosion of interest in the {Internet} following the
+ advent of the {web}, domain names (especially the
+ most significant two components, e.g. "sun.com", and
+ especially in the ".com" tld) have become a valuable part of
+ many companies' "brand". The allocation of these, overseen by
+ {ICANN}, has therefore become highly political and is
+ performed by a number of different registrars. There are
+ different registries for the different tlds.
+
+ A final dot on the end of a FQDN can be used to tell the DNS
+ that the name is fully qualified and so needs no extra
+ suffixes added, but it is not required.
+
+ See also {network, the}, {network address}.
+
+ (2005-06-09)
+
+fum
+
+ <jargon> At {Xerox PARC}, often the third standard
+ {metasyntactic variable} after {foo} and {bar}. {baz} is more
+ common outside PARC.
+
+ [{Jargon File}]
+
+ (2003-09-24)
+
+Fun
+
+ A {typed lambda-calculus}, similar to {SOL}[2]. "On
+ Understanding Types, Data Abstractions and Polymorphism",
+ L. Cardelli et al, ACM Comp Surveys 17(4) (Dec 1985).
+
+function
+
+ 1. <mathematics> (Or "map", "mapping") If D and C are sets
+ (the domain and codomain) then a function f from D to C,
+ normally written "f : D -> C" is a subset of D x C such that:
+
+ 1. For each d in D there exists some c in C such that (d,c) is
+ an element of f. I.e. the function is defined for every
+ element of D.
+
+ 2. For each d in D, c1 and c2 in C, if both (d,c1) and (d,c2)
+ are elements of f then c1 = c2. I.e. the function is uniquely
+ defined for every element of D.
+
+ See also {image}, {inverse}, {partial function}.
+
+ 2. <programming> Computing usage derives from the mathematical
+ term but is much less strict. In programming (except in
+ {functional programming}), a function may return different
+ values each time it is called with the same argument values
+ and may have {side effects}.
+
+ A {procedure} is a function which returns no value but has
+ only {side-effects}. The {C} language, for example, has no
+ procedures, only functions. {ANSI C} even defines a {type},
+ {void}, for the result of a function that has no result.
+
+ (1996-09-01)
+
+functional
+
+ 1. Working correctly.
+
+ 2. Pertaining to {functional programming}.
+
+ 3. {higher-order function}.
+
+functional database
+
+ <database, language> A {database} which uses a {functional
+ language} as its {query language}.
+
+ Databases would seem to be an inappropriate application for
+ functional languages since, a {purely functional language}
+ would have to return a new copy of the entire database every
+ time (part of) it was updated. To be practically {scalable},
+ the update mechanism must clearly be {destructive} rather than
+ functional; however it is quite feasible for the {query
+ language} to be purely functional so long as the database is
+ considered as an argument.
+
+ One approach to the update problem would use a {monad} to
+ encapsulate database access and ensure it was {single
+ threaded}. Alternative approaches have been suggested by
+ Trinder, who suggests non-destructive updating with shared
+ data structures, and Sutton who uses a variant of a Phil
+ Wadler's {linear type} system.
+
+ There are two main classes of functional database languages.
+ The first is based upon {Backus}' {FP} language, of which
+ {FQL} is probably the best known example. {Adaplan} is a more
+ recent language which falls into this category.
+
+ More recently, people have been working on languages which are
+ syntactically very similar to modern {functional programming
+ languages}, but which also provide all of the features of a
+ database language, e.g. bulk data structures which can be
+ incrementally updated, type systems which can be incrementally
+ updated, and all data persisting in a database. Examples are
+ {PFL} [Poulovassilis&Small, VLDB-91], and {Machiavelli} [Ohori
+ et al, ACM SIGMOD Conference, 1998].
+
+ {Query optimisation} is very important for database languages
+ in general and the {referential transparency} of functional
+ languages allows optimisations which would be harder to verify
+ in presence of {side-effects}.
+
+ [Trinder, P., "Referentially transparent database languages",
+ 1989 Glasgow Workshop on Functional programming]
+
+ [Breazu-Tannen et al., DBPL-91].
+
+ [Poulovassilis, VLDB-94].
+
+ (1995-05-09)
+
+functional dependency
+
+ <database> Given a relation R (in a {relational database}),
+ attribute Y of R is functionally dependent on attribute X of R
+ and X of R functionally determines Y of R (in symbols R.X ->
+ R.Y) if and only if each X in R has associated with it
+ precisely one Y in R (at any one time). Attributes X and Y
+ may be {composite}.
+
+ This is very close to a {function} in the mathematical sense.
+
+ (1997-09-01)
+
+functionality
+
+ <programming> Waffle for "{features}" or "function". The
+ capabilities or behaviours of a program, part of a program, or
+ system, seen as the sum of its {features}. Roughly, "the
+ things it can do". Generally used in a comparative sense,
+ e.g. "The latest update adds some useful functionality".
+
+ (1997-07-14)
+
+functional language
+
+ <language> A language that supports and encourages {functional
+ programming}.
+
+ (1995-11-08)
+
+functional program
+
+ <language> A program employing the {functional programming}
+ approach or written in a {functional language}.
+
+ (1995-11-07)
+
+functional programming
+
+ <programming> (FP) A program in a functional language consists
+ of a set of (possibly {recursive}) {function} definitions and
+ an expression whose value is output as the program's result.
+ Functional languages are one kind of {declarative language}.
+ They are mostly based on the {typed lambda-calculus} with
+ constants. There are no {side-effects} to expression
+ evaluation so an expression, e.g. a function applied to
+ certain arguments, will always evaluate to the same value (if
+ its evaluation terminates). Furthermore, an expression can
+ always be replaced by its value without changing the overall
+ result ({referential transparency}).
+
+ The order of evaluation of subexpressions is determined by the
+ language's {evaluation strategy}. In a {strict}
+ ({call-by-value}) language this will specify that arguments
+ are evaluated before applying a function whereas in a
+ non-strict ({call-by-name}) language arguments are passed
+ unevaluated.
+
+ Programs written in a functional language are generally
+ compact and elegant, but have tended, until recently, to run
+ slowly and require a lot of memory.
+
+ Examples of purely functional languages are {Clean}, {FP},
+ {Haskell}, {Hope}, {Joy}, {LML}, {Miranda}, and {SML}. Many
+ other languages such as {Lisp} have a subset which is purely
+ functional but also contain non-functional constructs.
+
+ See also {lazy evaluation}, {reduction}.
+
+ {Lecture notes
+ (ftp://ftp.cs.olemiss.edu/pub/tech-reports/umcis-1995-01.ps)}.
+ or the same {in dvi-format
+ (ftp://ftp.cs.olemiss.edu/pub/tech-reports/umcis-1995-01.dvi)}.
+
+ {FAQ
+ (http://cs.nott.ac.uk/Department/Staff/gmh/faq.html)}.
+
+ {SEL-HPC Article Archive
+ (http://lpac.ac.uk/SEL-HPC/Articles/)}.
+
+ (2003-03-25)
+
+functional programming language
+
+ <language> A language that supports and encourages {functional
+ programming}.
+
+ (1995-11-08)
+
+functional requirements
+
+ <specification> What a system should be able to do, the
+ functions it should perform.
+
+ This term is used at both the {user requirements} analysis and
+ {software requirements} specifications phases in the {software
+ life-cycle}.
+
+ An example of a non-functional requirement is an
+ initialisation sequence incorporated into the software that is
+ specific to a given customer.
+
+ (2001-05-22)
+
+functional specification
+
+ <programming, project> A description of what a system (e.g. a
+ piece of {software}) does or should do (but not how it should
+ do it). The functional specification is one of the inputs to
+ the {design} process.
+
+ See {IEEE}/{ANSI} Std. 610.12-1990.
+
+ (1999-04-07)
+
+functional testing
+
+ <testing> (Or "black-box testing", "closed-box testing") The
+ application of test data derived from {functional requirements}
+ without regard to how the system is implemented.
+
+ (1996-05-15)
+
+functional unit
+
+ A subsystem of the {central processing unit} of a computer.
+ E.g. {arithmetic and logic unit}, {memory address register},
+ {barrel shifter}, {register file}.
+
+ (1995-02-10)
+
+function application
+
+ A {function} applied to (some of) its {arguments}. If it is
+ not applied to all its argument then it is a "{partial
+ application}". Application is usually written in the form
+ f(x) but some languages such as command-line interpreters and
+ many {functional languages} use {juxtaposition}: f x. {Lisp}
+ places the parentheses around the whole application: (f x).
+
+function complete
+
+ <programming> State of a {software} component or system such
+ that each {function} described by the software's {functional
+ specification} can be reached by at least one {functional
+ path}, and attempts to operate as specified.
+
+ (1999-04-07)
+
+Function Graph Language
+
+ <language> (FGL) The {machine language} for the AMPS
+ ({Applicative Multi-Processing System}) proposed by Robert
+ Keller, Gary Lindstrom and Suhas Patil at the University of
+ Utah.
+
+ (2007-03-22)
+
+function inlining
+
+ <programming> Defining a {member function}'s {implementation}
+ within the {class} where it was also declared. This is
+ usually reserved for small functions since the inline function
+ must be re-compiled for every instance of the class.
+
+ (2007-03-22)
+
+function key
+
+ <hardware> (From the {IBM 3270} terminal's Programmed Function
+ Keys (PF keys)) One of a set of special keys on a computer or
+ {terminal} keyboard which can be programmed so as to cause an
+ {application program} to perform certain actions.
+
+ Function keys on a terminal may either generate short fixed
+ sequences of characters, often beginning with the {escape}
+ character ({ASCII} 27), or the characters they generate may be
+ configured by sending special character sequences to the
+ terminal.
+
+ On a {microcomputer} keyboard, the function keys may generate
+ a fixed, single byte code, outside the normal {ASCII} range,
+ which is translated into some other configurable sequence by
+ the keyboard {device driver} or interpreted directly by the
+ {application program}.
+
+ (1995-02-07)
+
+Function Point Analysis
+
+ <programming> (FPA) A standard metric for the relative size
+ and complexity of a software system, originally developed by
+ Alan Albrecht of {IBM} in the late 1970s.
+
+ Functon points (FPs) can be used to estimate the relative size
+ and complexity of software in the early stages of development
+ - analysis and design. The size is determined by identifying
+ the components of the system as seen by the end-user: the
+ inputs, outputs, inquiries, interfaces to other systems, and
+ logical internal files. The components are classified as
+ simple, average, or complex. All of these values are then
+ scored and the total is expressed in Unadjusted FPs (UFPs).
+ Complexity factors described by 14 general systems
+ characteristics, such as reusability, performance, and
+ complexity of processing can be used to weight the UFP.
+ Factors are also weighted on a scale of 0 - not present, 1 -
+ minor influence, to 5 - strong influence. The result of these
+ computations is a number that correlates to system size.
+
+ Although the FP metric doesn't correspond to any actual
+ physical attribute of a software system (such as {lines of
+ code} or the number of subroutines) it is useful as a relative
+ measure for comparing projects, measuring productivity, and
+ estimating the amount a development effort and time needed for
+ a project.
+
+ See also {International Function Point Users Group}.
+
+ (1996-05-16)
+
+functor
+
+ In {category theory}, a functor F is an operator on types. F
+ is also considered to be a {polymorphic} operator on functions
+ with the type
+
+ F : (a -> b) -> (F a -> F b).
+
+ Functors are a generalisation of the function "{map}". The
+ type operator in this case takes a type T and returns type
+ "list of T". The map function takes a function and applies it
+ to each element of a list.
+
+ (1995-02-07)
+
+funky
+
+ Said of something that functions, but in a slightly strange,
+ {kluge}y way. It does the job and would be difficult to
+ change, so its obvious non-optimality is left alone. Often
+ used to describe interfaces. The more bugs something has that
+ nobody has bothered to fix because workarounds are easier, the
+ funkier it is. {TECO} and {UUCP} are funky. The {Intel}
+ {i860}'s exception handling is extraordinarily funky. Most
+ standards acquire funkiness as they age. "The new mailer is
+ installed, but is still somewhat funky; if it bounces your
+ mail for no reason, try resubmitting it." "This {UART} is
+ pretty funky. The data ready line is active-high in interrupt
+ mode and active-low in {DMA} mode."
+
+ [{Jargon File}]
+
+FUNLOG
+
+ Functional programming plus unification. "Lazy" in the sense
+ that expressions are reduced only if they are not unifiable.
+
+ ["FUNLOG: A Computational Model Integrating Logic Programming
+ and Functional Programming", P.A. Subrahmanyam et al, in Logic
+ Programming: Functions, Relations and Equations, D. DeGroot et
+ al eds, P-H 1986].
+
+FunnelWeb
+
+ A {literate-programming} tool by Ross Williams
+ <ross@spam.adelaide.edu.au>. It emphasises simplicity and
+ reliability. It provides a {macro} facility and assists in
+ the production of typeset {documentation}. It is independent
+ of the input programming language.
+
+ Posted to comp.sources.unix volume 26 under {CopyLeft}. Runs
+ on {Sun}, {Vax}, {Macintosh} and {IBM PC}.
+
+ (1993-04-11)
+
+funny money
+
+ Notional units of computing time and/or storage handed to
+ students at the beginning of a computer course; also called
+ "play money" or "purple money" (in implicit opposition to real
+ or "green" money).
+
+ In New Zealand and Germany the odd usage "paper money" has
+ been recorded; in Germany, the particularly amusing synonym
+ "transfer ruble" commemorates the funny money used for trade
+ between COMECON countries back when the Soviet Bloc still
+ existed.
+
+ When your funny money ran out, your account froze and you
+ needed to go to a professor to get more. Fortunately, the
+ plunging cost of {time-sharing} cycles has made this less
+ common. The amounts allocated were almost invariably too
+ small, even for the non-hackers who wanted to slide by with
+ minimum work. In extreme cases, the practice led to
+ small-scale black markets in bootlegged computer accounts. By
+ extension, phantom money or quantity tickets of any kind used
+ as a resource-allocation hack within a system.
+
+ [{Jargon File}]
+
+furigana
+
+ <human language, Japanese> (Or "rubi") Small {hiragana},
+ written above {kanji} (and these days sometimes above Latin
+ characters) as a phonetic comment and reading aid. The
+ singular and plural are both "furigana".
+
+ (2000-12-30)
+
+furrfu
+
+ <jargon> Written-only {rot13} "Sheesh!". "furrfu" evolved in
+ mid-1992 as a response to postings repeating urban myths on
+ {newsgroup} {news:alt.folklore.urban}, after some posters
+ complained that "Sheesh!" as a response to {newbies} was being
+ overused.
+
+ (1995-10-25)
+
+FUSE
+
+ A {DEC} {software development environment} for {ULTRIX},
+ offering an integrated toolkit for developing, testing,
+ debugging and maintenance.
+
+FUSION
+
+ Software package supplied by Network Research Corporation
+ claiming to connect various different configurations of LAN.
+
+fusion
+
+ <programming> A {program transformation} where a {composition}
+ of two functions is replaced by in-lining them and combining
+ their bodies. E.g.
+
+ f x = g (h x) ==> f x = g (2 * x)
+ g x = x + 1 f x = 2 * x + 1
+ h x = 2 * x
+
+ This has the beneficial effect of reducing the number of
+ function calls. It can be especially useful where the
+ intermediate result is a large data structure which can be
+ eliminated.
+
+ See also {vertical loop combination}.
+
+ (1994-12-05)
+
+FutureBasic
+
+ <language> A {BASIC} compiler for the {Macintosh}.
+
+ {(http://stazsoftware.com/futurebasic/)}.
+
+ [Summary? Version?]
+
+ (2002-08-28)
+
+future date testing
+
+ <testing> The process of setting a computer's date to a future
+ date to test a program's (expected or unexpected) date
+ sensitivity. Future date testing only shows the effects of
+ dates on the computer(s) under scrutiny, it does not take into
+ account knock-on effects of dates on other connected systems.
+
+ (2000-09-11)
+
+futz
+
+ <jargon> ("futzing around") To waste time on activity
+ that is often experimental and may or may not be
+ productive. Not normally used for game playing.
+
+ (2008-11-27)
+
+fuzzball
+
+ A {DEC} {LSI-11} running a particular suite of homebrewed
+ software written by Dave Mills and assorted co-conspirators,
+ used in the early 1980s for {Internet} {protocol} testbedding
+ and experimentation. These were used as {NSFnet} {backbone}
+ sites in its early 56KB-line days. A few were still active on
+ the {Internet} in early 1991, doing odd jobs such as network
+ time service.
+
+ [{Jargon File}]
+
+ (1994-12-05)
+
+fuzzy computing
+
+ {fuzzy logic}
+
+fuzzy logic
+
+ A superset of {Boolean logic} dealing with the concept of
+ partial truth -- {truth values} between "completely true" and
+ "completely false". It was introduced by Dr. Lotfi Zadeh of
+ {UCB} in the 1960's as a means to model the uncertainty of
+ {natural language}.
+
+ Any specific theory may be generalised from a discrete (or
+ "crisp") form to a continuous (fuzzy) form, e.g. "fuzzy
+ calculus", "fuzzy differential equations" etc. Fuzzy logic
+ replaces Boolean truth values with degrees of truth which are
+ very similar to probabilities except that they need not sum to
+ one. Instead of an assertion pred(X), meaning that X
+ definitely has the property associated with {predicate}
+ "pred", we have a truth function truth(pred(X)) which gives
+ the degree of truth that X has that property. We can combine
+ such values using the standard definitions of fuzzy logic:
+
+ truth(not x) = 1.0 - truth(x)
+ truth(x and y) = minimum (truth(x), truth(y))
+ truth(x or y) = maximum (truth(x), truth(y))
+
+ (There are other possible definitions for "and" and "or",
+ e.g. using sum and product). If truth values are restricted to
+ 0 and 1 then these functions behave just like their Boolean
+ counterparts. This is known as the "extension principle".
+
+ Just as a Boolean predicate asserts that its argument
+ definitely belongs to some subset of all objects, a fuzzy
+ predicate gives the degree of truth with which its argument
+ belongs to a {fuzzy subset}.
+
+ {Usenet} newsgroup: {news:comp.ai.fuzzy}.
+
+ E-mail servers: <fuzzynet@aptronix.com>,
+ <rnalib@its.bldrdoc.gov>, <fuzzy-server@til.com>.
+
+ {(ftp://ftp.hiof.no/pub/Fuzzy)},
+ {(ftp://ntia.its.bldrdoc.gov/pub/fuzzy)}.
+
+ {FAQ
+ (ftp://rtfm.mit.edu/pub/usenet-by-group/comp.answers/fuzzy-logic)}.
+
+ {James Brule, "Fuzzy systems - a tutorial", 1985
+ (http://life.anu.edu.au/complex_systems/fuzzy.html)}.
+
+ {STB Software Catalog
+ (http://krakatoa.jsc.nasa.gov/stb/catalog.html)}, includes a
+ few fuzzy tools.
+
+ [H.J. Zimmerman, "Fuzzy Sets, Decision Making and Expert
+ Systems", Kluwer, Dordrecht, 1987].
+
+ ["Fuzzy Logic, State of the Art", Ed. R. Lowen, Marc Roubens,
+ Theory and Decision Library, D: System theory, Knowledge
+ Engineering and Problem Solving 12, Kluwer, Dordrecht, 1993,
+ ISBN 0-7923-2324-6].
+
+ (1995-02-21)
+
+fuzzy subset
+
+ In {fuzzy logic}, a fuzzy subset F of a set S is defined by a
+ "membership function" which gives the degree of membership of
+ each element of S belonging to F.
+
+fweep
+
+ ({WPI}) One step below a {gweep}, a person who uses the system
+ solely to play games and use {electronic mail}.
+
+ Compare {dweeb}, {twink}, {terminal junkie}, {tourist},
+ {weenie}.
+
+ (1995-01-31)
+
+FWIW
+
+ For what it's worth.
+
+fx
+
+ <networking> The {country code} for metropolitan France.
+
+ Apprently not widely used.
+
+ (1999-01-27)
+
+FX-87
+
+ Effects. A {polymorphic} language based on {Scheme}, allowing
+ {side effects} and {first-class} functions. It attempts to
+ integrate functional and {imperative programming}.
+ Expressions have types, side effects (e.g. reading, writing or
+ allocating) and regions (stating where the effects may occur).
+
+ Versions: FX-89, {FX-90}.
+
+ {(ftp://brokaw.lcs.mit.edu/)}.
+
+ ["The FX-87 Reference Manual", D.K. Gifford
+ <gifford@lcs.mit.edu> et al, MIT/LCS/TR-407, Oct 1987].
+
+ (1995-01-31)
+
+FX-90
+
+ <language> A language with partial type and effect
+ reconstruction and {first-class} {modules}.
+
+ (1995-01-31)
+
+FXO
+
+ {Foreign eXchange Office}
+
+FXS
+
+ {Foreign eXchange Subscriber}
+
+FYA
+
+ For your amusement.
+
+FYI
+
+ {For Your Information}
+
+FYI4
+
+ [Malkin, G., and A. Marine, "FYI on Questions and Answers:
+ Answers to Commonly asked "New Internet User" Questions", FYI
+ 4, RFC 1325, Xylogics, SRI, May 1992.]
+
+G
+
+ 1. <unit> The abbreviated form of {giga-}.
+
+ 2. <language> ["G: A Functional Language with Generic Abstract
+ Data Types", P.A.G. Bailes, Computer Langs 12(2):69-94, 1987].
+
+ 3. <language> A language developed at {Oregon State
+ University} in 1988 which combines {functional programming},
+ {object-oriented programming}, relational, {imperative
+ programming} and {logic programming} (you name it we got it).
+
+ ["The Multiparadigm Language G", J. Placer, Computer Langs
+ 16:235-258, 1991].
+
+ [{Jargon File}]
+
+ (1996-08-12)
+
+<g>
+
+ <chat> grin. An alternative to {smiley}.
+
+ [{Jargon File}]
+
+ (1998-01-18)
+
+G2
+
+ A {real-time} {expert system} from {Gensym Corporation}.
+
+G3
+
+ 1. <protocol, compression> {Group 3} fax.
+
+ 2. <hardware, processor> {PowerPC G3}.
+
+ (1998-09-10)
+
+G4
+
+ {Group 4}
+
+GA
+
+ {genetic algorithm}
+
+ga
+
+ <networking> The {country code} for Gabon.
+
+ (1999-01-27)
+
+Gabriel
+
+ <language> A graphical {DSP} language for {simulation} and
+ real systems.
+
+ ["A Design Tool for Hardware and Software for Multiprocessor
+ DSP Systems," E.A. Lee, E. Goei, J. Bier & S. Bhattacharya,
+ DSP Systems, Proc ISCAS-89, 1989].
+
+ [{Jargon File}]
+
+ (1994-12-23)
+
+gabriel
+
+ /gay'bree-*l/ (After {Richard Gabriel}) An unnecessary (in the
+ opinion of the opponent) stalling tactic, e.g. tying one's
+ shoelaces or combing one's hair repeatedly, asking the time,
+ etc. Also used to refer to the perpetrator of such tactics.
+ Also, "pulling a Gabriel", "Gabriel mode".
+
+ [{Jargon File}]
+
+ (1999-10-12)
+
+Gabriel, Richard
+
+ {Richard Gabriel}
+
+GADS
+
+ Picture retrieval language. "Integrated Geographical
+ Databases: The GADS Experience", P.E. Mantey et al, in
+ Database Techniques for Pictorial Applications, A. Blaser ed,
+ pp.193-198.
+
+Gaelic
+
+ For automated test programs. Used in military, essentially
+ replaced by ATLAS.
+
+gag
+
+ Equivalent to {choke}, but connotes more disgust. "Hey, this
+ is Fortran code. No wonder the C compiler gagged." See also
+ {barf}.
+
+ [{Jargon File}]
+
+GAIA
+
+ GUI Application Interoperability Architecture. An {OSF}
+ project.
+
+GAL
+
+ <hardware> {Generic Array Logic}.
+
+ (1995-12-09)
+
+Galaxy
+
+ <language> An extensible language in the vein of {EL/1} and
+ {RCC}.
+
+ ["Introduction to the Galaxy Language", Anne F. Beetem et al,
+ IEEE Software 6(3):55-62].
+
+ (1995-12-09)
+
+Galileo
+
+ ["Galileo: A Strongly Typed Interactive Conceptual Language",
+ A. Albano et al, ACM Trans Database Sys 10(2):230-260 (June
+ 1985)].
+
+Gambit
+
+ <language> A variant of {Scheme} R3.99 supporting the {future}
+ construct of {Multilisp} by Marc Feeley
+ <feeley@iro.umontreal.ca>. Implementation includes optimising
+ compilers for {Macintosh} (with Toolbox and built-in editor)
+ and {Motorola} {680x0} {Unix} systems and {HP300}, {BBN}
+ {GP100} and {NeXT}. Version 2.0 conforms to the {IEEE}
+ {Scheme} standard.
+
+ Gambit used {PVM} as its intermediate language.
+
+ {(ftp://acorn.cs.brandeis.edu/dist)},
+ {(ftp://ftp.cso.uiuc.edu/pub/amiga/fish/f7/ff764/Gambit_Terp)}.
+ {(ftp://ftp.iro.umontreal.ca/pub/parallele/gambit/)}.
+
+ Mailing list: gambit@trex.umontreal.ca.
+
+ (1998-02-10)
+
+games
+
+ <games> "The time you enjoy wasting is not time wasted." --
+ {Bertrand Russell}.
+
+ Here are some games-related pages on the {Web}: {Imperial
+ Nomic (http://mit.edu:8001/people/achmed/fascist/)},
+ {Thoth's games and recreations page
+ (http://cis.ufl.edu/~thoth/library/recreation.html)},
+ {Games Domain (http://wcl-rs.bham.ac.uk/GamesDomain)},
+ {Zarf's List of Games on the Web
+ (http://leftfoot.com/games.html)},
+ {Dave's list of pointers to games resources
+ (http://wcl-rs.bham.ac.uk/~djh/index.html)},
+ {Collaborative Fiction
+ (http://asylum.cid.com/fiction/fiction.html)}.
+
+ See also {3DO}, {ADL}, {ADVENT}, {ADVSYS}, {alpha/beta
+ pruning}, {Amiga}, {CHIP-8}, {Core Wars}, {DROOL}, {empire},
+ {I see no X here.}, {Infocom}, {Inglish}, {initgame}, {life},
+ {minimax}, {moria}, {mudhead}, {multi-user Dimension},
+ {nethack}, {ogg}, {plugh}, {rogue}, {SPACEWAR}, {virtual
+ reality}, {wizard mode}, {wumpus}, {xyzzy}, {ZIL}, {zorkmid}.
+
+ See also {game theory}.
+
+ (1996-03-03)
+
+game tree
+
+ <games> A {tree} representing contingencies in a game. Each
+ {node} in a game tree represents a possible position (e.g.,
+ possible configuration of pieces on a chessboard) in the game,
+ and each branching ("edge" in graph terms) represents a
+ possible move.
+
+ (1998-11-14)
+
+GAMMA
+
+ <language> 1. A language for matrices and generation of
+ mathematical programming reports.
+
+ ["GAMMA 3.3 for MPS/MPSX, IBM System:/360", Bonnor & Moore
+ Assocs (Mar 1975)].
+
+ 2. A high-level parallel language.
+
+ [Research Directions in High-Level Parallel Languages,
+ LeMetayer ed, Springer 1992].
+
+ (1994-11-29)
+
+gamma correction
+
+ <hardware> Adjustments applied during the display of a digital
+ representation of colour on a screen in order to compensate
+ for the fact that the {Cathode Ray Tubes} used in computer
+ {monitors} (and televisions) produce a light intensity which
+ is not proportional to the input {voltage}. The light
+ intensity is actually proportional to the input voltage raised
+ to the inverse power of some constant, called gamma. Its
+ value varies from one display to another, but is usually
+ around 2.5.
+
+ Because it is more intuitive for the colour components (red,
+ green and blue) to be varied linearly in the computer, the
+ actual voltages sent to the monitor by the {display hardware}
+ must be adjusted in order to make the colour component
+ intensity on the screen proportional to the value stored in
+ the computer's {display memory}. This process is most easily
+ achieved by a dedicated module in the display hardware which
+ simply scales the outputs of the {display memory} before
+ sending them to the {digital-to-analogue converters}.
+
+ More expensive {graphics cards} and {workstations}
+ (particularly those used for {CAD} applications) will have a
+ gamma correction facility.
+
+ In combination with the "{white-point}" gamma correction is
+ used to achieve precise colour matching.
+
+ {Robert Berger's explanation of monitor gamma
+ (http://cs.cmu.edu/afs/cs.cmu.edu/user/rwb/www/gamma.html)}.
+
+ [{"Digital Imaging in C and the World Wide Web", W. David
+ Schwaderer (http://itknowledge.com/)}].
+
+ (1999-02-01)
+
+GAMS
+
+ {Guide to Available Mathematical Software}
+
+gamut
+
+ The gamut of a {monitor} is the set of colours it can display.
+ There are some colours which can't be made up of a mixture of
+ red, green and blue phosphor emissions and so can't be
+ displayed by any monitor.
+
+ [Examples?]
+
+ (1994-11-29)
+
+GAN
+
+ Generating and Analyzing Networks. "GAN - A System for
+ Generating and Analyzing Activity Networks", A. Schurmann,
+ CACM 11(10) (Oct 1968).
+
+GANDALF
+
+ A software development environment from Carnegie Mellon
+ University.
+
+gang bang
+
+ The use of large numbers of loosely coupled programmers in an
+ attempt to wedge a great many features into a product in a
+ short time. Though there have been memorable gang bangs
+ (e.g. that over-the-weekend assembler port mentioned in
+ Steven Levy's "Hackers"), most are perpetrated by large
+ companies trying to meet deadlines; the inevitable result is
+ enormous buggy masses of code entirely lacking in
+ {orthogonal}ity. When market-driven managers make a list of
+ all the features the competition has and assign one programmer
+ to implement each, the probability of maintaining a coherent
+ (or even functional) design goes infinitesimal. See also
+ {firefighting}, {Mongolian Hordes technique}, {Conway's Law}.
+
+ [{Jargon File}]
+
+GAP
+
+ <mathematics, tool> Groups Algorithms and Programming.
+
+ A system for {symbolic mathematics} for computational discrete
+ algebra, especially group theory, by Johannes Meier, Alice
+ Niemeyer, Werner Nickel, and Martin Schonert of Aachen. GAP
+ was designed in 1986 and implemented 1987. Version 2.4 was
+ released in 1988 and version 3.1 in 1992.
+
+ {Sun version (ftp://ftp.math.rwth-aachen.de/pub/gap)}.
+
+ ["GAP 3.3 Manual, M. Schonert et al, Lehrstuhl D Math, RWTH
+ Aachen, 1993].
+
+ (1995-04-12)
+
+GAPLog
+
+ General Amalgamated Programming with Logic. {LOGPRO} group,
+ Linkoping Sweden. A restricted version of {constraint logic
+ programming}, using {S-unification} but not restricted to a
+ single domain.
+
+ [Chapter in forthcoming Springer book on ESPRIT]
+
+garbageabetical order
+
+ <humour> 1. The result of using an {insertion} sort to merge
+ data into an unsorted list.
+
+ 2. The state of any file or list that is supposed to be
+ sorted, but is not.
+
+ (1997-02-11)
+
+garbage collect
+
+ {garbage collection}
+
+garbage collection
+
+ <programming> (GC) The process by which dynamically allocated
+ storage is reclaimed during the execution of a program. The
+ term usually refers to automatic periodic storage reclamation
+ by the garbage collector (part of the {run-time system}), as
+ opposed to explicit code to free specific blocks of memory.
+
+ Automatic garbage collection is usually triggered during
+ memory allocation when the amount free memory falls below some
+ threshold or after a certain number of allocations. Normal
+ execution is suspended and the garbage collector is run.
+ There are many variations on this basic scheme.
+
+ Languages like {Lisp} represent expressions as {graphs} built
+ from {cells} which contain pointers and data. These languages
+ use automatic {dynamic storage allocation} to build
+ expressions. During the evaluation of an expression it is
+ necessary to reclaim space which is used by subexpressions but
+ which is no longer pointed to by anything. This reclaimed
+ memory is returned to the free memory pool for subsequent
+ reallocation.
+
+ Without garbage collection the program's memory requirements
+ would increase monotonically throughout execution, possibly
+ exceeding system limits on {virtual memory} size.
+
+ The three main methods are {mark-sweep garbage collection},
+ {reference counting} and {copying garbage collection}.
+
+ See also the {AI koan} about garbage collection.
+
+ (1997-08-25)
+
+Garbage In, Garbage Out
+
+ <humour> (GIGO) /gi:'goh/ {Wilf Hey}'s maxim expressing the
+ fact that computers, unlike humans, will unquestioningly
+ process nonsensical input data and produce nonsensical output.
+ Of course a properly written program will reject input data
+ that is obviously erroneous but such checking is not always
+ easy to specify and is tedious to write.
+
+ GIGO is usually said in response to {lusers} who complain that
+ a program didn't "do the right thing" when given imperfect
+ input or otherwise mistreated in some way. Also commonly used
+ to describe failures in human decision making due to faulty,
+ incomplete, or imprecise data.
+
+ The expansion "Garbage In, Gospel Out" is an ironic comment on
+ the tendency to put excessive trust in "computerised" data.
+
+ [{Jargon File}]
+
+ (2004-10-03)
+
+Gargoyle
+
+ A language for compiler writing.
+
+ [J.V. Garwick, CACM 7(1):16-20, (Jan 1964)].
+
+ (1994-11-04)
+
+Garnet
+
+ 1. A graphical object editor and {Macintosh} environment.
+
+ 2. A user interface development environment for {Common Lisp}
+ and {X11} from The Garnet project team. It helps you create
+ graphical, interactive user interfaces.
+
+ Version 2.2 includes the following: a custom {object-oriented
+ programming} system which uses a {prototype-instance model}.
+ automatic {constraint} maintenance allowing properties of
+ objects to depend on properties of other objects and be
+ automatically re-evaluated when the other objects change. The
+ constraints can be arbitrary Lisp expressions. Built-in,
+ high-level input event handling. Support for {gesture
+ recognition}. {Widgets} for multi-font, multi-line,
+ mouse-driven text editing. Optional automatic layout of
+ application data into lists, tables, trees or graphs.
+ Automatic generation of {PostScript} for printing. Support
+ for large-scale applications and data {visualisation}.
+
+ Also supplied are: two complete widget sets, one with a
+ {Motif} {look and feel} implemented in {Lisp} and one with a
+ custom {look and feel}. Interactive design tools for creating
+ parts of the interface without writing code: Gilt interface
+ builder for creating {dialog box}es. Lapidary interactive
+ tool for creating new {widgets} and for drawing
+ application-specific objects. C32 {spreadsheet} system for
+ specifying complex {constraints}.
+
+ Not yet available: Jade automatic dialog box creation system.
+ Marquise interactive tool for specifying behaviours.
+
+ {(ftp://a.gp.cs.cmu.edu/usr/garnet/garnet)}.
+
+ (1999-07-02)
+
+GARP
+
+ A graphical language for {concurrent} programming.
+
+ ["Visual Concurrent Programmint in GARP", S.K. Goering er al,
+ PARLE '89 v.II, LNCS 366, pp. 165-180].
+
+ (1994-11-03)
+
+garply
+
+ /gar'plee/ A {metasyntactic variable} like {foo}, once popular
+ among {SAIL} hackers.
+
+ [{Jargon File}]
+
+ (1994-11-03)
+
+Gartner Group
+
+ <company> One of the biggest IT industry research firms.
+
+ Address: Connecticut, USA.
+
+ [URL?]
+
+ (1997-09-30)
+
+gas
+
+ {GNU assembler}
+
+GASP
+
+ 1. {Graph Algorithm and Software Package}.
+
+ 2. <simulation> {General Activities Simulation Program}.
+
+ 3. <simulation> {General Aerodynamic Simulation Program}.
+
+ (2003-09-27)
+
+gas plasma display
+
+ <electronics> A type of display containing super-energised
+ neon gas, used mostly in flat {monitor} and television
+ {screens}. Each {pixel} has a {transistor} that controls its
+ colour and brightness.
+
+ {Plasma
+ (http://kipinet.com/mmp/mmp_apr96/dep_techwatch.html)}.
+ {Flat Screen Technology
+ (http://montegonet.com/plasma.html)}. {More about Gas
+ Plasma (http://advancedplasma.com/whatis.html)}.
+
+ [How does it work?]
+
+ (1998-04-30)
+
+GAT
+
+ Generalized Algebraic Translator. Improved version of IT. On
+ IBM 650 RAMAC.
+
+ [Sammet 1969, p. 142].
+
+GATE
+
+ GAT Extended? Based on {IT}.
+
+ [Sammet 1969, p. 139].
+
+gate
+
+ <hardware> A low-level {digital} logic component. Gates
+ perform {Boolean} {functions} (e.g. {AND}, {NOT}), store
+ {bits} of data (e.g. a {flip-flop}), and connect and
+ disconnect various parts of the overall circuit to control the
+ flow of data ({tri-state} buffer).
+
+ In a {CPU}, the term applies particularly to the buffers that
+ route data between the various {functional units}. Each gate
+ allows data to flow from one unit to another or enables data
+ from one output onto a certain {bus}.
+
+ (1999-09-02)
+
+gated
+
+ /gayt-dee/ Gate daemon.
+
+ A program which supports multiple routing {protocols} and
+ protocol families. It may be used for routing, and makes an
+ effective {platform} for routing {protocol} research.
+
+ {(ftp://gated.cornell.edu)}.
+
+ See also {Exterior Gateway Protocol}, {Open Shortest Path
+ First}, {Routing Information Protocol}, {routed}.
+
+ (1994-12-07)
+
+Gates
+
+ {Bill Gates}
+
+gateway
+
+ 1. <networking> A deprecated term for a device that enables
+ data to flow between different networks (forming an
+ {internet}).
+
+ Preferred terms are "{protocol converter}" (connects networks
+ that use different {protocols}), "{router}" (connects two
+ broadcast networks at layer 3 ({network layer}). Another
+ example is a {mail gateway}, which is a layer 7 ({application
+ layer}) gateway.
+
+ 2. <hypertext> An {interface} between an information source
+ and a {web server}. {Common Gateway Interface}
+ is a {standard} for such interfaces. The information source
+ can be any system that can be accessed by a program running on
+ the web server. A typical example is a {relational
+ database}.
+
+ (2000-05-24)
+
+Gateway 2000
+
+ <company> One of the lagest US manufacturers of {IBM
+ compatibles}, founded by CEO Ted Waitt in September 1985, in
+ Sioux City, Iowa. In 1990 the company moved to North Sioux
+ City, South Dakota.
+
+ In August 1994, quarterly profits were $4 million on sales of
+ $617 million. Sales for the first quarter of 1997 were $1.42
+ billion.
+
+ On 1997-05-15 Gateway bought the {Amiga} brand.
+
+ {(http://gw2k.com/)}.
+
+ (1998-07-30)
+
+Gauss
+
+ 1. <person> {Carl Friedrich Gauss}.
+
+ 2. <statistics> Gaussian distribution.
+
+ See {normal distribution}.
+
+ 3. <unit> The unit of magnetic field strength. 1 gauss = 1
+ Maxwell / cm^2.
+
+ A good loudspeaker coil magnet flux density is of the order of
+ 10000 gauss.
+
+ 4. <language> A powerful {matrix} programming language by
+ {Aptech Systems}. Gauss is very popular with econometricians.
+
+ {(http://rhkoning.xs4all.nl/gauss/index.htm)}.
+
+ (2003-10-25)
+
+Gaussian distribution
+
+ {normal distribution}
+
+gawk
+
+ <tool, language> {GNU} {awk}. Gawk is a superset of standard
+ awk and includes some {Plan 9} features.
+
+ David Trueman and Arnold Robbins of {Georgia Institute of
+ Technology} were developing it in 1993. It has been ported to
+ {Unix}, {MS-DOS}, {Macintosh}, and {Archimedes}.
+
+ Latest version: 2.15.3, as of 1993-11-08.
+
+ Available by {FTP} from your nearest {GNU archive site}.
+
+ {Mac version
+ (ftp://archive.umich.edu/mac/utilities/developerhelps/macgawk2.11.cpt.hqx)}.
+
+ (2000-10-21)
+
+GB
+
+ <unit> {gigabytes} or {gigabits} - see {MB}. Giga stands for
+ 10^9 - a US billion, or in computing for 2^30.
+
+ The text of a thirty volume encyclopaedia would require about
+ one gigabyte of {ASCII} storage.
+
+ (1997-03-27)
+
+Gb
+
+ <unit> Gigabit. 10^9 {bits}. Might also be wrongly used for
+ {gigabyte} ({GB}).
+
+ (1997-03-27)
+
+gb
+
+ <networking> (Great Britain) A {country code} for United
+ Kingdom. "{uk}" is generally used instead.
+
+ (1999-01-27)
+
+g-bell
+
+ {bell}
+
+GBIP
+
+ {General Purpose Interface Bus}
+
+GBML
+
+ {Genetics Based Machine Learning}
+
+gbps
+
+ {gigabits per second}
+
+GC
+
+ 1. {garbage collection}.
+
+ 2. A storage allocator with {garbage collection} by
+ Hans-J. Boehm and Alan J. Demers. Gc is a plug-in replacement
+ for {C}'s {malloc}. Since the collector does not require
+ {pointers} to be tagged, it does not attempt to ensure that
+ all inaccessible storage is reclaimed.
+
+ Version 3.4 has been ported to {Sun-3}, {Sun-4}, {Vax}/{BSD},
+ {Ultrix}, {Intel 80386}/{Unix}, {SGI}, {Alpha}/{OSF/1},
+ {Sequent} (single threaded), {Encore} (single threaded),
+ {RS/600}, {HP-UX}, {Sony News}, {A/UX}, {Amiga}, {NeXT}.
+
+ {(ftp://parcftp.xerox.com/pub/russell/gc3.4.tar.Z)}.
+
+ (2000-04-19)
+
+GCAL
+
+ <text, tool> The Cambridge {Phoenix} equivalent of {troff}.
+ So called because all Cambridge utilities were named after
+ birds, GCAL was a "run off" equivalent, and Geococcyx
+ californianus is the Latin name of the roadrunner. GCAL was
+ eventually obsoleted by {TeX}.
+
+ It is believed that even more obscure puns lurked in the
+ depths of Phoenix. Perhaps it is better they stayed there.
+
+ (2003-12-05)
+
+GCC
+
+ <compiler, programming> The {GNU} {Compiler} Collection, which
+ currently contains front ends for {C}, {C++}, {Objective-C},
+ {Fortran}, {Java}, and {Ada}, as well as libraries for these
+ languages (libstdc++, libgcj, etc).
+
+ GCC formerly meant the GNU {C} compiler, which is a very high
+ quality, very portable compiler for {C}, {C++} and {Objective
+ C}.
+
+ The compiler supports multiple {front-ends} and multiple
+ {back-ends} by translating first into {Register Transfer
+ Language} and from there into {assembly code} for the target
+ architecture.
+
+ {(http://gcc.gnu.org/)}.
+ {Bug Reports (http://gcc.gnu.org/bugzilla/)}.
+ {FTP} gcc-2.X.X.tar.gz from your nearest {GNU archive site}.
+ {MS-DOS (ftp://oak.oakland.edu/pub/msdos/djgpp/)}.
+
+ Mailing lists: gcc-help@gcc.gnu.org, gcc-announce@gcc.gnu.org
+ (announcements).
+
+ ["Using and Porting GNU CC", R.M. Stallman, 1992-12-16].
+
+ (2003-08-05)
+
+GCL
+
+ General Control Language. A portable job control language.
+
+ ["A General Control Interface for Satellite Systems",
+ R.J. Dakin in Command Languages, C. Unger ed, N-H 1973].
+
+G-Code
+
+ 1. Johnsson & Augustsson, Chalmers Inst Tech. Intermediate
+ language used by the G-machine, an implementation of graph
+ reduction based on supercombinators. "Efficient Compilation
+ of Lazy Evaluation", T. Johnsson, SIGPLAN Notices 19(6):58-69
+ (June 1984).
+
+ 2. A machine-like language for the representation and
+ interpretation of attributed grammars. Used as an
+ intermediate language by the Coco compiler generator. "A
+ Compiler Generator for Microcomputers", P. Rechenberg et al,
+ P-H 1989.
+
+GCOS
+
+ <operating system> /jee'kohs/ An {operating system} developed
+ by {General Electric} from 1962; originally called GECOS (the
+ General Electric Comprehensive Operating System).
+
+ The GECOS-II operating system was developed by {General
+ Electric} for the 36-bit {GE-635} in 1962-1964. Contrary to
+ rumour, GECOS was not cloned from {System/360} [{DOS/360}?] -
+ the GE-635 architecture was very different from the {IBM 360}
+ and GECOS was more ambitious than DOS/360.
+
+ GE Information Service Divsion developed a large special
+ multi-computer system that was not publicised because they did
+ not wish {time sharing} customers to challenge their bills.
+ Although GE ISD was marketing {DTSS} - the first commercial
+ time sharing system - GE Computer Division had no license from
+ Dartmouth and GE-ISD to market it to external customers, so
+ they designed a time-sharing system to sell as a standard part
+ of GECOS-III, which replaced GECOS-II in 1967. GECOS TSS was
+ more general purpose than DTSS, it was more a programmer's
+ tool (program editing, e-mail on a single system) than a BASIC
+ TSS.
+
+ The {GE-645}, a modified 635 built by the same people, was
+ selected by {MIT} and {Bell} for the {Multics} project.
+ Multics' infancy was as painful as any infancy. Bell pulled
+ out in 1969 and later produced {Unix}.
+
+ After the buy-out of GE's computer division by {Honeywell},
+ GECOS-III was renamed GCOS-3 (General Comprehensive Operating
+ System). Other OS groups at Honeywell began referring to it
+ as "God's Chosen Operating System", allegedly in reaction to
+ the GCOS crowd's uninformed and snotty attitude about the
+ superiority of their product. [Can anyone confirm this?]
+ GCOS won and this led in the orphaning and eventual death of
+ Honeywell {Multics}.
+
+ Honeywell also decided to launch a new product line called
+ Level64, and later DPS-7. It was decided to mainatin, at
+ least temporarily, the 36-bit machine as top of the line,
+ because GCOS-3 was so successfull in the 1970s. The plan in
+ 1972-1973 was that GCOS-3 and Multics should converge. This
+ plan was killed by Honeywell management in 1973 for lack of
+ resources and the inability of Multics, lacking {databases}
+ and {transaction processing}, to act as a business operating
+ system without a substantial reinvestment.
+
+ The name "GCOS" was extended to all Honeywell-marketed product
+ lines and GCOS-64, a completely different 32-bit operating
+ system, significanctly inspired by Multics, was designed in
+ France and Boston. GCOS-62, another different 32-bit low-end
+ DOS level was designed in Italy. GCOS-61 represented a new
+ version of a small system made in France and the new {DPS-6}
+ 16-bit {minicomputer} line got GCOS-6.
+
+ When the intended merge between GCOS-3 and Multics failed, the
+ Phoenix designers had in mind a big upgrade of the
+ architecture to introduce {segmentation} and {capabilities}.
+ GCOS-3 was renamed GCOS-8, well before it started to use the
+ new features which were introduced in next generation
+ hardware.
+
+ The GCOS licenses were sold to the Japanese companies {NEC}
+ and {Toshiba} who developed the Honeywell products, including
+ GCOS, much further, surpassing the {IBM 3090} and {IBM 390}.
+
+ When Honeywell decided in 1984 to get its top of the range
+ machines from NEC, they considered running Multics on them but
+ the Multics market was considered too small. Due to the
+ difficulty of porting the ancient Multics code they considered
+ modifying the NEC hardware to support the Multics compilers.
+
+ GCOS3 featured a good {Codasyl} {database} called IDS
+ (Integrated Data Store) that was the model for the more
+ successful {IDMS}.
+
+ Several versions of transaction processing were designed for
+ GCOS-3 and GCOS-8. An early attempt at TP for GCOS-3, not
+ taken up in Europe, assumed that, as in {Unix}, a new process
+ should be started to handle each transaction. IBM customers
+ required a more efficient model where multiplexed {threads}
+ wait for messages and can share resources. Those features
+ were implemented as subsystems.
+
+ GCOS-3 soon acquired a proper {TP monitor} called Transaction
+ Driven System (TDS). TDS was essentially a Honeywell
+ development. It later evolved into TP8 on GCOS-8. TDS and
+ its developments were commercially successful and predated IBM
+ {CICS}, which had a very similar architecture.
+
+ GCOS-6 and GCOS-4 (ex-GCOS-62) were superseded by {Motorola
+ 68000}-based {minicomputers} running {Unix} and the product
+ lines were discontinued.
+
+ In the late 1980s Bull took over Honeywell and Bull's
+ management chose Unix, probably with the intent to move out of
+ hardware into {middleware}. Bull killed the Boston proposal
+ to port Multics to a platform derived from DPS-6. Very few
+ customers rushed to convert from GCOS to Unix and new machines
+ (of CMOS technology) were still to be introduced in 1997 with
+ GCOS-8. GCOS played a major role in keeping Honeywell a
+ dismal also-ran in the {mainframe} market.
+
+ Some early Unix systems at {Bell Labs} used GCOS machines for
+ print spooling and various other services. The field added to
+ "/etc/passwd" to carry GCOS ID information was called the
+ "{GECOS field}" and survives today as the "pw_gecos" member
+ used for the user's full name and other human-ID information.
+
+ [{Jargon File}]
+
+ (1998-04-23)
+
+GCOS Macro Assembler Program
+
+ <language> (GMAP) The {macro assembler} for the {GCOS 8}
+ {operating system} on {Honeywell}/{Bull} {DPS-8} computers.
+
+ ["GCOS8 OS GMAP User's Guide", Bull].
+
+ (2009-01-14)
+
+GCR
+
+ {Group Code Recording}
+
+GCT
+
+ <programming, tool> A {test-coverage} tool by Brian Marick
+ <marick@testing.com>, based on {GNU C}. Version 1.4 was
+ ported to {Sun-3}, {Sun-4}, {RS/6000}, {68000}, {88000},
+ {HP-PA}, {IBM 3090}, {Ultrix}, {Convex}, {SCO} but not
+ {Linux}, {Solaris}, or {Microsoft Windows}.
+
+ Commercial support is available from the author (+1 217 351
+ 7228).
+
+ {(ftp://cs.uiuc.edu/pub/testing/gct.file/)}.
+
+ (1999-07-08)
+
+gd
+
+ <networking> The {country code} for Grenada.
+
+ (1999-01-27)
+
+GDA
+
+ <application> (Genetic Data Analysis) A program by Paul
+ O. Lewis and Dmitri Zaykin, designed to accompany the
+ referenced book, that computes linkage and hardy-weinberg
+ disequilibrium and some genetic distances, and provides
+ method-of-moments estimators for hierarchical F-statistics.
+
+ A command-line version by Chris Basten runs under Mac OS.
+
+ ["Genetic Data Analysis" by Bruce S. Weir, 1996, Sinaur
+ Associates].
+
+ (2009-10-15)
+
+GDB
+
+ <programming, tool> {GNU} debugger. The {FSF}'s {source-level
+ debugger} for {C}, {C++} and other languages. Developed by
+ many people but most recently Fred Fish <fnf@cygnus.com>, Stu
+ Grossman <grossman@cygnus.com> and {John Gilmore}
+ <gnu@cygnus.com> all of {Cygnus} Support. GDB fills the same
+ niche as {dbx}. Programs must be compiled to include
+ debugging symbols.
+
+ Version 4.11. Distributed under {GNU} {CopyLeft}. It runs on
+ most {Unix} variants, {VMS}, {VXWorks}, {Amiga} and {MS-DOS}.
+
+ FTP gdb-*.tar.[zZ] from a {GNU archive site}.
+ E-mail: <bug-gdb@gnu.org> (bug reports).
+
+ (1993-10-29)
+
+GDBPSK
+
+ {Gaussian Differential Binary Phase-Shift Keying}
+
+Gödel, Kurt
+
+ {Kurt Gödel}
+
+GDI
+
+ {Graphic Display Interface}
+
+GDMO
+
+ Guidelines for the Definition of Managed Objects.
+
+ A standard (ISO/IEC 10165-4) for defining data models on ASN.1
+
+GDPL
+
+ Generalized Distributed Programming Language. "GDPL - A
+ Generalized Distributed Programming Language", K. Ng et al,
+ Proc 4th Intl Conf Distrib Comp Sys, IEEE 1984, pp.69-78.
+
+GE
+
+ {General Electric}
+
+ge
+
+ <networking> The {country code} for Georgia.
+
+ (1999-01-27)
+
+GE-645
+
+ <computer> A computer built by {General Electric}, the
+ successor to the {GE-635}, designed to provide the extra CPU
+ features required by the {Multics} project.
+
+ The GE-645 was designed in 1965 by John Couleur and Edward
+ Glaser at MIT. It had several security levels and
+ instructions for handling {virtual memory}. Addressing used
+ an 18-bit segment in addition to the 18-bit address,
+ dramatically increasing the theoretical memory size and making
+ virtual memory easier to support.
+
+ Design of the GE-645's successor, the {GE-655}, started in 1967.
+
+ (2006-09-24)
+
+GEA
+
+ Graph Extended ALGOL. Extension of ALGOL 60 for graph
+ manipulation, on UNIVAC 1108. "A Language for Treating
+ Graphs", S. Crespi-Reghizzi et al, CACM 13(5) (May 1970).
+
+GEANT
+
+ A simulation, tracking and drawing package for HEP.
+
+GECOM
+
+ <language> A language for the {GE-255} series, like {COBOL}
+ with some {ALGOL} features added, in use around 1964-5. GECOM
+ included many of the early COBOL constructs including {report
+ writer} and {TABSOL} (programming by {truth table}). Another
+ (planned but unimplemented?) component was {FRINGE}.
+
+ [Sammet 1969, p. 329].
+
+ [Dates?]
+
+ (1996-09-15)
+
+GECOS
+
+ {GCOS}
+
+Gedanken
+
+ John Reynolds, 1970. "GEDANKEN - A Simple Typeless Language
+ Based on the Principle of Completeness and the Reference
+ Concept", J.C. Reynolds, CACM 13(5):308-319 (May 1970).
+
+ [{Jargon File}]
+
+gedanken
+
+ /g*-dahn'kn/ Ungrounded; impractical; not well-thought-out;
+ untried; untested.
+
+ "Gedanken" is a German word for "thought". A thought
+ experiment is one you carry out in your head. In physics, the
+ term "gedanken experiment" is used to refer to an experiment
+ that is impractical to carry out, but useful to consider
+ because it can be reasoned about theoretically. (A classic
+ gedanken experiment of relativity theory involves thinking
+ about a man in an elevator accelerating through space.)
+ Gedanken experiments are very useful in physics, but must be
+ used with care. It's too easy to idealise away some important
+ aspect of the real world in constructing the "apparatus".
+
+ Among hackers, accordingly, the word has a pejorative
+ connotation. It is typically used of a project, especially
+ one in artificial intelligence research, that is written up in
+ grand detail (typically as a Ph.D. thesis) without ever being
+ implemented to any great extent. Such a project is usually
+ perpetrated by people who aren't very good hackers or find
+ programming distasteful or are just in a hurry. A "gedanken
+ thesis" is usually marked by an obvious lack of intuition
+ about what is programmable and what is not, and about what
+ does and does not constitute a clear specification of an
+ algorithm. See also {AI-complete}, {DWIM}.
+
+geef
+
+ (Ostensibly from "gefingerpoken") {mung}.
+
+ See also {blinkenlights}.
+
+ [{Jargon File}]
+
+ (1995-01-18)
+
+geek
+
+ {computer geek}
+
+geek out
+
+ To temporarily enter techno-nerd mode while in a non-hackish
+ context, for example at parties held near computer equipment.
+ Especially used when you need to do or say something highly
+ technical and don't have time to explain: "Pardon me while I
+ geek out for a moment."
+
+ See {computer geek}, {propeller head}.
+
+ [{Jargon File}]
+
+ (1995-01-18)
+
+GEI
+
+ A German software engineering company.
+
+GE Information Services
+
+ <networking, company> One of the leading on-line services,
+ started on 1st October 1985, providing subscribers with
+ hundreds of special interest areas, computer hardware and
+ software support, award-winning multi-player games, the most
+ software files in the industry (over 200 000), worldwide news,
+ sports updates, business news, investment strategies, and
+ {Internet} {electronic mail} and fax (GE Mail). Interactive
+ conversations (Chat Lines) and {bulletin boards} (Round
+ Tables) with associated software archives are also provided.
+
+ GEnie databases (through the ARTIST gateway) allow users to
+ search the full text of thousands of publications, including
+ Dun & Bradstreet Company Profiles; a GEnie NewsStand with more
+ than 900 newspapers, magazines, and newsletters; a Reference
+ Center with information ranging from Agriculture to World
+ History; the latest in medical information from MEDLINE; and
+ patent and trademark registrations.
+
+ {(http://genie.com/)}. {Shopping 2000
+ (http://shopping2000.com/shopping2000/genie/)}.
+
+ Telephone: +1 (800) 638 9636.
+
+ TDD: +1 (800) 238 9172.
+
+ E-mail: <info@genie.geis.com>.
+
+ [Connection with: GE Information Services, Inc., a division of
+ General Electric Company, Headquarters: Rockville, Maryland,
+ USA?]
+
+ (1995-04-13)
+
+GEM
+
+ <operating system> One of the first commercially available
+ {GUIs}. Borrowing heavily from the {Macintosh} {WIMP}-style
+ interface it was available for both the {IBM} compatible
+ market (being packaged with {Amstrad}'s original {PC} series)
+ and more successfully for the {Atari} ST range. The PC
+ version was produced by {Digital Research} (more famous for
+ {DR-DOS}, their {MS-DOS} clone), and was not developed very
+ far. The Atari version, however, continued to be developed
+ until the early 1990s and the later versions supported 24-bit
+ colour modes, full colour {icons} and a nice looking sculpted
+ 3D interface.
+
+ (1997-01-10)
+
+gen
+
+ {generate}
+
+gender mender
+
+ <hardware> (Or "gender bender", "gender blender", "sex
+ changer", and even "homosexual adaptor") A cable connector
+ shell with either two male or two female connectors on it,
+ used to correct the mismatches that result when some {loser}
+ didn't understand the {EIA-232C} specification and the
+ distinction between {DTE} and {DCE}. Used especially for
+ EIA-232C parts in either the original {D-25} or the {IBM PC}'s
+ {D-9} connector.
+
+ There appears to be some confusion as to whether a "male
+ homosexual adaptor" has pins on both sides (is doubly male) or
+ sockets on both sides (connects two males).
+
+ [{Jargon File}]
+
+ (1995-04-16)
+
+Gene Amdahl
+
+ <person> A former {IBM} engineer who founded {Amdahl
+ Corporation}.
+
+ (1995-05-23)
+
+General Activities Simulation Program
+
+ <simulation, library> (GASP) A set of {discrete system}
+ {simulation} {subroutines} for {Fortran}.
+
+ (2003-09-27)
+
+General Aerodynamic Simulation Program
+
+ <simulation> (GASP)
+
+ {(http://aerosft.com/Gasp/References/main.php3)}.
+
+ [Summary?]
+
+ (2003-09-27)
+
+General Dynamics Canada Ltd
+
+ <company> A Canadian defence electronics company that makes direct
+ and indirect fire control {systems}, vehicle electronics,
+ reconnaissance vehicle surveillance systems, computerised laser
+ sight for anti-tank weapons, tactical {communication systems},
+ headquarters information distribution system, tactical voice and
+ distribution systems, acoustic signal processing, ASW mission
+ systems, sonobuoy {processors}, active sonar systems, towed array
+ sonar systems, tactical acoustic trainer, {Mil-Spec}
+ {electroluminiscent displays}, large multi-sensor displays,
+ coastal intrusion detection systems and {fibre-optic} distribution
+ systems.
+
+ The company was founded in 1948 as "Computing Devices Canada
+ Ltd.", part of the Ceridian group of companies. It was renamed
+ General Dynamics Canada Ltd. on 2002-01-01.
+
+ {General Dynamics Canada (http://www.gdcanada.com/)}.
+
+ (2013-01-20)
+
+General Electric
+
+ <company> (GE) A US company that manufactured computers from
+ 1956 until 1970, when it sold its computer division to
+ {Honeywell} and left the computer business. Notable GE
+ computers were the {GE-265}, which supported the {Dartmouth
+ Time-sharing System} (DTSS), and the {GE-645} used for
+ {Multics} development.
+
+ See also {GCOS}.
+
+ Not to be confused with the General Electric Company (GEC) in
+ the UK (where FOLDOC's first seeds were sown).
+
+ (2002-02-27)
+
+General Electric Comprehensive Operating System
+
+ {GCOS}
+
+General Magic
+
+ A software company based in Mountain View, California.
+ Products released in 1994 after four years in development
+ include: {Telescript} - a communications-oriented programming
+ language; {Magic Cap} - an {OOPS} designed for {PDAs}; and a
+ new, third generation {GUI}. {Motorola}'s {Envoy}, due for
+ release in the third quarter of 1994, will use {Magic Cap} as
+ its {OS}.
+
+ What {PostScript} did for cross-{platform}, device-independent
+ documents, Telescript aims to do for cross-{platform},
+ network-independent messaging. Telescript protects
+ programmers from many of the complexities of network
+ protocols.
+
+ Competitors for Magic Cap include {Microsoft}'s {Windows for
+ Pens}/{Winpad}, {PenPoint}, {Apple Computer}'s {Newton
+ Intelligence} and {GEOS} by {GeoWorks}.
+
+ {(http://genmagic.com/)}.
+
+ (1995-02-23)
+
+General Packet Radio Service
+
+ <communications> (GPRS) A {GSM} data transmission technique
+ that does not set up a continuous channel from a portable
+ terminal for the transmission and reception of data, but
+ transmits and receives data in {packets}. It makes very
+ efficient use of available radio spectrum, and users pay only
+ for the volume of data sent and received.
+
+ See also: {packet radio}.
+
+ (1999-09-12)
+
+General Protection Failure
+
+ (GPF, or General Protection Fault) An addressing error, caught
+ by the processor's {memory protection} hardware, that cannot
+ be attributed to any expected condition such as a {page
+ fault}.
+
+ (1995-03-28)
+
+General Protection Fault
+
+ {General Protection Failure}
+
+General Public Licence
+
+ <spelling> It's spelled "{General Public License}".
+
+ (In the UK, "licence" is a noun and "license" is a verb (like
+ "advice"/"advise") but in the US both are spelled "license").
+
+ (1995-05-12)
+
+General Public License
+
+ <legal> (GPL, note US spelling) The licence applied to most
+ {software} from the {Free Software Foundation} and the {GNU}
+ project and other authors who choose to use it.
+
+ The licences for most software are designed to prevent users
+ from sharing or changing it. By contrast, the GNU General
+ Public License is intended to guarantee the freedom to share
+ and change {free software} - to make sure the software is free
+ for all its users. The GPL is designed to make sure that
+ anyone can distribute copies of free software (and charge for
+ this service if they wish); that they receive source code or
+ can get it if they want; that they can change the software or
+ use pieces of it in new free programs; and that they know they
+ can do these things. The GPL forbids anyone to deny others
+ these rights or to ask them to surrender the rights. These
+ restrictions translate to certain responsibilities for those
+ who distribute copies of the software or modify it.
+
+ See also {General Public Virus}.
+
+ (1994-10-27)
+
+General Public Virus
+
+ <software, legal> A pejorative name for some versions of the
+ {GNU} project {copyleft} or {General Public License} (GPL),
+ which requires that any tools or {application programs}
+ incorporating copylefted code must be source-distributed on
+ the same terms as GNU code. Thus it is alleged that the
+ copyleft "infects" software generated with GNU tools, which
+ may in turn infect other software that reuses any of its code.
+
+ {Copyright} law limits the scope of the GPL to "programs
+ textually incorporating significant amounts of GNU code" so
+ GPL is only passed on if actual GNU source is transmitted.
+ This used to be the case with the {Bison} {parser} skeleton
+ until its licence was fixed.
+
+ {(http://org.gnu.de/manual/bison/html_chapter/bison_2.html#SEC2)}.
+
+ [{Jargon File}]
+
+ (1999-07-14)
+
+General Purpose Graphic Language
+
+ ["A General Purpose Graphic Language", H.E. Kulsrud, CACM
+ 11(4) (Apr 1968)].
+
+General Purpose Interface Bus
+
+ {IEEE 488}
+
+General Purpose Language
+
+ (GPL) An {ALGOL 60} variant with user-definable types and
+ operators.
+
+ [Sammet 1969, p. 195].
+
+ ["The GPL Language", J.V. Garwick et al, TER-05, CDC, Palo
+ Alto 1969].
+
+General Purpose Macro-generator
+
+ <language> (GPM) An early text-processing language similar to
+ {TRAC}, implemented on the {Atlas 2} by {Christopher
+ Strachey}.
+
+ ["A General Purpose Macrogenerator", C. Strachey, Computer J
+ 8(3):225-241, Oct 1965].
+
+ (2006-07-21)
+
+General Recursion Theorem
+
+ <mathematics> {Cantor}'s {theorem}, originally stated for
+ {ordinals}, which extends {inductive} proof to {recursive}
+ construction. The proof is by pasting together "attempts"
+ (partial solutions).
+
+ [Better explanation?]
+
+ (1995-06-15)
+
+generate
+
+ To produce something according to an {algorithm} or program or
+ set of rules, or as a (possibly unintended) {side effect} of
+ the execution of an algorithm or program.
+
+ The opposite of {parse}.
+
+ [{Jargon File}]
+
+ (1995-06-15)
+
+generation
+
+ An attempt to classify the degree of sophistication of
+ programming languages.
+
+ See {First generation language} -- {Fifth generation
+ language}.
+
+ (1995-06-15)
+
+Generic Array Logic
+
+ <hardware, integrated circuit> (GAL) A newer kind of
+ {Programmable Array Logic} based on {EEPROM} storage cells,
+ been pioneered by {Lattice}. GALs can be erased and
+ reprogrammed and usually replace a whole set of different PALs
+ (hence the name).
+
+ (1995-12-09)
+
+Generic Expert System Tool
+
+ <artificial intelligence> (GEST) An {expert system shell} for
+ {Symbolics} {Lisp machine}, with {frames}, {forward chaining},
+ {backward chaining} and {fuzzy logic}; written by {John
+ Gilmore}(?) at GA Tech.
+
+ Latest version: 4.0, as of 1995-04-16.
+
+ {(ftp://ftp.gatech.edu/pub/ai/gest.tar.Z)}.
+
+ (1995-04-16)
+
+generic identifier
+
+ <language, text> A string constituting the name of a {element}
+ in an {SGML} {document}.
+
+ (2001-01-31)
+
+genericity
+
+ <programming> The possibility for a language to provided
+ parameterised {modules} or types. E.g. List(of:Integer) or
+ List(of:People).
+
+ (1996-05-19)
+
+generic markup
+
+ <text> In computerised document preparation, a method of
+ adding information to the text indicating the logical
+ components of a document, such as paragraphs, headers or
+ footnotes. {SGML} is an example of such a system. Specific
+ instructions for layout of the text on the page do not appear
+ in the markup.
+
+ (1996-05-19)
+
+generic programming
+
+ <programming> A programming technique which aims to make
+ programs more adaptable by making them more general. Generic
+ programs often embody non-traditional kinds of {polymorphism};
+ ordinary programs are obtained from them by suitably
+ instantiating their parameters. In contrast with normal
+ programs, the parameters of a generic programs are often quite
+ rich in structure. For example they may be other programs,
+ {types} or {type constructors} or even programming
+ {paradigms}.
+
+ (1997-11-22)
+
+Generic Routing Encapsulation
+
+ <networking, protocol> (GRE) A {protocol} which allows an
+ arbitrary network protocol A to be transmitted over any other
+ arbitrary network protocol B, by encapsulating the {packets}
+ of A within GRE packets, which in turn are contained within
+ packets of B.
+
+ Defined in {RFC 1701} and {RFC 1702} (GRE over IP).
+
+ (1998-07-19)
+
+Generic Security Service Application Programming Interface
+
+ <security, programming> (GSS-API) An application level
+ interface ({API}) to system security services. It provides a
+ generic interface to services which may be provided by a
+ variety of different security mechanisms. {Vanilla} GSS-API
+ supports {security contexts} between two entities (known as
+ "principals").
+
+ GSS-API is a draft internet standard which is being developed
+ in the {Common Authentication Technology Working Group}
+ (cat-wg) of the {Internet Engineering Task Force} (IETF).
+
+ Initial specifications for GSS-API appeared in {RFC 1508} and
+ {RFC 1509}. Subsequent revisions appeared in several draft
+ standards documents.
+
+ {(http://dstc.qut.edu.au/~barton/work/project.html)}.
+
+ (1996-05-19)
+
+generic thunk
+
+ <programming> A software mechanism that allows a 16-bit
+ {Windows} application to load and call a {Win32} {DLL} under
+ {Windows NT} and {Windows 95}.
+
+ See also {flat thunk}, {universal thunk}.
+
+ (1999-04-05)
+
+generic type variable
+
+ <programming> (Also known as a "schematic type variable").
+ Different occurrences of a generic type variable in a type
+ expression may be instantiated to different types. Thus, in
+ the expression
+
+ let id x = x in
+ (id True, id 1)
+
+ id's type is (for all a: a -> a). The universal {quantifier}
+ "for all a:" means that a is a generic type variable. For the
+ two uses of id, a is instantiated to Bool and Int. Compare
+ this with
+
+ let id x = x in
+ let f g = (g True, g 1) in
+ f id
+
+ This looks similar but f has no legal {Hindley-Milner type}.
+ If we say
+
+ f :: (a -> b) -> (b, b)
+
+ this would permit g's type to be any instance of (a -> b)
+ rather than requiring it to be at least as general as (a ->
+ b). Furthermore, it constrains both instances of g to have
+ the same result type whereas they do not. The type variables
+ a and b in the above are implicitly quantified at the top
+ level:
+
+ f :: for all a: for all b: (a -> b) -> (b, b)
+
+ so instantiating them (removing the {quantifiers}) can only be
+ done once, at the top level. To correctly describe the type
+ of f requires that they be locally quantified:
+
+ f :: ((for all a: a) -> (for all b: b)) -> (c, d)
+
+ which means that each time g is applied, a and b may be
+ instantiated differently. f's actual argument must have a
+ type at least as general as ((for all a: a) -> (for all b:
+ b)), and may not be some less general instance of this type.
+ Type variables c and d are still implicitly quantified at the
+ top level and, now that g's result type is a generic type
+ variable, any types chosen for c and d are guaranteed to be
+ instances of it.
+
+ This type for f does not express the fact that b only needs to
+ be at least as general as the types c and d. For example, if
+ c and d were both Bool then any function of type (for all a: a
+ -> Bool) would be a suitable argument to f but it would not
+ match the above type for f.
+
+Genesia
+
+ An {expert system} developed by Electricite de France and
+ commercialised by {STERIA} (Paris).
+
+genetic algorithm
+
+ (GA) An {evolutionary algorithm} which generates each
+ individual from some encoded form known as a "chromosome" or
+ "genome". Chromosomes are combined or mutated to breed new
+ individuals. "Crossover", the kind of recombination of
+ chromosomes found in sexual reproduction in nature, is often
+ also used in GAs. Here, an offspring's chromosome is created
+ by joining segments choosen alternately from each of two
+ parents' chromosomes which are of fixed length.
+
+ GAs are useful for multidimensional optimisation problems in
+ which the chromosome can encode the values for the different
+ variables being optimised.
+
+ {Illinois Genetic Algorithms Laboratory
+ (http://GAL4.GE.UIUC.EDU/illigal.home.html)} (IlliGAL).
+
+ (1995-02-03)
+
+genetic algorithms
+
+ {genetic algorithm}
+
+genetic programming
+
+ <programming> (GP) A programming technique which extends the
+ {genetic algorithm} to the domain of whole computer programs.
+ In GP, populations of programs are genetically bred to solve
+ problems. Genetic programming can solve problems of system
+ identification, classification, control, robotics,
+ optimisation, game playing, and {pattern recognition}.
+
+ Starting with a primordial ooze of hundreds or thousands of
+ randomly created programs composed of functions and terminals
+ appropriate to the problem, the population is progressively
+ evolved over a series of generations by applying the
+ operations of Darwinian fitness proportionate reproduction and
+ crossover (sexual recombination).
+
+ (1995-03-31)
+
+GEnie Services
+
+ {GE Information Services}
+
+Genken Programming Language
+
+ <language> (GPL) A variant of {PL360} by K. Asai of the Japan
+ Atomic Energy Research Institute.
+
+ ["Experience With GPL", K. Asai, in Machine Oriented Higher
+ Level Languages, W. van der Poel, N-H 1974, pp. 371-376].
+
+ (1995-04-13)
+
+GENOVA
+
+ An old statistical package still in use on some {VM}
+ computers.
+
+ (1995-11-28)
+
+gensym
+
+ <library> /jen'sim/ (From the {MacLISP} for "generated
+ symbol") To invent a new name for something temporary, in
+ such a way that the name is almost certainly not in conflict
+ with one already in use.
+
+ The canonical form of a gensym is "Gnnnn" where nnnn
+ represents a number; any {LISP} {hacker} would recognise G0093
+ (for example) as a gensym. Gensymmed names are useful for
+ storing or uniquely identifying crufties.
+
+ [{Jargon File}]
+
+ (1999-10-31)
+
+Gensym Corporation
+
+ <company> A company that supplies software and services for
+ intelligent operations management. Common applications
+ include quality management, process optimisation, dynamic
+ scheduling, network management, energy and environmental
+ management, and process modelling and simulation.
+
+ Their products include {G2}.
+
+ {(http://gensym.com/)}.
+
+ (1999-10-31)
+
+Gensym Standard Interface
+
+ <programming> (GSI) A set of {C} libraries and programming
+ tools used to interface {G2} to external systems.
+ Commercially available bridges are available to {SCADA}
+ systems and {PLCs}.
+
+ (1997-02-11)
+
+Gentleman's Portable Coroutine System
+
+ A {coroutine} package in {Fortran}.
+
+ ["A Portable Coroutine System", W.M. Gentleman, Info Proc 71,
+ C.V. Freiman ed, 1972].
+
+ (1995-02-01)
+
+GEN-X
+
+ An expert system developed by General Electric.
+
+Geographical Information System
+
+ {Geographic Information System}
+
+ [Which is more common?]
+
+ (1995-12-21)
+
+Geographic Information System
+
+ <application> (GIS) A computer system for capturing, storing,
+ checking, integrating, manipulating, analysing and displaying
+ data related to positions on the Earth's surface. Typically,
+ a GIS is used for handling maps of one kind or another. These
+ might be represented as several different layers where each
+ layer holds data about a particular kind of feature
+ (e.g. roads). Each feature is linked to a position on the
+ graphical image of a map.
+
+ Layers of data are organised to be studied and to perform
+ statistical analysis (i.e. a layer of customer locations could
+ include fields for Name, Address, Contact, Number, Area).
+ Uses are primarily government related, town planning, local
+ authority and public utility management, environmental,
+ resource management, engineering, business, marketing, and
+ distribution.
+
+ {GIS dictionary
+ (http://geo.ed.ac.uk/root/agidict/html/welcome.html)}.
+
+ {(http://ncl.ac.uk/~ngraphic/wotzagis.html)}.
+
+ (1995-12-21)
+
+geometric mean
+
+ <mathematics> The Nth {root} of the {product} of N numbers.
+
+ If each number in a list of numbers was replaced with their
+ geometric mean, then multiplying them all together would still
+ give the same result. The geometric mean thus gives an
+ average "factor" in a context where numbers are multiplied
+ together, e.g. compound interest.
+
+ {Wolfram (http://mathworld.wolfram.com/GeometricMean.html)}.
+
+ (2007-03-16)
+
+GEORGE
+
+ <language> One of the earliest programming languages,
+ developed by Charles Hamblin in 1957. GEORGE was a {stack
+ oriented language}, using {reverse Polish notation}. It was
+ implemented on the {English Electric} {DEUCE}.
+
+ ["GEORGE: A Semi-Translation Programming Scheme for the DEUCE,
+ Programming and Operations Manual", C. L. Hamblin, U New S
+ Wales, 1958].
+
+ ["Computer Languages", C.L. Hamblin, Aust J Sci 20(5):135-139,
+ Dec 1957 and Aust Comp J 17(4):195-198, Nov 1985]
+
+ (2007-03-18)
+
+GEORGE 3
+
+ <operating system> The {operating system} for the {ICL 1900}
+ {mainframe}. Lots of two-letter commands.
+
+ (2003-09-20)
+
+George Boole
+
+ <person> 1815-11-02 - 2008-05-11 22:58
+ best known for his contribution to symbolic logic ({Boolean
+ Algebra}) but also active in other fields such as probability
+ theory, {algebra}, analysis, and differential equations. He
+ lived, taught, and is buried in Cork City, Ireland. The Boole
+ library at University College Cork is named after him.
+
+ For centuries philosophers have studied logic, which is
+ orderly and precise reasoning. George Boole argued in 1847
+ that logic should be allied with mathematics rather than with
+ philosophy.
+
+ Demonstrating logical principles with mathematical symbols
+ instead of words, he founded {symbolic logic}, a field of
+ mathematical/philosophical study. In the new discipline he
+ developed, known as {Boolean algebra}, all objects are divided
+ into separate classes, each with a given property; each class
+ may be described in terms of the presence or absence of the
+ same property. An electrical circuit, for example, is either
+ on or off. Boolean algebra has been applied in the design of
+ {binary} computer circuits and telephone switching equipment.
+ These devices make use of Boole's two-valued (presence or
+ absence of a property) system.
+
+ Born in Lincoln, Lincolnshire, UK, George Boole was the son of
+ a tradesman and was largely self-taught. He began teaching at
+ the age of 16 to help support his family. In his spare time
+ he read mathematical journals and soon began to write articles
+ for them. By the age of 29, Boole had received a gold medal
+ for his work from the British Royal Society. His
+ 'Mathematical Analysis of Logic', a pamphlet published in
+ 1847, contained his first statement of the principles of
+ symbolic logic. Two years later he was appointed professor of
+ mathematics at Queen's College in Ireland, even though he had
+ never studied at a university.
+
+ He died in Ballintemple, Ireland, on 1864-12-08.
+
+ {Compton's Encyclopedia Online
+ (http://comptons2.aol.com/encyclopedia/ARTICLES/00619_A.html)}.
+
+ (1998-11-19)
+
+Georg Simon Ohm
+
+ <person> (1789-1854) A German physicist who became Professor
+ of Physics at Munich University, after whom the unit of
+ electrical resistance was named.
+
+ (2003-12-02)
+
+GEOS
+
+ A small windowing, {microkernel} (less than 64 kbytes long)
+ operating system written in heavily {bum}med {assembly
+ language} for {MS-DOS} computers. It {multitasks} rather
+ nicely on a 6 Mhz {Intel 80286} with at least 512K memory.
+
+ It was adapted to {PDAs} by adding pen recognition, which
+ doesn't work very well.
+
+ {Usenet} newsgroup: {news:comp.os.geos}.
+
+ (1995-01-21)
+
+GEPURS
+
+ An early system on the {IBM 701}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1995-01-21)
+
+Gerald
+
+ ["Gerald: An Exceptional Lazy Functional Programming
+ Language", A.C. Reeves et al, in Functional Programming,
+ Glasgow 1989, K. Davis et al eds, Springer 1990].
+
+ (1995-01-10)
+
+Gerald Sussman
+
+ <person> (Gerald J. Sussman, Jerry) A noted {hacker} at {MIT}
+ and one of the developers of {SCHEME} and {6.001}.
+
+ {(http://martigny.ai.mit.edu/~gjs/gjs.html)}.
+
+ (1996-11-29)
+
+German
+
+ <human language> \j*r'mn\ A human language written (in latin
+ alphabet) and spoken in Germany, Austria and parts of
+ Switzerland.
+
+ German writing normally uses four non-{ASCII} characters: "ä", "ö"
+ and "ü" have "umlauts" (two dots over the top) and "ß" is a
+ double-S ("scharfes S") which looks like the Greek letter beta
+ (except in capitalised words where it should be written "SS").
+ These can be written in ASCII in several ways, the most common are
+ ae, oe ue AE OE UE ss or sz and the {TeX} versions "a "o "u "A "O
+ "U "s.
+
+ See also {ABEND}, {blinkenlights}, {DAU}, {DIN}, {gedanken},
+ {GMD}, {kluge}.
+
+ {Usenet} newsgroup: {news:soc.culture.german}.
+ {(ftp://src.doc.ic.ac.uk/usenet/news-info/soc.answers/german-faq)},
+ {(ftp://alice.fmi.uni-passau.de/pub/dictionaries/german.dat.Z)}.
+
+ (1995-03-31)
+
+GEST
+
+ {Generic Expert System Tool}
+
+Get a life!
+
+ <abuse> Standard way of suggesting that someone has succumbed
+ to terminal {geek}dom. Often heard on {Usenet}, especially as
+ a way of suggesting that the target is taking some obscure
+ issue of {theology} too seriously. This exhortation was
+ popularised by William Shatner on a "Saturday Night Live"
+ episode in a speech that ended "Get a *life*!", but some
+ respondents believe it to have been in use before then. It
+ was certainly in wide use among hackers for at least five
+ years before achieving mainstream currency in early 1992.
+
+ [{Jargon File}]
+
+ (1995-01-18)
+
+Get a real computer!
+
+ <jargon> A typical {hacker} response to news that somebody is
+ having trouble getting work done on a {toy} system or {bitty
+ box}.
+
+ The threshold for "real computer" rises with time. As of
+ mid-1993 it meant {multi-tasking}, with a {hard disk}, and an
+ {address space} bigger than 16 {megabytes}. At this time,
+ according to {GLS}, computers with character-only displays
+ were verging on "unreal". In 2001, a real computer has a one
+ {gigahertz} processor, 128 MB of {RAM}, 20 GB of hard disk,
+ and runs {Linux}.
+
+ [{Jargon File}]
+
+ (2001-06-22)
+
+get.com
+
+ <operating system> A command which can be created using debug
+ in {MS DOS} to set the errorlevel according to which key is
+ pressed. The errorlevel can then be interrogated from a
+ {batch file} by a series of commands like this:
+
+ get
+ if errorlevel 118 goto E118
+ if errorlevel 117 goto E117
+ if errorlevel 116 goto E116
+ if errorlevel 115 goto E115
+ if errorlevel 114 goto E114
+
+ where E118 etc. are labels in the batch file.
+
+ (1996-02-01)
+
+getty
+
+ <operating system> A {Unix} program which sets terminal type,
+ modes, speed and line discipline for a {serial port}, and is
+ used in the login process.
+
+ (1996-12-08)
+
+gf
+
+ <networking> The {country code} for French Guiana.
+
+ (1999-01-27)
+
+GFDL
+
+ {GNU Free Documentation License}
+
+g file
+
+ <messaging> (General file) A mid 1980s term for text files,
+ usually short and unpublished found on {BBSs}. The g-files
+ section on BBSs contain text files of general interest,
+ viewable on-line; this is as opposed to files in the file
+ transfer section, which are generally downloadable but not
+ viewable on-line.
+
+ When used on the {Internet}, this term generally refers to the
+ types of file most often associated with old BBSs such as
+ instructions on {phreak}ing or making bombs.
+
+ (1996-06-20)
+
+GFLOPS
+
+ {gigaflops}
+
+GFR
+
+ {Grim File Reaper}
+
+GFS
+
+ {Grandfather, Father, Son}
+
+gh
+
+ <networking> The {country code} for Ghana.
+
+ (1999-01-27)
+
+GHC
+
+ <language>
+
+ 1. {Guarded horn clauses}.
+
+ 2. {Glasgow Haskell Compiler}.
+
+ (1999-01-05)
+
+ghetto code
+
+ <humour, programming> A particularly inelegant and obviously
+ suboptimal section of {code} that still meets the original
+ requirements.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2014-05-14)
+
+ghost
+
+ <chat> (Or "zombie") The image of a user's session on {IRC}
+ and similar systems, left when the session has been terminated
+ (properly or, often, improperly) but the server (or the
+ network at large) believes the connection is still active and
+ belongs to a real user.
+
+ Compare {clonebot}.
+
+ (1997-04-07)
+
+Ghostscript
+
+ <graphics, tool> The {GNU} {interpreter} for {PostScript} and
+ {PDF}, with {previewers} for serval systems and many {fonts}.
+ Ghostscript was originally written by L. Peter Deutsch
+ <ghost@aladdin.com> of {Aladdin Enterprises}. The first
+ public release was v1.0 on 1988-08-11.
+
+ Latest version: 8.11, as of 2003-08-29.
+
+ {GNU Home (http://gnu.org/software/ghostscript/)}.
+
+ {News & community (http://ghostscript.com/)}.
+
+ (2003-09-24)
+
+ghostview
+
+ An {X Window System} interface to the {ghostscript}
+ {PostScript} {interpreter}.
+
+GHz
+
+ {GigaHertz}
+
+GI
+
+ {generic identifier}
+
+gi
+
+ <networking> The {country code} for Gibraltar.
+
+ (1999-01-27)
+
+Gibson, William
+
+ {William Gibson}
+
+gid
+
+ 1. <operating system> {group identifier}.
+
+ 2. <filename extension> {global index}.
+
+ (1997-01-30)
+
+GIF
+
+ {Graphics Interchange Format}
+
+GIF89
+
+ {Graphics Interchange Format}
+
+GIF89a
+
+ {animated GIF}
+
+GIFF
+
+ Do you mean {GIF} or is this some kind of {IFF}?
+
+gig
+
+ {gigabyte}
+
+giga-
+
+ {prefix}
+
+gigabit
+
+ <unit> 2^30 {bits}, 1,073,741,824 bits.
+
+ See {prefix}.
+
+ (1995-11-12)
+
+gigabits per second
+
+ <unit> (Gbps) A unit of information transfer rate equal to one
+ billion {bits} per second. Note that, while a {gigabit} is
+ defined as a power of two (2^30 bits), a gigabit per second is
+ defined as a power of ten (10^9 bits per second, which is
+ slightly less) than 2^30).
+
+ (2004-02-10)
+
+gigabyte
+
+ <unit, data> (GB or colloquially "gig") A unit of {data} equal to
+ one billion {bytes} but see {binary prefix} for other definitions.
+ A gigabyte is 1000^3 {bytes} or 1000 {megabytes}.
+
+ A human gene sequence (including all the redundant codons)
+ contains about 1.5 gigabytes of data.
+
+ 1000 gigabytes are one {terabyte}.
+
+ See {prefix}.
+
+ {Human genome data content
+ (http://bitesizebio.com/articles/how-much-information-is-stored-in-the-human-genome/)}.
+
+ (2013-11-03)
+
+gigaflop
+
+ {gigaflops}
+
+gigaflops
+
+ <unit> (GFLOPS) One thousand million (10^9) {floating point}
+ operations per second.
+
+ One of them is strictly "one gigaflops" in the same way that
+ one mile per hour isn't 1 MP.
+
+ See {prefix}.
+
+ (1998-04-19)
+
+GigaHertz
+
+ <unit> (GHz) Billions of cycles per second.
+
+ The unit of frequency used to measure the {clock rate} of
+ modern {digital logic}, including {microprocessors}.
+
+ (2001-05-14)
+
+GIGO
+
+ {Garbage In, Garbage Out}
+
+gilley
+
+ <humour> ({Usenet}) The unit of analogical bogosity.
+ According to its originator, the standard for one gilley was
+ "the act of bogotoficiously comparing the shutting down of
+ 1000 machines for a day with the killing of one person". The
+ milligilley has been found to suffice for most normal
+ conversational exchanges.
+
+ (1995-03-17)
+
+gillion
+
+ <unit> /gil'y*n/ or /jil'y*n/ (From {giga-} by analogy with
+ mega/million and tera/trillion) 10^9.
+
+ Same as an American billion or a British "milliard". How one
+ pronounces this depends on whether one speaks {giga-} with a
+ hard or soft "g".
+
+ [{Jargon File}]
+
+ (1995-03-17)
+
+Gilmore, John
+
+ {John Gilmore}
+
+GIM-1
+
+ Generalized Information Management Language. Nelson, Pick,
+ Andrews. Proc SJCC 29:169-73, AFIPS (Fall 1966).
+
+GIN
+
+ A special-purpose {macro assembler} used to build the {GEORGE
+ 3} {operating system} for {ICL1900} series computers.
+
+ (1994-11-02)
+
+GINA
+
+ Generic Interactive Application. An {application framework}
+ based on {Common Lisp} and {OSF}/{Motif}, designed to simplify
+ the construction of graphical interactive applications.
+
+ GINA consists of {CLM} - a language binding for {OSF}/{Motif}
+ in {Common Lisp}; the GINA application framework - a {class
+ library} in {CLOS}; the GINA interface builder - an
+ interactive tool implemented with GINA to design {Motif}
+ windows.
+
+ Version 2.2 requires {OSF}/{Motif} 1.1 or better, {Common
+ Lisp} with {CLX}, {CLOS}, {PCL} and processes. It runs with
+ {Franz Allegro}, {Lucid}, {CMU CL} and {Symbolics} {Genera}.
+
+ {Germany (ftp://ftp.gmd.de/gmd/gina)}. {N. America
+ (ftp://export.lcs.mit.edu/contrib/)}. Mailing list:
+ gina-users-request@gmdzi.gmd.de.
+
+ (1994-11-02)
+
+Ginger
+
+ A simple {functional language} from the {University of
+ Warwick} with parallel constructs.
+
+ (1994-11-02)
+
+GIP
+
+ 1. General Interpretive Programme.
+
+ A 1956 interpreted language for the {English Electric}
+ {DEUCE}, with {array} operations and an extensive library of
+ numerical methods.
+
+ ["Interpretive and Brick Schemes, with Special Reference to
+ Matrix Operations", English Electric COmpany, DEUCE News
+ No. 10 (1956)].
+
+ (1994-11-02)
+
+ 2. An erroneous singular of {GIPS}.
+
+GIPS
+
+ /gips/ or /jips/ [Analogy with {MIPS}] Giga-Instructions per
+ Second (or possibly "Gillions of Instructions per Second"; see
+ {gillion}).
+
+ In 1991, this was used of only a handful of highly parallel
+ machines and one sequential processor built with {Josephson
+ devices}. {DEC}'s {Alpha AXP 21164} processor was the first
+ commercially available 1 GIPS sequential processor (7 Sep
+ 1994). Compare {KIPS}.
+
+ ["A 1-GIPS Josephson Data Processor", Yuji Hatano et al, IEEE
+ J Solid State Circuits, vol 26, 6, June 1991]
+
+ [{Jargon File}]
+
+ (1994-11-02)
+
+GIRL
+
+ Graph Information Retrieval Language. A language for handling
+ {directed graphs}.
+
+ ["Graph Information Retrieval Language", S. Berkowitz, Report
+ 76-0085, Naval Ship Res Dev Center, (Feb 1976)].
+
+ (1994-11-02)
+
+GIS
+
+ {Geographical Information System}
+
+Giuseppe Peano
+
+ <person, mathematics, logic> (1858-08-27 - 1932-04-20) An Italian
+ mathematician who wrote over 200 books and papers, was a founder
+ of {mathematical logic} and {set theory} and taught at the
+ University of Turin. He contributed to mathematical {analysis},
+ {logic}, the teaching of {calculus}, {differential equations},
+ {vector analysis} and the axiomatization of mathematics. The
+ standard {axiomatization} of the {natural numbers} is named {Peano
+ arithmetic} or the {Peano axioms} after him. He also invented the
+ {Peano curve}, an early example of a {fractal}.
+
+ (2013-03-23)
+
+GIYF
+
+ <chat, WWW> Google Is Your Friend. See {STFW}.
+
+ (2014-05-23)
+
+GKS
+
+ {Graphical Kernel System}
+
+GKS-3D
+
+ The three-dimensional version of {GKS}, a {standard} for
+ graphics I/O ({ISO} 8805).
+
+ (1994-11-02)
+
+GL
+
+ Graphics Language. A graphics package from {Silicon
+ Graphics}.
+
+gl
+
+ <networking> The {country code} for Greenland.
+
+ (1999-01-27)
+
+Glammar
+
+ A pattern transformation language for text-to-text
+ translation. Used for compiler writing and linguistics.
+
+ {(ftp://phoibos.cs.kun.nl/pub/GLASS/glammar.tar.Z)}.
+
+glark
+
+ /glark/ To figure something out from context. "The System III
+ manuals are pretty poor, but you can generally glark the
+ meaning from context." Interestingly, the word was originally
+ "glork"; the context was "This gubblick contains many
+ nonsklarkish English flutzpahs, but the overall pluggandisp
+ can be glorked [sic] from context" (David Moser, quoted by
+ Douglas Hofstadter in his "Metamagical Themas" column in the
+ January 1981 "Scientific American"). It is conjectured that
+ hackish usage mutated the verb to "glark" because {glork} was
+ already an established jargon term.
+
+ Compare {grok}, {zen}.
+
+ [{Jargon File}]
+
+Glasgow Haskell Compiler
+
+ <language> (GHC) A {Haskell} 1.2 compiler written in Haskell
+ by the AQUA project at {Glasgow University}, headed by Simon
+ Peyton Jones <simonpj@dcs.glasgow.ac.uk> throughout the 1990's
+ [started?]. GHC can generate either {C} or {native code} for
+ {SPARC}, {DEC} {Alpha} and other platforms. It can take
+ advantage of features of {gcc} such as global register
+ variables and has an extensive set of optimisations.
+
+ GHC features an extensible I/O system based on a "{monad}",
+ in-line {C} code, fully fledged {unboxed} data types,
+ incrementally-updatable {arrays}, {mutable reference types},
+ {generational garbage collector}, {concurrent} {threads}.
+ Time and space {profiling} is also supported.
+
+ It requires {GNU} gcc 2.1+ and {Perl}.
+
+ GHC runs on {Sun-4}, {DEC Alpha}, {Sun-3}, {NeXT}, {DECstation},
+ {HP-PA} and {SGI}.
+
+ Latest version: 4.01, as of 1998-11-30.
+
+ {Glasgow FTP
+ (ftp://ftp.dcs.glasgow.ac.uk/pub/haskell/glasgow/)}. {Yale
+ (ftp://nebula.cs.yale.edu/pub/haskell/glasgow/)}. {Sweden
+ (ftp://ftp.cs.chalmers.se/pub/haskell/glasgow/)}.
+
+ {Papers (ftp://ftp.dcs.glasgow.ac.uk/pub/glasgow-fp)}.
+
+ ["Imperative functional programming", Peyton Jones & Wadler,
+ POPL '93].
+
+ ["Unboxed data types as first-class citizens", Peyton Jones &
+ Launchbury, FPCA '91].
+
+ ["Profiling lazy functional languages", Sansom & Peyton Jones,
+ Glasgow workshop '92].
+
+ ["Implementing lazy functional languages on stock hardware",
+ Peyton Jones, Journal of Functional Programming, Apr 1992].
+
+ E-mail: <glasgow-haskell-request@dcs.glasgow.ac.uk>.
+
+ (1999-01-05)
+
+GLASS
+
+ General LAnguage for System Semantics.
+
+ An {Esprit} project at the {University of Nijmegen}.
+
+ {(ftp://phoibos.cs.kun.nl/pub/GLASS)}.
+
+ (1995-01-25)
+
+glass
+
+ (IBM) {silicon}.
+
+ [{Jargon File}]
+
+glass box testing
+
+ {white box testing}
+
+glassfet
+
+ /glas'fet/ [Analogy with {MOSFET}] (or "{firebottle}") A
+ humorous way to refer to a {vacuum tube}.
+
+ [{Jargon File}]
+
+glass tty
+
+ /glas T-T-Y/ or /glas ti'tee/ A terminal that has a display
+ screen but which, because of hardware or software limitations,
+ behaves like a teletype or some other printing terminal,
+ thereby combining the disadvantages of both: like a printing
+ terminal, it can't do fancy display hacks, and like a display
+ terminal, it doesn't produce hard copy. An example is the
+ early "dumb" version of Lear-Siegler ADM 3 (without cursor
+ control). See {tube}, {tty}; compare {dumb terminal}, {smart
+ terminal}. See "{TV Typewriters}" for an interesting true
+ story about a glass tty.
+
+GLB
+
+ {greatest lower bound}
+
+glibc
+
+ {GNU C Library}
+
+Glish
+
+ Glish is an interpretive language for building loosely-coupled
+ distributed systems from modular, event-oriented programs.
+ Written by Vern Paxson <vern@ee.lbl.gov>. These programs are
+ written in conventional languages such as C, C++, or Fortran.
+
+ Glish scripts can create local and remote processes and
+ control their communication. Glish also provides a full,
+ array-oriented programming language (similar to {S}) for
+ manipulating binary data sent between the processes. In
+ general Glish uses a centralised communication model where
+ interprocess communication passes through the Glish
+ {interpreter}, allowing dynamic modification and rerouting of
+ data values, but Glish also supports point-to-point links
+ between processes when necessary for high performance.
+
+ Version 2.4.1 includes an {interpreter}, {C++} {class} library
+ and user manual. It requires C++ and there are ports to
+ {SunOS}, {Ultrix}, an {HP/UX} (rusty).
+
+ {(ftp://ftp.ee.lbl.gov/glish/glish-2.4.1.tar.Z)}.
+
+ ["Glish: A User-Level Software Bus for Loosely-Coupled
+ Distributed Systems," Vern Paxson and Chris Saltmarsh,
+ Proceedings of the 1993 Winter USENIX Conference, San Diego,
+ CA, January, 1993].
+
+ (1993-11-01)
+
+Glisp
+
+ Generalized LISP. D.C. Smith, Aug 1990. A coordinated set of
+ high-level syntaxes for Common LISP. Contains Mlisp, Plisp
+ and ordinary LISP, with an extensible framework for adding
+ others. Written in Plisp.
+
+ {(ftp://bric-a-brac.apple.com/dts/mac/lisp)}.
+
+glitch
+
+ /glich/ [German "glitschen" to slip, via Yiddish "glitshen",
+ to slide or skid] 1. (Electronics) When the inputs of a
+ circuit change, and the outputs change to some {random} value
+ for some very brief time before they settle down to the
+ correct value. If another circuit inspects the output at just
+ the wrong time, reading the random value, the results can be
+ very wrong and very hard to debug (a glitch is one of many
+ causes of electronic {heisenbugs}).
+
+ 2. A sudden interruption in electric service, sanity,
+ continuity, or program function. Sometimes recoverable. An
+ interruption in electric service is specifically called a
+ "power glitch" (or {power hit}), of grave concern because it
+ usually crashes all the computers. See also {gritch}.
+
+ 2. [Stanford] To scroll a display screen, especially several
+ lines at a time. {WAITS} terminals used to do this in order
+ to avoid continuous scrolling, which is distracting to the
+ eye.
+
+ 4. Obsolete. Same as {magic cookie}.
+
+ [{Jargon File}]
+
+glob
+
+ <file system, programming> /glob/ A mechanism that returns a list
+ of {pathnames} that match a pattern containing {wild card}
+ characters. Globbing was available in early versions of {Unix}
+ and, in more limited form, in {Microsoft Windows}.
+
+ The characters are:
+
+ * = zero or more characters, e.g. "probab*" would match
+ probabilistic, probabilistically, probabilities, probability,
+ probable, probably.
+
+ ? = any single character, e.g. "b?g" would match bag, big, bog,
+ bug.
+
+ [] any of the enclosed characters, e.g. "b[ao]g" would match bag,
+ bog (not on Windows).
+
+ These have become sufficiently pervasive that hackers use them in
+ written messages. E.g. "He said his name was [KC]arl" (expresses
+ ambiguity). "I don't read talk.politics.*" (any of the
+ talk.politics subgroups on {Usenet}). Other examples are given
+ under the entry for {X}.
+
+ Later Unix shells introduced the {x,y,z} syntax which expands to a
+ comma-separated list of alternatives, thus foo{baz,qux} would
+ expand to "foobaz" and "fooqux". This differs from a glob because
+ it generates a list of all possible expansions, rather than
+ matching against existing files.
+
+ Glob patterns are similar, but not identical, to {regular
+ expressions}.
+
+ "glob" was a subprogram that expanded wild cards in archaic
+ pre-{Bourne} versions of the {Unix} {shell}. It is also a
+ {bulit-in function} in {Perl}.
+
+ (2014-08-22)
+
+global index
+
+ <filename extension> (gid) The filename extension of a
+ {Windows 95} "global index" file. .gid files are created by
+ the help {browser} internal to Windows 95 (also available for
+ other Windows versions) for WinHelp files ({hlp}), as well as
+ for storing user preferences, such as window position.
+
+ (1997-01-30)
+
+globalisation
+
+ {internationalisation}
+
+Global Network Navigator
+
+ (GNN) A collection of free services provided by {O'Reilly &
+ Associates}.
+
+ The Whole Internet Catalog describes the most useful Net
+ resources and services with live links to those resources.
+ The GNN Business Pages list companies on the Internet. The
+ Internet Help Desk provides help in starting {Internet}q
+ exploration. NetNews is a weekly publication that reports on
+ the news of the {Internet}, with weekly articles on Internet
+ trends and special events, sports, weather, and comics. There
+ are also pages aobut travel and personal finance.
+
+ {Home page (http://gnn.com/)}.
+
+ E-mail: <support@gnn.com>.
+
+ Telephone: (800) 998 9938 (USA), +1 (707) 829 0515 (outside
+ USA).
+
+ (1995-01-10)
+
+Global Positioning System
+
+ <communications> (GPS) A system for determining postion on the
+ Earth's surface by comparing radio signals from several
+ satellites. When completed the system will consist of 24
+ satellites equipped with radio transmitters and atomic clocks.
+
+ Depending on your geographic location, the GPS receiver
+ samples data from up to six satellites, it then calculates the
+ time taken for each satellite signal to reach the GPS
+ receiver, and from the difference in time of reception,
+ determines your location.
+
+ ["Global Positioning by Satellite"? Precison? Coverage? Web
+ page?]
+
+ (1998-02-10)
+
+Global System for Mobile Communications
+
+ <communications> (GSM, originally "Groupe de travail Sp?ciale
+ pour les services Mobiles") One of the major {standards} for
+ digital {cellular} communications, in use in over 60 countries
+ and serving over one billion subscribers. The GSM standard is
+ currently used in the 900 MHz, 1800 MHz and 1900 MHz bands.
+
+ {GPRS} allows {circuit switched} data communications over GSM,
+ and is widely used for {World Wide Web} and {electronic mail}
+ access from cellular devices.
+
+ {GSM World (http://gsmworld.com/)}.
+
+ (2005-01-26)
+
+glork
+
+ /glork/ 1. Used as a name for just about anything.
+
+ See {foo}.
+
+ 2. Similar to {glitch}, but usually used reflexively. "My
+ program just glorked itself."
+
+ See also {glark}.
+
+ [{Jargon File}]
+
+GLOS
+
+ {Graphics Language Object System}.
+
+GLOW
+
+ <language> A POP-11 variant with {lexical scope}.
+
+ Available from Andrew Arnblaster, Bollostraat 6, B-3140
+ Keerbergen, Belgium, for Mac or {MS-DOS}.
+
+ [Byte's UK edition, May 1992, p.84UK-8].
+
+ (1997-02-07)
+
+GLS
+
+ {Guy Lewis Steele, Jr.}
+
+GLU
+
+ <language> A practical {coarse grain} implementation of the
+ Lucid dataflow language for networks.
+
+ (1998-03-07)
+
+glue
+
+ <jargon> A generic term for any interface logic or {protocol}
+ that connects two component blocks. For example, {Blue Glue}
+ is IBM's SNA protocol, and hardware designers call anything
+ used to connect large VLSI's or circuit blocks "glue logic".
+
+ [{Jargon File}]
+
+ (1999-02-22)
+
+glue language
+
+ <language> Any language, usually a {scripting language}, used
+ to write {glue} to integrate tools and other programs to solve
+ some problem.
+
+ (1999-02-22)
+
+glyph
+
+ <character> An {image} used in the visual representation of
+ {characters}; roughly speaking, how a character looks. A
+ {font} is a set of glyphs.
+
+ In the simple case, for a given {font} ({typeface} and size),
+ each character corresponds to a single glyph but this is not
+ always the case, especially in a language with a large
+ alphabet where one character may correspond to several glyphs
+ or several characters to one glyph (a {character encoding}).
+
+ Usually used in reference to {outline fonts}, in particular
+ {TrueType}.
+
+ (1998-05-31)
+
+Glypnir
+
+ 1966. An ALGOL-like language with parallel extensions.
+ Similar to Actus. "GLYPNIR - A Programming Language for the
+ Illiac IV", D.H. Lawrie et al, CACM 18(3) (Mar 1975).
+
+gm
+
+ <networking> The {country code} for Gambia.
+
+ (1999-01-27)
+
+GMAP
+
+ {GCOS Macro Assembler Program}
+
+GMD
+
+ <company> Full name: "GMD - Forschungszentrum
+ Informationstechnik GmbH" (German National Research Center for
+ Information Technology).
+
+ Before April 1995, GMD stood for "Gesellschaft für Mathematik
+ und Datenverarbeitung" - National Research Center for Computer
+ Science, it is retained for historical reasons.
+
+ {(http://gmd.de/GMDHome.english.html)}.
+
+ Address: D-53754 Sankt Augustin, Germany.
+
+ (1995-04-10)
+
+GMD Toolbox for Compiler Construction
+
+ (Or Cocktail) A huge set of compiler building tools for
+ {MS-DOS}, {Unix} and {OS/2}.
+
+ parser generator (LALR -> C, Modula-2), documentation, parser
+ generator (LL(1) -> C, Modula-2), tests, scanner generator (->
+ C, Modula-2), tests translator (Extended BNF -> BNF),
+ translator (Modula-2 -> C), translator (BNF (yacc) -> Extended
+ BNF), examples abstract syntax tree generator,
+ attribute-evaluator generator, code generator
+
+ Latest version: 9209.
+
+ The {MS-DOS} version requires DJ Delorie's DOS extender
+ ({go32}) and the {OS/2} version requires the {emx} programming
+ environment.
+
+ {(ftp://ftp.karlsruhe.gmd.de/pub/cocktail/dos)}. {OS/2 FTP
+ (ftp://ftp.eb.ele.tue.nl/pub/src/cocktail/dos-os2.zoo)}.
+
+ Mailing list: listserv@eb.ele.tue.nl (subscribe to Cocktail).
+ E-mail: Josef Grosch <grosch@karlsruhe.gmd.de>, Willem Jan
+ Withagen <wjw@eb.ele.tue.nl> (OS/2).
+
+ (1992-01-01)
+
+GMT
+
+ {Universal Time 1}
+
+gn
+
+ <networking> The {country code} for Guinea.
+
+ (1999-01-27)
+
+gnarly
+
+ <jargon> /nar'lee/ Both obscure and {hairy}. "{Yow}! - the
+ tuned {assembler} implementation of {BitBlt} is really
+ gnarly!" From a similar but less specific usage in surfer
+ slang.
+
+ [{Jargon File}]
+
+ (1996-09-17)
+
+Gnat
+
+ <language, tool> An {Ada} {compiler} written in {Ada} using
+ the {gcc} {code generator} to allow easy {porting} to a
+ variety of {platforms}. Gnat is the only Ada compiler that
+ completely implements the Ada standard, including all the
+ annexes.
+
+ The compiler is released under the {GNU} license and is
+ currently maintained by {Ada Core Technologies} (ACT).
+
+ {(http://gnat.com/)}.
+
+ (1999-06-24)
+
+GNATS
+
+ {GNU Problem Report Management System}
+
+GNN
+
+ {Global Network Navigator}
+
+GNOME
+
+ {GNU Network Object Model Environment}
+
+Gnome Computers
+
+ <company> A small UK hardware and software company. They make
+ {transputer} boards for the {Acorn} {Archimedes} among other
+ things.
+
+ E-mail: Chris Stenton <chris@gnome.co.uk>.
+
+ (1994-09-30)
+
+GNU
+
+ <body, project> /g*noo/ 1. A {recursive acronym}:
+ "GNU's Not Unix!". The {Free Software Foundation}'s project
+ to provide a freely distributable replacement for {Unix}. The
+ GNU Manifesto was published in the March 1985 issue of
+ Dr. Dobb's Journal but the GNU project started a year and a
+ half earlier when {Richard Stallman} was trying to get funding
+ to work on his freely distributable editor, {Emacs}.
+
+ {Emacs} and the GNU {C} compiler, {gcc}, two tools designed
+ for this project, have become very popular. GNU software is
+ available from many {GNU archive sites}.
+
+ See also {Hurd}.
+
+ 2. <person> {John Gilmore}.
+
+ [{Jargon File}]
+
+ (1997-04-12)
+
+GNU archive site
+
+ <body> The main {GNU} {FTP archive} is on gnu.org but
+ copies ("{mirrors}") of some or all of the files there are
+ also held on many other computers around the world. To avoid
+ overloading gnu.org and the {Internet} you should
+ {FTP} files from the machine closest to yours (you may be able
+ to use {traceroute} to determine which is logically closest if
+ it's not obvious from the transfer rate). Trans-ocean
+ {TCP/IP} links are very expensive and usually very slow.
+
+ The following {hosts} mirror GNU files. Look for a directory
+ like /pub/gnu, /mirrors/gnu, /systems/gnu or /archives/gnu.
+ {Electronic mail addresses} of administrators and {Internet
+ address}es are given for some hosts.
+
+ {Original list (ftp://src.doc.ic.ac.uk/gnu/GNUinfo/FTP)}.
+
+ Australia: archie.au, archie.oz, archie.oz.au
+
+ Brazil: ccsun.unicamp.br (143.106.1.5, <root@ccsun.unicamp.br>)
+
+ Denmark: ftp.denet.dk
+
+ Europe: archive.eu.net (192.16.202.1)
+
+ Finland: ftp.funet.fi (128.214.6.100, gnu-adm)
+
+ France: irisa.irisa.fr, ftp.univ-lyon1.fr
+ (<ftpmaint@ftp.univ-lyon1.fr>)
+
+ {Germany (ftp://ftp.informatik.tu-muenchen.de/)},
+ {(ftp://ftp.informatik.rwth-aachen.de/)},
+ {ftp://ftp.germany.eu.net/)}.
+
+ Israel: ftp.technion.ac.il (<ftp-admin@ftp.technion.ac.il>)
+
+ Japan: utsun.s.u-tokyo.ac.jp, ftp.cs.titech.ac.jp
+
+ Korea: cair.kaist.ac.kr (143.248.11.170)
+
+ Netherlands: hp4nl.nluug.nl, ftp.win.tue.nl (131.155.70.100)
+
+ Norway: ugle.unit.no (129.241.1.97)
+
+ South Africa: ftp.sun.ac.za
+
+ Sweden: isy.liu.se, ftp.stacken.kth.se, ftp.luth.se,
+ ftp.sunet.se, <archive@ftp.sunet.se>, sdi.slu.se.
+
+ Switzerland: ftp.eunet.ch, nic.switch.ch
+
+ Thailand: ftp.nectec.or.th (192.150.251.32,
+ <ftp@nwg.nectec.or.th>)
+
+ UK: src.doc.ic.ac.uk (146.169.3.7, <info-server@doc.ic.ac.uk>,
+ <lmjm@doc.ic.ac.uk> also sun cartridge or exabyte tapes);
+ info-server@cs.nott.ac.uk (<jpo@cs.nott.ac.uk>);
+ I.G.Batten@fulcrum.bt.co.uk (also qic-21 and qic-24 tapes);
+ ftp.mcc.ac.uk (130.88.203.12); Unix.hensa.ac.uk;
+ ftp.warwick.ac.uk (137.205.192.14, <Unixhelp@warwick.ac.uk>).
+
+ USA: louie.udel.edu, ftp.kpc.com (Silicon Valley, CA)
+ ftp.hawaii.edu, f.ms.uky.edu, ftp.digex.net (Internet address
+ 164.109.10.23, run by <mcguire@digex.net>),
+ wuarchive.wustl.edu, col.hp.com, ftp.cs.columbia.edu,
+ vixen.cso.uiuc.edu, mrcnext.cso.uiuc.edu, jaguar.utah.edu,
+ gatekeeper.dec.com, labrea.stanford.edu, ftp.cs.widener.edu,
+ archive.cis.ohio-state.edu, and ftp.uu.net.
+
+ Western Canada: ftp.cs.ubc.ca (<ftp-admin@cs.ubc.ca>)
+
+ (1999-12-09)
+
+GNU assembler
+
+ (GAS) A {Unix} {assembler} for the {GNU} project. Many {CPU}
+ types are handled and {COFF} and {IEEE-695} formats are
+ supported as well as standard {a.out}.
+
+ Current version 2.2 ported to {Sun-3}, {Sun-4}, {i386},
+ {386BSD}, {BSD/386}, {Linux}, {PS/2-AIX}, {VAX}, {Ultrix},
+ {BSD}, {VMS}.
+
+ The assembler has been merged with {GNU Binutils}.
+
+ E-mail: <bug-gnu-utils@gnu.org>.
+
+ (1995-04-18)
+
+GNU awk
+
+ {gawk}
+
+GNU BC
+
+ A {GNU} version of {BC} which is self-contained and internally
+ executes its own compiled code rather than acting as a
+ {front-end} to {DC} like the standard {Unix} bc.
+
+ Version 1.02
+
+ parser (yacc), interpreter, BC math library
+
+ Philip A. Nelson <phil@cs.wwu.edu>
+
+ FTP bc-1.02.tar.Z from a {GNU archive site}.
+
+ requires: vsprintf and vfprintf routines
+
+ ports: Unix (BSD, System V, MINIX, POSIX) Superset of POSIX BC
+ (P10003.2/D11), with a POSIX-only mode.
+
+GNU C
+
+ <language> The extension of {C} compiled by {gcc}.
+
+ (1997-09-30)
+
+GNU C Library
+
+ <library> (glibc) The {run-time} library for the {GNU C}
+ {compiler}, {gcc}, and others. glibc is the {source code} for
+ libc.a. It is maintained separately from the compilers and is
+ a superset of {ANSI C} and {POSIX}.1 and a large subset of
+ POSIX.2.
+
+ Latest version: 2.1.3, as of 2000-04-29
+
+ {(http://gnu.org/glibc)}.
+
+ Mailing list: <bug-glibc@gnu.org> (bugs).
+
+ (2000-05-31)
+
+GNU DC
+
+ GNU Desktop Calculator.
+
+ An {interpreter} for a subset of the standard {Unix} {DC} that
+ handles all its operations, except the (undocumented) {array}
+ operations. Integration with GNU BC is being attempted.
+
+ Version 0.2.
+
+ {FTP} dc-0.2.tar.Z from your nearest {GNU archive site}.
+
+ (1993-05-21)
+
+GNU E
+
+ A persistent C++ variant
+
+ Version 2.3.3
+
+ compiler
+
+ {(ftp://ftp.cs.wisc.edu/exodus/E/)}.
+
+ GNU E is a persistent, object oriented programming language
+ developed as part of the Exodus project. GNU E extends C++
+ with the notion of persistent data, program level data objects
+ that can be transparently used across multiple executions of a
+ program, or multiple programs, without explicit input and
+ output operations.
+
+ GNU E's form of {persistence} is based on extensions to the
+ C++ type system to distinguish potentially persistent data
+ objects from objects that are always memory resident. An
+ object is made persistent either by its declaration (via a new
+ "persistent" storage class qualifier) or by its method of
+ allocation (via persistent dynamic allocation using a special
+ overloading of the new operator). The underlying object
+ storage system is the Exodus storage manager, which provides
+ concurrency control and recovery in addition to storage for
+ persistent data.
+
+ restriction: Copyleft; not all run-time sources are available
+ (yet)
+
+ requires: release 2.1.1 of the Exodus storage manager
+
+ E-mail: <exodus@cs.wisc.edu>.
+
+ (1993-01-20)
+
+GNU Emacs
+
+ {Emacs}
+
+GNU Free Documentation License
+
+ <legal> (GFDL) The {Free Software Foundation}'s license
+ designed to ensure the same freedoms for {documentation} that
+ the {GPL} gives to {software}.
+
+ This dictionary is distributed under the GFDL, see the
+ copyright notice in the {Free On-line Dictionary of Computing}
+ section (at the start of the source file). The full text
+ follows.
+
+ Version 1.1, March 2000
+
+ Copyright 2000 Free Software Foundation, Inc.
+
+ 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+ 0. PREAMBLE
+
+ The purpose of this License is to make a manual, textbook, or
+ other written document "free" in the sense of freedom: to
+ assure everyone the effective freedom to copy and redistribute
+ it, with or without modifying it, either commercially or
+ noncommercially. Secondarily, this License preserves for the
+ author and publisher a way to get credit for their work, while
+ not being considered responsible for modifications made by
+ others.
+
+ This License is a kind of "copyleft", which means that
+ derivative works of the document must themselves be free in
+ the same sense. It complements the GNU General Public
+ License, which is a copyleft license designed for free
+ software.
+
+ We have designed this License in order to use it for manuals
+ for free software, because free software needs free
+ documentation: a free program should come with manuals
+ providing the same freedoms that the software does. But this
+ License is not limited to software manuals; it can be used for
+ any textual work, regardless of subject matter or whether it
+ is published as a printed book. We recommend this License
+ principally for works whose purpose is instruction or
+ reference.
+
+ 1. APPLICABILITY AND DEFINITIONS
+
+ This License applies to any manual or other work that contains
+ a notice placed by the copyright holder saying it can be
+ distributed under the terms of this License. The "Document",
+ below, refers to any such manual or work. Any member of the
+ public is a licensee, and is addressed as "you".
+
+ A "Modified Version" of the Document means any work containing
+ the Document or a portion of it, either copied verbatim, or
+ with modifications and/or translated into another language.
+
+ A "Secondary Section" is a named appendix or a front-matter
+ section of the Document that deals exclusively with the
+ relationship of the publishers or authors of the Document to
+ the Document's overall subject (or to related matters) and
+ contains nothing that could fall directly within that overall
+ subject. (For example, if the Document is in part a textbook
+ of mathematics, a Secondary Section may not explain any
+ mathematics.) The relationship could be a matter of historical
+ connection with the subject or with related matters, or of
+ legal, commercial, philosophical, ethical or political
+ position regarding them.
+
+ The "Invariant Sections" are certain Secondary Sections whose
+ titles are designated, as being those of Invariant Sections,
+ in the notice that says that the Document is released under
+ this License.
+
+ The "Cover Texts" are certain short passages of text that are
+ listed, as Front-Cover Texts or Back-Cover Texts, in the
+ notice that says that the Document is released under this
+ License.
+
+ A "Transparent" copy of the Document means a machine-readable
+ copy, represented in a format whose specification is available
+ to the general public, whose contents can be viewed and edited
+ directly and straightforwardly with generic text editors or
+ (for images composed of pixels) generic paint programs or (for
+ drawings) some widely available drawing editor, and that is
+ suitable for input to text formatters or for automatic
+ translation to a variety of formats suitable for input to text
+ formatters. A copy made in an otherwise Transparent file
+ format whose markup has been designed to thwart or discourage
+ subsequent modification by readers is not Transparent. A copy
+ that is not "Transparent" is called "Opaque".
+
+ Examples of suitable formats for Transparent copies include
+ plain ASCII without markup, Texinfo input format, LaTeX input
+ format, SGML or XML using a publicly available DTD, and
+ standard-conforming simple HTML designed for human
+ modification. Opaque formats include PostScript, PDF,
+ proprietary formats that can be read and edited only by
+ proprietary word processors, SGML or XML for which the DTD
+ and/or processing tools are not generally available, and the
+ machine-generated HTML produced by some word processors for
+ output purposes only.
+
+ The "Title Page" means, for a printed book, the title page
+ itself, plus such following pages as are needed to hold,
+ legibly, the material this License requires to appear in the
+ title page. For works in formats which do not have any title
+ page as such, "Title Page" means the text near the most
+ prominent appearance of the work's title, preceding the
+ beginning of the body of the text.
+
+ 2. VERBATIM COPYING
+
+ You may copy and distribute the Document in any medium, either
+ commercially or noncommercially, provided that this License,
+ the copyright notices, and the license notice saying this
+ License applies to the Document are reproduced in all copies,
+ and that you add no other conditions whatsoever to those of
+ this License. You may not use technical measures to obstruct
+ or control the reading or further copying of the copies you
+ make or distribute. However, you may accept compensation in
+ exchange for copies. If you distribute a large enough number
+ of copies you must also follow the conditions in section 3.
+
+ You may also lend copies, under the same conditions stated
+ above, and you may publicly display copies.
+
+ 3. COPYING IN QUANTITY
+
+ If you publish printed copies of the Document numbering more
+ than 100, and the Document's license notice requires Cover
+ Texts, you must enclose the copies in covers that carry,
+ clearly and legibly, all these Cover Texts: Front-Cover Texts
+ on the front cover, and Back-Cover Texts on the back cover.
+ Both covers must also clearly and legibly identify you as the
+ publisher of these copies. The front cover must present the
+ full title with all words of the title equally prominent and
+ visible. You may add other material on the covers in
+ addition. Copying with changes limited to the covers, as long
+ as they preserve the title of the Document and satisfy these
+ conditions, can be treated as verbatim copying in other
+ respects.
+
+ If the required texts for either cover are too voluminous to
+ fit legibly, you should put the first ones listed (as many as
+ fit reasonably) on the actual cover, and continue the rest
+ onto adjacent pages.
+
+ If you publish or distribute Opaque copies of the Document
+ numbering more than 100, you must either include a
+ machine-readable Transparent copy along with each Opaque copy,
+ or state in or with each Opaque copy a publicly-accessible
+ computer-network location containing a complete Transparent
+ copy of the Document, free of added material, which the
+ general network-using public has access to download
+ anonymously at no charge using public-standard network
+ protocols. If you use the latter option, you must take
+ reasonably prudent steps, when you begin distribution of
+ Opaque copies in quantity, to ensure that this Transparent
+ copy will remain thus accessible at the stated location until
+ at least one year after the last time you distribute an Opaque
+ copy (directly or through your agents or retailers) of that
+ edition to the public.
+
+ It is requested, but not required, that you contact the
+ authors of the Document well before redistributing any large
+ number of copies, to give them a chance to provide you with an
+ updated version of the Document.
+
+ 4. MODIFICATIONS
+
+ You may copy and distribute a Modified Version of the Document
+ under the conditions of sections 2 and 3 above, provided that
+ you release the Modified Version under precisely this License,
+ with the Modified Version filling the role of the Document,
+ thus licensing distribution and modification of the Modified
+ Version to whoever possesses a copy of it. In addition, you
+ must do these things in the Modified Version:
+
+ A. Use in the Title Page (and on the covers, if any) a title
+ distinct from that of the Document, and from those of previous
+ versions (which should, if there were any, be listed in the
+ History section of the Document). You may use the same title
+ as a previous version if the original publisher of that
+ version gives permission.
+
+ B. List on the Title Page, as authors, one or more persons or
+ entities responsible for authorship of the modifications in
+ the Modified Version, together with at least five of the
+ principal authors of the Document (all of its principal
+ authors, if it has less than five).
+
+ C. State on the Title page the name of the publisher of the
+ Modified Version, as the publisher.
+
+ D. Preserve all the copyright notices of the Document.
+
+ E. Add an appropriate copyright notice for your modifications
+ adjacent to the other copyright notices.
+
+ F. Include, immediately after the copyright notices, a license
+ notice giving the public permission to use the Modified
+ Version under the terms of this License, in the form shown in
+ the Addendum below.
+
+ G. Preserve in that license notice the full lists of Invariant
+ Sections and required Cover Texts given in the Document's
+ license notice.
+
+ H. Include an unaltered copy of this License.
+
+ I. Preserve the section entitled "History", and its title, and
+ add to it an item stating at least the title, year, new
+ authors, and publisher of the Modified Version as given on the
+ Title Page. If there is no section entitled "History" in the
+ Document, create one stating the title, year, authors, and
+ publisher of the Document as given on its Title Page, then add
+ an item describing the Modified Version as stated in the
+ previous sentence.
+
+ J. Preserve the network location, if any, given in the
+ Document for public access to a Transparent copy of the
+ Document, and likewise the network locations given in the
+ Document for previous versions it was based on. These may be
+ placed in the "History" section. You may omit a network
+ location for a work that was published at least four years
+ before the Document itself, or if the original publisher of
+ the version it refers to gives permission.
+
+ K. In any section entitled "Acknowledgements" or
+ "Dedications", preserve the section's title, and preserve in
+ the section all the substance and tone of each of the
+ contributor acknowledgements and/or dedications given therein.
+
+ L. Preserve all the Invariant Sections of the Document,
+ unaltered in their text and in their titles. Section numbers
+ or the equivalent are not considered part of the section
+ titles.
+
+ M. Delete any section entitled "Endorsements". Such a section
+ may not be included in the Modified Version.
+
+ N. Do not retitle any existing section as "Endorsements" or to
+ conflict in title with any Invariant Section. If the Modified
+ Version includes new front-matter sections or appendices that
+ qualify as Secondary Sections and contain no material copied
+ from the Document, you may at your option designate some or
+ all of these sections as invariant. To do this, add their
+ titles to the list of Invariant Sections in the Modified
+ Version's license notice. These titles must be distinct from
+ any other section titles.
+
+ You may add a section entitled "Endorsements", provided it
+ contains nothing but endorsements of your Modified Version by
+ various parties--for example, statements of peer review or
+ that the text has been approved by an organization as the
+ authoritative definition of a standard.
+
+ You may add a passage of up to five words as a Front-Cover
+ Text, and a passage of up to 25 words as a Back-Cover Text, to
+ the end of the list of Cover Texts in the Modified
+ Version. Only one passage of Front-Cover Text and one of
+ Back-Cover Text may be added by (or through arrangements made
+ by) any one entity. If the Document already includes a cover
+ text for the same cover, previously added by you or by
+ arrangement made by the same entity you are acting on behalf
+ of, you may not add another; but you may replace the old one,
+ on explicit permission from the previous publisher that added
+ the old one.
+
+ The author(s) and publisher(s) of the Document do not by this
+ License give permission to use their names for publicity for
+ or to assert or imply endorsement of any Modified Version.
+
+ 5. COMBINING DOCUMENTS
+
+ You may combine the Document with other documents released
+ under this License, under the terms defined in section 4 above
+ for modified versions, provided that you include in the
+ combination all of the Invariant Sections of all of the
+ original documents, unmodified, and list them all as Invariant
+ Sections of your combined work in its license notice.
+
+ The combined work need only contain one copy of this License,
+ and multiple identical Invariant Sections may be replaced with
+ a single copy. If there are multiple Invariant Sections with
+ the same name but different contents, make the title of each
+ such section unique by adding at the end of it, in
+ parentheses, the name of the original author or publisher of
+ that section if known, or else a unique number. Make the same
+ adjustment to the section titles in the list of Invariant
+ Sections in the license notice of the combined work.
+
+ In the combination, you must combine any sections entitled
+ "History" in the various original documents, forming one
+ section entitled "History"; likewise combine any sections
+ entitled "Acknowledgements", and any sections entitled
+ "Dedications". You must delete all sections entitled
+ "Endorsements."
+
+ 6. COLLECTIONS OF DOCUMENTS
+
+ You may make a collection consisting of the Document and other
+ documents released under this License, and replace the
+ individual copies of this License in the various documents
+ with a single copy that is included in the collection,
+ provided that you follow the rules of this License for
+ verbatim copying of each of the documents in all other
+ respects.
+
+ You may extract a single document from such a collection, and
+ distribute it individually under this License, provided you
+ insert a copy of this License into the extracted document, and
+ follow this License in all other respects regarding verbatim
+ copying of that document.
+
+ 7. AGGREGATION WITH INDEPENDENT WORKS
+
+ A compilation of the Document or its derivatives with other
+ separate and independent documents or works, in or on a volume
+ of a storage or distribution medium, does not as a whole count
+ as a Modified Version of the Document, provided no compilation
+ copyright is claimed for the compilation. Such a compilation
+ is called an "aggregate", and this License does not apply to
+ the other self-contained works thus compiled with the
+ Document, on account of their being thus compiled, if they are
+ not themselves derivative works of the Document.
+
+ If the Cover Text requirement of section 3 is applicable to
+ these copies of the Document, then if the Document is less
+ than one quarter of the entire aggregate, the Document's Cover
+ Texts may be placed on covers that surround only the Document
+ within the aggregate. Otherwise they must appear on covers
+ around the whole aggregate.
+
+ 8. TRANSLATION
+
+ Translation is considered a kind of modification, so you may
+ distribute translations of the Document under the terms of
+ section 4. Replacing Invariant Sections with translations
+ requires special permission from their copyright holders, but
+ you may include translations of some or all Invariant Sections
+ in addition to the original versions of these Invariant
+ Sections. You may include a translation of this License
+ provided that you also include the original English version of
+ this License. In case of a disagreement between the
+ translation and the original English version of this License,
+ the original English version will prevail.
+
+ 9. TERMINATION
+
+ You may not copy, modify, sublicense, or distribute the
+ Document except as expressly provided for under this
+ License. Any other attempt to copy, modify, sublicense or
+ distribute the Document is void, and will automatically
+ terminate your rights under this License. However, parties who
+ have received copies, or rights, from you under this License
+ will not have their licenses terminated so long as such
+ parties remain in full compliance.
+
+ 10. FUTURE REVISIONS OF THIS LICENSE
+
+ The Free Software Foundation may publish new, revised versions
+ of the GNU Free Documentation License from time to time. Such
+ new versions will be similar in spirit to the present version,
+ but may differ in detail to address new problems or concerns.
+ See {here (http://gnu.org/copyleft/)}.
+
+ Each version of the License is given a distinguishing version
+ number. If the Document specifies that a particular numbered
+ version of this License "or any later version" applies to it,
+ you have the option of following the terms and conditions
+ either of that specified version or of any later version that
+ has been published (not as a draft) by the Free Software
+ Foundation. If the Document does not specify a version number
+ of this License, you may choose any version ever published
+ (not as a draft) by the Free Software Foundation.
+
+ End of full text of GFDL.
+
+ (2002-03-09)
+
+GNU General Public License
+
+ {General Public License}
+
+GNUMACS
+
+ /gnoo'maks/ [contraction of "GNU Emacs"] Often-heard
+ abbreviated name for the {GNU} project's flagship tool,
+ {Emacs}. Used especially in contrast with {GOSMACS}.
+
+ [{Jargon File}]
+
+GNU mirror site
+
+ {GNU archive site}
+
+GNU Network Object Model Environment
+
+ <operating system> (GNOME) A project to build a complete,
+ {user-friendly} {desktop} based entirely on {free software}.
+ GNOME is part of the {GNU project} and part of the
+ {OpenSource} movement. The desktop will consist of small
+ {utilities} and larger {applications} which share a consistent
+ {look and feel}. GNOME uses {GTK+} as the {GUI} {toolkit} for
+ applications.
+
+ GNOME is intended to run on any modern and functional
+ {Unix}-like system. The current version runs on {Linux},
+ {FreeBSD}, {IRIX} and {Solaris}.
+
+ {(http://gnome.org/)}.
+
+ (1998-10-17)
+
+Gnuplot
+
+ <tool> A command-driven interactive graphing program. Gnuplot
+ can plot two-dimensional functions and data points in many
+ different styles (points, lines, error bars); and
+ three-dimensional data points and surfaces in many different
+ styles (contour plot, mesh). It supports {complex} arithmetic
+ and user-defined functions and can label title, axes, and data
+ points. It can output to several different graphics file
+ formats and devices. Command line editing and history are
+ supported and there is extensive on-line help.
+
+ Gnuplot is {copyright}ed, but freely distributable. It was
+ written by Thomas Williams, Colin Kelley, Russell Lang, Dave
+ Kotz, John Campbell, Gershon Elber, Alexander Woo and many
+ others. Despite its name, gnuplot is not related to the {GNU}
+ project or the {FSF} in any but the most peripheral sense. It
+ was designed completely independently and is not covered by
+ the {General Public License}. However, the {FSF} has decided
+ to distribute gnuplot as part of the {GNU} system, because it
+ is useful, redistributable software.
+
+ Gnuplot is available for: {Unix} ({X11} and {NEXTSTEP}),
+ {VAX}/{VMS}, {OS/2}, {MS-DOS}, {Amiga}, {MS-Windows},
+ {OS-9}/68k, {Atari ST} and {Macintosh}.
+
+ E-mail: <info-gnuplot@dartmouth.edu>.
+
+ {FAQ} - {Germany
+ (http://fg70.rz.uni-karlsruhe.de/~ig25/gnuplot-faq/)}, {UK
+ (ftp://src.doc.ic.ac.uk/usenet/news-info/comp.graphics.gnuplot)},
+ {USA
+ (http://cis.ohio-state.edu/hypertext/faq/usenet/graphics/gnuplot-faq/faq.html)}.
+
+ {Usenet} newsgroup: {news:comp.graphics.gnuplot}.
+
+ (1995-05-04)
+
+GNU Privacy Guard
+
+ <tool, cryptography} (GPG) {GNU}'s encryption and digital
+ signature tool intended to be a free replacement for {PGP}.
+
+ (2003-04-12)
+
+GNU Problem Report Management System
+
+ <programming> (GNATS) {GNU}'s {bug tracking system}. Users
+ who experience problems use electronic mail, web-based or
+ other clients communicating with the GNATS network daemon
+ running at the support site, or direct database submissions to
+ communicate these problems to maintainers at that Support
+ Site.
+
+ {(http://gnu.org/software/gnats)}.
+
+ (2002-06-12)
+
+GNU public licence
+
+ <legal> Properly known as the {General Public License}.
+ Improperly known as the {General Public Virus}.
+
+ (1995-05-04)
+
+GNUS
+
+ <tool, networking> GNU news.
+
+ A {GNU} {Emacs} subsystem for reading and sending {Usenet}
+ {news}, written by Masanobu Umeda <umerin@mse.kyutech.ac.jp>.
+ You can use GNUS to browse through news groups, look at
+ summaries of articles in a specific group, and read articles
+ of interest. You can respond to authors or write articles or
+ replies to all the readers of a news group.
+
+ GNUS can be configured to use the {NNTP} {protocol} to get
+ news from a remove {server} or it can read it from local news
+ {spool} files.
+
+ {Usenet} newsgorup: {news:gnu.emacs.gnus}.
+
+ (1995-05-04)
+
+GNU sed
+
+ <tool, text> A {GNU} version of the standard {Unix} {Sed}
+ stream editor. GNU sed was written by Tom Lord
+ <lord+@andrew.cmu.edu>. Version 2.03.
+
+ FTP from your nearest {GNU archive site}.
+
+ E-mail: <bug-gnu-utils@gnu.org> (bugs).
+
+ (1993-08-09)
+
+GNU Smalltalk
+
+ <language> A {GNU} version of {Smalltalk}, by Steven Byrne
+ <sbb@eng.sun.com>.
+
+ Version 1.1.1,
+
+ {FTP} from your nearest {GNU archive site}.
+
+ {msgGUI} is a {graphical user interface} library for GNU
+ Smalltalk.
+
+ (1991-09-15)
+
+GNUStep
+
+ <operating system> A {GNU} implementation of {OpenStep}. Work
+ has started on an implementation using an existing library
+ written in {Objective-C}. Much work remains to be done to
+ bring this library close to the OpenStep specifications. Adam
+ Fedor is head of the project.
+
+ {(http://gnustep.org/)}.
+
+ [Current status? Newsgroup?]
+
+ (1999-11-25)
+
+GNU superoptimiser
+
+ (GSO) A function sequence generator that uses an exhaustive
+ generate-and-test approach to find the shortest instruction
+ sequence for a given function. Written by Torbjorn Granlund
+ <tege@gnu.ai.mit.edu> and Tom Wood. You have to tell the
+ superoptimiser which function and which {CPU} you want to get
+ code for. This is useful for compiler writers.
+
+ FTP superopt-2.2.tar.Z from a {GNU archive site}.
+
+ Generates code for {DEC} {Alpha}, {SPARC}, {Intel 80386},
+ {88000}, {RS/6000}, {68000}, {29000} and {Pyramid} (SP, AP and
+ XP).
+
+ (1993-02-16)
+
+Go
+
+ <games, application> A thinking game with an oriental origin
+ estimated to be around 4000 years old. Nowadays, the game is
+ played by millions of people in (most notably) China, Japan,
+ Korea and Taiwan. In the Western world the game is practised
+ by a yearly increasing number of players. On the {Internet}
+ Go players meet, play and talk 24 hours/day on the {Internet
+ Go Server} (IGS).
+
+ {(http://cwi.nl/~jansteen/go/go.html)}.
+
+ {Usenet} newsgroup: {news:rec.games.go}.
+
+ (1995-03-17)
+
+goal
+
+ <programming> In {logic programming}, a {predicate} applied to
+ its {arguments} which the system attempts to prove by matching
+ it against the {clauses} of the program. A goal may fail or
+ it may succeed in one or more ways.
+
+ (1997-07-14)
+
+goal seek
+
+ {what-if analysis}
+
+Go Back N
+
+ <networking> A {data link layer} {protocol}.
+
+ [Details?]
+
+ (2010-01-19)
+
+gobble
+
+ <jargon>
+
+ 1. To consume, usually used with "up". "The output spy
+ gobbles characters out of a {tty} output buffer."
+
+ 2. To obtain, usually used with "down". "I guess I'll gobble
+ down a copy of the documentation tomorrow."
+
+ See also {snarf}.
+
+ [{Jargon File}]
+
+ (2010-01-19)
+
+GObject Introspection
+
+ <programming> A {GNOME} project that defines a {syntax} for
+ {introspection annotation} {pragmas} to be used in the
+ {GObject library} {source code}. Rather than actual
+ {introspection}, these are intended to allow automatic
+ generation of {bindings} ({API}s) to expose the library to
+ higher-level languages. The sort of information provided is
+ the type and direction (in, out, inout) of function parameters
+ and the responsibility for freeing memory used by data
+ structures.
+
+ {GObject Introspection Home
+ (http://live.gnome.org/GObjectIntrospection/)}.
+
+ (2010-01-19)
+
+Godwin's Law
+
+ <usenet, humour> "As a {Usenet} discussion grows longer, the
+ probability of a comparison involving Nazis or Hitler
+ approaches one." There is a tradition in many groups that,
+ once this occurs, that {thread} is over, and whoever mentioned
+ the Nazis has automatically lost whatever argument was in
+ progress. Godwin's Law thus practically guarantees the
+ existence of an {upper bound} on thread length in those
+ groups. However there is also a widely recognised codicil
+ that any intentional triggering of Godwin's Law in order to
+ invoke its thread-ending effects will be unsuccessful.
+
+ [{Jargon}].
+
+ (2003-10-06)
+
+Godzillagram
+
+ <networking> /god-zil'*-gram/ (From Japan's national hero and
+ {datagram}) 1. A {network packet} that in theory is a
+ {broadcast} to every machine in the universe. The typical
+ case is an {IP} {datagram} whose destination IP address is
+ [255.255.255.255]. Fortunately, few {gateways} are foolish
+ enough to attempt to implement this case!
+
+ 2. A network packet of maximum size. An {IP} Godzillagram has
+ 65,536 {octets}. Compare {super source quench}.
+
+ (2003-10-07)
+
+Goedel
+
+ <language> (After the mathematician {Kurt Gödel}) A
+ {declarative}, general-purpose language for {artificial
+ intelligence} based on {logic programming}. It can be
+ regarded as a successor to {Prolog}. The {type system} is
+ based on {many-sorted logic} with {parametric polymorphism}.
+ Modularity is supported, as well as {infinite precision
+ arithmetic} and {finite sets}.
+
+ Goedel has a rich collection of system {modules} and provides
+ {constraint} solving in several domains. It also offers
+ {metalogical} facilities that provide significant support for
+ {metaprograms} that do analysis, transformation, compilation,
+ verification, and debugging.
+
+ A significant subset of Goedel has been implemented on top of
+ {SISCtus Prolog} by Jiwei Wang <jiwei@lapu.bristol.ac.uk>.
+
+ {FTP Bristol, UK (ftp://ftp.cs.bris.ac.uk/goedel)}, {FTP K U
+ Leuven (ftp://ftp.cs.kuleuven.ac.be/pub/logic-prgm/goedel)}.
+
+ E-mail: <goedel@compsci.bristol.ac.uk>.
+
+ (1995-05-02)
+
+go-faster stripes
+
+ <jargon> {chrome}. Mainstream in some parts of UK.
+
+ [{Jargon File}]
+
+ (1998-07-05)
+
+Gofer
+
+ <language> A {lazy} {functional language} designed by Mark
+ Jones <mpj@cs.nott.ac.uk> at the {Programming Research Group},
+ Oxford, UK in 1991. It is very similar to {Haskell} 1.2. It
+ has {lazy evaluation}, {higher order functions}, {pattern
+ matching}, and {type class}es, lambda, case, conditional and
+ let expressions, and wild card, "as" and {irrefutable
+ patterns}. It lacks {modules}, {arrays} and standard
+ {classes}.
+
+ Gofer comes with an {interpreter} (in C), a {compiler} which
+ compiles to {C}, documentation and examples. Unix Version
+ 2.30 (1994-06-10) Mac_Gofer version 0.16 beta. Ported to
+ {Sun}, {Acorn} {Archimedes}, {IBM PC}, {Macintosh}, {Atari},
+ {Amiga}.
+
+ Version 2.30 added support for contexts in datatype and member
+ function definitions, Haskell style {arrays}, an external
+ function calling mechanism for gofc, an experimental
+ implementation of Launchbury/Peyton Jones style lazy
+ functional state threads, an experimental implementation of
+ "do" notation for {monad comprehensions}.
+
+ Latest version: {HUGS}.
+
+ ["Introduction to Gofer 2.20", M.P. Jones.]
+
+ [The implementation of the Gofer functional programming
+ system, Mark P. Jones, Research Report YALEU/DCS/RR-1030, Yale
+ University, Department of Computer Science, May 1994. FTP:
+ nebula.cs.yale.edu/pub/yale-fp/reports].
+
+ {(http://cs.nott.ac.uk/Department/Staff/mpj/)}.
+
+ {FTP Yale (ftp://nebula.cs.yale.edu/)}, {FTP Glasgow
+ (ftp://ftp.dcs.glasgow.ac.uk/)}, {FTP Chalmers
+ (ftp://ftp.cs.chalmers.se/pub/haskell/gofer/)}.
+
+ (1995-02-14)
+
+Goffin
+
+ <language> A {definitional constraint language} for
+ {declarative} parallel programming. Goffin systematically
+ integrates {equational constraints} and functions within a
+ uniform framework of {concurrent} programming.
+
+ Goffin is an embedding of a functional language kernel
+ ({Haskell}) into a layer of constraint logic, which allows
+ {logical variables} inside functional expressions. In order
+ to preserve {referential transparency}, functional {reduction}
+ suspends until logical variables become bound.
+
+ Logical variables are bound by equational constraints, which
+ impose relations over expressions. Hence, constraints are the
+ means to structure the concurrent reduction of functional
+ expressions.
+
+ (1995-02-21)
+
+go flatline
+
+ [{Cyberpunk} SF, refers to flattening of EEG traces upon
+ brain-death] also "flatlined". 1. To {die}, terminate, or
+ fail, especially irreversibly. In hacker parlance, this is
+ used of machines only, human death being considered somewhat
+ too serious a matter to employ jargon-jokes about.
+
+ 2. To go completely quiescent; said of machines undergoing
+ controlled shutdown. "You can suffer file damage if you shut
+ down Unix but power off before the system has gone flatline."
+
+ 3. Of a video tube, to fail by losing vertical scan, so all
+ one sees is a bright horizontal line bisecting the screen.
+
+ [{Jargon File}]
+
+GO-GO
+
+ {ALPS}
+
+go gold
+
+ <testing> The point in the life of a software product where it
+ is declared ready to release for sale. This may be because it
+ has reached sufficiently high quality (freedom from {bugs},
+ etc.), or because it is financially expedient.
+
+ (2004-08-02)
+
+GOL
+
+ General Operating Language. Subsystem of {DOCUS}. [Sammet
+ 1969, p.678].
+
+golden
+
+ [Probabaly from folklore's "golden egg"] When used to describe
+ a magnetic medium (e.g. "golden disk", "golden tape"),
+ describes one containing a tested, up-to-spec, ready-to-ship
+ software version. Compare {platinum-iridium}.
+
+ [{Jargon File}]
+
+golf ball printer
+
+ {IBM 2741}
+
+GOM
+
+ Good Old MAD.
+
+ Don Boettner, U Mich. MAD for the IBM 360. Parts of the MTS
+ {time-sharing} system were written in GOM.
+
+gonk
+
+ <jargon> /gonk/ 1. To prevaricate or to embellish the truth
+ beyond any reasonable recognition. In German the term is
+ (mythically) "gonken"; in Spanish the verb becomes "gonkar".
+ "You're gonking me. That story you just told me is a bunch of
+ gonk." In German, for example, "Du gonkst mir" (You're
+ pulling my leg).
+
+ See also {gonkulator}.
+
+ 2. (British) To grab some sleep at an odd time.
+
+ Compare {gronk out}.
+
+ [{Jargon File}]
+
+ (1995-03-07)
+
+gonkulator
+
+ /gon'kyoo-lay-tr/ (From "Hogan's Heroes", the TV series) A
+ pretentious piece of equipment that actually serves no useful
+ purpose. Usually used to describe one's least favourite piece
+ of computer hardware.
+
+ See {gonk}.
+
+ [{Jargon File}]
+
+ (1995-03-07)
+
+GOOD
+
+ {Graph-Oriented Object Database}
+
+Good Thing
+
+ <convention> (From the 1930 Sellar and Yeatman parody "1066
+ And All That") Often capitalised; always pronounced as if
+ capitalised.
+
+ 1. Self-evidently wonderful to anyone in a position to notice:
+ "The {Trailblazer}'s 19.2 K{baud} {PEP} mode with {on-the-fly}
+ {Lempel-Ziv compression} is a Good Thing for sites relaying
+ {netnews}".
+
+ 2. Something that can't possibly have any ill side-effects and
+ may save considerable grief later: "Removing the
+ {self-modifying code} from that {shared library} would be a
+ Good Thing".
+
+ 3. When said of software tools or libraries, as in "{Yacc} is
+ a Good Thing", specifically connotes that the thing has
+ drastically reduced a programmer's work load.
+
+ Opposite: {Bad Thing}, compare {big win}.
+
+ [{Jargon File}]
+
+ (1995-05-07)
+
+Google
+
+ <web> The {web} {search engine} that indexes the greatest number
+ of web pages - over two billion by December 2001 and provides a
+ free service that searches this index in less than a second.
+
+ The site's name is apparently derived from "{googol}", but
+ note the difference in spelling.
+
+ The "Google" spelling is also used in "The Hitchhikers Guide
+ to the Galaxy" by Douglas Adams, in which one of Deep
+ Thought's designers asks, "And are you not," said Fook,
+ leaning anxiously foward, "a greater analyst than the
+ Googleplex Star Thinker in the Seventh Galaxy of Light and
+ Ingenuity which can calculate the trajectory of every single
+ dust particle throughout a five-week Dangrabad Beta sand
+ blizzard?"
+
+ {(http://google.com/)}.
+
+ (2001-12-28)
+
+googol
+
+ <mathematics> The number represented in base-ten by a one with
+ a hundred zeroes after it.
+
+ According to Webster's Dictionary, the name was coined in 1938
+ by Milton Sirotta, the nine-year-old nephew of American
+ mathematician, Edward Kasner.
+
+ See also {googolplex}.
+
+ (2001-03-29)
+
+googolplex
+
+ <mathematics> The number represented in base-ten by a one with
+ a {googol} zeroes after it.
+
+ (2001-03-29)
+
+gopher
+
+ <networking, protocol> A {distributed} document retrieval
+ system which started as a {Campus Wide Information System} at
+ the {University of Minnesota}, and which was popular in the
+ early 1990s.
+
+ Gopher is defined in {RFC 1436}. The protocol is like a
+ primitive form of {HTTP} (which came later). Gopher lacks the
+ {MIME} features of HTTP, but expressed the equivalent of a
+ document's {MIME type} with a one-character code for the
+ "{Gopher object type}". At time of writing (2001), all Web
+ browers should be able to access gopher servers, although few
+ gopher servers exist anymore.
+
+ {Tim Berners-Lee}, in his book "Weaving The Web" (pp.72-73),
+ related his opinion that it was not so much the protocol
+ limitations of gopher that made people abandon it in favor of
+ HTTP/{HTML}, but instead the legal missteps on the part of the
+ university where it was developed:
+
+ "It was just about this time, spring 1993, that the University
+ of Minnesota decided that it would ask for a license fee from
+ certain classes of users who wanted to use gopher. Since the
+ gopher software being picked up so widely, the university was
+ going to charge an annual fee. The browser, and the act of
+ browsing, would be free, and the server software would remain
+ free to nonprofit and educational institutions. But any other
+ users, notably companies, would have to pay to use gopher
+ server software.
+
+ "This was an act of treason in the academic community and the
+ Internet community. Even if the university never charged
+ anyone a dime, the fact that the school had announced it was
+ reserving the right to charge people for the use of the gopher
+ protocols meant it had crossed the line. To use the
+ technology was too risky. Industry dropped gopher like a hot
+ potato."
+
+ (2001-03-31)
+
+Gopher client
+
+ <networking> A program which runs on your local computer and
+ provides a {user interface} to the {Gopher} {protocol} and to
+ gopher servers. {Web browsers} can act as Gopher clients and
+ simple Gopher-only clients are available for ordinary
+ terminals, the {X Window System}, {GNU Emacs}, and other
+ systems.
+
+ {(ftp://boombox.micro.umn.edu/)}.
+
+ (2001-03-31)
+
+Gopher object type
+
+ A character specifying how to display a {Gopher} document.
+ Current types are:
+
+ 0 document
+ 1 menu
+ 2 CSO phone book entity
+ 3 error
+ 4 binhex binary
+ 5 DOS binary (deprecated)
+ 6 UU binary (deprecated)
+ 7 index search
+ 8 telnet connection
+ 9 binary
+ + duplicate server for previous object
+ I image
+ M MIME document
+ T tn3270 based telnet connection
+ c cal
+ g GIF image
+ h HTML
+ s binary
+ u {Usenet} newsgroup
+
+ (1999-10-14)
+
+Gopherspace
+
+ <networking> The sum of all files that can be reached using
+ {gopher}.
+
+ (2005-06-08)
+
+gorets
+
+ /gor'ets/ The unknown ur-noun, fill in your own meaning.
+ Found especially on the {Usenet} newsgroup alt.gorets, which
+ seems to be a running contest to redefine the word by
+ implication in the funniest and most peculiar way, with the
+ understanding that no definition is ever final. [A
+ correspondent from the Former Soviet Union informs me that
+ "gorets" is Russian for "mountain dweller" - ESR] Compare
+ {frink}.
+
+ [{Jargon File}]
+
+gorilla arm
+
+ The side-effect that destroyed touch-screens as a mainstream
+ input technology despite a promising start in the early 1980s.
+ It seems the designers of all those {spiffy} touch-menu
+ systems failed to notice that humans aren't designed to hold
+ their arms in front of their faces making small motions.
+ After more than a very few selections, the arm begins to feel
+ sore, cramped, and oversized - the operator looks like a
+ gorilla while using the touch screen and feels like one
+ afterward. This is now considered a classic cautionary tale
+ to human-factors designers; "Remember the gorilla arm!" is
+ shorthand for "How is this going to fly in *real* use?".
+
+go root
+
+ [Unix] To temporarily enter {root mode} in order to perform a
+ privileged operation. This use is deprecated in Australia,
+ where the verb "root" refers to animal sex. See {su}.
+
+ [{Jargon File}]
+
+gorp
+
+ /gorp/ (CMU, perhaps from the canonical hiker's food, Good Old
+ Raisins and Peanuts) Another {metasyntactic variable}, like
+ {foo} and {bar}.
+
+GOSIP
+
+ {Government OSI Profile}
+
+Gosling, James
+
+ {James Gosling}
+
+GOSMACS
+
+ /goz'maks/ Gosling Emacs. The first {Emacs} implementation in
+ {C}, predating but now largely eclipsed by {GNU} {Emacs}.
+ Originally {freeware}; a commercial version is now modestly
+ popular as {UniPress Emacs}. The author (James Gosling) went
+ on to invent {NeWS}.
+
+ [{Jargon File}]
+
+Gosperism
+
+ /gos'p*r-izm/ A hack, invention, or saying due to arch-hacker
+ R. William (Bill) Gosper. This notion merits its own term
+ because there are so many of them. Many of the entries in
+ {HAKMEM} are Gosperisms.
+
+ See also {life}.
+
+GOSPL
+
+ Graphics-Oriented Signal Processing Language. A graphical DSP
+ language for simulation.
+
+ ["Graphic Oriented Signal Processing Language - GOSPL",
+ C.D. Covington et al, Proc ICASSP-87, 1987].
+
+gotcha
+
+ <jargon, programming> A {misfeature} of a system, especially a
+ programming language or environment, that tends to breed
+ {bugs} or mistakes because it both enticingly easy to invoke
+ and completely unexpected and/or unreasonable in its outcome.
+
+ For example, a classic gotcha in {C} is the fact that
+
+ if (a=b) {code;}
+
+ is syntactically valid and sometimes even correct. It puts
+ the value of "b" into "a" and then executes "code" if "a" is
+ non-zero. What the programmer probably meant was
+
+ if (a==b) {code;}
+
+ which executes "code" if "a" and "b" are equal.
+
+ [{Jargon File}]
+
+ (1995-04-17)
+
+goto
+
+ <programming> (Or "GOTO", "go to", "GO TO", "JUMP", "JMP") A
+ construct and {keyword} found in several higher-level
+ programming languages (e.g. {Fortran}, {COBOL}, {BASIC}, {C})
+ to cause an {unconditional jump} or transfer of {control} from
+ one point in a program to another. The destination of the
+ jump is usually indicated by a {label} following the GOTO
+ keyword.
+
+ In some languages, a label is a line number, in which case
+ every statement may be labelled, in others a label is an
+ optional alphanumeric {identifier}.
+
+ Use of the GOTO instruction in {high level language}
+ programming fell into disrepute with the development and
+ general acceptance of {structured programming}, and especially
+ following the famous article "GOTO statement {considered
+ harmful}". Since a GOTO is effectively an {assignment} to the
+ {program counter}, it is tempting to make the generalisation
+ "assignment considered harmful" and indeed, this is the basis
+ of {functional programming}.
+
+ Nearly(?) all {machine language} {instruction sets} include a
+ GOTO instruction, though in this context it is usually called
+ branch or jump or some {mnemonic} based on these.
+
+ See also {COME FROM}.
+
+ (2000-12-13)
+
+Gottlob Frege
+
+ <person, history, philosophy, mathematics, logic, theory>
+ (1848-1925) A mathematician who put mathematics on a new and
+ more solid foundation. He purged mathematics of mistaken,
+ sloppy reasoning and the influence of {Pythagoras}.
+ Mathematics was shown to be a subdivision of {formal logic}.
+
+ [Where?]
+
+ (1997-07-14)
+
+gov
+
+ <networking> The {top-level domain} for US government bodies.
+
+ (1999-01-26)
+
+governance
+
+ {information technology governance}
+
+Government OSI Profile
+
+ <networking, standard> (GOSIP) A subset of {OSI} {standards}
+ specific to US Government procurements, designed to maximize
+ {interoperability} in areas where plain OSI standards are
+ ambiguous or allow excessive options.
+
+ (1995-12-13)
+
+go voice
+
+ <communications> When two or more parties stop communicating
+ digitally and resuming the conversation via voice
+ communication over the telephone.
+
+ Prototypically this is used (e.g., "Wanna go voice?") between
+ two modem users to denote the action of picking up the phone
+ while shutting off the modem, in order to use the same line
+ for voice communication as had was being used for data
+ transmission.
+
+ Compare: {Voice-Net}.
+
+ (1997-01-31)
+
+GP
+
+ Early system on UNIVAC I or II. Listed in CACM 2(5):16 (May
+ 1959).
+
+gp
+
+ <networking> The {country code} for Guadeloupe.
+
+ (1999-01-27)
+
+GPF
+
+ {General Protection failure}/fault
+
+GPIB
+
+ {IEEE 488}
+
+GPL
+
+ 1. {General Purpose Language}.
+
+ 2. ["A Sample Management Application Program in a Graphical
+ Data-driven Programming language", A.L. Davis et al, Digest of
+ Papers, Compcon Spring 81, Feb 1981, pp. 162-167].
+
+ 3. {Genken Programming Language}.
+
+ 4. {General Public License}.
+
+ [{Jargon File}]
+
+GPM
+
+ {General Purpose Macro-generator}
+
+GPRS
+
+ {General Packet Radio Service}
+
+GPS
+
+ {Global Positioning System}
+
+GPSS
+
+ General Purpose Systems Simulator. Geoffrey Gordon, 1960.
+ Discrete simulations. "The Application of GPSS V to Discrete
+ System Simulation", G. Gordon, P-H 1975. Versions include
+ GPSS II (1963), GPSS III (1965), GPS/360 (1967), and GPSS V
+ (1970).
+
+GPV
+
+ {General Public Virus}
+
+GPX
+
+ Early system on UNIVAC II. Listed in CACM 2(5):16 (May 1959).
+
+gq
+
+ <networking> The {country code} for Equatorial Guinea.
+
+ (1999-01-27)
+
+gr
+
+ <networking> The {country code} for Greece.
+
+ (1999-01-27)
+
+GRAAL
+
+ ("Grail") General Recursive Applicative and Algorithmic
+ Language. FP with polyadic combinators. "Graal: A Functional
+ Programming System with Uncurryfied Combinators and its
+ Reduction Machine", P. Bellot in ESOP 86, G. Goos ed, LNCS
+ 213, Springer 1986.
+
+grabber pointer
+
+ <operating system> A {mouse pointer} {sprite} in the shape of
+ a small hand that closes when a {mouse button} is clicked,
+ indicating that the object on the screen under the pointer has
+ been selected.
+
+ (2012-07-08)
+
+Grace Hopper
+
+ <person> US Navy Rear Admiral Grace Brewster Hopper
+ (1906-12-09 to 1992-01-01), née Grace Brewster Murray.
+
+ Hopper is believed to have concieved the concept of the
+ {compiler} with the {A-0} in 1952. She also developed the
+ first commercial {high-level language}, which eventually
+ evolved into {COBOL}. She worked on the {Mark I} computer
+ with Howard Aiken and with {BINAC} in 1949.
+
+ She is credited with having coined the term "debug", and the
+ adage "it is always easier to ask forgiveness than it is to
+ get permission" (with various wordings), which has been the
+ guiding principle in {sysadmin} decisions ever since.
+
+ See also the entries {debug} and {bug}.
+
+ Hopper is buried at Arlington National Cemetery. In 1994, the
+ US Navy named a new ship, the guided-missile destroyer {USS
+ Hopper (http://hopper.navy.mil/)}, after her.
+
+ (1999-06-29)
+
+GRAF
+
+ GRaphic Additions to Fortran.
+
+ {Fortran} plus graphic data types.
+
+ ["GRAF: Graphic Additions to Fortran", A. Hurwitz et al, Proc
+ SJCC 30 (1967)].
+
+ [Sammet 1969, p. 674].
+
+ (1995-01-23)
+
+Graffiti
+
+ Handwriting recognition software for the {Newton} and {Zoomer}
+ which recognises symbols that aren't necessarily letters.
+ This gives greater speed and accuracy. It was written by
+ {Berkeley Softworks}.
+
+ (1995-01-24)
+
+GRAIL
+
+ Graphical Input Language.
+
+ A {flow chart} language entered on a graphics tablet. The
+ graphical follow-on to {JOSS}.
+
+ ["The GRAIL Language and Operations", T.O. Ellis et al,
+ RM-6001-ARPA, RAND, Sept 1969].
+
+ (1995-01-23)
+
+GRAIN
+
+ A pictorial {query language}.
+
+ ["Pictorial Information Systems", S.K. Chang et al eds,
+ Springer 1980].
+
+ (1995-01-23)
+
+grain
+
+ {granularity}
+
+GRAM
+
+ An extension of {BNF} used by the {SIS} compiler generator.
+
+ ["SIS - Semantics Implementation System", P.D. Mosses, TR
+ DAIMI MD-30, Aarhus U, Denmark].
+
+ (1995-01-23)
+
+grammar
+
+ <language> A formal definition of the syntactic structure (the
+ {syntax}) of a language.
+
+ A grammar is normally represented as a set of {production
+ rules} which specify the order of constituents and their
+ sub-constituents in a {sentence} (a well-formed string in the
+ language). Each rule has a left-hand side symbol naming a
+ syntactic category (e.g. "noun-phrase" for a {natural
+ language} grammar) and a right-hand side which is a sequence
+ of zero or more symbols. Each symbol may be either a
+ {terminal symbol} or a non-terminal symbol. A terminal symbol
+ corresponds to one "{lexeme}" - a part of the sentence with no
+ internal syntactic structure (e.g. an identifier or an
+ operator in a computer language). A non-terminal symbol is
+ the left-hand side of some rule.
+
+ One rule is normally designated as the top-level rule which
+ gives the structure for a whole sentence.
+
+ A {parser} (a kind of {recogniser}) uses a grammar to parse a
+ sentence, assigning a terminal syntactic category to each
+ input token and a non-terminal category to each appropriate
+ group of tokens, up to the level of the whole sentence.
+ Parsing is usually preceded by {lexical analysis}. The
+ opposite, generation, starts from the top-level rule and
+ chooses one alternative production wherever there is a choice.
+
+ In computing, a formal grammar, e.g. in {BNF}, can be used to
+ {parse} a linear input stream, such as the {source code} of a
+ program, into a data structure that expresses the (or a)
+ meaning of the input in a form that is easier for the computer
+ to work with. A {compiler compiler} like {yacc} might be used
+ to convert a grammar into code for the parser of a {compiler}.
+ A grammar might also be used by a {transducer}, a {translator}
+ or a {syntax directed editor}.
+
+ See also {attribute grammar}.
+
+ (2009-02-06)
+
+grammar analysis
+
+ <language> A program written in {ABC} for answering such
+ questions as "what are the start symbols of all rules", "what
+ symbols can follow this symbol", "which rules are left
+ recursive", and so on. Includes a grammar of {ISO Pascal}.
+
+ Version 1 by Steven Pemberton <Steven.Pemberton@cwi.nl>.
+ Ports to {Unix}, {MS-DOS}, {Atari}, {Macintosh}. FTP:
+ ftp.eu.net, ftp.nluug.net
+ programming/languages/abc/examples/grammar/.
+
+ (1993-07-05)
+
+grammatical inference
+
+ Deducing a {grammar} from given examples. Also known as
+ "inductive inference" and recently as "computational
+ learning".
+
+Grandfather, Father, Son
+
+ <operating system> (GFS) A {backup rotation} scheme in which a
+ "grandfather" backup is performed on the first Monday of each
+ month, a "father" backup is performed on every other Monday
+ and a "son" backup is performed on every other day of the
+ week. Grandfather tapes are kept for a year, father tapes for
+ a month and son tapes for a week. The exact schedule (and
+ thus the number of tapes required) may vary, as may the choice
+ of {full backup} or {incremental backup}, but the idea is that
+ it should be possible to restore versions of any file of
+ different ages: e.g. yesterday's, last week's or last year's
+ version.
+
+ (2004-10-11)
+
+granularity
+
+ <jargon, parallel> The size of the units of {code} under
+ consideration in some context. The term generally refers to
+ the level of detail at which code is considered, e.g. "You can
+ specify the granularity for this profiling tool".
+
+ The most common computing use is in {parallelism} or {concurrency}
+ where "fine grain parallelism" means individual tasks are
+ relatively small in terms of code size and execution time, "coarse
+ grain" is the opposite. You talk about the "granularity" of the
+ parallelism.
+
+ The smaller the granularity, the greater the potential for
+ parallelism and hence speed-up but the greater the overheads
+ of synchronisation and communication.
+
+ (1997-05-08)
+
+Grapes
+
+ A {Modula}-like system description language.
+
+ E-mail: <peter@cadlab.cadlab.de>.
+
+ ["GRAPES Language Description. Syntax, Semantics and Grammar
+ of GRAPES-86", Siemens Nixdorf Inform, Berlin 1991, ISBN
+ 3-8009-4112-0].
+
+Grapevine
+
+ A distributed system project.
+
+ [Who? Where? Why?]
+
+graph
+
+ 1. <mathematics> A collection of {nodes} and {edges}.
+
+ See also {connected graph}, {degree}, {directed graph}, {Moore
+ bound}, {regular graph}, {tree}.
+
+ 2. <graphics> A visual representation of algebraic equations
+ or data.
+
+ (1996-09-22)
+
+Graph Algorithm and Software Package
+
+ <library> (GASP) A {PL/I} extension for programming graph
+ {algorithms}.
+
+ ["GASP - Gprah Algorithm Software Package", S. Chase, TR CS
+ Dept, U Illinois, Dec 1969].
+
+ (1998-02-27)
+
+graph coloring
+
+ {graph colouring}
+
+graph colouring
+
+ <application> A {constraint-satisfaction} problem often used
+ as a test case in research, which also turns out to be
+ equivalent to certain real-world problems (e.g. {register
+ allocation}). Given a {connected graph} and a fixed number of
+ colours, the problem is to assign a colour to each node,
+ subject to the constraint that any two connected nodes cannot
+ be assigned the same colour. This is an example of an
+ {NP-complete} problem.
+
+ See also {four colour map theorem}.
+
+Graphic ALGOL
+
+ <language> A extension of {ALGOL 60} for {real-time}
+ generation of shaded perspective pictures.
+
+ ["An Extended ALGOL 60 for Shaded Computer Graphics",
+ B. Jones, Proc ACM Symp on Graphic Languages, Apr 1976].
+
+ (2011-03-08)
+
+Graphical Kernel System
+
+ <graphics, standard> (GKS) The widely recognised standard
+ {ANSI} X3.124 for graphical input/output. GKS is worked on by
+ the {ISO}/{IEC} group {JTC1/SC24}. It provides applications
+ programmers with standard methods of creating, manipulating,
+ and displaying or printing computer graphics on different
+ types of computer graphics output devices. It provides an
+ abstraction to save programmers from dealing with the detailed
+ capabilities and interfaces of specific hardware.
+
+ GKS defines a basic two-dimensional graphics system with:
+ uniform input and output {primitives}; a uniform interface to
+ and from a {GKS metafile} for storing and transferring
+ graphics information. It supports a wide range of graphics
+ output devices including such as {printers}, {plotters},
+ {vector graphics} devices, {storage tubes}, {refresh
+ displays}, {raster displays}, and {microfilm recorders}.
+
+ (1999-04-01)
+
+Graphical User Interface
+
+ <operating system> (GUI) The use of pictures rather than just
+ words to represent the input and output of a program. A
+ program with a GUI runs under some {windowing system}
+ (e.g. The {X Window System}, {MacOS}, {Microsoft Windows},
+ {Acorn} {RISC OS}, {NEXTSTEP}). The program displays certain
+ {icons}, {buttons}, {dialogue boxes}, etc. in its {windows} on
+ the screen and the user controls it mainly by moving a
+ {pointer} on the screen (typically controlled by a {mouse})
+ and selecting certain objects by pressing buttons on the mouse
+ while the pointer is pointing at them. This contrasts with a
+ {command line interface} where communication is by exchange of
+ strings of text.
+
+ Windowing systems started with the first {real}-time graphic
+ display systems for computers, namely the {SAGE} Project
+ [Dates?] and {Ivan Sutherland}'s {Sketchpad} (1963). {Douglas
+ Engelbart}'s {Augmentation of Human Intellect} project at
+ {SRI} in the 1960s developed the {On-Line System}, which
+ incorporated a mouse-driven cursor and multiple windows.
+ Several people from Engelbart's project went to Xerox PARC in
+ the early 1970s, most importantly his senior engineer, {Bill
+ English}. The Xerox PARC team established the {WIMP} concept,
+ which appeared commercially in the {Xerox 8010} (Star) system
+ in 1981.
+
+ Beginning in 1980(?), led by {Jef Raskin}, the {Macintosh}
+ team at {Apple Computer} (which included former members of the
+ Xerox PARC group) continued to develop such ideas in the first
+ commercially successful product to use a GUI, the Apple
+ Macintosh, released in January 1984. In 2001 Apple introduced
+ {Mac OS X}.
+
+ {Microsoft} modeled the first version of {Windows}, released
+ in 1985, on Mac OS. Windows was a GUI for {MS-DOS} that had
+ been shipped with {IBM PC} and compatible computers since
+ 1981. Apple sued Microsoft over infringement of the
+ look-and-feel of the MacOS. The court case ran for many
+ years.
+
+ [Wikipedia].
+
+ (2002-03-25)
+
+Graphic Display Interface
+
+ <hardware> (GDI) {graphics adaptor}.
+
+ (1995-03-16)
+
+Graphic Language
+
+ For specifying graphic operations.
+
+ ["A Problem Oriented Graphic Language", P.J. Schwinn, proc ACM
+ 22nd Natl Conf, 1967].
+
+ [Sammet 1969, p. 677].
+
+graphics
+
+ <graphics> Any kind of visible output including {text},
+ {images}, {movies}, {line art} and {digital photographs};
+ stored in {bitmap} or {vector graphic} form.
+
+ Most modern computers can display non-{text} data and most use
+ a {graphical user interface} (GUI) for virtually all
+ interaction with the user. Special {hardware}, typically some
+ kind of {graphics adaptor}, is required to allow the computer
+ to display graphics (as opposed to, say, printing text on a
+ {teletype}) but since GUIs became ubiquitous this has become
+ the default form of visual output. The most demanding
+ applications for computer graphics are those where the
+ computer actually generates moving images in {real time},
+ especially in {video games}.
+
+ There are many kinds of {software} devoted to manipulating
+ graphical data, including image editing (e.g. {Photoshop}),
+ {drawing} (e.g. {Illustrator}), user interface toolkits
+ (e.g. {X Window System}), {CAD}, {CGI}.
+
+ (2009-06-24)
+
+graphics accelerator
+
+ <graphics, hardware> {Hardware} (often an extra circuit board)
+ to perform tasks such as plotting lines and surfaces in two or
+ three dimensions, filling, shading and hidden line removal.
+
+ (1997-07-14)
+
+graphics adapter
+
+ {graphics adaptor}
+
+graphics adaptor
+
+ <hardware, graphics> (Or "graphics adapter", "graphics card",
+ "video adaptor", etc.) A circuit board fitted to a computer,
+ especially an {IBM PC}, containing the necessary {video
+ memory} and other electronics to provide a {bitmap display}.
+
+ Adaptors vary in the {resolution} (number of {pixels}) and
+ number of colours they can display, and in the {refresh rate}
+ they support. These parameters are also limited by the
+ {monitor} to which the adaptor is connected. A number of such
+ {display standards}, e.g. {SVGA}, have become common and
+ different {software} requires or supports different sets.
+
+ (1996-09-16)
+
+graphics card
+
+ {graphics adaptor}
+
+Graphics Interchange Format
+
+ <graphics, file format> /gif/, occasionally /jif/ (GIF, GIF
+ 89A) A standard for digitised {images} compressed with the
+ {LZW} {algorithm}, defined in 1987 by {CompuServe} (CIS).
+
+ Graphics Interchange Format and GIF are service marks of
+ {CompuServe} Incorporated. This only affects use of GIF
+ within Compuserve, and pass-through licensing for software to
+ access them, it doesn't affect anyone else's use of GIF. It
+ followed from a 1994 legal action by {Unisys} against CIS for
+ violating Unisys's {LZW} {software patent}. The CompuServe
+ Vice President has stated that "CompuServe is committed to
+ keeping the GIF 89A specification as an open, fully-supported,
+ non-proprietary specification for the entire on-line community
+ including the {web}".
+
+ {Filename extension}: .gif.
+
+ {File format (ftp://peipa.essex.ac.uk/ipa/info/file-formats)}.
+
+ {GIF89a specification
+ (http://asterix.seas.upenn.edu/~mayer/lzw_gif/gif89a.html)}.
+
+ See also {progressive coding}, {animated GIF}.
+
+ (2000-09-12)
+
+Graphics Interface Format
+
+ <spelling> You mean "{Graphics Interchange Format}".
+
+ (1999-10-11)
+
+Graphics Language Object System
+
+ <graphics, language> (GLOS) A language with statements for
+ describing graphics objects (line, circle, polygon, etc.),
+ written by Michael J McLean and Brian Hicks at the University
+ of Queensland, St. Lucia in 1978. New objects are defined
+ using {procedures}. 2-D transformations are context dependent
+ and may be nested.
+
+ [M.J. McLean, "The Semantics of Computer Drafting Languages",
+ PhD thesis, University of Queensland, 1978].
+
+ [Hicks, B.W., and McLean, M.J. "A Graphic Language for
+ Describing Line Objects", Proceedings of the DECUS-Australia
+ August 1973 Symposium, Melbourne, 1973].
+
+ (2002-06-01)
+
+graphic workstation
+
+ <graphics, computer> A {workstation} specifically configured
+ for graphics works such as {image manipulation}, {bitmap
+ graphics} ("paint"), and {vector graphics} ("draw") type
+ applications. Such work requires a powerful {CPU} and a high
+ {resolution} display.
+
+ A graphic workstation is very similar to a {CAD} workstation
+ and, given the typical specifications of personal computers
+ currently available in 1999, the distinctions are very blurred
+ and are more likely to depend on availability of specific
+ {software} than any detailed hardware requirements.
+
+ (1999-05-04)
+
+Graph-Oriented Object Database
+
+ <language, database> (GOOD) A graph manipulation language for
+ use as a {database query language}.
+
+ ["A Graph-Oriented Object Database Model", M. Gyssens et al,
+ Proc ACM Symp Princs of Database Sys, Mar 1990].
+
+ (1995-03-07)
+
+graph plotter
+
+ {plotter}
+
+graph reduction
+
+ A technique invented by Chris Wadsworth where an expression is
+ represented as a {directed graph} (usually drawn as an
+ inverted tree). Each node represents a function call and its
+ subtrees represent the arguments to that function. Subtrees
+ are replaced by the expansion or value of the expression they
+ represent. This is repeated until the tree has been reduced
+ to a value with no more function calls (a {normal form}).
+
+ In contrast to {string reduction}, graph reduction has the
+ advantage that common subexpressions are represented as
+ pointers to a single instance of the expression which is only
+ reduced once. It is the most commonly used technique for
+ implementing {lazy evaluation}.
+
+graph rewriting system
+
+ An extension of a {term rewriting system} which uses {graph
+ reduction} on terms represented by {directed graphs} to avoid
+ duplication of work by sharing expressions.
+
+GRAPPLE
+
+ GRAPh Processing LanguagE. 1968.
+
+ ["A Directed Graph Representation for Computer Simulation of
+ Belief Systems", L.G. Tesler et al, Math Biosciences 2:19-40
+ (1968)].
+
+GRAS
+
+ A {public domain} {graph-oriented database} system for
+ {software engineering} applications from {RWTH Aachen}.
+
+GRASP/Ada
+
+ Graphical Representation of Algorithms, Structures and
+ Processes.
+
+ ["A Graphically Oriented Specification Language for Automatic
+ Code Generation", J.H. Cross, Auburn U, NASA CR-183212, 1989].
+
+GRASPIN
+
+ An Esprit project to develop a personal software engineering
+ environment to support the construction and verification of
+ distributed and non-sequential software systems.
+
+grault
+
+ /grawlt/ Yet another {metasyntactic variable}, invented by
+ Mike Gallaher and propagated by the {GOSMACS} documentation.
+ See {corge}.
+
+ [{Jargon File}]
+
+Gray
+
+ A {parser generator} written in {Forth} by Martin Anton Ertl
+ <anton@mips.complang.tuwien.ac.at>. Gray takes grammars in an
+ {extended BNF} and produces executable Forth code for
+ {recursive descent parsers}. There is no special support for
+ error handling. Version 3 runs under {Tile Forth} Release 2
+ by Mikael Patel.
+
+ (1992-05-22)
+
+graybar land
+
+ <jargon> The place you go while you're staring at a computer
+ that's processing something very slowly (while you watch the
+ grey bar creep across the screen).
+
+ "I was in graybar land for hours, waiting for that CAD
+ rendering".
+
+ (1997-04-17)
+
+Gray code
+
+ <hardware> A {binary} sequence with the property that only one
+ {bit} changes between any two consecutive elements (the two
+ codes have a {Hamming distance} of one).
+
+ The Gray code originated when {digital logic} circuits were
+ built from {vacuum tubes} and electromechanical {relays}.
+ Counters generated tremendous power demands and noise spikes
+ when many bits changed at once. E.g. when incrementing a
+ register containing 11111111, the {back-EMF} from the relays'
+ collapsing magnetic fields required copious noise suppression.
+ Using Gray code counters, any increment or decrement changed
+ only one bit, regardless of the size of the number.
+
+ Gray code can also be used to convert the angular position of
+ a disk to digital form. A radial line of sensors reads the
+ code off the surface of the disk and if the disk is half-way
+ between two positions each sensor might read its bit from both
+ positions at once but since only one bit differs between the
+ two, the value read is guaranteed to be one of the two valid
+ values rather than some third (invalid) combination (a
+ {glitch}).
+
+ One possible {algorithm} for generating a Gray code sequence
+ is to toggle the lowest numbered bit that results in a new
+ code each time. Here is a four bit Gray code sequence
+ generated in this way:
+
+ 0 0 0 0
+ 0 0 0 1
+ 0 0 1 1
+ 0 0 1 0
+ 0 1 1 0
+ 0 1 1 1
+ 0 1 0 1
+ 0 1 0 0
+ 1 1 0 0
+ 1 1 0 1
+ 1 1 1 1
+ 1 1 1 0
+ 1 0 1 0
+ 1 0 1 1
+ 1 0 0 1
+ 1 0 0 0
+
+ The codes were patented in 1953 by Frank Gray, a {Bell Labs}
+ researcher.
+
+ {(http://nist.gov/dads/HTML/graycode.html)}.
+
+ (2002-08-29)
+
+gray-scale
+
+ <spelling> US spelling of "{grey-scale}".
+
+<gr&d>
+
+ <chat> Grinning, running and ducking.
+
+ See {emoticon}.
+
+ (1995-03-17)
+
+GRE
+
+ {Generic Routing Encapsulation}
+
+greater than
+
+ <character> ">" {ASCII} character 62.
+
+ Common names: {ITU-T}: greater than; ket ("<" = bra); right
+ angle; right angle bracket; right broket. Rare: into,
+ toward; write to; blow ("<" = suck); gozinta; out; zap (all
+ from {Unix} {I/O redirection}); {INTERCAL}: right angle.
+
+ See also {less than}.
+
+ (1995-03-17)
+
+greatest common divisor
+
+ <mathematics> (GCD) A function that returns the largest
+ positive {integer} that both arguments are integer multiples
+ of.
+
+ See also {Euclid's Algorithm}. Compare: {lowest common
+ multiple}.
+
+ (1999-11-02)
+
+greatest lower bound
+
+ <theory> (glb, meet, infimum) The greatest lower bound of two
+ elements, a and b is an element c such that c <= a and c <= b
+ and if there is any other lower bound c' then c' <= c.
+
+ The greatest lower bound of a set S is the greatest element b
+ such that for all s in S, b <= s. The glb of mutually
+ comparable elements is their minimum but in the presence of
+ incomparable elements, if the glb exists, it will be some
+ other element less than all of them.
+
+ glb is the dual to {least upper bound}.
+
+ (In {LaTeX} "<=" is written as {\sqsubseteq}, the glb of two
+ elements a and b is written as a {\sqcap} b and the glb of set
+ S as \bigsqcap S).
+
+ (1995-02-03)
+
+Great Renaming
+
+ <history> The {flag day} in 1986 on which all of the non-local
+ groups on the {Usenet} had their names changed from the net.-
+ format to the current multiple-hierarchies scheme. Used
+ especially in discussing the history of newsgroup names. "The
+ oldest sources group is comp.sources.misc; before the Great
+ Renaming, it was net.sources."
+
+ {FAQ (http://vrx.net/usenet/history/rename.html)}.
+
+ [{Jargon File}]
+
+ (2000-07-14)
+
+Great Runes
+
+ Uppercase-only text or display messages. Some archaic
+ {operating systems} still emit these.
+
+ See also {runes}, {smash case}, {fold case}.
+
+ Decades ago, back in the days when it was the sole supplier of
+ long-distance hardcopy transmittal devices, the Teletype
+ Corporation was faced with a major design choice. To shorten
+ code lengths and cut complexity in the printing mechanism, it
+ had been decided that teletypes would use a monocase font,
+ either ALL UPPER or all lower. The Question Of The Day was
+ therefore, which one to choose. A study was conducted on
+ readability under various conditions of bad ribbon, worn print
+ hammers, etc. Lowercase won; it is less dense and has more
+ distinctive letterforms, and is thus much easier to read both
+ under ideal conditions and when the letters are mangled or
+ partly obscured. The results were filtered up through
+ {management}. The chairman of Teletype killed the proposal
+ because it failed one incredibly important criterion:
+
+ "It would be impossible to spell the name of the Deity
+ correctly."
+
+ In this way (or so, at least, hacker folklore has it)
+ superstition triumphed over utility. Teletypes were the major
+ input devices on most early computers, and terminal
+ manufacturers looking for corners to cut naturally followed
+ suit until well into the 1970s. Thus, that one bad call stuck
+ us with Great Runes for thirty years.
+
+ (1994-12-02)
+
+Great Worm
+
+ {Internet Worm}
+
+greek
+
+ 1. <text, graphics> To display text as abstract dots and lines
+ in order to give a preview of layout without actually being
+ legible. This is faster than drawing the characters correctly
+ which may require scaling or other transformations. Greeking
+ is particularly useful when displaying a reduced image of a
+ document where the text would be too small to be legible on
+ the display anyway.
+
+ A related technique is {lorem ipsum}.
+
+ (2006-09-18)
+
+greeking
+
+ {greek}
+
+Green
+
+ <language> A language proposed by Cii {Honeywell-Bull} to meet
+ the DoD {Ironman} requirements which led to {Ada}. This
+ language won in 1979.
+
+ ["On the GREEN Language Submitted to the DoD", E.W. Dijkstra,
+ SIGPLAN Notices 13(10):16-21 (Oct 1978)].
+
+ (1994-12-02)
+
+Green Book
+
+ 1. <publication> Informal name for one of the four standard
+ references on {PostScript}. The other three official guides
+ are known as the {Blue Book}, the {Red Book}, and the {White
+ Book}.
+
+ ["PostScript Language Program Design", Adobe Systems,
+ Addison-Wesley, 1988 (ISBN 0-201-14396-8)].
+
+ 2. <publication> Informal name for one of the three standard
+ references on {SmallTalk}. Also associated with blue and red
+ books.
+
+ ["Smalltalk-80: Bits of History, Words of Advice", by Glenn
+ Krasner (Addison-Wesley, 1983; QA76.8.S635S58; ISBN
+ 0-201-11669-3)].
+
+ 3. <publication> The "X/Open Compatibility Guide", which
+ defines an international standard {Unix} environment that is a
+ proper superset of {POSIX}/SVID. It also includes
+ descriptions of a standard utility toolkit, systems
+ administrations features, and the like. This grimoire is
+ taken with particular seriousness in Europe. See {Purple
+ Book}.
+
+ 4. <publication> The {IEEE} 1003.1 {POSIX} Operating Systems
+ Interface standard has been dubbed "The Ugly Green Book".
+
+ 5. <publication> Any of the 1992 standards issued by the
+ {ITU-T}'s tenth plenary assembly. These include, among other
+ things, the dreadful {X.400} {electronic mail} standard and
+ the Group 1 through 4 fax standards.
+
+ 6. {Green Book CD-ROM}.
+
+ See also {book titles}.
+
+ [{Jargon File}]
+
+ (1996-12-03)
+
+Green Book CD-ROM
+
+ A standard {CD-ROM} format developed by {Philips} for {CD-i}.
+ It is {ISO 9660} compliant and uses mode 2 form 2 addressing.
+ It can only be played on drives which are XA ({Extended
+ Architecture}) compatible.
+
+ Many Green Book discs contain {CD-i} applications which can
+ only be played on a {CD-i} player but many others contain
+ films or music videos. Video CDs in Green Book format are
+ normally labelled "Digital Video on CD"
+
+ Green Book was obsoleted by {White book CD-ROM} in March 1994.
+
+ (1994-11-02)
+
+green bytes
+
+ <jargon> (Or "green words") {Meta-information} embedded in a
+ file, such as the length of the file or its name; as opposed
+ to keeping such information in a separate description file or
+ record.
+
+ By extension, the non-data bits in any self-describing format.
+ "A {GIF} file contains, among other things, green bytes
+ describing the packing method for the image".
+
+ At a meeting of the SHARE Systems Division, November 22, 1964,
+ in Washington, DC, George Mealy of {IBM} described the new
+ block tape format for {FORTRAN} in which unformatted binary
+ records had a Control Word. George used green chalk to
+ describe it. No one liked the contents of the Green Word (not
+ information, wrong location, etc.) so Conrad Weisert and
+ Channing Jackson made badges saying "Stamp out Green Words".
+ This was the first computer badge.
+
+ Compare {out-of-band}, {zigamorph}, {fence}.
+
+ {Button 251 (http://mxg.com/thebuttonman/search.asp)}.
+
+ [{Jargon File}]
+
+ (1994-11-02)
+
+green card
+
+ [after the "IBM System/360 Reference Data" card] A summary of
+ an assembly language, even if the colour is not green. Less
+ frequently used now because of the decrease in the use of
+ assembly language. "I'll go get my green card so I can check
+ the {addressing mode} for that instruction." Some green cards
+ are actually booklets.
+
+ The original green card became a yellow card when the
+ System/370 was introduced, and later a yellow booklet. An
+ anecdote from IBM refers to a scene that took place in a
+ programmers' terminal room at Yorktown in 1978. A luser
+ overheard one of the programmers ask another "Do you have a
+ green card?" The other grunted and passed the first a thick
+ yellow booklet. At this point the luser turned a delicate
+ shade of olive and rapidly left the room, never to return.
+
+ [{Jargon File}]
+
+green lightning
+
+ [IBM] 1. Apparently random flashing streaks on the face of
+ 3278-9 terminals while a new symbol set is being downloaded.
+ This hardware bug was left deliberately unfixed, as some
+ genius within IBM suggested it would let the user know that
+ "something is happening". That, it certainly does. Later
+ microprocessor-driven IBM colour graphics displays were
+ actually *programmed* to produce green lightning!
+
+ 2. [proposed] Any bug perverted into an alleged feature by
+ adroit rationalisation or marketing. "Motorola calls the CISC
+ {cruft} in the 88000 architecture "compatibility logic", but I
+ call it green lightning". See also {feature}.
+
+green machine
+
+ A computer or peripheral device that has been designed and
+ built to military specifications for field equipment (that is,
+ to withstand mechanical shock, extremes of temperature and
+ humidity, and so forth). Comes from the olive-drab "uniform"
+ paint used for military equipment.
+
+ [{Jargon File}]
+
+green monitor
+
+ {Advanced Power Management}
+
+Green's Theorem
+
+ <humour> (TMRC) For any story, in any group of people there
+ will be at least one person who has not heard the story. A
+ refinement of the theorem states that there will be *exactly*
+ one person (if there were more than one, it wouldn't be as bad
+ to re-tell the story). The name of this theorem is a play on
+ a fundamental theorem in calculus.
+
+ [{Jargon File}]
+
+ (1994-12-16)
+
+Greenwich Mean Time
+
+ <time, standard> (GMT) The local time on the Greenwich
+ meridian, based on the hypothetical mean sun (which averages
+ out the effects of the Earth's elliptical orbit and its tilted
+ axis). GMT is the basis of the civil time for the UK.
+
+ In 1925 the reference point was changed from noon to midnight
+ and it was recommended that the term "{Universal Time}" should
+ be used for the new GMT.
+
+ Authorities disagreed on whether GMT equates with {UT0} or
+ {UT1}, however the differences between the two are of the
+ order of thousandths of a second. GMT is no longer used for
+ scientific purposes.
+
+ (2001-08-02)
+
+green words
+
+ {green bytes}
+
+Greg Olson
+
+ <person> President and CEO of {Sendmail Inc.}. Olson is an
+ industry veteran who worked on {distributed systems} at
+ {Summit Systems Inc.} then at {Britton Lee Inc.}, {Sybase
+ Inc.} and {Integrated Systems Inc.}.
+
+ (1998-08-25)
+
+Gregorian calendar
+
+ <time> The system of dates used by most of the world. The
+ Gregorian calendar was proposed by the Calabrian doctor
+ Aloysius Lilius and was decreed by, and named after, Pope
+ Gregory XIII on 1582-02-24. It corrected the Julian calendar
+ whose years were slightly longer than the solar year. It also
+ replaced the lunar calendar which was also out of time with
+ the seasons. The correction was achieved by skipping several
+ days as a one-off resynchronisation and then dropping three
+ leap days every 400 hundred years. In the revised system,
+ leap years are all years divisible by 4 but excluding those
+ divisible by 100 but including those divisible by 400. This
+ gives a mean calendar year of 365.2425 days = 52.1775 weeks =
+ 8,765.82 hours = 525,949.2 minutes = 31,556,952 seconds.
+ {leap seconds} are occasionally added to this to correct for
+ irregularities in the Earth's rotation.
+
+ (2007-01-10)
+
+grep
+
+ <tool, information science> <tool> A {Unix} command for
+ searching files for lines matching a given {regular
+ expression} (RE). Named after the {qed}/{ed} editor
+ subcommand "g/re/p", where re stands for a regular expression,
+ to Globally search for the Regular Expression and Print the
+ lines containing matches to it. There are two other variants,
+ fgrep which searches only for fixed strings and {egrep} which
+ accepts extended REs but is usually the fastest of the three.
+
+ Used by extension to mean "to look for something by pattern".
+ When browsing through a large set of files, one may speak of
+ "grepping around". "Grep the bulletin board for the system
+ backup schedule, would you?" See also {vgrep}.
+
+ [{Jargon File}]
+
+grey-scale
+
+ <graphics> (US "gray-scale") 1. Composed of (discrete) shades
+ of grey. If the {pixels} of a grey-scale {image} have N
+ {bits}, they may take values from zero, representing black up
+ to 2^N-1, representing white with intermediate values
+ representing increasingly light shades of grey. If N=1 the
+ image is not called grey-scale but could be called
+ {monochrome}.
+
+ 2. A range of acurately known shades of grey printed out for
+ use in calibrating those shades on a display or printer.
+
+ (1995-03-17)
+
+Greystone Technologies
+
+ <company> The producers of the {GT/M} {MUMPS} compiler and
+ {GT/SQL} {pre-processor} for {VAX} and {DEC Alpha}.
+
+ [Address?]
+
+ (1995-01-10)
+
+GRG
+
+ A computer algebra system for differential geometry,
+ gravitation and field theory. Version 3.1 works with
+ PSL-based REDUCE 3.3 or 3.4.
+
+ E-mail: V.V. Zhytnikov <vvzhy@phy.ncu.edu.tw>.
+
+ (1994-12-16)
+
+GRIB
+
+ GRid In Binary.
+
+ The World Meteorological Organization's data format.
+
+ (1995-01-10)
+
+grick
+
+ /grik/ ({WPI}, first used by Tim Haven to describe "grick
+ trigonometry", a shortcut method of determing attack angles in
+ grid-based games like Star Trek) Any integral increment of
+ measurement. E.g. "Please turn the stereo up a few gricks".
+
+ (1995-01-31)
+
+grilf
+
+ Girl-friend.
+
+ Like {newsfroup} and {filk}, a typo incarnated as a new word.
+ Seems to have originated sometime in 1992.
+
+ [{Jargon File}]
+
+ (1995-01-31)
+
+Grim File Reaper
+
+ <storage, operating system> (GFR) An {ITS} and {LISP Machine}
+ utility to remove files according to some program-automated or
+ semi-automatic manual procedure, especially one designed to
+ reclaim mass storage space or reduce name-space clutter (the
+ original GFR actually moved files to tape).
+
+ See also {prowler}, {reaper}. Compare {GC}, which discards
+ only provably worthless stuff.
+
+ (1996-06-20)
+
+GRIND
+
+ GRaphical INterpretive Display.
+
+ A graphics input language for the {PDP-9}.
+
+ ["GRIND: A Language and Translator for Computer Graphics",
+ A.P. Conn, Dartmouth, June 1969].
+
+ [{Jargon File}]
+
+ (1995-01-31)
+
+grind
+
+ 1. (MIT and Berkeley) To prettify hardcopy of code, especially
+ LISP code, by reindenting lines, printing keywords and
+ comments in distinct fonts (if available), etc. This usage
+ was associated with the MacLISP community and is now rare;
+ {prettyprint} was and is the generic term for such operations.
+
+ 2. (Unix) To generate the formatted version of a document from
+ the {nroff}, {troff}, {TeX}, or Scribe source.
+
+ 3. To run seemingly interminably, especially (but not
+ necessarily) if performing some tedious and inherently useless
+ task. Similar to {crunch} or {grovel}. Grinding has a
+ connotation of using a lot of CPU time, but it is possible to
+ grind a disk, network, etc.
+
+ See also {hog}.
+
+ 4. To make the whole system slow. "Troff really grinds a
+ PDP-11."
+
+ 5. "grind grind" excl. Roughly, "Isn't the machine slow
+ today!"
+
+ [{Jargon File}]
+
+ (1994-12-16)
+
+grind crank
+
+ A mythical accessory to a {terminal}. A crank on the side of
+ a monitor, which when operated makes a zizzing noise and
+ causes the computer to run faster. Usually one does not refer
+ to a grind crank out loud, but merely makes the appropriate
+ gesture and noise. See {grind}.
+
+ Historical note: At least one real machine actually had a
+ grind crank - the R1, a research machine built toward the
+ end of the days of the great vacuum tube computers, in 1959.
+ R1 (also known as "The Rice Institute Computer" (TRIC) and
+ later as "The Rice University Computer" (TRUC)) had a
+ {single-step}/free-run switch for use when debugging programs.
+ Since single-stepping through a large program was rather
+ tedious, there was also a crank with a cam and gear
+ arrangement that repeatedly pushed the single-step button.
+ This allowed one to "crank" through a lot of code, then slow
+ down to single-step for a bit when you got near the code of
+ interest, poke at some registers using the console typewriter,
+ and then keep on cranking.
+
+ [{Jargon File}]
+
+GRIP
+
+ Graph Reduction In Parallel.
+
+ Simon Peyton Jones's GRIP machine built at {UCL}, now at the
+ {University of Glasgow}. It has many processors ({Motorola
+ 68020} or other) on {Futurebus} with intelligent memory units.
+
+ (1994-12-14)
+
+gripenet
+
+ [IBM] A wry (and thoroughly unofficial) name for {IBM}'s
+ internal {VNET} system, deriving from its common use by IBMers
+ to voice pointed criticism of IBM management that would be
+ taboo in more formal channels.
+
+ [{Jargon File}]
+
+gritch
+
+ /grich/ 1. A complaint (often caused by a {glitch}).
+
+ 2. To complain. Often verb-doubled: "Gritch gritch".
+
+ 3. A synonym for {glitch} (as verb or noun).
+
+ (1995-01-31)
+
+grix
+
+ /griks/ ({WPI}) A meta-number, said to be an integer between 6
+ and 7. Used either alone or with {flib} or suffixes such as
+ -ty, -teen, etc. to denote an arbitrary integer (see {N}).
+ "This system will {bomb} if there are grixty-flib users on
+ it."
+
+ (1995-01-31)
+
+groff
+
+ GNU roff.
+
+ {GNU}'s implementation of {roff} in {C++}.
+
+ See also {nroff}, {troff}.
+
+ Version 1.07 by James J. Clark <jjc@jclark.com>.
+
+ FTP groff-1.07.tar.z from a {GNU archive site}.
+
+ (1993-03-03)
+
+grok
+
+ /grok/, /grohk/ (From the novel "Stranger in a Strange Land",
+ by Robert A. Heinlein, where it is a Martian word meaning
+ literally "to drink" and metaphorically "to be one with")
+
+ 1. To understand, usually in a global sense. Connotes
+ intimate and exhaustive knowledge.
+
+ Contrast {zen}, which is similar supernal understanding
+ experienced as a single brief flash. See also {glark}.
+
+ 2. Used of programs, may connote merely sufficient
+ understanding. "Almost all C compilers grok the "void" type
+ these days."
+
+ [{Jargon File}]
+
+ (1995-01-31)
+
+gronk
+
+ /gronk/ Popularised by Johnny Hart's comic strip "B.C." but
+ the word apparently predates that.
+
+ 1. To clear the state of a {wedged} device and restart it.
+ More severe than "to {frob}" (sense 2).
+
+ 2. [TMRC] To cut, sever, smash, or similarly disable.
+
+ 3. The sound made by many 3.5-inch diskette drives. In
+ particular, the microfloppies on a Commodore {Amiga} go
+ "grink, gronk".
+
+ [{Jargon File}]
+
+gronked
+
+ 1. Broken. "The teletype scanner was gronked, so we took the
+ system down."
+
+ 2. Of people, the condition of feeling very tired or (less
+ commonly) sick. "I've been chasing that bug for 17 hours now
+ and I am thoroughly gronked!" Compare {broken}, which means
+ about the same as {gronk} used of hardware, but connotes
+ depression or mental/emotional problems in people.
+
+group
+
+ A group G is a non-empty {set} upon which a {binary} operator
+ * is defined with the following properties for all a,b,c in G:
+
+ Closure: G is closed under *, a*b in G
+ Associative: * is associative on G, (a*b)*c = a*(b*c)
+ Identity: There is an identity element e such that
+ a*e = e*a = a.
+ Inverse: Every element has a unique inverse a' such that
+ a * a' = a' * a = e. The inverse is usually
+ written with a superscript -1.
+
+ (1998-10-03)
+
+Group 3
+
+ <protocol, compression> (G3) The {CCITT} fax {protocol} which
+ uses data {compression} and allows a variety of file types
+ (e.g. {electronic mail}, pictures, {PostScript}) to be
+ transmitted over {analogue} telephone lines.
+
+ The Group 3 protocol was published by {CCITT} in 1993. Full
+ details of the protocol are available from {ITU-T}.
+
+ See also {Group 4}.
+
+ (1998-10-03)
+
+Group 4
+
+ <protocol, compression> (G4) The {CCITT} fax {protocol} which
+ uses data {compression} and allows a variety of file types
+ (e-mail, pictures, {PostScript}, etc.) to be transmitted over
+ digital ({ISDN}) telephone lines.
+
+ The Group 4 protocol was published by {CCITT} in 1993. Full
+ details of the protocol are available from {ITU-T}.
+
+ See also {Group 3}.
+
+ (1998-09-10)
+
+Group Code Recording
+
+ <storage> (GCR) A recording method used for 6250 BPI {magnetic
+ tapes}.
+
+ GCR typically uses a group of five {bits} of code to represent
+ four bits of data. The encoding ensures no more than two or
+ three zeros occur in a row, and no more than eight or so ones
+ occur in a row, where zeros represent an absense of magnetic
+ change.
+
+ GCR is also used on {Commodore Business Machines} {diskette}
+ drives; the 4040, 8050, 154x, 157x and 158x series of 5.25"
+ and 3.5" low and high density diskette drives used with 8-bit
+ home computers circa 1977 to 1992. It was also supported on
+ {Amiga} internal and external drives but only used for reading
+ non-Amiga disks.
+
+ Compare {NRZI}, {PE}.
+
+ (2004-06-01)
+
+group identifier
+
+ <operating system> (gid) A unique number, between 0 an 32767,
+ identifying a set of {users} under {Unix}. Gids are found in
+ the /etc/{passwd} and /etc/group databases (or their {NIS}
+ equivalents) and one is also associated with each file,
+ indicating the group to which its group {permissions} apply.
+
+ (1996-12-01)
+
+Group Separator
+
+ <character> (GS) {ASCII} character 29.
+
+ (1996-06-28)
+
+Group-Sweeping Scheduling
+
+ <storage, algorithm> (GSS) A disk scheduling strategy in which
+ requests are served in cycles, in a round-robin manner. To
+ reduce disk arm movements ("{seek}ing"), the set of streams is
+ divided into groups that are served in fixed order. Streams
+ within a group are served according to "{SCAN}".
+
+ If all clients are assigned to one group, GSS reduces to SCAN,
+ and if all clients are assigned to separate groups, GSS
+ effectively becomes round-robin scheduling. The service order
+ within one group is not fixed, and a stream may in fact be
+ first in one cycle while last in the next. This variation has
+ to be masked by extra buffering but whereas SCAN requires
+ buffer space for all streams, GSS can reuse the buffer for
+ each group and effect a trade-off between {seek optimisation}
+ and buffer requirements.
+
+ (1995-11-12)
+
+Groupware
+
+ {CSCW}
+
+Groupwise
+
+ <software, networking> A {workgroup} application suite
+ offering {electronic mail} and diary scheduling from {Novell,
+ Inc.}. It can operate on a number of {platforms}.
+
+ Groupwise was previously known as {WordPerfect Office}, and is
+ an extensible system suitable for {LAN} or {WAN} operation.
+ {Mail gateway} software is available for a number of
+ {protocols} including {SMTP}, allowing the exchange of mail
+ with the {Internet}.
+
+ (1995-09-23)
+
+grovel
+
+ 1. To work interminably and without apparent progress. Often
+ used transitively with "over" or "through". "The file
+ scavenger has been groveling through the /usr directories for
+ 10 minutes now." Compare {grind} and {crunch}. Emphatic
+ form: "grovel obscenely".
+
+ 2. To examine minutely or in complete detail. "The compiler
+ grovels over the entire source program before beginning to
+ translate it." "I grovelled through all the documentation,
+ but I still couldn't find the command I wanted."
+
+ [{Jargon File}]
+
+grunge
+
+ /gruhnj/ 1. That which is grungy, or that which makes it so.
+
+ 2. [Cambridge] Code which is inaccessible due to changes in
+ other parts of the program. The preferred term in North
+ America is {dead code}.
+
+gry
+
+ <puzzle> "Angry" and "hungry" are two words that end in "gry".
+ What is the third word. Everyone knows what it means and
+ everyone uses it every day. Look closely and I have already
+ given you the third word. What is it?
+
+ Answer: "what".
+
+ Variants of this puzzle have circulated widely on the Internet
+ for some years, usually in a corrupted form such as "Name
+ three common English words ending in 'gry'", which has no
+ third answer.
+
+ {(http://www.worldwidewords.org/articles/gry.htm)}.
+ {(http://word-detective.com/gry.html)}.
+
+ (2007-04-04)
+
+GS
+
+ {Group Separator}
+
+gs
+
+ <networking> The {country code} for South Georgia and the
+ South Sandwich Islands.
+
+ (1999-01-27)
+
+GSBL
+
+ <language>
+
+ ["GSBL: An Algebraic Specification Language Based on
+ Inheritance", S. Clerici et al in ECOOP '88, S. Gjessing et
+ al eds, LNCS 322, Springer 1988, pp.78-92].
+
+ (2003-06-02)
+
+GSI
+
+ {Gensym Standard Interface}
+
+GSL
+
+ Grenoble System Language. M. Berthaud, IBM, Grenoble. "GSL
+ Language Reference Manual", M. Berthaud et al, March 1973. "A
+ MOL-Based Software Construction System", M. Berthaud et al, in
+ Machine Oriented Higher Level Languages, W. van der Poel, N-H
+ 1974, pp.151-157.
+
+GSM
+
+ {Global System for Mobile Communications}
+
+GSPL
+
+ <language> {Greenberg's System Programming Language}.
+
+ Bernard Greenberg.
+
+ (1995-05-09)
+
+GSS
+
+ <storage> {Group-Sweeping Scheduling}.
+
+ (1995-11-12)
+
+GSS-API
+
+ {Generic Security Service Application Programming Interface}
+
+gt
+
+ <networking> The {country code} for Guatemala.
+
+ (1999-01-27)
+
+gtg
+
+ <chat> Got to go. The user is about to stop chatting.
+
+ (1999-06-07)
+
+GTK+
+
+ <graphics, interface, library, open source> ("The {GIMP}
+ ToolKit", or incorrectly "{Gnu} ToolKit" or "Generic ToolKit")
+ A {multi-platform} toolkit for creating {graphical user
+ interfaces}. Offering a complete set of {widgets}, GTK+ is
+ suitable for projects ranging from small one-off projects to
+ complete application suites.
+
+ GTK+ consists of the three parts; {GLib}, providing basic data
+ structures, {event handling}, {threads}, etc., {Pango}, for
+ {layout} and {rendering} of text, and {ATK}, providing
+ interfaces for {accessibility}.
+
+ {GTK+ Home (http://gtk.org/)}.
+
+ (2003-12-03)
+
+GTL
+
+ {Gunning Transceiver Logic}
+
+GT/SQL
+
+ <tool> An {SQL} {pre-processor} from {Greystone Technologies}
+ which combines {MUMPS} code with {SQL} code and generates code
+ that can work with a {database} from both the MUMPS and SQL
+ perspectives. This is often done when a database is to be
+ made available in a {client/server} environment, where the
+ MUMPS database serves one or more SQL {clients}.
+
+ (1995-01-10)
+
+gu
+
+ <networking> The {country code} for Guam.
+
+ (1999-01-27)
+
+guaranteed scheduling
+
+ <algorithm> A scheduling {algorithm} used in {multitasking}
+ {operating systems} that guarantees fairness by monitoring the
+ amount of {CPU time} spent by each user and allocating
+ resources accordingly.
+
+ [How does it allocate resources?]
+
+ (1998-04-26)
+
+guard
+
+ <programming> 1. In {functional programming}, a {Boolean}
+ expression attached to a function definition specifying when
+ (for what arguments) that definition is appropriate.
+
+ 2. In (parallel) {logic programming}, a Boolean expression
+ which is used to select a {clause} from several alternative
+ matching clauses.
+
+ See {Guarded Horn Clauses}.
+
+ 3. In {parallel} languages, a {Boolean} expression which
+ specifies when an message may be sent or received.
+
+ (1995-05-09)
+
+Guarded Horn Clauses
+
+ <language> (GHC) A parallel dialect of {Prolog} by K. Ueda in
+ which each {clause} has a {guard}. GHC is similar to
+ {Parlog}. When several clauses match a {goal}, their guards
+ are evaluated in parallel and the first clause whose guard is
+ found to be true is used and others are rejected. It uses
+ {committed-choice nondeterminism}.
+
+ See also {FGHC}, {KL1}.
+
+ (1995-05-09)
+
+gubbish
+
+ <jargon> /guhb'*sh/ (A portmanteau of "garbage" and "rubbish"
+ which may have originated with SF author Philip K. Dick)
+ Garbage; crap; nonsense. "What is all this gubbish?" The
+ opposite portmanteau "rubbage" is also reported.
+
+ [{Jargon File}]
+
+ (1995-05-09)
+
+guest book
+
+ <web> The electronic equivalent of the physical
+ notebooks found in some small hotels, in which visitors can
+ write their names, comments and suggestions for the benefit of
+ the proprietors and future visitors or purely for posterity.
+ The electronic version is a form on a {website} into which
+ users can enter similar details for display on the site.
+
+ (2009-01-15)
+
+GUI
+
+ {Graphical User Interface}
+
+GUIDE
+
+ {Graphical User Interface} Development Environment from {Sun}.
+
+Guide
+
+ A {hypertext} system from the University of Kent (GB) and
+ {OWL} for displaying on-line documentation.
+
+Guide to Available Mathematical Software
+
+ <mathematics>
+
+ {(http://gams.nist.gov/)}.
+
+ (1995-04-28)
+
+guiltware
+
+ /gilt'weir/ 1. A piece of {freeware} decorated with a message
+ telling one how long and hard the author worked on it and
+ intimating that one is a no-good freeloader if one does not
+ immediately send the poor suffering martyr gobs of money.
+
+ 2. {Shareware} that works.
+
+ [{Jargon File}]
+
+gun
+
+ <jargon> ({ITS}, from the ":GUN" command) To forcibly
+ terminate a program or job (computer, not career). "Some
+ idiot left a background process running soaking up half the
+ cycles, so I gunned it."
+
+ Compare {can}.
+
+ (1995-02-27)
+
+gunch
+
+ /guhnch/ <jargon> ({TMRC}) To push, prod, or poke at a device
+ that has almost (but not quite) produced the desired result.
+ Implies a threat to {mung}.
+
+ [{Jargon File}]
+
+ (1995-02-27)
+
+Gunning Transceiver Logic
+
+ <electronics, hardware, integrated circuit, standard> (GTL) A
+ {standard} for electrical signals in {CMOS} circuits used to
+ provide higher data transfer speeds with smaller voltage
+ swings [compared with what?].
+
+ The GTL signal swings between 0.4 volts and 1.2 volts with a
+ reference voltage of about 0.8 volts. Only a small deviation
+ of 0.4 volts (or thereabouts) from the reference voltage is
+ required to switch between on and off states. Therefore, a
+ GTL signal is said to be a low voltage swing logic signal.
+
+ Gunning Transceiver Logic has several advantages. The
+ {resistive termination} of a GTL signal provides a clean
+ signalling environment [what?]. Moreover, the low terminating
+ voltage of 1.2 volts results in reduced voltage drops across
+ the resistive elements. GTL has low power dissipation and can
+ operate at high frequency and causes less {electromagnetic
+ interference} (EMI).
+
+ {GTL/BTL: A Low-Swing Solution for High-Speed Digital Logic
+ (http://edtn.com/scribe/reference/appnotes/md003ecc.htm)}.
+
+ (2000-01-16)
+
+gunzip
+
+ <tool, compression> The decompression utility corresponding to
+ {gzip}. In operating systems with links, gunzip is just a
+ link to gzip and its function can be invoked by passing a "-d"
+ flag to gzip.
+
+ (1996-01-03)
+
+Gupta Corporation
+
+ <company> The vendor of {SQLWindows}.
+
+ Gupta Corporation provides application development and
+ deployment software for {client-server} {applications},
+ consisting of a {relational database}, application development
+ tools and transparent connectivity software.
+
+ Gupta employs 400 people in 15 offices worldwide, including
+ the United States, Europe and Asia. Gupta's 1993 fiscal year
+ income was $5.6 million and their revenue was $56.1 million.
+ Gupta sells client-server system components for networks of
+ {personal computers}.
+
+ {(http://wji.com/gupta/htmls/homepage.html)}.
+
+ Address: 1060 Marsh Road, Menlo Park, CA 94025, USA.
+
+ Telephone: +1 (415) 321 9500. Fax: +1 (415) 321 5471.
+
+ (1997-04-28)
+
+gurfle
+
+ <exclamation> /ger'fl/ An expression of shocked disbelief.
+ "He said we have to recode this thing in {Fortran} by next
+ week. Gurfle!"
+
+ Compare {weeble}.
+
+ [{Jargon File}]
+
+ (1996-06-01)
+
+guru
+
+ <job> An expert, especially in "{Unix} guru". Implies not
+ only {wizard} skill but also a history of being a knowledge
+ resource for others. Less often, used (with a qualifier) for
+ other experts on other systems, as in "VMS guru".
+
+ See {source of all good bits}.
+
+ [{Jargon File}]
+
+ (1996-06-01)
+
+guru meditation
+
+ <operating system, exception> The {Amiga} equivalent of
+ {Unix}'s {panic} (sometimes just called a "guru" or "guru
+ event"). When the system crashes, a cryptic message of the
+ form "GURU MEDITATION #XXXXXXXX.YYYYYYYY" may appear,
+ indicating what the problem was. An Amiga guru can figure
+ things out from the numbers.
+
+ In the earliest days of the Amiga, there was a device called a
+ "Joyboard" which was basically a plastic board built onto a
+ joystick-like device; it was sold with a skiing game cartridge
+ for the Atari game machine. It is said that whenever the
+ prototype OS crashed, the system programmer responsible would
+ concentrate on a solution while sitting cross-legged, balanced
+ on a Joyboard, resembling a meditating guru. Sadly, the joke
+ was removed in AmigaOS 2.04.
+
+ The {Jargon File} claimed that a {guru} event had to be
+ followed by a {Vulcan nerve pinch} but, according to a
+ correspondent, a mouse click was enough to start a reboot.
+
+ (2002-06-25)
+
+Guy Lewis Steele, Jr.
+
+ <person> (GLS) A software engineer whose most notable
+ contributions to the art of computing include the design of
+ {Scheme} (in cooperation with {Gerald Sussman}) and the design
+ of the original command set of {Emacs}. He is also known for
+ his contribution to the {Jargon File} and for being the first
+ to port {TeX} (from {WAITS} to {ITS}). He wrote the book
+ "Common Lisp", which virtually defines the language.
+
+ He was working at {Sun Microsystems, Inc.} from 1996 to the
+ present (June 2001).
+
+ (2001-06-14)
+
+Guy Steele
+
+ {Guy Lewis Steele, Jr.}
+
+GVL
+
+ Graphical View Language. A visual language for specifying
+ interactive graphical output by T.C.N. Graham & J.R. Cordy,
+ Queen's University, Canada.
+
+ ["GVL: A Graphical, Functional Language for the Specification
+ of Output in Programming Languages", J.R. Cordy &
+ T.C.N. Graham, Proc IEEE Intl Conf on Comp Lang ICCL'90 (March
+ 1990)].
+
+gw
+
+ <networking> The {country code} for Guinea-Bissau.
+
+ (1999-01-27)
+
+GW-Ada
+
+ A new version of {Ada/Ed}?
+
+ {MS-DOS version
+ (ftp://wuarchive.wustl.edu/languages/ada/compiler/adaed/gwu/9309/dos)},
+ {Macintosh version
+ (ftp://wuarchive.wustl.edu/languages/ada/compilers/adaed/gwu/mac)}.
+
+ (1993-09-01)
+
+GW-BASIC
+
+ <language> An early version of {MS-BASIC}.
+
+ (1995-05-12)
+
+gweep
+
+ /gweep/ To {hack}, usually at night, or one who does so. At
+ {WPI}, from 1977 onward, gweeps could often be found at the
+ College Computing Center punching cards or crashing the
+ {PDP-10} or, later, the {DEC-20}. The term has survived the
+ demise of those technologies, however, and is still alive in
+ late 1991. "I'm going to go gweep for a while. See you in
+ the morning." "I gweep from 8 PM till 3 AM during the week."
+
+ "Gweep" originated as an onomatopeiac term, evoking the sound
+ of the (once-ubiquitous) {Hazeltine 9000} terminals' bell on
+ WPI campus.
+
+ A gweep is one step above a {fweep}.
+
+ [{Jargon File}]
+
+ (1995-01-31)
+
+GWHIS
+
+ <web> A commercial version of {NCSA} {Mosaic} for
+ {MS Windows} 3.x and {Windows for Workgroups}. GWHIS was
+ released by {Quadralay} Corporation on 30 September 1994.
+
+ GWHIS Viewer for {Microsoft Windows} differs from {NCSA}
+ {Mosaic} for {Microsoft Windows} in several ways including:
+
+ A {hotlist} similiar to the {X Window System} version. Edit
+ Annotation and Delete Annotation work. All Buttons and Menu
+ Items are "greyed out" while files are being retreived and
+ processed. This prevents the user from queing up requests to
+ the {TCP/IP} stack which causes many crashes. {Look and Feel}
+ are similiar to the X version. On-line help is complete.
+ Functional Setup program. Greater overall stability.
+
+ (1994-12-16)
+
+GWM
+
+ Generic Window Manager. An extensible window manager for the
+ {X Window System}. It is built on top of an {interpreter} for
+ the {WOOL} language.
+
+ {(ftp://export.lcs.mit.edu/contrib/gwm)},
+ {(ftp://avahi.inria.fr/contrib/gwm)}.
+
+gy
+
+ <networking> The {country code} for Guyana.
+
+ (1999-01-27)
+
+Gypsy
+
+ Specification and verification of {concurrent} systems
+ software. {Message} passing using named {mailbox}es.
+ Separately compilable units: routine (procedure, function, or
+ process), type and constant definition, each with a list of
+ access rights.
+
+ ["Report on the Language Gypsy", A.L. Ambler et al, UT Austin
+ ICSCS-CMP-1976-08-1].
+
+gz
+
+ {gzip}
+
+gzip
+
+ <tool, compression> {GNU} compression utility. Gzip reduces
+ the size of the named files using {Lempel-Ziv} {LZ77
+ compression}. Whenever possible, each file is replaced by one
+ with the {filename extension} ".gz". Compressed files can be
+ restored to their original form using gzip -d or gunzip or
+ zcat.
+
+ The Unix "{compress}" utility is patented (by two separate
+ patents, in fact) and is thus shunned by the GNU Project since
+ it is not {free software}. They have therefore chosen gzip,
+ which is free of any known {software patents} and which tends
+ to compress better anyway. All compressed files in the {GNU}
+ {anonymous FTP} area (gnu.org/pub/gnu) are in gzip
+ format and their names end in ".gz" (as opposed to
+ "compress"-compressed files, which end in ".Z").
+
+ Gzip can uncompress "compress"-compressed files and "pack"
+ files (which end in ".z"). The decompression algorithms are
+ not patented, only compression is.
+
+ The gzip program is available from any {GNU archive site} in
+ {shar}, {tar}, or gzipped tar format (for those who already
+ have a prior version of gzip and want faster data
+ transmission). It works on virtually every {Unix} system,
+ {MS-DOS}, {OS/2} and {VMS}.
+
+h
+
+ 1. A simple {markup} language intended for quick conversion of
+ existing text to {hypertext}.
+
+ 2. A method of marking common words to call attention to the
+ fact that they are being used in a nonstandard, ironic, or
+ humorous way. Originated in the fannish catchphrase "Bheer
+ is the One True Ghod!" from decades ago. H-infix marking of
+ "Ghod" and other words spread into the 1960s counterculture
+ via underground comix, and into early hackerdom either from
+ the counterculture or from SF fandom (the three overlapped
+ heavily at the time). More recently, the h infix has become
+ an expected feature of benchmark names (Dhrystone, Rhealstone,
+ etc.); this follows on from the original Whetstone (the name
+ of a laboratory) but may have been influenced by the
+ fannish/counterculture h infix.
+
+ [{Jargon File}]
+
+ (1994-11-04)
+
+H.261
+
+ <networking, standard> A {video compression} {standard}
+ developed by {ITU-T} before 1992 to work with {integrated
+ service digital network}. Data is compressed at the rate of
+ 64P kilobits per second, where P can range from 1 to 30
+ depending on the number of ISDN channels used. This standard
+ was developed primarily to support {video phones} and {video
+ conferencing}.
+
+ See also {ivs}.
+
+ {(http://crs4.it/~luigi/MPEG/mpeggloss-h.html#H.261)}.
+
+ [Date? Details?]
+
+ (1994-11-03)
+
+H.264
+
+ <video, standard> (Or Advanced Video Coding, AVC) A low {bit
+ rate} visual communication {standard} used in {video
+ conferencing}. H.264 was developed by {MPEG} and {ITU-T}
+ {VCEG} to replace {H.263}.
+
+ {Video and image compression resources and research
+ (http://www.vcodex.fsnet.co.uk/h264.html)}.
+
+ (2007-03-16)
+
+H.323
+
+ <communications, standard> The {ITU-T standard} for sending
+ {voice} ({audio}) and {video} using {IP} on a {LAN} without
+ {QoS}.
+
+ H.323 includes {Q.931} for call setup, {H.225} for call
+ signalling, {H.245} for exchanging terminal capabilities,
+ {RTP}/{RTCP} for packet streaming, {G.711}/{G.712} for
+ {CODECs}, and several other {protcols}, many of which need to
+ be negotiated to setup a simple voice call.
+
+ The complexity of H.323 has lead to the {IETF} proposing the
+ simpler alternatives {SIP} and {MGCP}/{Megaco}.
+
+ (2003-11-30)
+
+Habitat
+
+ <networking, graphics> The original term for on-line graphical
+ {virtual communities} or worlds. Created at Lucasfilm in 1985
+ by Randy Farmer and Chip Morningstar.
+
+ {(http://communities.com/habitat.html)}.
+
+ (1996-06-12)
+
+hack
+
+ <jargon> 1. Originally, a quick job that produces what is
+ needed, but not well.
+
+ 2. An incredibly good, and perhaps very time-consuming, piece
+ of work that produces exactly what is needed.
+
+ 3. To bear emotionally or physically. "I can't hack this
+ heat!"
+
+ 4. To work on something (typically a program). In an
+ immediate sense: "What are you doing?" "I'm hacking TECO."
+ In a general (time-extended) sense: "What do you do around
+ here?" "I hack TECO." More generally, "I hack "foo"" is
+ roughly equivalent to ""foo" is my major interest (or
+ project)". "I hack solid-state physics." See {Hacking X for
+ Y}.
+
+ 5. To pull a prank on. See {hacker}.
+
+ 6. To interact with a computer in a playful and exploratory
+ rather than goal-directed way. "Whatcha up to?" "Oh, just
+ hacking."
+
+ 7. Short for {hacker}.
+
+ 8. See {nethack}.
+
+ 9. (MIT) To explore the basements, roof ledges, and steam
+ tunnels of a large, institutional building, to the dismay of
+ Physical Plant workers and (since this is usually performed at
+ educational institutions) the Campus Police. This activity
+ has been found to be eerily similar to playing adventure games
+ such as {Dungeons and Dragons} and {Zork}. See also
+ {vadding}.
+
+ See also {neat hack}, {real hack}.
+
+ [{Jargon File}]
+
+ (1996-08-26)
+
+hackathon
+
+ <jargon> A planned {hacking run} that is intended to last for
+ about a week with lots of {hackers}. The term was used in
+ 2005 by the {Apache} Foundation and the {OpenBSD} Project,
+ among others.
+
+ (2005-01-26)
+
+hack attack
+
+ <jargon> (Possibly by analogy with "Big Mac Attack" from
+ advertisements for the McDonald's fast-food chain; the variant
+ "big hack attack" is reported) Nearly synonymous with {hacking
+ run}, though the latter more strongly implies an all-nighter.
+
+ [{Jargon File}]
+
+ (1996-08-26)
+
+hacked off
+
+ <jargon> (Analogous to "pissed off") Said of {system
+ administrators} who have become annoyed, upset, or touchy
+ owing to suspicions that their sites have been or are going to
+ be victimised by {crackers}, or used for inappropriate,
+ technically illegal, or even overtly criminal activities. For
+ example, having unreadable files in your home directory called
+ "worm", "lockpick", or "goroot" would probably be an effective
+ (as well as impressively obvious and stupid) way to get your
+ sysadmin hacked off at you.
+
+ [{Jargon File}]
+
+ (1996-08-26)
+
+hacked up
+
+ <jargon, programming> Sufficiently {patched}, {kluge}d, and
+ {tweaked} that the surgical scars are beginning to crowd out
+ normal tissue (compare {critical mass}). Not all programs
+ that are hacked become "hacked up"; if modifications are done
+ with some eye to coherence and continued maintainability, the
+ software may emerge better for the experience.
+
+ Contrast {hack up}.
+
+ [{Jargon File}]
+
+ (1996-08-26)
+
+hacker
+
+ <person, jargon> (Originally, someone who makes furniture with
+ an axe) 1. A person who enjoys exploring the details of
+ programmable systems and how to stretch their capabilities, as
+ opposed to most users, who prefer to learn only the minimum
+ necessary.
+
+ 2. One who programs enthusiastically (even obsessively) or who
+ enjoys programming rather than just theorizing about
+ programming.
+
+ 3. A person capable of appreciating {hack value}.
+
+ 4. A person who is good at programming quickly.
+
+ 5. An expert at a particular program, or one who frequently
+ does work using it or on it; as in "a {Unix} hacker".
+ (Definitions 1 through 5 are correlated, and people who fit
+ them congregate.)
+
+ 6. An expert or enthusiast of any kind. One might be an
+ astronomy hacker, for example.
+
+ 7. One who enjoys the intellectual challenge of creatively
+ overcoming or circumventing limitations.
+
+ 8. (Deprecated) A malicious meddler who tries to discover
+ sensitive information by poking around. Hence "password
+ hacker", "network hacker". The correct term is {cracker}.
+
+ The term "hacker" also tends to connote membership in the
+ global community defined by the net (see {The Network} and
+ {Internet address}). It also implies that the person
+ described is seen to subscribe to some version of the {hacker
+ ethic}.
+
+ It is better to be described as a hacker by others than to
+ describe oneself that way. Hackers consider themselves
+ something of an elite (a meritocracy based on ability), though
+ one to which new members are gladly welcome. Thus while it is
+ gratifying to be called a hacker, false claimants to the title
+ are quickly labelled as "bogus" or a "{wannabee}".
+
+ 9. (University of Maryland, rare) A programmer who does not
+ understand proper programming techniques and principles and
+ doesn't have a Computer Science degree. Someone who just
+ bangs on the keyboard until something happens. For example,
+ "This program is nothing but {spaghetti code}. It must have
+ been written by a hacker".
+
+ [{Jargon File}]
+
+ (1996-08-26)
+
+hacker ethic
+
+ <philosophy> 1. The belief that information-sharing is a
+ powerful positive good, and that it is an ethical duty of
+ hackers to share their expertise by writing free software and
+ facilitating access to information and to computing resources
+ wherever possible.
+
+ 2. The belief that system-cracking for fun and exploration is
+ ethically OK as long as the cracker commits no theft,
+ vandalism, or breach of confidentiality.
+
+ Both of these normative ethical principles are widely, but by
+ no means universally, accepted among hackers. Most hackers
+ subscribe to the hacker ethic in sense 1, and many act on it
+ by writing and giving away free software. A few go further
+ and assert that *all* information should be free and *any*
+ proprietary control of it is bad; this is the philosophy
+ behind the {GNU} project.
+
+ Sense 2 is more controversial: some people consider the act of
+ cracking itself to be unethical, like breaking and entering.
+ But the belief that "ethical" cracking excludes destruction at
+ least moderates the behaviour of people who see themselves as
+ "benign" crackers (see also {samurai}). On this view, it may
+ be one of the highest forms of hackerly courtesy to (a) break
+ into a system, and then (b) explain to the sysop, preferably
+ by e-mail from a {superuser} account, exactly how it was done
+ and how the hole can be plugged - acting as an unpaid (and
+ unsolicited) {tiger team}.
+
+ The most reliable manifestation of either version of the
+ hacker ethic is that almost all hackers are actively willing
+ to share technical tricks, software, and (where possible)
+ computing resources with other hackers. Huge cooperative
+ networks such as {Usenet}, {FidoNet} and Internet (see
+ {Internet address}) can function without central control
+ because of this trait; they both rely on and reinforce a sense
+ of community that may be hackerdom's most valuable intangible
+ asset.
+
+ (1995-12-18)
+
+hacker humour
+
+ A distinctive style of shared intellectual humour found among
+ hackers, having the following marked characteristics:
+
+ 1. Fascination with form-vs.-content jokes, paradoxes, and
+ humour having to do with confusion of metalevels (see {meta}).
+ One way to make a hacker laugh: hold a red index card in front
+ of him/her with "GREEN" written on it, or vice-versa (note,
+ however, that this is funny only the first time).
+
+ 2. Elaborate deadpan parodies of large intellectual
+ constructs, such as specifications (see {write-only memory}),
+ standards documents, language descriptions (see {INTERCAL}),
+ and even entire scientific theories (see {quantum
+ bogodynamics}, {computron}).
+
+ 3. Jokes that involve screwily precise reasoning from bizarre,
+ ludicrous, or just grossly counter-intuitive premises.
+
+ 4. Fascination with puns and wordplay.
+
+ 5. A fondness for apparently mindless humour with subversive
+ currents of intelligence in it - for example, old Warner
+ Brothers and Rocky & Bullwinkle cartoons, the Marx brothers,
+ the early B-52s, and Monty Python's Flying Circus. Humour
+ that combines this trait with elements of high camp and
+ slapstick is especially favoured.
+
+ 6. References to the symbol-object antinomies and associated
+ ideas in Zen Buddhism and (less often) Taoism. See {has the X
+ nature}, {Discordianism}, {zen}, {ha ha only serious}, {AI
+ koan}.
+
+ See also {filk} and {retrocomputing}. If you have an itchy
+ feeling that all 6 of these traits are really aspects of one
+ thing that is incredibly difficult to talk about exactly, you
+ are (a) correct and (b) responding like a hacker. These
+ traits are also recognizable (though in a less marked form)
+ throughout {science-fiction fandom}.
+
+ (1995-12-18)
+
+hacking run
+
+ <jargon> (Analogy with "bombing run" or "speed run") A hack
+ session extended long outside normal working times, especially
+ one longer than 12 hours. May cause you to "change {phase}
+ the hard way".
+
+ [{Jargon File}]
+
+ (1996-08-26)
+
+Hacking X for Y
+
+ [ITS] Ritual phrasing of part of the information which ITS
+ made publicly available about each user. This information
+ (the INQUIR record) was a sort of form in which the user could
+ fill out various fields. On display, two of these fields were
+ always combined into a project description of the form
+ "Hacking X for Y" (e.g. ""Hacking perceptrons for Minsky"").
+ This form of description became traditional and has since been
+ carried over to other systems with more general facilities for
+ self-advertisement (such as Unix {plan files}).
+
+ [{Jargon File}]
+
+Hackintosh
+
+ 1. <jargon, computer> An {Apple Lisa} that has been hacked
+ into emulating a {Macintosh} (also called a "Mac XL").
+
+ 2. <jargon, computer> A {Macintosh} assembled from parts
+ theoretically belonging to different models in the line.
+
+ (1995-03-08)
+
+hackish
+
+ <jargon> /hak'ish/ 1. Said of something that is or involves a
+ {hack}.
+
+ 2. Of or pertaining to {hackers} or the hacker subculture.
+
+ See also {true-hacker}.
+
+ [{Jargon File}]
+
+ (1995-03-08)
+
+hackishness
+
+ <jargon> The quality of being or involving a {hack}. This
+ term is considered mildly silly.
+
+ Synonym {hackitude}.
+
+ [{Jargon File}]
+
+ (1995-03-08)
+
+hackitude
+
+ <jargon> An even sillier word for {hackishness}.
+
+ [{Jargon File}]
+
+ (1995-03-08)
+
+hack mode
+
+ <jargon> Engaged in {hack}ing. A Zen-like state of total
+ focus on The Problem that may be achieved when one is hacking
+ (this is why every good hacker is part mystic). Ability to
+ enter such concentration at will correlates strongly with
+ wizardliness; it is one of the most important skills learned
+ during {larval stage}. Sometimes amplified as "deep hack
+ mode".
+
+ Being yanked out of hack mode (see {priority interrupt}) may
+ be experienced as a physical shock, and the sensation of being
+ in hack mode is more than a little habituating. The intensity
+ of this experience is probably by itself sufficient
+ explanation for the existence of hackers, and explains why
+ many resist being promoted out of positions where they can
+ code. See also {cyberspace}.
+
+ Some aspects of hackish etiquette will appear quite odd to an
+ observer unaware of the high value placed on hack mode. For
+ example, if someone appears at your door, it is perfectly okay
+ to hold up a hand (without turning one's eyes away from the
+ screen) to avoid being interrupted. One may read, type, and
+ interact with the computer for quite some time before further
+ acknowledging the other's presence (of course, he or she is
+ reciprocally free to leave without a word). The understanding
+ is that you might be in {hack mode} with a lot of delicate
+ state in your head, and you dare not {swap} that context out
+ until you have reached a good point to pause. See also
+ {juggling eggs}.
+
+ [{Jargon File}]
+
+ (1996-07-31)
+
+hack on
+
+ To {hack}; implies that the subject is some pre-existing hunk
+ of code that one is evolving, as opposed to something one
+ might {hack up}.
+
+ [{Jargon File}]
+
+hack together
+
+ <jargon> To throw something together so it will work. Unlike
+ "kluge together" or "{cruft together}", this does not
+ necessarily have negative connotations.
+
+ (2003-09-02)
+
+hack up
+
+ <jargon> To {hack}, but generally implies that the result is a
+ quick hack. Contrast this with {hack on}. To "hack up on"
+ implies a {quick-and-dirty} modification to an existing
+ system. Contrast {hacked up}; compare {kluge up}, {monkey
+ up}, {cruft together}.
+
+ [{Jargon File}]
+
+ (2003-09-02)
+
+hack value
+
+ Often adduced as the reason or motivation for expending effort
+ toward a seemingly useless goal, the point being that the
+ accomplished goal is a hack. For example, MacLISP had
+ features for reading and printing Roman numerals, which were
+ installed purely for hack value. See {display hack} for one
+ method of computing hack value, but this cannot really be
+ explained, only experienced. As Louis Armstrong once said
+ when asked to explain jazz: "Man, if you gotta ask you'll
+ never know." (Feminists please note Fats Waller's explanation
+ of rhythm: "Lady, if you got to ask you ain't got it.")
+
+ha ha only serious
+
+ (SF fandom, originally as mutation of HHOK, "Ha Ha Only
+ Kidding") A phrase (often seen abbreviated as HHOS) that aptly
+ captures the flavour of much hacker discourse. Applied
+ especially to parodies, absurdities, and ironic jokes that are
+ both intended and perceived to contain a possibly disquieting
+ amount of truth, or truths that are constructed on in-joke and
+ self-parody.
+
+ The {Jargon File} contains many examples of ha-ha-only-serious
+ in both form and content. Indeed, the entirety of hacker
+ culture is often perceived as ha-ha-only-serious by hackers
+ themselves; to take it either too lightly or too seriously
+ marks a person as an outsider, a {wannabee}, or in {larval
+ stage}. For further enlightenment on this subject, consult
+ any Zen master. See also {AI koan}.
+
+ [{Jargon File}]
+
+hair
+
+ [back-formation from {hairy}] The complications that make
+ something hairy. "Decoding {TECO} commands requires a certain
+ amount of hair." Often seen in the phrase "infinite hair",
+ which connotes extreme complexity. Also in "hairiferous"
+ (tending to promote hair growth): "GNUMACS elisp encourages
+ {lusers} to write complex editing modes." "Yeah, it's pretty
+ hairiferous all right." (Or just: "Hair squared!")
+
+hairy
+
+ 1. Annoyingly complicated. "{DWIM} is incredibly hairy."
+
+ 2. Incomprehensible. "{DWIM} is incredibly hairy."
+
+ 3. Of people, high-powered, authoritative, rare, expert,
+ and/or incomprehensible. Hard to explain except in context:
+ "He knows this hairy lawyer who says there's nothing to worry
+ about." See also {hirsute}.
+
+ The adjective "long-haired" is well-attested to have been in
+ slang use among scientists and engineers during the early
+ 1950s; it was equivalent to modern "hairy" and was very likely
+ ancestral to the hackish use. In fact the noun "long-hair"
+ was at the time used to describe a hairy person. Both senses
+ probably passed out of use when long hair was adopted as a
+ signature trait by the 1960s counterculture, leaving hackish
+ "hairy" as a sort of stunted mutant relic.
+
+ 4. <topology> {hairy ball}.
+
+ [{Jargon File}]
+
+ (2001-03-29)
+
+hairy ball
+
+ <topology> A result in {topology} stating that a continuous
+ {vector field} on a sphere is always zero somewhere. The name
+ comes from the fact that you can't flatten all the hair on a
+ hairy ball, like a tennis ball, there will always be a tuft
+ somewhere (where the tangential projection of the hair is
+ zero). An immediate corollary to this theorem is that for any
+ {continuous map} f of the sphere into itself there is a point
+ x such that f(x)=x or f(x) is the {antipode} of x. Another
+ corollary is that at any moment somewhere on the Earth there
+ is no wind.
+
+ (2002-01-07)
+
+HAKMEM
+
+ <publication> /hak'mem/ MIT AI Memo 239 (February 1972). A
+ legendary collection of neat mathematical and programming
+ hacks contributed by many people at MIT and elsewhere. (The
+ title of the memo really is "HAKMEM", which is a 6-letterism
+ for "hacks memo".) Some of them are very useful techniques,
+ powerful theorems, or interesting unsolved problems, but most
+ fall into the category of mathematical and computer trivia.
+ Here is a sampling of the entries (with authors), slightly
+ paraphrased:
+
+ Item 41 (Gene Salamin): There are exactly 23,000 prime numbers
+ less than 2^18.
+
+ Item 46 (Rich Schroeppel): The most *probable* suit
+ distribution in bridge hands is 4-4-3-2, as compared to
+ 4-3-3-3, which is the most *evenly* distributed. This is
+ because the world likes to have unequal numbers: a
+ thermodynamic effect saying things will not be in the state of
+ lowest energy, but in the state of lowest disordered energy.
+
+ Item 81 (Rich Schroeppel): Count the magic squares of order 5
+ (that is, all the 5-by-5 arrangements of the numbers from 1 to
+ 25 such that all rows, columns, and diagonals add up to the
+ same number). There are about 320 million, not counting those
+ that differ only by rotation and reflection.
+
+ Item 154 (Bill Gosper): The myth that any given programming
+ language is machine independent is easily exploded by
+ computing the sum of powers of 2. If the result loops with
+ period = 1 with sign +, you are on a sign-magnitude machine.
+ If the result loops with period = 1 at -1, you are on a
+ twos-complement machine. If the result loops with period
+ greater than 1, including the beginning, you are on a
+ ones-complement machine. If the result loops with period
+ greater than 1, not including the beginning, your machine
+ isn't binary - the pattern should tell you the base. If you
+ run out of memory, you are on a string or bignum system. If
+ arithmetic overflow is a fatal error, some fascist pig with a
+ read-only mind is trying to enforce machine independence. But
+ the very ability to trap overflow is machine dependent. By
+ this strategy, consider the universe, or, more precisely,
+ algebra: Let X = the sum of many powers of 2 = ...111111 (base
+ 2). Now add X to itself: X + X = ...111110. Thus, 2X = X -
+ 1, so X = -1. Therefore algebra is run on a machine (the
+ universe) that is two's-complement.
+
+ Item 174 (Bill Gosper and Stuart Nelson): 21963283741 is the
+ only number such that if you represent it on the {PDP-10} as
+ both an integer and a {floating-point} number, the bit
+ patterns of the two representations are identical.
+
+ Item 176 (Gosper): The "banana phenomenon" was encountered
+ when processing a character string by taking the last 3
+ letters typed out, searching for a random occurrence of that
+ sequence in the text, taking the letter following that
+ occurrence, typing it out, and iterating. This ensures that
+ every 4-letter string output occurs in the original. The
+ program typed BANANANANANANANA.... We note an ambiguity in
+ the phrase, "the Nth occurrence of." In one sense, there are
+ five 00's in 0000000000; in another, there are nine. The
+ editing program TECO finds five. Thus it finds only the first
+ ANA in BANANA, and is thus obligated to type N next. By
+ Murphy's Law, there is but one NAN, thus forcing A, and thus a
+ loop. An option to find overlapped instances would be useful,
+ although it would require backing up N - 1 characters before
+ seeking the next N-character string.
+
+ Note: This last item refers to a {Dissociated Press}
+ implementation. See also {banana problem}.
+
+ HAKMEM also contains some rather more complicated mathematical
+ and technical items, but these examples show some of its fun
+ flavour.
+
+ HAKMEM is available from MIT Publications as a {TIFF} file.
+
+ {(ftp://ftp.netcom.com/pub/hb/hbaker)}.
+
+ (1996-01-19)
+
+hakspek
+
+ <jargon> /hak'speek/ A shorthand method of spelling found on
+ many British academic bulletin boards and {chat} systems.
+ Syllables and whole words in a sentence are replaced by single
+ {ASCII} characters the names of which are phonetically similar
+ or equivalent, while multiple letters are usually dropped.
+ Hence, "for" becomes "4"; "two", "too", and "to" become "2";
+ "ck" becomes "k". "Before I see you tomorrow" becomes "b4 i c
+ u 2moro". First appeared in London about 1986, and was
+ probably caused by the slowness of available {talk} systems,
+ which operated on archaic machines with outdated {operating
+ systems} and no standard methods of communication. Has become
+ rarer since.
+
+ See also {chat}, {B1FF}, {ASCIIbonics}.
+
+ [{Jargon File}]
+
+ (1998-01-25)
+
+HAL
+
+ 1. <computer> HAL 9000, the murdering computer on the
+ spaceship in the science fiction classic "2001, A Space
+ Odyssey" by Arthur C. Clark.
+
+ "HAL" is "{IBM}" with each letter changed to the one before
+ and there is an unconfirmed rumour that 9000 is the sum of the
+ various IBM computer numbers that were in service at the time.
+ However, in the sequel "2010", Clarke emphatically denies that
+ HAL's name is supposed to be "one step ahead of IBM". It is,
+ rather, short for "heuristic algorithm".
+
+ 2. <operating system> {Hardware Abstraction Layer}.
+
+ (1995-11-09)
+
+half-duplex
+
+ <communications> (hdx, from {telegraphy}) 1. A type of
+ communication channel using a single circuit which can carry
+ data in either direction but not both directions at once.
+
+ Compare: {simplex}, {full-duplex}.
+
+ 2. An obsolete term for {local echo}.
+
+ (2001-07-21)
+
+halftone
+
+ <graphics> The reproducion of {greyscale} {images} using dots
+ of a single shade but varying size to simulate the different
+ shades of grey.
+
+ {Laser printers} that cannot print different sized dots,
+ halftones are produced by varying the numbers of dots in a
+ given area.
+
+ This process is also used to produce a black and white version
+ of a colour original using shades of grey in place of colours.
+
+ See also {device independent bitmap}.
+
+ (1996-09-20)
+
+HALGOL
+
+ <language> A simple language from {Hewlett-Packard} for
+ communicating with devices such as {modems} and {X.25} {PADs}.
+
+ (1995-04-12)
+
+HALMAT
+
+ Intermediate language used by {HAL/S}.
+
+Hal/S
+
+ <language> (Hal/Shuttle) A {real-time} {high-level language}
+ for flight control applications. Hal was developed for {NASA}
+ by {Intermetrics, Inc.} in the 1970s for on-board {software}.
+ The initial version was a {Fortran} {preprocessor}, written in
+ Fortran. In 1972, as the space shuttle project advanced, the
+ language was renamed Hal/S and made more adaptable to
+ {architecture} of different computers by using {XPL}. In all,
+ 11 different implementations, mostly based on {IBM 360}, were
+ created. Applications also included projects by {JPL}
+ (Galileo probe, Deep Space network).
+
+ ["Two-Dimensional Characteristics of HAL, A Language for
+ Spaceflight Applications", J.S. Miller, SIGPLAN Notices 7(10),
+ Oct 1972].
+
+ ["Space Station Flight Software: Hal/S or Ada?", Allan
+ R. Klumpp, "Computer", March 1985].
+
+ (2002-07-13)
+
+Halt and Catch Fire
+
+ <humour, processor> (HCF) Any of several undocumented and
+ semi-mythical {machine instructions} with destructive
+ side-effects, supposedly included for test purposes on several
+ well-known architectures going as far back as the {IBM 360}.
+
+ The {Motorola 6800} {microprocessor} was the first for which an
+ HCF {opcode} became widely known. This instruction caused the
+ processor to read every memory location sequentially until reset.
+
+ [{Gerry Wheeler, Byte, December 1977, p46, "Undocumented M6800
+ Instructions"
+ (https://archive.org/details/byte-magazine-1977-12)}].
+
+ (2014-09-20)
+
+halting problem
+
+ The problem of determining in advance whether a particular
+ program or {algorithm} will terminate or run forever. The
+ halting problem is the {canonical} example of a {provably
+ unsolvable} problem. Obviously any attempt to answer the
+ question by actually executing the algorithm or simulating
+ each step of its execution will only give an answer if the
+ algorithm under consideration does terminate, otherwise the
+ algorithm attempting to answer the question will itself run
+ forever.
+
+ Some special cases of the halting problem are partially
+ solvable given sufficient resources. For example, if it is
+ possible to record the complete state of the execution of the
+ algorithm at each step and the current state is ever identical
+ to some previous state then the algorithm is in a loop. This
+ might require an arbitrary amount of storage however.
+ Alternatively, if there are at most N possible different
+ states then the algorithm can run for at most N steps without
+ looping.
+
+ A program analysis called {termination analysis} attempts to
+ answer this question for limited kinds of input algorithm.
+
+ (1994-10-20)
+
+Hamilton
+
+ {William Hamilton}
+
+Hamiltonian cycle
+
+ {Hamiltonian problem}
+
+Hamiltonian path
+
+ {Hamiltonian problem}
+
+Hamiltonian problem
+
+ <computability> (Or "Hamilton's problem") A problem in {graph
+ theory} posed by {William Hamilton}: given a {graph}, is there
+ a path through the graph which visits each {vertex} precisely
+ once (a "Hamiltonian path")? Is there a Hamiltonian path
+ which ends up where it started (a "Hamiltonian cycle" or
+ "Hamiltonian tour")?
+
+ Hamilton's problem is {NP-complete}. It has numerous
+ applications, sometimes completely unexpected, in computing.
+
+ {(http://ing.unlp.edu.ar/cetad/mos/Hamilton.html)}.
+
+ (1997-07-18)
+
+Hamiltonian tour
+
+ {Hamiltonian problem}
+
+Hamilton's problem
+
+ {Hamiltonian problem}
+
+hammer
+
+ Commonwealth hackish synonym for {bang on}.
+
+ [{Jargon File}]
+
+ (1995-02-16)
+
+Hamming code
+
+ <algorithm> Extra, redundant bits added to stored or
+ transmitted data for the purposes of {error detection and
+ correction}.
+
+ Named after the mathematician {Richard Hamming}, Hamming codes
+ greatly improve the reliability of data, e.g. from distant
+ space probes, where it is impractical, because of the long
+ transmission delay, to correct errors by requesting
+ retransmission.
+
+ [Detail? Connection with {Hamming Distance}?]
+
+ (2002-07-02)
+
+Hamming distance
+
+ <data> The minimum number of {bits} that must be changed in
+ order to convert one {bit string} into another.
+
+ Named after the mathematician {Richard Hamming}.
+
+ [Connection with {Hamming code}?].
+
+ (2002-07-02)
+
+Hamming, Richard
+
+ {Richard Hamming}
+
+hamster
+
+ 1. <programming> (From {Fairchild}) A particularly slick
+ little piece of code that does one thing well; a small,
+ self-contained hack. The image is of a hamster {happily}
+ spinning its exercise wheel.
+
+ 2. <hardware> A tailless mouse; that is, one with an infrared
+ link to a receiver on the machine, as opposed to the
+ conventional cable.
+
+ 3. <product> (UK) Any item of hardware made by {Amstrad}, a
+ company famous for its cheap plastic PC-almost-compatibles.
+
+ [{Jargon File}]
+
+ (1995-02-16)
+
+Han character
+
+ <character> (From the Han dynasty, 206 B.C.E to 25 C.E.) One
+ of the set of {glyphs} common to Chinese (where they are
+ called "hanzi"), Japanese (where they are called {kanji}), and
+ Korean (where they are called {hanja}).
+
+ Han characters are generally described as "ideographic", i.e.,
+ picture-writing; but see the reference below.
+
+ Modern Korean, Chinese and Japanese {fonts} may represent a
+ given Han character as somewhat different glyphs. However, in
+ the formulation of {Unicode}, these differences were {folded},
+ in order to conserve the number of {code positions} necessary
+ for all of {CJK}. This unification is referred to as "Han
+ Unification", with the resulting character repertoire
+ sometimes referred to as "Unihan".
+
+ {Unihan reference at the Unicode Consortium
+ (http://charts.unicode.org/unihan.html)}.
+
+ [John DeFrancis, "The Chinese Language: Fact and Fantasy",
+ University of Hawaii Press, 1984].
+
+ (1998-10-18)
+
+HAND
+
+ <chat> Have A Nice Day. Often used sarcastically and in
+ connection with {HTH}, as in:
+
+ > Where's the point of alt.stupidity?
+
+ Between the 't' and the 's'. HTH. HAND.
+
+ (1998-03-06)
+
+hand cruft
+
+ <jargon> (After "hand craft") To write something {by hand}
+ that would be better done automatically, e.g. writing
+ {assembly language} instead of using a compiler (see {hand
+ hacking}).
+
+ [{Jargon File}]
+
+ (2006-01-19)
+
+Handel
+
+ <language> An {imperative language} with {primitives} for
+ controlling {parallel programs}.
+
+ Used by Wayne Luk for work in compilation of programs to
+ hardware ({FPGAs}).
+
+ (1995-02-28)
+
+hand hack
+
+ <jargon> 1. (Or "{hand cruft}") To Translate a {hot spot} of a
+ program in a {HLL} into {assembly language} {by hand}, as
+ opposed to trying to coerce the {compiler} into generating
+ better code. Both the term and the practice are becoming
+ uncommon.
+
+ See {tune}, {bum}.
+
+ 2. More generally, manual construction or patching of data
+ sets that would normally be generated by a translation utility
+ and interpreted by another program, and aren't really designed
+ to be read or modified by humans.
+
+ [{Jargon File}]
+
+ (1995-02-16)
+
+Hand-held Personal Computer
+
+ {palmtop}
+
+handle
+
+ 1. <programming, operating system> A simple item of data that
+ identifies a resource. For example, a {Unix} file handle
+ identifies an open file and associated data such as whether it
+ was opened for read or write and the current read/write
+ position. On the {Macintosh}, a handle is a pointer to a
+ pointer to some dynamically-allocated memory. The extra level
+ of indirection allows on-the-fly {memory compaction} or
+ {garbage collection} without invalidating application program
+ references to the allocated memory.
+
+ 2. <jargon> An alias used intended to conceal a user's true
+ identity in an electronic message. The term is common on
+ Citizen's Band and other amateur radio but, in that context
+ usually means the user's real name as {FCC} rules forbid
+ concealing one's identity.
+
+ Use of grandiose handles is characteristic of {crackers},
+ {weenies}, {spods}, and other lower forms of network life;
+ true hackers travel on their own reputations.
+
+ Compare {nick}.
+
+ [{Jargon File}]
+
+ 3. <networking> {domain handle}.
+
+ (2004-07-20)
+
+handoff
+
+ {handover}
+
+handover
+
+ <communications> (HO, or "handoff") the mechanism by which an
+ on going cellular connection between a {mobile terminal} (MT,
+ typically a {mobile phone}) or {mobile host} (MH) and a
+ corresponding terminal or host is transferred from one point
+ of access of the fixed network to another.
+
+ Handover may occur because the phone is leaving its current
+ cell, to balance demand between cells, to reduce interference
+ or to transfer a user who has stopped moving to a nearby cell
+ with shorter range.
+
+ (2010-05-07)
+
+hand-roll
+
+ <jargon> (From mainstream slang "hand-rolled cigarette" in
+ opposition to "ready-made") To perform a normally automated
+ software installation or configuration process {by hand};
+ implies that the normal process failed due to bugs or was
+ defeated by something exceptional in the local environment.
+ "The worst thing about being a gateway between four different
+ nets is having to hand-roll a new sendmail configuration every
+ time any of them upgrades."
+
+ [{Jargon File}]
+
+ (1995-02-28)
+
+handshake
+
+ {handshaking}
+
+handshaking
+
+ 1. Predetermined hardware or software activity designed to
+ establish or maintain two machines or programs in
+ synchronisation. Handshaking often concerns the exchange of
+ messages or {packets} of data between two systems with limited
+ {buffers}. A simple handshaking {protocol} might only involve
+ the receiver sending a message meaning "I received your last
+ message and I am ready for you to send me another one." A
+ more complex handshaking {protocol} might allow the sender to
+ ask the receiver if he is ready to receive or for the receiver
+ to reply with a negative acknowledgement meaning "I did not
+ receive your last message correctly, please resend it" (e.g. if
+ the data was corrupted en route).
+
+ {Hardware handshaking} uses voltage levels or pulses on wires
+ to carry the handshaking signals whereas {software
+ handshaking} uses data units (e.g. {ASCII} characters) carried
+ by some underlying communication medium.
+
+ {Flow control} in bit-serial data transmission such as
+ {EIA-232} may use either hardware or software handshaking.
+
+ 2. The method used by two {modems} to establish contact with
+ each other and to agreee on {baud rate}, {error correction}
+ and {compression} {protocols}.
+
+ 3. The exchange of predetermined signals between agents
+ connected by a communications channel to assure each that it
+ is connected to the other (and not to an imposter). This may
+ also include the use of passwords and codes by an operator.
+
+ [{Jargon File}]
+
+ (1995-01-13)
+
+handwave
+
+ [possibly from gestures characteristic of stage magicians] To
+ gloss over a complex point; to distract a listener; to support
+ a (possibly actually valid) point with blatantly faulty logic.
+
+ If someone starts a sentence with "Clearly..." or
+ "Obviously..." or "It is self-evident that...", it is a good
+ bet he is about to handwave (alternatively, use of these
+ constructions in a sarcastic tone before a paraphrase of
+ someone else's argument suggests that it is a handwave). The
+ theory behind this term is that if you wave your hands at the
+ right moment, the listener may be sufficiently distracted to
+ not notice that what you have said is wrong. Failing that, if
+ a listener does object, you might try to dismiss the objection
+ with a wave of your hand.
+
+ The use of this word is often accompanied by gestures: both
+ hands up, palms forward, swinging the hands in a vertical
+ plane pivoting at the elbows and/or shoulders (depending on
+ the magnitude of the handwave); alternatively, holding the
+ forearms in one position while rotating the hands at the wrist
+ to make them flutter. In context, the gestures alone can
+ suffice as a remark; if a speaker makes an outrageously
+ unsupported assumption, you might simply wave your hands in
+ this way, as an accusation, far more eloquent than words could
+ express, that his logic is faulty.
+
+ [{Jargon File}]
+
+hang
+
+ 1. To wait for an event that will never occur. "The system is
+ hanging because it can't read from the crashed drive". See
+ {wedged}, {hung}.
+
+ 2. To wait for some event to occur; to hang around until
+ something happens. "The program displays a menu and then
+ hangs until you type a character." Compare {block}.
+
+ 3. To attach a peripheral device, especially in the
+ construction "hang off": "We're going to hang another tape
+ drive off the file server." Implies a device attached with
+ cables, rather than something that is strictly inside the
+ machine's chassis.
+
+hanja
+
+ {Han characters}
+
+Hanoi
+
+ {Towers of Hanoi}
+
+Han Unification
+
+ {Han character}
+
+hanzi
+
+ {Han characters}
+
+happily
+
+ Of software, used to emphasise that a program is unaware of
+ some important fact about its environment, either because it
+ has been fooled into believing a lie, or because it doesn't
+ care. The sense of "happy" here is not that of elation, but
+ rather that of blissful ignorance. "The program continues to
+ run, happily unaware that its output is going to /dev/null."
+
+ [{Jargon File}]
+
+Happy
+
+ <tool> A dyslexic acronym for "A Yacc-like Haskell Parser
+ generator".
+
+ An {LALR1 grammar} {parser generator} for {Haskell}. Happy is
+ written in Haskell, uses a parser generated by itself, and can
+ be compiled using {ghc}, {hbc} or {gofer}. Happy uses an
+ implementation of {monadic IO} built on top of stream IO, but
+ this should change when the {Haskell 1.3} {standard} has been
+ implemented.
+
+ Version: 0.9 (1996-02-28).
+
+ Happy is covered by the {General Public License}.
+
+ {(http://dcs.gla.ac.uk/fp/software/happy.html)}.
+
+ {(ftp://ftp.dcs.gla.ac.uk/pub/haskell/happy/)}.
+
+ E-mail: <andy@dcs.gla.ac.uk>, <simonm@dcs.gla.ac.uk>.
+
+ (1996-03-21)
+
+haptic interface
+
+ <interface, hardware> A touch interface to a computer that
+ provides {feedback}, such as a {data glove}.
+
+ (2003-10-17)
+
+haptics
+
+ <interface> The science of applying tactile sensation to human
+ interaction with computers.
+
+ {Haptics Community (http://haptic.mech.northwestern.edu/)}.
+
+ (2003-10-17)
+
+haque
+
+ <spelling, jargon> /hak/ ({Usenet}) A variant spelling of
+ {hack}, used only for the noun form and connoting an {elegant}
+ hack.
+
+ [{Jargon File}]
+
+ (1995-02-22)
+
+hard boot
+
+ <operating system> A {boot} which resets the entire {system}.
+
+ The phrase has connations of hostility toward, or frustration
+ with, the computer being booted. For example, "I'll have to
+ hard boot this {losing} {Sun}", or "I recommend booting it
+ hard".
+
+ Hard boots are often performed with a {power cycle}.
+
+ Contrast {soft boot}. See also {cold boot} and {reboot}
+
+ [{Jargon File}]
+
+ (1995-11-27)
+
+hard-coded
+
+ <jargon> (By analogy with "{hard-wired}") Said of a data value
+ or behaviour written directly into a program, possibly in
+ multiple places, where it cannot be easily modified. There
+ are several alternatives, depending on how often the value is
+ likely to change. It may be replaced with a {compile-time}
+ constant, such as a {C} "#define" {macro}, in which case a
+ change will still require recompilation; or it may be read at
+ {run time} from a {profile}, resource (see {de-rezz}), or
+ {environment variable} that a {user} can easily modify; or it
+ may be read as part of the program's input data.
+
+ To change something hard-coded requires recompilation (if
+ using a compiled language of course) but, more seriously, it
+ requires sufficient understanding of the implementation to be
+ sure that the change will not introduce inconsistency and
+ cause the program to fail.
+
+ For example, "The line terminator is hard-coded as newline;
+ who in their right mind would use anything else?"
+
+ See {magic number}.
+
+ [{Jargon File}]
+
+ (1999-10-18)
+
+hardcopy
+
+ <jargon> A paper printout of data displayed on a screen.
+
+ Contrast {softcopy}.
+
+ (1995-08-31)
+
+hard crash
+
+ <programming> When a program stops running completely and
+ unexpectedly, often due to external events, e.g. the {CPU}
+ overheating or an unrecoverable memory error.
+
+ See also {disk crash}.
+
+ (2009-07-01)
+
+hard disk
+
+ <storage> (In contrast to {floppy disk}) A {magnetic disk}
+ data storage device where the disks are rigid and fixed to a
+ central axle. They are usually packaged with associated
+ read/write heads and electronics. Most hard disks are
+ permanently connected to the drive (fixed disks) though there
+ are also {removable hard disks}.
+
+ See {magnetic disk}.
+
+ (2007-06-14)
+
+hard disk drive
+
+ <storage> (HDD) A {disk drive} used to read and write {hard
+ disks}.
+
+ (1995-03-14)
+
+hard drive
+
+ {hard disk drive}
+
+hard link
+
+ <file system> One of several directory entries which refer to
+ the same {Unix} {file}. A hard link is created with the "ln"
+ (link) command:
+
+ ln <old name> <new name>
+
+ where <old name> and <new name> are {pathnames} within the
+ same {file system}. Hard links to the same file are
+ indistinguishable from each other except that they have
+ different pathnames. They all refer to the same {inode} and
+ the inode contains all the information about a file.
+
+ The standard ln command does not usually allow you to create a
+ hard link to a directory, chiefly because the standard {rm}
+ and {rmdir} commands do not allow you to delete such a link.
+ Some systems provide link and {unlink} commands which give
+ direct access to the {system calls} of the same name, for
+ which no such restrictions apply.
+
+ Normally all hard links to a file must be in the same {file
+ system} because a directory entry just relates a pathname to
+ an inode within the same file system. The only exception is a
+ {mount point}.
+
+ The restrictions on hard links to directories and between
+ file systems are very common but are not mandated by {POSIX}.
+ {Symbolic links} are often used instead of hard links because
+ they do not suffer from these restrictions.
+
+ The space associated with a file is not freed until all the
+ hard links to the file are deleted. This explains why the
+ system call to delete a file is called "unlink".
+
+ {Microsoft Windows} {NTFS} supports hard links via the
+ {fsutil} command.
+
+ {Unix manual page}: ln(1).
+
+ {(http://microsoft.com/windowsxp/home/using/productdoc/en/fsutil_hardlink.asp)}.
+
+ (2004-02-24)
+
+hard linking
+
+ {hard link}
+
+hard sector
+
+ <storage> An archaic {floppy disk} format employing multiple
+ synchronisation holes in the media to define the {sectors}.
+
+ (1995-01-24)
+
+hardware
+
+ <hardware> The physical, touchable, material parts of a
+ computer or other system. The term is used to distinguish
+ these fixed parts of a system from the more changeable
+ {software} or {data} components which it executes, stores, or
+ carries.
+
+ Typical computer hardware consists of electronic devices
+ ({CPU}, {memory}, {display}) with some electromechanical parts
+ (keyboard, {printer}, {disk drives}, {tape drives},
+ loudspeakers) for input, output and storage. Completely
+ non-electronic (mechanical, electromechanical, hydraulic,
+ biological) computers have also been conceived of and built.
+
+ See also {firmware}, {wetware}.
+
+ (1997-01-23)
+
+Hardware Abstraction Layer
+
+ <operating system> (HAL) The layer of {Microsoft} {Windows NT}
+ where they have isolated their {assembly language} code.
+
+ (1995-04-17)
+
+hardware circular buffer
+
+ <programming, hardware> {digital signal processors} which
+ support hardware {circular buffers} automatically generate and
+ increment {pointers} for {memory} accesses which wrap to the
+ beginning of the {buffer} when its end is reached, thus saving
+ the time and instructions otherwise needed to ensure that the
+ address pointer stays within the boundary of the buffer, and
+ speeding the execution of repetitive DSP algorithms.
+
+ {Digital Signal Processor For Digital Audio Applications
+ (http://analog.com/publications/documentation/21065L_Audio_Tutorial.PDF)}.
+
+ (2000-06-17)
+
+Hardware Description Language
+
+ <language> (HDL) A kind of language used for the conceptual
+ design of {integrated circuits}. Examples are {VHDL} and
+ {Verilog}.
+
+ (1995-04-18)
+
+hardware handshaking
+
+ <communications> A technique for regulating the flow of data
+ across an interface by means of signals carried on separate
+ wires.
+
+ A common example is the RTS (Request to Send) and CTS (Clear
+ to Send) signals on an {EIA-232} {serial line}.
+
+ The alternative, {software handshaking}, uses two special
+ characters inserted into the data stream to carry the same
+ information.
+
+ (1995-01-23)
+
+hardware register
+
+ <hardware, system administration> (Or "hardware log") A list
+ of all {hardware}, both internal and external, that is
+ attached to a particular computer.
+
+ (2006-09-07)
+
+hardwarily
+
+ /hard-weir'*-lee/ In a way pertaining to hardware. "The
+ system is hardwarily unreliable." The adjective "hardwary" is
+ *not* traditionally used, though it has recently been reported
+ from the U.K.
+
+ See {softwarily}.
+
+ [{Jargon File}]
+
+ (1995-01-23)
+
+hard-wired
+
+ 1. <electronics> An aspect of an electronic circuit which is
+ determined by the wiring of the hardware, as opposed to being
+ programmable in software or controlled by a switch.
+
+ 2. <software, jargon> In software, a synonym for {hard-coded}.
+
+ 3. By extension, anything that is not modifiable, especially
+ in the sense of customisable to one's particular needs or
+ tastes.
+
+ [{Jargon File}]
+
+ (1999-10-18)
+
+Harris Semiconductor Ltd.
+
+ <company>
+
+ Address: Riverside Way, Camberley, Surrey, CU15 3YQ, UK.
+
+ Telephone: +44 (1276) 686 886. Fax: +44 (1276) 682 323.
+
+ (1995-11-21)
+
+Harvard architecture
+
+ <architecture> A computer {architecture} in which program
+ instructions are stored in different memory from data. Each
+ type of memory is accessed via a separate {bus}, allowing
+ instructions and data to be fetched in parallel.
+
+ Contrast: {von Neumann architecture}.
+
+ [Why Harvard?]
+
+ (2004-01-14)
+
+Harvard Graphics
+
+ <graphics, tool> A presentation graphics product by {Software
+ Publishing Corporation} (SPC) for creating presentations,
+ speeches, slides, etc..
+
+ (1998-07-20)
+
+Harvard Mark II Machine
+
+ <computer, history> A {relay}-based computer designed and
+ built by {Howard Aiken}, with support from {IBM}, for the
+ United States Navy's Naval Proving Ground, between 1942 -
+ 1947. The Harvard Mark II was the second in a series of four
+ {electro-mechanical} computers that were forerunners of the
+ {ENIAC}.
+
+ {Harvard machines
+ (http://hoc.co.umist.ac.uk/storylines/compdev/electromechanical/harvardmarkmachines.html)}.
+
+ (2003-09-13)
+
+Harvest
+
+ <tool, networking> A highly scalable, customisable system for
+ discovering resources on the {Internet}.
+
+ Version: 1.3.
+
+ {(http://tardis.ed.ac.uk/harvest/)}.
+
+ (1999-01-16)
+
+Harvest C
+
+ A {C} compiler, assembler and linker for the {Macintosh} by
+ Eric W. Sink. The parts of the system are integrated in a
+ single application, which manages a "project" composed by
+ several C source files and resource files (which contain
+ data). Version 1.3.
+
+ {(ftp://archive.umich.edu/mac/development/languages/)}.
+
+ (1992-05-26)
+
+hash
+
+ 1. <character> {hash character}.
+
+ 2. <programming> {hash coding}.
+
+ 3. The preferred term for a {Perl} {associative array}.
+
+ (1995-03-06)
+
+hash bucket
+
+ {hash coding}
+
+hash character
+
+ <character> "#", {ASCII} character 35.
+
+ Common names: number sign; pound; pound sign; hash; sharp;
+ {crunch}; hex; {INTERCAL}: mesh. Rare: grid; crosshatch;
+ octothorpe; flash; {ITU-T}: square, pig-pen; tictactoe;
+ scratchmark; thud; thump; {splat}.
+
+ The pronunciation of "#" as "pound" is common in the US but a
+ bad idea; {Commonwealth Hackish} has its own, rather more
+ apposite use of "pound sign" (confusingly, on British
+ keyboards the pound graphic happens to replace "#"; thus
+ Britishers sometimes call "#" on a US-ASCII keyboard "pound",
+ compounding the American error). The US usage derives from an
+ old-fashioned commercial practice of using a "#" suffix to tag
+ pound weights on bills of lading. The character is usually
+ pronounced "hash" outside the US.
+
+ The name "octothorpe" was made up by a {Bell Labs} supervisor,
+ Don Macpherson.
+
+ {Octothorpe story
+ (http://sigtel.com/tel_tech_octothorpe.html)}.
+
+ (2003-07-05)
+
+hash coding
+
+ <programming, algorithm> (Or "hashing") A scheme for providing
+ rapid access to data items which are distinguished by some
+ {key}. Each data item to be stored is associated with a key,
+ e.g. the name of a person. A {hash function} is applied to
+ the item's key and the resulting hash value is used as an
+ index to select one of a number of "hash buckets" in a hash
+ table. The table contains pointers to the original items.
+
+ If, when adding a new item, the hash table already has an
+ entry at the indicated location then that entry's key must be
+ compared with the given key to see if it is the same. If two
+ items' keys hash to the same value (a "{hash collision}") then
+ some alternative location is used (e.g. the next free location
+ cyclically following the indicated one). For best
+ performance, the table size and {hash function} must be
+ tailored to the number of entries and range of keys to be
+ used. The hash function usually depends on the table size so
+ if the table needs to be enlarged it must usually be
+ completely rebuilt.
+
+ When you look up a name in the phone book (for example), you
+ typically hash it by extracting its first letter; the hash
+ buckets are the alphabetically ordered letter sections.
+
+ See also: {btree}, {checksum}, {CRC}, {pseudorandom number},
+ {random}, {random number}, {soundex}.
+
+ (1997-08-03)
+
+hash collision
+
+ <programming> (Or "hash clash") When two different keys hash
+ to the same value, i.e. to the same location in a {hash
+ table}.
+
+ {ESR} once asked a friend what he expected Berkeley to be
+ like. The friend replied, "Well, I have this mental picture
+ of naked women throwing Molotov cocktails, but I think that's
+ just a collision in my hash tables."
+
+ [{Jargon File}]
+
+ (1995-01-23)
+
+hash function
+
+ <programming> A {hash coding} {function} which assigns a data
+ item distinguished by some "key" into one of a number of
+ possible "hash buckets" in a hash table. The hash function is
+ usually combined with another more precise function.
+
+ For example a program might take a string of letters and put
+ it in one of twenty six lists depending on its first letter.
+ Ideally, a hash function should distribute items evenly
+ between the buckets to reduce the number of {hash collisions}.
+ If, for example, the strings were names beginning with "Mr.",
+ "Miss" or "Mrs." then taking the first letter would be a very
+ poor hash function because all names would hash the same.
+
+ (1997-08-03)
+
+hashing
+
+ {hash coding}
+
+hash table
+
+ {hash coding}
+
+Haskell
+
+ <language> (Named after the logician {Haskell Curry}) A {lazy}
+ {purely functional} language largely derived from {Miranda}
+ but with several extensions. Haskell was designed by a
+ committee from the {functional programming} community in April
+ 1990. It features static {polymorphic} typing, {higher-order
+ functions}, user-defined {algebraic data types}, and
+ {pattern-matching} {list comprehensions}. Innovations include
+ a {class} system, systematic operator {overloading}, a
+ {functional I/O} system, functional {arrays}, and {separate
+ compilation}.
+
+ Haskell 1.3 added many new features, including {monadic I/O},
+ standard libraries, {constructor classes}, {labeled fields} in
+ datatypes, {strictness} {annotations}, an improved {module}
+ system, and many changes to the Prelude.
+
+ {Gofer} is a cut-down version of Haskell with some extra
+ features.
+
+ {Filename extension}: .hs, .lhs ({literate programming}).
+
+ {(http://haskell.org/)}.
+
+ ["Report on the Programming Language Haskell Version 1.1",
+ Paul Hudak & P. Wadler eds, CS Depts, U Glasgow and Yale U.,
+ Aug 1991].
+
+ [Version 1.2: SIGPLAN Notices 27(5), Apr 1992].
+
+ {Haskell 1.3 Report
+ (http://haskell.cs.yale.edu/haskell-report/haskell-report.html)}.
+
+ Mailing list: <haskell-request@cs.yale.edu>.
+
+ Yale Haskell - Version 2.0.6, Haskell 1.2 built on {Common
+ Lisp}.
+
+ {(ftp://nebula.cs.yale.edu/pub/haskell/yale/)}.
+
+ Glasgow Haskell (GHC) - Version 2.04 for {DEC Alpha}/{OSF}2;
+ {HPPA1.1}/{HPUX}9,10; {SPARC}/{SunOs} 4, {Solaris} 2;
+ {MIPS}/{Irix} 5,6; {Intel 80386}/{Linux},{Solaris}
+ 2,{FreeBSD},{CygWin} 32; {PowerPC}/{AIX}. GHC generates {C}
+ or {native code}.
+
+ {(ftp://ftp.dcs.glasgow.ac.uk/pub/haskell/glasgow/)}.
+
+ E-mail: <glasgow-haskell-request@dcs.glasgow.ac.uk>.
+
+ Haskell-B - Haskell 1.2 implemented in {LML}, generates
+ {native code}.
+
+ {(ftp://ftp.cs.chalmers.se/pub/haskell/chalmers/)}.
+
+ E-mail: <hbc@cs.chalmers.se>.
+
+ (1997-06-06)
+
+Haskell B
+
+ <language> An early version of {Haskell} by Lennart Augustsson
+ <augustss@cs.chalmers.se> from {Chalmers}. Haskell B evolved
+ into a full-featured implementation of Haskell 1.2, with quite
+ a few extensions.
+
+ Ports exist for many {platforms} including {Sun}, {DEC},
+ {Sequent}, {IBM PC}, {Symmetry} and unsupported versions for
+ {NS32000}, {IBM RT/PC}, {Cray}, {Sun-3}, {Vax}, {ARM}, and
+ {RS/6000}.
+
+ Version 0.999.5 included a compiler, interpreter, library,
+ documentation, and examples.
+
+ {(ftp://ftp.cs.chalmers.se/pub/haskell/chalmers/)}.
+
+ Mailing list: <haskell-request@cs.yale.edu>.
+
+ E-mail: <hbc@cs.chalmers.se>.
+
+ (1996-08-21)
+
+Haskell Curry
+
+ <person> Haskell Brooks Curry (1900-09-12 - 1982-09-01). The
+ logician who re-invented and developed {combinatory logic}.
+
+ The {functional programming} language {Haskell} was named
+ after him.
+
+ {Biography
+ (http://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Curry.html)}.
+
+ (1999-01-08)
+
+Haskell User's Gofer System
+
+ <language> (HUGS) An implementation of {Haskell} derived from
+ {Gofer} 2.30b with an interactive development environment much
+ like Gofer's. Almost all of the features of Haskell 1.2 are
+ implemented with the exception of the {module} system. Hugs
+ supports Haskell style {type class}es, a full prelude,
+ {derived instances}, defaults, {overloaded} numeric {literals}
+ and {pattern matching}, and {bignum} arithmetic.
+
+ {Home
+ (http://cs.nott.ac.uk/Department/Staff/mpj/hugs.html)}.
+
+ {(ftp://ftp.cs.nott.ac.uk/pub/haskell/hugs)}.
+
+ E-mail: Mark P. Jones <mpj@cs.nott.ac.uk>.
+
+ (1995-02-14)
+
+HASL
+
+ <language> {SASL} plus {conditional unification}.
+
+ ["A Prological Definition of HASL, A Purely Functional
+ Language with Unification Based Conditional Binding
+ Expressions", H. Abramson in Logic Programming: Functions,
+ Relations and Equations, D. DeGroot et al eds, P-H 1986].
+
+ (1996-08-21)
+
+HASP
+
+ {Houston Automatic Spooling Program}
+
+has the X nature
+
+ (From Zen Buddhist koans of the form "Does an X have the
+ Buddha-nature?") Common hacker construction for "is an X",
+ used for humorous emphasis. "Anyone who can't even use a
+ program with on-screen help embedded in it truly has the
+ {loser} nature!" See also {the X that can be Y is not the
+ true X}.
+
+ [{Jargon File}]
+
+ (1995-01-11)
+
+hat
+
+ A common (spoken) name for the circumflex ("^", ASCII 94)
+ character.
+
+ See {ASCII} for other synonyms.
+
+ [{Jargon File}]
+
+Hayes
+
+ A {modem} manufacturer.
+
+ {(gopher://leapfrog.almac.co.uk:70/00/business/comms/hayes/corporat.txt)}.
+
+ Address: Atlanta, Georgia, USA.
+
+ (1995-01-30)
+
+Hayes-compatible
+
+ <communications> A description of a {modem} which understands
+ the same set of commands as one made by {Hayes}.
+
+ [What are the commands?]
+
+ (1996-12-08)
+
+Haze
+
+ <graphics> An {X Window System} {window manager} designed to
+ be light-weight and look like {MacOS}. Haze is based on
+ {mlvwm}. It support {virtual desktops}, configurable menu
+ bar and shaded windows.
+
+ {Haze home (http://www.escomposlinux.org/jes/description.html)}.
+
+ (2010-05-03)
+
+HBOOK
+
+ A histogramming package in the CERN program library.
+
+hc
+
+ The compiler for the {h} {hyperbook} language.
+
+HC-900
+
+ <hardware> A hybrid {controller} made by {Honeywell}.
+
+ {Honeywell
+ (http://honeywell.silverw.com/docs/51-52-03-31.pdf)}.
+
+ [Hybrid of what and what?]
+
+ (2004-03-31)
+
+HCF
+
+ 1. <operating system> {Host Command Facility}.
+
+ 2. <architecture> {Halt and Catch Fire}.
+
+ [{Jargon File}]
+
+ (1999-01-24)
+
+HCI
+
+ 1. {Human-Computer Interaction}.
+
+ 2. {Human-Computer Interface}.
+
+ 3. {Host Control Interface}.
+
+ (2002-06-21)
+
+HCLP
+
+ Hierarchical {CLP}.
+
+ ["Constraint Hierarchies and Logic Programming", A. Borning et
+ al, in Proc Sixth Intl Logic Prog Conf, June 1989,
+ pp. 149-164].
+
+HCPRVR
+
+ "HCPRVR: An Interpreter for Logic Programs", D. Chester in
+ Proc First Natl Conf on AI, Stanford, 1980.
+
+HCS
+
+ {Heterogeneous Computer System}
+
+ A {distributed system} project.
+
+ [Where? When? What?]
+
+ (1995-02-01)
+
+HD
+
+ {high density}
+
+HD6309
+
+ {Hitachi 6309}
+
+HDA
+
+ {Head Disk Assembly}
+
+HDC
+
+ {Disk Controller}
+
+HDD
+
+ {hard disk drive}
+
+HDF
+
+ {Hierarchical Data Format}
+
+HDFL
+
+ A {single assignment} language.
+
+ ["Methods for Handling Structures in Data-Flow Systems",
+ J.L. Gaudiot, Proc 12th Intl Symp Comp Arch, June 1985].
+
+HDL
+
+ {Hardware Description Language}
+
+HDLC
+
+ {High-level Data Link Control}
+
+HDM
+
+ {Hierarchical Design Methodology}
+
+HDMI
+
+ {High-Definition Multimedia Interface}
+
+HDSL
+
+ {High bit-rate Digital Subscriber Line}
+
+HDTV
+
+ {High Definition Television}
+
+hdx
+
+ {half-duplex}
+
+Head Disk Assembly
+
+ <hardware, storage> (HDA) A sealed, high capacity {mainframe}
+ {hard disk} with integral heads, as opposed to a {removable
+ disk}.
+
+ (1999-01-13)
+
+header
+
+ 1. The portion of a {packet}, preceding the actual data,
+ containing source and destination addresses, error checking
+ and other fields.
+
+ 2. The part of an {electronic mail} message or {news} article
+ that precedes the body of a message and contains, among other
+ things, the sender's name and e-mail address and the date and
+ time the message was sent.
+
+Head Normal Form
+
+ <theory, reduction> (HNF) A term describing a {lambda
+ expression} whose top level is either a variable, a data
+ value, a built-in function applied to too few arguments, or a
+ {lambda abstraction} whose body is not reducible. I.e. the
+ top level is neither a {redex} nor a lambda abstraction with a
+ reducible body.
+
+ An expression in HNF may contain redexes in argument postions
+ whereas a {normal form} may not.
+
+ Compare {Weak Head Normal Form}.
+
+ (2003-01-08)
+
+head normalisation theorem
+
+ Under the typed lambda-calculus, beta/delta reduction of the
+ left-most redex (normal order reduction) is guaranteed to
+ terminate with a head normal form if one exists. See also
+ Church-Rosser theorem.
+
+heads down
+
+ [Sun] Concentrating, usually so heavily and for so long that
+ everything outside the focus area is missed. See also {hack
+ mode} and {larval stage}, although this mode is hardly
+ confined to fledgling hackers.
+
+ [{Jargon File}]
+
+head-strict
+
+ <theory> A head-strict function will not necessarily evaluate
+ every {cons} cell of its (list) argument, but whenever it does
+ evaluate a cons cell it will also evaluate the element in the
+ head of that cell. An example of a head-strict function is
+
+ beforeZero :: [Int] -> [Int]
+ beforeZero [] = []
+ beforeZero (0:xs) = []
+ beforeZero (x:xs) = x : beforeZero xs
+
+ which returns a list up to the first zero.
+
+ This pattern of evaluation is important because it is common
+ in functions which operate on a list of inputs.
+
+ See also {tail-strict}, {hyperstrict}.
+
+ (1995-05-11)
+
+heap
+
+ 1. <programming> An area of memory used for {dynamic memory
+ allocation} where blocks of memory are allocated and freed in
+ an arbitrary order and the pattern of allocation and size of
+ blocks is not known until {run time}. Typically, a program
+ has one heap which it may use for several different purposes.
+
+ Heap is required by languages in which functions can return
+ arbitrary data structures or functions with {free variables}
+ (see {closure}). In {C} functions {malloc} and {free} provide
+ access to the heap.
+
+ Contrast {stack}. See also {dangling pointer}.
+
+ 2. <programming> A data structure with its elements partially
+ ordered (sorted) such that finding either the minimum or the
+ maximum (but not both) of the elements is computationally
+ inexpensive (independent of the number of elements), while
+ both adding a new item and finding each subsequent
+ smallest/largest element can be done in O(log n) time, where n
+ is the number of elements.
+
+ Formally, a heap is a {binary tree} with a key in each {node},
+ such that all the {leaves} of the tree are on two adjacent
+ levels; all leaves on the lowest level occur to the left and
+ all levels, except possibly the lowest, are filled; and the
+ key in the {root} is at least as large as the keys in its
+ children (if any), and the left and right subtrees (if they
+ exist) are again heaps.
+
+ Note that the last condition assumes that the goal is finding
+ the minimum quickly.
+
+ Heaps are often implemented as one-dimensional {arrays}.
+ Still assuming that the goal is finding the minimum quickly
+ the {invariant} is
+
+ heap[i] <= heap[2*i] and heap[i] <= heap[2*i+1] for all i,
+
+ where heap[i] denotes the i-th element, heap[1] being the
+ first. Heaps can be used to implement {priority queues} or in
+ {sort} algorithms.
+
+ (1996-02-26)
+
+heartbeat
+
+ 1. <networking> The signal emitted by a Level 2 Ethernet
+ transceiver at the end of every {packet} to show that the
+ collision-detection circuit is still connected.
+
+ 2. A periodic synchronisation signal used by software or
+ hardware, such as a {bus} clock or a periodic {interrupt}.
+
+ 3. The "natural" oscillation frequency of a computer's clock
+ crystal, before frequency division down to the machine's clock
+ rate.
+
+ 4. A signal emitted at regular intervals by software to
+ demonstrate that it is still alive. Sometimes hardware is
+ designed to reboot the machine if it stops hearing a
+ heartbeat. See also {breath-of-life packet}, {watchdog}.
+
+ [{Jargon File}]
+
+ (1996-03-12)
+
+heatseeker
+
+ <person, jargon> (IBM) A customer who can be relied upon to
+ buy, without fail, the latest version of an existing product
+ (not quite the same as a member of the {lunatic fringe}). A
+ 1993 example of a heatseeker is someone who, owning a 286 PC
+ and Windows 3.0, goes out and buys {Windows 3.1} (which offers
+ no worthwhile benefits unless you have a 386). If all
+ customers were heatseekers, vast amounts of money could be
+ made by just fixing the bugs in each release (n) and selling
+ it to them as release (n+1).
+
+ [{Jargon File}]
+
+ (1996-03-12)
+
+heat sink
+
+ <hardware> /heet sink/ (from "sink", electronics jargon for
+ something which takes in current) A piece of thermally
+ conductive metal attached to a {semiconductor} or other
+ electronic device and designed to prevent it from overheating
+ by conducting heat away from it and radiating it to the
+ environment. Heat sinks often have fins to increase their
+ surface area. They occasionally have fans attached. Heat
+ sink compound can be smeared between the device and the heat
+ sink to improve thermal conduction.
+
+ (1997-06-10)
+
+heat slug
+
+ <hardware, processor> A metal plate that helps dissipate heat
+ away from the {silicon} {core} of a {processor} to the
+ packaging or {heat-sink}.
+
+ (2000-08-26)
+
+heavy metal
+
+ {big iron}
+
+heavyweight
+
+ High-overhead; {baroque}; code-intensive; featureful, but
+ costly. Especially used of communication protocols, language
+ designs, and any sort of implementation in which maximum
+ generality and/or ease of implementation has been pushed at
+ the expense of mundane considerations such as speed, memory
+ use and startup time. {Emacs} is a heavyweight editor; {X} is
+ an *extremely* heavyweight window system. This term isn't
+ pejorative, but one hacker's heavyweight is another's
+ {elephantine} and a third's monstrosity.
+
+ Opposite: "lightweight". Usage: now borders on technical
+ especially in the compound "heavyweight process".
+
+ (1994-12-22)
+
+heavy wizardry
+
+ Code or designs that trade on a particularly intimate
+ knowledge or experience of a particular operating system or
+ language or complex application interface. Distinguished from
+ {deep magic}, which trades more on arcane *theoretical*
+ knowledge. Writing device drivers is heavy wizardry; so is
+ interfacing to {X} (sense 2) without a toolkit. Especially
+ found in source-code comments of the form "Heavy wizardry
+ begins here".
+
+ Compare {voodoo programming}.
+
+ [{Jargon File}]
+
+Hebbian learning
+
+ <artificial intelligence> The most common way to train a
+ {neural network}; a kind of {unsupervised learning}; named
+ after canadian neuropsychologist, Donald O. Hebb.
+
+ The {algorithm} is based on Hebb's Postulate, which states
+ that where one cell's firing repeatedly contributes to the
+ firing of another cell, the magnitude of this contribution
+ will tend to increase gradually with time. This means that
+ what may start as little more than a coincidental relationship
+ between the firing of two nearby neurons becomes strongly
+ causal.
+
+ Despite limitations with Hebbian learning, e.g., the inability
+ to learn certain patterns, variations such as {Signal Hebbian
+ Learning} and {Differential Hebbian Learning} are still used.
+
+ {(http://neuron-ai.tuke.sk/NCS/VOL1/P3_html/node14.html)}.
+
+ (2003-11-07)
+
+heisenbug
+
+ <jargon> /hi:'zen-buhg/ (From Heisenberg's Uncertainty
+ Principle in quantum physics) A bug that disappears or alters
+ its behaviour when one attempts to probe or isolate it. (This
+ usage is not even particularly fanciful; the use of a debugger
+ sometimes alters a program's operating environment enough that
+ buggy code, such as that which relies on the values of
+ uninitialised memory, behaves quite differently.)
+
+ In {C}, nine out of ten heisenbugs result from uninitialised
+ {auto variables}, {fandango on core} phenomena (especially
+ corruption of the malloc {arena}) or errors that {smash the
+ stack}.
+
+ Opposite: {Bohr bug}. See also {mandelbug}, {schroedinbug}.
+
+ [{Jargon File}]
+
+ (1995-02-28)
+
+Helen Keller mode
+
+ 1. State of a hardware or software system that is deaf, dumb,
+ and blind, i.e. accepting no input and generating no output,
+ usually due to an infinite loop or some other excursion into
+ {deep space}. (Unfair to the real Helen Keller, whose success
+ at learning speech was triumphant.) See also {go flatline},
+ {catatonic}.
+
+ 2. On {IBM PCs} under {MS-DOS}, refers to a specific failure
+ mode in which a screen saver has kicked in over an
+ {ill-behaved} application which bypasses the very interrupts
+ the screen saver watches for activity. Your choices are to
+ try to get from the program's current state through a
+ successful save-and-exit without being able to see what you're
+ doing, or to {re-boot} the machine. This isn't (strictly
+ speaking) a crash.
+
+ [{Jargon File}]
+
+Helix
+
+ A {hardware description language} from {Silvar-Lisco}.
+
+hello
+
+ {hello, world}
+
+hello packet
+
+ <networking, communications> An {OSPF} {packet} sent
+ periodically on each {network interface}, real or {virtual},
+ to discover and test connections to neighbours. Hello packets
+ are multicast on physical networks capable of {multicasting}
+ or {broadcasting} to enable dynamic {router} discovery. They
+ include the parameters that routers connected to a common
+ network must agree on.
+
+ Hello packets increase network resilience by, e.g., allowing a
+ router to establish a secondary connection when a primary
+ connection fails.
+
+ (1999-11-02)
+
+hello, sailor!
+
+ <jargon> Occasional West Coast equivalent of {hello, world};
+ seems to have originated at SAIL, later associated with the
+ game {Zork} (which also included "hello, aviator" and "hello,
+ implementor"). Originally from the traditional hooker's
+ greeting to a swabbie fresh off the boat, of course.
+
+ [{Jargon File}]
+
+ (2007-10-30)
+
+hello, world
+
+ <programming> The canonical, minimal, first program that a
+ programmer writes in a new {programming language} or {development
+ environment}. The program just prints "hello, world" to {standard
+ output} in order to verify that the programmer can successfully
+ edit, compile and run a simple program before embarking on
+ anything more challenging.
+
+ Hello, world is the first example program in the {C} programming
+ book, {K&R}, and the tradition has spread from there to pretty
+ much every other language and many of their textbooks.
+
+ Environments that generate an unreasonably large executable
+ for this trivial test or which require a {hairy}
+ compiler-linker invocation to generate it are considered bad.
+
+ {Hello, World in over 400 programming languages
+ (http://www.roesler-ac.de/wolfram/hello.htm)}.
+
+ (2013-10-27)
+
+HELP
+
+ 1. <language, robotics> {DEA}. A Language for industrial
+ robots.
+
+ 2. (Help Est un Lisp Paresseux - Help Is a Lazy Lisp). A
+ {lazy} version of {Scheme} with strictness {annotations}, by
+ Thomas Schiex <schiex@europe.cert.fr>.
+
+Helvetica
+
+ <text> One of the most widely used {sans-serif} {typefaces},
+ developed in 1957 by Swiss typeface designer Max Miedinger with
+ Eduard Hoffmann. Originally called Neue Haas Grotesk, it was
+ renamed Helvetica for the international market. Helvetica is very
+ similar to the common {Arial} typeface. The name is Latin for
+ Swiss.
+
+ {Linotype (http://www.linotype.com/526/helvetica-family.html)}.
+
+ (2013-09-19)
+
+henry
+
+ <unit> (H) The {SI} unit of inductance: one henry is the
+ inductance of a closed loop in which the induced voltage is
+ one volt if the current flowing through it changes by one
+ ampere each second, i.e., 1 H = 1 Vs/A. Named after the
+ American physicist Joseph Henry (1797-1878).
+
+ (1997-03-16)
+
+HENSA
+
+ {Higher Education National Software Archive}
+
+HEP
+
+ High Energy (Particle) Physics.
+
+HEPDB
+
+ A {database management system} for {HEP}.
+
+HEPiX
+
+ A recently formed collaboration among various HEP institutes
+ aiming at providing "compatible" versions of the Unix
+ operating system at their sites.
+
+HEPnet
+
+ An association concerned with networking requirements for high
+ energy physicists.
+
+HEPVM
+
+ A collaboration among various HEP institutes to implement
+ "compatible" versions of IBM's VM-CMS operating system at
+ their sites.
+
+HEQS
+
+ E. Derman. Constraint language for financial modelling. Uses
+ an extension of the equation solver in IDEAL. "A Simple
+ Equation Solver and Its Application to Financial Modeling",
+ E. Derman et al, Soft Prac & Exp 14(12):1169-1181 (Dec 1984).
+
+HERA
+
+ An electron-proton collider at DESY, W. Germany.
+
+HERAKLIT
+
+ <language> A distributed {object-oriented} language.
+
+ ["Definition einer objektorientierten Programmiersprache mit
+ hierarchischem Typkonzept", B. Hindel, diss U
+ Erlangen-Nuernberg, Dec 1987].
+
+ (1995-03-16)
+
+here document
+
+ <operating system> Data included in a {Unix} {shell script} or
+ {Perl} script using the "<<" syntax.
+
+ (1995-04-19)
+
+Herman Hollerith
+
+ <person> The promulgator of the {punched card}. Hollerith was
+ born on 1860-02-29 and died on 1929-11-17. He graduated from
+ Columbia University, NewYork, NY, USA. He joined the US
+ Census Bureau as a statistician where he used a punched card
+ device to help analyse the 1880 US census data. This punched
+ card system stored data in 80 columns. This "80-column"
+ concept has carried forward in various forms into modern
+ applications.
+
+ In 1896, Hollerith founded the {Tabulating Machine Company} to
+ exploit his invention and in 1924 his firm became part of
+ {IBM}. The Hollerith system was used for the 1911 UK census.
+
+ A correspondant writes:
+
+ Wasn't Hollerith's original machine first used for the 1990 US
+ census? And I think I am right in saying that the physical
+ layout was a 20x12 grid of round holes. The one I have seen
+ (picture only, unfortunately, not the real thing) did not use
+ 'columns' as such but holes were grouped into
+ irregularly-shaped fields, such that each hole had a
+ more-or-less independent function.
+
+ (2001-08-30)
+
+Hermes
+
+ <language> An experimental, very high level, integrated
+ language and system from the {IBM} {Watson Research Centre},
+ produced in June 1990. It is designed for implementation of
+ large systems and distributed applications, as well as for
+ general-purpose programming. It is an {imperative language},
+ {strongly typed} and is a {process-oriented} successor to
+ {NIL}.
+
+ Hermes hides distribution and heterogeneity from the
+ programmer. The programmer sees a single {abstract machine}
+ containing processes that communicate using calls or sends.
+ The {compiler}, not the programmer, deals with the complexity
+ of data structure layout, local and remote communication, and
+ interaction with the {operating system}. As a result, Hermes
+ programs are portable and easy to write. Because the
+ programming paradigm is simple and high level, there are many
+ opportunities for optimisation which are not present in
+ languages which give the programmer more direct control over
+ the machine.
+
+ Hermes features {threads}, {relational tables}Hermes is,
+ {typestate} checking, {capability}-based access and {dynamic
+ configuration}.
+
+ Version 0.8alpha patchlevel 01 runs on {RS/6000}, {Sun-4},
+ {NeXT}, {IBM-RT}/{BSD4.3} and includes a {bytecode compiler},
+ a bytecode->C compiler and {run-time support}.
+
+ {0.7alpha for Unix
+ (ftp://software.watson.ibm.com/pub/hermes)}.
+
+ E-mail: <hermes-request@watson.ibm.com>, Andy Lowry
+ <lowry@watson.ibm.com>.
+
+ {Usenet} newsgroup: {news:comp.lang.hermes}.
+
+ ["Hermes: A Language for Distributed Computing". Strom,
+ Bacon, Goldberg, Lowry, Yellin, Yemini. Prentice-Hall,
+ Englewood Cliffs, NJ. 1991. ISBN: O-13-389537-8].
+
+ (1992-03-22)
+
+Hesiod
+
+ <project> The {name server} of the {Athena} project.
+
+ [Details?]
+
+ (1997-10-27)
+
+heterogeneous
+
+ Composed of unrelated parts, different in kind.
+
+ Often used in the context of {distributed systems} that may be
+ running different {operating systems} or network {protocols}
+ (a {heterogeneous network}).
+
+ For examples see: {interoperable database}, {middleware}.
+
+ Constrast {homogeneous}.
+
+ (1999-05-06)
+
+heterogeneous network
+
+ <networking> A {network} running multiple {network layer}
+ {protocols} such as {DECnet}, {IP}, {IPX}, {XNS}.
+
+ (1997-10-27)
+
+heterogenous
+
+ <spelling> It's spelled {heterogeneous}.
+
+ (1999-06-10)
+
+heuristic
+
+ 1. <programming> A rule of thumb, simplification, or educated
+ guess that reduces or limits the search for solutions in
+ domains that are difficult and poorly understood. Unlike
+ {algorithms}, heuristics do not guarantee optimal, or even
+ {feasible}, solutions and are often used with no theoretical
+ guarantee.
+
+ 2. <algorithm> {approximation algorithm}.
+
+ (2001-04-12)
+
+heuristics testing
+
+ {failure-directed testing}
+
+Hewlett-Packard
+
+ (HP) Hewlett-Packard designs, manufactures and services
+ electronic products and systems for measurement, computation
+ and communications. The company's products and services are
+ used in industry, business, engineering, science, medicine and
+ education in approximately 110 countries.
+
+ HP was founded in 1939 and employs 96600 people, 58900 in the
+ USA. They have manufacturing and R&D establishments in 54
+ cities in 16 countries and approximately 600 sales and service
+ offices in 110 countries. Their revenue (in 1992/1993?) was
+ $20.3 billion. The Chief Executive Officer is Lewis E. Platt.
+ HP's stock is traded on the New York Stock Exchange and the
+ Pacific, Tokyo, London, Frankfurt, Zurich and Paris exchanges.
+
+ Quarterly sales $6053M, profits $347M (Aug 1994).
+
+ {(http://hp.com/home.html)}.
+
+ (1994-09-26)
+
+Hewlett-Packard Graphics Language
+
+ <graphics, language> (HP-GL) A {vector graphics} language used
+ by {HP} plotters.
+
+ [Details? On-line spec?]
+
+ (1994-10-27)
+
+Hewlett-Packard Interface Bus
+
+ {IEEE 488}
+
+Hewlett Packard Multi Processing Executive
+
+ <operating system> (HP-MPE) The standard {operating system} on
+ all {HP3000} {minicomputers}, in the same way that HP9000
+ computers run {HP-UX}.
+
+ Latest version: MPE/IX Version 5.5.04, as of 1998-02-17.
+
+ (1998-02-17)
+
+Hewlett Packard Precision Architecture
+
+ (HP-PA) {Hewlett Packard}'s range of RISC processors.
+
+ [Details?]
+
+ (1995-02-22)
+
+Hewlett-Packard Visual Engineering Environment
+
+ (HP VEE) A package similar in intention to {LabVIEW}, running
+ on {Unix} {workstations} under {OSF}/{Motif}.
+
+ (1997-05-12)
+
+hex
+
+ 1. {hexadecimal}.
+
+ 2. A 6-pack of anything (compare {quad}). Neither usage has
+ anything to do with {magic} or {black art}, though the pun is
+ appreciated and occasionally used by hackers. True story: As
+ a joke, some hackers once offered some surplus ICs for sale to
+ be worn as protective amulets against hostile magic. The
+ chips were, of course, hex inverters.
+
+ 3. <character> The {hash} character, used to introduce
+ {hexadecimal} constants in some {assembly languages}.
+
+ [{Jargon File}]
+
+ (1995-03-06)
+
+hexadecimal
+
+ <mathematics> (Or "hex") {Base} 16. A number representation
+ using the digits 0-9, with their usual meaning, plus the
+ letters A-F (or a-f) to represent hexadecimal digits with
+ values of (decimal) 10 to 15. The right-most digit counts
+ ones, the next counts multiples of 16, then 16^2 = 256, etc.
+
+ For example, hexadecimal BEAD is decimal 48813:
+
+ digit weight value
+ B = 11 16^3 = 4096 11*4096 = 45056
+ E = 14 16^2 = 256 14* 256 = 3584
+ A = 10 16^1 = 16 10* 16 = 160
+ D = 13 16^0 = 1 13* 1 = 13
+ -----
+ BEAD = 48813
+
+ There are many conventions for distinguishing hexadecimal
+ numbers from decimal or other bases in programs. In {C} for
+ example, the prefix "0x" is used, e.g. 0x694A11.
+
+ Hexadecimal is more succinct than {binary} for representing
+ {bit-masks}, machines addresses, and other low-level constants
+ but it is still reasonably easy to split a hex number into
+ different bit positions, e.g. the top 16 bits of a 32-bit word
+ are the first four hex digits.
+
+ The term was coined in the early 1960s to replace earlier
+ "sexadecimal", which was too racy and amusing for stuffy
+ {IBM}, and later adopted by the rest of the industry.
+
+ Actually, neither term is etymologically pure. If we take
+ "binary" to be paradigmatic, the most etymologically correct
+ term for base ten, for example, is "denary", which comes from
+ "deni" (ten at a time, ten each), a Latin "distributive"
+ number; the corresponding term for base sixteen would be
+ something like "sendenary". "Decimal" is from an ordinal
+ number; the corresponding prefix for six would imply something
+ like "sextidecimal". The "sexa-" prefix is Latin but
+ incorrect in this context, and "hexa-" is Greek. The word
+ {octal} is similarly incorrect; a correct form would be
+ "octaval" (to go with decimal), or "octonary" (to go with
+ binary). If anyone ever implements a base three computer,
+ computer scientists will be faced with the unprecedented
+ dilemma of a choice between two *correct* forms; both
+ "ternary" and "trinary" have a claim to this throne.
+
+ [{Jargon File}]
+
+ (1996-03-09)
+
+hexidecimal
+
+ <spelling> Mis-spelling of "{hexadecimal}".
+
+ (1998-03-03)
+
+hexit
+
+ <jargon> /hek'sit/ A {hexadecimal} digit (0-9, and A-F or
+ a-f). Used by people who claim that there are only *ten*
+ digits, sixteen-fingered human beings being rather rare,
+ despite what some keyboard designs might seem to imply (see
+ {space-cadet keyboard}).
+
+ [{Jargon File}]
+
+ (1996-03-09)
+
+HFC
+
+ 1. <networking> {Hybrid Fiber Coax}.
+
+ 2. <hardware> {hydrofluorocarbon}.
+
+ (1999-11-02)
+
+HHCP
+
+ {Host Host Copy}
+
+HHOJ
+
+ <chat> ha ha only joking.
+
+ Contrast {ha ha only serious}.
+
+ (1998-01-18)
+
+HHOK
+
+ ha ha only kidding. See {ha ha only serious}.
+
+ [{Jargon File}]
+
+HHOS
+
+ {ha ha only serious}
+
+hi
+
+ {hmake interactive}
+
+HIBOL
+
+ <language> A variant of {DIBOL}, used in {Infotec} computers.
+ HIBOL was considered to be a very high level language and
+ significantly easier to maintain than {COBOL}. It uses a
+ single type of data object, called a flow, which is an indexed
+ stream of data values. Computation is expressed as operations
+ acting on flows.
+
+ {Language List
+ (http://people.ku.edu/~nkinners/LangList/Langs/H/HIBOL.htm)}.
+
+ {Translation of COBOL to HIBOL
+ (http://dl.acm.org/citation.cfm?id=889862)}.
+
+ ["HIBOL: a language for fast prototyping in data processing
+ environments", Roland T. Mittermeir, Technische Universitaet
+ Wien, Vienna, Austria, Proceedings of the workshop on Rapid
+ Prototyping, ACM New York, NY, USA 1982, ISBN:0-89791-094-X,
+ {(http://dl.acm.org/citation.cfm?id=1006282)}].
+
+ [R. T. Mittermeir, "HIBOL - A very High Level Business
+ Oriented Language, User Manual", TR DA 81/04/04, Institut fuer
+ Angewandte Informatik und Systemanalyse, Technische
+ Universitaet Wien, Wien, 1981].
+
+ (2012-01-08)
+
+HID
+
+ {Human Interface Device}
+
+hidden flag
+
+ (scientific computation) An extra option added to a routine
+ without changing the calling sequence. For example, instead
+ of adding an explicit input variable to instruct a routine to
+ give extra diagnostic output, the programmer might just add a
+ test for some otherwise meaningless feature of the existing
+ inputs, such as a negative mass. The use of hidden flags can
+ make a program very hard to debug and understand, but is all
+ too common wherever programs are hacked in a hurry.
+
+ [{Jargon File}]
+
+ (1994-11-24)
+
+hierarchical database
+
+ <database> A kind of {database management system} that links
+ records together like a family tree such that each record type
+ has only one owner, e.g. an order is owned by only one
+ customer. Hierarchical structures were widely used in the
+ first {mainframe} database management systems. However, due
+ to their restrictions, they often cannot be used to relate
+ structures that exist in the real world.
+
+Hierarchical Data Format
+
+ <file format, data> (HDF) A {library} and multi-object file
+ format for the transfer of graphical and numerical data
+ between computeres. The freely available HDF distribution
+ consists of the library, command line utilities, test suite
+ source, {Java} interface, and the Java-based HDF Viewer (JHV).
+
+ HDF supports several different {data models}, including
+ multidimensional {arrays}, {raster images}, and tables. Each
+ defines a specific aggregate data type and provides an {API}
+ for reading, writing, and organising the data and {metadata}.
+ New data models can be added by the HDF developers or users.
+
+ HDF is self-describing, allowing an application to interpret
+ the structure and contents of a file without any outside
+ information.
+
+ One HDF file can hold a mixture of related objects which can
+ be accessed as a group or as individual objects. Users can
+ create their own grouping structures called "vgroups".
+
+ HDF files can be shared across most common {platforms},
+ including many workstations and high performance computers.
+ An HDF file created on one computer can be read on a different
+ system without modification.
+
+ {(http://hdf.ncsa.uiuc.edu/)}.
+
+ (2001-07-02)
+
+Hierarchical Design Methodology
+
+ <programming> (HDM) A method for specifying {software} and
+ systems using hierarchies of {abstract machines}, developed by
+ Larry Robinson at SRI International circa 1975-1976. The
+ specifications were written in {SPECIAL}.
+
+ (2012-07-08)
+
+hierarchical file system
+
+ <file system> A {file system} in which the {files} are
+ organised into a {hierarchy}. The nodes of the hierarchy are
+ called {directories} while the leaves are the files
+ themselves.
+
+ See also {root directory}. Compare {flat file system}.
+
+ (1996-11-21)
+
+Hierarchical Music Specification Language
+
+ <language, music> (HMSL) A programming language for
+ experimental music composition and performance. It is a set
+ of {object-oriented} extensions to {Forth}. (Its near-total
+ unintelligibility to people unfamiliar with {Forth} has led
+ some to expand "HMSL" as "Her Majesty's Secret Language".)
+
+ Phil Burk (who also later developed {pForth}), Larry Polansky,
+ and David Rosenboom started developing HMSL in 1980 while
+ working at the {Mills College Center for Contemporary Music
+ (http://mills.edu/LIFE/CCM/CCM.homepage.html)}. As of
+ June 1998, development is ongoing.
+
+ {(http://softsynth.com/hmsl/)}.
+
+ (1998-09-07)
+
+hierarchical navigation
+
+ <web> On a {web page}, any type of menu whose
+ hierarchical structure matches that of the site to which the
+ page belongs. A hierarchical navigation menu allows the user
+ to jump ("navigate") directly to a section of the site several
+ levels below the top. The menu may present only a fixed
+ number of levels rather than the whole structure.
+
+ (2003-10-01)
+
+Hierarchical Object Oriented Design
+
+ <programming> (HOOD) An architectural design method, primarily
+ for {Ada}, leading to automated checking, {documentation} and
+ {source code} generation.
+
+ (2009-01-14)
+
+hierarchical routing
+
+ The complex problem of routing on large networks can be
+ simplified by breaking a network into a hierarchy of smaller
+ networks, where each level is responsible for its own routing.
+ The Internet has, basically, three levels: the backbones, the
+ mid-levels, and the stub networks. The backbones know how to
+ route between the mid-levels, the mid-levels know how to route
+ between the sites, and each site (being an autonomous system)
+ knows how to route internally. See also Exterior Gateway
+ Protocol, Interior Gateway Protocol, transit network.
+
+hierarchy
+
+ An organisation with few things, or one thing, at the top and
+ with several things below each other thing. An inverted tree
+ structure. Examples in computing include a directory
+ hierarchy where each directory may contain files or other
+ directories; a hierarchical {network} (see {hierarchical
+ routing}), a {class hierarchy} in {object-oriented
+ programming}.
+
+ (1994-10-11)
+
+Higgs Bugson
+
+ <humour> A hypothetical {bug} predicted to exist based on a
+ small number of possibly related event log entries and vague
+ anecdotal user reports. The Higgs Bugson is difficult to
+ reproduce because you don't really know if it's there, and if
+ it is there what is causing it. To find one you will need a
+ Large Hadron Debugger.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2012-08-31)
+
+high bit
+
+ (Or "high-order bit") The most significant {bit} in a {byte}.
+
+ See also {meta bit}, {hobbit}, {dread high bit disease}.
+
+ [{Jargon File}]
+
+ (2012-08-31)
+
+High bit-rate Digital Subscriber Line
+
+ <communications, protocol> (HDSL) A form of {Digital
+ Subscriber Line}, providing {T1} or {E1} connections over two
+ or three {twisted-pair} copper lines, respectively. Unlike
+ most other forms of DSL HDSL is not a typical consumer
+ service, it's used mostly to replace traditional T1/E1
+ connections, such as connecting {PBXes} to {telco} offices.
+ The advantage of HDSL over the {Alternate Mark Inversion} line
+ coding scheme traditionally used on T1/E1 lines is that it
+ requires about an order of magnitude lower bandwidth to carry
+ the same traffic.
+
+ (1998-05-18)
+
+high colour
+
+ <hardware> A {colour depth} of 16 (or 15) {bits per pixel}.
+
+ Compare {true colour}.
+
+ (1999-08-01)
+
+High-Definition Multimedia Interface
+
+ <video, standard> (HDMI) an industry standard for connecting
+ digital audio and video devices via a single cable. HDMI can
+ connect any audio/video source, such as a {set-top box}, {DVD
+ player}, or {A/V receiver} to an audio and/or video output
+ device such as a digital television (DTV).
+
+ HDMI supports standard, enhanced, or high-definition video,
+ plus multi-channel digital audio. It transmits all {ATSC}
+ HDTV standards and supports 8-channel, 192kHz, uncompressed
+ digital audio and all currently-available compressed formats
+ (such as {Dolby Digital} and {DTS}), HDMI 1.3 adds additional
+ support for new lossless digital audio formats {Dolby TrueHD}
+ and {DTS-HD Master Audio} with {bandwidth} to spare to
+ accommodate future enhancements. HDMI 1.4 incorporates
+ connection via {Ethernet}.
+
+ HDMI was created by {Hitachi}, {Panasonic Corporation},
+ {Philips}, {Sony}, {Thomson} (RCA), {Toshiba} and {Silicon
+ Image} and has the support of several major motion picture
+ producers and distributors.
+
+ Latest version: 1.4 (2009-06-08), as of 2009-06-29.
+
+ {hdmi.org (http://hdmi.org/)}.
+
+ (2009-06-29)
+
+high density
+
+ {floppy disk}
+
+Higher Education National Software Archive
+
+ (HENSA)
+
+ {(http://hensa.ac.uk/)}.
+
+ (1995-01-06)
+
+higher-order function
+
+ (HOF) A function that can take one or more functions as
+ argument and/or return a function as its value. E.g. map in
+ (map f l) which returns the list of results of applying
+ function f to each of the elements of list l. See also
+ {curried function}.
+
+higher-order macro
+
+ A means of expressing certain {higher-order functions} in a
+ first order language. Proposed by Phil Wadler. Higher-order
+ macros cannot be recursive at the top level but they may
+ contain recursive definitions. E.g.
+
+ map f l = m l
+ where
+ m [] = []
+ m (x:xs) = f x : m xs
+
+ Expanding a call to this macro is equivalent to specialising a
+ call to map in its first argument.
+
+ See {partial evaluation}.
+
+High-level Data Link Control
+
+ <networking> (HDLC) A general-purpose {data link} control
+ {protocol} defined by {ISO} for use on both point-to-point and
+ {multipoint} (multidrop) data links. It supports
+ {full-duplex}, {transparent-mode} operation. It is used
+ extensively in both multipoint and computer networks.
+
+ Some manufacturers and other standards bodies still use their
+ own acronyms, e.g. {IBM}'s SDLC ({Synchronous Data Link
+ Control}), the forerunner of HDLC and {ANSI}'s ADCCP
+ ({Advanced Data Communications Control Procedure}).
+
+ [Fred Halsall, "Data Communications, Computer Networks and
+ Open Systems" 4th edition, 1996, p.237, Addison-Wesley
+ Publishing Co. Reading, Mass., USA].
+
+ (1997-11-09)
+
+high-level language
+
+ (HLL) A programming language which provides some level of
+ abstraction above {assembly language}. These normally use
+ statements consisting of English-like keywords such as "FOR",
+ "PRINT" or "GOTO", where each statement corresponds to several
+ {machine language} instructions. It is much easier to program
+ in a high-level language than in {assembly language} though
+ the efficiency of execution depends on how good the {compiler}
+ or {interpreter} is at optimising the program.
+
+ Rarely, the variants "{VHLL}" and "{MLL}" are found.
+
+ See also {languages of choice}, {generation}.
+
+ (1994-12-07)
+
+high memory area
+
+ <storage> (HMA) The first 64 {kilobytes} (minus 16 byte) of
+ the {extended memory} on an {IBM PC}. By a strange design
+ glitch the {Intel 80x86} processors can actually address 17*64
+ kbyte minus 16 byte of memory (from 0000:0000 to ffff:ffff) in
+ real mode. In the {Intel 8086} and {Intel 8088} processors,
+ unable to handle more than 1 {megabyte} of memory, addressing
+ wrapped around, that is, address ffff:0010 was equivalent to
+ 0000:0000. For compatibility reasons, later processors still
+ wrapped around by default, but this feature could be switched
+ off. Special programs called {A20 handlers} can control the
+ addressing mode dynamically, thereby allowing programs to load
+ themselves into the 1024--1088 kbyte region and run in {real
+ mode}. From version 5.0 parts of {MS-DOS} can be loaded into
+ HMA as well freeing up to 46 kbytes of {conventional memory}.
+
+ (1995-01-10)
+
+high moby
+
+ /hi:' mohb'ee/ The high half of a 512K {PDP-10}'s physical
+ address space; the other half was of course the low moby.
+ This usage has been generalised in a way that has outlasted
+ the {PDP-10}; for example, at the 1990 Washington D.C. Area
+ Science Fiction Conclave (Disclave), when a miscommunication
+ resulted in two separate wakes being held in commemoration of
+ the shutdown of MIT's last {ITS} machines, the one on the
+ upper floor was dubbed the "high moby" and the other the "low
+ moby". All parties involved {grok}ked this instantly. See
+ {moby}.
+
+ [{Jargon File}]
+
+High Performance Computing and Communications
+
+ (HPCC) High performance computing includes scientific
+ workstations, supercomputer systems, high speed networks,
+ special purpose and experimental systems, the new generation
+ of large scale parallel systems, and application and systems
+ software with all components well integrated and linked over a
+ high speed network.
+
+ ["Grand Challenges 1993: High Performance Computing and
+ Communications", Committee on Physical, Mathematical and
+ Engineering Sciences of the Federal Coordinating Council for
+ Science, Engineering and Technology.]
+
+High Performance File System
+
+ <file system> (HPFS) The {native} {file system} for {IBM}'s
+ {OS/2}.
+
+ (1995-03-06)
+
+High Performance Fortran
+
+ <language> (HPF) A {data parallel} language extension to
+ {Fortran 90} which provides a portable programming interface
+ for a wide variety of target {platforms}. The original HPF
+ language specification was produced by the High Performance
+ Fortran Forum, a broad consortium of industry and academia,
+ which met regularly throughout 1992 and early 1993. HPF
+ {compilers} are now available on most commonly-used computing
+ systems, and users are beginning to gain first hand experience
+ with this language. The Forum has continued to meet in order
+ to address advanced topics.
+
+ {HPF+ at Vienna (http://par.univie.ac.at/hpf+/)}.
+
+ ["High Performance Fortran: Status Report", G.L. Steele Jr
+ <gls@think.com>, SIGPLAN Notices 28(1):1-4 (Jan 1993)].
+
+ (1996-09-09)
+
+High Performance Parallel Interface
+
+ <hardware, standard> (HIPPI, previously HPPI) A
+ {connection-oriented}, point-to-point networking {standard}
+ using {circuit-switching} technology at a speed of 800 Mbits/s
+ or 1.6 Gbits/s (simplex or full-duplex). HIPPI is often used
+ for short distances (up to 10km depending on cable type) to
+ connect a {supercomputer} to {routers}, {frame buffers},
+ {mass-storage} peripherals and other computers.
+
+ HIPPI was developed at {Los Alamos National Laboratory} and is
+ now {ANSI} standard X3T9/88-127. Standards for
+ interconnecting with {ATM}, {SONet}, and {fibre channel} are
+ in development.
+
+ {HIPPI Networking Forum (http://esscom.com/hnf)}.
+
+ (1997-06-29)
+
+High Performance Routing
+
+ <networking> (HPR) Routing designed to work in conjunction
+ with {APPN} {Intermediate Session Routing} (ISR) network
+ nodes. HPR nodes perform many of the same functions as ISR
+ nodes. For example, HPR nodes use the same method of
+ calculating routes based on the {Topology} Routing Service
+ database and {class of service} tables. HPR nodes also
+ supports such APPN features as connection networks and support
+ for parallel {transmission groups} (TGs). In the HPR
+ architecture, both partner nodes must support HPR for {RTP}
+ connections to take place between the nodes. If one node
+ supports HPR and the partner node does not, then the link will
+ support ISR functionality only.
+
+ ["APPN Architecture and Product Implementations Tutorial",
+ IBM, GG24-3669-92].
+
+ (1997-05-08)
+
+High Performance Serial Bus
+
+ <hardware, standard> (Or "{IEEE} 1394") A 1995 {Macintosh}/{IBM
+ PC} {serial bus} interface {standard} offering {isochronous}
+ {real-time} data transfer.
+
+ 1394 can transfer data between a computer and its {peripherals} at
+ 100, 200, or 400 {Mbps}, with a planed increase to 2 {Gbps}.
+ Cable length is limited to 4.5 m but up to 16 cables can be
+ daisy-chained yielding a total length of 72 m.
+
+ It can {daisy-chain} together up to 63 peripherals in a tree-like
+ structure (as opposed to {SCSI}'s linear structure). It allows
+ peer-to-peer communication, e.g. between a {scanner} and a
+ {printer}, without using system memory or the {CPU}. It is
+ designed to support {plug-and-play} and {hot swapping}.
+
+ Its six-wire cable is not only more convenient than SCSI cables
+ but can supply up to 60 watts of power, allowing low-consumption
+ devices to operate without a separate power cord.
+
+ Some expensive camcorders included this bus from 1995. It is
+ expected to be used to carry {SCSI}, with possible application to
+ {home automation} using {repeaters}.
+
+ {Sony} calls it {I-Link}, most people call it "FireWire".
+
+ See also {Universal Serial Bus}, {FC-AL}.
+
+ (2014-09-06)
+
+High Speed Circuit Switched Data
+
+ <communications> (HSCSD) A planned feature of {GSM Phase 2}
+ defining a standard for {circuit switched} data transmission
+ over a {GSM} link at up to 57.6 (78.8?) {kbps}. This is
+ achieved by concatenating up to four consecutive GSM
+ {timeslots}, each of which is capable of 14.4 kbit/s. It uses
+ {multiplexing} and {compression} or filtering.
+
+ The following services toward the fixed network are
+ supported: {V.34} up to 28.8 kbps and {V.110} with rate
+ adaptation up to 38.4 kbps.
+
+ HSCSD is aimed at {mobile workstation} users. As it is
+ circuit switched, it is suited to {streaming} applications
+ such as {video conferencing} and {multimedia}. {Bursty}
+ applications like {electronic mail}, are more suited to
+ {packet switched} data (as in {GPRS}).
+
+ {Ericsson
+ (http://ericsson.com/wireless/products/mobsys/gsm/subpages/wise/subpages/hscsd.shtml)}.
+
+ {(http://gsmworld.com/)}.
+
+ (1999-12-04)
+
+High Speed Connect
+
+ <hardware> (HSC) A {Hewlett-Packard} bus like {EISA}.
+
+ [HP9000 Configuration Guide, January 1996].
+
+ [Details?]
+
+ (1996-06-06)
+
+High-speed Net Connect
+
+ <hardware, communications> (HNC) A network interface unit for
+ {BS2000} {mainframes} based on {Novell NetWare}, supporting
+ {Ethernet} and {FDDI}.
+
+ (2005-02-11)
+
+high speed serial interface
+
+ <hardware, communications> (HSSI) A {serial port} which
+ supports serial transmit speeds of up to 52 megabits per
+ second. It is typically used for leased lines such as {DS3}
+ (44.736 Mbps) and {E3} (34 Mbps) and for {Wide Area Network}
+ devices such as {routers}.
+
+ (1995-11-20)
+
+High Voltage Differential
+
+ <hardware> (HVD) {Differential SCSI} scheme that has been in
+ use for years. The {terminators} run on 5 Volts DC.
+
+ See also {LVD}.
+
+ (1999-02-16)
+
+HIGZ
+
+ High Level Interface to Graphics and Zebra. Part of the {PAW}
+ system.
+
+hill climbing
+
+ <algorithm> A {graph} search {algorithm} where the current
+ path is extended with a successor node which is closer to the
+ solution than the end of the current path.
+
+ In simple hill climbing, the first closer node is chosen
+ whereas in steepest ascent hill climbing all successors are
+ compared and the closest to the solution is chosen. Both
+ forms fail if there is no closer node. This may happen if
+ there are local maxima in the {search space} which are not
+ solutions. Steepest ascent hill climbing is similar to {best
+ first search} but the latter tries all possible extensions of
+ the current path in order whereas steepest ascent only tries
+ one.
+
+ (1995-12-09)
+
+HiLog
+
+ A {higher-order logic} programming language. An extension of
+ normal {logic programming} where {predicate} symbols may be
+ variable or structured. This allows {unification} to be
+ performed on the predicate symbols themselves in addition to
+ their arguments.
+
+ {(ftp://sbcs.sunysb.edu/SB-hilog)}.
+
+ ["HiLog as a Platform for Database Languages (Or Why Predicate
+ Calculus is Not Enough)", W. Chen et al, Stony Brook, 2nd Intl
+ Workshop on Database Prog Langs, Morgan Kaufmann, 1989].
+
+ (1994-12-07)
+
+HIMEM
+
+ <software, storage> An {IBM PC} {extended memory manager},
+ part of {MS-DOS} version 5.00 or higher. HIMEM can also act
+ as an {A20 handler}.
+
+ (1996-01-10)
+
+Hindenbug
+
+ <humour> A catastrophic, data-destroying {bug}, after the 1937
+ Hindenburg airship disaster.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2012-10-20)
+
+hing
+
+ ({IRC}) Fortuitous typo for "hint", now in wide intentional
+ use among players of {initgame}.
+
+ Compare {newsfroup}, {filk}.
+
+ [{Jargon File}]
+
+ (1994-12-07)
+
+HINT
+
+ Hierarchical Information NeTs.
+
+ A language for the {CDC 3600}.
+
+ ["HINT: A Graph Processing Language", R.D. Hart, Michigan
+ State U, Apr 1970].
+
+ (1994-12-07)
+
+HiPAC
+
+ An active DBMS from Xerox Advanced Information Technology.
+
+HIPPI
+
+ {High Performance Parallel Interface}
+
+hiragana
+
+ <Japanese> The cursive formed Japanese {kana} syllabary.
+ Hiragana is mostly used for grammatical particles,
+ verb-inflection, and Japanese words which are not written in
+ {kanji} or which are too difficult for an educated person to
+ read or write in {kanji}. Hiragana are also used for
+ {furigana}.
+
+ (2001-03-18)
+
+hirsute
+
+ Occasionally used as a humorous synonym for {hairy}.
+
+ [{Jargon File}]
+
+HISTORIAN
+
+ A {source code management} system sold by {OPCODE, Inc.}
+
+history
+
+ 1. <history> {Virginia Tech history of computing
+ (http://ei.cs.vt.edu/~history/index.html)}. {IT Rentals computing
+ timeline (http://www.itrentals.com/historyofcomputing/)}.
+
+ 2. <operating system> A record of previous user inputs (e.g. to a
+ {command interpreter}) which can be re-entered without re-typing
+ them. The major improvement of the {C shell} (csh) over the
+ {Bourne shell} (sh) was the addition of a command history. This
+ was still inferior to the history mechanism on {VMS} which allowed
+ you to recall previous commands as the current input line. You
+ could then edit the command using cursor motion, insert and
+ delete. These sort of history editing facilities are available
+ under {tcsh} and {GNU Emacs}.
+
+ 3. The history of the world was once discussed in {Usenet}
+ newsgroups {news:soc.history} and {news:alt.history}.
+
+ (2013-08-04)
+
+hit
+
+ 1. <architecture> {cache hit}.
+
+ 2. <web> A request to a {web server} from a {web
+ browser} or other {client} (e.g. a {robot}).
+
+ The number of hits on a server may be important for
+ determining advertising revenue.
+
+ In the course of loading a single {web page}, a browser may
+ hit a web server many times e.g. to retrieve the page itself
+ and each {image} on the page. In contrast, caching by
+ browsers and {web proxies} reduces the number of hits on the
+ server because some requests are satisfied from the cache.
+
+ 3. <jargon> To press and release a key on the keyboard. Some
+ prefer the less aggressive "tap".
+
+ (2000-02-20)
+
+Hitachi 6309
+
+ <processor> (HD6309) {Hitachi}'s version of the {Motorola
+ 6809} {microprocessor}. Compatible with the 6809, it added
+ two new eight-bit {registers} that could be added to form a
+ second 16-bit register, and all four eight-bit registers could
+ form a 32-bit register. It also featured division, and some
+ 32-bit arithmetic and was generally 30% faster in native mode.
+ This information, surprisingly, was never published by
+ Hitachi.
+
+ {Technical reference
+ (http://sandelman.ottawa.on.ca/People/Alan_DeKok/interests/6309.techref)}.
+
+ (1997-03-21)
+
+Hitachi HD64180
+
+ <processor> A processor family which adds peripherals and an
+ {MMU} to the {Zilog Z80}.
+
+ (1995-10-06)
+
+HITL
+
+ {Human Interface Technology Laboratory}
+
+hit rate
+
+ <architecture> The fraction of all memory reads which are
+ satisfied from the {cache}.
+
+ (1997-01-21)
+
+hk
+
+ <networking> The {country code} for Hong Kong.
+
+ (1999-01-27)
+
+HL7
+
+ <protocol> An information exchange {protocol} used in
+ medicine, and possibly elsewhere. It is different from
+ {DICOM}.
+
+ [Details?]
+
+ (1998-12-23)
+
+HLISP
+
+ "Monocopy and Associative Algorithms in an Extended Lisp",
+ E. Goto, U Tokyo May 1974.
+
+HLL
+
+ {high-level language}
+
+HLLAPI
+
+ {High Level Language Application Programming Interface}
+
+hlp
+
+ <filename extension> A {Microsoft Windows} {filename
+ extension} for {hypertext} {WinHelp} files. These are in a
+ {proprietary} format, and are compiled from {source files}
+ written in a dialect of {RTF}.
+
+ See also {gid}.
+
+ {Usenet} newsgroup:
+ {news:comp.os.ms-windows.programmer.winhelp}.
+
+ (1997-01-30)
+
+hm
+
+ <networking> The {country code} for the Heard and McDonald
+ Islands.
+
+ (1999-01-27)
+
+HMA
+
+ {High Memory Area}
+
+HMAC
+
+ {Keyed-Hashing Message Authentication}
+
+hmake
+
+ <programming> A {compilation manager} for {Haskell}. hmake
+ recompiles a given module or program by extracting
+ dependencies between {source} modules and issuing appropriate
+ compiler commands to rebuild only changed modules. hmake can
+ use whatever Haskell compilers and preprocessors you have
+ installed.
+
+ If an .hi interface file is unchanged then changes in the
+ corresponding implementation code will not trigger
+ recompilation of calling code.
+
+ {hmake interactive} is an interactive development environment
+ built on hmake.
+
+ Malcolm Wallace of the {York Functional Programming Group}
+ developed hmake in 2005 based on Thomas Hallgren's hbcmake and
+ nhc13make.
+
+ {hmake home (http://www.cs.york.ac.uk/fp/hmake/hmake.html)}.
+
+ (2009-11-24)
+
+HMP
+
+ {hybrid multiprocessing}
+
+HMSL
+
+ {Hierarchical Music Specification Language}
+
+HMTL
+
+ <spelling> Do you mean {HTML}?
+
+ (1998-06-30)
+
+hn
+
+ <networking> The {country code} for Honduras.
+
+ (1999-01-27)
+
+HNC
+
+ {High-speed Net Connect}
+
+HO
+
+ {handover}
+
+Hoare powerdomain
+
+ {powerdomain}
+
+Hobbit
+
+ A {Scheme} to {C} compiler by Tanel Tammet
+ <tammet@cs.chalmers.se>. Hobbit attempts to retain most of
+ the original Scheme program structure, making the output C
+ program readable and modifiable. Hobbit is written in Scheme
+ and is able to self-compile. Hobbit release 1 works together
+ with the {scm} release scm4b3. Future releases of scm and
+ hobbit will be coordinated.
+
+ Latest version: release 2.
+
+ {(ftp://altdorf.ai.mit.edu/archive/scm/hobbit2.tar.Z)}.
+
+ (1993-04-25)
+
+ 2. The non-{ITS} name of <vad@ai.mit.edu> (*Hobbit*), master of
+ lasers.
+
+hobbit
+
+ High order bit. The most significant bit (of a byte). Also
+ known as the {meta bit} or {high bit}.
+
+ [{Jargon File}]
+
+hog
+
+ <jargon> A term used to describe programs, hardware or people that
+ use more than their share of a system's resources, especially
+ those which noticeably degrade interactive response.
+
+ The term is usually qualified, e.g. "memory hog", "core hog", "hog
+ the processor", "hog the disk". E.g. "A {controller} that never
+ gives up the {I/O bus} gets killed after the bus-hog timer
+ expires."
+
+ User also hog resources, particularly disk, where it seems that
+ 10% of the people use 90% of the disk, no matter how big the disk
+ is or how many people use it. Once a disk hog fills up one file
+ system, he typically finds a new one to consume, claiming to the
+ sysadmin that they have an important new project to complete.
+
+ (2014-08-16)
+
+HOL
+
+ Higher Order Logic. A proof-generating system for {higher
+ order logic} based on {LCF}. Implementations include {HOL-88}
+ and {HOL-90}.
+
+ {(ftp://ted.cs.uidaho.edu/pub/hol)}. Mailing list:
+ info-hol@ted.cs.uidaho.edu.
+
+ ["HOL: A Machine Oriented Formulation of Higher Order Logic",
+ M.J.C. Gordon, Report 68, Comp Lab U Cambridge (1985)].
+
+ ["Introduction to HOL", M.J.C. Gordon et al, Cambridge U Press
+ 1993 ISBN 0-521-441897].
+
+HOL-88
+
+ An implementation of {HOL} built on {ML} by Mike Gordon
+ <mjcg@cl.cam.ac.uk>.
+
+HOL-90
+
+ An implementation of {HOL} built on {SML/NJ} by Brian Graham
+ <graham@cpsc.ucalgary.ca>. Runs on {Sun-4}.
+
+ {(ftp://fsa.cpsc.ucalgary.ca/pub/hol90.tar.Z)}. Mailing list:
+ info-hol@clover.ucdavis.edu.
+
+hole
+
+ <electronics> The absence of an {electron} in a
+ {semiconductor} material. In the {electron model}, a hole can
+ be thought of as an incomplete outer electron shell in a
+ doping substance. Holes can also be thought of as positive
+ charge carriers; while this is in a sense a fiction, it is a
+ useful abstraction.
+
+ (1995-10-06)
+
+hole model
+
+ <electronics> A {model} of semiconductor behaviour in which
+ {donors} contribute a positive charge equal in magnitude to
+ the charge of an {electron}, and {acceptors} contribute space
+ for such a charge within the crystal lattice. Honored by
+ history well before electrons were discovered and described,
+ much of {electronics}, especially at the engineering level,
+ continues to consider {current} as flowing from positive to
+ negative.
+
+ (1995-10-05)
+
+Hollerithabetical order
+
+ <algorithm> Sorted into the order a standard {Hollerith} {card
+ sorting machine} produces, with special characters interleaved
+ within the alphabet.
+
+ (1997-02-11)
+
+Hollerith, Herman
+
+ {Herman Hollerith}
+
+Hollywired
+
+ {Siliwood}
+
+HOL-UNITY
+
+ A verification tool for {UNITY}? Version 2.1.
+
+ E-mail: Flemming Andersen <fa@tfl.dk>?
+
+holy wars
+
+ [{Usenet}, but may predate it] {flame wars} over {religious
+ issues}. The paper by Danny Cohen that popularised the terms
+ {big-endian} and {little-endian} was entitled "On Holy Wars
+ and a Plea for Peace". Other perennial Holy Wars have
+ included {Emacs} vs. {vi}, my personal computer vs. everyone
+ else's personal computer, {ITS} vs. {Unix}, {Unix} vs. {VMS},
+ {BSD} Unix vs. {USG Unix}, {C} vs. {Pascal}, {C} vs. Fortran,
+ etc., ad nauseam. The characteristic that distinguishes holy
+ wars from normal technical disputes is that in a holy wars
+ most of the participants spend their time trying to pass off
+ personal value choices and cultural attachments as objective
+ technical evaluations. See also {theology}.
+
+ [{Jargon File}]
+
+home
+
+ 1. <file system> {home directory}.
+
+ 2. <web> {home page}.
+
+ 3. <hardware> {home keys}.
+
+home box
+
+ <jargon, computer> A {hacker}'s personal machine, especially
+ one he or she owns. "Yeah? Well, *my* home box runs a full
+ {4.2BSD}, so there!"
+
+ (2006-12-01)
+
+home keys
+
+ <hardware> The eight keys on a typewriter or computer keyboard
+ on which a touch-typist positions their eight finger tips when
+ starting to type or when resting between words or phrases.
+ Typists learn the position of all keys on the keyboard in
+ relation to the home keys.
+
+ On a standard english keyboard layout, the home keys are ASDF
+ for the left hand and JKL; for the right. Most keyboards have
+ small raised bumps on the left and right index finger keys (F
+ and J) so you can find the home keys by touch without looking.
+
+ (2006-12-01)
+
+home machine
+
+ 1. Synonym {home box}.
+
+ 2. The machine that receives your e-mail. These senses might
+ be distinct, for example, for a hacker who owns one computer
+ at home, but reads e-mail at work.
+
+ [{Jargon File}]
+
+ (2006-12-01)
+
+home page
+
+ <web> 1. The top-level entry point {web page}
+ relating to an individual or institution, or possibly a
+ subject area. This often has a {URL} consisting of just a
+ {hostname}, e.g. http://ncsa.uiuc.edu/. All other pages
+ on a {website} are usually accessible by following {links}
+ from the home page.
+
+ 2. The {web page} a user's {web browser} is configured to load
+ each time it is started. This will typically default to the
+ {home page} (sense 1) of the organisation that produced or
+ distributed the browser.
+
+ (1999-03-21)
+
+Home Phoneline Networking Alliance
+
+ <communications, networking, protocol, standard> (HomePNA) A
+ non-profit association of more than 100 technology companies
+ working together to ensure adoption of a phone line
+ {networking} standard which should provide high-speed,
+ affordable home networking.
+
+ The Home Phoneline Networking Alliance (HomePNA) was founded
+ in June 1998 by {3Com}, {AMD}, {AT&T Wireless Services},
+ {Compaq}, Conexant, Epigram, {Hewlett-Packard}, {IBM},
+ {Intel}, {Lucent Technologies}, Rockwell Semiconductor
+ Systems, and Tut Systems. The membership now spans the
+ networking, telecommunications, {hardware}, {software}, and
+ consumer electronics industries.
+
+ The alliance was originally formed because of the increasing
+ demand for home networking caused by the growing number of
+ homes with multiple PCs (and other devices) to connect
+ together to provide facilities such as shared {Internet}
+ access, {networked gaming}, and sharing of {peripherals},
+ {files} and {applications}.
+
+ The member companies aimed to develop {open standards} to
+ ensure compatibility between different manufacturers'
+ products. They also decided that this should be done using
+ the phone wiring that already existed in people's homes. The
+ concept of "no new wires" networking meant installation was
+ simpler.
+
+ HomePNA's original specifications could be used to create a 1
+ {Mbps} (megabits per second) {Ethernet}-compatible {LAN} with
+ no {hubs}, {routers}, {splitters} or {terminations}. Adapters
+ would allow any computer (or other device) with an Ethernet
+ port to be linked to the home network. Up to 25 PCs,
+ peripherals and network devices can be connected to such a
+ network.
+
+ On 1999-12-01, the HomePNA announced a new release of its
+ networking technology specification, called Home PNA 2.0.
+ Like the first specification, it uses existing phone lines,
+ but it can operate at speeds up to 10 Mbps. The new version
+ is {backwardly compatible} with the original 1 Mbps HomePNA
+ technology, and is designed to provide faster networks
+ suitable for future voice, video and data applications.
+
+ {HomePNA.org (http://homepna.org/)}. {HomePNA.Com
+ (http://HomePNA.com/)}.
+
+ (2000-03-24)
+
+HomePNA
+
+ {Home Phoneline Networking Alliance}
+
+home row keys
+
+ {home keys}
+
+homogeneous
+
+ (Or "homogenous") Of uniform nature, similar in kind.
+
+ 1. In the context of {distributed systems}, {middleware} makes
+ {heterogeneous} systems appear as a homogeneous entity. For
+ example see: {interoperable network}.
+
+ Constrast {heterogeneous}.
+
+ 2. <mathematics> (Of a {polynomial}) containing terms of the
+ same degree with respect to all the variables, as in x^2 + 2xy
+ + y^2.
+
+ 3. <mathematics> (Of a {function}) containing a set of
+ variables such that when each is multiplied by a constant,
+ this constant can be eliminated without altering the value of
+ the function, as in cos x/y + x/y.
+
+ 4. <mathematics> (of an equation) containing a homogeneous
+ function made equal to 0.
+
+ (1999-05-06)
+
+homogenous
+
+ {homogeneous}
+
+homomorphism
+
+ <mathematics> A {map} f between groups A and B is a
+ homomorphism of A into B if
+
+ f(a1 * a2) = f(a1) * f(a2) for all a1, a2 in A.
+
+ where the *s are the respective group operations.
+
+ (2009-01-14)
+
+Honeywell
+
+ <company> A US company known for its {mainframes} and
+ {operating systems}.
+
+ The company's history is long and tortuous, with many mergers,
+ acquisitions and name changes. A company formed on 1886-04-23
+ to make furnace regulators eventually merged in 1927 with
+ another company formed in 1904 by a young plumbing and heating
+ engineer named Mark Honeywell who was perfecting the heat
+ generator.
+
+ A 1955 joint venture with {Raytheon Corp.}, called {Datamatic
+ Corporation}, marked Honeywell's entry into the computer
+ business. Their first computer was the {D-1000}. In 1960
+ Honeywell bought out Raytheon's interest and the name changed
+ to {Electronic Data Processing} (EDP) then in 1963 it was
+ officially renamed Honeywell Inc.
+
+ In 1970 Honeywell merged its computer business with {General
+ Electric}'s to form Honeywell Information Systems. In 1986 a
+ joint venture with the french company {Bull} and japanese {NEC
+ Corporation} created Honeywell Bull. By 1991 Honeywell had
+ withdrawn from the computer business, focussing more on
+ aeropspace.
+
+ {CII Honeywell} was an important department. Honeywell
+ operating systems included {GCOS} and {Multics}.
+
+ See also: {brain-damaged}.
+
+ {History
+ (http://www51.honeywell.com/honeywell/about-us/our-history.html)}.
+
+ (2009-01-14)
+
+Honeywell-800 Business Compiler
+
+ {Fully Automated Compiling Technique}
+
+HOOD
+
+ {Hierarchical Object Oriented Design}
+
+HOOK
+
+ ? Object Oriented Kernel. Delphia. An object-oriented
+ extension of Delphia Prolog.
+
+ [{Jargon File}]
+
+hook
+
+ <programming> A {software} or {hardware} feature included in
+ order to simplify later additions or changes by a user.
+
+ For example, a simple program that prints numbers might always
+ print them in base 10, but a more flexible version would let a
+ variable determine what base to use; setting the variable to 5
+ would make the program print numbers in base 5. The variable
+ is a simple hook. An even more flexible program might examine
+ the variable and treat a value of 16 or less as the base to
+ use, but treat any other number as the address of a
+ user-supplied routine for printing a number. This is a
+ {hairy} but powerful hook; one can then write a routine to
+ print numbers as Roman numerals, say, or as Hebrew characters,
+ and plug it into the program through the hook.
+
+ Often the difference between a good program and a superb one
+ is that the latter has useful hooks in judiciously chosen
+ places. Both may do the original job about equally well, but
+ the one with the hooks is much more flexible for future
+ expansion of capabilities.
+
+ {Emacs}, for example, is *all* hooks.
+
+ The term "user exit" is synonymous but much more formal and
+ less hackish.
+
+ (1997-06-25)
+
+hop
+
+ 1. <messaging> One point-to-point transmission in a series
+ required to get a message from point A to point B on a {store
+ and forward} network. On such networks (including {UUCPNET}
+ and {FidoNet}), an important inter-machine metric is the hop
+ count of the shortest path between them. This can be more
+ significant than their geographical separation.
+
+ Each {exclamation mark} in a {bang path} represents one hop.
+
+ 2. <networking> One direct host-to-host connection forming
+ part of the route between two hosts in a {routed} {network}
+ such as the {Internet}. Some {protocols} place an upper limit
+ on the hop count in order to detect routing loops.
+
+ 3. <jargon, networking> To {log in} to a {remote} computer,
+ especially via {rlogin} or {telnet}. "I'll hop over to foovax
+ to FTP that."
+
+ [{Jargon File}]
+
+ (1997-06-25)
+
+Hope
+
+ <language> A {functional programming} language designed by
+ R.M. Burstall, D.B. MacQueen and D.T. Sanella at {University
+ of Edinburgh} in 1978. It is a large language supporting
+ user-defined {prefix}, {infix} or {distfix} operators. Hope
+ has {polymorphic} typing and allows {overloading} of operators
+ which requires explicit type declarations. Hope has {lazy
+ lists} and was the first language to use {call-by-pattern}.
+
+ It has been ported to {Unix}, {Macintosh}, and {IBM PC}.
+
+ See also {Hope+}, {Hope+C}, {Massey Hope}, {Concurrent Massey
+ Hope}.
+
+ {(ftp://brolga.cc.uq.oz.au/pub/hope)}.
+
+ [R.M.Burstall, D.B.MacQueen, D.T.Sanella, "HOPE: An
+ experimental applicative language", Proc. 1980 Lisp conf.,
+ Stanford, CA, p.136-143, Aug 1980].
+
+ ["A HOPE Tutorial", R. Bailey, BYTE Aug 1985, pp.235-258].
+
+ ["Functional Programming with Hope", R. Bailey, Ellis Horwood
+ 1990].
+
+ (1992-11-27)
+
+Hope+
+
+ <language, functional programming> An extension of {Hope}
+ implemented in the Alvey {Flagship} project at {Imperial
+ College}. Hope+ has vectors, real numbers, best fit {pattern
+ matching}, lazy data constructors, absolute {set abstractions}
+ and {constraints}. It has a {continuation}-based I/O system
+ with {referential transparency} and is capable of handling all
+ common I/O tasks such as terminal and file I/O, {signal}
+ handling and interprocess communications. It has {modules}
+ and {separate compilation}.
+
+ See also {Hope+C}, {Massey Hope}, {Concurrent Massey Hope}.
+
+ ["Hope+", N. Perry, Imperial College, IC/FPR/LANG/2.5.1/7,
+ 1988.]
+
+ (1999-08-24)
+
+Hope+C
+
+ <language> A further evolution of {Hope+} with
+ {continuation-based I/O}, {coroutines}, and {RFCs}. Hope+C
+ was developed as part of the {Flagship} project at {Imperial
+ College}. It has been implemented for {Sun-3s} with
+ {Motorola} {FPUs}.
+
+ See also {Massey Hope}, {Concurrent Massey Hope}.
+
+ E-mail: John Darlington <jd@doc.ic.ac.uk>.
+
+ [What kind of RFCs?]
+
+ (1999-06-23)
+
+Hopfield model
+
+ {Hopfield network}
+
+Hopfield network
+
+ <artificial intelligence> (Or "Hopfield model") A kind of
+ {neural network} investigated by John Hopfield in the early
+ 1980s. The Hopfield network has no special input or output
+ neurons (see {McCulloch-Pitts}), but all are both input and
+ output, and all are connected to all others in both directions
+ (with equal weights in the two directions). Input is applied
+ simultaneously to all neurons which then output to each other
+ and the process continues until a stable state is reached,
+ which represents the network output.
+
+ (1997-10-11)
+
+horizontal application
+
+ An {application program} common to different business
+ processes, e.g. {office automation}.
+
+ Compare {vertical application}.
+
+ (1994-12-12)
+
+horizontal encoding
+
+ <processor> An {instruction set} where each field (a bit or
+ group of bits) in an instruction word controls some
+ {functional unit} or {gate} directly, as opposed to {vertical
+ encoding} where instruction fields are decoded (by
+ {hard-wired} {logic} or {microcode}) to produce the control
+ signals. Horizontal encoding allows all possible combinations
+ of control signals (and therefore operations) to be expressed
+ as instructions whereas vertical encoding uses a shorter
+ instruction word but can only encode those combinations of
+ operations built into the decoding logic.
+
+ An {instruction set} may use a mixture of horizontal and
+ vertical encoding within each instruction. Because an
+ architecture using horizontal encoding typically requires more
+ instruction word bits it is sometimes known as a {very long
+ instruction word} (VLIW) architecture.
+
+ (1995-04-23)
+
+horizontal loop combination
+
+ {tupling}
+
+horizontal microcode
+
+ <processor> {Microcode} using {horizontal encoding}.
+
+ (1995-04-23)
+
+horizontal scan rate
+
+ <hardware> (HSR) The measure of how many {scan lines} of
+ {pixels} a {monitor} can display in one second, expressed in
+ kHz (generally somewhere between 20 and 100 kHz).
+
+ The HSR is controlled by the horizontal sync signal generated
+ by the {video controller}, but is limited by the speed with
+ which the monitor can scan the electron beam horizontally
+ across the screen and then return it to the beginning of the
+ next line.
+
+ (1996-02-09)
+
+horizontal tabulation
+
+ <character> (tab, Control-I, HT, {ASCII 9}) A character which
+ when displayed or printed causes the following character to be
+ placed at the next "tabstop" - the column whose number is a
+ multiple of the current tab width. Commonly (especially in
+ Unix(?)) the tab width is eight, so, counting from the left
+ margin (column zero), the tab stops are at columns 8, 16, 24,
+ up to the width of the screen or page.
+
+ A tab width of four or two is often preferred when indenting
+ program {source code} to conserve indentation.
+
+ Represented as "\t" in {C}, {Unix}, and derivatives.
+
+ (1999-07-05)
+
+Horn clause
+
+ <logic> A set of {atomic literals} with at most one {positive
+ literal}. Usually written
+
+ L <- L1, ..., Ln
+ or
+ <- L1, ..., Ln
+
+ where n>=0, "<-" means "is implied by" and comma stands for
+ {conjuction} ("AND"). If L is false the clause is regarded as
+ a {goal}. Horn clauses can express a subset of statements of
+ {first order logic}.
+
+ The name "Horn Clause" comes from the logician Alfred Horn,
+ who first pointed out the significance of such clauses in
+ 1951, in the article "On sentences which are true of direct
+ unions of algebras", Journal of Symbolic Logic, 16, 14-21.
+
+ A {definite clause} is a Horn clause that has exactly one
+ positive literal.
+
+ (2000-01-24)
+
+hose
+
+ 1. To make non-functional or greatly degraded in performance.
+ "That big ray-tracing program really hoses the system." See
+ {hosed}.
+
+ 2. A narrow channel through which data flows under pressure.
+ Generally denotes data paths that represent performance
+ bottlenecks.
+
+ 3. Cabling, especially {thick Ethernet cable}. This is
+ sometimes called "bit hose" or "hosery" (a play on "hosiery")
+ or "etherhose". See also {washing machine}.
+
+ [{Jargon File}]
+
+hosed
+
+ <jargon> A somewhat humorous variant of "{down}", used
+ primarily by {Unix} {hackers}. "Hosed" implies a condition
+ thought to be relatively easy to reverse. It is also widely
+ used of people in the mainstream sense of "in an extremely
+ unfortunate situation". The term was popularised by fighter
+ pilots refering to being hosed by machine gun fire (date?).
+ Usage in hackerdom dates back to {CMU} in the 1970s or
+ earlier.
+
+ {"Acronyms and Abbreviations" from UCC, Ireland
+ (http://ucc.ie/cgi-bin/acronym)} expands it as "Hardware
+ Or Software Error Detected", though this is probably a
+ back-formation.
+
+ The {Jargon File} version 4.1.4 1999-06-17 says that it was
+ probably derived from the Canadian slang "hoser" (meaning "a
+ man, esp. one who works at a job that uses physical rather
+ than mental skills and whose habits are slightly offensive but
+ amusing").
+
+ One correspondant speculates about an allusion to a hose-like
+ body part.
+
+ Once upon a time, a {Cray} that had been experiencing periodic
+ difficulties crashed, and it was announced to have been hosed.
+ It was discovered that the crash was due to the disconnection
+ of some coolant hoses. The problem was corrected, and users
+ were then assured that everything was OK because the system
+ had been rehosed. See also {dehose}.
+
+ See also: {hose}.
+
+ (1999-10-28)
+
+HOS-STPL
+
+ Hospital Operating System - STructured Programming Language.
+ A {Fortran}-like language with structured extensions.
+
+ ["HOS-STPL User Manual", Health Services Research, US Public
+ Health Service (Jan 1975)].
+
+host
+
+ 1. <networking> A computer connected to a {network}.
+
+ The term {node} includes devices such as routers and printers
+ which would not normally be called "hosts".
+
+ 2. <communications> A computer to which one connects using a
+ {terminal emulator}.
+
+ (1995-02-16)
+
+host adaptor
+
+ {SCSI adaptor}
+
+Host Command Facility
+
+ <operating system> (HCF) Used to access {IBM S/36} and
+ {AS/400} computers from a {mainframe}.
+
+ [What is it?]
+
+ (1999-01-24)
+
+Host Control Interface
+
+ <hardware, wireless> (HCI) A {network layer} in the {Bluetooth}
+ {Core Protocol Stack}, lying between the {software} and the
+ {hardware} stacks and serving as the {interface} through which the
+ {software} controls two of {Bluetooth}'s four core {protocols}.
+
+ (2002-06-28)
+
+host-host layer
+
+ {transport layer}
+
+hosting
+
+ {web hosting}
+
+hostname
+
+ 1. (Or "sitename"). The unique name by which a computer is
+ known on a {network}, used to identify it in {electronic
+ mail}, {Usenet} {news}, or other forms of electronic
+ information interchange.
+
+ On the {Internet} the hostname is an {ASCII} string,
+ e.g. "foldoc.doc.ic.ac.uk" which, consists of a local part
+ (foldoc) and a {domain} name (doc.ic.ac.uk). The hostname is
+ translated into an {Internet address} either via the {hosts
+ file}, {NIS} or by the {Domain Name System} (DNS) or
+ {resolver}. It is possible for one computer to have several
+ hostnames (aliases) though one is designated as its
+ {canonical} name.
+
+ It is often possible to guess a hostname for a particular
+ institution. This is useful if you want to know if they
+ operate network services like {anonymous FTP}, {World-Wide
+ Web} or {finger}. First try the institution's name or obvious
+ abbreviations thereof, with the appropriate {domain} appended,
+ e.g. "mit.edu". If this fails, prepend "ftp." or "www." as
+ appropriate, e.g. "www.data-io.com". You can use the {ping}
+ command as a quick way to test whether a hostname is valid.
+
+ The folklore interest of hostnames stems from the creativity
+ and humour they often display. Interpreting a sitename is not
+ unlike interpreting a vanity licence plate; one has to
+ mentally unpack it, allowing for mono-case and length
+ restrictions and the lack of whitespace. Hacker tradition
+ deprecates dull, institutional-sounding names in favour of
+ punchy, humorous, and clever coinages (except that it is
+ considered appropriate for the official public gateway machine
+ of an organisation to bear the organisation's name or
+ acronym). Mythological references, cartoon characters, animal
+ names, and allusions to SF or fantasy literature are probably
+ the most popular sources for sitenames (in roughly descending
+ order). The obligatory comment is Harris's Lament: "All the
+ good ones are taken!"
+
+ See also {network address}.
+
+ 2. {Berkeley} {Unix} command to set and get the application
+ level name used by the host.
+
+ {Unix manual page}: hostname(1).
+
+ (1995-02-16)
+
+host number
+
+ <networking> The host part of an {Internet address}. The rest
+ is the {network number}.
+
+ (1994-10-27)
+
+hosts file
+
+ <networking> A {text file} on a networked computer used to
+ associate {host names} with {IP addresses}. A hosts file
+ contains lines consisting of {whitespace}-separated fields
+ giving an IP address followed by list of host names or
+ {aliases} associated with that address. The {name resolution}
+ library software can use this file to look up the IP address
+ for a host name. The hosts file is "/etc/hosts" on {Unix} and
+ "C:\Windows\System32\drivers\etc\hosts" or "lmhosts" on
+ {Microsoft Windows},
+
+ In most cases, hosts files have now been almost entirely
+ replaced by {DNS}, in which distributed servers provide the
+ same information. A hosts file can still be used to override
+ DNS for testing purposes or other special situations.
+
+ (2007-05-09)
+
+Hot Fix
+
+ <storage> {Novell, Inc.}'s term for the feature of their
+ network {file server} {operating system}, {Novell NetWare},
+ which handles errors in disk write operations. The OS
+ re-reads every block it writes to disk while it holds the data
+ to be written in memory. In the case of an error, the data
+ block is written to a spare area on the disk.
+
+ The feature lost much of its importance with the widespread
+ use of hard disk drives with built-in {error correction} and
+ {bad block} re-mapping.
+
+ (1997-05-27)
+
+HotJava
+
+ <web> A modular, extensible {web}
+ {browser} from {Sun Microsystems} that can execute programs
+ written in the {Java} programming language. These programs,
+ known as "{applets}", can be included (like images) in {HTML}
+ pages. Because Java programs are compiled into machine
+ independent {bytecodes}, applets can run on any {platform} on
+ which HotJava runs - currently (December 1995)
+ {SPARC}/{Solaris} 2 and {Intel 80x86}/{Windows 95}, {Windows
+ NT}.
+
+ {(http://java.sun.com/hotjava.html)}.
+
+ (1995-12-10)
+
+Hotline
+
+ 1. <company> {Hotline Communications Ltd.}.
+
+ 2. <messaging> {Hotline Connect}.
+
+ (1999-12-07)
+
+Hotline Communications Ltd.
+
+ <company> The company that developes and distributes {Hotline
+ Connect}.
+
+ {(http://BigRedH.com/index2.html)}.
+
+ (1999-12-07)
+
+Hotline Connect
+
+ <messaging> A suite of communication products developed by
+ {Hotline Communications Ltd.} Hotline Connect is a
+ {real-time}, {multi-platform Internet}/{Intranet}
+ communication suite, that operates independent of the
+ {web}. It provides easy-to-use private and public
+ {virtual community} building and live interaction with
+ real-time {chat}, conferencing, {messaging}, {data
+ warehousing}, {file transfer}, and viewing.
+
+ Version: 1.7.2, as of 1999-12-07.
+
+ (1999-12-07)
+
+hotlink
+
+ A mechanism for sharing data between two {application
+ programs} where changes to the data made by one application
+ appear instantly in the other's copy.
+
+ Under {System 7} on the {Macintosh} the users establishes a
+ hotlink by doing a "Create Publisher" on the server and
+ "Subscribe" on the client.
+
+ Under {Windows 3} it's "Cut Special"(?) and "Paste Special"
+ (as opposed to the normal Cut and Paste).
+
+ (1995-02-16)
+
+hotlist
+
+ <web> (From {hypertext} "{hot spot}") A {document}
+ on the {web} or a user's {browser} configuration
+ file containing {hypertext} {links}, often unorganised and
+ undocumented, to notable pages on the Web.
+
+ Compare the 19th century notion of a {commonplace book
+ (http://c.gp.cs.cmu.edu:5103/prog/webster?commonplace+book)}.
+
+ (1995-04-16)
+
+Hotmail
+
+ <messaging> A {web mail} service bought by {Microsoft}.
+
+ {(http://hotmail.com/)}.
+
+ (2006-10-30)
+
+hot spot
+
+ 1. (primarily used by {C}/{Unix} programmers, but spreading)
+ It is received wisdom that in most programs, less than 10% of
+ the code eats 90% of the execution time; if one were to graph
+ instruction visits versus code addresses, one would typically
+ see a few huge spikes amidst a lot of low-level noise. Such
+ spikes are called "hot spots" and are good candidates for
+ heavy optimisation or {hand-hacking}. The term is especially
+ used of tight loops and recursions in the code's central
+ algorithm, as opposed to (say) initial set-up costs or large
+ but infrequent I/O operations.
+
+ See {tune}, {bum}, {hand-hacking}.
+
+ 2. The active location of a cursor on a bit-map display. "Put
+ the mouse's hot spot on the "ON" widget and click the left
+ button."
+
+ 3. A screen region that is sensitive to mouse clicks, which
+ trigger some action. {Hypertext} help screens are an example,
+ in which a hot spot exists in the vicinity of any word for
+ which additional material is available.
+
+ 4. In a {massively parallel} computer with {shared memory},
+ the one location that all 10,000 processors are trying to read
+ or write at once (perhaps because they are all doing a
+ {busy-wait} on the same lock).
+
+ 5. More generally, any place in a hardware design that turns
+ into a performance {bottleneck} due to resource contention.
+
+ 6. {wireless hotspot}.
+
+ [{Jargon File}]
+
+ (1995-02-16)
+
+Hot Standby Routing Protocol
+
+ <protocol> (HSRP) A {CISCO} standard, defined in {RFC 2281},
+ that calls for a {mirrored router} in {passive mode} to send
+ {hello packets}, wait for a {lead router} to die and, without
+ dropping a {packet}, take over from that router.
+
+ Note: "standby", not "swappable" (and certainly not
+ "swapable").
+
+ (2005-01-26)
+
+Hot Swapable Routing Protocol
+
+ <spelling> Incorrect spelling of incorrect expansion of HSRP -
+ {Hot Standby Routing Protocol}.
+
+ (2005-01-26)
+
+Hot Swappable Routing Protocol
+
+ <spelling> Incorrect expansion of HSRP - {Hot Standby Routing
+ Protocol}.
+
+ (2005-01-26)
+
+hot swapping
+
+ <hardware> The connection and disconnection of {peripherals}
+ or other components without interrupting system operation.
+ This facility may have design implications for both hardware
+ and software.
+
+ [More detail?]
+
+ (1997-03-15)
+
+HOTT
+
+ (Hot Off The Tree) An {Internet}-based electronic magazine
+ edited by David Scott Lewis <d.s.lewis@ieee.org> and
+ distributed by {electronic mail}.
+
+ (1994-12-23)
+
+house wizard
+
+ (Probably from ad-agency tradetalk, "house freak") A hacker
+ occupying a technical-specialist, R&D, or systems position at
+ a commercial shop. A really effective house wizard can have
+ influence out of all proportion to his/her ostensible rank and
+ still not have to wear a suit. Used especially of {Unix}
+ {wizards}. The term "house guru" is equivalent.
+
+ [{Jargon File}]
+
+ (1995-02-16)
+
+Houston Automatic Spooling Program
+
+ <operating system> (HASP) A program developed by {IBM} for
+ {NASA} in the 1960s to {SPOOL} output on {OS/MFT} and {OS/MVT}
+ to improve job processing performance.
+
+ (2003-05-19)
+
+Howe, Denis
+
+ {Denis Howe}
+
+how many nibbles in a byte
+
+ <data> There are two {nibbles} in a {byte}.
+
+ (2009-09-17)
+
+HP
+
+ {Hewlett-Packard}
+
+hp2ps
+
+ <tool> An {HP-GL} {interpreter} written in {PostScript} by
+ Alun Jones. hp2ps runs on the printer itself. Version 1.9c.
+
+ (1999-11-23)
+
+H/PC
+
+ {Hand-held Personal Computer}
+
+HPCC
+
+ {High Performance Computing and Communications}
+
+HPcode
+
+ Stack-based intermediate language used by {HP} in many of its
+ compilers for {RISC} and stack-based architectures. Supports
+ {Fortran}, {Ada}, {Pascal}, {COBOL} and {C++}. Descended from
+ Stanford's {U-code}.
+
+HPCode-Plus
+
+ A descendant of {HPcode} with {data types}, developed to be an
+ {ANDF} language.
+
+ ["ANDF: Finally an UNCOL After 30 Years", M.E. Benitez, Jack
+ Davidson <jwd@virginia.edu> et al, CS TR-91-05 U Virginia (Mar
+ 1991)].
+
+ (1995-03-16)
+
+HPF
+
+ {High Performance Fortran}
+
+HPFS
+
+ {High Performance File System}
+
+HP-GL
+
+ {Hewlett-Packard Graphics Language}
+
+HP-GL/2
+
+ "HP-GL/2 Programmer's Guide", No. 5959-9733, HP. (See PCL.)
+
+HP-IB
+
+ {IEEE 488}
+
+HPL
+
+ Language used in HP9825A/S/T "Desktop Calculators", 1978(?)
+ and ported to the early Series 200 family (9826 and 9836,
+ 68000). Fairly simple and standard, but with extensive I/O
+ support for data acquisition and control (BCD, Serial, 16 bit
+ custom and {IEEE 488} interfaces), including interrupt
+ handling. Currently owned by Structured Software Systems.
+ "HPL Operating Manual for Series 200, Models 216, 226 and
+ 235\6", HP 98614-90010, Jan 1984.
+
+HPLOT
+
+ A graphical output facility for {HBOOK}.
+
+ (1995-02-22)
+
+HP-MPE
+
+ {Hewlett Packard Multi Processing Executive}
+
+HP-PA
+
+ {Hewlett Packard Precision Architecture}
+
+HPPI
+
+ {High Performance Parallel Interface}
+
+HPR
+
+ {High Performance Routing}
+
+HP-SUX
+
+ <abuse, operating system> /H-P suhks/ An unflattering
+ hackerism for {HP-UX} which features some truly unique
+ bogosities in the {file system} internals and elsewhere (these
+ occasionally create portability problems). HP-UX is often
+ referred to as "hockey-pux" inside HP, and one respondent
+ claims that the proper pronunciation is /H-P ukkkhhhh/ as
+ though one were about to spit. Another such alternate
+ spelling and pronunciation is "H-PUX" /H-puhks/. Hackers at
+ HP/Apollo (the former Apollo Computers which was swallowed by
+ HP in 1989) have been heard to complain that Mr. Packard
+ should have pushed to have his name first, if for no other
+ reason than the greater eloquence of the resulting acronym.
+
+ Compare {AIDX}, {buglix}, {Telerat}, {Open DeathTrap},
+ {ScumOS}, {sun-stools}.
+
+ [{Jargon File}]
+
+ (1997-05-12)
+
+HP-UX
+
+ <operating system> The version of {Unix} running on
+ {Hewlett-Packard} {workstations}.
+
+ HP-UX conforms to {X/Open}'s Portability Guide Issue 4
+ ({XPG4}), Federal Information Processing Specification (FIPS)
+ 151.1, {POSIX} 1003.1, POSIX 1003.2, {AT&T}'s System V
+ Interface Definition 2 ({SVID} 2). HP-UX incorporates
+ selected features from the University of California at
+ Berkeley Software Distribution 4.3 ({4.3BSD}).
+
+ It is known by some as "{HP-SUX}".
+
+ [Features?]
+
+ (1997-05-12)
+
+HP VEE
+
+ {Hewlett-Packard Visual Engineering Environment}
+
+hqx
+
+ {binhex}
+
+hr
+
+ <networking> The {country code} for Croatia.
+
+ (1999-01-27)
+
+href
+
+ <web> ({hypertext} reference) The attribute of an
+ {HTML} "a" (anchor or link) tag, whose value gives the {URL}
+ of the {web page} or other resource that the link points to.
+ For example,
+
+ <a href="http://foldoc.org/">FOLDOC href definition</a>
+
+ would display an anchor pointing to this dictionary.
+
+ (2008-02-22)
+
+hs
+
+ {Haskell}
+
+HSB
+
+ {hue, saturation, brightness}
+
+HSC
+
+ {High Speed Connect}
+
+HSCSD
+
+ {High Speed Circuit Switched Data}
+
+HSL-FX
+
+ {Hierarchical Specification Language - Function Extension}
+
+HSM
+
+ {Hierarchical Storage Management}
+
+HSRP
+
+ {Hot Standby Routing Protocol}
+
+HSSI
+
+ {high speed serial interface}
+
+HSV
+
+ {hue, saturation, value}
+
+HT
+
+ {horizontal tabulation}
+
+ht
+
+ <networking> The {country code} for Haiti.
+
+ (1999-01-27)
+
+HTH
+
+ <chat> Hope This Helps. Often used sarcastically, see {HAND}.
+
+ (1998-03-06)
+
+HTLM
+
+ Do you mean {HTML}?
+
+HTML
+
+ {Hypertext Markup Language}
+
+HTML+
+
+ <hypertext, standard> A proposed successor to {HTML}. HTML+
+ was a superset of HTML designed to extend the capabilities of
+ the language to incorporate better support for {multimedia}
+ objects in documents.
+
+ (1994-10-27)
+
+htmlcommentbox.com
+
+ <web> A service for adding a comment box to any web
+ page, allowing visitors to leave comments and the site owner to
+ review them.
+
+ {(http://htmlcommentbox.com/)}
+
+ (2013-03-20)
+
+HTTL
+
+ Do you mean {HTTP} or {HTML}?
+
+HTTP
+
+ {Hypertext Transfer Protocol}
+
+HTTP/1.0
+
+ {Hypertext Transfer Protocol} version 1.0.
+
+HTTP cookie
+
+ <web> A small string of information sent by a {web
+ server} to a {web browser} that will be sent back by the browser
+ each time it accesses that server.
+
+ Cookies were invented by {Netscape} to make it easier to maintain
+ {state} between {HTTP} {transactions}. They can contain any
+ arbitrary information the server chooses to put in them.
+
+ The most common use of cookies is to identify and authenticate a
+ user who has logged in to a {website}, so they don't have to sign
+ in every time they visit. Other example uses are maintaining a
+ {shopping basket} of goods you have selected to purchase during a
+ session at an online shop or site {personalisation} (presenting
+ different pages to different users).
+
+ The browser limits the size of each cookie and the number each
+ server can store. This prevents a malicious site consuming lots
+ of disk space on the user's computer. The only information that
+ cookies can return to the server is what that server previously
+ sent out.
+
+ The main privacy concern is that it is not obvious when a site is
+ using cookies or what for. Even if you don't log in or supply any
+ personal information to a site, it can still assign you a unique
+ identifier and store it in a "tracking cookie". This can then be
+ used to track every page you ever visit on the site. However,
+ since it is possible to do the same thing without cookies, the UK
+ law requiring sites to declare their use of cookies makes little
+ sense and has been widely ignored.
+
+ After using a shared computer, e.g. in an {Internet cafe}, you
+ should remove all cookies to prevent the browser identifying
+ the next user as you if they happen to visit the same sites.
+
+ {Cookie Central (http://cookiecentral.com/c_concept.htm)}.
+
+ {Stupid cookie law
+ (http://blog.silktide.com/2013/01/the-stupid-cookie-law-is-dead-at-last/)}.
+
+ (2013-12-05)
+
+HTTPd
+
+ <web> (Hypertext transfer protocol daemon).
+
+ An {HTTP/1.0}-compatible {server}, written by Rob McCool
+ <robm@ncsa.uiuc.edu> of {NCSA}, for making {hypertext} and
+ other documents available to {web browsers}.
+
+ HTTPd is designed to be small and fast and to work with most
+ HTTP/0.9 and HTTP/1.0 {browsers}. You can customise your
+ server to execute searches and handle {HTML} {forms}. It also
+ supports {server side include} files, allowing you to include
+ the output of commands or other files in {HTML} documents.
+
+ The current (1994-08-08) version is 1.3.
+
+ {(http://hoohoo.ncsa.uiuc.edu/docs/Overview.html)}.
+
+ E-mail: <httpd@ncsa.uiuc.edu>.
+
+ (1995-01-16)
+
+HTTP proxy server
+
+ <web> A {proxy server} for {HTTP} requests.
+ Typically an HTTP proxy or "web proxy" accepts HTTP requests
+ containing {URLs} with a special prefix. The proxy removes
+ the prefix and looks for the resulting URL in its local
+ {cache} (if it is a caching proxy). If found, it returns the
+ document immediately, otherwise it fetches it from the remote
+ server, saves a copy in its cache and returns it to the
+ requester. The cache will usually have an expiry {algorithm}
+ which flushes documents according to their age, size and
+ access history.
+
+ The purpose is to reduce the amount of data flowing over the
+ proxy's Internet connection and to speed up clients' access to
+ frequently requested pages, e.g. at an {ISP} or on a large
+ company's {firewall}. The proxy may also reject requests
+ where the URL or content matches certain conditions.
+
+ The {Apache} HTTP server can be configured to act as a proxy
+ server. Another popular software proxy is {Squid}.
+
+ (2008-07-01)
+
+HTTPS
+
+ {HyperText Transmission Protocol, Secure}
+
+HTTP server
+
+ <web> (Or "web server") A {server} process running
+ at a {website} which sends out {web pages} in response to
+ {HTTP} requests from remote {browsers}.
+
+ If one site runs more than one server they must use different
+ {port numbers}. Alternatively, several hostnames may be
+ mapped to the same computer in which case they are known as
+ "{virtual servers}".
+
+ {Apache} and {NCSA} {HTTPd} are two popular web servers.
+ There are many others including some for practically every
+ {platform}. Servers differ mostly in the "server-side"
+ features they offer such as {server-side include}, and in
+ their {authentication} and access control mechanisms. All
+ decent servers support {CGI} and most have some binary {API}
+ as well.
+
+ (1997-02-05)
+
+hu
+
+ <networking> The {country code} for Hungary.
+
+ (1999-01-27)
+
+hub
+
+ <networking> (By analogy with the hub of a wheel) A device
+ connected to several other devices.
+
+ In {ARCnet}, a hub is used to connect several computers
+ together. In a message handling service, a number of local
+ computers might exchange messages solely with a hub computer.
+ The hub would be responsible for exchanging messages with
+ other hubs and non-local computers.
+
+ (1995-01-16)
+
+Hubnet
+
+ <networking> A 50 Mb/s {optical fibre} {network} developed at
+ {Toronto University}. Network {topology} is a rooted tree
+ with a maximum of 65536 hosts with maximum separation of 2 km.
+ The {protocol} is multiple access, collision avoidance, echo
+ detect and retry.
+
+ [Computer Systems Equipment Design, Jan 85].
+
+ (1994-11-22)
+
+hubs
+
+ {hub}
+
+hue
+
+ <graphics> (Or "tint") The coordinate in the {HSB} {colour
+ model} that determines the frequency of light or the position
+ in the spectrum or the relative amounts of red, green and
+ blue. Hue corresponds to the common definition of colour,
+ e.g. "red", "orange", "violet" etc. The other coordinates are
+ {saturation} and {brightness}.
+
+ (1999-07-05)
+
+hue, saturation, brightness
+
+ <graphics> (HSB) A {colour model} that describes colours in
+ terms of {hue}, {saturation}, and {brightness}.
+
+ In the tables below, a hue is a "pure" colour, i.e. one with
+ no black or white in it. A shade is a "dark" colour, i.e. one
+ produced by mixing a hue with black. A tint is a "light"
+ colour, i.e. one produced by mixing a hue with white. A tone
+ is a colour produced by mixing a hue with a shade of grey.
+
+ {Microsoft Windows} colour dialogs, {PagePlus}, and {Paint
+ Shop Pro} use {HSB} but call the third dimension "luminosity"
+ or "lightness". It ranges from 0% (black) to 100% (white). A
+ pure hue is 50% luminosity, 100% saturation.
+
+ Colour type S L
+ Black Any 0%
+ White Any 100%
+ Grey 0% 1-99%
+ Hue 100% 50%
+ Shade 100% 1-49%
+ Tint 100% 51-99%
+ Tone 1-99% 1-99%
+
+ {Quattro Pro}, {CorelDraw}, and {PhotoShop} use a variant
+ (Quattro Pro calls the third parameter "brightness") in which
+ a brightness of 100% can produce white, a pure hue, or
+ anything in between, depending on the saturation.
+
+ Colour type S B
+ Black Any 0%
+ White 0% 100%
+ Grey 0% 1-99%
+ Hue 100% 100%
+ Shade 100% 1-99%
+ Tint 1-99% 100%
+ Tone 1-99% 1-99%
+
+ [Same as {HSV}?]
+
+ (1999-07-05)
+
+hue, saturation, value
+
+ <graphics> (HSV) A {colour model} that describes colours in
+ terms of {hue} (or "tint"), {saturation} (or "shade") and
+ {value} (or "tone" or "luminance").
+
+ [Same as {HSB}?]
+
+ (1999-07-05)
+
+huff
+
+ <compression> To compress data using {Huffman coding}.
+ Various programs that use such methods have been called "HUFF"
+ or some variant thereof.
+
+ Opposite: {puff}. Compare {crunch}, {compress}.
+
+ [{Jargon File}]
+
+ (1994-12-23)
+
+Huffman
+
+ {Huffman coding}
+
+Huffman code
+
+ {Huffman coding}
+
+Huffman coding
+
+ <algorithm> A {data compression} technique which varies the
+ length of the encoded symbol in proportion to its information
+ content, that is the more often a symbol or token is used, the
+ shorter the {binary string} used to represent it in the
+ compressed stream. Huffman codes can be properly decoded
+ because they obey the prefix property, which means that no
+ code can be a prefix of another code, and so the complete set
+ of codes can be represented as a binary tree, known as a
+ Huffman tree. Huffman coding was first described in a seminal
+ paper by D.A. Huffman in 1952.
+
+ (1994-12-23)
+
+Huffman encoding
+
+ {Huffman coding}
+
+Hugh Loebner
+
+ <person> Dr. Hugh Gene Loebner, the instigator of the {Loebner
+ Prize} in {artificial intelligence}.
+
+ {(http://loebner.net/)}.
+
+ E-mail address: Hugh Loebner <hugh@loebner.net>.
+
+ (2003-11-30)
+
+HUGO
+
+ A {bytecode}-interpreted {transaction handler} from {Geac}.
+
+ (1994-12-23)
+
+HUGS
+
+ {Haskell User's Gofer System}
+
+Human-Computer Interaction
+
+ <software, hardware> (HCI) The study of how humans interact
+ with computers, and how to design computer systems that are
+ easy, quick and productive for humans to use.
+
+ See also {Human-Computer Interface}.
+
+ {HCI Sites (http://acm.org/sigchi/hci-sites/)}.
+
+ (1999-05-09)
+
+Human-Computer Interface
+
+ <software, hardware> (HCI) Any {software} or {hardware} that
+ allows a user to interact with a computer. Examples are
+ {WIMP}, {command-line interpreter}, or {virtual reality}.
+
+ See also {Human-Computer Interaction}.
+
+ (1999-05-09)
+
+Human Interface Device
+
+ <hardware> (HID) Any device to interact directly with humans
+ (mostly input) like {keyboard}, {mouse}, {joystick}, or {graphics
+ tablet}.
+
+ (2001-03-29)
+
+Human Interface Technology Laboratory
+
+ (HITL) The Human Interface Technology Laboratory at the
+ {University of Washington} was founded in 1990. It is a
+ centre for research and development of advanced interface
+ technology. Located on the university campus, HITL forms a
+ bridge between academia and industry. It maintains its
+ industrial focus via the Virtual Worlds Consortium and
+ maintains contacts with academia by training students and
+ teaching courses. The lab has access to faculty and students
+ throughout the State of Washington.
+
+ Address: Human Interface Technology Laboratory, University of
+ Washington, Seattle, USA.
+
+ (1995-02-13)
+
+humanist technology
+
+ <philosophy> Technology centered around the interests, needs,
+ and well-being of humans.
+
+ (2002-07-16)
+
+humma
+
+ <chat> A filler word used on various "chat" and "talk"
+ programs when you had nothing to say but felt that it was
+ important to say something.
+
+ The word apparently originated (at least with this definition)
+ on the MECC Timeshare System (MTS, a now-defunct educational
+ {time-sharing} system running in Minnesota during the 1970s
+ and the early 1980s) but was later sighted on early Unix
+ systems.
+
+ [{Jargon File}]
+
+ (1999-02-27)
+
+humor
+
+ {hacker humour}
+
+humour
+
+ {hacker humour}
+
+hung
+
+ ["hung up"] Equivalent to {wedged}, but more common at Unix/C
+ sites. Not generally used of people. Synonym with {locked
+ up}, {wedged}; compare {hosed}. See also {hang}. A hung
+ state is distinguished from {crash}ed or {down}, where the
+ program or system is also unusable but because it is not
+ running rather than because it is waiting for something.
+ However, the recovery from both situations is often the same.
+
+ [{Jargon File}]
+
+Hungarian Notation
+
+ <language, convention> A linguistic convention requiring one
+ or more letters to be added to the start of {variable} names
+ to denote {scope} and/or {type}.
+
+ Hungarian Notation is mainly confined to {Microsoft Windows}
+ programming environments, such as Microsoft {C}, {C++} and
+ {Visual Basic}. It was originally devised by {Charles
+ Simonyi}, a Hungarian, who was a senior programmer at
+ {Microsoft} for many years. He disliked the way that names in
+ C programs gave no clue as to the type, leading to frequent
+ programmer errors.
+
+ According to legend, fellow programmers at Microsoft, on
+ seeing the convoluted, vowel-less variable names produced by
+ his scheme, said, "This might as well be in Greek - or even
+ Hungarian!". They made up the name "Hungarian notation"
+ (possibly with "{reverse Polish notation}" in mind).
+
+ Hungarian Notation is not really necessary when using a modern
+ {strongly-typed language} as the {compiler} warns the
+ programmer if a variable of one type is used as if it were
+ another type. It is less useful in {object-oriented
+ programming} languages such as {C++}, where many variables are
+ going to be instances of {classes} and so begin with "obj".
+
+ In addition, variable names are essentially only {comments},
+ and thus are just as susceptible to becoming out-of-date and
+ incorrect as any other comment. For example, if a {signed}
+ {short} {int} becomes an unsigned {long} int, the variable
+ name, and every use of it, should be changed to reflect its
+ new type.
+
+ A variable's name should describe the values it holds. Type
+ and scope are aspects of this, but Hungarian Notation
+ overemphasises their importance by allocating so much of the
+ start of the name to them. Furthermore, type and scope
+ information can be found from the variable's declaration.
+ Ironically, this is particularly easy in the development
+ environments in which Hungarian Notation is typically used.
+
+ {Simonyi's original monograph
+ (http://msdn.microsoft.com/library/techart/hunganotat.htm)}.
+
+ {Microsoft VB Naming Conventions
+ (http://support.microsoft.com/support/kb/articles/Q110/2/64.asp)}.
+
+ (2003-09-11)
+
+Hungry Programmers
+
+ <body> A group of programmers producing {free software}.
+
+ {(http://hungry.com/)}.
+
+ (1995-03-20)
+
+hungry puppy
+
+ Synonym {slopsucker}.
+
+ [{Jargon File}]
+
+Hungry ViewKit
+
+ <operating system, library> A {C++} {class} library for
+ developing {Motif} {application programs} (although this
+ restriction will be lifted once {LessTif} is finished). It
+ follows the {API} of the {Iris}(tm) {ViewKit}, put out by
+ {SGI}. The Hungry ViewKit is a superset of the Iris ViewKit,
+ so any code developed for the Iris version will work with the
+ Hungry version, but possibly not vice versa.
+
+ {(http://hungry.com/products/viewkit/)}.
+
+ (1995-03-20)
+
+hungus
+
+ <jargon> /huhng'g*s/ (Perhaps related to slang "humongous")
+ Large, unwieldy, usually unmanageable. E.g. "{TCP} is a
+ hungus piece of code."
+
+ [{Jargon File}]
+
+ (1999-01-26)
+
+Hunt the Wumpus
+
+ <games, history> (Or "Wumpus") /wuhm'p*s/ A famous fantasy
+ computer game, created by {Gregory Yob} in about 1973.
+
+ Hunt the Wumpus appeared in Creative Computing, Vol 1, No 5,
+ Sep - Oct 1975, where Yob says he had come up with the game
+ two years previously, after seeing the grid-based games
+ Hurkle, Snark and Mugwump at {People's Computing Company}
+ (PCC). He later delivered Wumpus to PCC who published it in
+ their newsletter.
+
+ ESR says he saw a version including termites running on the
+ {Dartmouth Time-Sharing System} in 1972-3.
+
+ Magnus Olsson, in his 1992-07-07 {USENET} article
+ <9207071854.AA21847@thep.lu.se>, posted the {BASIC} {source
+ code} of what he believed was pretty much the version that was
+ published in 1973 in David Ahl's "101 Basic Computer Games",
+ by {Digital Equipment Corporation}.
+
+ The wumpus lived somewhere in a cave with the topology of an
+ dodecahedron's edge/vertex graph (later versions supported
+ other topologies, including an icosahedron and M"obius
+ strip). The player started somewhere at random in the cave
+ with five "crooked arrows"; these could be shot through up to
+ three connected rooms, and would kill the wumpus on a hit
+ (later versions introduced the wounded wumpus, which got very
+ angry). Unfortunately for players, the movement necessary to
+ map the maze was made hazardous not merely by the wumpus
+ (which would eat you if you stepped on him) but also by
+ bottomless pits and colonies of super bats that would pick you
+ up and drop you at a random location (later versions added
+ "anaerobic termites" that ate arrows, bat migrations and
+ earthquakes that randomly changed pit locations).
+
+ This game appears to have been the first to use a non-random
+ graph-structured map (as opposed to a rectangular grid like
+ the even older Star Trek games). In this respect, as in the
+ dungeon-like setting and its terse, amusing messages, it
+ prefigured {ADVENT} and {Zork} and was directly ancestral to
+ both (Zork acknowledged this heritage by including a super-bat
+ colony).
+
+ There have been many {ports} including one distributed with
+ {SunOS}, a {freeware} one for the {Macintosh} and a {C}
+ emulation by {ESR}.
+
+ [Does "101 Basic Computer Games" give any history?]
+
+ (2004-10-04)
+
+Hurd
+
+ <operating system> The {GNU} project's replacement for the
+ {Unix} {kernel}. The Hurd is a collection of {servers} that
+ run on the {Mach} {microkernel} to implement {file systems},
+ {network protocols}, file access control, and other features
+ that are implemented by the Unix kernel or similar kernels
+ such as {Linux}. The GNU {C Library} provides the {Unix}
+ {system call} interface, and calls the Hurd for services it
+ can't provide itself.
+
+ The Hurd aims to establish a framework for shared development
+ and maintenance, allowing a broad range of users to share
+ projects without knowing much about the internal workings of
+ the system - projects that might never have been attempted
+ without freely available source, a well-designed interface,
+ and a multi-server-based design.
+
+ Currently there are free ports of the {Mach} {kernel} to the
+ {Intel 80386} {IBM PC}, the {DEC} {PMAX} {workstation}, the
+ {Luna} {88k}, with more in progress, including the {Amiga} and
+ {DEC} {Alpha}-3000 machines.
+
+ According to Thomas Bushnell, BSG, the primary architect of
+ the Hurd: 'Hurd' stands for 'Hird of Unix-Replacing Daemons'
+ and 'Hird' stands for 'Hurd of Interfaces Representing Depth'.
+ Possibly the first software to be named by a pair of {mutually
+ recursive} acronyms.
+
+ {The Hurd Home (http://gnu.org/software/hurd/hurd.html)}.
+
+ [June 1994 GNU's Bulletin].
+
+ (2004-02-24)
+
+HVD
+
+ {High Voltage Differential}
+
+Hybrid
+
+ A {concurrent} {object-oriented} language.
+
+ ["Active Objects in Hybrid", O.M. Nierstrasz, SIGPLAN Notices
+ 22(12):243-253 (OOPSLA '87) (Dec 1987)].
+
+ (1994-12-07)
+
+Hybrid Fiber Coax
+
+ <networking> (HFC) A kind of physical connection used in
+ networks for audio, video, and data. DVB (Digital Video
+ Broadcast) is used in Europe and DOCSIS is used in N America.
+
+ [What is the relationship between HFC, DVB, DOCSIS?]
+
+ (1999-11-02)
+
+hybrid multiprocessing
+
+ <parallel> (HMP) The kind of {multitasking} which {OS/2}
+ supports. HMP provides some elements of {symmetric
+ multiprocessing}, using add-on {IBM} software called MP/2.
+ OS/2 SMP was planned for release in late 1993.
+
+ (1995-03-19)
+
+hybrid testing
+
+ <testing> A combination of {top-down testing} with {bottom-up
+ testing} of prioritised or available components.
+
+ (1996-05-22)
+
+hydra code
+
+ <humour, programming> {Code} that cannot be fixed because each
+ time a {bug} is remove, two new bugs grow in its place. Named
+ after the many-headed Hydra of Greek mythology.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2014-01-04)
+
+hydrofluorocarbon
+
+ <hardware> (HFC) A suggested replacement for the
+ chlorofluorocarbon (CFC) coolant gas used in chillers and air
+ conditioners.
+
+ (1996-11-05)
+
+HyperBase
+
+ <database> An experimental active multi-user {database} for
+ {hypertext} systems from the {University of Aalborg}, written
+ in {C++}. It is built on the {client-server} model enabling
+ distributed, {concurrent}, and shared access from
+ {workstations} in a {local area network}.
+
+ See also {EHTS}.
+
+ (1995-03-19)
+
+Hyper-C
+
+ A {data parallel} extension of {C} from HyperParallel Tech,
+ France, for {PVM}, {CM} and {Maspar}. It is available from
+ Fortunel Systems <fortunel@vnet.net>, +1 (919) 319 1624.
+
+ E-mail: <hyperc-support@hyperparallel.polytechnique.fr>.
+
+ (1994-11-17)
+
+HyperCard
+
+ A software package by Bill Atkinson for storage and retrieval
+ of information on the {Macintosh}. It can handle {images} and
+ is designed for {browsing}. The powerful customisable
+ interactive {user interface} allows new {applications} to be
+ easily constructed by manipulating objects on the screen,
+ often without conventional programming, though the language
+ {HyperTalk} can be used for more complex tasks.
+
+ {Usenet} newsgroup: {news:comp.sys.mac.hypercard}.
+
+ ["Apple Macintosh HyperCard User Guide", Apple Computer 1987].
+
+ (1995-02-10)
+
+hypercube
+
+ A cube of more than three dimensions. A single (2^0 = 1)
+ point (or "node") can be considered as a zero dimensional
+ cube, two (2^1) nodes joined by a line (or "edge") are a one
+ dimensional cube, four (2^2) nodes arranged in a square are a
+ two dimensional cube and eight (2^3) nodes are an ordinary
+ three dimensional cube. Continuing this geometric
+ progression, the first hypercube has 2^4 = 16 nodes and is a
+ four dimensional shape (a "four-cube") and an N dimensional
+ cube has 2^N nodes (an "N-cube"). To make an N+1 dimensional
+ cube, take two N dimensional cubes and join each node on one
+ cube to the corresponding node on the other. A four-cube can
+ be visualised as a three-cube with a smaller three-cube
+ centred inside it with edges radiating diagonally out (in the
+ fourth dimension) from each node on the inner cube to the
+ corresponding node on the outer cube.
+
+ Each node in an N dimensional cube is directly connected to N
+ other nodes. We can identify each node by a set of N
+ {Cartesian coordinates} where each coordinate is either zero
+ or one. Two node will be directly connected if they differ in
+ only one coordinate.
+
+ The simple, regular geometrical structure and the close
+ relationship between the coordinate system and binary numbers
+ make the hypercube an appropriate topology for a parallel
+ computer interconnection network. The fact that the number of
+ directly connected, "nearest neighbour", nodes increases with
+ the total size of the network is also highly desirable for a
+ {parallel computer}.
+
+ (1994-11-17)
+
+Hyperion
+
+ <computer> An {MS-DOS} {personal computer} that was
+ manufactured in Kanata (near Ottawa, Ontario, Canada) in the
+ mid-1980s. It received considerable government subsidies and,
+ while it was considered well-designed and manufactured and a
+ real threat to the {Compaq Portable}, the Ottawa firm that
+ designed it was unable to beat {Compaq}.
+
+ (1997-07-21)
+
+hyperlink
+
+ {hypertext link}
+
+Hyper-Man
+
+ A {browser} available with {Epoch} giving {hypertext} access
+ to the {Unix} manual.
+
+hypermedia
+
+ {hypertext}
+
+HyperNeWS
+
+ A Hypertext system from the Turing Institute Glasgow, based on
+ {NeWS}.
+
+Hyperscript
+
+ Informix. The object-based programming language for Wingz,
+ used for creating charts, graphs, graphics, and customised
+ data entry.
+
+hyperspace
+
+ /hi:'per-spays/ A memory location that is *far* away from
+ where the {program counter} should be pointing, often
+ inaccessible because it is not even mapped in. (Compare {jump
+ off into never-never land}.)
+
+ This usage is from the SF notion of a spaceship jumping "into
+ hyperspace", that is, taking a shortcut through
+ higher-dimensional space - in other words, bypassing this
+ universe. The variant "east hyperspace" is recorded among
+ {CMU} and {Bliss} hackers.
+
+ [{Jargon File}]
+
+ (1994-11-23)
+
+HyperSPARC
+
+ <processor> The successor to the {SuperSPARC} processor, based
+ on the {SPARC} {ISA}. The HyperSPARC has smaller {caches}
+ than the {SuperSPARC}: 8kb on-chip and 256kb off-chip
+ (compared with 36kb and 1Mb). The HyperSPARC's {memory
+ management} is optimised for more efficient out-of-cache
+ addressing which means quicker access to external (slower,
+ cheaper) memory.
+
+ (1994-11-23)
+
+Hyperstrict
+
+ A function which is hyperstrict in some argument will fully
+ evaluate that argument. To fully evaluate an object, evaluate
+ it to WHNF and if it is a constructed data object (e.g. a list
+ or tuple) then fully evaluate every component and so on
+ recursively. Thus a hyperstrict function will fail to
+ terminate if its argument or any component or sub-component of
+ its argument fails to terminate (i.e. if its argument is not
+ "total").
+
+HyperTalk
+
+ A verbose semicompiled language by Bill Atkinson and Dan
+ Winkler, with loose {syntax} and high readability.
+
+ HyperTalk uses {HyperCard} as an object management system,
+ development environment and interface builder. Programs are
+ organised into "stacks" of "cards", each of which may have
+ "buttons" and "fields". All data storage is in
+ zero-terminated strings in fields, local, or global variables;
+ all data references are through "chunk expressions" of the
+ form:
+
+ 'last item of background field
+ "Name List" of card ID 34217'.
+
+ Flow of control is {event-driven} and uses message-passing
+ among scripts that are attached to stack, background, card,
+ field and button objects.
+
+ {Apple Computer} has taken back distribution and maintenance of
+ HyperCard from {Claris} Corporation
+
+ ["HyperTalk Language Reference Manual", A-W 1988].
+
+ (1994-11-17)
+
+hypertext
+
+ <hypertext> A term coined by Ted Nelson around 1965 for a
+ collection of documents (or "nodes") containing
+ cross-references or "links" which, with the aid of an
+ interactive {browser} program, allow the reader to move easily
+ from one document to another.
+
+ The extension of hypertext to include other media - {sound},
+ {graphics}, and {video} - has been termed "{hypermedia}", but
+ is usually just called "hypertext", especially since the
+ advent of the {web} and {HTML}.
+
+ (2000-09-10)
+
+hypertext link
+
+ <hypertext> (Or "{hyperlink}", "button", formerly "span",
+ "region", "extent") A pointer from within the content of one
+ {hypertext} {node} (e.g. a {web page}) to another node. In
+ {HTML} (the language used to write web pages), the source and
+ destination of a {link} are known as "anchors". A source
+ anchor may be a word, phrase, image or the whole node. A
+ destination anchor may be a whole node or some position within
+ the node.
+
+ A {hypertext browser} displays source anchors in some
+ distinctive way. When the user activates the link (e.g. by
+ clicking on it with the {mouse}), the browser displays the
+ destination anchor to which the link refers. Anchors should
+ be recognisable at all times, not, for example, only when the
+ mouse is over them. Originally links were always underlined
+ but the modern preference is to use {bold} text.
+
+ In {HTML}, anchors are created with <a..>..</a> anchor
+ elements. The opening "a" tag of a source anchor has an
+ "href" (hypertext reference) {attribute} giving the
+ destination in the form of a {URL} - usually a whole "page".
+ E.g.
+
+ <a href="http://foldoc.org/">
+ Free On-line Dictionary of Computing</a>
+
+ Destination anchors can be used in HTML to name a position
+ within a page using a "name" attribute. E.g.
+
+ <a name="chapter3">
+
+ The name or "fragment identifier" is appended to the URL of
+ the page after a "#":
+
+ http://fairystory.com/goldilocks.html#chapter3
+
+ (2008-12-10)
+
+Hypertext Markup Language
+
+ <hypertext, web, standard> (HTML) A {hypertext}
+ document format used on the {web}. HTML is built
+ on top of {SGML}. "Tags" are embedded in the text. A tag
+ consists of a "<", a "directive" (in lower case), zero or
+ more parameters and a ">". Matched pairs of directives, like
+ "<title>" and "</title>" are used to delimit text which is to
+ appear in a special place or style.
+
+ Links to other documents are in the form
+
+ <a href="http://machine.edu/subdir/file.html">foo</a>
+
+ where "<a>" and "</a>" delimit an "anchor", "href" introduces
+ a hypertext reference, which is most often a {Uniform Resource
+ Locator} (URL) (the string in double quotes in the example
+ above). The link will be represented in the browser by the
+ text "foo" (typically shown underlined and in a different
+ colour).
+
+ A certain place within an HTML document can be marked with a
+ named anchor, e.g.:
+
+ <a name="baz">
+
+ The "fragment identifier", "baz", can be used in an href by
+ appending "#baz" to the document name.
+
+ Other common tags include <p> for a new paragraph, <b>..</b>
+ for bold text, <ul> for an unnumbered list, <pre> for
+ preformated text, <h1>, <h2> .. <h6> for headings.
+
+ {HTML} supports some standard {SGML} {national characters} and
+ other non-{ASCII} characters through special {escape
+ sequences}, e.g. "&eacute;" for a lower case 'e' with an acute
+ accent. You can sometimes get away without the terminating
+ semicolon but it's bad style.
+
+ Most systems will ignore the case of tags and attributes but
+ lower case should be used for compatibility with {XHTML}.
+
+ The {web Consortium} (W3C) is the international
+ {standards} body for HTML.
+
+ Latest version: {XHTML} 1.0, as of 2000-09-10.
+
+ {(http://w3.org/MarkUp/)}.
+
+ {Character escape sequences
+ (http://w3.org/hypertext/WWW/MarkUp/ISOlat1.html)}.
+
+ See also {weblint}.
+
+ (2006-01-19)
+
+Hypertext Transfer Protocol
+
+ <protocol> (HTTP) The {client-server} {TCP/IP} {protocol} used
+ on the {web} for the exchange of {HTML} documents.
+ It conventionally uses {port} 80.
+
+ Latest version: HTTP 1.1, defined in {RFC 2068}, as of May
+ 1997.
+
+ See also {Uniform Resource Locator}.
+
+ (1994-10-27)
+
+HyperText Transmission Protocol, Secure
+
+ <protocol> (HTTPS) A variant of {HTTP} used by {Netscape} for
+ handling secure transactions.
+
+ The {Netscape Navigator} supports a {URL} {access method},
+ "https", for connecting to {HTTP} {servers} using {SSL}.
+
+ "https" is a unique protocol that is simply {SSL} underneath
+ {HTTP}. You need to use "https://" for HTTP {URLs} with
+ {SSL}, whereas you continue to use "http://" for HTTP URLs
+ without SSL. The default "https" {port} number is 443, as
+ assigned by the {Internet Assigned Numbers Authority}.
+
+ {(http://netscape.com/info/security-doc.html)}.
+
+ (1995-01-16)
+
+hyperware
+
+ <hypertext> {Software} that implements or uses {hypertext}.
+
+ (2000-09-11)
+
+hypotenuse
+
+ <mathematics> The side of a right-angled triangle opposite the
+ right angle.
+
+ (2004-02-15)
+
+hysterical reasons
+
+ (Or "hysterical raisins") A variant on the stock phrase "for
+ historical reasons", indicating specifically that something
+ must be done in some stupid way for backward compatibility,
+ and moreover that the feature it must be compatible with was
+ the result of a bad design in the first place. "All IBM PC
+ video adaptors have to support MDA text mode for hysterical
+ reasons." Compare {bug-for-bug compatible}.
+
+ [{Jargon File}]
+
+Hytelnet
+
+ <networking> A {hypertext} database of publicly accessible
+ {Internet} sites created and maintained by Peter Scott
+ <scottp@moondog.usask.ca>. Hytelnet currently lists over 1400
+ sites, including Libraries, Campus-Wide Information Systems,
+ {Gopher}, {WAIS}, {WWW} and {Freenets}.
+
+ Hytelnet software is available for the {IBM PC}, {Macintosh},
+ {Unix} and {VMS} systems.
+
+ {(ftp://ftp.usask.ca/pub/hytelnet)} (128.233.3.11). {Telnet
+ (telnet://access.usask.ca/)}, login: hytelnet.
+
+ Mailing list: listserv@library.berkeley.edu (no subject, body:
+ subscribe hytelnet FirstName LastName).
+
+ (1995-10-18)
+
+HyTime
+
+ Hypermedia/Time-based Structuring Language: an emerging
+ ANSI/ISO Standard from the {SGML} Users' Group's Special
+ Interest Group on Hypertext and Multimedia (SIGhyper). A
+ hypermedia extension of {SGML}.
+
+ ["The HyTime Hypermedia/Time-based Document Structuring
+ Language", S. Newcomb et al, CACM 34(11):67-83 (Nov 1991)].
+
+i18n
+
+ {internationalisation}
+
+I2O
+
+ {Intelligent Input/Output}
+
+i386
+
+ {Intel 80386}
+
+i486
+
+ {Intel 486}
+
+i487
+
+ {Intel 487SX}
+
+i860
+
+ <processor> A 32/64-bit {superscalar} {RISC} {microprocessor}
+ from {Intel}, released in 1989. Originally codenamed "N10".
+ It has a 32-bit integer {ALU} and a 64-bit {floating-point
+ unit}. It has a 64-bit {data bus} with an initialisation mode
+ which only uses eight bits of the data bus to allow the use of
+ a small {boot ROM}. It has a 32-bit wide {instruction cache}
+ and a separate 64-bit wide {data cache}. It uses {register
+ scoreboarding} and {register bypassing}. The {clock rate} is
+ 33 MHz with a clock-doubled version available.
+
+ (1998-03-28)
+
+IA
+
+ {Information Appliance}
+
+IA32
+
+ <architecture> The {processor} chip architecture and
+ {instruction set} used by {Intel} in its {Pentium} processors.
+
+ (2007-06-17)
+
+IAB
+
+ {Internet Architecture Board}
+
+IAD
+
+ A dynamic analyser from {IBM} giving information on run-time
+ performance and code use.
+
+IAL
+
+ {ALGOL 58}
+
+IAM
+
+ Interactive Algebraic Manipulation. Interactive {symbolic
+ mathematics} for {PDP-10}.
+
+ ["IAM, A System for Interactive Algebraic Manipulation", C.
+ Christensen et al, Proc Second Symp Symb Alg Manip, ACM Mar
+ 1971].
+
+IANA
+
+ {Internet Assigned Numbers Authority}
+
+IANAL
+
+ <chat> I Am Not A Lawyer (but my legal opinion is...).
+
+ (1998-07-28)
+
+IAP
+
+ {Internet Access Provider}
+
+I-APL
+
+ A version of {APL}.
+ {(ftp://watserv1.waterloo.edu/languages/apl/)}.
+
+ (1992-07-06)
+
+IAR
+
+ Instruction Address Register.
+
+ The {IBM} name for {program counter}.
+
+ (1995-03-21)
+
+IAS
+
+ 1. <computer> The first modern computer. It had main
+ {registers}, processing circuits, information paths within the
+ {central processing unit}, and used {Von Neumann}'s
+ {fetch-execute cycle}.
+
+ The IAS machine's basic unit of information was a 40-bit
+ {word} and the memory had 4096 words. A word stored in memory
+ could represent either an instruction or data. Each IAS
+ instruction was twenty bits long, so that two instructions
+ could be stored in each 40-bit memory location. Each
+ instruction consisted of an 8-bit {operation code} and a
+ 12-bit address that could identify any of 2^12 locations that
+ may be used to store an {operand} of the instruction.
+
+ The {CPU} consisted of a data processing unit and a program
+ control unit. It contained various processing and control
+ circuits along with a set of high-speed {registers} for the
+ temporary storage of instructions, memory addresses, and data.
+
+ The main actions specified by instructions were performed by
+ the arithmetic-logic circuits of the data processing unit. An
+ electronic clock circuit was used to generate the signals
+ needed to synchronise the operation of the different parts of
+ the system.
+
+ [Who? Where? When? Implemented using what?]
+
+ 2. {Immediate Access Storage}.
+
+ (2003-10-24)
+
+IAW
+
+ <chat> inactive window.
+
+ Used in {talk} systems to mean that that person will not be
+ taking part in the conversation for a while. The sadly
+ mispelled alternative, "unactive window" (UAW) has also been
+ reported.
+
+ (1994-12-05)
+
+IAYSDAH
+
+ <chat> I acknowledge your strangely depressing attempt at
+ humour.
+
+ (2004-03-04)
+
+IBEX
+
+ <language> The command language for {Honeywell}'s {CP-6}
+ {operating system}.
+
+ (1994-12-06)
+
+IBM
+
+ {International Business Machines}
+
+IBM 1130
+
+ <computer> A computer introduced by {IBM} in 1965. It was
+ their cheapest computer to date, and was aimed at
+ price-sensitive, computing-intensive technical markets like
+ education and engineering. It notably included inexpensive
+ disk storage. Non-IBM {clones} were produced.
+
+ {IBM 1130 Enthusiasts (http://ibm1130.org/)}.
+
+ (2005-01-17)
+
+IBM 1403
+
+ <printer> A printer used with the {IBM 360} {mainframe}, a
+ successor to the 1401.
+
+ (1999-01-11)
+
+IBM 1620
+
+ <computer> A computer built by {IBM} and released in late
+ 1959. The 1620 cost from around $85,000(?) up to hundreds of
+ thousands of dollars(?) according to the configuration. It
+ was billed as a "small scientific computer" to distinguish it
+ from the business-oriented {IBM 1401}. It was regarded as
+ inexpensive, and many schools started out with one.
+
+ It was either developed for the US Navy to teach computing, or
+ as a replacement for the very successful {IBM 650} which did
+ quite well in the low end scientific market. Rumour has it
+ that the Navy called this computer the CADET - Can't Add,
+ Doesn't Even Try.
+
+ The {ALU} used lookup tables to add, subtract and multiply but
+ it could do address increments and the like without the
+ tables. You could change the number base by adjusting the
+ tables, which were input during the boot sequence from
+ {Hollerith} cards. The divide instruction required additional
+ hardware, as did {floating point} operations.
+
+ The basic machine had 20,000 decimal digits of {ferrite core
+ memory} arranged as a 100 by 100 array of 12-bit locations,
+ each holding two digits. Each digit was stored as four
+ numeric bits, one flag bit and one parity bit. The numeric
+ bits stored a decimal digit (values above nine were illegal).
+
+ Memory was logically divided into fields. On the high-order
+ digit of a field the flag bit indicated the end of the field.
+ On the low-order digit it indicated a negative number. A flag
+ bit on the low order of the address indicated {indirect
+ addressing} if you had that option installed. A few "illegal"
+ bit combinations were used to store things like record marks
+ and "numeric blanks".
+
+ On a {subroutine} call it stored the {return address} in the
+ five digits just before the entry point to the routine, so you
+ had to build your own {stack} to do {recursion}.
+
+ The enclosure was grey, and the core was about four or five
+ inches across. The core memory was kept cool inside a
+ temperature-controlled box. The machine took a few minutes to
+ warm up after power on before you could use it. If it got too
+ hot there was a thermal cut-out switch that would shut it
+ down.
+
+ Memory could be expanded up to 100,000 digits in a second
+ cabinet. The cheapest package used {paper tape} for I/O. You
+ could also get {punched cards} and later models could be
+ hooked up to a 1311 {disk drive} (a two-{megabyte} {washing
+ machine}), a 1627 {plotter}, and a 1443 {line printer}.
+
+ Because the 1620 was popular with colleges, IBM ran a clearing
+ house of software for a nominal cost such as {Snobol},
+ {COBOL}, chess games, etc.
+
+ The model II, released about three years later, could add and
+ subtract without tables. The {clock period} decreased from 20
+ to 10 microseconds, instruction fetch sped up by a few cycles
+ and it added {index registers} of some sort. Some of the
+ model I's options were standard on the model II, like
+ {indirect addressing} and the {console} {teletype} changed
+ from a model C to a {Selectric}. Later still, IBM marketed
+ the {IBM 1710}.
+
+ A favorite use was to tune a FM radio to pick up the
+ "interference" from the lights on the console. With the right
+ delay loops you could generate musical notes. Hackers wrote
+ {interpreters} that played music from notation like "C44".
+
+ 1620 consoles were used as props to represent {Colossus} in
+ the film "The Forbin Project", though most of the machines had
+ been scrapped by the time the film was made.
+
+ {A fully configured 1620
+ (http://uranus.ee.auth.gr/TMTh/exhibit.htm)}.
+
+ {IBM 1620 console picture (/pub/misc/IBM1620-console.jpg)}.
+
+ {IBM 1620 at Tuck School of Business, Dartmouth College, Hanover,
+ NH, USA (/pub/misc/IBM1620-Tuck1960s.jpg)} (Thanks Victor
+ E. McGee, pictured).
+
+ ["Basic Programming Concepts and the IBM 1620 Computer",
+ Leeson and Dimitry, Holt, Rinehart and Winston, 1962].
+
+ (1997-08-05)
+
+IBM 1710
+
+ <computer> An {IBM 1620} with additional features useful for
+ industrial process control: {A/D convertors}, {D/A
+ convertors}, general-purpose I/O lines, and {interrupts}.
+
+ [Date?]
+
+ (1997-07-20)
+
+IBM 2741
+
+ <printer> A slow, letter-quality printing device and
+ {terminal} based on the {IBM Selectric} {typewriter}. The
+ print head was a little sphere resembling a golf ball, bearing
+ reversed embossed images of 88 different characters arranged
+ on four parallels of latitude; one could change the font by
+ changing the golf ball. The device communicated at 134.5 bits
+ per second, {half duplex}. When the computer transmitted, it
+ physically locked the keyboard.
+
+ This was the technology that enabled {APL} to use a
+ non-{EBCDIC}, non-{ASCII}, and in fact completely non-standard
+ {character set}. This put it 10 years ahead of its time -
+ where it stayed, firmly rooted, for the next 20, until
+ {character displays} gave way to programmable {bit-mapped}
+ devices with the flexibility to support other character sets.
+
+ (2006-08-04)
+
+IBM 3270
+
+ <hardware> A class of {terminals} made by {IBM} known as
+ "Display Devices", normally used to talk to {IBM}
+ {mainframes}. The 3270 attempts to minimise the number of
+ {I/O} {interrupts} required by accepting large blocks of data,
+ known as datastreams, in which both text and control (or
+ formatting functions) are interspersed allowing an entire
+ screen to be "painted" as a single output operation. The
+ concept of "formatting" in these devices allows the screen to
+ be divided into clusters of contiguous character cells for
+ which numerous attributes (color, highlighting, {character
+ set}, protection from modification) can be set. Further,
+ using a technique known as 'Read Modified' the changes from
+ any number of formatted fields that have been modified can be
+ read as a single input without transferring any other data,
+ another technique to enhance the terminal throughput of the
+ CPU.
+
+ The 3270 had twelve, and later twenty-four, special Programmed
+ Function Keys, or PF keys. When one of these keys was
+ pressed, it would cause the device to generate an I/O
+ {interrupt} and present a special code identifying which key
+ was pressed. {Application program} functions such as
+ termination, page-up, page-down or help could be invoked by a
+ single key-push, thereby reducing the load on very busy
+ processors.
+
+ A version of the {IBM PC} called the "3270 PC" was released in
+ October 1983. It included 3270 {terminal emulation}.
+
+ {tn3270} is modified version of {Telnet} which acts as a 3270
+ {terminal emulator} and can be used to connect to an IBM
+ computer over a network.
+
+ See also {broken arrow}.
+
+ (1995-02-07)
+
+IBM 360
+
+ {System/360}
+
+IBM 370
+
+ {System/370}
+
+IBM 370ESA
+
+ <computer, IBM> (Enterprise System Architecture) An {IBM}
+ {mainframe} {computer} introduced in 1988. Successor to the
+ {IBM 370XA} had enhanced access registers that allowed access
+ to other forms of virtual memory. This enhancement allowed
+ more data storage in main and virtual memory, reducing {I/O}
+ operating and improving speed and efficiency. The IBM 370ESA
+ was rebranded as the IBM390, and later as the zSeries.
+
+ (2004-06-06)
+
+IBM 370XA
+
+ <computer, IBM> An {IBM} {mainframe} {computer} introduced in
+ 1983. Successor to the {System/370}, this machine had an
+ enhanced {address space}.
+
+ (2004-05-27)
+
+IBM 3720
+
+ <hardware> A {communications controller} made by {IBM},
+ suitable for use in an {IBM S/390}. Official service support
+ was withdrawn in 1999 in favour of the {IBM 3745}.
+
+ {(http://ibm.com/search?q=3720&realm=Networking)}.
+
+ (2000-02-21)
+
+IBM390
+
+ {IBM 370ESA}
+
+IBM 650
+
+ <computer> A computer, produced ca. 1955 and in use in the
+ late 1950s, with rotating {magnetic drum} storage and {punched
+ card} input. Its memory words could store 10-digit decimal
+ numbers and each instruction had two addresses, one for the
+ {operand} and one for address of the next instruction on the
+ drum.
+
+ {SOAP} was its (optimising) {assembler}. Languages used on it
+ included {BACAIC}, {BALITAC}, {BELL}, {CASE SOAP III}, {DRUCO
+ I}, {EASE II}, {ELI}, {ESCAPE}, {FAST}, {FLAIR}, {FORTRANSIT},
+ {FORTRUNCIBLE}, {GAT}, {IPL}, {Internal Translator}, {KISS},
+ {MITILAC}, {MYSTIC}, {OMNICODE}, {PIT}, {RELATIVE},
+ {RUNCIBLE}, {SIR}, {SOAP}, {Speedcoding}, {SPIT}, {SPUR}.
+
+ [More details?]
+
+ (1995-03-30)
+
+IBM 700 series
+
+ <computer> A family of computers made by IBM, including the
+ {IBM 701}, {IBM 702}, {IBM 704}, {IBM 705} and {IBM 709}.
+
+ (2005-06-20)
+
+IBM 701
+
+ <computer> ("Defense Calculator") The first of the {IBM 700
+ series} of computers.
+
+ The IBM 701 was annouced internally on 1952-04-29 as "the most
+ advanced, most flexible high-speed computer in the world".
+ Known as the Defense Calculator while in development at {IBM
+ Poughkeepsie Laboratory}, it went public on 1953-04-07 as the
+ "IBM 701 Electronic Data Processing Machines" (plural because
+ it consisted of eleven connected units).
+
+ The 701 was the first IBM large-scale electronic computer
+ manufactured in quantity and their first commercial
+ {scientific computer}. It was the first IBM machine in which
+ programs were stored in an internal, addressable, electronic
+ memory. It was developed and produced in less than two years
+ from "first pencil on paper" to installation. It was key to
+ IBM's transition from {punched card} machines to electronic
+ computers.
+
+ It consisted of four {magnetic tape drives}, a {magnetic drum}
+ memory unit, a {cathode-ray tube storage unit}, an L-shaped
+ {arithmetic and control unit} with an operator's panel, a
+ {punched card {reader}, a printer, a card punch and three
+ power units. It performed more than 16,000 additions or
+ subtractions per second, read 12,500 digits a second from
+ tape, print 180 letters or numbers a second and output 400
+ digits a second from punched-cards.
+
+ The IBM 701 ran the following languages and systems: {BACAIC},
+ {BAP}, {DOUGLAS}, {DUAL-607}, {FLOP}, {GEPURS}, {JCS-13},
+ {KOMPILER}, {LT-2}, {PACT I}, {QUEASY}, {QUICK}, {SEESAW},
+ {SHACO}, {SO 2}, {Speedcoding}, {SPEEDEX}.
+
+ {IBM History
+ (http://www-03.ibm.com/ibm/history/exhibits/701/701_intro.html)}.
+
+ (2005-06-20)
+
+IBM 704
+
+ <computer> A large, scientific computer made by {IBM} and used
+ by the largest commercial, government and educational
+ institutions.
+
+ The IBM 704 had 36-bit memory words, 15-bit addresses and
+ instructions with one address. A few {index register}
+ instructions had the infamous 15-bit decrement field in
+ addition to the 15-bit address.
+
+ The 704, and {IBM 709} which had the same basic architecture,
+ represented a substantial step forward from the {IBM 650}'s
+ {magnetic drum} storage as they provided random access at
+ electronic speed to {core storage}, typically 32k words of 36
+ bits each.
+
+ [Or did the 704 actually come *before* the 650?]
+
+ A typical 700 series installation would be in a specially
+ built room of perhaps 1000 to 2000 square feet, with cables
+ running under a raised floor and substantial air conditioning.
+ There might be up to eight {magnetic tape} transports, each
+ about 3 x 3 x 6 feet, on one or two "channels." The 1/2 inch
+ tape had seven tracks and moved at 150 inches per second,
+ giving a read/write speed of 15,000 six bit characters (plus
+ parity) per second.
+
+ In the centre would be the operator's {console} consisting of
+ cabinets and tables for storage of tapes and boxes of cards;
+ and a {card reader}, a {card punch}, and a {line printer},
+ each perhaps 4 x 4 x 5 feet in dimension. Small {jobs} could
+ be entered via {punched cards} at the console, but as a rule
+ the user jobs were transferred from cards to {magnetic tape}
+ by {off-line} equipment and only control information was
+ entered at the console (see {SPOOL}). Before each job, the
+ {operating system} was loaded from a read-only system tape
+ (because the system in {core} could have been corrupted by the
+ previous user), and then the user's program, in the form of
+ card images on the input tape, would be run. Program output
+ would be written to another tape (typically on another
+ channel) for printing off-line.
+
+ Well run installations would transfer the user's cards to
+ tape, run the job, and print the output tape with a turnaround
+ time of one to four hours.
+
+ The processing unit typically occupied a position symmetric
+ but opposite the operator's console. Physically the largest
+ of the units, it included a glass enclosure a few feet in
+ dimension in which could be seen the "core" about one foot on
+ each side. The 36-bit word could hold two 18-bit addresses
+ called the "Contents of the Address Register" ({CAR}) and the
+ "Contents of the Decrement Register" ({CDR}).
+
+ On the opposite side of the floor from the tape drives and
+ operator's console would be a desk and bookshelves for the
+ ever-present (24 hours a day) "field engineer" dressed in, you
+ guessed it, a grey flannel suit and tie. The maintenance of
+ the many thousands of {vacuum tubes}, each with limited
+ lifetime, and the cleaning, lubrication, and adjustment of
+ mechanical equipment, was augmented by a constant flow of
+ {bug} reports, change orders to both hardware and software,
+ and hand-holding for worried users.
+
+ The 704 was oriented toward scientific work and included
+ {floating point} hardware and the first {Fortran}
+ implementation. Its hardware was the basis for the
+ requirement in some programming languages that loops must be
+ executed at least once.
+
+ The {IBM 705} was the business counterpart of the 704. The
+ 705 was a decimal machine with a circular register which could
+ hold several variables (numbers, values) at the same time.
+
+ Very few 700 series computers remained in service by 1965, but
+ the {IBM 7090}, using {transistors} but similar in logical
+ structure, remained an important machine until the production
+ of the earliest {integrated circuits}.
+
+ [Was the 704 scientific, business or general purpose?
+ Difference between 704 and 709?]
+
+ (1996-01-24)
+
+IBM 7040
+
+ <computer> A scaled down version of the {IBM 7090}.
+
+ (1997-02-23)
+
+IBM 705
+
+ <computer> A business-oriented counterpart of the {IBM 704}.
+ The 705 was a decimal machine with a circular {register} which
+ could hold several values at the same time.
+
+ Languages incuded {ACOM}, {Autocode}, {ELI}, {PRINT}, {PRINT
+ I}, {SOHIO}, {SYMBOLIC ASSEMBLY}.
+
+ (2000-06-01)
+
+IBM 709
+
+ <computer> A computer made by {IBM} oriented toward
+ scientific work. The 709 had the same basic architecture as
+ the {IBM 704} but with many {I/O} and performance refinements
+ over the 704.
+
+ The IBM 709 (like the 704) had 36-bit memory words, 15-bit
+ addresses and instructions with one address. A few {index
+ register} instructions had the infamous 15-bit decrement field
+ in addition to the 15-bit address.
+
+ The {IBM 7090} was a transistorised version of the 709.
+
+ [Difference between 704 and 709?]
+
+ (1999-01-19)
+
+IBM 7090
+
+ <computer> A transistorised version of the {IBM 709} which was
+ a very popular high end computer in the early 1960s. The 7090
+ had 32Kbytes of 36-bit {core} memory and a hardware {floating
+ point unit}. {Fortran} was its most popular language, but it
+ supported many others. It was later upgraded to the {IBM
+ 7094}, and a scaled down version, the IBM 7040 was also
+ introduced.
+
+ IBM 7090s controlled the Mercury and Gemini space flights, the
+ Balistic Missile Early Warning System (until well into the
+ 1980s), and the {CTSS} {time sharing} system at {MIT}.
+
+ The 7090 was not good at unit record I/O, so in small
+ configurations an {IBM 1401} was used for {SPOOL} I/O and in
+ large configurations (such as a 7090/94) a 7040/44 would be
+ directly coupled and dedicated to handling printers and {card
+ readers}. (See the film Dr Strangelove).
+
+ (1999-01-19)
+
+IBM 7094
+
+ <computer> A faster version of the {IBM 7090} with more {index
+ registers}.
+
+ (1997-02-23)
+
+IBM 801
+
+ The original {IBM} {RISC} processor, developed as a research
+ project. It was named after the building in which it was
+ designed.
+
+ [Features? Dates?]
+
+ (1995-03-01)
+
+IBM compatible
+
+ <computer> A computer which can use hardware and software
+ designed for the {IBM PC} (or, less often, IBM {mainframes}).
+
+ This was once a key phrase in marketing a new PC {clone} but
+ now in 1998 is rarely used, the non-IBM {wintel} {personal
+ computer} manufacturers such as {Compaq}, {Dell} and {Gateway
+ 2000} and OS vendor {Microsoft} having taken control of the
+ market, marginalising IBM.
+
+ (1998-07-30)
+
+IBM Customer Engineer
+
+ <job> (CE) A hardware guy from {IBM}.
+
+ [Are/were any CEs female?]
+
+ (1998-07-08)
+
+IBM discount
+
+ A price increase. Outside IBM, this derives from the common
+ perception that IBM products are generally overpriced (see
+ {clone}); inside, it is said to spring from a belief that
+ large numbers of IBM employees living in an area cause prices
+ to rise.
+
+ [{Jargon File}]
+
+ (1995-02-07)
+
+IBM PC
+
+ <computer> International Business Machines Personal Computer.
+
+ IBM PCs and compatible models from other vendors are the most
+ widely used computer systems in the world. They are typically
+ single user {personal computers}, although they have been
+ adapted into multi-user models for special applications.
+
+ Note: "IBM PC" is used in this dictionary to denote IBM and
+ compatible personal computers, and to distinguish these from
+ other {personal computers}, though the phrase "PC" is often
+ used elsewhere, by those who know no better, to mean "IBM PC
+ or compatible".
+
+ There are hundreds of models of IBM compatible computers.
+ They are based on {Intel}'s {microprocessors}: {Intel 8086},
+ {Intel 8088}, {Intel 80286}, {Intel 80386}, {Intel 486} or
+ {Pentium}. The models of IBM's first-generation Personal
+ Computer (PC) series have names: IBM PC, {IBM PC XT}, {IBM PC
+ AT}, Convertible and Portable. The models of its second
+ generation, the Personal System/2 ({PS/2}), are known by model
+ number: Model 25, Model 30. Within each series, the models
+ are also commonly referenced by their {CPU} {clock rate}.
+
+ All IBM personal computers are software compatible with each
+ other in general, but not every program will work in every
+ machine. Some programs are time sensitive to a particular
+ speed class. Older programs will not take advantage of newer
+ higher-resolution {display standards}.
+
+ The speed of the {CPU} ({microprocessor}) is the most
+ significant factor in machine performance. It is determined
+ by its {clock rate} and the number of bits it can process
+ internally. It is also determined by the number of bits it
+ transfers across its {data bus}. The second major performance
+ factor is the speed of the {hard disk}.
+
+ {CAD} and other graphics-intensive {application programs} can
+ be sped up with the addition of a mathematics {coprocessor}, a
+ chip which plugs into a special socket available in almost all
+ machines.
+
+ {Intel 8086} and {Intel 8088}-based PCs require {EMS}
+ (expanded memory) boards to work with more than one megabyte
+ of memory. All these machines run under {MS-DOS}. The
+ original {IBM PC AT} used an {Intel 80286} processor which can
+ access up to 16 megabytes of memory (though standard {MS-DOS}
+ applications cannot use more than one megabyte without {EMS}).
+ {Intel 80286}-based computers running under {OS/2} can work
+ with the maximum memory.
+
+ Although IBM sells {printers} for PCs, most printers will work
+ with them. As with display hardware, the software vendor must
+ support a wide variety of printers. Each program must be
+ installed with the appropriate {printer driver}.
+
+ The original 1981 IBM PC's keyboard was severely criticised by
+ typists for its non-standard placement of the return and left
+ shift keys. In 1984, IBM corrected this on its AT keyboard,
+ but shortened the backspace key, making it harder to reach.
+ In 1987, it introduced its Enhanced keyboard, which relocated
+ all the function keys and placed the control key in an awkward
+ location for touch typists. The escape key was relocated to
+ the opposite side of the keyboard. By relocating the function
+ keys, IBM made it impossible for software vendors to use them
+ intelligently. What's easy to reach on one keyboard is
+ difficult on the other, and vice versa. To the touch typist,
+ these deficiencies are maddening.
+
+ An "IBM PC compatible" may have a keyboard which does not
+ recognize every key combination a true IBM PC does,
+ e.g. shifted cursor keys. In addition, the "compatible"
+ vendors sometimes use proprietary keyboard interfaces,
+ preventing you from replacing the keyboard.
+
+ The 1981 PC had 360K {floppy disks}. In 1984, IBM introduced
+ the 1.2 megabyte floppy disk along with its AT model.
+ Although often used as {backup} storage, the high density
+ floppy is not often used for interchangeability. In 1986, IBM
+ introduced the 720K 3.5" microfloppy disk on its Convertible
+ {laptop computer}. It introduced the 1.44 megabyte double
+ density version with the PS/2 line. These disk drives can be
+ added to existing PCs.
+
+ Fixed, non-removable, {hard disks} for IBM compatibles are
+ available with storage capacities from 20 to over 600
+ megabytes. If a hard disk is added that is not compatible
+ with the existing {disk controller}, a new controller board
+ must be plugged in. However, one disk's internal standard
+ does not conflict with another, since all programs and data
+ must be copied onto it to begin with. Removable hard disks
+ that hold at least 20 megabytes are also available.
+
+ When a new peripheral device, such as a {monitor} or
+ {scanner}, is added to an IBM compatible, a corresponding, new
+ controller board must be plugged into an {expansion slot} (in
+ the bus) in order to electronically control its operation.
+ The PC and XT had eight-bit busses; the AT had a 16-bit bus.
+ 16-bit boards will not fit into 8-bit slots, but 8-bit boards
+ will fit into 16-bit slots. {Intel 80286} and {Intel 80386}
+ computers provide both 8-bit and 16-bit slots, while the 386s
+ also have proprietary 32-bit memory slots. The bus in
+ high-end models of the PS/2 line is called "{Micro Channel}".
+ {EISA} is a non-IBM rival to Micro Channel.
+
+ The original IBM PC came with {BASIC} in {ROM}. Later, Basic
+ and BasicA were distributed on floppy but ran and referenced
+ routines in ROM.
+
+ IBM PC and PS/2 models
+
+ PC range
+
+ Intro CPU Features
+ PC Aug 1981 8088 Floppy disk system
+ XT Mar 1983 8088 Slow hard disk
+ XT/370 Oct 1983 8088 IBM 370 mainframe emulation
+ 3270 PC Oct 1983 8088 with 3270 terminal emulation
+ PCjr Nov 1983 8088 Floppy-based home computer
+ PC Portable Feb 1984 8088 Floppy-based portable
+ AT Aug 1984 286 Medium-speed hard disk
+ Convertible Apr 1986 8088 Microfloppy laptop portable
+ XT 286 Sep 1986 286 Slow hard disk
+
+ PS/2 range
+
+ Intro CPU Features
+ Model 1987-08-25 8086 PC bus (limited expansion)
+ Model 1987-04-30 8086 PC bus
+ Model 30 1988-09-286 286 PC bus
+ Model 1987-04-50 286 Micro Channel bus
+ Model 50Z Jun 1988 286 Faster Model 50
+ Model 55 SX May 1989 386SX Micro Channel bus
+ Model 1987-04-60 286 Micro Channel bus
+ Model 1988-06-70 386 Desktop, Micro Channel bus
+ Model P1989-05-70 386 Portable, Micro Channel bus
+ Model 1987-04-80 386 Tower, Micro Channel bus
+
+ IBM PC compatible specifications
+
+ CPU CPU Clock Bus Floppy Hard
+ bus speed width RAM disk disk OS
+ bit Mhz bit byte inch byte Mbyte
+
+ 8088 16 4.8-9.5 8 1M* 5.25 360K 10-40 DOS
+ 3.5 720K
+ 3.5 1.44M
+
+ 8086 16 6-12 16 1M* 20-60
+
+ 286 16 6-25 16 1-8M* 5.25 360K 20-300 DOS
+ 5.25 1.2M OS/2
+
+ 386 32 16-33 32 1-16M** 3.5 720K Unix
+ 3.5 1.44M 40-600
+
+ 386SX 32 16-33 16 1-16M** 40-600
+
+ *Under DOS, RAM is expanded beyond 1M with EMS memory boards
+
+ **Under DOS, RAM is expanded beyond 1M with normal "extended"
+ memory and a memory management program.
+
+ See also {BIOS}, {display standard}.
+
+ (1995-05-12)
+
+IBM PC AT
+
+ <computer> ("Advanced Technology") A version of the {IBM PC},
+ released in Aug 1984 with an {Intel 80286} processor, a 16-bit
+ {bus}, a medium-speed {hard disk} and a 1.2 {megabyte}
+ {floppy} {disk drive}. It had a larger case than the PC,
+ which allowed it to accept "{tall cards}".
+
+ The AT keyboard corrected the PC's non-standard placement of
+ the {return} and left shift keys but shortened the {backspace}
+ key, making it harder to reach.
+
+ (1995-03-01)
+
+IBM PCjr
+
+ <computer> ({IBM PC} Junior) A {floppy disk}-based home
+ computer with an {Intel 8088} {CPU} and a {chiclet keyboard},
+ released in November 1983. The PCjr could be expanded to have
+ two floppy drives and 640 kilobytes of {RAM} using {sidecars}.
+ Some even had a {mouse} and could run drawing programs with
+ {popup menus}.
+
+ (1995-10-06)
+
+IBM PC XT
+
+ <computer> An {IBM PC} with a (slow) {hard disk}. The XT was
+ released in March 1983. It had an {Intel 8088} {CPU}. The
+ XT/370, released in October 1983, added {IBM 370} {mainframe}
+ {emulation}, and the XT 286 followed in September 1986 with an
+ {Intel 80286} CPU [Why?].
+
+ (1996-05-21)
+
+IBM System/36
+
+ <computer> A mid-range {computer} introduced in 1983, which
+ remained popular in the 1990s because of its low cost and high
+ performance. Prices started in the $20k range for the small
+ 5362 to $100+k for the expanded 5360. In 1994, IBM introduced
+ the Advanced 36 for $9,000.
+
+ The largest 5360 had 7MB of {RAM} and 1432MB of {hard disk}.
+ The smallest 5362 had 256K of RAM and 30MB of hard disk. The
+ Advanced 36 had 64MB of RAM and 4300MB of hard disk, but
+ design issues limit the amount of storage that can actually be
+ addressed by the {operating system}; underlying {microcode}
+ allowed additional RAM to cache disk reads and writes,
+ allowing the Advanced 36 to outperform the S/36 by 600 to
+ 800%.
+
+ There was only one operating system for the S/36: SSP ({System
+ Support Product}). SSP consumed about 7-10MB of hard drive
+ space. Computer programs on the S/36 reside in "libraries,"
+ and the SSP itself resides in a special system library called
+ #LIBRARY.
+
+ Components of SSP include the {Data File Utility} (DFU), the
+ {Source Entry Utility} (SEU), the largely obselete {Work
+ Station Utility} (WSU), the {Screen Design Aid} (SDA) and
+ {Operational Control Language} (OCL).
+
+ Using the IBM S/36 is relatively simple. The operator sits in
+ front of a computer monitor, types on a keyboard, and
+ interacts using a series of on-screen forms. S/36 is
+ command-oriented, like MS-DOS, however, S/36 additionally uses
+ more than 70 menus which allow operators to type the number of
+ an appropriate command or response, and application writers
+ can create their own menus and commands ("procedures.")
+
+ Programmers use SEU to create or modify a {source} program
+ which is then compiled into an {object program}. SEU uses 50
+ or so {templates} to assist the operator with the {syntax} of
+ different types of sources.
+
+ By 1985, an application called {Programmer/Operator
+ Productivity} was widely available and was probably the most
+ popular (and pirated) S/36 software ever written. POP
+ included a {full-screen editor} called {FSEDIT} which could be
+ used in place of SEU, which only allowed single-line editing.
+
+ Data File Utility allows the programmer to quickly create a
+ simple, single-record display program to add, update and
+ delete {records} within a file. Also, simple report programs
+ can be created.
+
+ Screen Design Aid allows the programmer to create menus,
+ create and update simple forms which are called "display
+ formats" or "prompt screens", and view existing display
+ formats.
+
+ By using Operational Control Language, the programmer can
+ assign files and resources to a particular program and pass
+ run-time information like a processing date, order number, or
+ user name to the compiled program. Programs can acquire up to
+ 8 workstations, or run in the background, but usually they run
+ on only one workstation. The largest program size is 64K.
+
+ Whenever a program is called, SSP searches in the named user
+ library and then #LIBRARY. Therefore, a system program can be
+ called from any library and all users have access to it.
+
+ S/36 has three types of security: (1) password security, (2) a
+ badge reader option that almost no-one ever bought, and (3)
+ resource security. There are five levels of users access and
+ five levels of resource access. By using password and
+ resource security effectively, the administrator (who was at
+ that time often called a DP Manager or Information Systems
+ Manager) can restrict access to critical and secure
+ applications.
+
+ The cheapest, and therefore most popular, language {compiler}
+ for the S/36 is {RPG II}, a language based on fixed logic
+ cycles which arose in the days of {card readers}. Other
+ languages include {COBOL}, {FORTRAN} and {BASIC}. Almost
+ every S/36 shop with in-house design uses RPG.
+
+ It's interesting to note that the S/36 allows the operator to
+ change a program while it is being used, which can be very
+ dangerous on live data. The S/38 and the iSeries computer do
+ not allow this.
+
+ IBM has not marketed the S/36 or Advanced 36 since 2000.
+ Price/performance of the {AS/400} (aka iSeries) and hardware
+ technology of the present-generation {PC} makes the S/36 a
+ much less attractive offering from a different era in
+ computing.
+
+ (2005-04-05)
+
+IBM Systems Engineer
+
+ <job> (SE) A software person from {IBM}.
+
+ (1998-07-08)
+
+IBM zSeries
+
+ {IBM 370ESA}
+
+Ibpag2
+
+ {Icon-Based Parser Generation System 2}
+
+Iburg
+
+ A program by Christopher W. Fraser <cwf@research.att.com>,
+ David R. Hanson <drh@princeton.edu> and Todd A. Proebsting
+ <todd@cs.arizona.edu> that generates a fast tree parser.
+
+ Iburg is compatible with {Burg}. Both programs accept a
+ cost-augmented tree {grammar} and emit a {C} program that
+ discovers an optimal parse of trees in the language described
+ by the grammar. They have been used to construct fast optimal
+ instruction selectors for use in code generation. Burg uses
+ {BURS}. Iburg's matchers do {dynamic programming} at compile
+ time.
+
+ {(ftp://ftp.cs.princeton.edu/pub/iburg.tar.Z)}.
+
+ (1993-02-10)
+
+IC
+
+ 1. <hardware> {integrated circuit}.
+
+ 2. {Independent Carrier}.
+
+ 3. {Imperial College}.
+
+ (1997-04-12)
+
+ICA
+
+ {Independent Computing Architecture}
+
+ICAM
+
+ {Integrated Computer Aided Manufacturing}
+
+ICANN
+
+ {Internet Corporation for Assigned Names and Numbers}
+
+I-CASE
+
+ Integrated {CASE}. Another term for an {IPSE}.
+
+ICBM address
+
+ <networking, humour> (Or "missile address") The form used to
+ register a site with the {Usenet} mapping project includes a
+ space for longitude and latitude, preferably to seconds-of-arc
+ accuracy. This is actually used for generating
+ geographically-correct maps of {Usenet} links on a plotter;
+ however, it has become traditional to refer to this as one's
+ "ICBM address" or "missile address", and many people include
+ it in their {sig block} with that name. (A real missile
+ address would include target altitude.)
+
+ [{Jargon File}]
+
+ (1994-12-15)
+
+ICE
+
+ 1. <electronics> {in-circuit emulator}.
+
+ 2. <security, jargon> {Intrusion Countermeasure Electronics}.
+
+ (2000-03-18)
+
+icebreaker
+
+ <security, jargon> A program designed for cracking security on
+ a system.
+
+ See also: {ICE}.
+
+ [{Jargon File}]
+
+ (2000-03-18)
+
+ICES
+
+ Integrated Civil Engineering System. Subsystems include COGO,
+ STRUDL, BRIDGE, LEASE, PROJECT, ROADS and TRANSET. Internal
+ languages include ICETRAN and CDL. "An Integrated Computer
+ System for Engineering Problem Solving", D. Roos, Proc SJCC
+ 27(2), AFIPS (Spring 1965). Sammet 1969, pp.615-620.
+
+ICETRAN
+
+ An extension of {Fortran IV} and a component of {ICES}.
+
+ [Sammet 1969, p. 617].
+
+ICI
+
+ <language> An extensible, interpretated language by Tim Long
+ with {syntax} similar to {C}. ICI adds high-level
+ garbage-collected {associative} data structures, {exception}
+ handling, sets, {regular expressions}, and {dynamic arrays}.
+
+ Libraries provide additional types and functions to support
+ common needs such as I/O, simple {databases}, character based
+ screen handling, direct access to {system calls}, {safe
+ pointers}, and {floating-point}.
+
+ ICI runs on {Microsoft Windows}, {MS-DOS}, {Unix}, and {Linux}
+ and in {embedded} environments.
+
+ {(http://zeta.org.au/~atrn/ici/)}.
+
+ {(ftp://ftp.research.canon.com.au/pub/misc/ici)}.
+
+ E-mail: Andy Newman <andy@research.canon.com.au>.
+
+ Mailing list: ici@research.canon.com.au.
+
+ (1999-12-07)
+
+ICL
+
+ {International Computers Limited}.
+
+ICMP
+
+ {Internet Control Message Protocol}
+
+ICMP Router Discovery Protocol
+
+ <protocol> (IRDP) A {routing} {protocol} used by {Microsoft
+ Windows} {DHCP} clients and various {Unix} flavors.
+
+ {Vulnerability
+ (http://securiteam.com/securitynews/Most_DHCP_clients_are_vulnerable_to_an_IRDP_attack.html)}.
+
+ [Details? Reference?]
+
+ (1999-10-31)
+
+I-Comm
+
+ <tool, web> A graphical {web browser}
+ for {IBM PCs} with a {window system} ({Windows 95}, {Windows
+ NT} or {OS/2}). I-Comm does NOT require a {SLIP} or {PPP}
+ connection, just a {modem}. It is available as a {shareware}
+ program.
+
+ Version: 1.15 Beta1.
+
+ {(http://talentcom.com/icomm/icomm.htm)}, {mirror
+ (http://best.com:80/~icomm/icomm/icomm.htm)}.
+
+ {FTP netcom.com (ftp://ftp.netcom.com/pub/ic/icomm/)},
+ {FTP best.com (ftp://ftp.best.com/pub/icomm/icomm/)}.
+
+ E-Mail: <icomm@talentcom.com>.
+
+ (1996-03-22)
+iCOMP
+
+ {Intel Comparative Microprocessor Performance index}
+
+Icon
+
+ <language> A descendant of {SNOBOL4} with {Pascal}-like
+ syntax, produced by Griswold in the 1970's. Icon is a
+ general-purpose language with special features for string
+ scanning. It has dynamic types: records, sets, lists,
+ strings, tables. If has some {object oriented} features but
+ no {modules} or {exceptions}. It has a primitive {Unix}
+ interface.
+
+ The central theme of Icon is the generator: when an expression
+ is evaluated it may be suspended and later resumed, producing
+ a result sequence of values until it fails. Resumption takes
+ place implicitly in two contexts: iteration which is
+ syntactically loop-like ('every-do'), and goal-directed
+ evaluation in which a conditional expression automatically
+ attempts to produce at least one result. Expressions that
+ fail are used in lieu of Booleans. Data {backtracking} is
+ supported by a reversible {assignment}. Icon also has
+ {co-expressions}, which can be explicitly resumed at any time.
+
+ Version 8.8 by Ralph Griswold <ralph@cs.arizona.edu> includes
+ an {interpreter}, a compiler (for some {platforms}) and a
+ library (v8.8). Icon has been ported to {Amiga}, {Atari},
+ {CMS}, {Macintosh}, {Macintosh/MPW}, {MS-DOS}, {MVS}, {OS/2},
+ {Unix}, {VMS}, {Acorn}.
+
+ See also {Ibpag2}.
+
+ {(ftp://cs.arizona.edu/icon/)}, {MS-DOS FTP
+ (ftp://bellcore.com norman/iconexe.zip)}.
+
+ {Usenet} newsgroup: {news:comp.lang.icon}.
+
+ E-mail: <icon-project@cs.arizona.edu>, <mengarini@delphi.com>.
+
+ Mailing list: icon-group@arizona.edu.
+
+ ["The Icon Programmming Language", Ralph E. Griswold and Madge
+ T. Griswold, Prentice Hall, seond edition, 1990].
+
+ ["The Implementation of the Icon Programmming Language", Ralph
+ E. Griswold and Madge T. Griswold, Princeton University Press
+ 1986].
+
+ (1992-08-21)
+
+icon
+
+ <graphics> A small picture intended to represent something (a
+ file, directory, or action) in a {graphical user interface}.
+ When an icon is clicked on, some action is performed such as
+ opening a directory or aborting a file transfer.
+
+ Icons are usually stored as {bitmap} images. {Microsoft
+ Windows} uses a special bitmap format with file name extension
+ ".ico" as well as embedding icons in executable (".exe") and
+ {Dynamically Linked Library} (DLL) files.
+
+ The term originates from {Alan Kay}'s theory for designing
+ interfaces which was primarily based on the work of Jerome
+ Bruner. Bruner's second developmental stage, iconic, uses a
+ system of representation that depends on visual or other
+ sensory organization and upon the use of summarising images.
+
+ {IEEE publication
+ (http://ieee.org/organizations/history_center/cht_papers/Barnes.pdf)}.
+
+ [What MS tool can create .ico files?]
+
+ (2003-08-01)
+
+Icon-Based Parser Generation System 2
+
+ <language> (Ibpag2) A {parser generator} for {Icon} by Richard
+ L. Goerwitz <goer@midway.uchicago.edu>. It can handle both
+ {SLR1 grammars} and even {GLR grammars} ({Tomita grammars}).
+ Ibpag2 runs under {Unix}.
+
+ Latest version: 1.0 (beta), as of 1993-07-13.
+
+ (2004-06-06)
+
+Iconicode
+
+ 1990-1992. Visual dataflow language, token-based with
+ hierarchical, recursive and iterative constructs. Version:
+ IDF with extensions for image processing.
+
+ ["IDF: A Graphical Data Flow Programming Language for Image
+ Processing and Computer Vision", Neil Hunt, Proc IEEE Conf on
+ Systems Man & Cybernetics, IEEE, Nov 1990. Available from
+ Iconicon <icon@teleos.com>].
+
+ICONIX Software Engineering, Inc.
+
+ <company> Makers of {ICONIX PowerTools}, software development
+ tools, and the first {CD-ROM} training course in
+ {object-oriented} methods. ICONIX started operating in 1984.
+
+ {(http://biap.com/iconix/)}.
+
+ Address: 2800 28th Street, Suite 320, Santa Monica, CA 90405,
+ USA. Telephone: +1 (310) 458 0092
+
+ (1995-04-30)
+
+IC-Prolog
+
+ Clark & McCabe, Imperial College 1979. Logic language with
+ coroutining.
+
+ ["IC-Prolog Language Features", K.L. Clark <klc@doc.ic.ac.uk>
+ et al in Logic Programming, K.L. Clark et al eds, pp.253-266,
+ Academic Press 1982].
+
+IC Prolog II
+
+ <language, Prolog> {Imperial College} Prolog. A {Prolog} with
+ {multi-threading}, {TCP} primitives for {interprocess
+ communication}, {mailboxes}, and an interface to {Parlog}.
+
+ {(ftp://doc.ic.ac.uk/computing/programming/languages)}.
+
+ ["IC Prolog II: A Language for Implementing Multi-Agent
+ Systems", Y. Cosmadopoulos et al, in Tutorial and Workshop on
+ Cooperating Knowledge Based Systems, Keele U 1992].
+
+ (1994-11-01)
+
+ICQ
+
+ <chat> 1. Abbreviation for "I seek you".
+
+ 2. A proprietary {chat} system created by a couple of israeli
+ guys, who later founded "mirabilis". ICQ was sold to {America
+ On-Line} around 1998.
+
+ The name "ICQ" is a play on "cq", the radio signal for seeking
+ conversation.
+
+ {(http://icq.com/)}.
+
+ [Confirm derivation? TCP? Summary?]
+
+ (2000-04-03)
+
+ICSI
+
+ {International Computer Science Institute} at Berkeley, CA.
+
+ICT
+
+ 1. <education> {Information and Communication Technology}.
+
+ 2. <testing> {In Circuit Test}.
+
+ (2000-04-04)
+
+ICW
+
+ {Interactive CourseWare}
+
+ICWS
+
+ International {Core War} Society.
+
+Id
+
+ {Irvine Dataflow}
+
+id
+
+ <networking> The {country code} for Indonesia.
+
+ (1999-01-27)
+
+I-D
+
+ {Internet-Draft}
+
+ID10T
+
+ <abuse> /I D ten T/ A grade of user problem somewhere between
+ {PEBCAK} and {UBD}. Considered friendlier than saying, "You
+ called me down here to exit a modal dialog box for you?"
+
+ (2003-06-07)
+
+IDAMS
+
+ A pictorial retrieval language implemented in {APL}.
+
+ ["Concept of the Diagnostic Image Workstation",
+ D. Meyer-Ebrecht, Proc 2nd Conf on Picture Archiving (PACS
+ II), SPIE 418, pp.180-183 (1983)].
+
+IDD
+
+ {international direct dialing}
+
+IDE
+
+ 1. <storage> Integrated Drive Electronics, see {Advanced
+ Technology Attachment}.
+
+ 2. <programming, tool> {integrated development environment}.
+
+ 3. <company> {Interactive Development Environments}.
+
+ (2002-04-14)
+
+IDEA
+
+ 1. <language> {Interactive Data Entry/Access}.
+
+ 2. <algorithm> {International Data Encryption Algorithm}.
+
+ (1996-02-16)
+
+IDEAL
+
+ 1. Ideal DEductive Applicative Language. A language by Pier
+ Bosco and Elio Giovannetti combining {Miranda} and {Prolog}.
+ Function definitions can have a {guard} condition (introduced
+ by ":-") which is a conjunction of equalities between
+ arbitrary terms, including functions. These guards are solved
+ by normal {Prolog} {resolution} and {unification}. It was
+ originally compiled into {C-Prolog} but was eventually to be
+ compiled to {K-leaf}.
+
+ 2. A numerical {constraint} language written by Van Wyk of
+ {Stanford} in 1980 for {typesetting} graphics in documents.
+ It was inspired partly by {Metafont} and is distributed as
+ part of {Troff}.
+
+ ["A High-Level Language for Specifying Pictures", C.J. Van
+ Wyk, ACM Trans Graphics 1(2):163-182 (Apr 1982)].
+
+ (1994-12-15)
+
+ideal
+
+ <theory> In {domain theory}, a non-empty, {downward closed}
+ subset which is also closed under binary {least upper bounds}.
+ I.e. anything less than an element is also an element and the
+ least upper bound of any two elements is also an element.
+
+ (1997-09-26)
+
+Idealized CSP
+
+ <language> A programming language combining simply typed,
+ {call-by-name} {procedures} with {asynchronous} communicating
+ processes, assuming fair parallel execution. Idealized CSP
+ generalises {Anthony Hoare}'s original {CSP} and Kahn's
+ networks of {deterministic} processes, and is closely related
+ to {Parallel Algol} by Stephen Brookes of {CMU}.
+
+ Procedures permit the encapsulation of common {protocols} and
+ parallel programming idioms. {Local variables} and local
+ channel declarations provide a way to delimit the scope of
+ interference between parallel agents, and allow a form of
+ concurrent {object-oriented programming}.
+
+ [Was this language also designed by Brookes?]
+
+ (1997-09-26)
+
+Idealized Instruction Set
+
+ <language> (IIS) The {assembly language} for the {Flagship}
+ parallel machine.
+
+ ["An Idealized Instruction Set for a Packet Rewrite Machine",
+ J. Sargeant, Manchester U, 1988].
+
+ (1994-11-07)
+
+IDEF
+
+ {ICAM} Definition.
+
+IDEF0
+
+ <modeling> A minor elaboration on {SADT}.
+
+ {IDEF Home (http://www.idef.com/idef0.html)}.
+
+ (2007-02-12)
+
+idempotent
+
+ 1. A function f : D -> D is idempotent if
+
+ f (f x) = f x for all x in D.
+
+ I.e. repeated applications have the same effect as one. This
+ can be extended to functions of more than one argument,
+ e.g. Boolean & has x & x = x. Any value in the {image} of an
+ idempotent function is a {fixed point} of the function.
+
+ 2. This term can be used to describe {C} header files, which
+ contain common definitions and declarations to be included by
+ several source files. If a header file is ever included twice
+ during the same compilation (perhaps due to nested #include
+ files), compilation errors can result unless the header file
+ has protected itself against multiple inclusion; a header file
+ so protected is said to be idempotent.
+
+ 3. The term can also be used to describe an initialisation
+ subroutine that is arranged to perform some critical action
+ exactly once, even if the routine is called several times.
+
+ [{Jargon File}]
+
+ (1995-01-11)
+
+identifier
+
+ 1. <programming, operating system> A formal name used in
+ {source code} to refer to a {variable}, {function},
+ {procedure}, {package}, etc. or in an {operating system} to
+ refer to a {process}, {user}, {group}, etc.
+
+ Each different type of entity may have a different range of
+ valid identifiers or "name space". For example, an identifier
+ in {C} is a series of one or more letters, digits and
+ {underscores} that does not begin with a digit. An identifier
+ has a type, e.g. integer variable, {hash}, {variant} and a
+ {scope}, e.g. {block}, {global}.
+
+ (2006-05-29)
+
+ 2. <database> (id) A {primary key}. The column containing a
+ table's primary key is frequently named after the table with
+ "_id" appended, e.g. "customer_id".
+
+ (2006-05-29)
+
+ideogram
+
+ <text, graphics> A {symbol} representing a concept. Nearly all
+ ideograms are {pictograms} - pictures of the thing represented,
+ others are merely conventional. An example of non-pictorial
+ ideogram might be the {degree} symbol (a superfix circle) when
+ used for temperature.
+
+ (2014-07-30)
+
+{IDF}
+
+ <networking> {Intermediate Distribution Frame}.
+
+I didn't change anything!
+
+ An aggrieved cry often heard as bugs manifest during a
+ regression test. The {canonical} reply to this assertion is
+ "Then it works just the same as it did before, doesn't it?"
+ See also {one-line fix}. This is also heard from applications
+ programmers trying to blame an obvious applications problem on
+ an unrelated systems software change, for example a
+ divide-by-0 fault after terminals were added to a network.
+ Usually, their statement is found to be false. Upon close
+ questioning, they will admit some major restructuring of the
+ program that shouldn't have broken anything, in their opinion,
+ but which actually {hosed} the code completely.
+
+ [{Jargon File}]
+
+idk
+
+ <chat> I don't know.
+
+ (2003-09-23)
+
+IDL
+
+ <language>
+
+ 1. {Interactive Data analysis Language} ({Xerox}).
+
+ 2. {Interface Description Language} (Snodgrass, UNC, Arizona).
+
+ 3. {Interface Definition Language} ({SunSoft}, {OMG}).
+
+ 4. {Interactive Data Language} ({Research Systems}).
+
+ (2004-05-07)
+
+IDMS
+
+ 1. <language, database> A pictorial {query language},
+ an extension of {Sequel2}.
+
+ ["A Management System for an Integrated Database of Pictures
+ and Alphanumeric Data", G.Y. Tang, Computer Graphics Image
+ Processing 16:270-286 (1981)].
+
+ 2. <database> {Integrated Database Management System}.
+
+ (2002-06-10)
+
+IDMSX
+
+ <database> {IDMS} extended.
+
+ (1995-04-19)
+
+Id Nouveau
+
+ A {dataflow} language by Arvind <arvind@lcs.mit.edu> and
+ R.S. Nikhil <nikhil@crl.dec.com>, {MIT} {LCS}, ca. 1986.
+
+ Id Nouveau began as a {functional language}, added {streams},
+ resource managers and {I-structures} ({mutable arrays}).
+ Loops are {syntactic sugar} for {tail recursion}.
+
+ See also {Id}.
+
+ ["Id Nouveau Reference Manual", R.S. Nikhil, CS TR, MIT,
+ March 1988].
+
+ ["Id (Version 90.1) Reference Manual", R.S. Nikhil, CSG Memo
+ 284-2, LCS MIT, July 15, 1991].
+
+IDOL
+
+ Icon-Derived Object Language. An {object-oriented}
+ {preprocessor} for {Icon}.
+
+ {(ftp://src.doc.ic.ac.uk/pub/languages/icon/idol.tar.Z)}.
+
+ ["Programming in Idol: An Object Primer", C.L. Jeffery, U
+ Arizona CS TR #90-10].
+
+IDS/I
+
+ Integrated Data Store. An extension to {COBOL} involving
+ "chains" (circular lists), for {General Electric} computers.
+
+ ["A General Purpose Programming System for Random Access
+ Memories", C.W. Bachman et al, Proc FJCC 26(1), AFIPS (Fall
+ 1964)].
+
+ [Sammet 1969, p. 376].
+
+IDSN
+
+ {ISDN}
+
+id Software
+
+ <games> Creators and publishers of the {DOOM} game for {IBM
+ PCs}.
+
+ E-mail: <help@idsoftware.com>. Telephone: +1 800-ID-GAMES
+ (Orders only).
+
+IDSS
+
+ {Intelligent Decision Support Systems}
+
+IE
+
+ {Internet Explorer}
+
+ie
+
+ <networking> The {country code} for Ireland.
+
+ (1999-01-27)
+
+IEC
+
+ {International Electrotechnical Commission}
+
+IEC 559
+
+ {IEEE Floating Point Standard}
+
+IEEE
+
+ {Institute of Electrical and Electronics Engineers}
+
+IEEE 1076
+
+ The {IEEE} standard for {VHDL}.
+
+IEEE 1394
+
+ {High Performance Serial Bus}
+
+IEEE 488
+
+ <hardware, standard> (GPIB, General-Purpose Interface Bus,
+ HP-IB, Hewlett-Packard Interface Bus) An 8-bit parallel {bus}
+ common on {test equipment}.
+
+ The IEEE-488 standard was proposed by {Hewlett-Packard} in the
+ late 1970s and has undergone a couple of revisions. HP
+ documentation (including data sheets and manuals) calls it
+ HP-IB, or Hewlett-Packard Interface Bus.
+
+ It allows up to 15 intelligent devices to share a single bus,
+ with the slowest device participating in the control and data
+ transfer handshakes to drive the speed of the transaction.
+ The maximum data rate is about one {megabit} per second.
+
+ Other standards committees have adopted HP-IB (American
+ Standards Institute with ANSI Standard MC 1.1 and
+ International Electro-technical Commission with IEC
+ Publication 625-1).
+
+ To paraphrase from the HP 1989 Test & Measurement Catalog (the
+ 50th Anniversary version): The HP-IB has a party-line
+ structure wherein all devices on the bus are connected in
+ parallel. The 16 signal lines within the passive
+ interconnecting HP-IB (IEEE-488) cable are grouped into three
+ clusters according to their functions (Data Bus, Data Byte
+ Transfer Control Bus, General Interface Management Bus).
+
+ In June 1987 the IEEE approved a new standard for programmable
+ instruments called IEEE Std. 488.2-1987 Codes, Formats,
+ Protocols, and Common Commands. It works with the IEEE
+ Standard Digital Interface for Programmable Instrumentation,
+ IEEE 488-1978 (now 488.1). HP-IB is Hewlett-Packard's
+ implementation of IEEE 488.1.
+
+ (1996-05-10)
+
+IEEE 754
+
+ {IEEE Floating Point Standard}
+
+IEEE 802
+
+ <networking, standard> The {IEEE} standards for {local area
+ networks}. The {spanning tree algorithm} is defined in {IEEE
+ 802.1} (under consideration), {Logical Link Control} (LLC, the
+ upper portion of the {data link layer}) in {IEEE 802.2},
+ {Ethernet} in {IEEE 802.3}, {Token Bus} in IEEE 802.4 and IBM
+ {Token Ring} in {IEEE 802.5}.
+
+ The equivalent {ISO} {standard} is IS 8802.
+
+ (1995-02-15)
+
+IEEE 802.1
+
+ <networking, standard> An {IEEE} working group concerned with
+ the {IEEE 802} family of {networking} {standards},
+ specifically {bridging} and {network management}.
+
+ The {spanning tree protocol} is standardised as 802.1D.
+
+ (2010-09-26)
+
+IEEE 802.2
+
+ (Networks) The {IEEE} standard defining {Logical Link Control}
+ (LLC, the upper portion of the {data link layer}) for {local
+ area networks}.
+
+ (1995-02-14)
+
+IEEE 802.3
+
+ <networking> The {IEEE} standard defining the {hardware layer}
+ and {transport layer} of (a varient of) {Ethernet}. The
+ maximum {segment} length is 500m and the maximum total length
+ is 2.5km. The maximum number of hosts is 1024.
+
+ The maximum {packet} size is 1518 bytes. If the upper layer
+ {protocol} submits a {PDU} less than 64 bytes, 802.3 will pad
+ the {LLC Info} field to achieve the minimum 64 bytes.
+
+ Although it is not technically correct, the terms "{packet}"
+ and frame are used interchangeably. The {ISO}/{IEC} 8802-3
+ {ANSI}/{IEEE} 802.3 Standards refer to {MAC} sub-layer
+ {frames} consisting of the Destination Address, Source
+ Address, Length, LLC Info., and {FCS} fields. The {Preamble}
+ and {SFD} are (usually) considered a header to the {MAC}
+ Frame. This header plus the MAC Frame constitute a "Packet".
+
+ (1995-07-09)
+
+IEEE 802.3u
+
+ <networking, standard> The {IEEE} committee working on
+ standards for {Fast Ethernet}.
+
+ (1998-06-30)
+
+IEEE 802.3z
+
+ <networking, standard> The {IEEE} committee working on
+ standards for {Gigabit Ethernet}.
+
+ (1998-06-30)
+
+IEEE 802.4
+
+ <networking, standard> The {IEEE} {Token Bus} {standard}.
+
+ (1996-12-12)
+
+IEEE 802.5
+
+ The {IEEE} {token ring} {standard}. The most common type of
+ token ring.
+
+ (1994-10-27)
+
+IEEE Computer Society
+
+ <body> The society of the {IEEE} which publishes the journal
+ "Computer".
+
+ {(http://computer.org/)}.
+
+ (1995-03-10)
+
+IEEE Floating Point Standard
+
+ <standard, mathematics> (IEEE 754) "{IEEE} Standard for Binary
+ {Floating-Point} Arithmetic (ANSI/IEEE Std 754-1985)" or {IEC}
+ 559: "Binary floating-point arithmetic for microprocessor
+ systems". A {standard}, used by many {CPUs} and {FPUs}, which
+ defines formats for representing floating-point numbers;
+ representations of special values (e.g. {infinity}, very small
+ values, {NaN}); five {exceptions}, when they occur, and what
+ happens when they do occur; four {rounding modes}; and a set
+ of floating-point operations that will work identically on any
+ conforming system.
+
+ IEEE 754 specifies formats for representing floating-point
+ values: single-precision (32-bit) is required,
+ double-precision (64-bit) is optional. The standard also
+ mentions that some implementations may include single-extended
+ precision (80-bit) and double-extended precision (128-bit)
+ formats.
+
+ [On-line document?]
+
+ (2003-06-17)
+
+IEEE Standard 1149.1
+
+ {Joint Test Action Group}
+
+IEF
+
+ {Advantage Gen}
+
+IEN
+
+ {Internet Experiment Note}
+
+IEPG
+
+ {Internet Engineering and Planning Group}
+
+IESG
+
+ {Internet Engineering Steering Group}
+
+IETF
+
+ {Internet Engineering Task Force}
+
+IF1
+
+ <language> A graph language used as an intermediate language
+ for {dataflow} hardware. Used by the {OSC} {SISAL} compiler.
+
+ ["The Manchester Prototype Dataflow Computer", J.R. Gurd et
+ al, CACM 28(1):34-52, Jan 1985].
+
+ (1996-01-05)
+
+IF2
+
+ <language> S graph language used by the {OSC} {SISAL}
+ compiler, a superset of {IF1}.
+
+ ["IF2: An Applicative Language Intermediate Form with Explicit
+ Memory Management", M. L. Welcome et al, UC-LLNL, Nov 1986].
+
+ (1996-01-05)
+
+IFAC
+
+ International Federation of Automatic Control, involved in
+ informatics related to control systems.
+
+IFC
+
+ {Internet Foundation Classes}
+
+ifdef out
+
+ /if'def owt/ v. Synonym for {condition out}, specific
+ to {C}.
+
+ [{Jargon File}]
+
+IFDL
+
+ <language> Independent Form Description Language.
+
+ {DEC}'s language for describing form-based human interfaces in
+ {DECforms}.
+
+ (1995-04-21)
+
+IFF
+
+ 1. <file format> {Interchange File Format}.
+
+ 2. Identify friend or foe (radar).
+
+iff
+
+ <mathematics, logic> if and only if, i.e. necessary and
+ sufficient. For example, two figures are {congruent} iff one
+ can be placed over the other so that they coincide.
+
+ (2002-12-28)
+
+IFIP
+
+ 1. {International Federation for Information Processing}.
+
+ 2. A subset of {ALGOL}.
+
+ [Sammet 1969, p. 180].
+
+IFP
+
+ {Illinois Functional Programming}
+
+IFS
+
+ 1. <operating system> {internal field separators}.
+
+ 2. <operating system> {Installable File System}.
+
+ 3. <graphics> {Iterated Function System}.
+
+ (1999-04-07)
+
+IFX
+
+ ["Type Reconstruction with First-Class Polymorphic Values",
+ J. O'Toole et al, SIGPLAN Notices 24(7):207-217 (Jul 1989)].
+
+If you want X, you know where to find it.
+
+ <exclamation> There is a legend that {Dennis Ritchie},
+ inventor of {C}, once responded to demands for features
+ resembling those of what at the time was a much more popular
+ language by observing "If you want {PL/I}, you know where to
+ find it." Ever since, this has been hackish standard form for
+ fending off requests to alter a new design to mimic some older
+ (and, by implication, inferior and {baroque}) one. The case X
+ = {Pascal} manifests semi-regularly on {Usenet}'s
+ {news:comp.lang.c} {newsgroup}. Indeed, the case X = X has
+ been reported in discussions of graphics software (see {X
+ Window System}).
+
+ [{Jargon File}]
+
+ (1995-10-25)
+
+IGC
+
+ {Institute for Global Communications}
+
+IGES
+
+ Initial Graphics Exchange Specification: an ASME/ANSI standard
+ for the exchange of CAD data.
+
+IGL
+
+ Interactive Graphic Language. Used primarily by Physics Dept
+ at Brooklyn Poly, uses numerical methods on vectors to
+ approximate continuous function problems that don't have
+ closed form solutions.
+
+ [Is this being confused with Tektronix's graphics library by
+ the same name?]
+
+IGMP
+
+ {Internet Group Management Protocol}
+
+IGP
+
+ {Interior Gateway Protocol}
+
+IGPL
+
+ {Interest Group in Pure and Applied Logics}
+
+IGS
+
+ {Internet Go Server}.
+
+IGU
+
+ <chat> I Give Up. Often found appended to documents, e-mail,
+ programs that don't work, etc.
+
+ (1999-09-30)
+
+IHS
+
+ {Integrated Home System}
+
+IHV
+
+ {Independent Hardware Vendor}
+
+IIcx
+
+ {Apple IIcx}
+
+IIDMS/R
+
+ {Integrated database management system}
+
+IIL
+
+ {Integrated Injection Logic}
+
+IINREN
+
+ {Interagency Interim National Research and Education Network}
+
+IIOP
+
+ {Internet Inter-ORB Protocol}
+
+IIR
+
+ {Infinite Impulse Response}
+
+IIRC
+
+ <chat> If I recall/remember correctly.
+
+ (1996-11-28)
+
+IIS
+
+ 1. <web> {Internet Information Server}.
+
+ 2. <language> {Idealized Instruction Set}.
+
+ (1999-08-26)
+
+IIT
+
+ {Integrated Information Technology}
+
+IITF
+
+ {Information Infrastructure Task Force}
+
+IITRAN
+
+ Simple PL/I-like language for students, on IBM 360.
+
+ ["The IITRAN Programming Language", R. Dewar et al, CACM
+ 12(10):569-575 (Oct 1969)].
+
+il
+
+ <networking> The {country code} for Israel.
+
+ (1999-01-27)
+
+ILBM
+
+ {interleaved bit-map}
+
+ILF
+
+ {Independent Logical File}
+
+ILIAD
+
+ <language, real-time> A {real-time} language.
+
+ ["On the Design of a Language for Programming Real-Time
+ Concurrent Processes", H.A. Schutz, IEEE Trans Soft Eng
+ SE-5(3):248-255, May 1979].
+
+ (2000-09-03)
+
+I-Link
+
+ {High Performance Serial Bus}
+
+ILISP
+
+ A somewhat {LISP Machine}-like interface to {lisp listeners}
+ from {Emacs}.
+
+ Version 5.0 Emacs interface by ? Ivan Vazquez
+ <ivan@haldane.bu.edu>.
+
+ {(ftp://haldane.bu.edu/)} (128.197.54.25). E-mail:
+ <ilisp-bug@darwin.bu.edu>, <ilisp-bugs@darwin.bu.edu>,
+ <ilisp-request@darwin.bu.edu> (discussion).
+
+ (1993-06-28)
+
+ill-behaved
+
+ 1. [numerical analysis] Said of an {algorithm} or
+ computational method that tends to blow up because of
+ accumulated roundoff error or poor convergence properties.
+
+ 2. Software that bypasses the defined {operating system}
+ interfaces to do things (like screen, keyboard, and disk I/O)
+ itself, often in a way that depends on the hardware of the
+ machine it is running on or which is nonportable or
+ incompatible with other pieces of software.
+
+ In the {IBM PC}/{mess-dos} world, there is a folk theorem
+ (nearly true) to the effect that (owing to gross inadequacies
+ and performance penalties in the OS interface) all interesting
+ applications are ill-behaved.
+
+ See also {bare metal}. Opposite: {well-behaved}, compare
+ {PC-ism}.
+
+ [{Jargon File}]
+
+ILLIAC
+
+ Assembly language for the ILLIAC computer. Listed in CACM
+ 2(5):16, (May 1959) p.16.
+
+Illiac IV
+
+ <computer> One of the most infamous {supercomputers} ever. It
+ used early ideas on {SIMD} (single instruction stream,
+ multiple data streams). The project started in 1965, it used
+ 64 processors and a 13MHz clock. In 1976 it ran its first
+ sucessfull application. It had 1MB memory (64x16KB).
+
+ Its actual performance was 15 MFLOPS, it was estimated in
+ initial predictions to be 1000 MFLOPS. It totally failed as a
+ computer, only a quarter of the fully planned machine was ever
+ built, costs escalated from the $8 million estimated in 1966
+ to $31 million by 1972, and the computer took three more years
+ of enginering before it was operational.
+
+ The only good it did was to push research forward a bit,
+ leading way for machines such as the {Thinking Machines}
+ {CM-1} and CM-2.
+
+ (1995-04-28)
+
+Illinois Functional Programming
+
+ <language> (IFP) An {interpreter} written in {portable} {C} by
+ Arch D. Robison for a variant of {Backus}'s {FP} with syntax
+ like {ALGOL} or {Modula-2}. IFP Runs under {Unix}, {CTSS}
+ ({Cray}) and {MS-DOS}.
+
+ Version: 0.5.
+
+ {(ftp://a.cs.uiuc.edu/pub/ifp)}. Posted to comp.sources.unix
+ volume 10.
+
+ ["The Illinois Functional Programming Interpreter",
+ A.D. Robison, Proc 1987 SIGPLAN Conf on Interpreters and
+ Interpretive Techniques (June 1987), pp. 64-73].
+
+ ["Illinois Functional Programming: A Tutorial", A.D. Robison,
+ BYTE Feb 1987, pp. 115-125].
+
+ (1994-10-24)
+
+ILOC
+
+ Rice U. Register-oriented intermediate language targeted to
+ PC/RT. Source languages include {Fortran} and {Russell}.
+
+Ilog Solver
+
+ A commercial {constraint} programming system.
+
+ (1994-11-15)
+
+iMac
+
+ <computer> One of the trademark/brand names that {Apple Inc}
+ use for their {Mac} family of {personal computers}.
+
+ (2009-05-05)
+
+image
+
+ 1. <data, graphics> Data representing a two-dimensional scene.
+ A digital image is composed of {pixels} arranged in a
+ rectangular array with a certain height and width. Each pixel
+ may consist of one or more {bits} of information, representing
+ the brightness of the image at that point and possibly
+ including colour information encoded as {RGB} triples.
+
+ {Images} are usually taken from the real world via a {digital
+ camera}, {frame grabber}, or {scanner}; or they may be
+ generated by computer, e.g. by {ray tracing} software.
+
+ See also {image formats}, {image processing}.
+
+ (1994-10-21)
+
+ 2. <mathematics> The image (or range) of a {function} is the
+ set of values obtained by applying the function to all
+ elements of its {domain}. So, if f : D -> C then the set f(D)
+ = \{ f(d) | d in D \} is the image of D under f. The image is
+ a subset of C, the {codomain}.
+
+ (2000-01-19)
+
+image formats
+
+ <graphics, file format> There are many formats used to store
+ {images} in files. {GIF}, {TIFF} and {JPEG} are very common.
+ Others are {BIFF}, {bmp}, {Clear}, {FITS}, {IFF}, {NFF},
+ {OFF}, {PCX}, {PNG}, {TGA}, {XBM}.
+
+ Some of these are documented on-line at the following sites:
+
+ {The Graphics File Format Page
+ (http://dcs.ed.ac.uk/~mxr/gfx/)}.
+ {The NCSA file formats archive
+ (ftp://ftp.ncsa.uiuc.edu/misc/file.formats/graphics.formats)}.
+ {The Avalon repository
+ (ftp://avalon.viewpoint.com/pub/format_specs)}.
+
+ [Others?]
+
+ (1997-08-07)
+
+image map
+
+ <web> An image in an {HTML} document with "hot
+ spots" which when clicked on in a suitable {browser}, act as
+ {anchors} or links to other information. For example, an
+ image of a map of the world might provide links to resources
+ related to different countries. Clicking on a country would
+ take the user to the relevant information.
+
+ [Documentation URL?]
+
+ (1995-12-05)
+
+image processing
+
+ <graphics> Computer manipulation of {images}. Some of the
+ many {algorithms} used in image processing include
+ {convolution} (on which many others are based), {FFT}, {DCT},
+ {thinning} (or {skeletonisation}), {edge detection} and
+ {contrast enhancement}. These are usually implemented in
+ {software} but may also use special purpose {hardware} for
+ speed.
+
+ Image processing contrasts with {computer graphics}, which is
+ usually more concerned with the generation of artificial
+ images, and {visualisation}, which attempts to understand
+ (real-world) data by displaying it as an artificial image
+ (e.g. a graph). Image processing is used in {image
+ recognition} and {computer vision}.
+
+ {Silicon Graphics} manufacture {workstations} which are often
+ used for image processing. There are a few programming
+ languages designed for image processing, e.g. {CELIP}, {VPL}.
+
+ See also {Pilot European Image Processing Archive}.
+
+ {Usenet} newsgroup: {news:sci.image.processing}.
+
+ [Other algorithms, languages? FAQ?]
+
+ (1995-04-12)
+
+image recognition
+
+ <graphics, artificial intelligence> The identification of
+ objects in an {image}. This process would probably start with
+ {image processing} techniques such as {noise removal},
+ followed by (low-level) {feature extraction} to locate lines,
+ regions and possibly areas with certain textures.
+
+ The clever bit is to interpret collections of these shapes as
+ single objects, e.g. cars on a road, boxes on a conveyor belt
+ or cancerous cells on a microscope slide. One reason this is
+ an {AI} problem is that an object can appear very different
+ when viewed from different angles or under different lighting.
+ Another problem is deciding what features belong to what
+ object and which are background or shadows etc. The human
+ visual system performs these tasks mostly unconsciously but a
+ computer requires skillful programming and lots of processing
+ power to approach human performance.
+
+ (1997-07-20)
+
+imaging
+
+ <graphics> The production of graphic {images}, either from a
+ video camera or from digitally generated data (see
+ {visualisation}), or the recording of such images on
+ microfilm, videotape or laser disk.
+
+ See also {scanner}.
+
+ (1997-07-20)
+
+Imago Europe plc
+
+ A UK {Internet} provider. There sevice is called {Imago
+ On-line}. E-mail: <info@imago.com>.
+
+Imago On-line
+
+ An {Internet} {electronic mail} and {news} service in the
+ United Kingdom provided by {Imago Europe} plc.
+
+ A one year subscription to the service costs just seventy five
+ pounds plus VAT and offers {dial-up} access with a {graphical
+ user interface} for users of {Macintosh} and {Microsoft
+ Windows} {PCs} and the {Apple Newton} {MessagePad} {PDA}
+ family.
+
+imake
+
+ A tool which generates {Makefiles} from a template, a set of
+ {cpp} {macros}, and a per-directory input file called an
+ Imakefile. This allows machine dependencies (such has
+ compiler options, alternate command names, and special make
+ rules) to be kept separate from the descriptions of the
+ various items to be built.
+
+ imake is distributed with, and used extensively by, the {X
+ Window System}.
+
+ (1995-02-21)
+
+IMAO
+
+ {IMHO}
+
+IMAP
+
+ {Internet Message Access Protocol}
+
+imc
+
+ <language> A {REXX} {interpreter} for {SunOS}.
+
+ Current version 1.3 [?].
+
+ {(ftp://rexx.uwaterloo.ca/pub/freerexx/imc/)}.
+
+ (2000-11-07)
+
+IMD
+
+ {intermodulation distortion}
+
+IMHO
+
+ <chat> (From SF fandom via {Usenet}) In My Humble Opinion.
+ Also seen in variant forms such as IMO, IMNSHO (In My
+ Not-So-Humble Opinion) and IMAO (In My Arrogant Opinion).
+
+ [{Jargon File}]
+
+ (1998-09-24)
+
+IML
+
+ {Initial Microprogram Load}
+
+immediate version
+
+ {child version}
+
+Imminent Death Of The Net Predicted!
+
+ <messaging> Since {Usenet} first got off the ground in
+ 1980-81, it has grown exponentially, approximately doubling in
+ size every year. On the other hand, most people feel the
+ {signal-to-noise ratio} of {Usenet} has dropped steadily.
+ These trends led, as far back as mid-1983, to predictions of
+ the imminent collapse (or death) of the net. Ten years and
+ numerous doublings later, enough of these gloomy
+ prognostications have been confounded that the phrase
+ "Imminent Death Of The Net Predicted!" has become a running
+ joke, hauled out any time someone grumbles about the {S/N
+ ratio} or the huge and steadily increasing volume, or the
+ possible loss of a key node or link, or the potential for
+ lawsuits when ignoramuses post copyrighted material etc.
+
+ [{Jargon File}]
+
+ (1998-09-24)
+
+IMNSHO
+
+ {IMHO}
+
+IMO
+
+ {IMHO}
+
+IMP
+
+ 1. <language> {IMProved Mercury autocode}.
+
+ 2. <language> An extensible dialect of {ALGOL 60}, for {CDC
+ 1604}.
+
+ ["Experience with an Extensible Language", Edgar T. Irons,
+ CACM 13(1):31-39, Jan 1970].
+
+ 3. <language> {Interpretive Menu Processor}.
+
+ 4. <language> {IMPlementation language}.
+
+ 5. <networking> {Interface Message Processor}.
+
+ (1996-04-07)
+
+impact printer
+
+ <printer> The earlier, noisier kind of {printer} where part of
+ the mechanism comes into contact with the paper. The term
+ would only be only used in contrast to "{non-impact printer}".
+ Examples include {line printer}, {daisy wheel printer}, {golf
+ ball printer}, {dot matrix printer}, {Braille printer}.
+
+ (1998-10-13)
+
+impedance
+
+ <electronics, physics> Opposition to flow of alternating
+ current. Impedance consists of {resistance} plus {reactance}
+ (capacitive or inductive). Measured in {Ohms}.
+
+ (2003-12-02)
+
+imperative
+
+ {imperative language}
+
+imperative language
+
+ <language> Any {programming language} that specifies explicit
+ manipulation of the state of the computer system, not to be
+ confused with a {procedural language}, which specifies an
+ explicit sequence of steps to perform.
+
+ An example of an imperative (but non-procedural) language is a
+ {data manipulation language} for a {relational database
+ management system}. This specifies changes to the database
+ but does not necessarily require anyone to specify a sequence
+ of steps.
+
+ Both contrast with {declarative languages}, which specify
+ neither explicit state manipulation nor a sequence of steps.
+
+ (2007-10-02)
+
+imperative programming
+
+ {imperative language}
+
+Imperial College of Science, Technology and Medicine
+
+ <education> (IC, ICST&M) One of the colleges of London
+ University. The Department of Computing is the home of
+ {FOLDOC}.
+
+ {IC Home (http://ic.ac.uk/)}.
+
+ (2005-05-09)
+
+Imperial Software Technology
+
+ <company> A {software engineering} company which emerged from
+ {Imperial College} in about 1982. It enjoys a world-wide
+ reputation for technical excellence as a software product and
+ technology provider in the Open Systems market. Its flagship
+ product is {X-Designer}, the award-winning {graphical user
+ interface builder}. It also has considerable expertise in the
+ {Z} language and {Formal Methods}.
+
+ {(http://ist.co.uk/)}.
+
+ (1995-11-23)
+
+IMPlementation language
+
+ <language> (IMP) An extension of {B} with {floating-point}
+ operations, developed by W. Davidsen at {General Electric} in
+ 1970 for the {GE 600}. It was also {cross-compiled} to {VAX}
+ and {Intel 8080}.
+
+ (1996-04-07)
+
+implication
+
+ {implies}
+
+implicit parallelism
+
+ <parallel> A feature of a programming language for a {parallel
+ processing} system which decides automatically which parts to
+ run in parallel.
+
+ The best way of providing implicit parallelism is still (1995)
+ an active research topic. The problem is to generate the
+ right number of parallel tasks of the right size (or
+ "{granularity}"). Too many tasks and the system gets bogged
+ down in house-keeping, or memory for waiting tasks runs out,
+ too few tasks and processors are left idle.
+
+ The best performance is usually achieved with {explicit
+ parallelism} where the programmer can annotate his program to
+ indicate which parts should be executed as independent
+ parallel tasks.
+
+ (1995-02-16)
+
+implicit type conversion
+
+ <programming> (Or "coercion") The abilty of some {compilers}
+ to automatically insert {type} conversion {functions} where an
+ expression of one type is used in a context where another type
+ is expected.
+
+ A common example is coercion of {integers} to {reals} so that
+ an expression like sin(1) is compiled as sin(integerToReal(1))
+ where sin is of type Real -> Real.
+
+ A coercion is usually performed automatically by the compiler
+ whereas a {cast} is an {explicit type conversion} inserted by
+ the programmer.
+
+ See also {subtype}.
+
+ (1997-07-28)
+
+implies
+
+ <logic> (=> or a thin right arrow) A binary {Boolean} function
+ and {logical connective}. A => B is a true implication unless
+ A is true and B is false. The {truth table} is
+
+ A B | A => B
+ ----+-------
+ F F | T
+ F T | T
+ T F | F
+ T T | T
+
+ It is surprising at first that A => B is always true if A is
+ false, but if X => Y then we would expect that (X & Z) => Y
+ for any Z.
+
+ If A is actually an expression X & Y then the implication is
+ called a {syllogism}.
+
+ (2009-10-28)
+
+imply
+
+ {implies}
+
+import
+
+ <data> To read data that is not in the native format of the
+ application. For example, a {web browser} will have its own
+ way of storing {bookmarks} but it will usually provide a
+ function to import bookmarks from {Internet Explorer}. The
+ alternative is to provide an independent external conversion
+ utility but this is usually less convenient for the user.
+
+ (2004-11-15)
+
+imprecise probability
+
+ <probability> A {probability} that is represented as an
+ interval (as opposed to a single number) included in [0,1].
+
+ (2001-02-21)
+
+IMProved Mercury autocode
+
+ <language> (IMP) A version of {Autocode} used to program the
+ {Edinburgh Multi Access System} (EMAS), one of the first
+ {operating systems} written in a {high-level language},
+ apparently predating {Unix}.
+
+ Luis Damas' {Prolog} {interpreter} in IMP for EMAS led to
+ {C-Prolog}.
+
+ [Papers in J. {British Computer Society}].
+
+ (1996-04-07)
+
+IMR
+
+ {Internet Monthly Report}
+
+IMS
+
+ {Information Management System}
+
+IMS 6100
+
+ {Intersil 6100}
+
+Imsai
+
+ <company> One of the companies that made very early
+ {microprocessor} systems.
+
+ [Where? When? Who? What?]
+
+ (1995-05-12)
+
+IMS/Data Base
+
+ <database> (IMS/DB) A hierarchical high performance {database}
+ for {IBM} {mainframes}, part of {IMS}. IMS/DB is implemented
+ on top of {VSAM} and uses its underlying data structures.
+
+ (1999-01-11)
+
+IMS/Data Communications
+
+ <database> (IMS/DC) The {teleprocessing monitor}/{transaction
+ processing} sytem in {IMS} from {IBM}.
+
+ (1999-01-11)
+
+IMSE
+
+ {Integrated Modelling Support Environment}
+
+IMTC
+
+ {International Multimedia Teleconferencing Consortium}
+
+in
+
+ 1. <networking> The {country code} for India.
+
+ (1999-01-27)
+
+ 2. The typical type or "mode" of {function} {parameter} that
+ passes information in one direction - from the caller to the
+ function. Other modes are {out} and {inout}.
+
+ (2010-01-19)
+
+Ina Jo
+
+ <specification, language> [FDM?]
+
+ ["The Ina Jo Specification Language Reference Manual", J.
+ Scheid et al, TR TM-(L)-6021/001/00, SDC Mar 1985].
+
+ (2000-02-24)
+
+InARP
+
+ {Inverse Address Resolution Protocol}
+
+in-band signaling
+
+ {in-band signalling}
+
+in-band signalling
+
+ <communications> (Or CAS, channel associated signaling)
+ Transmission of control signals in the same channel as data.
+ This is commonly used in the {Public Switched Telephone
+ Network} where the same pair of wires carry both voice and
+ control signals (e.g. dialling, ringing). Another example is
+ the use on a computer {serial line} of Control-S and Control-Q
+ characters for {flow control} as opposed to {hardware flow
+ control} which would be out-of-band signalling.
+
+ In digital communications, in-band signalling often uses
+ "bit-robbing" where, for example, one {bit} in each {frame} is
+ used for signalling instead of data. This is the reason why a
+ {D1} channel in the T-carrier system can only carry 56 Kbps of
+ usable data instead of the 64 Kbps carried by the {D0} channel
+ in the E-carrier system.
+
+ (2007-01-26)
+
+inc
+
+ /ink/ increment, i.e. increase by one. Especially used by
+ {assembly} programmers, as many assembly languages have an
+ "inc" {mnemonic}.
+
+ Antonym: {dec}.
+
+ [{Jargon File}]
+
+incantation
+
+ Any particularly arbitrary or obscure command that one must
+ mutter at a system to attain a desired result. Not used of
+ passwords or other explicit security features. Especially
+ used of tricks that are so poorly documented that they must be
+ learned from a {wizard}. "This compiler normally locates
+ initialised data in the data segment, but if you {mutter} the
+ right incantation they will be forced into text space."
+
+include
+
+ [{Usenet}] 1. To duplicate a portion (or whole) of another's
+ message (typically with attribution to the source) in a reply
+ or followup, for clarifying the context of one's response.
+ See the discussion of inclusion styles under "Hacker Writing
+ Style".
+
+ 2. [{C}] "#include <disclaimer.h>" has appeared in {sig
+ blocks} to refer to a notional "standard {disclaimer} file".
+
+ [{Jargon File}]
+
+include war
+
+ Excessive multi-leveled including within a discussion
+ {thread}, a practice that tends to annoy readers. In a forum
+ with high-traffic newsgroups, such as {Usenet}, this can lead
+ to {flames} and the urge to start a {kill file}.
+
+inclusive
+
+ <theory> In {domain theory}, a {predicate} P : D -> Bool is
+ inclusive iff
+
+ For any {chain} C, a subset of D, and
+ for all c in C,
+ P(c) => P(lub C)
+
+ In other words, if the predicate holds for all elements of an
+ increasing sequence then it holds for their {least upper
+ bound}.
+
+ ("lub is written in {LaTeX} as {\sqcup}).
+
+ (1995-02-03)
+
+incomparable
+
+ <mathematics> Two elements a, b of a set are incomparable
+ under some relation <= if neither a <= b, nor b <= a.
+
+ (1995-09-21)
+
+incremental analysis
+
+ <testing> Partial analysis of an incomplete product to allow
+ early feedback on its development.
+
+ (1996-05-22)
+
+incremental backup
+
+ <operating system> A kind of {backup} that copies all files
+ which have changed since the date of the previous backup. The
+ first backup of a file system should include all files - a
+ "{full backup}". Call this level 0. The next backup could
+ also be a full level 0 backup but it is usually much quicker
+ to do a level 1 backup which will include only those files
+ which have changed since the level 0 backup. Together the
+ level 0 and level 1 backups will include the latest version of
+ every file. Level 1 backups can be made until, say, the
+ backup tape is nearly full, after which we can switch to level
+ 2. Each level includes those files which have changed since
+ the last backup at a lower level. The more levels you use,
+ the longer it will take to restore the latest version of a
+ file (or all files) if you don't know when it was last
+ modified.
+
+ Compare {differential backup}.
+
+ (2004-03-01)
+
+incremental constraint solver
+
+ A system in which a {constraint solver} is given {constraints}
+ one at a time by an {inference engine} (as is found in
+ {Prolog}). The solver adds the new constraint to an initially
+ empty set of solved constraints. If the new constraint is
+ consistent with the solved constraints it will be added to the
+ set. If it was inconsistent, the inference engine
+ {backtracks}. This is the basis of {Constraint Logic
+ Programming}.
+
+ (1994-11-01)
+
+Incremental Prototyping Technology for Embedded Realtime Systems
+
+ <project> An {Esprit} project.
+
+ [Partners? Results?]
+
+ (1998-11-27)
+
+[incr Tcl]
+
+ <language> An extension of {Tcl} that adds {classes} and
+ {inheritence}.
+
+ The name is a pun on {C++} - an {object-oriented} extension of
+ {C} - [incr variable] is the Tcl {syntax} for adding one to a
+ variable.
+
+ [Origin? Availability?]
+
+ (1998-11-27)
+
+indent
+
+ {indentation}
+
+indentation
+
+ <document, text, programming> Space and/or {tab} characters
+ added at the beginning of one or more consecutive lines to
+ indicate the structure of a piece of text, e.g. indenting a
+ passage to make it stand out.
+
+ Indentation is important in {source code} for readability.
+ See {indent style}. Some programming languages go further and
+ use indentation as the main method to represent block
+ structure to the {compiler} or {interpreter}, see {off-side
+ rule}.
+
+ (2008-10-23)
+
+indent style
+
+ <programming> Rules for formatting {code} to make it easier to
+ visually match up the beginning and end of a {block} of
+ statements, particularly one controlled by a {control
+ statement} such as "if", "else", "for", "while", "do". This
+ becomes important with large, nested blocks of code.
+
+ The {C} programming language's four indent styles vary in the
+ placement of "{" and "}" with respect to the statement(s) they
+ enclose and the controlling statement.
+
+ "Allman style" is named after {Eric Allman}, a {Berkeley} {hacker}
+ who wrote many {BSD} {utilities} in it. It is sometimes called
+ "BSD style". It resembles normal indent style in {Pascal} and
+ {ALGOL}. Basic indent per level is eight or four spaces. This is
+ the only indent style to clearly associate the controlling
+ statement and the beginning and the end of the block by aligning
+ them vertically, which probably explains its widespread adoption.
+
+ if (cond)
+ {
+ <body>
+ }
+
+ "K&R style" is named after {Kernighan} & {Ritchie} because the
+ examples in {K&R} are formatted this way. It is also called
+ "kernel style" because the {Unix} {kernel} was written in it, or
+ "{One True Brace Style}" (1TBS) by its partisans, or {Egyptian
+ brackets}. The basic indent shown here is eight spaces (or one
+ tab) per level; four spaces are much less common. This style was
+ popular when programmers worked on small displays (or paper!)
+ becuase it saves vertical space but the opening brace is easy to
+ miss at the end of a long condition in an "if" or "while"
+ statement.
+
+ if (cond) {
+ <body>
+ }
+
+ "Whitesmiths style" - popularised by the examples that came
+ with {Whitesmiths C}, an early commercial C compiler. Basic
+ indent per level shown here is eight spaces, but four spaces
+ are occasionally seen.
+
+ if (cond)
+ {
+ <body>
+ }
+
+ "GNU style" - Used throughout {GNU} {Emacs} and the {Free
+ Software Foundation} code, and just about nowhere else.
+ Indents are always four spaces per level, with "{" and "}"
+ halfway between the outer and inner indent levels.
+
+ if (cond)
+ {
+ <body>
+ }
+
+ Many related languages such as {Perl} offer the same choices while
+ others, following {B}, eschew braces and rely entirely on relative
+ indentation to express block structure. In {Python}, braces can
+ be used to override indentation.
+
+ [{Jargon File}]
+
+ (2013-05-14)
+
+Independent Computing Architecture
+
+ <protocol> (ICA) {Citrix}'s {proprietary} {protocol} that
+ allows {client} {desktop computers} to run {applications} on
+ {application servers}. Originally used between {Windows}
+ systems, ICA is now also suported on {Unix} and {Macintosh}
+ desktops and servers as well as some {thin client} hardware.
+
+ (2012-07-08)
+
+Independent Logical File
+
+ <database> (ILF) One kind of {dynamic database management
+ system}.
+
+ Examples of ILF databases are {INQUIRE}, {ADABAS}, {NOMAD},
+ {FOCUS} and {DATACOM}.
+
+ [More details?]
+
+ (1998-10-07)
+
+Independent Verification and Validation
+
+ <testing> (IV&V) The verification and validation of a software
+ product by an organisation that is both technically and
+ managerially separate from the organisation responsible for
+ developing the product.
+
+ (1996-12-27)
+
+index
+
+ (Plural "indices" or "indexes")
+
+ 1. <programming> A number used to select an element of a list,
+ vector, {array} or other sequence. Such indices are nearly
+ always non-negative integers but see {associative array}.
+
+ 2. <database> See {inverted index}. [Other kinds?]
+
+ 3. <web> A {search engine}.
+
+ 4. <web> A {subject index}.
+
+ [{Jargon File}]
+
+ (1997-04-09)
+
+Index Data
+
+ <company> A Danish company who have released a lot of {ANSI
+ Z39.50} related source under {GPL}.
+
+ {(http://130.228.5.168)}.
+
+ (1996-07-22)
+
+Indexed Sequential Access Method
+
+ <database> (ISAM) An {IBM} file management system allowing
+ records to be accessed either sequentially (in the order they
+ were entered) or via an index. Each index orders the records
+ on a different key.
+
+ ISAM was followed by VSAM ({Virtual Storage Access Method})
+ and pre-dated {relational databases}.
+
+ (2003-07-13)
+
+index.htm
+
+ {index.html}
+
+index.html
+
+ <web> The default {HTML} page served by most {web
+ servers} in response to a request for a {directory}. The name
+ suggests that the page will contain some kind of index of the
+ contents of the requested directory.
+
+ For example, if the content for {website} example.com is stored
+ in the {file system} in directory /var/www/example.com, then a
+ request for http://example.com/products would return the contents
+ of file /var/www/example.com/products/index.html.
+
+ A {website}'s {home page} follows the same logic. For the above
+ example, a request for http://example.com/ would return the
+ contents of /var/www/example.com/index.html.
+
+ It is often possible, and occasionally necessary, to specify
+ index.html explicitly in the URL, as in
+ http://example.com/index.html, though modern practice is to omit
+ it.
+
+ If you're looking for {FOLDOC's home page (/)} at
+ http://foldoc.org/index.html, then you followed an out-of-date
+ link. Please update your bookmark to http://foldoc.org/ or inform
+ the owner of the site you came from.
+
+ {Microsoft}, of course, has to be different and uses default.htm
+ instead of index.html. The variant index.htm is a throw-back to
+ the days when some file systems only allowed three-character file
+ name extensions.
+
+ (2014-06-22)
+
+index register
+
+ <processor> A {register} found in some {CPUs}, whose contents
+ can be added to the address {operand} to give the {effective
+ address}. Incrementing the index register then allows the
+ program to access the next location in memory and so on,
+ making it very useful for working with {arrays} or blocks of
+ memory.
+
+ Index registers first appeared around April 1949 in the
+ {Manchester Mark I}. The Mark I's index register's contents
+ were simply added to the entire instruction, thus potentially
+ changing the {opcode} (see {The story of Mel})!
+
+ (2006-09-20)
+
+indices
+
+ <spelling> A plural of "{index}".
+
+indirect address
+
+ <processor> An {addressing mode} found in many processors'
+ {instruction sets} where the instruction contains the address
+ of a memory location which contains the address of the operand
+ (the "{effective address}") or specifies a {register} which
+ contains the effective address. In the first case
+ (indirection via memory), accessing the operand requires two
+ memory accesses - one to fetch the effective address and
+ another to read or write the actual operand. Register
+ indirect addressing requires only one memory access.
+
+ An indirect address may be indicated in {assembly language} by
+ an operand in parentheses, e.g. in {Motorola 68000} assembly
+
+ MOV D0,(A0)
+
+ writes the contents of register D0 to the location pointed to
+ by the address in register A0.
+
+ Indirect addressing is often combined with pre- or post-
+ increment or decrement addressing, allowing the address of the
+ operand to be increased or decreased by one (or some specified
+ number) either before or after using it.
+
+ (1994-11-07)
+
+indirect addressing
+
+ {indirect address}
+
+indirection
+
+ <programming> Manipulating data via its address. Indirection
+ is a powerful and general programming technique. It can be
+ used for example to process data stored in a sequence of
+ consecutive memory locations by maintaining a {pointer} to the
+ current item and incrementing it to point to the next item.
+
+ Indirection is supported at the {machine language} level by
+ {indirect addressing}. Many processor and {operating system}
+ architectures use {vectors} which are also an instance of
+ indirection, being locations which hold the address of a
+ routine to handle a particular event. The event handler can
+ be changed simply by pointing the vector at a new piece of
+ code.
+
+ {C} includes operators "&" which returns the address of a
+ {variable} and its inverse "*" which returns the variable at a
+ given address.
+
+ (1997-02-06)
+
+indirect jump
+
+ <programming> A {jump} via an {indirect address}, i.e. the
+ jump {instruction} contains the address of a memory location
+ that contains the address of the next instruction to execute.
+
+ The location containing the address to jump to is sometimes
+ called a {vector}.
+
+ Indirect jumps make normal code hard to understand because the
+ jump target is a run-time property of the program that depends
+ on the execution history. They are useful for, e.g. allowing
+ user code to replace operating system code or setting up
+ {event handlers}.
+
+ (2010-01-01)
+
+induction
+
+ <logic> A method of proving statements about {well-ordered
+ sets}. If S is a well-ordered set with ordering "<", and we
+ want to show that a property P holds for every element of S,
+ it is sufficient to show that, for all s in S,
+
+ IF for all t in S, t < s => P(t) THEN P(s)
+
+ I.e. if P holds for anything less than s then it holds for s.
+ In this case we say P is proved by induction.
+
+ The most common instance of proof by induction is induction
+ over the {natural numbers} where we prove that some property
+ holds for n=0 and that if it holds for n, it holds for n+1.
+
+ (In fact it is sufficient for "<" to be a {well-founded}
+ {partial order} on S, not necessarily a well-ordering of S.)
+
+ (1999-12-09)
+
+inductive inference
+
+ {grammatical inference}
+
+inductive relation
+
+ A relation R between {domains} D and E is inductive if for all
+ {chains} {d1 .. dn} in D and {e1 .. en} in E,
+
+ For all i, di R ei => lub(d) R lub(e)
+
+Industrial Programming, Inc.
+
+ <company> The company which developed {MTOS}.
+
+ {(http://ipi.com)}.
+
+ E-mail: <info@ipi.com>.
+
+ Telephone: +1 (516) 938 6600. Address: 100 Jericho
+ Quadrangle, Jericho, NY 11753, USA.
+
+ (1997-07-23)
+
+Industrial Robot Language
+
+ <language, robotics> (IRL) A {high-level language} for
+ programming industrial {robots}.
+
+ ["IRL, Industrial Robot Language", DIN 66312, Beuth-Verlag
+ 1992].
+
+ (1996-11-28)
+
+Industry Standard Architecture
+
+ <architecture, standard> (ISA) A {bus} {standard} for {IBM
+ compatibles} that extends the {XT bus architecture} to 16
+ bits. It also allows for {bus mastering} although only the
+ first 16 {MB} of {main memory} is available for direct access.
+ In reference to the XT bus architecture it is sometimes
+ referred to as "AT bus architecture".
+
+ Compare {EISA}, {MCA}.
+
+ (1996-06-25)
+
+inetd
+
+ <networking, tool> Berkeley daemon program that listens for
+ connection requests or messages for certain ports and starts
+ server programs to perform the services associated with those
+ ports. Sometimes known as netd.
+
+ {Unix manual page}: inetd(8).
+
+ (1995-03-20)
+
+inews
+
+ <messaging, application> A {Unix} program for posting {Usenet}
+ news articles, written by Rich $alz <rsalz@uunet.uu.net> for
+ {InterNetNews}. inews reads an article (perhaps with headers)
+ from a file or {standard}, adds some {headers} and possibly a
+ {signature}, and, if the article passes some consistency
+ checks (too much quoting, non-existent {newsgroup}) then inews
+ sends the article to the local news {server} for distribution.
+
+ If an unapproved posting is made to a {moderated} newsgroup,
+ inews will try to send the article to the moderator (specified
+ in a configuration file) by {electronic mail}.
+
+ Version: 1.25, dated 1993/03/18.
+
+ {Unix manual page}: inews(1).
+
+ (1996-02-27)
+
+infant mortality
+
+ <hardware> It is common lore among hackers (and in the
+ electronics industry at large) that the chances of sudden
+ hardware failure drop off exponentially with a machine's time
+ since first use (that is, until the relatively distant time at
+ which enough mechanical wear in I/O devices and
+ thermal-cycling stress in components has accumulated for the
+ machine to start going senile). Up to half of all chip and
+ wire failures happen within a new system's first few weeks;
+ such failures are often referred to as "infant mortality"
+ problems (or, occasionally, as "sudden infant death
+ syndrome").
+
+ See {bathtub curve}, {burn-in period}.
+
+ [{Jargon File}]
+
+ (1995-03-20)
+
+infeasible path
+
+ {dead code}
+
+inference
+
+ <logic> The logical process by which new facts are derived
+ from known facts by the application of {inference rules}.
+
+ See also {symbolic inference}, {type inference}.
+
+ (1995-03-20)
+
+inference engine
+
+ A program that infers new {facts} from known facts using
+ {inference rules}. Commonly found as part of a {Prolog}
+ {interpreter}, {expert system} or {knowledge based system}.
+
+ (1994-11-01)
+
+inference rule
+
+ <logic> A procedure which combines known facts to produce
+ ("infer") new facts. For example, given that
+
+ 1. Socrates is a man and that
+ 2. all men are motal,
+
+ we can infer that Socrates is mortal. This uses the rule
+ known as "modus ponens" which can be written in {Boolean
+ algebra} as
+
+ (A & A => B) => B
+
+ (if {proposition} A is true, and A implies B, then B is true).
+
+ Or given that,
+
+ 1. Either Denis is programming or Denis is sad and
+ 2. Denis is not sad,
+
+ we can infer that Denis is programming. This rule can be
+ written
+
+ ((A OR B) & not B) => A
+
+ (If either A is true or B is true (or both), and B is false,
+ then A must be true).
+
+ Compare {syllogism}.
+
+ (1994-10-31)
+
+infimum
+
+ {greatest lower bound}
+
+infinite
+
+ <mathematics> 1. Bigger than any {natural number}. There are
+ various formal set definitions in {set theory}: a set X is
+ infinite if
+
+ (i) There is a {bijection} between X and a {proper subset} of X.
+
+ (ii) There is an {injection} from the set N of natural numbers to
+ X.
+
+ (iii) There is an injection from each natural number n to X.
+
+ These definitions are not necessarily equivalent unless we
+ accept the {Axiom of Choice}.
+
+ 2. The length of a line extended indefinitely.
+
+ See also {infinite loop}, {infinite set}.
+
+ [{Jargon File}]
+
+ (1995-03-29)
+
+Infinite Impulse Response
+
+ <electronics, DSP> A type of {digital signal} {filter}, in
+ which every {sample} of output is the weighted sum of past and
+ current samples of input, using all past samples, but the
+ weights of past samples are an inverse function of the sample
+ age, approaching zero for old samples.
+
+ (2001-06-06)
+
+infinite loop
+
+ <programming> (Or "endless loop") Where a piece of program is
+ executed repeatedly with no hope of stopping. This is nearly
+ always because of a {bug}, e.g. if the condition for exiting
+ the loop is wrong, though it may be intentional if the program
+ is controlling an {embedded system} which is supposed to run
+ continuously until it is turned off. The programmer may also
+ intend the program to run until interrupted by the user. An
+ endless loop may also be used as a last-resort error handler
+ when no other action is appropriate. This is used in some
+ {operating system} kernels following a {panic}.
+
+ A program executing an infinite loop is said to {spin} or
+ {buzz} forever and goes {catatonic}. The program is "wound
+ around the axle".
+
+ A standard joke has been made about each generation's exemplar
+ of the ultra-fast machine: "The Cray-3 is so fast it can
+ execute an infinite loop in under 2 seconds!"
+
+ See also {black hole}, {recursion}, {infinite loop}.
+
+ [{Jargon File}]
+
+ (1996-05-11)
+
+Infinite Monkey Theorem
+
+ <humour> "If you put an {infinite} number of monkeys at
+ typewriters, eventually one will bash out the script for
+ Hamlet." (One may also hypothesise a small number of monkeys
+ and a very long period of time.) This theorem asserts nothing
+ about the intelligence of the one {random} monkey that
+ eventually comes up with the script (and note that the mob
+ will also type out all the possible *incorrect* versions of
+ Hamlet). It may be referred to semi-seriously when justifying
+ a {brute force} method; the implication is that, with enough
+ resources thrown at it, any technical challenge becomes a
+ {one-banana problem}.
+
+ This theorem was first popularised by the astronomer Sir
+ Arthur Eddington. It became part of the idiom through the
+ classic short story "Inflexible Logic" by Russell Maloney, and
+ many younger hackers know it through a reference in Douglas
+ Adams's "Hitchhiker's Guide to the Galaxy".
+
+ See also: {RFC 2795}.
+
+ [{Jargon File}]
+
+ (2002-04-07)
+
+infinite set
+
+ <mathematics> A set with an infinite number of elements.
+ There are several possible definitions, e.g.
+
+ (i) ("Dedekind infinite") A set X is infinite if there exists
+ a {bijection} (one-to-one mapping) between X and some proper
+ subset of X.
+
+ (ii) A set X is infinite if there exists an {injection} from N
+ (the set of {natural numbers}) to X.
+
+ In the presence of the {Axiom of Choice} all such definitions
+ are equivalent.
+
+ (1995-03-27)
+
+infinity
+
+ 1. <mathematics> The size of something {infinite}.
+
+ Using the word in the context of sets is sloppy, since
+ different {infinite sets} aren't necessarily the same size
+ {cardinality} as each other.
+
+ See also {aleph 0}
+
+ 2. <programming> The largest value that can be represented in
+ a particular type of variable ({register}, memory location,
+ data type, whatever).
+
+ See also {minus infinity}.
+
+ [{Jargon File}]
+
+ (1994-11-18)
+
+infix notation
+
+ <language> One of the possible orderings of {functions} and
+ {operands}: in infix notation the functions are placed between
+ their operands, such as "1+2". Although infix notation is
+ limited to binary functions most languages mix infix notation
+ with {prefix} or {postfix} notation, as a form of {syntactic
+ sugar}.
+
+ (1997-01-17)
+
+infix syntax
+
+ {infix notation}
+
+inflate
+
+ {deflate}
+
+INFN
+
+ Istituto Nazionale di Fisica Nucleare: an Italian State
+ research organisation.
+
+Infobahn
+
+ (After the German "Autobahn") {Information Superhighway}.
+
+Info BASIC
+
+ Variant of {Pick BASIC} used with {PRIME}'s {PRIMOS}.
+
+infobot
+
+ <chat> A {bot} that serves as a common database of information
+ (often noteworthy {URLs}) for users on a {chat} system.
+ Infobots often have a simple {chatbot interface}, responding
+ to key-phrases, as well as to direct queries.
+
+ Here, in a real conversation, the bot Purl's first response is
+ triggered by the phrase "just tell me", and its second
+ response is triggered by being directly asked "perlfunc?":
+
+ <eesh> can someone tell me what: $num9 =
+ substr($number,9,1); means
+
+ <Tkil> eesh -- man perlfunc, look at "substr".
+
+ <eesh> just tell me
+
+ <purl> Didn't your momma ever tell you, "Go
+ look it up in the dictionary"?!
+
+ <Tkil> eesh -- no. that's all we'll tell
+ you. read the documentation.
+
+ <Tkil> eesh -- if you haven't man pages or
+ perldoc, you can read them on the 'net.
+
+ <Tkil> purl, perlfunc?
+
+ <purl> well, perlfunc is Perl builtin
+ functions, at man perlfunc or
+ http://perl.com/CPAN-local/doc/manual/html/pod/perlfunc.html
+
+ {(http://cs.cmu.edu/~lenzo/infobot.html/)}.
+
+ (1998-10-30)
+
+Informatics Corporation
+
+ <company> Renamed to {Sterling Software Corp}.
+
+ [When?]
+
+ (1998-10-30)
+
+information
+
+ <data> The result of applying {data processing} to {data},
+ giving it context and meaning. Information can then be
+ further processed to yeild {knowledge}.
+
+ People or computers can find patterns in data to perceive
+ information, and information can be used to enhance
+ {knowledge}. Since knowledge is prerequisite to wisdom, we
+ always want more data and information. But, as modern
+ societies verge on {information overload}, we especially need
+ better ways to find patterns.
+
+ 1234567.89 is data.
+
+ "Your bank balance has jumped 8087% to $1234567.89" is
+ information.
+
+ "Nobody owes me that much money" is knowledge.
+
+ "I'd better talk to the bank before I spend it, because of
+ what has happened to other people" is wisdom.
+
+ (2007-09-10)
+
+Information Algebra
+
+ Theoretical formalism for DP, never resulted in a language.
+ Language Structure Group of CODASYL, ca. 1962. Sammet 1969,
+ 709.
+
+Information and Communication Technology
+
+ <education> (ICT) The study of the technology used to handle
+ information and aid communication. The phrase was coined by
+ [?] Stevenson in his 1997 report to the UK government and
+ promoted by the new National Curriculum documents for the UK
+ in 2000. In addition to the subjects included in {Information
+ Technology} (IT), ICT emcompasses areas such as {telephony},
+ {broadcast media} and all types of {audio} and {video}
+ processing and transmission.
+
+ {(http://rubble.ultralab.anglia.ac.uk/stevenson/ICTUKIndex.html)}.
+
+ (2008-09-19)
+
+Information Appliance
+
+ <hardware> (IA) A consumer device that performs only a few
+ targeted tasks and is controlled by a simple {touch-screen}
+ interface or push buttons on the device's enclosure.
+
+ [How does this differ from a {PDA}?]
+
+ (1998-02-24)
+
+Information Builders
+
+ Distributors of {LEVEL5 OBJECT}. Telephone +1 800 969 INFO.
+
+Information Engineering Facility
+
+ {Advantage Gen}
+
+information highway
+
+ {information superhighway}
+
+Information Infrastructure Task Force
+
+ <networking, body> (IITF) A US government body created in 1993 by
+ President Clinton to control and oversee the {NII} project. The
+ IITF consists of representatives of the federal agencies involved
+ in information technology. They work with the private sector to
+ develop policy. Various IITF committees work on
+ telecommunications, {IPR}, {privacy}, government information and
+ applications.
+
+ In 2013, the IITF does not appear to have any presence on the
+ {WWW}, which strongly suggests that it no longer exists (or that
+ it is pretty out of touch with modern information infrastructure).
+
+ {(http://itlaw.wikia.com/wiki/Information_Infrastructure_Task_Force)}.
+
+ [Did it ever achieve anything? What happened to it?]
+
+ (2013-11-16)
+
+Information Innovation
+
+ A group of companies with offices in Amsterdam and New York
+ which acts as an information filter for the {web}.
+ They analyse what happens in the Web community and organise
+ the Web's information so that it is accessible and efficient
+ to use.
+
+ Information Innovation provides:
+
+ "The Management Guide" - a guide for managers in the
+ information age. The Guide consists of 22 parts, each
+ concentrating on a particular technology or issue facing
+ managers. Topics range from {Artificial Intelligence} and
+ Telecommunications to Finance and Marketing. Each part
+ contains references to additional valuable information,
+ including {CD ROMs}, conferences, magazines, articles and
+ books.
+
+ "The Hypergraphic Matrix" - a "hypergraphic" matrix of 250
+ graphics discussing the interrelationships between technology,
+ change, business functions and specific industries.
+
+ "Dictionary" - the largest Internet dictionary on management
+ and technology.
+
+ "The Delphi Oracle" - a comprehensive guide to the latest
+ management ideas and issues. Over 500 articles and books have
+ been read, analysed, rated and catalogued.
+
+ "Management Software" - a guide to software which is useful to
+ managers. Both Web software, Internet software and commecial
+ products are included in this guide.
+
+ "The Web Word" - an information service about the Web. It
+ includes a regular newsletter and databases about Web
+ resources, news, interviews with Web personalities and, of
+ course, the most comprehensive guide to sites.
+
+ "Web Bibliography" - a guide to the latest Web information
+ printed. Over 150 articles, magazines, market research
+ reports and books are catalogued.
+
+ "The Power Launch Pad" - our own list of useful sites on the
+ Web. Also includes links to our own lists of special subjects
+ such as Finance, Telecommunications, Manufacturing, Technology
+ and so forth.
+
+ {(http://euro.net/innovation/WelcomeHP.html)}. E-mail:
+ <innovation@euronet.nl>.
+
+ (1994-10-27)
+
+information island
+
+ <jargon> A body of information (i.e. electronic files) that
+ needs to be shared but has no network connection.
+
+ (1995-03-16)
+
+Information Management
+
+ The planning, budgeting, control and exploitation of the
+ information resources in an organisation. The term
+ encompasses both the information itself and the related
+ aspects such as personnel, finance, marketing, organisation
+ and technologies and systems. Information Managers are
+ responsible for the coordination and integration of a wide
+ range of information handling activities within the
+ organisation. These include the formulation of corporate
+ information policy, design, evaluation and integration of
+ effective information systems and services, the exploitation
+ of IT for competitive advantage and the integration of
+ internal and external information and data.
+
+Information Management System
+
+ <database> (IMS, IMS/VS, IMS/ESA) A database system from {IBM}
+ consisting of {IMS/Data Base} and {IMS/Data Communications}.
+
+ (1999-01-11)
+
+information overload
+
+ <jargon> When a person feels unable to read all the
+ information that is presented or available to them,
+ particularly where they need to make decisions based on that
+ information but can't because there is just too much to take
+ in in the time available.
+
+ (2005-01-09)
+
+Information Processing Language
+
+ (IPL) Said to be the first list-processing language, also the
+ first language to support {recursion}. Written by Allen
+ Newell, J.C. Shaw and H. Simon at Carnegie ca. 1956. It was
+ very low level.
+
+ Versions: IPL-I (never implemented), IPL-II (1957 for
+ {JOHNNIAC}), IPL-III (existed briefly), IPL-IV, IPL-V (1958,
+ for {IBM 650}, {IBM 704}, {IBM 7090}, many others. Widely
+ used), IPL-VI.
+
+ [Sammet 1969, pp. 388-400].
+
+ ["Information Processing Language-V Manual", A. Newell ed, P-H
+ 1965].
+
+ (1994-11-04)
+
+Information Resource Management
+
+ (IRM) A philosophical and practical approach to managing
+ government information. Information is regarded as a valuable
+ resource which should be managed like other resources, and
+ should contribute directly to accomplishing organisational
+ goals and objectives. IRM provides an integrated view for
+ managing the entire life-cycle of information, from
+ generation, to dissemination, to archiving and/or destruction,
+ for maximising the overall usefulness of information, and
+ improving service delivery and program management.
+
+ IRM views information and {Information Technology} as an
+ integrating factor in the organisation, that is, the various
+ organisational positions that manage information are
+ coordinated and work together toward common ends. Further,
+ IRM looks for ways in which the management of information and
+ the management of Information Technology are interrelated, and
+ fosters that interrelationship and organisational integration.
+
+ IRM includes the management of (1) the broad range of
+ information resources, e.g., printed materials, electronic
+ information, and microforms, (2) the various technologies and
+ equipment that manipulate these resources, and (3) the people
+ who generate, organise, and disseminate those resources.
+ Overall the intent of IRM is to increase the usefulness of
+ government information both to the government and to the
+ public.
+
+ [Gary D. Blass et al. "Finding Government Information: The
+ Federal Information Locator System (FILS)", Government
+ Information Quarterly, JAI Press, Inc., Greenwich,
+ Connecticut. Vol. 8, No. 1, pp. 11-32. 1991].
+
+ (1995-11-12)
+
+information superhighway
+
+ <communications> (Or "Infobahn", "Info Strada") The name
+ coined by US Vice-president Al Gore in the early 1990s for the
+ emerging high-speed global communications network capable of
+ carrying voice, data, video, and other services around the
+ world. These services use satellite, copper cable, {optical
+ fibre}, {cellular telecommunications}, and are accessible via
+ {set-top boxes} or suitably equipped computers.
+
+ See also {National Information Infrastructure}.
+
+ (2001-03-31)
+
+Information Systems Factory
+
+ (ISF) An equivalent to an {SEE}.
+
+ [{Simultaneous Engineering Environment} or {Software
+ Engineering Environment}?]
+
+ (2000-12-30)
+
+information technology
+
+ <business, jargon> (IT) Applied computer systems - both
+ {hardware} and {software}, and often including {networking}
+ and {telecommunications}, usually in the context of a business
+ or other enterprise. Often the name of the part of an
+ enterprise that deals with all things electronic.
+
+ The term "{computer science}" is usually reserved for the more
+ theoretical, academic aspects of computing, while the vaguer
+ terms "information systems" (IS) or "information services" may
+ include more of the human activities and non-computerised
+ business processes like {knowledge management}. Others say
+ that IT includes computer science.
+
+ (2000-10-02)
+
+information technology governance
+
+ <business> The structure, oversight and management processes
+ which ensure the delivery of the expected benefits of IT in a
+ controlled way to help enhance the long term sustainable
+ success of the enterprise.
+
+ (2009-04-27)
+
+Information Technology Infrastructure Library
+
+ (ITIL) A method of organising the system and network
+ management departments of large organisations. ITIL defines
+ the (work) processes involved and the interfaces between them.
+
+ (1995-06-27)
+
+Informix
+
+ A {relational DBMS} vendor.
+
+InfoSeek
+
+ <company> A company providing InfoSeek Net Search, a free
+ {web} search service which, in August 1995, indexed
+ the full text of over 400,000 web pages. Net Search was rated
+ as the fourth most popular site on the web by Interactive Age
+ magazine.
+
+ The also sell a commercial service, InfoSeek Search, that
+ offers access to all the {Usenet} {news groups}, daily
+ newswires, business and computer periodicals, and more.
+
+ {(http://www2.infoseek.com/)}.
+
+ (1995-11-09)
+
+InfoStreet, Inc.
+
+ <company> An Internet consulting and development company
+ dedicated to assisting companies in establishing an Internet
+ presence. InfoStreet develope Internet strategies, design and
+ create web pages, and host and maintain {websites}.
+
+ InfoStreet, has been recognized by PC/Computing as the "Best
+ of the Top Home Page Services" (August 1996) and has been
+ featured in Netguide magazine and the Wiley and Son's
+ Electronic Marketing book.
+
+ {(http://InfoStreet.com/)}.
+
+ {Home page hosting service (http://instantweb.com)}.
+
+ (1997-01-30)
+
+infotainment
+
+ <application> {Interactive} services or software that provides
+ some combination of information and entertainment.
+
+ (2010-03-02)
+
+InfoWord Office
+
+ <tool> A suite of applications for {Unix} including a {word
+ processor}, {spreadsheet} and {database}.
+
+ {Light Infocon S.A. (http://light.com.br/)}.
+
+ (1998-07-21)
+
+infrared
+
+ <electronics> (IR) Electromagnetic waves in the frequency
+ range just below visible light corresponding to radiated heat.
+ IR waves can be generated by a kind of {LED} and are often
+ used for remote controls for televisions etc. and in some
+ {docking stations}.
+
+ (1997-01-30)
+
+Infrared Data Association
+
+ <standard, body> (IrDA) A non-profit trade association
+ providing standards to ensure the quality and interoperability
+ of {infrared} (IR) hardware.
+
+ The association currently has a membership of over 160
+ companies from around the world, representing computer and
+ telecommunications hardware, software, components and
+ adapters.
+
+ IrDA typically uses direct infrared i.e. {point-to-point},
+ {line-of-sight}, one-to-one communications. The standards
+ include: {IrDA Data} ({SIR}, {FIR}, {VFIR}), {IrDA Control},
+ and {AIR}.
+
+ Ports built to the above standards can be found in products
+ such as {PDAs}, {Palm} devices, {printers}, desktop adapters,
+ {notebooks}, and {digital cameras}.
+
+ {(http://irda.org)}.
+
+ {IrDA Serial Infrared Interface
+ (http://cesdis1.gsfc.nasa.gov/linux/misc/irda.html)}.
+
+ {Linux-IrDA support (http://cs.uit.no/linux-irda/)}.
+
+ (1999-10-14)
+
+infrastructure
+
+ <systems> Basic support services for computing, particularly
+ national networks.
+
+ See also {information superhighway}.
+
+ (1995-06-27)
+
+Inglish
+
+ <games> An English-like language used for {Adventure} games
+ like "The Hobbit". Inglish could distinguish between "take
+ the rope and axe" and "take the money and run".
+
+ (1995-06-27)
+
+INGRES
+
+ A {relational DBMS} vendor.
+
+inheritance
+
+ <programming, object-oriented> In {object-oriented
+ programming}, the ability to derive new {classes} from
+ existing classes. A {derived class} (or "subclass") inherits
+ the {instance variables} and {methods} of the "{base class}"
+ (or "superclass"), and may add new instance variables and
+ methods. New methods may be defined with the same names as
+ those in the base class, in which case they override the
+ original one.
+
+ For example, bytes might belong to the class of integers for
+ which an add method might be defined. The byte class would
+ inherit the add method from the integer class.
+
+ See also {Liskov substitution principle}, {multiple
+ inheritance}.
+
+ (2000-10-10)
+
+initgame
+
+ <games> /in-it'gaym/ [IRC] An {IRC} version of the venerable
+ trivia game "20 questions", in which one user changes his
+ {nick} to the initials of a famous person or other named
+ entity, and the others on the channel ask yes or no questions,
+ with the one to guess the person getting to be "it" next. As
+ a courtesy, the one picking the initials starts by providing a
+ 4-letter hint of the form sex, nationality, life-status,
+ reality-status. For example, MAAR means "Male, American,
+ Alive, Real" (as opposed to "fictional"). Initgame can be
+ surprisingly addictive. See also {hing}.
+
+ [{Jargon File}]
+
+initialise
+
+ <programming> To give a {variable} its first value. This may
+ be done automatically by some languages or it may require
+ explicit code by the programmer. Some languages allow
+ initialisation to be combined with variable definition,
+ e.g. in {C}:
+
+ int i = 0;
+
+ Failing to initialise a variable before using it is a common
+ programming error, but one which compilers and automatic
+ checkers like {lint} can easily detect.
+
+ (1997-06-08)
+
+Initial Microprogram Load
+
+ <operating system> (IML) Loading {microcode} into microcode
+ memory.
+
+ (1997-08-31)
+
+Initial Operational Test and Evaluation
+
+ <testing> (IOT&E) The first phase of {operational test} and
+ evaluation conducted on {pre-protectional} items,
+ {prototypes}, or pilot production items and normally completed
+ prior to the first major production decision. Conducted to
+ provide a valid estimate of expected system operational
+ effectiveness and suitability.
+
+ (1996-12-27)
+
+Initial Program Load
+
+ <operating system> (IPL) The procedure used to (re-)start a
+ computer system by copying the {operating system} {kernel}
+ into {main memory} and running it. Part of the {boot
+ sequence}.
+
+ (1997-08-31)
+
+Initial Program Loader
+
+ <operating system> (IPL) A {bootstrap loader} which loads the
+ part of an {operating system} needed to load the remainder of
+ the operating system.
+
+ (1997-08-31)
+
+initiator
+
+ {SCSI initiator}
+
+injection
+
+ 1. <mathematics> A {function}, f : A -> B, is injective or
+ one-one, or is an injection, if and only if
+
+ for all a, b in A, f(a) = f(b) => a = b.
+
+ I.e. no two different inputs give the same output (contrast
+ many-to-one). This is sometimes called an embedding. Only
+ injective functions have left inverses f' where f'(f(x)) = x,
+ since if f were not an injection, there would be elements of B
+ for which the value of f' was not unique. If an injective
+ function is also a {surjection} then is it a {bijection}.
+
+ 2. <reduction> An injection function is one which takes
+ objects of type T and returns objects of type C(T) where C is
+ some {type constructor}. An example is
+
+ f x = (x, 0).
+
+ The opposite of an injection function is a {projection}
+ function which extracts a component of a constructed object,
+ e.g.
+
+ fst (x,y) = x.
+
+ We say that f injects its argument into the data type and fst
+ projects it out.
+
+ (1995-03-14)
+
+inkjet printer
+
+ <hardware, printer> A class of printer in which small ink
+ droplets are sprayed electrostatically from a nozzle onto the
+ paper.
+
+ Inkjet printers are very quiet in comparison to {impact
+ printers}.
+
+ A popular example is the {Olivetti} {BJ10}.
+
+ (1995-03-14)
+
+ink printer
+
+ <printer> A {retronym} used by Blind users to refer to all
+ printers which are not {Braille printers}, regardless of
+ whether they actually use ink.
+
+ (1998-10-13)
+
+inline
+
+ <programming> (Or "unfold") To replace a {function} call with
+ an instance of the function's body. {Actual argument}
+ expressions are substituted for {formal parameters} as in
+ {beta reduction}. Inlining is usually done as a
+ {compile-time} transformation.
+
+ If done recklessly (e.g. attempting to inline a {recursive}
+ function) the {compiler} will fail to terminate. If done
+ over-enthusiastically the code size may increase
+ exponentially, e.g. if function f calls g twice, and g calls h
+ twice and h is inlined in g which is inlined in f (in either
+ order) then there will be four copies of h's body in f.
+
+ See also {linear argument}, {unfold/fold}.
+
+ (1994-11-03)
+
+inline element
+
+ <web> Any {HTML element} that is rendered in the
+ same position as normal plain text, i.e. to the right of the
+ preceding text (for left-to-right scripts).
+
+ This contrasts with a {block-level elements} that is always
+ placed below the preceding text line.
+
+ Inline elements typically specify formatting, e.g. <B>
+ ({bold}), <SMALL> or the kind of content, e.g. <CODE>, <KBD>,
+ though they also include things like {inline images} (<IMG>)
+ and {text areas} (<TEXTAREA>).
+
+ {(http://htmlhelp.com/reference/html40/inline.html)}
+
+ (2011-01-04)
+
+inline image
+
+ <web> An image that appears within the body of a
+ {web page}. Most graphical {web browsers} display images
+ inline (with an option to turn off inline images, to speed up
+ the display of web pages).
+
+ Other {image formats} may have to be displayed in a separate
+ {window} and/or by another {application program}.
+
+ An inline image in a web page is specified with the <IMG>
+ {HTML} {tag}, which can take many {attributes}, the most
+ important of which is the SRC attribute that gives the {URL}
+ from which to fetch the image. The ALT attribute gives text
+ to display in place of the image for users with images
+ disabled or who are using text-only browsers or text-to-speech
+ convertors (e.g. blind users).
+
+ (2011-01-04)
+
+INMOS transputer
+
+ {transputer}
+
+inner class
+
+ <Java> In {Java}, a non-{static}, {nested class}.
+
+ (2006-11-18)
+
+inner join
+
+ <database> (Commonly "join", but see also "{outer join}") A
+ {relational database} operation which selects rows from two
+ {tables} such that the value in one {column} of the first
+ table also appears in a certain column of the second table.
+
+ An example in {SQL}:
+
+ select * from A, B
+ where A.x = B.y
+
+ The column names (x and y in this example) are often, but not
+ necessarily, the same.
+
+ (1998-11-23)
+
+inner product
+
+ <mathematics> In {linear algebra}, any linear map from a
+ {vector space} to its {dual} defines a product on the vector
+ space: for u, v in V and linear g: V -> V' we have gu in V' so
+ (gu): V -> scalars, whence (gu)(v) is a scalar, known as the
+ inner product of u and v under g. If the value of this scalar
+ is unchanged under interchange of u and v (i.e. (gu)(v) =
+ (gv)(u)), we say the inner product, g, is symmetric.
+ Attention is seldom paid to any other kind of inner product.
+
+ An inner product, g: V -> V', is said to be positive definite
+ iff, for all non-zero v in V, (gv)v > 0; likewise negative
+ definite iff all such (gv)v < 0; positive semi-definite or
+ non-negative definite iff all such (gv)v >= 0; negative
+ semi-definite or non-positive definite iff all such (gv)v <=
+ 0. Outside relativity, attention is seldom paid to any but
+ positive definite inner products.
+
+ Where only one inner product enters into discussion, it is
+ generally elided in favour of some piece of syntactic sugar,
+ like a big dot between the two vectors, and practitioners
+ don't take much effort to distinguish between vectors and
+ their duals.
+
+ (1997-03-16)
+
+InnovAda
+
+ An {object-oriented} extension to {Ada}, said to be
+ {Lisp}-like. Implemented as an {Ada} {preprocessor}.
+
+ (1994-11-03)
+
+ [Where? Who? When?]
+
+inode
+
+ A data structure holding information about files in a {Unix}
+ {file system}. There is an inode for each file and a file
+ is uniquely identified by the file system on which it
+ resides and its inode number on that system. Each inode
+ contains the following information: the device where the inode
+ resides, locking information, mode and type of file, the
+ number of links to the file, the owner's user and group ids,
+ the number of bytes in the file, access and modification
+ times, the time the inode itself was last modified and the
+ addresses of the file's blocks on disk. A {Unix} directory is
+ an association between file leafnames and inode numbers. A
+ file's inode number can be found using the "-i" switch to ls.
+
+ {Unix manual page}: fs(5).
+
+ See also /usr/include/ufs/inode.h.
+
+in-order traversal
+
+ {traverse}
+
+inout
+
+ <programming> A type or "mode" of {function} {parameter} that
+ passes information in both directions - from the caller to the
+ function and back to the caller, combining the {in} and {out}
+ modes. An "inout" parameter might be used where the function
+ needs to read and update some data belonging to the caller as
+ a side effect of its main purpose.
+
+ (2010-01-19)
+
+IN point
+
+ <unit, text> (l'Imprimerie nationale point) A variant of the
+ {point} equal to 0.4 mm.
+
+ (2002-03-11)
+
+Inprise Corporation
+
+ {Borland Software Corporation}.
+
+Input
+
+ {ALPHA}
+
+input
+
+ <architecture> {Data} transferred from the outside world into
+ a computer system via some kind of {input device}.
+
+ Opposite: {output}.
+
+ (1997-04-28)
+
+input device
+
+ <hardware> A {peripheral} used to transfer data from the
+ outside world into a computer system. Some input devices are
+ operated directly by the user, e.g. {keyboard}, {mouse},
+ {touch screen}, {joystick}, {digitising tablet}, {microphone};
+ others are sensors or transducers which convert external
+ signals into data, e.g. using an {ananlog to digital
+ converter} (this would also be true of a microphone). Other
+ kinds of inputs are really one half of a bidirectional link
+ with another computer or storage device, e.g. {serial line},
+ {SCSI} interface.
+
+ (1996-11-03)
+
+input/output
+
+ <programming, operating system> (I/O) Communication between a
+ computer and its users, its storage devices, other computers
+ (via a {network}) or the outside world. The devices the
+ computer uses to do this are called "{peripherals}". What
+ actually counts as I/O depends on what level of detail you are
+ considering, e.g. communication between processors would not
+ be considered I/O when considering a {multiprocessor} as a
+ single system.
+
+ Important aspects of I/O are {throughput}, {latency}, and
+ whether the communications is {synchronous} or {asynchronous}
+ (using some kind of {buffer}).
+
+ (2003-12-04)
+
+input/output redirection
+
+ <operating system> In {Unix}, to send ouput from a {process}
+ to different {file} or {device} or to another process via a
+ {pipe}, or to have a process read its input from a different
+ file, device or pipe. Some other {operating systems} have
+ similar facilities.
+
+ To redirect input to come from a file instead of the keyboard,
+ use "<":
+
+ myprog < myfile
+
+ Similarly to redirect output to a file instead of the screen:
+
+ ls > filelist
+
+ A pipe redirects the output of one process directly into the
+ input of another
+
+ who | wc -l
+
+ A common misuse by beginners is
+
+ cat myfile | myprog
+
+ Which is more or less equivalent to "myprog < myfile" except
+ that it introduces an extra unnecessary cat process and buffer
+ space for the pipe. Even the "<" is unnecessary with many
+ standard Unix commands since they accept input file names as
+ command line arguments anyway.
+
+ Unix's concept of {standard input/output} and I/O redirection
+ make it easy to combine simple processes in powerful ways and
+ to use the same commands for different purposes.
+
+ (1998-04-24)
+
+inquiry/response system
+
+ <business> Any computer system in which data is entered
+ {offline} and processed in {batch} form, but information can
+ be retrieved on-line. An example is the checking of credit
+ cards.
+
+ ["Computer Information Systems for Business V", Thomas Dock
+ and James C Wetherbe, West Publishing Company 1988].
+
+ (1996-06-24)
+
+INRIA
+
+ {Institut National de Recherche en Informatique et Automatique}
+
+insanely great
+
+ ({Macintosh} community, from {Steve Jobs}; also {BSD Unix}
+ people via {Bill Joy}) Something so incredibly {elegant} that
+ it is imaginable only to someone possessing the most puissant
+ of {hacker}-natures.
+
+ [{Jargon File}]
+
+ (1994-12-06)
+
+insertion sort
+
+ <algorithm> A sorting {algorithm} that inserts each item in
+ the proper place into an initially empty list by comparing it
+ with each item in the list until it finds the new element's
+ successor or the end of the list.
+
+ Compare {bubble sort}.
+
+ (1997-02-12)
+
+INSIGHT
+
+ A {simulation} and modelling language especially for health
+ care problems.
+
+ ["Simulation Modeling with INSIGHT", S.D. Roberts Proc 1983
+ Winter Sim Conf, S.D. Roberts et al eds, pp.7-16].
+
+ (1995-03-03)
+
+Insignia Solutions, Inc.
+
+ <company> /in-sig'nee-* s*-loosh'nz/ A company that made its
+ name as a provider of software that allows users to run
+ {Microsoft Windows} and {MS-DOS} {application programs} on
+ {Digital}, {HP}, {IBM}, {Motorola}, {NeXT}, {Silicon Graphics}
+ and {Sun}/{SPARC} {workstations}, {X terminals}, {Java}
+ desktops, and {Apple Computer}'s {Power Mac} and {Motorola
+ 68000}-based computers.
+
+ Insignia Solutions was founded in 1986. Their first product,
+ {SoftPC} 1.0 for Sun workstations, was introduced in 1988.
+ Also in 1988, Insignia shipped its first version of SoftPC for
+ Apple Computer's Macintosh. As the demand to run Windows and
+ MS-DOS applications on non-Intel computers grew, Insignia
+ signed {OEM} agreements with several companies including {Data
+ General}, Digital, {Fujitsu}, HP, {Intergraph Corp.},
+ Motorola, Silicon Graphics, and Sun Microsystems.
+
+ Insignia Solutions sold its {SoftWindows} and {RealPC} product
+ lines to {FWB Software} [when?]. Its major product in 2000 is
+ the {Jeode} platform, a {Java virtual machine} for {Internet
+ appliances} and {embedded} devices.
+
+ {Home Page (http://insignia.com/)}.
+
+ (2000-02-14)
+
+inspection
+
+ <testing> A formal evaluation technique in which software
+ {requirements}, design, or code are examined in detail by a
+ person or group other than the author to detect faults,
+ violations of development standards, and other problems.
+
+ (1996-05-22)
+
+installable file system
+
+ <operating system> (IFS or "File System Driver", "FSD") An
+ {API} that allows you to extend {OS/2} to access files stored
+ on disk in formats other than {FAT} and {HPFS}, and access
+ files that are stored on a {network file server}.
+
+ For example an IFS could provide programs running under OS/2
+ (including DOS and Windows programs) with access to files
+ stored under {Unix} using the {Berkeley fast file system}.
+
+ The other variety of IFS (a "remote file system" or
+ "redirector") allows file sharing over a {LAN}, e.g. using
+ Unix's {Network File System} {protocol}. In this case, the
+ IFS passes a program's file access requests to a remote file
+ server, possibly also translating between different file
+ attributes used by OS/2 and the remote system.
+
+ Documentation on the IFS API has been available only by
+ special request from IBM.
+
+ An IFS is structured as an ordinary 16-bit {DLL} with entry
+ points for opening, closing, reading, and writing files, the
+ swapper, file locking, and {Universal Naming Convention}. The
+ main part of an IFS that runs in {ring} 0 is called by the
+ OS/2 {kernel} in the context of the caller's process and
+ {thread}. The other part that runs in ring 3 is a utility
+ library with entry points for FORMAT, RECOVER, SYS, and
+ CHKDSK.
+
+ {EDM/2 article (http://edm2.com/0103/)}.
+
+ (1999-04-07)
+
+installed user base
+
+ {user base}
+
+installer
+
+ <operating system> A {utility program} to ease the
+ installation of another, probably larger, {application}. It
+ is also possible for {hardware} to have an installer accompany
+ it, to install any low level {device drivers} required.
+
+ The installer commonly asks the user to enter desired
+ configuration options for the main program or hardware, and
+ sets up various initialisation files accordingly, as well as
+ copying the main program to a {hard disc}.
+
+ Some badly designed operating systems require applications to
+ provide an {uninstaller} because of the number of different
+ files modified or created during the installation process.
+
+ (1998-02-09)
+
+instance
+
+ <programming> An individual {object} of a certain {class}.
+ While a class is just the type definition, an actual usage of
+ a class is called "instance". Each instance of a class can
+ have different values for its {instance variables}, i.e. its
+ {state}.
+
+ (1998-03-06)
+
+instance variable
+
+ <programming> In {object-oriented programming}, one of the
+ variables of a {class template} which may have a different
+ value for each {object} of that {class}. Instance variables
+ hold the {state} of an object.
+
+ (1998-01-16)
+
+instantiate
+
+ {instantiation}
+
+instantiation
+
+ <programming> Producing a more defined version of some object
+ by replacing variables with values (or other variables).
+
+ 1. In {object-oriented programming}, producing a particular
+ {object} from its {class template}. This involves allocation
+ of a structure with the types specified by the template, and
+ initialisation of {instance variables} with either default
+ values or those provided by the class's {constructor}
+ function.
+
+ 2. In {unification}, (as used in {logic programming}, {type
+ checking} and {type inference}), binding a {logic variable}
+ ({type variable}) to some value (type).
+
+ (1995-03-28)
+
+Institute for Global Communications
+
+ (IGC) Provider of computer networking tools for international
+ communications and information exchange. The IGC Networks --
+ PeaceNet, EcoNet, ConflictNet and LaborNet -- comprise the
+ world's only computer communications system dedicated solely
+ to environmental preservation, peace, and human rights. New
+ technologies are helping these worldwide communities cooperate
+ more effectively and efficiently.
+
+ Address: 18 De Boom Street, San Francisco, CA 94107 USA. A
+ division of the Tides Foundation, a 501(c)(3) tax-exempt
+ organisation. A founding member of the world-wide Association
+ of Progressive Communications (APC).
+
+ {(ftp://igc.apc.org)}.
+
+ E-mail: <support@igc.apc.org>.
+
+ (1996-06-24)
+
+Institute of Electrical and Electronics Engineers, Inc.
+
+ (IEEE) The world's largest technical professional society,
+ based in the USA. Founded in 1884 by a handful of
+ practitioners of the new electrical engineering discipline,
+ today's Institute has more than 320,000 members who
+ participate in its activities in 147 countries. The IEEE
+ sponsors technical conferences, symposia and local meetings
+ worldwide, publishes nearly 25% of the world's technical
+ papers in electrical, electronics and computer engineering and
+ computer science, provides educational programs for its
+ members and promotes standardisation. Areas covered include
+ aerospace, computers and communications, biomedical
+ technology, electric power and consumer electronics.
+
+ {(http://ieee.org/)}.
+ {Gopher (gopher://gopher.ieee.org/)}.
+ {(ftp://ftp.ieee.org/)}.
+
+ E-mail file-server: <fileserver-help@info.ieee.org>.
+
+ { IEEE Standards Process Automation (SPA) System
+ (http://stdsbbs.ieee.org/)},
+ {telnet (telnet:stdsbbs.ieee.org)} [140.98.1.11].
+
+ (1995-03-10)
+
+Institut National de Recherche en Informatique et Automatique
+
+ <body> (INRIA) A French research institute for computer
+ science, {control theory}, and applied mathematics. INRIA has
+ research units in Rocquencourt (near Paris), Sophia-Antipolis
+ (near Nice), Grenoble, Nancy (also known as LORIA) and Rennes
+ (known as IRISA), the last two in partnership with {CNRS} and
+ local universities.
+
+ INRIA works on various projects, including the development of
+ {free software} such as {SciLab}, {Objective Caml}, {Bigloo},
+ and projects such as {GNU MP}.
+
+ (2003-07-13)
+
+instruction
+
+ {machine instruction}
+
+Instruction Address Register
+
+ <architecture> (IAR) The {IBM} name for {program counter}.
+
+ The IAR can be accessed by way of a {supervisor} call in
+ {supervisor state}, but cannot be directly addressed in
+ {problem state}.
+
+ (1995-03-21)
+
+instructional technology
+
+ <education> Design, development, use, management and
+ evaluation of process and resources for learning.
+
+ Instructional technology aims to promote the application of
+ validated, practical procedures in the design and delivery of
+ instruction. It is often defined either in terms of media and
+ other technology used (e.g. {audiovisual media} and equipment
+ and computers), or in terms of a systematic process which
+ encompasses instructional design, development, delivery and
+ evaluation.
+
+ ["Instructional Technology: The Definition and Domains of the
+ Field", 1994, Barbara Seels and Rita Richey, Washington, D.C.,
+ Association for Educational Communications and Technology].
+
+ (2010-01-29)
+
+instruction mnemonic
+
+ <programming> A word or acronym used in {assembly language} to
+ represent a {binary} machine instruction {operation code}.
+ Different processors have different {instruction sets} and
+ therefore use a different set of {mnemonics} to represent
+ them.
+
+ E.g. ADD, B (branch), BLT (branch if less than), {SVC}, MOVE,
+ LDR (load register).
+
+ (1997-02-18)
+
+instruction prefetch
+
+ <architecture> A technique which attempts to minimise the time
+ a {processor} spends waiting for {instructions} to be fetched
+ from memory. Instructions following the one currently being
+ executed are loaded into a prefetch queue when the processor's
+ {external bus} is otherwise idle. If the processor executes a
+ {branch} instruction or receives an {interrupt} then the queue
+ must be flushed and reloaded from the new address.
+
+ Instruction prefetch is often combined with {pipelining} in
+ an attempt to keep the pipeline busy.
+
+ By 1995 most processors used prefetching, e.g. {Motorola
+ 680x0}, {Intel 80x86}.
+
+ [First processors using prefetch?]
+
+ (1998-03-29)
+
+instruction scheduling
+
+ The {compiler} phase that orders instructions on a
+ {pipelined}, {superscalar}, or {VLIW} architecture so as to
+ maximise the number of function units operating in parallel
+ and to minimise the time they spend waiting for each other.
+
+ Examples are filling a {delay slot}; interspersing
+ {floating-point} instructions with integer instructions to
+ keep both units operating; making adjacent instructions
+ independent, e.g. one which writes a register and another which
+ reads from it; separating memory writes to avoid filling the
+ {write buffer}.
+
+ Norman P. Jouppi and David W. Wall, {"Available
+ Instruction-Level Parallelism for Superscalar and
+ Superpipelined Processors"
+ (ftp://gatekeeper.dec.com/archive/pub/DEC/WRL/research-reports/WRL-TR-89.7.ps.Z)},
+ Proceedings of the Third International Conference on
+ Architectural Support for Programming Languages and Operating
+ Systems, pp. 272--282, 1989.
+
+ [The SPARC Architecture Manual, v8, ISBN 0-13-825001-4]
+
+instruction set
+
+ <architecture> The collection of {machine language}
+ {instructions} that a particular {processor} understands.
+
+ The term is almost synonymous with "{instruction set
+ architecture}" since the instructions are fairly meaningless
+ in isolation from the {registers} etc. that they manipulate.
+
+ (1999-07-05)
+
+instruction set architecture
+
+ <architecture> (ISA) The parts of a {processor}'s design that
+ need to be understood in order to write {assembly language},
+ such as the {machine language} instructions and {registers}.
+ Parts of the architecture that are left to the implementation,
+ such as number of {superscalar} {functional units}, {cache}
+ size and {cycle} speed, are not part of the ISA.
+
+ The definition of {SPARC}, for example, carefully
+ distinguishes between an implementation and a specification.
+
+ (1999-01-16)
+
+Instruction Set Processor
+
+ <language> (ISP) A family of languages for describing the
+ {instruction sets} of computers.
+
+ ["Computer Structures: Readings and Examples", D.P. Siewiorek
+ et al, McGraw-Hill 1982].
+
+ (1995-10-12)
+
+instrument
+
+ <programming> To install devices or instructions into hardware
+ or software to monitor the operation of a system or component.
+
+ (1996-05-22)
+
+int
+
+ 1. <programming> A common name for the {integer} data type.
+ In {C} for example, it means a (signed) integer of the
+ computer's native {word length}.
+
+ 2. <networking> The {top-level domain} for international
+ organisations.
+
+ (1999-01-26)
+
+INTCODE
+
+ <language> A low-level {interpreted language} used in
+ {bootstrapping} the {BCPL} compiler. The INTCODE machine has six
+ control {registers} and eight functions. {OCODE} was used as the
+ intermediate language.
+
+ ["INTCODE - An Interpretive Machine Code for BCPL",
+ M. Richards, Computer Lab, U Cambridge 1972].
+
+ ["BCPL - The Language and its Compiler", Martin Richards &
+ Colin Whitby-Stevens, Cambridge U Press 1979].
+
+ (2014-08-21)
+
+integer
+
+ <mathematics> (Or "whole number") One of the numbers in the set
+
+ ..., -3, -2, -1, 0, 1, 2, 3, ...
+
+ There are an {infinite} number of integers, though each one is
+ {finite}.
+
+ An {inductive definition} of an integer is a number that is either
+ zero or an integer plus or minus one. An integer has no
+ {fractional} part. If written as a {real} number, e.g. 42.0, the
+ part after the decimal point will be zero.
+
+ A {natural number} is a non-negative integer.
+
+ Computers usually store integers in {binary}. Natural numbers can
+ be stored as {unsigned integers} and integers that may be negative
+ require a {sign bit} and typically use {twos complement}
+ representation. Other representations have been used, such as
+ {binary-coded decimal}.
+
+ (2002-04-07)
+
+Integer SPECbaserate
+
+ {SPECrate_base_int92}
+
+Integer SPECbaseratio
+
+ {SPECbase_int92}
+
+Integer SPECrate
+
+ {SPECrate_int92}
+
+Integer SPECratio
+
+ {SPECint92}
+
+integrated circuit
+
+ <electronics> (IC, or "chip") A microelectronic
+ {semiconductor} device consisting of many interconnected
+ transistors and other components. ICs are constructed
+ ("fabricated") on a small rectangle (a "die") cut from a
+ Silicon (or for special applications, Sapphire) wafer. This
+ is known as the "substrate". Different areas of the substrate
+ are "doped" with other elements to make them either "p-type"
+ or "n-type" and polysilicon or aluminium tracks are etched in
+ one to three layers deposited over the surface. The die is
+ then connected into a package using gold wires which are
+ welded to "pads", usually found around the edge of the die.
+
+ Integrated circuits can be classified into analogue, digital
+ and hybrid (both analogue and digital on the same chip).
+ Digital integrated circuits can contain anything from one to
+ millions of {logic gates} - {inverters}, {AND}, {OR}, {NAND}
+ and {NOR} gates, {flip-flops}, {multiplexors} etc. on a few
+ square millimeters. The small size of these circuits allows
+ high speed, low power dissipation, and reduced manufacturing
+ cost compared with board-level integration.
+
+ The first integrated circuits contained only a few
+ {transistors}. Small Scale Integration ({SSI}) brought
+ circuits containing transistors numbered in the tens. Later,
+ Medium Scale Integration ({MSI}) contained hundreds of
+ transistors. Further development lead to Large Scale
+ Integration ({LSI}) (thousands), and VLSI (hundreds of
+ thousands and beyond). In 1986 the first one {megabyte} {RAM}
+ was introduced which contained more than one million
+ transistors.
+
+ LSI circuits began to be produced in large quantities around
+ 1970 for computer main memories and pocket calculators. For
+ the first time it became possible to fabricate a {CPU} or even
+ an entire {microprocesor} on a single integrated circuit. The
+ most extreme technique is {wafer-scale integration} which uses
+ whole uncut wafers as components.
+
+ [Where and when was the term "chip" introduced?]
+
+ (1997-07-03)
+
+Integrated Database Management System
+
+ <database> (IDMS) A network {DBMS} written by the staff of
+ B.F.Goorich (Akron, Ohio, USA) circa 1972 and sold to
+ {Cullinet} (Originally Cullinane, now part of {Computer
+ Associates}).
+
+ IDMS was licensed to {ICL} in 1976 for porting to, and
+ subsequent development on, their computers. It was
+ implemented on the {ICL 1900} Series ({DME} {George 2},
+ {George 3}, {CME}, {TME}), {System 4}, and {ICL 2900} Series
+ (later Series 39 Corporate Servers). The latest version runs
+ on Series 39 {OpenVME} as IDMSX (IDMS extended).
+
+ [Was it a {relational database}?]
+
+ (1995-04-19)
+
+integrated development environment
+
+ {interactive development environment}
+
+Integrated Drive Electronics
+
+ {Advanced Technology Attachment}
+
+Integrated Information Technology
+
+ <company> (IIT) A Santa Clara based company producing a
+ programmable, single chip {H.261} and {MPEG} system. The chip
+ contains a {RISC} processor, originally based on the {MIPS}
+ architecture but now called {RISCit}, and a "Pixel Processor".
+
+ (1994-11-03)
+
+Integrated Modelling Support Environment
+
+ <project> (IMSE) An {Esprit} programme.
+
+ [Details?]
+
+ (1999-04-26)
+
+Integrated Project Support Environment
+
+ <software> (IPSE) A set of management and technical tools to
+ support software development, usually integrated in a coherent
+ framework, equivalent to a {Software Engineering Environment}.
+
+ (1999-04-26)
+
+Integrated Services Digital Network
+
+ <communications> (ISDN) A set of communications {standards}
+ allowing a single wire or {optical fibre} to carry voice,
+ digital network services and video. ISDN is intended to
+ eventually replace the {plain old telephone system}.
+
+ ISDN was first published as one of the 1984 {ITU-T} {Red Book}
+ recommendations. The 1988 {Blue Book} recommendations added
+ many new features. ISDN uses mostly existing {Public Switched
+ Telephone Network} (PSTN) switches and wiring, upgraded so
+ that the basic "call" is a 64 kilobits per second, all-digital
+ end-to-end channel. {Packet} and {frame} modes are also
+ provided in some places.
+
+ There are different kinds of ISDN connection of varying
+ bandwidth (see {DS level}):
+
+ DS0 = 1 channel PCM at 64 kbps
+ T1 or DS1 = 24 channels PCM at 1.54 Mbps
+ T1C or DS1C = 48 channels PCM at 3.15 Mbps
+ T2 or DS2 = 96 channels PCM at 6.31 Mbps
+ T3 or DS3 = 672 channels PCM at 44.736 Mbps
+ T4 or DS4 = 4032 channels PCM at 274.1 Mbps
+
+ Each channel here is equivalent to one voice channel. DS0 is
+ the lowest level of the circuit. T1C, T2 and T4 are rarely
+ used, except maybe for T2 over microwave links. For some
+ reason 64 kbps is never called "T0".
+
+ A {Basic Rate Interface} (BRI) is two 64K "bearer" channels
+ and a single "delta" channel ("2B+D"). A {Primary Rate
+ Interface} (PRI) in North America and Japan consists of 24
+ channels, usually 23 B + 1 D channel with the same physical
+ interface as T1. Elsewhere the PRI usually has 30 B + 1 D
+ channel and an {E1} interface.
+
+ A {Terminal Adaptor} (TA) can be used to connect ISDN channels
+ to existing interfaces such as {EIA-232} and {V.35}.
+
+ Different services may be requested by specifying different
+ values in the "Bearer Capability" field in the call setup
+ message. One ISDN service is "telephony" (i.e. voice), which
+ can be provided using less than the full 64 kbps bandwidth (64
+ kbps would provide for 8192 eight-bit samples per second) but
+ will require the same special processing or {bit diddling} as
+ ordinary PSTN calls. Data calls have a Bearer Capability of
+ "64 kbps unrestricted".
+
+ ISDN is offered by local telephone companies, but most readily
+ in Australia, France, Japan and Singapore, with the UK
+ somewhat behind and availability in the USA rather spotty.
+
+ (In March 1994) ISDN deployment in Germany is quite
+ impressive, although (or perhaps, because) they use a
+ specifically German signalling specification, called {1.TR.6}.
+ The French {Numeris} also uses a non-standard protocol (called
+ {VN4}; the 4th version), but the popularity of ISDN in France
+ is probably lower than in Germany, given the ludicrous
+ pricing. There is also a specifically-Belgian V1 experimental
+ system. The whole of Europe is now phasing in {Euro-ISDN}.
+
+ See also {Frame Relay}, {Network Termination}, {SAPI}.
+
+ {FAQ
+ (ftp://src.doc.ic.ac.uk/usenet/news-info/comp.dcom.isdn/)}.
+
+ {Usenet} newsgroup: {news:comp.dcom.isdn}.
+
+ (1998-03-29)
+
+Integrated Systems Architecture
+
+ (ISA for {ODP}) An {Esprit} 2 project continuing the {ANSA}
+ project.
+
+ (1995-02-21)
+
+Integrated Systems Laboratory
+
+ <company> A joint project of {Control Data Corporation} and
+ {NCR Corporation}, established in 1973 and dissolved in 1976.
+
+ Integrated Systems Laboratory developed {Software Writer's
+ Language}.
+
+ Address: Escondidio, California, USA.
+
+ (2003-12-31)
+
+integration
+
+ <programming> Combining software or hardware components or
+ both into an overall system.
+
+ (1996-05-22)
+
+integration testing
+
+ <testing> A type of {testing} in which {software} and/or
+ {hardware} components are combined and tested to confirm that
+ they interact according to their requirements. Integration
+ testing can continue progressively until the entire system has
+ been integrated.
+
+ (2003-09-24)
+
+integrity
+
+ 1. <data> {data integrity}.
+
+ 2. <database> {referential integrity}.
+
+integrity constraint
+
+ <database> A {constraint} (rule) that must remain true for a
+ {database} to preserve {data integrity}. Integrity
+ constraints are specified at database creation time and
+ enforced by the {database management system}.
+
+ Examples from a genealogical database would be that every
+ individual must be their parent's child or that they can have
+ no more than two natural parents.
+
+ (1995-11-11)
+
+Intel
+
+ {Intel Corporation}
+
+Intel 4004
+
+ <processor> The world's first {microprocessor}, released in
+ 1971. The 4004 contained 2300 transistors (compared with 5.5
+ million in the 1996 {Pentium Pro}) and was intended for use in
+ a calculator. It processed data in 4 bits, but its
+ instructions were 8 bits long. Program and Data memory were
+ separate, it had 1 {kilobyte} of data memory and a 12-bit {PC}
+ for 4K of program memory (in the form of a 4 level {stack},
+ used for CALL and RET instructions). There were also sixteen
+ 4-bit (or eight 8-bit) general purpose {registers}. The 4004
+ had 46 instructions.
+
+ (1997-03-30)
+
+Intel 4040
+
+ <processor> An enhanced version of the {Intel 4004}, adding 14
+ instructions, larger (8 level) {stack}, 8 kbyte program memory
+ and {interrupt} abilities (including shadows of the first 8
+ {registers}). The 4040 was similar to the {Intel 8008}.
+
+ (1994-10-31)
+
+Intel 486
+
+ <processor> (Or "i486", "iAPX 80486", and "Intel DX4" but
+ usually just "486"). A range of {Intel} {CISC}
+ {microprocessors} which is part of the {Intel 80x86} family of
+ processors.
+
+ The 486s are very similar to their immediate predecessor, the
+ {Intel 80386}DX. The main differences are that the 486 has an
+ optimised {instruction set}, has an on-chip unified
+ instruction and data {cache}, an optional on-chip
+ {floating-point unit} (FPU), and an enhanced {bus interface
+ unit}. These improvements yield a rough doubling in
+ performance over an {Intel 80386} at the same {clock rate}.
+
+ There are several suffixes and variants including:
+
+ {Intel 486SX} - a 486DX with a faulty {FPU} that has been
+ disabled in the factory.
+
+ {Intel 486DX} - 486SX with a working {FPU}.
+
+ 486DX-2 - runs at twice the external {clock rate}.
+
+ 486SX-2 - runs at twice the external {clock rate}.
+
+ 486SL - 486DX with power conservation circuitry.
+
+ 486SL-NM - 486SX with power conservation circuitry; SL
+ enhanced suffix, denotes a 486 with special power conservation
+ circuitry similar to that in the 486SL processors.
+
+ 487 - 486DX with a slightly different pinout for use in 486SX
+ systems.
+
+ OverDrive - 486DX-2 with a slightly different pinout for use
+ in 486SX systems.
+
+ {RapidCAD} - 486DX in a special package with a companion {FPU}
+ dummy package for use in {Intel 80386} systems.
+
+ {Intel DX4}, {Cyrix} {Cy486SLC}.
+
+ External {clock rates} include 16MHz, 20MHz, 25MHz, 33MHz,
+ 40MHz, although 16Mhz is rare now, and the 20MHz processors
+ are often clock doubled.
+
+ The 486 processor has been licensed or reverse engineered by
+ other companies such as {IBM}, {AMD}, {Cyrix}, and {Chips &
+ Technologies}. Some are almost exact duplicates in
+ specications and performance, some aren't.
+
+ The successor to the 486 is the {Pentium}.
+
+ (1995-02-21)
+
+Intel 486DX
+
+ <processor> One of {Intel}'s {Intel 486} family of
+ {microprocessors} (one of the last before the {Pentium}). The
+ 486DX has a working built-in {floating point unit} (FPU). The
+ {Intel 486SX} is effectively a DX with the FPU disabled. The
+ DX has a pin to select the external {data bus} width (16 or
+ 32).
+
+ The {Intel 487SX} is a 486DX with a 486SX pinout.
+
+ (1995-05-09)
+
+Intel 486SX
+
+ <processor> An {Intel 486DX} {microprocessor} with its
+ {floating-point unit} disconnected. All 486SX chips were
+ fabricated with FPUs. If testing showed that the CPU was OK
+ but the FPU was defective, the FPU's power and bus connections
+ were destroyed with a laser and the chip was sold cheaper as
+ an SX, if the FPU worked it was sold as a DX.
+
+ [Was this true of all 486SX chips?]
+
+ Some systems, e.g. Aopen 486SX, allowed a DX to be plugged
+ into an expansion socket. A board jumper would disable the SX
+ which was hard to remove because it was surface mounted.
+
+ Some SX chips only had a 16-bit wide external {data bus}. The
+ DX has a pin to select the data bus width (16 or 32). On the
+ smaller SX, that line is {hard-wired} to 16 inside the
+ package. This is similar to the 286 SX, which was a 16-bit
+ processor with an 8-bit external data bus.
+
+ The {Jargon File} claimed that the SX was deliberately
+ disabled {crippleware}. The German computer magazine, "c't",
+ made this same theory the basis of an {April Fools Joke}.
+ They claimed that if one drilled a hole of a specified
+ diameter through the right point on a SX chip, this would
+ brake the circuit that disables the FPU. Some people actually
+ tried (and then bought themselves new processors).
+
+ (1997-02-14)
+
+Intel 487SX
+
+ <processor> A version of the {Intel 486DX} {microprocessor}
+ with an extra pin, for use in the {coprocessor} socket of an
+ {Intel 486SX} system. The 487SX provides the {FPU} which is
+ missing in the 486SX.
+
+ Although the 486SX is completely disabled when you install a
+ 487SX, the 487SX design requires that you leave the 486SX in
+ your PC [why?], rather than use it elsewhere. Intel admits
+ that in some systems you can unplug the 486SX and fit a 487SX
+ in its place but they don't guarantee that it will always
+ work.
+
+ See {Intel 486}.
+
+ (1995-05-10)
+
+Intel 8008
+
+ <processor> A {microprocessor} intended for use as a terminal
+ controller, and similar to the {Intel 4040}. The 8008 had a
+ 14-bit {PC} and addressing and an eight level internal
+ {stack}. It was followed by the {Intel 8080}.
+
+ [Date?]
+
+ (1994-10-31)
+
+Intel 80186
+
+ <processor> A {microprocessor} developed by {Intel} circa
+ 1982. The 80186 was an improvement on the {Intel 8086} and
+ {Intel 8088}. As with the 8086, it had a 16-bit {external
+ bus} and was also available as the {Intel 80188}, with an
+ 8-bit external {data bus}. The initial {clock rate} of the
+ 80186 and 80188 was 6 MHz. They were not used in many
+ computers, but one notable exception was the {Mindset}, a very
+ advanced computer for the time. They were used as {embedded
+ processors}.
+
+ One major function of the 80186/80188 series was to reduce the
+ number of chips required.
+
+ "To satisfy this market, we defined a processor with a
+ significant performance increase over the 8086 that also
+ included such common peripheral functions as
+ software-controlled wait state and chip select logic, three
+ timers, priority interrupt controller, and two channels of DMA
+ (direct memory access). This processor, the 80186, could
+ replace up to 22 separate VLSI (very large scale integration)
+ and TTL (transistor-transistor logic) packages and sell for
+ less than the cost of the parts it replaced."
+
+ -- Paul Wells of Intel Corporation writing in Byte (reference
+ below)
+
+ New instructions were also introduced as follows:
+
+ ENTER Make stcak frame for procedure parameters
+ LEAVE High-level procedure exit
+ PUSHA Push all general registers
+ POPA Pop all general registers
+ BOUND Check array index against bounds
+ IMUL Signed (integer) multiply
+ INS Input from port to string
+ OUTS Output string to port
+
+ ["The Evolution of the iAPX 286", Bob Greene, Intel
+ Corporation, PC Tech Journal, December 1984, page 134].
+
+ ["The 80286 Microprocessor", Paul Wells, Intel Corporation,
+ Byte, November 1984, p. 231].
+
+ (1999-05-10)
+
+Intel 80188
+
+ <processor> A version of the {Intel 80186} with an 8 bit
+ external data bus (instead of 16 bit). This makes it cheaper
+ to connect to peripherals.
+
+ (1995-01-13)
+
+Intel 80286
+
+ <processor> (Or "286", "i286") A {microprocessor} developed by
+ {Intel}. THe 80286 processor has a 16-bit {data bus} and
+ incorporates a {memory management unit} that allowed a limited
+ amount of {multitasking}. The 80286 only has a segmented MMU
+ while the later processors add a {page}d MMU "behind" the
+ segmented one.
+
+ The 80286 was the processor in the {IBM PC AT} {personal
+ computer}.
+
+ (1995-02-21)
+
+Intel 80386
+
+ <processor> (Commonly abbreviated to "386", trademark
+ "Intel386") The successor to the {Intel 80286}
+ {microprocessor}. It was the first Intel processor with
+ 32-bit data and address {buss}es. It can address four
+ {gigabytes} (2^32 bytes) of memory; however, 16 megabytes is a
+ typical maximum in {IBM PCs}. The 386 allows multiple
+ {application programs} to run at the same time (when running
+ under 386-specific {operating systems}) using "{protected
+ mode}".
+
+ The first {IBM compatible} to use the 386 was the {Compaq}
+ 386, before {IBM} used it in high-end models of their {PS/2}
+ series. It is also used in {HP}'s {RS} series and many
+ others.
+
+ It does not require special {EMS} memory boards to expand
+ {MS-DOS} memory limits. With the 386, the EMS standard can be
+ simulated in normal {extended memory}, and many DOS add-ons
+ provide this "Expanded Memory Manager" feature.
+
+ See also {Intel 80386SX}, {BSD386}.
+
+ (1995-02-21)
+
+Intel 80386DX
+
+ <processor> A version of the {Intel 80386} with a 32-bit {data
+ bus} and 32-bit {address bus}, a BGA. The 386DX was clocked
+ at 16 to 33 MHz by {Intel} and up to 40 MHz by {AMD}. It
+ comes in a {BGA} package.
+
+ (2003-07-05)
+
+Intel 80386SX
+
+ <processor> A lower-speed version of the {Intel 80386}. It
+ uses a 16-bit data bus instead of a 32-bit data bus. It has a
+ 24-bit {address bus}. It is faster than the 286, and more
+ importantly, like the full-size 386, provides more flexibility
+ in running existing DOS applications. Intel's version runs at
+ 16 MHz, while {AMD}'s can run at up to 33 MHz. It comes in a
+ {PFP} package.
+
+ (2003-07-05)
+
+Intel 8048
+
+ <processor> The {microcontroller} used in {IBM PC} keyboards.
+ The 8048 was inspired by, and similar to, the {Fairchild F8}
+ microprocessor but, being a microcontroller, was designed for
+ low cost and small size. The 8048 has a modified {Harvard
+ architecture}, with program {ROM} on chip and 64 to 256 bytes
+ of {RAM} also on chip. I/O is mapped in its own {address
+ space}.
+
+ Though the 8048 was eventually replaced by the very popular
+ but bizarre {Intel 8051} and {Intel 8052}, even in 2000 it is
+ still very popular due to its low cost, wide availability, and
+ development tools.
+
+ [Was it really __the_first__ microcontroller? Are the ROM and
+ RAM both on-chip?]
+
+ (2000-06-01)
+
+Intel 80486
+
+ {Intel 486}
+
+Intel 8051
+
+ <processor> A {microcontroller} developed by {Intel} in 1980
+ for use in {embedded} products and still (1999) one of the
+ most popular microcontrollers.
+
+ The 8051/8031 {cores} are used in over 100 devices from 10
+ independent manufacturers such as Dallas and Philips.
+
+ [What is the difference between the 8031/8051/8052?]
+
+ See also {CAS 8051 Assembler}, {as31} assembler, {51forth}.
+
+ {8051 FAQ
+ (http://ece.orst.edu/~pricec/8051/faq/index.html)}.
+
+ {The 8031/51 series microcontroller
+ (http://rehn.org/YAM51/)}.
+
+ {Intel MCS51 series microcontrollers
+ (http://intel.com/design/mcs51/)}.
+
+ (1999-11-21)
+
+Intel 8080
+
+ <processor> The successor to the {Intel 8008}. The 8080 had a
+ 16-bit {address bus} and an 8-bit {data bus}. It had seven
+ 8-bit {registers} (six which could also be combined as three
+ 16-bit registers), a 16-bit {stack pointer} to memory which
+ replaced the 8008's internal stack and a 16-bit {program
+ counter}. It also had 256 I/O ports (so I/O devices could be
+ connected without needing to allocate any addressing space as
+ is required for {memory mapped} devices) and a signal pin that
+ allowed the {stack} to occupy a separate bank of memory.
+
+ Shortly after the 8080, the {Motorola 6800} was introduced.
+
+ [Date?]
+
+ (1994-10-31)
+
+Intel 8085
+
+ <processor> A {microprocessor} intended to be an improved
+ {Intel 8080}, as was the {Zilog Z80}.
+
+ (1994-10-31)
+
+Intel 8086
+
+ <processor> A sixteen bit {microprocessor} chip used in early
+ {IBM PCs}. The {Intel 8088} was a version with an eight-bit
+ external data bus.
+
+ The Intel 8086 was based on the design of the {Intel 8080} and
+ {Intel 8085} (it was {source compatible} with the 8080) with a
+ similar {register set}, but was expanded to 16 bits. The Bus
+ Interface Unit fed the instruction stream to the Execution
+ Unit through a 6 byte {prefetch} queue, so fetch and execution
+ were concurrent - a primitive form of {pipelining} (8086
+ instructions varied from 1 to 4 bytes).
+
+ It featured four 16-bit general {registers}, which could also
+ be accessed as eight 8-bit registers, and four 16-bit {index
+ registers} (including the {stack pointer}). The data
+ registers were often used implicitly by instructions,
+ complicating {register allocation} for temporary values. It
+ featured 64K 8-bit I/O (or 32K 16 bit) ports and fixed
+ {vectored interrupts}. There were also four {segment
+ registers} that could be set from index registers.
+
+ The segment registers allowed the CPU to access 1 meg of
+ memory in an odd way. Rather than just supplying missing
+ bytes, as most segmented processors, the 8086 actually shifted
+ the segment registers left 4 bits and added it to the address.
+ As a result, segments overlapped, and it was possible to have
+ two pointers with the same value point to two different memory
+ locations, or two pointers with different values pointing to
+ the same location. Most people consider this a {brain
+ damaged} design.
+
+ Although this was largely acceptable for {assembly language},
+ where control of the segments was complete (it could even be
+ useful then), in higher level languages it caused constant
+ confusion (e.g. near/far pointers). Even worse, this made
+ expanding the address space to more than 1 meg difficult. A
+ later version, the {Intel 80386}, expanded the design to 32
+ bits, and "fixed" the segmentation, but required extra modes
+ (suppressing the new features) for compatibility, and retains
+ the awkward architecture. In fact, with the right assembler,
+ code written for the 8008 can still be run on the most recent
+ {Intel 486}.
+
+ The {Intel 80386} added new {op codes} in a kludgy fashion
+ similar to the {Zilog Z80} and {Zilog Z280}. The {Intel
+ 486} added full {pipelines}, and {clock doubling} (like the
+ {Zilog Z280}).
+
+ So why did {IBM} chose the 8086 series when most of the
+ alternatives were so much better? Apparently IBM's own
+ engineers wanted to use the {Motorola 68000}, and it was used
+ later in the forgotten {IBM Instruments} 9000 Laboratory
+ Computer, but IBM already had rights to manufacture the 8086,
+ in exchange for giving Intel the rights to its {bubble memory}
+ designs. Apparently IBM was using 8086s in the IBM
+ {Displaywriter} {word processor}.
+
+ Other factors were the 8-bit {Intel 8088} version, which could
+ use existing {Intel 8085}-type components, and allowed the
+ computer to be based on a modified 8085 design. 68000
+ components were not widely available, though it could use
+ {Motorola 6800} components to an extent.
+
+ {Intel} {bubble memory} was on the market for a while, but
+ faded away as better and cheaper memory technologies arrived.
+
+ (1994-12-23)
+
+Intel 8088
+
+ <processor> An {Intel 8086} with 16-bit {registers} and an
+ 8-bit data bus.
+
+ The 8088 was the processor used in the original {IBM PC}.
+
+ (1995-02-21)
+
+Intel 80x86
+
+ <processor> (x86) One of the family of {Intel}
+ {microprocessors} including the {Intel 80186}, {Intel 80286},
+ {Intel 80386}, {Intel 486}, in a more general sense also
+ {Intel 8086}, {Pentium}, {Pentium Pro}, and {Pentium II}.
+
+ The abbreviation "x86" also includes compatible processors,
+ e.g. from {Cyrix} or {AMD}.
+
+ (2004-02-27)
+
+Intel 8751
+
+ <processor> A {microcontroller} from {Intel} including a
+ {CPU}, two timers. 128 bytes of {RAM}, 4 kBytes of {EEPROM},
+ four eight-bit biderectional I/O ports and an {EIA-232} port.
+
+ The 8751 belongs to the Intel i51 Microcontroller family. It
+ was designed by Intel but is now manufactured by Intel,
+ {Philips}, {Siemens}, {AMD} and others. Motorola's
+ microcontroller families (68HC05, 68HC08 and 68HC11) are meant
+ to compete with the i51 family.
+
+ (1995-04-22)
+
+Intel Comparative Microprocessor Performance index
+
+ <benchmark, unit> (iCOMP) A unit used by {Intel} to indicate
+ the relative performance of their {80x86} {microprocessors}.
+
+ {(http://134.134.214.1/procs/perf/icomp/)}.
+
+ (1997-06-07)
+
+Intel Corporation
+
+ <company> A US microelectronics manufacturer. They produced
+ the {Intel 4004}, {Intel 8080}, {Intel 8086}, {Intel 80186},
+ {Intel 80286}, {Intel 80386}, {Intel 486} and {Pentium}
+ {microprocessor} families as well as many other {integrated
+ circuits} and {personal computer} networking and
+ communications products.
+
+ Gordon Moore and Robert Noyce founded Intel in 1968 to design,
+ manufacture, and market semiconductor computer memory to
+ replace {magnetic core} memory, the dominant computer memory
+ at that time. Dr. Andrew S. Grove joined Intel soon after its
+ incorporation. Three years later, in 1971, Intel introduced
+ the world's first {microprocessor}, the {Intel 4004}.
+
+ Intel has design, development, production, and administration
+ facilities throughout the western US, Europe and Asia. In
+ 1995 nearly 75% of the world's {personal computers} use Intel
+ architecture. Annual revenues are rapidly approaching $10
+ billion. In March, 1994, "Business Week" named Intel one of
+ the top ten American companies in terms of profit, one of the
+ top 15 market value winners, and 16th out of the magazine's
+ top 1,000 companies overall.
+
+ Intel invested a record $2.9 billion in capital and R&D in
+ 1993, and expects to increase combined spending on these
+ activities to $3.5 billion in 1994. Quarterly sales were
+ $2770M and profits, $640M in Aug 1994.
+
+ {(http://intel.com/)}.
+
+ Address: Santa Clara, CA, USA.
+
+ (1995-03-01)
+
+IntelDX4
+
+ <processor> Essentially an {Intel 486DX} {microprocessor} with
+ a 16 kilobyte on-chip {cache}.
+
+ The DX4 is the fastest member of the {Intel 486} family. 75
+ and 100MHz versions are available. At an iCOMP index rating
+ of 435, the 100 MHz DX4 performs up to 50% faster than the 66
+ MHz {Intel DX2}. The DX4's {clock multiplier} allows the
+ processor to run three times faster than the {system clock}.
+ This performance is achieved in part by a 16K on-chip {cache}
+ (double that of the other 486s). The DX4 has an integrated
+ {floating point unit}.
+
+ Like the other 486s, the DX4 achieves performance through a
+ {RISC} integer core that executes frequently used instructions
+ in a single {clock cycle} (the {Pentium}'s can execute
+ multiple instructions in a single clock cycle).
+
+ Low power consumption has been achieved with {SL} Technology
+ and a 0.6 micron manufacturing process, giving 1.6 million
+ {transistors} on a single chip operating at only 3.3 Volts.
+
+ "IntelDX4" is the entire name, the "486" has been dropped and
+ I am assured that there is no space in the same.
+
+ (1995-04-28)
+
+Intel i960
+
+ <processor> A {superscalar} 32-bit {RISC} {microprocessor}
+ from {Intel} intended for {embedded} applications.
+
+ The i960 CA variant can reach 66 native MIPS peak performance
+ with a sustained execution of two instructions per clock
+ cycle. The i960 CF has an on-chip, four kilobyte two-way
+ {set-associative} {instruction cache} and a one kilobyte {data
+ cache}. Both the CA and CF processors have on-chip {RAM}; a
+ four-channel {DMA} unit; and integrated peripherals.
+
+ (1996-05-23)
+
+INTELLECT
+
+ <language> A {query language} written by Larry Harris in 1977,
+ close to natural English.
+
+ (1995-04-14)
+
+intellectual property
+
+ <legal> (IP) The ownership of ideas and control over the
+ tangible or virtual representation of those ideas. Use of
+ another person's intellectual property may or may not involve
+ royalty payments or permission, but should always include
+ proper credit to the source.
+
+ (1997-03-27)
+
+intelligent backtracking
+
+ <algorithm> An improved {backtracking} {algorithm} for
+ {Prolog} {interpreters}, which records the point at which each
+ {logic variable} becomes bound and, when a given set of
+ bindings leads to failure, ignores any {choice point} which
+ does not bind any of those variables. No choice from such a
+ choice point can succeed since it does not change the bindings
+ which caused the failure.
+
+ (1996-04-06)
+
+intelligent database
+
+ <database> A {database management system} which performs data
+ validation and processing traditionally done by {application
+ programs}. Most DBMSs provide some data validation,
+ e.g. rejecting invalid dates or alphabetic data entered into
+ money fields, but often most processing is done by application
+ programs. There is however no limit to the amount of
+ processing that can be done by an intelligent database as long
+ as the process is a standard function for that data.
+
+ Examples of techniques used to implement intelligent databases
+ are {constraints}, {triggers} and {stored procedures}.
+
+ Moving processing to the database aids {data integrity}
+ because it is guaranteed to be consistent across all uses of
+ the data. {Mainframe} databases have increasingly become more
+ intelligent and personal computer database systems are rapidly
+ following.
+
+ (1998-10-07)
+
+Intelligent Input/Output
+
+ <architecture> /i:-too-oh/ (I2O) A specification which aims to
+ provide an {I/O} {device driver} architecture that is
+ independent of both the specific device being controlled and
+ the host {operating system}. The Hardware Device Module (HDM)
+ manages the device and the OS Services Module (OSM) interfaces
+ to the host operating system. The HDM is portable across
+ multiple operating systems, processors and busses. The HDM
+ and OSM communicate via a two layer {message passing}
+ {protocol}. A Message Layer sets up a communications session
+ and runs on top of a Transport Layer which defines how the two
+ parties share information.
+
+ I2O is also designed to facilitate intelligent I/O subsystems,
+ with support for {message passing} between multiple
+ independent processors. By relieving the host of {interrupt}
+ intensive I/O tasks required by the various layers of a driver
+ architecture, the I2O intelligent I/O architecture greatly
+ improves I/O performance. I2O systems will be able to more
+ efficiently deliver the I/O throughput required by a wide
+ range of high bandwidth applications, such as networked
+ {video}, {groupware} and {client-server} processing. I2O does
+ not restrict where the layered modules execute, providing
+ support for single processor, {multiprocessor}, and
+ {clustered} systems.
+
+ I2O is not intended to replace the driver architectures
+ currently in existence. Rather, the objective is to provide
+ an open, standards-based approach, which is complementary to
+ existing drivers, and provides a framework for the rapid
+ development of a new generation of portable, intelligent I/O.
+
+ {(http://i2osig.org/)}.
+
+ (1997-11-04)
+
+Intelligent I/O
+
+ {Intelligent Input/Output}
+
+intelligent key
+
+ <database> A {relational database} {key} which depends wholly
+ on one or more other columns in the same table. An
+ intelligent key might be identified for implementation
+ convenience, where there is no good {candidate key}.
+
+ For example, if the three-letter initials of a group of people
+ are known to be unique but only their full names are recorded,
+ a three letter acronym for their names (e.g. John Doe Smith ->
+ JDS) would be an intelligent key.
+
+ Intelligent keys are a {Bad Thing} because it is hard to
+ guarantee uniqueness, and if the value on which an intelligent
+ key depends changes then the key must either stay the same,
+ creating an inconsistency within the containing table, or
+ change, requiring changes to all other tables in which it
+ appears as a {foreign key}. The correct solution is to use a
+ {surrogate key}.
+
+ (1999-12-07)
+
+intelligent terminal
+
+ <hardware> (or "smart terminal", "programmable terminal") A
+ terminal that often contains not only a keyboard and screen,
+ but also comes with a disk drive and printer, so it can
+ perform limited processing tasks when not communicating
+ directly with the central computer. Some can be programmed by
+ the user to perform many basic tasks, including both
+ arithmetic and logic operations. In some cases, when the user
+ enters data, the {data} will be checked for errors and some
+ type of report will be produced. In addition, the valid data
+ that is entered may be stored on the disk, it will be
+ transmitted over communication lines to the central computer.
+
+ An intelligent terminal may have enough computing capability
+ to draw graphics or to offload some kind of front-end
+ processing from the computer it talks to.
+
+ The development of {workstations} and {personal computers} has
+ made this term and the product it describes semi-obsolescent,
+ but one may still hear variants of the phrase "act like a
+ smart terminal" used to describe the behaviour of workstations
+ or PCs with respect to programs that execute almost entirely
+ out of a remote {server}'s storage, using said devices as
+ displays.
+
+ The term once meant any terminal with an {addressable cursor};
+ the opposite of a {glass tty}. Today, a terminal with merely
+ an addressable cursor, but with none of the more-powerful
+ features mentioned above, is called a {dumb terminal}.
+
+ There is a classic quote from Rob Pike (inventor of the {blit}
+ terminal): "A smart terminal is not a smart*ass* terminal, but
+ rather a terminal you can educate". This illustrates a common
+ design problem: The attempt to make peripherals (or anything
+ else) intelligent sometimes results in finicky, rigid "special
+ features" that become just so much dead weight if you try to
+ use the device in any way the designer didn't anticipate.
+ Flexibility and programmability, on the other hand, are
+ *really* smart.
+
+ Compare {hook}.
+
+ (1995-04-14)
+
+IntelliMouse
+
+ {Microsoft IntelliMouse Explorer}
+
+Intel Literature Sales
+
+ Address: PO Box 58130, Santa Clara, CA 95052, USA.
+
+ Telephone: +1 800 548 4725.
+
+ (1995-01-12)
+
+Intelsat
+
+ <company, communications> A private satellite communications
+ company that provides telephony, corporate network, {video}
+ and {Internet} solutions around the globe via capacity on 25
+ geosynchronous satellites.
+
+ (2003-05-13)
+
+Intel x86
+
+ {Intel 80x86}
+
+intensional
+
+ <philosophy> A description of properties, e.g. intensional
+ equality, that relate to how an object is implemented as
+ opposed to extensional properties which concern only how its
+ output depends on its input.
+
+ (1995-01-12)
+
+Intent to Package
+
+ <Debian> (ITP) A notice, posted to the {Debian} developer
+ {mailing list}, announcing a developer's intent to make a new
+ Debian package, including a brief description of the package
+ and its license.
+
+ (2000-05-31)
+
+INTERACTIVE
+
+ A network simulation language.
+
+ ["Design and Implementation of a Pascal Based Interactive
+ Network Simulation Language", R. Lakshmanan, PhD Thesis,
+ Oakland U, Rochester MI 1983].
+
+ (1995-01-12)
+
+interactive
+
+ <programming> A term describing a program whose input and
+ output are interleaved, like a conversation, allowing the
+ user's input to depend on earlier output from the same run.
+
+ The interaction with the user is usually conducted through
+ either a text-based interface or a {graphical user interface}.
+ Other kinds of interface, e.g. using {speech recognition}
+ and/or {speech synthesis}, are also possible.
+
+ This is in contrast to {batch} processing where all the input
+ is prepared before the program runs and so cannot depend on
+ the program's output.
+
+ (1996-06-21)
+
+Interactive CourseWare
+
+ (ICW) A training program controlled by a computer that relies
+ on trainee input to determine the order and pace of
+ instruction delivery. The trainee advances through the
+ sequence of instructional events by making decisions and
+ selections. The instruction branches according to the
+ trainee's responses.
+
+ ICW is a US military term which includes {computer-aided
+ instruction} and {computer-based training}.
+
+ (1995-11-08)
+
+Interactive Data analysis Language
+
+ <language> (IDL) A language from {Xerox}, built on
+ {Interlisp-D}.
+
+ (2004-05-07)
+
+Interactive Data Entry/Access
+
+ <language> (IDEA) A language from {Data General} in which you
+ designed the screen first, and then wrote the program around
+ the predefined fields. IDEA was a precursor to the {DG COBOL}
+ {Screen Section}.
+
+ (1996-02-16)
+
+Interactive Data Language
+
+ (IDL) A commercial {array}-oriented language with numerical
+ analysis and display features, first released in 1977. It
+ supports interactive {reduction}, analysis, and
+ {visualisation} of scientific data. It is sold by {Research
+ Systems, Inc.}
+
+ Version: 3.6.1 runs under {Unix}, {MS-DOS}, {MS Windows},
+ {VAX}/{VMS} and {Macintosh}.
+
+ Not to be confused with any of the other {IDLs}.
+
+ {(ftp://gateway.rs.inc.com/pub/idl)}.
+
+ E-mail: <info@rsinc.com>.
+
+ (1994-10-07)
+
+interactive development environment
+
+ <programming, tool> (IDE, integrated development environment)
+ A system for supporting the process of writing software. Such
+ a system may include a {syntax-directed editor}, graphical
+ tools for program entry, and integrated support for compiling
+ and running the program and relating compilation errors back
+ to the {source}.
+
+ Such systems are typically both interactive and integrated,
+ hence the ambiguous acronym. They are interactive in that the
+ developer can view and alter the execution of the program at
+ the level of statements and variables. They are integrated in
+ that, partly to support the above interaction, the source code
+ editor and the execution environment are tightly coupled,
+ e.g. allowing the developer to see which line of source code
+ is about to be executed and the current values of any
+ variables it refers to.
+
+ Examples include {Visual C++} and {Visual Basic}.
+
+ (2002-09-21)
+
+Interactive Development Environments
+
+ <company> (IDE) A US {software engineering} company.
+
+ (1996-03-04)
+
+Interactive Software Engineering
+
+ <company> (ISE) The company set up by {Bertrand Meyer}, now
+ its president, to develop and distribute {Eiffel}, the
+ language which he created. ISE also organises the {TOOLS}
+ conference (Technology of Object-Oriented Languages and
+ Systems).
+
+ {(http://eiffel.com/)}.
+
+ E-mail: info@eiffel.com.
+
+ Telephone: +1 (805) 685 1006.
+
+ Address: Santa Barbara, Goleta CA, USA.
+
+ (1995-12-28)
+
+Interactive System Productivity Facility
+
+ <operating system> (ISPF) Something to do with {IBM}'s
+ {OS/390}.
+
+ {(http://s390.ibm.com/bookmgr-cgi/bookmgr.cmd/BOOKS/ISPDGD02/COVER?SHELF=ISP5BK01)}.
+
+ [Summary?]
+
+ (1999-07-14)
+
+Interactive Voice Response
+
+ <communications> (IVR) <communications> A {telecommunications}
+ system, prevelant with {PBX} and {voice mail} systems, that
+ uses a prerecorded database of voice messages to present
+ options to a user, typically over telephone lines. User input
+ is retrieved via {DTMF} tone key presses.
+
+ When used in conjunction with {voice mail}, for example, these
+ systems typically allow users to store, retrieve, and route
+ messages, as well as interact with an underlying {database}
+ server which may allow for automated transactions and {data
+ processing}.
+
+ (15 Sept 1997)
+
+ (1997-09-21)
+
+Interagency Interim National Research and Education Network
+
+ (IINREN) An evolving operating network system. Near term
+ (1992-1996) research and development activities will provide
+ for the smooth evolution of this networking infrastructure
+ into the future gigabit {NREN}.
+
+ (1994-12-06)
+
+InterBase
+
+ A commercial {active DBMS}.
+
+INTERCAL
+
+ <language, humour> /in't*r-kal/ (Said by the authors to stand
+ for "Compiler Language With No Pronounceable Acronym").
+
+ Possibly the most elaborate and long-lived joke in the history
+ of programming languages. It was designed on 1972-05-26 by
+ Don Woods and Jim Lyons at Princeton University.
+
+ INTERCAL is purposely different from all other computer
+ languages in all ways but one; it is purely a written
+ language, being totally unspeakable. The INTERCAL Reference
+ Manual, describing features of horrifying uniqueness, became
+ an underground classic. An excerpt will make the style of the
+ language clear:
+
+ It is a well-known and oft-demonstrated fact that a person
+ whose work is incomprehensible is held in high esteem. For
+ example, if one were to state that the simplest way to store a
+ value of 65536 in a 32-bit INTERCAL variable is:
+
+ DO :1 <- #0$#256
+
+ any sensible programmer would say that that was absurd. Since
+ this is indeed the simplest method, the programmer would be
+ made to look foolish in front of his boss, who would of course
+ have happened to turn up, as bosses are wont to do. The
+ effect would be no less devastating for the programmer having
+ been correct.
+
+ INTERCAL has many other peculiar features designed to make it
+ even more unspeakable. The Woods-Lyons implementation was
+ actually used by many (well, at least several) people at
+ {Princeton}.
+
+ Eric S. Raymond <esr@snark.thyrsus.com> wrote C-INTERCAL in
+ 1990 as a break from editing "The New Hacker's Dictionary",
+ adding to it the first implementation of {COME FROM} under its
+ own name. The compiler has since been maintained and extended
+ by an international community of technomasochists and is
+ consequently enjoying an unprecedented level of unpopularity.
+
+ The version 0.9 distribution includes the compiler, extensive
+ documentation and a program library. C-INTERCAL is actually
+ an INTERCAL-to-C source translator which then calls the local
+ {C} compiler to generate a binary. The code is thus quite
+ portable.
+
+ {Intercal Resource Page
+ (http://locke.ccil.org/~esr/intercal/)}.
+
+ {Usenet} newsgroup: {news:alt.lang.intercal}.
+
+ ["The INTERCAL Programming Language Reference Manual", Donald
+ R. Woods & James M. Lyon].
+
+ [{Jargon File}]
+
+ (1997-04-09)
+
+Interchange File Format
+
+ <file format> (IFF, full name "EA IFF 1985") A generic file
+ format published by {Electronic Arts} as an open standard.
+ IFF is {chunk}-based and hierarchical so files can include
+ other files. It is easily extensible and an all round Good
+ Idea.
+
+ An IFF file starts with one of the following "group IDs":
+ 'FORM', 'LIST' or 'CAT '. This is followed by an unsigned
+ 32-bit number of bytes in the remainder of the file. Then
+ comes an ID that indicates which type of IFF file this is.
+ The main image type is {ILBM}, {audio} is either {AIFF} or
+ {8SVX}, animations are {ANIM} etc. An IFF file will probably
+ have a {filename extension} related to this file type stored
+ in the file. The rest of the file is divided into {chunks}
+ each of which also has a four-byte header and byte count.
+
+ {Microsoft} {WAV} and {AVI} are all based around an almost
+ identical scheme to IFF called {RIFF}. The main difference is
+ that, in RIFF files, numbers are little-endian as on {Intel}
+ processors, whereas in IFF files they are big-endian, as on
+ the {Motorola 68000} processors in the {Amiga} where IFF files
+ were first used.
+
+ (1997-07-23)
+
+INTERCOM
+
+ <language> The {assembly language} for the {G-15}.
+
+ Versions: INTERCOM 101, INTERCOM 1000.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (1997-07-23)
+
+Interdata
+
+ <company> A computer manufacturer. Interdata became
+ {Perkin-Elmer}, then {Concurrent}.
+
+ (2004-05-12)
+
+Interest Group in Pure and Applied Logics
+
+ (IGPL) A body of 700 researchers in various aspects of {logic}
+ (symbolic, mathematical, computational, philosophical, etc.)
+ from all over the world. The group's main rôle is as a
+ research and information clearing house. The group also:
+ supports exchange of information about research problems,
+ references and common interest among group members; helps to
+ obtain photocopies of papers; supplies review copies of books
+ through the Journals on which some members are editors;
+ organises exchange visits and workshops; advises on papers for
+ publication; edits and distributes a Newsletter and an
+ electronic Bulletin; keeps an {FTP archive} of papers,
+ abstracts; obtains reductions on group purchases of logic
+ books from publishers.
+
+ {(http://theory.doc.ic.ac.uk/tfm/igpl.html)}.
+
+ E-mail: <igpl-request@doc.ic.ac.uk>.
+
+ (1995-02-10)
+
+interesting
+
+ In hacker parlance, this word has strong connotations of
+ "annoying", or "difficult", or both. Hackers relish a
+ challenge, and enjoy wringing all the irony possible out of
+ the ancient Chinese curse "May you live in interesting times".
+
+ [{Jargon File}]
+
+inter-exchange carrier
+
+ <communications> (IXC) A company allowed to handle
+ long-distance calls following the break-up of the Bell system
+ in the US by anti-trust regulators.
+
+ {Local Exchange Carriers} (LEC) are not allowed to handle
+ long-distance traffic and Inter Exchange carriers are not
+ allowed to handle local calls.
+
+ (2002-08-28)
+
+interface
+
+ <jargon> A boundary across which two systems communicate. An
+ interface might be a hardware connector used to link to other
+ devices, or it might be a convention used to allow
+ communication between two software systems. Often there is
+ some intermediate component between the two systems which
+ connects their interfaces together. For example, two {EIA-232}
+ interfaces connected via a serial cable.
+
+ See also {graphical user interface}, {Application Program
+ Interface}.
+
+ (1996-05-22)
+
+interface analysis
+
+ <testing> A software test which checks the interfaces between
+ program elements for consistency and adherence to predefined
+ rules or {axioms}.
+
+ (1996-07-09)
+
+Interface Architect
+
+ An interface builder for Motif distributed by Hewlett-Packard
+ (see UIMX).
+
+Interface Definition Language
+
+ (IDL) 1. An {OSF} standard for defining {RPC} stubs.
+
+ [Details?]
+
+ 2. Part of an effort by {Project DOE} at {SunSoft, Inc.} to
+ integrate distributed {object} technology into the {Solaris}
+ {operating system}. IDL provides the standard interface
+ between objects, and is the base mechanism for object
+ interaction.
+
+ The {Object Management Group}'s {CORBA} 1.1 (Common Object
+ Request Broker Architecture) specifies the interface between
+ objects. IDL (Interface Definition Language) is the base
+ mechanism for object interaction.
+
+ The SunSoft OMG IDL CFE (Compiler Front End) version 1.2
+ provides a complete framework for building CORBA 1.1-compliant
+ preprocessors for OMG IDL. To use it you write a back-end. A
+ complete compiler of IDL would translate IDL into {client}
+ side and {server} side routines for remote communication in
+ the same manner as {Sun}'s current {RPCL} compiler. The IDL
+ compiler front end allows integration of new back ends which
+ can translate IDL to various programming languages.
+
+ Several companies including Sunsoft are building back ends to
+ the CFE which translate IDL into target languages,
+ e.g. {Pascal} or {C++}, in the context of planned
+ CORBA-compliant products. IDL requires C++ 2.1.
+
+ Not to be confused with any of the other {IDLs}.
+
+ E-mail: <idl-cfe@sun.com>.
+
+ {(ftp://omg.org/pub/omg_idl_cfe.tar.Z)},
+ {(ftp://omg.org/pub/OMG_IDL_CFE_1.2/)}.
+
+ Telephone: Mache Creeger, SunSoft, Inc. +1 (415) 336 5884.
+
+ (1993-05-04)
+
+Interface Description Language
+
+ (IDL) A language designed by Nestor, Lamb and Wulf of {CMU} in
+ 1981 for describing the data structures passed between parts
+ of an application, to provide a language-independent
+ intermediate representation.
+
+ It forms part of Richard Snodgrass <rts@cs.arizona.edu>'s
+ {Scorpion} environment development system.
+
+ Not to be confused with any of the other {IDLs}.
+
+ Mailing list: info-idl@sei.cmu.edu.
+
+ ["The Interface Description Language: Definition and Use," by
+ Richard Snodgrass, Computer Science Press, 1989, ISBN
+ 0-7167-8198-0].
+
+ [SIGPLAN Notices 22(11) (Nov 1987) special issue].
+
+ (1994-11-11)
+
+Interface Message Processor
+
+ <networking> (IMP) The original {message switching node} on
+ the {ARPANET}.
+
+ [More details?]
+
+ (1996-04-07)
+
+Interior Gateway Protocol
+
+ (IGP) An {Internet} {protocol} which distributes {routing}
+ information to the {routers} within an {autonomous system}.
+ The term "{gateway}" is historical, "router" is currently the
+ preferred term.
+
+ See also {Exterior Gateway Protocol}, {Open Shortest Path
+ First}, {Routing Information Protocol}.
+
+ (1994-11-09)
+
+interlace
+
+ {progressive coding}
+
+interlaced image
+
+ {progressive coding}
+
+interlacing
+
+ 1. <hardware> A {video} display system which builds an {image}
+ on the {VDU} in two phases, known as "fields", consisting of
+ even and odd horizontal lines.
+
+ The complete image (a "frame") is created by scanning an
+ electron beam horizontally across the screen, starting at the
+ top and moving down after each horizontal scan until the
+ bottom of the screen is reached, at which point the scan
+ starts again at the top. On an interlaced display, even
+ numbered {scan lines} are displayed in the first field and
+ then odd numbered lines in the second field.
+
+ For a given screen {resolution}, {refresh rate} (frames per
+ second) and {phosphor} {persistence}, interlacing reduces
+ flicker because the top and bottom of the screen are redrawn
+ twice as often as if the scan simply proceded from top to
+ bottom in a single vertical sweep.
+
+ 2. <graphics> {progressive coding}.
+
+ (1998-02-25)
+
+Interlan
+
+ A brand of {Ethernet} card.
+
+ (1994-11-09)
+
+Interleaf
+
+ A document preparation system for {Sun}, {VAX}, {Apollo} and
+ other {workstations}.
+
+ (1994-11-09)
+
+interleave
+
+ {interleaving}
+
+interleaving
+
+ {sector interleave}
+
+INTERLINK
+
+ A commercial product comprising hardware and software for file
+ transfer between IBM and VAX computers.
+
+Interlisp
+
+ <language> A dialect of {Lisp} developed in 1967 by {Bolt,
+ Beranek and Newman} (Cambridge, MA) as a descendant of
+ {BBN-Lisp}. It emphasises user interfaces. It is
+ currently[?] supported by {Xerox PARC}.
+
+ Interlisp was one of two main branches of LISP (the other
+ being {MACLISP}). In 1981 {Common LISP} was begun in an
+ effort to combine the best features of both. Interlisp
+ includes a Lisp programming environment. It is {dynamically
+ scoped}. LAMBDA functions evaluate their arguments, NLAMBDA
+ functions do not. Any function could be called with optional
+ arguments.
+
+ See also {AM}, {CLISP}, {Interlisp-10}, {Interlisp-D}.
+
+ ["Interlisp Programming Manual", W. Teitelman, TR, Xerox Rec
+ Ctr 1975].
+
+ (2004-05-07)
+
+Interlisp-10
+
+ An {Interlisp} with {shallow binding}.
+
+Interlisp-D
+
+ {Xerox}'s {Interlisp} with {deep binding}.
+
+Intermedia
+
+ A hypertext system developed by a research group at IRIS
+ (Brown University).
+
+Intermedia Interchange Format
+
+ A Standard {Hypertext} Interchange format from IRIS.
+
+intermediate code
+
+ {intermediate language}
+
+Intermediate Distribution Frame
+
+ <networking> (IDF) A {network closet} containing a secondary
+ {hub}, fed from the main hub.
+
+ (1995-05-05)
+
+Intermediate Programming Language
+
+ <language> A very early attempt by Arthur W. Burks to express
+ machine language at a higher level of abstraction. Like
+ {Plankalkul}, it used a right-handed style of {assignment}, in
+ which the location appears on the right.
+
+ (1995-05-09)
+
+Intermediate System
+
+ <networking> (IS) An {Open Systems Interconnection} system
+ which performs {network layer} forwarding. It is analogous to
+ an {IP} {router}.
+
+ (1994-11-29)
+
+Intermediate System-Intermediate System
+
+ <networking> (IS-IS) The {OSI} {Interior Gateway Protocol}.
+
+ (2003-07-12)
+
+intermercial
+
+ {interstitial}
+
+Intermetrics, Inc.
+
+ {AverStar}
+
+intermodulation distortion
+
+ <electronics, communications> (IMD) {Nonlinear} {distortion}
+ in a system or {transducer}, characterised by the appearance
+ in the output of frequencies equal to the sums and differences
+ of integral multiples of the two or more component frequencies
+ present in the {input} waveform.
+
+ (2000-08-21)
+
+internal field separators
+
+ <operating system> ($IFS) A predefined {environment variable}
+ in the {Unix} {Bourne shell} whose default value is the
+ three-character string containing {space}, {tab} and {line
+ feed}. Any string of one or more of these characters
+ separates the command and each of its arguments in a command
+ line.
+
+ $IFS also tells the shell's built-in read command where to
+ split an input line when reading into multiple variables.
+ E.g. setting IFS=: would be appropriate for reading a file
+ with ':'-separated fields, such as /etc/passwd.
+
+ (1999-04-07)
+
+Internal Translator
+
+ <language, mathematics> (IT) An early {compiler} for
+ mathematics developed by A.J. {Perlis} et al at Carnegie Tech
+ ca 1957. IT was originally written for the {Burroughs 205},
+ then the {IBM 650}.
+
+ IT was the forerunner of RUNCIBLE, GATE, CORRELATE and GAT.
+ IT source code was converted to PIT, thence to SPIT.
+
+ IT-2 produced machine language directly, IT-3 developed at
+ Carnegie added double-precision {floating-point}.
+
+ [Sammet 1969, pp. 139-141].
+
+ [CACM 1(5):22 1958].
+
+ (1994-11-30)
+
+International Algebraic Language
+
+ {ALGOL 58}
+
+International Atomic Time
+
+ <time, standard> (TAI) An international standard measurement
+ of time based on the comparison of many {atomic clocks}. TAI
+ is maintained by the Bureau International des Poids et Mesures
+ (BIPM), the world's governing body for civil atomic time
+ measurement. TAI is the basis for {Coordinated Universal
+ Time}.
+
+ {BIPM
+ (http://www.bipm.org/enus/5_Scientific/c_time/time_1.html)}.
+
+ (2001-08-02)
+
+International Business Machines
+
+ <company> (IBM) The best known American computer manufacturer,
+ founded by Thomas J. Watson (born 1874-02-17), known as "Big
+ Blue" after the colour of its logo. IBM makes everything from
+ {mainframes} to {personal computers} (PCs) and has been
+ immensely successful in selling them, chiefly to business. It
+ has often been said that "Nobody has ever been sacked for
+ buying IBM".
+
+ The {IBM PC} in its various versions has been so successful
+ that unqualified reference to a "PC" almost certainly means a
+ PC from IBM, or one of the many brands of {clone} produced by
+ other manufacturers to cash in on IBM's original success.
+
+ Alternative expansions of "IBM" such as Inferior But
+ Marketable; It's Better Manually; Insidious Black Magic; It's
+ Been Malfunctioning; Incontinent Bowel Movement, illustrate
+ the considerable antipathy most hackers have long felt toward
+ the "industry leader" (see {fear and loathing}).
+
+ Quarterly sales $15351M, profits $689M (Aug 1994).
+
+ {(http://ibm.com/)}.
+
+ (1999-04-07)
+
+International Computers Limited plc
+
+ <company> (ICL) A UK hardware and software manufacturer
+ specialising in systems integration in selected markets,
+ supported by its service and technology businesses. ICL
+ operates in over 80 countries worldwide, with 24000 employees
+ and revenues of £2.6 billion in 1993.
+
+ ICL produced {George 2}, {George 3}, {VME}, {OpenVME}, {Series
+ 39}, {DME}, {CME}, the {ICL 1900} and {ICL 2900} series.
+
+ {(http://icl.co.uk/)}.
+
+ {Usenet} newsgroup: {news:alt.sys.icl}.
+
+ (1995-04-19)
+
+International Core War Society
+
+ <games, standard, body> (ICWS) The official standards body for
+ {Core War}.
+
+ (1996-02-16)
+
+International Data Encryption Algorithm
+
+ <algorithm, cryptography> (IDEA) A conventional {encryption}
+ {algorithm}, written by Xuejia Lai and James Massey, in 1992.
+
+ It is a {block cipher}, considered to be the best and most
+ secure available, and operates on 64-bit blocks with a 128 bit
+ {key}.
+
+ It is used by {Pretty Good Privacy}.
+
+ (1996-03-07)
+
+International Electrotechnical Commission
+
+ <standard, body> (IEC) A {standard}isation body at the same
+ level as {ISO}.
+
+ [Relationship? Why separate?]
+
+ (1995-04-21)
+
+International Federation for Information Processing
+
+ <body> A multinational federation of professional and technical
+ organisations (or national groupings of such organisations)
+ concerned with information processing. From any one country,
+ only one such organisation - which must be representative of
+ the national activities in the field of information processing
+ - can be admitted as a Full Member. In addition, a regional
+ group of developing countries can be admitted as a Full
+ Member. On 1 October 1993, 46 organisations were Full Members
+ of the Federation, representing 66 countries.
+
+ IFIP was founded under the auspices of UNESCO and advises them
+ and the {ITU-T}.
+
+ {(http://dit.upm.es/~cdk/ifip.html)}.
+
+ (1995-03-10)
+
+International Function Point Users Group
+
+ <body, programming> (IFPUG) A forum for the exchange of ideas
+ about {Function Point Analysis}. IFPUG's membership now
+ includes over 500 companies on four continents.
+
+ Telephone: +1 (614) 8957130.
+
+ (1995-03-10)
+
+internationalisation
+
+ <programming> (i18n, globalisation, enabling, software
+ enabling) The process and philosophy of making software
+ portable to other {locales}.
+
+ For successful {localisation}, products must be technically
+ and culturally neutral. Effective internationalisation
+ reduces the time and resources required for localisation,
+ improving time-to-market abroad and allowing {simultaneous
+ shipment}. In orther words, internationalisation abstracts
+ out local details, localisation specifies those details for a
+ particular locale.
+
+ Technically this may include allowing {double-byte character
+ sets} such as {unicode} or Japanese, local numbering, date and
+ currency formats, and other local format conventions.
+
+ It also includes the separation of {user interface} text
+ e.g. in {dialog boxes} and {menus}. All the text used by an
+ application may be kept in a separate file or directory, so
+ that it can be translated all at once. User interfaces may
+ require more screen space for text in other languages.
+
+ The simplest form of internationalisation may be to make use
+ of {operating system} calls that format time, date and
+ currency values according to the operating system's
+ configuration.
+
+ The abbreviation i18n means "I - eighteen letters - N".
+
+ (1999-06-28)
+
+internationalization
+
+ {internationalisation}
+
+International Multimedia Teleconferencing Consortium
+
+ <body> (IMTC) A non-profit corporation formed in September
+ 1994 comprising more than 150 companies from around the world.
+ The IMTC encourages the development and implementation of
+ interoperable {multimedia} {teleconferencing} systems based on
+ international {open standards}.
+
+ {(http://imtc.org/)}.
+
+ (1999-03-17)
+
+International Olympiad in Informatics
+
+ <event> (IOI) An annual competition in computing science for
+ senior pupils at secondary schools all over the world.
+
+ {(http://win.tue.nl/win/ioi/)}.
+
+ (1996-12-07)
+
+International Organisation for Standardisation
+
+ {International Organization for Standardization}
+
+International Organization for Standardization
+
+ <standard, body> (ISO) A voluntary, nontreaty organisation
+ founded in 1946, responsible for creating international
+ {standards} in many areas, including computers and
+ communications. Its members are the national standards
+ organisations of 89 countries, including the {American
+ National Standards Institute}.
+
+ ISO produced the {OSI} seven layer model for network
+ architecture.
+
+ The term "ISO" is not actually an acronym for anything. It is
+ a pun on the Greek prefix "iso-", meaning "same". Some ISO
+ documents say ISO is not an acronym even though it is an
+ anagram of the initials of the organisation's name.
+
+ {(http://iso.ch/)}.
+
+ (1999-06-22)
+
+International Phonetic Alphabet
+
+ <text, human language> (IPA) A system of symbols for
+ representing pronunciation. There is no commonly agreed way
+ to represent IPA in {ASCII} characters though it can be
+ represented in {Unicode}.
+
+ [Reference?]
+
+ (1998-12-30)
+
+International Programmable Airline Reservation System
+
+ <application> (IPARS) The international version of {PARS},
+ designated by {IBM} for use in all IBM World trade countries
+ (i.e. outside domestic USA).
+
+ (1999-01-18)
+
+International Smalltalk Association
+
+ <body> (ISA) A user group which published newsletters on
+ {Smalltalk}-related issues, technical and general information.
+ Its goal was to champion Smalltalk and its uses. It was
+ disbanded around 1991.
+
+ (1995-02-16)
+
+International Standard
+
+ <standard> The series of {standards} from {ISO} and its
+ subcommitees.
+
+ [List? Text?]
+
+ (1995-04-21)
+
+International Telecommunications Union
+
+ <body, standard> (ITU) ITU-T, the telecommunication
+ standardisation sector of ITU, is responsible for making
+ technical recommendations about telephone and data (including
+ fax) communications systems for {PTTs} and suppliers. Before
+ 1993-03-01 ITU-T was known as CCITT. Every four years they
+ hold plenary sessions where they adopt new standards; there
+ was one in 1992.
+
+ ITU works closely with all {standards} organisations to form
+ an international uniform standards system for communication.
+ Study Group XVII is responsible for recommending standards for
+ data communications over telephone networks. They publish the
+ V.XX standards and X.n {protocols}. {V.21} is the same as
+ {EIA}'s {EIA-232}. {V.24} is the same as EIA's {EIA-232C}.
+ {V.28} is the same as EIA's {EIA-232D}.
+
+ Address: International Telecommunication Union, Information
+ Services Department, Place des Nations, 1211 Geneva 20,
+ Switzerland.
+
+ Telephone: +41 (22) 730 5554. Fax: +41 (22) 730 5337.
+
+ E-mail: <helpdesk@itu.ch>, <teledoc@itu.arcom.ch> (Mail body:
+ HELP).
+
+ {(http://itu.ch/)}.
+
+ ITU-T standards can be obtained by {FTP} from {Korea
+ (ftp://kum.kaist.ac.kr/doc/STANDARDS/ccitt)}; UK - {Imperial
+ (ftp://src.doc.ic.ac.uk/pub/computing/ccitt/ccitt-standards/)},
+ {HENSA
+ (ftp://unix.hensa.ac.uk/pub/uunet/doc/literary/obi/Standards/CCITT)};
+ France - {INRIA (ftp://croton.inria.fr/ITU/ccitt)}, {IMAG
+ (ftp://imag.imag.fr/doc/ccitt)}; {Israel
+ (ftp://cs.huji.ac.il/pub/doc/standards/ccitt)}; FTP USA:
+ {UUNET (ftp://ftp.uu.net/pub/lietrary/obi/Standards/CCITT)},
+ {gatekeeper
+ (ftp://gatekeeper.dec.com/pub/net/info/bruno.cs.colorado.edu/pub/standards/ccitt)},
+ {world.std.com (ftp://world.std.com/obi/Standards/CCITT)};
+ {Australia (ftp://metro.ucc.su.oz.au/pub/ccitt)}; {Germany
+ (ftp://quepasa.cs.tu-berlin.de/pub/doc/CCITT)}; {Japan
+ (ftp://sh.wide.ad.jp/CCITT)};
+
+ (1995-01-16)
+
+International Traffic in Arms Regulation
+
+ <legal> (ITAR) Now called the {Defense Trade Regulations}.
+
+Internaut
+
+ <jargon, web> (From "Internet" + "astronaut") A
+ person who explores the {Internet} (or "{cyberspace}"),
+ normally searching for information.
+
+ (2002-06-30)
+
+Internet
+
+ <networking> (Note: capital "I"). The Internet is the largest
+ {internet} (with a small "i") in the world. It is a three
+ level {hierarchy} composed of {backbone networks}, {mid-level
+ networks}, and {stub networks}. These include commercial
+ (.com or .co), university (.ac or .edu) and other research
+ networks (.org, .net) and military (.mil) networks and span
+ many different physical networks around the world with various
+ {protocols}, chiefly the {Internet Protocol}.
+
+ Until the advent of the {web} in 1990, the Internet
+ was almost entirely unknown outside universities and corporate
+ research departments and was accessed mostly via {command
+ line} interfaces such as {telnet} and {FTP}. Since then it
+ has grown to become an almost-ubiquitous aspect of modern
+ information systems, becoming highly commercial and a widely
+ accepted medium for all sort of customer relations such as
+ advertising, brand building, and online sales and services.
+ Its original spirit of cooperation and freedom have, to a
+ great extent, survived this explosive transformation with the
+ result that the vast majority of information available on the
+ Internet is free of charge.
+
+ While the web (primarily in the form of {HTML} and {HTTP}) is
+ the best known aspect of the Internet, there are many other
+ {protocols} in use, supporting applications such as
+ {electronic mail}, {Usenet}, {chat}, {remote login}, and {file
+ transfer}.
+
+ There were 20,242 unique commercial domains registered with
+ {InterNIC} in September 1994, 10% more than in August 1994.
+ In 1996 there were over 100 {Internet access providers} in the
+ US and a few in the UK (e.g. the {BBC Networking Club},
+ {Demon}, {PIPEX}).
+
+ There are several bodies associated with the running of the
+ Internet, including the {Internet Architecture Board}, the
+ {Internet Assigned Numbers Authority}, the {Internet
+ Engineering and Planning Group}, {Internet Engineering
+ Steering Group}, and the {Internet Society}.
+
+ See also {NYsernet}, {EUNet}.
+
+ {The Internet Index (http://openmarket.com/intindex)} -
+ statistics about the Internet.
+
+ (2000-02-21)
+
+internet
+
+ <networking> (Note: not capitalised) Any set of networks
+ interconnected with {routers}. The {Internet} is the biggest
+ example of an internet.
+
+ (1996-09-17)
+
+Internet Access Provider
+
+ <networking, company> (IAP) A company or other origanisation
+ which provides access to the {Internet} to businesses and/or
+ consumers. An IAP purchases an Internet link from another
+ company that has a direct link to the Internet and resells
+ portions of that {bandwidth} to the general public.
+
+ For example, an IAP may purchase a {T1} link (1.544Mb/s) and
+ resell that bandwidth in chunks consisting of {ISDN} (64Kb/s,
+ 128Kb/s) and analog {modems} (14.4Kb/s, 28.8Kb/s). The IAP's
+ customer base is likely to include both businesses and
+ individuals. Individual customers usually connect to the IAP
+ via a modem and telephone line to a (preferably local) {point
+ of presence}.
+
+ An IAP may also be an {Internet Service Provider}.
+
+ (1996-06-25)
+
+Internet Adapter
+
+ <networking, product> The Internet Adapter (TIA). A program
+ from {Cyberspace Development} which runs on a {Unix} shell
+ account and acts as a {SLIP} {emulator}. A TIA emulated SLIP
+ account is not quite the same as a real SLIP account but TIA's
+ SLIP emulation is completely standard in terms of working with
+ {MacTCP}-based software on the {Macintosh} (or {WinSock} on a
+ {Microsoft Windows} machine).
+
+ You do not get your own {Internet Address} as you do with a
+ real SLIP account, instead, TIA uses the IP number of the
+ machine it runs on and "redirects" traffic back to you. You
+ cannot set up your machine as an {FTP} {server}, for instance,
+ since there's no IP number for an {FTP} {client} elsewhere to
+ connect to.
+
+ TIA's performance is reportedly good, faster than normal SLIP
+ in fact, and about as fast as {Compressed SLIP}. Future
+ releases will support {CSLIP} and even {PPP}.
+
+ {Cyberspace Development} has ported TIA to several versions of
+ {Unix} and more are on the way.
+
+ {TERM} is a free program which performs a similar function
+ between two machines both running {Unix}.
+
+ {(http://marketplace.com/)}.
+
+ {Setting up TIA
+ (http://webcom.com/~llarrow/tiarefg.html)}.
+
+ {Telnet (telnet://marketplace.com)}.
+
+ {Gopher (gopher://marketplace.com/)}.
+
+ {FTP (ftp://marketplace.com/tia/)}.
+
+ E-mail: <tia-info@marketplace.com>.
+
+ (1995-04-12)
+
+Internet address
+
+ {IP address}
+
+internet address
+
+ <networking> (Note lower case "i"). An {IP} address that
+ uniquely identifies a node on an {internet}.
+
+ [{Jargon File}]
+
+ (1995-04-12)
+
+Internet Architecture Board
+
+ (IAB) The technical body that oversees the development of the
+ {Internet} suite of {protocols}. It has two task forces: the
+ {Internet Engineering Task Force} and the {Internet Research
+ Task Force}.
+
+ "IAB" previously stood for Internet Activities Board.
+
+ (1994-12-06)
+
+Internet Assigned Numbers Authority
+
+ <body, networking> (IANA) The central registry for various
+ "{assigned numbers}": {Internet Protocol} parameters, such as
+ {port}, {protocol}, and {enterprise} numbers; and options,
+ codes, and types. The currently assigned values are listed in
+ the "Assigned Numbers" document {STD 2}. To request a number
+ assignment, e-mail <iana@isi.edu>.
+
+ (1994-12-06)
+
+Internet backbone
+
+ <communications, networking> High-speed networks that carry
+ {Internet} traffic.
+
+ These {communications} {networks} are provided by companies
+ such as {AT&T}, {GTE}, {IBM}, {MCI}, {Netcom}, {Sprint},
+ {UUNET} and consist of high-speed links in the {T1}, {T3},
+ {OC1} and {OC3} ranges. The {backbones} carry {Internet}
+ traffic around the world and meet at {Network Access Points}
+ (NAPs).
+
+ {Internet Service Providers} (ISPs) connect either directly to
+ a backbone, or they connect to a larger ISP with a connection
+ to a backbone.
+
+ The {topology} of the "backbone" and its interconnections may
+ once have resembled a spine with ribs connected along its
+ length but is now almost certainly more like a fishing net
+ wrapped around the world with many circular paths.
+
+ [Map?]
+
+ (1998-07-02)
+
+Internet Chess Server
+
+ <networking, games> An interactive meeting-place on the
+ {Internet} where people can play {chess} against each other.
+
+ {Usenet} newsgroup: {news:alt.chess.ics}.
+
+ [Server address?]
+
+ (1995-03-25)
+
+Internet Control Message Protocol
+
+ <protocol> (ICMP) An extension to the {Internet Protocol} (IP)
+ that allows for the generation of error messages, test
+ packets, and informational messages related to IP. It is
+ defined in STD 5, {RFC 792}.
+
+ (1999-09-18)
+
+Internet Corporation for Assigned Names and Numbers
+
+ <body, networking> (ICANN) The non-profit corporation that was
+ formed to assume responsibility for {IP address} allocation,
+ protocol parameter assignment, {domain name system}
+ management, and {root server} system management functions now
+ performed under U.S. Government contract by {IANA} and other
+ entities.
+
+ {ICANN Home (http://icann.org/)}.
+
+ (2002-01-09)
+
+Internet-Draft
+
+ (I-D) A draft working document of the {Internet Engineering
+ Task Force}, its Areas, and its Working Groups. As the name
+ implies, Internet-Drafts are purely discussion documents with
+ no formal status. They are valid for a maximum of six months
+ and may be updated, replaced, or obsoleted by other documents
+ at any time. Very often, an I-D is a precursor to a {Request
+ For Comments}.
+
+ (1994-12-08)
+
+Internet Engineering and Planning Group
+
+ (IEPG) {(http://iepg.org/)}.
+
+Internet Engineering Steering Group
+
+ (IESG) A body composed of the {Internet Engineering Task
+ Force} Area Directors and the IETF Chair. It provides the
+ first technical review of {Internet} standards and is
+ responsible for day-to-day "management" of the IETF.
+
+ (1994-12-08)
+
+Internet Engineering Task Force
+
+ <networking, standard, body> (IETF) The IETF is a large, open
+ international community of network designers, operators,
+ vendors and researchers whose purpose is to coordinate the
+ operation, management and evolution of the {Internet} and to
+ resolve short- and mid-range {protocol} and architectural
+ issues. It is a major source of proposals for {protocol}
+ {standards} which are submitted to the {Internet Architecture
+ Board} (IAB) for final approval. The IETF meets three times a
+ year and extensive minutes are included in the IETF
+ Proceedings.
+
+ The IETF Secretariat, run by The {Corporation for National
+ Research Initiatives} with funding from the US government,
+ maintains an index of {Internet-Drafts} whereas {RFCs} are
+ maintained by The {Internet Architecture Board}.
+
+ {(http://ietf.org)}.
+
+ (1999-01-27)
+
+Internet Experiment Note
+
+ (IEN) A series of reports pertinent to the {Internet}. IENs
+ were published in parallel to RFCs and are no longer active.
+
+ See also {Internet-Draft}, {Request For Comments}.
+
+ (1994-12-08)
+
+Internet Explorer
+
+ <web> (IE, MSIE) {Microsoft}'s free {World-Wide
+ Web} {browser} for {Microsoft Windows}, {Windows 95}, {Windows
+ NT}, and {Macintosh}. Internet Explorer is the main rival to
+ {Netscape Navigator} (which runs on many more {platforms}).
+ Both support the same core features and offer incompatible
+ extensions.
+
+ Microsoft combined later versions of IE with their {file
+ system} browser, "Explorer" and bundled it with {Windows 95}
+ in an attempt to use their dominance of the {desktop}
+ {operating system} market to force users to abandon Netscape's
+ browser, which they perceived as a potential threat. This,
+ and other dubious business moves, became the subject of a US
+ Department of Justice antitrust trial in late 1998/early 1999.
+
+ {(http://microsoft.com/ie/)}.
+
+ (1999-01-31)
+
+Internet Express
+
+ An {Internet provider} in Colorado Springs, USA. Formerly
+ called the Community News Service. They provide {SLIP}
+ accounts at no extra charge.
+
+ (1994-12-08)
+
+Internet Foundation Classes
+
+ <language, library, programming, standard> (IFC) A {library}
+ of {classes} used in the creation of {Java} {applets} with
+ {GUIs}.
+
+ Created by {Netscape}, the Internet Foundation Classes provide
+ GUI elements, as well as classes for {Applications Services},
+ {Security}, {Messaging}, and {Distributed Objects}.
+
+ The IFC code, which is exclusively Java, is layered on top of
+ the Java {Abstract Windowing Toolkit} (AWT), thus preserving
+ {platform independence}.
+
+ The AWT and IFC collectively form the {Java Foundation
+ Classes}, which provide a standardised framework for
+ developing powerful Java applications.
+
+ {IFC download (http://wp.netscape.com/eng/ifc/download.html)}.
+
+ (2003-08-17)
+
+Internet Go Server
+
+ <games, networking> (IGS) A place for {Go} players to meet and
+ play via the {Internet}.
+
+ {IGS Home (http://pandanet.co.jp/English/)}.
+
+ (1995-03-17)
+
+Internet Group Management Protocol
+
+ <protocol> (IGMP) An extension to the {Internet Protocol},
+ used by IP {hosts} to report their {host group} memberships to
+ immediately-neighbouring {multicast} {routers}.
+
+ See also {MBONE}.
+
+ Version 1 of IGMP is defined in Appendix 1 of {RFC 1112}.
+
+ Version 2 is proposed in {RFC 2236}.
+
+ (1999-11-08)
+
+Internet Information Server
+
+ <web> (IIS) {Microsoft's} {web server} and {FTP
+ server} for {Windows NT}.
+
+ IIS is intended to meet the needs of a range of users: from
+ workgroups and departments on a corporate {intranet} to {ISPs}
+ hosting {websites} that receive millions of {hits} per day.
+
+ Features include innovative web publishing, customisable
+ tools, {wizards}, customisable management tools, flexible
+ administration options, and analysis tools.
+
+ IIS makes it easy to share documents and information across a
+ company intranet or the {Internet}, and is completely
+ integrated with {Windows NT Directory Services}.
+
+ IIS 1.0 was released for {Windows NT 3.51} and had a limited
+ feature set.
+
+ IIS 2.0 was released with {Windows NT 4.0} with a similar
+ feature set to IIS 1.0.
+
+ IIS 3.0 quickly followed with many additions including
+ {Active Server Pages} (ASP), {ISAPI} and {ADO} 1.0.
+
+ IIS 4.0 is built into {Windows NT Server 4.0}. It includes
+ ASP 2.0, ISAPI and ADO 1.5.
+
+ {(http://microsoft.com/iis)}.
+
+ Rival servers include {Apache} and {Netscape Enterprise
+ Server}.
+
+ (1999-08-04)
+
+Internet Inter-ORB Protocol
+
+ <protocol, standard> (IIOP) A protocol which will be mandatory
+ for all {CORBA} 2.0 compliant {platforms}. The initial phase
+ of the project is to build an infrastructure consisting of: an
+ IIOP to {HTTP} {gateway} which allows CORBA {clients} to
+ access {WWW} resources; an HTTP to IIOP gateway to let WWW
+ clients access CORBA resources; a {web server} which makes
+ resources available by both IIOP and HTTP; web browsers which
+ can use IIOP as their {native} protocol.
+
+ {(http://ansa.co.uk/ANSA/ISF/wwwCorba_1.html)}.
+
+ (1996-04-01)
+
+Internet Message Access Protocol
+
+ <protocol, messaging> (IMAP) A {protocol} allowing a {client}
+ to access and manipulate {electronic mail} messages on a
+ {server}. It permits manipulation of remote message folders
+ ({mailboxes}), in a way that is functionally equivalent to
+ local mailboxes.
+
+ IMAP includes operations for creating, deleting, and renaming
+ mailboxes; checking for new messages; permanently removing
+ messages; searching; and selective fetching of message
+ attributes, texts, and portions thereof. It does not specify
+ a means of posting mail; this function is handled by a mail
+ transfer protocol such as {SMTP}.
+
+ Latest version: 4.
+
+ See {RFC 2060}, {RFC 2061}, and others.
+
+ Compare: {POP}.
+
+ (1999-03-14)
+
+Internet Monthly Report
+
+ (IMR) Publication designed to communicate to the {Internet
+ Research Group} the accomplishments, milestones reached, or
+ problems discovered by the participating organisations.
+
+ (1994-12-08)
+
+Internet Network Information Center
+
+ <networking> (InterNIC) An umbrella entity created by the
+ {National Science Foundation} in Spring 1992, in cooperation
+ with the Internet community, consisting of Network Information
+ Service Managers who provided and/or coordinated {NSFNet}
+ services. {General Atomics} provided information services,
+ {AT&T} provided directory and database services, and {Network
+ Solutions, Inc.} (NSI) provided registration services.
+
+ In 1999 Internic was replaced by {ICANN}.
+
+ {(http://internic.net/)}.
+
+ {(http://nic.net/)}.
+
+ (2003-04-16)
+
+internet number
+
+ {internet address}
+
+Internet Open Trading Protocol
+
+ <protocol, business> (IOTP, Formerly "Open Trading Protocol",
+ OTP) A specification that provides an interoperable framework
+ for Internet commerce. It is optimised for the case where the
+ buyer and the merchant do not have a prior acquaintance and is
+ payment system independent. It will be able to encapsulate
+ and support payment systems such as {SET}, {Mondex},
+ CyberCash's {CyberCoin}, DigiCash's {e-cash}, GeldKarte, etc.
+ IOTP is able to handle cases where such merchant roles as the
+ shopping site, the payment handler, the deliverer of goods or
+ services, and the provider of customer support are performed
+ by different Internet sites.
+
+ The IOTP specification is maintained by the {IETF} {Internet
+ Open Trading Protocol (trade) Working Group
+ (http://ietf.org/html.charters/trade-charter.html)}.
+
+ {(http://otp.org/)}.
+
+ (2001-09-22)
+
+Internet Protocol
+
+ <networking> (IP) The {network layer} for the {TCP/IP}
+ {protocol} suite widely used on {Ethernet} networks, defined
+ in {STD} 5, {RFC} 791. IP is a {connectionless},
+ {best-effort} {packet switching} protocol. It provides
+ {packet} {routing}, {fragmentation} and re-assembly through
+ the {data link layer}.
+
+ IPv4 is the version in widespread use and {IPv6} was just
+ beginning to come into use in 2000 but is still not widespread
+ by 2008.
+
+ [Other versions? Dates?]
+
+ (2000-12-19)
+
+Internet Protocol Control Protocol
+
+ <networking> (IPCP) The {Control Protocol} for {Internet
+ Protocol}.
+
+ [Details?]
+
+ (2002-06-29)
+
+Internet Protocol version 4
+
+ <networking, protocol> The version of {Internet Protocol} in
+ widespread use in 2000.
+
+ (2000-12-19)
+
+Internet Protocol version 6
+
+ <networking, protocol> (IPv6, IPng, IP next generation) The
+ most viable candidate to replace the current {Internet
+ Protocol}. The primary purpose of IPv6 is to solve the
+ problem of the shortage of {IP addresses}.
+
+ The following features have been purposed: 16-byte addresses
+ instead of the current four bytes; embedded {encryption} - a
+ 32-bit {Security Association ID} (SAID) plus a variable length
+ initialisation vector in {packet} headers; user
+ {authentication} (a 32-bit SAID plus variable length
+ {authentication} data in headers); autoconfiguration
+ (currently partly handled by {Dynamic Host Configuration
+ Protocol}); support for {delay-sensitive traffic} - a 24 bit
+ flow ID field in headers to denote voice or video, etc.
+
+ One possible solution is based on the {TUBA} protocol (RFC
+ 1347, 1526, 1561) which is itself based on the {OSI}
+ {Connectionless Network Protocol} (CNLP). Another is {TP/IX}
+ (RFC 1475) which changes {TCP} and {UDP} headers to give a
+ 64-bit {IP address}, a 32-bit {port} number, and a 64 bit
+ sequence number.
+
+ {RFC 1550} is a white paper on IPng.
+
+ {IPv6.org (http://ipv6.org/)}.
+
+ ["Doubts About IPng could create TCP/IP chaos", Johna Till
+ Johnson, Data Communications, Nov 1994].
+
+ (2004-06-17)
+
+Internet provider
+
+ {Internet Service Provider}
+
+Internet Public Library
+
+ (IPL) A project at the {University of Michigan} School of
+ Information and Library Studies to provide an on-line, 24 hour
+ public library, chaired by an assemblage of librarians and
+ information industry professionals. The library aims to
+ provide library services to a target audience estimated to
+ number 1/4 of the entire American population by the end of the
+ century.
+
+ The Internet Public Library is scheduled to go on-line in
+ March 1995. Among the first services will be on-line
+ reference; youth services; user education; and professional
+ services for librarians.
+
+ {(http://ipl.sils.umich.edu/)}.
+
+ {(telnet://ipl.sils.umich.edu/)}.
+
+ Mailing list: majordomo@sils.umich.edu.
+
+ (1995-07-20)
+
+Internet Registry
+
+ (IR) The {Internet Assigned Numbers Authority} has the
+ discretionary authority to delegate portions of its
+ responsibility and, with respect to {network address} and
+ {Autonomous System} identifiers, has lodged this
+ responsibility with the {IR}. The IR function is performed by
+ the {Defense Data Network} {Network Information Center}.
+
+Internet Relay Chat
+
+ <chat, messaging> (IRC) /I-R-C/, occasionally /*rk/ A
+ {client-server} {chat} system of large (often worldwide)
+ networks. IRC is structured as networks of {Internet}
+ {servers}, each accepting connections from {client} programs,
+ one per user.
+
+ The IRC community and the {Usenet} and {MUD} communities
+ overlap to some extent, including both {hackers} and regular
+ folks who have discovered the wonders of computer networks.
+ Some {Usenet} jargon has been adopted on IRC, as have some
+ conventions such as {emoticons}. There is also a vigorous
+ native jargon (see the entry for "{chat}").
+
+ The largest and first IRC network is {EFNet}, with a smaller
+ breakaway network called the {Undernet} having existed since
+ 1992, and dozens of other networks having appeared (and
+ sometimes disappeared) since.
+
+ See also {nick}, {bot}, {op}.
+
+ {Yahoo's IRC index
+ (http://yahoo.com/Computers_and_Internet/Internet/Chat/IRC/)}.
+
+ (1998-01-25)
+
+Internet Research Steering Group
+
+ <body, standard> (IRSG) The "governing body" of the {Internet
+ Research Task Force}.
+
+ (1994-12-08)
+
+Internet Research Task Force
+
+ (IRTF) The IRTF is chartered by the {Internet Architecture
+ Board} to consider long-term {Internet} issues from a
+ theoretical point of view. It has Research Groups, similar to
+ {Internet Engineering Task Force} Working Groups, which are
+ each tasked to discuss different research topics. Multi-cast
+ audio/video conferencing and {privacy enhanced mail} are
+ samples of IRTF output.
+
+ (1994-12-08)
+
+Internet Security Association and Key Management Protocol
+
+ <networking, protocol> (ISAKMP) The definitions and procedures
+ for {authenticating} communication between 2 {peers}. This
+ includes the creation and management of {Security
+ Associations}, {key} generation techniques, and {threat
+ mitigation}. ISAKMP is proposed in {RFC 2408}.
+
+ (2000-02-08)
+
+Internet Server Application Programming Interface
+
+ <web> (ISAPI) {Microsoft}'s programming interface
+ between applications and their {Internet Server}. Active
+ Servers created with ISAPI extensions can be complete
+ in-process applications themselves, or can "connect" to other
+ services. ISAPI is used for the same sort of functions as
+ {CGI} but uses {Microsoft Windows} {dynamic link libraries}
+ (DLL) for greater efficiency. The server loads the DLL the
+ first time a request is received and the DLL then stays in
+ memory, ready to service other requests until the server
+ decides it is no longer needed. This minimises the overhead
+ associated with executing such applications many times.
+
+ An HTTP server can unload ISAPI application DLLs to free
+ memory or preload them to speed up the first access.
+ Applications can also be enhanced by {ISAPI filters}
+
+ (1997-01-06)
+
+Internet Service Provider
+
+ <company, networking> (ISP) A company which provides other
+ companies or individuals with access to, or presence on, the
+ {Internet}. Most ISPs are also {Internet Access Providers};
+ extra services include help with design, creation and
+ administration of {website}s, training and
+ administration of {intranets} and {domain name} registration.
+
+ (2005-06-19)
+
+Internet Society
+
+ <body> (ISOC) A non-profit, professional membership
+ organisation which facilitates and supports the technical
+ evolution of the {Internet}, stimulates interest in and
+ educates the scientific and academic communities, industry and
+ the public about the technology, uses and applications of the
+ Internet, and promotes the development of new applications for
+ the system. The Society provides a forum for discussion and
+ collaboration in the operation and use of the global Internet
+ infrastructure.
+
+ The Internet Society publishes a quarterly newsletter, the
+ Internet Society News, and holds an annual conference, INET.
+ The development of Internet technical standards takes place
+ under the auspices of the Internet Society with substantial
+ support from the {Corporation for National Research
+ Initiatives} under a cooperative agreement with the US Federal
+ Government.
+
+ {(http://info.isoc.org/)}.
+
+ (1994-10-27)
+
+Internet Telephony
+
+ {IP Telephony}
+
+Internet Telephony Service Providers
+
+ <communications> (ITSP) Companies providing {IP Telephony}.
+
+ (1999-04-26)
+
+internetworking
+
+ The interconnection of two or more {networks}, usually {local
+ area networks} so that data can pass between {hosts} on the
+ different networks as though they were one network. This
+ requires some kind of {router} or {gateway}.
+
+ (1994-11-30)
+
+Internetwork Packet eXchange
+
+ <networking> (IPX) A {network layer} {protocol} initially
+ developed at {XEROX Corporation} and made popular by {Novell,
+ Inc.} as the basic protocol in its {Novell NetWare} {file
+ server} {operating system}.
+
+ A {router} with IPX routing can interconnect {Local Area
+ Networks} so that Netware {clients} and {servers} can
+ communicate.
+
+ The {SPX} {transport layer} protocol runs on top of IPX.
+
+ (1997-03-04)
+
+Internet Worm
+
+ <networking, security> The November 1988 {worm} perpetrated by
+ {Robert T. Morris}. The worm was a program which took
+ advantage of bugs in the {Sun} {Unix} {sendmail} program,
+ {Vax} programs, and other security loopholes to distribute
+ itself to over 6000 computers on the {Internet}. The worm
+ itself had a bug which made it create many copies of itself on
+ machines it infected, which quickly used up all available
+ processor time on those systems.
+
+ Some call it "The Great Worm" in a play on Tolkien (compare
+ {elvish}, {elder days}). In the fantasy history of his Middle
+ Earth books, there were dragons powerful enough to lay waste
+ to entire regions; two of these (Scatha and Glaurung) were
+ known as "the Great Worms". This usage expresses the
+ connotation that the RTM hack was a sort of devastating
+ watershed event in hackish history; certainly it did more to
+ make non-hackers nervous about the Internet than anything
+ before or since.
+
+ (1995-01-12)
+
+Internex On-Line
+
+ A rather cheap {Internet} service provider in Toronto, Canada.
+
+ {(http://io.org/)}.
+
+ (1994-11-30)
+
+InterNIC
+
+ {Internet Network Information Center}
+
+interoperability
+
+ The ability of software and hardware on multiple machines from
+ multiple vendors to communicate.
+
+interoperable database
+
+ A {database} {front-end} which communicates with multiple
+ heterogenous databases and makes them appear as a single
+ homogenous entity with {semantic calls}.
+
+ See {ODBC}.
+
+ (1995-02-06)
+
+inter-packet gap
+
+ <networking> A time delay between successive data {packets}
+ mandated by the network standard for {protocol} reasons.
+
+ In {Ethernet}, the medium has to be "silent" (i.e., no data
+ transfer) for a few microseconds before a {node} can consider
+ the network idle and start to transmit. This is necessary for
+ fairness reasons. The delay time, which approximately equals
+ the signal propagation time on the cable, allows the "silence"
+ to reach the far end so that all nodes consider the net idle.
+
+ (1995-11-11)
+
+interpolation
+
+ {extrapolation}
+
+Interpress
+
+ Interpreted {FORTH}-like graphics language, possibly the first
+ {page description language}, predating {PostScript}. Both are
+ descendants of {JaM}. Used on {Xerox} printers.
+
+ ["Interpress, The Source Book", Steven Harrington et al, P-H
+ 1988.]
+
+interpreted
+
+ {interpreter}
+
+interpreter
+
+ <programming> A program which executes other programs. This
+ is in contrast to a {compiler} which does not execute its
+ input program (the "{source code}") but translates it into
+ executable "{machine code}" (also called "{object code}")
+ which is output to a file for later execution. It may be
+ possible to execute the same source code either directly by an
+ interpreter or by compiling it and then executing the {machine
+ code} produced.
+
+ It takes longer to run a program under an interpreter than to
+ run the compiled code but it can take less time to interpret
+ it than the total required to compile and run it. This is
+ especially important when prototyping and testing code when an
+ edit-interpret-debug cycle can often be much shorter than an
+ edit-compile-run-debug cycle.
+
+ Interpreting code is slower than running the compiled code
+ because the interpreter must analyse each statement in the
+ program each time it is executed and then perform the desired
+ action whereas the compiled code just performs the action.
+ This run-time analysis is known as "interpretive overhead".
+ Access to variables is also slower in an interpreter because
+ the mapping of identifiers to storage locations must be done
+ repeatedly at run time rather than at compile time.
+
+ There are various compromises between the development speed
+ when using an interpreter and the execution speed when using a
+ compiler. Some systems (e.g. some {Lisps}) allow interpreted
+ and compiled code to call each other and to share variables.
+ This means that once a routine has been tested and debugged
+ under the interpreter it can be compiled and thus benefit from
+ faster execution while other routines are being developed.
+ Many interpreters do not execute the source code as it stands
+ but convert it into some more compact internal form. For
+ example, some {BASIC} interpreters replace {keywords} with
+ single byte tokens which can be used to {index} into a {jump
+ table}. An interpreter might well use the same {lexical
+ analyser} and {parser} as the compiler and then interpret the
+ resulting {abstract syntax tree}.
+
+ There is thus a spectrum of possibilities between interpreting
+ and compiling, depending on the amount of analysis performed
+ before the program is executed. For example {Emacs Lisp} is
+ compiled to "{byte-code}" which is a highly compressed and
+ optimised representation of the Lisp source but is not machine
+ code (and therefore not tied to any particular hardware).
+ This "compiled" code is then executed (interpreted) by a {byte
+ code interpreter} (itself written in {C}). The compiled code
+ in this case is {machine code} for a {virtual machine} which
+ is implemented not in hardware but in the byte-code
+ interpreter.
+
+ See also {partial evaluation}.
+
+ (1995-01-30)
+
+Interpretive Menu Processor
+
+ <language> (IMP) The language used to implement much of the
+ {user interface} of the {Alis} {office automation} package
+ from {Applix, Inc}.
+
+ (1996-04-07)
+
+Inter-process Communication
+
+ <programming, operating system> (IPC) Exchange of data between
+ one {process} and another, either within the same computer or
+ over a {network}. It implies a {protocol} that guarantees a
+ response to a request. Examples are {Unix} {sockets}, {RISC
+ OS}'s messages, {OS/2}'s {Named Pipes}, {Microsoft Windows}'
+ {DDE}, {Novell}'s {SPX} and {Macintosh}'s IAC.
+
+ Although IPC is performed automatically by programs, an
+ analogous function can be performed interactively when users
+ cut and paste data from one process to another using a
+ {clipboard}.
+
+ (1995-12-14)
+
+interrupt
+
+ <programming> 1. An {asynchronous} event that suspends normal
+ processing and temporarily diverts the {flow of control}
+ through an "{interrupt handler}" routine.
+
+ Interrupts may be caused by both {hardware} (I/O, timer,
+ machine check) and {software} (supervisor, {system call} or
+ {trap} instruction).
+
+ In general the computer responds to an interrupt by storing
+ the information about the current state of the running
+ program; storing information to identify the source of the
+ interrupt; and invoking a first-level {interrupt handler}.
+ This is usually a {kernel} level privileged process that can
+ discover the precise cause of the interrupt (e.g. if several
+ devices share one interrupt) and what must be done to keep
+ operating system tables (such as the process table) updated.
+ This first-level handler may then call another handler,
+ e.g. one associated with the particular device which generated
+ the interrupt.
+
+ 2. Under {MS-DOS}, nearly synonymous with "{system call}"
+ because the {OS} and {BIOS} routines are both called using the
+ INT instruction (see {interrupt list}) and because programmers
+ so often have to bypass the operating system (going directly
+ to a BIOS interrupt) to get reasonable performance.
+
+ [{Jargon File}]
+
+ (1995-02-07)
+
+interrupt handler
+
+ <software> A routine which is executed when an {interrupt}
+ occurs. Interrupt handlers typically deal with low-level
+ events in the hardware of a computer system such as a
+ character arriving at a {serial port} or a tick of a
+ {real-time clock}. Special care is required when writing an
+ interrupt handler to ensure that either the interrupt which
+ triggered the handler's execution is masked out (inhibitted)
+ until the handler exits, or the handler is {re-entrant} so
+ that multiple concurrent invocations will not interfere with
+ each other.
+
+ If interrupts are masked then the handler must execute as
+ quickly as possible so that important events are not missed.
+ This is often arranged by splitting the processing associated
+ with the event into "upper" and "lower" halves. The lower
+ part is the interrupt handler which masks out further
+ interrupts as required, checks that the appropriate event has
+ occurred (this may be necessary if several events share the
+ same interrupt), services the interrupt, e.g. by reading a
+ character from a {UART} and writing it to a {queue}, and
+ re-enabling interrupts.
+
+ The upper half executes as part of a user process. It waits
+ until the interrupt handler has run. Normally the {operating
+ system} is responsible for reactivating a process which is
+ waiting for some low-level event. It detects this by a shared
+ {flag} or by inspecting a shared queue or by some other
+ synchronisation mechanism. It is important that the upper and
+ lower halves do not interfere if an interrupt occurs during
+ the execution of upper half code. This is usually ensured by
+ disabling interrupts during {critical sections} of code such
+ as removing a character from a queue.
+
+ (2002-07-24)
+
+interrupt list
+
+ [{MS-DOS}] The list of all known {software interrupt} calls
+ (both documented and undocumented) for {IBM PCs} and
+ compatibles, maintained and made available for free
+ redistribution by Ralf Brown <ralf@cs.cmu.edu>. As of late
+ 1992, it had grown to approximately two megabytes in length.
+
+interrupt priority level
+
+ The {Motorola 68000} family of processors can be at an
+ interrupt priority level from 0 (no interrupt in progress) up
+ to 7. While the processor is handling an interrupt at one
+ level, it will ignore other interrupts at that level or lower.
+
+ (1994-11-23)
+
+interrupt request
+
+ (IRQ) The name of an input found on many processors which
+ causes the processor to suspend normal instruction execution
+ temporarily and to start executing an {interrupt handler}
+ routine. Such an input may be either "{level sensitive}" -
+ the {interrupt} condition will persist as long as the input is
+ active or "{edge triggered}" - an interrupt is signalled by a
+ low-to-high or high-to-low transition on the input. Some
+ processors have several interrupt request inputs allowing
+ different priority interrupts.
+
+ (1994-12-08)
+
+interrupts
+
+ {interrupt}
+
+Intersil 6100
+
+ <programming> (IMS 6100) A single chip design of the {DEC}
+ {PDP-8} {minicomputer}. The old PDP-8 design was very
+ strange, and if it hadn't been popular, an awkward {CPU} like
+ the 6100 would never been designed.
+
+ The 6100 was a 12-bit processor, which had three {registers}:
+ the {PC}, AC (accumulator), and MQ. All 2-operand
+ instructions read AC and MQ and wrote back to AC. It had a
+ 12-bit {address bus}, limiting {RAM} to only 4K. Memory
+ references were 7-bit, offset either from address 0, or from
+ the PC page base address (PC AND 7600 oct).
+
+ It had no {stack}. Subroutines stored the {PC} in the first
+ word of the subroutine code itself, so {recursion} required
+ fancy programming.
+
+ 4K RAM was pretty much hopeless for general purpose use. The
+ 6102 support chip (included in the 6120) added 3 address
+ lines, expanding memory to 32K the same way that the PDP-8/E
+ expanded the PDP-8. Two registers, IFR and DFR, held the page
+ for instructions and data respectively (IFR was always used
+ until a data address was detected). At the top of the 4K
+ page, the PC wrapped back to 0, so the last instruction on a
+ page had to load a new value into the IFR if execution was to
+ continue.
+
+ (2003-04-04)
+
+Intersil 6120
+
+ <processor> (IMS 6120) An improved version of the {Intersil
+ 6100}. The 6120 was used in the {DECmate}.
+
+ [Details?]
+
+ (1994-11-23)
+
+interstitial
+
+ <web> A {web} page that appears before
+ the expected content page. Interstitials can be used for
+ advertising (intermercial, transition ad) or to confirm that
+ the user is old enough to view the requested page, etc..
+
+ (2003-07-11)
+
+Intertec
+
+ <company> The computer manufacturer that built the {Superbrain}.
+
+ All Intertec systems were sold, installed and serviced by dealers.
+ Intertec manufactured the entire product including designing and
+ producing the circuit boards and molding the cabinets.
+
+ Intertec's first products were terminals - a {dumb terminal}
+ called "Intertube" and a {smart terminal} that emulated various
+ common terminals ({VT100} etc.) called "The Emulator". The
+ terminals looked similar to the Superbrain, but smaller.
+
+ {(http://www.old-computers.com/museum/computer.asp?st=1&c=204)}.
+
+ (2013-12-30)
+
+interupt
+
+ <spelling> It's spelled "{interrupt}".
+
+ (1996-12-13)
+
+InterViews
+
+ An object-oriented toolkit developed at Stanford University
+ for building graphical user interfaces. It is implemented in
+ C++ and provides a library of objects and a set of protocols
+ for composing them.
+
+interworking
+
+ <standard> Systems or components, possibly from different
+ origins, working together to perform some task. Interworking
+ depends crucially on {standards} to define the {interfaces}
+ between the components. The term implies that there is some
+ difference between the components which, in the absence of
+ common standards, would make it unlikely that they could be
+ used together. For example, {software} from different
+ companies, running on different {hardware} and {operating
+ systems} can interwork via standard network {protocols}.
+
+ (1998-11-22)
+
+intranet
+
+ <networking> Any {network} which provides similar services
+ within an organisation to those provided by the {Internet}
+ outside it but which is not necessarily connected to the
+ Internet. The commonest example is the use by a company of
+ one or more {web} servers on an internal {TCP/IP}
+ network for distribution of information within the company.
+
+ Since about 1995, intranets have become a major growth area in
+ corporate computing due to the availability of cheap or free
+ commercial {browser} and {web server} software which allows
+ them to provide a simple, uniform {hypertext} interface to
+ many kinds of information and {application programs}.
+
+ Some companies give limited access to their intranets to other
+ companies or the general public. This is known as an
+ "{extranet}".
+
+ (1997-07-14)
+
+Intrinsics
+
+ <operating system, graphics> A library package on top of
+ {Xlib}, extending the basic functions of the {X Window
+ System}. It provides mechanisms for building {widget sets}
+ and application environments.
+
+ (1996-08-26)
+
+introspection
+
+ <programming, philosophy> A feature of some {programming
+ languages} that allows a running {program} to obtain
+ information about its own implementation.
+
+ For example, the {Lisp} function, "symbol-function" takes a
+ Lisp symbol and returns the function definition associated
+ with that symbol. Lisp is particularly suited to
+ introspection because its {source code} uses the same
+ underlying representation as its data. Another example is
+ {Perl}'s "can" {method} which returns true if a given
+ {object}'s {class} provides a given method.
+
+ (2010-01-19)
+
+introspection annotation
+
+ <programming> A kind of {pragma} that makes information about
+ the implementation of a program available to the program at
+ {run-time}, allowing it to do {introspection}.
+
+ For example, {gtk-doc} defines a {GObject Introspection}
+ {syntax} for {annotations} that give {machine readable}
+ information about function {parameters} and {return values},
+ though these don't appear to be intended for actual
+ introspection.
+
+ (2010-01-19)
+
+Intrusion Countermeasure Electronics
+
+ <security, jargon> (ICE) A contrived acronym for security
+ software, coined by {Usenet}ter Tom Maddox and popularised by
+ {William Gibson}'s {cyberpunk} SF novels. In Gibson's novels
+ ICE software responds to intrusion by attempting to literally
+ kill the intruder.
+
+ The term is not in serious use as of 2000 apart from the
+ commercial software product, {BlackICE} and a growing number
+ of others.
+
+ See also: {icebreaker}.
+
+ [{Jargon File}]
+
+ (2000-03-18)
+
+Intrusive Testing
+
+ <testing> Testing that collects timing and processing
+ information during program execution that may change the
+ behaviour of the software from its behavior in a real
+ environment. Intrusive testing usually involves additional
+ code embedded in the software being tested or additional
+ processes running concurrently with software being tested on
+ the same processor.
+
+ (1996-12-01)
+
+Intuition
+
+ <operating system> The {Amiga} {windowing system} (a
+ shared-code library).
+
+ (1997-08-01)
+
+intuitionism
+
+ {intuitionistic logic}
+
+intuitionistic logic
+
+ <logic, mathematics> Brouwer's foundational theory of
+ mathematics which says that you should not count a proof of
+ (There exists x such that P(x)) valid unless the proof
+ actually gives a method of constructing such an x. Similarly,
+ a proof of (A or B) is valid only if it actually exhibits
+ either a proof of A or a proof of B.
+
+ In intuitionism, you cannot in general assert the statement (A
+ or not-A) (the principle of the {excluded middle}); (A or
+ not-A) is not proven unless you have a proof of A or a proof
+ of not-A. If A happens to be {undecidable} in your system
+ (some things certainly will be), then there will be no proof
+ of (A or not-A).
+
+ This is pretty annoying; some kinds of perfectly
+ healthy-looking examples of {proof by contradiction} just stop
+ working. Of course, excluded middle is a theorem of
+ {classical logic} (i.e. non-intuitionistic logic).
+
+ {History
+ (http://britanica.com/bcom/eb/article/3/0,5716,118173+14+109826,00.html)}.
+
+ (2001-03-18)
+
+intuitionistic probability
+
+ <logic> Florentin Smarandache's representation of the
+ probability of an event occuring, given by T, I, F which are real
+ subsets representing the truth, indeterminacy, and falsity
+ percentages respectively, and
+
+ n_sup = sup(T) + sup(I) + sup(F) < 100
+
+ Related to {intuitionistic logic}.
+
+ [Florentin Smarandache, "A Unifying Field in Logics. /
+ {Neutrosophy}: Neutrosophic Probability, Set, and Logic",
+ American Research Press, Rehoboth 1999].
+
+ (2001-03-18)
+
+intuitionist logic
+
+ <spelling> Incorrect term for "{intuitionistic logic}".
+
+ (1999-11-24)
+
+invariant
+
+ <programming> A rule, such as the {ordering} of an ordered
+ list or {heap}, that applies throughout the life of a data
+ structure or procedure. Each change to the data structure
+ must maintain the correctness of the invariant.
+
+ (1996-03-12)
+
+inverse
+
+ <mathematics> Given a {function}, f : D -> C, a function g : C
+ -> D is called a left inverse for f if for all d in D, g (f d)
+ = d and a right inverse if, for all c in C, f (g c) = c and an
+ inverse if both conditions hold. Only an {injection} has a
+ left inverse, only a {surjection} has a right inverse and only
+ a {bijection} has inverses. The inverse of f is often written
+ as f with a -1 superscript.
+
+ (1996-03-12)
+
+Inverse Address Resolution Protocol
+
+ <networking, protocol> (InARP) Additions to {ARP} typically
+ used for {Frame Relay}. [Any other examples of its use?]
+
+ {Frame Relay} stations {route} {frames} of a higher level
+ protocol between {LANs}, across a {Permanent Virtual Circuit}.
+ These stations are identified by their {Data Link Control
+ Identifier} (DLCI), equivalent to an {Ethernet address} in a
+ {LAN} itself.
+
+ InARP allows a station to determine a protocol address (e.g.
+ {IP address}) from a DLCI. This is useful if a new {virtual
+ circuit} becomes available. Signalling messages announce its
+ DLCI, but without the corresponding protocol address it is
+ unusable: no {frames} can be {routed} to it.
+
+ {Reverse ARP} (RARP) performs a similar task on an {Ethernet}
+ {LAN}, however RARP answers the question "What is my IP
+ Address?" whereas InARP answers the question "What is your
+ protocol address?".
+
+ See {RFC 2390}.
+
+ (2000-01-15)
+
+inverse comment convention
+
+ <programming> A kind of {literate programming} where the
+ program code is marked to distinguish it from the text, rather
+ than the other way around as in normal programs.
+
+ (2003-09-24)
+
+inverted index
+
+ <database, information science> A sequence of ({key}, pointer)
+ pairs where each pointer points to a {record} in a {database}
+ which contains the key value in some particular field. The
+ index is sorted on the key values to allow rapid searching for
+ a particular key value, using e.g. {binary search}. The index
+ is "inverted" in the sense that the key value is used to find
+ the record rather than the other way round. For databases in
+ which the records may be searched based on more than one
+ field, multiple indices may be created that are sorted on
+ those keys.
+
+ An index may contain gaps to allow for new entries to be added
+ in the correct sort order without always requiring the
+ following entries to be shifted out of the way.
+
+ (1995-02-08)
+
+invoking a method
+
+ {method invocation}
+
+InWorld VR
+
+ <company, virtual reality> Manufacturers of the {CyberWand}.
+
+ (1995-04-04)
+
+IO
+
+ <humour, abuse> Idiotic operator.
+
+ (2003-05-15)
+
+io
+
+ <networking> The {country code} for British Indian Ocean
+ territory.
+
+ (1999-01-27)
+
+I/O
+
+ {Input/Output}
+
+IOI
+
+ {International Olympiad in Informatics}
+
+Iomega Corporation
+
+ <company, storage> A storage device manufacturer whose major
+ products are the {Zip} and {Jaz} removable {disk drives} and
+ {Ditto} {tape drives}. They became popular with an early
+ product called the {Bernoulli Box}.
+
+ These products fall in line with their focus set in 1994 "to
+ help people manage their stuff". The company's stated aim is
+ to create portable, fast, large and cheap storage solutions.
+ Iomega's major competitor in the growing market for removable
+ disks is {SyQuest}, who seem to always be a few weeks behind
+ them.
+
+ In general, Iomega target the {Small Office/Home Office}.
+ They are also investigating the growing {digital photography}
+ market which also needs large removable storage devices.
+
+ Iomega's president and CEO is Kim Edwards. They have nearly
+ 2000 employees in offices world-wide. Revenue for the quarter
+ ending Dec 1996 was $371 million and net income was $20
+ million.
+
+ Headquarters: Roy, Utah, USA.
+
+ {(http://iomega.com/index.html)}.
+
+ (1997-04-15)
+
+I-OOA
+
+ A tool, developed and sold by the Kennedy-Carter company, that
+ supports the {Schlaer Mellor} design method, and that
+ generates code in {C} and {C++}. This tool can be modified to
+ generate code of different styles, and also, to generate code
+ in different programming languages.
+
+ (1995-01-31)
+
+I/O redirection
+
+ {input/output redirection}
+
+IOS
+
+ {Internetworking Operating System}
+
+Iota
+
+ <language, specification> A specification language.
+
+ ["The Iota Programming System", R. Nakajima er al, Springer
+ 1983].
+
+ (1994-12-08)
+
+IOT&E
+
+ {Initial Operational Test and Evaluation}
+
+IOW
+
+ <chat> in other words.
+
+ (1997-05-26)
+
+IP
+
+ {Internet Protocol}
+
+IPA
+
+ {International Phonetic Alphabet}
+
+iPad
+
+ <computer> A {tablet computer} announced by {Apple Computer,
+ Inc.} on 2010-01-27 to be released in March 2010. The iPad
+ runs {iPhone OS} 3.2, providing {multi-touch} interaction and
+ {multimedia} processing. Like {Apple}'s {iPhone} and {iPod},
+ it uses a {virtual keyboard} for text input and runs most
+ {iPhone apps}. It adds the {iBooks} application for reading
+ text in {ePub} format.
+
+ It has a 1GHz {Apple A4} {SoC} processor, up to 64GB of flash
+ memory, a 250mm LED-backlit colour LCD display ({resolution}
+ 1024x768 pixels) and a 25 {Wh} lithium-polymer battery.
+ {Internet} access will be {Wi-Fi} in early models with {HSDPA}
+ {3G} available soon after using a {micro-SIM}. It weighs
+ 730g. Features it lacks include a camera, the ability to
+ {multitask} and an open developement environment.
+
+ The iPad is the culmination of a series of attempts by Apple
+ to produce a tablet device, starting with the {Newton
+ MessagePad 100} in 1993 and including collaboration with
+ {Acorn Computers} in developing the {ARM6} processor.
+
+ {Apple iPad (http://www.apple.com/ipad)}.
+
+ (2010-01-31)
+
+IP address
+
+ <networking> (Internet address) The 32-bit number uniquely
+ identifying a {node} on a network using {Internet Protocol},
+ as defined in {STD} 5, {RFC} 791. An IP address is normally
+ displayed in {dotted decimal notation}, e.g. 128.121.4.5.
+
+ The address can be split into a {network number} (or network
+ address) and a {host number} unique to each host on the
+ network and sometimes also a {subnet address}.
+
+ The way the address is split depends on its "class", A, B or C
+ (but see also {CIDR}). The class is determined by the high
+ address bits:
+
+ Class A - high bit 0, 7-bit network number, 24-bit host
+ number. n1.a.a.a 0 <= n1 <= 127
+
+ Class B - high 2 bits 10, 14-bit network number, 16-bit host
+ number. n1.n2.a.a 128 <= n1 <= 191
+
+ Class C - high 3 bits 110, 21-bit network number, 8-bit host
+ number. n1.n2.n3.a 192 <= n1 <= 223
+
+ {DNS} translates a node's {fully qualified domain name} to an
+ Internet address which {ARP} (or {constant mapping})
+ translates to an {Ethernet address}.
+
+ [{Jargon File}]
+
+ (2006-01-27)
+
+IPARS
+
+ {International Programmable Airline Reservation System}
+
+I-Pay
+
+ <protocol> A Dutch only payment system for the {Internet}.
+
+ [Reference?]
+
+ (1998-04-28)
+
+IPC
+
+ {Inter-Process Communication}
+
+ipconfig
+
+ <networking> A {Microsoft Windows} program to display
+ information about the the computer's {Internet Protocol}
+ settings, including {IP address}, {DHCP} lease information,
+ network card {Ethernet address}, and {DNS} information.
+
+ [Was it ever "winipcfg"?]
+
+ (2006-02-12)
+
+IPCP
+
+ {Internet Protocol Control Protocol}
+
+IPE
+
+ {Integrated Programming Environment}
+
+Iperf
+
+ <networking, tool> A tool to measure maximum {TCP}
+ {bandwidth}, allowing the tuning of various parameters and
+ {UDP} characteristics. Iperf reports bandwidth, {delay
+ jitter}, and {datagram} loss. An {IPv6} version is also
+ available.
+
+ Latest version: 1.7.0, as of 2004-01-18.
+
+ {Iperf Home (http://dast.nlanr.net/Projects/Iperf/)}.
+
+ (2004-01-18)
+
+IPL
+
+ 1. {Information Processing Language}.
+
+ 2. {Internet Public Library}.
+
+ 3. {Initial Program Load}.
+
+ 4. {Initial Program Loader}.
+
+ (1997-08-31)
+
+IP next generation
+
+ {Internet Protocol Version 6}
+
+IPng
+
+ {Internet Protocol Version 6}
+
+IP number
+
+ {Internet address}
+
+IPS
+
+ A {thread}ed language.
+
+ ["IPS, An Unorthodox High Level Language", K. Meinzer, BYTE
+ pp. 146-159 (Jan 1979)].
+
+ (1994-11-04)
+
+IPSE
+
+ {Integrated Project Support Environment}
+
+IPsec
+
+ <networking, protocol, security> ("{IP} Secure"?) A {protocol}
+ that provides {security} for transmission of sensitive
+ information over unprotected {networks} such as the
+ {Internet}. IPsec acts at the {network layer}, protecting and
+ authenticating {IP} {packets} between participating devices
+ ("peers"), such as {Cisco} {routers}.
+
+ {IETF IPsec (http://ietf.org/ids.by.wg/ipsec.html)}.
+
+ (2002-05-06)
+
+IPT
+
+ {IP Telephony}
+
+IP Telephony
+
+ <communications> (IPT, Internet Telephony) Use of {IP} data
+ connections to exchange {voice} and {fax} data that have
+ traditionally been carried over the {public switched telephone
+ network}.
+
+ During the late 1990s, an increasing number of telephone calls
+ have been routed over the {Internet}. Calls made in this way
+ avoid PSTN charges. Unlike traditional telephony, IP
+ telephony is relatively unregulated.
+
+ Companies providing these services are known as {Internet
+ Telephony Service Providers} (ITSPs). They include telephone
+ companies, cable TV companies and {Internet Service Providers}
+ (ISPs).
+
+ There are still many problems with voice quality, {latency},
+ {compression} {algorithms}, and {quality of service}.
+
+ {Voice over IP} is an organised effort to standardise IP
+ telephony.
+
+ See also {Computer Telephone Integration}.
+
+ {Internet Telephony Overview
+ (http://fokus.gmd.de/research/cc/glone/projects/ipt/)}.
+
+ (1999-03-17)
+
+IPv4
+
+ {Internet Protocol version 4}
+
+IPv6
+
+ {Internet Protocol version 6}
+
+IPX
+
+ {Internetwork Packet eXchange}
+
+IPXCP
+
+ <networking> {Internetwork Packet eXchange} {Control
+ Protocol}.
+
+ (1995-09-27)
+
+IQ
+
+ Pictorial query language, implemented in Ratfor.
+
+ ["Structured Implementation of an Image Query Language",
+ Y.E. Lien et al, in Database Techniques for Pictorial
+ Applications, A. Blaser ed, pp.416-430].
+
+iq
+
+ <networking> The {country code} for Iraq.
+
+ (1999-01-27)
+
+IQL
+
+ An object-oriented deductive language/database system.
+
+IR
+
+ 1. <networking> {Internet Registry}.
+
+ 2. <electronics> {infrared}.
+
+ (1997-01-30)
+
+ir
+
+ <networking> The {country code} for Iran.
+
+ (1999-01-27)
+
+IrBUS
+
+ {IrDA Control}
+
+IRC
+
+ {Internet Relay Chat}
+
+ircop
+
+ <messaging> /*r'-kop/ ("{IRC}" + "{op}", but with the,
+ presumably intentional, alternate analysis "IRC" + "cop")
+ Someone who is endowed with privileges on {IRC}, not limited
+ to a particular {channel}. These privileges include {channel
+ op} privileges in any channel, but also notably include the
+ ability to disconnect a user from the IRC network.
+
+ Ircops are generally people who are in charge of the IRC
+ {server} at their particular {site}. Compare {op}.
+
+ (1997-12-12)
+
+IRC penis war
+
+ {penis war}
+
+IrDA
+
+ {Infrared Data Association}
+
+IrDA-C
+
+ {IrDA Control}
+
+IrDA Control
+
+ <standard> (IrDA-C, formerly IrBUS) {Infrared} standard from
+ {IrDA}. IrDA Control is a low speed communication standard
+ that allows cordless peripherals such as keyboards, mice,
+ {game pads}, and {joysticks} to interact with intelligent host
+ devices. Host devices include {PCs}, home appliances, game
+ machines, and television and web {set-top boxes}.
+
+ IrDA Control supports data rates of 75 Kbps at up to 8 metres,
+ and is designed to integrate with devices that use {USB}
+ {HID}. Parts and products featuring IrDA Control are expected
+ in 1998.
+
+ See also {IrDA Data}, {AIR}.
+
+ (1999-10-14)
+
+IrDA Data
+
+ <standard> (IrDA-D) {Infrared} standards from {IrDA}. IrDA
+ Data is designed for data transfer over a distance of up to 1
+ metre, acting as a point-to-point cable replacement. Several
+ IrDA Data standards exist, supporting data rates from 9600 bps
+ - 50 Mbps, namely {SIR}, {FIR}, and {VFIR}.
+
+ See also {IrDA Control}, {AIR}.
+
+ (1999-10-14)
+
+IRDATA
+
+ <robotics> Industrial Robot DATA. A standardised robot
+ control code. "IRDATA, Industrial Robot Data", DIN 66313,
+ Beuth-Verlag 1991.
+
+IRDP
+
+ {ICMP Router Discovery Protocol}
+
+IRDS
+
+ Information Resource Dictionary System. A set of ISO
+ standards for CASE repositories. It governs the definition of
+ data dictionaries to be implemented on top of relational
+ databases (see repository, data dictionary).
+
+IRET
+
+ {Return from interrupt}
+
+IRIS
+
+ <body> Institute for Research in Information and Scholarship
+ of Brown University (Providence RI).
+
+ (1994-11-04)
+
+Iris
+
+ An {object-oriented} {DBMS}.
+
+ (1994-11-04)
+
+IRISA
+
+ {INRIA}
+
+IRIS Explorer
+
+ <mathematics, tool> {Numerical Algorithms Group} (NAG)'s tool
+ for developing {visualisation} applications via a {visual
+ programming environment}. IRIS Explorer has a range of
+ visualisation techniques, from simple graphs to
+ multidimensional animation, that can help show trends and
+ relationships in data.
+
+ IRIS Explorer uses standard {Open Inventor}, {ImageVision} and
+ {OpenGL} libraries as well as NAG's own numerical libraries.
+ It is available for Windows, Unix and Linux. It has a
+ point-and-click interface and a library of "modules" (software
+ routines).
+
+ {IRIS Explorer home (http://www.nag.co.uk/Welcome_IEC.asp)}.
+
+ (2008-09-04)
+
+IRIX
+
+ <operating system> /ir'iks/ The main {operating system} used
+ by {Silicon Graphics} {workstations} and {servers}. IRIX is
+ {multiprocessor} and {multi-threaded}. It incorporates
+ substantial functionality from {UNIX} {System V}, Release 4.1
+ and 4.2.
+
+ (1997-06-17)
+
+IRL
+
+ 1. <jargon, chat> In real life. Generally synonymous with
+ {f2f}.
+
+ 2. <language, robotics> {Industrial Robot Language}.
+
+ (1997-01-31)
+
+IRM
+
+ {Information Resource Management}
+
+iron
+
+ Hardware, especially older and larger hardware of {mainframe}
+ class with big metal cabinets housing relatively low-density
+ electronics (but the term is also used of modern
+ {supercomputers}). Often in the phrase {big iron}. Oppose
+ {silicon}.
+
+ See also {dinosaur}.
+
+ [{Jargon File}]
+
+ (1994-11-04)
+
+Iron Age
+
+ <history> In the history of computing, 1961-1971 - the
+ formative era of commercial {mainframe} technology, when
+ {ferrite core memory} {dinosaurs} ruled the earth. The Iron
+ Age began, ironically enough, with the delivery of the first
+ {minicomputer} (the {PDP-1}) and ended with the introduction
+ of the first commercial {microprocessor} (the {Intel 4004}) in
+ 1971.
+
+ See also {Stone Age}; compare {elder days}.
+
+ [{Jargon File}]
+
+ (2003-09-27)
+
+iron box
+
+ [Unix/Internet] A special environment set up to trap a
+ {cracker} logging in over remote connections long enough to be
+ traced. May include a modified {shell} restricting the
+ cracker's movements in unobvious ways, and "bait" files
+ designed to keep him interested and logged on. See also {back
+ door}, {firewall machine}, {Venus flytrap}, and Clifford
+ Stoll's account in "{The Cuckoo's Egg}" of how he made and
+ used one. Compare {padded cell}.
+
+ [{Jargon File}]
+
+Ironman
+
+ HOLWG, DoD, Jan 1977, revised Jul 1977. Fourth of the series
+ of DoD requirements that led to Ada. "Department of Defense
+ Requirements for High Order Computer Programming Languages",
+ SIGPLAN Notices 12(12):39-54 (Dec 1977). "Revised Ironman
+ Requirements for High Order Computer Programming Languages",
+ US Dept of Defense, Jul 1977. (See Strawman, Woodenman,
+ Tinman, Steelman).
+
+ironmonger
+
+ [IBM] A hardware specialist (derogatory). Compare
+ {sandbender}, {polygon pusher}.
+
+ [{Jargon File}]
+
+IRQ
+
+ {interrupt request}
+
+irrational number
+
+ <mathematics> A {real number} which is not a {rational
+ number}, i.e. it is not the ratio of two {integers}.
+
+ The decimal expansion of an irrational is infinite but does
+ not end in an infinite repeating sequence of digits.
+
+ Examples of irrational numbers are {pi}, {e} and the square
+ root of two.
+
+ (1995-04-12)
+
+irrefutable
+
+ The opposite of {refutable}.
+
+IRSG
+
+ {Internet Research Steering Group}
+
+IRTF
+
+ {Internet Research Task Force}
+
+IRUS
+
+ {Irvine Research Unit in Software}
+
+Irvine Dataflow
+
+ <language> (Always called "Id") A non-{strict}, {single
+ assignment} language and {incremental compiler} developed by
+ Arvind and Gostelow and used on {MIT}'s {Tagged-Token Dataflow
+ Architecture} and planned to be used on {Motorola}'s
+ {Monsoon}.
+
+ See also {Id Nouveau}.
+
+ ["An Asynchronous Programming Language for a Large
+ Multiprocessor Machine", Arvind et al, TR114a, Dept ISC, UC
+ Irvine, Dec 1978].
+
+ ["The U-Interpreter", Arvind et al, Computer 15(2):42-50,
+ 1982].
+
+ (1998-02-14)
+
+Irvine Research Unit in Software
+
+ <body> (IRUS) The {University of California, Irvine}.
+
+ [Details?]
+
+ (1995-04-18)
+
+IS
+
+ 1. <standard> {International Standard}.
+
+ 2. {Intermediate System}.
+
+is
+
+ <networking> The {country code} for Iceland.
+
+ (1999-01-27)
+
+IS-11172
+
+ <standard> The {International Standard} for {MPEG-1}
+ {compression}.
+
+ (1999-01-06)
+
+IS-13818
+
+ <standard> The {International Standard} for {MPEG-2}
+ {compression}.
+
+ (1999-01-06)
+
+ISA
+
+ 1. <architecture> {Integrated Systems Architecture}.
+
+ 2. <body> {International Smalltalk Association}.
+
+ 3. <architecture> {instruction set architecture}.
+
+ 4. <architecture> {Industry Standard Architecture}.
+
+ (1997-02-13)
+
+Isabelle
+
+ <theory, tool> A generic {theorem prover} with support for
+ several {object-logics}, developed by Lawrence C. Paulson
+ <Larry.Paulson@cl.cam.ac.uk> in collaboration with {Tobias
+ Nipkow (http://in.tum.de/~nipkow/)} at the {Technical
+ University of Munich}.
+
+ A system of {type classes} allows {polymorphic} object-logics
+ with {overloading} and automatic {type inference}.
+
+ Isabelle supports {first-order logic} - {constructive} and
+ classical versions; {higher-order logic}, similar to Gordon's
+ {HOL}; {Zermelo Fränkel set theory}; an {extensional} version
+ of {Martin Löf}'s {type theory}, the classical first-order
+ {sequent calculus}, {LK}; the {modal logics} {T}, {S4}, and
+ {S43}; and {Logic for Computable Functions}.
+
+ An object logic's {syntax} and {inference rules} are specified
+ {declaratively} allowing single-step proof construction.
+ {Proof procedures} can be expressed using "tactics" and
+ "tacticals". Isabelle provides control structures for
+ expressing search procedures and generic tools such as
+ simplifiers and classical theorem provers which can be applied
+ to object-logics. Isabelle is built on top of {Standard ML}
+ and uses its user interface.
+
+ {(http://cl.cam.ac.uk/Research/HVG/Isabelle/)}.
+
+ Mailing list: isabelle-users@cl.cam.ac.uk.
+
+ ["tactics"? "tacticals"?]
+
+ (1999-07-26)
+
+Isabelle-92
+
+ {Isabelle}
+
+Isabelle-93
+
+ {Isabelle}
+
+ISA bus
+
+ {Industry Standard Architecture}
+
+ISAKMP
+
+ {Internet Security Association and Key Management Protocol}
+
+ISAM
+
+ {Indexed Sequential Access Method}
+
+ISAPI
+
+ {Internet Server Application Programming Interface}
+
+ISAPI filter
+
+ <web> A replaceable {DLL} which the {server} calls
+ whenever there is an {HTTP} request. When the filter is first
+ loaded, it communicates to the server what sort of
+ notifications will be accepted. After that, whenever a
+ selected event occurs, the filter is called to process the
+ event.
+
+ Example applications of ISAPI filters include custom
+ {authentication} schemes, {compression}, {encryption},
+ logging, traffic analysis or other request analyses.
+
+ (1997-01-06)
+
+ISBL
+
+ <language> A mathematical {query language}.
+
+ [Stands for? Details?]
+
+ (1997-01-06)
+
+ISDE
+
+ Integrated Software Development Environment: equivalent to an
+ IPSE.
+
+ISDN
+
+ {Integrated Services Digital Network}
+
+ISE
+
+ {Interactive Software Engineering}
+
+ISEE
+
+ Integrated {Software Engineering Environment} - equivalent to
+ {SEE}.
+
+I see no X here.
+
+ <games> Hackers (and the interactive computer games they
+ write) traditionally favour this slightly marked usage over
+ other possible equivalents such as "There's no X here!" or "X
+ is missing." or "Where's the X?". This goes back to the
+ original PDP-10 {ADVENT}, which would respond in this wise if
+ you asked it to do something involving an object not present
+ at your location in the game.
+
+ [{Jargon File}]
+
+ISETL
+
+ Interactive {SETL} by Gary Levin <gary@clutx.clarkson.edu>.
+
+ Latest version: 3.0.
+
+ {Binaries (ftp://sun.soe.clarkson.edu/)} and source for
+ {MS-DOS}, {Macintosh}, {Unix}, {VAX}/{VMS}.
+
+ [Clarkson U. "An Introduction to ISETL Version 1.9",
+ G.M. Levin, Dept MCS, Clarkson U].
+
+ ["Learning discrete mathematics with ISETL", Nancy Baxter.
+ Ed. Gary Levin Dubinsky. Springer-Verlag, c.1989.]
+
+ (Apr 1994)
+
+ISF
+
+ {Information Systems Factory}
+
+ISINDEX
+
+ <web> An {HTML} tag which tells the {browser} to
+ display a text entry box on the current page. Any text
+ entered in the box by the user is appended as a URL-encoded
+ query string to the current {URL} and sent to the {server}
+ using a GET method.
+
+ This is a simple way of making a {website} searchable or
+ allowing other kinds of simple user input. It relies on the
+ server mapping the query URL to an appropriate process,
+ probably depending on the page in which the ISINDEX appeared.
+ More complex input can be catered for using the {FORM} tag, or
+ {Java}.
+
+ (1996-12-22)
+
+ISIS
+
+ 1. A toolkit for implementing fault-tolerant distributed
+ systems, developed at Cornell and now available commercially
+
+ 2. A dialect of {JOSS}.
+
+ [Sammet 1969, p. 217].
+
+IS-IS
+
+ {Intermediate System-Intermediate System}
+
+ISL
+
+ Interface Specification Language. Xerox PARC. Interface
+ description language used by the ILU (Inter-Language
+ Unification) system. Includes descriptions of multiple
+ inheritance, exceptions and garbage collection.
+
+ E-mail: Bill Janssen <janssen@parc.xerox.com>.
+
+ISLisp
+
+ International Standard Lisp.
+
+ An {object-oriented} Lisp intended as an international
+ replacement for {Common Lisp}, {EuLisp}, {Le-Lisp} and
+ {Scheme}. The standard's goals are object orientation,
+ extensibility, efficiency, and suitability for non-academic
+ use.
+
+ The standard is defined in {ISO} WG 16, draft Dec 1992.
+
+ {(ftp://ma2s2.mathematik.uni-karlsruhe.de/pub/lisp/islisp/)}.
+
+ (1995-02-14)
+
+ISMAP
+
+ (web) An attribute of the {HTML} tag <IMG> (inline
+ image) which specifies that if the image is selected, the
+ {browser} will generate a request indicating the coordinates
+ of the point which was clicked. This request is then
+ interpreted by the server by mapping certain regions of the
+ image to certain actions.
+
+ {Documentation
+ (http://utirc.utoronto.ca/HTMLdocs/NewHTML/image.html)}.
+
+ (1995-02-14)
+
+ISO
+
+ {International Organization for Standardization}
+
+ISO 10646
+
+ {Universal Character Set}
+
+ISO 3166
+
+ {country code}
+
+ISO 639-1
+
+ {language code}
+
+ISO 639-2
+
+ {language code}
+
+ISO 8072
+
+ {transport layer}
+
+ISO 8073
+
+ {transport layer}
+
+ISO 8208
+
+ {X.25}
+
+ISO 8326
+
+ {session layer}
+
+ISO 8327
+
+ {session layer}
+
+ISO 8485
+
+ {A Programming Language}
+
+ISO 8613
+
+ {Open Document Architecture}
+
+ISO 8649
+
+ {Association Control Service Element}
+
+ISO 8650
+
+ {Association Control Service Element}
+
+ISO 8805
+
+ {GKS-3D}
+
+ISO 8807
+
+ {LOTOS}
+
+ISO 8822
+
+ {presentation layer}
+
+ISO 8823
+
+ {presentation layer}
+
+ISO 8825
+
+ {Basic Encoding Rules}
+
+ISO 8859
+
+ <standard, character> {ISO}/{IEC}'s set of 8-bit coded graphic
+ {character sets} for European languages.
+
+ Part 1 (full name: "ISO 8859-1:1987 Information processing --
+ 8-bit single-byte coded graphic character sets -- Part 1:
+ Latin alphabet No. 1") is a common extension of, and
+ replacement for, {ASCII}.
+
+ {ISO shop
+ (http://iso.ch/iso/en/CatalogueDetailPage.CatalogueDetail?CSNUMBER=28245)}.
+
+ (2001-12-28)
+
+ISO 8859-1
+
+ {ISO 8859}
+
+ISO 8879
+
+ <standard, character> The {ISO} standard defining {SGML}.
+
+ (1995-05-03)
+
+ISO 9000
+
+ A set of international {standards} for both quality management
+ and quality assurance that has been adopted by over 90
+ countries worldwide. The ISO 9000 standards apply to all
+ types of organisations, large and small, and in many
+ industries.
+
+ The standards require: standard language for documenting
+ quality processes; system to manage evidence that these
+ practices are instituted throughout an organisation; and
+ third-party auditing to review, certify, and maintain
+ certification of organisations. The ISO 9000 series
+ classifies products into generic product categories: hardware,
+ software, processed materials, and services.
+
+ Documentation is at the core of ISO 9000 conformance. In fact,
+ the standards have been paraphrased as:
+
+ "Say what you do. Do what you say. Write it down."
+
+ In Britain it is associated with BS5750 which may become
+ obsolete.
+
+ ["The ISO 9000 Guide," c. 1993 Interleaf, Inc].
+
+ (1995-01-30)
+
+ISO 9072
+
+ {Remote Operations Service Element}
+
+ISO 9660
+
+ <standard, storage> The {ISO} {standard} {file system} for
+ {CD-ROMs}, later extended by the {Joliet} standard to allow
+ {Unicode} characters.
+
+ (2006-09-25)
+
+ISO 9735
+
+ <standard, protocol> (Or "EDIFACT") {ISO}'s 1988 {standard}
+ for Electronic data interchange for administration, commerce
+ and transport. It defines {application layer} {syntax}. It
+ was amended and reprinted in 1990.
+
+ {(http://iso.ch/cate/d17592.html)}.
+
+ (1995-03-10)
+
+ISOC
+
+ {Internet Society}
+
+ISO C
+
+ {ANSI C}
+
+isochronous
+
+ <communications> /i:-sok'rn-*s/ A form of {multiplexing} that
+ guarantees to provide a certain minimum {data rate}, as
+ required for time-dependent data such as {video} or {audio}.
+
+ Isochronous transmission transmits asynchronous data over a
+ synchronous data link so that individual characters are only
+ separated by a whole number of bit-length intervals. This is
+ in contrast to {asynchronous} transmission, in which the
+ characters may be separated by arbitrary intervals, and with
+ {synchronous} transmission [which does what?].
+
+ An isochronous message protocol assigns each data source a
+ fixed amount of time to transmit (its "slot") within each
+ cycle through the sources. That guarantees that each source
+ will have regular opportunities to transmit the latest
+ information. If a source has no more data to transmit, then
+ the rest of its time slot is wasted. If it has more to send
+ than will fit in its slot, it has to either store the excess
+ data and transmit it in its next slot, or discard it.
+
+ Note that whether messages are isochronous or asynchronous is
+ independent of whether the transmision of individual bits is
+ {synchronous} or {asynchronous}.
+
+ Isochronous communication suits applications where a steady
+ data stream is more important than completeness and accuracy,
+ e.g. {video conferencing}.
+
+ {Asynchronous Transfer Mode} and {High Performance Serial Bus}
+ can provide isochronous service.
+
+ Compare: {plesiochronous}.
+
+ [ANIXTER, LAN Magazine 7.93]
+
+ (2006-06-13)
+
+isochronous transfer
+
+ {isochronous}
+
+ISODE
+
+ {ISO Development Environment}
+
+ISO Development Environment
+
+ (ISODE) /eye-so-dee-eee/ Software that implements a set of
+ {OSI} upper-layer services. It supports OSI applications on
+ top of OSI and {TCP/IP} networks.
+
+ (1994-12-15)
+
+ISO/IEC 10646-1
+
+ {Universal Character Set}
+
+ISO/IEC 26300
+
+ {OpenDocument}
+
+isolated
+
+ {compact}
+
+ISO Latin 1
+
+ {ISO 8859}
+
+isometric joystick
+
+ <hardware> Any kind of {joystick} where the input depends on
+ the force exerted rather than the position of the control,
+ e.g. {TrackPoint}.
+
+ (2003-06-26)
+
+isometry
+
+ <mathematics> A {mapping} of a {metric space} onto another or
+ onto itself so that the distance between any two points in the
+ original space is the same as the distance between their
+ images in the second space. For example, any combination of
+ rotation and translation is an isometry of the plane.
+
+ (1997-12-13)
+
+isomorphic
+
+ <mathematics> Two mathematical objects are isomorphic if they
+ have the same structure, i.e. if there is an {isomorphism}
+ between them. For every component of one there is a
+ corresponding component of the other.
+
+ (1995-03-25)
+
+isomorphism
+
+ <mathematics> A {bijective} {map} between two objects which
+ preserves, in both directions, any structure under
+ consideration. Thus a `group isomorphism' preserves group
+ structure; an order isomorphism (between {posets}) preserves
+ the order relation, and so on. Usually it is clear from
+ context what sort of isomorphism is intended.
+
+ (1995-03-25)
+
+isomorphism class
+
+ <mathematics> A collection of all the objects {isomorphic} to
+ a given object. Talking about the isomorphism class (of a
+ {poset}, say) ensures that we will only consider its
+ properties as a poset, and will not consider other incidental
+ properties it happens to have.
+
+ (1995-03-25)
+
+ISO Pascal
+
+ A {Lex} {scanner} and {Yacc} {parser} are in the
+ comp.sources.unix volume 13 archive.
+
+ [More detail?]
+
+ISO seven layer model
+
+ {Open Systems Interconnect}
+
+ISP
+
+ 1. {Internet Service Provider}.
+
+ 2. {Instruction Set Processor}.
+
+ISPBX
+
+ {Integrated Services Digital Network} {PBX}.
+
+ISPF
+
+ {Interactive System Productivity Facility}
+
+ISPL
+
+ Instruction Set Processor Language. The original {ISP}
+ language, written in {BLISS} ca 1971.
+
+ ["Computer Structures: Readings and Examples", D.P. Siewiorek
+ et al, McGraw-Hill 1982].
+
+ISPS
+
+ Instruction Set Processor Specifications. Operational
+ hardware specification language. Successor to ISPL.
+
+ ["Instruction Set Processor Specifications", M.R. Barbacci et
+ al, IEEE Trans Computers, C-30(1):24-80 (Jan 1981)].
+
+ [Bell, Newell, Siewiorek, Barbacci 1982?]
+
+IST
+
+ <company> {Imperial Software Technology}.
+
+ (1995-10-12)
+
+ISTAR
+
+ <programming, tool> An experimental {IPSE} from {Imperial
+ Software Technology}.
+
+ (1995-10-12)
+
+ISTM
+
+ <chat> It seems to me.
+
+ (2000-07-06)
+
+ISV
+
+ Independent Software Vendor (not a hardware manufacturer).
+
+ISWIM
+
+ <language> (If You See What I Mean) An influential but
+ unimplemented computer programming language described in the
+ article by {Peter J. Landin} cited below. Landin attempted to
+ capture all known programming language concepts, including
+ {assignment} and control operators such as {goto} and
+ {coroutines}, within a single {lambda calculus} based
+ framework.
+
+ ISWIM is an {imperative language} with a functional core,
+ consisting of {sugared} {lambda calculus} plus {mutable
+ variables} and {assignment}. A powerful control mechanism,
+ Landin's {J operator}, enables capture of the current
+ {continuation} (the {call/cc} operator of {Scheme} is a
+ simplified version). Being based on lambda calculus ISWIM had
+ {higher order functions} and {lexically scoped} variables.
+
+ The {operational semantics} of ISWIM are defined using
+ Landin's {SECD machine} and use {call-by-value} ({eager
+ evaluation}). To make ISWIM look more like mathematical
+ notation, Landin replaced {ALGOL}'s semicolons and begin end
+ blocks with the {off-side rule} and scoping based on
+ indentation.
+
+ An ISWIM program is a single {expression} qualified by "where"
+ clauses (auxiliary definitions including equations among
+ variables), conditional expressions and function definitions.
+ With {CPL}, ISWIM was one of the first programming languages
+ to use "where" clauses.
+
+ New {data types} could be defined as a (possibly recursive)
+ {sum of products} like the {algebraic data types} found in
+ modern functional languages. ISWIM variables were probably
+ {dynamically typed} but Landin may have planned some form of
+ {type inference}.
+
+ Concepts from ISWIM appear in Art Evan's {PAL} and John
+ Reynold's {Gedanken}, Milner's {ML} and purely functional
+ languages with lazy evaluation like {SASL}, {Miranda} and
+ {Haskell}.
+
+ [{"The Next 700 Programming Languages"
+ (http://www.cs.utah.edu/~wilson/compilers/old/papers/p157-landin.pdf)},
+ P.J. Landin, CACM 9(3):157-166, Mar 1966].
+
+ (2007-03-20)
+
+IT
+
+ 1. <business, jargon> {Information Technology}.
+
+ 2. <language, mathematics, history> {Internal Translator}.
+
+ (2000-10-02)
+
+it
+
+ <networking> The {country code} for Italy.
+
+ (1999-01-27)
+
+ITAR
+
+ {International Traffic in Arms Regulation}
+
+Iterated Function System
+
+ <graphics> (IFS) A class of {fractals} that yield
+ natural-looking forms like ferns or snowflakes. Iterated
+ Function Systems use a very easy transformation that is done
+ recursively.
+
+ (1998-04-04)
+
+iteration
+
+ <programming> Repetition of a sequence of instructions. A
+ fundamental part of many {algorithms}. Iteration is
+ characterised by a set of initial conditions, an iterative
+ step and a termination condition.
+
+ A well known example of iteration in mathematics is
+ Newton-Raphson iteration. Iteration in programs is expressed
+ using {loops}, e.g. in {C}:
+
+ new_x = n/2;
+ do
+ {
+ x = new_x;
+ new_x = 0.5 * (x + n/x);
+ } while (abs(new_x-x) > epsilon);
+
+ Iteration can be expressed in functional languages using
+ recursion:
+
+ solve x n = if abs(new_x-x) > epsilon
+ then solve new_x n
+ else new_x
+ where new_x = 0.5 * (x + n/x)
+
+ solve n/2 n
+
+ (1998-04-04)
+
+iterative deepening
+
+ <algorithm> A {graph} search {algorithm} that will find the
+ shortest path with some given property, even when the graph
+ contains {cycles}. When searching for a path through a graph,
+ starting at a given initial {node}, where the path (or its end
+ node) has some desired property, a {depth-first search} may
+ never find a solution if it enters a cycle in the graph.
+ Rather than avoiding cycles (i.e. never extend a path with a
+ node it already contains), iterative deepening explores all
+ paths up to length (or "depth") N, starting from N=0 and
+ increasing N until a solution is found.
+
+ (2004-01-26)
+
+iterator
+
+ <programming> An {object} or {routine} for accessing items
+ from a {list}, {array} or {stream} one at a time.
+
+ By extension, the term can be used for an object or routine
+ for accesing items from any data structure that can be viewed
+ as a list. For example, a {traverser} is an {iterator} for
+ {tree}-shaped data structures.
+
+ (2001-10-04)
+
+Iternet
+
+ <spelling> It's spelled "{Internet}".
+
+ (1997-04-07)
+
+IT governance
+
+ {information technology governance}
+
+ITHACA
+
+ <project> An {Esprit} project to put a {4th generation}
+ {object-oriented} system to practical use in an industrial
+ environment. The ITHACA environment offered an application
+ support system incorporating advanced technologies in the
+ fields of object-oriented programming, programming languages,
+ {databases}, user interfaces and software development tools.
+
+ (2009-04-27)
+
+ITIL
+
+ {Information Technology Infrastructure Library}
+
+ITP
+
+ {Intent to Package}
+
+ITS
+
+ 1. Incompatible {time-sharing} System
+
+ An influential but highly idiosyncratic {operating system}
+ written for the {PDP-6} and {PDP-10} at {MIT} and long used at
+ the {MIT AI Lab}. Much AI-hacker jargon derives from ITS
+ folklore, and to have been "an ITS hacker" qualifies one
+ instantly as an old-timer of the most venerable sort. ITS
+ pioneered many important innovations, including transparent
+ file sharing between machines and terminal-independent I/O.
+ After about 1982, most actual work was shifted to newer
+ machines, with the remaining ITS boxes run essentially as a
+ hobby and service to the hacker community. The shutdown of
+ the lab's last ITS machine in May 1990 marked the end of an
+ era and sent old-time hackers into mourning nationwide (see
+ {high moby}). The Royal Institute of Technology in Sweden is
+ maintaining one "live" ITS site at its computer museum (right
+ next to the only {TOPS-10} system still on the {Internet}), so
+ ITS is still alleged to hold the record for OS in longest
+ continuous use (however, {WAITS} is a credible rival for this
+ palm).
+
+ 2. A mythical image of {operating system} perfection worshiped
+ by a bizarre, fervent retro-cult of old-time hackers and
+ ex-users (see {troglodyte}). ITS worshipers manage somehow to
+ continue believing that an OS maintained by {assembly
+ language} hand-hacking that supported only monocase
+ 6-character filenames in one directory per account remains
+ superior to today's state of commercial art (their venom
+ against {Unix} is particularly intense).
+
+ See also {holy wars}, {Weenix}.
+
+ [{Jargon File}]
+
+ (1994-12-15)
+
+it's a feature
+
+ <jargon> From the adage "It's not a bug, it's a feature."
+ Used sarcastically to describe an unpleasant experience that
+ you wish to gloss over.
+
+ (1997-04-29)
+
+ITSP
+
+ {Internet Telephony Service Providers}
+
+ITU
+
+ {International Telecommunications Union}
+
+ITU-T
+
+ {International Telecommunications Union}
+
+ITU-T X.680
+
+ {Coordinated Universal Time}
+
+ITU X.209
+
+ {Basic Encoding Rules}
+
+Ivan
+
+ A {Diana}-like language making up part of {VHDL}.
+
+ ["VHDL - The Designer Environment", A. Gilman, IEEE Design &
+ Test 3, (Apr 1986)].
+
+Ivan Sutherland
+
+ Ivan E. Sutherland is widely known for his pioneering
+ contributions. His 1963 MIT PhD thesis, {Sketchpad}, opened
+ the field of computer graphics. His 1966 work, with Sproull,
+ on a head-mounted display anticipated today's {virtual
+ reality} by 25 years. He co-founded {Evans and Sutherland},
+ which manufactures the most advanced computer image generators
+ now in use. As head of Computer Science Department of
+ {Caltech} he helped make {integrated circuit} design an
+ acceptable field of academic study. Dr. Sutherland is on the
+ boards of several small companies and is a member of the
+ National Academy of Engineering and the National Academy of
+ Sciences, the {ACM} and {IEEE}. He received the {ACM}'s
+ {Turing Award} in 1988. He is now Vice President and Fellow
+ of {Sun Microsystems} Laboratories in Mountain View, CA, USA.
+
+ (1994-11-16)
+
+Iverson's Language
+
+ {APL}, which went unnamed for many years.
+
+ [Sammet 1969, p.770].
+
+ (1994-11-16)
+
+IVR
+
+ {Interactive Voice Response}
+
+ivs
+
+ {INRIA} Videoconferencing System.
+
+ A {video-conferencing} tool for the {Internet} based on the
+ {H.261} {video compression} {standard}.
+
+ {(http://zenon.inria.fr:8003/rodeo/personnel/Thierry.Turletti/ivs.html)}.
+
+ (1994-11-16)
+
+IVTRAN
+
+ Parallel {Fortran} for the {Illiac IV}. 1966.
+
+IV&V
+
+ {Independent Verification and Validation}
+
+IVY
+
+ A language with a more pleasant syntax than {Perl}, {tcl} or
+ {Lisp}. It has nice features like low punctuation count,
+ blocks indicated by indentation, and similarity to normal
+ procedural languages. This language started out as an idea
+ for an extension language for the editor {JOE}.
+
+ An experimental {interpreter} by Joseph H Allen
+ <jhallen@world.std.com> was posted to {alt.sources} on 28 Sep
+ 1993.
+
+IWay
+
+ {Information Superhighway}
+
+IWBNI
+
+ It Would Be Nice If.
+
+ Compare {WIBNI}.
+
+ [{Jargon File}]
+
+ (1994-11-24)
+
+IXC
+
+ {IntereXchange Carrier}
+
+IXI Limited
+
+ <company> A Cambridge, England company who were the leading
+ supplier of {Unix} System windowing software when they were
+ acquired by {SCO} in February 1993.
+
+ (1994-12-12)
+
+IXO
+
+ {Telocator Alphanumeric Protocol}
+
+IYFEG
+
+ ({Usenet}) Insert Your Favourite Ethnic Group.
+
+ Used as a meta-name when telling ethnic jokes on the net to
+ avoid offending anyone.
+
+ See also {JEDR}.
+
+ [{Jargon File}]
+
+ (1994-11-24)
+
+J
+
+ A derivative and redesign of {APL} with added features and
+ control structures. J is {purely functional} with {lexical
+ scope} and more conventional control structures, plus several
+ new concepts such as {function rank} and {function arrays}. J
+ was designed and developed by Kennneth E. Iverson and Roger
+ Hui <hui@yrloc.ipsa.reuter.com>. J uses only the {ASCII}
+ character set but has a spelling scheme that retains the
+ advantages of {APL}'s special alphabet. J is a conventional
+ procedural programming language but can be used as a {purely
+ functional} language.
+
+ Version 4.1 for {MS-DOS}, Sun, Mac, Archimedes. Source
+ available in C from {Iverson Software}, +1 (416) 925 6096.
+
+ Version 6 package from ISI includes an interpreter and
+ tutorial. Ported to {DEC}, {NeXT}, {SGI}, {Sun-3}, {Sun-4},
+ {Vax}, {RS/6000}, {MIPS}, {Macintosh}, {Acorn Archimedes},
+ {IBM PC}, {Atari}, {3b1}, {Amiga}.
+
+ {(ftp://watserv1.waterloo.edu/languages/apl/j)}.
+
+ J-mode {GNU Emacs} macros available by
+ {(ftp://think.com/pub/j/gmacs/j-interaction-mode.el)}.
+
+ ["APL\?", Roger K.W. Hui et al, APL90 Conf Proc, Quote Quad
+ 20(4):192-200].
+
+ (1992-10-31)
+
+J2EE
+
+ {Java 2 Platform, Enterprise Edition}
+
+J2ME
+
+ {Java 2 Platform, Micro Edition}
+
+J2SE
+
+ {Java 2 Platform, Standard Edition}
+
+J3
+
+ A dialect of {JOVIAL}.
+
+ ["Military Standard JOVIAL (J3)", MIL-STD-1588 (USAF), June
+ 1976].
+
+ (1994-12-07)
+
+J73
+
+ A dialect of {JOVIAL}.
+
+ ["Military Standard JOVIAL (J73)", MIL-STD-1589 (USAF), Feb
+ 1977].
+
+ (1994-12-07)
+
+jabber
+
+ <networking> When a network {node} transmits a {packet} longer
+ than the maximum permissible length, usually due to a fault
+ condition.
+
+ (1996-05-10)
+
+JACAL
+
+ {JAffer's Canonical ALgebra}
+
+jaccl
+
+ <tool> An {LR1 grammar} {parser generator} written by Dave
+ Jones at Megatest.
+
+ (1989-09-08)
+
+jack in
+
+ To log on to a machine or connect to a network or {BBS},
+ especially for purposes of entering a {virtual reality}
+ simulation such as a {MUD} or {IRC} (leaving is "jacking
+ out"). This term derives from {cyberpunk} SF, in which it was
+ used for the act of plugging an electrode set into neural
+ sockets in order to interface the brain directly to a virtual
+ reality. It is primarily used by MUD and IRC fans and younger
+ hackers on BBS systems.
+
+ [{Jargon File}]
+
+Jack Kilby
+
+ <person> (1924 - 2005-06-20) The electronics engineer who
+ invented the {integrated circuit} in 1958 at {Texas
+ Instruments}.
+
+ {TI Biography
+ (http://ti.com/corp/docs/kilbyctr/jackstclair.shtml)}.
+
+ [Was the {JK flip-flop} named after him?]
+
+ (2005-06-22)
+
+Jackson method
+
+ <programming> A proprietary structured method for software
+ analysis, design and programming.
+
+ (2005-06-22)
+
+Jacquard, Joseph-Marie
+
+ {Joseph-Marie Jacquard}
+
+Jacquard loom
+
+ <history> /zhah-kar'/ A mechanical loom, invented by
+ {Joseph-Marie Jacquard} in 1801, which used the holes punched
+ in pasteboard {punch cards} (which see) to control the weaving
+ of patterns in fabric. It was the first machine to use punch
+ cards, although it did no computation based on them.
+
+ {(http://history.rochester.edu/steam/hollerith/loom.htm)}.
+
+ (1998-10-19)
+
+JAD
+
+ {Joint Application Design}
+
+ Or "Joint Application Development".
+
+ [What is it?]
+
+ (1995-11-15)
+
+JADE
+
+ {James' DSSSL Engine}
+
+Jade
+
+ 1. U Washington, late 80's. A strongly-typed language,
+ object-oriented but without classes. For type research. The
+ compiler output is Smalltalk. [Submitter claimed that Jade
+ has exactly one user!]
+
+ 2. Implicit {coarse-grained concurrency}. The constructs
+ 'with', 'withonly' and 'without' create tasks with specified
+ side effects to shared data objects. Implemented as a C
+ preprocessor. "Coarse-Grain Parallel Programming in Jade",
+ M.S. Lam et al, SIGPLAN Notices 26(7):94-105 (Jul 1991).
+
+jadeTeX
+
+ <text, tool> A program which uses {TeX} as a back-end for
+ producing {DVI} (or {PDF}) printable output from {James' DSSSL
+ Engine}.
+
+ {(ftp://ftp.tug.org/tex-archive/macros/jadetex/)}.
+
+ (1997-11-20)
+
+JAffer's Canonical ALgebra
+
+ <mathematics, tool> (JACAL) A {symbolic mathematics} program,
+ most of which was written in {Scheme} by Aubrey Jaffer.
+
+ {(http://swissnet.ai.mit.edu/~jaffer/JACAL.html)}.
+
+ (1999-06-27)
+
+jaggies
+
+ <graphics> /jag'eez/ (Or "staircase") The "staircase" effect
+ observable when an edge (especially a linear edge of very
+ shallow or steep slope) is rendered on a {bitmap display} (as
+ opposed to a {vector display}). The effect is even more
+ pronounced when a bitmap image or text in a bitmap font is
+ enlarged. {Outline fonts} and {anti-aliasing} are two
+ techniques used to solve this problem with text.
+
+ [{Jargon File}]
+
+ (1997-12-01)
+
+JaM
+
+ John and Martin. An interpreted {FORTH}-like graphics
+ language by John Warnock and Martin Newell, {Xerox PARC},
+ 1978. JaM was the forerunner of both {Interpress} and
+ {PostScript}. It is mentioned in PostScript Language
+ reference Manual, Adobe Systems, A-W 1985.
+
+jam
+
+ A condition on a network where two nodes transmitting
+ simultaneously detect the collision and continue to transmit
+ for a certain time (4 to 6 bytes on Ethernet) to ensure that
+ the collision has been detected by all nodes involved.
+
+ (1994-12-12)
+
+James Clark
+
+ {Dr. James H. Clark}
+
+James' DSSSL Engine
+
+ <text, tool> (JADE) A {DSSSL} tool by {James J. Clark}. Jade
+ is an implementation of the DSSSL style language for {Unix}
+ and {Microsoft Windows}. It can turn the {SGML} source of the
+ DSSSL standard into an {RTF} file of about 200 pages using a
+ fairly complex DSSSL specification.
+
+ {(http://jclark.com/)}.
+
+ (1996-10-13)
+
+James Gosling
+
+ <person> The software engineer who wrote {GOSMACS}, and served
+ as {Sun Microsystems, Inc.} project leader for both {NeWS},
+ and {Java}. He is currently (1997) a Vice President and
+ "Distinguished Engineer" at Sun.
+
+ {(http://java.sun.com:80/people/jag/)}.
+
+ {Biography
+ (http://sun.com/sunergy/Bios/gosling_bio.html)}.
+
+ (1997-03-12)
+
+James H. Clark
+
+ {Dr. James H. Clark}
+
+JAM Programming Language
+
+ <language> (JPL) A string-based {imperative language} from
+ {JYACC Corporation}, part of the JAM tool for developing
+ screen (non-window) applications.
+
+ (2007-10-02)
+
+JANET
+
+ {Joint Academic NETwork}
+
+JANET IP Service
+
+ <networking> (JIPS) {Joint Academic NETwork} {Internet
+ Protocol}.
+
+ E-mail: <jips-nosc@nic.ja.net>.
+
+ [Details?]
+
+ (1994-12-12)
+
+Janus
+
+ 1. Distributed language with an ask/tell constraint system.
+
+ {qdjanus} is a Janus-to-{Prolog} compiler for {Sicstus Prolog}
+ and {jc} is compiles to {C}.
+
+ ["Janus: A Step Towards Distributed Constraint Programming",
+ V. Saraswat <saraswat@parc.xerox.com> et al in Logic
+ Programming: Proc 1990 North Am Conf, S. Debray et al eds, MIT
+ Press 1990].
+
+ ["Programming in Janus", Saraswat, Kahn, and Levy].
+
+ 2. W.M. Waite, U Colorado. Intermediate language, claimed as
+ an implementation of {UNCOL}. Used on {CDC 6600}.
+
+ ["Experience with the Universal Intermediate Language Janus",
+ B.K. Haddon et al, Soft Prac & Exp 8(5):601- 616 (Sep 1978)].
+
+japh
+
+ <programming> A {Perl} program which prints "Just another Perl
+ hacker" using extremely obfuscated methods, typically ones
+ based on obscure behaviours of sometimes rarely-used functions,
+ in the spirit of the {Obfuscated C Contest}.
+
+ The obfuscation can result from the code being total
+ gibberish, e.g.:
+
+ $_="krJhruaesrltre c a cnp,ohet";$_.=$1,print$2while s/(..)(.)//;
+
+ or from having "Just another Perl hacker" embedded in opaque
+ code:
+
+ $_='987;s/^(\d+)/$1-1/e;$1?eval:print"Just another Perl hacker,"';eval
+
+ or from looking like it does something simple and completely
+ unrelated to printing "Just another Perl hacker":
+
+ $_ = "wftedskaebjgdpjgidbsmnjgc";
+ tr/a-z/oh, turtleneck Phrase Jar!/; print;
+
+ {Examples (http://perl.com/CPAN/misc/japh)}.
+
+ (1997-09-14)
+
+jar
+
+ {Java archive}
+
+jargon
+
+ <human language, jargon> Language specific to some field of human
+ endeavour, in this case, computing, that might not be understood
+ by those outside that area.
+
+ {This dictionary} contains many {examples of jargon
+ (/contents/jargon.html)}.
+
+ The {Jargon File} is the definitive collection of computing
+ jargon.
+
+ (2014-09-01)
+
+Jargon File
+
+ <jargon, publication, humour> The on-line hacker Jargon File
+ maintained by {Eric S. Raymond}. A large collection of
+ definitions of computing terms, including much wit, wisdom,
+ and history.
+
+ {Many definitions (/contents/jargon.html)} in {this dictionary}
+ are from v3.0.0 of 1993-07-27.
+
+ {Jargon File Home (http://catb.org/~esr/jargon/)}.
+
+ See also {Yellow Book, Jargon}.
+
+ (2014-08-14)
+
+Java
+
+ <programming, language> An {object-oriented}, {distributed},
+ {interpreted}, {architecture-neutral}, {portable},
+ {multithreaded}, dynamic, buzzword-compliant, general-purpose
+ programming language developed by {Sun Microsystems} in the early
+ 1990s (initially for set-top television controllers) and released
+ to the public in 1995.
+
+ Java was named after the Indonesian island, a source of
+ {programming fluid}.
+
+ Java first became popular as the earliest portable dynamic
+ client-side content for the {web} in the form of
+ {platform}-independent {Java applets}. In the late 1990s and
+ into the 2000s it also became very popular on the server side,
+ where an entire set of {APIs} defines the {J2EE}.
+
+ Java is both a set of public specifications (controlled by
+ {Oracle}, who bought {Sun Microsystems}, through the {JCP}) and a
+ series of implementations of those specifications.
+
+ Java is syntactially similar to {C++} without user-definable
+ {operator overloading}, (though it does have {method}
+ overloading), without {multiple inheritance} and extensive
+ automatic {coercions}. It has automatic {garbage collection}.
+ Java extends {C++}'s {object-oriented} facilities with those
+ of {Objective C} for {dynamic method resolution}.
+
+ Whereas programs in C++ and similar languages are compiled and
+ linked to platform-specific binary executables, Java programs
+ are typically compiled to portable {architecture-neutral}
+ {bytecode} ".class" files, which are run using a {Java Virtual
+ Machine}. The JVM is also called an {interpreter}, though it
+ is more correct to say that it uses {Just-In-Time Compilation}
+ to convert the {bytecode} into {native} {machine code},
+ yielding greater efficiency than most interpreted languages,
+ rivalling C++ for many long-running, non-GUI applications.
+ The run-time system is typically written in {POSIX}-compliant
+ {ANSI C} or {C++}. Some implementations allow Java class
+ files to be translated into {native} {machine code} during or
+ after compilation.
+
+ The Java compiler and {linker} both enforce {strong type
+ checking} - procedures must be explicitly typed. Java
+ aids in the creation of {virus}-free, tamper-free systems
+ with {authentication} based on {public-key encryption}.
+
+ Java has an extensive library of routines for all kinds of
+ programming tasks, rivalling that of other languages. For
+ example, the {java.net} package supports {TCP/IP} {protocols}
+ like {HTTP} and {FTP}. Java applications can access objects
+ across the {Internet} via {URLs} almost as easily as on the
+ local {file system}. There are also capabilities for several
+ types of distributed applications.
+
+ The Java {GUI} libraries provide portable interfaces. For
+ example, there is an abstract {Window} class with implementations
+ for {Unix}, {Microsoft Windows} and the {Macintosh}. The
+ {java.awt} and {javax.swing} classes can be used either in
+ web-based {Applets} or in {client-side applications} or {desktop
+ applications}.
+
+ There are also packages for developing {XML} applications,
+ {web services}, {servlets} and other web applications,
+ {security}, date and time calculations and I/O formatting,
+ database ({JDBC}), and many others.
+
+ Java is not related to {JavaScript} despite the name.
+
+ {(http://oracle.com/java)}.
+
+ (2011-08-21)
+
+Java 2
+
+ {Java 2 Platform, Standard Edition}
+
+Java 2 Platform
+
+ {Java 2 Platform, Standard Edition}
+
+Java 2 Platform, Enterprise Edition
+
+ <language, programming> (J2EE) {Sun}'s {Java} platform for
+ {multi-tier} {server}-oriented {enterprise} {applications}.
+
+ The basis of J2EE is {Enterprise JavaBeans} (EJB).
+
+ See also the Standard edition {J2SE} and the Micro edition
+ {J2ME}.
+
+ {(http://java.sun.com/j2ee/)}.
+
+ (2000-04-20)
+
+Java 2 Platform, Micro Edition
+
+ <language, programming> (J2ME) {Sun}'s {Java} platform for
+ consumer devices.
+
+ J2ME defines Configurations and Profiles for different classes
+ of small memory device, from {smart cards} to {pagers} to
+ {set-top boxes}. It can run on various {Java virtual
+ machines} including {KVM}.
+
+ Related products include {PersonalJava} and {EmbeddedJava}.
+
+ See also the Standard edition {J2SE} and the Enterprise
+ edition {J2EE}.
+
+ (Home (http://javasoft.com/j2me/)}.
+
+ (2000-04-20)
+
+Java 2 Platform, Standard Edition
+
+ <language, programming> (J2SE) {Sun}'s {Java} programming
+ platform aimed at network-oriented enterprise applications.
+ J2SE comprises the {Java 2 Software Development Kit} (SDK) and
+ the {Java 2 Run-Time Environment}.
+
+ See also the Micro edition {J2ME} and the Enterprise edition
+ {J2EE}.
+
+ {Java 2 Platform (http://javasoft.com/j2se/)}.
+
+ (2000-04-20)
+
+Java 2 SDK
+
+ {Java 2 Software Development Kit}
+
+Java 2 Software Development Kit
+
+ <language, programming> (Java 2 SDK) {Sun}'s tools to develop
+ {Java} applications, part of the {Java 2 Platform}.
+
+ Latest version: Java 2 SDK version 1.2.2, as of April 2000.
+
+ Versions prior to 1.2 were known as the {Java Development Kit}
+ (JDK).
+
+ {(http://javasoft.com/j2se/)}.
+
+ (2000-04-20)
+
+Java archive
+
+ <file format, filename extension> (jar) A compressed {archive}
+ file containing {Java} {class} files, filename extension:
+ ".jar". The {Java Development Kit} contains a tool called
+ "jar" for creating .jar files, similar to the standard {Unix}
+ {tar} command. As well as archiving and compressing the Java
+ class files, it also inserts a "manifest" file which can
+ contain information about the class files, such as a {digital
+ signature}. Combining class files into a single archive file
+ makes it possible to download them in a single {HTTP}
+ transaction. This, and the {compression}, speeds up execution
+ of Java programs delivered via the {Internet}.
+
+ (2001}-02-03)
+
+JavaBeans
+
+ <programming> A {component architecture} for the {Java}
+ programming language, developed initially by {Sun}, but now
+ available from several other vendors. JavaBeans components
+ are called "{beans}".
+
+ JavaBeans allows developers to create reusable software
+ components that can then be assembled together using visual
+ application builder tools including {Sybase}'s {PowerJ},
+ {Borland}'s {JBuilder}, {IBM}'s {Visual Age for Java},
+ {SunSoft}'s {Java Workshop} and {Symantec}'s {Visual Cafe}.
+
+ JavaBeans support Introspection (a builder tool can analyze
+ how a Bean works), Customisation (developers can customise the
+ appearance and behaviour of a Bean), Events (Beans can
+ communicate), Properties (developers can customise and program
+ with Beans(?)) and Persistence (customised Beans can be stored
+ and reused).
+
+ {(http://javasoft.com/beans/)}.
+
+ (1997-11-20)
+
+Java Community Process
+
+ <project> (JCP) An organization controlled by {Sun Microsystems}
+ to further the growth of the {Java} language and runtime.
+ The JCP produces {standards} called Java Standard Requests,
+ which are "requests" in the same sense as {RFCs}.
+
+ (2005-01-21)
+
+Java Database Connectivity
+
+ <database, programming> (JDBC) Part of the {Java Development
+ Kit} which defines an {application programming interface} for
+ {Java} for standard {SQL} access to {databases} from Java
+ {programs}.
+
+ {Home
+ (http://java.sun.com/products/jdk/1.1/docs/guide/jdbc/index.html)}.
+
+ {FAQ (http://yoyoweb.com/Javanese/JDBC/FAQ.html)}.
+
+ See also {Open Database Connectivity}.
+
+ (1997-09-04)
+
+Java Development Kit
+
+ <language, compiler> (JDK) A free {Sun Microsystems} product
+ which provides the {environment} required for programming in
+ {Java}. The JDK is available for a variety of {platforms},
+ but most notably {Sun Solaris} and {Microsoft Windows}.
+
+ {(http://java.sun.com/products/jdk/1.1/index.html)}.
+
+ [Version?]
+
+ (1997-09-04)
+
+Java Message Service
+
+ <programming, messaging> (JMS) An {API} for accessing
+ enterprise messaging systems from {Java} programs. Java
+ Message Service, part of the {J2EE} suite, provides standard
+ APIs that Java developers can use to access the common
+ features of enterprise message systems. JMS supports the
+ {publish/subscribe} and {point-to-point} models and allows the
+ creation of message types consisting of arbitrary Java
+ objects. JMS provides support for administration, security,
+ error handling, and recovery, optimisation, distributed
+ transactions, message ordering, message acknowledgment, and
+ more.
+
+ {(http://java.sun.com/products/jms)}.
+
+ {Overview
+ (http://developer.java.sun.com/developer/technicalArticles/Networking/messaging/)}.
+
+ (2001-06-22)
+
+Java Native Interface
+
+ <programming> (JNI) A {native} programming interface for
+ {Java} that allows Java code running inside a {Java Virtual
+ Machine} to interoperate with {applications} and {libraries}
+ written in other programming languages such as {C}, {C++} and
+ {assembly language}.
+
+ (1997-12-07)
+
+Java Open Language Toolkit
+
+ <project> (JOLT) A project aimed at providing a freely
+ available and redistributale implementation of {Sun
+ Microsystems}'s {Java} language and tools.
+
+ {(http://redhat.com/linux-info/jolt/)}.
+
+ (1996-12-17)
+
+Java Remote Method Protocol
+
+ <protocol> (JRMP) A proprietary {wire-level protocol} designed
+ by {Sun Microsystems} to transport {Java} {RMI}.
+
+ JRMP serves the same function as {IIOP}, but also supports
+ object passing. {Sun} plans to offer {IIOP} as an alternative
+ to JRMP.
+
+ Sun do not appear to use this term any longer, simply
+ referring to the "RMI transport protocol".
+
+ {(http://java.sun.com/j2se/1.3.0/docs/guide/rmi/spec/rmi-protocol3.html)}.
+
+ {Comparison (http://execpc.com/~gopalan/misc/compare.html)}.
+
+ (2001-07-21)
+
+Java Run-Time Environment
+
+ <language> (JRE) The part of the {Java Development Kit}
+ required to run Java programs. The JRE consists of the {Java
+ Virtual Machine}, the {Java} platform core {classes} and
+ supporting files. It does not include the compiler, debugger
+ or other tools present in the JDK. The JRE is the smallest
+ set of executables and files that constitute the standard Java
+ platform.
+
+ (1998-11-30)
+
+JavaScript
+
+ <language> (Formerly "LiveScript") {Netscape}'s simple,
+ cross-{platform}, {web} {scripting language}, only
+ very vaguely related to {Java} (which is a {Sun} trademark).
+ JavaScript is intimately tied to the {web}, and
+ currently runs in only three environments - as a {server}-side
+ {scripting} language, as an embedded language in
+ {server-parsed HTML}, and as an embedded language run in web
+ {browsers} where it is the most important part of {DHTML}.
+
+ JavaScript has a simplified {C}-like {syntax} and is tightly
+ integrated with the browser {Document Object Model}. It is
+ useful for implementing enhanced {forms}, simple web
+ {database} {front-ends}, and navigation enhancements. It is
+ unusual in that the {scope} of {variables} extends throughout
+ the function in which they are declared rather than the
+ smallest enclosing block as in C.
+
+ JavaScript originated from {Netscape} and, for a time, only
+ their products supported it. {Microsoft} now supports a
+ work-alike which they call JScript. The resulting
+ inconsistencies make it difficult to write JavaScript that
+ behaves the same in all browsers. This could be attributed to
+ the slow progress of JavaScript through the standards bodies.
+
+ JavaScript runs "100x" slower than {C}, as it is purely
+ interpreted ({Java} runs "10x" slower than C code).
+ {Netscape} and allies say JavaScript is an "open standard" in
+ an effort to keep {Microsoft} from monopolising web software
+ as they have desktop software. {Netscape} and {Sun} have
+ co-operated to enable {Java} and JavaScript to exchange
+ messages and data.
+
+ See also {VBScript}.
+
+ {Usenet} newsgroup: {news:comp.lang.javascript}.
+
+ Mailing List: <majordomo@obscure.org> ("subscribe javascript"
+ in body).
+
+ (2003-04-28)
+
+JavaScript Object Notation
+
+ <programming> (JSON) {Syntax} for serialising {JavaScript}
+ objects, often used as a data carrier format. JSON is based
+ on a subset of the JavaScript programming language. It uses a
+ file extension of .json and is considered a
+ language-independent data format.
+
+ (2008-05-28)
+
+Java servelet
+
+ {Java servlet}
+
+JavaServer Faces
+
+ <programming, Java> (JSF) A system for building {web
+ applications} by assembling reusable {user interface}
+ components in a web page, connecting these components to a
+ data source and passing client events to server handlers.
+
+ {(http://java.sun.com/j2ee/javaserverfaces/overview.html)}.
+
+ (2006-07-21)
+
+JavaServer Pages
+
+ <programming, web> (JSP) A freely available
+ specification for extending the {Java Servlet} {API} to
+ generate dynamic {web pages} on a {web server}. The JSP
+ specification was written by industry leaders as part of the
+ Java development program.
+
+ JSP assists developers in creating {HTML} or {XML} pages that
+ combine static (fixed) page templates with dynamic content.
+ Separating the {user interface} from content generation allows
+ page designers to change the page layout without having to
+ rewrite program code. JSP was designed to be simpler than
+ pure servlets or {CGI} {scripting}.
+
+ JSP uses XML-like tags and scripts written in Java to generate
+ the page content. HTML or XML formatting {tags} are passed
+ back to the client. Application logic can live on the server,
+ e.g. in {JavaBeans}.
+
+ JSP is a {cross-platform} alternative to {Microsoft's} {Active
+ Server Pages}, which only runs in {IIS} on {Windows NT}.
+
+ Applications written to the JSP specification can be run on
+ compliant web servers, and web servers such as {Apache},
+ {Netscape Enterprise Server}, and Microsoft {IIS} that have
+ had Java support added. JSP should soon be available on
+ {Unix}, {AS/400}, and {mainframe} platforms.
+
+ {JavaServer Pages (http://java.sun.com/products/jsp/)}.
+
+ {Infoworld Article
+ (http://infoworld.com/cgi-bin/displayStory.pl?99063.ecjsp.htm)}.
+
+ (1999-11-28)
+
+Java servlet
+
+ <web> (By analogy with "{applet}") A {Java} program
+ that runs as part of a {network} service, typically an {HTTP
+ server} and responds to requests from {clients}.
+
+ The most common use for a servlet is to extend a {web server}
+ by generating {web content} dynamically. For example, a
+ {client} may need {information} from a {database}; a servlet
+ can be written that receives the request, gets and processes
+ the data as needed by the {client} and then returns the result
+ to the {client}.
+
+ {Applets} are also written in {Java} but run inside the {JVM}
+ of a {HTML} {browser} on the {client}. Servlets and applets
+ allow the server and client to be extended in a modular way by
+ dynamically loading code which communicates with the main
+ program via a standard programming interface.
+
+ Servlets are more flexible than {CGI scripts} and, being
+ written in {Java}, more portable.
+
+ The spelling "servelet" is occasionally seen but {JavaSoft}
+ spell it "servlet". There is no such thing as a "serverlet".
+
+ {(http://java.sun.com/products/servlet/)}.
+
+ (2002-10-06)
+
+Java Servlet Development Kit
+
+ <web> (JSDK) A suite of software for easing the
+ development of {Java servlets}.
+
+ {JavaSoft Servlet Development Kit
+ (http://javasoft.com/products/jdk/1.2/docs/ext/servlet/)}.
+
+ (1998-05-26)
+
+Java Virtual Machine
+
+ <language, architecture> (JVM) A specification for software
+ which interprets {Java} programs that have been compiled into
+ {byte-codes}, and usually stored in a ".class" file. The JVM
+ {instruction set} is {stack}-oriented, with variable
+ instruction length. Unlike some other instruction sets, the
+ JVM's supports {object-oriented} programming directly by
+ including instructions for object {method} invocation (similar
+ to {subroutine} call in other instruction sets).
+
+ The JVM itself is written in {C} and so can be {ported} to run
+ on most {platforms}. It needs {thread} support and {I/O} (for
+ {dynamic class loading}). The Java byte-code is independent
+ of the platform.
+
+ There are also some hardware implementations of the JVM.
+
+ {Specification
+ (http://javasoft.com/docs/books/vmspec/html/VMSpecTOC.doc.html)}.
+
+ {Sun's Java chip
+ (http://news.com/News/Item/0,4,9328,00.html)}.
+
+ [Documentation? Versions?]
+
+ (2000-01-03)
+
+Java VM
+
+ {Java Virtual Machine}
+
+JAZ
+
+ <language> An early system on the {LGP-30}.
+
+ [CACM 2(5):16, May 1959].
+
+ (1997-05-16)
+
+Jaz
+
+ {Jaz Drive}
+
+Jaz Drive
+
+ <hardware, storage> {Iomega Corporation}'s drive which takes
+ removable one or two {gigabyte} disk cartridges which contain
+ conventional {hard disks}.
+
+ Internal and external drives are available claiming an average
+ transfer rate of 330 {megabytes} per minute - though that is
+ dependant on the {SCSI} adapter, the parallel port adapter is
+ unlikely to reach anything like this speed. The Jaz drive was
+ the successor to the company's more establistablished {Zip
+ Drive}.
+
+ (1998-08-28)
+
+JAZELLE
+
+ <database> A data management system for High Energy Physics
+ from Stanford Linear Accelerator.
+
+ (1995-02-22)
+
+JBIG
+
+ {Joint Bi-level Image Experts Group}
+
+JBOD
+
+ {Just a Bunch Of Disks}
+
+JBOPS
+
+ <business, jargon> A nickname for the major {ERP} and
+ enterprise software application companies: {JD Edwards},
+ {Baan}, {Oracle}, {PeopleSoft}, and {SAP}.
+
+ (1999-07-27)
+
+jc
+
+ <language> Version 1.50 alpha
+
+ compiler(->C)
+
+ David Gudeman <gudeman@cs.arizona.edu>
+
+ {(ftp://cs.arizona.edu/janus/jc/)}.
+
+ A janus-to-C compiler (considerably faster than qdjanus). jc
+ is a {sequential} implementation of a {concurrent} language.
+
+ bugs: <jc-bugs@cs.arizona.edu>
+
+ ports: sun-4, sun-3, Sequent Symmetry
+
+ jc is an experimental system, undergoing rapid development.
+
+ Mailing list: janusinterest-request@parc.xerox.com
+
+ (1992-06-09)
+
+JCL
+
+ {Job Control Language}
+
+JCOOL
+
+ <language> A version of the {COOL} {C++} {class library} that
+ uses real C++ {templates}.
+
+ (2007-10-14)
+
+JCP
+
+ {Java Community Process}
+
+JCS-13
+
+ <language> An early system on the {IBM 701}.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (1997-06-16)
+
+JDBC
+
+ {Java Database Connectivity}
+
+JDK
+
+ {Java Development Kit}
+
+JEAN
+
+ <language> A dialect of {JOSS}.
+
+ [Details?]
+
+ (1997-09-14)
+
+Jean E. Sammet
+
+ <person> Author of several surveys of early programming
+ languages, refererred to in many entries in this dictionary.
+
+ E-mail: sammet@vtvm1.cc.vt.edu
+
+ Relevant publications include:
+
+ [Sammet, Jean E., "Programming Languages: History and
+ Fundamentals", P-H 1969. QA76.5 .S213]. The definitive work
+ on early computer language development.
+
+ [Sammet, Jean E., "Programming Languages: History and Future",
+ CACM 15(7):601-610, Jul 1972].
+
+ [Sammet, Jean E., "Roster of Programming Languages"
+ Computers & Automation 16(6):80-82, June 1967;
+ Computers & Automation 17(6):120-123, June 1968;
+ Computers & Automation 18(7):153-158, June 1969;
+ Computers & Automation 19(6B):6-11, 30 Nov 1970;
+ Computers & Automation 20(6B):6-13, 30 Jun, 1971;
+ Computers & Automation 21(6B), 30 Aug 1972;
+ Computing Reviews 15(4): 147-160, April 1974;
+ CACM 19(12):655-669, Dec 1976;
+ SIGPLAN Notices 13(11):56, Nov 1978].
+
+ (1998-10-03)
+
+Jean-Maurice-Émile Baudot
+
+ <person> (1845-1903) The inventor of the {Baudot code}. Baudot
+ joined the French Post & Telegraph Administration in 1869 as a
+ telegraph operator. In his own time he developed a code for
+ sending several messages at once. In 1874 Baudot patented his
+ first printing telegraph where signals were translated onto paper
+ tape. The {Baudot code} was adopted first in France and then by
+ other nations for <telegraph> and <teletype> transmissions.
+
+ The unit of transmission speed, {baud}, is named after him.
+
+ (2013-01-12)
+
+JEDR
+
+ <person, abuse, humour> Synonymous with {IYFEG}. At one time,
+ people in the {Usenet} {newsgroup} {news:rec.humor.funny}
+ tended to use "JEDR" instead of {IYFEG} or "<ethnic>"; this
+ stemmed from a public attempt to suppress the group once made
+ by a loser with initials JEDR after he was offended by an
+ ethnic joke posted there. (The practice was {retcon}ned by
+ expanding these initials as "Joke Ethnic/Denomination/Race".)
+ After much sound and fury JEDR faded away; this term appears
+ to be doing likewise. JEDR's only permanent effect on the
+ net.culture was to discredit "sensitivity" arguments for
+ censorship so thoroughly that more recent attempts to raise
+ them have met with immediate and near-universal rejection.
+
+ [{Jargon File}]
+
+ (1994-11-22)
+
+Jef Raskin
+
+ <person> The person who started the {Macintosh} project at
+ {Apple Computer, Inc.} but left the company before the product
+ was launched.
+
+ (1999-08-24)
+
+Jenga Code
+
+ <humour, programming> A style of programming which results in the
+ whole thing collapsing when you touch a single block of code.
+ Named after the game where players try to remove wooden blocks
+ from a tower without it falling down.
+
+ Also known as Crispy Noodle Code.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ [Why crispy noodle?]
+
+ (2013-12-25)
+
+Jerry Sussman
+
+ {Gerald Sussman}
+
+JES
+
+ {job entry system}
+
+JES2
+
+ <operating system> One of {IBM}'s {job entry systems} for
+ {MVS}.
+
+ (1995-08-16)
+
+JES3
+
+ <operating system> One of {IBM}'s {job entry systems} for
+ {MVS}.
+
+ (1995-08-16)
+
+JFCL
+
+ /jif'kl/, /jaf'kl/, /j*-fi'kl/ (obsolete) To cancel or annul
+ something. "Why don't you jfcl that out?" The fastest
+ do-nothing instruction on older models of the {PDP-10}
+ happened to be JFCL, which stands for "Jump if Flag set and
+ then CLear the flag"; this does something useful, but is a
+ very fast no-operation if no flag is specified. Geoff
+ Goodfellow, one of the jargon-1 co-authors, had JFCL on the
+ licence plate of his BMW for years. Usage: rare except among
+ old-time PDP-10 hackers.
+
+ [{Jargon File}]
+
+ (1994-11-22)
+
+JFDI
+
+ <chat> Just fucking do it.
+
+ (2008-04-18)
+
+JFET
+
+ {Junction Field Effect Transistor}
+
+JFGI
+
+ <chat, WWW> Just Fucking Google It. See {STFW}.
+
+ (2014-05-23)
+
+JFIF
+
+ {JPEG File Interchange Format}
+
+jiffy
+
+ 1. The duration of one {tick} of the computer's {system
+ clock}. Often one AC cycle time (1/60 second in the US and
+ Canada, 1/50 most other places), but more recently 1/100 sec
+ has become common.
+
+ 2. Confusingly, the term is sometimes also used for a
+ 1-millisecond {wall time} interval. Even more confusingly,
+ physicists semi-jokingly use "jiffy" to mean the time required
+ for light to travel one foot in a vacuum, which turns out to
+ be close to one *nanosecond*.
+
+ [{Jargon File}]
+
+ (2002-03-02)
+
+Jim Clark
+
+ {Dr. James H. Clark}
+
+Jini
+
+ <networking> /jee'nee/ {Sun}'s {Java}-based system for
+ networking home appliances, {desktop computers} and other
+ kinds of consumer electronics.
+
+ {(http://java.sun.com/products/jini/)}.
+
+ [Details?]
+
+ (1998-11-14)
+
+JIPS
+
+ {JANET IP Service}
+
+JIT
+
+ {dynamic translation}
+
+jitter
+
+ Random variation in the timing of a signal, especially a
+ clock.
+
+ (1995-01-16)
+
+JK flip-flop
+
+ <hardware> An {edge triggered} {SR flip-flop} with extra logic
+ such that only one of the R and S inputs is enabled at any
+ time. This prevents a {race condition} which can occur when
+ both inputs of an RS flip-flop are active at the same time.
+ In a JK flip-flop the R and S inputs are renamed J and K. The
+ set input (J) is only enabled when the flip-flop is reset and
+ K when it is set.
+
+ If both J and K inputs are held active then the outputs will
+ change ("togle") on each falling edge of the clock. JK
+ flip-flops can be used to build a {binary counter} with a
+ reset input.
+
+ {(http://play-hookey.com/digital/logic7.html)}.
+
+ [Was it named after {Jack Kilby}?]
+
+ (2004-07-17)
+
+jm
+
+ <networking> The {country code} for Jamaica.
+
+ (1999-01-27)
+
+J.M.E. Baudot
+
+ {Jean-Maurice-Émile Baudot}
+
+JMHO
+
+ <chat> Just My Humble Opinion.
+
+ (1999-02-18)
+
+JMS
+
+ {Java Message Service}
+
+JNI
+
+ {Java Native Interface}
+
+jo
+
+ <networking> The {country code} for Jordan.
+
+ (1999-01-27)
+
+job
+
+ <operating system> All activities involved in completing any
+ project on a computer from start to finish. A job may involve
+ several {processes} and several {programs}.
+
+ This term originates from a time when a user would manually
+ submit a job as a deck of {punched cards} which would
+ typically include {source code} interspersed with {job control
+ language} instructions to guide phases of the job such as
+ {compilation}, {linking}, {execution} and printing.
+
+ (2005-03-16)
+
+Job Control Language
+
+ <language, operating system> (JCL) {IBM}'s supremely {rude}
+ {script} language, used to control the execution of programs
+ in IBM {OS/360}'s {batch} systems. JCL has a very {fascist}
+ {syntax}, and some versions will, for example, {barf} if two
+ spaces appear where it expects one.
+
+ Most programmers confronted with JCL simply copy a working
+ file (or {card deck}), changing the file names. Someone who
+ actually understands and generates unique JCL is regarded with
+ the mixed respect one gives to someone who memorises the phone
+ book. It is reported that hackers at IBM itself sometimes
+ sing "Who's the breeder of the crud that mangles you and me?
+ I-B-M, J-C-L, M-o-u-s-e" to the tune of the "Mickey Mouse
+ Club" theme to express their opinion of the beast.
+
+ As with {COBOL}, JCL is often used as an archetype of ugliness
+ even by those who haven't experienced it. However, no
+ self-respecting {mainframe} {MVS} programmer would admit
+ ignorance of JCL.
+
+ See also {fear and loathing}.
+
+ (1999-03-03)
+
+Job Entry System
+
+ <operating system> (JES) An {IBM} {mainframe} term. There are
+ really two JESs. JES2 is smaller and simpler, and can handle
+ 99.99% of most jobs that run on IBM's {MVS} {operating
+ system}. JES3 is much bigger and requires really {big iron}
+ to run.
+
+ (1996-03-23)
+
+Jobs
+
+ {Stephen Jobs}
+
+job security
+
+ <jargon> When some piece of code is written in a particularly
+ obscure fashion, and no good reason (such as time or space
+ optimisation) can be discovered, it is often said that the
+ programmer was attempting to increase his job security (i.e.
+ by making himself indispensable for maintenance). This sour
+ joke seldom has to be said in full; if two hackers are looking
+ over some code together and one points at a section and says
+ "job security", the other one may just nod.
+
+ [{Jargon File}]
+
+ (1996-09-17)
+
+jock
+
+ 1. A programmer who is characterised by large and somewhat
+ {brute-force} programs.
+
+ 2. When modified by another noun, describes a specialist in
+ some particular computing area. The compounds "compiler jock"
+ and "systems jock" seem to be the best-established examples.
+
+ [{Jargon File}]
+
+ (1995-01-19)
+
+joe
+
+ <jargon, security> A computer account whose user name and
+ password are the same. Joes are {considered harmful}, as are
+ any passwords which are easy to guess.
+
+ (1995-06-21)
+
+joe code
+
+ /joh' kohd"/ 1. Code that is overly {tense} and
+ unmaintainable. "{Perl} may be a handy program, but if you
+ look at the source, it's complete joe code."
+
+ 2. Badly written, possibly buggy code.
+
+ Correspondents wishing to remain anonymous have fingered a
+ particular Joe at the Lawrence Berkeley Laboratory and
+ observed that usage has drifted slightly; the original
+ sobriquet "Joe code" was intended in sense 1.
+
+ [{Jargon File}]
+
+John Atanasoff
+
+ {John Vincent Atanasoff}
+
+John Gilmore
+
+ <person> A noted {Unix} {hacker} who cofounded {Usenet}'s
+ anarchic alt.* {newsgroup} {hierarchy} with {Brian Reid}. He
+ also worked on {GDB}.
+
+ E-mail: John Gilmore <gnu@toad.com>.
+
+ (1995-04-18)
+
+John Mauchly
+
+ <person> /jon W mok'*-lee/ (rhymes with "broccoli") Dr. John
+ W. Mauchly, one of the developers of {ENIAC}.
+
+ (2002-10-06)
+
+John McCarthy
+
+ <person, artificial intelligence> A pioneer of {artificial
+ intelligence} (he coined ther term). He invented {Lisp} at
+ {MIT} in the late 1950s and later worked at {SAIL}.
+
+ {(ftp://www-formal.stanford.edu/jmc)}.
+
+ E-mail: <jmc@cs.stanford.edu>.
+
+ (2003-08-06)
+
+Johnniac
+
+ <computer> A {mainframe} computer based on a design by {John
+ von Neuman} built at the {Institute for Advanced Study}, USA.
+ The Johnniac went live in 1953 and was decommissioned in 1966.
+ Its memory consisted of 80 special "{Selectron}" {vacuum
+ tubes}, each of which held 256 bits of data.
+
+ (2003-06-07)
+
+JOHNNIAC Open Shop System
+
+ <language> (JOSS) An early, simple, {interactive} calculator
+ language developed by Charles L. Baker at Rand in 1964. There
+ were two versions: JOSS I and JOSS II.
+
+ [Connection with {Johnniac}?]
+
+ ["JOSS Users' Reference Manual", R.L. Clark, Report F-1535/9,
+ RAND Corp (Jan 1975)].
+
+ [Sammet 1969, pp. 217-226].
+
+ (2004-07-11)
+
+John Ousterhout
+
+ <person> /oh'st*r-howt/ John K. Ousterhout, the designer of
+ {Tcl} and {Tk}, and founder of {Scriptics}.
+
+ See also: {Ousterhout's dichotomy}.
+
+ E-mail: john.ousterhout@scriptics.com.
+
+ (1999-02-21)
+
+John Tukey
+
+ <person> The eminent statistician credited with coining the
+ term "{bit}" in 1949.
+
+ {(http://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Tukey.html)}.
+
+ (2003-02-28)
+
+John Vincent Atanasoff
+
+ <person> John Vincent Atanasoff, 1903-10-04 - 1995-06-15. An
+ American mathemetical physicist, and the inventor of the
+ electronic {digital computer}. Between 1937 and 1942 he built
+ the {Atanasoff-Berry Computer} with {Clifford Berry}, at the
+ {Iowa State University}.
+
+ Atanasoff was born on 1903-10-04 in Hamilton, New York. In
+ 1925, he got a Bachelor of Science degree in Electrical
+ Engineering from the University of Florida. In 1926 he
+ received a Master's degree in Maths from Iowa State
+ University. He received a PhD as a theoretical physicist from
+ the University of Wisconsin in 1930.
+
+ While an associate professor of mathematics and physics at
+ Iowa State University, Atanasoff began to envision a {digital}
+ computational device, believing {analogue} devices to be too
+ restrictive. Whilst working on his electronic {digital
+ computer}, Atanasoff was introduced to a graduate student
+ named {Clifford Berry}, who helped him build the {computer}.
+
+ The first prototype of the {Atanasoff-Berry Computer} was
+ demonstrated in December 1939. Although no patent was awarded
+ for the new {computer}, in 1973 US District Judge Earl R.
+ Larson declared Atanasoff the inventor of the digital computer
+ (declaring the {ENIAC} patent invalid).
+
+ Atanasoff was awarded the National Medal of {Technology} by US
+ President Bush on 1990-11-13. He died following a stroke on
+ 1995-06-15.
+
+ {John Vincent Atanasoff and the Birth of the Digital Computer
+ (http://cs.iastate.edu/jva/jva-archive.shtml)}.
+
+ ["Atanasoff Forgotten Father of the Computer", C. R.
+ Mollenhoff, Iowa State University Press 1988].
+
+ (2001-10-03)
+
+John von Neumann
+
+ <person> /jon von noy'mahn/ Born 1903-12-28, died 1957-02-08.
+
+ A Hungarian-born mathematician who did pioneering work in
+ quantum physics, game theory, and {computer science}. He
+ contributed to the USA's Manhattan Project that built the
+ first atomic bomb.
+
+ von Neumann was invited to Princeton University in 1930, and
+ was a mathematics professor at the {Institute for Advanced
+ Studies} from its formation in 1933 until his death.
+
+ From 1936 to 1938 {Alan Turing} was a visitor at the Institute
+ and completed a Ph.D. dissertation under von Neumann's
+ supervision. This visit occurred shortly after Turing's
+ publication of his 1934 paper "On Computable Numbers with an
+ Application to the Entscheidungs-problem" which involved the
+ concepts of logical design and the universal machine. von
+ Neumann must have known of Turing's ideas but it is not clear
+ whether he applied them to the design of the IAS Machine ten
+ years later.
+
+ While serving on the BRL Scientific Advisory Committee, von
+ Neumann joined the developers of {ENIAC} and made some
+ critical contributions. In 1947, while working on the design
+ for the successor machine, {EDVAC}, von Neumann realized that
+ ENIAC's lack of a centralized control unit could be overcome
+ to obtain a rudimentary stored program computer. He also
+ proposed the {fetch-execute cycle}. His ideas led to what is
+ now often called the {von Neumann architecture}.
+
+ {(http://sis.pitt.edu/~mbsclass/is2000/hall_of_fame/vonneuma.htm)}.
+
+ {(http://ei.cs.vt.edu/~history/VonNeumann.html)}.
+
+ {(http://ftp.arl.mil/~mike/comphist/54nord/)}.
+
+ (2004-01-14)
+
+join
+
+ 1. <database> {inner join} (common) or {outer join} (less
+ common).
+
+ 2. <theory> {least upper bound}.
+
+ (1998-11-23)
+
+Joint Academic NETwork
+
+ (JANET) The {wide area network} which links UK academic and
+ research institutes. JANET is controlled by the {Joint
+ Network Team} (JNT) and Network Executive (NE). It is an
+ {internet} (a large number of interconnected sub-networks)
+ that provides connectivity within the community as well as
+ access to external services and other communities. The {hub}
+ is the JANET subnetwork, a private {X.25} {packet-switched}
+ network that interconnects over 100 sites. At the majority of
+ sites, {local area networks} (LANs) are connected to JANET
+ allowing off-site access for the computers and terminals
+ connected to these networks. The {Coloured Book} {protocol}
+ architecture is used to support interactive terminal access to
+ computers (for both character terminals and screen terminals),
+ inter-host file transfers, {electronic mail} and remote
+ {batch} job submission.
+
+ {(http://nic.ja.net/)}.
+
+ See also {JIPS}, {SuperJanet}.
+
+ (1995-02-07)
+
+Joint Bi-level Image Experts Group
+
+ <algorithm> (JBIG) An experts group of {ISO}, {IEC} and
+ {ITU-T} (JTC1/SC2/WG9 and SGVIII) working to define a
+ {compression} {standard} for {lossless} {image} coding. Their
+ proposed {algorithm} features compatible {progressive coding}
+ and {sequential coding} and is lossless - the image is
+ unaltered after compression and decompression.
+
+ JBIG can handle images with from one to 255 bits per {pixel}.
+ Better compression algorithms exist for more than about eight
+ bits per pixel. With multiple bits per pixel, {Gray code} can
+ be used to reduce the number of bit changes between adjacent
+ decimal values (e.g. 127 and 128), and thus improve the
+ compression which JBIG does on each {bitplane}.
+
+ JBIG uses discrete steps of detail by successively doubling
+ the {resolution}. The sender computes a number of resolution
+ layers and transmits these starting at the lowest resolution.
+ Resolution reduction uses pixels in the high resolution layer
+ and some already computed low resolution pixels as an index
+ into a lookup table. The contents of this table can be
+ specified by the user.
+
+ Compatibility between progressive and sequential coding is
+ achieved by dividing an image into stripes. Each stripe is a
+ horizontal bar with a user definable height. Each stripe is
+ separately coded and transmitted, and the user can define in
+ which order stripes, resolutions and bitplanes are intermixed
+ in the coded data. A progressively coded image can be decoded
+ sequentially by decoding each stripe, beginning by the one at
+ the top of the image, to its full resolution, and then
+ proceeding to the next stripe. Progressive decoding can be
+ done by decoding only a specific resolution layer from all
+ stripes.
+
+ After dividing an image into {bitplanes}, {resolution layers}
+ and stripes, eventually a number of small bi-level {bitmaps}
+ are left to compress. Compression is done using a {Q-coder}.
+
+ The Q-coder codes bi-level pixels as symbols using the
+ probability of occurrence of these symbols in a certain
+ context. JBIG defines two kinds of context, one for the
+ lowest resolution layer (the base layer), and one for all
+ other layers (differential layers). Differential layer
+ contexts contain pixels in the layer to be coded, and in the
+ corresponding lower resolution layer.
+
+ For each combination of pixel values in a context, the
+ probability distribution of black and white pixels can be
+ different. In an all white context, the probability of coding
+ a white pixel will be much greater than that of coding a black
+ pixel. The Q-coder, like {Huffman coding}, achieves
+ {compression} by assigning more bits to less probable symbols.
+ The Q-coder can, unlike a Huffman coder, assign one output
+ code bit to more than one input symbol, and thus is able to
+ compress bi-level pixels without explicit {clustering}, as
+ would be necessary using a Huffman coder.
+
+ [What is "clustering"?]
+
+ Maximum compression will be achieved when all probabilities
+ (one set for each combination of pixel values in the context)
+ follow the probabilities of the pixels. The Q-coder therefore
+ continuously adapts these probabilities to the symbols it
+ sees.
+
+ JBIG can be regarded as two combined algorithms:
+
+ (1) Sending or storing multiple representations of images at
+ different resolutions with no extra storage cost.
+ Differential layer contexts contain pixels in two resolution
+ layers, and so enable the Q-coder to effectively code the
+ difference in information between the two layers, instead of
+ the information contained in every layer. This means that,
+ within a margin of approximately 5%, the number of resolution
+ layers doesn't effect the compression ratio.
+
+ (2) A very efficient compression algorithm, mainly for use
+ with bi-level images. Compared to {CCITT Group 4}, JBIG is
+ approximately 10% to 50% better on text and line art, and even
+ better on {halftones}. JBIG, just like Group 4, gives worse
+ compression in the presence of noise in images.
+
+ An example application would be browsing through an image
+ database.
+
+ ["An overview of the basic principles of the Q-coder adaptive
+ binary arithmetic coder", W.B. Pennebaker, J.L. Mitchell,
+ G.G. Langdon, R.B. Arps, IBM Journal of research and
+ development, Vol.32, No.6, November 1988, pp. 771-726].
+
+ {(http://crs4.it/~luigi/MPEG/jbig.html)}.
+
+ (1998-03-29)
+
+Joint Photographic Experts Group
+
+ <image, body, file format, standard> (JPEG) The original name
+ of the committee that designed the standard {image}
+ {compression} {algorithm}. JPEG is designed for compressing
+ either {full-colour} or {grey-scale} {digital} images of
+ "natural", real-world scenes. It does not work so well on
+ non-realistic images, such as cartoons or line drawings. JPEG
+ does not handle compression of black-and-white (1
+ bit-per-pixel) images or {moving pictures}. Standards for
+ compressing those types of images are being worked on by other
+ committees, named {JBIG} and {MPEG}.
+
+ {(http://jpeg.org/)}.
+
+ {Filename extension}: .jpg, .jpeg.
+
+ See also {PJPEG}.
+
+ (2000-09-11)
+
+Joint Technical Committee
+
+ <standard, body> (JTC) A {standards} body straddling {ISO} and
+ {IEC}.
+
+ (1995-04-21)
+
+Joint Test Action Group
+
+ <architecture, body, electronics, integrated circuit, standard,
+ testing> (JTAG, or "IEEE Standard 1149.1") A {standard} specifying
+ how to control and monitor the pins of compliant devices on a
+ {printed circuit board}.
+
+ Each device has four JTAG control lines. There is a
+ common reset (TRST) and clock (TCLK). The data line
+ {daisy chains} one device's test data out (TDO) pin
+ to the test data in (TDI) pin on the next device.
+
+ The {protocol} contains commands to read and set the values of
+ the pins (and, optionally {internal registers}) of devices.
+ This is called "{boundary scanning}". The protocol makes
+ board testing easier as signals that are not visible at the
+ board connector may be read and set.
+
+ The protocol also allows the testing of equipment, connected
+ to the JTAG port, to identify components on the board (by
+ reading the device identification register) and to control and
+ monitor the device's outputs.
+
+ JTAG is not used during normal operation of a board.
+
+ {JTAG Technologies B.V. (http://jtag.com/)}.
+
+ {Boundary Scan/JTAG Technical Information - Xilinx, Inc.
+ (http://xilinx.com/support/techsup/journals/jtag/)}.
+
+ {Java API for Boundary Scan FAQs - Xilinx Inc.
+ (http://xilinx.com/products/software/sx/sxfaqs.htm)}.
+
+ {JTAG Boundary-Scan Test Products - Corelis, Inc.
+ (http://corelis.com/products/scanovrv.html)}.
+
+ {"Logic analyzers stamping out bugs at the cutting edge", EDN
+ Access, 1997-04-10
+ (http://ednmag.com/ednmag/reg/1997/041097/08df_02.htm)}.
+
+ {IEEE 1149.1 Device Architecture - Boundary-Scan Tutorial from
+ ASSET InterTech, Inc.
+ (http://asset-intertech.com/tutorial/arch.htm)}.
+
+ {"Application-Specific Integrated Circuits", Michael John
+ Sebatian Smith, published Addison-Wesley - Design Automation
+ Cafe
+ (http://dacafe.com/DACafe/EDATools/EDAbooks/ASIC/Book/CH14/CH14.2.htm)}.
+
+ {Software Debug options on ASIC cores - Embedded Systems
+ Programming Archive (http://embedded.com/97/feat9701.htm)}.
+
+ {Designing for On-Board Programming Using the IEEE 1149.1
+ (JTAG) Access Port - Intel
+ (http://developer.intel.com/design/flcomp/applnots/292186.htm)}.
+
+ {Built-In Self-Test Using Boundary Scan by Texas Instruments -
+ EDTN Network
+ (http://edtn.com/scribe/reference/appnotes/md003e9a.htm)}.
+
+ (1999-11-15)
+
+Joliet
+
+ <standard, storage> An extension of the {ISO 9660:1988} {ISO}
+ {standard} {file system} for {CD-ROMs} that allows {Unicode}
+ characters in file names and other enhancements. Version 1 of
+ Joliet was released on 1995-05-22.
+
+ Joiliet supports file and directory names up to 128 bytes (64
+ unicode characters) long, directory names with file name
+ extensions, a directory hierarchy deeper than 8 levels and the
+ {volume recognition sequence} supports {multisession}.
+
+ Joliet uses ISO 9660's "supplementary volume descriptor" (SVD)
+ to specify Unicode files. Use of the previously unused escape
+ sequence ISO 2022 means that Joliet is {backward compatible}
+ with ISO 9660..
+
+ {(http://www-plateau.cs.berkeley.edu/people/chaffee/jolspec.html)}.
+
+ (2006-09-25)
+
+jolix
+
+ {386BSD}
+
+JOLT
+
+ {Java Open Language Toolkit}
+
+Jonathan's Own Version Of Emacs
+
+ <editor> (jove) A version of the {GNU} {Emacs} editor.
+ Similar to {MicroGnuEmacs}.
+
+ (2008-05-29)
+
+Jon Postel
+
+ <person> (Jonathan Bruce Postel, 1943 - 1998-10-16) /p*-stel'/
+ One of the {Internet}'s founding fathers. Jon's name is
+ prominent on many of the fundamental {standards} on which the
+ Internet is built, such as {UDP}. He ran {IANA} for as long
+ as anybody could remember, in fact for most of the time he
+ *was* IANA.
+
+ He wrote {STD 1}, {STD 2} and several dozen other {RFCs}. His
+ friend {Vinton Cerf} noted his passing in {RFC 2468}.
+
+ (1998-10-21)
+
+JOOP
+
+ {Journal of Object-Oriented Programming}
+
+Joseph-Marie Jacquard
+
+ <person> /zhoh-zef' mah-ree' zhah-kar'/ (1752-07-07 to
+ 1834-08-07) The inventor of the {Jacquard loom}.
+
+ (1998-10-19)
+
+Josephson Junction
+
+ <electronics> A type of {electronic} {circuit} capable of
+ switching at very high speeds when operated at temperatures
+ approaching {absolute zero}. The low power dissipation of a
+ Josepshson Junction makes it useful in {high density computer
+ circuits}.
+
+ (2004-06-28)
+
+JOSS
+
+ {JOHNNIAC Open Shop System}.
+
+Jossle
+
+ <language> A type checked language with {separate compilation}
+ using a program library.
+
+ Mentioned in ["Rationale for the Design of Ada", J. Ichbiah,
+ Cambridge U Press, 1986, p.192].
+
+ (2005-02-19)
+
+journal
+
+ <operating system> An on-going record of transactions, such as
+ {database} updates, {file system} writes, procedure calls or
+ message transmissions. A journal differs from a simple {log}
+ in that the contents of the journal can be used to reconstruct
+ the state of the system after a failure by re-applying the
+ transactions in the journal to a snapshot of the system
+ previous state.
+
+ (2008-05-29)
+
+journalling
+
+ {journal}
+
+jove
+
+ {Jonathan's Own Version Of Emacs}.
+
+JOVIAL
+
+ <language> (Jule's Own Version of IAL) A version of {IAL}
+ produced by Jules I. Schwartz in 1959-1960. JOVIAL was based
+ on {ALGOL 58}, with extensions for large scale {real-time}
+ programming. It saw extensive use by the US Air Force. The
+ data elements were items, entries ({records}) and tables.
+
+ Versions include JOVIAL I ({IBM 709}, 1960), JOVIAL II ({IBM
+ 7090}, 1961) and JOVIAL 3 (1965). Dialects: {J3}, {JOVIAL
+ J73}, {JS}, {JTS}.
+
+ Ada/Jovial Newsletter, Dale Lange +1 (513) 255-4472.
+
+ [CACM 6(12):721, Dec 1960].
+
+ (1996-07-19)
+
+Joy
+
+ <language> A {functional programming} language by Manfred von
+ Thun. Joy is unusual because it is not based on {lambda
+ calculus}, but on the {composition} of {functions}. Functions
+ take a stack as argument, consume any number of parameters
+ from it, and return it with any number of results on it. The
+ concatenation of programs denotes the composition of
+ functions. One of the datatypes of Joy is that of quoted
+ programs, of which lists are a special case.
+
+ {Joy Home
+ (http://latrobe.edu.au/philosophy/phimvt/joy.html)}.
+
+ (2003-06-13)
+
+Joyce
+
+ A distributed language based on {Pascal} and {CSP}, by Per
+ Brinch Hansen.
+
+ ["Joyce - A Programming Language for Distributed Systems", Per
+ Brinch Hansen, Soft Prac & Exp 17(1):29-50 (Jan 1987)].
+
+ (1994-12-06)
+
+joystick
+
+ <hardware, games> A device consisting of a hand held stick that
+ pivots about one end and transmits its angle in two dimensions
+ to a computer. Joysticks are often used to control games, and
+ usually have one or more push-buttons whose state can also be
+ read by the computer. Most I/O interface cards for {IBM PCs}
+ have a joystick (game control) port.
+
+ (1995-03-08)
+
+Joy, William
+
+ {William Joy}
+
+jp
+
+ <networking> The {country code} for Japan.
+
+ (1999-01-27)
+
+JPEG
+
+ {Joint Photographic Experts Group}
+
+JPEG-2000
+
+ <image, file format> A potential successor to {JPEG} with
+ better compression and {multiresolution} {images}. JPEG-2000
+ gives reasonable quality down to 0.1 bits/pixel (JPEG quality
+ drops dramatically below about 0.4 bits/pixel).
+
+ (2001-12-02)
+
+JPEG File Interchange Format
+
+ <graphics, file format> (JFIF) The technical name for the file
+ format better known as {JPEG}. This term is used only when
+ the difference between the JPEG file format and the JPEG image
+ {compression} {algorithm} is crucial.
+
+ (1998-02-10)
+
+jpg
+
+ {JPEG}
+
+JPL
+
+ <language> {JAM Programming Language}.
+
+JPLDIS
+
+ {Jet Propulsion Laboratory} Display Information System. Query
+ system for {UNIVAC 1108} [or PDP's?] written in {Fortran},
+ based on {Tymshare}'s "Retrieve". Indirectly led to {Vulcan}
+ which led to {dBASE II}. Jack Hatfield, George Masters,
+ W. Van Snyder, Jeb Long et al, JPL.
+
+J. Presper Eckert
+
+ <person> One of the developers of {ENIAC}.
+
+ {Biography
+ (http://www-groups.dcs.st-and.ac.uk/~history/ShortBiogs/E.html)}.
+
+ [Summary?]
+
+ (1995-11-14)
+
+J. Random
+
+ <jargon> /J rand'm/ (Generalised from {J. Random Hacker})
+ Arbitrary; ordinary; any one; any old. "J. Random" is often
+ prefixed to a noun to make a name out of it. It means roughly
+ "some particular" or "any specific one". "Would you let
+ J. Random Loser marry your daughter?" The most common uses
+ are "J. Random Hacker", "J. Random Loser", and "J. Random
+ Nerd" ("Should J. Random Loser be allowed to {gun} down other
+ people?"), but it can be used simply as an elaborate version
+ of {random} in any sense.
+
+ [{Jargon File}]
+
+J. Random Hacker
+
+ <jargon> /J rand'm hak'r/ {MIT} jargon for a mythical figure;
+ the archetypal {hacker} {nerd}.
+
+ This may originally have been inspired by "J. Fred Muggs", a
+ show-biz chimpanzee whose name was a household word back in
+ the early days of {TMRC}, and was probably influenced by
+ {J. Presper Eckert} (one of the co-inventors of the electronic
+ computer).
+
+ See {random}, {Suzie COBOL}.
+
+ (1996-10-16)
+
+JRE
+
+ {Java Run-Time Environment}
+
+JRL
+
+ {J. Random} Loser. The names JRL and JRN were sometimes used
+ as example names when discussing a kind of user ID used under
+ {TOPS-10} and {WAITS}. They were understood to be the
+ initials of (fictitious) programmers named "J. Random Loser"
+ and "J. Random Nerd". For example, if one said "To log in,
+ type log one comma jay are en" (that is, "log 1,JRN"), the
+ listener would have understood that he should use his own
+ computer ID in place of "JRN".
+
+JRMP
+
+ {Java Remote Method Protocol}
+
+JRN
+
+ {J. Random} Nerd. See {JRL}.
+
+JRST
+
+ /jerst/ [based on the {PDP-10} jump instruction, obsolete] To
+ suddenly change subjects, with no intention of returning to
+ the previous topic. Usage: rather rare except among PDP-10
+ diehards, and considered silly. See also {AOS}.
+
+ [{Jargon File}]
+
+JS
+
+ Dialect of {JOVIAL}. [Sammet 1969, p.639].
+
+JSA
+
+ Japanese Standards Association.
+
+JSDK
+
+ {Java Servlet Development Kit}
+
+JSF
+
+ {JavaServer Faces}
+
+JSON
+
+ {JavaScript Object Notation}
+
+JSP
+
+ {JavaServer Pages}
+
+JTAG
+
+ {Joint Test Action Group}
+
+JTB
+
+ {jump trace buffer}
+
+JTC
+
+ <standard, body> {Joint Technical Committee}.
+
+JTC1/SC24
+
+ The {ISO}/{IEC} group which has worked on {standards} like
+ {GKS}, {PHIGS}, {CGM}, and is now also involved in the area of
+ standardisation in {Multimedia Presentation}.
+
+ {(http://cwi.nl/JTC1SC24/)}.
+
+ (1995-01-04)
+
+JTS
+
+ A simple dialect of {JOVIAL}.
+
+ [Sammet 1969, p. 528].
+
+ (1995-01-04)
+
+juggling eggs
+
+ Keeping a lot of {state} in your head while modifying a
+ program. "Don't bother me now, I'm juggling eggs", means that
+ an interrupt is likely to result in the program's being
+ scrambled. In the classic first-contact SF novel "The Mote in
+ God's Eye", by Larry Niven and Jerry Pournelle, an alien
+ describes a very difficult task by saying "We juggle priceless
+ eggs in variable gravity." See also {hack mode}.
+
+ [{Jargon File}]
+
+Jughead
+
+ Jughead is a tool for Gopher administrators to get menu
+ information from various gopher servers, and is an acronym
+ for: Jonzy's Universal Gopher Hierarchy Excavation And
+ Display. Jughead was written in ANSI C. Gopher:
+ gopher.cc.utah.edu, About U of U Gopher/Gopher Tools/jughead.
+
+ {(ftp://ftp.cc.utah.edu/pub/gopher/GopherTools)}. Mailing
+ list: jughead-news@lists.utah.edu.
+
+jukebox
+
+ <hardware, storage> A hardware mechanism for allowing access
+ to one of a group of discs, especially CD-ROMs or other
+ optical media.
+
+ [Or magnetic tapes?]
+
+ (1996-12-10)
+
+jump
+
+ <programming> (Or "branch") The term for a {goto} instruction,
+ usually in a context of {machine languages}. "Branch" may be
+ synonymous with "jump", or may refer to jumps that depend on a
+ condition.
+
+ (1998-11-14)
+
+jumper
+
+ <hardware> A removable wire or small plug whose presence or
+ absence is used to determine some aspect of hardware
+ configuration.
+
+ (1995-03-14)
+
+jump off into never-never land
+
+ [J. M. Barrie's "Peter Pan"] Same as {branch to Fishkill}, but
+ more common in technical cultures associated with non-{IBM}
+ computers that use the term "jump" rather than "branch".
+
+ Compare {hyperspace}.
+
+ [{Jargon File}]
+
+ (1994-12-15)
+
+jump trace buffer
+
+ (JTB) A feature of some {pipelined} processors (e.g. {Amulet},
+ {Pentium}?) which stores the source and destination addresses
+ of the last few branch instuctions executed. When a branch
+ instruction is fetched, its source is looked for in the JTB.
+ If found, the next instuction fetch will be from the previous
+ destination of that branch. If it turns out that the branch
+ shouldn't have been taken this time, then the {pipeline} is
+ flushed. This means that in a {tight loop} it is not
+ necessary to flush the {pipeline} every time you jump back to
+ the start.
+
+ (1994-12-15)
+
+Junction FET
+
+ {Junction Field Effect Transistor}
+
+Junction Field Effect Transistor
+
+ <electronics> (JFET, Junction FET) A {Field Effect Transistor}
+ in which the conducting channel lies between pn junctions in
+ the silicon material. A pn junction acts as a {diode}, so it
+ becomes conductive if the gate voltage gets reversed.
+
+ (1997-02-24)
+
+Juno
+
+ A numerical {constraint}-oriented language for graphics
+ applications. It solves its constraints using
+ {Newton-Raphson} {relaxation}. It was inspired partly by
+ {Metafont}.
+
+ ["Juno, a Constraint-Based Graphics System", G. Nelson in
+ SIGGRAPH '85 Conf Readings, B.A. Barsky ed, Jul 1985,
+ pp. 235-243].
+
+ (1994-11-23)
+
+jupiter
+
+ To kill an {IRC} {robot} or user and then take its place by
+ adopting its {nick} so that it cannot reconnect. Named after
+ a particular IRC user who did this to {NickServ}, the robot in
+ charge of preventing people from inadvertently using a nick
+ claimed by another user.
+
+ [{Jargon File}]
+
+ (1994-11-23)
+
+Just a Bunch Of Disks
+
+ <jargon, storage> (JBOD, or "Just a Bunch of Drives") A
+ storage subsystems using multiple independent {disk drives},
+ as opposed to one form of {RAID} or another.
+
+ For example, {Unisys} open storage provides JBOD in both
+ {SCSI} and {fibre channel} interfaces.
+
+ {Unisys JBOD
+ (http://marketplace.unisys.com/storage/jbod.html)}.
+
+ (1998-12-21)
+
+just-in-time
+
+ {dynamic translation}
+
+JVM
+
+ {Java Virtual Machine}
+
+Jym
+
+ A predecessor to {Graal} by Patrick Bellot, France.
+
+K
+
+ <unit> {kilo-}, a {kilobyte}. Used both as a spoken word and
+ a written suffix, like {meg} and {gig} for {megabyte} and
+ {gigabyte}.
+
+ See {prefix}.
+
+ [{Jargon File}]
+
+ (1995-09-29)
+
+K5
+
+ An early system on the {Larc} computer.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1994-11-23)
+
+K56flex
+
+ <protocol> A modem standard developed by {Rockwell} for 56
+ {kbps} communications. K56flex Became more popular than the
+ rival {X2} but will be superseded by the official {V.90}
+ standard.
+
+ [Already superseded?]
+
+ (1998-09-08)
+
+K6
+
+ <processor> A {Pentium II} class {microprocessor},
+ manufactured by {AMD}.
+
+ [100% Compatible? Speed?]
+
+ (1998-02-27)
+
+K7
+
+ {Athlon}
+
+KA9Q
+
+ <networking> A popular implementation of {TCP/IP} and
+ associated {protocols} for amateur {packet radio} systems and
+ {personal computers} connected via {serial lines}. It was
+ named after the call-sign of Phil Karn - the radio ham who
+ first wrote it for {MS-DOS} on the {IBM PC}.
+
+ KA9Q is currently maintained by Anthony Frost
+ <vulch@kernow.demon.co.uk> (call-sign G8UDV) and Adam
+ Goodfellow <tcpip2@comptech.demon.co.uk>. It has been ported
+ to the {Archimedes} by Jonathan Naylor (G4KLX).
+
+ [FTP?]
+
+ (1994-11-08)
+
+KADS
+
+ {Knowledge Analysis and Design System}
+
+kahuna
+
+ <person> /k*-hoo'n*/ (From the Hawaiian title for a shaman) An
+ {IBM} synonym for {wizard} or {guru}.
+
+ [{Jargon File}]
+
+ (1994-11-09)
+
+Kaleidoscope
+
+ <language> An {object-oriented} language which mixes
+ {imperative programming} and {constraint}-oriented features.
+ Kaleidoscope was written by Freeman-Benson of the {University
+ of Washington}, {Universite de Nantes}, 1989; {University of
+ Victoria}, 1992. It is similar to {Siri} and vaguely related
+ to {Prose}.
+
+ Versions: Kaleidoscope '90 and Kaleidoscope '91.
+
+ ["Kaleidoscope: Mixing Objects, Constraints and Imperative
+ Programming", B.N. Freeman-Benson, SIGPLAN Notices
+ 25(10):77-88 (OOPSLA/ECOOP '90) (Oct 1990)].
+
+ ["Constraint Imperative Programming", B.N. Freeman-Benson,
+ Ph.D. Thesis, TR 91-07-02, U Wash (1991)].
+
+ ["Constraint Imperative Programming", Freeman-Benson et al,
+ IEEE Conf on Comp Lang, Apr 1992].
+
+ (1994-11-09)
+
+Kali
+
+ A {data parallel} language.
+
+ ["Supporting Shared Data Structures on Distributed Memory
+ Architectures", C. Koelbel et al in Second ACM SIGPLAN Symp on
+ Princ and Prac of Parallel Programming, pp.177-186, Mar 1990].
+
+ (1994-11-09)
+
+kamikaze packet
+
+ {Christmas tree packet}
+
+Kamin's interpreters
+
+ <language, tool> A set of {interpreters} for {Pascal}, {Lisp},
+ {APL}, {Scheme}, {SASL}, {CLU}, {Smalltalk}, and {Prolog}.
+ Tim Budd <budd@cs.orst.edu> implemented them as {subclasses}
+ in {C++} sometime before 1991-09-12.
+
+ {(ftp://cs.orst.edu/pub/budd/kamin/)}.
+
+ ["Programming Languages, An Interpreter-Based Approach",
+ Samuel Kamin].
+
+ (2002-03-14)
+
+kana
+
+ <Japanese> The two Japanese syllabaries, {hiragana} and
+ {katakana}.
+
+ (2001-03-18)
+
+kangaroo code
+
+ {spaghetti code}
+
+kanji
+
+ <human language, character> /kahn'jee/ (From the Japanese
+ "kan" - the Chinese Han dynasty, and "ji" - {glyph} or letter
+ of the alphabet. Not capitalised. Plural "kanji") The
+ Japanese word for a {Han character} used in Japanese. Kanji
+ constitute a part of the {writing system} used to represent
+ the Japanese language in written, printed and displayed form.
+ The term is also used for the collection of all kanji
+ {letters}.
+
+ {US-ASCII} doesn't include kanji characters, but some
+ {character encodings}, including {Unicode}, do.
+
+ The Japanese writing system also uses hiragana, katakana, and
+ sometimes romaji ({Roman alphabet} letters). These characters
+ are distinct from, though commonly used in combination with,
+ kanji. {Furigana} are also added sometimes.
+
+ (2000-12-30)
+
+KAOS
+
+ {Kent Applicative Operating System}
+
+KAP
+
+ Kernel Andorra Prolog. The predecessor of {AKL}.
+
+ ["Kernel Andorra Prolog and its Computation Model", S. Haridi
+ <seif@sics.se> et al, in Logic Programming: Proc 7th Intl
+ Conf, MIT Press 1990].
+
+ (1994-11-02)
+
+Karel
+
+ Language featured in Karel the Robot: A Gentle Introduction to
+ Computer Programming, Richard E. Pattis, Wiley 1981.
+
+ {(ftp://ftp.wustl.edu/mirrors/Unix-c/languages/pascal/karel.tar-z)}.
+
+katakana
+
+ <Japanese> The square-formed Japanese {kana} syllabary.
+ Katakana is mostly used to write foreign names, foreign words,
+ and loan words as well as many onomatopeia, plant and animal
+ names.
+
+ (2001-03-18)
+
+Katmai New Instructions
+
+ {Streaming SIMD Extensions}
+
+KB
+
+ {kilobyte}
+
+KBMS
+
+ An {expert system}.
+
+kbps
+
+ {kilobits per second}
+
+KBS
+
+ {Knowledge-Based System}
+
+KC-85/1
+
+ <computer> A commercial {home computer} from East Germany.
+ The KC-85/1 runs at 2.45 {MHz} and uses a {Z80} {clone}
+ {CPU}. The computer allows for only semigraphics.
+
+ (2004-03-31)
+
+KC85/2
+
+ <computer> A commercial {home computer} introduced in East
+ Germany in 1984. The KC85/2 has 32 {KB} of {RAM} and uses a
+ {Z80} {clone} {CPU}.
+
+ (2004-03-31)
+
+KC85/3
+
+ <computer> A commercial {home computer} introduced in East
+ Germany in 1986. The KC85/3 has 32 {KB} of {RAM} and uses a
+ {Z80} {clone} {CPU}.
+
+ (2004-03-31)
+
+KC85/4
+
+ <computer> The last commercial home computer from East Germany
+ in the KC series. The KC85/4 was introduced in 1988. It runs
+ at 1.77 {MHz}, has 64 {KB} of {RAM} and uses a {Z80} {clone}
+ {CPU}. It displays graphics at a {resolution} of 320x256.
+
+ (2004-03-31)
+
+KCL
+
+ {Kyoto Common Lisp}
+
+ke
+
+ <networking> The {country code} for Kenya.
+
+ (1999-01-27)
+
+KEE
+
+ Knowledge Engineering Environment. Frame-based expert system.
+ Supports dynamic inheritance, {multiple inheritance},
+ polymorphism. Classes, meta-classes and objects are all
+ treated alike. A class is an instance of a meta-class. Can
+ control rules for merging of each field when multiple
+ inheritance takes place. Methods are written in LISP.
+ Actions may be triggered when fields are accessed or modified.
+ Extensive GUI integrates with objects. Can easily make object
+ updates to be reflected on display or display selections to
+ update fields. This can in turn trigger other methods or
+ inference rules which may then update other parts of the
+ display. Intellicorp, for TI Explorer. "The Role of
+ Frame-Based Representation in Reasoning", R. Fikes et al, CACM
+ 28(9):904- 920 (Sept 1985).
+
+keep-alive
+
+ <communications> A short message sent periodically on a
+ communication channel that would otherwise {time out} and
+ close due to inactivity.
+
+ (2012-07-18)
+
+Keldysh Institute of Applied Mathematics
+
+ Address: Russian Academy of Sciences Miusskaya Pl. 4, 125047
+ Moscow, Russia.
+
+ (1994-12-12)
+
+ken
+
+ /ken/ 1. {Ken Thompson}
+
+ 2. A flaming user. This was originated by the Software
+ Support group at {Symbolics} because the two greatest flamers
+ in the user community were both named Ken.
+
+ [{Jargon File}]
+
+Ken Thompson
+
+ <person> The principal inventor of the {Unix} {operating
+ system} and author of the {B} language, the predecessor of
+ {C}.
+
+ In the early days Ken used to hand-cut {Unix} distribution
+ tapes, often with a note that read "Love, ken". Old-timers
+ still use his first name (sometimes uncapitalised, because
+ it's a login name and mail address) in third-person reference;
+ it is widely understood (on {Usenet} in particular) that
+ without a last name "Ken" refers only to Ken Thompson.
+ Similarly, Dennis without last name means {Dennis Ritchie}
+ (and he is often known as dmr).
+
+ Ken was first hired to work on the {Multics} project, which
+ was a huge production with many people working on it. Multics
+ was supposed to support hundreds of on-line logins but could
+ barely handle three.
+
+ In 1969, when Bell Labs withdrew from the project, Ken got fed
+ up with Multics and went off to write his own operating
+ system. People said "well, if zillions of people wrote
+ Multics, then an OS written by one guy must be Unix!". There
+ was some joking about eunichs as well.
+
+ Ken's wife Bonnie and son Corey (then 18 months old) went to
+ visit family in San Diego. Ken spent one week each on the
+ {kernel}, {file system}, etc., and finished UNIX in one month
+ along with developing {SPACEWAR} (or was it "Space Travel"?).
+
+ See also {back door}, {brute force}, {demigod}, {wumpus}.
+
+ (1999-01-26)
+
+Kent Recursive Calculator
+
+ <language> (KRC) A {lazy} {functional language} developed by
+ {David Turner} in 1981, based on {SASL}, with {pattern
+ matching} and {ZF expressions}.
+
+ ["Functional Programming and its Applications", David
+ A. Turner, Cambridge U Press 1982].
+
+ See also {continental drift}.
+
+ (2011-11-30)
+
+Kerberos
+
+ <security> The {authentication} system of {MIT}'s Project
+ {Athena}. It is based on {symmetric key cryptography}.
+ Adopted by {OSF} as the basis of security for {DME}.
+
+ (1997-02-04)
+
+Kermit
+
+ <communications> A popular {packet-oriented} {protocol} from
+ {Columbia University} for transferring {text files} and
+ {binary files} on both {full-duplex} and {half-duplex} 8 bit
+ and 7-bit serial connections in a system- and
+ medium-independent fashion, and implemented on hundreds of
+ different computer and {operating system} {platforms}. On
+ full-duplex connections a {sliding window} protocol with
+ selective retransmission provides excellent performance and
+ error recovery characteristics. On 7-bit connections, locking
+ shifts provide efficient transfer of 8-bit data.
+
+ When properly implemented, as in the Columbia University
+ Kermit Software collection, performance is equal to or better
+ than other protocols such as {ZMODEM}, {YMODEM}, and {XMODEM},
+ especially on poor connections.
+
+ Kermit is an open protocol - anybody can base their own
+ program on it, but some Kermit software and {source code} is
+ {copyright} by Columbia University.
+
+ {(http://columbia.edu/kermit/)}.
+
+ (1996-01-29)
+
+kernal
+
+ {kernel}
+
+kernel
+
+ (Note: NOT "kernal").
+
+ 1. <operating system> The essential part of {Unix} or other
+ {operating systems}, responsible for resource allocation,
+ low-level hardware interfaces, security etc. See also
+ {microkernel}.
+
+ 2. <language> An essential subset of a programming language,
+ in terms of which other constructs are (or could be) defined.
+ Also known as a {core} language.
+
+ (1996-06-07)
+
+Kernel Parlog
+
+ <language> A {modeless} {intermediate language} for {Parlog}
+ compilation.
+
+ ["Notes on the Implementation of Parlog", K.L. Clark et al, J
+ Logic Prog 2(1):17-42 1985].
+
+ (1996-06-07)
+
+Kernel User Interface Package
+
+ <tool> (KUIP) The human interface to {Physics Analysis
+ Workbench} (PAW).
+
+ (1994-11-11)
+
+kerning
+
+ <text> In {typography}, the process of adjusting the spacing
+ between certain pairs of {characters} to improve the appearance of
+ the text. Roughly speaking, this can be thought of as equalising
+ the area of space between adjacent characters. Each {character}
+ of a {proportional font} has a width that includes some space on
+ either side so that adjacent letters don't touch. Some pairs of
+ characters such as A and V, look better if the spaces overlap
+ slightly, bringing the characters closer together (but still not
+ touching). In most cases, kerning reduces the spacing ("negative
+ kerning") but some pairs like "r" and "y" look better with extra
+ space ("positive kerning").
+
+ See also {tracking}, {leading}.
+
+ (2014-01-14)
+
+Kevo
+
+ <language> A {prototype}-based {object-oriented} language
+ written for {Macintosh} by Antero Taivalsaari at UTA, Finland.
+ Kevo is built around a {threaded code} {interpreter} and
+ features a unique prototype-based {object} model (which is
+ based neither on {classes} nor {Self}-style {delegation}),
+ {pre-emptive multitasking}, {cooperative multitasking},
+ dynamic {memory management}, an icon-based {object browser}
+ and editor modelled loosely after Mac {Finder}. Kevo's
+ {syntax} is close to {Forth} and its {semantics} resembles
+ {Self} and {Omega}.
+
+ Latest version: 0.9b6.
+
+ {(ftp://cs.uta.fi/pub/kevo/)}.
+
+ E-mail: <kevo-interest@ursamajor.uvic.ca>.
+
+ [TR DCS-197-19, U Victoria, June 1992].
+
+ (1993-05-18)
+
+key
+
+ 1. <database> A value used to identify a {record} in a
+ database, derived by applying some fixed function to the
+ record. The key is often simply one of the {fields} (a
+ {column} if the database is considered as a table with records
+ being rows, see "{key field}"). Alternatively the key may be
+ obtained by applying some function, e.g. a {hash function}, to
+ one or more of the fields. The set of keys for all records
+ forms an {index}. Multiple indexes may be built for one
+ database depending on how it is to be searched.
+
+ 2. <cryptography> A value which must be fed into the
+ {algorithm} used to decode an encrypted message in order to
+ reproduce the original {plain text}. Some encryption schemes
+ use the same (secret) key to encrypt and decrypt a message,
+ but {public key encryption} uses a "private" (secret) key and
+ a "public" key which is known by all parties.
+
+ 3. <hardware> An electromechanical {keyboard} button.
+
+ (2003-07-04)
+
+keyboard
+
+ <hardware> A {hardware} device consisting of a number of
+ mechanical buttons (keys) which the user presses to input
+ characters to a computer.
+
+ Keyboards were originally part of {terminals} which were
+ separate {peripheral} devices that performed both input and
+ output and communicated with the computer via a {serial line}.
+ Today a keyboard is more likely to be connected more directly
+ to the processor, allowing the processor to scan it and detect
+ which key or keys are currently pressed. Pressing a key sends
+ a low-level {key code} to the keyboard input driver routine
+ which translates this to one or more {characters} or special
+ actions.
+
+ Keyboards vary in the keys they have, most have keys to
+ generate the {ASCII} {character set} as well as various
+ {function keys} and special purpose keys, e.g. reset or volume
+ control.
+
+ (2003-07-04)
+
+Keyboard Commando
+
+ <messaging> A {bulletin board} user who posts authoritatively
+ on military or combat topics, but who has never served in
+ uniform or heard a shot fired in anger. A poseur.
+
+ (1997-04-25)
+
+keyboard plaque
+
+ <jargon> The disgusting buildup of dirt and crud found on
+ computer keyboards. "Are there any other terminals I can use?
+ This one has a bad case of keyboard plaque."
+
+ (1997-04-30)
+
+Keyboard Send Receive
+
+ <hardware> (KSR) Part of a designation for a hard-copy
+ {terminal}, manufactured by {Teletype Corporation}. The KSR
+ range were lower cost versions of the {ASR} models.
+
+ (1995-11-23)
+
+Keyboard Video Mouse
+
+ <hardware> (KVM) Used to describe a "KVM switch" that allows
+ one keyboard, one video display and one mouse to be switched
+ between two or more computers.
+
+ (2007-03-22)
+
+Keyed-Hashing Message Authentication
+
+ <messaging, cryptography> (HMAC) A mechanism for message
+ {authentication} using cryptographic {hash functions}. HMAC
+ can be used with any iterative cryptographic hash function,
+ e.g., {MD5}, {SHA-1}, in combination with a secret shared key.
+ The cryptographic strength of HMAC depends on the properties
+ of the underlying hash function.
+
+ [RFC 2104].
+
+ (1997-05-10)
+
+Keyed Sequenced Data Set
+
+ <database> (KSDS) One of the access methods used by {VSAM}.
+ KSDS has indexes and data split into CI (Control Interval) in
+ CA (Control Area) and multi index levelled. Forward and
+ backward compression is applied to key values.
+
+ (1999-01-11)
+
+key escrow
+
+ <security> A controversial arrangement where the {keys} needed
+ to decrypt encrypted data must be held in {escrow} by a third
+ party so that government agencies can obtain them to decrypt
+ messages which they suspect to be relevant to national
+ security.
+
+ (1999-12-14)
+
+key field
+
+ <database> A field of a {database} (typically a {relational
+ database}) {table} which together form a unique identifier for
+ a record (a table entry). The aggregate of these fields is
+ usually referred to simply as "the {key}".
+
+ (1997-08-03)
+
+key frame
+
+ <graphics> A frame in an animated sequence of frames which was
+ drawn or otherwise constructed directly by the user rather
+ than generated automatically, e.g. by {tweening}.
+
+ (1995-04-06)
+
+KeyNote Software
+
+ A company which offers {software}-based business contact
+ directories for people who develop, manufacture, market, or
+ distribute {software} or {multimedia} products.
+
+ E-mail: <server@netmail.com> (Subject: SEND INDEX).
+
+keypad
+
+ <hardware> An input device with a small array of {push
+ buttons} labeled with numbers or other symbols, designed to
+ allow rapid entry of characters from a small set, e.g. decimal
+ digits 0-9 or, historically, hexadecimal digits.
+
+ The most common form of keypad is the {numeric keypad} found
+ on a standard {PC} {keyboard}.
+
+ (2008-10-10)
+
+keypal
+
+ The {electronic mail} equivalent of a pen pal - someone with
+ whom to exchange electronic mail for the simple joy of
+ communicating.
+
+ {Request for keypals
+ (gopher://wealaka.okgeosurvey1.gov/11/K12/keypals)}.
+
+ [Is there some kind of central clearing-house for requests on
+ the net?]
+
+KeySpell
+
+ <text, tool, education> A spell checker and teaching aid from
+ UK company KeySpell Limited for {Microsoft Windows}. KeySpell
+ offers a selection of phonetically similar words, phrases,
+ confusable terms, and examples in context. Even correctly
+ spelt homophones can be checked.
+
+ KeySpell can be run with {Microsoft Word} 97 or stand-alone.
+ It includes 225,000 words and phrases and can use subsets of
+ these.
+
+ {(http://keyspell.com)}.
+
+ (1999-05-21)
+
+keyword
+
+ 1. One of a fixed set of symbols built into the syntax of a
+ language. Typical keywords would be if, then, else, print,
+ goto, while, switch. There are usually restrictions about
+ reusing keywords as names for user-defined objects such as
+ variables or procedures. Languages vary as to what is
+ provided as a keyword and what is a library routine, for
+ example some languages provide keywords for input/output
+ operations whereas in others these are library routines.
+
+ 2. A small set of words designed to convey the subject of a
+ technical article. Some publications specify a fixed set of
+ keywords from which those for a particular article should be
+ chosen.
+
+keyword in context
+
+ <algorithm, information science> (KWIC) A document search
+ method that creates indexes of document text or titles. Each
+ keyword is stored in the resulting index along with some
+ surrounding text, usually the word or phrase that precedes or
+ follows the keyword in the text or title.
+
+ (2004-02-17)
+
+KFX
+
+ <language> The {kernel} language of {FX-87}.
+
+ ["Polymorphic Effect Systems", J.M. Lucassen et al, Proc 15th
+ Ann ACM Conf POPL, ACM 1988, pp.47-57].
+
+ (1995-02-15)
+
+kg
+
+ <networking> The {country code} for Kyrgyzstan.
+
+ (1999-01-27)
+
+kgbvax
+
+ {kremvax}
+
+kh
+
+ <networking> The {country code} for Cambodia (formerly
+ Kampuchea).
+
+ (1999-01-27)
+
+Khornerstone
+
+ A multipurpose {benchmark} from {Workstation Labs} used in
+ various periodicals. The source is not free. Results are
+ published in "UNIX Review".
+
+ (1993-04-15)
+
+Khwarizmi
+
+ {Muhammad ibn Musa al-Khwarizmi}
+
+ki
+
+ <networking> The {country code} for Kiribati.
+
+ (1999-01-27)
+
+kibibyte
+
+ <unit> The official ISO[?] name for 1024 {bytes}, to
+ distinguish it from 1000 bytes which they call a kilobyte.
+ "Mebibyte", "Gibibyte", etc, are prefixes for other powers of
+ 1024. Although this new naming standard has been widely
+ reported in 2003, it seems unlikely to catch on.
+
+ (2003-09-27)
+
+KIBO
+
+ /ki:'boh/ 1. [acronym] Knowledge In, Bullshit Out. A summary
+ of what happens whenever valid data is passed through an
+ organisation (or person) that deliberately or accidentally
+ disregards or ignores its significance. Consider, for
+ example, what an advertising campaign can do with a product's
+ actual specifications. Compare {GIGO}; see also {SNAFU
+ principle}.
+
+ 2. James Parry <kibo@world.std.com>, a {Usenet}ter infamous
+ for various surrealist net.pranks and an uncanny,
+ machine-assisted knack for joining any thread in which his nom
+ de guerre is mentioned.
+
+ {(http://kibo.com/)}.
+
+ [{Jargon File}]
+
+ (2003-05-20)
+
+kiboze
+
+ [{Usenet}] To {grep} the {Usenet} news for a string,
+ especially with the intention of posting a follow-up. This
+ activity was popularised by {Kibo}.
+
+kick
+
+ [IRC] To cause somebody to be removed from a {IRC} channel, an
+ option only available to {CHOPs}. This is an extreme measure,
+ often used to combat extreme {flamage} or {flood}ing, but
+ sometimes used at the chop's whim. Compare {gun}.
+
+ [{Jargon File}]
+
+kicking dead whales down the beach
+
+ <jargon, humour> A simile for a slow, difficult, and
+ disgusting process. First popularised by a famous quote about
+ the difficulty of getting work done under one of {IBM}'s
+ {mainframe} {OS}es. "Well, you *could* write a C compiler in
+ COBOL, but it would be like kicking dead whales down the
+ beach."
+
+ [{Jargon File}]
+
+ (2012-09-21)
+
+Kid
+
+ {Kernel} language for {Id}. A refinement of {P-TAC}, used as
+ an intermediate language for Id. {Lambda-calculus} with
+ first-class {let}-blocks and {I-structures}.
+
+ ["A Syntactic Approach to Program Transformations", Z. Ariola
+ et al, SIGPLAN Notices 26(9):116-129 (Sept 1991)].
+
+ (1996-07-22)
+
+KIDASA Software
+
+ <company> A company which develops project management software
+ for {Microsoft Windows}.
+
+ {(http://kidasa.com)}.
+
+ (1996-07-22)
+
+killer micro
+
+ [Popularised by Eugene Brooks] A {microprocessor}-based
+ machine that infringes on mini, mainframe, or supercomputer
+ performance turf. Often heard in "No one will survive the
+ attack of the killer micros!", the battle cry of the
+ downsizers. Used especially of {RISC} architectures.
+
+ The popularity of the phrase "attack of the killer micros" is
+ doubtless reinforced by the movie title "Attack Of The Killer
+ Tomatoes" (one of the {canonical} examples of
+ so-bad-it's-wonderful among hackers). This has even more
+ flavour now that killer micros have gone on the offensive not
+ just individually (in workstations) but in hordes (within
+ {massively parallel computers}).
+
+ [{Jargon File}]
+
+killer poke
+
+ A recipe for inducing hardware damage on a machine via
+ insertion of invalid values (see {poke}) into a
+ {memory-mapped} control {register}; used especially of various
+ fairly well-known tricks on {bitty box}es without hardware
+ memory management (such as the {IBM PC} and {Commodore} {PET})
+ that can overload analog electronics in the monitor.
+
+ See also {HCF}.
+
+ (1994-11-04)
+
+kill file
+
+ [{Usenet}] Per-user file(s) used by some {Usenet} reading
+ programs (originally {Larry Wall}'s {rn}) to discard summarily
+ (without presenting for reading) articles matching some
+ particularly uninteresting (or unwanted) patterns of subject,
+ author, or other header lines. Thus to add a person (or
+ subject) to one's kill file is to arrange for that person to
+ be ignored by one's newsreader in future. By extension, it
+ may be used for a decision to ignore the person or subject in
+ other media. See also {plonk}.
+
+ [{Jargon File}]
+
+kilo-
+
+ {prefix}
+
+kilobaud
+
+ <unit> 1000 {baud}.
+
+ (1996-02-12)
+
+kilobit
+
+ <unit> 2^10 = 1024 {bits} of storage (1 Kb).
+
+ Compare {kilobits per second}.
+
+ (2002-03-23)
+
+kilobits per second
+
+ <unit> (kbps, kb/s) A unit of {data rate} where 1 kb/s = 1000
+ bits per second. This contrasts with units of storage where 1
+ Kb = 1024 bits (note upper case K).
+
+ (2002-03-23)
+
+kilobyte
+
+ <unit, data> (KB) A unit of {data} equal to 1000 {bytes} (but see
+ {binary prefix} for other definitions).
+
+ One kilobyte is the amount of data in 1000 {ASCII} (or {UTF-8})
+ characters or about 250 English words (whose average length is
+ about four characters).
+
+ 1000 kilobytes are one {megabyte}.
+
+ (2014-07-21)
+
+kiloflops
+
+ <unit> 1000 {FLOPS}.
+
+ See {prefix}.
+
+ (1998-09-07)
+
+kiosk
+
+ A stall set up in a public place where one can obtain
+ information, e.g. tourist information. The information may be
+ provided by a human or by a computer. In the latter case, the
+ data may be stored locally (e.g. on {CD-ROM}) or accessed via
+ a network using some kind of distributed information retreival
+ system such as {Gopher} or {web}.
+
+ (1998-09-07)
+
+KIPS
+
+ /kips/ [by analogy with {MIPS}] Thousands (*not* 1024s) of
+ instructions per second. Usage: rare.
+
+ [{Jargon File}]
+
+KIS
+
+ {Knowbot Information Service}
+
+KISS
+
+ Early system on IBM 650. Listed in CACM 2(5):16 (May 1959).
+
+KISS Principle
+
+ /kis' prin'si-pl/ Keep It Simple, Stupid.
+
+ A maxim often invoked when discussing design to fend off
+ {creeping featurism} and control complexity of development.
+ Possibly related to the {marketroid} maxim on sales
+ presentations, "Keep It Short and Simple".
+
+ See also {Occam's Razor}.
+
+ [{Jargon File}]
+
+ (1994-11-18)
+
+kit
+
+ <jargon> ({Usenet}, possibly from {DEC}) Slang for a full
+ software distribution, as opposed to a {patch} or upgrade. A
+ source software distribution that has been packaged in such a
+ way that it can (theoretically) be unpacked and installed
+ according to a series of steps using only standard {Unix}
+ tools, and entirely documented by some reasonable chain of
+ references from the top-level {README file}. The more general
+ term {distribution} may imply that special tools or more
+ stringent conditions on the host environment are required.
+
+ [{Jargon File}]
+
+ (1994-11-18)
+
+KL0
+
+ Kernel Language 0.
+
+ A sequential {logic language} based on {Prolog}, used in the
+ Japanese {ICOT} project.
+
+ (1994-11-18)
+
+KL1
+
+ Kernel Language 1.
+
+ An experimental {AND-parallel} version of {KL0} for the {ICOT}
+ project in Japan. KL1 is an implementation of {FGHC}.
+
+ Not to be confused with {KL-ONE}.
+
+ ["Design of the Kernel Language for the Parallel Inference
+ Machine", U. Kazunori et al, Computer J (Dec 1990)].
+
+ (1994-10-24)
+
+Klamath
+
+ <processor> The pre-release "code name" for {Intel}'s {Pentium
+ II} {microprocessor}.
+
+ (1998-09-07)
+
+KLB
+
+ {Known Lazy Bastard}
+
+Kleene closure
+
+ {Kleene star}
+
+Kleene star
+
+ <text> (Or "Kleene closure", named after {Stephen Kleene}) The
+ {postfix} "*" operator used in {regular expressions},
+ {Extended Backus-Naur Form}, and similar formalisms to specify
+ a match for zero or more occurrences of the preceding
+ expression. For example, the regular expression "be*t" would
+ match the string "bt", "bet", "beet", "beeeeet", and so on.
+
+ (2000-07-26)
+
+Kleene, Stephen Cole
+
+ {Stephen Kleene}
+
+Klerer-May System
+
+ Early system from {Columbia University} with special
+ mathematics symbols. Its reference manual was two pages long!
+
+ ["Further Advances in Two-Dimensional Input-Output by
+ Typewriter Terminals", M. Klerer et al, Proc FJCC 31 (1967)].
+
+ [Sammet 1969, pp. 284-294].
+
+ (1994-10-24)
+
+KLOC
+
+ <unit, programming> Thousand (kilo-) {Lines of code}.
+
+ (1995-03-12)
+
+klone
+
+ /klohn/ {clone}.
+
+ [{Jargon File}]
+
+KL-ONE
+
+ A {frame language}.
+
+ Not to be confused with {KL1}.
+
+ ["An Overview of the KL-ONE Knowledge Representation System",
+ R.J. Brachman and J. Schmolze, Cognitive Sci 9(2), 1985].
+
+ (1994-11-18)
+
+kludge
+
+ <jargon> /kluhj/ (From the old Scots "kludgie" meaning an
+ outside toilet) A Scottish engineering term for anything added
+ in an ad hoc (and possibly unhygenic!) manner. At some point
+ during the Second World War, Scottish engineers met Americans
+ and the meaning, spelling and pronunciation of kludge became
+ confused with that of "{kluge}".
+
+ The spelling "kludge" was apparently popularised by the
+ "Datamation" cited below which defined it as "An ill-assorted
+ collection of poorly matching parts, forming a distressing
+ whole."
+
+ The result of this tangled history is a mess; in 1993, many
+ (perhaps even most) hackers pronounce the word /klooj/ but
+ spell it "kludge" (compare the pronunciation drift of {mung}).
+ Some observers consider this appropriate in view of its
+ meaning.
+
+ ["How to Design a Kludge", Jackson Granholme, Datamation,
+ February 1962, pp. 30-31].
+
+ [{Jargon File}]
+
+ (1998-12-09)
+
+kluge
+
+ <jargon> /klooj/, /kluhj/ (From German "klug" /kloog/ - clever
+ and Scottish "{kludge}") 1. A Rube Goldberg (or Heath
+ Robinson) device, whether in {hardware} or {software}.
+
+ The spelling "kluge" (as opposed to "kludge") was used in
+ connection with computers as far back as the mid-1950s and, at
+ that time, was used exclusively of *hardware* kluges.
+
+ 2. <programming> A clever programming trick intended to solve
+ a particular nasty case in an expedient, if not clear, manner.
+ Often used to repair bugs. Often involves {ad-hockery} and
+ verges on being a {crock}. In fact, the TMRC Dictionary
+ defined "kludge" as "a crock that works".
+
+ 3. Something that works for the wrong reason.
+
+ 4. ({WPI}) A {feature} that is implemented in a {rude} manner.
+
+ In 1947, the "New York Folklore Quarterly" reported a classic
+ shaggy-dog story "Murgatroyd the Kluge Maker" then current in
+ the Armed Forces, in which a "kluge" was a complex and
+ puzzling artifact with a trivial function. Other sources
+ report that "kluge" was common Navy slang in the WWII era for
+ any piece of electronics that worked well on shore but
+ consistently failed at sea.
+
+ However, there is reason to believe this slang use may be a
+ decade older. Several respondents have connected it to the
+ brand name of a device called a "Kluge paper feeder" dating
+ back at least to 1935, an adjunct to mechanical printing
+ presses. The Kluge feeder was designed before small, cheap
+ electric motors and control electronics; it relied on a
+ fiendishly complex assortment of cams, belts, and linkages to
+ both power and synchronise all its operations from one motive
+ driveshaft. It was accordingly tempermental, subject to
+ frequent breakdowns, and devilishly difficult to repair - but
+ oh, so clever! One traditional folk etymology of "klugen"
+ makes it the name of a design engineer; in fact, "Kluge" is a
+ surname in German, and the designer of the Kluge feeder may
+ well have been the man behind this myth.
+
+ {TMRC} and the MIT hacker culture of the early 1960s seems to
+ have developed in a milieu that remembered and still used some
+ WWII military slang (see also {foobar}). It seems likely that
+ "kluge" came to MIT via alumni of the many military
+ electronics projects run in Cambridge during the war (many in
+ MIT's venerable Building 20, which housed {TMRC} until the
+ building was demolished in 1999).
+
+ [{Jargon File}]
+
+ (2002-10-02)
+
+kluge around
+
+ <jargon> To avoid a bug or difficult condition by inserting a
+ {kluge}.
+
+ Compare {workaround}.
+
+ [{Jargon File}]
+
+ (1995-03-10)
+
+km
+
+ <networking> The {country code} for Comoros.
+
+ (1999-01-27)
+
+KMODEL
+
+ An ancestor of Model-K. "Preliminary Results on the BEHAVIOUR
+ Specifications Language KMODEL-0", BEHAVIOUR Memo 5-91, 1991,
+ GMD, Sankt Augustin, Germany
+
+KMS
+
+ {Knowledge Management System}
+
+kn
+
+ <networking> The {country code} for Saint Kitts and Nevis.
+
+ (1999-01-27)
+
+knapsack problem
+
+ <application, mathematics> Given a {set} of items, each with a
+ cost and a value, determine the number of each item to include
+ in a collection so that the total cost is less than some given
+ cost and the total value is as large as possible.
+
+ The 0/1 knapsack problem restricts the number of each items to
+ zero or one.
+
+ Such {constraint satisfaction} problems are often solved using
+ {dynamic programming}.
+
+ The general knapsack problem is {NP-hard}, and this has led to
+ attempts to use it as the basis for {public-key encryption}
+ systems. Several such attempts failed because the knapsack
+ problems they produced were in fact solvable by
+ {polynomial-time algorithms}.
+
+ [Are there any trusted knapsack-based public-key
+ cryptosystems?].
+
+ (1995-04-10)
+
+KNI
+
+ {Streaming SIMD Extensions}
+
+Knights of the Lambda-Calculus
+
+ A semi-mythical organisation of wizardly LISP and Scheme
+ hackers. The name refers to a mathematical formalism invented
+ by Alonzo Church, with which LISP is intimately connected.
+ There is no enrollment list and the criteria for induction are
+ unclear, but one well-known LISPer has been known to give out
+ buttons and, in general, the *members* know who they are.
+
+ [{Jargon File}]
+
+knowbot
+
+ <web> A kind of {bot} that collects information by
+ automatically gathering certain specified information from
+ {websites}.
+
+ (1999-06-19)
+
+Knowbot Information Service
+
+ <networking, information science> (KIS) Also known as
+ netaddress. The Knowbot Information Service (KIS) provides a
+ uniform user interface to a variety of {remote directory
+ services} such as {whois}, {finger}, {X.500}, {MCIMail}. By
+ submitting a single query to KIS, a user can search a set of
+ remote {white pages} services and see the results of the
+ search in a uniform format.
+
+ There are several interfaces to the KIS service including
+ {electronic mail} and {telnet}. Another KIS interface
+ imitates the Berkeley {whois} command.
+
+ KIS consists of two distinct types of modules which interact
+ with each other (typically across a network) to provide the
+ service. One module is a user agent module that runs on the
+ KIS mail host machine. The second module is a remote server
+ module (possibly on a different machine) that interrogates
+ various database services across the network and provides the
+ results to the user agent module in a uniform fashion.
+ Interactions between the two modules can be via messages
+ between Knowbots or by actual movement of Knowbots.
+
+ There are electronic mail interfaces for KIS at the hosts
+ cnri.reston.va.us and sol.bucknell.edu. Send a message
+ containing just the word "man" to <kis@cnri.reston.va.us> or
+ <netaddress@sol.bucknell.edu>. Telnet: info.cnri.reston.va.us
+ port 185.
+
+knowledge
+
+ <artificial intelligence, information science> The objects,
+ concepts and relationships that are assumed to exist in some
+ area of interest. A collection of {knowledge}, represented
+ using some {knowledge representation} language is known as a
+ {knowledge base} and a program for extending and/or querying a
+ knowledge base is a {knowledge-based system}.
+
+ Knowledge differs from {data} or {information} in that new
+ knowledge may be created from existing knowledge using logical
+ {inference}. If information is data plus meaning then
+ knowledge is information plus processing.
+
+ A common form of knowledge, e.g. in a {Prolog} program, is a
+ collection of {facts} and {rules} about some subject.
+
+ For example, a {knowledge base} about a family might contain
+ the facts that John is David's son and Tom is John's son and
+ the rule that the son of someone's son is their grandson.
+ From this knowledge it could infer the new fact that Tom is
+ David's grandson.
+
+ See also {Knowledge Level}.
+
+ (1994-10-19)
+
+Knowledge Analysis and Design System
+
+ <process> (KADS) A structured way of developing
+ {knowledge-based systems} ({expert systems}). KADS was
+ developed as an alternative to an evolutionary approach and is
+ now accepted as the European standard for knowledge based
+ systems.
+
+ {(http://cse.unsw.edu.au/~timm/pub/slides/kltut/index.html)}.
+
+ ["Knowledge Based Systems Analysis and Design: A KADS
+ Developers Handbook", Tansley and Hayball]
+
+ (1998-03-12)
+
+knowledge base
+
+ <artificial intelligence> A collection of {knowledge}
+ expressed using some formal {knowledge representation}
+ language. A knowledge base forms part of a {knowledge-based
+ system} (KBS).
+
+ (1994-10-19)
+
+knowledge-based system
+
+ <artificial intelligence> (KBS) A program for extending and/or
+ querying a {knowledge base}.
+
+ The related term {expert system} is normally used to refer to
+ a highly domain-specific type of KBS used for a specialised
+ purpose such as medical diagnosis.
+
+ The {Cyc} project is an example of a large KBS.
+
+ (1999-09-07)
+
+knowledge level
+
+ <artificial intelligence> A level of description of the
+ {knowledge} of an {agent} that is independent of the agent's
+ internal {symbol-level} representation. Knowledge can be
+ attributed to agents by observing their actions. An agent
+ "knows" something if it acts as if it had the information and
+ is acting rationally to achieve its goals. The "actions" of
+ agents, including knowledge base servers and {knowledge-based
+ systems}, can be seen through a "tell and ask" functional
+ interface, where a client interacts with an agent by making
+ {logical assertions} (tell), and posing queries (ask).
+
+ (1994-10-19)
+
+Knowledge Management System
+
+ (KMS) A distributed {hypermedia} system for managing knowledge
+ in organisations. KMS is a commercial system from {Knowledge
+ Systems, Inc.} running on {workstations}, based on previous
+ research with {ZOG} at {Carnegie Mellon University}.
+
+ (1994-10-28)
+
+Knowledge Query and Manipulation Language
+
+ <language, protocol, artificial intelligence> (KQML) A
+ language and {protocol}, based on {SGML}, for exchanging
+ {information} and {knowledge}, proposed in 1993(?).
+
+ Work on KQML is led(?) by Tim Finin <finin@umbc.edu> of the
+ University of Maryland Baltimore County, Lab for Advanced
+ Information Technology. It is part of the {ARPA} {Knowledge
+ Sharing Effort}.
+
+ The KQML message format and protocol can be used to interact
+ with an intelligent system, either by an {application
+ program}, or by another intelligent system. KQML's
+ "performatives" are operations that agents perform on each
+ other's knowledge and {goal} stores. Higher-level
+ interactions such as {contract nets} and negotiation are built
+ using these. KQML's "communication facilitators" coordinate
+ the interactions of other agents to support knowledge sharing.
+
+ Experimental prototype systems support concurrent engineering,
+ intelligent design, intelligent planning, and scheduling.
+
+ {(http://cs.umbc.edu/kqml/)}.
+
+ (1999-09-28)
+
+knowledge representation
+
+ The subfield of {artificial intelligence} concerned with
+ designing and using systems for storing knowledge - {facts}
+ and {rules} about some subject.
+
+ A body of formally represented knowledge is based on a
+ {conceptualisation} - an {abstract} view of the world that we
+ wish to represent. In order to manipulate this knowledge we
+ must specify how the abstract conceptualisation is represented
+ as a {concrete} data structure. An {ontology} is an explicit
+ specification of a conceptualisation.
+
+ (1994-10-19)
+
+Knowledge Sharing Effort
+
+ <project> An {ARPA} project developing techniques and methods
+ for building large-scale {knowledge bases} which are sharable
+ and reusable.
+
+ {KQML} is part of it.
+
+ (1999-09-28)
+
+Knowledge Systems Laboratory
+
+ (KSL) An {artificial intelligence} research laboratory within
+ the Department of Computer Science at {Stanford University}.
+ Current work focuses on {knowledge representation} for
+ sharable engineering knowledge bases and systems,
+ computational environments for modelling physical devices,
+ architectures for adaptive intelligent systems, and {expert
+ systems} for science and engineering.
+
+ (1994-12-06)
+
+Known Lazy Bastard
+
+ <abuse> (KLB) A term, used among technical support staff, for
+ a user who repeatedly asks for help with problems whose
+ solutions are clearly explained in the documentation, and
+ persists in doing so after having been told to {RTFM}.
+
+ KLBs are singled out for special treatment (i.e. ridicule),
+ especially if they have been heard to say "It's so boring to
+ read the manual! Why don't you just tell me?". The deepest
+ pit in Hell is reserved for KLBs whose questions reveal total
+ ignorance of the basic concepts (e.g., "How do I make a font
+ in {Excel}?", "Where do I turn on my {RAM}?"), and who refuse
+ to accept that their questions are neither simple nor
+ well-formed.
+
+ (1998-09-07)
+
+Knuth
+
+ /knooth/ 1. {Donald Knuth}.
+
+ 2. ["The Art of Computer Programming", Donald E. Knuth]
+ Mythically, the reference that answers all questions about
+ data structures or algorithms. A safe answer when you do not
+ know: "I think you can find that in Knuth."
+
+ Contrast {literature}. See also {bible}.
+
+ [{Jargon File}]
+
+Kodak
+
+ <company> The photographic company responsible for {Photo CD}.
+
+ {(http://kodak.com/)}.
+
+ (1995-12-13)
+
+Kohonen
+
+ {T. Kohonen}
+
+KOMPILER
+
+ <language> An early system on the {IBM 701}.
+
+ Versions: KOMPILER 2 for IBM 701, KOMPILER 3 for IBM 704.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (2005-06-20)
+
+Konrad Zuse
+
+ <person> The designer of the first programming language,
+ {Plankalkül}, and the first fully functional
+ program-controlled electromechanical {digital computer} in the
+ world, the {Z3}. He died on 1995-12-18 in Huenfeld, Germany.
+
+ {Biography (http://ei.cs.vt.edu/~history/Zuse.html)}.
+
+ ["Konrad Zuse: Mein Leben" (My Life), published 1956].
+
+ ["Konrad Zuse: The Computer my Life, Springer, 1993].
+
+ (1999-02-18)
+
+Korf, Richard
+
+ {Richard Korf}
+
+Korn Shell
+
+ (ksh) A {command interpreter} for {Unix}.
+
+ {SKsh} is an {AmigaDos}-specific version and {pdksh} is a free
+ {Unix} version.
+
+ [More details?]
+
+kp
+
+ <networking> The {country code} for North Korea.
+
+ (1999-01-27)
+
+KQML
+
+ {Knowledge Query and Manipulation Language}
+
+KR
+
+ {knowledge representation}
+
+kr
+
+ <networking> The {country code} for South Korea.
+
+ [{Jargon File}]
+
+ (1999-01-27)
+
+K&R
+
+ <publication> Kernighan and Ritchie. {Brian Kernighan} and
+ {Dennis Ritchie}'s book, cited below, describing the basis of
+ {K&R C}, especially the classic and influential first edition.
+
+ Synonyms: {White Book}, {Old Testament}. See also {New
+ Testament}.
+
+ [{Jargon File}]
+
+ [Brian Kernighan, Dennis Ritchie, "The C Programming
+ Language", Prentice-Hall 1978; ISBN 0-113-110163-3].
+
+ (2011-11-30)
+
+KRC
+
+ {Kent Recursive Calculator}
+
+K&R C
+
+ <language> (C Classic) The {C} programming language as defined
+ in the first edition of {K&R}, with some small additions. The
+ name "C Classic", a play on "Coke Classic", came into use
+ while {ANSI C} was being standardised by the {ANSI X3J11}
+ committee.
+
+ See also {classic}.
+
+ [{Jargon File}]
+
+ (2006-09-26)
+
+kremvax
+
+ /krem-vaks/ (Or kgbvax) Originally, a fictitious {Usenet} site
+ at the Kremlin, named like the then large number of {Usenet}
+ {VAXen} with names of the form foovax. Kremvax was announced
+ on April 1, 1984 in a posting ostensibly originated there by
+ Soviet leader Konstantin Chernenko. The posting was actually
+ forged by Piet Beertema as an April Fool's joke. Other
+ fictitious sites mentioned in the hoax were moskvax and
+ {kgbvax}. This was probably the funniest of the many April
+ Fool's forgeries perpetrated on {Usenet} (which has negligible
+ security against them), because the notion that {Usenet} might
+ ever penetrate the Iron Curtain seemed so totally absurd at
+ the time.
+
+ In fact, it was only six years later that the first genuine
+ site in Moscow, demos.su, joined {Usenet}. Some readers
+ needed convincing that the postings from it weren't just
+ another prank. Vadim Antonov, senior programmer at Demos and
+ the major poster from there up to mid-1991, was quite aware of
+ all this, referred to it frequently in his own postings, and
+ at one point twitted some credulous readers by blandly
+ asserting that he *was* a hoax!
+
+ Eventually he even arranged to have the domain's gateway site
+ *named* kremvax, thus neatly turning fiction into truth and
+ demonstrating that the hackish sense of humour transcends
+ cultural barriers. Mr. Antonov also contributed some
+ Russian-language material for the {Jargon File}.
+
+ In an even more ironic historical footnote, kremvax became an
+ electronic centre of the anti-communist resistance during the
+ bungled hard-line coup of August 1991. During those three
+ days the Soviet UUCP network centreed on kremvax became the
+ only trustworthy news source for many places within the USSR.
+ Though the sysops were concentrating on internal
+ communications, cross-border postings included immediate
+ transliterations of Boris Yeltsin's decrees condemning the
+ coup and eyewitness reports of the demonstrations in Moscow's
+ streets. In those hours, years of speculation that
+ totalitarianism would prove unable to maintain its grip on
+ politically-loaded information in the age of computer
+ networking were proved devastatingly accurate - and the
+ original kremvax joke became a reality as Yeltsin and the new
+ Russian revolutionaries of "glasnost" and "perestroika" made
+ kremvax one of the timeliest means of their outreach to the
+ West.
+
+ [{Jargon File}]
+
+KRL
+
+ {Knowledge Representation} Language. A {frame}-based
+ language.
+
+ ["An Overview of KRL, a Knowledge Representation Language",
+ D.G. Bobrow and T. Winograd, Cognitive Sci 1:1 (1977)].
+
+KRS
+
+ <language> A {frame-based language} built on {Common LISP}.
+
+ (2011-12-05)
+
+K&R stlye
+
+ <programming> The ugly and hard-to-read {indent style} used in
+ {K&R}.
+
+ (2011-11-30)
+
+KRYPTON
+
+ <language> A {frame language}.
+
+ ["An Essential Hybrid Reasoning System: Knowledge and Symbol
+ Level Accounts of KRYPTON", R.J. Brachman et al, Proc
+ IJCAI-85, 1985].
+
+ (2011-12-05)
+
+ksh
+
+ {Korn Shell}
+
+KSL
+
+ {Knowledge Systems Laboratory}
+
+KSR
+
+ 1. {Keyboard Send Receive}.
+
+ 2. <company> {Kendall Square Research}.
+
+ (1995-11-23)
+
+KTH
+
+ {Kungliga Tekniska Högskolan}
+
+kthx
+
+ <chat> OK, thanks. Can be used as a (sarcastic) prefix, as in
+ "plz2stfukthx".
+
+ (2008-03-14)
+
+KUIP
+
+ {Kernel User Interface Package}
+
+Kungliga Tekniska Högskolan
+
+ <body, education> (KTH, Royal Institute of Art and Technology)
+ A Swedish university founded in 1827 that is strong in
+ engineering and computing (e.g. {AI}, {Virtual Reality}). In
+ 1998 KTH had nearly 11,000 undergraduate students, 1,300
+ postgraduate students, and 2,900 staff, making it the largest
+ of Sweden's six universitites of technology.
+
+ {(http://kth.se/index-eng.html)}.
+
+ Address: Stockholm, Sweden.
+
+ (2001-03-18)
+
+KUTGW
+
+ <chat> Keep up the good work.
+
+ (1999-03-08)
+
+Kvatro Telecom AS
+
+ <company> The company that maintains {Mary}.
+
+ Address: Trondheim, Norway.
+
+ {(http://kvatro.no/)}.
+
+ (1998-11-10)
+
+Kvikkalkul
+
+ <language> /kveek`kahl-kool'/ A deliberately cryptic
+ programming language said to have been devised by the Swedish
+ Navy in the 1950s as part of their abortive attempt at a
+ nuclear weapons program. What little is known about it comes
+ from a series of an anonymous posts to {Usenet} in 1994. The
+ poster described the language, saying that he had programmed
+ in Kvikkalkul when he worked for the Swedish Navy in the
+ 1950s. It is an open question whether the posts were a
+ {troll}, a subtle parody or truth stranger than fiction could
+ ever be.
+
+ Assuming it existed, Kvikkalkul is so much a
+ {bondage-and-discipline language} that it is, in its own ways,
+ even more bizarre than the deliberate parody language
+ {INTERCAL}. Among its notable "features", all symbols in
+ Kvikkalkul, including variable names and program labels, can
+ consist only of digits. Operators consist entirely of the
+ punctuation symbols (, ), -, and :. Kvikkalkul allows no
+ {comments} - they might not correspond with the code.
+ Kvikkalkul's only data type is the signed fixed-point
+ fractional number, i.e. a number between (but not including)
+ -1 and 1. Dealings with the {Real World} that require numbers
+ outside that range are done with functions that notionally map
+ that range to a larger range (e.g., -16383 to -16383) and
+ back. Kvikkalkul had a probabilistic jump operator which, if
+ given a negative probability, would act like a {COME FROM}.
+ This was, sadly, deleted in later versions of the language.
+
+ {(http://prefect.com/home24/kvikkalkul/)}.
+
+ (1998-11-14)
+
+KVM
+
+ {Keyboard Video Mouse}
+
+kw
+
+ <networking> The {country code} for Kuwait.
+
+ (1999-01-27)
+
+KWIC
+
+ {keyword in context}
+
+ky
+
+ <networking> The {country code} for the Cayman Islands.
+
+ (1999-01-27)
+
+Kyoto Common Lisp
+
+ <language> (KCL) An implementation of {Common Lisp} by
+ T. Yuasa <yuasa@tutics.tut.ac.jp> and M. Hagiya
+ <hagiya@is.s.u-tokyo.ac.jp>, written in {C} to run under
+ {Unix}-like {operating systems}. KCL is compiled to {ANSI C}.
+ It conforms to {Common Lisp} as described in {Guy Steele}'s
+ book and is available under a licence agreement.
+
+ {(ftp://rascal.ics.utexas.edu/pub/kcl.tar.Z)}.
+
+ E-mail: <kcl@cli.com> (bug reports).
+
+ Mailing list: kcl-request@cli.com, kcl@rascal.ics.utexas.edu.
+
+ ["Design and Implementation of Kyoto Common Lisp", T. Yuasa
+ <yuasa@tutics.tut.ac.jp>, J Info Proc 13(3):284-295 (1990)].
+
+ ["Kyoto Common Lisp Report", T. Yuasa & M. Hagiya].
+
+ (1987-06-01)
+
+kyrka
+
+ {feature key}
+
+kz
+
+ <networking> The {country code} for Kazakhstan.
+
+ (1999-01-27)
+
+L0
+
+ <language> A low-level language developed at the {Technical
+ University of Munich}. L0 was typed and had the usual {flow
+ control}, but only 3-address expressions. Higher level
+ languages, L1 and L2 were planned.
+
+ ["Brief Survey of L0", H. Scheidig, in Machine Oriented Higher
+ Level Languages, W. van der Poel ed, N-H 1974, pp. 239-247].
+
+ (2003-06-12)
+
+L0pht
+
+ <security> /loft/ An Internet security organisation that
+ merged with {@stake} in January 2000.
+
+ (2003-06-12)
+
+l10n
+
+ {localisation}
+
+L1 cache
+
+ {primary cache}
+
+L2 cache
+
+ {secondary cache}
+
+L2CAP
+
+ {Logical Link Control and Adaptation Protocol}
+
+L2TP
+
+ {Layer Two Tunneling Protocol}
+
+L6
+
+ Bell Telephone Laboratories Low-Level Linked List Language.
+ Ken Knowlton, 1965. List processing language, typeless.
+
+ ["A Programmer's Description of L6, Bell Telephone
+ Laboratories' Low-Level Linked List Language", K. Knowlton
+ CACM 9(8):616-625 (Aug 1966). Sammet 1969, pp.400- 405].
+
+la
+
+ <networking> The {country code} for Laos.
+
+ (1999-01-27)
+
+label
+
+ 1. <programming> An identifier used to mark a position in a
+ program so that it can be the destination of a {goto}
+ statement.
+
+ 2. <networking> The identifier assigned to a {datagram} for
+ {label switching}.
+
+ (2007-10-17)
+
+label edge router
+
+ <networking> (LER) A device that sits at the edge of an {MPLS
+ domain}, that uses {routing} information to assign labels to
+ {datagrams} and then forwards them into the MPLS domain.
+
+ (1999-06-14)
+
+Label Forwarding Information Base
+
+ <networking> (LFIB) A {label switching} scheme used in
+ {MultiProtocol Label Switching} (MPLS).
+
+ [Details?]
+
+ (2007-06-25)
+
+label switched path
+
+ <networking> (LSP) The specific path through a network that a
+ {datagram} follows, based on its {MPLS} labels.
+
+ (1999-06-14)
+
+label switching
+
+ <networking> A routing technique that uses information from
+ existing IP routing protocols to identify {IP} {datagrams}
+ with labels and forwards them to a modified {switch} or
+ {router}, which then uses the labels to switch the datagrams
+ through the network.
+
+ Label switching combines the best attributes of {data link
+ layer} (layer two) {switching} (as in {ATM} and {Frame Relay})
+ with the best attributes of {network layer} (layer three)
+ {routing} (as in {IP}).
+
+ Prior to the formation of the {MPLS} Working Group in 1997, a
+ number of vendors had announced and/or implemented proprietary
+ label switching.
+
+ (2007-10-17)
+
+Label Switching Router
+
+ <networking> (LSR) A device that typically resides somewhere
+ in the middle of a {network} and is capable of forwarding
+ {datagrams} by {label switching}. In many cases, especially
+ early versions of {MPLS} networks, a LSR will typically be a
+ modified {ATM} {switch} that forwards datagrams based upon a
+ label in the {VPI}/{VCI} field.
+
+ (1999-06-14)
+
+Lab for Computer Science
+
+ {MIT}. {(http://lcs.mit.edu/)}.
+
+Laboratoire lorrain de recherche en informatique et ses applications
+
+ <body> (LORIA) A French research institute associated with
+ {INRIA}.
+
+ (2007-06-01)
+
+Laboratory INstrument Computer
+
+ <computer> (LINC) A computer which was originally designed in
+ 1962 by {Wesley Clark}, {Charles Molnar}, Severo Ornstein and
+ others at the {Lincoln Laboratory Group}, to facilitate
+ scientific research. With its {digital logic} and {stored
+ programs}, the LINC is accepted by the {IEEE Computer Society}
+ to be the World's first {interactive} {personal computer}.
+
+ The machine was developed to fulfil a need for better
+ laboratory tools by doctors and medical researchers. It would
+ supplant the 1958 {Average Response Computer}, and was
+ designed for individual use.
+
+ Led by William N. Papian and mainly funded by the {National
+ Institute of Health}, Wesley Clark designed the logic while
+ Charles Molnar did the engineering. The first LINC was
+ finished in March 1962.
+
+ In January 1963, the project moved to {MIT}, and then to
+ {Washington University} (in St. Louis) in 1964.
+
+ The LINC had a simple {operating system}, four "knobs" (which
+ was used like a {mouse}), a {Soroban keyboard} (for
+ alpha-numeric data entry), two {LINCtape} drives and a small
+ {CRT} display. It originally had one {kilobit} of {core
+ memory}, but this was expanded to 2 Kb later. The computer
+ was made out of {Digital Equipment Corporation} (DEC) hardware
+ modules.
+
+ Over 24 LINC systems had been built before late 1964 when
+ DEC began to sell the LINC commercially.
+
+ After the introduction of the {PDP-8}, {Dick Clayton} at
+ DEC produced a rather frightening hybrid of the LINC and
+ PDP-8 called a LINC-8. This really was not a very
+ satisfactory machine, but it used the new PDP-8 style DEC
+ cards and was cheaper and easier to produce. It still
+ didn't sell that well.
+
+ In the late 1960s, Clayton brought the design to its pinnacle
+ with the PDP-12, an amazing tour de force of the LINC concept;
+ along with about as seamless a merger as could be done with
+ the PDP-8. This attempted to incorporate {TTL logic} into the
+ machine. The end of the LINC line had been reached.
+
+ Due to the success of the LINC-8, {Spear, Inc.} produced a
+ LINC clone (since the design was in the {public domain}).
+ The interesting thing about the Spear {micro-LINC 300} was
+ that it used {MECL} II logic. MECL logic was known for its
+ blazing speed (at the time!), but the Spear computer ran at
+ very modest rates.
+
+ In 1995 the last of the classic LINCs was turned off for
+ the final time after 28 years of service. This LINC had
+ been in use in the Eaton-Peabody Laboratory of Auditory
+ Physiology (EPL) of the Massachusetts Eye and Ear
+ Infirmary.
+
+ On 15 August 1995, it was transferred to the MIT {Computer
+ Museum} where it was put on display.
+
+ {LINC/8, PDP-12
+ (http://faqs.org/faqs/dec-faq/pdp8/section-7.html)}.
+
+ {Lights out for last LINC
+ (http://rleweb.mit.edu/publications/currents/6-1linc.HTM)}.
+
+ ["Computers and Automation", Nov. 1964, page 43].
+
+ (1999-05-20)
+
+Laboratory Virtual Instrument Engineering Workbench
+
+ <tool> (LabVIEW) A package from National Instruments Corp
+ originally developed to provide a {graphical user interface}
+ to instruments connected by the {IEEE 488} (GPIB) bus. It has
+ powerful graphical editing facilities for defining and
+ interconnecting "virtual instruments".
+
+ (1996-04-24)
+
+LaborNet
+
+ An {IGC} network serving groups, unions and labour advocates
+ interested in information sharing and collaboration with the
+ intent of enhancing the human rights and economic justice of
+ workers. Issues covered include workplace and community
+ health and safety issues, trade issues and international union
+ solidarity and collaboration.
+
+Labtech Notebook
+
+ <tool, product> Commercial {data aquisition} software.
+
+ (1995-03-08)
+
+LabVIEW
+
+ {Laboratory Virtual Instrument Engineering Workbench}
+
+Lace
+
+ Language for Assembling Classes in Eiffel. Specifies how to
+ assemble an Eiffel system : in which directories to find the
+ clusters, which class to use as the root, permits class
+ renaming to avoid name clashes. "Eiffel: The Language",
+ Bertrand Meyer, P-H 1992.
+
+lace card
+
+ (Obsolete) A {punched card} with all holes punched (also
+ called a "whoopee card" or "ventilator card"). Card readers
+ tended to jam when they got to one of these, as the resulting
+ card had too little structural strength to avoid buckling
+ inside the mechanism. Card punches could also jam trying to
+ produce these things owing to power-supply problems. When
+ some practical joker fed a lace card through the reader, you
+ needed to clear the jam with a "card knife" - which you used
+ on the joker first.
+
+ [{Jargon File}]
+
+ladder logic
+
+ <programming> {Source code} formatted in two columns with
+ conditions on the left that lead to outputs on the right:
+
+ if (c1) s1 else
+ if (c2) s2 else
+ if (c3) s3 ...
+
+ (2007-03-15)
+
+LADY
+
+ <language> ["Key Concepts in the INCAS Multicomputer Project",
+ J. Nehmer et al IEEE Trans Soft Eng SE-13(8):913-923 (Aug
+ 1987)].
+
+ (1996-06-21)
+
+lag
+
+ {netlag}
+
+Lakota
+
+ Scripting language, extends existing OS commands.
+ E-mail: Richard Harter <rh@smds.UUCP>, SMDS, Inc.
+
+LALR
+
+ {Look Ahead Left-to-right parse, Rightmost-derivation}
+
+lalr.ss
+
+ <tool> An {LALR1 grammar} {parser generator} written in, and
+ outputting, {Scheme} by Mark Johnson <mj@cs.brown.edu>.
+
+ Version 0.9 (before 1995-10-30).
+
+ FTP new/lalr.shar from the {Scheme Repository}.
+
+ (1993-05-24)
+
+Lambada-Calculus
+
+ <humour, logic> (A pun on "{lambda-calculus}") Teaching logic
+ thru spanish dance steps. Invented by P. van der Linden
+ <linden@eng.sun.com>.
+
+ (1996-08-10)
+
+LAMBDA
+
+ A version of {typed lambda-calculus}, used to describe
+ semantic {domains}.
+
+ ["Outline of a Mathematical Theory of Computation",
+ D.S. Scott, TM PRG-2, PRG, Oxford U, 1971].
+
+lambda abstraction
+
+ A term in {lambda-calculus} denoting a function. A lambda
+ abstraction begins with a lower-case lambda (represented as
+ "\" in this document), followed by a variable name (the "bound
+ variable"), a full stop and a {lambda expression} (the body).
+ The body is taken to extend as far to the right as possible
+ so, for example an expression,
+
+ \ x . \ y . x+y
+
+ is read as
+
+ \ x . (\ y . x+y).
+
+ A nested abstraction such as this is often abbreviated to:
+
+ \ x y . x + y
+
+ The lambda expression (\ v . E) denotes a function which takes
+ an argument and returns the term E with all {free} occurrences
+ of v replaced by the {actual argument}. Application is
+ represented by {juxtaposition} so
+
+ (\ x . x) 42
+
+ represents the identity function applied to the constant 42.
+
+ A {lambda abstraction} in {Lisp} is written as the symbol
+ lambda, a list of zero or more variable names and a list of
+ zero or more terms, e.g.
+
+ (lambda (x y) (plus x y))
+
+ Lambda expressions in {Haskell} are written as a backslash,
+ "\", one or more patterns (e.g. variable names), "->" and an
+ expression, e.g. \ x -> x.
+
+ (1995-01-24)
+
+lambda-calculus
+
+ <mathematics> (Normally written with a Greek letter lambda).
+ A branch of mathematical logic developed by {Alonzo Church} in
+ the late 1930s and early 1940s, dealing with the application
+ of {functions} to their arguments. The {pure lambda-calculus}
+ contains no constants - neither numbers nor mathematical
+ functions such as plus - and is untyped. It consists only of
+ {lambda abstractions} (functions), variables and applications
+ of one function to another. All entities must therefore be
+ represented as functions. For example, the natural number N
+ can be represented as the function which applies its first
+ argument to its second N times ({Church integer} N).
+
+ Church invented lambda-calculus in order to set up a
+ foundational project restricting mathematics to quantities
+ with "{effective procedures}". Unfortunately, the resulting
+ system admits {Russell's paradox} in a particularly nasty way;
+ Church couldn't see any way to get rid of it, and gave the
+ project up.
+
+ Most {functional programming} languages are equivalent to
+ lambda-calculus extended with constants and types. {Lisp}
+ uses a variant of lambda notation for defining functions but
+ only its {purely functional} subset is really equivalent to
+ lambda-calculus.
+
+ See {reduction}.
+
+ (1995-04-13)
+
+lambda expression
+
+ <mathematics> A term in the {lambda-calculus} denoting an
+ unnamed function (a "{lambda abstraction}"), a variable or a
+ constant. The {pure lambda-calculus} has only functions and
+ no constants.
+
+ (1995-04-13)
+
+lambda lifting
+
+ A program transformation to remove free variables. An
+ expression containing a free variable is replaced by a
+ function applied to that variable. E.g.
+
+ f x = g 3 where g y = y + x
+
+ x is a free variable of g so it is added as an extra argument:
+
+ f x = g 3 x where g y x = y + x
+
+ Functions like this with no free variables are known as
+ supercombinators and are traditionally given upper-case names
+ beginning with "$". This transformation tends to produce many
+ supercombinators of the form f x = g x which can be eliminated
+ by {eta reduction} and substitution. Changing the order of
+ the parameters may also allow more optimisations. References
+ to global (top-level) constants and functions are not
+ transformed to function parameters though they are technically
+ free variables.
+
+ A closely related technique is closure conversion. See also
+ Full laziness.
+
+LambdaMOO
+
+ <games> The most frequently used {server} {software} for
+ running a {MOO} and also the nerve-center (of sorts) of the
+ MOO community.
+
+ {(ftp://ftp.lambda.moo.mud.org/pub/MOO/)}.
+
+ {Telnet (telnet://lambda.moo.mud.org:8888)}.
+
+ (1999-05-25)
+
+Lambda Prolog
+
+ <language> An extension of standard {Prolog} defined by Dale
+ A. Miller and Gopalan Nadathur in 1986, in which terms are
+ {strongly typed} lambda terms. {Clauses} are {higher order}
+ {hereditary Harrop formulas}. The main novelties are
+ {universal quantification} on {goals} and {implication}.
+
+ The {Prolog/Mali} compiler compiles Lambda Prolog for the
+ {MALI} abstract memory system.
+
+ {Teyjus (http://teyjus.cs.umn.edu/)} is an implementation of
+ Lambda Prolog.
+
+ {Lambda Prolog home (http://cse.psu.edu/~dale/lProlog/)}.
+
+ Mailing list: lprolog@cs.umn.edu.
+
+ ["Higher-order logic programming", Miller D.A. and Nadathur
+ G., 3rd International Conference on Logic Programming, pp
+ 448-462, London 1986].
+
+ [Nadathur G. "A Higher-Order Logic as a Basis for Logic
+ Programming", Thesis, University of Pennsylvania, 1987].
+
+ (2002-10-15)
+
+lamer
+
+ <jargon> A hopelessly clueless {luser}.
+
+ (1997-01-31)
+
+LAMINA
+
+ A {concurrent} {object-oriented} language.
+
+ ["Experiments with a Knowledge-based System on a
+ Multiprocessor", Third Intl Conf Supercomputing Proc, 1988].
+
+ ["ELINT in LAMINA, Application of a Concurrent Object
+ language", Delagi et al, KSL-88-3, Knowledge Sys Labs,
+ Stanford U].
+
+lamp-post error
+
+ {fencepost error}
+
+LAN
+
+ {local area network}
+
+LAN administrator
+
+ <job> A person who installs and maintains {LAN} {hardware} and
+ {software}. A LAN administrator troubleshoots network usage
+ and computer peripherals. He installs new users, performs
+ system {backups} and data recovery, and resolves LAN
+ communications problems.
+
+ (2004-03-12)
+
+LANCE
+
+ Local Area Network Controller for Ethernet.
+
+ The alternative name for the Am7990 {integrated circuit} used
+ in a {Filtabyte} {Ethernet} controller card.
+
+ (1995-02-15)
+
+language
+
+ 1. <language, programming> {programming language}.
+
+ 2. <human language> {natural language}.
+
+ (1998-09-07)
+
+language-based editor
+
+ {language-sensitive editor}
+
+language code
+
+ <human language, standard> A set of standard names and
+ abbreviations maintained by {ISO} for identifying human
+ languages, natural and invented, past and present. Each
+ language has a list of English and French names and an ISO
+ 639-2 three-letter code. Some also have an ISO 639-1
+ two-letter code.
+
+ The list even includes the Klingon language from the Star Trek
+ science fiction series.
+
+ {Latest list
+ (http://www.loc.gov/standards/iso639-2/php/English_list.php)}.
+
+ There are also {country codes}.
+
+ (2006-12-11)
+
+Language for Communicating Systems
+
+ <language> (LCS) A {concurrent} {SML} by Bernard Berthomieu
+ with {behaviours} and processes, based upon {higher order
+ CCS}. LCS is implemented as a {bytecode interpreter} and runs
+ on {Sun} {SPARC}, {SGI} {MIPS}, and {Linux}.
+
+ Latest version: 5.1, as of 2000-03-17.
+
+ {(http://laas.fr/~bernard/lcs.html)}.
+
+ E-mail: Bernard Berthomieu <Bernard.Berthomieu@laas.fr>.
+
+ Mailing list: lcs@laas.fr
+
+ (2000-03-28)
+
+Language for the On-Line Investigation and Transformation of Abstractions
+
+ <language> (LOLITA) An extension of the {Culler-Fried System}
+ for {symbolic mathematics}.
+
+ ["An On- line Symbol Manipulation System", F.W. Blackwell, Proc
+ ACM 22nd Natl Conf, 1967].
+
+ [Sammet 1969, p. 464].
+
+ (2003-07-29)
+
+Language H
+
+ An early business-oriented language from {NCR}.
+
+language lawyer
+
+ A person, usually an experienced or senior software engineer,
+ who is intimately familiar with many or most of the numerous
+ restrictions and features (both useful and esoteric)
+ applicable to one or more computer programming languages. A
+ language lawyer is distinguished by the ability to show you
+ the five sentences scattered through a 200-page manual that
+ together imply the answer to your question "if only you had
+ thought to look there".
+
+ Compare {wizard}, {legal}, {legalese}.
+
+ [{Jargon File}]
+
+ (1995-02-15)
+
+Language Of Temporal Ordering Specification
+
+ <language> (LOTOS) A formal {specification language} based on
+ temporal ordering used for {protocol} specfication in {ISO}
+ {OSI} {standards}. It is published as ISO 8807 in 1990 and
+ describes the order in which events occur.
+
+ ["The Formal Description Technique LOTOS", P.H.J. van Eijk et
+ al eds, N-H 1989].
+
+ (1995-03-18)
+
+Language Sensitive Editor
+
+ (LSE) A {language-sensitive editor} from {DEC}.
+
+ (1995-02-15)
+
+language-sensitive editor
+
+ An editor that is aware of the syntactic, semantic and in some
+ cases the structural rules of a specific programming language
+ and provides a framework for the user to enter {source code}.
+ Programs or changes to previously stored programs are
+ incrementally parsed into an {abstract syntax tree} and
+ automatically checked for correctness.
+
+ (1995-02-15)
+
+languages of choice
+
+ {C} and {Lisp}. Nearly every hacker knows one of these, and
+ most good ones are fluent in both. Smalltalk and Prolog are
+ also popular in small but influential communities.
+
+ There is also a rapidly dwindling category of older hackers
+ with Fortran, or even assembler, as their language of choice.
+ They often prefer to be known as {Real Programmers}, and other
+ hackers consider them a bit odd (see "{The Story of Mel}").
+ Assembler is generally no longer considered interesting or
+ appropriate for anything but {HLL} implementation, {glue}, and
+ a few time-critical and hardware-specific uses in systems
+ programs. Fortran occupies a shrinking niche in scientific
+ programming.
+
+ Most hackers tend to frown on languages like {Pascal} and
+ {Ada}, which don't give them the near-total freedom considered
+ necessary for hacking (see {bondage-and-discipline language}),
+ and to regard everything even remotely connected with {COBOL}
+ or other traditional {card walloper} languages as a total and
+ unmitigated {loss}.
+
+ [{Jargon File}]
+
+Laning and Zierler
+
+ <language> Possibly the first true working algebraic
+ {compiler}. Written by J.H. Laning Jr and N. Zierler in
+ 1953-1954 to run on {MIT}'s {Whirlwind} computer.
+
+ [Sammet 1969, pp. 131-132].
+
+ [Did the language have a name?]
+
+ (1994-11-01)
+
+Lan Kanal Adapter
+
+ <networking> (LKA) A sort of external {LAN} interface for a
+ {BS200} computer.
+
+ (2005-02-11)
+
+LANL
+
+ Los Alamos National Laboratory, Los Alamos, NM, USA.
+
+Lan Manager
+
+ <operating system> {Microsoft}'s {OS/2}-based {network
+ operating system}. Developed in conjunction with {3Com}, Lan
+ Manager runs as a task under OS/2. Because of this, a {file
+ server} may concurrently be used for other tasks, such as
+ {database} services. It offers good {mulitasking}.
+
+ (1997-03-19)
+
+LANtastic
+
+ <networking, product> A trademarked name for numerous products
+ of {Artisoft, Inc.}.
+
+ (1995-04-16)
+
+LAP
+
+ LISP Assembly Program. The {assembly language} embedded into
+ early {Lisp}. LAP was also used by the {Liar} compiler for
+ {MIT Scheme} and {MACLISP}.
+
+ [Sammet 1969, p. 597].
+
+ (1994-11-01)
+
+LAP4
+
+ Early assembly language for Linc-8 machine.
+
+LAPB
+
+ {Link Access Protocol Balanced}
+
+LAPD
+
+ 1. {Link Access Procedure on the D channel}.
+
+ 2. Los Angeles Police Department.
+
+LAPM
+
+ {Link Access Protocol for Modems}
+
+LAPSE
+
+ <language> A {single assignment} language for the {Manchester
+ dataflow machine}.
+
+ ["A Single Assignment Language for Data Flow Computing",
+ J.R.W. Glauert, M.Sc Diss, Victoria U Manchester, 1978].
+
+ (1994-12-21)
+
+laptop
+
+ {portable computer}
+
+laptop computer
+
+ {portable computer}
+
+LaQuey
+
+ <networking> [LaQuey, T. (with J. Ryer), "The Internet
+ Companion: A Beginner's Guide to Global Networking",
+ Addison-Wesley, Reading, MA, 1992]
+
+ (2007-09-27)
+
+Larch
+
+ The Larch Project develops aids for formal specifications.
+ Each Larch specification has two components: an interface
+ containing predicates written in the LIL ({Larch Interface
+ Language}) designed for the target language and a 'trait'
+ containing assertions about the {predicates} written in LSL,
+ the {Larch Shared Language} common to all.
+
+ ["The Larch Family of Specification Languages", J. Guttag et
+ al, IEEE Trans Soft Eng 2(5):24-365 (Sep 1985)].
+
+Larch/C++
+
+ An interface specification language which can be used to
+ formally specify {C++} program {modules}.
+
+LARCH/CLU
+
+ <language, specification> The {Larch} specification language
+ for {CLU}. Used in "Abstraction and Specification in Program
+ Development", B. Liskov & J. Guttag, MIT Press 1986.
+
+ (1996-01-02)
+
+Large Installation Systems Administration
+
+ (LISA) The {USENIX} systems administration conference. It is
+ now more general that its title suggests. It is sponsored and
+ organised by {SAGE}, the USENIX Systems Administrators Guild.
+
+ {(ftp://ftp.sage.usenix.org/pub/sage/)}.
+
+ (1996-01-02)
+
+Larry Wall
+
+ <person> A {demigod}, the author of {Perl}, {patch}, and {rn}.
+
+ In the Perl {README}, he says, "I want you to know that I
+ create nice things like this because it pleases the Author of
+ my story. If this bothers you, then your notion of Authorship
+ needs some revision. But you can use Perl anyway."
+
+ E-mail: Larry Wall <lwall@sems.com>.
+
+ (1996-06-04)
+
+LART
+
+ {Luser Attitude Re-adjustment Tool}
+
+larval stage
+
+ Describes a period of monomaniacal concentration on coding
+ apparently passed through by all fledgling hackers. Common
+ symptoms include the perpetration of more than one 36-hour
+ {hacking run} in a given week; neglect of all other activities
+ including usual basics like food, sleep, and personal hygiene;
+ and a chronic case of advanced bleary-eye. Can last from 6
+ months to 2 years, the apparent median being around 18 months.
+ A few so afflicted never resume a more "normal" life, but the
+ ordeal seems to be necessary to produce really wizardly (as
+ opposed to merely competent) programmers. See also
+ {wannabee}. A less protracted and intense version of larval
+ stage (typically lasting about a month) may recur when one is
+ learning a new {OS} or programming language.
+
+ [{Jargon File}]
+
+lase
+
+ /layz/ To print a given document via a laser printer. "OK,
+ let's lase that sucker and see if all those graphics-macro
+ calls did the right things."
+
+laser
+
+ <hardware> (Light Amplification by Stimulated Emission of
+ Radiation) The type of light source used in a {laser
+ printer}.
+
+ (2003-05-08)
+
+laser printer
+
+ <printer> A non-impact high-resolution printer which uses a
+ rotating disk to reflect laser beams to form an electrostatic
+ image on a selenium imaging drum. The developer drum
+ transfers toner from the toner bin to the charged areas of the
+ imaging drum, which then transfers it onto the paper into
+ which it is fused by heat. Toner is dry ink powder, generally
+ a plastic heat-sensitive polymer.
+
+ Print resolution currently (2001) ranges between 300 and 2400
+ dots per inch (DPI). Laser printers using chemical
+ photoreproduction techniques can produce resolutions of up to
+ 2400 DPI.
+
+ Print speed is limited by whichever is slower - the printer
+ hardware (the "engine speed"), or the software {rendering}
+ process that converts the data to be printed into a {bit map}.
+
+ The print speed may exceed 21,000 lines per minute, though
+ printing speed is more often given in pages per minute. If a
+ laser printer is rated at 12 pages per minute (PPM), this
+ figure would be true only if the printer is printing the same
+ data on each of the twelve pages, so that the bit map is
+ identical. This speed however, is rarely reached if each page
+ contains different codes, text, and graphics.
+
+ In 2001, Xerox's Phaser 1235 and 2135 (with Okidata engines)
+ could print up to 21 colour ppm at 1200x1200 DPI using a
+ single-pass process.
+
+ Colour laser printers can reach 2400 DPI easily (e.g. an HP
+ LaserJet 8550). Some printers with large amounts of RAM can
+ print at engine speed with different text pages and some of
+ the larger lasers intended for graphics design work can print
+ graphics at full engine speed.
+
+ Although there are dozens of retail brands of laser printers,
+ only a few {original equipment manufacturers} make {print
+ engines}, e.g. {Canon}, {Ricoh}, {Toshiba}, and {Xerox}.
+
+ (2002-01-06)
+
+Lasherism
+
+ <jargon, algorithm> (Harvard) A program that solves a standard
+ problem (such as the {Eight Queens Puzzle} or implementing the
+ {life} {algorithm}) in a deliberately nonstandard way.
+ Distinguished from a {crock} or {kluge} by the fact that the
+ programmer did it on purpose as a mental exercise. Such
+ constructions are quite popular in exercises such as the
+ {Obfuscated C contest}, and occasionally in {retrocomputing}.
+ Lew Lasher was a student at Harvard around 1980 who became
+ notorious for such behaviour.
+
+ [{Jargon File}]
+
+ (1994-12-07)
+
+last call optimisation
+
+ <programming> (Or "tail call optimisation") Discarding the
+ immediate calling context ({call stack} {frame}) when the last
+ action of a function or procedure, A, is to call another
+ function or procedure, B. B will then return directly to A's
+ caller, or possibly further up the call stack if the
+ optimisation has been applied to several consecutive calls.
+
+ Last call optimisation allows arbitrarily deep nesting of
+ procedure calls without consuming memory to store useless
+ environments. This is particularly useful in the special case
+ of {tail recursion optimisation}, where a procedure's last
+ action is to call itself (possibly indirectly).
+
+ (2007-03-16)
+
+last-in first-out
+
+ {stack}
+
+LAT
+
+ {Local Area Transport}
+
+latch
+
+ A digital logic circuit used to store one or more bits. A
+ latch has a data input, a clock input and an output. When the
+ clock input is active, data on the input is "latched" or
+ stored and transfered to the output either immediately or when
+ the clock input goes inactive. The output will then retain
+ its value until the clock goes active again.
+
+ See also {flip-flop}.
+
+ (1995-02-03)
+
+latency
+
+ <communications> 1. The time it takes for a {packet} to cross
+ a network connection, from sender to receiver.
+
+ 2. The period of time that a frame is held by a network device
+ before it is forwarded.
+
+ Two of the most important parameters of a communications
+ channel are its latency, which should be low, and its
+ {bandwidth}, which should be high. Latency is particularly
+ important for a {synchronous} {protocol} where each packet
+ must be acknowledged before the next can be transmitted.
+
+ (2000-02-27)
+
+LaTeX
+
+ <language, text, tool> (Lamport TeX) Leslie Lamport
+ <lamport@pa.dec.com>'s document preparation system built on
+ top of {TeX}. LaTeX was developed at {SRI International}'s
+ Computer Science Laboratory and was built to resemble
+ {Scribe}.
+
+ LaTeX adds commands to simplify typesetting and lets the user
+ concentrate on the structure of the text rather than on
+ formatting commands.
+
+ {BibTeX} is a LaTeX package for bibliographic citations.
+
+ Lamport's LaTeX book has an exemplary index listing every
+ symbol, concept and example in the book. The index in the,
+ now obsolete, first edition includes (on page 221) the
+ mysterious entry "Gilkerson, Ellen, 221". The second edition
+ (1994) has an entry for "infinite loop" instead.
+
+ ["LaTeX, A Document Preparation System", Leslie Lamport, A-W
+ 1986, ISBN 0-201-15790-X (first edition, now obsolete)].
+
+ (1997-11-17)
+
+Latin 1
+
+ {ISO 8859}
+
+lattice
+
+ <theory> A {partially ordered set} in which all finite subsets
+ have a {least upper bound} and {greatest lower bound}.
+
+ This definition has been standard at least since the 1930s and
+ probably since Dedekind worked on lattice theory in the 19th
+ century; though he may not have used that name.
+
+ See also {complete lattice}, {domain theory}.
+
+ (1999-12-09)
+
+LAU
+
+ Langage a Assignation Unique. A {single assignment} language
+ for the LAU {dataflow} machine, Toulouse.
+
+ ["Pipelining, Parallelism and Asynchronism in the LAU System",
+ J.C. Syre et al, Proc 1977 Intl Conf Parallel Proc,
+ pp. 87-92].
+
+laundromat
+
+ <jargon, storage> Synonym {disk farm}; see {washing machine}.
+
+ [{Jargon File}]
+
+ (1998-02-01)
+
+LAURE
+
+ <language> A language for {knowledge representation} combining
+ {object-oriented} features and {logic programming}. It has
+ set operations, object-oriented {exception} handling and a
+ {polymorphic} type system.
+
+ ["An Object-Oriented Language for Advanced Applications", in
+ Proc TOOLS 5, Santa Barbara 1991, P-H].
+
+ (1998-02-01)
+
+LAVA
+
+ A language for {VLSI} that deals with "sticks", i.e. wires
+ represented as lines with thickness.
+
+ ["A Target Language for Silicon Compilers", R.J. Matthews et
+ al, IEEE COMPCON, 1982, pp. 349-353].
+
+ (1994-12-07)
+
+law
+
+ {software law}
+
+LAWN
+
+ {wireless local area network}
+
+Lawrence Livermore Labs
+
+ {Lawrence Livermore National Laboratory}
+
+Lawrence Livermore National Laboratory
+
+ <body> (LLNL) A research organaisatin operated by the
+ {University of California} under a contract with the US
+ Department of Energy. LLNL was founded on 2 September 1952 at
+ the site of an old World War II naval air station.
+
+ The Lab employs researchers from many scientific and
+ engineering disciplines. Some of its departments are the
+ National Ignition Facility, the Human Genome Center, the ASCI
+ Tera-Scale Computing partnership, the Computer Security
+ Technology Center, and the Site 300 Experimental Test
+ Facility. Other research areas are Astronomy and
+ Astrophysics, Atmospheric Science, Automation and Robotics,
+ Biology, Chemistry, Computing, Energy Research, Engineering,
+ Environmental Science, Fusion, Geology and Geophysics, Health,
+ Lasers and Optics, Materials Science, National Security,
+ Physics, Sensors and Instrumentation, Space Science.
+
+ LLNL also works with industry in research and licensing
+ projects. At the end of fiscal year 1995, the lab had signed
+ agreements for 193 cost-shared research projects involving 201
+ companies and worth nearly $600m.
+
+ {(http://llnl.gov/)}.
+
+ Address: Fremont, California, USA.
+
+ (1996-10-30)
+
+LAX
+
+ LAnguage eXample.
+
+ A {toy language} used to illustrate {compiler} design.
+
+ ["Compiler Construction", W.M. Waite et al, Springer 1984].
+
+ (1994-12-07)
+
+layer
+
+ {protocol layer}
+
+layer 1
+
+ {physical layer}
+
+layer 2
+
+ {data link layer}
+
+layer 3
+
+ {network layer}
+
+layer 4
+
+ {transport layer}
+
+layer 5
+
+ {session layer}
+
+layer 6
+
+ {presentation layer}
+
+layer 7
+
+ {application layer}
+
+Layer Two Tunneling Protocol
+
+ <protocol> (L2TP) An {IETF} standard {protocol} for creating
+ {Virtual Private Networks}. L2TP is an {open standard} with
+ mutlivendor {interoperability} and acceptance.
+
+ Compare: {PPTP}.
+
+ [Sponsored by {Cisco Systems, Inc.}?]
+
+ (1998-09-24)
+
+laziness
+
+ {lazy evaluation}
+
+lazy evaluation
+
+ <reduction> An {evaluation strategy} combining {normal order
+ evaluation} with updating. Under normal order evaluation
+ (outermost or call-by-name evaluation) an expression is
+ evaluated only when its value is needed in order for the
+ program to return (the next part of) its result. Updating
+ means that if an expression's value is needed more than once
+ (i.e. it is shared), the result of the first evaluation is
+ remembered and subsequent requests for it will return the
+ remembered value immediately without further evaluation. This
+ is often implemented by graph reduction. An unevaluated
+ expression is represented as a {closure} - a data structure
+ containing all the information required to evaluate the
+ expression.
+
+ Lazy evaluation is one {evaluation strategy} used to implement
+ non-{strict} functions. Function arguments may be infinite
+ data structures (especially lists) of values, the components
+ of which are evaluated as needed.
+
+ According to Phil Wadler the term was invented by Jim Morris.
+
+ Opposite: {eager evaluation}.
+
+ A partial kind of lazy evaluation implements lazy data
+ structures or especially {lazy lists} where function arguments
+ are passed evaluated but the arguments of data constructors
+ are not evaluated.
+
+ {Full laziness} is a {program transformation} which aims to
+ optimise lazy evaluation by ensuring that all subexpressions
+ in a function body which do not depend on the function's
+ arguments are only evaluated once.
+
+ (1994-12-14)
+
+lazy list
+
+ A list which is built using a non-strict constructor. Any
+ head or tail of the list may be an unevaluated closure. Also
+ known as streams since they may be used to carry a sequence of
+ values from the output of one function to an input of another.
+ See also Lazy evaluation.
+
+Lazy SML
+
+ {Lazy Standard ML}
+
+lazy sml2c
+
+ A {lazy} version {sml2c}. Portable, written in {SML}.
+ Language extensions include {first-class continuations},
+ {asynchronous signal} handling.
+
+ E-mail: <david.tarditi@cs.cmu.edu>.
+ {(ftp://dravido.soar.cs.cmu.edu/usr/nemo/sml2c)}.
+
+Lazy Standard ML
+
+ <language> (LSML) A {lazy} varient of {SML}, allowing cyclic
+ val definitions, by Prateek Mishra <mishra@sbcs.sunysb.edu>.
+
+ Latest version: 0.43-1, as of 1993-11-15.
+
+ Not to be confused with {LML}.
+
+ {(ftp://sbcs.sunysb.edu/pub/lsml)}.
+
+ (1999-08-30)
+
+lb
+
+ <networking> The {country code} for Lebanon.
+
+ (1999-01-27)
+
+LBA
+
+ {Logical Block Addressing}
+
+LBE
+
+ {Language-Based Editor}
+
+LBL
+
+ Lawrence Berkeley Laboratory, Berkeley, CA, USA.
+
+LBX
+
+ {Low Bandwidth X}.
+
+lc
+
+ <networking> The {country code} for Saint Lucia.
+
+ (1999-01-27)
+
+LCC
+
+ Language for Conversational Computing. Written at {CMU} in
+ the 1960's. Similar to {JOSS}, with declarations, pointers
+ and block structure from {ALGOL 60}. Implemented for {IBM
+ 360}/{IBM 370} under {TSS}.
+
+ ["LCC Reference Manual", H.R. Van Zoeren, CMU 196]9.
+
+lcc
+
+ <programming, tool> A hand-coded, {retargetable} compiler for
+ {ANSI C} written by Dave Hanson <drh@cs.princeton.edu>. lcc's
+ {parser} is faster than {yacc} and the code it generates is
+ "as good as {GCC}".
+
+ Version 1.8 includes a {compiler}, test suite and
+ documentation. lcc has been ported to {Vax}, commercial
+ backends for {MIPS}, {SPARC}, {68000} are cheap for
+ universities. {Chop} is a {code generator} for use with lcc.
+
+ {(http://cs.princeton.edu/software/lcc/)}.
+
+ E-mail: <lcc-requests@princeton.edu>.
+
+ ["A Retargetable C Compiler: Design and Implementation",
+ Addison-Wesley, 1995, ISBN 0-8053-1670-1].
+
+ (1998-03-20)
+
+LCD
+
+ {liquid crystal display}
+
+LCF
+
+ {Logic for Computable Functions}
+
+LCL
+
+ 1. The Larch interface language for ANSI standard C.
+
+ [J.V. Guttag et al, TR 74, DEC SRC, Palo Alto CA, 1991].
+
+ 2. Liga Control Language.
+
+ Controls the attribute evaluator generator LIGA, part of the
+ {Eli} {compiler-compiler}.
+
+ ["LCL: Liga Control Language", U. Kastens
+ <uwe@uni-paderborn.de>, U Paderborn].
+
+ (1995-01-23)
+
+lclint
+
+ <tool, programming> A lint-like {ANSI C} source checker from
+ {MIT}. If formal specifications are supplied (in a separate
+ file), lclint can do more powerful checking to detect
+ inconsistencies between specifications and code. Adding
+ specifications enables further checking, types can be defined
+ as {abstract} and lclint can detect inconsistent use of
+ {global variables}; undocumented modification of
+ client-visible state; inconsistent use of an uninitialised
+ {formal parameter}; or failure to initialise an actual
+ parameter.
+
+ {(http://larch-www.lcs.mit.edu:8001/larch/lclint.html)}.
+
+ (1995-05-11)
+
+LCP
+
+ {Link Control Protocol}
+
+LCS
+
+ {Language for Communicating Systems}
+
+ld
+
+ 1. <programming, tool> (Load) {Unix}'s {linker}.
+
+ 2. <mathematics> {logarithmus dualis}.
+
+ (1999-03-19)
+
+LDAP
+
+ {Lightweight Directory Access Protocol}
+
+LDB
+
+ /l*'d*b/ [PDP-10 instruction] To extract from the middle.
+ "LDB me a slice of cake, please." This usage has been kept
+ alive by Common LISP's function of the same name. Considered
+ silly. See also {DPB}.
+
+ [{Jargon File}]
+
+LDL
+
+ ["LDL: A Logic-Based Data-Language", S. Tsur et al, Proc VLDB
+ 1986, Kyoto Japan, Aug 1986, pp.33-41].
+
+LDL1
+
+ Successor of LDL. "Sets and Negation in a Logic Database
+ Language", C. Beeri et al, in Proc 6th Ann ACM Symp Princs
+ Database Sys (1987), pp.21- 37.
+
+LDP
+
+ {Linux Documentation Project}
+
+LDT
+
+ Logic Design Translator.
+
+ Computer system design analysis.
+
+ [Sammet 1969, p. 621].
+
+ (1994-12-01)
+
+LE/1
+
+ Langage External.
+
+ ["An Evaluation of the LE/1 Network Command Language Designed
+ for the SOC Network", J. du Masle, in Command Languages,
+ C. Unger ed, N-H 1973].
+
+ (1994-12-01)
+
+leading
+
+ <text> /ledding/ The spacing between lines of {text}. This is
+ defined when a {font} is designed but can often be altered in
+ order to change the appearance of the text or for special
+ effects. It is measured in {points} and is normally 120% of
+ the height of the text.
+
+ See also {kerning}, {tracking}.
+
+ (1996-06-07)
+
+LEAF
+
+ <language> 1. {LISP Extended Algebraic Facility}.
+
+ 2. "LEAF: A Language which Integrates Logic, Equations and
+ Functions", R. Barbuti et al in Logic Programming, Functions
+ Relations and Equations, D. DeGroot et al eds, P-H 1986,
+ pp.201-238.
+
+leaf
+
+ <mathematics, data> (Or "terminal node") In a {tree}, a node
+ which has no {daughter}.
+
+ (1998-11-14)
+
+Leaf Distribution Limited
+
+ A UK connectivity software supplier which also provides
+ SERVELAN, a country-wide {Internet} access service.
+
+ E-mail: <sales@leaf.co.uk>.
+
+ Address: 7 Elmwood, Chineham Business Park, Crockford Lane,
+ BASINGSTOKE RG24 0WG. Telephone: +44 (1256) 707 777. Fax:
+ +44 (1256) 707 555.
+
+ (1995-01-04)
+
+leaf site
+
+ A machine that merely originates and reads {Usenet} news or
+ mail, and does not relay any third-party traffic. Often
+ uttered in a critical tone; when the ratio of leaf sites to
+ backbone, rib, and other relay sites gets too high, the
+ network tends to develop bottlenecks. Compare {backbone
+ site}, {rib site}.
+
+ [{Jargon File}]
+
+League for Programming Freedom
+
+ <body, legal> (LPF) A grass-roots organisation of professors,
+ students, businessmen, programmers and users dedicated to
+ bringing back the freedom to write programs. Once programmers
+ were allowed to write programs using all the techniques they
+ knew, and providing whatever features they felt were useful.
+ Monopolies, {software patents} and {interface copyrights} have
+ taken away freedom of expression and the ability to do a good
+ job.
+
+ "{Look and feel}" lawsuits attempt to monopolise well-known
+ command languages; some have succeeded. Copyrights on command
+ languages enforce gratuitous incompatibility, close
+ opportunities for competition and stifle incremental
+ improvements.
+
+ {Software patents} are even more dangerous; they make every
+ design decision in the development of a program carry a risk
+ of a lawsuit, with draconian pre-trial seizure. It is
+ difficult and expensive to find out whether the techniques you
+ consider using are patented; it is impossible to find out
+ whether they will be patented in the future.
+
+ The League is not opposed to the legal system that Congress
+ intended -- {copyright} on individual programs. They aim to
+ reverse the changes made by judges in response to special
+ interests, often explicitly rejecting the public interest
+ principles of the Constitution.
+
+ The League works to abolish the monopolies by publishing
+ articles, talking with public officials, boycotting egregious
+ offenders and in the future may intervene in court cases. On
+ 1989-05-24, the League picketed {Lotus} headquarters on
+ account of their lawsuits, and then again on 1990-08-02.
+ These marches stimulated widespread media coverage for the
+ issue.
+
+ The League's funds are used for filing briefs; printing
+ handouts, buttons and signs and whatever will persuade the
+ courts, the legislators and the people. The League is a
+ non-profit corporation, but not considered a tax-exempt
+ charity.
+
+ {LPF Home (http://progfree.org/)}.
+
+ (2007-02-28)
+
+leak
+
+ <programming> With a qualifier, one of a class of
+ resource-management bugs that occur when resources are not
+ freed properly after operations on them are finished, so they
+ effectively disappear (leak out). This leads to eventual
+ exhaustion as new allocation requests come in.
+
+ One might refer to, say, a "window handle leak" in a {window
+ system}.
+
+ See {memory leak}, {fd leak}.
+
+ [{Jargon File}]
+
+ (1995-04-18)
+
+leaky heap
+
+ {memory leak}
+
+Lean
+
+ An experimental language from the {University of Nijmegen} and
+ {University of East Anglia}, based on graph rewriting and
+ useful as an intermediate language. Lean is descended from
+ {Dactl0}.
+
+ {Clean} is a subset of Lean.
+
+ ["Towards an Intermediate Language Based on Graph Rewriting",
+ H.P. Barendregt et al in PARLE: Parallel Architectures and
+ Languages Europe, G. Goos ed, LNCS 259, Springer 1987,
+ pp.159-175].
+
+ (1995-01-25)
+
+LEAP
+
+ Language for the Expression of Associative Procedures.
+
+ ALGOL-based formalism for sets and associative retrieval, for
+ TX-2. Became part of SAIL.
+
+ "An ALGOL-based Associative Language", J.A. Feldman et al,
+ CACM 12(8):439-449 (Aug 1969).
+
+leapfrog attack
+
+ Use of userid and password information obtained illicitly from
+ one {host} (e.g. {download}ing a file of account IDs and
+ passwords, tapping {TELNET}, etc.) to compromise another host.
+ Also, the act of TELNETting through one or more hosts in order
+ to confuse a trace (a standard {cracker} procedure).
+
+ [{Jargon File}]
+
+leap second
+
+ {Coordinated Universal Time}
+
+learning curve
+
+ <jargon> A graph showing some measure of the cost of
+ performing some action against the number of times it has been
+ performed. The term probably entered engineering via the
+ aircraft industry in the 1930s, where it was used to describe
+ plots showing the cost of making some particular design of
+ aeroplane against the number of units made.
+
+ The term is also used in psychology to mean a graph showing
+ some measure of something learned against the number of
+ trials. The psychology graphs normally slope upward whereas
+ the manufacturing ones normally slope downward but they are
+ both usually steep to start with and then level out.
+
+ {Marketroids} often misuse the term to mean the amount of time
+ it takes to learn to use something ("reduce the learning
+ curve") or the ease of learning it ("easy learning curve").
+ The phrase "steep learning curve" is sometimes used
+ incorrectly to mean "hard to learn" whereas of course it
+ implies rapid learning.
+
+ {Engineering
+ (http://computerworld.com/cwi/story/0,1199,NAV47-68-85-1942_STO61762,00.html)}.
+
+ {Psychology
+ (http://sun.science.wayne.edu/~wpoff/cor/mem/opereinf.html)}.
+
+ (2002-01-22)
+
+leased line
+
+ <communications, networking> A private telephone circuit
+ permanently connecting two points, normally provided on a
+ lease by a local {PTT}.
+
+ (1998-03-24)
+
+least fixed point
+
+ <mathematics> A {function} f may have many {fixed points} (x
+ such that f x = x). For example, any value is a fixed point
+ of the identity function, (\ x . x).
+
+ If f is {recursive}, we can represent it as
+
+ f = fix F
+
+ where F is some {higher-order function} and
+
+ fix F = F (fix F).
+
+ The standard {denotational semantics} of f is then given by
+ the least fixed point of F. This is the {least upper bound}
+ of the infinite sequence (the {ascending Kleene chain})
+ obtained by repeatedly applying F to the totally undefined
+ value, bottom. I.e.
+
+ fix F = LUB {bottom, F bottom, F (F bottom), ...}.
+
+ The least fixed point is guaranteed to exist for a
+ {continuous} function over a {cpo}.
+
+ (2005-04-12)
+
+least recently used
+
+ (operating systems) (LRU) A rule used in a {paging} system
+ which selects a page to be {paged out} if it has been used
+ (read or written) less recently than any other page. The same
+ rule may also be used in a {cache} to select which cache entry
+ to {flush}.
+
+ This rule is based on {temporal locality} - the observation
+ that, in general, the page (or cache entry) which has not been
+ accessed for longest is least likely to be accessed in the
+ near future.
+
+ (1995-02-15)
+
+least significant bit
+
+ <data> (LSB) {Bit} zero, the bit of a {binary} number giving
+ the number of ones, the last or rightmost bit when the number
+ is written in the usual way.
+
+ (1995-07-13)
+
+least upper bound
+
+ <theory> (lub or "join", "supremum") The least upper bound of
+ two elements a and b is an upper bound c such that a <= c and
+ b <= c and if there is any other upper bound c' then c <= c'.
+ The least upper bound of a set S is the smallest b such that
+ for all s in S, s <= b. The lub of mutually comparable
+ elements is their maximum but in the presence of incomparable
+ elements, if the lub exists, it will be some other element
+ greater than all of them.
+
+ Lub is the dual to {greatest lower bound}.
+
+ (In {LaTeX}, "<=" is written as {\sqsubseteq}, the lub of two
+ elements a and b is written a {\sqcup} b, and the lub of set S
+ is written as \bigsqcup S).
+
+ (1995-02-03)
+
+leaves
+
+ {leaf}
+
+LEC
+
+ {Local Exchange Carrier}
+
+LECOM
+
+ Version of COMIT on GE 225 ca. 1966. Sammet 1969, p.419.
+
+LED
+
+ <electronics> {Light-Emitting Diode}.
+
+LEDA
+
+ {Library of Efficient Data types and Algorithms}
+
+Leda
+
+ <language> A multi-paradigm language supporting {imperative
+ programming}, {declarative programming}, {procedural
+ programming}, {functional programming}, {logic programming}
+ and {object-oriented programming} developed by Tim Budd
+ <budd@cs.orst.edu> at Oregon State University in 1990-1993.
+
+ ["Blending Imperative and Relational Programming", Tim Budd,
+ IEEE Software 8(1):58-65 (Jan 1991)]. Forthcoming book.
+
+ {(ftp://cs.orst.edu/pub/budd/leda/)}.
+
+ (2007-10-02)
+
+LED page printer
+
+ {LED printer}
+
+LED printer
+
+ <printer> (Or "LED page printer") A printer which is similar
+ in operation to a {laser printer}, but where an array of
+ {LEDs} is used in place of the laser.
+
+ (1996-12-08)
+
+leech
+
+ <networking> Someone who {downloads} files but provides
+ nothing for others to download. The term is common on
+ {BitTorrent}, which relies on having multiple sources for
+ files to improve download speed.
+
+ (2007-03-27)
+
+leet
+
+ {elite}
+
+left arrow
+
+ <character> The graphic which the 1963 version of {ASCII} had
+ in place of the {underscore} character, {ASCII} 95.
+
+ (1995-03-06)
+
+left brace
+
+ <character> "{". {ASCII} character 123.
+
+ Common names: open brace; left brace; left squiggly; left
+ squiggly bracket/brace; left curly bracket/brace; {ITU-T}:
+ opening brace. Rare: brace ("}" = unbrace); curly ("}" =
+ uncurly); leftit ("}" = rytit); left squirrelly; {INTERCAL}:
+ embrace ("}" = bracelet).
+
+ Paired with {right brace} ("}").
+
+ (1995-03-16)
+
+left bracket
+
+ <character> "[". {ASCII} character 91.
+
+ Common: left square bracket; {ITU-T}: opening bracket;
+ bracket. Rare: square; {INTERCAL}: U turn.
+
+ Paired with {right bracket} ("]").
+
+ (1995-03-16)
+
+left join
+
+ {outer join}
+
+left outer join
+
+ {outer join}
+
+left parenthesis
+
+ <character> "(". {ASCII} character 40.
+
+ Common names: left paren; left parenthesis; left; {open};
+ paren (")" = thesis); open paren; open parenthesis; left
+ parenthesis; left banana. Rare: so (")" = already); lparen;
+ {ITU-T}: opening parenthesis; open round bracket, left round
+ bracket, {INTERCAL}: wax (")" = wane); parenthisey (")" =
+ unparenthisey); left ear.
+
+ Paired with {right parenthesis} (")").
+
+ (1995-03-06)
+
+LeFun
+
+ Logic, Equations and Functions. An integration of {logic
+ programming} and {functional programming} by H. Ait-Kaci et al
+ of {MCC}, Austin TX.
+
+ ["LeFun: Logic, Equations and Functions", H. Ait-Kaci et al,
+ Proc 1987 Symp on Logic Programming, San Francisco].
+
+ (1994-10-21)
+
+legacy
+
+ {legacy system}
+
+legacy code
+
+ {legacy system}
+
+legacy software
+
+ {legacy system}
+
+legacy system
+
+ <jargon> A computer system or {application program} which
+ continues to be used because of the cost of replacing or
+ redesigning it and often despite its poor competitiveness and
+ compatibility with modern equivalents. The implication is
+ that the system is large, monolithic and difficult to modify.
+
+ If legacy software only runs on antiquated {hardware} the cost
+ of maintaining this may eventually outweigh the cost of
+ replacing both the software and hardware unless some form of
+ {emulation} or {backward compatibility} allows the software to
+ run on new hardware.
+
+ (1998-08-09)
+
+legal
+
+ Loosely used to mean "in accordance with all the relevant
+ rules", especially in connection with some set of constraints
+ defined by software. "The older =+ alternate for += is no
+ longer legal syntax in ANSI C." "This parser processes each
+ line of legal input the moment it sees the trailing linefeed."
+ Hackers often model their work as a sort of game played with
+ the environment in which the objective is to maneuver through
+ the thicket of "natural laws" to achieve a desired objective.
+ Their use of "legal" is flavoured as much by this game-playing
+ sense as by the more conventional one having to do with courts
+ and lawyers. Compare {language lawyer}, {legalese}.
+
+ [{Jargon File}]
+
+legalese
+
+ Dense, pedantic verbiage in a language description, product
+ specification, or interface standard; text that seems designed
+ to obfuscate and requires a {language lawyer} to {parse} it.
+ Though hackers are not afraid of high information density and
+ complexity in language (indeed, they rather enjoy both), they
+ share a deep and abiding loathing for legalese; they associate
+ it with deception, {suits}, and situations in which hackers
+ generally get the short end of the stick.
+
+LEGOL
+
+ "Application of MP/3 to the Design and Implementation of
+ LEGOL, A Legally Oriented Language", S.H. Mandil et al, Intl
+ Symp Programming, Paris 1974.
+
+Le-Lisp
+
+ Jerome Chailloux and Emmanuel St James, INRIA, France. A LISP
+ dialect close to Common Lisp, lexically scoped, with a
+ CLOS-like object system. Uses both packages and modules.
+ "le-lisp: A Portable and Efficient Lisp System", J. Chailloux
+ et al, Proc 1984 ACM Symp on Lisp and Functional Programming,
+ ACM. Version v.16, available from ILOG, France.
+
+lemma
+
+ <logic> A result already proved, which is needed in the proof
+ of some further result.
+
+ (1995-03-25)
+
+Lempel-Ziv compression
+
+ {Substitutional compression} schemes proposed by Jakob Ziv and
+ Abraham Lempel in 1977 and 1978. There are two main schemes,
+ {LZ77} and {LZ78}. {Lempel-Ziv Welch compression} is a
+ variant of {LZ78}.
+
+Lempel-Ziv Welch compression
+
+ (LZW) The {algorithm} used by the {Unix} {compress} command to
+ reduce the size of files, e.g. for archival or transmission.
+ LZW was designed by Terry Welch in 1984 for implementation in
+ hardware for high-performance disk controllers. It is a
+ variant of {LZ78}, one of the two {Lempel-Ziv compression}
+ schemes.
+
+ The LZW algorithm relies on reoccurrence of byte sequences
+ (strings) in its input. It maintains a table mapping input
+ strings to their associated output codes. The table initially
+ contains mappings for all possible strings of length one.
+ Input is taken one byte at a time to find the longest initial
+ string present in the table. The code for that string is
+ output and then the string is extended with one more input
+ byte, b. A new entry is added to the table mapping the
+ extended string to the next unused code (obtained by
+ incrementing a counter). The process repeats, starting from
+ byte b. The number of bits in an output code, and hence the
+ maximum number of entries in the table is usually fixed and
+ once this limit is reached, no more entries are added.
+
+ LZW compression and decompression are licensed under {Unisys}
+ Corporation's 1984 U.S. Patent 4,558,302 and equivalent
+ foreign patents. This kind of patent isn't legal in most
+ coutries of the world (including the UK) except the USA.
+ Patents in the UK can't describe {algorithms} or mathematical
+ methods.
+
+ [A Technique for High Performance Data Compression, Terry A.
+ Welch, IEEE Computer, 17(6), June 1984, pp. 8-19]
+
+ [J. Ziv and A. Lempel, "A Universal Algorithm for Sequential
+ Data Compression," IEEE Transactions on Information Theory,
+ Vol. IT-23, No. 3, May 1977, pp. 337-343].
+
+Lenat, Doug
+
+ {Doug Lenat}
+
+lenient evaluation
+
+ <reduction> An {evaluation strategy}, described in [Traub,
+ FPCA 89], under which all {redex}es are evaluated in parallel
+ except inside the arms of conditionals and inside {lambda
+ abstractions}. Lenient evaluation is an example of an {eager}
+ evaluation strategy.
+
+ (2004-01-22)
+
+LEO
+
+ {Low Earth Orbit}
+
+Leo
+
+ 1. <language> A general-purpose {systems language},
+ syntactically like {Pascal} and {Y}, semantically like {C}.
+
+ ["The Leo Programming Language", G. Townsend, CS TR 84-7, U
+ Arizona 1984].
+
+ (1996-02-06)
+
+ 2. <application> A general data management environment which
+ can show user-created relationships among any kind data. It
+ can also be used as an {outlining editor} as it embeds the
+ {noweb} and {CWEB} markup languages in an outline context.
+
+ Leo is written in pure {Python} using {Tk/tcl} and so runs on
+ {Windows}, {Linux} and {MacOS X}. It isdistributed under the
+ {Python License}.
+
+ (2006-07-12)
+
+LER
+
+ 1. <networking> {Label Edge Router}.
+
+ 2. <electronics, humour> {Light-Emitting Resistor}.
+
+ [{Jargon File}]
+
+ (1999-06-30)
+
+LERP
+
+ /lerp/ vi., Quasi-acronym for Linear Interpolation, used as a
+ verb or noun for the operation. "Bresenham's algorithm lerps
+ incrementally between the two endpoints of the line."
+
+ [{Jargon File}]
+
+less than
+
+ <character> "<" {ASCII} character 60.
+
+ Common names: {ITU-T}: less than; bra (">" = ket); left angle;
+ left angle bracket; left broket. Rare: from; read from; suck
+ (">" = blow); comes-from; in; crunch (all from Unix);
+ {INTERCAL}: angle.
+
+ See also {greater than}.
+
+ (1995-03-20)
+
+LessTif
+
+ <library> The {Hungry Programmers}' version of {OSF}/{Motif}.
+ It will be source code compatible with Motif, meaning that the
+ same source will compile with both libraries and work exactly
+ the same. All the programming is being done with no reference
+ to the header files for the motif widgets, so that LessTif can
+ be distributed as {free software}.
+
+ {(http://hungry.com/products/lesstif)}.
+
+ (1995-03-20)
+
+let floating
+
+ <programming> A {program transformation} used in {functional
+ programming} to implement {full laziness}. E.g. the function
+
+ f x = x + sqrt 4
+
+ can be expressed as
+
+ f x = let t = sqrt 4 in x + t
+
+ but note that t does not depend on the argument x so we can
+ automatically transform this to
+
+ t = sqrt 4
+ f x = x + t
+
+ Making t into a global constant which need only be evaluated
+ at most once, rather than every time f is called. The general
+ idea is to float each subexpression as far out (toward the
+ top level) as possible to maximise sharing.
+
+ (1997-07-09)
+
+letterbomb
+
+ <messaging> 1. An {e-mail} message containing {live data}
+ intended to do nefarious things to the recipient's computer or
+ terminal. It is possible, for example, to send letterbombs
+ that will lock up some specific kinds of terminals when they
+ are viewed, so thoroughly that the user must turn the terminal
+ off to unwedge it. Under {Unix}, a letterbomb can also try to
+ get part of its contents interpreted as a shell command. The
+ results of this could range from silly to tragic.
+
+ See also {Trojan horse}; compare {nastygram}, {talk bomb}.
+
+ 2. Loosely, a {mailbomb}.
+
+ [{Jargon File}]
+
+ (1998-01-16)
+
+level 1 cache
+
+ {primary cache}
+
+level 2 cache
+
+ {secondary cache}
+
+LEVEL5 OBJECT
+
+ From {Information Builders}.
+
+ [What is it?]
+
+level one cache
+
+ {primary cache}
+
+level-sensitive scan design
+
+ (circuit design) (LSSD) A kind of {scan design} which uses
+ separate system and scan clocks to distinguish between normal
+ and test mode. Latches are used in pairs, each has a normal
+ data input, data output and clock for system operation. For
+ test operation, the two latches form a master/slave pair with
+ one scan input, one scan output and non-overlapping scan
+ clocks A and B which are held low during system operation but
+ cause the scan data to be latched when pulsed high during
+ scan.
+
+ ____
+ | |
+ Sin ----|S |
+ A ------|> |
+ | Q|---+--------------- Q1
+ D1 -----|D | |
+ CLK1 ---|> | |
+ |____| | ____
+ | | |
+ +---|S |
+ B -------------------|> |
+ | Q|------ Q2 / SOut
+ D2 ------------------|D |
+ CLK2 ----------------|> |
+ |____|
+
+ In a single latch LSSD configuration, the second latch is used
+ only for scan operation. Allowing it to be use as a second
+ system latch reduces the silicon overhead.
+
+ (1995-02-15)
+
+level two cache
+
+ {secondary cache}
+
+Lex
+
+ 1. <tool> A {lexical analyser} generator for {Unix} and its
+ input language. There is a {GNU} version called {flex} and a
+ version written in, and outputting, {SML/NJ} called {ML-lex}.
+ A version, by David Poole at Montana has been retargeted to
+ {Turbo Pascal}, {(ftp://iecc.com/pub/file/lyprg.zip)}.
+
+ ["Lex - A Lexical Analyzer Generator", M.E. Lesk, CS TR 39,
+ Bell Labs, Oct 1975].
+
+ 2. <language, specification> The lexical specification
+ language for {COPS}.
+
+ ["Metalanguages of the Compiler Production System COPS",
+ J. Borowiec, in GI Fachgesprach "Compiler-Compiler", ed
+ W. Henhapl, Tech Hochs Darmstadt 1978, pp.122-159].
+
+ (2000-11-15)
+
+lexeme
+
+ <grammar> A minimal lexical unit of a language. {Lexical
+ analysis} converts strings in a language into a list of
+ lexemes. For a programming language these word-like pieces
+ would include {keywords}, {identifiers}, {literals} and
+ punctutation. The lexemes are then passed to the {parser} for
+ syntactic analysis.
+
+ (1996-04-06)
+
+lexer
+
+ {lexical analyser}
+
+lexical analyser
+
+ <language> (Or "scanner") The initial input stage of a
+ language processor (e.g. a {compiler}), the part that performs
+ {lexical analysis}.
+
+ (1995-04-05)
+
+lexical analysis
+
+ <programming> (Or "linear analysis", "scanning") The first
+ stage of processing a language. The stream of characters
+ making up the source program or other input is read one at a
+ time and grouped into {lexemes} (or "tokens") - word-like
+ pieces such as keywords, identifiers, {literals} and
+ punctutation. The lexemes are then passed to the {parser}.
+
+ ["Compilers - Principles, Techniques and Tools", by Alfred
+ V. Aho, Ravi Sethi and Jeffrey D. Ullman, pp. 4-5]
+
+ (1995-04-05)
+
+lexical scope
+
+ <programming> (Or "static scope") When the {scope} of an
+ {identifier} is fixed at {compile time} to some region in the
+ {source code} containing the identifier's declaration. This
+ means that an identifier is only accessible within that region
+ (including procedures declared within it).
+
+ This contrasts with {dynamic scope} where the scope depends on
+ the nesting of {procedure} and {function} calls at {run time}.
+
+ Statically scoped languages differ as to whether the scope is
+ limited to the smallest {block} (including {begin}/end blocks)
+ containing the identifier's declaration (e.g. {C}, {Perl}) or
+ to whole function and procedure bodies (e.g. {ECMAScript}), or
+ some larger unit of code (e.g. ?). The former is known as
+ {static nested scope}.
+
+ (2005-07-28)
+
+lexical scoping
+
+ {lexical scope}
+
+lexiphage
+
+ <graphics> /lek'si-fayj"/ A notorious word {chomper},
+ implemented and named by John Doty in late 1972 on and {HP}
+ calculator and later on {ITS}. The lexiphage program would
+ draw on a selected victim's {bitmapped} terminal the words
+ "THE BAG" in ornate letters, followed a pair of jaws biting
+ pieces of it off.
+
+ {http://lexiphage.com/)}.
+
+ [{Jargon File}]
+
+ (2002-06-12)
+
+LF
+
+ {Line Feed}
+
+LFIB
+
+ {Label Forwarding Information Base}
+
+LG
+
+ Simple language for analytic geometry, with graphic output.
+ "LG: A Language for Analytic Geometry", J. Reymond, CACM 12(8)
+ (Aug 1969).
+
+LGDF
+
+ Large-Grain DataFlow.
+
+ ["A Large-grain Data Flow Scheduler for Parallel Processing on
+ Cyberplus", R.G. Babb et al, Proc 1986 Intl Conf on Parallel
+ Proc, Aug 1986].
+
+ (2000-07-07)
+
+LGEN
+
+ A {logic language} for {VLSI} implementation by {S.C. Johnson}
+ of {Bell Labs}.
+
+ [S.C. Johnson, "Code Generation for Silicon", Proc 10th POPL,
+ 1983].
+
+ (1995-02-15)
+
+LGN
+
+ {Linear Graph Notation}
+
+lha
+
+ 1. <filename extension> The {filename extension} for a file
+ produced by the {shareware} {compression} and {archive}
+ software {LHARC}.
+
+ 2. <tool> A {compression} program for {MS-DOS}. Output files
+ have the extension ".lzh".
+
+ [Does it use {LZH} compression?]
+
+ (2002-07-28)
+
+LHARC
+
+ <compression, algorithm> A {compression} program developed by
+ Rahul Dhesi. LHARC was later replaced with {LHA}, which
+ produces files with extension ".lzh".
+
+ (2002-07-28)
+
+lhs
+
+ <filename extension> The {filename extension} for {literate}
+ {Haskell} source files.
+
+ (1995-02-15)
+
+li
+
+ <networking> The {country code} for Liechtenstein.
+
+ (1999-01-27)
+
+Liana
+
+ <language> A {C}-like, interpretive, {object-oriented
+ programming} language, {class} library, and integrated
+ development environment designed specifically for development
+ of {application programs} for {Microsoft Windows} and {Windows
+ NT}. Designed by Jack Krupansky <Jack@BaseTechnology.com> of
+ {Base Technology}, Liana was first released as a commercial
+ product in August 1991. The language is designed to be as
+ easy to use as {BASIC}, as concise as {C}, and as flexible as
+ {Smalltalk}.
+
+ The {OOP} {syntax} of {C++} was chosen over the less familiar
+ syntax of {Smalltalk} and {Objective-C} to appeal to {C}
+ programmers and in recognition of C++ being the leading OOP
+ language. The syntax is a simplified subset of {C/C++}. The
+ {semantics} are also a simplified subset of C/C++, but
+ extended to achieve the flexibility of Smalltalk.
+
+ Liana is a typeless language (like {Lisp}, {Snobol} and
+ {Smalltalk}), which means that the datatypes of variables,
+ function parameters, and function return values are not needed
+ since values carry the type information. Hence, variables are
+ simply containers for values and function parameters are
+ simply pipes through which any type of value can flow.
+ {Single inheritance}, but not {multiple inheritance}, is
+ supported. {Memory management} is automatic using {reference
+ counting}.
+
+ The library includes over 150 {classes}, for {dynamic arrays},
+ {associative lookup} tables, windows, menus, dialogs,
+ controls, bitmaps, cursors, icons, mouse movement, keyboard
+ input, fonts, text and graphics display, {DDE}, and {MDI}.
+
+ Liana provides flexible OOP support for Windows programming.
+ For example, a {list box} automatically fills itself from an
+ associated {object}. That object is not some sort of special
+ object, but is merely any object that "behaves like" an array
+ (i.e., has a "size" member function that returns the number of
+ elements, a "get" function that returns the ith element, and
+ the text for each element is returned by calling the "text"
+ member function for the element).
+
+ A related product, C-odeScript, is an embeddable application
+ scripting language. It is an implementation of Liana which
+ can be called from C/C++ applications to dynamically evaluate
+ expressions and statement sequences. This can be used to
+ offer the end-user a macro/scripting capability or to allow
+ the C/C++ application to be customized without changing the
+ C/C++ source code.
+
+ Here's a complete Liana program which illustrates the
+ flexibility of the language semantics and the power of the
+ class library:
+
+ main
+ {
+ // Prompt user for a string.
+ // No declaration needed for "x" (becomes a global variable.)
+ x = ask ("Enter a String");
+
+ // Use "+" operator to concatenate strings. Memory
+ // management for string temporaries is automatic. The
+ // "message" function displays a Windows message box.
+ message ("You entered: " + x);
+
+ // Now x will take on a different type. The "ask_number"
+ // function will return a "real" if the user's input
+ // contains a decimal point or an "int" if no decimal
+ // point.
+ x = ask_number ("Enter a Number");
+
+ // The "+" operator with a string operand will
+ // automatically convert the other operand to a string.
+
+ message ("You entered: " + x);
+
+ // Prompt user for a Liana expression. Store it in a
+ // local variable (the type, string, is merely for
+ // documentation.)
+ string expr = ask ("Enter an Expression");
+
+ // Evaluate the expression. The return value of "eval"
+ // could be any type. The "source_format" member function
+ // converts any value to its source format (e.g., add
+ // quotes for a string.) The "class_name" member function
+ // return the name of the class of an object/value.
+ // Empty parens can be left off for member function calls.
+ x = eval (expr);
+ message ("The value of " + expr + " is " + x.source_format +
+ " its type is " + x.class_name);
+ }
+
+ The author explained that the "Li" of Liana stands for
+ "Language interpreter" and liana are vines that grow up trees
+ in tropical forests, which seemed quite appropriate for a tool
+ to deal with the complexity of MS Windows! It is also a
+ woman's name.
+
+ ["Liana for Windows", Aitken, P., PC TECHNIQUES, Dec/Jan
+ 1993].
+
+ ["Liana: A Language For Writing Windows Programs", Burk, R.,
+ Tech Specialist (R&D Publications), Sep 1991].
+
+ ["Liana v. 1.0." Hildebrand, J.D., Computer Language, Dec
+ 1992].
+
+ ["Liana: A Windows Programming Language Based on C and C++",
+ Krupansky, J., The C Users Journal, Jul 1992].
+
+ ["Writing a Multimedia App in Liana", Krupansky, J.,
+ Dr. Dobb's Journal, Winter Multimedia Sourcebook 1994].
+
+ ["The Liana Programming Language", R. Valdes, Dr Dobbs J Oct
+ 1993, pp.50-52].
+
+ (1999-06-29)
+
+Liar
+
+ {MIT Scheme}
+
+liar paradox
+
+ <philosophy> A sentence which asserts its own falsity,
+ e.g. "This sentence is false" or "I am lying". These
+ paradoxical assertions are meaningless in the sense that there
+ is nothing in the world which could serve to either support or
+ refute them. Philosophers, of course, have a great deal more
+ to say on the subject.
+
+ ["The Liar: an Essay on Truth and Circularity", Jon Barwise
+ and John Etchemendy, Oxford University Press (1987). ISBN
+ 0-19-505944-1 (PBK), Library of Congress BC199.P2B37].
+
+ (1995-02-22)
+
+lib
+
+ <operating system> Library. In {Unix}, the directories /lib
+ and /usr/lib traditionally contain files with {filename
+ extension} ".lib" that are special {archives} containing
+ modules of standard {object code}. In modern Unixes the same
+ directories contain ".so" (shared object) files, which are
+ similar except that the object code they contain is designed
+ to be loaded once and shared by all application code that
+ needs it, thus saving memory.
+
+ (2008-11-25)
+
+libg++
+
+ <library> The {run-time library} for the {GNU} {C++} compiler,
+ {g++}. Version: 2.5.1 is a superset of {ANSI} and {POSIX.1}.
+
+ libg++ is no longer maintained, use libstd++ instead if
+ possible.
+
+ Available by {FTP} from a {GNU archive site}.
+
+ Bug reports: <bug-lib-g++@gnu.org>.
+
+ (2000-04-24)
+
+library
+
+ <programming, library> A collection of {subroutines} and
+ {functions} stored in one or more files, usually in compiled
+ form, for linking with other programs. Libraries are one of
+ the earliest forms of organised {code reuse}. They are often
+ supplied by the {operating system} or {software development
+ environment} developer to be used in many different programs.
+ The routines in a library may be general purpose or designed
+ for some specific function such as three dimensional animated
+ graphics.
+
+ Libraries are linked with the user's program to form a
+ complete {executable}. The linking may be {static linking}
+ or, in some systems, {dynamic linking}.
+
+ (1998-11-21)
+
+Library of Efficient Data types and Algorithms
+
+ <library> (LEDA) A {class library} for {C++} of efficient data
+ types (e.g. {graph} {classes}) and {algorithms} by Stefan
+ N"aher <stefan@mpi-sb.mpg.de> of the {University of
+ Saarbruecken}. Version 3.0 includes both {template} and
+ non-template versions.
+
+ {(ftp://ftp.mpi-sb.mpg.de/pub/LEDA)}.
+
+ (1996-04-15)
+
+librery
+
+ <spelling> It's spelled "{library}".
+
+ (1996-12-13)
+
+LIDO
+
+ An input language for the attribute evaluator generator {LIGA}
+ (a successor of {GAG} and a subsystem of the {Eli}
+ compiler-compiler). LIDO is derived from GAG's input language
+ {ALADIN}.
+
+ ["LIDO: A Specification Language for Attribute Grammars",
+ U. Kastens <uwe@uni-paderborn.de>, Fab Math-Inf, U Paderborn
+ (Oct 1989)].
+
+ (1994-10-20)
+
+LiE
+
+ A {symbolic mathematics} package aimed at {Lie groups}.
+
+ ["LiE, a Package for Lie Group Computations", M.A.A. van
+ Leeuwen et al, in Computer Algebra Nederland, 1992 (ISBN
+ 90-741160-02-7)].
+
+ (1994-10-20)
+
+LIF
+
+ 1. <hardware> {Low Insertion Force}.
+
+ 2. <file format> {Logical Interchange Format}.
+
+ (2003-10-15)
+
+LIFE
+
+ <language> Logic of Inheritance, Functions and Equations.
+
+ An {object-oriented}, {functional}, {constraint}-based
+ language by Hassan Ait-Kacy <hak@prl.dec.com> et al of {MCC},
+ Austin TX, 1987. LIFE integrates ideas from {LOGIN} and
+ {LeFun}.
+
+ Mailing list: life-users@prl.dec.com.
+
+ See also {Wild_LIFE}.
+
+ ["Is There a Meaning to LIFE?", H. Ait-Kacy et al, Intl Conf
+ on Logic Prog, 1991].
+
+ [{Jargon File}]
+
+ (1995-04-21)
+
+Life
+
+ <games> The first popular {cellular automata} based
+ {artificial life} "game". Life was invented by British
+ mathematician {John Horton Conway} in 1970 and was first
+ introduced publicly in "Scientific American" later that year.
+
+ Conway first devised what he called "The Game of Life" and
+ "ran" it using plates placed on floor tiles in his house.
+ Because of he ran out of floor space and kept stepping on the
+ plates, he later moved to doing it on paper or on a
+ checkerboard, and then moved to running Life as a computer
+ program on a {PDP-7}. That first implementation of Life as a
+ computer program was written by M. J. T. Guy and
+ {S. R. Bourne} (the author of {Unix}'s {Bourne shell}).
+
+ Life uses a rectangular grid of binary (live or dead) cells
+ each of which is updated at each step according to the
+ previous state of its eight neighbours as follows: a live cell
+ with less than two, or more than three, live neighbours dies.
+ A dead cell with exactly three neighbours becomes alive.
+ Other cells do not change.
+
+ While the rules are fairly simple, the patterns that can arise
+ are of a complexity resembling that of organic systems -- hence
+ the name "Life".
+
+ Many hackers pass through a stage of fascination with Life,
+ and hackers at various places contributed heavily to the
+ mathematical analysis of this game (most notably {Bill Gosper}
+ at {MIT}, who even implemented Life in {TECO}!; see
+ {Gosperism}). When a hacker mentions "life", he is more
+ likely to mean this game than the magazine, the breakfast
+ cereal, the 1950s-era board game or the human state of
+ existence.
+
+ {Yahoo!
+ (http://yahoo.com/Science/Artificial_Life/Conway_s_Game_of_Life/)}.
+
+ {Demonstration
+ (http://research.digital.com/nsl/projects/life/)}.
+
+ ["Scientific American" 223, October 1970, p120-123, 224;
+ February 1971 p121-117, Martin Gardner].
+
+ ["The Garden in The Machine: the Emerging Science of
+ Artificial Life", Claus Emmeche, 1994].
+
+ ["Winning Ways, For Your Mathematical Plays", Elwyn
+ R. Berlekamp, John Horton Conway and Richard K. Guy, 1982].
+
+ ["The Recursive Universe: Cosmic Complexity and the Limits of
+ Scientific Knowledge", William Poundstone, 1985].
+
+ [{Jargon File}]
+
+ (1997-09-07)
+
+life
+
+ <jargon> The opposite of {Usenet}. As in "{Get a life!}"
+
+ [{Jargon File}]
+
+ (1995-04-21)
+
+life-cycle
+
+ {software life-cycle}
+
+Life is hard
+
+ [XEROX PARC] This phrase has two possible interpretations: (1)
+ "While your suggestion may have some merit, I will behave as
+ though I hadn't heard it." (2) "While your suggestion has
+ obvious merit, equally obvious circumstances prevent it from
+ being seriously considered." The charm of the phrase lies
+ precisely in this subtle but important ambiguity.
+
+ [{Jargon File}]
+
+LIFIA
+
+ Laboratoire d'Informatique Fondamentale et d'Intelligence
+ Artificielle.
+
+LIFO
+
+ {stack}
+
+lifted domain
+
+ <theory> In {domain theory}, a {domain} with a new {bottom}
+ element added. Given a domain D, the lifted domain, lift D
+ contains an element lift d corresponding to each element d in
+ D with the same ordering as in D and a new element bottom
+ which is less than every other element in lift D.
+
+ In {functional languages}, a lifted domain can be used to
+ model a {constructed type}, e.g. the type
+
+ data LiftedInt = K Int
+
+ contains the values K minint .. K maxint and K bottom,
+ corresponding to the values in Int, and a new value bottom.
+ This denotes the fact that when computing a value v = (K n)
+ the computation of either n or v may fail to terminate
+ yielding the values (K bottom) or bottom respectively.
+
+ (In LaTeX, a lifted domain or element is indicated by a
+ subscript {\perp}).
+
+ See also {tuple}.
+
+LIGHT
+
+ LIfecycle Global HyperText.
+
+ A project in the CERN ECP/TP group whereby documents resulting
+ from the {software life cycle} are available as {hypertext}.
+
+ (1995-02-03)
+
+light client
+
+ {thin client}
+
+light-emitting diode
+
+ <electronics> (LED) a type of {diode} that emits light when
+ current passes through it. Depending on the material used the
+ colour can be visible or infrared. LEDs have many uses,
+ visible LEDs are used as indicator lights on all sorts of
+ electronic devices and in moving-message panels, while
+ infrared LEDs are the heart of remote control devices.
+
+ See also {smoke-emitting diode}.
+
+ (1996-01-05)
+
+light-emitting resistor
+
+ <electronics, humour> (LER, from "{light-emitting diode}") A
+ {resistor} in the final stages of burning up.
+
+ (Though intended as purely humorous, the term could sensibly
+ describe the filament of a common incandescent electric light
+ bulb).
+
+ See also {SED}.
+
+ (1996-02-06)
+
+light pen
+
+ <hardware> An early {pointing device} which the user pointed
+ at a {raster}-scanned display screen. A {photocell} in the
+ pen detected the flying spot of the raster scan. The position
+ of the spot at that instant, obtained from the scanning
+ electronics, was made available to software as (x, y)
+ co-ordinates.
+
+ (2003-12-02)
+
+light pipe
+
+ {optical fibre}
+
+light-weight
+
+ <jargon> Opposite of {heavy-weight}; usually found in
+ combining forms such as "{light-weight process}".
+
+ [{Jargon File}]
+
+ (1996-02-22)
+
+Lightweight Directory Access Protocol
+
+ <protocol> (LDAP) A {protocol} for accessing on-line
+ {directory services}.
+
+ LDAP was defined by the {IETF} in order to encourage adoption
+ of {X.500} directories. The {Directory Access Protocol} (DAP)
+ was seen as too complex for simple {internet clients} to use.
+ LDAP defines a relatively simple protocol for updating and
+ searching directories running over {TCP/IP}.
+
+ LDAP is gaining support from vendors such as {Netscape},
+ {Novell}, {Sun}, {HP}, {IBM}/Lotus, {SGI}, {AT&T}, and
+ {Banyan}
+
+ An LDAP directory entry is a collection of attributes with a
+ name, called a distinguished name (DN). The DN refers to the
+ entry unambiguously. Each of the entry's attributes has a
+ {type} and one or more values. The types are typically
+ mnemonic strings, like "cn" for common name, or "mail" for
+ {e-mail address}. The values depend on the type. For
+ example, a mail attribute might contain the value
+ "donald.duck@disney.com". A jpegPhoto attribute would contain
+ a photograph in binary {JPEG}/{JFIF} format.
+
+ LDAP directory entries are arranged in a {hierarchical}
+ structure that reflects political, geographic, and/or
+ organisational boundaries. Entries representing countries
+ appear at the top of the tree. Below them are entries
+ representing states or national organisations. Below them
+ might be entries representing people, organisational units,
+ printers, documents, or just about anything else.
+
+ {RFC 1777}, {RFC 1778}, {RFC 1959}, {RFC 1960}, {RFC 1823}.
+
+ {LDAP v3
+ (http://kingsmountain.com/LDAPRoadmap/CurrentState.html)}.
+
+ [Difference v1, v2, v3?]
+
+ (2003-09-27)
+
+light-weight process
+
+ <operating system, parallel> (LWP) A single-threaded
+ sub-process which, unlike a {thread}, has its own {process
+ identifier} and may also differ in its inheritance and
+ controlling features.
+
+ Several {operating systems}, e.g. {SunOS} 5.x, provide {system
+ calls} for creating and controlling LWPs.
+
+ (1996-02-22)
+
+like kicking dead whales down the beach
+
+ {kicking dead whales down the beach}
+
+like nailing jelly to a tree
+
+ <jargon, humour> Used to describe a task thought to be
+ impossible, especially one in which the difficulty arises from
+ poor specification or inherent slipperiness in the problem
+ domain. "Trying to display the "prettiest" arrangement of
+ nodes and arcs that diagrams a given graph is like nailing
+ jelly to a tree, because nobody's sure what "prettiest" means
+ algorithmically."
+
+ [{Jargon File}]
+
+ (1997-12-23)
+
+like this
+
+ You weren't supposed to follow that link, it was just an
+ example of what a link looks like.
+
+Lila
+
+ Patrick Salle'<salle@geocub.greco-prog.fr>. A small
+ assembly-like language used for implementation of Actor
+ languages. [Plasma perhaps?].
+
+Lilith
+
+ <computer> The {workstation} for which {Modula-2} was
+ developed as the system language.
+
+ [Details?]
+
+ (1995-10-25)
+
+LILLIAC IV
+
+ <computer> A {supercomputer} designed in the late 1960s at the
+ {University of Illinois} which had 64 separate {CPUs} all
+ supervised by a common control unit and all capable of
+ operating simultaneously.
+
+ (1996-11-25)
+
+lilo
+
+ 1. <operating system> {Linux Loader}.
+
+ 2. {first-in first-out}.
+
+ (2001-03-26)
+
+Lily
+
+ (LIsp LibrarY) A {C++} {class} library by Roger Sheldon
+ <sheldon@kong.gsfc.nasa.gov> which gives C++ programmers the
+ capability to write {Lisp}-style code. Lily's {garbage
+ collection} mechanism is not sufficient for commercial use
+ however and the documentation is incomplete. It is
+ distributed under the {GNU} Library {General Public License}.
+
+ Version: 0.1.
+
+ {(ftp://sunsite.unc.edu/uploads/lily-0.1.tar.gz)}.
+
+ (1993-11-08)
+
+LIMDEP
+
+ A {linear programming} language used by economists.
+
+LIM EMS
+
+ {Expanded Memory Specification}
+
+LIMP
+
+ ["Messages in Typed Languages", J. Hunt et al, SIGPLAN Notices
+ 14(1):27-45 (Jan 1979)].
+
+Linc
+
+ 1. <language> A {Burroughs}/{Unisys} {4GL} designed in New
+ Zealand.
+
+ 2. {Laboratory Instrument Computer}.
+
+ (1999-03-29)
+
+Lincoln Reckoner
+
+ An interactive mathematics program including matrix
+ operations, written about 1965. It ran on the {TX-2}.
+
+ ["The Lincoln Reckonere: An Operation-Oriented On-line
+ Facility with Distributed Control", A.N. Stowe et al, Proc
+ FJCC 29 (1966)].
+
+ [Sammet 1969, pp. 245-247].
+
+LINCtape
+
+ <storage> A formatted, block-oriented, high-reliability,
+ {random access} tape system used on the {Laboratory Instrument
+ Computer}. The tape was 3/4" wide.
+
+ The funny {DECtape} is actually a variant of the original
+ LINCtape. According to {Wesley Clark}, DEC tried to "improve"
+ the LINCtape system, which mechanically, was wonderfully
+ simple and elegant. The DEC version had pressure fingers and
+ tape guides to force alignment as well as huge {DC} servo
+ motors and complex control circuitry. These literally
+ shredded the tape to bits if not carefully adjusted, and
+ required frequent cleaning to remove all the shedded tape
+ oxide. That was amazing, because the tape had a micro-thin
+ plastic layer OVER the oxide to protect it. What happened was
+ that all the forced alignment stuff caused shredding at the
+ edge.
+
+ An independent company, Computer Operations[?], built LINCtape
+ drives for use in nuclear submarines. This was based on the
+ tape system's high reliability. Correspondent Brian Converse
+ has a picture of himself holding a LINCtape punched full of
+ 1/4" holes. It still worked!
+
+ (1999-03-29)
+
+Linda
+
+ <language> A "coordination language" from {Yale}, providing a
+ model for {concurrency} with communication via a shared
+ {tuple} space. Linda is usually implemented as a subroutine
+ library for a specific base language, as in {C-Linda},
+ {Fortran-Linda}, {LindaLISP} and {Prolog-Linda}. It is
+ available from {Scientific Computing Associates, Inc.} [What
+ is?]
+
+ {(http://cs.yale.edu/HTML/YALE/CS/Linda/linda.html)}.
+
+ There is a {Multi-BinProlog} Linda implementation available by
+ {(ftp://clement.info.umoncton.ca/)}.
+
+ ["Generative Communication in Linda", D. Gelernter
+ <gelernter@cs.yale.edu>, ACM TOPLAS 7(1):80-112 (1985)].
+
+ ["Linda in Context", N. Carreiro et al, Yale U., CACM
+ 32(4):444-458, Apr 1989].
+
+ See also {Ease}, {Lucinda}, {Melinda}.
+
+ (2000-07-07)
+
+LindaLISP
+
+ {Linda} for {Lisp}.
+
+line
+
+ 1. <hardware> An electrical conductor. For distances larger
+ than a breadbox, a single line may consist of two electrical
+ conductors in twisted, parallel, or concentric arrangement
+ used to transport one logical signal.
+
+ By extension, a (usually physical) medium such as an {optical
+ fibre} which carries a signal.
+
+ (1995-09-29)
+
+line 666
+
+ <jargon> (Christian eschatological myth) The notional line of
+ source at which a program fails for obscure reasons, implying
+ either that *somebody* is out to get it (when you are the
+ programmer), or that it richly deserves to be got (when you
+ are not).
+
+ E.g. "It works when I trace through it, but seems to crash on
+ line 666 when I run it." "What happens is that whenever a
+ large batch comes through, mmdf dies on the Line of the Beast.
+ Probably some twit {hard-coded} a buffer size."
+
+ [{Jargon File}]
+
+ (1999-03-01)
+
+linear address space
+
+ A memory addressing scheme used in processors where the whole
+ memory can be accessed using a single address that fits in a
+ single register or instruction. This contrasts with a
+ {segmented memory} architecture, such as that used on the
+ {Intel 8086}, where an address is given by an offset from a
+ base address held in one of the "segment registers". Linear
+ addressing greatly simplifies programming at the {assembly
+ language} level but requires more instruction word bits to be
+ allocated for an address.
+
+ (1995-02-16)
+
+linear argument
+
+ <theory> A function argument which is used exactly once by the
+ function.
+
+ If the argument is used at most once then it is safe to
+ {inline} the function and replace the single occurrence of the
+ formal parameter with the actual argument expression. If the
+ argument was used more than once this transformation would
+ duplicate the argument expression, causing it to be evaluated
+ more than once.
+
+ If the argument is sure to be used at least once then it is
+ safe to evaluate it in advance (see {strictness analysis})
+ whereas if the argument was not used then this would waste
+ work and might prevent the program from terminating.
+
+ (1994-11-03)
+
+linear assignment
+
+ {assignment problem}
+
+linear function
+
+ A {recursive} function is linear if it is of the form
+
+ f x = if p x then q x else h f x
+
+ where h is a "linear functional" which means that
+
+ (1) for all functions, a, b c and some function ht
+
+ h (if a then b else c) = if ht a then h b else h c
+
+ Function ht is known as the "predicate transformer" of h.
+
+ (2) If for some x,
+
+ h (\ y . bottom) x /= bottom
+
+ then
+
+ for all g, ht g x = True.
+
+ I.e. if h g x terminates despite g x not terminating then ht g
+ x doesn't depend on g.
+
+ See also {linear argument}.
+
+ (1995-02-15)
+
+Linear Graph Notation
+
+ (LGN) A linearised representation of {TCOL} trees.
+
+ [B.W. Leverett et al, "An Overview of the Production Quality
+ Compiler-Compiler Projects", TR CMU-CS-79-105, Carnegie Mellon
+ 1979].
+
+ (1995-01-23)
+
+linear logic
+
+ <theory> A {logic} invented by Girard in 1987 that can be used
+ in proofs related to resource usage.
+
+ {(http://brics.dk/LS/96/6/BRICS-LS-96-6/BRICS-LS-96-6.html)}.
+
+ [Wadler, P., "Is there a use for linear logic", ACM/IFIP PEPM
+ Conference, 1991].
+
+ [Summary?]
+
+ (2003-05-02)
+
+linear map
+
+ <mathematics> (Or "linear transformation") A {function} from a
+ {vector space} to a vector space which respects the {additive}
+ and {multiplicative} structures of the two: that is, for any
+ two {vectors}, u, v, in the source vector space and any
+ scalar, k, in the {field} over which it is a vector space, a
+ linear map f satisfies f(u+kv) = f(u) + kf(v).
+
+ (1996-09-30)
+
+linear programming
+
+ <application> A procedure for finding the maximum or minimum
+ of a {linear function} where the arguments are subject to
+ linear {constraints}. The {simplex method} is one well known
+ {algorithm}.
+
+ (1995-04-06)
+
+linear space
+
+ <mathematics> A {vector space} where all {linear combinations}
+ of elements are also elements of the space. This is easy for
+ spaces of numbers but not for a space of functions. Roughly,
+ this is to say that multiplication by numbers, and addition of
+ elements is defined in the space.
+
+ (2000-03-10)
+
+linear topology
+
+ <theory> A linear topology on a {left A-module} M is a {topology}
+ on M that is invariant under translations and admits a
+ {fundamental system of neighborhood} of 0 that consists of
+ {submodules} of M. If there is such a topology, M is said to be
+ linearly topologized. If A is given a {discrete topology}, then M
+ becomes a topological A-module with respect to a linear topology.
+
+ [Wikipedia]
+
+ (2014-06-30)
+
+linear transformation
+
+ {linear map}
+
+linear type
+
+ 1. <theory, programming> An attribute of values which are used
+ exactly once: they are neither duplicated nor destroyed. Such
+ values require no {garbage collection}, and can safely be
+ updated in place, even if they form part of a data structure.
+
+ Linear types are related to the {linear logic} of J.-Y Girard.
+ They extend Schmidt's notion of {single threading}, provide an
+ alternative to Hudak and Bloss' {update analysis}, and offer a
+ practical complement to Lafont and Holmström's elegant {linear
+ languages}.
+
+ ['Use-Once' Variables and Linear Objects - Storage Management,
+ Reflection and Multi-Threading, Henry Baker.
+ {(http://home.pipeline.com/~hbaker1/Use1Var.html)}].
+
+ ["Linear types can change the world!", Philip Wadler,
+ "Programming Concepts and Methods", April 1990, eds. M. Broy,
+ C. Jones, pub. North-Holland, IFIP TC2 Working Conference on
+ Programming Concepts and Methods, Sea of Galilee, Israel].
+
+ (1995-03-03)
+
+line conditioning
+
+ <communications> The adjustment of electrical characteristics
+ of, e.g., {twisted pair} telephone lines by insertion of
+ components such as resistors, capacitors, transformers or
+ (commonly) inductors. Lines intended for analogue voice
+ signals usually have inductors inserted every few miles; such
+ a line is said to be "loaded".
+
+ The special purpose lines which have neither inductors nor the
+ DC voltage which powers ordinary telephones are said to be
+ "dry," and are much better for data transmission.
+
+ (1996-04-07)
+
+line eater
+
+ <messaging> 1. A {bug} in some now-obsolete versions of the
+ {Usenet} software that used to eat up to {BUFSIZ} bytes of the
+ article text. The bug was triggered by having the text of the
+ article start with a space or tab. This bug was quickly
+ personified as a mythical creature called the "line eater",
+ and postings often included a dummy line of "line eater food".
+ Ironically, line eater "food" not beginning with a space or
+ tab wasn't actually eaten, since the bug was avoided; but if
+ there *was* a space or tab before it, then the line eater
+ would eat the food *and* the beginning of the text it was
+ supposed to be protecting. The practice of "sacrificing to
+ the line eater" continued for some time after the bug had been
+ {nailed to the wall}, and is still humorously referred to.
+ The bug itself is still (in mid-1991) occasionally reported to
+ be lurking in some mail-to-netnews {gateways}.
+
+ 2. {NSA line eater}.
+
+ (1996-04-09)
+
+line editor
+
+ <tool, text> An early kind of {text editor} suited to use on a
+ {teletype}. The user enters editing commands which apply to
+ the current line or some given range of lines. These include
+ moving forward and backward through the buffer, inserting and
+ deleting lines, substituting a string for a pattern match, and
+ printing lines. Visual feedback is restricted to explicitly
+ requesting the display of one or more lines, in contrast to a
+ {screen editor}.
+
+ {ed} is {Unix}'s line editor.
+
+ (1999-03-01)
+
+line feed
+
+ <character> (LF, control-J, {ASCII} 10) The {ASCII} character
+ meaning move the {cursor} down to the same column on the next
+ line. Originally this would have been done by "feeding" paper
+ through the printer.
+
+ {Unix} uses line feed as its text line terminator ({newline}
+ character).
+
+ (1997-07-14)
+
+line noise
+
+ <communications> 1. Spurious characters due to electrical
+ {noise} in a communications link, especially an {EIA-232}
+ serial connection. Line noise may be induced by poor
+ connections, interference or {crosstalk} from other circuits,
+ electrical storms, {cosmic rays}, or (notionally) birds
+ crapping on the phone wires.
+
+ 2. Any chunk of data in a file or elsewhere that looks like
+ the results of electrical line noise.
+
+ 3. Text that is theoretically a readable text or program
+ source but employs {syntax} so bizarre that it looks like line
+ noise. Yes, there are languages this ugly. The canonical
+ example is {TECO}, whose input syntax is often said to be
+ indistinguishable from line noise. Other non-{WYSIWYG}
+ editors, such as {Multics} "{qed}" and {Unix} "{ed}", in the
+ hands of a real hacker, also qualify easily, as do
+ deliberately {obfuscate}d languages such as {INTERCAL}.
+
+ [{Jargon File}]
+
+ (1994-12-22)
+
+line printer
+
+ <printer> A {printer} that prints one entire line at a time.
+ Print quality is low compared with a {laser printer}. Line
+ printers typically use {sprocket feed} and wide fanfold paper.
+
+ Line printer speed is usually measured in lines per minute
+ (lpm). 1200 lpm is a good rate for a line printer like a 3205
+ m5. 66 lines per page is typical, giving 18 pages per minute
+ (ppm). This assumes all upper case, if a mixed case print
+ train is used, throughput is halved. By comparison, a fast
+ {laser printer} can output 100+ ppm
+
+ (1999-01-13)
+
+line probing
+
+ A feature of some {V.34} {modems} that will allow them to
+ identify the capacity and quality of the phone line and adjust
+ themselves to allow, for each individual connection, for
+ maximum throughput using the highest possible data
+ transmission rate.
+
+ (1994-06-09)
+
+lines of code
+
+ <programming, unit> (LOC) A common measure of the size or
+ progress of a programming project. For example, one can
+ describe a completed project as consisting of 100,000 LOC; or
+ one can characterise a week's progress as 5000 LOC.
+
+ Using LOC as a metric of progress encourages programmers to
+ {reinvent the wheel} or split their code into lots of short
+ lines.
+
+ (2001-05-28)
+
+lines per minute
+
+ <unit> (lpm) A unit used to measure {line printer} throughput.
+
+ (1999-01-13)
+
+line starve
+
+ (MIT, opposite of {line feed}) 1. To feed paper through a
+ printer the wrong way by one line (most printers can't do
+ this). On a display terminal, to move the cursor up to the
+ previous line of the screen. "To print "X squared", you just
+ output "X", line starve, "2", line feed." (The line starve
+ causes the "2" to appear on the line above the "X", and the
+ line feed gets back to the original line.)
+
+ 2. A character (or character sequence) that causes a terminal
+ to perform this action. ASCII 26, also called SUB or
+ control-Z, was one common line-starve character in the days
+ before {microcomputers} and the {X3.64} terminal standard.
+ Unlike "line feed", "line starve" is *not* standard {ASCII}
+ terminology. Even among hackers it is considered silly.
+
+ 3. (Proposed) A sequence such as \c (used in {System V}
+ {echo}, as well as {nroff} and {troff}) that suppresses a
+ {newline} or other character(s) that would normally be
+ emitted.
+
+ [{Jargon File}]
+
+ (1995-02-03)
+
+Lingo
+
+ An animation scripting language.
+
+ [MacroMind Director V3.0 Interactivity Manual, MacroMind
+ 1991].
+
+LINGOL
+
+ LINguistics Oriented Language. Natural language processing.
+
+ ["A Linguistics Oriented Programming Language", V.R. Pratt,
+ Third Intl Joint Conf on AI, 1973].
+
+link
+
+ 1. <file system> {hard link} or {symbolic link}.
+
+ 2. <hypertext> {hypertext link}.
+
+ (1997-10-22)
+
+Link Access Procedure on the D channel
+
+ (LAPD) (Q.921). An {Integrated Services Digital Network}
+ {data link layer} protocol.
+
+Link Access Protocol Balanced
+
+ <protocol> (LAPB) {X.25} layer 2 ({data link layer})
+ {protocol}.
+
+ [Details?]
+
+ (1996-01-22)
+
+Link Access Protocol for Modems
+
+ (LAPM) The {Automatic Repeat Request} system used in the
+ {V.42} {protocol}.
+
+linkage editor
+
+ {linker}
+
+Link Control Protocol
+
+ <protocol> A {protocol} used to automatically agree upon
+ {encapsulation} format options, handle varying packet size
+ limits, authenticate the identity of its {peer} on the link,
+ determine when a link is functioning properly and when it is
+ defunct, detect a looped-back link and other common
+ misconfiguration errors, and terminate the link.
+
+ [RFC 1570].
+
+ (1997-05-10)
+
+link-dead
+
+ Said of a {MUD} character who has frozen in place because of a
+ dropped network connection.
+
+ [{Jargon File}]
+
+ (1995-01-24)
+
+link editor
+
+ {linker}
+
+linked list
+
+ <programming> A data structure in which each element contains
+ a pointer to the next element, thus forming a linear list.
+
+ A doubly linked list contains pointers to both the next and
+ previous elements.
+
+ (1995-03-28)
+
+linker
+
+ <programming, tool> (link editor, linkage editor, link loader)
+ A program that combines one or more files containing {object
+ code} from separately compiled program {modules} into a single
+ file containing loadable or executable code
+
+ This process involves resolving references between the
+ {modules} and fixing the {relocation} information used by the
+ operating system {kernel} when loading the file into memory to
+ run it.
+
+ Under {Unix}, the linker is called "ld" and {object files}
+ have filename extension .o (object), .so (shared object), or
+ .lib ({library}), and the resulting {executable} is called
+ "a.out" by default.
+
+ (2001-10-13)
+
+link farm
+
+ <file system, Unix> A directory tree that contains mostly
+ {symbolic links} to files in a master directory tree of files.
+ Link farms save space when one is maintaining several nearly
+ identical copies of the same source tree - for example, when
+ the only difference is architecture-dependent object files.
+ They also mean that changes to the master tree are instantly
+ visible in the link farm. Good {text editors} provide the
+ option to replace a link with a new version of the target file
+ when saving thus allowing the farm to have its own versions of
+ just those files that differ from the master tree.
+
+ E.g. "Let's freeze the source and then rebuild the FROBOZZ-3
+ and FROBOZZ-4 link farms."
+
+ Link farms may also be used to get around restrictions on the
+ number of "-I" (include-file directory) arguments on older C
+ preprocessors. However, they can also get completely out of
+ hand, becoming the file system equivalent of {spaghetti code}.
+
+ [{Jargon File}]
+
+ (2001-02-08)
+
+link loader
+
+ {linker}
+
+link rot
+
+ <web> The process by which links on a {web page}
+ became unusable as the pages they point to change location or
+ are removed.
+
+ (1997-03-29)
+
+links
+
+ {link}
+
+Link State Routing Protocol
+
+ <networking, communications> A {routing} {protocol} such as
+ {OSPF} which permits routers to exchange information with one
+ another about the reachability of other networks and the cost
+ or metric to reach the other networks.
+
+ The cost/metric is based on number of {hops}, link speeds,
+ traffic congestion, and other factors as determined by the
+ network designer. Link state routers use {Dijkstra's
+ algorithm} to calculate shortest (lowest cost) paths, and
+ normally update other routers with whom they are connected
+ only when their own routing tables change.
+
+ Link state routing is an improvement over {distance-vector
+ routing} protocols such as {RIP} which normally use only a
+ single metric (such as hop count) and which exchange all of
+ their table information with all other routers on a regular
+ schedule. Link state routing normally requires more
+ processing but less transmission overhead.
+
+ (2000-03-14)
+
+LINPACK
+
+ 1. A package of {linear algebra} routines.
+
+ 2. The kernel {benchmark} developed from the "LINPACK" package
+ of linear algebra routines. It was written by Jack Dongarra
+ <dongarra@cs.utk.edu> in {Fortran} and is commonly used in
+ that language but there is also a {C} version.
+
+ Source Code by FTP: {single precision Fortran
+ (ftp://netlib.att.com/netlib/benchmark/linpacks.Z)},
+ {double precision Fortran
+ (ftp://netlib.att.com/netlib/benchmark/linpackd.Z)},
+ {C (ftp://netlib.att.com:/netlib/benchmark/linpackc.Z)}.
+
+ {Results
+ (http://performance.netlib.org/performance/html/linpack.data.col0.html)}.
+
+ (1994-11-14)
+
+lint
+
+ A {Unix} {C} language processor which carries out more
+ thorough checks on the code than is usual with C {compilers}.
+
+ Lint is named after the bits of fluff it supposedly picks from
+ programs. Judging by references on {Usenet} this term has
+ become a shorthand for {desk check} at some non-Unix shops,
+ even in languages other than {C}. Also used as {delint}.
+
+ [{Jargon File}]
+
+ (1994-11-14)
+
+Linux
+
+ <operating system> ("Linus Unix") /li'nuks/ (but see below)
+ An implementation of the {Unix} {kernel} originally written
+ from scratch with no proprietary code.
+
+ The kernel runs on {Intel} and {Alpha} hardware in the general
+ release, with {SPARC}, {PowerPC}, {MIPS}, {ARM}, {Amiga},
+ {Atari}, and {SGI} in active development. The SPARC, PowerPC,
+ ARM, {PowerMAC} - {OSF}, and 68k ports all support {shells},
+ {X} and {networking}. The Intel and SPARC versions have
+ reliable {symmetric multiprocessing}.
+
+ Work on the kernel is coordinated by Linus Torvalds, who holds
+ the copyright on a large part of it. The rest of the
+ copyright is held by a large number of other contributors (or
+ their employers). Regardless of the copyright ownerships, the
+ kernel as a whole is available under the {GNU} {General Public
+ License}. The GNU project supports Linux as its kernel until
+ the research {Hurd} kernel is completed.
+
+ This kernel would be no use without {application programs}.
+ The GNU project has provided large numbers of quality tools,
+ and together with other {public domain} software it is a rich
+ Unix environment. A compilation of the Linux kernel and these
+ tools is known as a Linux distribution. Compatibility modules
+ and/or {emulators} exist for dozens of other computing
+ environments.
+
+ The kernel version numbers are significant: the odd numbered
+ series (e.g. 1.3.xx) is the development (or beta) kernel which
+ evolves very quickly. Stable (or release) kernels have even
+ major version numbers (e.g. 1.2.xx).
+
+ There is a lot of commercial support for and use of Linux,
+ both by hardware companies such as {Digital}, {IBM}, and
+ {Apple} and numerous smaller network and integration
+ specialists. There are many commercially supported
+ distributions which are generally entirely under the GPL. At
+ least one distribution vendor guarantees {Posix} compliance.
+ Linux is particularly popular for {Internet Service
+ Providers}, and there are ports to both parallel
+ supercomputers and {embedded} {microcontrollers}. {Debian} is
+ one popular {open source} distribution.
+
+ The pronunciation of "Linux" has been a matter of much debate.
+ Many, including Torvalds, insist on the short I pronunciation
+ /li'nuks/ because "Linus" has an /ee/ sound in Swedish
+ (Linus's family is part of Finland's 6% ethnic-Swedish
+ minority) and Linus considers English short /i/ to be closer
+ to /ee/ than English long /i:/ dipthong. This is consistent
+ with the short I in words like "linen". This doesn't stop
+ others demanding a long I /li:'nuks/ following the english
+ pronunciation of "Linus" and "minus". Others say /li'niks/
+ following {Minix}, which Torvalds was working on before Linux.
+
+ {More on pronunciation (/pub/misc/linux-pronunciation)}.
+
+ {LinuxHQ (http://linuxhq.com/)}. {slashdot
+ (http://slashdot.org/)}. {freshmeat (http://freshmeat.net/)}.
+ {Woven Goods (http://fokus.gmd.de/linux/)}. {Linux
+ Gazette (http://ssc.com/lg)}.
+
+ {funet Linux Archive (ftp://ftp.funet.fi/pub/Linux)}, {US
+ mirror (ftp://sunsite.unc.edu/pub/Linux/)}, {UK Mirror
+ (ftp://sunsite.doc.ic.ac.uk/packages/Linux/)}.
+
+ (2000-06-09)
+
+Linux Documentation Project
+
+ <project> (LDP) A team of volunteers developing documentation
+ for the {Linux} {operating system}. The LDP aims to handle
+ all of the issues of Linux documentation, ranging from on-line
+ documentation to printed manuals, covering topics such as
+ installing, using, and running Linux. The LDP has no central
+ organisation; anyone can join in.
+
+ {(http://metalab.unc.edu/LDP/)}.
+
+ (1999-06-10)
+
+Linux Loader
+
+ <operating system> (LILO) A {boot loader} for {Linux}. LILO
+ does not depend on a specific {file system}, it can boot Linux
+ {kernel images} from {floppy disks} and {hard disks} and can
+ even boot other {operating systems}. One of up to sixteen
+ differernt images can be selected at {boot time}. Various
+ {parameters}, such as the {root device}, can be set
+ independantly for each kernel. LILO can even be used as the
+ {master boot record}.
+
+ (2006-09-12)
+
+Linux Network Administrators' Guide
+
+ (NAG) A book on setting up and running {Unix} networks. NAG
+ is freely available in electronic form. It was produced by
+ Olaf Kirch, <okir@monad.swb.de> and others as part of the
+ {Linux Documentation Project} with help from {O'Reilly and
+ Associates}.
+
+ It includes the following sections: Introduction to
+ Networking, Issues of {TCP/IP} Networking, Configuring the
+ Networking Hardware, Setting up the Serial Hardware,
+ Configuring TCP/IP Networking, {Name Service} and {Resolver}
+ Configuraton, {Serial Line IP}, The {Point-to-Point Protocol},
+ Various Network Applications, The {Network Information
+ System}, The {Network File System}, Managing {Taylor UUCP},
+ {Electronic Mail}, Getting {smail} Up and Running,
+ {Sendmail+IDA}, {Netnews}, {C} News, A Description of NNTP,
+ Newsreader Configuration, Glossary, Annotated Bibliography.
+
+ {FTP from UNC (ftp://sunsite.unc.edu/pub/Linux/docs/LDP)}.
+ {FTP from MIT (ftp://tsx-11.mit.edu/pub/linux/docs/LDP)}.
+
+ (1994-12-01)
+
+Linux User Group
+
+ <body, operating system> (LUG) Any organisation of {Linux} users
+ in a local area, university, etc., that offers mutual technical
+ support, companionship with people of similar interests and
+ promotes the use of Linux among computer users generally.
+
+ LUGs often hold Install Fests for the general public, in which
+ experienced Linux users explain and supervise the installation
+ of Linux on new users' systems.
+
+ (2003-09-14)
+
+lion food
+
+ <humour> (IBM) Middle management or HQ staff, or, by
+ extension, administrative drones in general. The term derives
+ from an old joke:
+
+ Two lions escape from the zoo and split up to increase their
+ chances. When they finally meet after two months, one is
+ skinny and the other overweight. The thin one says, "How did
+ you manage? I ate a human just once and they turned out a
+ small army to chase me with guns and nets, it was terrible.
+ Since then I've been reduced to eating mice, insects, even
+ grass." The fat one replies: "Well, *I* hid near an IBM
+ office and ate a manager every day. Nobody even noticed!"
+
+ [{Jargon File}]
+
+ (1994-12-01)
+
+Lions Book
+
+ <publication> "Source Code and Commentary on Unix level 6", by
+ John Lions.
+
+ The two parts of this book contained the entire source listing
+ of the {Unix} Version 6 {kernel}, and a commentary on the
+ source discussing the {algorithms}. These were circulated
+ internally at the {University of New South Wales} beginning
+ 1976-77, and were, for years after, the *only* detailed kernel
+ documentation available to anyone outside {Bell Labs}.
+ Because {Western Electric} wished to maintain trade secret
+ status on the kernel, the Lions book was never formally
+ published and was only supposed to be distributed to
+ affiliates of source licensees (it is still possible to get a
+ Bell Labs reprint of the book by sending a copy of a V6 {source
+ licence} to the right person at {Bellcore}, but *real* insiders
+ have the UNSW edition). In spite of this, it soon spread by
+ {samizdat} to a good many of the early Unix hackers.
+
+ {(http://peer-to-peer.com/catalog/history/lions.html)}.
+
+ In 1996 it was reprinted as a "classic":
+
+ [John Lions, "Lions' Comentary on UNIX 6th Edition with Source
+ Code", Computer Classics Revisited Series, Peer-to-Peer
+ Communications, 1996, ISBN 1-57398-013-7].
+
+ [{Jargon File}]
+
+ (1997-06-25)
+
+LIPL
+
+ Linear IPL.
+
+ A linearised (i.e. horizontal format) version of IPL-V.
+
+ [Sammet 1969, p. 394].
+
+ [R. Dupchak, "LIPL - Linear Information Processing Language",
+ Rand Memo RM-4320-PR, Feb 1965].
+
+ (1994-12-01)
+
+liquid crystal display
+
+ <hardware> (LCD) An electro-optical device used to display
+ digits, characters or images, commonly used in digital
+ watches, calculators, and portable computers.
+
+ The heart of the liquid crystal display is a piece of {liquid
+ crystal} material placed between a pair of transparent
+ {electrodes}. The liquid crystal changes the phase of the
+ light passing through it and this phase change can be
+ controlled by the {voltage} applied between the electrodes.
+ If such a unit is placed between a pair of {plane polariser}
+ plates then light can pass through it only if the correct
+ voltage is applied. Liquid crystal displays are formed by
+ integrating a number of such cells, or more usually, by using
+ a single liquid crystal plate and a pattern of electrodes.
+
+ The simplest kind of liquid crystal displays, those used in
+ digital watches and calculators, contain a common electrode
+ plane covering one side and a pattern of electrodes on the
+ other. These electrodes can be individually controlled to
+ produce the appropriate display. Computer displays, however,
+ require far too many pixels (typically between 50,000 and
+ several millions) to make this scheme, in particular its
+ wiring, feasible. The electrodes are therefore replaced by a
+ number of row electrodes on one side and column electrodes on
+ the other. By applying voltage to one row and several columns
+ the {pixels} at the intersections are set.
+
+ The pixels being set one row after the other, in {passive
+ matrix} displays the number of rows is limited by the ratio of
+ the setting and fading times. In the setup described above
+ (known as "{twisted nematic}") the number of rows is limited
+ to about 20. Using an alternative "{supertwisted nematic}"
+ setup {VGA} quality displays (480 rows) can be easily built.
+ As of 1995 most {notebook computers} used this technique.
+
+ Fading can be slowed by putting an active element, such as a
+ {transistor}, on the top of each pixel. This "remembers" the
+ setting of that pixel. These {active matrix} displays are of
+ much better quality (as good as {CRTs}) but are much more
+ expensive than the passive matrix displays.
+
+ LCDs are slimmer, lighter and consume less power than the
+ previous dominant display type, the {cathode ray tube}, hence
+ their importance for {portable computers}.
+
+ (1995-12-09)
+
+LIS
+
+ Langage Implementation Systeme.
+
+ A predecessor of {Ada} developed by Ichbiah in 1973. It was
+ influenced by {Pascal}'s data structures and {Sue}'s control
+ structures. A type declaration can have a low-level
+ implementation specification.
+
+ ["The System Implementation Language LIS", J.D. Ichbiah et al,
+ CII Honeywell-Bull, TR 4549 E/EN, Louveciennes France (Dec
+ 1974)].
+
+ ["The Two-Level Approach to Data Independent Programming in
+ LIS", J.D. Ichbiah et al, in Machine Oriented Higher Level
+ Languages, W. van der Poel ed, N-H 1974, pp.161-169].
+
+ (1994-12-01)
+
+LISA
+
+ 1. <computer> Local Integrated Software Architecture.
+
+ A {personal computer} introduced by {Apple Computer, Inc.} in
+ 1983. The LISA was a predecessor of the {Macintosh} and was
+ the first personal computer on the market with a {graphical
+ user interface}.
+
+ It was origionally named after {Steve Jobs}'s daughter. The
+ acronym was applied later.
+
+ [Spec?]
+
+ 2. <tool> A system for statistical data analysis, similar to
+ {S}.
+
+ {FTP MIT (ftp://dolphin.mit.edu/)}.
+
+ 3. <event> {Large Installation Systems Administration}.
+
+ (2001-10-16)
+
+Liskov, Barbara
+
+ {Barbara Liskov}
+
+Liskov substitution principle
+
+ <programming, theory> (LSP) The principle that
+ {object-oriented} {functions} that use {pointers} or
+ references to a {base class} must be able to use {objects} of
+ a {derived class} without knowing it.
+
+ {Barbara Liskov} first wrote it as follows: If for each object
+ o1 of type S there is an object o2 of type T such that for all
+ programs P defined in terms of T, the behaviour of P is
+ unchanged when o1 is substituted for o2 then S is a {subtype}
+ of T.
+
+ A function that violates the LSP uses a reference to a base
+ class and must know about all the derivatives of that base
+ class. Such a function violates the {open/closed principle}
+ because it must be modified whenever a new derivative of the
+ base class is created.
+
+ [Liskov, B. Data Abstraction and Hierarchy, SIGPLAN
+ Notices. 23(5), May 1988].
+
+ (2001-09-14)
+
+Lisp
+
+ <language> LISt Processing language.
+
+ (Or mythically "Lots of Irritating Superfluous Parentheses").
+ {Artificial Intelligence}'s mother tongue, a symbolic,
+ {functional}, {recursive} language based on the ideas of
+ {lambda-calculus}, variable-length lists and trees as
+ fundamental data types and the interpretation of code as data
+ and vice-versa.
+
+ Data objects in Lisp are lists and {atoms}. Lists may contain
+ lists and atoms. Atoms are either numbers or symbols.
+ Programs in Lisp are themselves lists of symbols which can be
+ treated as data. Most implementations of Lisp allow functions
+ with {side-effects} but there is a core of Lisp which is
+ {purely functional}.
+
+ All Lisp functions and programs are expressions that return
+ values; this, together with the high memory use of Lisp, gave
+ rise to {Alan Perlis}'s famous quip (itself a take on an Oscar
+ Wilde quote) that "Lisp programmers know the value of
+ everything and the cost of nothing".
+
+ The original version was {LISP 1}, invented by {John McCarthy}
+ <jmc@sail.stanford.edu> at {MIT} in the late 1950s. Lisp is
+ actually older than any other {high level language} still in
+ use except {Fortran}. Accordingly, it has undergone
+ considerable change over the years. Modern variants are quite
+ different in detail. The dominant {HLL} among hackers until
+ the early 1980s, Lisp now shares the throne with {C}. See
+ {languages of choice}.
+
+ One significant application for Lisp has been as a proof by
+ example that most newer languages, such as {COBOL} and {Ada},
+ are full of unnecessary {crocks}. When the {Right Thing} has
+ already been done once, there is no justification for
+ {bogosity} in newer languages.
+
+ See also {Association of Lisp Users}, {Common Lisp}, {Franz
+ Lisp}, {MacLisp}, {Portable Standard Lisp}, {Interlisp},
+ {Scheme}, {ELisp}, {Kamin's interpreters}.
+
+ [{Jargon File}]
+
+ (1995-04-16)
+
+*LISP
+
+ (StarLISP) A {data-parallel} extension of {Common LISP} for
+ the {Connection Machine}, uses "{pvars}".
+
+ {A *LISP simulator
+ (ftp://think.com/public/starsim-f19-sharfile)}.
+
+ E-mail: <customer-support@think.com>,
+ <documentation-order@think.com>.
+
+ [Cliff Lasser, Jeff Mincy, J.P. Massar, Thinking Machines
+ Corporation "The Essential *LISP Manual", TM Corp 1986].
+
+ [{Jargon File}]
+
+LISP 1
+
+ The original {Lisp}. Invented by John McCarthy et al at {MIT}
+ in the late 50's. Followed by {LISP 1.5}.
+
+LISP 1.5
+
+ The second version of {Lisp}, successor to {LISP 1}.
+ Developed at {MIT} in 1959. Followed by LISP 1.75, LISP 1.9,
+ {Lisp 2} and many other versions.
+
+LISP 2
+
+ {LISP 1.5} with an {ALGOL 60}-like surface syntax. Also
+ optional type declarations, new data types including
+ integer-indexed {arrays} and character strings, partial-word
+ extraction/insertion operators and {macros}. A
+ {pattern-matching} facility similar to {COMIT} was proposed.
+ Implemented for the {Q-32} computer.
+
+ ["The LISP 2 Programming Language and System", P.W. Abrahams
+ et al, Proc FJCC 29:661-676, AFIPS (Fall 1966).]
+
+LISP70
+
+ A {Lisp} dialect descended from {MLISP} and {MLISP2}. Also
+ known as PLISP and VEL. Useful for parsing. Only the
+ pattern-matching system was published and fully implemented.
+ According to Alan Kay, LISP70 had an influence on
+ {Smalltalk-72}. "The LISP70 Pattern Matching System, Larry
+ Tesler et al, IJCAI 73.
+
+LISP A
+
+ "LISP A: A LISP-like System for Incremental Computing", E.J.
+ Sandewall, Proc SJCC 32 (1968).
+
+LISP Extended Algebraic Facility
+
+ <language> (LEAF)
+
+ ["An Algebraic Extension to LISP", P.H. Knowlton, Proc FJCC 35
+ 1969].
+
+ (1996-06-07)
+
+Lispkit
+
+ <language> A {functional programming} language designed by
+ Peter Henderson with Lisp syntax. Designed for portability.
+ The Lispkit implementation is an extension to Landin's SECD
+ machine that supports lazy evaluation. See also Stack
+ environment control dump machine.
+
+Lispkit Lisp
+
+ Purely functional version of LISP. "Functional Programming,
+ Application and Implementation", P. Henderson, P-H 1980.
+
+Lisp-Linda
+
+ P. Dourish, U Edinburgh 1988.
+
+Lisp Machine
+
+ 1. <architecture> Any {machine} (whether notional or actual)
+ whose instruction set is {Lisp}.
+
+ 2. <hardware, operating system> A line of {workstations} made
+ by {Symbolics, Inc.} from the mid-1970s (having grown out of
+ the {MIT AI Lab}) to late 1980s. All system code for
+ Symbolics Lisp Machines was written in {Lisp Machine Lisp}.
+ Symbolics Lisp Machines were also notable for having had
+ {space-cadet keyboards}.
+
+ [More details and historical background?]
+
+ {Lisp Machine Museum
+ (http://kogs-www.informatik.uni-hamburg.de/~moeller/symbolics-info/symbolics.html)}.
+
+ (2003-07-03)
+
+LISP Machine LISP
+
+ <language> An extension of {Maclisp}, now called {Zetalisp}.
+
+ (1998-12-13)
+
+Lisp Object-Oriented Programming System
+
+ (LOOPS) An {object-oriented} extension of {Lisp} from the
+ {Intelligent Systems Laboratory} at {Xerox} {Palo Alto
+ Research Center}. It is used in the development of
+ {knowledge-based systems}.
+
+ See also {CommonLoops}.
+
+ ["The LOOPS Manual", D.G. Bobrow & M. Stefik, Xerox Corp
+ 1983].
+
+LISP, Objects, and Symbolic Programming
+
+ A book with compiler included by Robert R. Kessler and Amy
+ R. Petajan, published by Scott, Foresman and Company,
+ Glenview, IL, USA. (1988).
+
+Lisptalk
+
+ "Concurrent Programming Language Lisptalk", C. Li, SIGPLAN
+ Notices 23(4):71-80 (Apr 1988).
+
+LispView
+
+ CLOS based windowing system on OpenWindows.
+
+list
+
+ <data> A data structure holding many values, possibly of
+ different types, which is usually accessed sequentially,
+ working from the head to the end of the tail - an "ordered
+ list". This contrasts with a (one-dimensional) {array}, any
+ element of which can be accessed equally quickly.
+
+ Lists are often stored using a cell and pointer arrangement
+ where each value is stored in a cell along with an associated
+ pointer to the next cell. A special pointer, e.g. zero, marks
+ the end of the list. This is known as a (singly) "linked
+ list". A doubly linked list has pointers from each cell to
+ both next and previous cells.
+
+ An unordered list is a {set}.
+
+ (1998-11-12)
+
+list comprehension
+
+ <functional programming> An expression in a {functional
+ language} denoting the results of some operation on (selected)
+ elements of one or more lists. An example in {Haskell}:
+
+ [ (x,y) | x <- [1 .. 6], y <- [1 .. x], x+y < 10]
+
+ This returns all pairs of numbers (x,y) where x and y are
+ elements of the list 1, 2, ..., 10, y <= x and their sum is
+ less than 10.
+
+ A list comprehension is simply "{syntactic sugar}" for a
+ combination of applications of the functions, concat, map and
+ filter. For instance the above example could be written:
+
+ filter p (concat (map (\ x -> map (\ y -> (x,y))
+ [1..x]) [1..6]))
+ where
+ p (x,y) = x+y < 10
+
+ According to a note by Rishiyur Nikhil <nikhil@crl.dec.com>,
+ (August 1992), the term itself seems to have been coined by
+ Phil Wadler circa 1983-5, although the programming construct
+ itself goes back much further (most likely Jack Schwartz and
+ the SETL language).
+
+ The term "list comprehension" appears in the references below.
+
+ The earliest reference to the notation is in Rod Burstall and
+ John Darlington's description of their language, NPL.
+
+ David Turner subsequently adopted this notation in his
+ languages SASL, KRC and Miranda, where he has called them "{ZF
+ expressions}", set abstractions and list abstractions (in his
+ 1985 FPCA paper [Miranda: A Non-Strict Functional Language
+ with Polymorphic Types]).
+
+ ["The OL Manual" Philip Wadler, Quentin Miller and Martin
+ Raskovsky, probably 1983-1985].
+
+ ["How to Replace Failure by a List of Successes" FPCA
+ September 1985, Nancy, France, pp. 113-146].
+
+ (1995-02-22)
+
+List Enhanced
+
+ <operating system, tool> An {MS-DOS} file browsing utility
+ written by Vern Buerg in 1983. A former {mainframe} systems
+ programmer, Buerg wrote DOS utilities when he began using an
+ {IBM PC} and missed the file-scanning ability he had on
+ mainframes. The software became an instant success, and his
+ list utility was in use on an estimated 5 million PCs.
+
+ {shareware version (http://buerg.com/ftp.html)}.
+
+ (1997-05-16)
+
+listless
+
+ <programming> In {functional programming}, a property of a
+ {function} which allows it to be combined with other functions
+ in a way that eliminates intermediate data structures,
+ especially lists.
+
+ {Phil Wadler}'s thesis gives the conditions for a function to
+ be in listless form: each input list is traversed only once,
+ one element at a time, from left to right. Each output list
+ is generated once, one element at a time, from left to right.
+ No other lists are generated or traversed.
+
+ Not all functions can be expressed in listless form
+ (e.g. reverse).
+
+ (1995-02-22)
+
+Listproc
+
+ A {mailing list} processor owned and developed by {BITNET}
+ which runs under {Unix}.
+
+ See also {Listserv}, {Majordomo}.
+
+ [Details?]
+
+ (1995-02-22)
+
+lists
+
+ {list}
+
+Listserv
+
+ <messaging> An automatic {mailing list} server, initially
+ written to run under {IBM}'s {VM} {operating system} by Eric
+ Thomas.
+
+ Listserv is a {user name} on some computers on {BITNET}/{EARN}
+ which processes {electronic mail} requests for addition to or
+ deletion from mailing lists. Examples are listserv@ucsd.edu,
+ listserver@nysernet.org.
+
+ Some listservs provide other facilities such as retrieving
+ files from {archives} and {database} search. Full details of
+ available services can usually be obtained by sending a
+ message with the word HELP in the subject and body to the
+ listserv address.
+
+ Eric Thomas, has recently formed an international corporation,
+ L-Soft, and has ported Listserv to a number of other
+ {platforms} including {Unix}. Listserv has simultaneously
+ been enhanced to use both the {Internet} and {BITNET}.
+
+ Two other major {mailing list} processors, both of which run
+ under {Unix}, are {Majordomo}, a {freeware} system, and
+ {Listproc}, currently owned and developed by {BITNET}.
+
+ (1995-02-22)
+
+Liszt
+
+ A {Franz Lisp} compiler in {C} which emits {C}, by Jeff
+ W. Dalton <jeff@festival.ed.ac.uk>.
+
+ Mailing list: franz-friends-request@berkeley.edu.
+
+ (1994-10-20)
+
+lite
+
+ <spelling> (Misspelling of "light", when used to mean
+ "lightweight") A suffix denoting a scaled-down or crippled
+ product, often designed to be distributed without charge,
+ e.g. on a magazine {coverdisk}. An example is {pklite}.
+
+ (1995-10-06)
+
+literal
+
+ <programming> A constant made available to a process, by
+ inclusion in the executable text. Most modern systems do not
+ allow texts to modify themselves during execution, so literals
+ are indeed constant; their value is written at compile-time
+ and is read-only at run time.
+
+ In contrast, values placed in variables or files and accessed
+ by the process via a symbolic name, can be changed during
+ execution. This may be an asset. For example, messages can
+ be given in a choice of languages by placing the translation
+ in a file.
+
+ Literals are used when such modification is not desired. The
+ name of the file mentioned above (not its content), or a
+ physical constant such as 3.14159, might be coded as a
+ literal. Literals can be accessed quickly, a potential
+ advantage of their use.
+
+ (1996-01-23)
+
+literate programming
+
+ <programming, text> Combining the use of a {text formatting}
+ language such as {TeX} and a conventional programming language
+ so as to maintain {documentation} and {source code} together.
+
+ Literate programming may use the {inverse comment convention}.
+
+ {Perl}'s literate programming system is called {pod}.
+
+ (2003-09-24)
+
+literature
+
+ The literature. Computer-science journals and other
+ publications, vaguely gestured at to answer a question that
+ the speaker believes is trivial. Thus, one might answer an
+ annoying question by saying "It's in the literature." Oppose
+ {Knuth}, which has no connotation of triviality.
+
+ (1994-11-04)
+
+LITHE
+
+ Object-oriented with extensible syntax.
+
+ "LITHE: A Language Combining a Flexible Syntax and Classes",
+ D. Sandberg, Conf Rec 9th Ann ACM Sym POPL, ACM 1982,
+ pp.142-145.
+
+lithium lick
+
+ {NeXT} employees who have had too much attention from their
+ esteemed founder, {Steve Jobs}, are said to have "lithium
+ lick" when they begin to show signs of Jobsian fervour and
+ repeat the most recent catch phrases in normal conversation,
+ e.g. "It just works, right out of the box!"
+
+ [{Jargon File}]
+
+LitProg
+
+ {literate programming}
+
+LITTLE
+
+ A typeless language used to produce machine-independent
+ software. LITTLE has been used to implement SETL.
+
+ "Guide to the LITTLE Language", D. Shields, LITTLE Newsletter
+ 33, Courant Inst (Aug 1977).
+
+little-endian
+
+ <data, architecture> A computer architecture in which, within
+ a given 16- or 32-bit {word}, bytes at lower addresses have
+ lower significance (the word is stored "little-end-first").
+ The {PDP-11} and {VAX} families of computers and {Intel}
+ {microprocessors} and a lot of communications and networking
+ hardware are little-endian.
+
+ The term is sometimes used to describe the ordering of units
+ other than bytes; most often, bits within a byte.
+
+ Compare {big-endian}, {middle-endian}. See {NUXI problem}.
+
+ [{Jargon File}]
+
+ (1995-08-16)
+
+Little Smalltalk
+
+ A line-oriented near-subset of {Smalltalk-80} written in {C}
+ by Tim Budd <budd@cs.orst.edu>. Version 3 runs on {Unix},
+ {IBM PC}, {Atari} and {VMS}.
+
+ {(ftp://cs.orst.edu/pub/budd/)}.
+
+ ["A Little Smalltalk", Timothy Budd, A-W 1987].
+
+live data
+
+ 1. Data that is written to be interpreted and takes over
+ program flow when triggered by some un-obvious operation, such
+ as viewing it. One use of such hacks is to break security.
+ For example, some smart terminals have commands that allow one
+ to download strings to program keys; this can be used to write
+ live data that, when listed to the terminal, infects it with a
+ security-breaking {virus} that is triggered the next time a
+ hapless user strikes that key. For another, there are some
+ well-known bugs in {vi} that allow certain texts to send
+ arbitrary commands back to the machine when they are simply
+ viewed.
+
+ 2. In {C}, data that includes pointers to functions
+ (executable code).
+
+ 3. An object, such as a {trampoline}, that is constructed on
+ the fly by a program and intended to be executed as code.
+
+ 4. Actual real-world data, as opposed to "test data". For
+ example, "I think I have the record deletion module finished."
+ "Have you tried it out on live data?" This usage usually
+ carries the connotation that live data is more fragile and
+ must not be corrupted, or bad things will happen. So a more
+ appropriate response to the above claim might be: "Well, make
+ sure it works perfectly before we throw live data at it." The
+ implication here is that record deletion is something pretty
+ significant, and a haywire record-deletion module running amok
+ on live data would probably cause great harm.
+
+ [{Jargon File}]
+
+Live Free Or Die!
+
+ 1. The state motto of New Hampshire, which appears on that
+ state's automobile licence plates.
+
+ 2. A slogan associated with Unix in the romantic days when
+ Unix aficionados saw themselves as a tiny, beleaguered
+ underground tilting against the windmills of industry. The
+ "free" referred specifically to freedom from the {fascist}
+ design philosophies and {crufty} misfeatures common on
+ commercial operating systems. Armando Stettner, one of the
+ early Unix developers, used to give out fake licence plates
+ bearing this motto under a large Unix, all in New Hampshire
+ colours of green and white. These are now valued collector's
+ items.
+
+livelock
+
+ <parallel> /li:v'lok/ When two or more processes continuously
+ change their state in response to changes in the other
+ process(es) without doing any useful work.
+
+ This is similar to {deadlock} in that no progress is made but
+ differs in that neither process is blocked or waiting for
+ anything.
+
+ A human example of livelock would be two people who meet
+ face-to-face in a corridor and each moves aside to let the
+ other pass, but they end up swaying from side to side without
+ making any progress because they always move the same way at
+ the same time.
+
+ [{Jargon File}]
+
+ (1998-07-05)
+
+LiveScript
+
+ {JavaScript}
+
+liveware
+
+ /li:v'weir/ 1. A less common synonym for {wetware}
+
+ 2. (Cambridge) Vermin. "Waiter, there's some liveware in my
+ salad."
+
+ [{Jargon File}]
+
+ (1995-10-30)
+
+lk
+
+ <networking> The {country code} for Sri Lanka.
+
+ (1999-01-27)
+
+LKA
+
+ {Lan Kanal Adapter}
+
+LL
+
+ <grammar> A class of language {grammars}, which can
+ be {parse}d without {backtrack}ing. The first L stands for
+ Left-to-right scan, the second for Leftmost derivation.
+
+ Often found in the form LL(k) where k is the number of
+ {tokens} of {look-ahead} required when parsing a sentence of
+ the language. In particular, LL(1) is a fairly restrictive
+ class of grammar, but allows simple {top-down} parsing
+ (e.g. {recursive-descent}) to be used without wasteful
+ {backtracking}. A number of programming languages are LL(1)
+ (or close).
+
+ (1995-10-30)
+
+LLC
+
+ {Logical Link Control}
+
+LLGen
+
+ <tool> A {BNF}-based {LL1} {parser generator} by Fischer and
+ LeBlanc. It conforms to a subset of {FMQ}.
+
+ {(ftp://csczar.ncsu.edu/)}.
+
+ ["Crafting A Compiler", Fischer and LeBlanc].
+
+ (1990-03-31)
+
+LLM3
+
+ /el el em trwa/ The {assembly language} for a {virtual
+ machine} used as the implementation language for {Le-Lisp}.
+ Developed by J. Chailloux of {INRIA}.
+
+LLNL
+
+ {Lawrence Livermore National Laboratory}
+
+LLP
+
+ {Lower Layer Protocol}
+
+LM3
+
+ The {Larch} interface language for {Modula-3}.
+
+ ["LM3: A Larch/Modula-3 Interface Language", Kevin D. Jones,
+ TR 72, DEC SRC, Palo Alto CA].
+
+LMAO
+
+ <chat> laughed my ass off. Seen on {Compuserve}.
+
+ (1996-02-04)
+
+LMDS
+
+ {Local Multipoint Distribution System}
+
+lmgtfy.com
+
+ <humour, WWW> A somewhat sarcastic {web} service that
+ animates the action of searching on {Google}.
+
+ Instead of displaying the search results, the site creates a
+ self-referential URL like
+
+ {(http://lmgtfy.com/?q=GIYF)}
+
+ that takes you to a page showing an animation of the actions of
+ clicking in the Google search box, entering some text and clicking
+ the submit button. It then takes you to the results on Google.
+
+ The link is intended be sent to in answer to a question that could
+ easily have been answered by Google. It is a more polite, if
+ long-winded, way of saying {JFGI} or {STFW}.
+
+ In the belief that it is better to teach a man to fish than to
+ give him a fish, the service helps the recipient to help himself
+ while succinctly conveying the message that he is too stupid to
+ use Google.
+
+ (2014-05-23)
+
+LML
+
+ 1. Lazy ML.
+
+ A {lazy}, {purely functional} variant of {ML} designed by
+ Thomas Johnson and Lennart Augustsson at the Chalmers
+ University of Technology, Gothenburg, Sweden in 1984. LML is
+ implemented on the {G-machine}, and was used to implement the
+ first {Haskell B compiler}. There is a compiler (lmlc) and
+ interpreter.
+
+ {(ftp://ftp.cs.chalmers.se/pub/haskell/chalmers)}.
+
+ (1994-12-14)
+
+ 2. Logical ML.
+
+ Adds to {Lazy ML} a data type of "theories" whose objects
+ represent {logic programs}.
+
+ ["Logic Programming within a Functional Framework", A. Brogi
+ et al, in Programming Language Implementation and Logic
+ Programming, P. Deransart et al eds, LNCS 456, Springer 1990].
+
+ (1994-12-14)
+
+LM-Prolog
+
+ Lisp Machine Prolog.
+
+ A {Prolog} {interpreter} in {Zetalisp} for the {Lisp Machine}
+ developed by Ken Kahn and Mats Carlsson in 1983.
+
+ {(ftp://sics.se/archive/lm-prolog.tar.Z)}.
+
+ ["LM-Prolog User Manual", M. Carlsson et al, Uppsala Dec
+ 1983].
+
+ (1994-12-14)
+
+LMTP
+
+ {Local Mail Transfer Protocol}
+
+LNF
+
+ ["A Fully Lazy Higher Order Purely Functional Programming
+ Language With Reduction Semantics", K.L. Greene, CASE Center
+ TR 8503, Syracuse U 1985].
+
+LO
+
+ Linear Objects. A {concurrent} {logic programming} language
+ based on {linear logic}, an extension of {Horn logic} with a
+ new kind of {OR-concurrency}.
+
+ ["LO and Behold! Concurrent Structured Processes", J. Andreoli
+ et al, SIGPLAN Notices 25(10):44-56 (OOPSLA/ECOOP '90) (Oct
+ 1990)].
+
+L&O
+
+ Logic and Objects. A front end for {IC Prolog}.
+
+ {(ftp://src.doc.ic.ac.uk/computing/programming/languages/pd-ICP-0,90.tar.Z)}.
+ E-mail: Zacharias Bobolakis <zb@doc.ic.ac.uk>.
+
+ ["Logic and Objects", Frank McCabe, Prentice-Hall].
+
+load
+
+ 1. To copy {data} (often {program} {code} to be {run}) into
+ {memory}, possibly {parsing} it somehow in the process.
+ E.g. "{WordPerfect} can't load this {RTF} file - are you sure
+ it didn't get corrupted in the {download}?" Opposite of
+ {save}.
+
+ 2. The degree to which a computer, {network}, or other
+ resource is used, sometimes expressed as a percentage of the
+ maximum available. E.g. "What kind of CPU load does that
+ program give?", "The network's constantly running at 100%
+ load". Sometimes used, by extension, to mean "to increase the
+ level of use of a resource". E.g. "Loading a spreadsheet
+ really loads the CPU". See also: {load balancing}.
+
+ 3. To {install} a piece of {software} onto a system.
+ E.g. "The computer guy is gonna come load Excel on my laptop
+ for me". This usage is widely considered to be incorrect.
+
+ (2002-07-02)
+
+load balancing
+
+ <operating system, parallel> Techniques which aim to spread
+ tasks among the processors in a {parallel processor} to avoid
+ some processors being idle while others have tasks queueing
+ for execution. Load balancing may be performed either by
+ heavily loaded processors (with many tasks in their queues)
+ sending tasks to other processors; by idle processors
+ requesting work from others; by some centralised task
+ distribution mechanism; or some combination of these. Some
+ systems allow tasks to be moved after they have started
+ executing ("{task migration}") others do not. It is important
+ that the {overhead} of executing the load balancing
+ {algorithm} does not contribute significantly to the overall
+ processing or communications load.
+
+ Distributed scheduling {algorithms} may be static, dynamic or
+ preemptive. Static algorithms allocate processes to
+ processors at run time while taking no account of current
+ network load. Dynamic algorithms are more flexible, though
+ more computationally expensive, and give some consideration to
+ the network load before allocating the new process to a
+ processor. Preemptive algorithms are more expensive and
+ flexible still, and may migrate running processes from one
+ host to another if deemed beneficial. Research to date
+ indicates that dynamic algorithms yield significant
+ performance benefits, but that further (though lesser) gains
+ may be had through the addition of process migration
+ facilities.
+
+ (1995-03-13)
+
+load-bearing printf
+
+ <programming, humour> The kind of {bug} present in a {program}
+ which works correctly when producing debug output but fails when
+ the {debugging} is turned off.
+
+ The expression combines {load-bearing wall
+ (http://en.wikipedia.org/wiki/The_Builders)} and {printf} as used
+ in {debugging by printf}.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2013-05-10)
+
+lobotomy
+
+ 1. What a hacker subjected to formal management training is
+ said to have undergone. At {IBM} and elsewhere this term is
+ used by both hackers and low-level management; the latter
+ doubtless intend it as a joke.
+
+ 2. The act of removing the processor from a {microcomputer} in
+ order to replace or upgrade it. Some very cheap {clone}
+ systems are sold in "lobotomised" form - everything but the
+ brain.
+
+ [{Jargon File}]
+
+LOC
+
+ {lines of code}
+
+local area network
+
+ <networking> (LAN) A data communications network which is
+ geographically limited (typically to a 1 km radius) allowing
+ easy interconnection of terminals, {microprocessors} and
+ computers within adjacent buildings. {Ethernet} and {FDDI}
+ are examples of standard LANs.
+
+ Because the network is known to cover only a small area,
+ optimisations can be made in the network signal protocols that
+ permit data rates up to 100Mb/s.
+
+ See also {token ring}, {wide area network}, {metropolitan area
+ network}..
+
+ {Usenet} newsgroup: {news:comp.dcom.lans.misc}.
+
+ (1995-03-13)
+
+Local Area Terminal
+
+ <protocol> (LAT) A {DECnet}-related, non-routable network
+ {protocol}.
+
+ [Details?]
+
+ (1999-01-14)
+
+local bus
+
+ <hardware> A {bus} connecting a {processor} to {memory},
+ usually on the same {circuit board} as opposed to a
+ {backplane} and therefore faster.
+
+ Various proprietary local busses for {personal computers} are
+ still in use. The most common are {Vesa local bus} (VLB or
+ VL), and {Peripheral Component Interconnect} (PCI). Some
+ computers, e.g. {notebook computers}, use a local bus with no
+ expansion slots. Previous non-local bus standards include
+ {ISA}, {EISA} and {MCA}.
+
+ (1997-08-25)
+
+locale
+
+ <programming> A geopolitical place or area, especially in the
+ context of configuring an {operating system} or {application
+ program} with its {character sets}, date and time formats,
+ currency formats etc.
+
+ Locales are significant for {internationalisation} and
+ {localisation}.
+
+ (1999-06-09)
+
+local echo
+
+ <communications> (Obsolete: "{half-duplex}") A mode of
+ operation of a communications program or device in which it
+ displays the characters the user enters at the same time as it
+ sends them to the remote system.
+
+ In communications between computers or computing processes,
+ particularly those involving human keyboarding and/or reading,
+ duplex came to mean the re-transmission of a keyboard
+ character to the output display.
+
+ Early input device such as the Teletype {ASR-33}
+ {teleprinter}, being descended from the electric typewriter,
+ printed all input characters as they were typed (i.e. they did
+ local echo). Local echo was typically optional on the {video
+ terminals} that replaced them, and usually disabled in favour
+ of {remote echo}. A disadvantage of local echo is that it
+ will continue, even when the communication circuit has failed,
+ which can be misleading.
+
+ (2000-03-30)
+
+local exchange carrier
+
+ <communications> (LEC) A company allowed to handle local calls
+ following the break-up of the Bell system in the US by
+ anti-trust regulators. These vary from Regional Bell
+ Operating Companies (RBOC) through to small independents such
+ as Farmers Cooperative.
+
+ Local exchange carriers are not allowed to handle
+ long-distance traffic. This is handled by inter-exchange
+ carriers (IXC) who are not allowed to handle local calls.
+
+ (2002-08-28)
+
+localisation
+
+ <programming> (l10n) Adapting a product to meet the language,
+ cultural and other requirements of a specific target market
+ "{locale}".
+
+ Localisation includes the translation of the {user interface},
+ {on-line help} and {documentation}, and ensuring the images
+ and concepts are culturally appropriate and sensitive. There
+ may be subtle cross-cultural considerations, e.g. do the icons
+ make sense in other parts of the world?
+
+ {Internationalisation} is the process that occurs during
+ application development that makes localisation easier by
+ separating the details that differ between locales from the
+ rest of the program that stays the same. If
+ internationalisation is thorough, localisation will require no
+ programming.
+
+ The abbreviation l10n means "L - 10 letters - N".
+
+ (1999-06-09)
+
+localised
+
+ {localisation}
+
+locality
+
+ 1. In sequential architectures programs tend to access data
+ that has been accessed recently (temporal locality) or that is
+ at an address near recently referenced data (spatial
+ locality). This is the basis for the speed-up obtained with a
+ {cache} memory.
+
+ 2. In a multi-processor architecture with distributed memory
+ it takes longer to access the memory attached to a different
+ processor. This overhead increases with the number of
+ communicating processors. Thus to efficiently employ many
+ processors on a problem we must increase the proportion of
+ references which are to local memory.
+
+ (1995-02-28)
+
+local loop
+
+ <communications> The circuits between a telephone subscriber's
+ residence or business and the switching equipment at the local
+ {central office}.
+
+ (1995-03-17)
+
+local loopback addresses
+
+ The special {Internet address}, 127.0.0.1, defined by the
+ {Internet Protocol}. A {host} can use local the loopback
+ address to send messages to itself.
+
+ (1995-03-21)
+
+Local Mail Transfer Protocol
+
+ <messaging, protocol> (LMTP) A {protocol} designed as an
+ alternative to {ESMTP} for cases where the mail receiver does
+ not manage a queue. LMTP is an {application level} {protocol}
+ that runs on top of {TCP/IP}. It was initially defined in
+ {RFC 2033}, and uses (with a few changes) the syntax and
+ semantics of {ESMTP}. It should be used only by specific
+ prior arrangement and configuration, and it must not be used
+ on TCP {port} 25 (the {SMTP} port).
+
+ (2002-03-09)
+
+Local Multipoint Distribution System
+
+ <wireless> (LMDS) A {broadband wireless} technology.
+
+ [Details?]
+
+locals
+
+ The users on one's local network (as opposed, say, to people
+ one reaches via public {Internet} or {UUCP} connections). The
+ marked thing about this usage is how little it has to do with
+ real-space distance. "I have to do some tweaking on this mail
+ utility before releasing it to the locals."
+
+ (1994-11-29)
+
+Local Shared Resources
+
+ <operating system> (LSR) A way of controlling {VSAM} buffers
+ in {OS/390}.
+
+ (2002-02-17)
+
+LocalTalk
+
+ <networking> An {Apple Computer} {network} {standard} using
+ {Apple Computer}'s own networking hardware.
+
+ Compare {EtherTalk}.
+
+ (1994-11-29)
+
+local variable
+
+ <programming> A {variable} with {lexical scope}, i.e. one
+ which only exists in some particular part of the {source
+ code}, typically within a {block} or a {function} or
+ {procedure} body. This contrasts with a {global variable},
+ which is defined throughout the whole program.
+
+ Code is easier to understand and modify when the scope of
+ variables is as small as possible because it is easier to see
+ how the variable is set and used. Code containing global
+ variables is harder to modify because its behaviour may depend
+ on and affect other sections of code that refer to that
+ variable.
+
+ (2009-12-14)
+
+location
+
+ {memory location}
+
+Loch Ness Monster Bug
+
+ <humour> (Or "Bugfoot") A {bug} which cannot be reproduced or has
+ only been sighted by one person. Named after the mythical
+ creature claimed to inhabit Loch Ness in Scotland.
+
+ (2012-12-29)
+
+locked and loaded
+
+ [Military slang for an M-16 rifle with magazine inserted and
+ prepared for firing] Said of a removable disk volume properly
+ prepared for use - that is, locked into the drive and with
+ the heads loaded. Ironically, because their heads are
+ "loaded" whenever the power is up, this description is never
+ used of {Winchester} drives (which are named after a rifle).
+
+ [{Jargon File}]
+
+locked up
+
+ Synonym for {hung}, {wedged}.
+
+lock-in
+
+ <standard> When an existing standard becomes almost impossible
+ to supersede because of the cost or logistical difficulties
+ involved in convincing all its users to switch something
+ different and, typically, {incompatible}.
+
+ The common implication is that the existing standard is
+ notably inferior to other comparable standards developed
+ before or since.
+
+ Things which have been accused of benefiting from lock-in in
+ the absence of being truly worthwhile include: the {QWERTY}
+ keyboard; any well-known {operating system} or programming
+ language you don't like (e.g., see "{Unix conspiracy}"); every
+ product ever made by {Microsoft Corporation}; and most
+ currently deployed formats for transmitting or storing data of
+ any kind (especially the {Internet Protocol}, 7-bit (or even
+ 8-bit) {character sets}, analog video or audio broadcast
+ formats and nearly any file format).
+
+ Because of {network effects} outside of just computer
+ networks, {Real World} examples of lock-in include the current
+ spelling conventions for writing English (or French, Japanese,
+ Hebrew, Arabic, etc.); the design of American money; the
+ imperial (feet, inches, ounces, etc.) system of measurement;
+ and the various and anachronistic aspects of the internal
+ organisation of any government (e.g., the American Electoral
+ College).
+
+ (1998-01-15)
+
+Locus
+
+ A distributed system project supporting transparent access to
+ data through a network-wide file system.
+
+Loebner Prize
+
+ <artificial intelligence> An annual competition in {artificial
+ intelligence} started by Dr. {Hugh Loebner} of New York City
+ in 1991. A $100,000 prize is offered to the author of the
+ first computer program to pass an unrestricted {Turing test}.
+ Annual competitions are held each year with a $2000 prize for
+ the best program on a restricted {Turing test}.
+
+ Sponsors of previous competitions include: {Apple Computer},
+ {Computerland}, Crown Industries, GDE Systems, {IBM} Personal
+ Computer Company's {Center for Natural Computing}, Greenwich
+ Capital Markets, {Motorola}, the {National Science
+ Foundation}, The Alfred P. Sloan Foundation, and The Weingart
+ Foundation.
+
+ The 1995 and 1996 events were unrestricted Turing Tests,
+ requiring computer entries to converse indefinitely with no
+ topic restrictions. So far, even the best programs give
+ themselves away almost immediately, either by simple
+ grammatical mistakes or by repetition.
+
+ Complete transcripts and {IBM compatible} diskettes that play
+ the 1991, 1992, and 1993 conversations in real-time are
+ available for purchase from the Cambridge Center for
+ Behavioral Studies (telephone: +1 (617) 491 9020, Fax: 1072).
+ Sponsorship opportunities are available.
+
+ {Loebner Prize Home (http://loebner.net/)}.
+
+ (2003-11-30)
+
+log
+
+ 1. <mathematics, programming> {logarithm}.
+
+ 2. <operating system, programming> A record of the activity of
+ some system, often stored in a particular file.
+
+ Different {operating systems} have different conventions and
+ support for storing logs. {Unix} has the {syslog} system and
+ the /var/log directory hierarchy, {Microsoft Windows} has
+ {event logs}. {Web servers}, for example, typically record
+ information about every page accessed in one or more "web
+ logs".
+
+ (2009-05-29)
+
+{log}
+
+ ["{log}: A Logic Programming Language with Finite Sets", A
+ Dovier et al, Proc 8th Intl Conf Logic Prog, June 1991,
+ pp.111-124].
+
+logarithmus dualis
+
+ <mathematics> (ld) Latin for {logarithm} base two. More
+ commonly written as "log" with a subscript "2".
+
+ Roughly the number of {bits} required to represent an
+ {integer}.
+
+ (1999-03-19)
+
+LogC
+
+ A {C} extension incorporating {rule-oriented programming}, for
+ {AI} {application programs}. {Production rules} are
+ encapsulated into functional components called rulesets. LogC
+ uses a {search network algorithm} similar to {RETE}.
+
+ Version 1.6.
+
+ ["LogC: A Language and Environment for Embedded Rule Based
+ Systems", F. Yulin et al, SIGPLAN Notices 27(11):27-32 (Nov
+ 1992)].
+
+logic
+
+ 1. <philosophy, logic> A branch of philosophy and mathematics
+ that deals with the formal principles, methods and criteria of
+ validity of {inference}, reasoning and {knowledge}.
+
+ Logic is concerned with what is true and how we can know
+ whether something is true. This involves the formalisation of
+ logical arguments and {proofs} in terms of symbols
+ representing {propositions} and {logical connectives}. The
+ meanings of these logical connectives are expressed by a set
+ of rules which are assumed to be self-evident.
+
+ {Boolean algebra} deals with the basic operations of truth
+ values: AND, OR, NOT and combinations thereof. {Predicate
+ logic} extends this with existential and universal
+ {quantifiers} and symbols standing for {predicates} which may
+ depend on variables. The rules of {natural deduction}
+ describe how we may proceed from valid premises to valid
+ conclusions, where the premises and conclusions are
+ expressions in {predicate logic}.
+
+ Symbolic logic uses a {meta-language} concerned with truth,
+ which may or may not have a corresponding expression in the
+ world of objects called existance. In symbolic logic,
+ arguments and {proofs} are made in terms of symbols
+ representing {propositions} and {logical connectives}. The
+ meanings of these begin with a set of rules or {primitives}
+ which are assumed to be self-evident. Fortunately, even from
+ vague primitives, functions can be defined with precise
+ meaning.
+
+ {Boolean logic} deals with the basic operations of {truth
+ values}: AND, OR, NOT and combinations thereof. {Predicate
+ logic} extends this with {existential quantifiers} and
+ {universal quantifiers} which introduce {bound variables}
+ ranging over {finite} sets; the {predicate} itself takes on
+ only the values true and false. Deduction describes how we
+ may proceed from valid {premises} to valid conclusions, where
+ these are expressions in {predicate logic}.
+
+ Carnap used the phrase "rational reconstruction" to describe
+ the logical analysis of thought. Thus logic is less concerned
+ with how thought does proceed, which is considered the realm
+ of psychology, and more with how it should proceed to discover
+ truth. It is the touchstone of the results of thinking, but
+ neither its regulator nor a motive for its practice.
+
+ See also fuzzy logic, logic programming, arithmetic and logic unit,
+ first-order logic,
+
+ See also {Boolean logic}, {fuzzy logic}, {logic programming},
+ {first-order logic}, {logic bomb}, {combinatory logic},
+ {higher-order logic}, {intuitionistic logic}, {equational
+ logic}, {modal logic}, {linear logic}, {paradox}.
+
+ 2. <electronics> {Boolean} logic circuits.
+
+ See also {arithmetic and logic unit}, {asynchronous logic},
+ {TTL}.
+
+ (1995-03-17)
+
+logical
+
+ (From the technical term "logical device", wherein a physical
+ device is referred to by an arbitrary "logical" name) Having
+ the role of. If a person (say, Les Earnest at SAIL) who had
+ long held a certain post left and were replaced, the
+ replacement would for a while be known as the "logical" Les
+ Earnest. (This does not imply any judgment on the
+ replacement).
+
+ Compare {virtual}.
+
+ At Stanford, "logical" compass directions denote a coordinate
+ system in which "logical north" is toward San Francisco,
+ "logical west" is toward the ocean, etc., even though logical
+ north varies between physical (true) north near San Francisco
+ and physical west near San Jose. (The best rule of thumb here
+ is that, by definition, El Camino Real always runs logical
+ north-and-south.) In giving directions, one might say: "To
+ get to Rincon Tarasco restaurant, get onto {El Camino Bignum}
+ going logical north." Using the word "logical" helps to
+ prevent the recipient from worrying about that the fact that
+ the sun is setting almost directly in front of him. The
+ concept is reinforced by North American highways which are
+ almost, but not quite, consistently labelled with logical
+ rather than physical directions.
+
+ A similar situation exists at MIT: Route 128 (famous for the
+ electronics industry that has grown up along it) is a
+ 3-quarters circle surrounding Boston at a radius of 10 miles,
+ terminating near the coastline at each end. It would be most
+ precise to describe the two directions along this highway as
+ "clockwise" and "counterclockwise", but the road signs all say
+ "north" and "south", respectively. A hacker might describe
+ these directions as "logical north" and "logical south", to
+ indicate that they are conventional directions not
+ corresponding to the usual denotation for those words. (If
+ you went logical south along the entire length of route 128,
+ you would start out going northwest, curve around to the
+ south, and finish headed due east, passing along one infamous
+ stretch of pavement that is simultaneously route 128 south and
+ Interstate 93 north, and is signed as such!)
+
+ [{Jargon File}]
+
+ (1995-01-24)
+
+logical address
+
+ {virtual address}
+
+Logical Block Addressing
+
+ <storage> (LBA) A {hard disk} {sector} addressing scheme used
+ on all {SCSI} hard disks, and on {ATA-2} conforming {IDE} hard
+ disks. The addressing conversion is performed by the hard
+ disk firmware.
+
+ Prior to LBA, combined limitations of {IBM PC} {BIOS} and
+ {ATA} restricted the useful capacity of IDE hard disks on IBM
+ PCs and compatibles to 1024 cylinders * 63 sectors per track *
+ 16 heads * 512 bytes per sector = 528 million bytes = 504
+ megabytes. Modern BIOSes select LBA mode automatically, and
+ work around the 1024-cylinder BIOS limit by representing a
+ hard disk to the OS as having e.g. half as many cylinders and
+ twice as many heads. However, there is still an unbreakable
+ BIOS disk size limit of 1024 cylinders * 63 sectors per track
+ * 256 heads * 512 bytes per sector = 8 gigabytes, but modern
+ OSes (including {Windows 9x}, {Windows NT} and {Linux}) are
+ not affected by it, since they issue direct LBA-based calls,
+ bypassing the BIOS hard disk services completely.
+
+ (2000-04-30)
+
+logical complement
+
+ <logic> In {Boolean algebra}, the logical complement or
+ negation of a Boolean value is the opposite value, given by
+ the following {truth table}:
+
+ A | -A
+ --+---
+ T | F
+ F | T
+
+ -A is also written as A with a bar over it or with a small
+ vertical line hanging from the right-hand end of the "-"
+ ({LaTeX} \neg) or as A'. In the {C} programming language, it
+ is !A and in digital circuit design, /A.
+
+ (1995-01-24)
+
+Logical Interchange Format
+
+ <file format, file system> (LIF) A {Hewlett-Packard} simple
+ {file system} format used to {boot} {HP-PA} machines and to
+ interchange files between older HP machines. A LIF file
+ system is a header, containing a single directory, with
+ 10-character {case sensitive} filenames and 2-byte {file
+ types}, followed by the files.
+
+ {LIF Utilities for linux
+ (http://hpcc.org/hpil/lif_utils.html)}.
+
+ (2003-10-09)
+
+Logical Link Control
+
+ <networking> (LLC) The upper portion of the {data link layer},
+ as defined in {IEEE 802.2}. The LLC sublayer presents a
+ uniform interface to the user of the data link service, usually
+ the {network layer}. Beneath the LLC sublayer is the {Media
+ Access Control} (MAC) sublayer.
+
+ (1995-02-14)
+
+Logical Link Control and Adaptation Protocol
+
+ <protocol> (L2CAP) A {Bluetooth} {protocol} in the {Core
+ Protocol Stack} providing data services to higher layer
+ Bluetooth protocols.
+
+ {L2CAP Layer Tutorial
+ (http://palowireless.com/infotooth/tutorial/l2cap.asp)}.
+
+ (2002-06-28)
+
+logical relation
+
+ A {relation} R satisfying
+
+ f R g <=> For all a, b, a R b => f a R g b
+
+ This definition, by Plotkin, can be used to extend the
+ definition of a relation on the types of a and b to a relation
+ on functions.
+
+logical shift
+
+ <programming> (Either shift left logical or shift right
+ logical) Machine-level operations available on nearly all
+ processors which move each bit in a word one or more bit
+ positions in the given direction. A left shift moves the bits
+ to more significant positions (like multiplying by two), a
+ right shift moves them to less significant positions (like
+ dividing by two). The comparison with multiplication and
+ division breaks down in certain circumstances - a logical
+ shift may discard bits that are shifted off either end of the
+ word and does not preserve the sign of the word (positive or
+ negative).
+
+ Logical shift is approriate when treating the word as a {bit
+ string} or a sequence of {bit fields}, whereas {arithmetic
+ shift} is appropriate when treating it as a binary number.
+ The word to be shifted is usually stored in a {register}, or
+ possibly in memory.
+
+ (1996-07-02)
+
+logical shift left
+
+ {logical shift}
+
+logical shift right
+
+ {logical shift}
+
+Logical Unit
+
+ <networking> (LU) A primary component of {SNA}, an {LU} is a
+ type of {NAU} that enables end users to communicate with each
+ other and gain access to SNA network resources.
+
+ (1997-04-30)
+
+Logical Unit 6.2
+
+ <networking> (LU6.2) A type of {logical unit} that governs
+ peer-to-peer {SNA} communications. LU6.2 supports general
+ communication between programs in a distributed processing
+ environment.
+
+ LU6.2 is characterised by a {peer} relationship between
+ {session partners}, efficient use of a session for multiple
+ {transactions}, comprehensive end-to-end error processing and
+ a generic {application program interface} consisting of
+ {structured verbs} that are mapped into a product
+ inplementation.
+
+ LU6.2 is used by {IBM}'s {TPF} {operating system}.
+
+ [IBM Dictionary of Computing, McGraw-Hill 1993].
+
+ (1996-08-26)
+
+Logical Unit Number
+
+ <storage> (LUN) A 3-bit identifier used on a {SCSI} bus to
+ distinguish between up to eight devices ({logical units}) with
+ the same {SCSI ID}.
+
+ (1999-02-11)
+
+logic bomb
+
+ <programming, security> Code surreptitiously inserted into an
+ application or {operating system} that causes it to perform
+ some destructive or security-compromising activity whenever
+ specified conditions are met.
+
+ Compare {back door}.
+
+ [{Jargon File}]
+
+ (1996-07-02)
+
+Logic Design Language
+
+ <language> A language for computer design.
+
+ ["A System Description Language Using Parametric Text
+ Generation", R.H. Williams, TR 02.487, IBM San Jose, Aug
+ 1970].
+
+ (1994-11-29)
+
+logic emulator
+
+ A system of {FPGAs}, programmable interconnect and software
+ which automatically configures itself into an operating
+ prototype of a large-scale logic design, such as a
+ {microprocessor}. An emulated design can be connected into
+ the target system and really operated and tested before the
+ design is made into an {integrated circuit}.
+
+ {Quickturn} is the leading logic emulation system.
+
+ (1994-11-29)
+
+Logic for Computable Functions
+
+ <language> (LCF) Part of the {Edinburgh proof assistant}.
+
+ [What is it? Address?]
+
+ (1995-01-06)
+
+logic gate
+
+ An {integrated circuit} or other device whose inputs and
+ outputs represent {Boolean} or binary values as voltages
+ ({TTL} uses 0V for False or 0, +5V for True or 1). Different
+ gates implement different Boolean functions: {AND}, {OR},
+ {NAND}, {NOR} (these may take two or more inputs) {NOT} (one
+ input), {XOR} (two inputs). NOT, NAND and NOR are often
+ constructed from single {transistors} and the other gates made
+ from combinations of these basic ones. These functions are
+ all {combinatorial logic} functions, i.e. their outputs depend
+ only on their inputs and there is no internal state. Gates
+ with state, such as {latches} and {flip-flops}, are
+ constructed by feeding some of their outputs back to their
+ inputs.
+
+ (1995-02-08)
+
+logic programming
+
+ <artificial intelligence, programming, language> A
+ {declarative}, {relational} style of programming based on
+ {first-order logic}. The original logic programming language
+ was {Prolog}. The concept is based on {Horn clauses}.
+
+ The programmer writes a "database" of "{facts}", e.g.
+
+ wet(water).
+
+ ("water is wet") and "{rules}", e.g.
+
+ mortal(X) :- human(X).
+
+ ("X is mortal is implied by X is human"). Facts and rules are
+ collectively known as "{clauses}".
+
+ The user supplies a "{goal}" which the system attempts to
+ prove using "{resolution}" or "{backward chaining}". This
+ involves matching the current goal against each fact or the
+ left hand side of each rule using "{unification}". If the
+ goal matches a fact, the goal succeeds; if it matches a rule
+ then the process recurses, taking each sub-goal on the right
+ hand side of the rule as the current goal. If all sub-goals
+ succeed then the rule succeeds.
+
+ Each time a possible clause is chosen, a "{choice point}" is
+ created on a {stack}. If subsequent {resolution} fails then
+ control eventually returns to the choice point and subsequent
+ clauses are tried. This is known as "{backtracking}".
+
+ Clauses may contain {logic variables} which take on any value
+ necessary to make the fact or the left hand side of the rule
+ match a goal. Unification binds these variables to the
+ corresponding subterms of the goal. Such bindings are
+ associated with the {choice point} at which the clause was
+ chosen and are undone when backtracking reaches that choice
+ point.
+
+ The user is informed of the success or failure of his first
+ goal and if it succeeds and contains variables he is told what
+ values of those variables caused it to succeed. He can then
+ ask for alternative solutions.
+
+ (1997-07-14)
+
+Logic Replacement Technology
+
+ (LRT) Reading, BERKS. Tel: (0734) 751087. Marketing Director
+ Bob Barrett. Manufacturers of the Ethernet hardware including
+ the Filtabyte Ethernet controller card and EtherGate open
+ access gateway.
+
+logic variable
+
+ <programming> A variable in a {logic programming} language
+ which is initially undefined ("unbound") but may get bound to
+ a value or another logic variable during {unification} of the
+ containing clause with the current {goal}. The value to which
+ it is bound may contain other variables which may themselves
+ be bound or unbound.
+
+ For example, when unifying the clause
+
+ sad(X) :- computer(X, ibmpc).
+
+ with the goal
+
+ sad(billgates).
+
+ the variable X will become bound to the atom "billgates"
+ yielding the new subgoal "computer(billgates, ibmpc)".
+
+ (1995-03-14)
+
+LOGIN
+
+ 1. An {object-oriented} {deductive language} and {database}
+ system integrating {logic programming} and {inheritance}.
+
+ ["LOGIN: A Logic Programming Language with Built-In
+ Inheritance", H. Ait-Kaci et al, J Logic Programming
+ 3(3):185-215 (1986)].
+
+log in
+
+ <security> (Or "login", "log on", "logon") To start a
+ {session} with a system, usually by giving a {user name} and
+ {password} as a means of user {authentication}. The term is
+ also used to mean the ability to access a service (also called
+ an account), e.g. "Have you been given a login yet?"
+
+ "Log in/on" is occasionally misused to refer to starting a
+ session where no authorisation is involved, or to access where
+ there is no session involved. E.g. "Log on to our {Web
+ site}!"
+
+ "login" is also the {Unix} program which reads and verifies a
+ user's user name and password and starts an {interactive}
+ session.
+
+ The noun forms are usually written as a single word whereas
+ the verb forms are often written as two words.
+
+ To end a session is to "{log out}" or "off".
+
+ (2006-07-10)
+
+LOGISCOPE
+
+ Software quality analysis tools from {Verilog} SA, used to
+ evaluate the quality of software, both statically (based on
+ {software metrics}) and dynamically.
+
+Loglan
+
+ <human language> An artificial human language designed by
+ James Cooke Brown in the late 1950s.
+
+ Most artificial human languages devised in the 19th and 20th
+ centuries (e.g. Esperanto) were designed to be easy to learn.
+ Loglan, however, is unique in that its chief design goal was
+ to avoid synactic ambiguity -- the kind that arises when
+ trying to {parse} sentences like "The blind man picked up the
+ hammer and saw".
+
+ Loglan is thus the only human language unambiguously parseable
+ by a formal grammar (assuming you count Loglan as a human
+ language; its grammar is not at all like that of any natural
+ human language).
+
+ Most later development on Loglan continued under the name
+ "Lojban".
+
+ The Loglan Institute, Inc. is a non-profit research
+ corporation.
+
+ Loglan is unrelated to the programming languages {Loglan'82}
+ or {Loglan-88}.
+
+ {Halcyon Loglan (http://halcyon.com/loglan/welcome.html)}.
+
+ E-mail: loglan@compuserve.com
+
+ Telephone: +1 (619) 270 1691.
+
+ Address: The Loglan Institute, Inc., 3009 Peters Way, San
+ Diego, CA, 92117-4313 U.S.A.
+
+ ["Scientific American", June 1960].
+
+ (1999-01-14)
+
+Loglan'82
+
+ <language> A teaching language including all the programming
+ tools used in {object-oriented programming}, {modular
+ programming}, and {structured programming} as well as
+ programming by rules and {functional programming}.
+
+ Supported {object-oriented programming} features include
+ {classes}, {objects}, {coroutines}, processes (in Loglan'82
+ {processes} are {objects} which are able to act in parallel),
+ {inheritance}, {exception handling}, and {dynamic arrays}.
+
+ Loglan'82 is apparently unrelated to {Loglan}.
+
+ {(http://univ-pau.fr/~salwicki/loghome.html)}.
+
+ A {cross-compiler} to {C} is {here
+ (ftp://infpc1.univ-pau.fr/pub/Loglan82)}.
+
+ [Related to {Loglan-88}?]
+
+ (1999-07-02)
+
+Loglan-88
+
+ <language> An {object-oriented} language from the Institute of
+ Informatics at {Warsaw University}.
+
+ Loglan-88 is apparently unrelated to {Loglan}.
+
+ [Loglan-88, "Report on the Programming Language, LNCS 414,
+ Springer-Verlag, 1990, ISBN 3-540-52325-1].
+
+ [Related to {Loglan'82}?]
+
+ (1997-08-01)
+
+LOGLISP
+
+ A version of {Prolog} implemented by Robinson in {Lisp} which
+ allows Prolog programs to call Lisp and vice versa.
+
+ ["LOGLISP: An Alternative to Prolog", J. Alan Robinson et al
+ in Machine Intelligence 10, D. Michie ed, Ellis Horwood 1982].
+
+LOGO
+
+ <language, education> A {Lisp}-like language for teaching
+ programming, noted for its "turtle graphics" used to draw
+ geometric shapes. LOGO was developed in 1966-1968 by a group
+ at Bolt, Beranek & Newman (now "{BBN Technologies}") headed
+ by Wally Fuerzeig <fuerzeig@bbn.com> (who still works there in
+ 2003) and including Seymour Papert <seymour@media.mit.edu>.
+
+ There are Logo {interpreters} for {Macintosh}, {Unix}, {IBM
+ PC}, {X Window System}, and many PCs. Implmentations include
+ {Berkeley Logo}, {MswLogo}.
+
+ (2000-03-28)
+
+log off
+
+ {log out}
+
+LOGOL
+
+ Strings are stored on cyclic lists or 'tapes', which are
+ operated upon by finite automata. J. Mysior et al, "LOGOL, A
+ String manipulation Language", in Symbol Manipulations
+ Languages and Techniques, D.G. Bobrow ed, N-H 1968,
+ pp.166-177.
+
+logon
+
+ 1. <jargon> {login}.
+
+ 2. <networking> In {ACF}/{VTAM}, an unformatted
+ session-initiation request for a session between two {logical
+ units}.
+
+ (1996-03-07)
+
+log out
+
+ <security> (Or "log off") To end an authenticated session,
+ undoing what happens when you {log in}. This is primarily to
+ prevent other users gaining access to your logged in session,
+ e.g. at an unattended computer, but typically also terminates
+ any processes and network connections started as part of your
+ session.
+
+ (2004-11-16)
+
+Lojban
+
+ <human language> /lozh'bahn/ A language for humans developed
+ by former members of the {Loglan} project.
+
+ {Helsinki Lojban (http://xiron.pc.helsinki.fi/lojban/)}.
+
+ (2007-02-18)
+
+LOL
+
+ <chat> "laughing out loud", or "lots of love" or "luck".
+
+ (2003-07-29)
+
+LOLITA
+
+ {Language for the On-Line Investigation and Transformation of Abstractions}
+
+Lolli
+
+ <language> (Named after the "lollipop" operator "-o") An
+ {interpreter} for {logic programming} based on {linear logic},
+ written by Josh Hodas <hodas@saul.cis.upenn.edu>.
+
+ Lolli can be viewed as a refinement of the {Hereditary Harrop
+ formulas} of {Lambda-Prolog}. All the operators (though not
+ the {higher order unification}) of Lambda-Prolog are
+ supported, but with the addition of linear variations. Thus a
+ Lolli program distinguishes between clauses which can be used
+ as many, or as few, times as desired, and those that must be
+ used exactly once. Lolli is implemented in {SML/NJ}.
+
+ {(ftp://ftp.cis.upenn.edu/pub/Lolli/Lolli-0.7.tar.Z)}.
+
+ [Josh Hodas et al, "Logic Programming in a Fragment of
+ Intuitionistic Linear Logic", Information and Computation, to
+ appear].
+
+ (1992-11-18)
+
+LOM
+
+ <language> A programming language developed in Toulouse in the
+ early 1980s for {data processing}.
+
+ (1996-03-01)
+
+longitudinal parity
+
+ <storage, communications> An extra {byte} (or word) appended
+ to a block of data in order to reveal corruption of the data.
+ Bit n of this byte indicates whether there was an even or odd
+ number of "1" bits in bit position n of the bytes in the
+ block. The parity byte is computed by {XOR}ing the data bytes
+ in the block. Longitudinal parity allows single bit errors to
+ be detected.
+
+ (1996-03-01)
+
+Longitudinal Redundancy Check
+
+ <storage, communications> (LRC, Block Redundancy Check) An
+ {error checking} method that generates a {longitudinal parity}
+ {byte} from a specified {string} or block of {bytes} on a
+ longitudinal track.
+
+ The longitudinal parity byte is created by placing individual
+ bytes of a string in a two-dimensional {array} and performing
+ a {Vertical Redundancy Check} vertically and horizontally on
+ the array, creating an extra byte. This is an improvement
+ over the VRC because it will catch two errors in the
+ individual characters of the string, beyond the odd errors.
+
+ (2004-01-26)
+
+LOOK
+
+ A specification language.
+
+ ["A Look at Algebraic Specifications", S.N. Zilles et al, IBM
+ RR, 1982].
+
+ (1994-11-16)
+
+Look Ahead Left-to-right parse, Rightmost-derivation
+
+ <algorithm> (LALR, Look ahead LR) A type of {LR parser} that can
+ deal with more {context-free grammars} than {SLR parsers} but less
+ than {LR[1]} parsers. LALR parsers are popular because they give
+ a good trade-off between the number of grammars they can deal with
+ and the size of the {parsing table} required.
+
+ {Compiler compilers} like {yacc} and {Bison} generate LALR
+ parsers.
+
+ {Wikipedia (http://wikipedia.org/wiki/LALR_parser)}.
+
+ (2003-05-13)
+
+Look ahead LR
+
+ {Look Ahead Left-to-right parse, Rightmost-derivation}
+
+look and feel
+
+ <operating system> The appearance and function of a program's
+ {user interface}. The term is most often applied to
+ {graphical user interfaces} (GUI) but might also be used by
+ extension for a textual command language used to control a
+ program.
+
+ Look and feel includes such things as the {icons} used to
+ represent certain functions such as opening and closing files,
+ directories and {application programs} and changing the size
+ and position of windows; conventions for the meaning of
+ different buttons on a {mouse} and keys on the keyboard; and
+ the appearance and operation of menus.
+
+ A {user interface} with a consistent look and feel is
+ considered by many to be an important factor in the ease of
+ use of a computer system. The success of the {Macintosh user
+ interface} was partly due to its consistency.
+
+ Because of the perceived importance of look and feel, there
+ have been several legal actions claiming breech of {copyright}
+ on the look and feel of user interfaces, most notably by
+ {Apple Computer} against {Microsoft} and {Hewlett-Packard} (which Apple
+ lost) and, later, by {Xerox} against {Apple Computer}. Such legal
+ action attempts to force suppliers to make their interfaces
+ inconsistent with those of other vendors' products. This can
+ only be bad for users and the industry as a whole.
+
+ (1995-03-03)
+
+Looking Glass
+
+ A {desktop} manager for {Unix} from {Visix}.
+
+LOOKS
+
+ ["LOOKS: Knowledge-Representation System for Designing Expert
+ Systems in a Logical Programming Framework", F. Mizoguchi,
+ Proc Intl Conf 5th Gen Comp Sys, ICOT 1984].
+
+loop
+
+ <programming> A sequence of {instructions} that the
+ {processor} repeats, either until some condition is met, or
+ indefinitely.
+
+ In an {structured language} (e.g. {C}, {Pascal}, {BASIC}, or
+ {Fortran}), a loop is usually achieved with {for loop}, {while
+ loop} or {repeat loop} constructs.
+
+ In other languages these constructs may be synthesised with a
+ {jump} ({assembly language}) or a {GOTO} (early Fortran or
+ BASIC).
+
+ (1999-05-06)
+
+loop combination
+
+ A {program transformation} where the bodies of two loops are
+ merged into one thus reducing the overhead of manipulating and
+ testing the control variable and branching. Further
+ optimisation of the merged code may then become possible.
+
+ In {horizontal loop combination} the bodies of the loops are
+ largely independent so only the loop overhead is saved.
+ {Vertical loop combination} applies where the results of the
+ first loop are used by the second. Combining the two allows
+ the intermediate results to be used immediately (in
+ {registers}) rather than requiring them to be stored in an
+ {array}.
+
+ The functional equivalent of horizontal and vertical loop
+ combination are {tupling} and {fusion}.
+
+loop fusion
+
+ {loop combination}
+
+LOOPN
+
+ <language, simulation> A {compiler}, {simulator}, and associated
+ {source} control for an {object-oriented} {Petri net} language
+ developed by Charles Lakos <Charles.Lakos@adelaide.edu.au> at the
+ {University of Tasmania}. In LOOPN, a Petri net is an extension
+ of a {coloured timed Petri net}. The extension means firstly that
+ token types are {class}es. In other words, they consist of both
+ data fields and functions, they can be declared by inheriting from
+ other token types, and they can be used {polymorphic}ally. The
+ object-oriented extensions also mean that module or subnet types
+ are classes.
+
+ LOOPN has been developed over a period of about five years at
+ the University of Tasmania, where it has been used in teaching
+ computer simulation and the modelling of {network}
+ {protocols}.
+
+ {(ftp://ftp.cs.adelaide.edu.au/pub/OPN/loopn/)}.
+
+ (2000-09-02)
+
+LOOPS
+
+ {Lisp Object-oriented Programming System}
+
+loop through
+
+ To process each element of a list of things. "Hold on, I've
+ got to loop through my paper mail." Derives from the
+ computer-language notion of an iterative loop; compare "cdr
+ down" (under {cdr}), which is less common among C and Unix
+ programmers. ITS hackers used to say "IRP over" after an
+ obscure pseudo-op in the MIDAS PDP-10 assembler.
+
+ [{Jargon File}]
+
+loose bytes
+
+ Commonwealth hackish term for the padding bytes or {shims}
+ many compilers insert between members of a {record} or
+ {structure} to cope with alignment requirements imposed by the
+ machine architecture.
+
+LOP
+
+ A language based on {first-order logic}.
+
+ ["SETHEO - A High-Perormance Theorem Prover for First-Order
+ Logic", Reinhold Letz et al, J Automated Reasoning
+ 8(2):183-212 (1992)].
+
+lord high fixer
+
+ [Primarily British, from Gilbert & Sullivan's "Lord High
+ Executioner"] The person in an organisation who knows the most
+ about some aspect of a system. See {wizard}.
+
+ [{Jargon File}]
+
+Lore
+
+ 1. Object-oriented language for knowledge representation.
+ "Etude et Realisation d'un Language Objet: LORE", Y. Caseau,
+ These, Paris-Sud, Nov 1987.
+
+ 2. CGE, Marcoussis, France. Set-based language [same as 1?]
+ E-mail: Christophe Dony <chd.ibp.fr>
+
+Lorem ipsum
+
+ <text> A common piece of text used as mock-{content} when
+ testing a given page layout or {font}.
+
+ The following text is often used:
+
+ "Lorem ipsum dolor sit amet, consectetaur adipisicing elit,
+ sed do eiusmod tempor incididunt ut labore et dolore magna
+ aliqua. Ut enim ad minim veniam, quis nostrud exercitation
+ ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis
+ aute irure dolor in reprehenderit in voluptate velit esse
+ cillum dolore eu fugiat nulla pariatur. Excepteur sint
+ occaecat cupidatat non proident, sunt in culpa qui officia
+ deserunt mollit anim id est laborum."
+
+ This continues at length and variously. The text is not
+ really Greek, but badly garbled Latin. It started life as
+ extracted phrases from sections 1.10.32 and 1.10.33 of
+ Cicero's "De Finibus Bonorum et Malorum" ("The Extremes of
+ Good and Evil"), which read:
+
+ Sed ut perspiciatis unde omnis iste natus error sit voluptatem
+ accusantium doloremque laudantium, totam rem aperiam, eaque
+ ipsa quae ab illo inventore veritatis et quasi architecto
+ beatae vitae dicta sunt explicabo. Nemo enim ipsam voluptatem
+ quia voluptas sit aspernatur aut odit aut fugit, sed quia
+ consequuntur magni dolores eos qui ratione voluptatem sequi
+ nesciunt. Neque porro quisquam est, qui dolorem ipsum quia
+ dolor sit amet, consectetur, adipisci velit, sed quia non
+ numquam eius modi tempora incidunt ut labore et dolore magnam
+ aliquam quaerat voluptatem. Ut enim ad minima veniam, quis
+ nostrum exercitationem ullam corporis suscipit laboriosam,
+ nisi ut aliquid ex ea commodi consequatur? Quis autem vel eum
+ iure reprehenderit qui in ea voluptate velit esse quam nihil
+ molestiae consequatur, vel illum qui dolorem eum fugiat quo
+ voluptas nulla pariatur?
+
+ At vero eos et accusamus et iusto odio dignissimos ducimus qui
+ blanditiis praesentium voluptatum deleniti atque corrupti quos
+ dolores et quas molestias excepturi sint occaecati cupiditate
+ non provident, similique sunt in culpa qui officia deserunt
+ mollitia animi, id est laborum et dolorum fuga. Et harum
+ quidem rerum facilis est et expedita distinctio. Nam libero
+ tempore, cum soluta nobis est eligendi optio cumque nihil
+ impedit quo minus id quod maxime placeat facere possimus,
+ omnis voluptas assumenda est, omnis dolor repellendus.
+ Temporibus autem quibusdam et aut officiis debitis aut rerum
+ necessitatibus saepe eveniet ut et voluptates repudiandae sint
+ et molestiae non recusandae. Itaque earum rerum hic tenetur a
+ sapiente delectus, ut aut reiciendis voluptatibus maiores
+ alias consequatur aut perferendis doloribus asperiores
+ repellat.
+
+ Translation:
+
+ But I must explain to you how all this mistaken idea of
+ denouncing pleasure and praising pain was born and I will give
+ you a complete account of the system, and expound the actual
+ teachings of the great explorer of the truth, the
+ master-builder of human happiness. No one rejects, dislikes,
+ or avoids pleasure itself, because it is pleasure, but because
+ those who do not know how to pursue pleasure rationally
+ encounter consequences that are extremely painful. Nor again
+ is there anyone who loves or pursues or desires to obtain pain
+ of itself, because it is pain, but because occasionally
+ circumstances occur in which toil and pain can procure him
+ some great pleasure. To take a trivial example, which of us
+ ever undertakes laborious physical exercise, except to obtain
+ some advantage from it? But who has any right to find fault
+ with a man who chooses to enjoy a pleasure that has no
+ annoying consequences, or one who avoids a pain that produces
+ no resultant pleasure?
+
+ On the other hand, we denounce with righteous indignation and
+ dislike men who are so beguiled and demoralized by the charms
+ of pleasure of the moment, so blinded by desire, that they
+ cannot foresee the pain and trouble that are bound to ensue;
+ and equal blame belongs to those who fail in their duty
+ through weakness of will, which is the same as saying through
+ shrinking from toil and pain. These cases are perfectly
+ simple and easy to distinguish. In a free hour, when our
+ power of choice is untrammelled and when nothing prevents our
+ being able to do what we like best, every pleasure is to be
+ welcomed and every pain avoided. But in certain circumstances
+ and owing to the claims of duty or the obligations of business
+ it will frequently occur that pleasures have to be repudiated
+ and annoyances accepted. The wise man therefore always holds
+ in these matters to this principle of selection: he rejects
+ pleasures to secure other greater pleasures, or else he
+ endures pains to avoid worse pains.
+
+ -- Translation by H. Rackham, from his 1914 edition of De
+ Finibus.
+
+ However, since textual fidelity was unimportant to the goal of
+ having {random} text to fill a page, it has degraded over the
+ centuries, into "Lorem ipsum...".
+
+ The point of using this text, or some other text of incidental
+ intelligibility, is that it has a more-or-less normal (for
+ English and Latin, at least) distribution of ascenders,
+ descenders, and word-lengths, as opposed to just using "abc
+ 123 abc 123", "Content here content here", or the like.
+
+ The text is often used when previewing the layout of a
+ document, as the use of more understandable text would
+ distract the user from the layout being examined. A related
+ technique is {greeking}.
+
+ {Lorem Ipsum - All the facts (http://lipsum.com/)}.
+
+ (2006-09-18)
+
+Lorenz attractor
+
+ <mathematics> (After {Edward Lorenz}, its discoverer) A region
+ in the {phase space} of the solution to certain systems of
+ (non-linear) {differential equations}. Under certain
+ conditions, the motion of a particle described by such as
+ system will neither converge to a steady state nor diverge to
+ infinity, but will stay in a bounded but chaotically defined
+ region. By {chaotic}, we mean that the particle's location,
+ while definitely in the attractor, might as well be randomly
+ placed there. That is, the particle appears to move randomly,
+ and yet obeys a deeper order, since is never leaves the
+ attractor.
+
+ Lorenz modelled the location of a particle moving subject to
+ atmospheric forces and obtained a certain system of {ordinary
+ differential equations}. When he solved the system
+ numerically, he found that his particle moved wildly and
+ apparently randomly. After a while, though, he found that
+ while the momentary behaviour of the particle was chaotic, the
+ general pattern of an attractor appeared. In his case, the
+ pattern was the butterfly shaped attractor now known as the
+ {Lorenz attractor}.
+
+ (1996-01-13)
+
+LORIA
+
+ {Laboratoire lorrain de recherche en informatique et ses applications}
+
+lose
+
+ <jargon> ({MIT}) 1. To fail. A program loses when it
+ encounters an exceptional condition or fails to work in the
+ expected manner.
+
+ 2. To be exceptionally unesthetic or crocky.
+
+ 3. Of people, to be obnoxious or unusually stupid (as opposed
+ to ignorant).
+
+ 4. Refers to something that is {losing}, especially in the
+ phrases "That's a lose!" and "What a lose!"
+
+ [{Jargon File}]
+
+ (1995-04-19)
+
+loser
+
+ <jargon> An unexpectedly bad situation, program, programmer,
+ or person. Someone who habitually loses. (Even winners can
+ lose occasionally). Someone who knows not and knows not that
+ he knows not. Emphatic forms are "real loser", "total loser",
+ and "complete loser" (but not **"moby loser", which would be a
+ contradiction in terms).
+
+ See {luser}.
+
+ [{Jargon File}]
+
+ (1995-04-19)
+
+losing
+
+ <jargon> Said of anything that is or causes a {lose} or
+ {lossage}.
+
+ [{Jargon File}]
+
+loss
+
+ <jargon> Something (not a person) that loses; a situation in
+ which something is losing. Emphatic forms include "moby
+ loss", and "total loss", "complete loss". Common
+ interjections are "What a loss!" and "What a moby loss!"
+ Note that "moby loss" is OK even though **"moby loser" is not
+ used; applied to an abstract noun, moby is simply a magnifier,
+ whereas when applied to a person it implies substance and has
+ positive connotations.
+
+ Compare {lossage}.
+
+ (1995-04-19)
+
+lossage
+
+ <jargon> /los'*j/ The result of a {bug} or malfunction. This
+ is a mass or collective noun. "What a loss!" and "What
+ lossage!" are nearly synonymous. The former is slightly more
+ particular to the speaker's present circumstances; the latter
+ implies a continuing {lose} of which the speaker is currently
+ a victim. Thus (for example) a temporary hardware failure is
+ a loss, but bugs in an important tool (like a compiler) are
+ serious lossage.
+
+ [{Jargon File}]
+
+ (1995-04-19)
+
+lossless
+
+ <algorithm, compression> A term describing a data
+ {compression} {algorithm} which retains all the information in
+ the data, allowing it to be recovered perfectly by
+ decompression.
+
+ {Unix} {compress} and {GNU} {gzip} perform lossless
+ compression.
+
+ Opposite: {lossy}.
+
+ (1995-03-29)
+
+lossless audio compression
+
+ <audio, compression> Any kind of {audio compression} in which
+ the original signal and the decoded signal are bitwise
+ identical. Lossless audio compression algorithms are usually
+ based on a data compression algorithm like {PKzip} or {gzip}
+ but specialized for {PCM} audio data. The signal is divided
+ into predictable {tonal} components and unpredictable noisy
+ components. Tonal components are stored as coefficients of a
+ predictor, the remaining signal is coded by {Rice coding},
+ {Huffman coding} or {arithmetic coding}.
+
+ (2001-12-24)
+
+Lossless Predictive Audio Compression
+
+ <audio, compression> (LPAC) A {lossless} {audio} {compression}
+ {algorithm} with compression ratios from 1.5 to 4, depending
+ on the input. Software is available for {Microsoft Windows},
+ {Linux} and {Solaris}. LPAC files (*.pac) can be played with
+ a {Winamp} {plug-in}.
+
+ {(http://www-ft.ee.tu-berlin.de/~liebchen/lpac.html)}.
+
+ (2001-12-17)
+
+lossy
+
+ <algorithm> A term describing a data {compression} {algorithm}
+ which actually reduces the amount of information in the data,
+ rather than just the number of bits used to represent that
+ information. The lost information is usually removed because
+ it is subjectively less important to the quality of the data
+ (usually an {image} or {sound}) or because it can be recovered
+ reasonably by {interpolation} from the remaining data.
+
+ {MPEG} and {JPEG} are examples of lossy compression
+ techniques.
+
+ Opposite: {lossless}.
+
+ (1995-03-29)
+
+lossy audio compression
+
+ <audio, compression> Any audio compression algorithm which
+ does not retain every bit of data but only reproduces a signal
+ that sounds more or less like the original. Examples are
+ {MP1}, {MP2}, {MP3}, {AAC}.
+
+ (2001-12-24)
+
+lost in the noise
+
+ Synonym {lost in the underflow}. This term is from signal
+ processing, where signals of very small amplitude cannot be
+ separated from low-intensity noise in the system. Though
+ popular among hackers, it is not confined to hackerdom;
+ physicists, engineers, astronomers, and statisticians all use
+ it.
+
+ [{Jargon File}]
+
+lost in the underflow
+
+ <jargon> Too small to be worth considering; more specifically,
+ small beyond the limits of accuracy or measurement. This is a
+ reference to "{floating point underflow}".
+
+ The {Hacker's Jargon File} claimed that it is also a pun on
+ "undertow" (a kind of fast, cold current that sometimes runs
+ just offshore and can be dangerous to swimmers).
+
+ "Well, sure, photon pressure from the stadium lights alters
+ the path of a thrown baseball, but that effect gets lost in
+ the underflow".
+
+ Compare {epsilon}, {epsilon squared}; see also {overflow bit}.
+
+ (1997-09-05)
+
+LOTIS
+
+ LOgic, TIming, Sequencing. A language which describes a
+ computer via its data flow.
+
+ [Sammet 1969, p. 620].
+
+LOTOS
+
+ {Language Of Temporal Ordering Specification}
+
+lots of MIPS but no I/O
+
+ Used to describe a person who is technically brilliant but
+ can't seem to communicate with human beings effectively.
+ Technically it describes a machine that has lots of processing
+ power but is bottlenecked on input-output (in 1991, the IBM
+ Rios, a.k.a. RS/6000, is a notorious recent example).
+
+ [{Jargon File}]
+
+Lotus 1-2-3
+
+ <tool, product> A {spreadsheet} for {MS-DOS} from {Lotus
+ Development Corporation}. It can be programmed using
+ "{macros}" and comes with a separate program to produce graphs
+ and charts but this cannot be run at the same time as the
+ spreadsheet. It has keyboard-driven {pop-up menus} as well as
+ one-key commands, making it fast to operate. Lotus 1-2-3
+ supported {EGA} and later {VGA} graphics. Early versions used
+ the {filename extension} "WK1".
+
+ Version: 4.
+
+ Lotus 1-2-3 has been the subject of several {user interface
+ copyright} court cases in the US.
+
+ {(http://nyweb.com/lotus/123.html)}.
+
+ 1-2-3's successor, {Symphony}, had simultaneous update of
+ spreadsheet, graph and {word processor} windows.
+
+ (1995-11-28)
+
+Lotus Development Corporation
+
+ <company> A software company who produced {Lotus 1-2-3}, the
+ {Symphony} {spreadsheet} and {Lotus Notes} for the {IBM PC}.
+
+ Disliked by the {League for Programming Freedom} on account of
+ their lawsuits.
+
+ Quarterly sales $224M, profits $10M (Aug 1994).
+
+ Telephone: +1 (617) 225 1284.
+
+ [Where are they? Founded when? Other products? E-mail?
+ Internet?]
+
+ (1994-11-16)
+
+Lotus Notes
+
+ A group of {application programs} from {Lotus Development
+ Corporation} which allows organisations to share documents and
+ exchange {electronic mail} messages. Notes supports
+ {replication}.
+
+ (1994-10-27)
+
+Lotus Notes Formula Language
+
+ <language> A {macro} language for {Lotus Notes} that uses
+ commands starting with @, e.g. @If, @Left, @Right, @Username.
+ Many Notes applications are built with just this language.
+
+ (2003-10-06)
+
+LotusScript
+
+ <language> A {Visual BASIC}-like {scripting language} for
+ {Lotus Notes} and {Lotus SmartSuite}. LotusScript is
+ {object-oriented} and can be used for complex Notes
+ programming, although {Java} is also available.
+
+ {LotusScript Documentation
+ (http://lotus.com/products/lotusscript.nsf)}.
+
+ (2003-10-06)
+
+loudspeaker
+
+ <audio, hardware> An electromechanical device for converting
+ an electrical signal into sound.
+
+ (2008-10-09)
+
+Lout
+
+ Lout is a batch text formatting system and an embedded
+ language by Jeffrey H. Kingston <jeff@cs.su.oz.au>. The
+ language is procedural, with {Scribe}-like {syntax}.
+
+ Lout features equation formatting, tables, diagrams, rotation
+ and scaling, sorted indexes, bibliographic databases, running
+ headers and odd-even pages and automatic cross-referencing.
+ Lout is easily extended with definitions which are very much
+ easier to write than {troff} of {TeX} {macros} because Lout is
+ a {high-level language}, the outcome of an eight-year research
+ project that went back to the beginning.
+
+ Version 2.05 includes a translator from Lout to {PostScript}
+ and documentation. and runs under {Unix} and on the {Amiga}.
+
+ {Author's site (ftp://ftp.cs.su.oz.au/jeff/lout.2.03.tar.Z)},
+ {(ftp://ftp.uu.net/tmp/lout.tar.Z)}. {Amiga
+ (ftp://ftp.wustl.edu/pub/aminet/text/dtp/loutBin203.lha)}.
+
+ (1993-07-30)
+
+love
+
+ <humour> What some users feel for computers.
+
+ "There is no truth in the rumour that I love computers, it's
+ just what I tell them to get them to bed."
+
+ -- Terry Pratchett
+
+ [What did you expect in a computing dictionary?]
+
+ (2007-05-11)
+
+low-bandwidth
+
+ [communication theory] Used to indicate a talk that, although
+ not {content-free}, was not terribly informative. "That was a
+ low-bandwidth talk, but what can you expect for an audience of
+ {suits}!" Compare {zero-content}, {bandwidth}, {math-out}.
+
+ [{Jargon File}]
+
+Low Bandwidth X
+
+ <networking> (LBX) An implementation of the {X Window System}
+ designed to improve performance over {ISDN}, {WAN}, and
+ {serial lines}.
+
+ [Details?]
+
+ (2003-07-09)
+
+low earth orbit
+
+ <communications> (LEO) The kind of orbit used by
+ communications satellites that will offer high {bandwidth} for
+ {video on demand}, television, and {Internet} communications.
+ A satellite in LEO, in contrast to one in a {geostationary
+ orbit}, is not in a fixed position relative to the Earth's
+ surface so several satellites are required to provide
+ continuous service.
+
+ [Ovum report, "Applications for the superhighway", John
+ Moroney].
+
+ (1996-02-06)
+
+Lower Layer Protocol
+
+ <networking, protocol> (LLP, or lower-layer protocol)
+ Any {protocol} residing in {OSI} layers one to four.
+
+ These protocols package, {route}, verify and transmit
+ {datagrams}. A prime example would be {TCP/IP}. Lower layer
+ protocols support the {upper layer protocols}.
+
+ (1999-02-17)
+
+lower set
+
+ <mathematics> A {finite} non-empty {downward closed} subset of
+ a {partial order}.
+
+ (1999-03-17)
+
+Low Insertion Force
+
+ <hardware> (LIF) {PGA}/{SPGA} sockets with no handle. The
+ {integrated circuit} is simply pushed into the socket, and
+ levered out to remove. Most {motherboard} {processor} sockets
+ are now {ZIF} rather than LIF.
+
+ (1999-08-05)
+
+LOWL
+
+ <language> The {abstract machine} for {bootstrapping} {ML/1},
+ developed by P.J. Brown of the {University of Kent at
+ Canterbury}.
+
+ ["Macro Processors and Techniques for Portable Software",
+ P.J. Brown, published by Wiley, ISBN 0.471.11005.1].
+
+ [Mentioned in "Machine Oriented Higher Level Languages",
+ W. van der Poel, N-H 1974, p. 271].
+
+ [What does LOWL stand for?]
+
+ (1997-11-04)
+
+low-level language
+
+ <language> Any {programming language} which either is
+ {assembly language}, or which is meant to be closely related
+ to, and easily translated into, {machine language}. Low-level
+ languages lack the amenities of {high-level languages} but it
+ may be possible to write more efficient code in them.
+
+ (2000-08-10)
+
+low pass filter
+
+ <electronics, graphics> A filter that attenuates high
+ frequency components of a signal.
+
+ In {image processing}, a low pass filter might be used to
+ remove {noise} from an {image}.
+
+ (2000-04-19)
+
+Low Voltage Differential
+
+ <hardware> (LVD) A method of driving {SCSI} cables that will
+ be formalised in the {SCSI-3} specifications. LVD uses less
+ power than the current differential drive ({HVD}), is less
+ expensive and will allow the higher speeds of {Ultra-2 SCSI}.
+ LVD requires 3.3 Volts DC instead of 5 Volts DC for HVD.
+
+ (1999-02-16)
+
+LPAC
+
+ 1. <audio, compression> {Lossless Predictive Audio Compression}.
+
+ 2. {London Parallel Applications Centre}.
+
+ (2001-12-17)
+
+LPC
+
+ <language> A variant of {C} designed ca 1988 to program
+ {LP MUDs}.
+
+ (1995-04-18)
+
+LPF
+
+ {League for Programming Freedom}
+
+LPG
+
+ 1. Linguaggio Procedure Grafiche (Italian for "Graphical
+ Procedures Language"). dott. Gabriele Selmi. Roughly a cross
+ between Fortran and APL, with graphical-oriented extensions
+ and several peculiarities. Underlies the products of CAD.LAB
+ Spa. "Graphical Procedure Language User's Guide and Reference
+ Manual", CAD.LAB, Bologna, Italy, 1989, order code GO89/9.
+
+ 2. Langage de Programmation Generique. An applicative
+ language, both specification and functional. Special emphasis
+ on parametrised declarations. "Design and Implementation of a
+ Generic, Logic and Functional Programming Language", D. Bert
+ et al, ESOP 86, LNCS 213, Springer 1986.
+
+LPI
+
+ <language> A {PL/I} {interpreter} for {IBM PCs} and
+ {workstations}.
+
+ {(ftp://ftp.wustl.edu/mirrors/msdos/pli/runpli1a.arc)}.
+
+ E-mail: <rcg@lpi.liant.com>.
+
+ (1999-09-03)
+
+LPL
+
+ List Programming Language. LISP-like language with ALGOL-like
+ syntax, for IBM 360. "LPL - LISP Programming Language",
+ F.W. Blair et al, RC 3062, IBM TJWRC, Sep 1970.
+
+lpm
+
+ {lines per minute}
+
+LP MUD
+
+ <games> A kind of player-programmable multi-user adventure
+ game.
+
+ [More details?]
+
+ See {MUD}.
+
+lpr
+
+ Line printer. The {Unix} print command. This does not
+ actually print files but rather copies (or links) them to a
+ {spool} area from where a {daemon} copies them to the printer.
+
+LPS
+
+ Sets with restricted {universal quantifiers}.
+
+ ["Logic Programming with Sets", G. Kuper, J Computer Sys Sci
+ 41:44-64 (1990)].
+
+lp spooler
+
+ <printer> A {line printer} {spooler}.
+
+ (2000-04-03)
+
+LPT
+
+ /L-P-T/ or /lip'it/ or /lip-it'/ Line printer. Rare under
+ {Unix}, more common among hackers who grew up with {ITS},
+ {MS-DOS}, {CP/M} and other {operating systems} that were
+ strongly influenced by early {DEC} conventions.
+
+ [{Jargon File}]
+
+lr
+
+ <networking> The {country code} for Liberia.
+
+ (1999-01-27)
+
+LRC
+
+ {Longitudinal Redundancy Check}
+
+LRLTRAN
+
+ Lawrence Radiation Laboratory TRANslator.
+
+ A {Fortran} extension with vector arithmetic and {dynamic
+ storage}, used for scientific work and systems programming,
+ including the {LTSS} {operating system}.
+
+ ["The LRLTRAN Compiler", S.F. Mendicino, CACM 11(11):747-775
+ (Nov 1969)].
+
+LRU
+
+ {Least Recently Used}
+
+ls
+
+ 1. <file system, tool> The {Unix} command for listing a
+ {directory}.
+
+ {Unix manual page}: ls(1).
+
+ 2. <networking> The {country code} for Lesotho.
+
+ (2000-03-18)
+
+LSA
+
+ {Link State Advertisement}
+
+LSB
+
+ 1. {Least Significant Bit}.
+
+ 2. (Rarely) Least Significant Byte.
+
+LSE
+
+ {Language Sensitive Editor}
+
+LSL
+
+ 1. Larch Shared Language. An assertion language. (See
+ Larch).
+
+ 2. Link and Selector Language. Graphic query language. "LSL:
+ A Link and Selector Language", D.C. Tsichritzis, Proc Intl
+ Conf Management of Data, ACM 1976, pp.123-134.
+
+LSML
+
+ {Lazy Standard ML}
+
+L-Soft
+
+ An international corporation formed by Eric Thomas, the author
+ of {Listserv}, to develop it and port it to platforms other
+ than the {IBM} {VM} {operating system}, including {Unix}.
+ Listserv has been enhanced to use both the {Internet} and
+ {BITNET}.
+
+ (1995-02-22)
+
+LSP
+
+ {Label Switched Path}
+
+LSR
+
+ 1. <networking> {Label Switching Router}.
+
+ 2. <operating system> {Local Shared Resources}.
+
+ (2002-02-17)
+
+LSSD
+
+ {level-sensitive scan design}
+
+LSYD
+
+ Language for SYstems Development.
+
+ A {PL/I}-like language with data structure and character
+ extensions.
+
+ ["Systems Programming Languages", R.D. Bergeron et al, in
+ Advances in Computers 1971, A-P].
+
+ (1995-01-31)
+
+lt
+
+ <networking> The {country code} for Lithuania.
+
+ (1999-01-27)
+
+LT-2
+
+ An early system on the {IBM 701}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1995-01-31)
+
+LTL
+
+ {Linear Temporal Logic}
+
+LTPS
+
+ {Low Temperature Polysilicon}
+
+LTR
+
+ Langage Temps-Réel.
+
+ (French for "real-time language") A French predecessor to
+ {Ada}, LTR is {Modula}-like with a set of special-purpose
+ {real-time} constructs based on an event model. It was
+ mentioned in the reference below.
+
+ ["An Overview of Ada", J.G.P. Barnes, Soft Prac & Exp
+ 10:851-887 (1980)].
+
+ (1995-01-31)
+
+LTR3
+
+ Version three of {LTR}, by A. Parayre of Delegation Generale
+ pour l'Armement, France. LTR3 was widely used by the French
+ military and avionics companies.
+
+ ["The LTR3 Reference Manual", A. Parayre, Delegation Generale
+ pour l'Armement, France].
+
+ (1995-01-31)
+
+lu
+
+ <networking> The {country code} for Luxembourg.
+
+ (1999-01-27)
+
+LU6.2
+
+ {Logical Unit 6.2}
+
+lub
+
+ {least upper bound}
+
+Lubarsky's Law of Cybernetic Entomology
+
+ <humour> There is always one more {bug}.
+
+ [{Jargon File}]
+
+ (2001-07-12)
+
+Lucent Technologies
+
+ <company, telecommunications, Unix> The former systems and
+ equipment portion of {AT&T} (including {Bell Laboratories}),
+ split off in 1996.
+
+ {Lucent Home (http://lucent.com/)}.
+
+ (2002-06-23)
+
+LUCID
+
+ 1. Early query language, ca. 1965, System Development Corp,
+ Santa Monica, CA. [Sammet 1969, p.701].
+
+ 2. A family of dataflow languages descended from {ISWIM},
+ {lazy} but {first-order}.
+
+ Ashcroft & Wadge <wwadge@csr.uvic.ca>, 1981.
+
+ They use a dynamic {demand driven} model. Statements are
+ regarded as equations defining a network of processors and
+ communication lines, through which the data flows. Every data
+ object is thought of as an infinite {stream} of simple values,
+ every function as a {filter}. Lucid has no {data
+ constructors} such as {arrays} or {records}. {Iteration} is
+ simulated with 'is current' and 'fby' (concatenation of
+ sequences). Higher-order functions are implemented using pure
+ dataflow and no closures or heaps.
+
+ ["Lucid: The Dataflow Language" by Bill Wadge
+ <wwadge@csr.UVic.CA> and Ed Ashcroft, c. 1985]. ["Lucid, the
+ Dataflow Programming Language", W. Wadge, Academic Press
+ 1985].
+
+ (1995-02-16)
+
+Lucid Emacs
+
+ {Xemacs}
+
+Lucinda
+
+ <language> A language which combines {Russell}-like
+ {polymorphism} with {Linda}-like {concurrency}. Lucinda is
+ implemented as a {threaded interpreter} written in {C}, for a
+ {Sun} network and a {Meiko Computing Surface}.
+
+ ["Lucinda - An Overview", P. Butcher, U York et al, SIGPLAN
+ Notices 26(8):90-100, Aug 1991].
+
+ E-mail: Alan Wood <wood@cs.york.ac.uk>.
+
+ (1996-08-20)
+
+Lucy
+
+ <language> A {distributed} {constraint programming} language,
+ which is an {actor} subset of {Janus}.
+
+ ["Actors as a Special Case of Concurrent Constraint
+ Programming", K. Kahn <kahn@parc.xerox.com> et al, SIGPLAN
+ Notices 25(10):57-66 (OOPSLA/ ECOOP '90), Oct 1990].
+
+ (2001-03-04)
+
+LUG
+
+ {Linux User Group}
+
+luminance
+
+ {brightness}
+
+lump uncurrying
+
+ Chin's generalisation of {uncurrying}. A curried function
+ taking several {tuples} as arguments can be transformed to
+ take a single tuple containing all the components of the
+ original tuples.
+
+LUN
+
+ {Logical Unit Number}
+
+lunatic fringe
+
+ [IBM] Customers who can be relied upon to accept release 1
+ versions of software.
+
+ [{Jargon File}]
+
+Lund Simula
+
+ <language> A version of {SIMULA} from {Lund Software House}.
+
+ Version 4.07.
+
+ (FTP: rascal.ics.utexas.edu/misc/mac/programming/ no longer
+ exists).
+
+ (1995-03-29)
+
+Lund Software House AB
+
+ <company> The company who produced {Lund Simula}.
+
+ Address: Box 7056, S-22007 Lund, Sweden.
+
+ (1995-03-29)
+
+lurk
+
+ {lurking}
+
+lurker
+
+ {lurking}
+
+lurking
+
+ <messaging, jargon> The activity of one of the "silent
+ majority" in a electronic forum such as {Usenet}; posting
+ occasionally or not at all but reading the group's postings
+ regularly. This term is not pejorative and indeed is casually
+ used reflexively: "Oh, I'm just lurking". Often used in "the
+ lurkers", the hypothetical audience for the group's
+ {flamage}-emitting regulars.
+
+ Lurking and reading the {FAQ} are recommended {netiquette} for
+ beginners who need to learn the history and practises of the
+ group before posting.
+
+ (1997-06-14)
+
+luser
+
+ <jargon, abuse> /loo'zr/ A {user}; especially one who is also
+ a {loser}. ({luser} and {loser} are pronounced identically.)
+ This word was coined around 1975 at {MIT}.
+
+ Under {ITS}, when you first walked up to a terminal at MIT and
+ typed Control-Z to get the computer's attention, it printed
+ out some status information, including how many people were
+ already using the computer; it might print "14 users", for
+ example. Someone thought it would be a great joke to patch
+ the system to print "14 losers" instead. There ensued a great
+ controversy, as some of the users didn't particularly want to
+ be called losers to their faces every time they used the
+ computer. For a while several hackers struggled covertly,
+ each changing the message behind the back of the others; any
+ time you logged into the computer it was even money whether it
+ would say "users" or "losers". Finally, someone tried the
+ compromise "lusers", and it stuck.
+
+ Later one of the ITS machines supported "luser" as a
+ request-for-help command. ITS died the death in mid-1990,
+ except as a museum piece; the usage lives on, however, and the
+ term "luser" is often seen in program comments.
+
+ See: also {LART}. Compare: {tourist}, {weenie}.
+
+ [{Jargon File}]
+
+ (1998-07-01)
+
+Luser Attitude Re-adjustment Tool
+
+ <jargon> (LART) Something large, heavy and painful, used to
+ respond appropriately to particularly annoying {lusers}.
+
+ The alt.sysadmin.recovery {FAQ} recommends the following
+ LARTs. A 2x4 works fine, but a real professional needs
+ something a little more effective. Unfortunately, this is a
+ very personal thing, and no consensus has yet been reached on
+ the group. Everything from a simple, 7.65mm Walther (for the
+ Bond fans only, it's not a very good gun) to a 155mm with
+ depleted Uranium rounds has been suggested, some even going
+ for exotic things like Thermite, nukes or flamethrowers. For
+ further info, look at the rec.guns home page.
+
+ {alt.sysadmin.recovery FAQ
+ (http://ctrl-c.liu.se/~ingvar/asr/overview.html)}.
+
+ (1998-12-09)
+
+LUSTRE
+
+ (A French acronym for Synchronous real-time Lucid). Real-time
+ dataflow language for synchronous systems, especially
+ automatic control and signal processing. A {Lucid} subset,
+ plus timing operators and user-defined clocks.
+
+ Designed for automatic control applications. It is based on
+ the idea that automatic control engineers use to analyse, and
+ specify their systems in terms of functions over sequences
+ (sampled signals). It thus seems both safe and cost effective
+ to try to compile directly those descriptions into executable
+ code. A lot of work has been done, so as to get efficient
+ compilation, and also in formal verification. The language
+ has been used in nuclear plant control, and will be used in
+ aircraft control.
+
+ ["Outline of a Real-Time Data-Flow Language", J.-L. Bergerand
+ et al, Proc IEE-CS Real Time Systems Symp, San Diego, IEEE Dec
+ 1985, pp. 33-42].
+
+ ["LUSTRE: A Declarative Language for Programming Synchronous
+ Systems", P. Caspi et al, Conf Rec 14th Ann ACM Symp on Princ
+ Prog Langs, 1987].
+
+ (1994-10-12)
+
+lv
+
+ <networking> The {country code} for Latvia.
+
+ (1999-01-27)
+
+lvalue
+
+ <programming> A reference to a location, an expression which
+ can appear as the destination of an {assignment} operator
+ indicating where a value should be stored. For example, a
+ variable or an array element are lvalues but the constant 42
+ and the expression i+1 are not. A constant string may or may
+ not be an lvalue (it usually is in {C}).
+
+ (1995-04-28)
+
+LVD
+
+ {Low Voltage Differential}
+
+LWP
+
+ <programming> {light-weight process}.
+
+ (1996-02-22)
+
+ly
+
+ <networking> The {country code} for Libya.
+
+ (1999-01-27)
+
+LYaPAS
+
+ (Russian acronym for "Logical Language for the Representation
+ of Synthesis Algorithms")
+
+ A language for the {URAL-1} computer. It was coded in
+ {octal}!
+
+ ["LYaPAS: A Programming Language for Logic and Coding
+ Algorithms", M.A. Gavrilov et al eds, Academic Press 1969].
+
+ (1995-02-16)
+
+Lycos
+
+ <web> A {web} index, served by {Carnegie
+ Mellon University}. It allows you to search on document title
+ and content for a list of keywords. Lycos is probably the
+ biggest such index on the web. By April 1995, the Lycos
+ database contained 2.95 million unique documents.
+
+ The Lycos database is built by a {Web crawler} that can bring
+ in 5000 documents per day. The index searches document title,
+ headings, links, and keywords it locates in these documents.
+
+ The Lycos servers are efficient but overloaded. Failure to
+ connect or "please try later" messages are common.
+
+ {(http://lycos.cs.cmu.edu/)}.
+
+ (1995-04-06)
+
+lylafklc
+
+ <chat> Love you like a fat kid loves cake.
+
+ (2006-12-12)
+
+lynix
+
+ <spelling> Misspelling of "{Linux}" (the {Unix} {clone}), or
+ possibly "{lynx}" (the {web browser}).
+
+ (1995-04-06)
+
+LYNX
+
+ A language for large distributed {networks}, using {remote
+ procedure calls}, developed by the {University of Wisconsin}
+ in 1984.
+
+ ["The Lynx Distributed Programming Language: Motivation,
+ Design and Experience", M.L. Scott, Computer Langs 16:209-233
+ (1991)].
+
+ (1994-10-12)
+
+Lynx
+
+ 1. A {WWW} {browser} from the {University of Kansas} for use
+ on {cursor-addressable}, {character cell} {terminals} or
+ {terminals emulators} under {Unix} or {VMS}. Lynx is a
+ product of the Distributed Computing Group within Academic
+ Computing Services of The {University of Kansas}. Lynx was
+ originally developed by Lou Montulli, Michael Grobe and
+ Charles Rezac. Garrett Blythe created {DosLynx} and later
+ joined the Lynx effort as well. Foteos Macrides ported much
+ of Lynx to VMS and is now maintaining it.
+
+ Version: 2.4-FM (1995-10-25).
+
+ {(http://cc.ukans.edu/about_lynx/about_lynx.html)}.
+
+ Mailing list: lynx-dev@ukanaix.cc.ukans.edu (send "subscribe
+ lynx-dev <your-name>" in the message body to
+ listserv@ukanaix.cc.ukans.edu).
+
+ (1994-12-07)
+
+ 2. {Lynx Real-Time Systems}.
+
+ (1996-03-25)
+
+LynxOS
+
+ A {POSIX} compliant {real-time} {operating system} from {Lynx
+ Real-Time Systems}. It has a {Unix}-like interface to
+ {application programs}.
+
+ (1994-10-12)
+
+Lynx Real-Time Systems
+
+ A company in Los Gatos, California who distribute {LynxOS}.
+
+ {(http://lynx.com/)}.
+
+ E-mail: <sales@lynx.com>, <support@lynx.com>.
+
+ Address: 16780 Lark Avenue, Los Gatos, CA 95030, USA.
+
+ Telephone:: +1 (408) 354 7770, +1 (800) 255 LYNX. Fax: +1
+ (408) 354 7085.
+
+ (1995-01-18)
+
+LYRIC
+
+ Language for Your Remote Instruction by Computer. A {CAI}
+ language implemented as a {Fortran} {preprocessor}.
+
+ ["Computer Assisted Instruction: Specification of Attributes
+ for CAI Programs and Programmers", G.M. Silvern et al, Proc
+ ACM 21st Natl Conf (1966)].
+
+ (1994-10-12)
+
+LZ77 compression
+
+ The first {algorithm} to use the {Lempel-Ziv} {substitutional
+ compression} schemes, proposed in 1977. LZ77 compression
+ keeps track of the last n bytes of data seen, and when a
+ phrase is encountered that has already been seen, it outputs a
+ pair of values corresponding to the position of the phrase in
+ the previously-seen buffer of data, and the length of the
+ phrase. In effect the compressor moves a fixed-size "window"
+ over the data (generally referred to as a "sliding window"),
+ with the position part of the (position, length) pair
+ referring to the position of the phrase within the window.
+
+ The most commonly used {algorithms} are derived from the
+ {LZSS} scheme described by James Storer and Thomas Szymanski
+ in 1982. In this the compressor maintains a window of size N
+ bytes and a "lookahead buffer", the contents of which it tries
+ to find a match for in the window:
+
+ while (lookAheadBuffer not empty)
+ {
+ get a pointer (position, match) to the longest match in
+ the window for the lookahead buffer;
+
+ if (length > MINIMUM_MATCH_LENGTH)
+ {
+ output a (position, length) pair;
+ shift the window length characters along;
+ }
+ else
+ {
+ output the first character in the lookahead buffer;
+ shift the window 1 character along;
+ }
+ }
+
+ Decompression is simple and fast: whenever a (POSITION,
+ LENGTH) pair is encountered, go to that POSITION in the window
+ and copy LENGTH bytes to the output.
+
+ Sliding-window-based schemes can be simplified by numbering
+ the input text characters mod N, in effect creating a circular
+ buffer. The sliding window approach automatically creates the
+ {LRU} effect which must be done explicitly in {LZ78} schemes.
+ Variants of this method apply additional compression to the
+ output of the LZSS compressor, which include a simple
+ variable-length code ({LZB}), dynamic {Huffman coding}
+ ({LZH}), and {Shannon-Fano} coding ({ZIP} 1.x), all of which
+ result in a certain degree of improvement over the basic
+ scheme, especially when the data are rather random and the
+ LZSS compressor has little effect. An algorithm was developed
+ which combines the ideas behind LZ77 and LZ78 to produce a
+ hybrid called {LZFG}. LZFG uses the standard sliding window,
+ but stores the data in a modified {trie} data structure and
+ produces as output the position of the text in the trie.
+ Since LZFG only inserts complete *phrases* into the
+ dictionary, it should run faster than other LZ77-based
+ compressors.
+
+ All popular archivers ({arj}, {lha}, {zip}, {zoo}) are
+ variations on LZ77.
+
+ [comp.compression {FAQ}].
+
+ (1995-04-07)
+
+LZ78 compression
+
+ A {substitutional compression} scheme which works by entering
+ phrases into a dictionary and then, when a reoccurrence of
+ that particular phrase is found, outputting the dictionary
+ index instead of the phrase. Several {algorithms} are based
+ on this principle, differing mainly in the manner in which
+ they manage the dictionary.
+
+ The most well-known Lempel-Ziv scheme is Terry Welch's
+ {Lempel-Ziv Welch} variant of LZ78.
+
+ [comp.compression {FAQ}].
+
+LZ compression
+
+ {Lempel-Ziv compression}
+
+lzexe
+
+ An executable file {compression} utility for {MS-DOS}. It
+ adds a minimal header to the executable to decompress it when
+ it is executed. See also {pklite}.
+
+lzh
+
+ <filename extension> The {filename extension} for a file
+ produced by the {LHA} program.
+
+ (1995-04-03)
+
+LZH compression
+
+ <algorithm> (After Lempel-Ziv and Haruyasu, the inventors) A
+ {compression} {algorithm} derived from the {LZSS} scheme with
+ a sliding window and additional compression applied to the
+ output of the LZSS compressor by {dynamic Huffman coding}.
+
+ (1995-04-07)
+
+LZW compression
+
+ {Lempel-Ziv Welch compression}
+
+M
+
+ 1. Alternative name for {MUMPS}.
+
+ 2. A {C}-like language from {Silicon Compiler Systems} for
+ multilevel {hardware description}. It is currently available
+ in the {GDT} package from {Mentor Graphics}.
+
+ [{Jargon File}]
+
+ (1994-10-26)
+
+ 3. <unit> The abbreviated for of {mega-}.
+
+ (1995-01-10)
+
+m2
+
+ A {Modula-2} {compiler} for {VAX} and {MIPS}. A {Pascal}
+ compiler for VAX is also included. The Pascal compiler
+ accepts a language that is almost identical to {Berkeley
+ Pascal}. It was originally designed and built by Michael L.
+ Powell in 1984. Joel McCormack made it faster, fixed lots of
+ bugs, and swiped/wrote a User's Manual. Len Lattanzi ported
+ it to the MIPS.
+
+ It has the following extensions: {foreign function} and data
+ interface, {dynamic array} variables, {subarray parameters},
+ multi-dimensional {open array parameters}, {inline
+ procedures}, longfloat type, type-checked interface to {C}
+ library I/O routines.
+
+ It runs on {VAX} ({Ultrix}, {BSD}) and {MIPS} ({Ultrix}).
+
+ {(ftp://gatekeeper.dec.com/pub/DEC/Modula-2/m2.tar.Z)}.
+
+ E-mail: <modula-2@decwrl.pa.dec.com>.
+
+ (1992-07-06)
+
+M2toM3
+
+ A simple {Modula-2} to {Modula-3} translator by Peter Klein
+ <pk@i3.informatik.rwth-aachen.de> which covers most of the
+ syntactic differences between those languages. No context
+ sensitive analysis is done, so WITH statements, local
+ {modules}, {enumeration type} literals and {variant RECORDs}
+ have to be dealt with by hand. Part of the {Sun} Modula 2
+ library is emulated by the Modula 3 library.
+
+ Version 1.01.
+
+ {(ftp://martha.informatik.rwth-aachen.de/pub/Modula3)}.
+
+ (1992-12-01)
+
+M3
+
+ A {macro} processor, forerunner of {M4}, for the {AP-3}
+ {minicomputer}.
+
+m4
+
+ A {macro} processor for {Unix} and {GCOS} which is more
+ flexible than {cpp}. m4 copies its input to the output,
+ expanding macros which can be either built-in or user-defined.
+ m4 has built-in functions for including files, running {Unix}
+ commands, doing integer arithmetic, manipulating text in
+ various ways and recursing. m4 can be used either as a
+ {front-end} to a compiler or as a stand-alone tool.
+
+ {sendmail}'s configuration file (/etc/sendmail.cf) is writen
+ in m4 macros.
+
+ There is a {GNU m4 v1.1
+ (ftp://gnu.org/pub/gnu/m4-1.0.tar.Z)} by Francois
+ Pinard <pinard@iro.umontreal.ca> and a {public domain} version
+ by Ozan Yigit <oz@sis.yorku.ca> and Richard A. O'Keefe
+ <ok@goanna.cs.rmit.OZ.AU> (FTP from any {386BSD}, {NetBSD} or
+ {FreeBSD} archive). A {Macintosh} version is {here
+ (ftp://nic.switch.ch/pub/software/mac/src/mpw-c/)}.
+
+ See also {m3}, {m5}.
+
+ ["The M4 Macro Processor",
+ Kernighan & Ritchie, Jul 1977].
+
+M5
+
+ Macro processor, a generalisation of {M4} by A. Dain, U
+ Cincinnati, 1992. For Unix and DOS.
+
+ {(ftp://thor.exe.u.edu/pub/dain/m5)}.
+
+ma
+
+ <networking> The {country code} for Morocco.
+
+ (1999-01-27)
+
+MAC
+
+ 1. {Media Access Control}.
+
+ 2. Early system on {Ferranti} {Mercury}. Listed in CACM
+ 2(5):16 (May 1959).
+
+Mac
+
+ <computer> The line of computers manufactured by {Apple Inc}.
+ "Mac" is not primarily a nickname or an abbreviation, but a
+ brand name and trademark in its own right. Apple currently
+ (2009) refer to the brand as any of "Mac", "iMac" or
+ "Macintosh" (all registered trademarks).
+
+ The Mac was Apple's successor to the {Lisa}. The project was
+ proposed by {Jef Raskin} some time before {Steve Jobs}'s
+ famous visit to {Xerox PARC}. Jobs tried to scuttle the
+ Macintosh project and only joined it later because he wasn't
+ trusted to manage the {Lisa} project.
+
+ The {Macintosh user interface} was notable for popularising
+ the {graphical user interface}, with its easy to learn and
+ easy to use {desktop} metaphor.
+
+ The first Macintosh, introduced in January 1984, had a
+ {Motorola 68000} {CPU}, 128K of {RAM}, a small {monochrome}
+ screen, and one built-in {floppy disk} drive with an external
+ slot for one more, two {serial ports} and a four-voice sound
+ generator. This was all housed in one small plastic case,
+ including the screen. When more memory was available later in
+ the year, a 512K Macintosh was nicknamed the "Fat Mac."
+
+ The Mac Plus (January 1986) added expandability by providing
+ an external {SCSI} port for connecting {hard disks}, {magnetic
+ tape}, and other high-speed devices.
+
+ The Mac SE (March 1987) had up to four megabytes of {RAM}, an
+ optional built-in 20 megabyte hard disk and one internal
+ expansion slot for connecting a third-party device.
+
+ The Mac II (March 1987) used the faster {Motorola 68020} {CPU}
+ with a 32-bit {bus}.
+
+ In 1994 the {Power Mac} was launched, and in 1999 the {iMac}
+ was introduced. The {SuperDrive} appeared in the iMac in 2002.
+
+ The {Macintosh Operating System} is now officially called "Mac
+ OS". Mac OS X is the successor to Mac OS 9, although its
+ technological parent is the {NEXTSTEP} OS from {Next, Inc.},
+ founded by Steve Jobs after he left Apple the first time. OS
+ X is based largely on the {BSD} UNIX system. The core of the
+ OS X operating system is released as free {source code} under
+ the project name {Darwin}.
+
+ The standard Macintosh screen {resolution} is 72 {dpi} (making
+ one {point} = one {pixel}), exactly half the 144 dpi
+ resolution of the ancient {Apple Imagewriter} {dot matrix}
+ printer.
+
+ If "Macintosh" were an acronym, some say it would stand for
+ "Many Applications Crash, If Not, The Operating System Hangs".
+ While this was true for pre Mac OS 9 systems, it is less true
+ for Mac OS 9, and totally incorrect for Mac OS X, which has
+ protected memory, so even if one application crashes, the
+ system and other applications are unaffected.
+
+ See also {Macintosh file system}, {Macintosh user interface}.
+
+ {Apple Home (http://apple.com/mac)}.
+
+ (2009-05-05)
+
+Mac-1
+
+ <language> The {assembly language} used in the book cited
+ below.
+
+ See {Mic-1}.
+
+ ["Structured Computer Organization", A.S. Tanenbaum, 3rd
+ Edition, P-H 1989, Sect. 4.3].
+
+ (1996-04-07)
+
+MAC-360
+
+ A system for solving numerical problems using equation-like
+ input. Developed around 1967.
+
+ ["User's Guide to MAC-360", Charles Stark Draper Lab,
+ Cambridge MA (Aug 1973)].
+
+ [Sammet 1969, p. 264].
+
+MACA
+
+ {Multiple Access with Colision Avoidance}
+
+MAC address
+
+ The hardware address of a device connected to a shared
+ {network} medium. See also {Media Access Control}.
+
+MACAnalyst
+
+ An analysis {CASE} tool for the {Macintosh} from {Excel
+ Software, Inc.}
+
+Macaulay
+
+ A {symbolic mathematics} package for {commutative algebra},
+ {algebraic geometry} and {cohomology}, written in {C} by Mike
+ Stillman <mike@mssun7.msi.cornell.edu> and Dave Bayer
+ <bayer@cUnixa.columbia.edu> in 1977. Version 3 runs on {Sun},
+ {Macintosh} and {Amiga}.
+
+ {(ftp://zariski.harvard.edu/)}.
+
+ (1994-10-12)
+
+MacBinary
+
+ <file format> An eight-bit wide representation of the data and
+ {resource forks} of an {Macintosh} file and of relevant
+ {Finder} information. MacBinary files are recognised as
+ "special" by several MacIntosh {terminal emulators}. These
+ emulators, using {Kermit} or {XMODEM} or any other file
+ transfer protocol, can separate the incoming file into {forks}
+ and appropriately modify the {Desktop} to display {icons},
+ types, creation dates, and the like.
+
+ (1995-03-08)
+
+MACDesigner
+
+ A design CASE tool for the Mac from {Excel Software, Inc.}
+
+macdink
+
+ /mak'dink/ To make many incremental and unnecessary cosmetic
+ changes to a program or file. Often the subject of the
+ macdinking would be better off without them. The {Macintosh}
+ is said to encourage such behaviour.
+
+ See also {fritterware}, {window shopping}.
+
+ [{Jargon File}]
+
+ (1994-11-22)
+
+MACE
+
+ A concurrent {object-oriented} language.
+
+Mach
+
+ An operating system kernel under development at
+ Carnegie-Mellon University to support distributed and parallel
+ computation. Mach is designed to support computing
+ environments consisting of networks of uniprocessors and
+ multiprocessors. Mach is the kernel of the {OSF}/1.
+
+Machiavelli
+
+ An extension of {Standard ML} developed by Peter Buneman &
+ Atsushi Ohori of the {University of Pennsylvania} in 1989,
+ based on {orthogonal persistence}.
+
+ ["Database Programming in Machiavelli: A Polymorphic Language
+ with Static Type Inference", A. Ohori, Proc SIGMOD Conf, ACM,
+ June 1989].
+
+ (1995-02-21)
+
+machinable
+
+ {Machine-readable}. Having the {softcopy} nature.
+
+ [{Jargon File}]
+
+machine
+
+ Common term for "computer", usually when considered at the
+ hardware level. The {Turing Machine}, an early example of
+ this usage, was however neither hardware nor software, but
+ only an idea.
+
+ [Earlier use?]
+
+ (1995-02-15)
+
+machine code
+
+ <language> The representation of a {computer program} that is
+ read and interpreted by the computer hardware (rather than by
+ some other machine code program). A program in machine code
+ consists of a sequence of "instructions" (possibly
+ interspersed with data). An instruction is a {binary string},
+ (often written as one or more {octal}, {decimal} or
+ {hexadecimal} numbers). Instructions may be all the same size
+ (e.g. one 32-bit word for many modern {RISC}
+ {microprocessors}) or of different sizes, in which case the
+ size of the instruction is determined from the first {word}
+ (e.g. {Motorola} {68000}) or {byte} (e.g. {Inmos}
+ {transputer}). The collection of all possible instructions
+ for a particular computer is known as its "{instruction set}".
+
+ Each instruction typically causes the {Central Processing
+ Unit} to perform some fairly simple operation like loading a
+ value from memory into a {register} or adding the numbers in
+ two registers. An instruction consists of an {op code} and
+ zero or more {operands}. Different processors have different
+ {instruction sets} - the collection of possible operations
+ they can perform.
+
+ Execution of machine code may either be {hard-wired} into the
+ {central processing unit} or it may be controlled by
+ {microcode}. The basic execution cycle consists of fetching
+ the next instruction from {main memory}, decoding it
+ (determining which action the {operation code} specifies and
+ the location of any {arguments}) and executing it by opening
+ various {gates} (e.g. to allow data to flow from main memory
+ into a CPU {register}) and enabling {functional units}
+ (e.g. signalling to the {ALU} to perform an addition).
+
+ Humans almost never write programs directly in machine code.
+ Instead, they use {programming languages}. The simplest kind
+ of programming language is {assembly language} which usually
+ has a one-to-one correspondence with the resulting machine
+ code instructions but allows the use of {mnemonics} (ASCII
+ strings) for the "{op codes}" (the part of the instruction
+ which encodes the basic type of operation to perform) and
+ names for locations in the program (branch labels) and for
+ {variables} and {constants}. Other languages are either
+ translated by a {compiler} into machine code or executed by an
+ {interpreter}
+
+ (2009-06-16)
+
+machine cycle
+
+ <processor> The four steps which the {CPU} carries out for
+ each {machine language} instruction: fetch, decode, execute,
+ and store. These steps are performed by the {control unit},
+ and may be fixed in the logic of the CPU or may be programmed
+ as {microcode} which is itself usually fixed (in {ROM}) but
+ may be (partially) modifiable (stored in {RAM}).
+
+ The fetch cycle places the current {program counter} contents
+ (the address of the next instruction to execute) on the
+ {address bus} and reads in the word at that location into the
+ {instruction register} (IR). In {RISC} CPUs instructions are
+ usually a single word but in other architectures an
+ instruction may be several words long, necessitating several
+ fetches.
+
+ The decode cycle uses the contents of the IR to determine
+ which {gates} should be opened between the CPU's various
+ {functional units} and busses and what operation the {ALU}(s)
+ should perform (e.g. add, {bitwise and}). Each gate allows
+ data to flow from one unit to another (e.g. from {register} 0
+ to ALU input 1) or enables data from one output onto a certain
+ {bus}. In the simplest case ("{horizontal encoding}") each
+ bit of the instruction register controls a single gate or
+ several bits may control the ALU operation. This is rarely
+ used because it requires long instruction words (such an
+ architecture is sometimes called a {very long instruction
+ word} architecture). Commonly, groups of bits from the IR are
+ fed through {decoders} to control higher level aspects of the
+ CPU's operation, e.g. source and destination registers,
+ {addressing mode} and {ALU} operation. This is known as
+ {vertical encoding}. One way {RISC} processors gain their
+ advantage in speed is by having simple instruction decoding
+ which can be performed quickly.
+
+ The execute cycle occurs when the decoding logic has settled
+ and entails the passing of values between the various function
+ units and busses and the operation of the ALU. A simple
+ instruction will require only a single execute cycle whereas a
+ complex instruction (e.g. subroutine call or one using memory
+ {indirect addressing}) may require three or four.
+ Instructions in a RISC typically (but not invariably) take
+ only a single cycle.
+
+ The store cycle is when the result of the instruction is
+ written to its destination, either a {register} or a memory
+ location. This is really part of the execute cycle because
+ some instructions may write to multiple destinations as part
+ of their execution.
+
+ (1995-04-13)
+
+MAchine INdependent SAIL
+
+ (MAINSAIL) From {XIDAK}, Palo Alto CA, +1 (415) 855 9271.
+
+ (2006-12-06)
+
+machine instruction
+
+ <programming> The smallest element of a {machine code} program.
+
+ (2009-06-23)
+
+machine language
+
+ {machine code}
+
+machine learning
+
+ The ability of a machine to improve its performance based on
+ previous results.
+
+ {Neural networks} are one kind of machine learning.
+
+ [More examples? Net resources? Web page?]
+
+ (1995-02-15)
+
+Mach Interface Generator
+
+ <tool, programming> (MIG) An implementation of a subset of
+ {Matchmaker} that generates {C} and {C++} {remote procedure
+ call} interfaces for {interprocess communication} between
+ {Mach} tasks.
+
+ ["MIG - The Mach Interface Generator", R.P. Draves et al, CS
+ CMU, (1989-08-4)].
+
+ (1994-11-22)
+
+machoflops
+
+ /mach'oh-flops/ A pun on "{megaflops}" referring to the
+ inflated performance figures often quoted by computer
+ manufacturers. Real {application programs} are lucky to get
+ half the quoted speed.
+
+ See {Your mileage may vary}, {benchmark}.
+
+ [{Jargon File}]
+
+ (1995-02-15)
+
+Mac II
+
+ {Macintosh II}
+
+Mac IIcx
+
+ {Macintosh IIcx}
+
+Macintosh
+
+ <computer> One of the trademark/brand names that {Apple Inc}
+ use for their {Mac} family of {personal computers}.
+
+ (2009-05-05)
+
+Macintosh Common Lisp
+
+ <language> (MCL) {Common Lisp} for the {Apple Macintosh}.
+
+ Guillaume Cartier, of the Mathematics Department at UQAM,
+ Canada, has written some libraries.
+
+ Latest version: 1.2.
+
+ {(ftp://cambridge.apple.com/pub/mcl2/contrib/)}.
+
+ (1992-11-30)
+
+Macintosh file system
+
+ <file system> A file on the {Macintosh} consists of two parts,
+ called forks. The "data fork" contains the data which would
+ normally be stored in the file on other operating systems.
+ The "resource fork" contains a collection of arbitrary
+ attribute/value pairs, including program segments, {icon}
+ {bitmaps}, and parametric values. Yet more information
+ regarding Macintosh files is stored by the {Finder} in a
+ hidden file, called the "Desktop Database".
+
+ Because of the complications in storing different parts of a
+ Macintosh file in non-Macintosh file systems that only handle
+ consecutive data in one part, it is common to only send the
+ Data fork or to convert the Macintosh file into some other
+ format before transferring it.
+
+ (1996-03-03)
+
+Macintosh II
+
+ <computer> (Mac II) A version of {Apple}'s {Macintosh}
+ {personal computer}, released in March 1987, using the
+ {Motorola 68020} {CPU}, which runs at a higher {clock rate}
+ than the {Motorola 68000} used in the original Mac. The Mac
+ II has a full 32-bit data bus instead of a 16-bit bus. Mac II
+ models have built-in 40 to 160 megabyte {hard disks} and can
+ take up to eight megabytes of {RAM} (and more as denser memory
+ chips arive).
+
+ The Mac II was the first Macintosh to provide a colour
+ graphics option, with up to 256 colours on screen at a 640x480
+ resolution. Mac II models are designed for expandability with
+ three ({Macintosh IIcx}) or six (II & IIx) built-in {NuBus}
+ {expansion slots} for additional {peripheral} and
+ {coprocessor} boards.
+
+ (1996-05-25)
+
+Macintosh IIcx
+
+ <computer> (Mac IIcx) A version of {Apple}'s {Macintosh II}
+ {personal computer}, introduced in 1989, with a {Motorola
+ 68030} processor running at 16 MHz and up to 128 MB of {RAM}
+ (120 ns, 30-pin {DRAM} chips). The IIcx requires System 6.0.3
+ or later and requires "Mode 32" or "32-bit Enabler" to use
+ more than 8MB of RAM. It was discontinued 1991, and in 1996
+ is still considered one of the best-designed Macs ever.
+
+ (1996-05-25)
+
+Macintosh Operating System
+
+ <operating system> (Mac OS) {Apple Computer, Inc.}'s
+ proprietary {operating system} for their {Macintosh} family of
+ {personal computers}.
+
+ The part of the operating system that simulates the desktop is
+ called "{Finder}." The {multitasking} version of Finder was
+ called "{MultiFinder}" until {multitasking} was integrated
+ into the core of the OS with the introduction of System 7.0 in
+ 1990.
+
+ The Macintosh series provides a built-in graphics language,
+ called "{QuickDraw}", which provides a {standard} for software
+ developers.
+
+ Mac OS 8, scheduled for delivery in July 1997, included new
+ human-interface features, increased system stability and
+ performance, a {PowerPC} processor-native Finder, tighter
+ integration of {Internet} access through panel-based
+ "assistants," Personal Web Sharing and the ability to run
+ {Java applets} and programs through Mac OS Run Time for
+ {Java}. Version 9.2 was the last version of the bespoke Mac
+ OS. The next version, {Mac OS X} is quite different, being
+ based on {Unix}.
+
+ See also {Macintosh file system}, {Macintosh user interface}.
+
+ (2007-03-15)
+
+Macintosh user interface
+
+ <operating system> The {graphical user interface} used by
+ {Apple Computer}'s {Macintosh} family of {personal computers},
+ based on graphical representations of familiar office objects
+ (sheets of paper, files, wastepaper bin, etc.) positioned on a
+ two-dimensional "{desktop}" workspace.
+
+ Programs and data files are represented on screen by small
+ pictures ({icons}). An object is selected by moving a {mouse}
+ over the real desktop which correspondingly moves the
+ {pointer} on screen. When the pointer is over an icon on
+ screen, the icon is selected by pressing the button on the
+ mouse.
+
+ A {hierarchical file system} is provided that lets a user
+ "{drag}" a document (a file) icon into and out of a {folder}
+ (directory) icon. Folders can also contain other folders and
+ so on. To delete a document, its icon is dragged into a
+ {trash can} icon. For people that are not computer
+ enthusiasts, managing files on the Macintosh is easier than
+ using the {MS-DOS} or {Unix} {command-line interpreter}.
+
+ The Macintosh always displays a row of menu titles at the top
+ of the screen. When a mouse button is pressed over a title, a
+ {pull-down menu} appears below it. With the mouse button held
+ down, the option within the menu is selected by pointing to it
+ and then releasing the button.
+
+ Unlike the {IBM PC}, which, prior to {Microsoft Windows} had
+ no standard {graphical user interface}, Macintosh developers
+ almost always conform to the Macintosh interface. As a
+ result, users are comfortable with the interface of a new
+ program from the start even if it takes a while to learn all
+ the rest of it. They know there will be a row of menu options
+ at the top of the screen, and basic tasks are always performed
+ in the same way. Apple also keeps technical jargon down to a
+ minimum.
+
+ Although the Macintosh user interface provides consistency; it
+ does not make up for an {application program} that is not
+ designed well. Not only must the application's menus be clear
+ and understandable, but the locations on screen that a user
+ points to must be considered. Since the mouse is the major
+ selecting method on a Macintosh, mouse movement should be kept
+ to a minimum. In addition, for experienced typists, the mouse
+ is a cumbersome substitute for well-designed keyboard
+ commands, especially for intensive text editing.
+
+ {Urban legned} has it that the Mac user interface was copied
+ from {Xerox}'s {Palo Alto Research Center}. Although it is
+ true that Xerox's {smalltalk} had a GUI and Xerox introduced
+ some GUI concepts commercially on the {Xerox Star} computer in
+ 1981, and that {Steve Jobs} and members of the Mac and {Lisa}
+ project teams visited PARC, Jef Raskin, who created the Mac
+ project, points out that many GUI concepts which are now
+ considered fundamental, such as dragging objects and pull-down
+ menus with the mouse, were actually invented at Apple.
+
+ {Pull-down menus} have become common on {IBM}, {Commodore} and
+ {Amiga} computers. {Microsoft Windows} and {OS/2}
+ {Presentation Manager}, {Digital Research}'s {GEM},
+ {Hewlett-Packard}'s {New Wave}, the {X Window System}, {RISC
+ OS} and many other programs and operating environments also
+ incorporate some or all of the desktop/mouse/icon features.
+
+ {Apple Computer} have tried to prevent other companies from
+ using some {GUI} concepts by taking legal action against them.
+ It is because of such restrictive practises that organisations
+ such as the {Free Software Foundation} previously refused to
+ support ports of their software to Apple machines, though this
+ ban has now been lifted. [Why? When?]
+
+ (1996-07-19)
+
+Macintoy
+
+ /mak'in-toy/ The Apple {Macintosh}, considered as a {toy}.
+ Less pejorative than {Macintrash}.
+
+ [{Jargon File}]
+
+Macintrash
+
+ /mak'in-trash"/ The Apple {Macintosh}, as described by a
+ hacker who doesn"t appreciate being kept away from the *real
+ computer* by the interface. The term {maggotbox} has been
+ reported in regular use in the Research Triangle area of North
+ Carolina. Compare {Macintoy}.
+
+ See also {beige toaster}, {WIMP environment}, {point-and-drool
+ interface}, {drool-proof paper}, {user-friendly}.
+
+ (1995-05-02)
+
+MACL
+
+ {Macintosh} {Allegro CL}.
+
+ E-mail: <info-macl@cambridge.apple.com>.
+
+MacLisp
+
+ <language> A dialect of {Lisp} developed at {MIT} AI Lab in
+ 1966, known for its efficiency and programming facilities.
+ MacLisp was later used by {Project MAC}, {Mathlab} and
+ {Macsyma}. It ran on the {PDP-10}. It introduced the {LEXPR}
+ (a function with variable {arity}), {macros}, {arrays}, and
+ {CATCH/THROW}.
+
+ MacLisp was one of two main branches of LISP (the other being
+ {Interlisp}). In 1981 {Common LISP} was begun in an effort to
+ combine the best features of both.
+
+ ["MACLISP Reference Manual", D.A. Moon
+ <moon@cambridge.apple.com>, TR Project MAC, MIT 1974].
+
+ (2004-05-07)
+
+MacMinix
+
+ <operating system> The {Macintosh} version of {MINIX}.
+
+ [Details? URL?]
+
+ (1997-06-17)
+
+Mac OS
+
+ {Macintosh Operating System}
+
+Mac OS X
+
+ <operating system> /mak oss ten/ Version 10 of the {Macintosh
+ Operating System}, based on {FreeBSD} unlike prevoius
+ versions. Apple released the {kernel} of Mac OS X Server as
+ "{darwin}", under an {open source} license. Mac OS X incldues
+ a code {framework} called the "Core Foundation" and an
+ "Application Kit" framework for {GUI} and {widgets} strongly
+ derived from {NEXTSTEP}.
+
+ (2007-03-15)
+
+Mac Playmate
+
+ <games> An early (~1985) example of a pornographic computer
+ game. Mac Playmate runs on the {Macintosh} and involves
+ trying to stimulate a simulated woman to orgasm by applying
+ various implements to her erogenous zones.
+
+ (2002-03-08)
+
+MacPPP
+
+ <networking> An implementation of {PPP} for the {Macintosh}
+ developed by Larry J. Blunk and others at Merit Network, Inc.
+ MacPPP was revised in 1993 with the release of MacPPP 2.0.1.
+ The latest incarnation of MacPPP is {FreePPP}.
+
+ (2000-11-25)
+
+MACRO
+
+ 1. Assembly language for {VAX/VMS}.
+
+ 2. {PL/I}-like language with extensions for string processing.
+ "MACRO: A Programming Language", S.R. Greenwood, SIGPLAN
+ Notices 14(9):80-91 (Sep 1979).
+
+ [{Jargon File}]
+
+macro
+
+ A name (possibly followed by a {formal argument} list) that is
+ equated to a text or symbolic expression to which it is to be
+ expanded (possibly with the substitution of {actual
+ arguments}) by a macro expander.
+
+ The term "macro" originated in early {assemblers}, which
+ encouraged the use of macros as a structuring and
+ information-hiding device. During the early 1970s, macro
+ assemblers became ubiquitous, and sometimes quite as powerful
+ and expensive as {HLLs}, only to fall from favour as improving
+ {compiler} technology marginalised {assembly language}
+ programming (see {languages of choice}). Nowadays the term is
+ most often used in connection with the {C preprocessor},
+ {Lisp}, or one of several special-purpose languages built
+ around a macro-expansion facility (such as {TeX} or {Unix}'s
+ {troff} suite).
+
+ Indeed, the meaning has drifted enough that the collective
+ "macros" is now sometimes used for code in any special-purpose
+ application control language (whether or not the language is
+ actually translated by text expansion), and for macro-like
+ entities such as the "keyboard macros" supported in some text
+ editors (and {PC} {TSRs} or {Macintosh} INIT/CDEV keyboard
+ enhancers).
+
+ (1994-12-06)
+
+macro-
+
+ Prefix large. Opposite of {micro-}. In the mainstream and
+ among other technical cultures (for example, medical people)
+ this competes with the prefix {mega-}, but hackers tend to
+ restrict the latter to quantification.
+
+ [{Jargon File}]
+
+macrology
+
+ /mak-rol'*-jee/ 1. Set of usually complex or {crufty} {macros},
+ e.g. as part of a large system written in {Lisp}, {TECO}, or
+ (less commonly) {assembler}.
+
+ 2. The art and science involved in comprehending a macrology.
+ Sometimes studying the macrology of a system is not unlike
+ archaeology, ecology, or {theology}, hence the sound-alike
+ construction. See also {boxology}.
+
+ (2003-09-02)
+
+Macromedia
+
+ <company> A company supplying {multimedia} and interactive
+ television services and digital arts software tools in the US
+ and worldwide. They produce products for {Microsoft Windows}
+ and the {Macintosh} including: Macromedia FreeHand, a tool for
+ design and illustration; Macromedia Director, an animation and
+ authoring tool for multimedia production; Authorware
+ Professional, a multiplatform authoring tool for interactive
+ learning; MacroModel, a 3D modelling tool for multimedia,
+ graphics and product design; SoundEdit 16, a digital sound
+ recording and editing system; Fontographer, a typeface editing
+ programme; and Action!, a multimedia presentation application.
+
+ Chief Executive Officer: Bud Colligan.
+
+ (1995-01-10)
+
+macro preprocessor
+
+ {preprocessor}
+
+Macro SAP
+
+ Macro processing modification of SAP. D.E. Eastwood and D.M.
+ McIlroy, unpublished memorandum, Bell Labs 1959. Led to TRAC.
+
+macrotape
+
+ <storage> /mak'roh-tayp/ An industry-standard reel of
+ {magnetic tape}, as opposed to a {microtape}.
+
+ See also {round tape}.
+
+ [{Jargon File}]
+
+ (1994-10-20)
+
+MACSYMA
+
+ {Project MAC}'s SYmbolic MAnipulator. The first comprehensive
+ {symbolic mathematics} system, written in {Lisp} by Joel Moses
+ <moses@larch.lcs.mit.edu> of {MIT} in 1969, later {Symbolics},
+ Inc.
+
+ Versions include {Symbolics Macsyma}, {DOE Maxima} (ANL, in
+ Common LISP) and {Vaxima}.
+
+ {(ftp://rascal.ics.utexas.edu/pub/maxima-4-155.tar.Z)}.
+ E-mail: <macsyma-service@symbolics.com>.
+
+ ["MACSYMA - The Fifth Year", J. Moses, SIGSAM Bulletin 8(3)
+ (Aug 1974)].
+
+ (1994-11-01)
+
+MacTCP
+
+ <networking> Part of earlier versions of {MacOS} that provided
+ access to {TCP/IP} services. {Apple} removed MacTCP from
+ MacOS in revision 7.5.3 in favor of the new {OpenTransport}
+ (OT) TCP/IP stack. However, MacTCP lives on as a community
+ development effort.
+
+ See also {MacPPP}.
+
+ [How did it work? Where was it from?]
+
+ (2000-06-25)
+
+MacX
+
+ A package allowing the {Macintosh} to be used as an {X}
+ server.
+
+MAD
+
+ <language> 1. {Michigan Algorithm Decoder}.
+
+ 2. A {data flow} language.
+
+ ["Implementation of Data Structures on a Data Flow Computer",
+ D.L. Bowen, Ph.D. Thesis, Victoria U Manchester, Apr 1981].
+
+ (1999-12-10)
+
+Mad/1
+
+ <language> A later, much enhanced version of {Michigan
+ Algorithm Decoder} (MAD), for the {IBM 360}. Mad/1 was
+ University of Michigan's answer to {PL/I}.
+
+ (1999-12-10)
+
+Madaline
+
+ A structure of many ADALINE units.
+
+MADCAP
+
+ Math and set problems, for the Maniac II and CDC 6600.
+ "MADCAP - A Scientific Compiler for a Displayed Formula
+ Texbook Language", M.B. Wells, CACM 4(1):31-36 (Jan 1961).
+ Sammet 1969, pp.271-281. Versions: Madcap 5 (1964), Madcap 6.
+ "The Unified Data Structure Capability in Madcap 6",
+ M.B. Wells et al, Intl J Comp Info Sci 1(3) (sep 1972).
+
+MADTRAN
+
+ Early preprocessor that translated Fortran to MAD, for gain in
+ speed.
+
+maggotbox
+
+ <abuse> /mag'*t-boks/ An even more derogatory term than
+ {Macintrash}.
+
+ [{Jargon File}]
+
+ (1995-01-25)
+
+MAGIC
+
+ An early system on the {Midac} computer.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ [{Jargon File}]
+
+ (1995-01-25)
+
+magic
+
+ 1. As yet unexplained, or too complicated to explain; compare
+ {automagically} and (Arthur C.) Clarke's Third Law:
+
+ Any sufficiently advanced technology is
+ indistinguishable from magic.
+
+ "TTY echoing is controlled by a large number of magic bits."
+ "This routine magically computes the parity of an 8-bit byte
+ in three instructions."
+
+ 2. Characteristic of something that works although no one
+ really understands why (this is especially called {black
+ magic}).
+
+ 3. (Stanford) A feature not generally publicised that allows
+ something otherwise impossible or a feature formerly in that
+ category but now unveiled.
+
+ Compare {wizardly}, {deep magic}, {heavy wizardry}.
+
+ For more about hackish "magic" see {Magic Switch Story}.
+
+ 4. {magic number}.
+
+ [{Jargon File}]
+
+ (2001-03-19)
+
+magic bullet
+
+ <jargon> (Or "silver bullet" from vampire legends) A term
+ widely used in software engineering for a supposed quick,
+ simple cure for some problem. E.g. "There's no silver bullet
+ for this problem".
+
+ (1999-01-13)
+
+magic cookie
+
+ 1. Something passed between routines or programs that enables
+ the receiver to perform some operation; a {capability} ticket
+ or {opaque identifier}. Especially used of small data objects
+ that contain data encoded in a strange or intrinsically
+ machine-dependent way. E.g. on non-{Unix} {operating systems}
+ with a non-byte-stream model of files, the result of "{ftell}"
+ may be a magic cookie rather than a byte offset; it can be
+ passed to "{fseek}", but not operated on in any meaningful
+ way. The phrase "it hands you a magic cookie" means it
+ returns a result whose contents are not defined but which can
+ be passed back to the same or some other program later.
+
+ 2. An in-band code for changing graphic rendition (e.g. inverse
+ video or underlining) or performing other control functions.
+ Some older terminals would leave a blank on the screen
+ corresponding to mode-change magic cookies; this was also
+ called a {glitch} (or occasionally a "turd"; compare {mouse
+ droppings}).
+
+ See also {cookie}.
+
+ [{Jargon File}]
+
+ (1995-01-25)
+
+magic number
+
+ <jargon, programming> 1. In {source code}, some non-obvious
+ constant whose value is significant to the operation of a
+ program and that is inserted inconspicuously in-line
+ ({hard-coded}), rather than expanded in by a symbol set by a
+ commented "#define". Magic numbers in this sense are bad
+ style.
+
+ 2. A number that encodes critical information used in an
+ {algorithm} in some opaque way. The classic examples of these
+ are the numbers used in {hash} or {CRC} functions or the
+ coefficients in a {linear congruential generator} for
+ {pseudorandom} numbers. This sense actually predates, and
+ was ancestral to, the more common sense 1.
+
+ 3. Special data located at the beginning of a {binary} data
+ file to indicate its type to a utility. Under {Unix}, the
+ system and various {applications programs} (especially the
+ {linker}) distinguish between types of executable file by
+ looking for a magic number. Once upon a time, these magic
+ numbers were {PDP-11} branch instructions that skipped over
+ header data to the start of executable code; 0407, for
+ example, was {octal} for "branch 16 bytes relative". Nowadays
+ only a {wizard} knows the spells to create magic numbers. {MS
+ DOS} executables begin with the magic string "MZ".
+
+ *The* magic number, on the other hand, is 7+/-2. The paper
+ cited below established the number of distinct items (such as
+ numeric digits) that humans can hold in short-term memory.
+ Among other things, this strongly influenced the interface
+ design of the phone system.
+
+ ["The magical number seven, plus or minus two: some limits on
+ our capacity for processing information", George Miller, in
+ the "Psychological Review" 63:81-97, 1956].
+
+ [{Jargon File}]
+
+ (2003-07-02)
+
+Magic Paper
+
+ An early interactive {symbolic mathematics} system.
+
+ [Sammet 1969, p. 510].
+
+ (1995-01-25)
+
+magic smoke
+
+ <electronics, humour> A substance trapped inside {integrated
+ circuit} packages that enables them to function (also called
+ "blue smoke"; this is similar to the archaic "phlogiston"
+ hypothesis about combustion). Its existence is demonstrated
+ by what happens when a chip burns up - the magic smoke gets
+ let out, so it doesn't work any more.
+
+ See {Electing a Pope}, {smoke test}.
+
+ {Usenet}ter Jay Maynard tells the following story:
+
+ "Once, while hacking on a dedicated {Zilog Z80} system, I was
+ testing code by blowing {EPROMs} and plugging them in the
+ system then seeing what happened. One time, I plugged one in
+ backward. I only discovered that *after* I realised that
+ {Intel} didn't put power-on lights under the quartz windows on
+ the tops of their EPROMs - the die was glowing white-hot.
+ Amazingly, the EPROM worked fine after I erased it, filled it
+ full of zeros, then erased it again. For all I know, it's
+ still in service. Of course, this is because the magic smoke
+ didn't get let out."
+
+ Compare the original phrasing of {Murphy's Law}.
+
+ [{Jargon File}]
+
+ (1995-01-25)
+
+Magic Switch Story
+
+ Some years ago, I was snooping around in the cabinets that
+ housed the {MIT AI Lab}'s {PDP-10}, and noticed a little
+ switch glued to the frame of one cabinet. It was obviously a
+ homebrew job, added by one of the lab's hardware hackers
+ (no-one knows who).
+
+ You don't touch an unknown switch on a computer without
+ knowing what it does, because you might crash the computer.
+ The switch was labelled in a most unhelpful way. It had two
+ positions, and scrawled in pencil on the metal switch body
+ were the words "magic" and "more magic". The switch was in
+ the "more magic" position.
+
+ I called another hacker over to look at it. He had never seen
+ the switch before either. Closer examination revealed that
+ the switch had only one wire running to it! The other end of
+ the wire did disappear into the maze of wires inside the
+ computer, but it's a basic fact of electricity that a switch
+ can't do anything unless there are two wires connected to it.
+ This switch had a wire connected on one side and no wire on
+ its other side.
+
+ It was clear that this switch was someone's idea of a silly
+ joke. Convinced by our reasoning that the switch was
+ inoperative, we flipped it. The computer instantly crashed.
+
+ Imagine our utter astonishment. We wrote it off as
+ coincidence, but nevertheless restored the switch to the "more
+ magic" position before reviving the computer.
+
+ A year later, I told this story to yet another hacker, {David
+ Moon} as I recall. He clearly doubted my sanity, or suspected
+ me of a supernatural belief in the power of this switch, or
+ perhaps thought I was fooling him with a bogus saga. To prove
+ it to him, I showed him the very switch, still glued to the
+ cabinet frame with only one wire connected to it, still in the
+ "more magic" position. We scrutinized the switch and its lone
+ connection, and found that the other end of the wire, though
+ connected to the computer wiring, was connected to a ground
+ pin. That clearly made the switch doubly useless: not only
+ was it electrically nonoperative, but it was connected to a
+ place that couldn't affect anything anyway. So we flipped the
+ switch.
+
+ The computer promptly crashed.
+
+ This time we ran for Richard Greenblatt, a long-time {MIT}
+ hacker, who was close at hand. He had never noticed the
+ switch before, either. He inspected it, concluded it was
+ useless, got some diagonal cutters and {dike}d it out. We
+ then revived the computer and it has run fine ever since.
+
+ We still don't know how the switch crashed the machine. There
+ is a theory that some circuit near the ground pin was
+ marginal, and flipping the switch changed the electrical
+ capacitance enough to upset the circuit as
+ millionth-of-a-second pulses went through it. But we'll never
+ know for sure; all we can really say is that the switch was
+ {magic}.
+
+ I still have that switch in my basement. Maybe I'm silly, but
+ I usually keep it set on "more magic".
+
+ {GLS}
+
+ (1995-02-22)
+
+Magma
+
+ <symbolic mathematics, tool> A program used for heavy duty
+ algebraic computation in many branches of mathematics. Magma,
+ developed by John Cannon and associates at the University of
+ Sydney, succeeded {Cayley}. It runs at several hundred sites.
+
+ E-mail: <magma@maths.usyd.edu.au>.
+
+ {(http://maths.usyd.edu.au:8000/u/magma/)}.
+
+ [W. Bosma, J. Cannon and C. Playoust, The Magma algebra system
+ I: The user language, J. Symb. Comp., 24, 3/4, 1997, 235-265].
+
+ (2000-12-21)
+
+Magma2
+
+ <language> A language that allows programmability of the
+ control environment, e.g. {recursion}, {backtracking},
+ {coroutines}, {nondeterminism}, etc. Magma2 was the successor
+ to {MagmaLISP}.
+
+ ["Magma2: A Language Oriented Toward Experiments in Control",
+ Franco Turini, ACM TOPLAS 6(4):468-486 (Oct 1984)].
+
+ (1995-07-30)
+
+MagmaLISP
+
+ <language> The predecessor of {Magma2}.
+
+ ["MagmaLISP: A Machine Language for Artificial Intelligence",
+ C. Mantagero et al, Proc 4th Intl Joint Conf Artif Intell,
+ 1975, pp. 556-561].
+
+ (1995-07-30)
+
+magnetic disk
+
+ <storage> A flat rotating disc covered on one or both sides
+ with magnetisable material. The two main types are the {hard
+ disk} and the {floppy disk}.
+
+ Data is stored on either or both surfaces of discs in
+ concentric rings called "{tracks}". Each track is divided
+ into a whole number of "{sectors}". Where multiple (rigid)
+ discs are mounted on the same axle the set of tracks at the
+ same radius on all their surfaces is known as a "{cylinder}".
+
+ Data is read and written by a {disk drive} which rotates the
+ discs and positions the {read/write heads} over the desired
+ track(s). The latter radial movement is known as "{seeking}".
+ There is usually one head for each surface that stores data.
+ To reduce {rotational latency} it is possible, though
+ expensive, to have multiple heads at different angles.
+
+ The head writes binary data by magnetising small areas or
+ "zones" of the disk in one of two opposing orientations. It
+ reads data by detecting current pulses induced in a coil as
+ zones with different magnetic alignment pass underneath it.
+
+ In theory, bits could be read back as a time sequence of pulse
+ (one) or no pulse (zero). However, a run of zeros would give
+ a prolonged absence of signal, making it hard to accurately
+ divide the signal into individual bits due to the variability
+ of motor speed. {Run Length Limited} is one common solution
+ to this {clock recovery} problem.
+
+ High speed disks have an {access time} of 28 {milliseconds} or
+ less, and low-speed disks, 65 milliseconds or more. The
+ higher speed disks also transfer their data faster than the
+ slower speed units.
+
+ The disks are usually aluminium with a magnetic coating. The
+ heads "float" just above the disk's surface on a current of
+ air, sometimes at lower than atmospheric pressure in an
+ air-tight enclosure. The head has an aerodynamic shape so the
+ current pushes it away from the disk. A small spring pushes
+ the head towards the disk at the same time keeping the head at
+ a constant distance from the disk (about two microns).
+
+ Disk drives are commonly characterised by the kind of
+ interface used to connect to the computer, e.g. {ATA}, {IDE},
+ {SCSI}.
+
+ See also {winchester}. Compare {magnetic drum}, {compact
+ disc}, {optical disk}, {magneto-optical disk}.
+
+ {Suchanka's PC-DISK library (http://pc-disk.de/)}.
+
+ (2007-06-14)
+
+Magnetic Ink Character Recognition
+
+ <business, printer> (MICR) A {character recognition} system
+ using special ink and characters which can be magnetised and
+ read automatically.
+
+ MICR is used almost exclusively in the banking industry where
+ it is used to print details on cheques to enable automatic
+ processing.
+
+ (1995-04-13)
+
+magnetic stripe
+
+ <storage> A black stripe, printed on the back of a credit card
+ or similar, that stores a {machine-readable} copy of the
+ information on the card. The stripe contains iron particles
+ about 500 nanometers long that can be magnetised like
+ {magnetic tape}. The data can be read by swiping the card
+ through a {card reader}.
+
+ (2007-06-04)
+
+magnetic tape
+
+ <storage> (Or "magtape", "tape" - {paper tape} is now
+ obsolete) A data storage medium consisting of a magnetisable
+ oxide coating on a thin plastic strip, commonly used for
+ {backup} and {archiving}.
+
+ Early industry-standard magnetic tape was half an inch wide
+ and wound on removable reels 10.5 inches in diameter.
+ Different lengths were available with 2400 feet and 4800 feet
+ being common. {DECtape} was a variation on this "{round
+ tape}".
+
+ In modern magnetic tape systems the reels are much smaller and
+ are fixed inside a {cartridge} to protect the tape and for
+ ease of handling ("{square tape}" - though it's really
+ rectangular). Cartridge formats include {QIC}, {DAT}, and
+ {Exabyte}.
+
+ Tape is read and written on a tape drive (or "deck") which
+ winds the tape from one reel to the other causing it to move
+ past a read/write head. Early tape had seven parallel tracks
+ of data along the length of the tape allowing six bit
+ characters plus {parity} written across the tape. A typical
+ recording density was 556 characters per inch. The tape had
+ reflective marks near its end which signaled beginning of tape
+ (BOT) and end of tape (EOT) to the hardware.
+
+ Data is written to tape in {blocks} with {inter-block gaps}
+ between them. Each block is typically written in a single
+ operation with the tape running continuously during the write.
+ The larger the block the larger the data {buffer} required in
+ order to supply or receive the data written to or read from
+ the tape. The smaller the block the more tape is wasted as
+ inter-block gaps. Several logical {records} may be combined
+ into one physical block to reduce wastage ("{blocked
+ records}"). Finding a certain block on the tape generally
+ involved reading sequentially from the beginning, in contrast
+ to {magnetic disks}. Tape is not suitable for {random
+ access}. The exception to this is that some systems allow
+ {tape marks} to be written which can be detected while winding
+ the tape forward or rewinding it at high speed. These are
+ typically used to separate logical files on a tape.
+
+ Most tape drives now include some kind of {data compression}.
+ There are several {algorithms} which provide similar results:
+ {LZ} (most), {IDRC} ({Exabyte}), {ALDC} ({IBM}, {QIC}) and
+ {DLZ1} ({DLT}).
+
+ See also {cut a tape}, {flap}, {Group Code Recording},
+ {spool}, {macrotape}, {microtape}, {Non Return to Zero
+ Inverted}, {Phase Encoded}.
+
+ (1997-04-05)
+
+magnetic tape drive
+
+ <storage> (Or "tape drive") A {peripheral} device that reads
+ and writes {magnetic tape}.
+
+ (1996-05-25)
+
+magneto-optical disk
+
+ <hardware, storage> (MO) A plastic or glass disk coated with a
+ compound (often TbFeCo) with special optical, magnetic and
+ thermal properties. The disk is read by bouncing a
+ low-intensity {laser} off the disk. Originally the laser was
+ infrared, but frequencies up to blue may be possible giving
+ higher {storage density}. The polarisation of the reflected
+ light depends on the polarity of the stored magnetic field.
+
+ To write, a higher intensity laser heats the coating up to its
+ Curie point, allowing its magnetisation to be altered in a way
+ that is retained when it has cooled.
+
+ Although optical, they appear as hard drives to the {operating
+ system} and do not require a special {filesystem} (they can be
+ formatted as {FAT}, {HPFS}, {NTFS}, etc.).
+
+ The initial 5.25" MO drives, introduced at the end of the
+ 1980s, were the size of a full-height 5.25" {hard drive} (like
+ in {IBM PC XT}) and the disks looked like a {CD-ROM} enclosed
+ in an old-style cartridge
+
+ In 2006, a 3.5" drive has the size of 1.44 {megabyte}
+ {diskette drive} with disks about the size of a regular 1.44MB
+ {floppy disc} but twice the thickness.
+
+ {Storage FAQ
+ (http://cis.ohio-state.edu/hypertext/faq/usenet/arch-storage/part1/faq.html)}.
+
+ (2006-07-25)
+
+magneto-optical drive
+
+ {magneto-optical disk}
+
+magnetostrictive delay line
+
+ <storage, history> An early storage device that used tensioned
+ wires of nickel alloy carrying longitudinal waves produced and
+ detected electromagnetically.
+
+ They had better storage behaviour than {mercury delay lines}.
+
+ [H. Epstein and O.B. Stram, "A High Performance
+ Magnetostriction-Sonic Delay Line," Transactions, Institute of
+ Radio Engineers, Professional Group on Ultrasonic Engineering,
+ 1957, pp. 1-24].
+
+ (2002-11-08)
+
+MAGNUM
+
+ A {database} language for {DEC-10}'s, used internally by
+ {Tymshare, Inc.}. MAGNUM was designed in the late 1970's by
+ Dale Jordan, Rich Strauss and Dave McQuoid originally, and was
+ written in {BLISS-10}. It was the world's first commercial
+ {relational database}. It was in the process of being written
+ in 1976.
+
+ (1995-01-25)
+
+Magritte
+
+ A {constraint} language for interactive graphical layout by
+ J. Gosling. It solves constraints using algebraic
+ transformations.
+
+ ["Algebraic Constraints", J. Gosling, PhD Thesis, TR
+ CS-83-132, CMU, May 1983].
+
+ (1994-10-20)
+
+mail
+
+ <messaging> 1. {electronic mail}.
+
+ 2. The {Berkeley Unix} program for composing and reading
+ {electronic mail}. It normally uses {sendmail} to handle
+ delivery.
+
+ {Unix manual page}: mail(1)
+
+ (1997-12-03)
+
+Mail Application Programming Interface
+
+ {Messaging Application Programming Interface}
+
+mail bomb
+
+ <messaging> To send, or urge others to send, massive amounts
+ of {electronic mail} to a single system or person, with intent
+ to crash or {spam} the recipient's system. A successful mail
+ bomb may cause the victim's {disk quota} to be exhausted, the
+ disk holding his mailbox to fill up, or his computer to spend
+ a large proportion of its time processing mail.
+
+ Mail-bombing is sometimes done in retaliation against someone
+ persistently abusing {Usenet} and violating {netiquette}.
+ While it may inconvenience the intended victim (if they gave
+ their real address), it will probably also inconvenience other
+ users and administrators of the computers and networks
+ involved. Mailbombing is thus a serious offense itself.
+
+ See {netiquette} for the correct way to respond to perceived
+ violations.
+
+ Compare {letterbomb}, {nastygram}.
+
+ [{Jargon File}]
+
+ (1995-04-04)
+
+mailbox
+
+ 1. <messaging> A file belonging to a particular user on a
+ particular computer in which received {electronic mail}
+ messages are stored ready for the user to read them. A
+ mailbox may be just an {electronic mail address} to which
+ messages are sent and may not actually correspond to a file if
+ the messages are processed automatically, e.g. a {mail server}
+ or {mailing list}.
+
+ 2. <programming> A destination for interprocess messages in a
+ {message passing} system. A mailbox is a {message} queue,
+ usually stored in the memory of the processor on which the
+ receiving process is running. {Primitives} are provided for
+ sending a message to a named mailbox and for reading messages
+ from a mailbox.
+
+ (1994-10-20)
+
+mail bridge
+
+ <messaging> A {mail gateway} that {forwards} {electronic mail}
+ messages between two or more networks if they meet certain
+ administrative criteria.
+
+ (1996-02-26)
+
+mail exchanger
+
+ <messaging> A {server} running {SMTP} {Message Transfer Agent}
+ {software} that accepts incoming {electronic mail} and either
+ delivers it locally or forwards it to another server. The
+ mail exchanger to use for a given domain can be discovered by
+ querying {DNS} for {Mail Exchange Records}.
+
+ (2007-01-29)
+
+Mail Exchange Record
+
+ <messaging> (MX Record) A {DNS} resource record type that says
+ which {SMTP} server handles {electronic mail} for a particular
+ {domain}. E.g. the MX record
+
+ foo.co.uk. 1054 IN MX 10 mail.foo.co.uk.
+
+ means that mail for an address like "denis@foo.co.uk" should
+ be sent to "mail.foo.co.uk".
+
+ There can be several servers for a domain. The "10" is a
+ priority - the server with the lowest number will be tried
+ first.
+
+ (2007-01-29)
+
+mail exploder
+
+ <messaging> Part of an {electronic mail} delivery system which
+ allows a message to be delivered to a list of addresses. Mail
+ exploders are used to implement {mailing lists}. Users send
+ messages to a single address and the mail exploder takes care
+ of delivery to the individual {mailboxes} in the list.
+
+ (1996-02-26)
+
+mail filter
+
+ <messaging> A program which sorts and processes incoming
+ {mail} based on patterns found in the mail {headers}.
+
+ {procmail} is an example for {Unix}.
+
+ (1996-12-09)
+
+mail gateway
+
+ <messaging> A machine that connects two or more {electronic
+ mail} systems (including dissimilar mail systems) and
+ transfers messages between them. Sometimes the mapping and
+ translation can be quite complex, and it generally requires a
+ {store and forward} scheme whereby the message is received
+ from one system completely before it is transmitted to the
+ next system, after suitable translations.
+
+ (1996-02-26)
+
+mail hub
+
+ {mail server}
+
+mailing list
+
+ <messaging> (Often shortened in context to "list") An
+ {electronic mail address} that is an alias (or {macro}, though
+ that word is never used in this connection) which is expanded
+ by a {mail exploder} to yield many other e-mail addresses.
+ Some mailing lists are simple "reflectors", redirecting mail
+ sent to them to the list of recipients. Others are filtered
+ by humans or programs of varying degrees of sophistication;
+ lists filtered by humans are said to be "moderated".
+
+ The term is sometimes used, by extension, for the people who
+ receive e-mail sent to such an address.
+
+ Mailing lists are one of the primary forms of hacker
+ interaction, along with {Usenet}. They predate {Usenet},
+ having originated with the first {UUCP} and {ARPANET}
+ connections. They are often used for private
+ information-sharing on topics that would be too specialised
+ for or inappropriate to public {Usenet} groups. Though some
+ of these maintain almost purely technical content (such as the
+ {Internet Engineering Task Force} mailing list), others (like
+ the "sf-lovers" list maintained for many years by Saul Jaffe)
+ are recreational, and many are purely social. Perhaps the
+ most infamous of the social lists was the eccentric bandykin
+ distribution; its latter-day progeny, {lectroids} and
+ {tanstaafl}, still include a number of the oddest and most
+ interesting people in hackerdom.
+
+ Mailing lists are easy to create and (unlike {Usenet}) don't
+ tie up a significant amount of machine resources (until they
+ get very large, at which point they can become interesting
+ torture tests for mail software). Thus, they are often
+ created temporarily by working groups, the members of which
+ can then collaborate on a project without ever needing to meet
+ face-to-face.
+
+ There are several programs to automate mailing list
+ maintenance, e.g. {Listserv}, {Listproc}, {Majordomo}.
+
+ Requests to subscribe to, or leave, a mailing list should
+ ALWAYS be sent to the list's "-request" address (e.g.
+ ietf-request@cnri.reston.va.us for the IETF mailing list).
+ This prevents them being sent to all recipients of the list
+ and ensures that they reach the maintainer of the list, who
+ may not actually read the list.
+
+ [{Jargon File}]
+
+ (2001-04-27)
+
+mail merge
+
+ <messaging> A function of some {word processing} software
+ (e.g. {Microsoft Word}) that produces multiple instances of a
+ document by substituting different text strings from a
+ {database} in place of certain field markers. This is often
+ done with envelopes, resumes, spam, and various other mass
+ mailings.
+
+ {(http://mtroyal.ab.ca/programs/academserv/ADC/workshops/staff/mail_merge/mail_merge_tutorial.html)}.
+
+ (2002-07-26)
+
+mail path
+
+ {source route}
+
+.mailrc
+
+ <messaging> (mail run commands) The configuration file for the
+ standard {Unix} {mail} program. This file is found in a
+ user's {home directory} and can contain special commands to
+ set options and define mail aliases.
+
+ See also {rc}.
+
+ (1996-04-09)
+
+mail server
+
+ 1. <tool, messaging> A program that distributes files or
+ information in response to requests sent via {electronic
+ mail}. Examples on the {Internet} include {Almanac} and
+ {netlib}. Mail servers are also used on {Bitnet}.
+
+ In the days before {Internet} access was widespread and {UUCP}
+ mail links were common, mail servers could be used to provide
+ remote services which might now be provided via {FTP} or
+ {WWW}.
+
+ 2. <messaging> (Or "mail hub") A computer used to store and/or
+ forward {electronic mail}.
+
+ (1995-05-05)
+
+Mail Transfer Agent
+
+ {Message Transfer Agent}
+
+Mail Transport Agent
+
+ {Message Transfer Agent}
+
+mail user agent
+
+ <messaging> (MUA) The program that allows the user to compose
+ and read {electronic mail} messages. The MUA provides the
+ interface between the user and the {Message Transfer Agent}.
+ Outgoing mail is eventually handed over to an MTA for delivery
+ while the incoming messages are picked up from where the MTA
+ left it (although MUA's running on single-user machines may
+ pick up mail using {POP}).
+
+ Popular MUAs for {Unix} include {elm}, {mush}, {pine}, and
+ {RMAIL}.
+
+ {FAQ
+ (http://cis.ohio-state.edu/hypertext/faq/usenet/mail/setup/unix/part2/faq-doc-3.html)}.
+
+ (1996-03-21)
+
+Mail Users' Shell
+
+ <messaging> (mush) A {MUA} for {Unix} and {MS-DOS}. It has both
+ {line-mode} and {full-screen} interfaces as well as a
+ {SunView} interface.
+
+ mush provides a very powerful shell interface with a
+ {csh}-like {scripting language}, plenty of {environment
+ variables}, command-line {aliases}, filename {completion},
+ {conditionals}, and command {piping}.
+
+ {z-mail} is a more recent commercial version of mush.
+
+ {Usenet} newsgroup: {news:comp.mail.mush}.
+
+ (1996-02-26)
+
+main
+
+ <programming> The name of the {subroutine} called by the
+ {run-time system} (RTS) when it executes a {C} program. The
+ RTS passes the program's {command-line arguments} to main as a
+ count and an {array} of {pointers} to strings. If the main
+ subroutine returns then the program exits.
+
+ {Java} has inheritted the name "main" from C but in Java it's
+ more complicated of course. The main routine must have a
+ signature of exactly
+
+ public static void main(String [])
+
+ And it must be inside a public class with the same name as the
+ {source} file where it is defined.
+
+ (2008-11-12)
+
+MAINBOL
+
+ <language> MAcro ImplementatioN of {SNOBOL4}.
+
+ (1997-09-14)
+
+Main Distribution Frame
+
+ <networking> (MDF) The {network closet} containing the main
+ {hub}.
+
+ (1995-05-05)
+
+mainframe
+
+ <computer> A term originally referring to the cabinet
+ containing the central processor unit or "main frame" of a
+ room-filling {Stone Age} batch machine. After the emergence
+ of smaller "{minicomputer}" designs in the early 1970s, the
+ traditional {big iron} machines were described as "mainframe
+ computers" and eventually just as mainframes. The term
+ carries the connotation of a machine designed for batch rather
+ than interactive use, though possibly with an interactive
+ {time-sharing} operating system retrofitted onto it; it is
+ especially used of machines built by {IBM}, {Unisys} and the
+ other great {dinosaurs} surviving from computing's {Stone
+ Age}.
+
+ It has been common wisdom among hackers since the late 1980s
+ that the mainframe architectural tradition is essentially dead
+ (outside of the tiny market for {number crunching}
+ {supercomputers} (see {Cray})), having been swamped by the
+ recent huge advances in {integrated circuit} technology and
+ low-cost personal computing. As of 1993, corporate America is
+ just beginning to figure this out - the wave of failures,
+ takeovers, and mergers among traditional mainframe makers have
+ certainly provided sufficient omens (see {dinosaurs mating}).
+
+ Supporters claim that mainframes still house 90% of the data
+ major businesses rely on for mission-critical applications,
+ attributing this to their superior performance, reliability,
+ scalability, and security compared to microprocessors.
+
+ [{Jargon File}]
+
+ (1996-07-22)
+
+mainframe programmer/analyst
+
+ <job> A peson who writes and maintains business applications.
+ He develops and supports large-scale batch or high-volume
+ transaction environments that require {IBM/MVS} {mainframe}
+ processing power or equivalent. He programs in
+ business-oriented languages such as {COBOL}, {CICS}, or
+ {fourth-generation languages}.
+
+ (2004-03-12)
+
+main loop
+
+ <programming> The top-level {control flow} construct in an
+ input- or {event-driven} program, the one which receives and
+ acts or dispatches on the program's input {events}.
+
+ See also {driver}.
+
+ [{Jargon File}]
+
+ (2004-03-12)
+
+main memory
+
+ <storage, architecture> The {storage device} used by a
+ {computer} to hold the currently executing {program} and its
+ {working data}. A modern computer's main memory is built from
+ {random-access memory} {integrated circuits}. In the old days
+ {ferrite core memory} was one popular form of main memory,
+ leading to the use of the term "{core}" for main memory.
+
+ Computers have several other sorts of memory, distinguished by
+ their access time, storage capicity, cost, and the typical
+ lifetime or rate of change of the data they hold. {Registers}
+ in the {CPU} are fast, few, expensive and typically change
+ every few {machine instructions}. Other kinds are {cache},
+ {PROM}, {magnetic disk} (which may be used for {virtual
+ memory}) and {magnetic tape}.
+
+ (1996-11-04)
+
+MAINSAIL
+
+ {MAchine INdependent SAIL}.
+
+main store
+
+ {main memory}
+
+maintainer
+
+ <software> The person responsible for coordinating changes to
+ a package of {software} and arranging the distribution of
+ updates. The term usually applies only to {free software}
+ where the maintainer (often the author) is doing it as a free
+ public service.
+
+ (2001-01-27)
+
+maintainer script
+
+ <Debian> One of the scripts (preinst, prerm, postinst, postrm)
+ that may be included in a {Debian} {binary package}. These
+ scripts may create and/or remove {symlinks}, files or
+ directories that, for some reason, could not be done directly
+ by {dpkg}. Maintainer scripts frequently create or update the
+ symlinks in the /etc/rc?.d directories and start, stop, or
+ restart {daemons}.
+
+ (2000-05-31)
+
+maintenance
+
+ <programming> The modification of a software product, after
+ delivery, to correct faults, to improve performance or other
+ attributes, or to adapt the product to a changed environment.
+
+ Maintenance is an important part of the {software life-cycle}.
+ It is expensive in manpower and resources, and one of the aims
+ of {software engineering} is to reduce its cost.
+
+ (1996-12-27)
+
+Maisie
+
+ A {C}-based parallel programming language by Wen-Toh Liao
+ <wentoh@may.CS.UCLA.EDU>. Maisie extends C with
+ {asynchronous} typed {message passing} and {lightweight
+ process}es. Programs can define, create and destroy
+ processes, send and receive messages and manipulate the system
+ clock.
+
+ Maisie has been ported to {PVM}/3.1, {Cosmic} Environment and
+ {SUN} {sockets}.
+
+ {Version 2.1.1.3 (ftp://cs.ucla.edu/pub/maisie.2.1.1.3.tar.Z)}.
+
+ (1993-06-14)
+
+major delivery
+
+ <programming> A (chiefly British) synonym for {major release}.
+ E.g, the ninth major release of a piece of software might be
+ called MD9. The {release} notation would be "v9.0".
+
+ (1996-08-04)
+
+Majordomo
+
+ <messaging, tool> A popular {freeware} {mailing list}
+ processor written in {Perl} which runs under {Unix}.
+ Majordomo is a "groupware" project which evolved from code by
+ Brent Chapman <brent@greatcircle.com>, with maintenance by
+ John Rouillard <rouilj@cs.umb.edu>. The current Majordomo
+ maintainer is Chan Wilson <cwilson@sgi.com>.
+
+ A majordomo is a person who speaks, makes arrangements, or
+ takes charge for another; from Latin "major domus" - "master
+ of the house".
+
+ {(http://greatcircle.com/majordomo/)}.
+
+ (2001-04-27)
+
+major release
+
+ <programming> A {release} of a piece of software which is not
+ merely a {revision} or a {bug fix release} but which contains
+ substantial changes (e.g., an overhaul of the {interface},
+ change in compatibility).
+
+ Traditionally, major releases are numbered as X.0; for
+ example, WordPerfect 6.0 is a major release, significantly
+ different from any previous version; whereas WordPerfect 6.1
+ has only minor changes, and is, thus, only a {revision}.
+
+ See also {major delivery}.
+
+ (1996-08-04)
+
+Make
+
+ <programming, tool> The {Unix} tool to automate the
+ recompilation, linking etc. of programs, taking account of the
+ interdependencies of {modules} and their modification times.
+ Make reads instructions from a "makefile" which specifies a
+ set of targets to be built, the files they depend on and the
+ commands to execute in order to produce them.
+
+ Most {C} systems come with a make. There is also one produce
+ by {GNU}.
+
+ ["Make - A Program for Maintaining Computer Programs",
+ A.I. Feldman, TR No 57, Bell Labs Apr 1977].
+
+ (1995-01-05)
+
+Makedoc
+
+ A program from Carleton University, Ottawa that generates
+ documentation for Objective C programs. It will also generate
+ a class hierarchy diagram. The output format is similar to
+ that used by StepStone.
+
+makefile
+
+ A script which tells the Unix program "{make}" how to build a
+ particular computer program or set of programs. A makefile
+ contains variable assignments and rules of the form
+
+ target: inputs
+ commands
+
+ which say if any of the files in "inputs" has been modified
+ more recently than file "target" (or if the target does not
+ exist) then execute "commands", which will normally bulid
+ "target" from "inputs".
+
+ If make is run with no arguments, it looks for a makefile
+ called "Makefile" or "makefile".
+
+ (1995-01-05)
+
+Maker Interchange Format
+
+ (MIF) A language used to describe a {FrameMaker} document in a
+ text file. MIF is used to exchange information between
+ FrameMaker and other applications.
+
+ ["Using FrameMaker 4," Windows and Macintosh Version,
+ c. 1986-1993 Frame Technology Corporation].
+
+ (1995-01-30)
+
+MAL
+
+ {Micro Assembly Language}
+
+Malamud
+
+ <publication> The book:
+
+ [Malamud, C., "Analyzing Sun Networks", Van Nostrand Reinhold,
+ New York, NY, 1992.]
+
+ (1995-04-10)
+
+MALI
+
+ A hardware memory device for {logic programming} computers
+ with {real time} {garbage collection}.
+
+mall
+
+ <web> A collection of {web} documents
+ featuring commercial products and services, usually served by
+ one particualr {Internet} {access provider}.
+
+ (1995-04-10)
+
+malloc
+
+ {C}'s standard library routine for storage allocation. It
+ takes the number of bytes required and returns a pointer to a
+ block of that size. Storage is allocated from a heap which
+ lies after the end of the program and data areas. Memory
+ allocated with malloc must be freed explicitly using the
+ "free" routine before it can be re-used.
+
+ {gc} is a storage allocator with {garbage collection} that is
+ intended to be used as a plug-in replacement for malloc.
+
+malware
+
+ <security> Any {software} designed to do something that the
+ user would not wish it to do, hasn't asked it to do, and often
+ has no knowledge of until it's too late. Types of malware
+ include {backdoor}, {virus}, {worm}, {Trojan horse}.
+
+ Malware typically affects the system on which it is run,
+ e.g. by deleting or corrupting files on the local disks.
+ Since Internet connections became common, malware has
+ increasingly targeted remote systems. An early example was
+ malware consisting of a malicious e-mail attachment that
+ targeted security flaws in {Microsoft Outlook} (the most
+ common {e-mail client}) to send itself to all the user's
+ contacts. A more recent kind of malware "recruits" the
+ infected computer to become part of a {botnet} consisting of
+ thousands of infected computers that can then be remotely
+ controlled and used to launch {DDoS} attacks.
+
+ (2007-11-15)
+
+MAN
+
+ {Metropolitan Area Network}
+
+man
+
+ {Unix manual page}
+
+managed code
+
+ <operating system> Code that is executed by the {.NET} {common
+ language runtime} (CLR). {VB.NET} code is always managed code
+ but {C++ .NET} can optionally use unmanaged code. Managed
+ code provides {metadata} allowing the CLR to manage security
+ (role-based as well as new approaches to code access
+ security). The CLR also handles errors, manages the program
+ {stack} and finds {methods} in assembly modules. Managed data
+ is memory that's subject to {garbage collection}. There are
+ additional restrictions to permit interoperability of
+ different languages, for example, {Visual Basic} {arrays} must
+ be zero-based.
+
+ (2007-07-13)
+
+management
+
+ 1. Corporate power elites distinguished primarily by their
+ distance from actual productive work and their chronic failure
+ to manage (see also {suit}). Spoken derisively, as in
+ "*Management* decided that ...".
+
+ 2. Mythically, a vast bureaucracy responsible for all the
+ world's minor irritations. Hackers' satirical public notices
+ are often signed "The Mgt"; this derives from the
+ "Illuminatus!" novels.
+
+ [{Jargon File}]
+
+ (1995-02-28)
+
+Management Information Base
+
+ <networking> (MIB) A {database} of managed objects acessed by
+ {network management} {protocols}. An {SNMP} MIB is a set of
+ parameters which an {SNMP} {management station} can query or
+ set in the {SNMP agent} of a network device (e.g. {router}).
+
+ {SNMP} has two {standard} MIBs. The first, MIB I, was
+ established in {RFC 1156}, was defined to manage
+ {TCP/IP}-based {internets}. MIB II, defined in {RFC 1213}, is
+ an update.
+
+ Standard minimal MIBs have been defined, and many hardware
+ (and certain software, e.g. {DBMS}) providers have developed
+ private MIBs in {ASN.1} format allowing them to be compiled
+ for use in a {Network Management System}. In theory, any
+ {SNMP manager} can talk to any {SNMP agent} with a properly
+ defined MIB.
+
+ See also {client-server model}.
+
+ (2004-07-22)
+
+Management Information System
+
+ <application> (MIS) A computer system, usually based on a
+ {mainframe} or {minicomputer}, designed to provide management
+ personnel with up-to-date information on an organisation's
+ performance, e.g. inventory and sales. These systems output
+ information in a form that is useable by managers at all
+ levels of the organisation: strategic, tactical, and
+ operational. A good example of an MIS report is an annual
+ report for a stockholder (a scheduled report).
+
+ [Que's Computer User's Dictionary Second Edition, 1992].
+
+ (2001-04-01)
+
+Manager of Business Applications
+
+ <job> A person who plans and oversees multiple projects and
+ project managers. He works with the {CIO} and senior
+ management to determine systems development strategy and
+ standards. He administers the department budget and reviews
+ project managers.
+
+ (2004-03-18)
+
+Manchester Autocode
+
+ <language, history> The predecessor of {Mercury Autocode}.
+
+ ["The Programming Strategy Used with the Manchester University
+ Mark I Computer", R.A. Brooker, Proc IEE 103B Suppl:151-157,
+ 1956].
+
+ (2000-10-02)
+
+Manchester encoding
+
+ <communications, protocol> A method of transmitting bits which
+ enables the receiver to easily synchronise with the sender.
+
+ A simple way of signalling bits might be to transmit a high
+ voltage for some period for a 1-bit and a low voltage for a 0
+ bit:
+
+ Bits Sent: 1 1 0 0
+
+ Signal: High ___________
+ Low |___________
+
+ Time: -> . . . . .
+
+ However, when several identical bits are sent in succession,
+ this provides no information to the receiver about when each
+ bit starts and stops.
+
+ Manchester encoding splits each bit period into two, and
+ ensures that there is always a transition between the signal
+ levels in the middle of each bit. This allows the receiver to
+ synchronise with the sender.
+
+ In normal Manchester encoding, a 1-bit is transmitted with a
+ high voltage in the first period, and a low voltage in the
+ second, and vice verse for the 0 bit:
+
+ Bits Sent: 1 1 0 0
+
+ Signal: High __ __ __ __
+ Low |__| |_____| |__|
+
+ Time: -> . ' . ' . ' . ' .
+
+ In Differential Manchester encoding, a 1-bit is indicated by
+ making the first half of the signal equal to the last half of
+ the previous bit's signal and a 0-bit is indicated by making
+ the first half of the signal opposite to the last half of the
+ previous bit's signal. That is, a zero bit is indicated by a
+ transition at the beginning of the bit.
+
+ Like normal Manchester encoding, there is always a transition
+ in the middle of the transmission of the bit.
+
+ Differential Manchester Encoding
+
+ Bits Sent: 1 1 0 0
+
+ Signal: High ____ __ __ __
+ Low |_____| |__| |__|
+
+ Time: -> . ' . ' . ' . ' .
+
+ With each bit period half as long, twice as much {bandwidth}
+ is required when using either of the Manchester encoding
+ schemes.
+
+ (1995-11-23)
+
+Mandala
+
+ <language> A system based on {Concurrent Prolog}, developed at
+ {ICOT}, Japan.
+
+ ["Mandala: A Logic Based Knowledge Programming System",
+ K. Furukawa et al, Intl Conf 5th Gen Comp Sys 1984].
+
+ (1995-11-23)
+
+Mandelbrot, Benoit
+
+ {Benoit Mandelbrot}
+
+Mandelbrot set
+
+ <mathematics, graphics> (After its discoverer, {Benoit
+ Mandelbrot}) The set of all {complex numbers} c such that
+
+ | z[N] | < 2
+
+ for arbitrarily large values of N, where
+
+ z[0] = 0
+ z[n+1] = z[n]^2 + c
+
+ The Mandelbrot set is usually displayed as an {Argand
+ diagram}, giving each point a colour which depends on the
+ largest N for which | z[N] | < 2, up to some maximum N which
+ is used for the points in the set (for which N is infinite).
+ These points are traditionally coloured black.
+
+ The Mandelbrot set is the best known example of a {fractal} -
+ it includes smaller versions of itself which can be explored
+ to arbitrary levels of detail.
+
+ {The Fractal Microscope
+ (http://ncsa.uiuc.edu/Edu/Fractal/Fractal_Home.html/)}.
+
+ (1995-02-08)
+
+mandelbug
+
+ <jargon, programming> /man'del-buhg/ (From the {Mandelbrot
+ set}) A {bug} whose underlying causes are so complex and
+ obscure as to make its behaviour appear chaotic or even
+ {nondeterministic}. This term implies that the speaker thinks
+ it is a {Bohr bug}, rather than a {heisenbug}.
+
+ See also {schroedinbug}.
+
+ [{Jargon File}]
+
+ (1995-02-08)
+
+Mandy Rice-Davis Applies
+
+ <chat> (MRDA) An acronym used to imply that someone is lying
+ to protect their own interests.
+
+ During the trial of Stephen Ward (who was charged with living
+ off the immoral earnings of Christine Keeler and Rice-Davies),
+ the prosecuting counsel pointed out that Lord Astor denied any
+ involvement with her and Rice-Davies replied, "Well, he would,
+ wouldn't he?"
+
+ (2010-01-01)
+
+manged
+
+ /mahnjd/ [probably from the French "manger" or Italian
+ "mangiare", to eat; perhaps influenced by English "mange",
+ "mangy"] Refers to anything that is mangled or damaged,
+ usually beyond repair. "The disk was manged after the
+ electrical storm." Compare {mung}.
+
+ [{Jargon File}]
+
+mangle
+
+ Used similarly to {mung} or {scribble}, but more violent
+ in its connotations; something that is mangled has been
+ irreversibly and totally trashed.
+
+mangler
+
+ [DEC] A manager. Compare {mango}; see also {management}.
+ Note that {system mangler} is somewhat different in
+ connotation.
+
+ [{Jargon File}]
+
+mango
+
+ <jargon> /mang'go/ (Originally in-house jargon at {Symbolics})
+ A manager.
+
+ Compare {mangler}. See also {devo} and {doco}.
+
+ (1995-03-21)
+
+MANIAC
+
+ {Mathematical Analyzer, Numerical Integrator and Computer}
+
+man page
+
+ {Unix manual page}
+
+MANTIS
+
+ <language> A structured, full-function procedural {4GL} and
+ application development system from {Cincom}. MANTIS enables
+ the developer to design prototypes, create transaction screens
+ and reports, define logical data views, write structured
+ procedures, and dynamically test, correct, document, secure,
+ and release applications for production in a single,
+ integrated, interactive session.
+
+ MANTIS applications can be enhanced with gOOi, the graphical
+ object-oriented interface, which creates graphical Windows
+ representations of existing MANTIS screens.
+
+ {(http://cincom.com/products/mantis/)}.
+
+ (2003-08-08)
+
+mantissa
+
+ 1. <programming> The part of a {floating point} number which,
+ when multiplied by its {radix} raised to the power of its
+ {exponent}, gives its value. The mantissa may include the
+ number's sign or this may be considered to be a separate part.
+
+ 2. <mathematics> The fractional part of a {logarithm}.
+
+ (1996-06-15)
+
+manual testing
+
+ <testing> That part of software testing that requires human
+ input, analysis, or evaluation.
+
+ (1996-12-27)
+
+Manufacturer Resource Planning
+
+ <application> (MRP II) A system based on {MRP} which allows
+ manufacturers to optimise materials, procurement,
+ manufacturing processes, etc., and provide financial and
+ planning reports.
+
+ In the late 1970s and early 1980s, manufacturers integrated
+ MRP and other manufacturing and business functions. This
+ renaissance is commonly known as Manufacturing Resource
+ Planning (MRP II). According to the American Production and
+ Inventory Control Society, Inc. (APICS), MRP II is a method
+ for the effective planning of all resources of a manufacturing
+ company. Ideally, it addresses operational planning in units,
+ financial planning in dollars, and has a simulation capability
+ to answer "what if" questions. It includes business planning,
+ sales and operations planning, production scheduling, material
+ requirements planning (MRP), capacity requirements planning,
+ and the execution support systems for capacity and material.
+ Output from these systems is integrated with financial reports
+ such as the business plan, purchase commitment report,
+ shipping budget, and inventory projections in dollars.
+ Manufacturing resource planning is a direct outgrowth and
+ extension of closed-loop MRP.
+
+ See also {Enterprise Resource Planning}, {SAP} R/2, R/3, and
+ {Baan}.
+
+ (1999-02-16)
+
+Manufacturers Automation Protocol
+
+ {Manufacturing Automation Protocol}
+
+Manufacturing Automation Protocol
+
+ <protocol> (MAP) A set of {protocols} developed by General
+ Motors based on {Token Bus} ({IEEE 802.4}) and giving
+ predictable {real-time} response.
+
+ (1994-10-21)
+
+manularity
+
+ /man"yoo-la"ri-tee/ ("manual" + "granularity") A notional
+ measure of the manual labor required for some task,
+ particularly one of the sort that {automation} is supposed to
+ eliminate. "Composing English on paper has much higher
+ manularity than using a text editor, especially in the
+ revising stage." Hackers tend to consider manularity a
+ symptom of primitive methods; in fact, a true hacker
+ confronted with an apparent requirement to do a computing task
+ {by hand} will inevitably seize the opportunity to build
+ another tool (see {toolsmith}).
+
+ [{Jargon File}]
+
+ (1994-10-26)
+
+MAO
+
+ An early {symbolic mathematics} system.
+
+ [A. Rom, Celest Mech 1:309-319 (1969)].
+
+ (1995-02-10)
+
+MAP
+
+ 1. <protocol> {Manufacturing Automation Protocol}.
+
+ 2. {Mathematical Analysis without Programming}.
+
+ (1996-12-01)
+
+map
+
+ 1. <mathematics> {function}.
+
+ 2. <programming> In {functional programming}, the most common
+ {higher-order function} over lists. Map applies its first
+ argument to each element of its second argument (a list) and
+ returns the list of results.
+
+ map :: (a -> b) -> [a] -> [b]
+ map f [] = []
+ map f (x:xs) = f x : map f xs
+
+ This can be generalised to types other than lists.
+
+ (1997-11-05)
+
+MAPI
+
+ {Messaging Application Programming Interface}
+
+Maple
+
+ A {symbolic mathematics} package by B. Char, K. Geddes,
+ G. Gonnet, M. Monagan and S. Watt of the {University of
+ Waterloo}, Canada and {ETH} Zurich, Switzerland in 1980.
+ Version: Maple V.
+
+ E-mail: <wmsi@daisy.waterloo.edu>. Mailing list:
+ glabahn@daisy.waterloo.edu.
+
+ (1994-10-21)
+
+mapping
+
+ {function}
+
+marbles
+
+ <jargon> (From the mainstream "lost his marbles") The minimum
+ needed to build your way further up some hierarchy of tools or
+ abstractions. After a bad system {crash}, you need to
+ determine if the machine has enough marbles to come up on its
+ own, or enough marbles to allow a rebuild from {backups}, or
+ if you need to rebuild from scratch. "This {compiler} doesn't
+ even have enough marbles to compile {hello, world}."
+
+ [{Jargon File}]
+
+ (1998-05-21)
+
+Marc Andreessen
+
+ <person> The man who founded {Netscape Communications
+ Corporation} in April 1994 with {Dr. James H. Clark}.
+ Andreessen has been a director since September 1994.
+
+ As an undergraduate at the {University of Illinois} in
+ Champaign, Andreessen created the {Mosaic} {web browser}
+ prototype with a team of students and staff at the
+ university's {National Center for Supercomputing Applications}
+ (NCSA). With a friendly, {point-and-click} method for
+ {navigating} the {Internet} and free distribution to network
+ users, NCSA Mosaic gained an estimated two million users
+ worldwide in just over one year. Andreessen earned his
+ Bachelor of Science degree in Computer Science at the
+ University of Illinois in 1993.
+
+ {Home
+ (http://netscape.com/columns/techvision/index.html)}.
+
+ (1999-04-12)
+
+marginal
+
+ <jargon> 1. Extremely small. "A marginal increase in {core}
+ can decrease {GC} time drastically." In everyday terms, this
+ means that it is a lot easier to clean off your desk if you
+ have a spare place to put some of the junk while you sort
+ through it.
+
+ 2. Of extremely small merit. "This proposed new feature seems
+ rather marginal to me."
+
+ 3. Of extremely small probability of {win}ning. "The power
+ supply was rather marginal anyway; no wonder it fried."
+
+ [{Jargon File}]
+
+ (1994-10-21)
+
+Marginal Hacks
+
+ <humour> Margaret Jacks Hall, a building into which the
+ {Stanford AI Lab} was moved near the beginning of the 1980s
+ (from the {D.C. Power Lab}).
+
+ [{Jargon File}]
+
+ (1998-05-21)
+
+Maril
+
+ Machine description language used by the {Marion} code
+ generator.
+
+ ["The Marion System for Retargetable Instruction Scheduling",
+ D.G. Bradlee et al, SIGPLAN Notices 26(6):229-240 (June
+ 1991)].
+
+Mark 1
+
+ <computer> (Or "Automatic Sequence Controlled Calculator") A
+ {first generation computer} developed in 1944 by {Howard
+ Aiken} of {Harvard University}. The Mark 1 is seen as the
+ first full-sized digital computer. It weighed 5 tons, had 500
+ miles of wiring, was used only for numeric calculations, and
+ took three seconds to carry out one multiplication.
+
+ [Mechanism? Capacity? Programmability?]
+
+ (1996-11-24)
+
+marketroid
+
+ /mar'k*-troyd/ (Or "marketing slime", "marketeer", "marketing
+ droid", "marketdroid") A member of a company's marketing
+ department, especially one who promises users that the next
+ version of a product will have features that are not actually
+ scheduled for inclusion, are extremely difficult to implement,
+ and/or are in violation of the laws of physics; and/or one who
+ describes existing features (and misfeatures) in ebullient,
+ buzzword-laden adspeak. Derogatory.
+
+ [{Jargon File}]
+
+ (1995-02-23)
+
+Markov
+
+ See {Andrei Markov}, {Markov chain}, {Markov model}, {Markov
+ process}.
+
+ (1995-02-23)
+
+Markov chain
+
+ <probability> (Named after {Andrei Markov}) A model of
+ sequences of events where the probability of an event
+ occurring depends upon the fact that a preceding event
+ occurred.
+
+ A {Markov process} is governed by a Markov chain.
+
+ In {simulation}, the principle of the Markov chain is applied
+ to the selection of samples from a probability density
+ function to be applied to the model. {Simscript} II.5 uses
+ this approach for some modelling functions.
+
+ [Better explanation?]
+
+ (1995-02-23)
+
+Markov model
+
+ <probability, simulation> A model or {simulation} based on
+ {Markov chains}.
+
+ (2000-10-29)
+
+Markov process
+
+ <probability, simulation> A process in which the sequence of
+ events can be described by a {Markov chain}.
+
+ (1995-02-23)
+
+Markowitz
+
+ The author of the original {Simscript} language.
+
+mark-sweep garbage collection
+
+ Each cell has a bit reserved for marking which is clear
+ initially. During garbage collection all active cells are
+ traced from the root and marked. Then all cells are examined.
+ Unmarked cells are freed.
+
+markup
+
+ <text> In computerised document preparation, a method of adding
+ information to the text to indicate the logical components of a
+ document, instructions for layout of the text on the page or other
+ information which can be interpreted by some automatic system.
+
+ For example, {HTML} (Hypertext Markup Language) adds tags to the
+ text to indicate the appearance and behaviour it should have when
+ displayed by a {web browser}. E.g.:
+
+ <b>This is bold text.</b>
+
+ <a href="http://foldoc.org/">This is a link to FOLDOC</a>.
+
+ Other examples of markup languages are {troff}, {SGML} (on which
+ HTML was based) and {XML}.
+
+ (2012-12-14)
+
+Marlais
+
+ <language> A simple-minded {interpreter} by Brent Benson at
+ Harris for a programming language strongly resembling {Dylan}.
+ Marlais version 0.2a is a "hackers release" for education,
+ experimentation, porting, extension, and bug fixing.
+
+ It has been ported to {Sun-3}, {Sun-4}, {VAX}/{BSD}, {OS/2},
+ {Linux}, {Sequent Symmetry}, {Encore}, {HP-UX}, {Ultrix},
+ {SGI}, {Sony News}, and {A/UX}.
+
+ {(ftp://travis.csd.harris.com/pub/marlais-0.2a.tar.gz)}.
+
+ (1993-09-23)
+
+Mars
+
+ A legendary tragic failure, the archetypal Hacker Dream Gone
+ Wrong. Mars was the code name for a family of PDP-10
+ compatible computers built by Systems Concepts (now, The SC
+ Group): the multi-processor SC-30M, the small uniprocessor
+ SC-25M, and the never-built superprocessor SC-40M. These
+ machines were marvels of engineering design; although not much
+ slower than the unique {Foonly} F-1, they were physically
+ smaller and consumed less power than the much slower DEC KS10
+ or Foonly F-2, F-3, or F-4 machines. They were also
+ completely compatible with the DEC KL10, and ran all KL10
+ binaries (including the operating system) with no
+ modifications at about 2--3 times faster than a KL10.
+
+ When DEC cancelled the Jupiter project in 1983, Systems
+ Concepts should have made a bundle selling their machine into
+ shops with a lot of software investment in PDP-10s, and in
+ fact their spring 1984 announcement generated a great deal of
+ excitement in the PDP-10 world. {TOPS-10} was running on the
+ Mars by the summer of 1984, and {TOPS-20} by early fall.
+
+ Unfortunately, the hackers running Systems Concepts were much
+ better at designing machines than at mass producing or selling
+ them; the company allowed itself to be sidetracked by a bout
+ of perfectionism into continually improving the design, and
+ lost credibility as delivery dates continued to slip. They
+ also overpriced the product ridiculously; they believed they
+ were competing with the KL10 and VAX 8600 and failed to reckon
+ with the likes of Sun Microsystems and other hungry startups
+ building workstations with power comparable to the KL10 at a
+ fraction of the price.
+
+ By the time SC shipped the first SC-30M to Stanford in late
+ 1985, most customers had already made the traumatic decision
+ to abandon the PDP-10, usually for VMS or Unix boxes. Most of
+ the Mars computers built ended up being purchased by
+ {CompuServe}.
+
+ This tale and the related saga of {Foonly} hold a lesson for
+ hackers: if you want to play in the {Real World}, you need to
+ learn Real World moves.
+
+ [{Jargon File}]
+
+Marseille Prolog
+
+ <language> One of the two main dialects of {Prolog}, the other
+ being {Edinburgh Prolog}. The difference is largely {syntax}.
+ The original Marseille Interpreter (1973) was written in
+ {Fortran}.
+
+ [Developed by?]
+
+ (1998-03-16)
+
+marshaling
+
+ <spelling> Alternative US spelling of "{marshalling}".
+
+ (1998-03-16)
+
+marshalling
+
+ <communications> (US -ll- or -l-) The process of packing one
+ or more items of data into a message {buffer}, prior to
+ transmitting that message buffer over a communication channel.
+ The packing process not only collects together values which
+ may be stored in non-consecutive memory locations but also
+ converts data of different types into a standard
+ representation agreed with the recipient of the message.
+
+ (2000-06-09)
+
+MARSYAS
+
+ MARshall SYstem for Aerospace Simulation.
+
+ A software system for digital simulation of large physical
+ systems.
+
+ ["MARSYAS - A Software System for the Digital Simulation of
+ Physical Systems", H. Trauboth et al, Proc SJCC, 36 (1970)].
+
+ (1994-12-02)
+
+Martian
+
+ {Packets} that turn up unexpectedly on the wrong {network}
+ because of bogus {routing} entries. Also a packet which has
+ an altogether bogus (non-registered or ill-formed) {internet
+ address}, such as the test loopback interface [127.0.0.1].
+ Such a packet will come back labelled with a source address
+ that is clearly not of this earth. "The domain server is
+ getting lots of packets from Mars. Does that gateway have a
+ martian filter?"
+
+ [{Jargon File}]
+
+Martin Marietta Laboratories Moorestown
+
+ {(http://atlgw.atl.ge.com/)}.
+
+ Address: Building 145, Moorestown Corporate Center,
+ Moorestown, NJ 08057, USA.
+
+ (1995-02-06)
+
+MARVIN
+
+ U Dortmund, 1984. Applicative language based on Modula-2,
+ enhanced by signatures (grammars) terms (trees) and attribute
+ couplings (functions on trees). Used for specification of
+ language translators.
+
+ ["MARVIN - A Tool for Applicative and Modular Compiler
+ Specification", H. Ganziger et al, Forsch 220, U Dortmund,
+ Jul 1986].
+
+Mary
+
+ <language> An extensible, machine-oriented superset of
+ {ALGOL68} developed by Mark Rain.
+
+ Mary is maintained (and used) by {Kvatro Telecom AS}.
+ Although dated, it still offers a nice strongly typed {3GL}
+ with {macros} but without most of {C}'s flaws.
+
+ It runs on {SPARC} and {x86} computers.
+
+ Hidden on the back cover of the manual: MARY HAD A LITTLE LAMB
+ - COERCION IMPOSSIBLE.
+
+ ["Mary Programmer's Reference Manual", M. Rain et al, R Unit,
+ Trondheim Norway, 1974].
+
+ ["Operator Expressions in Mary", M. Rain, SIGPLAN Notices
+ 8(1), Jan 1973].
+
+ (1998-11-10)
+
+MAS
+
+ Modula-2 Algebra System. Runs on {IBM PC}, {Atari}, {Amiga}.
+
+ {(ftp://alice.fmi.uni-passau.de)}.
+
+ ["Modula-2 Algebra System", H. Kredel, Proc DISCO 90 Capri,
+ LNCS 429, Springer 1990, pp270-271].
+
+MASCOT
+
+ Modular Approach to Software Construction Operation and Test:
+ a method for software design aimed at real-time embedded
+ systems from the Royal Signals and Research Establishment, UK.
+
+Mask Read-Only Memory
+
+ <storage> (MROM) A kind of {ROM} in which the memory contents
+ are determined by one of the masks used to manufacture the
+ {integrated circuit}. MROM can give high storage density
+ (bits per millimeter squared) making it a cheap solution for
+ high volume applications.
+
+ [Other ROM types?]
+
+ (1995-04-22)
+
+MASM
+
+ {Microsoft} {Assembler} for {MS-DOS}.
+
+ (1995-04-22)
+
+MasPar Unity
+
+ A translator from {UNITY} to {MPL} by Martin Huber, University
+ of Karlsruhe, Germany. Version 1.0.
+
+ {(ftp://SanFrancisco.ira.uka.de/pub/maspar/maspar_unity.tar.Z)}.
+ E-mail: Lutz Prechelt <prechelt@ira.uka.de>.
+
+masquerading
+
+ 1. <networking> "{NAT}" ({Linux} {kernel} name).
+
+ 2. <messaging> Hiding the names of internal e-mail {client}
+ and {gateway} machines from the outside world by rewriting the
+ "From" address and other {headers} as the message leaves the
+ organisation.
+
+ This is good practise because external users do not need to
+ know about internal changes in message routing. The external
+ mail gateway needs to know how to route incoming replies back
+ to the original sender.
+
+ (1998-03-03)
+
+Massachusetts Institute of Technology
+
+ (MIT) An independent, coeducational university located in
+ Cambridge, MA, USA. Its best-known computer-related labs are
+ the {Artificial Intelligence Lab}, the {Lab for Computer
+ Science} and the Media Lab. It is also known for its {hacks}
+ or practical jokes, such as {The Great Dome Police Car Hack
+ (http://the-tech.mit.edu/Bulletins/hack.html)}. Resident
+ computer {hackers} include {Richard Stallman}, {Gerald
+ Sussman} and {Tom Knight}.
+
+ See also {6.001}.
+
+ {(http://web.mit.edu/)}.
+
+massage
+
+ Vague term used to describe "smooth" transformations of a data
+ set into a different form, especially transformations that do
+ not lose information. Connotes less pain than {munch} or
+ {crunch}. "He wrote a program that massages {X bitmap} files
+ into {GIF} format." Compare {slurp}.
+
+ [{Jargon File}]
+
+Massey Hope
+
+ <language, functional programming> A refinement of {Hope+C} by
+ Nigel Perry <N.Perry@massey.ac.nz> of {Massey University}, NZ,
+ with improved {syntax}.
+
+ {Concurrent Massey Hope} is derived directly from Massey
+ Hope.
+
+ (1999-08-04)
+
+Massively Multiplayer Online Game
+
+ (MMOG, MMO) Any game that allows dozens, hundreds or even
+ thousands of players to interact with a game via the
+ {Internet}. Typically the game runs on a central {server
+ farm} and players access it via a {personal computer}, {game
+ console} or mobile phone. The most popular genre is the
+ Massively Multiplayer Online Role Playing Game (MMORPG), of
+ which {World of Warcraft} is probably the most popular
+ example.
+
+ Note that an MMOG is not necessarily a _massive_ game (though
+ often they are based in large, complex worlds), their
+ distinguishing characteristic is the number of players.
+
+ (2012-05-30)
+
+Massively Multiplayer Online Role-Playing Game
+
+ {Massively Multiplayer Online Game}
+
+master
+
+ {botmaster}
+
+master boot record
+
+ <operating system, storage> A special area on a computer's
+ main {hard disk} that gives the location of the disk's {boot
+ block} or bootable {partition} where the {operating system} is
+ installed.
+
+ (2009-05-19)
+
+Matchmaker
+
+ A language for specifying and automating the generation of
+ multi-lingual interprocess communication interfaces. {MIG} is
+ an implementation of a subset of Matchmaker.
+
+ (1994-11-22)
+
+Material Requirements Planning
+
+ <application> (MRP) A system for effectively managing material
+ requirements in a manufacturing process.
+
+ Information systems have long been an important part of the
+ manufacturing environment. In the 1960s, manufacturers
+ developed Material Requirements Planning (MRP). According to
+ the American Production and Inventory Control Society,
+ Inc. (APICS), MRP is a set of techniques that uses bill of
+ material data, inventory data, and the master production
+ schedule to calculate requirements for materials. It makes
+ recommendations to reorder materials. Furthermore, because it
+ is time-phased, it makes recommendations to reschedule open
+ orders when due dates and need dates are not in phase.
+ Time-phased MRP begins with the items listed on the Master
+ Production Schedule and determines the quantity of all
+ components and materials required to fabricate those items and
+ the date that the components and material are required.
+ Time-phased MRP is accomplished by exploding the bill of
+ material, adjusting for inventory quantities on hand or on
+ order and offsetting the net requirements by the appropriate
+ lead times.
+
+ See also {Manufacturer Resource Planning}.
+
+ (1999-02-16)
+
+Mathcad
+
+ A {symbolic mathematics} environment.
+
+Mathematica
+
+ <tool, mathematics> A popular {symbolic mathematics} and
+ graphics system, developed in 1988 by Stephen Wolfram and sold
+ by {Wolfram Research}. The language emphasises rules and
+ {pattern-matching}. The name was suggested by {Steve Jobs}.
+
+ {(http://wri.com/mathematica/)}.
+
+ {Stanford FTP (ftp://otter.stanford.edu/)}, {NCSA FTP
+ (ftp://ftp.ncsa.uiuc.edu/)}.
+
+ Mailing list: mathgroup-request@yoda.ncsa.uiuc.edu.
+
+ {Usenet} newsgroup: {news:comp.soft-sys.math.mathematica}.
+
+ ["Mathematica: A System for Doing Mathematics by Computer",
+ Stephen Wolfram, A-W 1988].
+
+ (1995-05-01)
+
+Mathematical Analysis without Programming
+
+ (MAP) An On-line system for mathematics under {CTSS}.
+
+ [Sammet 1969, p. 240].
+
+ (1995-02-10)
+
+Mathematical Analyzer, Numerical Integrator and Computer
+
+ <computer, history> (MANIAC, Or "Mathematical Analyzer, Numerator,
+ Integrator, and Computer") An early computer, built for the {Los
+ Alamos Scientific Laboratory}. MANIAC began operation in March
+ 1952. Typical of early computers, it ran its own propriatery
+ language. It was succeeded by MANIAC II in 1957. A MANIAC III
+ was built at the University of Chicago in 1964.
+
+ Contrary to legend, MANIAC did not run {MAD} ({Michigan Algorithm
+ Decoder}), which was not invented until 1959.
+
+ (2013-05-05)
+
+Mathematics in Recognizable Form Automatically Compiled
+
+ <language> (MIRFAC) An early interactive system resembling
+ {BASIC} using typewriter output with special mathematical
+ symbols.
+
+ [Sammet 1969, pp. 281-284].
+
+ (1997-08-01)
+
+MATHLAB
+
+ Symbolic math system, MITRE, 1964. Later version: MATHLAB 68
+ (PDP-6, 1967).
+
+ ["The Legacy of MATHLAB 68", C. Engelman, Proc 2nd Symp on
+ Symbolic and Algebraic Manip, ACM (Mar 1971)].
+
+ [Sammet 1969, p. 498].
+
+MATH-MATIC or MATHMATIC
+
+ Alternate name for AT-3. Early, pre-Fortran
+ language for UNIVAC I or II. Sammet 1969.
+
+math-out
+
+ (Possibly from "white-out", the blizzard variety) A paper or
+ presentation so encrusted with mathematical or other formal
+ notation as to be incomprehensible. This may be a device for
+ concealing the fact that it is actually {content-free}.
+
+ See also {numbers}, {social science number}.
+
+ [{Jargon File}]
+
+ (1994-12-14)
+
+MathWorks
+
+ {The MathWorks, Inc.}
+
+MATLAB
+
+ <mathematics, language, application> A {high-level language}
+ and {interactive} program from {The MathWorks} for {numeric
+ computation} and {visualisation}. MATLAB supports {numerical
+ analysis}, {matrix} computation, {signal processing}, {linear
+ algebra}, {statistics}, {Fourier analysis}, filtering,
+ optimisation and {numerical integration}. It can output two
+ and three dimensional graphics and can be integrated with {C},
+ {C++}, {Fortran}, {Java}, {COM} and {Microsoft Excel}.
+
+ {(http://mathworks.com/products/matlab/)}.
+
+ Latest version: 7.0.4, as of 2005-08-13.
+
+ (2005-08-13)
+
+Matrix
+
+ [FidoNet] 1. What the Opus BBS software and sysops call
+ {FidoNet}.
+
+ 2. Fanciful term for a {cyberspace} expected to emerge from
+ current networking experiments (see {network, the}).
+
+ 3. The totality of present-day computer networks.
+
+ [{Jargon File}]
+
+Matrix Compiler
+
+ Early matrix computations on UNIVAC. Sammet 1969, p.642.
+
+MATRIX MATH
+
+ <language> An early system on the {UNIVAC I} or II.
+
+ [Listed in CACM 2(5):1959-05-16].
+
+ (1997-02-27)
+
+Matrix Math eXtensions
+
+ <processor> (MMX) (NOT an acronym for "MultiMedia eXtension",
+ according to Intel, but an Intel brand name) A set of 57 extra
+ instructions built into some versions of {Intel}'s {Pentium}
+ {microprocessors} for supporting {SIMD} operations on
+ {multimedia} and communications data types.
+
+ MMX-enhanced processors are due to be released early in 1997.
+ They will be fully compatible with previous Intel processors
+ and software but software will only benefit if it is written
+ to use the new instructions. They can handle many common
+ multimedia operations, such as {digital signal processing},
+ normally handled by a separate {sound card} or {video card}.
+
+ (1996-12-21)
+
+MAU
+
+ {Media Access Unit}
+
+Mauchly, John W.
+
+ {John Mauchly}
+
+mawk
+
+ <language, tool> An faster implementation of {nawk} written by
+ Mike Brennan at Boeing in 1991 and distributed under {GPL} but
+ distinct from {GNU}'s {gawk}.
+
+ Interpreter version 1.1.3 has been ported to {Sun-3},
+ {Sun-4}/{SunOS} 4.0.3; {Vax}/{BSD} 4.3, {ULTRIX} 4.1;
+ {Stardent} 3000/{SYSV}R3; {DECStation}/{ULTRIX} 4.1,
+ {MS-DOS}/{Turbo C++}.
+
+ {(ftp://oxy.edu/public/mawk)}.
+
+ (2000-05-04)
+
+maximal free expression
+
+ (MFE) A {free expression} is sub-expression of a {lambda
+ abstraction} not containing the {bound variable}. A maximal
+ free expression is a free expression not contained within any
+ other free expression. See {full laziness}.
+
+maximin
+
+ {minimax}
+
+MAXIMOP
+
+ "Job Control Languages: MAXIMOP and CAFE", J. Brandon, Proc
+ BCS Symp on Job Control Languages--Past Present and Future,
+ NCC, Manchester, ENgland 1974.
+
+maximum Maytag mode
+
+ <storage, humour> (From the US brand of washing machine) What
+ a {washing machine} or, by extension, any {hard disk} is in
+ when it's being used so heavily that it's shaking like an old
+ Maytag with an unbalanced load. If prolonged for any length
+ of time, can lead to disks becoming {walking drives}.
+
+ [{Jargon File}]
+
+ (1997-07-22)
+
+maximum seek time
+
+ <storage> (Or full stroke seek time) The time it takes to
+ {seek} over all {tracks}, i.e., from the innermost to the
+ outermost or vice versa. The maximum seek time gives a
+ worst-case measure of the speed of the drive which is useful
+ in some {real-time} applications where it is important that
+ data flows continuously (such as video editing or CD
+ recording).
+
+ (1997-07-15)
+
+maximum segment size
+
+ <networking> (MSS) The maximum amount of {TCP} data that a
+ {node} can send in one {segment}. This should be the size of
+ the receiver's reassembly buffer to try to avoid
+ {fragmentation}.
+
+ The equivalent at the {physical layer} is "{Maximum
+ Transmission Unit}".
+
+ (1998-03-06)
+
+Maximum Transmission Unit
+
+ <networking> (MTU) The largest number of bytes of "payload"
+ {data} a {frame} can carry, not counting the frame's header
+ and trailer.
+
+ A frame is a single unit of transportation on the {data link
+ layer}. It consists of header data plus data which was passed
+ down from the {network layer} (e.g. an {IP} {datagram}) plus
+ sometimes trailer data.
+
+ An Ethernet (V2) frame has a MTU of 1500 bytes but the size of
+ the frame can be up to 1526 bytes (22 byte header, 4 byte CRC
+ trailer).
+
+ See also {fragmentation}.
+
+ (2000-10-07)
+
+Maxis Software
+
+ The developers of {SimCity} and {SimCity 2000}.
+
+ {(http://maxis.com/)}.
+
+ Address: 2 Theatre Square, Suite 230, Orinda, CA 94563-3346,
+ USA.
+
+ Telephone: +1 (800) 33-MAXIS.
+
+ (1995-02-08)
+
+MB
+
+ <unit> (Or "Mb") {megabytes} or {megabits}. When referring to
+ the size or data transfer rate of a storage device which is
+ accessed in multiples of eight bits (e.g. {RAM}, {hard disk})
+ this almost certainly means megabytes, but when referring to
+ the data transfer rate of a communications system it probably
+ means {megabits}. Some years ago, it is claimed, "MB" always
+ meant megabytes and "Mb" meant megabits but recently this
+ useful distinction has been lost.
+
+ (1996-09-22)
+
+MBASIC
+
+ {Microsoft} BASIC.
+
+Mbogo, Dr. Fred
+
+ /*m-boh'goh, dok'tr fred/ [Stanford] The archetypal man you
+ don't want to see about a problem, especially an incompetent
+ professional; a shyster. "Do you know a good eye doctor?"
+ "Sure, try Mbogo Eye Care and Professional Dry Cleaning." The
+ name comes from synergy between "bogus" and the original
+ Dr. Mbogo, a witch doctor who was Gomez Addams' physician on
+ the old "Addams Family" TV show. Compare {Bloggs Family,
+ the}, see also {fred}.
+
+ [{Jargon File}]
+
+ (2002-04-14)
+
+MBONE
+
+ Virtual Internet Backbone for Multicast IP.
+
+ {IP-Multicast} is the {class-D} addressing scheme in {IP}
+ implemented by Steve Deering at {Xerox PARC}. It was adopted
+ at the {IETF} March 1992 meeting and acquired the name MBONE
+ after the July 1992 IETF meeting.
+
+ IP Multicast-based routing allows distributed applications to
+ achieve {real-time} communication over {IP} {wide area
+ networks} through a lightweight, highly {thread}ed model of
+ communication.
+
+ Each network-provider participant in the MBONE provides one or
+ more IP multicast routers to connect with tunnels to other
+ participants and to customers. The multicast routers are
+ typically separate from a network's production routers since
+ most production routers don't yet support IP multicast. Most
+ sites use workstations running the mrouted program, but the
+ experimental MOSPF software for Proteon routers is an
+ alternative.
+
+ Ideally, the machines running mrouted should be dedicated to
+ this task, for reasons of real-time performance and ease of
+ installing kernel patches. Since most intermediate nodes have
+ at least three tunnels, each carrying a separate ({unicast})
+ copy of each packet, it is also useful to have multiple
+ network interfaces so it can be installed parallel to the
+ unicast router for those sites with configurations like this:
+
+ +----------+
+ | Backbone |
+ | Node |
+ +----------+
+ |
+ ------------------------------------------ External DMZ Ethernet
+ | |
+ +----------+ +----------+
+ | Router | | mrouted |
+ +----------+ +----------+
+ | |
+ ------------------------------------------ Internal DMZ Ethernet
+
+ This configuration allows the mrouted machine to connect with
+ tunnels to other regional networks over the external {DMZ} and
+ the physical backbone network, and connect with tunnels to the
+ lower-level mrouted machines over the internal {DMZ}, thereby
+ splitting the load of the replicated packets. The mrouted
+ machine would not do any unicast forwarding.
+
+ Note that end-user sites may participate with as little as one
+ workstation that runs the packet audio and video software and
+ has a tunnel to a network-provider node.
+
+ {RFC 1112} gives the details.
+
+ {FAQ (http://eit.com/techinfo/mbone/mbone.html)}.
+
+ (1994-11-11)
+
+MBps
+
+ {megabytes per second}
+
+mbps
+
+ {megabits per second}
+
+MBS
+
+ {mobile broadband services}
+
+MC
+
+ <language> An extension of {C} with {modules}. Symbols in
+ other modules can be referenced using a dot notation.
+
+ ["Design and Implementation of a C-Based Language for
+ Distributed Real-Time Systems", A. Rizk et al, SIGPLAN Notices
+ 22(6):83-96 (June 1987)].
+
+ (1995-10-06)
+
+mc
+
+ <networking> The {country code} for Monaco.
+
+ (1999-01-27)
+
+MC68000
+
+ {Motorola 68000}
+
+MC68010
+
+ {Motorola 68010}
+
+MC68020
+
+ {Motorola 68020}
+
+MC68030
+
+ {Motorola 68030}
+
+MC68040
+
+ {Motorola 68040}
+
+MC6809
+
+ {Motorola 6809}
+
+MCA
+
+ {Micro Channel Architecture}
+
+MCAD
+
+ {Microsoft Certified Application Developer}
+
+MCC
+
+ 1. {Mosaic Communications Corporation}.
+
+ 2. The {Microelectronics and Computer Technology Corporation}.
+
+McCulloch-Pitts neuron
+
+ <artificial intelligence> The basic building block of
+ {artificial neural networks}. It receives one or more inputs
+ and produces one or more identical outputs, each of which is a
+ simple non-linear function of the sum of the inputs to the
+ neuron. The non-linear function is typically a threshhold or
+ step function which is usually smoothed (i.e. a {sigmoid}) to
+ facilitate {learning}.
+
+ (1997-10-11)
+
+MCDBA
+
+ {Microsoft Certified Database Administrator}
+
+MCDST
+
+ {Microsoft Certified Desktop Support Technician}
+
+McG360
+
+ Interactive, similar to PAL[5], for IBM 360.
+
+ "McG360 Programmer's Guide", RC 2693, IBM TJWRC, Nov 1969.
+
+MCGA
+
+ {Multi-Color Graphics Array}
+
+MCI
+
+ <company> A United States long-distance telecommunications
+ company. Recently bought from {British Telecom} [by ?].
+
+ (1998-05-18)
+
+MCI Mail
+
+ <messaging> The first commercial Internet {electronic mail}
+ service, launched by {MCI} in about 1981. {Vint Cerf} was the
+ chief engineer.
+
+ Reading mail was free but you had to pay to send. Users
+ discovered you could communicate for free by sharing an
+ account. One user would save a message as a draft and the
+ other would read it and replace it with his response.
+
+ (2004-08-25)
+
+MCL
+
+ {Macintosh Common LISP}
+
+M-Code
+
+ <language> 1. {Intermediate language} produced by some
+ {Modula-2} compilers.
+
+ [Which compilers?]
+
+ 2. The {intermediate language} for an {SECD}-like machine,
+ used by the {Concert} implementation of {MultiLISP}.
+
+ (1996-01-22)
+
+MCP
+
+ {motion compensated prediction}
+
+MCP-1600
+
+ A processor made by {Western Digital}, consisting of at least
+ four separate {integrated circuits}, including the control
+ circuitry unit, the {ALU}, two or four {ROM} chips with
+ {microcode}, and timing circuitry.
+
+ The ALU chip contained twenty-six 8-bit {registers} and an
+ 8-bit {ALU}, while the control unit supervised the moving of
+ data, memory access, and other control functions. The {ROM}
+ allowed the chip to function as either an 8- or 16-bit chip,
+ with clever use of the 8-bit {ALU}. Further, {microcode}
+ allowed the addition of {floating-point} routines (40 + 8 bit
+ format), simplifying programming (and possibly producing a
+ floating-point coprocessor).
+
+ Two standard {microcode} {ROMs} were available. This
+ flexibility was one reason it was also used to implement the
+ {DEC} {LSI-11} processor as well as the {WD} {Pascal
+ Microengine}.
+
+ (1994-11-18)
+
+MCPD
+
+ {Microsoft Certified Professional Developer}
+
+MCS
+
+ {Meta Class System}
+
+MCSA
+
+ <education> 1. {Microsoft Certified Systems Administrator}.
+
+ 2. {Microsoft Certified Solutions Associate}.
+
+ (2013-09-02)
+
+MCSD
+
+ {Microsoft Certified Solution Developer}
+
+MCSE
+
+ 1. <education> {Microsoft Certified System Engineer}.
+
+ 2. <humour> {Minesweeper, Chess, Solitaire Expert}.
+
+ (2013-03-16)
+
+mcvax
+
+ mcvax.cwi.nl used to be the international {backbone} node of
+ {EUnet}, the European Unix network. It was located in
+ Amsterdam, Netherlands and belonged to "Centrum voor Wiskunde
+ en Informatica" (Centre for Mathematics and Computer Science)
+ which is an institute belonging to a foundation called
+ "Mathematisch Centrum". Since the first mcvax was on of the
+ first {VAXen} in Europe and one of it's first {uucp}
+ connections was to a machine called decvax it was quickly
+ christened mcvax. Some also say this was done to give Jim
+ McKie a nice mail address: mcvax!mckie. But this is certainly
+ not true at all. The function of EUnet international backbone
+ moved to another VAX later but the name moved with it, because
+ in those days of mainly uucp based mail and before widespread
+ use of {pathalias} it was simply not feasible to rename the
+ machine to "europa" as was suggested at one stage.
+
+ Mcsun (or relay.eu.net or net.eu.relay in some parts of
+ Europe) replaced the international backbone host of EUnet
+ around 1990. This machine was donated by {Sun Microsystems}
+ owned by the {European Unix Systems User Group} (EUUG). It
+ was located about 5m from where mcvax used to be and operated
+ by the same people.
+
+ Mcvax has finally ceased to exist in the {domain} and {uucp}
+ {namespaces}. It still exists in the {EARN}/{BITNET}
+ namespace.
+
+ [Posting by Daniel Karrenberg <dfk@eu.net> to eunet.general].
+
+ (1990-03-02)
+
+mcvert
+
+ <tool> A {Unix} program for reading and writing {Apple Computer}
+ {Macintosh} {binary files}. It was written by Doug Moore, now
+ at {Rice University} (Jan 1990).
+
+ See {BinHex}, {HQX}, {MacBinary}.
+
+ (1995-04-22)
+
+MD
+
+ 1. <audio, storage> {Mini Disk}.
+
+ 2. <programming> {major delivery}.
+
+ 3. {message digest function}.
+
+ (2001-12-02)
+
+md
+
+ <networking> The {country code} for Moldova.
+
+ (1999-01-27)
+
+MD5
+
+ {Message Digest 5}
+
+MDA
+
+ {Monochrome Display Adapter}
+
+MDAC
+
+ {Microsoft Data Access Components}
+
+MDCT
+
+ {Modified Discrete Cosine Transform}
+
+MDF
+
+ {Main Distribution Frame}
+
+MDI
+
+ {Multiple Document Interface}
+
+MDL
+
+ (Originally "Muddle"). C. Reeve, {Carl Hewitt} and {Gerald
+ Sussman}, Dynamic Modeling Group, MIT ca. 1971. Intended as a
+ successor to Lisp, and a possible base for Planner-70.
+ Basically LISP 1.5 with data types and arrays. Many of its
+ features were advanced at the time (I/O, interrupt handling
+ and coroutining), and were incorporated into later LISP
+ dialects ("optional", "rest" and "aux" markers). In the mid
+ 80's there was an effort to use bytecoding to make the
+ language portable. CLU was first implemented in MDL. Infocom
+ wrote Zork in MDL, and used it as the basis for the ZIL
+ interpreter.
+
+ Implementations exist for ITS, {TOPS-20}, BSD 4.3, Apollo
+ Domain, SunOS and A/UX.
+
+ ["The MDL Programming Language", S.W. Galley et al, Doc
+ SYS.11.01, Project MAC, MIT (Nov 1975)].
+
+Mean Time Between Failures
+
+ <specification> (MTBF, or "Mean Time Between Faults") The
+ {average} time (usually expressed in hours) that a {component}
+ works without failure. It is calculated by dividing the total
+ number of failures into the total number of operating hours
+ observed. The term can also mean the length of time a user
+ may reasonably expect a device or system to work before an
+ incapacitating fault occurs.
+
+ See also {Mean Time To Recovery}.
+
+ (1998-05-01)
+
+Mean Time Between Faults
+
+ {Mean Time Between Failures}
+
+Mean Time To Recovery
+
+ <specification> (MTTR) The average time that a device will
+ take to recover from a non-terminal failure. Examples of such
+ devices range from self-resetting fuses (where the MTTR would
+ be very short, probably seconds), up to whole systems which
+ have to be replaced.
+
+ The MTTR would usually be part of a maintenance contract,
+ where the user would pay more for a system whose MTTR was 24
+ hours, than for one of, say, 7 days. This means the supplier
+ is guaranteeing to have the system up and running again within
+ 24 hours (or 7 days) of being notified of the failure.
+
+ Some devices have a MTTR of zero, which means that they have
+ redundant components which can take over the instant the
+ primary one fails, see {RAID} for example.
+
+ See also {Mean Time Between Failures}.
+
+ (1998-05-01)
+
+measure
+
+ <testing> To ascertain or appraise by comparing to a
+ {standard}; to apply a {metric}.
+
+ (1996-12-27)
+
+measurement
+
+ <testing> The act or process of measuring; a figure, extent,
+ or amount obtained by measuring.
+
+ (1996-12-27)
+
+meatspace
+
+ <jargon> The physical world (as opposed {virtual reality})
+ where you might spend {facetime} with the {carbon community}.
+
+ (1999-01-15)
+
+meatware
+
+ Less common synonym for {wetware}.
+
+ [Was it Marvin Minsky who described brains as
+ "machines?/computers? made of meat"?]
+
+ [{Jargon File}]
+
+ (1994-10-21)
+
+media
+
+ 1. <data> Any kind of {data} including {graphics}, {images},
+ {audio} and {video}, though typically excluding {raw text} or
+ {executable code}.
+
+ The term {multimedia} suggests a collection of different types
+ of media or the ability to handle such collections.
+
+ 2. <storage> The physical object on which {data} is stored, as
+ opposed to the device used to read and write it.
+
+ 3. <networking> The object at the {physical layer} that
+ carries data, typically an electrical or optical cable,
+ though, in a {wireless network}, the term refers to the space
+ through which radio waves propagate. Most often used in the
+ context of {Media Access Control} (MAC).
+
+ (2010-01-07)
+
+Media Access Control
+
+ <networking> (MAC) The lower sublayer of the {OSI} {data link
+ layer}. The interface between a {node}'s {Logical Link
+ Control} and the network's {physical layer}. The MAC differs
+ for various physical media.
+
+ See also {MAC Address}, {Ethernet}, {IEEE 802.3}, {token ring}.
+
+ [What does it do? Examples?]
+
+ (1996-01-29)
+
+Media Access Unit
+
+ <networking> (MAU or Multistation Access Unit, MSAU) In a
+ {Token Ring} network, a device to attach multiple network
+ stations in a star topology, internally wired to connect the
+ stations into a logical ring. The MAU contains relays to
+ short out nonoperating stations. Multiple MAUs can be
+ connected into a larger ring through their Ring In/Ring Out
+ connectors.
+
+ (1997-05-27)
+
+Media Converter
+
+ <networking> A component used in {Ethernet}, although it is
+ not part of the {IEEE} standard. The IEEE standard states
+ that all {segments} must be linked with {repeaters}. Media
+ converters were developed as a simpler, cheaper alternative to
+ repeaters. However, in the 1990s the cost difference between
+ the two is negligible.
+
+ (1996-12-09)
+
+Media Gateway Control Protocol
+
+ <communications, protocol> (MGCP) A {protocol} used within a
+ {Voice over IP} system. MGCP is an {IETF} work in progress,
+ it superseded {SGCP}.
+
+ MGCP is an internal protocol used within a {distributed}
+ system that appears to the outside world as a single VoIP
+ {gateway}.
+
+ This system is composed of a {Call Agent}, and a set of
+ gateways, including at least one "media gateway" that performs
+ the conversion of media signals between {circuits} and
+ {packets}, and at least one "signalling gateway" when
+ connected to an {SS7} controlled network.
+
+ {IETF MGCP draft
+ (http://ietf.org/internet-drafts/draft-huitema-megaco-mgcp-v0r1-05.txt)}.
+
+ (1999-03-17)
+
+Medium Access Control
+
+ {Media Access Control}
+
+meeces
+
+ <jargon> /mees'*z/ ({TMRC}) Occasional furry visitors who are
+ not {urchins}; that is, mice. This may no longer be in live
+ use. According to {ESR} it derives from the refrain of the
+ early-1960s cartoon character Mr. Jinx: "I hate meeces to
+ *pieces*!"
+
+ [{Jargon File}]
+
+ (1996-12-09)
+
+Meet
+
+ {greatest lower bound}
+
+meg
+
+ {megabyte}
+
+mega-
+
+ {prefix}
+
+megabits per second
+
+ <unit> (Mbps, Mb/s) Millions of {bits} per second. A unit of
+ {data rate}. 1 Mb/s = 1,000,000 bits per second (not
+ 1,048,576).
+
+ E.g. {Ethernet} can carry 10 Mbps.
+
+ (2002-03-23)
+
+megabyte
+
+ <unit, data> (MB, colloquially "meg") A Unit of {data} equal to
+ one million {bytes} but see {binary prefix} for other definitions.
+ A megabyte is 1000^2 bytes or 1000 {kilobytes}.
+
+ The text of a six hundred page paperback book stored as {ASCII}
+ {characters} contains about a megabyte of data.
+
+ 1000 megabytes are one {gigabyte}.
+
+ See {prefix}.
+
+ (2013-11-04)
+
+megabytes per second
+
+ <unit> (MBps, MB/s) Millions of {bytes} per second. A unit of
+ {data rate}. 1 MB/s = 1,000,000 bytes per second (not
+ 1,048,576).
+
+ (2007-02-20)
+
+megaflop
+
+ <unit> Etymologically incorrect singular of "{megaflops}".
+
+ (1995-02-28)
+
+megaflops
+
+ <unit> One million {floating-point} operations per second. A
+ common unit of measurement of performance of computers used
+ for numerical work.
+
+ (2000-08-03)
+
+MegaHertz
+
+ (MHz) Millions of cycles per second. The unit of frequency
+ used to measure the {clock rate} of modern digital logic,
+ including {microprocessors}.
+
+ (1994-10-27)
+
+megapenny
+
+ /meg'*-pen"ee/ $10,000 (1 cent * 10^6). Used semi-humorously
+ as a unit in comparing computer cost and performance figures.
+
+ [{Jargon File}]
+
+MEGO
+
+ /me"goh/ or /mee'goh/ ["My Eyes Glaze Over", often "Mine Eyes
+ Glazeth (sic) Over", attributed to the futurologist Herman
+ Kahn] Also "MEGO factor". 1. A {handwave} intended to
+ confuse the listener and hopefully induce agreement because
+ the listener does not want to admit to not understanding what
+ is going on. MEGO is usually directed at senior management by
+ engineers and contains a high proportion of {TLAs}.
+ 2. excl. An appropriate response to MEGO tactics. 3. Among
+ non-hackers, often refers not to behaviour that causes the
+ eyes to glaze, but to the eye-glazing reaction itself, which
+ may be triggered by the mere threat of technical detail as
+ effectively as by an actual excess of it.
+
+Mei
+
+ <library> A set of {class libraries} by Atsushi Aoki
+ <aoki@sra.co.jp> and others for {Objectworks Smalltalk}
+ Release 4.1. Mei includes: Grapher Library for drawing
+ diagrams; Meta Grapher Library (grapher to develop grapher);
+ Drawing tools and painting tools (structured diagram editors
+ and drawing editors); {GUI builder}; {Lisp} {interpreter};
+ {Prolog} interpreter; Pluggable gauges; Extended browser;
+ (package, history, recover, etc.)
+
+ Mei is available under {General Public License} and requires
+ Objectworks Smalltalk Release 4.1.
+
+ Latest version: 0.50, as of 1993-01-20.
+
+ {Home
+ (http://sra.co.jp/people/aoki/htmls/FreeSoftwareForSmalltalk.html)}.
+
+ E-mail: Watanabe Katsuhiro <katsu@sran14.sra.co.jp>
+
+ (1999-12-08)
+
+Mel
+
+ {The story of Mel}
+
+MELD
+
+ A {concurrent}, {object-oriented}, {dataflow}, {modular} and
+ {fault-tolerant} language! MELD is comparable to {SR}.
+
+ ["MELDing Multiple Granularities of Parallelism", G. Kaiser et
+ al, ECOOP '89, pp. 147-166, Cambridge U Press 1989].
+
+ (1994-11-11)
+
+MELDC
+
+ A {reflective} {object-oriented} {concurrent} programming
+ language developed in 1990 by the MELD Project of the
+ Programming Systems Laboratory at {Columbia University}.
+ MELDC is a redesign of {MELD} based on {C}.
+
+ The core of the architecture is a {micro-kernel} (the MELDC
+ kernel), which encapsulates a minimum set of entities that
+ cannot be modelled as objects. All components outside of the
+ kernel are implemented as objects in MELDC itself and are
+ modularised in the MELDC libraries. MELDC is reflective in
+ three dimensions: structural, computational and architectural.
+ The structural reflection indicates that classes and
+ meta-classes are objects, which are written in MELDC. The
+ computational reflection means that object behaviours can be
+ computed and extended at run time. The architectural
+ reflection indicates that new features/properties
+ (e.g. persistency and remoteness) can be constructed in MELDC.
+
+ Version 2.0 runs on {Sun-4}/{SunOS} 4.1 and {DECstation} and
+ {MIPS}/{Ultrix} 4.2.
+
+ E-mail: Gail Kaiser <meldc@cs.columbia.edu>.
+
+ MELDC is available under licence from <MeldC@cs.columbia.edu>
+ and may not be used for commercial purposes.
+
+ (1992-12-15)
+
+Melinda
+
+ ["Melinda: Linda with Multiple Tuple Spaces", S. Hupfer,
+ <hupfer-susanne@yale.edu> YALEU/DCS/RR-766, Yale U Feb 1990].
+
+ (1994-11-11)
+
+Mel Kaye
+
+ <person> The hero of {The Story of Mel, a Real Programmer}.
+ The preface to the manuals for the {Royal McBee} {LGP-30} ACT
+ 1 ({Algebraic Compiler and Translator}) {compiler} (dated
+ 1959) contain the following attribution from Clay S. Boswell,
+ Jr. (apparently ACT 1's designer):
+
+ I wish to acknowledge my appreciation to the many people who
+ offered suggestions and criticisms of the ACT 1 System. In
+ particular, Mel Kaye of Royal McBee who did the bulk of the
+ programming.
+
+ (2008-08-04)
+
+Mellor
+
+ {Schlaer-Mellor}
+
+meltdown
+
+ {network meltdown}
+
+member function
+
+ A {method} in {C++}.
+
+membership function
+
+ {fuzzy subset}
+
+meme
+
+ <philosophy> /meem/ [By analogy with "gene"] Richard Dawkins's
+ term for an idea considered as a {replicator}, especially with
+ the connotation that memes parasitise people into propagating
+ them much as viruses do.
+
+ Memes can be considered the unit of cultural evolution. Ideas
+ can evolve in a way analogous to biological evolution. Some
+ ideas survive better than others; ideas can mutate through,
+ for example, misunderstandings; and two ideas can recombine to
+ produce a new idea involving elements of each parent idea.
+
+ The term is used especially in the phrase "meme complex"
+ denoting a group of mutually supporting memes that form an
+ organised belief system, such as a religion. However, "meme"
+ is often misused to mean "meme complex".
+
+ Use of the term connotes acceptance of the idea that in humans
+ (and presumably other tool- and language-using sophonts)
+ cultural evolution by selection of adaptive ideas has become
+ more important than biological evolution by selection of
+ hereditary traits. Hackers find this idea congenial for
+ tolerably obvious reasons.
+
+ See also {memetic algorithm}.
+
+ [{Jargon File}]
+
+ (1996-08-11)
+
+meme plague
+
+ <philosophy> The spread of a successful but pernicious {meme},
+ especially one that parasitises the victims into giving their
+ all to propagate it. Astrology, BASIC, and the other guy's
+ religion are often considered to be examples. This usage is
+ given point by the historical fact that "joiner" ideologies
+ like Naziism or various forms of millennarian Christianity
+ have exhibited plague-like cycles of exponential growth
+ followed by collapses to small reservoir populations.
+
+ [{Jargon File}]
+
+ (1996-08-11)
+
+memetic algorithm
+
+ <algorithm> A {genetic algorithm} or {evolutionary algorithm}
+ which includes a non-genetic local search to improve
+ genotypes. The term comes from the Richard Dawkin's term
+ "{meme}".
+
+ One big difference between memes and genes is that memes are
+ processed and possibly improved by the people that hold them -
+ something that cannot happen to genes. It is this advantage
+ that the memetic algorithm has over simple genetic or
+ evolutionary algorithms.
+
+ These algorithms are useful in solving complex problems, such
+ as the "{Travelling Salesman Problem}," which involves finding
+ the shortest path through a large number of nodes, or in
+ creating {artificial life} to test evolutionary theories.
+
+ Memetic algorithms are one kind of {metaheuristic}.
+
+ {UNLP memetic algorithms home page
+ (http://ing.unlp.edu.ar/cetad/mos/memetic_home.html)}.
+
+ (07 July 1997)
+
+memetics
+
+ <philosophy> /me-met'iks/ The study of {memes}.
+
+ As of mid-1993, this is still an extremely informal and
+ speculative endeavor, though the first steps toward at least
+ statistical rigor have been made by H. Keith Henson and
+ others. Memetics is a popular topic for speculation among
+ hackers, who like to see themselves as the architects of the
+ new information ecologies in which memes live and replicate.
+
+ [{Jargon File}]
+
+ (2000-01-09)
+
+Memex
+
+ <hypertext> {Vannevar Bush}'s original name for {hypertext},
+ which he invented in the 1930s.
+
+ {Fantastic article
+ (http://jefferson.village.virginia.edu/elab/hfl0051.html)}.
+
+ (2000-01-09)
+
+memo function
+
+ <programming> (Or "memoised function") A {function} that
+ remembers which {arguments} it has been called with and the
+ result returned and, if called with the same arguments again,
+ returns the result from its memory rather than recalculating
+ it.
+
+ Memo functions were invented by Professor {Donald Michie} of
+ {Edinburgh University}. The idea was further developed by
+ {Robin Popplestone} in his {Pop2} language long before it was
+ ever worked into LISP.
+
+ This same principle is found at the hardware level in computer
+ architectures which use a {cache} to store recently accessed
+ memory locations.
+
+ A {Common Lisp} package by Marty Hall
+ <hall@aplcenmp.apl.jhu.edu>
+ {(ftp://archive.cs.umbc.edu/pub/Memoization)}.
+
+ ["'Memo' functions: and machine learning", Donald Michie,
+ Nature, 218, 19-22, 1968].
+
+ (2002-07-02)
+
+memoisation
+
+ {memo function}
+
+memoised function
+
+ {memo function}
+
+memoization
+
+ {memo function}
+
+memoized function
+
+ {memo function}
+
+memory
+
+ <storage> These days, usually used synonymously with {Random
+ Access Memory} or {Read-Only Memory}, but in the general sense
+ it can be any device that can hold {data} in
+ {machine-readable} format.
+
+ (1996-05-25)
+
+memory address space
+
+ <architecture> 1. Any part of a {processor}'s {address space}
+ that is occupied by {memory}.
+
+ 2. The range of addresses seen by a memory device relative to
+ the base address at which it is mapped into the processor's
+ address space.
+
+ (1999-11-01)
+
+memory dump
+
+ <programming, operating system, jargon> (Or "core dump") A
+ {file} on {hard disk} (traditionally called "core") containing
+ a copy of the contents of a {process}'s memory, produced when
+ a process is aborted by certain kinds of internal error or
+ {signal}.
+
+ {Debuggers} like {adb} and {gdb} can load the dump file and
+ display the information it contains about the state of the
+ running program. This can be related to the program code,
+ both {object code} and, in a {source-level debugger}, the
+ {source code}. Information includes the contents of
+ {registers}, the {call stack} and all other program data.
+
+ (2007-05-09)
+
+memory farts
+
+ <jargon, humour> The flatulent sounds that some {MS-DOS} box
+ {BIOS}es (most notably {AMI}'s) make when checking memory at
+ {boot} time.
+
+ [{Jargon File}]
+
+ (1994-11-02)
+
+memory leak
+
+ <programming> A {leak} in a program's {dynamic store}
+ allocation logic that causes it to fail to reclaim memory in
+ the {heap} after it has finished using it, eventually causing
+ the program to fail due to lack of memory.
+
+ These problems were severe on older machines with small,
+ fixed-size address spaces, and special "leak detection" tools
+ were written to diagnose them.
+
+ The introduction of {virtual memory} made memory leaks a less
+ serious problem, although if you run out of {virtual
+ memory}, it means you've got a *real* leak!
+
+ See {aliasing bug}.
+
+ [{Jargon File}]
+
+ (2003-10-07)
+
+memory location
+
+ <storage> A {byte}, {word} or other small unit of storage
+ space in a computer's {main memory} that is identified by its
+ starting {address} (and size).
+
+ (1999-04-19)
+
+memory management
+
+ <memory management, storage> A collection of techniques for
+ providing sufficient memory to one or more processes in a
+ computer system, especially when the system does not have
+ enough memory to satisfy all processes' requirements
+ simultaneously. Techniques include {swapping}, {paging} and
+ {virtual memory}. Memory management is usually performed
+ mostly by a {hardware} {memory management unit}.
+
+ (1995-01-23)
+
+Memory Management Unit
+
+ <hardware, memory management> (MMU, "Paged Memory Management
+ Unit", PMMU) A {hardware} device or circuit that supports
+ {virtual memory} and {paging} by translating {virtual
+ addresses} into {physical addresses}.
+
+ The virtual {address space} (the range of addresses used by
+ the processor) is divided into {pages}, whose size is 2^N,
+ usually a few {kilobytes}. The bottom N {bits} of the address
+ (the offset within a page) are left unchanged. The upper
+ address bits are the (virtual) {page number}. The MMU
+ contains a {page table} which is indexed (possibly
+ associatively) by the page number. Each page table entry
+ (PTE) gives the physical page number corresponding to the
+ virtual one. This is combined with the page offset to give
+ the complete physical address.
+
+ A PTE may also include information about whether the page has
+ been written to, when it was last used (for a {least recently
+ used} {replacement algorithm}), what kind of processes ({user
+ mode}, {supervisor mode}) may read and write it, and whether
+ it should be {cache}d.
+
+ It is possible that no physical memory ({RAM}) has been
+ allocated to a given virtual page, in which case the MMU will
+ signal a "{page fault}" to the {CPU}. The {operating system}
+ will then try to find a spare page of RAM and set up a new PTE
+ to map it to the requested virtual address. If no RAM is free
+ it may be necessary to choose an existing page, using some
+ {replacement algorithm}, and save it to disk (this is known as
+ "{paging}"). There may also be a shortage of PTEs, in which
+ case the OS will have to free one for the new mapping.
+
+ In a {multitasking} system all processes compete for the use
+ of memory and of the MMU. Some {memory management}
+ architectures allow each process to have its own area or
+ configuration of the page table, with a mechanism to switch
+ between different mappings on a process switch. This means
+ that all processes can have the same virtual address space
+ rather than require load-time relocation.
+
+ An MMU also solves the problem of {fragmentation} of memory.
+ After blocks of memory have been allocated and freed, the free
+ memory may become fragmented (discontinuous) so that the
+ largest contiguous block of free memory may be much smaller
+ than the total amount. With {virtual memory}, a contiguous
+ range of virtual addresses can be mapped to several
+ non-contiguous blocks of physical memory.
+
+ In early designs memory management was performed by a separate
+ {integrated circuit} such as the {MC 68851} used with the
+ {Motorola 68020} {CPU} in the {Macintosh II} or the {Z8015}
+ used with the {Zilog Z80} family of processors. Later CPUs
+ such as the {Motorola 68030} and the {ZILOG Z280} have MMUs on
+ the same IC as the CPU.
+
+ (1999-05-24)
+
+memory mapped I/O
+
+ <architecture> The use of the same instructions and {bus} to
+ communicate with both {main memory} and {input/output}
+ devices. This is in contrast to processors that have a
+ separate I/O {bus} and special instructions to access it.
+
+ The I/O devices are addressed at certain reserved address
+ ranges on the main memory bus. These addresses cannot
+ therefore be used for {RAM}. {Motorola} and {Mostec}
+ architectures, among others, use memory mapped I/O.
+
+ {Video cards} and other cards with on-board memory might be
+ accessed in this way though the term applies not just to
+ devices containing memory but to any device connected to the
+ memory bus. Accessing the devices usually consists of reading
+ and writing certain built-in {registers} though sometimes the
+ mere presence of a particular address can trigger the device.
+
+ (1997-04-14)
+
+memory protection
+
+ <memory management> A system to prevent one {process}
+ corrupting the memory (or other resources) of any other,
+ including the {operating system}. Memory protection usually
+ relies on a combination of hardware (a {memory management
+ unit}) and software to allocate memory to processes and handle
+ {exceptions}.
+
+ The effectiveness of memory protection varies from one
+ operating system to another. In most versions of {Unix} it is
+ almost impossible to corrupt another process' memory, except
+ in some archaic implementations and {Lunix} (not {Linux}!).
+ Under {Microsoft Windows} (version? hardware?) any {16 bit
+ application}(?) can circumvent the memory protection, often
+ leading to one or more {GPFs}. Currently (April 1996) neither
+ {Microsoft Windows} 3.1, {Windows 95}, nor {Mac OS} offer
+ memory protection. {Windows NT} has it, and Mac OS System 8
+ will offer a form of memory protection.
+
+ [MS DOS {EMM386} relevant?]
+
+ (1996-09-10)
+
+memory smash
+
+ <jargon> A {Xerox PARC} term for writing to the location
+ addressed by a {dangling pointer}.
+
+ [{Jargon File}]
+
+ (1994-11-02)
+
+Memory Type Range Registers
+
+ <architecture, video> (MTRR) Registers in the {Pentium Pro}
+ and {Pentium II} processors that can be used to specify a
+ strategy for communication with the external memory and
+ {caches} for a number of {physical address} ranges.
+
+ Strategies include {write-through}, {write-back}, or
+ uncached(?). Such control is useful where the memory is
+ located on a device and is accessed via some kind of device
+ bus, e.g. a {PCI} or {AGP} {graphics card}, where caching
+ would be of no benefit.
+
+ (1999-07-02)
+
+MEMS
+
+ {microelectromechanical system}
+
+Mentat
+
+ <language> (After the human computers in Frank Herbert's SF
+ classic, "Dune") An {object-oriented} distributed language
+ developed at the {University of Virginia} some time before Dec
+ 1987. Mentat is an extension of {C++} and is portable to a
+ variety of {MIMD} architectures.
+
+ By 1994 Mentat was available for {Sun-3}, {Sun-4}, {iPSC}/2
+ with plans for {Mach}, {iPSC860}, {RS/6000} and {Iris}. The
+ language is now (May 1998) supported in a new project,
+ {Legion}.
+
+ E-mail: <mentat@uvacs.cs.virginia.edu>.
+
+ ["Mentat: An Object-Oriented Macro Data Flow System",
+ A. Grimshaw <grimshaw@cs.virginia.edu> et al, SIGPLAN Notices
+ 22(12):35-47, Dec 1987, OOPSLA '87].
+
+ (1998-05-15)
+
+MENTOR
+
+ CAI language. "Computer Systems for Teaching Complex
+ Concepts", Report 1742, BBN, Mar 1969.
+
+menu
+
+ <operating system> A list from which the user may select an
+ operation to be performed. This is often done with a {mouse}
+ or other pointing device under a {graphical user interface}
+ but may also be controlled from the keyboard.
+
+ Menus are very convenient for beginners because they show what
+ commands are available and make experimentating with a new
+ program easy, often reducing the need for user documentation.
+ Experienced users however, often prefer keyboard commands,
+ especially for frequently user operations, because they are
+ faster to use. In situations such as text entry where the
+ keyboard must be used anyway, having to move your hand to the
+ mouse to invoke a menu operation is slow.
+
+ There are many different ways of presenting menus but the most
+ common are the {menu bar} (with {pull-down menus}) and the
+ {context-sensitive menu}.
+
+ The term "menu" tends to be reserved for a list of actions or
+ global options, whereas a "{list box}" or other graphical
+ {widget} might present any kind of choice.
+
+ See also {menuitis}.
+
+ (1994-12-02)
+
+menu bar
+
+ <operating system> A permanently displayed {menu} spread
+ horizontally across the top of the screen or window. When the
+ mouse is pressed over an item on the menu bar, a {pull-down
+ menu} appears.
+
+ (1999-09-22)
+
+menuitis
+
+ /men"yoo-i:"tis/ A notional disease suffered by software with
+ an obsessively simple-minded {menu} interface and no escape.
+ Hackers find this intensely irritating and much prefer the
+ flexibility of command-line or language-style interfaces,
+ especially those customisable via {macros} or a
+ special-purpose language in which one can encode useful hacks.
+
+ See {user-obsequious}, {drool-proof paper}, {WIMP}, {for the
+ rest of us}.
+
+ [{Jargon File}]
+
+ (1994-12-02)
+
+MENYMA/S
+
+ ["A Message Oriented Language for System Applications",
+ A. Koch et al, Proc 3rd Intl Conf Distrib Comp Sys, IEEE 1982,
+ pp. 824-832].
+
+ (1994-12-02)
+
+Mercury Autocode
+
+ {Autocode} for the {Ferranti} {Mercury} machine.
+
+mercury delay line
+
+ <storage, history> An archaic {first-in first-out} fixed time
+ period data storage device using {acoustic transducers} to
+ transmit data as waves in a trough or tube of mercury.
+
+ EDSAC (Cambridge) and UNIVAC I used delay lines.
+
+ (2002-06-12)
+
+MERISE
+
+ Methode d'Etude et de Realisation Informatique pour les
+ Systemes d'Enteprise.
+
+ A software engineering method popular in France; many {IPSEs}
+ are based on it.
+
+ (1995-01-24)
+
+Merlin
+
+ {OS/2}
+
+MEROON
+
+ <language> An {object-oriented} system built on {Scheme}.
+
+ [What kind of system?]
+
+ {(ftp://nexus.yorku.ca/pub/scheme/new/)}.
+
+ (1997-05-05)
+
+Mesa
+
+ Xerox PARC, 1977. System and application programming for
+ proprietary hardware: Alto, Dolphin, Dorado and Dandelion.
+ Pascal-like syntax, ALGOL68-like semantics. An early version
+ was weakly typed. Mesa's modules with separately compilable
+ definition and implementation parts directly led to Wirth's
+ design for Modula. Threads, coroutines (fork/join),
+ exceptions, and monitors. Type checking may be disabled.
+ Mesa was used internally by Xerox to develop ViewPoint, the
+ Xerox Star, MDE, and the controller of a high-end copier. It
+ was released to a few universitites in 1985. Succeeded by
+ Cedar.
+
+ ["Mesa Language Manual", J.G. Mitchell et al, Xerox PARC,
+ CSL-79-3 (Apr 1979)].
+
+ ["Early Experience with Mesa", Geschke et al, CACM
+ 20(8):540-552 (Aug 1977)].
+
+mesh
+
+ <character> The {INTERCAL} name for {hash}.
+
+MESI protocol
+
+ <processor> Modified, Exclusive, Shared, Invalid.
+
+ A {cache coherency} {protocol} where each {cache line} is
+ marked with one of the four states.
+
+ The MESI protocol is used by the {Pentium} processor.
+
+ (1995-05-05)
+
+message
+
+ In {object-oriented programming} sending a message to an
+ {object} (to invoke a {method}) is equivalent to calling a
+ {procedure} in traditional programming languages, except that
+ the actual code executed may only be selected at run time
+ depending on the {class} of the object. Thus, in response to
+ the message "drawSelf", the method code invoked would be
+ different if the target object were a circle or a square.
+
+ (1995-02-16)
+
+message board
+
+ {bulletin board system}
+
+Message Digest 5
+
+ <messaging> The {message digest function} defined in {RFC
+ 1321}.
+
+ (1996-08-04)
+
+message digest function
+
+ {one-way hash function}
+
+Message Handling System
+
+ <messaging, standard> (MHS) The {standard} defined by {ITU-T}
+ as {X.400} and by {ISO} as {Message-Oriented Text Interchange
+ Standard} (MOTIS). MHS is the X.400 family of services and
+ {protocols} that provides the functions for global {electronic
+ mail} transfer among local mail systems and {MTAs}.
+
+ It is used by {CompuServe}, among others.
+
+ (1996-09-25)
+
+message passing
+
+ One of the two techniques for communicating between parallel
+ processes (the other being {shared memory}).
+
+ A common use of message passing is for communication in a
+ {parallel computer}. A process running on one processor may
+ send a message to a process running on the same processor or
+ another. The actual transmission of the message is usually
+ handled by the {run-time support} of the language in which the
+ processes are written, or by the {operating system}.
+
+ Message passing scales better than {shared memory}, which is
+ generally used in computers with relatively few processors.
+ This is because the total communications {bandwidth} usually
+ increases with the number of processors.
+
+ A message passing system provides primitives for sending and
+ receiving messages. These primitives may by either
+ {synchronous} or {asynchronous} or both. A synchronous send
+ will not complete (will not allow the sender to proceed) until
+ the receiving process has received the message. This allows
+ the sender to know whether the message was received
+ successfully or not (like when you speak to someone on the
+ telephone). An asynchronous send simply queues the message
+ for transmission without waiting for it to be received (like
+ posting a letter). A synchronous receive primitive will wait
+ until there is a message to read whereas an asynchronous
+ receive will return immediately, either with a message or to
+ say that no message has arrived.
+
+ Messages may be sent to a named process or to a named
+ {mailbox} which may be readable by one or many processes.
+
+ Transmission involves determining the location of the
+ recipient and then choosing a route to reach that location.
+ The message may be transmitted in one go or may be split into
+ {packets} which are transmitted independently (e.g. using
+ {wormhole routing}) and reassembled at the receiver. The
+ message passing system must ensure that sufficient memory is
+ available to buffer the message at its destination and at
+ intermediate nodes.
+
+ Messages may be typed or untyped at the programming language
+ level. They may have a priority, allowing the receiver to
+ read the highest priority messages first.
+
+ Some message passing computers are the {MIT J-Machine
+ (http://ai.mit.edu/projects/cva/cva_j_machine.html)}, the
+ {Illinois Concert Project
+ (http://www-csag.cs.uiuc.edu/projects/concert.html)} and
+ {transputer}-based systems.
+
+ {Object-oriented programming} uses message passing between
+ {objects} as a metaphor for procedure call.
+
+ (1994-11-11)
+
+Message Passing Interface
+
+ <communications, protocol> A {de facto standard} for
+ communication among the {nodes} running a {parallel program}
+ on a {distributed memory system}. MPI is a {library} of
+ {routines} that can be called from {Fortran} and{ C} programs.
+ MPI's advantage over older message passing libraries is that
+ it is both {portable} (because MPI has been implemented for
+ almost every distributed memory {architecture}) and fast
+ (because each implementation is {optimised} for the {hardware}
+ it runs on).
+
+ [Address?]
+
+ (1997-06-09)
+
+message switching
+
+ {store and forward}
+
+Message Transfer Agent
+
+ <messaging> (MTA, Mail Transfer Agent) Any program responsible
+ for delivering {e-mail} messages. Upon receiving a message
+ from a {Mail User Agent} or another MTA, often by {SMTP} over
+ the {Internet}, it stores it temporarily locally and analyses
+ the recipients and delivers it to any local addressees and/or
+ forwards it to other remote MTAs ({routing}) for delivery to
+ remote recipients. In either case it may edit and/or add to
+ the message {headers}.
+
+ The most widely used MTA for {Unix} is {sendmail}, which
+ communicates using {SMTP}.
+
+ [Other OSes?]
+
+ {RFC 2821} (SMTP) expands MTA as "Mail Transfer Agent" though
+ this is less common. Alternatives with "Transport" are also
+ seen but less correct.
+
+ (2007-06-01)
+
+Message Transport Agent
+
+ {Message Transfer Agent}
+
+Messaging Application Programming Interface
+
+ <messaging> (MAPI) A messaging architecture and a {client}
+ interface component for applications such as {electronic
+ mail}, scheduling, calendaring and document management. As a
+ messaging architecture, MAPI provides a consistent interface
+ for multiple {application programs} to interact with multiple
+ messaging systems across a variety of {hardware} {platforms}.
+
+ MAPI provides better performance and control than {Simple
+ MAPI}, {Common Messaging Calls} (CMC) or the {Active Messaging
+ Library}. It has a comprehensive, open, dual-purpose
+ interface, integrated with {Microsoft Windows}. MAPI can be
+ used by all levels and types of client application and
+ "service providers" - driver-like components that provide a
+ MAPI interface to a specific messaging system. For example, a
+ {word processor} can send documents and a {workgroup}
+ application can share and store different types of data using
+ MAPI.
+
+ MAPI separates the programming interfaces used by the client
+ applications and the service providers. Every component works
+ with a common, {Microsoft Windows}-based user interface. For
+ example, a single messaging client application can be used to
+ receive messages from {fax}, a {bulletin board} system, a
+ host-based messaging system and a {LAN}-based system.
+ Messages from all of these systems can be delivered to a
+ single "universal Inbox".
+
+ MAPI is aimed at the powerful, new market of workgroup
+ applications that communicate with such different messaging
+ systems as fax, {DEC} {All-In-1}, {voice mail} and public
+ communications services such as {AT&T} Easylink Services,
+ {CompuServe} and {MCI} MAIL. Because workgroup applications
+ demand more of their messaging systems, MAPI offers much more
+ than basic messaging in the programming interface and supports
+ more than {local area network} (LAN)-based messaging systems.
+ Applications can, for example, format text for a single
+ message with a variety of fonts and present to their users a
+ customised view of messages that have been filtered, sorted or
+ preprocessed.
+
+ MAPI is built into {Windows 95} and {Windows NT} and can be
+ used by 16-bit and 32-bit Windows applications. The
+ programming interface and subsystem contained in the MAPI
+ {DLL} provide objects which conform to the {Component Object
+ Model}. MAPI includes standard messaging client applications
+ that demonstrate different levels of messaging support.
+
+ MAPI provides cross platform support through such industry
+ standards as {SMTP}, {X.400} and Common Messaging Calls. MAPI
+ is the messaging component of {Windows Open Services
+ Architecture} (WOSA).
+
+ [Correct expansion? Relatonship with Microsoft?]
+
+ (1997-12-03)
+
+Messaging Applications Programming Interface
+
+ {Messaging Application Programming Interface}
+
+mess-dos
+
+ /mes-dos/ (Or MS-DOG, Messy-DOS, mess-dross, mess-loss,
+ mush-dos) Derisory term for {MS-DOS}. Often followed by the
+ ritual banishing "Just say No!"
+
+ Most hackers (even many {MS-DOS} hackers) loathe {MS-DOS} for
+ its single-tasking nature, its limits on application size, its
+ nasty primitive interface, and its ties to {IBM}ness (see
+ {fear and loathing}).
+
+ In Ireland and the UK it is sometimes called "Domestos" after
+ a brand of toilet cleanser.
+
+ [{Jargon File}]
+
+ (1994-11-16)
+
+META
+
+ <language> The {assembly language} for the {CYBER 200},
+ developed at {CDC} ca 1977.
+
+ [CDC Pub 60256020].
+
+ [{Jargon File}]
+
+ (1994-11-16)
+
+meta
+
+ <philosophy> /me't*/ or /may't*/ or (Commonwealth) /mee't*/ A
+ prefix meaning one level of description higher. If X is some
+ concept then meta-X is data about, or processes operating on,
+ X.
+
+ For example, a {metasyntax} is {syntax} for specifying syntax,
+ {metalanguage} is a language used to discuss language,
+ {metadata} is data about data, and {meta-reasoning} is
+ reasoning about reasoning.
+
+ This is difficult to explain briefly, but much hacker humour
+ turns on deliberate confusion between meta-levels.
+
+ [{Jargon File}]
+
+ (1999-04-06)
+
+META 5
+
+ Early syntax-directed {compiler-compiler}, used for
+ translating one {high-level language} to another.
+
+ Versions: META II, META-3.
+
+ ["META 5: A Tool to Manipulate Strings of Data",
+ D.K. Oppenheim et al, Proc 21st Natl Conf, ACM 1966].
+
+ [Sammet 1969, p. 638].
+
+ (1995-01-23)
+
+meta bit
+
+ The top bit of an 8-bit character, which is on in character
+ values 128--255. Also called {high bit}, {alt bit}, or
+ {hobbit}. Some terminals and consoles (see {space-cadet
+ keyboard}) have a META shift key. Others (including,
+ *mirabile dictu*, keyboards on IBM PC-class machines) have an
+ ALT key. See also {bucky bits}.
+
+ Historical note: although in modern usage shaped by a universe
+ of 8-bit bytes the meta bit is invariably {hex} 80 ({octal}
+ 0200), things were different on earlier machines with 36 bit
+ words and 9-bit bytes. The MIT and Stanford keyboards (see
+ {space-cadet keyboard}) generated hex 100 (octal 400) from
+ their meta keys.
+
+ [{Jargon File}]
+
+MetaCard
+
+ A commercial human interface and {hypertext} system for {Unix}
+ and the {X Window System}, similar to {Hypercard}.
+
+ (1994-11-17)
+
+Meta-CASE tool
+
+ A term sometimes used for software packages (like TBK or VSF)
+ which allow users to develop or customise their own CASE
+ tools.
+
+metaclass
+
+ <programming> The {class} of a class in an {object-oriented
+ programming} language. A metaclass is a class whose {instances}
+ are themselves classes. Typically there will only be one
+ metaclass, called "Class" or similar, which is the class of all
+ classes including itself. In some languages there will be no
+ metaclass.
+
+ The idea of a metaclass is closely associated with {introspection}
+ - the ability of a program to access the structure and logic of
+ itself or other programs.
+
+ (2013-09-02)
+
+Meta Class System
+
+ <language> (MCS) A portable {object-oriented} extension of {Common
+ Lisp} from {GMD}. It integrates the functionality of {CLOS} and
+ {TELOS}.
+
+ {(ftp://gmdzi.gmd.de/pub/lisp/mcs)}.
+
+ (1994-10-21)
+
+Meta-Crystal
+
+ A language for transformations of Crystal programs.
+ Implemented in T. "Meta-Crystal- A Metalanguage for
+ Parallel-Program Optimisation", J.A. Yang et al, TR
+ YALEU/DCS/TR-786, Yale Apr 1990. (See Crystal).
+
+metadata
+
+ <data> /me't*-day`t*/, or combinations of /may'-/ or
+ (Commonwealth) /mee'-/; /-dah`t*/ (Or "meta-data") Data about
+ {data}. In {data processing}, metadata is definitional data
+ that provides information about or documentation of other data
+ managed within an application or environment.
+
+ For example, metadata would document data about {data
+ elements} or {attributes}, (name, size, data type, etc) and
+ data about {records} or {data structures} (length, fields,
+ columns, etc) and data about data (where it is located, how it
+ is associated, ownership, etc.). Metadata may include
+ descriptive information about the context, quality and
+ condition, or characteristics of the data.
+
+ A collection of metadata, e.g. in a {database}, is called a
+ {data dictionary}.
+
+ Myers of {The Metadata Company} claims to have coined the term
+ in 1969 though it appears in the book, "Extension of
+ programming language concepts" published in 1968, by {Philip
+ R. Bagley}. Bagley was a pioneer of computer document
+ retrieval. "A survey of extensible programming languages" by
+ Solntsseff and Yezerski (Annual Review in Automatic
+ Programming, 1974, pp267-307) cites "the notion of 'metadata'
+ introduced by Bagley".
+
+ (2010-05-15)
+
+Metadata Information Partners
+
+ {The Metadata Company}
+
+META element
+
+ <web> An {element}, with tag name of "META",
+ expressing {meta-data} about a given {HTML} document. HTML
+ standards do not require that documents have META elements;
+ but if META elements occur, they must be inside the document's
+ HEAD element.
+
+ The META element can be used to identify properties of a
+ document (e.g., author, expiration date, a list of key words,
+ etc.) and assign values to those properties, typically by
+ specifying a NAME {attribute} (to name the property) and a
+ CONTENT attribute (to assign a value for that property). The
+ HTML 4 specification doesn't standardise particular NAME
+ properties or CONTENT values; but it is conventional to use a
+ "Description" property to convey a short summary of the
+ document, and a "Keywords" property to provide a list of
+ {keywords} relevant to the document, as in:
+
+ <META NAME="Description" CONTENT="Information from around the
+ world on kumquat farming techniques and current kumquat
+ production and consumption data">
+ <META NAME="Keywords" CONTENT="kumquat, Fortunella">
+
+ META elements with HTTP-EQUIV and CONTENT attributes can
+ simulate the effect of {HTTP} header lines, as in:
+
+ <META HTTP-EQUIV="Expires" CONTENT="Tue, 22 Mar 2000 16:18:35 GMT">
+ <META HTTP-EQUIV="Refresh" CONTENT="10; URL=http://foldoc.org/">
+
+ Other properties may be application-specific. For example,
+ the {Robots Exclusion
+ (http://info.webcrawler.com/mak/projects/robots/norobots.html)}.
+ standard uses the "robots" property for asserting that the
+ given document should not be indexed by robots, nor should
+ links in it be followed:
+
+ <META NAME="robots" CONTENT="noindex,follow">
+
+ (2001-02-07)
+
+metafile
+
+ <graphics, file format> 1. An image file format for transport
+ between different machines, often as a {device independent
+ bitmap}.
+
+ 2. A {functional specification} for encoding computer
+ {graphics} for later display on some suitable device.
+
+ (1996-09-20)
+
+METAFONT
+
+ A system for the design of raster-based alphabets by {Donald
+ Knuth}. A companion to {TeX}.
+
+ ["The METAFONT Book," Donald Knuth, A-W 1986. Version 2.0,
+ March 1990].
+
+ (1994-11-04)
+
+metaheuristic
+
+ <algorithm, complexity, computability> A top-level general
+ strategy which guides other {heuristics} to search for
+ feasible solutions in domains where the task is hard.
+
+ Metaheuristics have been most generally applied to problems
+ classified as {NP-Hard} or {NP-Complete} by the theory of
+ {computational complexity}. However, metaheuristics would
+ also be applied to other {combinatorial} {optimisation}
+ problems for which it is known that a {polynomial-time}
+ solution exists but is not practical.
+
+ Examples of metaheuristics are {Tabu Search}, {simulated
+ annealing}, {genetic algorithms} and {memetic algorithms}.
+
+ (1997-10-30)
+
+Meta-II
+
+ An early {compiler-compiler}.
+
+ ["Meta-II: a Syntax Oriented Compiler Writing Language",
+ V. Schorre, Proc 19th ACM Natl Conf 1964].
+
+ (1995-01-23)
+
+metainformation
+
+ {meta-data}
+
+Meta-IV
+
+ {Vienna Development Method Specification Language}
+
+METAL
+
+ 1. Mega-Extensive Telecommunications Applications Language.
+ BBS language for PRODOS 8 on Apple II.
+
+ 2. The syntax-definition formalism of the Mentor system.
+ Metal specifications are compiled to specifications for a
+ scanner/parser generator such as Lex/Yacc. "Metal: A
+ Formalism to Specify Formalisms", G. Kahn et al, Sci Comp
+ Prog 3:151-188 (1983).
+
+metalanguage
+
+ 1. [theorem proving] A language in which proofs are
+ manipulated and tactics are programmed, as opposed to the
+ logic itself (the "{object language}"). The first {ML} was
+ the metalanguage for the Edinburgh {LCF} proof assistant.
+
+ 2. [logic] A language in which to discuss the truth of
+ statements in another language.
+
+Metal Oxide Semiconductor
+
+ <electronics> (MOS) The three materials used to form a {gate}
+ in the most common kind of {Field Effect Transistor} - a
+ {MOSFET}.
+
+ [Other MOS devices?]
+
+ (1996-05-27)
+
+Metal Oxide Semiconductor Field Effect Transistor
+
+ <electronics> (MOSFET) A {Field Effect Transistor} in which
+ the conducting channel is insulated from the gate terminal by
+ a layer of oxide. Therefore it does not conduct even if a
+ reverse voltage is applied to the gate.
+
+ (1997-02-24)
+
+metaphone
+
+ <algorithm, text> An {algorithm} for encoding a word so that
+ similar sounding words encode the same. It's similar to
+ {soundex} in purpose, but as it knows the basic rules of
+ English pronunciation it's more accurate. The higher accuracy
+ doesn't come free, though, metaphone requires more
+ computational power as well as more storage capacity, but
+ neither of these requirements are usually prohibitive. It is
+ in the public domain so it can be freely implemented.
+
+ Metaphone was developed by Lawrence Philips
+ <lphilips@verity.com>. It is described in ["Practical
+ Algorithms for Programmers", Binstock & Rex, Addison Wesley,
+ 1995].
+
+ (1998-12-22)
+
+metaprogram
+
+ A program which modifies or generates other programs. A
+ {compiler} is an example of a metaprogram: it takes a program
+ as input and produces another (compiled) one as output.
+
+ (1994-10-24)
+
+metasyntactic variable
+
+ <grammar> Strictly, a {variable} used in {metasyntax}, but
+ often used for any name used in examples and understood to
+ stand for whatever thing is under discussion, or any random
+ member of a class of things under discussion. The word {foo}
+ is the {canonical} example. To avoid confusion, hackers never
+ (well, hardly ever) use "foo" or other words like it as
+ permanent names for anything.
+
+ In filenames, a common convention is that any filename
+ beginning with a metasyntactic-variable name is a {scratch}
+ file that may be deleted at any time.
+
+ To some extent, the list of one's preferred metasyntactic
+ variables is a cultural signature. They occur both in series
+ (used for related groups of variables or objects) and as
+ singletons. Here are a few common signatures:
+
+ {foo}, {bar}, {baz}, {quux}, quuux, quuuux...: MIT/Stanford
+ usage, now found everywhere. At MIT (but not at Stanford),
+ {baz} dropped out of use for a while in the 1970s and '80s. A
+ common recent mutation of this sequence inserts {qux} before
+ {quux}.
+
+ bazola, ztesch: Stanford (from mid-'70s on).
+
+ {foo}, {bar}, thud, grunt: This series was popular at CMU.
+ Other CMU-associated variables include ack, barf, foo, and
+ {gorp}.
+
+ {foo}, {bar}, fum: This series is reported to be common at
+ {Xerox PARC}.
+
+ {fred}, {barney}: See the entry for {fred}. These tend to be
+ Britishisms.
+
+ {toto}, titi, tata, tutu: Standard series of metasyntactic
+ variables among francophones.
+
+ {corge}, {grault}, {flarp}: Popular at Rutgers University and
+ among {GOSMACS} hackers.
+
+ zxc, spqr, {wombat}: Cambridge University (England).
+
+ shme: Berkeley, GeoWorks, Ingres. Pronounced /shme/ with a
+ short /e/.
+
+ {foo}, {bar}, zot: {Helsinki University of Technology},
+ Finland.
+
+ blarg, wibble: New Zealand
+
+ Of all these, only "foo" and "bar" are universal (and {baz}
+ nearly so). The compounds {foobar} and "foobaz" also enjoy
+ very wide currency.
+
+ Some jargon terms are also used as metasyntactic names; {barf}
+ and {mumble}, for example.
+
+ See also {Commonwealth Hackish} for discussion of numerous
+ metasyntactic variables found in Great Britain and the
+ Commonwealth.
+
+ [{Jargon File}]
+
+ (1995-11-13)
+
+metasyntax
+
+ <grammar> {Syntax} used to describe {syntax}. The best known
+ example is {BNF} and its variants such as {EBNF}.
+
+ A {metasyntactic variable} is a {variable} used in
+ {metasyntax}.
+
+ (1999-04-06)
+
+META tag
+
+ {META element}
+
+Meta-Vlisp
+
+ <language> An innovative {Lisp} dialect by E. St.James of IBP,
+ France.
+
+ (2000-12-19)
+
+Met-English
+
+ A {Fortran}-like language designed at {Metropolitan Life} in
+ the early 1960s. It had support for variable-length bit
+ fields. Most MetLife {DP} in the 1960s and 1970s was in
+ Met-English. It was originally developed for {Honeywell}
+ machines, but many programs still run under {IBM} {MVS} via a
+ Honeywell {emulator}.
+
+ (1995-02-15)
+
+METEOR
+
+ A version of COMIT with Lisp-like syntax, written in MIT Lisp
+ 1.5 for the IBM 7090. "METEOR - A List Interpreter for String
+ Transformation", D.G. Bobrow in The Programming Language LISP
+ and its Interpretation, E.D. and D.G. Bobrow eds, 1964.
+
+meter
+
+ <spelling> US spelling of "{metre}".
+
+ (1998-02-07)
+
+method
+
+ <programming> In {object-oriented programming}, a {function} that
+ can be called on an {object} of a given {class}. When a method is
+ called (or {invoked (method invocation)}) on an object, the object
+ is passed as an implicit {argument} to the method, usually
+ referred to by the special variable "this". If the method is not
+ defined in the object's class, it is looked for in that class's
+ {superclass}, and so on up the {class hierarchy} until it is
+ found. A {subclass} thus {inherits {inheritance}} all the methods
+ of its superclasses.
+
+ Different classes may define methods with the same name
+ (i.e. methods may be {polymorphic}).
+
+ Methods are sometimes called "object methods" or "instance
+ methods". "{Class methods}" are methods that operate on objects
+ of class "class". "Static methods" are not methods but normal
+ {functions} packaged with the class.
+
+ (2000-03-22)
+
+method invocation
+
+ <programming> In {object-oriented programming}, the way the
+ program looks up the right {code} to run when a {method} with a
+ given name is called ("invoked") on an {object}. The method is
+ first looked for in the object's {class}, then that class's
+ {superclass} and so on up the {class hierarchy} until a method
+ with the given name is found (the name is "resolved").
+
+ Generally, method lookup cannot be performed at {compile time}
+ because the object's class is not known until {run time}. This is
+ the case for an {object method} whereas a {class method} is just
+ an ordinary function (that is bundled with a given class) and can
+ be resolved at compile time (or load time in the case of a
+ {dynamically loaded library}).
+
+ (2014-09-06)
+
+methodology
+
+ 1. <programming> An organised, documented set of procedures
+ and guidelines for one or more phases of the {software life
+ cycle}, such as analysis or design. Many methodologies
+ include a diagramming notation for documenting the results of
+ the procedure; a step-by-step "cookbook" approach for carrying
+ out the procedure; and an objective (ideally quantified) set
+ of criteria for determining whether the results of the
+ procedure are of acceptable quality.
+
+ An example is The {Yourdon methodology}.
+
+ 2. A pretentious way of saying "method".
+
+ (1995-04-10)
+
+Methods
+
+ <language> A line-oriented {Smalltalk} for {PC}'s, produced by
+ Digitalk ca 1985. Methods was the predecessor of
+ {Smalltalk/V}.
+
+ (1995-04-16)
+
+me too
+
+ A {functional language} for executable specifications
+ developed by Peter Henderson in 1984. It is like {LispKit
+ Lisp}, but with sets, maps and sequences to describe the
+ specification.
+
+ ["Functional Programming, Formal Specification and Rapid
+ Prototyping", IEEE Trans Soft Eng, SE-12(2):241-250 (Feb
+ 1986)].
+
+ (1994-10-21)
+
+metre
+
+ <unit> (US "meter") The fundamental {SI} unit of length.
+
+ From 1889 to 1960, the metre was defined to be the distance
+ between two scratches in a platinum-iridium bar kept in the
+ vault beside the Standard Kilogram at the International Bureau
+ of Weights and Measures near Paris.
+
+ This replaced an earlier definition as 10^-7 times the
+ distance between the North Pole and the Equator along a
+ meridian through Paris; unfortunately, this had been based on
+ an inexact value of the circumference of the Earth.
+
+ From 1960 to 1984 it was defined to be 1650763.73 wavelengths
+ of the orange-red line of krypton-86 propagating in a vacuum.
+
+ It is now defined as the length of the path traveled by light
+ in a vacuum in the time interval of 1/299,792,458 of a second.
+
+ (1998-02-07)
+
+metric
+
+ {software metric}
+
+metric space
+
+ <mathematics> A set of points together with a {function}, d,
+ called a metric function or distance function. The function
+ assigns a positive {real number} to each pair of points,
+ called the distance between them, such that:
+
+ 1. For any point x, d(x,x)=0;
+
+ 2. For any two distinct points x and y, d(x,y)>0;
+
+ 3. For any two points x and y, not necessarily distinct,
+
+ d(x,y) = d(y,x).
+
+ 4. For any three points x, y, and z, that are not necessarily
+ distinct,
+
+ d(x,z) <= d(x,y) + d(y,z).
+
+ The distance from x to z does not exceed the sum of the
+ distances from x to y and from y to z. The sum of the lengths
+ of two sides of a triangle is equal to or exceeds the length
+ of the third side.
+
+ (2003-06-26)
+
+Metropolitan Area Network
+
+ (MAN) A data network intended to serve an area the size of a
+ large city. Such networks are being implemented by innovative
+ techniques, such as running {optical fibre} through subway
+ tunnels. A popular example of a MAN is {SMDS}.
+
+ See also {Local Area Network}, {Wide Area Network}.
+
+ (1994-11-22)
+
+M-expression LISP
+
+ (MLISP) The original "{meta-language}" {syntax} of {Lisp},
+ designed by {John McCarthy} in 1962. MLISP was intended for
+ external use in place of the parenthesised {S-expression}
+ {syntax}.
+
+ ["LISP 1.5 Programmer's Manual", J. McCarthy et al, MIT Press
+ 1962].
+
+ (1994-11-22)
+
+MFC
+
+ {Microsoft Foundation Class}
+
+ (1995-11-16)
+
+MFE
+
+ {maximal free expression}
+
+MFLOPS
+
+ 1. <unit> {megaflops}.
+
+ 2. <benchmark> A {benchmark} which attemps to estimate a
+ system's {floating-point} "MFLOPS" rating for specific {FADD},
+ {FSUB}, {FMUL} and {FDIV} instruction mixes.
+
+ {C Source (ftp://ftp.nosc.mil/pub/aburto/flops20.c)}.
+ {Results
+ (http://performance.netlib.org/performance/html/flops.html)},
+ {(ftp://ftp.nosc.mil/pub/aburto/flops_1.tbl)},
+ {(ftp://ftp.nosc.mil/pub/aburto/flops_2.tbl)},
+ {(ftp://ftp.nosc.mil/pub/aburto/flops_3.tbl)},
+ {(ftp://ftp.nosc.mil/pub/aburto/flops_4.tbl)}.
+
+ (1994-11-14)
+
+MFM
+
+ {Modified Frequency Modulation}
+
+MFTL
+
+ {My Favourite Toy Language}
+
+mg
+
+ <networking> The {country code} for Madagascar.
+
+ <text, tool> {MicroGnuEmacs}.
+
+MGCP
+
+ {Media Gateway Control Protocol}
+
+mh
+
+ <networking> The {country code} for Marshall Islands.
+
+ (1999-01-27)
+
+MHDL
+
+ 1. {MIMIC Hardware Description Language}.
+
+ 2. {Microwave Hardware Description Language}.
+
+MHEG
+
+ {Multimedia and Hypermedia information coding Expert Group}
+
+MHS
+
+ {message handling system}
+
+MHz
+
+ {MegaHertz}
+
+MIB
+
+ {Management Information Base}
+
+MIB Variable
+
+ A managed object that is defined in a {Management Information
+ Base} (MIB). The object is defined by a textual name and a
+ corresponding object identifier, a {syntax}, an access mode, a
+ status, and a description of the semantics of the managed
+ object. The MIB Variable contains pertinent management
+ information that is accessible as defined by the access mode.
+
+ (1995-03-22)
+
+Mic-1
+
+ Microprogramming language, used in {Andrew Tanenbaum}'s book.
+
+ See {Mac-1}.
+
+ [Structured Computer Organization, A.S. Tanenbaum, 3rd ed, P-H
+ 1989, Sect 4.4, 4.5].
+
+Mic-2
+
+ Microprogramming language, used in {Tanenbaum}'s book.
+
+ See {Mac-1}.
+
+ [Structured Computer Organization, A.S. Tanenbaum, 3rd ed, P-H
+ 1989, Sect 4.4, 4.5].
+
+MICE
+
+ {Multimedia Integrated Conferencing for European Researchers}
+
+mice
+
+ {mouse}
+
+Michigan Algorithm Decoder
+
+ <language> (MAD) An early programming language, based on
+ {IAL}, developed at the University of Michigan by R. Graham,
+ Bruce Arden, and Bernard Galler in 1959. MAD was one of the
+ first {extensible languages}: the user could define his own
+ {operators} and {data types}.
+
+ MAD ran on the {IBM 704}, {IBM 709} and {IBM 7090}. It was
+ ported to the {IBM 7040} at the City College of New York by
+ Robert Teitel and also to {Philco}, {Univac} and {CDC}
+ computers.
+
+ {Mad/1} was a later version.
+
+ ["Michigan Algorithm Decoder (The MAD Manual)", U Michigan
+ Computing Center, 1966].
+
+ [Sammet 1969, p. 205].
+
+ (2005-02-09)
+
+mickey
+
+ <unit, humour> The unit of resolution of {mouse} movement.
+
+ It has been suggested that the "disney" will become a
+ benchmark unit for animation graphics performance.
+
+ [{Jargon File}]
+
+ (1999-06-30)
+
+mickey mouse program
+
+ <jargon> The North American equivalent of a "{noddy} program",
+ i.e. trivial. The term doesn't necessarily have the belittling
+ connotations of mainstream slang "Oh, that's just mickey mouse
+ stuff!"; sometimes trivial programs can be very useful.
+
+ [{Jargon File}]
+
+ (1995-04-10)
+
+MICR
+
+ {Magnetic Ink Character Recognition}
+
+micro
+
+ {microprocessor}
+
+micro-
+
+ {prefix}
+
+microarray
+
+ A technique for performing many DNA experiments in parallel.
+ Nothing to do with computers.
+
+ (2007-05-14)
+
+Micro Assembly Language
+
+ <language> (MAL) A {microprogramming} language with high-level
+ {syntax}, used in the reference below.
+
+ See also {Mic-1}, {Mac-1}.
+
+ [Structured Computer Organization, A.S. Tanenbaum, 3rd ed, P-H
+ 1989, Sect 4.4].
+
+ (1995-04-10)
+
+microcentury
+
+ One CS professor used to characterise the standard length of
+ his lectures as a microcentury - that is, about 52.6 minutes
+ (see also {attoparsec}, {nanoacre}, and especially
+ {microfortnight}).
+
+Micro Channel Architecture
+
+ <architecture> (MCA) {IBM}'s proprietary 32-bit {bus}, used in
+ high-end {PS/2} {personal computers}. Micro Channel is
+ designed for {multiprocessing}. It eliminates potential
+ conflicts that arise when installing new peripheral devices.
+ MCA is *not* compatible with either {EISA} or {XT bus
+ architecture} so older cards cannot be used with it.
+
+ As with the {ROM} {BIOS} in the first {IBM PCs}, figuring out
+ the Micro Channel's secrets has been an arduous task of
+ {reverse engineering} ever since the PS/2 line was announced.
+ Consequently, the MCA has never become as wide spread as the
+ competing {EISA} standard.
+
+ (1996-08-16)
+
+microchip art
+
+ <hardware> (chip art, chip graffiti) Images etched on
+ {integrated circuits} purely for decoration, visible only
+ under a microscope.
+
+ {Smithsonian Institute Chip Art
+ (http://smithsonianchips.si.edu/chipfun/graff.htm)}.
+
+microcode
+
+ <programming> A technique for implementing the {instruction
+ set} of a processor as a sequence of microcode instructions
+ ("microinstructions"), each of which typically consists of a
+ (large) number of bit fields and the address of the next
+ microinstruction to execute. Each bit field controls some
+ specific part of the processor's operation, such as a gate
+ which allows some {functional unit} to drive a value onto the
+ {bus} or the operation to be performed by the {ALU}. Several
+ microinstructions will usually be required to fetch, decode
+ and execute each {machine code} instruction
+ ("{macroinstruction}"). The microcode may also be responsible
+ for {polling} for hardware {interrupts} between each
+ macroinstruction. Writing microcode is known as
+ "microprogramming".
+
+ Microcode may be classified as "horizontally encoded" or
+ "vertically encoded". Horizontal microcode is as described
+ above where there is a fairly direct correspondence between
+ the bit fields in a microinstruction and the control signals
+ sent to the various parts of the CPU. Not all combinations of
+ bits will be valid (e.g. two units driving the bus at once).
+ Vertical microcode is closer to {machine code} because a bit
+ field value may pass through some intermediate combinatory
+ logic which generates the actual control signals. This allows
+ a few bits of a microinstruction to determine several control
+ signals and ensure that only valid combinations of those
+ signals are generated (e.g. a field may be decoded to determine
+ which unit drives the bus). The disadvantage with vertical
+ encoding is that the encoding is usually fixed and takes extra
+ time compared with horizontal encoding which allows any
+ combination of signals to be generated and takes no time to
+ decode.
+
+ The alternative to a microcoded processor is a {hard-wired}
+ one where the control signals are generated directly from the
+ bits of the {machine code} instruction. This is more common
+ in modern {RISC} architectures because it is faster.
+
+ Microcode is usually stored in {ROM} chips though some
+ processors (e.g. the {Orion}) use fast RAM, making them
+ dynamically microprogrammable.
+
+ (1996-11-26)
+
+Microcom Networking Protocol
+
+ (MNP) One of the most common {modem} {protocols} with
+ {compression}. Also the name of a product.
+
+ [Details? On-line spec?]
+
+ (1995-01-31)
+
+microcomputer
+
+ A computer based on a {microprocessor}.
+
+ Contrast with {minicomputer}, {mainframe}.
+
+ (1995-02-07)
+
+microcontroller
+
+ <processor> A {microprocessor} on a single {integrated
+ circuit} intended to operate as an {embedded} system. As well
+ as a {CPU}, a microcontroller typically includes small amounts
+ of {RAM} and {PROM} and timers and I/O ports.
+
+ An example is the {Intel 8751}.
+
+ (1995-04-22)
+
+MicroDroid
+
+ [{Usenet}] A {Microsoft} employee, especially one who posts to
+ various operating-system advocacy newsgroups. MicroDroids post
+ follow-ups to any messages critical of {Microsoft}'s operating
+ systems, and often end up sounding like visiting Mormon
+ missionaries.
+
+ [{Jargon File}]
+
+microelectromechanical system
+
+ <hardware> (MEMS) The integration of mechanical structures
+ (moving parts) with microelectronics. MEMS devices are
+ "custom" designed for a purpose which requires a mechanical
+ action to be controlled by a computer.
+
+ Applications include sensors, medical devices, process
+ controls.
+
+ {(http://mems.mcnc.org/)}.
+
+ See also {nanotechnology}.
+
+ (1999-03-25)
+
+Microelectronics and Computer Technology Corporation
+
+ <body> (MCC) One of the first, and now one of the largest, US
+ computer industry research and development consortia.
+
+ Founded in late 1982 by major computer and semiconductor
+ manufacturers, MCC's membership has diversified to include a
+ broad range of high-profile corporations from electronics,
+ computers, aerospace, semiconductors, and related industries,
+ reflecting the full range of companies vital to the life cycle
+ of {Information Technology} products. Active involvement of
+ small- and medium-sized firms and technology users, along with
+ well-established alliances with government research and
+ development agencies and leading universities, allows MCC's
+ partners to maximise the benefit of scarce research and
+ development resources.
+
+ Some of the technical areas in which MCC has distinguished
+ itself are:
+
+ System Architecture and Design (optimise hardware and software
+ design, provide for scalability and interoperability, allow
+ rapid prototyping for improved time-to-market, and support the
+ re-engineering of existing systems for open systems).
+
+ Advanced Microelectronics Packaging and Interconnection
+ (smaller, faster, more powerful, and cost-competitive).
+
+ Hardware Systems Engineering (tools and methodologies for
+ cost-efficient, up-front design of advanced electronic
+ systems, including modelling and design-for-test techniques to
+ improve cost, yield, quality, and time-to-market).
+
+ Environmentally Conscious Technologies (process control and
+ optimisation tools, information management and analysis
+ capabilities, and non-hazardous material alternatives
+ supporting cost-efficient production, waste minimisation, and
+ reduced environmental impact).
+
+ Distributed {Information Technology} (managing and maintaining
+ physically distributed corporate information resources on
+ different {platforms}, building blocks for the {national
+ information infrastructure}, networking tools and services for
+ integration within and between companies, and electronic
+ commerce).
+
+ Intelligent Systems (systems that "intelligently" support
+ business processes and enhance performance, including
+ {decision support}, {data management}, forecasting and
+ prediction).
+
+ {(http://mcc.com/)}.
+
+ Address: Austin, Texas, USA.
+
+ (1995-04-25)
+
+MicroEmacs
+
+ (uemacs) A simple, portable text editor with versions for most
+ {microcomputers} and many other computers. It is both
+ relatively easy for the novice to use, but also very powerful
+ in the hands of an expert. MicroEmacs can be extensibly
+ customised.
+
+ Most versions use only a screen and keyboard - mouse and
+ windowing facilities are not standard.
+
+ MicroEmacs was written by Dave G Conroy, Steve Wilhite, George
+ Jones, and for nearly ten years: Daniel Lawrence.
+
+ Version: 3.11.
+
+ {(ftp://midas.mgmt.purdue.edu/dist/)}.
+
+ [FTP? Differences from GNU Emacs?]
+
+ (1995-01-05)
+
+microfloppies
+
+ 3.5-inch floppies, as opposed to 5.25-inch {vanilla} or
+ mini-floppies and the now-obsolete 8-inch variety. This term
+ may be headed for obsolescence as 5.25-inchers pass out of
+ use, only to be revived if anybody floats a sub-3-inch floppy
+ standard. See {stiffy}, {minifloppies}.
+
+ [{Jargon File}]
+
+microfortnight
+
+ One millionth of the fundamental unit of time in the
+ Furlong/Firkin/Fortnight system of measurement; 1.2096 sec.
+ (A furlong is 1/8th of a mile; a firkin is 1/4th of a barrel;
+ the mass unit of the system is taken to be a firkin of water).
+
+ The VMS operating system has a lot of tuning parameters that
+ you can set with the SYSGEN utility, and one of these is
+ TIMEPROMPTWAIT, the time the system will wait for an operator
+ to set the correct date and time at boot if it realises that
+ the current value is bogus. This time is specified in
+ microfortnights!
+
+ Multiple uses of the millifortnight (about 20 minutes) and
+ {nanofortnight} have also been reported.
+
+MicroGnuEmacs
+
+ <text, tool> (mg) A {Public Domain} {Emacs}-style editor
+ modified from {MicroEmacs} to be more compatible with {GNU}
+ Emacs. mg is essentially free, it is not associated with the
+ GNU project, and does not have the GNU copyright restrictions.
+ It is a small, fast, portable editor for people who can't run
+ real Emacs thing for one reason or another. It has few if any
+ of the MicroEmacs features that were incompatible with GNU
+ Emacs and adds missing features that seemed essential.
+
+ MicroGnuEmacs is derived from, and aims to replace, v30 of
+ MicroEmacs, the latest version from the original MicroEmacs
+ author Dave Conroy. The chief contributors were Mike Meyer
+ <mwm@ucbopal.berkeley.edu>, Mic Kaczmarczik
+ <mic@ngp.utexas.edu>, Bob Larson, and Dave Brower
+ <rtech!daveb@sun.com>.
+
+ mg version 1a of 1986-11-16 works with {4.2BSD}, {4.3BSD},
+ {Ultrix-32}, {OS9/68k}, {VMS}, {Amiga}, {System V}, {Eunice}.
+ It is included in base {OpenBSD}. It should also support
+ {MS-DOS}, {PC-DOS} and the {Rainbow}.
+
+ {(http://www.isc.org/index.pl?/sources/editors)}.
+
+ (2007-05-25)
+
+Micro Instrumentation and Telemetry Systems
+
+ <company> (MITS) The company which made the {Altair 8800}
+ {micrcomputer} kit. They also made instrumentation kits for
+ model rockets and RC vehicles. Ed Roberts owned MITS for a
+ few years until he sold out, moved to Georgia, and went to med
+ school.
+
+ Address: Albuquerque NM, USA.
+
+ (2002-06-17)
+
+Micro Interpreter for Knowledge Engineering
+
+ <artificial intelligence, tool> (MIKE) An {expert system
+ shell} for teaching purposes, with {forward chaining},
+ {backward chaining}, and user-definable {conflict resolution}
+ strategies. MIKE is written in {Edinburgh Prolog}.
+
+ Version 2.03.
+
+ [BYTE, Oct 1990].
+
+ {(ftp://hcrl.open.ac.uk/pub/software/src/MIKE-v2.03)}.
+
+ Contact: Marc Eisenstadt, HCRL, {Open University}.
+
+ (1995-01-10)
+
+microkernel
+
+ <operating system> An approach to {operating system} design
+ emphasising small {modules} that implement the basic features
+ of the system {kernel} and can be flexibly configured.
+
+ (1999-08-02)
+
+microLenat
+
+ /mi:"-kroh-len"-*t/ The unit of {bogosity}, written uL; the
+ consensus is that this is the largest unit practical for
+ everyday use. The microLenat, originally invented by David
+ Jefferson, was promulgated as an attack against noted computer
+ scientist {Doug Lenat} by a {tenured graduate student} at
+ {CMU}. Doug had failed the student on an important exam for
+ giving only "AI is bogus" as his answer to the questions. The
+ slur is generally considered unmerited, but it has become a
+ running gag nevertheless. Some of Doug's friends argue that
+ *of course* a microLenat is bogus, since it is only one
+ millionth of a Lenat. Others have suggested that the unit
+ should be redesignated after the grad student, as the
+ microReid.
+
+ [{Jargon File}]
+
+microlog
+
+ <architecture> A section of {non-volitile memory} used to
+ record state information. Often used for retaining {crash}
+ information after a {reboot} in {embedded systems}.
+
+ ["before" a reboot?]
+
+ (2004-02-24)
+
+micrometre
+
+ <unit> (Or "micron") One millionth of a {metre}. The symbol
+ is a Greek letter {mu} followed by "m".
+
+ Features on modern {integrated circuits} are typically
+ measured in microns. The smallest features in 1999 are around
+ 0.1 microns across.
+
+ (1999-09-28)
+
+Micro ML
+
+ (uML) An {interpreter} for a subset of {SML}. Runs on
+ {MS-DOS}. Written at the University of Umea, Sweden.
+
+ {(ftp://ftp.cs.umu.se/pub/umlexe01.zoo)}.
+
+Micron
+
+ {Micron Electronics, Inc.}
+
+micron
+
+ {micrometre}
+
+Micron Electronics, Inc.
+
+ <company> An electronics company that develops, markets,
+ manufactures, and supports high-performance {notebook
+ computers}, {desktop} {personal computers}, {PC servers} and
+ related {hardware} and {software} products.
+
+ (1997-03-10)
+
+Micronetics Standard MUMPS
+
+ (MSM) A version of {MUMPS} for the {IBM PC RT} and {R6000}.
+
+ [Address?]
+
+ (1995-01-10)
+
+Micro$oft
+
+ <abuse, company> {Microsoft} written with a dollar sign, as though
+ there was any doubt that they are a money-making enterprise. This
+ little witticism was probably created before Microsoft's founder,
+ {Bill Gates} established the philanthropic {Bill & Melinda Gates
+ Foundation}.
+
+ {Why I hate Microsoft
+ (http://www.vanwensveen.nl/rants/microsoft/IhateMS.html)}.
+
+ (2013-12-30)
+
+microperation
+
+ <processor> An elementary operation performed on {data} stored
+ in {registers} or in {memory}. Microperations are classified
+ as transfer, arithmetic, logic, or shift/rotate.
+
+ [Relationship with {microcode}?]
+
+ (2003-12-29)
+
+microphone
+
+ <hardware, audio> Any electromechanical device designed to
+ convert sound into an electrical signal.
+
+ A microphone converts an acoustic waveform consisting of
+ alternating high and low air pressure travelling through the
+ air into a voltage. To do this it uses some kind of pressure
+ or movement sensor. The simplest kind of microphone is
+ actually very similar in construction to a {loudspeaker}.
+
+ The analogue electrical signal can be fed into a computer's
+ {sound card} where it is amplified and {sampled} to convert it
+ into a {digital} waveform for storage or transmission.
+
+ (2002-11-04)
+
+microPLANNER
+
+ A subset of {PLANNER}, implemented in {Lisp} by {Gerald
+ Sussman} et al at {MIT}. Its important features were
+ goal-oriented, pattern-directed procedure invocation, an
+ embedded knowledge base, and automatic {backtracking}.
+
+ microPLANNER was superseded by {Conniver}.
+
+ ["microPLANNER Reference Manual", G.J. Sussman et al, AI Memo
+ 203, MIT AI Lab, 1970].
+
+ (1995-01-10)
+
+microprocesor
+
+ <spelling> It's spelled {microprocessor}.
+
+ (1997-02-13)
+
+microprocessor
+
+ <architecture> (Or "micro") A computer whose entire {CPU} is
+ contained on one (or a small number of) {integrated circuits}.
+
+ The important characteristics of a microprocessor are the
+ widths of its internal and external {address bus} and {data
+ bus} (and instruction), its {clock rate} and its {instruction
+ set}. Processors are also often classified as either {RISC}
+ or {CISC}.
+
+ The first commercial microprocessor was the {Intel 4004} which
+ appeared in 1971. This was the CPU member of a set of four
+ {LSI} {integrated circuits} called the MCS-4, which was
+ originally designed for use in a calculator but was marketed
+ as "programmable controller for logic replacement". The 4004
+ is referred to as a 4-bit microprocessor since it processed
+ only 4 bits of data at a time. This very short word size is
+ due mainly to the limitations imposed by the maximum
+ integrated circuit density then achievable.
+
+ As integrated circuit densities increased with the rapid
+ development of integrated circuit manufacturing technology,
+ the power and performance of the microprocessors also
+ increased. This is reflected in the increase in the CPU word
+ size to 4, 8, 16, and by mid-1980s, 32 bits. The smaller
+ microprocessors have relatively simple {instruction sets},
+ e.g., no {floating point} instructions, but they are
+ nevertheless suitable as controllers for a very wide range of
+ applications such as car engines and microwave ovens.
+
+ The {Intel 4004} was followed with, among others the {4040},
+ {8008}, {8080}, {8086}, {80186}, {80286}, {80386}, {486} and
+ {Pentium}. Other families include the {Motorola} {6800} and
+ {680x0} families, {National Semiconductor 16000} and {National
+ Semiconductor 32000}, {SPARC}, {ARM}, {MIPS}, {Zilog Z8000},
+ {PowerPC} and the {Inmos} {Transputer} family.
+
+ The larger, more recent microprocessors families have
+ gradually acquired most of the features of large computers.
+ As the microprocessor industry has matured, several families
+ of microprocessors have evolved into de facto industrial
+ standards with multiple manufacturers and numerous "support"
+ chips including {RAM}, {ROM}, {I/O controllers} etc.
+
+ A single chip microprocessor may include other components such
+ as memory ({RAM}, {ROM}, {PROM}), {memory management},
+ {caches}, {floating-point unit}, input/output ports and
+ timers. Such devices are also known as {microcontrollers}.
+
+ The one-chip microcomputer is in many respects, a landmark
+ development in computer technology because it reduces the
+ computer to a small, inexpensive, and easily replaceable
+ design component.
+
+ Microcomputers have given rise to a new class of
+ general-purpose machines called {personal computers}. These
+ are small low cost computers that are designed to sit on an
+ ordinary office desk or to be portable and fuelled the
+ computer boom of the late 1980s. The most widespread example
+ is the also {IBM PC}, based on microprocessors from {Intel
+ Corporation}. {Apple Computers, Inc.} have also produced a
+ range of personal computers, as have several other companies.
+
+ See also {killer micro}, {minicomputer}, {CPU Info Center}.
+
+ (2002-07-16)
+
+Microprocessor without Interlocked Pipeline Stages
+
+ <processor> (MIPS) A project at {Stanford University} intended
+ to simplify processor design by eliminating hardware
+ {interlocks} between the five {pipeline} stages. This means
+ that only single execution cycle instructions can access the
+ thirty two 32-bit general {registers}, so that the {compiler}
+ can schedule them to avoid conflicts. This also means that
+ LOAD/STORE and branch instructions have a one-cycle delay to
+ account for. However, because of the importance of multiply
+ and divide instructions, a special HI/LO pair of
+ multiply/divide registers exist which do have hardware
+ interlocks, since these take several cycles to execute and
+ complicate {instruction scheduling}.
+
+ The project eventually lead to the commercial {MIPS R2000}
+ processor.
+
+ (1995-02-09)
+
+microprogramming
+
+ {microcode}
+
+microReid
+
+ /mi:'kroh-reed/ See {bogosity}.
+
+ [{Jargon File}]
+
+MICRO SAINT
+
+ <simulation> A general purpose {simulation} tool from US
+ company {Micro Analysis and Design}.
+
+ (2007-03-22)
+
+microsecond
+
+ <unit> One millionth (10^-6) of a second.
+
+ (1995-03-14)
+
+Microserf
+
+ <jargon> {Wired magazine}'s term for a {Microsoft} employee.
+
+ (1995-03-02)
+
+Microslop
+
+ <company, abuse> A derisive synonym for {Microsoft
+ Corporation}. It refers to the sloppy, {bug}-ridden "x.0"
+ versions of {MS-DOS}, {Microsoft Windows} and other Microsoft
+ products.
+
+ (1995-12-28)
+
+Microsloth Windows
+
+ <abuse, operating system> /mi:'kroh-sloth" win"dohz/ (Or
+ "Windoze", /win'dohz/) A derogatory term for {Microsoft
+ Windows} which is so limited by bug-for-bug compatibility with
+ {mess-dos} that it is agonisingly slow on anything less than a
+ fast {486}. Also called just "Windoze", with the implication
+ that you can fall asleep waiting for it to do anything; the
+ latter term is extremely common on {Usenet}.
+
+ Compare {X}, {sun-stools}.
+
+ [{Jargon File}]
+
+ (1996-10-08)
+
+Microsoft
+
+ {Microsoft Corporation}
+
+Microsoft Access
+
+ 1. <database> A {relational database} running under {Microsoft
+ Windows}. Data is stored as a number of "{tables}",
+ e.g. "Stock". Each table consists of a number of "{records}"
+ (e.g. for different items) and each record contains a number
+ of "{fields}", e.g. "Product code", "Supplier", "Quantity in
+ stock".
+
+ Access allows the user to create "{forms}" and "reports". A
+ form shows one record in a user-designed format and allows the
+ user to step through records one at a time. A report shows
+ selected records in a user-designed format, possibly grouped
+ into sections with different kinds of total (including sum,
+ minimum, maximum, average).
+
+ There are also facilities to use links ("{joins}") between
+ tables which share a common field and to filter records
+ according to certain criteria or search for particular field
+ values.
+
+ Version: 2 (date?).
+
+ {Usenet} newsgroup: {news:comp.databases.ms-access}.
+
+ 2. <communications> A communications program from Microsoft,
+ meant to compete with {ProComm} and other programs. It sucked
+ and was dropped. Years later they reused the name for their
+ database.
+
+ [Date?]
+
+ (1997-07-20)
+
+Microsoft Basic
+
+ <language> (MS-BASIC) A dialect of {BASIC} from {Microsoft},
+ originally developed by {Bill Gates} in a garage back in the
+ {CP/M} days. It was originally known as GWBasic, then QBASIC
+ and finally MS-BASIC.
+
+ When the {MS-DOS} {operating system} came out, it incorporated
+ the GWBASIC.EXE or BASICA.EXE interpreters. GWBASIC ("Gee
+ Whiz") incorporated graphics and a {screen editor} and was
+ compatible with earlier BASICs.
+
+ QBASIC was more sophisticated. Version 4.5 had a full screen
+ editor, debugger and compiler. The compiler could also
+ produce executable files but to run these a utility program
+ (BRUN44.EXE) had to be present. Thus {source code} could be
+ kept private.
+
+ From DOS 5.0 or 6.0 onward, MS-BASIC was standard.
+
+ Latest version: 1.1, also produces {stand-alone} executables
+ and can display graphics.
+
+ {Usenet} newsgroup: {news:comp.lang.basic.misc}.
+
+ [Relationship to BASIC in ROM on first IBM PC?]
+
+ (1995-05-12)
+
+Microsoft Certified Application Developer
+
+ <programming, education> (MCAD) Microsoft's qualification
+ signifying ability to build {applications} with Microsoft {Visual
+ Studio .NET} and {web services} on {Microsoft .NET Framework} 1.0
+ and 1.1. MCAD can no longer be earned.
+
+ {(http://www.microsoft.com/learning/en/in/certification/mcad.aspx)}
+
+ (2013-04-21)
+
+Microsoft Certified Database Administrator
+
+ <educational> (MCDBA) {Microsoft}'s certification of ability to
+ design, implement and manage {SQL Server 2000} {databases}. The
+ qualification was retired on 2012-09-30.
+
+ {(http://www.microsoft.com/learning/en/us/mcdba-certification.aspx)}.
+
+ (2013-06-15)
+
+Microsoft Certified Desktop Support Technician
+
+ <education> (MCDST) {Microsoft}'s qualification signifying ability
+ to troubleshoot {Windows XP} {desktop} environments and to solve
+ hardware and software operation and application problems on
+ Windows XP. MCDST can no longer be earned.
+
+ (2013-05-23)
+
+Microsoft Certified Professional Developer
+
+ <educational, job> (MCPD) {Microsoft}'s certification intended to
+ show comprehensive skills designing, developing and deploying
+ {applications} for a particular job role.
+
+ (2013-07-21)
+
+Microsoft Certified Solution Developer
+
+ <programming, education> (MCSD) A course for the {VAR} or
+ software {developer}. Candidates must pass three core exams
+ and an elective exam. The core exams cover {systems
+ analysis}, and {desktop} and {distributed} development.
+
+ {(http://microsoft.com/mcsd)}.
+
+ (2001-05-20)
+
+Microsoft Certified System Engineer
+
+ <education> (MCSE) A qualification obtained by passing
+ {Microsoft}'s system engineer certification exams.
+
+ {(http://microsoft.com/mcse)}.
+
+ (2002-07-02)
+
+Microsoft Certified Systems Administrator
+
+ <education> (MCSA) {Microsoft}'s qualification for people who
+ administer {network} and system environments based on {Windows}
+ {operating systems}. Specializations include Messaging and
+ Security.
+
+ Replaced by {Microsoft Certified Solutions Associate}.
+
+ (2013-09-02)
+
+Microsoft Certified Systems Developer
+
+ <spelling> Do you mean {Microsoft Certified Solution
+ Developer} or {Microsoft Certified System Engineer}?
+
+ (2001-05-20)
+
+Microsoft Corporation
+
+ <company> The biggest supplier of {operating systems} and
+ other software for {IBM PC} compatibles. Software products
+ include {MS-DOS}, {Microsoft Windows}, {Windows NT},
+ {Microsoft Access}, {LAN Manager}, {MS Client}, {SQL Server},
+ {Open Data Base Connectivity} (ODBC), {MS Mail}, and {SNA
+ Server} for Windows NT.
+
+ Microsoft was founded as "Micro-soft" in 1975 by {Bill Gates}
+ (now CEO) and his high school pal Paul Allen. Their first
+ product was a version of {BASIC} for the new {Altair} computer
+ [which one?]. In 1980, {IBM} chose Microsoft to supply the
+ {operating system} for the {IBM PC}.
+
+ On the UK television program "The Net" in May 1994, {Bill
+ Gates} said he was betting his company on the {information
+ highway}".
+
+ Quarterly sales $1293M, profits $362M (Aug 1994).
+
+ {(http://microsoft.com/)}.
+ {(ftp://ftp.microsoft.com/)}.
+
+ {Interesting Info and Other Microsoft WWW Servers
+ (http://www-drg.microsoft.com/devinfo.htm)}.
+
+ {Microsoft Windows Developer Information
+ (http://www-drg.microsoft.com/devinfo.htm)}.
+
+ {Microsoft Research Group Information
+ (http://research.microsoft.com)}.
+
+ {Win_News
+ (http://microsoft.com/chicago/ms-www/ms-intro.htm)}.
+ maintained by the Personal Operating Systems Division to
+ distribute information on {Microsoft Windows}, {MS-DOS} and
+ {Windows 95}.
+
+ (1998-11-06)
+
+Microsoft Data Access Components
+
+ <database> (MDAC) Microsoft's umbrella term for their {ActiveX
+ Data Objects} (ADO), {OLE DB}, and {Open Database
+ Connectivity} (ODBC) libraries. Together, these provide
+ access to a variety of data sources, both {relational} ({SQL})
+ and nonrelational. MDAC is the technology that supports
+ {Universal Data Access}, Microsoft's strategy for providing
+ access to information across the enterprise.
+
+ {(http://msdn.microsoft.com/library/en-us/mdacsdk/htm/mdacstartpage1.asp)}.
+
+ (2004-02-17)
+
+Microsoft Disc Operating System
+
+ <spelling> {Microsoft Disk Operating System}
+
+Microsoft Disk Operating System
+
+ <operating system> /M S doss/ (Or "MS-DOS", "PC-DOS",
+ "{MS-DOG}", "{mess-dos}") {Microsoft Corporation}'s {clone} of
+ the {CP/M} {disk operating system} for the {8088} {crufted}
+ together in 6 weeks by {hacker} {Tim Paterson}, who is said to
+ have regretted it ever since.
+
+ MS-DOS is a single user {operating system} that runs one
+ program at a time and is limited to working with one megabyte
+ of memory, 640 kilobytes of which is usable for the
+ {application program}. Special add-on {EMS} memory boards
+ allow EMS-compliant software to exceed the 1 MB limit.
+ Add-ons to DOS, such as {Microsoft Windows} and {DESQview},
+ take advantage of EMS and allow the user to have multiple
+ applications loaded at once and switch between them.
+
+ Numerous features, including vaguely {Unix}-like but rather
+ broken support for subdirectories, {I/O redirection} and
+ {pipelines}, were hacked into MS-DOS 2.0 and subsequent
+ versions; as a result, there are two or more incompatible
+ versions of many system calls, and MS-DOS programmers can
+ never agree on basic things like what character to use as an
+ option switch ("-" or "/"). The resulting mess became the
+ highest-unit-volume {operating system} in history. It was
+ used on many {Intel} 16 and 32 bit {microprocessors} and {IBM
+ PC} compatibles.
+
+ Many of the original DOS functions were calls to {BASIC} (in
+ {ROM} on the original {IBM PC}), e.g. Format and Mode. People
+ with non-IBM PCs had to buy {MS-Basic} (later called
+ {GWBasic}). Most version of DOS came with some version of
+ BASIC.
+
+ Also know as PC-DOS or simply DOS, ignoring the fact that
+ there were many other OSes with that name, starting in the
+ mid-1960s with {IBM}'s first disk operating system for the
+ {IBM 360}.
+
+ [{Jargon File}]
+
+ (2007-05-21)
+
+Microsoft DOS
+
+ {Microsoft Disk Operating System}
+
+Microsoft Excel
+
+ <tool> A {spreadsheet} program from {Microsoft}, part of their
+ {Microsoft Office} suite of productivity tools for {Microsoft
+ Windows} and {Macintosh}. Excel is probably the most widely
+ used spreadsheet in the world.
+
+ Latest version: Excel 97, as of 1997-01-14.
+
+ {(http://microsoft.com/msexcel/)}.
+
+ [Feature summary? History?]
+
+ (1997-01-14)
+
+Microsoft Exchange
+
+ <messaging> {Microsoft}'s messaging and enterprise
+ collaboration server. Exchange's primary role is as an
+ {electronic mail} {message store} but it can also store
+ calendars, task lists, contact details, and other data.
+
+ [Better descripton? URL?]
+
+ (1999-09-17)
+
+Microsoft Extended
+
+ <computer> (MSX) A Range of computers created in an attempt by
+ the industry to create a standard for home computers, similar
+ to {VHS} did with home video.
+
+ The basic MSX machine contained a {Z80} {CPU} working at
+ 3.58MHz.
+
+ MSX machines were produced by such giants as {Sony}, {Yamaha},
+ {Panasonic}, {Toshiba}, {Daewoo}, and {Philips}.
+
+ The MSX standard was designed by a company called ASCII in
+ cooperation with {Microsoft} who provided a {firmware} version
+ of its {BASIC} for the machine. Because this BASIC version
+ was an extended version of {MicroSoft Basic}, it was called
+ "MicroSoft eXtended BASIC"; Hence "MSX".
+
+ Microsoft also produced MSX-DOS - a stripped-down version of
+ {MS-DOS}.
+
+ Extensions to the MSX included MSX2, MSX2+ and TurboR.
+
+ {FAQ (http://faq.msxnet.org/)}.
+
+ (1999-02-26)
+
+Microsoft Foundation Classes
+
+ <programming> (MFC) Software structures in {C++}, the Windows
+ base {classes} which can respond to messages, make windows,
+ and from which application specific classes can be derived.
+
+ (1995-11-17)
+
+Microsoft IIS
+
+ {Internet Information Server}
+
+Microsoft IntelliMouse Explorer
+
+ <hardware> An {optical mouse} from {Microsoft}.
+
+ {(http://microsoft.com/presspass/features/1999/04-19mouse.htm)}.
+
+ (1999-07-21)
+
+Microsoft Internet Information Server
+
+ {Internet Information Server}
+
+Microsoft Mail
+
+ <messaging, tool> (MS Mail) A {Microsoft Windows} {electronic
+ mail} program.
+
+ [Features? Version?]
+
+ (1996-08-26)
+
+Microsoft Mail Application Program Interface
+
+ {Messaging Application Programming Interface}
+
+Microsoft Network
+
+ {The Microsoft Network}
+
+Microsoft Networking
+
+ <networking> {Microsoft's} name for the networking subsystems
+ of {Windows 95} and later. Not to be confused with {The
+ Microsoft Network}.
+
+ Microsoft networking uses the {SMB} file sharing protocol. It
+ is implemented as file system drivers i.e. "{installable file
+ systems}" (IFS).
+
+ The {network redirector} "Client for Microsoft Networks", is
+ implemented in the VREDIR.VXD {virtual device driver}. {Peer}
+ resource sharing is provided by "File and Printer Sharing for
+ Microsoft Networks" (VSERVER.VXD).
+
+ Windows 95's support for {Netware} ({NCP}) networks is
+ provided in a similar way via NWREDIR.VXD and NWSERVER.VXD.
+
+ (1999-08-08)
+
+Microsoft Office
+
+ <product> {Microsoft}'s bundles of {productivity tools}
+ including {Microsoft Word}, {Microsoft Excel}, {Microsoft
+ Powerpoint}, {Microsoft Outlook}, {Microsoft Access},
+ {Microsoft Publisher}, {Microsoft Front Page}, {Microsoft Team
+ Manager}, {Microsoft Project}, {Microsoft Schedule+},
+ {Microsoft Internet Explorer}, {Small Business Financial
+ Manager}, {Automap Streets Plus}.
+
+ Editions of Office include {Microsoft Office Professional
+ Edition}, {Microsoft Office Standard Edition}, {Microsoft
+ Office Small Business Edition}, {Microsoft Office Developer
+ Edition}. Different editions contain different subsets of the
+ above applications.
+
+ Current version, as of 2004-08-30: Office 2003.
+
+ {(http://microsoft.com/office)}.
+
+ (2004-08-30)
+
+Microsoft Office Small Business Edition
+
+ <application> (SBE) Editions of {Microsoft Office} 97, 2003,
+ and probably other versions, targetted at small businesses.
+ Small Business Edition includes {Microsoft Word}, {Microsoft
+ Excel}, {Microsoft PowerPoint}, {Microsoft Outlook} with
+ {Business Contact Manager} and {Microsoft Publisher}. SBE
+ 2003 doesn't include {Microsoft Access} or the addtional
+ {XML}, {IRM} and {Visual Studio} support found in {Microsoft
+ Office Professional Edition}, though the new user price is the
+ same.
+
+ {Office Editions
+ (http://microsoft.com/office/editions/howtobuy/compare.mspx)}.
+
+ (2004-08-31)
+
+Microsoft Point to Point Encryption
+
+ <protocol> (MPPE) An {encryption} {protocol} that may be used
+ with {PPTP} to provide an encrypted connection.
+
+ (1998-09-24)
+
+Microsoft Project
+
+ <product> A {Microsoft Windows} program offering various
+ {project management} tools.
+
+ {(http://microsoft.com/office/project/)}.
+
+ (2003-07-02)
+
+Microsoft SQL Server
+
+ <database> A {relational database management system} (RDBMS)
+ which is part of {Microsoft}'s {BackOffice} family of
+ {servers}. SQL Server was designed for {client/server} use
+ and is accessed by applications using {SQL}. It runs on
+ {Windows NT} version 3.5 or higher and is compliant with the
+ {ANSI} {SQL-92} and {FIPS} 127-2 {SQL} {standards}.
+
+ SQL Server supports {symmetric multiprocessing} hardware;
+ {SNMP}, {ODBC}, and major {open standard} communications
+ {protocols}. It has {Internet} integration, data
+ {replication}, and {data warehousing} features.
+
+ Microsoft SQL Server was originally developed by {Sybase
+ Corporation} but the cooperation was broken sometime [when?]
+ before version 6.0.
+
+ Latest version: 7.0. [Or is it 2000?]
+
+ {(http://microsoft.com/sql)}.
+
+ {Usenet} newsgroup: {news:comp.databases.ms-sqlserver}.
+
+ (2001-04-27)
+
+Microsoft Windows
+
+ <operating system> {Microsoft}'s proprietary {window system}
+ and {user interface} software released in 1985 to run on top
+ of {MS-DOS}. Widely criticised for being too slow (hence
+ "{Windoze}", "{Microsloth Windows}") on the machines available
+ then.
+
+ The 1996 market share of operating systems was:
+
+ DOS/Windows 70%
+ Windows 95 15%
+ Windows NT 2%
+ Other 13%
+
+ [Current shares?]
+
+ The version history goes something like: 1985 {Windows 1},
+ 1987 {Windows 2}, 1987 {Windows/386}, 1990 {Windows 3.0}, 1992
+ {Windows 3.1}, 1992 {Windows for Workgroups 3.1}, 1993
+ {Windows 3.11}, 1993 {Windows for Workgroups 3.11}, 1993
+ {Windows NT 3.1}, 1994 {Windows NT 3.5}, 1995 {Windows 95},
+ 199? {Windows NT 4}, 1998 {Windows 98}, ? {Windows NT 5}.
+
+ {Usenet} newsgroups:
+ {news:comp.os.ms-windows.comp.os.ms-windows.advocacy},
+ {news:comp.os.ms-windows.comp.os.ms-windows.announce},
+ {news:comp.os.ms-windows.apps.comm},
+ {news:comp.os.ms-windows.apps.compatibility.win95},
+ {news:comp.os.ms-windows.apps.financial},
+ {news:comp.os.ms-windows.apps.misc},
+ {news:comp.os.ms-windows.apps.utilities},
+ {news:comp.os.ms-windows.apps.utilities.win3x},
+ {news:comp.os.ms-windows.apps.utilities.win95},
+ {news:comp.os.ms-windows.apps.winsock.mail},
+ {news:comp.os.ms-windows.apps.winsock.misc},
+ {news:comp.os.ms-windows.apps.winsock.news},
+ {news:comp.os.ms-windows.apps.word-proc},
+ {news:comp.os.ms-windows.misc},
+ {news:comp.os.ms-windows.networking.misc},
+ {news:comp.os.ms-windows.networking.ras},
+ {news:comp.os.ms-windows.networking.tcp-ip},
+ {news:comp.os.ms-windows.networking.win95},
+ {news:comp.os.ms-windows.networking.windows},
+ {news:comp.os.ms-windows.nt.admin.misc},
+ {news:comp.os.ms-windows.nt.admin.networking},
+ {news:comp.os.ms-windows.nt.advocacy},
+ {news:comp.os.ms-windows.nt.announce},
+ {news:comp.os.ms-windows.nt.misc},
+ {news:comp.os.ms-windows.nt.pre-release},
+ {news:comp.os.ms-windows.nt.setup.hardware},
+ {news:comp.os.ms-windows.nt.setup.misc},
+ {news:comp.os.ms-windows.nt.software.backoffice},
+ {news:comp.os.ms-windows.nt.software.compatibility},
+ {news:comp.os.ms-windows.nt.software.services},
+ {news:comp.os.ms-windows.pre-release},
+ {news:comp.os.ms-windows.programmer},
+ {news:comp.os.ms-windows.programmer.controls},
+ {news:comp.os.ms-windows.programmer.graphics},
+ {news:comp.os.ms-windows.programmer.memory},
+ {news:comp.os.ms-windows.programmer.misc},
+ {news:comp.os.ms-windows.programmer.multimedia},
+ {news:comp.os.ms-windows.programmer.networks},
+ {news:comp.os.ms-windows.programmer.nt.kernel-mode},
+ {news:comp.os.ms-windows.programmer.ole},
+ {news:comp.os.ms-windows.programmer.tools.mfc},
+ {news:comp.os.ms-windows.programmer.tools.misc},
+ {news:comp.os.ms-windows.programmer.tools.owl},
+ {news:comp.os.ms-windows.programmer.tools.winsock},
+ {news:comp.os.ms-windows.programmer.vxd},
+ {news:comp.os.ms-windows.programmer.win32},
+ {news:comp.os.ms-windows.programmer.winhelp},
+ {news:comp.os.ms-windows.setup},
+ {news:comp.os.ms-windows.setup.win3x},
+ {news:comp.os.ms-windows.setup.win95},
+ {news:comp.os.ms-windows.video},
+ {news:comp.os.ms-windows.win95.misc},
+ {news:comp.os.ms-windows.win95.setup},
+ {news:comp.binaries.ms-windows}.
+
+ (1998-10-15)
+
+Microsoft Word
+
+ <text, tool, product> A popular {word processor}, part of the
+ {Microsoft Office} suite. The original Word (versions 1.0 to
+ 4.?/5.0?) was originally {text-based} (non-{GUI}) and ran
+ under {MS-DOS}. Then Microsoft released {Word for Windows}
+ 1.0 and 2.0. Later they produced new versions for each OS,
+ both numbered 6.0.
+
+ {(http://microsoft.com/catalog/products/word/)}.
+
+ [Features?]
+
+ (1997-02-11)
+
+MicroStation
+
+ <application> A full-featured 2-D and 3-D {CAD} program for
+ {MS-DOS}, {Microsoft Windows}, {Macintosh}, and {Unix}
+ {workstations} from {Bentley Systems, Inc.} Created in 1984,
+ MicroStation is a high-end package used worldwide in
+ environments where many designers work on large, complex
+ projects. MicroStation Modeler is a superset of MicroStation
+ that provides {solid modelling}, and MasterPiece is
+ MicroStation's {rendering} and {animation} program.
+
+ (2001-04-19)
+
+microtape
+
+ <hardware, storage> /mi:'kroh-tayp/ Occasionally used to mean
+ a {DECtape}, as opposed to a {macrotape}.
+
+ Apparently the term "microtape" was actually the official term
+ used within DEC for these tapes until someone coined the word
+ "DECtape", which, of course, sounded sexier to the
+ {marketroids}. Another version of the story holds that
+ someone discovered a conflict with another company's
+ "microtape" trademark.
+
+ [{Jargon File}]
+
+ (1995-03-16)
+
+Microware Corporation
+
+ Authors of {OS-9}.
+
+ Address: Des Moines, Iowa, USA.
+
+ (1995-02-02)
+
+Microwave Hardware Description Language
+
+ <language, hardware> (MHDL) A {Hardware Description Language}
+ by David Barton[?] from {Intermetrics} incorporating {Haskell}
+ 1.2.
+
+ Not to be confused with other {MHDLs}.
+
+ (2000-11-14)
+
+MIDAS
+
+ A digital simulation language.
+
+ [Sammet 1969, p.627].
+
+Midas
+
+ A {Motif}-based toolkit for interactive data analysis by
+ T. Johnson, SLAC. The basis for the {Midas-WWW} {browser}.
+
+Midas-WWW
+
+ <web> A {Motif}-based {browser} for {WWW} based on
+ the {Midas} toolkit.
+
+ (1998-08-09)
+
+middle-endian
+
+ <data, architecture> Neither {big-endian} nor {little-endian}.
+ Used of perverse byte orders such as 3-4-1-2 or 2-1-4-3,
+ occasionally found in the {packed decimal} formats of some
+ {minicomputer} manufacturers.
+
+ See {-endian}.
+
+ [{Jargon File}]
+
+ (1998-08-09)
+
+middleware
+
+ Software that mediates between an {application program} and a
+ {network}. It manages the interaction between disparate
+ applications across the heterogeneous computing {platforms}.
+ The {Object Request Broker} (ORB), software that manages
+ communication between {objects}, is an example of a middleware
+ program.
+
+MIDI
+
+ {Musical Instrument Digital Interface}
+
+mid-level network
+
+ (Or "regional network"). The kind of networks which make up
+ the second level of the {Internet} hierarchy. They are the
+ {transit networks} which connect the {stub networks} to the
+ {backbone networks}.
+
+MIF
+
+ {Maker Interchange Format}
+
+MIG
+
+ {Mach Interface Generator}
+
+MIGRAINES
+
+ <tool> A {graphical user interface} for evaluating and
+ interacting with the {Aspirin} {neural network} simulation.
+
+ Utilities exist for moving quickly from an {Aspirin}
+ description of a network directly to an executable program for
+ simulating and evaluating that network. MIGRAINES has been
+ kept separate from Aspirin so that its limitations do not
+ restrict the performance of Aspirin. However, in practice,
+ they are used together. This combination allows for simple
+ specification and creation of efficient neural network systems
+ that can be graphically analysed and tested.
+
+ [Aspirin/MIGRAINES Neural Network Software User's Manual,
+ Release v6.0 MP-91W00050, Copyright 1992 by Russel Leighton
+ and the MITRE Corporation].
+
+ (1995-03-07)
+
+MII
+
+ 1. <body> A consortium of {Microsoft}, {IBM}, and {Intel}.
+
+ [When? What did it do?]
+
+ 2. <storage> A broadcast component video tape format licensed
+ by Panasonic.
+
+ (1998-11-15)
+
+MIIS
+
+ <language> /Meese/ An interpreted language with one-letter
+ {keywords}.
+
+ [Details? Similar to {MUMPS}?]
+
+ (1995-01-10)
+
+MIKE
+
+ {Micro Interpreter for Knowledge Engineering}
+
+mil
+
+ <networking> The {top-level domain} for entities affiliated
+ with US armed forces.
+
+ (1999-01-26)
+
+Milarepa
+
+ <tool> A {Perl} {BNF} {parser generator} by Jeffrey Kegler
+ <jeffrey@netcom.com>. Milarepa takes a source {grammar}
+ written in a mixture of {BNF} and {Perl} and generates Perl
+ source, which, when enclosed in a simple wrapper, parses the
+ language described by the grammar. Milarepa is not restricted
+ to {LRn grammars}, and the parse logic follows directly from
+ the BNF. It handles {ambiguous grammars}, ambiguous tokens
+ (tokens which were not positively identified by the lexer) and
+ allows the programmer to change the start symbol. The grammar
+ may not be {left recursive}. The input must be divided into
+ sentences of a finite maximum length. There is no fixed
+ distinction between {terminals} and non-terminals, that is, a
+ symbol can both match the input AND be on the left hand side
+ of a production. Multiple Marpa grammars are allowed in a
+ single Perl program.
+
+ Version: Prototype 1.0.
+
+ Posted to comp.lang.perl.
+
+ The author is seeking an FTP site to hold the software.
+
+ (1993-03-17)
+
+MILITRAN
+
+ A {discrete simulation} system for military applications
+ produced by the Sys Res Group at {ONR} in 1964.
+
+ [Sammet 1969, p. 657].
+
+ (1994-11-11)
+
+mill
+
+ {Arithmetic and Logic Unit}
+
+millennium bug
+
+ {Year 2000}
+
+millennium meltdown
+
+ {Year 2000}
+
+milli-
+
+ {prefix}
+
+millihelen
+
+ <unit, humour> The amount of beauty required to launch one ship.
+
+ (2002-03-19)
+
+milliLampson
+
+ /mil'*-lamp"sn/ A unit of talking speed, abbreviated mL. Most
+ people run about 200 milliLampsons. The eponymous Butler
+ Lampson (a CS theorist and systems implementor highly regarded
+ among hackers) goes at 1000. A few people speak faster. This
+ unit is sometimes used to compare the (sometimes widely
+ disparate) rates at which people can generate ideas and
+ actually emit them in speech. For example, noted computer
+ architect C. Gordon Bell (designer of the {PDP-11}) is said,
+ with some awe, to think at about 1200 mL but only talk at
+ about 300; he is frequently reduced to fragments of sentences
+ as his mouth tries to keep up with his speeding brain.
+
+ [{Jargon File}]
+
+millisecond
+
+ <unit> (ms) One thousandth of a second, one thousand
+ {microseconds}. A long time for a modern computer.
+
+ (1995-08-18)
+
+MILNET
+
+ Military Network. Part of the {Defense Data Network} (DDN)
+ and of the {Internet}. Managed by the {Defense Information
+ Systems Agency} (DISA).
+
+ [Location? Number of hosts? Purpose?]
+
+MIMD
+
+ {Multiple Instruction/Multiple Data}
+
+MIME
+
+ {Multipurpose Internet Mail Extensions}
+
+mimencode
+
+ (Originally distributed as "mmencode"). A replacement for
+ {uuencode} for use in {electronic mail} and {news}. Part of
+ {MIME}. uuencode uses characters that don"t translate well
+ across all mail gateways (particularly those which convert
+ between {ASCII} and {EBCDIC}). Also, different variants of
+ uuencode encode data in different and incompatible ways, with
+ no standard. Finally, few uuencode variants work well in a
+ pipe. Mimencode implements the encodings which were defined
+ for {MIME} as uuencode replacements, and should be
+ considerably more robust for e-mail use. Written by Nathaniel
+ S. Borenstein of Bell Communications Research,
+ Inc. ({Bellcore}) in 1991.
+
+Mimer SQL
+
+ <database> A {relational database management system}, free for
+ non-commercial use, developed by the Swedish company {Upright
+ Database Technology AB}.
+
+ {Mimer Home (http://developer.mimer.com)}.
+
+ (2002-06-03)
+
+MIME type
+
+ <file format, protocol, multimedia> The unique identifier used
+ for different file types when conveyed across a {MIME}-based
+ {protocol} such as {MIME} {e-mail} or {HTTP}.
+
+ Registration of MIME types is explained in {RFC 2048}.
+
+ {Official MIME types
+ (ftp://ftp.isi.edu/in-notes/iana/assignments/media-types/media-types)}.
+
+ (1998-02-10)
+
+MIMIC
+
+ <language> An early language designed by J.H. Andrews of the
+ NIH in 1967 for solving engineering problems such as
+ differential equations that would otherwise have been done on
+ an {analog computer}.
+
+ ["MIMIC, An Alternative Programming Language for Industrial
+ Dynamics, N.D. Peterson, Socio-Econ Plan Sci. 6, Pergamon
+ 1972].
+
+ (1995-01-19)
+
+MIMOLA
+
+ Operational hardware specification language.
+
+ ["A Retargetable Compiler for a High-Level Microprogramming
+ Language", 17th Ann Workshop on Microprogramming, P. Marwedel,
+ IEEE 1984, pp. 267-274].
+
+mind mouse
+
+ <hardware> A {pointing device} (unlike a {mouse} in design,
+ but serving the same purpose) which works via sensors in
+ contact with the user's skin. The sensors are built into a
+ plastic base which fits on one finger and which is similar in
+ shape to a finger cast.
+
+ The principle of operation is presumably myoelectric, not
+ psionic, contrary to what the name implies.
+
+ As of the time of writing (1996), mind mice are not accurate
+ enough to be anything but novelties.
+
+ [Availability?]
+
+ (1997-04-07)
+
+mind uploading
+
+ <application> The science fiction concept of copying one's
+ mind into an artificial body or computer.
+
+ {Home
+ (http://sunsite.unc.edu/jstrout/uploading/MUHomePage.html)}.
+
+ (1995-04-10)
+
+Minerva software
+
+ A company producing software for the {Acorn} {Archimedes}.
+
+ {(http://zynet.co.uk/minerva/)}.
+
+ (1995-01-31)
+
+Minesweeper, Chess, Solitaire Expert
+
+ <humour> (MCSE) A humourous expansion of {MCSE} suggesting a more
+ realistic summary of a person's computer expertise.
+
+ (2013-03-16)
+
+minicomputer
+
+ <computer> A computer built between about 1963 and 1987,
+ smaller and less powerful than a {mainframe}, typically about
+ the size and shape of a wardrobe, mounted in a single tall
+ rack.
+
+ Minicomputers were characterised by short {word} lengths of 8
+ to 32 {bits}, limited hardware and software facilities and
+ small physical size. Their low cost made them suitable for a
+ wide variety of applications such as industrial control, where
+ a small, dedicated computer which is permanently assigned to
+ one application, is needed. In recent years, improvements in
+ device technology have resulted in minicomputers which are
+ comparable in performance to large {second generation
+ computers} and greatly exceed the performance of {first
+ generation} {computers}.
+
+ The processor was typically built using low integration logic
+ {integrated circuits} - {TTL} or maybe {ECL}, thus
+ distinguishing it from a {microcomputer} which is built around
+ a {microprocessor} - a processor on a single (or maybe a few)
+ ICs.
+
+ {DEC}'s {PDP-1} was the first minicomputer and their {PDP-11}
+ was the most successful, closely followed (in both time and
+ success) by the {VAX} (which {DEC} called a "{super
+ minicomputer}").
+
+ Another early minicomputer was the {LINC} developed at {MIT} in
+ 1963.
+
+ Other minicomputers were the {AS/400}, the {PRIME} series, the
+ {AP-3}, {Olivetti}'s {Audit 7} and the {Interdata 8/32}.
+
+ [Others?]
+
+ (2004-05-12)
+
+Mini Disc
+
+ <storage, music> A music medium designed by {Sony} as a
+ portable replacement for music {Compact Discs}. In 1994 Sony
+ announced a data version which can hold 140 MB or about 100 MB
+ using {error correction}. These will be competitive with 128
+ MB {magneto-optical} disks. Mini Discs may be either a
+ re-writable or mass-produced read-only type. Sony have also
+ announced a standard data format.
+
+ The transfer rate is similar to {CD-ROM} which is slow
+ compared to the current {magneto-optical} drives (which are
+ similar to an old hard disk, with writing noticeably slower
+ than reading). Pre-recorded read-only Mini Discs can be mass
+ manufactured on a modified CD press - this and the standard
+ format mean it could take off as a software distribution
+ medium.
+
+ An article in the December 1994 PCW quotes {access times} of
+ about 300 ms and data transfer rate of about 150 kb/s (i.e.
+ about single spin CD rate).
+
+ (1994-12-13)
+
+minifloppy
+
+ <storage> 5.25-inch {vanilla} floppy disks, as opposed to
+ 3.5-inch or {microfloppies} and the now-obsolescent 8-inch
+ variety.
+
+ At one time, this term was a trademark of {Shugart Associates}
+ for their SA-400 minifloppy drive. Nobody paid any attention.
+
+ See {stiffy}.
+
+ (1996-05-03)
+
+minimal automaton
+
+ <theory> An {automaton} possessing with {redundant states}.
+
+ (1996-05-03)
+
+minimax
+
+ <games> An {algorithm} for choosing the next move in a two
+ player game. A player moves so as to maximise the minimum
+ value of his opponent's possible following moves. If it is my
+ turn to move, I give a value to each legal move I might make.
+ If the result of a move is an immediate win for me I give it
+ positive infinity and, if it is an immediate win for you,
+ negative infinity. The value to me of any other move is the
+ minimum of the values resulting from each of your possible
+ replies.
+
+ The above algorithm will give every move a value of positive
+ or negative infinity since the value of every move will be the
+ value of some final winning or losing move. This can be
+ extended if we can supply a {heuristic} {evaluation function}
+ which gives values to non-final game states without
+ considering all possible following complete sequences. We can
+ then limit the minimax algorithm to look only a certain number
+ of moves ahead. This number is called the "look-ahead" or
+ "ply".
+
+ See also {alpha/beta pruning}.
+
+ [Is "maximin" used? Is it significantly different?]
+
+ (2000-12-07)
+
+Mini-ML
+
+ ["A Simple Applicative Language: Mini-ML", D. Clement et al,
+ Proc 1986 ACM Conf on LISP and Functional Prog, (Aug 1986)].
+
+minimum seek time
+
+ <storage> (Or track-to-track seek time) The time it takes to
+ move the head of a {disk drive} from one {track} to the next.
+ The minimum seek time gives a good measure of the speed of the
+ drive in a single-user/single-process environment where
+ successive read/write request are largely correlated and thus
+ if correlated data is stored in nearby cylinders most seeks
+ are from one cylinder to the next.
+
+ (1997-07-15)
+
+Mini PL/I
+
+ A commercial {PL/I} subset for the {Olivetti} {Audit 7}
+ {minicomputer}.
+
+MINITAB II
+
+ A system for interactive solution of small statistical
+ problems.
+
+ ["MINITAB Student Handbook", T.A. Ryan et al, Duxbury Press
+ 1976].
+
+ (1994-10-31)
+
+MINIX
+
+ <operating system> /MIN-ix/ A small {operating system} that is
+ very similar to {UNIX}. MINIX was written for educational
+ purposes by Prof. {Andrew S. Tanenbaum} of {Vrije
+ Universiteit, Amsterdam}.
+
+ MINIX has been written from scratch and contains no AT&T code
+ -- neither in the {kernel}, the {compiler}, the utilities, nor
+ the libraries. Although copyrighted by Prentice-Hall, all
+ {sources}, {binaries} and {documentation} can be obtained via
+ {Internet} for educational or research purposes.
+
+ Current versions as of 1996-11-15:
+
+ MINIX 2.0 - {Intel} {CPUs} from {Intel 8088} to {Pentium}
+
+ MINIX 1.5 - {Intel}, {Macintosh} ({MacMinix}), {Amiga}, {Atari
+ ST}, {Sun} {SPARC}.
+
+ {(http://cs.vu.nl/~ast/minix.html)}.
+
+ (1997-06-16)
+
+Minnesota Internet Users Essential Tool
+
+ <networking, tool> (Minuet) An integrated package for {IBM PC}
+ that includes modules for {electronic mail} (using the {POP}
+ {protocol}), {Gopher}, {telnet}, {Usenet} news and {FTP}.
+ Minuet provides an easy-to-use, {mouse}-driven {graphical user
+ interface} via the {TurboVision} libraries. It is a {TCP/IP}
+ {client} that runs over any type of TCP/IP {network} including
+ {Ethernet} and {SLIP}. It will work with either {static IP
+ address}es or {dynamic IP address}es ({bootp}).
+
+ {FAQ
+ (http://micro.umn.edu/products/minuet/minuet-1.html)}.
+ {(ftp://boombox.micro.umn.edu/pub/pc/minuet/beta16/minuarc.exe)}.
+
+ (1995-04-10)
+
+MINT
+
+ {Mint Is Not TRAC}
+
+MiNT
+
+ <operating system> (MinT is not TOS - a {recursive acronym}) A
+ freeware, {open source operating system} for the {Atari ST}
+ range of computers. MiNT was originally based on a {port} of
+ {BSD} to {Atari ST} computers by Eric R. Smith. MiNT gave the
+ Atari access to BSD's many network applications. A short
+ (1992-94) romance between MiNT and {Atari} Corp., who decided
+ to convert the system to the {MultiTOS} {kernel}, produced a
+ unique TOS/Unix hybrid, which provides simultaneous access to
+ both {GEM} and BSD application libraries.
+
+ Since MiNT is MultiTOS's kernel, it has kept all the features
+ described above and, if an {AES} replacement is installed, it
+ can show you a new face of MultiTOS. Unlike MultiTOS however,
+ MiNT is based on a different {file system}, that is faster and
+ more flexible than TOS's. Furthermore, thanks to the network
+ support, MiNT allows an Atari to be an {Internet} {server}
+ that can still run GEM and TOS applications! This has won
+ MiNT many devotees ("MiNTquisitors"), making it the main
+ competitor for {ASH}'s {MagiC}.
+
+ Unlike {Linux}, MiNT can run on a {Motorola 68000} with no
+ {FPU}. It needs at least 4 MB of RAM, more to run multiuser
+ or to run GEM applications at the same time.
+
+ {(http://orient.uw.edu.pl/~conradus/docs/mint.html)}.
+
+ (1999-07-20)
+
+Mint Is Not TRAC
+
+ <text, tool> (MINT) A version of {TRAC} used as the {extension
+ language} in the {Freemacs} editor.
+
+ {(ftp://sun.soe.clarkson.edu/pub/freemacs)}.
+
+ (1994-10-31)
+
+Minuet
+
+ <networking> {Minnesota Internet Users Essential Tool}.
+
+MINUIT
+
+ A program for {function minimisation} and {error analysis}.
+
+ (1994-10-31)
+
+minus
+
+ -
+
+ Common: dash; {ITU-T}: hyphen; {ITU-T}: minus. Rare:
+ {INTERCAL}: worm; option; dak; bithorpe.
+
+minus infinity
+
+ The most negative value, not necessarily or even usually the
+ simple negation of plus {infinity}. In N bit twos-complement
+ arithmetic, infinity is 2^(N-1) - 1 but minus infinity is
+ -(2^(N-1)), not -(2^(N-1) - 1).
+
+MIPS
+
+ 1. <unit, benchmark> Million instructions per second.
+
+ The unit commonly used to give the rate at which a processor
+ executes instructions.
+
+ Often rendered by hackers as "Meaningless Indication of
+ Processor Speed" or in other unflattering ways. This
+ expresses a nearly universal attitude about the value of most
+ {benchmark} claims, said attitude being one of the great
+ cultural divides between hackers and {marketroids}.
+
+ The etymologically incorrect singular "1 MIP" is sometimes
+ heard.
+
+ See also {KIPS} and {GIPS}.
+
+ 2. {VAX MIPS}.
+
+ 3. <processor> {Microprocessor without Interlocked Pipeline
+ Stages}.
+
+ 4. <company> {MIPS Technologies, Inc.}
+
+ [{Jargon File}]
+
+ (1996-03-01)
+
+MIPS project
+
+ {Microprocessor without Interlocked Pipeline Stages}
+
+MIPS R2000
+
+ <processor> The R2000 design came, in about 1987, from the
+ {Stanford} {MIPS project}, which stood for Microprocessor
+ without Interlocked Pipeline Stages.
+
+ Like the {AMD 29000}, the R2000 has no {condition code
+ register} considering it a potential {bottleneck}. The
+ {program counter} can be read like other registers.
+
+ The CPU includes an {MMU} that can also control a {cache}, and
+ the CPU can operate as {big-endian} or {little-endian}. There
+ is a {FPU}, the R2010.
+
+ Versions include the {MIPS R3000} and {MIPS R4000}.
+
+ (1995-02-09)
+
+MIPS R2010
+
+ A {FPU} for the {MIPS R2000}.
+
+ (1995-02-09)
+
+MIPS R3000
+
+ A version of the {MIPS R2000} with improved {cache} control.
+
+ (1995-02-09)
+
+MIPS R4000
+
+ A 64-bit version of the {MIPS R3000} with has more {pipeline}
+ stages for a higher {clock rate} and performance.
+
+ (1995-02-09)
+
+MIPS Technologies, Inc.
+
+ <company> A company which designs, develops, and licenses
+ {reduced instruction set computer} (RISC) {microprocessors}
+ and compilers. MIPS Technologies, Inc. is a wholly-owned
+ subsidiary of {Silicon Graphics, Inc.} and operates as an
+ independent unit. MIPS is the successor to the processor
+ business of MIPS Computer Systems which was founded in 1984
+ and merged with Silicon Graphics on 29 June 1992.
+
+ MIPS Technologies developed the world's first RISC {VLSI}
+ microprocessors (1985) (or was it the {ARM}?), the first
+ commercial 64-bit microprocessor ({MIPS R4000}, 1992),
+ announced MIPS R4300i - the first 64-bit RISC processor
+ designed for interactive consumer applications (April 1995).
+ They announced the MIPS R10000 - the next generation
+ general-purpose MIPS microprocessor and the most powerful
+ processor in the world (October 1994).
+
+ MIPS' semiconductor company partners participate in the design
+ and development of MIPS processors and software and then
+ produce, market, and support the processors. MIPS itself does
+ not fabricate or sell products. MIPS' semiconductor partners
+ are: {Integrated Device Technology}, {LSI Logic Corporation},
+ {NEC Corporation}, {NKK Corporation}, {Philips
+ Semiconductors}, {Siemens AG}, and {Toshiba Corporation}.
+
+ MIPS' products include:
+
+ R4000 - 100 MHz; 1.35M transistors, primary i/d cache 8KB/8KB,
+ SPECint92 58.3/ SPECfp92 61.4.
+
+ R4300i - 133 MHZ, 1.35M transistors; primary i/d cache,
+ 16KB/8KB, SPECint92 80, SPECfp92 60.
+
+ R4400 - 250 MHz, 2.3M transistors, primary i/d cache
+ 16KB/16KB, SPECint92 175.8, SPECfp92 164.4.
+
+ R4600 - 133 MHz, 1.9M transistors, primary i/d cache
+ 16KB/16KB, SPECint92 85, SPECfp92 75.
+
+ R8000/R8010 - 90 MHz, 2.6M, .83M transistors, primary i/d
+ cache, 16KB/16KB, SPECint92 132, SPECfp92 396.
+
+ R10000 - 200 MHz, 6.7M transistors, primary i/d cache
+ 32KB/32KB, SPECint92 >300, SPECfp92 >600.
+
+ MIPS' processor chips were used in the {DEC 3100} series of
+ {workstations}.
+
+ {(http://mips.com/)}.
+
+ {Usenet} newsgroup: {news:comp.sys.mips}.
+
+ (1996-03-01)
+
+Miracula
+
+ An implementation of a subset of {Miranda} by Stefan Kahrs
+ <smk@ed.ac.uk>, LFCS, no modules or files. Can be
+ interactively switched between {eager} and {lazy} evaluation.
+ Portable source in C from the author.
+
+Miranda
+
+ <language> (From the Latin for "admirable", also the heroine
+ of Shakespeare's "Tempest") A {lazy} {purely functional}
+ programming language and {interpreter} designed by {David
+ Turner} of the University of Kent in the early 1980s and
+ implemented as a product of his company, {Research Software
+ Limited}. Miranda combines the main features of {KRC} and
+ {SASL} with {strong typing} similar to that of {ML}.
+
+ It features terse {syntax} using the {offside rule} for
+ indentation. The {type} of an expression is inferred from the
+ {source} by the {compiler} but explicit type declarations are
+ also allowed. It has nested {pattern-matching}, {list
+ comprehensions} and {modules}. It uses {operator sections}
+ rather than {lambda abstractions}. User types are algebraic,
+ and in early versions could be constrained by {laws}.
+
+ It is implemented using {SKI combinator} {reduction}.
+ Originally implemented for {Unix}, there are versions for most
+ UNIX-like platforms including {Intel PC} under {Linux}. The
+ {KAOS} operating system is written entirely in Miranda.
+
+ There are translators from Miranda to {Haskell} {mira2hs
+ (/pub/misc/mira2hs)} and to {LML} {mira2lml (/pub/misc/mira2lml)}.
+ Non-commercial near-equivalents of Miranda include {Miracula} and
+ {Orwell}.
+
+ {(http://miranda.org.uk/)}.
+
+ [{"Miranda: A Non Strict Functional Language with Polymorphic
+ Types" (http://miranda.org.uk/nancy.html)}, D.A. Turner, in
+ Functional Programming Languages and Computer Architecture,
+ LNCS 201, Springer 1985].
+
+ [{"An Overview of Miranda"
+ (http://miranda.org.uk/overview.pdf)}, D. A. Turner, SIGPLAN
+ Notices, 21(12):158--166, December 1986].
+
+ ["Functional Programming with Miranda", Ian Holyer, Pitman
+ Press 0-273-03453-7].
+
+ (2007-03-22)
+
+MIRFAC
+
+ {Mathematics in Recognizable Form Automatically Compiled}
+
+mirror
+
+ 1. <hardware, storage> Writing duplicate data to more than one
+ device (usually two {hard disks}), in order to protect against
+ loss of data in the event of device failure. This technique
+ may be implemented in either hardware (sharing a {disk
+ controller} and cables) or in software. It is a common
+ feature of {RAID} systems.
+
+ Several {operating systems} support software disk mirroring or
+ {disk-duplexing}, e.g. {Novell NetWare}.
+
+ See also {Redundant Array of Independent Disks}.
+
+ Interestingly, when this technique is used with {magnetic
+ tape} storage systems, it is usually called "twinning".
+
+ A less expensive alternative, which only limits the amount of
+ data loss, is to make regular {backups} from a single disk to
+ {magnetic tape}.
+
+ 2. {mirror site}.
+
+ (1998-06-11)
+
+mirroring
+
+ {mirror}
+
+mirror site
+
+ <networking> An {archive site} or {website} which keeps a
+ copy of some or all files at another site so as to make them
+ more quickly available and to reduce the load on the source
+ site.
+
+ It is generally best to use the mirror that is physically
+ closest to you as this will usually give the fastest download.
+
+ Such mirroring is usually done for specific whole directories
+ or files on a specific remote server as opposed to a {cache}
+ or {proxy server} which keeps copies of everything that is
+ requested via it.
+
+ For example, src.doc.ic.ac.uk is the main UK mirror for the
+ {GNU} archive at gnu.org.
+
+ (2006-10-16)
+
+MIS
+
+ {Management Information System}
+
+misbug
+
+ /mis-buhg/ [MIT] An unintended property of a program that
+ turns out to be useful; something that should have been a
+ {bug} but turns out to be a {feature}. Usage: rare. Compare
+ {green lightning}. See {miswart}.
+
+ [{Jargon File}]
+
+MIS Director
+
+ {Chief Information Officer}
+
+misfeature
+
+ /mis-fee'chr/ or /mis'fee"chr/ A feature that eventually
+ causes lossage, possibly because it is not adequate for a new
+ situation that has evolved. Since it results from a
+ deliberate and properly implemented feature, a misfeature is
+ not a bug. Nor is it a simple unforeseen side effect; the
+ term implies that the feature in question was carefully
+ planned, but its long-term consequences were not accurately or
+ adequately predicted (which is quite different from not having
+ thought ahead at all). A misfeature can be a particularly
+ stubborn problem to resolve, because fixing it usually
+ involves a substantial philosophical change to the structure
+ of the system involved.
+
+ Many misfeatures (especially in user-interface design) arise
+ because the designers/implementors mistake their personal
+ tastes for laws of nature. Often a former feature becomes a
+ misfeature because trade-offs were made whose parameters
+ subsequently change (possibly only in the judgment of the
+ implementors). "Well, yeah, it is kind of a misfeature that
+ file names are limited to six characters, but the original
+ implementors wanted to save directory space and we"re stuck
+ with it for now."
+
+MISHAP
+
+ <language> An early system on the {IBM 1130}.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (2004-09-14)
+
+Missed'em-five
+
+ <operating system, abuse> (Or "SysVile" /sis-vi:l'/) A
+ pejorative hackerism for AT&T {System V} {Unix}, generally
+ used by {BSD} partisans in a bigoted mood.
+
+ See {software bloat}, {Berzerkeley}.
+
+ [{Jargon File}]
+
+ (1998-07-01)
+
+missile address
+
+ {ICBM address}
+
+missing
+
+ {Missing definition}
+
+miswart
+
+ /mis-wort/ [By analogy with {misbug}] A {feature} that
+ superficially appears to be a {wart} but has been determined
+ to be the {Right Thing}. For example, in some versions of the
+ {Emacs} text editor, the "transpose characters" command
+ exchanges the character under the cursor with the one before
+ it on the screen, *except* when the cursor is at the end of a
+ line, in which case the two characters before the cursor are
+ exchanged. While this behaviour is perhaps surprising, and
+ certainly inconsistent, it has been found through extensive
+ experimentation to be what most users want. This feature is a
+ miswart.
+
+ [{Jargon File}]
+
+MIT
+
+ {Massachusetts Institute of Technology}
+
+MIT AI Lab
+
+ <body> ({Massachusetts Institute of Technology} {artificial
+ intelligence} laboratory) Workplace of many famous AI
+ researchers at MIT including {GLS} and {RMS}.
+
+ {(http://ai.mit.edu/)}.
+
+ Address: 545 Technology Sq., Cambridge, MA 02139, USA.
+
+ (2003-02-28)
+
+MITI
+
+ {SQRIBE}
+
+MITILAC
+
+ <language> An early system on the {IBM 650}.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (1998-09-24)
+
+MIT Lisp Machine
+
+ {Lisp Machine}
+
+MITRE Corporation
+
+ <body> A US federally funded R&D center, spun off in 1958 from
+ the {MIT Lincoln Laboratory} (also an FFRDC). MITRE is a
+ non-profit corporation chartered to do R&D in the public
+ interest.
+
+ MITRE were responsible for system engineering and
+ implementation oversight of {SAGE}.
+
+ MITRE does not stand for MIT Research and Engineering, though
+ it could have.
+
+ {(http://mitre.org/)}.
+
+ (1999-12-16)
+
+MIT Research Laboratory for Electronics
+
+ <body>
+
+ See also {Jay Forrester}, {core memory}, the {Whirlwind}
+ computer, {MIT Lincoln Laboratory}.
+
+ [Summary?]
+
+ (1999-12-16)
+
+MITS
+
+ {Micro Instrumentation and Telemetry Systems}
+
+MIT Scheme
+
+ <language> (Previously "C-Scheme") A {Scheme} implementation
+ by the {MIT} Scheme Team (Chris Hanson, Jim Miller, Bill
+ Rozas, and many others) with a rich set of utilities, a
+ compiler called {Liar} and an editor called {Edwin}.
+
+ MIT Scheme includes an {interpreter}, large {run-time
+ library}, {Emacs} {macros}, {native-code compiler}, emacs-like
+ editor, and a {source-level debugger}.
+
+ Latest version: 7.7.1, as of 2002-06-18.
+
+ {MIT Scheme} conforms fully with {R4RS} and almost with the
+ {IEEE Scheme} {standard}. It runs on {Motorola 68000}:
+ {HP9000}, {Sun-3}, {NeXT}; {MIPS}: {Decstation}, {Sony}, {SGI};
+ {HP-PA}: 600, 700, 800; {VAX}: {Ultrix}, {BSD}, {DEC} {Alpha}:
+ {OSF}; {Intel i386}: {MS-DOS}, {MS Windows}, and various other
+ {Unix} systems.
+
+ See also: {LAP}, {Schematik}, {Scode}.
+
+ {(http://gnu.org/software/mit-scheme/)}.
+
+ {Usenet} newsgroup: {news:comp.lang.scheme.c}.
+
+ Mailing list: mit-scheme-announce@gnu.org (cross-posted to
+ news).
+
+ E-mail: <mit-scheme-devel@gnu.org> (maintainers).
+
+ (2003-08-14)
+
+MIX
+
+ Knuth's hypothetical machine, used in The Art of Computer
+ Programming v.1, Donald Knuth, A-W 1969.
+
+MIXAL
+
+ MIX Assembly Language.
+
+ The {assembly language} for {Donald Knuth}'s hypothetical
+ {MIX} machine.
+
+ (1995-01-05)
+
+MIX Communications
+
+ (MIX) Providers of {Internet} access and presentation services
+ for businesses and individuals in the Milwaukee, WI, USA
+ metropolitan area. MIX started providing Internet access
+ services to the Milwaukee area in 1990. It was the first
+ business in Milwaukee to provide Internet access services to
+ the public.
+
+ MIX Communications is owned and operated by Dean Roth.
+
+ {(http://mixcom.com/)}.
+
+ E-mail: <info@mixcom.com>.
+
+ Telephone: +1 (414) 351 1868 (Office), +1 (414) 351 1139
+ (BBS). Address: MIX Communications, P.O. Box 17166,
+ Milwaukee, WI 53217, USA.
+
+ (1995-01-05)
+
+M-JPEG
+
+ {Moving JPEG}
+
+MJS
+
+ <language> An early system on the {UNIVAC} I or II.
+
+ [Listed in CACM 2(5):1959-05-16].
+
+ (1996-12-15)
+
+mk
+
+ <networking> The {country code} for the Former Yugoslav
+ Republic of Macedonia.
+
+ (1999-01-27)
+
+ML
+
+ 1. <robotics> Manipulator Language. IBM language for handling
+ robots.
+
+ 2. Meta Language. R. Milner <rm@lfcs.edinburgh.ac.uk> et al,
+ 1973. A {strict} {higher-order} {functional language}. It
+ was the first language to include {polymorphic} typing which
+ was statically-checked. It also had {garbage collection} and
+ a formal {semantics}.
+
+ It began as the {metalanguage} for the Edinburgh {LCF} proof
+ assistant. (LCF="Logic for Computable Functions") People soon
+ noticed that ML could be a useful general programming language
+ and stand-alone versions were implemented. {Standard ML}
+ (SML) is a descendant of these (and related languages such as
+ {Hope}).
+
+ The "metalanguage" aspect has long since disappeared from the
+ language itself (although there are some systems that still
+ use it that way). The historical name is now so inappropriate
+ that asking what ML stands for is like asking what {C} or
+ {Unix} stands for. It doesn't stand for anything; it just is.
+
+ LCF ML was implemented in {Stanford LISP}. Cardelli (1981)
+ implemented ML in {Pascal} using the {Functional Abstract
+ Machine} (FAM). It has been significantly redesigned to
+ produce {Standard ML} and {Lazy ML}.
+
+ ["A Metalanguage for Interactive Proof in LCF", M.J.C. Gordon
+ et al, 5th POPL, ACM 1978].
+
+ (2006-07-21)
+
+ml
+
+ <networking> The {country code} for Mali.
+
+ (1999-01-27)
+
+ML-2000
+
+ An extension and redesign of {Standard ML}. Under
+ development.
+
+MLAB
+
+ Modeling LABoratory. An interactive mathematical modelling
+ system.
+
+ ["MLAB, An On-Line Modeling Laboratory", NIH (Mar 1975)].
+
+ (1994-10-13)
+
+ML/I
+
+ <language> An early {macro} language first implemented by
+ Peter Brown at the {Cambridge University} in 1966. ML/I has
+ been maintained by Bob Eager since 1973.
+
+ {ML/I Home (http://ml1.org.uk/)}.
+
+ [P.J. Brown, CACM 10(10):618-623, Oct 1967].
+
+ (2006-07-21)
+
+MLISP
+
+ 1. {M-expression LISP}.
+
+ 2. Meta-LISP. D.C. Smith & H. Enea. LISP variant with
+ ALGOL-like syntax. Not just a surface syntax, a full
+ language.
+
+ "MLISP", D.C. Smith, TR CS-179, CS Dept, Stanford (Oct 1970).
+ Version: MLISP2.
+
+ 3. A hybrid of M-expression LISP and Scheme.
+
+ "M-LISP: Its Natural Semantics and Equational Logic",
+ R. Muller, SIGPLAN Notices 26(9):234-242 (Sept 1991) (PEPM
+ '91).
+
+ML Kit
+
+ The ML Kit is a straight translation of the Definition of
+ Standard ML into a collection of Standard ML modules. For
+ example, every inference rule in the Definition is translated
+ into a small piece of Standard ML code which implements it.
+ The translation has been done with as little originality as
+ possible - even variable conventions from the Definition are
+ carried straight over to the Kit. The Kit is intended as a
+ tool box for those people in the programming language
+ community who may want a self-contained parser or type checker
+ for full Standard ML but do not want to understand the clever
+ bits of a high-performance compiler. We have tried to write
+ simple code and modular interfaces.
+
+ Version 1
+
+ interpreter, documentation
+
+ Nick Rothwell, David N. Turner, Mads Tofte <tofte@diku.dk>,
+ and Lars Birkedal at Edinburgh and Copenhagen Universities.
+
+ {(ftp://ftp.diku.dk/diku/users/birkedal/)}. UK: ftp
+ export/ml/mlkit/ from lfcs.ed.ac.uk
+
+ (1993-03-12)
+
+MLL
+
+ Medium-Level Language.
+
+ Sometimes used half-jokingly to describe {C}, alluding to its
+ "structured-assembler" image.
+
+ (1994-12-07)
+
+ML-lex
+
+ A version of {lex} in {SML/NJ} which outputs a {lexical
+ analyser} in {SML/NJ}.
+
+ {(ftp://research.att.com/dist/ml/75.tools.tar.Z)}.
+
+ML-Linda
+
+ U Edinburgh, under development.
+
+ML Threads
+
+ {SML/NJ} with mutual exclusion primitives similar to those in
+ {Modula-2+} and {Mesa}. Written by Greg Morrisett
+ <jgmorris@cs.cmu.edu>.
+
+ {Lightweight threads} are created using {fork}. They are
+ {pre-emptive}ly scheduled and communicate via {shared memory}
+ which can be protected by a "{mutex}" ({monitor}).
+
+ Implementations for {Motorola 68020}, {SPARC} and {MIPS} and
+ {VAX}- and {MIPS}-based multiprocessors.
+
+ ["Adding Threads to Standard ML", E. Cooper et al,
+ CMU-CS-90-186, CMU Dec 1990].
+
+ML-Twig
+
+ A variant of {TWIG} in {SML}, by Jussi Rintanen
+ <jur@cs.hut.fi>, which comes with {SML/NJ}.
+
+ (1995-02-14)
+
+mm
+
+ <networking> The {country code} for Myanmar (Burma).
+
+ (1999-01-27)
+
+Mma
+
+ A fast {Mathematica}-like system, in {Allegro CL} by
+ R. Fateman, 1991.
+
+ {(ftp://peoplesparc.berkeley.edu/pub/mma.tar.Z)}.
+
+mmap
+
+ The {Unix} {system call} which establishes a mapping between a
+ range of addresses in a user process's address space and a
+ portion of some "memory object" (typically a file, one of the
+ special "devices" /dev/mem or /dev/kmem or some
+ {memory-mapped} peripheral). This allows the process to
+ access a file at random byte offsets without using the seek
+ {system call} or to access physical addresses or {kernel}'s
+ {virtual address} space. It can also be used as an
+ alternative to writing a {device driver} since it is usually
+ simpler to code and faster to use.
+
+ (1995-02-14)
+
+MMCD
+
+ <storage> {MultiMedia Compact Disc}.
+
+ (1995-11-23)
+
+MMDF
+
+ {Multi-channel Memorandum Distribution Facility}
+
+MMI
+
+ 1. Man-Machine Interface.
+
+ 2. <company> The company which developed the first
+ {Programmable Array Logic} devices. MMI was bought by {AMD}.
+
+ [Dates?]
+
+ (1995-12-09)
+
+MML
+
+ Human-Machine Language.
+
+ A language from {ITU-T} for telecommunications applications.
+ It has a complex {natural-language} syntax.
+
+ [CCITT Recommendations Z.311-Z.318, Z-341, Nov 1984].
+
+ (1995-01-31)
+
+MMO
+
+ {Massively Multiplayer Online Game}
+
+MMOG
+
+ {Massively Multiplayer Online Game}
+
+MMORPG
+
+ {Massively Multiplayer Online Game}
+
+MMS
+
+ {Multimedia Messaging Services}
+
+MMU
+
+ {Memory Management Unit}
+
+MMX
+
+ {Matrix Math eXtensions}
+
+MMX technology
+
+ {Matrix Math eXtensions}
+
+mn
+
+ <networking> The {country code} for Mongolia.
+
+ (1999-01-27)
+
+mnemonic
+
+ <programming> A word or string which is intended to be easier
+ to remember than the thing it stands for. Most often used in
+ "{instruction mnemonic}" which are so called because they are
+ easier to remember than the {binary} patterns they stand for.
+ Non-printing {ASCII} characters also have mnemonics like
+ {NAK}, {ESC}, {DEL} intended to evoke their meaning on certain
+ systems.
+
+ (1995-05-11)
+
+MNP
+
+ {Microcom Networking Protocol}
+
+mo
+
+ <networking> The {country code} for Macau.
+
+ (1999-01-27)
+
+Mobile Subscriber Integrated Services Directory Number
+
+ <communications> A number string used to uniquely identify a
+ mobile telephone subscriber in {GSM}, {CDMA} and {UMTS}
+ cellular networks. The number is formatted according to the
+ {E.164} numbering plan, consisting of a country code (CC),
+ national destination code (NDC) and subscriber number (SN).
+
+ See also: {IMSI}, {IMEI}, {The GSM Specifications
+ (http://www.etsi.org/services_products/freestandard/home.htm)}.
+
+ (2006-12-28)
+
+Mobile Triton
+
+ <processor> (Official name 82430MX) A version of {Intel}'s {Triton}
+ I processor chip set intended for mobile computers.
+
+ Mobile Triton consists of one 82437MX and two 82438MX.
+
+ [Special features?]
+
+ (1996-04-03)
+
+mobo
+
+ {motherboard}
+
+MOBSSL-UAF
+
+ Merritt and Miller's Own Block-Structured Simulation
+ Language-Unpronounceable Acronym For.
+
+ A l for interactive continuous {simulation}.
+
+ ["MOBSSL - An Augmented Block Structured Continuous System
+ Simulation Language for Digital and Hybrid Computers",
+ M.J. Merritt et al, Proc FJCC 35, AFIPS (Fall 1969)].
+
+ (1995-01-31)
+
+moby
+
+ <jargon> /moh'bee/ (From {MIT}, seems to have been in use
+ among model railroad fans years ago. Derived from Melville's
+ "Moby Dick", some say from "Moby Pickle") 1. Large, immense,
+ complex, impressive. "A Saturn V rocket is a truly moby
+ frob." "Some MIT undergrads pulled off a moby hack at the
+ Harvard-Yale game."
+
+ 2. (Obsolete) The maximum {address space} of a computer (see
+ below). For a 680[234]0 or {VAX} or most modern 32-bit
+ architectures, it is 4,294,967,296 8-bit bytes (four
+ {gigabytes}).
+
+ 3. A title of address (never of third-person reference),
+ usually used to show admiration, respect, and/or friendliness
+ to a competent hacker. "Greetings, moby Dave. How's that
+ address-book thing for the Mac going?"
+
+ 4. In backgammon, doubles on the dice, as in "moby sixes",
+ "moby ones", etc. Compare this with {bignum}: double sixes
+ are both bignums and moby sixes, but moby ones are not bignums
+ (the use of "moby" to describe double ones is sarcastic).
+
+ 5. The largest available unit of something which is available
+ in discrete increments. Thus a "moby Coke" is not just large,
+ it's the largest size on sale.
+
+ This term entered hackerdom with the Fabritek 256K memory
+ added to the MIT AI PDP-6 machine, which was considered
+ unimaginably huge when it was installed in the 1960s (at a
+ time when a more typical memory size for a {time-sharing}
+ system was 72 kilobytes). Thus, a moby is classically 256K
+ 36-bit words, the size of a PDP-6 or PDP-10 moby. Back when
+ {address registers} were narrow the term was more generally
+ useful, because when a computer had {virtual memory} mapping,
+ it might actually have more physical memory attached to it
+ than any one program could access directly. One could then
+ say "This computer has six mobies" meaning that the ratio of
+ physical memory to address space is six, without having to say
+ specifically how much memory there actually is. That in turn
+ implied that the computer could timeshare six "full-sized"
+ programs without having to swap programs between memory and
+ disk.
+
+ Nowadays the low cost of processor logic means that address
+ spaces are usually larger than the most physical memory you
+ can cram onto a machine, so most systems have much *less* than
+ one theoretical "native" moby of {core}. Also, more modern
+ memory-management techniques (especially paging) make the
+ "moby count" less significant. However, there is one series
+ of widely-used chips for which the term could stand to be
+ revived --- the Intel 8088 and 80286 with their incredibly
+ {brain-damaged} segmented-memory designs. On these, a "moby"
+ would be the 1-megabyte address span of a segment/offset pair
+ (by coincidence, a PDP-10 moby was exactly one megabyte of
+ nine-bit bytes).
+
+ [{Jargon File}]
+
+ (1997-10-01)
+
+mockingbird
+
+ Software that intercepts communications (especially login
+ transactions) between users and hosts and provides system-like
+ responses to the users while saving their responses
+ (especially account IDs and passwords). A special case of
+ {Trojan horse}.
+
+ [{Jargon File}]
+
+Mockingboard
+
+ <hardware> A sound and speech board for the {Apple II}
+ computer, on sale in 1978.
+
+ See also {zxnrbl}.
+
+ (1997-03-18)
+
+Mock Lisp
+
+ The {Lisp} used by the {Gosling Emacs} editor.
+
+mod
+
+ 1. <filename extension, application, file format, music>
+ (module) The filename extension for a sampled music file
+ format that originated on the {Commodore} {Amiga}. A .MOD
+ file is composed of digitised sound samples, arranged in
+ patterns to create a song. There are .MOD players for most
+ {personal computers} including {Amiga}, {Archimedes}, {IBM
+ PC}, and {Macintosh}.
+
+ An {IBM PC} will require a {sound card} capable of handling
+ digitised samples ({Sound Blaster}, {Sound Blaster Pro},
+ {GUS}) and slower {Intel 80386}-based PCs may not be able to
+ do anything else while playing a module.
+
+ .MOD files differ from .MID ({MIDI}) files in that they
+ contain sound samples. This allows each song to use different
+ sounds but it also puts more load on the {CPU} than playing a
+ MIDI file, since more data must be processed for each note. A
+ slow CPU would benefit from a sound card with {wavetable
+ synthesis} which handles samples instead of the CPU.
+
+ Module files come in various formats including .MOD. Formats
+ evolved from .MOD include .S3M, .FAR and .669. Most contain
+ improvements on .MODs.
+
+ {(http://eskimo.com/~future/mods.htm)}.
+
+ 2. <jargon> modify or modification.
+
+ This abbreviation is very common - in fact the full terms are
+ considered formal. "Mods" is used especially with reference
+ to bug fixes or minor design changes in hardware or software,
+ most especially with respect to {patch} sets or a {diff}.
+
+ 3. <programming> A common name for the {modulo} operator.
+
+ (1999-07-14)
+
+*MOD
+
+ ("StarMOD") A {concurrent} language combining the {modules} of
+ {Modula} and the communications of {Distributed Processes}.
+
+ ["*MOD - A Language for Distributed Programming", R.P. Cook,
+ IEEE Trans Soft Eng SE-6(6):563-571 (Nov 1980)].
+
+ [{Jargon File}]
+
+ (1994-10-21)
+
+modal
+
+ 1. (Of an interface) Having {modes}. Modeless interfaces are
+ generally considered to be superior because the user does not
+ have to remember which mode he is in.
+
+ 2. See {modal logic}.
+
+ 3. In {MS Windows} programming, A window with the label
+ "WS_MODAL" will stay on the screen and claim all the
+ user-input. Other windows can only be accessed if the MODAL
+ window is closed. Such a window would typically be used for
+ an error {dialog box} to warn the user for something
+ important, like "Critical error, shut down the system and
+ restart".
+
+ (1995-02-07)
+
+modal logic
+
+ <logic> An extension of {propositional calculus} with
+ {operators} that express various "modes" of truth. Examples
+ of modes are: necessarily A, possibly A, probably A, it has
+ always been true that A, it is permissible that A, it is
+ believed that A.
+
+ "It is necessarily true that A" means that things being as
+ they are, A must be true, e.g.
+
+ "It is necessarily true that x=x" is TRUE
+
+ while
+
+ "It is necessarily true that x=y" is FALSE
+
+ even though "x=y" might be TRUE.
+
+ Adding modal operators [F] and [P], meaning, respectively,
+ henceforth and hitherto leads to a "{temporal logic}".
+
+ Flavours of modal logics include: {Propositional Dynamic
+ Logic} (PDL), {Propositional Linear Temporal Logic} (PLTL),
+ {Linear Temporal Logic} (LTL), {Computational Tree Logic}
+ (CTL), {Hennessy-Milner Logic}, S1-S5, T.
+
+ C.I. Lewis, "A Survey of Symbolic Logic", 1918, initiated the
+ modern analysis of modality. He developed the logical systems
+ S1-S5. JCC McKinsey used algebraic methods ({Boolean
+ algebras} with operators) to prove the decidability of Lewis'
+ S2 and S4 in 1941. Saul Kripke developed the {relational
+ semantics} for modal logics (1959, 1963). Vaughan Pratt
+ introduced {dynamic logic} in 1976. Amir Pnuelli proposed the
+ use of temporal logic to formalise the behaviour of
+ continually operating {concurrent} programs in 1977.
+
+ [Robert Goldblatt, "Logics of Time and Computation", CSLI
+ Lecture Notes No. 7, Centre for the Study of Language and
+ Information, Stanford University, Second Edition, 1992,
+ (distributed by University of Chicago Press)].
+
+ [Robert Goldblatt, "Mathematics of Modality", CSLI Lecture
+ Notes No. 43, Centre for the Study of Language and
+ Information, Stanford University, 1993, (distributed by
+ University of Chicago Press)].
+
+ [G.E. Hughes and M.J. Cresswell, "An Introduction to Modal
+ Logic", Methuen, 1968].
+
+ [E.J. Lemmon (with Dana Scott), "An Introduction to Modal
+ Logic", American Philosophical Quarterly Monograpph Series,
+ no. 11 (ed. by Krister Segerberg), Basil Blackwell, Oxford,
+ 1977].
+
+ (1995-02-15)
+
+modam
+
+ <spelling> Do you mean {modem}?
+
+ (2008-05-08)
+
+MODCAL
+
+ A version of {HP-PASCAL} enhanced with system programming
+ constructs, used internally by {HP}.
+
+ (1995-02-07)
+
+Mode
+
+ <language> An {object-oriented language}.
+
+ ["The Programming Language Mode: Language Definition and User
+ Guide", J. Vihavainen, C-1987-50, U Helsinki, 1987].
+
+ [{Jargon File}]
+
+ (1994-10-21)
+
+mode
+
+ 1. A general state, usually used with an adjective describing
+ the state. Use of the word "mode" rather than "state" implies
+ that the state is extended over time, and probably also that
+ some activity characteristic of that state is being carried
+ out. "No time to hack; I'm in thesis mode."
+
+ In its jargon sense, "mode" is most often attributed to
+ people, though it is sometimes applied to programs and
+ inanimate objects. In particular, see {hack mode}, {day
+ mode}, {night mode}, {demo mode}, {fireworks mode}, and {yoyo
+ mode}; also {chat}.
+
+ 2. More technically, a mode is a special state that certain
+ user interfaces must pass into in order to perform certain
+ functions. For example, in order to insert characters into a
+ document in the Unix editor "vi", one must type the "i" key,
+ which invokes the "Insert" command. The effect of this
+ command is to put vi into "insert mode", in which typing the
+ "i" key has a quite different effect (to wit, it inserts an
+ "i" into the document). One must then hit another special
+ key, "ESC", in order to leave "insert mode". Nowadays,
+ modeful interfaces are generally considered {losing} but
+ survive in quite a few widely used tools built in less
+ enlightened times.
+
+ [{Jargon File}]
+
+ 3. <hardware> {video mode}.
+
+ (1994-12-22)
+
+mode bit
+
+ A {flag}, usually in hardware, that selects between two
+ (usually quite different) modes of operation. The
+ connotations are different from {flag} bit in that mode bits
+ are mainly written during a boot or set-up phase, are seldom
+ explicitly read, and seldom change over the lifetime of an
+ ordinary program. The classic example was the
+ EBCDIC-vs.-ASCII bit (#12) of the Program Status Word of the
+ {IBM 360}. Another was the bit on a PDP-12 that controlled
+ whether it ran the PDP-8 or the LINC instruction set.
+
+ [{Jargon File}]
+
+MODEF
+
+ Pascal-like language with polymorphism and data abstraction.
+ "Definition of the Programming Language MODEF",
+ J. Steensgard-Madsen et al, SIGPLAN Notices 19(2):92-110 (Feb
+ 1984).
+
+MODEL
+
+ <language> A {Pascal}-like language with extensions for
+ large-scale system programming and interface with {Fortran}
+ applications. MODEL includes {generic procedures}, and a
+ "static" {macro}-like approach to {data abstraction}. It
+ produces {P-code} and was used to implement the {DEMOS}
+ {operating system} on the {Cray-1}.
+
+ ["A Manual for the MODEL Programming Language", J.B. Morris,
+ Los Alamos 1976].
+
+ (1996-05-29)
+
+model
+
+ 1. <simulation> A description of observed or predicted
+ behaviour of some system, simplified by ignoring certain
+ details. Models allow complex {systems}, both existent and
+ merely specified, to be understood and their behaviour
+ predicted. A model may give incorrect descriptions and
+ predictions for situations outside the realm of its intended
+ use. A model may be used as the basis for {simulation}.
+
+ Note: British spelling: "modelling", US: "modeling".
+
+ (2008-04-28)
+
+ 2. <programming> {Model View Controller}.
+
+ (2008-04-28)
+
+model checking
+
+ <theory, algorithm, testing> To algorithmically check whether
+ a program (the model) satisfies a specification.
+
+ The model is usually expressed as a {directed graph}
+ consisting of {nodes} (or {vertices}) and {edges}. A set of
+ {atomic propositions} is associated with each node. The nodes
+ represents states of a program, the edges represent possible
+ executions which alters the state, while the atomic
+ propositions represent the basic properties that hold at a
+ point of execution.
+
+ A specification language, usually some kind of {temporal
+ logic}, is used to express properties.
+
+ The problem can be expressed mathematically as: given a
+ temporal logic formula p and a model M with initial state s,
+ decide if M,s \models p.
+
+ ["Automatic verification of finite state concurrent systems
+ using temporal logic", E.M. Clarke, E.A. Emerson, and
+ A.P. Sisla, ACM Trans. on Programming Languages and Systems
+ 8(2), pp. 244--263, 1986].
+
+ (1997-06-26)
+
+modeling
+
+ <spelling> US spelling of "{model}ling".
+
+ (1999-12-10)
+
+modeling language
+
+ {modelling language}
+
+modelling
+
+ {model}
+
+modelling language
+
+ <language> Possibly a kind of {programming language} designed
+ for describing {models} and their behaviour.
+
+ See also {data modelling}, {object relational model},
+ {simulation}, {UML}, {VRML}.
+
+ (2009-05-11)
+
+Modelsim
+
+ <simulation> A simulation tool for programming {VLSI} {ASICs},
+ {FPGAs}, {CPLDs}, and {SoCs}.
+
+ {Manual by Arnd Riebartsch
+ (http://arieba.net/simulators.htm#ModelSim)}.
+
+ (2003-07-19)
+
+Model View Controller
+
+ <programming> (MVC) A way of partitioning the design of
+ {interactive} {software}. The "model" is the internal
+ workings of the program (the {algorithms}), the "view" is how
+ the user sees the state of the model and the "controller" is
+ how the user changes the state or provides input.
+
+ (2007-05-30)
+
+modem
+
+ <hardware, communications> (Modulator/demodulator) An
+ electronic device for converting between serial data
+ (typically {EIA-232}) from a computer and an audio signal
+ suitable for transmission over a telephone line connected to
+ another modem. In one scheme the audio signal is composed of
+ silence (no data) or one of two frequencies representing zero
+ and one.
+
+ Modems are distinguished primarily by the maximum data rate
+ they support. Data rates can range from 75 bits per second up
+ to 56000 and beyond. Data from the user (i.e. flowing from
+ the local terminal or computer via the modem to the telephone
+ line) is sometimes at a lower rate than the other direction,
+ on the assumption that the user cannot type more than a few
+ characters per second.
+
+ Various data {compression} and error correction {algorithms}
+ are required to support the highest speeds. Other optional
+ features are {auto-dial} (auto-call) and {auto-answer} which
+ allow the computer to initiate and accept calls without human
+ intervention. Most modern modems support a number of
+ different {protocols}, and two modems, when first connected,
+ will automatically negotiate to find a common protocol (this
+ process may be audible through the modem or computer's
+ loudspeakers). Some modem protocols allow the two modems to
+ renegotiate ("retrain") if the initial choice of data rate is
+ too high and gives too many transmission errors.
+
+ A modem may either be internal (connected to the computer's
+ {bus}) or external ("stand-alone", connected to one of the
+ computer's {serial ports}). The actual speed of transmission
+ in characters per second depends not just the modem-to-modem
+ data rate, but also on the speed with which the processor can
+ transfer data to and from the modem, the kind of compression
+ used and whether the data is compressed by the processor or
+ the modem, the amount of noise on the telephone line (which
+ causes retransmissions), the serial character format
+ (typically {8N1}: one {start bit}, eight data bits, no
+ {parity}, one {stop bit}).
+
+ See also {acoustic coupler}, {adaptive answering}, {baud
+ barf}, {Bulletin Board System}, {Caller ID}, {SoftModem},
+ {U.S. Robotics}, {UUCP}, {whalesong}.
+
+ {Usenet} newsgroup: {news:comp.dcom.modems}.
+
+ (2002-05-04)
+
+MODEM7
+
+ A {batch file transfer protocol}.
+
+ See also {XMODEM}.
+
+ (1995-05-02)
+
+moderator
+
+ A person, or small group of people, who manages a moderated
+ {mailing list} or {Usenet} {newsgroup}. Moderators are
+ responsible for determining which email submissions are passed
+ on to the list or newsgroup.
+
+Modified Frequency Modulation
+
+ <storage> (MFM, Modified {FM}, or sometimes "Multiple
+ Frequency Modulation") A modification to the original
+ {frequency modulation} scheme for encoding data on {magnetic
+ disks}. MFM allows more than 1 symbol per flux transition (up
+ to 3), giving greater density of data. It is used with a data
+ rate of between 250-500 kbit/s on industry standard 3.5" and
+ 5.25" low and high density {diskettes}, and up to 5 Mbit/s on
+ {ST-506} {hard disks}. Except for 1.44 MB floppy disks, this
+ encoding is obsolete.
+
+ Other data encoding schemes include {GCR}, {FM}, {RLL}. See
+ also: {PRML}.
+
+ (2002-06-24)
+
+modifier
+
+ <programming> An operation that alters the state of an
+ {object}. Modifiers often have names that begin with "set"
+ and corresponding {selector} functions whose names begin with
+ "get".
+
+ (1998-01-12)
+
+M O drive
+
+ {magneto-optical disk}
+
+MODSIM
+
+ <language> A general-purpose, modular, block-structured
+ language from {CACI}, which provides support for
+ {object-oriented programming} and {discrete event simulation}.
+ It is intended for building large process-based discrete event
+ simulation models through modular and object-oriented
+ mechanisms similar to those of {Modula-2}.
+
+ MODSIM is descended from {Modula-2} and {Simula}. It supports
+ {multiple inheritance}, {templates}, {reference types},
+ {polymorphism}, and {process-oriented simulation} with
+ synchronous and asynchronous activities using explicit
+ simulation time.
+
+ See also {MODSIM II}, {USAModSim}.
+
+ (1994-11-11)
+
+MODSIM II
+
+ 1986. Object-oriented modular language for discrete
+ simulation, with {multiple inheritance}, {strong typing},
+ integrated 2D and 3D graphics. Compiles to C. CACI, La
+ Jolla, (619) 457-9681. list: palmer@world.std.com
+
+Modula
+
+ {MODUlar LAnguage}
+
+Modula-2
+
+ <language> A high-level programming language designed by
+ {Niklaus Wirth} at {ETH} in 1978. It is a derivative of
+ {Pascal} with well-defined interfaces between {modules}, and
+ facilities for parallel computation. Modula-2 was developed
+ as the system language for the {Lilith} {workstation}.
+
+ The central concept is the {module} which may be used to
+ encapsulate a set of related subprograms and data structures,
+ and restrict their visibility from other portions of the
+ program. Each module has a definition part giving the
+ interface, and an implementation part.
+
+ The language provides limited single-processor {concurrency}
+ ({monitors}, {coroutines} and explicit transfer of control)
+ and hardware access ({absolute address}es and {interrupts}).
+ It uses {name equivalence}.
+
+ {DEC FTP archive
+ (ftp://gatekeeper.dec.com/.1/DEC/Modula-2/m2.tar.Z)}.
+
+ ["Programming in Modula-2", N. Wirth, Springer 1985].
+
+ (1995-10-25)
+
+Modula-2*
+
+ An extension of {Modula-2} by M. Philippsen
+ <philipp@ira.uka.de> of the {University of Karlsruhe}. It
+ uses a superset of {data parallelism}, allowing both
+ synchronous and asynchronous programs, both {SIMD} and {MIMD}.
+ Parallelism may be nested to any depth. There are version for
+ {MasPar} and a simulator for the {SPARC}.
+
+ {(ftp://iraun1.ira.uka.de/pub/programming/modula2star)}.
+ E-mail: Ernst Heinz <heinz@ira.uka.de>.
+
+ ["Modula-2*: An Extension of Modula-2 for Highly Parallel,
+ Portable Programs", W. Tichy et al, TR 4/90, U Karlsruhe, Jan
+ 1990].
+
+ (1994-10-21)
+
+Modula-2+
+
+ {Modula-2} plus {exceptions} and {threads} developed by
+ P. Rovner et al of {DEC} {SRC}, Palo Alto CA in 1984.
+
+ ["Modula-2+ User's Manual", M-C van Leunen].
+
+ ["Extending Modula-2 to Build Large, Integrated Systems",
+ P. Rovner, IEEE Software 3(6):46-57 (Nov 1986)].
+
+ (1994-10-21)
+
+Modula-3
+
+ L. Cardelli et al, DEC and Olivetti, 1988. A descendant of
+ Modula-2+ and Cedar, designed for safety and simplicity.
+ Objects, generics, threads, exceptions and garbage collection.
+ Modules are explicitly safe or unsafe. As in Mesa, any set of
+ variables can be monitored. No {multiple inheritance}, no
+ operator overloading. Uses structural equivalence. "Modula-3
+ Report", Luca Cardelli et al, TR 52, DEC SRC, and Olivetti
+ Research Center, Aug 1988 (revised Oct 1989). The changes are
+ described in "System Programming with Modula-3", Greg Nelson
+ ed, P-H 1991, ISBN 0-13-590464-1. "Modula-3", Sam Harbison,
+ P-H 1992. Version: SRC Modula-3 V1.5.
+
+ {(ftp://gatekeeper.dec.com/pub/DEC/Modula-3/release/)}.
+
+ See also {SRC Modula-3}.
+
+Modula-3*
+
+ Incorporation of {Modula-2*} ideas into {Modula-3}.
+
+ ["Modula-3*: An Efficiently Compilable Extension of Modula-3
+ for Problem-Oriented Explicitly Parallel Programming",
+ E. Heinz <heinze@ira.uka.de>, 1993].
+
+Modula-3pi
+
+ Machine-independent intermediate language for compilation of
+ Modula-3*. "Modula-3pi Language Definition", E.A. Heinz, TR,
+ U Karlsruhe 1993.
+
+Modula-P
+
+ "Modula-P: A Language for Parallel Programming Definition and
+ Implementation on a Transputer Network", R. Hoffart et al,
+ IEEE Conf Comp Langs 1992.
+
+Modula-Prolog
+
+ Adds a Prolog layer to Modula-2. "Modula-Prolog: A Software
+ Development Tool", C. Muller IEEE Software pp.39-45 (Nov
+ 1986).
+
+Modula/R
+
+ Modula with relational database constructs added. LIDAS Group
+ (J. Koch, M. Mall, P. Putfarken, M. Reimer, J.W. Schmidt,
+ C.A. Zehnder) "Modula/R Report", LIDAS Memo 091-83, ETH
+ Zurich, Sep 1983.
+
+modular arithmetic
+
+ <mathematics> (Or "clock arithmetic") A kind of integer
+ arithmetic that reduces all numbers to one of a fixed set
+ [0..N-1] (this would be "modulo N arithmetic") by effectively
+ repeatedly adding or subtracting N (the "modulus") until the
+ result is within this range.
+
+ The original mathematical usage considers only __equivalence__
+ modulo N. The numbers being compared can take any values,
+ what matters is whether they differ by a multiple of N.
+ Computing usage however, considers modulo to be an operator
+ that returns the remainder after integer division of its first
+ argument by its second.
+
+ Ordinary "clock arithmetic" is like modular arithmetic except
+ that the range is [1..12] whereas modulo 12 would be [0..11].
+
+ (2003-03-28)
+
+Modular C
+
+ A {preprocessor}-based extension to {C} allowing {modules}.
+
+ [Article by Stowe Boyd, Azrex Inc, SIGPLAN Notices, ca 1980].
+
+ (1994-10-25)
+
+MODUlar LAnguage
+
+ <language> (Modula) {Wirth}'s 1977 predecessor of {Modula-2}.
+ The original Modula was, more oriented toward {concurrent}
+ programming, but otherwise quite similar.
+
+ ["Modula - A Language for Modular Multiprogramming", N. Wirth,
+ Soft Prac & Exp 7(1):3-35, Jan 1977].
+
+ (1999-07-12)
+
+Modular Prolog
+
+ An {interpreter} for {SB-Prolog} version 3.1 extended with
+ {ML}-style {modules}. Runs on {SPARC}. Distributed under
+ {GNU} {General Public License}.
+
+ {(ftp://ftp.dcs.ed.ac.uk/pub/dts/mod-prolog.tar.Z)}. E-mail:
+ Brian Paxton <mprolog@dcs.ed.ac.uk>.
+
+ ["A Calculus for the Construction of Modular Prolog Programs",
+ D. Sannella et al, J Logic Prog 12:147-177 (1992)].
+
+ (1994-10-25)
+
+Modular SB-Prolog
+
+ {Modular Prolog}
+
+module
+
+ 1. <programming> An independent piece of {software} which
+ forms part of one or more larger {programs}. Different
+ languages have different concepts of a module but there are
+ several common ideas.
+
+ Modules are usually compiled seperately (in compiled
+ languages) and provide an {abstraction} or information hiding
+ mechanism so that a module's implementation can be changed
+ without requiring any change to other modules. In this
+ respect they are similar to {objects} in an {object-oriented
+ language}, though a module may contain many {procedures}
+ and/or {functions} which would correspond to many objects.
+
+ A module often has its own {name space} for {identifiers} so
+ the same identifier may be used to mean different things in
+ different modules.
+
+ [Difference from {package}?].
+
+ 2. <hardware> An independent assembly of electronic components
+ with some distinct function, e.g. a RAM module consisting of
+ several RAM chips mounted on a small circuit board.
+
+ (1997-10-27)
+
+Modulex
+
+ Based on Modula-2. Mentioned by M.P. Atkinson & J.W. Schmidt
+ in a tutorial in Zurich, 1989.
+
+modulo
+
+ /mod'yu-loh/
+
+ 1. <mathematics> {modular arithmetic}.
+
+ 2. <mathematics> {modulo operator}.
+
+ (1999-07-12)
+
+modulo arithmetic
+
+ {modular arithmetic}
+
+modulo operator
+
+ <mathematics> (mod) The operator that returns the remainder
+ after integer division of its first argument by its second.
+ Written as "%" in {C} and some other languages.
+
+ Where the second argument is a power of two, the result can be
+ calculated much more quickly using {bitwise and} with the
+ appropriate {bit-mask}.
+
+ (1999-07-12)
+
+Mohammed Al-Khawarizmi
+
+ {Muhammad ibn Musa al-Khwarizmi}
+
+molly-guard
+
+ /mol'ee-gard/ [University of Illinois] A shield to prevent
+ tripping of some {Big Red Switch} by clumsy or ignorant hands.
+ Originally used of the plexiglass covers improvised for the
+ BRS on an IBM 4341 after a programmer's toddler daughter
+ (named Molly) frobbed it twice in one day. Later generalised
+ to covers over stop/reset switches on disk drives and
+ networking equipment.
+
+ [{Jargon File}]
+
+monad
+
+ <theory, functional programming> /mo'nad/ A technique from
+ {category theory} which has been adopted as a way of dealing
+ with {state} in {functional programming languages} in such a
+ way that the details of the state are hidden or abstracted out
+ of code that merely passes it on unchanged.
+
+ A monad has three components: a means of augmenting an
+ existing type, a means of creating a default value of this new
+ type from a value of the original type, and a replacement for
+ the basic application operator for the old type that works
+ with the new type.
+
+ The alternative to passing state via a monad is to add an
+ extra argument and return value to many functions which have
+ no interest in that state. Monads can encapsulate state, side
+ effects, exception handling, global data, etc. in a purely
+ lazily functional way.
+
+ A monad can be expressed as the triple, (M, unitM, bindM)
+ where M is a function on types and (using {Haskell} notation):
+
+ unitM :: a -> M a
+ bindM :: M a -> (a -> M b) -> M b
+
+ I.e. unitM converts an ordinary value of type a in to monadic
+ form and bindM applies a function to a monadic value after
+ de-monadising it. E.g. a state transformer monad:
+
+ type S a = State -> (a, State)
+ unitS a = \ s0 -> (a, s0)
+ m `bindS` k = \ s0 -> let (a,s1) = m s0
+ in k a s1
+
+ Here unitS adds some initial state to an ordinary value and
+ bindS applies function k to a value m. (`fun` is Haskell
+ notation for using a function as an {infix} operator). Both m
+ and k take a state as input and return a new state as part of
+ their output. The construction
+
+ m `bindS` k
+
+ composes these two state transformers into one while also
+ passing the value of m to k.
+
+ Monads are a powerful tool in {functional programming}. If a
+ program is written using a monad to pass around a variable
+ (like the state in the example above) then it is easy to
+ change what is passed around simply by changing the monad.
+ Only the parts of the program which deal directly with the
+ quantity concerned need be altered, parts which merely pass it
+ on unchanged will stay the same.
+
+ In functional programming, unitM is often called initM or
+ returnM and bindM is called thenM. A third function, mapM is
+ frequently defined in terms of then and return. This applies
+ a given function to a list of monadic values, threading some
+ variable (e.g. state) through the applications:
+
+ mapM :: (a -> M b) -> [a] -> M [b]
+ mapM f [] = returnM []
+ mapM f (x:xs) = f x `thenM` ( \ x2 ->
+ mapM f xs `thenM` ( \ xs2 ->
+ returnM (x2 : xs2) ))
+
+ (2000-03-09)
+
+monadic
+
+ 1. <programming> {unary}, when describing an {operator} or
+ {function}. The term is part of the {dyadic}, {niladic}
+ sequence.
+
+ 2. <theory> See {monad}.
+
+ (1998-07-24)
+
+Mongolian Hordes technique
+
+ <programming, jargon> (Or "Chinese Army technique") Assigning
+ a large number of inexperienced programmers to a job which
+ would better performed by a few skilled ones. The term was
+ first used by Dr. Fred Brooks in his book "{The Mythical
+ Man-Month}", Chapter 3.
+
+ According to Dr. Brooks, he had in mind the vision of the
+ Mongol Hordes sweeping across Asia and Europe when he created
+ the term.
+
+ [{Jargon File}]
+
+ (1996-06-20)
+
+moniter
+
+ <spelling> It's spelled "{monitor}".
+
+ (1996-11-28)
+
+monitor
+
+ 1. A {cathode-ray tube} and associated electronics connected
+ to a computer's video output. A monitor may be either
+ {monochrome} (black and white) or colour ({RGB}). Colour
+ monitors may show either digital colour (each of the red,
+ green and blue signals may be either on or off, giving eight
+ possible colours: black, white, red, green, blue, cyan,
+ magenta and yellow) or analog colour (red, green and blue
+ signals are continuously variable allowing any combination to
+ be displayed). Digital monitors are sometimes known as {TTL}
+ because the voltages on the red, green and blue inputs are
+ compatible with TTL logic chips.
+
+ See also {gamut}, {multisync}, {visual display unit}.
+
+ 2. A programming language construct which encapsulates
+ variables, access procedures and initialisation code within an
+ abstract data type. The monitor's variable may only be
+ accessed via its access procedures and only one process may be
+ actively accessing the monitor at any one time. The access
+ procedures are {critical sections}. A monitor may have a
+ queue of processes which are waiting to access it.
+
+ 3. A hardware device that measures electrical events such as
+ pulses or voltage levels in a digital computer.
+
+ 4. To oversee a program during execution. For example, the
+ monitor function in the {Unix} {C} library enables profiling
+ of a certain range of code addresses. A histogram is produced
+ showing how often the {program counter} was found to be at
+ each position and how often each profiled function was called.
+
+ {Unix} {man} page: monitor(3).
+
+ 5. A control program within the {operating system} that
+ manages the allocation of system resources to active
+ programs.
+
+ 6. A program that measures software performance.
+
+monkey, scratch
+
+ {scratch monkey}
+
+monkey sort
+
+ {bogo-sort}
+
+monkey up
+
+ To hack together hardware for a particular task, especially a
+ one-shot job. Connotes an extremely {crufty} and consciously
+ temporary solution. Compare {hack up}, {kluge up}.
+
+Mono
+
+ <programming> An {open source} {.NET framework} for {Unix}.
+
+ {Mono Home (http://go-mono.com/)}.
+
+ (2003-09-24)
+
+monochrome
+
+ <graphics> Literally "one colour". Usually used for a black
+ and white (or sometimes green or orange) {monitor} as distinct
+ from a color monitor. Normally, each {pixel} on the display
+ will correspond to a single bit of {display memory} and will
+ therefore be one of two intensities. A {grey-scale} display
+ requires several bits per {pixel} but might still be called
+ monochrome.
+
+ Compare: {bitonal}.
+
+ (1994-11-24)
+
+Monochrome Display Adapter
+
+ <hardware, graphics> (MDA) One of {IBM}'s earliest hardware
+ video {display standards} for use in {IBM PC}. MDA can
+ display only {monochrome} 80*25 text ({IBM PC video mode} 7).
+ It is now obsolete.
+
+ (2011-03-20)
+
+monoid
+
+ An operator * and a value x form a monoid if * is
+ {associative} and x is its left and right {identity}.
+
+monotonic
+
+ In {domain theory}, a function f : D -> C is monotonic (or
+ monotone) if
+
+ for all x,y in D, x <= y => f(x) <= f(y).
+
+ ("<=" is written in {LaTeX} as {\sqsubseteq}).
+
+ (1994-11-24)
+
+MONSTR
+
+ <language> A {term graph rewriting} language from {Manchester
+ University}(?), designed to be easily implementable on
+ distributed architectures and featuring limited
+ synchronisation facilities.
+
+ (1995-03-20)
+
+Montage
+
+ An {object-relational database management system} from
+ {Montage Software}, the commercialisation of {POSTGRES}.
+
+ (1995-02-23)
+
+Monte Carlo
+
+ <algorithm> (After Monte Carlo, Monaco - a gambling mecca) Any
+ one of various methods involving statistical techniques for
+ finding the solutions to mathematical or physical problems.
+
+ For example, to calculate {pi}: draw a square then draw the
+ biggest circle that fits exactly inside it. Pick random
+ points on the square. The proportion of these that lie within
+ the circle should tend to pi/4.
+
+ (2005-04-05)
+
+monty
+
+ <programming, abuse> /mon'tee/ Any program with a ludicrously
+ complex user interface that performs a trivial task. An
+ example would be a menu-driven, button clicking, pulldown,
+ pop-up windows program for listing directories. The original
+ monty was a weather reporting program, Monty the Amazing
+ Weather Man, written at the USGS. Monty had a widget-packed
+ X-window interface with over 200 buttons; and all it actually
+ *did* was {FTP} files off the network.
+
+ [{Jargon File}]
+
+ (2005-04-05)
+
+MOO
+
+ {MUD Object Oriented}
+
+Moof
+
+ /moof/ [MAC users] 1. A semi-legendary creature, also called
+ the "dogcow", that lurks in the depths of the {Macintosh}
+ Technical Notes {Hypercard} stack V3.1; specifically, the full
+ story of the dogcow is told in technical note #31 (the
+ particular Moof illustrated is properly named "Clarus").
+ Option-shift-click will cause it to emit a characteristic
+ "Moof!" or "!fooM" sound. *Getting* to tech note 31 is the
+ hard part; to discover how to do that, one must needs examine
+ the stack script with a hackerly eye. Clue: {rot13} is
+ involved. A dogcow also appears if you choose "Page Setup..."
+ with a LaserWriter selected and click on the "Options" button.
+
+ 2. Used to flag software that's a hack, something untested and
+ on the edge. On one {Apple Computer} {CD-ROM}, certain {folders} such
+ as "Tools & Apps (Moof!)" and "Development Platforms (Moof!)",
+ are so marked to indicate that they contain software not fully
+ tested or sanctioned by the powers that be. When you open
+ these folders you cross the boundary into hackerland.
+
+ [{Jargon File}]
+
+Moore bound
+
+ An upper limit on the number of nodes in a {regular graph} of
+ {degree} d>2 and {diameter} k:
+
+ N(d,k) <= d(d-1)^k - 2
+ ------------
+ d-2
+
+Moore graph
+
+ A {graph} which achieves the {Moore bound}. These are
+ {complete graphs}, {polygon graphs} ({regular graphs} of
+ {degree} 2) and three others: (nodes, degree, diameter) =
+ (10,3,2), (50,7,2) and the possible but undiscovered
+ (3250,57,2).
+
+Moore's Law
+
+ <architecture> /morz law/ The observation, made in 1965 by
+ {Intel} co-founder {Gordon Moore} while preparing a speech,
+ that each new memory {integrated circuit} contained roughly
+ twice as much capacity as its predecessor, and each chip was
+ released within 18-24 months of the previous chip. If this
+ trend continued, he reasoned, computing power would rise
+ exponentially with time.
+
+ Moore's observation still holds in 1997 and is the basis for
+ many performance forecasts. In 24 years the number of
+ {transistors} on processor chips has increased by a factor of
+ almost 2400, from 2300 on the {Intel 4004} in 1971 to 5.5
+ million on the {Pentium Pro} in 1995 (doubling roughly every
+ two years).
+
+ Date Chip Transistors MIPS clock/MHz
+ -----------------------------------------------
+ Nov 1971 4004 2300 0.06 0.108
+ Apr 1974 8080 6000 0.64 2
+ Jun 1978 8086 29000 0.75 10
+ Feb 1982 80286 134000 2.66 12
+ Oct 1985 386DX 275000 5 16
+ Apr 1989 80486 1200000 20 25
+ Mar 1993 Pentium 3100000 112 66
+ Nov 1995 Pentium Pro 5500000 428 200
+ -----------------------------------------------
+
+ Moore's Law has been (mis)interpreted to mean many things over
+ the years. In particular, {microprocessor} performance has
+ increased faster than the number of transistors per chip. The
+ number of {MIPS} has, on average, doubled every 1.8 years for
+ the past 25 years, or every 1.6 years for the last 10 years.
+ While more recent processors have had wider {data paths},
+ which would correspond to an increase in transistor count,
+ their performance has also increased due to increased {clock
+ rates}.
+
+ Chip density in transistors per unit area has increased less
+ quickly - a factor of only 146 between the 4004 (12 mm^2) and
+ the Pentium Pro (196 mm^2) (doubling every 3.3 years).
+ {Feature size} has decreased from 10 to 0.35 microns which
+ would give over 800 times as many transistors per unit.
+ However, the automatic layout required to cope with the
+ increased complexity is less efficient than the hand layout
+ used for early processors.
+
+ {(http://intel.com/intel/museum/25anniv/html/hof/moore.htm)}.
+
+ {Intel Microprocessor Quick Reference Guide
+ (http://intel.com/pressroom/no_frame/quickref.htm)}.
+
+ {"Birth of a Chip", Linley Gwennap, Byte, Dec 1996
+ (http://byte.com/art/9612/sec6/art2.htm)}. See also March
+ 1997 "inbox".
+
+ {Chronology of Events in the History of Microcomputers
+ (http://islandnet.com/~kpolsson/comphist.htm)}, Ken
+ Polsson.
+
+ See also {Parkinson's Law of Data}.
+
+ [{Jargon File}]
+
+ (1997-03-04)
+
+moose call
+
+ {whalesong}
+
+MooZ
+
+ <language, specification> An {object-oriented} extension of
+ {Z}.
+
+ ["Object Orientation in Z", S. Stepney et al eds, Springer
+ 1992].
+
+ (1997-07-09)
+
+Mops
+
+ Like {Yerk}, Mops is descended from the ex-commercial
+ {object-oriented} language {Neon}. It was developed by
+ Michael Hore <mikeh@kralizec.zeta.org.au>. Mops features an
+ optimising {native}-code compiler; it is much faster than
+ Yerk, but less compatible with Neon. Mops includes extensions
+ such as {multiple inheritance}.
+
+ Version 2.3.1 includes a compiler, documentation and an
+ editor.
+
+ A {Macintosh} version is available.
+ {(ftp://oddjob.uchicago.edu/pub/Yerk)}.
+
+MORAL
+
+ Mentioned in "An Overview of Ada", J.G.P. Barnes, Soft Prac &
+ Exp 10:851-887 (1980).
+
+more
+
+ <tool> The standard {Unix} {pager} program.
+
+ See also: {less}.
+
+ (2008-09-08)
+
+moria
+
+ <games> /mor'ee-*/ Like {nethack} and {rogue}, one of the
+ large {PD} {Dungeons and Dragons}-like simulation games,
+ available for a wide range of machines and operating systems.
+ The name is from Tolkien's Mines of Moria; compare {elder
+ days}, {elvish}. The game is extremely addictive and a major
+ consumer of time better used for hacking.
+
+ [{Jargon File}]
+
+morphing
+
+ <graphics> The animated transformation of one image into
+ another by gradually distorting the first image so as to move
+ certain chosen points to the position of corresponding points
+ in the second image.
+
+ Compare {tweening}.
+
+ (1995-04-03)
+
+Morse code
+
+ <communications> A coding system invented by Samuel A. Morse,
+ for use in sending character data over extremely low-quality
+ pathways -- such as telegraphs and low-quality radio. Morse
+ code expresses characters as pulses of different durations.
+ Short signals are called "dots" and long signals are calles
+ "dashes". The coding assigns shorter sequences to the most
+ frequently used characters.
+
+ American Morse code is the first and original Morse code
+ {character set}. {Character sets} adapted to other languages
+ were developed later.
+
+ American Morse Code:
+
+ A . __ J . . S . . . 1 . __ __ .
+ B __ . . . K __ . __ T __ 2 . . __ . .
+ C . . . L ___ U . . __ 3 . . . __ .
+ D __ . . M __ __ V . . . __ 4 . . . . __
+ E . N __ . W . __ __ 5 __ __ __
+ F . __ . O . . X . __ . . 6 . . . . . .
+ G __ __ . P . . . . . Y . . . . 7 __ __ . .
+ H . . . . Q . . __ . Z . . . . 8 __ . . . .
+ I . . R . . . 0 ____ 9 __ . . __
+
+ Where . is a short pulse, __ a long pulse, ___ a very long
+ pulse and ____ a extra long pulse. There are also long and
+ short spaces character-internal. Intercharacter spaces are
+ very long and interword spaces are extra long. There is no
+ standarisation in these durations, and they vary depending on
+ the coder's preference and on the quality of the line.
+
+ Continental Morse Code or International Morse Code is a widely
+ used {de-facto standard}. This table summarises the Western
+ European usage of Continental Morse Code:
+
+ A .- G --. M -- S ... Y -.-- 4 ....-
+ B -... H .... N -. T - Z --.. 5 .....
+ C -.-. I .. O --- U ..- 0 ----- 6 -....
+ D -.. J .--- P .--. V ...- 1 .---- 7 --...
+ E . K -.- Q --.- W .-- 2 ..--- 8 ---..
+ F ..-. L .-.. R .-. X -..- 3 ...-- 9 ----.
+
+ A-umlaut (1) .-.- E-acute ..-..
+ A-acute .--.- N-tilde --.--
+ A-corona (11) .--.- O-umlaut (1) ---.
+ CH (2) ---- U-umlaut (1) ..--
+
+ Punctuation Marks: Other Signs:
+
+ period .-.-.- warning .-..-
+ comma --..-- error ........
+ question mark ..--.. repetition (ii ii) .. ..
+ hyphen -....- wait (AS) .-...
+ colon (3) ---... interruption (BK) -...-.-
+ underline (4) ..--.- understood (VE) ...-.
+ apostrophe .----. transmission received (R) .-.
+ quotation mark .-..-. beginning of message (KA) -.-.-
+ parenthesis open (5)-.--. end of message (AR) .-.-.
+ parenthesis (close) -.--.- end of transmission (K) (6) -.-
+ equal sign (7) -...- end of transmission (KN) (8) -.--.
+ plus sign .-.-. closing mark (SK) (9) ...-.-
+ multiplication sign -..- closing station (CL) -.-..-.
+ fraction mark -..-.
+ separator (10) .-..-
+
+ (1) Note: 'umlaut' is also known as 'diaeresis'
+ (2) Used only in German; not in Dutch.
+ (3) also: 'divided by'
+ (4) before and after the word to be underlined
+ (5) purportedly replaced by -.--.- for both "(" and ")"
+ (6) both and invitation to any station to start transmission
+ (7) also used as spacing between parts of transmission
+ (8) also an invitation to one station in particular to start
+ transmission
+ (9) connection will be closed.
+ (10) in fractions, for example.
+ (11) A-ring ?
+
+ Where '.' is a short pulse, '-' a long one. A '-' is three
+ times as long as a '.'; character-internal spaces are as long
+ as '.'s. Intercharacter space are as long as -'s. Spaces
+ between words are as long as seven '.'s.
+
+ (1996-11-23)
+
+MORTRAN
+
+ A {public domain} {Fortran} {preprocessor} for {structured
+ programming}.
+
+ (1995-09-20)
+
+MOS
+
+ {Metal Oxide Semiconductor}
+
+Mosaic
+
+ <web, tool> {NCSA}'s {browser} ({client}) for the
+ {web}.
+
+ Mosaic has been described as "the killer application of the
+ 1990s" because it was the first program to provide a slick
+ {multimedia} {graphical user interface} to the {Internet}'s
+ burgeoning wealth of distributed information services
+ (formerly mostly limited to {FTP} and {Gopher}) at a time when
+ access to the {Internet} was expanding rapidly outside its
+ previous domain of academia and large industrial research
+ institutions.
+
+ NCSA Mosaic was originally designed and programmed for the {X
+ Window System} by Marc Andreessen and Eric Bina at NCSA.
+ Version 1.0 was released in April 1993, followed by two
+ maintenance releases during summer 1993. Version 2.0 was
+ released in December 1993, along with version 1.0 releases for
+ both the {Apple Macintosh} and {Microsoft Windows}. An
+ {Acorn Archimedes} port is underway (May 1994).
+
+ Marc Andreessen, who created the NCSA Mosaic research
+ prototype as an undergraduate student at the {University of
+ Illinois} left to start {Mosaic Communications Corporation}
+ along with five other former students and staff of the
+ university who were instrumental in NCSA Mosaic's design and
+ development.
+
+ {(http://ncsa.uiuc.edu/SDG/Software/Mosaic/Docs/help-about.html)}.
+
+ {(ftp://ftp.ncsa.uiuc.edu/)}.
+
+ E-mail: <mosaic-x@ncsa.uiuc.edu> (X version),
+ <mosaic-mac@ncsa.uiuc.edu> (Macintosh), <mosaic-win@ncsa.uiuc.edu>
+ (Windows version), <mosaic@ncsa.uiuc.edu> (general help).
+
+ (1995-04-06)
+
+Mosaic Communications Corporation
+
+ {Netscape Communications Corporation}
+
+Moscow ML
+
+ A light-weight implementation of {Standard ML} written by
+ Sergei Romanenko <sergei-romanenko@refal.msk.su> of the
+ {Keldysh Institute of Applied Mathematics} with assistance
+ from Peter Sestoft <sestoft@dina.kvl.dk>, {Royal Veterinary
+ and Agricultural University}. Moscow ML is based on {CAML
+ Light}.
+
+ Version: 1.20 implements the Standard ML Core language.
+
+ The sublanguage of Modules implemented by Moscow ML contains
+ signatures and non-nested structures, and identifies
+ structures with source files. It is certainly less expressive
+ than the full Standard ML Modules language, but the
+ {type-safe} {separate compilation} facility is simple, useful,
+ and easy to use. It is the intention to implement the full
+ Standard ML Modules language (including functors) in due
+ course.
+
+ Compilation of a {signature} produces a compiled interface
+ file, which is used when compiling other signatures and
+ structures.
+
+ Compilation of a structure produces a {bytecode} file.
+ Bytecode files are compact and load fast. For instance, a
+ 3250-line program consisting of 24 structures and 17
+ signatures compiles to 221 KB of bytecode and 241 KB of
+ compiled signatures. Starting the ML system and loading the
+ 24 bytecode files takes 1-2 cpu seconds plus network delays,
+ less that 5 seconds real time in all.
+
+ Release 1.20 permits loading of precompiled bytecode files
+ into the top-level interactive session. The next release will
+ be able to create stand-alone executables by linking bytecode
+ files.
+
+ There is a mechanism for adding basis libraries, as in {Caml
+ Light}. Release 1.20 includes the basis libraries Array,
+ List, and Vector and the {MS-DOS} version includes the
+ Graphics library from {Caml Light}.
+
+ In principle, Moscow ML can be compiled on any {platform}
+ supported by {Caml Light}. So far we have tried {Intel
+ 80386}-based {IBM PCs} running {MS-DOS}, {Microsoft Windows},
+ {OS/2} or {Linux}, {DEC MIPS} running {Ultrix}, {DEC Alpha}
+ running {OSF/1}, {Sun-4} running {SunOS}, {HP9000} running
+ {HP/UX}, {SGI MIPS} running {IRIX} 5.
+
+ Moscow ML is particularly useful when fast compilation and
+ modest storage consumption are more important than fast
+ program execution.
+
+ Thanks to the efficient Caml Light run-time system used in
+ Moscow ML, it compiles fast and uses little memory, typically
+ 5-10 times less memory than {SML/NJ} 0.93 and 2-3 times less
+ than {Edinburgh ML}. Yet the bytecode is only 3 to 10 times
+ slower than SML/NJ 0.93 compiled native code (fast on {IBM
+ PCs}, slower on {RISCs}).
+
+ {DOS
+ (ftp://dina.kvl.dk/pub/Peter.Sestoft/mosml/mos12bin.zip)}.
+ {Linux
+ (ftp://dina.kvl.dk:pub/Peter.Sestoft/mosml/linux-mos12bin.tar.gz)}.
+ {Source
+ (ftp://dina.kvl.dk:pub/Peter.Sestoft/mosml/mos12src.tar.gz)}.
+
+ {Caml Light} 0.61 and {gcc} are required to recompile Moscow
+ ML for {Unix} or Caml Light 0.61, {djgpp}, {Perl}, and
+ {Borland C++} version 2.0 (or later) to recompile Moscow ML
+ for {DOS}.
+
+ (1994-12-12)
+
+MOSFET
+
+ {Metal Oxide Semiconductor Field-Effect Transistor}
+
+Mosiac
+
+ Do you mean {Mosaic}?
+
+MOS Technologies
+
+ {MOS Technology}
+
+MOS Technology
+
+ <company> A {microprocessor} design company started by some
+ ex-{Motorola} designers, shortly after the {Intel 8080} and
+ {Motorola 6800} appeared, in about 1975. MOS Technology
+ introduced the {650x} series, based on the {Motorola 6800}
+ design, though they were not exact clones for legal reasons.
+
+ The design goal was a low-cost (smaler chip) design, realized
+ by simplifying the decoder stage. There were no instructions
+ with the value xxxxxx11, reducing the 1-of-4 decoder to a
+ single {NAND} gate. Instructions with the value xxxxxx11
+ actually executed two instructions in paralell, some of them
+ useful.
+
+ The 6501 was pin-compatible with the 6800 for easier market
+ penetration. The 650x-series had an on-chip clock oscillator
+ while the 651x-series had none.
+
+ The 6510 was used in the {Commodore 64}, released September
+ 1981 and MOS made almost all the ICs for Commodore's {pocket
+ calculators}.
+
+ The {PET} was an idea of the of the 6500 developers. It was
+ completly developed by MOS, but was manufactured and marketed
+ by Commodore. By the time the it was ready for production
+ (and Commodore had cancelled all orders) MOS had been taken
+ over by {Rockwell} (Commodore's parent company). Just at this
+ time the 6522 (VIA) was finished, but the data sheet for it
+ was not and its developers had left MOS. For years, Rockwell
+ didn't know in detail how the VIA worked.
+
+ (2001-03-31)
+
+most general unifier
+
+ <logic> If U is the most general {unifier} of a set of
+ expressions then any other unifier, V, can be expressed as V =
+ UW, where W is another substitution.
+
+ See also {unification}.
+
+ (2000-03-07)
+
+Most Significant Bit
+
+ (MSB) {Bit} n-1 in an n bit {binary} number, the bit with the
+ greatest weight (2^(n-1)). The first or leftmost bit when the
+ number is written in the usual way.
+
+ (1995-07-13)
+
+motd
+
+ {message of the day}
+
+mother
+
+ {parent}
+
+motherboard
+
+ <hardware> (mobo) The main {printed circuit board} in an
+ electronic device, particularly a computer, which may contain
+ sockets that accept additional boards ("daughter-boards").
+
+ In a {personal computer}, the motherboard contains the {bus},
+ the {microprocessor}, and {integrated circuits} used for
+ controlling any built-in {peripherals} such as the {keyboard},
+ text and graphics display, {serial ports} and {parallel
+ ports}, {joystick}, and {mouse} {interfaces}.
+
+ (2000-08-10)
+
+Motif
+
+ The standard {graphical user interface} and {window manager}
+ from {OSF}, running on the {X Window System}.
+
+Motion JPEG
+
+ {Moving JPEG}
+
+Motion Picture Experts Group
+
+ <spelling> Incorrect expansion of MPEG, which stands for
+ {Moving Picture Experts Group}.
+
+ (2000-05-31)
+
+Motorola
+
+ {Motorola, Inc.}
+
+Motorola 14500B
+
+ <processor> (MC14500B) A 1-bit {ICU} from {Motorola}.
+ Probably the limit in small processors, the 14500B had a 4-bit
+ instruction and controlled a single data read/write line, used
+ for application control. It had no address bus - that was an
+ external unit that was added on. Another {CPU} could be used
+ to feed control instructions to the 14500B in an application.
+ It had only 16 pins, less than a typical {RAM} chip, and ran
+ at 1 {MHz}.
+
+ (1994-11-30)
+
+Motorola 6800
+
+ <processor> A {microprocessor} released shortly after the
+ {Intel 8080}, in about 1975. It had 78 instructions,
+ including the undocumented HCF ({Halt and Catch Fire}) bus
+ test instruction. The 6800 evolved into the {Motorola 6801}
+ and 6803.
+
+ The {6502} was based on the design of the 6800 but had one
+ less data register and one more {index register}.
+
+ (1994-10-31)
+
+Motorola 68000
+
+ <processor> (MC68000) The first member of {Motorola, Inc.}'s
+ family of 16- and 32-bit {microprocessors}. The successor to
+ the {Motorola 6809} and followed by the {Motorola 68010}.
+
+ The 68000 has 32-bit registers but only a 16-bit {ALU} and
+ external {data bus}. It has 24-bit addressing and a {linear
+ address space}, with none of the evil {segment registers} of
+ {Intel}'s contemporary processors that make programming them
+ unpleasant. That means that a single directly accessed
+ {array} or structure can be larger than 64KB in size.
+ Addresses are computed as 32 bit, but the top 8 bits are cut
+ to fit the address bus into a 64-pin package (address and data
+ share a bus in the 40 pin packages of the {8086} and {Zilog
+ Z8000}).
+
+ The 68000 has sixteen 32-bit {registers}, split into data and
+ address registers. One address register is reserved for the
+ {Stack Pointer}. Any register, of either type, can be used
+ for any function except direct addressing. Only address
+ registers can be used as the source of an address, but data
+ registers can provide the offset from an address.
+
+ Like the {Zilog Z8000}, the 68000 features a supervisor and
+ user mode, each with its own {Stack Pointer}. The {Zilog
+ Z8000} and 68000 are similar in capabilities, but the 68000 is
+ 32 bits internally, making it faster and eliminating forced
+ segmentations.
+
+ Like many other CPUs of its generation, it can fetch the next
+ instruction during execution (2 stage {pipeline}).
+
+ The 68000 was used in many {workstations}, notably early
+ {Sun-2} machines, and {personal computers}, notably {Apple
+ Computer}'s first {Macintoshes} and the {Amiga}. It was also
+ used in most of {Sega}'s early arcade machines, and in the
+ {Genesis}/{Megadrive} consoles.
+
+ Variants of the 68000 include the {68HC000} (a low-power HCMOS
+ implementation) and the {68008} (an eight-bit data bus version
+ used in the {Sinclair QL}).
+
+ ["The 68000: Principles and Programming", Leo Scanlon, 1981].
+
+ (2003-07-11)
+
+Motorola 6801
+
+ <processor> (And 6803) A version of the {Motorola 6800} with
+ {ROM}, some {RAM}, a serial I/O port and other functions on
+ the chip. It was meant for embedded controllers, where the
+ part count was to be minimised. The 6803 led to the 68HC11
+ and that was extended to 16 bits as the 68HC16.
+
+ (1994-11-07)
+
+Motorola 68010
+
+ <processor> A {microprocessor} from {Motorola}. It was the
+ successor to the {Motorola 68000} and was followed by the
+ {Motorola 68020}. Some instructions which were previously
+ {user mode} were made {system mode}, which necessitated
+ patches to a few programs.
+
+ The 68010's main advantage over the 68000 was that it could
+ recover from a {bus fault}. The 68000 {microcode} didn't save
+ enough state to restart all instructions; the 68010 corrected
+ this fault. This allowed it to use {paged virtual memory}.
+
+ The 68010's DBxx (decrement and branch) instructions could
+ hold and execute the preceding instruction in the {prefetch
+ buffer}, allowing some two-instruction loops to execute
+ without refetching instructions.
+
+ At one time there was a 68010 variant that was pin-for-pin
+ compatible with the 68000. Early {Amiga} hackers replaced
+ their 68000s with 68010s in order to get a small performance
+ increase.
+
+ (1995-11-29)
+
+Motorola 68020
+
+ <processor> A {microprocessor} from {Motorola}. It was the
+ successor to the {Motorola 68010} and was followed by the
+ {Motorola 68030}. The 68020 has 32-bit internal and external
+ data and address buses and a 256-byte {instruction buffer},
+ arranged as 64 {direct-mapped} 4-byte entries[?].
+
+ The 68020 added many improvements to the 68010 including a
+ 32-bit {ALU} and external {data bus} and {address bus}, and
+ new instrucitons and {addressing modes}. The 68020 (and
+ 68030) had a proper three-stage {pipeline}.
+
+ The new instructions included some minor improvements and
+ extensions to the supervisor state, some support for
+ {high-level languages} which didn't get used much (and was
+ removed from future 680x0 processors[?]), bigger (32 x 32-bit)
+ multiply and divide instructions, and bit field manipulations.
+
+ The new adderessing modes added another level of indirection
+ to many of the pre-existing modes, and added quite a bit of
+ flexibility to various indexing modes and operations.
+
+ The {instruction buffer} (an {instruction cache}) was 256
+ bytes, arranged as 64 direct-mapped 4-byte entries. Although
+ small, it made a significant difference in the performance of
+ many applications.
+
+ The 68881 and the faster 68882 {FPU} chips could be used with
+ the 68020.
+
+ The 68020 was used in many models of the {Apple Macintosh} II
+ series of {personal computers} and {Sun} 3 {workstations}.
+
+ (2001-03-07)
+
+Motorola 68030
+
+ <processor> A 32-bit {microprocessor} in {Motorola}'s
+ {Motorola 68000} family, with on-chip split instruction and
+ data {cache} of 256 {bytes} each. The 68030 has an on-chip
+ {MMU} (except in the 680EC30 version).
+
+ The 68881 and the faster 68882 {FPU} chips could be used with
+ the 68030.
+
+ The 68030 was the successor to the {Motorola 68020}, and was
+ followed by the {Motorola 68040}.
+
+ The 68030 is used in many models of the {Apple Macintosh} II
+ series of {personal computers}.
+
+ (2001-01-08)
+
+Motorola 68040
+
+ <processor> (MC68040) A {microprocessor} from {Motorola}. It
+ was the successor to the {Motorola 68030} and was followed by
+ the {Motorola 68060}.
+
+ The 68040 was the first {680x0} family member with an on-chip
+ {FPU}. It also had split instruction and data {caches} of 4
+ kilobytes(?) each. It was fully {pipelined}, with six stages.
+
+ The 68040 was used in the {Apple Macintosh} Quadra series of
+ {personal computers}.
+
+ The MC68LC040 is an MC68040 without a built-in {FPU}, and the
+ MC68EC040 is an MC68040 without an {MMU} or {FPU}.
+
+ (2003-10-25)
+
+Motorola 68050
+
+ There was no 68050. The successor to the {Motorola 68040} was
+ the {Motorola 68060}.
+
+ The even numbers (68000, 68020, 68060) were reserved for major
+ revisions to the 680x0 core. The odd numbers (68010, 68030,
+ 68050) were minor upgrades from the previous chip. For
+ example, the {Motorola 68010} was a {Motorola 68000} with some
+ minor enhancements and modifications to some user/superuser
+ instruction assignments. The {Motorola 68030} was a {Motorola
+ 68020} with an {MMU} and more minor enhancements. The 68050
+ would have been a 68040 with some bugs fixed, which didn't
+ really warrant a new name so it was sold as a 68040.
+
+ (1995-11-29)
+
+Motorola 68060
+
+ <processor> A 32-bit {microprocessor} from {Motorola}, the
+ successor to the {Motorola 68040}. The 68060 is the highest
+ performance {680x0} family processor currently (April 1995)
+ available. It has 2 to 3 times the performance of the
+ 68040.
+
+ The 68060 is probably the last development from Motorola in
+ the high performacnce 680x0 series. They don't want to
+ compete with their own {PowerPC} chips. The 680x0 series is
+ intended more for embedded systems, where it is already very
+ popular. New developments here seem to integrate more
+ peripheral functions on chip rather than increasing processing
+ power.
+
+ (1995-04-22)
+
+Motorola 6809
+
+ <processor> (MC6809) An eight-bit {microprocessor} from {Motorola,
+ Inc.}.
+
+ The 6809 was a major advance over both its predecessor, the
+ {Motorola 6800} and the {6502}. The 6809 had two 8-bit
+ {accumulators}, rather than one in the 6502, and could combine
+ them into a single 16-bit register. It also featured two {index
+ registers} and two {stack pointers}, which allowed for some very
+ advanced {addressing modes}. The 6809 was {source compatible}
+ with the 6800, even though the 6800 had 78 instructions and the
+ 6809 only had around 59 (including a {SEX} instruction). Some
+ instructions were replaced by more general ones which the
+ {assembler} would translate and some were replaced by {addressing
+ modes}.
+
+ The 6809 had one of the first multiplication instructions of the
+ time, 16-bit arithmetic and a special fast {interrupt}. But it
+ was also highly optimised, gaining up to five times the speed of
+ the 6800 series CPU. Like the 6800, it included the undocumented
+ HCF ({Halt and Catch Fire}) bus test instruction.
+
+ The {Hitachi 6309} was a version with extra {registers}. The
+ 6809 was used in the UK "{Dragon 32}" {personal computer} and
+ was followed by the {Motorola 68000}.
+
+ {Usenet} newsgroup: {news:comp.sys.m6809}.
+
+ Lennart Benschop <lennart@blade.stack.urc.tue.nl> posted a
+ {emulator} (originally called "usim") and a {cross-assembler} to
+ {Usenet} newsgroup {alt.sources} on 1993-11-03. Ray P. Bellis
+ <rpb@psy.ox.ac.uk> released a version 0.11.
+
+ {Benschop emulator (http://lennartb.home.xs4all.nl/m6809.html)}.
+
+ (2014-06-24)
+
+Motorola 680x0
+
+ <processor> Shorthand for any member for the {Motorola 68000}
+ family of {microprocessors} from {Motorola, Inc.} The "x"
+ stands for 0, 1, 2, 3, 4 or 6.
+
+ (1993-05-01)
+
+Motorola 68HC11
+
+ <processor> A {microcontroller} family from {Motorola}
+ descended from the {Motorola 6800} {microprocessor}.
+
+ The 68HC11 devices are more powerful and more expensive than
+ the 68HC05 family.
+
+ {FAQ
+ (ftp://src.doc.ic.ac.uk/usenet/usenet-by-group/comp.answers/microcontroller-faq/68hc11)}.
+
+ There is an {opcode} simulator for the 68HC11, by Ted Dunning
+ <ted@nmsu.edu>. Interrupts, hardware I/O, and half carries
+ are still outside the loop. Adding interrupts may require
+ simulating at the clock phase level. Version 1.
+
+ {(ftp://crl.nmsu.edu/pub/non-lexical/6811/sim6811.shar)}.
+
+ (1995-04-28)
+
+Motorola 68LC040
+
+ <processor> A version of the {Motorola 68040} with no {MMU} or
+ {FPU}, making it more like an enhanced {Motorola 68020}.
+
+ A {Power Macintosh} can emulate a Motorola 68LC040.
+
+ (1999-01-11)
+
+Motorola 88000
+
+ A family of {RISC} {microprocessors} from {Motorola}.
+
+ [Details?]
+
+ (1995-03-01)
+
+Motorola, Inc.
+
+ <company> One of the world's leading providers of wireless
+ communications, semiconductors and advanced electronic systems
+ and services. Major equipment businesses include cellular
+ telephone, two-way radio, paging and data communications,
+ personal communications, automotive, defense and space
+ electronics, computers, satellite communications systems,
+ police and emergency service radio systems, taxicab
+ dispatching (radio) systems. Communication devices, computers
+ and millions of consumer products are powered by Motorola
+ semiconductors.
+
+ They are probably best known in the computing world for their
+ {microprocessors}, including the {Motorola 6800} and {Motorola
+ 68000} {CISC} families and {Motorola 88000} {RISCs}, the
+ {Motorola DSP56000} {digital signal processors} and the
+ {PowerPC} on which they collaborated. They also led the
+ development of {VMEbus}.
+
+ Quarterly sales $5400M, profits $367M (Aug 1994).
+
+ See also {Envoy}, {Monsoon}, {MPL}.
+
+ {(http://mot.com/)}.
+
+ Address: Schaumberg, Illinois, USA.
+
+ (1994-12-01)
+
+mount
+
+ <file system> To make a {file system} available for access.
+
+ {Unix} does this by associating the file system with a
+ {directory} (the "mount point") within a currently mounted
+ file system. The "root" file system is mounted on the {root
+ directory}, "/" early in the {boot} sequence. "mount" is also
+ the {Unix} command to do this, "unmount" breaks the
+ association.
+
+ E.g., "mount attaches a named file system to the file system
+ hierarchy at the pathname location directory [...]" -- {Unix
+ manual page} mount(8).
+
+ File systems are usually mounted either at {boot time} under
+ control of {/etc/rc} (or one of its subfiles) or on demand by
+ an {automounter} {daemon}.
+
+ Other {operating systems} such as {VMS} and {DOS} mount file
+ systems as separate directory hierarchies without any common
+ ancestor or root directory.
+
+ Apparently derived from the physical sense of "mount" meaning
+ "attach", as in "head-mounted display", or "set up", as in
+ "always mount a {scratch monkey}, etc."
+
+ {Unix manual page}: mount(8).
+
+ (1997-04-14)
+
+Mouse
+
+ A mighty small {macro} language developed by Peter Grogono in
+ 1975.
+
+ ["Mouse, A Language for Microcomputers", P. Grogono
+ <grogono@concour.cs.concordia.ca> Petrocelli Books, 1983].
+
+ (1994-10-31)
+
+mouse
+
+ <hardware, graphics> The most commonly used computer {pointing
+ device}, first introduced by {Douglas Engelbart} in 1968.
+ The mouse is a device used to manipulate an on-screen
+ {pointer} that's normally shaped like an arrow. With the
+ mouse in hand, the computer user can select, move, and change
+ items on the screen.
+
+ A conventional {roller-ball mouse} is slid across the surface
+ of the desk, often on a {mouse mat}. As the mouse moves, a
+ ball set in a depression on the underside of the mouse rolls
+ accordingly. The ball is also in contact with two small
+ shafts set at right angles to each other inside the mouse.
+ The rotating ball turns the shafts, and sensors inside the
+ mouse measure the shafts' rotation. The distance and
+ direction information from the sensors is then transmitted to
+ the computer, usually through a connecting wire - the mouse's
+ "tail". The computer then moves the mouse pointer on the
+ screen to follow the movements of the mouse. This may be done
+ directly by the {graphics adaptor}, but where it involves the
+ processor the task should be assigned a high {priority} to
+ avoid any perceptible delay.
+
+ Some mice are contoured to fit the shape of a person's right
+ hand, and some come in left-handed versions. Other mice are
+ symmetrical.
+
+ Included on the mouse are usually two or three buttons that
+ the user may press, or click, to initiate various actions such
+ as running {programs} or opening {files}. The left-most
+ button (the {primary mouse button}) is operated with the index
+ finger to select and activate objects represented on the
+ screen. Different {operating systems} and {graphical user
+ interfaces} have different conventions for using the other
+ button(s). Typical operations include calling up a
+ {context-sensitive menu}, modifying the selection, or pasting
+ text. With fewer mouse buttons these require combinations of
+ mouse and keyboard actions. Between its left and right
+ buttons, a mouse may also have a wheel that can be used for
+ scrolling or other special operations defined by the software.
+ Some systems allow the mouse button assignments to be swapped
+ round for left-handed users.
+
+ Just moving the pointer across the screen with the mouse
+ typically does nothing (though some CAD systems respond to
+ patterns of mouse movement with no buttons pressed).
+ Normally, the pointer is positioned over something on the
+ screen (an {icon} or a {menu} item), and the user then clicks
+ a mouse button to actually affect the screen display.
+
+ The five most common "gestures" performed with the mouse are:
+ {point} (to place the pointer over an on-screen item), {click}
+ (to press and release a mouse button), {double-click} {to
+ press and release a mouse button twice in rapid succession},
+ {right-click} (to press and release the right mouse button},
+ and {drag} (to hold down the mouse button while moving the
+ mouse).
+
+ Most modern computers include a mouse as standard equipment.
+ However, some systems, especially portable {laptop} and
+ {notebook} models, may have a {trackball}, {touchpad} or
+ {Trackpoint} on or next to the {keyboard}. These input
+ devices work like the mouse, but take less space and don't
+ need a desk.
+
+ Many other alternatives to the conventional roller-ball mouse
+ exist. A {tailless mouse}, or {hamster}, transmits its
+ information with {infrared} impulses. A {foot-controlled
+ mouse (http://footmouse.com/)} is one used on the floor
+ underneath the desk. An {optical mouse} uses a
+ {light-emitting diode} and {photocells} instead of a rolling
+ ball to track its position. Some optical designs may require
+ a special mouse mat marked with a grid, others, like the
+ Microsoft IntelliMouse Explorer, work on nearly any surface.
+
+ {Yahoo!
+ (http://dir.yahoo.com/Business_and_Economy/Companies/Computers/Hardware/Peripherals/Input_Devices/Mice/)}.
+
+ {(http://peripherals.about.com/library/weekly/aa041498.htm)}.
+
+ {PC Guide's "Troubleshooting Mice"
+ (http://pcguide.com/ts/x/comp/mice.htm)}.
+
+ (1999-07-21)
+
+mouse ahead
+
+ The {point-and-click} analog of "{type ahead}". To manipulate
+ a computer's pointing device (almost always a mouse in this
+ usage, but not necessarily) and its selection or command
+ buttons before a computer program is ready to accept such
+ input, in anticipation of the program accepting the input.
+ Handling this properly is rare, but it can help make a {WIMP
+ environment} much more usable, assuming the users are familiar
+ with the behaviour of the user interface.
+
+ [{Jargon File}]
+
+ (1994-12-05)
+
+mouse around
+
+ To explore public portions of a large system, especially a
+ network such as Internet via {FTP} or {TELNET}, looking for
+ interesting stuff to {snarf}.
+
+ [{Jargon File}]
+
+ (1994-12-05)
+
+mouse arrest
+
+ <jargon> Getting busted for violating an on-line service's rule
+ of conduct. "Sorry I couldn't get back to you. {AOL} put me
+ under mouse arrest."
+
+ (1997-03-30)
+
+mouse belt
+
+ {rat belt}
+
+mouse droppings
+
+ 1. <graphics, operating system, jargon> {Pixels} (usually
+ single) that are not properly restored when the {mouse
+ pointer} moves away from a particular location on the screen,
+ producing the appearance that the mouse pointer has left
+ droppings behind. The major causes for this problem are
+ {MS-DOS} programs that write to the screen memory
+ corresponding to the mouse pointer's current location without
+ hiding the mouse pointer first, and mouse drivers that do not
+ quite support the {graphics mode} in use.
+
+ 2. <web, jargon> The client address recorded in a
+ {web} server's log whenever a client connects to a
+ site.
+
+ Users may be unaware that their activity is being logged in
+ this way but the potential for misuse of the information is
+ limited.
+
+ [March 1996 Macworld, p260, Viewpoint article by Larry Irving].
+
+ (1994-12-05)
+
+mouse elbow
+
+ <jargon, medical> A tennis-elbow-like fatigue syndrome
+ resulting from excessive use of a {WIMP}. Similarly, "mouse
+ shoulder". {GLS} reports that he used to get this a lot
+ before he taught himself to be ambimoustrous.
+
+ [{Jargon File}]
+
+ (1994-12-05)
+
+mouse mat
+
+ <hardware> (U.S.: "mouse pad") A small sheet with a special
+ surface for a rolling ball {mouse} to move on. Most mouse
+ mats are sheets of rubber or foam about 20cm by 25cm and about
+ 5mm thick with one side covered with cloth or sometimes hard
+ plastic. Deluxe versions come combined with a {wrist rest}.
+
+ It is rare to find a mouse mat which does not carry some form
+ of advertisement for some company or other. They are such a
+ common free gift that few people actually have to buy one.
+
+ Mats are supposed to provide better traction and a clean,
+ lint-free surface over which to move but it debatable whether
+ they are useful at all, or whether any appropriate surface
+ (preferably hard, even, flat, and clean) is as good.
+ Howevever, some mice which use optical (e.g. {Sun}) or
+ radio-frequency sensors (e.g. ?) to detect motion (instead of
+ using a rolling ball) will only work on specially designed
+ mouse mats. Critics may consider this to be part of the
+ {connector conspiracy}, though the designers would claim
+ greater reliability due to the absence of moving parts.
+
+ (1997-04-14)
+
+mouse pad
+
+ {mouse mat}
+
+mouse trails
+
+ <operating system> A feature (usually of {Graphical User
+ Interfaces}) which causes the {mouse} {pointer} to leave a
+ trail across the screen. This is done by keeping track of the
+ last eight or so (maybe configurable) pointer positions, and
+ only erasing the oldest. This means that at any time, there
+ may be up to eight pointers on the screen, but if the mouse is
+ still, they will all be in the same position, and so only one
+ will be visible. When the mouse moves, it appears to leave a
+ trail of pointers behind it, and this can dramatically
+ increase the visibility of the pointer when using {LCD}
+ screens. The older ones had such long {persistence} that a
+ single mouse pointer, when moving, tended to be completely
+ invisible, and on a cluttered screen, was very difficult to
+ find.
+
+ (1996-07-08)
+
+mouso
+
+ <jargon> /mow'soh/ (By analogy with "{typo}") An error in
+ {mouse} usage resulting in an inappropriate selection or
+ graphic garbage on the screen.
+
+ Compare {thinko}.
+
+ [{Jargon File}]
+
+ (1996-04-21)
+
+Moving JPEG
+
+ <graphics, compression> (M-JPEG) A compression technique for
+ moving {images} which applies {JPEG} still image compression
+ to each {frame} of a moving picture sequence.
+
+ Play-back requires a machine capable of decompressing and
+ displaying each JPEG image quickly enough to sustain the
+ required {frame rate} of the picture sequence.
+
+ There is no standard for Moving JPEG as with JPEG, but there
+ are JPEG compression chips (for example see {Zoran
+ (http://zoran.com/)}) which are designed to work at
+ television frame rates and {resolutions}.
+
+ See also {MPEG} and {MPEG2}.
+
+ (1996-12-15)
+
+Moving Picture Expert Group
+
+ <spelling> Incorrect expansion of MPEG, which stands for
+ {Moving Picture Experts Group}.
+
+ (2000-05-31)
+
+Moving Picture Experts Group
+
+ <compression, standard, algorithm, file format, body> (MPEG,
+ ISO/IEC JTC1/SC29 WG11) An {ISO} committee that generates
+ {standards} for digital {video compression} and audio. Also
+ the name of their {algorithms}.
+
+ {MPEG-1} is optimised for {CD-ROM} and is the basis for {MP3}.
+ {MPEG-2} is aimed at {broadcast quality video} for
+ applications such as {digital television} {set-top boxes} and
+ {DVD}. {MPEG-4} is a standard for low {bandwidth} {video
+ telephony} and {multimedia} on the {web}. MPEG-3
+ was merged into MPEG-2.
+
+ {(http://cselt.it/mpeg/)}. {MPEG.org
+ (http://mpeg.org/)}. {MPEG decoder
+ (ftp://toe.cs.berkeley.edu/pub/multimedia/mpeg/)}. {MPEG
+ routines (ftp://ftp.mni.mcgill.ca/pub/mpeg/)}.
+
+ (2000-05-31)
+
+Moving Pictures Experts Group
+
+ <spelling> Incorrect expansion of MPEG, which stands for
+ {Moving Picture Experts Group}.
+
+ (2000-05-31)
+
+Moxie
+
+ <language, music> A language for {real-time} computer music
+ synthesis, written in {XPL}.
+
+ ["Moxie: A Language for Computer Music Performance",
+ D. Collinge, Proc Intl Computer Music Conf, Computer Music
+ Assoc 1984, pp.217-220].
+
+ (1994-12-05)
+
+Mozilla
+
+ <web, open source> The {open source} {web
+ browser}, designed for standards-compliance, performance, and
+ portability, whose development is coordinated by the {Mozilla
+ Foundation}.
+
+ The Mozilla project started in March 1998 when {Netscape
+ Communications Corporation} released the {source code} of
+ {Netscape Communicator}. The now abandoned version based on
+ that code is referred to as "Mozilla Classic". Since then,
+ much has been rewritten, including the layout engine, the
+ networking library, and the front-end.
+
+ Mozilla 1.0 was finally released on 2002-06-05. Much of the
+ code was used to build {Firefox}.
+
+ Although a lot of Mozilla code is under the original Netscape
+ Public License, some parts of the code are under the Mozilla
+ Public License or dual MPL/GPL.
+
+ "Mozilla" was the original project code name for {Netscape
+ Navigator} and, according to some of the documentation, the
+ correct pronunciation of "Netscape".
+
+ [Derived from "{Mosaic} killer/Godzilla"?]
+
+ (2005-01-26)
+
+Mozilla Foundation
+
+ <body, web, open source> The body set up by
+ {Netscape} in January 1998 to coordinate development of the
+ {Mozilla} browser and to provide a point of contact.
+
+ {Mozilla Home (http://mozilla.org/)}.
+
+ (2005-01-26)
+
+Mozilla Public License
+
+ {open source license}
+
+mp
+
+ <networking> The {country code} for the Northern Mariana
+ Islands.
+
+ (1999-01-27)
+
+MP1
+
+ {MPEG-1 audio layer 1}
+
+MP-1
+
+ {Assembly language} for the {MasPar} computer.
+
+ (1994-12-05)
+
+MP2
+
+ {MPEG-1 audio layer 2}
+
+MP3
+
+ {MPEG-1 audio layer 3}
+
+MP3Pro
+
+ <audio, compression> An extention of {MP3} using {SBR},
+ targetting data rates of 64-96 kbps.
+
+ (2001-12-20)
+
+MPC
+
+ 1. <operating system> {Memory Protection Check}.
+
+ [Origin?]
+
+ 2. <computer> {Multimedia Personal Computer}.
+
+ 3. {Multiprocess Communications}.
+
+MPC Level 1 Specification
+
+ <multimedia> The original {Multimedia Personal Computer}
+ specification.
+
+ Minimum requirements are a 16 MHz {386SX} with 2 {megabytes}
+ of {RAM}, a 30 MB {hard disk drive}, and a {CD-ROM} drive with
+ a sustained data transfer rate of 150 KB/s at no more than 40%
+ of {CPU} {bandwidth} and reading at least 16 KB blocks. The
+ maximum average {seek time} is 1 second and the {Mean Time
+ Between Failure} 10000 hours. Capability Mode 1.
+
+ The computer must have 8-bit digital sound and an 8-note
+ synthesizer with {MIDI} playback. Sample rates of 22.05 and
+ 11.025 kHz must be supported by no more than 10% of CPU
+ bandwidth, preferably 44.1 kHz at no more than 15% of CPU
+ bandwidth. The synthesizer must support multi-voice,
+ multi-timbral generation of six simultaneous melody notes and
+ two simultaneous percussive notes with internal mixing
+ capabilities to combine input from three sources and present
+ the output as a stereo, line-level audio signal at the back
+ panel.
+
+ The video display must have a {resolution} of at least 640 x
+ 480 in 16 colours. MIDI, I/O, and joystick ports must be
+ previded.
+
+ Compare {MPC Level 2 Specification}.
+
+ (1997-01-19)
+
+MPC Level 2 Specification
+
+ <multimedia> An improved version of the {MPC Level 1
+ Specification} for {Multimedia Personal Computers}.
+
+ Minimum requirements are a 25 Mhz {486SX} with 4 MB of RAM and
+ a 160 MB {hard disk drive}. The {CD-ROM} drive must support a
+ sustained data transfer rate of 300 KB/s using at most 60% of
+ {CPU} {bandwidth} on 16 KB minimum block read size. Its
+ average {seek time} must be 400 milliseconds maximum.
+ Capability Mode 1, Mode 2 form 1, Mode 2 form 2, Multisession.
+ It must be {CD-ROM XA}-ready.
+
+ The computer must have 16-bit digital sound, an 8-note
+ synthesizer, and {MIDI} playback. A sample rate of 44.1 kHz
+ must be available on stereo channels with more than 15% of CPU
+ bandwidth.
+
+ A video display with a {resolution} of 640 x 480 in 65,536
+ colours, and MIDI, I/O, and joystick ports must be provided.
+
+ (1997-01-19)
+
+MPEG
+
+ {Moving Picture Experts Group}
+
+MPEG-1
+
+ <compression, standard, algorithm, file format> The first
+ {MPEG} format for compressed {video}, optimised for {CD-ROM}.
+ MPEG-1 was designed for the transmission rates of about 1.5
+ {Mbps} achievable with {Video-CD} and {CD-i}.
+
+ It uses {discrete cosine transform} (DCT) and {Huffman coding}
+ to remove spatially redundant data within a frame and
+ block-based {motion compensated prediction} (MCP) to remove
+ data which is temporally redundant between frames. Audio is
+ compressed using {subband encoding}. These {algorithms} allow
+ better than VHS quality video and almost CD quality audio to
+ be compressed onto and streamed off a {single speed} (1x)
+ {CD-ROM} drive.
+
+ MPEG encoding can introduce blockiness, colour bleed and
+ shimmering effects on video and lack of detail and
+ quantisation effects on audio.
+
+ The official name of MPEG-1 is {International Standard}
+ {IS-11172}.
+
+ (1999-01-06)
+
+MPEG-1 audio layer 1
+
+ <audio, compression, algorithm> (MP1) A simple 32-{subband}
+ {audio compressor} using a {floating point} representation for
+ subband samples. Resolution and scale factor are stored for
+ groups of 12 subsamples. MP1 is only used for {Philips} DCC
+ {Digital Compact cassette} with data rates of 384 kbps.
+
+ (2001-12-02)
+
+MPEG-1 audio layer 3
+
+ <music, file format> (MP3) A {digital audio} {compression
+ algorithm} that acheives a compression factor of about twelve
+ while preserving sound quality. It does this by optimising
+ the compression according to the range of sound that people
+ can actually hear. MP3 is currently (July 1999) the most
+ powerful algorithm in a series of audio encoding standards
+ developed under the sponsorship of the {Moving Picture Experts
+ Group} (MPEG) and formalised by the International Organization
+ for Standardization (ISO).
+
+ MP3 is very different from Layer 2, using an additional {MDCT}
+ layer to increase frequency resolution. Its scale factor
+ groups are more optimised for the human ear, and it uses
+ nonlinear {sample quantisation} and {Huffman coding}.
+
+ MP3 files ({filename extension} ".mp3") can be downloaded from
+ many {website}s and can be played using software available for
+ most {operating systems} (also downloadable), e.g. Winamp for
+ {PC}, MacAmp for {Macintosh}, and mpeg123 for {Unix}.
+
+ MP3 files are usually downloaded completely before playing but
+ {streaming} MP3 is also possible. A program called a "ripper"
+ can be used to copy a selection from a music {CD} onto your
+ {hard disk} and another program called an encoder can convert
+ it to an MP3 file.
+
+ (2001-12-04)
+
+MPEG-1 layer 3
+
+ {MPEG-1 audio layer 3}
+
+MPEG-2
+
+ <compression, standard, algorithm, file format> A variant of
+ the {MPEG} video and audio {compression} {algorithm} and file
+ format, optimised for {broadcast quality video}. MPEG-2 was
+ designed to transmit images using {progressive coding} at 4
+ {Mbps} or higher for use in broadcast {digital TV} and {DVD}.
+ An MPEG-2 player can handle {MPEG-1} data as well.
+
+ MPEG-2 has been approved as {International Standard}
+ {IS-13818}.
+
+ (1995-04-18)
+
+MPEG-21
+
+ <compression, standard, algorithm, file format> A {file
+ format} designed to merge very different things in one object,
+ so you can store interactive material in this format (audio,
+ video, questions, answers, overlays, non-linear order,
+ calculation from user inputs, etc.)
+
+ [Technical details?]
+
+ (2001-12-02)
+
+MPEG-2.5 audio layer 3
+
+ <compression, standard, algorithm, file format> A non-standard
+ extention of {MPEG-2 audio layer 3} by {FhG} for lowest
+ sampling rates (8-12 kHz) targeting bit rates from 16-32 kbps
+ (possibly 8-160 kbps).
+
+ (2001-12-04)
+
+MPEG-2 AAC Low Profile
+
+ <compression, standard, algorithm, file format> A successor of
+ {MP3} allowing transparent coding at data rates of 75-80% of
+ that of {MP3}. It is very different from MP3, only used
+ {MDCT}, no {subband coding}.
+
+ (2001-12-08)
+
+MPEG-2 audio layer 3
+
+ <compression, standard, algorithm, file format> An extention
+ of {MPEG-1 audio layer 3} for lower sampling rates (16-24 kHz)
+ targeting bit rates from 32-64 kbps (possibly 8-160 kbps). It
+ is often combined with {MPEG-2 LSF}.
+
+ (2001-12-04)
+
+MPEG-2 Low Sampling Frequencies Extention
+
+ <compression, standard, algorithm, file format> (MPEG-2 LSF)
+ An extension of {MPEG-2}, mostly used with {MPEG-2 audio layer
+ 3} because the aim was medium quality at low bit rates, not
+ lower sampling frequencies.
+
+ (2001-12-04)
+
+MPEG-2 LSF
+
+ {MPEG-2 Low Sampling Frequencies Extention}
+
+MPEG-2 MC
+
+ {MPEG-2 Multi Channel Extention}
+
+MPEG-2 Multi Channel Extention
+
+ <compression, standard, algorithm, file format> (MPEG-2 MC) An
+ extension of {MPEG-2} that uses up to 5 channels and about
+ 1200 kbps.
+
+ (2001-12-08)
+
+MPEG-3
+
+ <compression, standard, algorithm, file format> A proposed
+ variant of the {MPEG} {video} and {audio} {compression}
+ {algorithm} and {file} format. MPEG-3 was intended as an
+ extension of {MPEG-2} to cater for {HDTV} but was eventually
+ merged into MPEG-2.
+
+ Not to be confused with MP3 - {MPEG-1 layer 3}.
+
+ [Technical details?]
+
+ (1999-01-06)
+
+MPEG-4
+
+ <compression, standard, algorithm, file format> A {video
+ compression} standard planned for late 1998. MPEG-4 extends
+ the earlier {MPEG-1} and {MPEG-2} algorithms with synthesis of
+ speech and video, {fractal compression}, {computer
+ visualisation} and {artificial intelligence}-based {image
+ processing} techniques.
+
+ [Technical details?]
+
+ (1999-01-06)
+
+MPEG-4 AAC Main Profile
+
+ <compression, standard, algorithm> A successor of
+ {MP3} allowing transparent coding at data rates of 70-75% of
+ that of {MP3}. It is very different from MP3, only used
+ {MDCT}, no {subband coding}. It is much more complex that
+ {MP3} and {MPEG-2 AAC Low Profile}.
+
+ (2001-12-08)
+
+MPEG-4 AAC SSR
+
+ {MPEG-4 Advanced Audio Coding Scalable Sampling Rate}
+
+MPEG-4 Advanced Audio Coding Scalable Sampling Rate
+
+ <compression, standard, algorithm> (MPEG-4 AAC SSR) An {AAC}
+ flavour supporting different qualities for different targets.
+ One stream can contain up to 3 streams for 11.025 kHz (Stream
+ 1), 22.05 (Stream 1 and 2) and 44.1 kHz (all 3 Streams)
+ sampling frequency. Quality is between Low Profile and Main
+ profile. See also {JPEG-2000}.
+
+ (2001-12-09)
+
+MPEG-4 Harmonics, individual lines and noise
+
+ <compression, standard, algorithm> (MPEG-4 HILN) An {MPEG-4}
+ variant using {parametric encoding} with a target {bit rate}
+ of 30 kbps.
+
+ (2001-12-09)
+
+MPEG-4 Harmonic Vector eXCitation
+
+ <compression, standard, algorithm> (MPEG-4 HVXC) An {MPEG-4}
+ variant using {parametric encoding} with a target {bit rate}
+ of 20 kbps, for voice coding.
+
+ (2001-12-09)
+
+MPEG-4 HILN
+
+ {MPEG-4 Harmonics, individual lines and noise}
+
+MPEG-4 HVXC
+
+ {MPEG-4 Harmonic Vector eXCitation}
+
+MPEG-7
+
+ <compression, standard, algorithm> A successor to {MPEG-4},
+ not standardized yet.
+
+ (2001-12-02)
+
+MPEGplus
+
+ <compression, algorithm> A non-{ISO} standard compressed {audio}
+ file format derived from {MPEG-1 Layer 2}.
+
+ (2001-12-11)
+
+MPG
+
+ <jargon> Miles per gallon, as in "Your MPG may
+ vary", i.e. "{Your mileage may vary}".
+
+mpg
+
+ <filename extension> A {filename extension} for a file in
+ {MPEG} format.
+
+ (1995-03-07)
+
+MPI
+
+ {Message Passing Interface}
+
+MPL
+
+ 1. <language> An early possible name for {PL/I}.
+
+ [Sammet 1969, p.542].
+
+ 2. {MasPar} {data-parallel} version of {C}. See also {ampl}.
+
+ {Compiler version 3.1 (ftp://maspar.maspar.com/put/)}.
+
+ 3. Motorola Programming Language. A low-level {PL/I}-like
+ language, similar to {PL/M}, but for the {Motorola 6800}.
+
+ 4. MicroProgramming Language. Simple language for
+ microprogramming. Statements on the same line represent
+ {register} transfers caused by one microinstruction, and are
+ executed in parallel.
+
+ ["Structured Computer Organization", A.S. Tanenbaum, First
+ Edition, P-H 1976. (Replaced in later editions by Mic-1)].
+
+ (1995-03-07)
+
+MPL II
+
+ [Burroughs VMS MPL II Language Reference Manual].
+
+MPLS
+
+ {Multiprotocol Label Switching}
+
+MPLS domain
+
+ <networking> A portion of a {network} that contains devices
+ that understand {MPLS}.
+
+ (1999-06-14)
+
+MP/M
+
+ {Multi-tasking Program for Microcomputers}
+
+MPP
+
+ {Multiple Parallel Processing}
+MPPE
+
+ {Microsoft Point to Point Encryption}
+
+MPPL
+
+ <language> An early possible name for {PL/I}.
+
+ [Sammet 1969, p. 542].
+
+ (1995-03-07)
+
+MPR II
+
+ <standard> A green standard published by SWEDAC (the Swedish
+ Board for Technical Accreditation) that limits the maximum
+ amount of {ELF} and {VLF} electromagnetic radiation a computer
+ {monitor} may emit. Most {personal computer} monitors comply
+ with this standard or the more stringent European TCO
+ requirement.
+
+ (1996-02-19)
+
+M-Prolog
+
+ 1. Marseille Prolog.
+
+ 2. An extension to {Prolog} involving {modules}.
+
+ ["The MProlog System", J. Bendl et al, Proc Logic Prog
+ Workshop, 1980].
+
+ (1994-10-31)
+
+MPS III
+
+ Solving matrices and producing reports. "MPS III DATAFORM
+ User Manual", Management Science Systems (1976).
+
+MPSX
+
+ Mathematical Programming System Extended. Solution strategy
+ for mathematical programming. "Mathematical Programming
+ System Extended (MPSX) Control Language User's Manual",
+ SH20-0932, IBM. Sammet 1978.
+
+MPV
+
+ An extension of the {VRTX} {real-time} {operating system} to
+ support {multi-processing}.
+
+ (1994-11-08)
+
+MPX
+
+ {Multiplexor Channel}
+
+mq
+
+ <networking> The {country code} for Martinique.
+
+ (1999-01-27)
+
+MQG
+
+ {Multi-threaded Query Gate}
+
+mr
+
+ <networking> The {country code} for Mauritania.
+
+ (1999-01-27)
+
+MRAM
+
+ {Magnetic RAM}
+
+MRDA
+
+ {Mandy Rice-Davis Applies}
+
+MRDS
+
+ {Multics Relational Data Store}
+
+MRI
+
+ 1. <application> {Magnetic Resonance Imaging}.
+
+ 2. {Measurement Requirements and Interface}.
+
+MROC
+
+ {Miniature Ruggedized Optical Correlator}
+
+MROM
+
+ {Mask Read-Only Memory}
+
+MRP
+
+ {Material Requirements Planning}
+
+MRP II
+
+ {Manufacturer Resource Planning}
+
+MRS
+
+ Modifiable Representation System.
+
+ An integration of {logic programming} into {Lisp}.
+
+ ["A Modifiable Representation System", M. Genesereth et al,
+ HPP 80-22, CS Dept Stanford U 1980].
+
+ (1994-11-08)
+
+ms
+
+ 1. <unit> {millisecond}.
+
+ 2. <networking> The {country code} for Montserrat.
+
+ (1999-01-27)
+
+MS Access
+
+ {Microsoft Access}
+
+MSAU
+
+ {Media Access Unit}
+
+MSB
+
+ {Most Significant Bit}
+
+MS-BASIC
+
+ {Microsoft Basic}
+
+MS-DOG
+
+ <abuse> A pejorative name for {MS-DOS}.
+
+MS-DOS
+
+ {Microsoft Disk Operating System}
+
+MSG.84
+
+ <language> A language for the {functional specification} and
+ module design phases of the {software life cycle}, first
+ presented in Berzins and Gray's 1985 paper. Not unlike {PDL}.
+
+ ["Analysis and design in MSG.84: formalizing functional
+ specifications", Valdis Berzins, Michael Gray, Volume 11 Issue
+ 8, IEEE Transactions on Software Engineering, Aug 1985].
+
+ (2003-05-15)
+
+msgGUI
+
+ <library> A {graphical user interface} for {GNU Smalltalk}.
+ The msgGUI package contains the basics for creating window
+ {applications} in the manner available in other graphical
+ {Smalltalk} implementations. Version 1.0 of the library was
+ by Mark Bush, ECS, Oxford University, UK.
+
+ {(ftp://ftp.comlab.ox.ac.uk/pub/Packages/mst/mstGUI-1.0.tar.Z)}.
+
+ (2000-06-14)
+
+MSIE
+
+ {Internet Explorer}
+
+MSM
+
+ {Micronetics Standard MUMPS}
+
+MS Mail
+
+ {Microsoft Mail}
+
+MSN
+
+ {The Microsoft Network}
+
+MS Office
+
+ {Microsoft Office}
+
+MS Project
+
+ {Microsoft Project}
+
+MSS
+
+ {maximum segment size}
+
+MS-Windows
+
+ {Microsoft Windows}
+
+MswLogo
+
+ <language> A {Microsoft Windows} {front-end} for {Berkeley
+ Logo} by George Mills <george.mills AT softronix DOT com>.
+ MswLogo has 3D {primitives} and {GUI} support. It runs on
+ every flavour of Windows from 16-bit to NT.
+
+ {(http://softronix.com/logo.html)}.
+
+ (2006-02-28)
+
+MS Word
+
+ {Microsoft Word}
+
+MSX
+
+ {Microsoft Extended}
+
+MSX-DOS
+
+ {Microsoft Extended}
+
+mt
+
+ <networking> The {country code} for Malta.
+
+ (1999-01-27)
+
+MTA
+
+ 1. <messaging> {Message Transfer Agent}.
+
+ 2. <messaging> {Message Transfer Architecture}. ({AT&T}).
+
+ 3. {Multiple Terminal Access}.
+
+ 4. {Maintenance Task Analysis}.
+
+ (1997-02-28)
+
+MTBF
+
+ {Mean Time Between Failures}
+
+mtc
+
+ A {Modula-2} to {C} translator.
+
+ {(ftp://rusmv1.rus.uni-stuttgart.de/soft/Unixtools/compilerbau/mtc.tar.Z)}.
+
+ (1991-10-25)
+
+M Technology Association
+
+ <body> The {MUMPS} User's Group that disbanded some time
+ between 1995 and 2003.
+
+ Address: 1738 Elton Road, Suite 205, Silver Spring, MD
+ 20903-1725, USA.
+
+ Telephone: +1 301 431-4070. Fax: +1 301 431-0017.
+
+ (2003-06-04)
+
+MTOS
+
+ 1. <operating system> A family of {real-time} {operating systems}
+ for use in {embedded systems}. It is developed and marketed by
+ {Industrial Programming, Inc.}.
+
+ 2. <operating system> {MultiTOS}
+
+ (1997-06-03)
+
+MTS
+
+ 1. {Message Transport System}.
+
+ 2. <programming> {Microsoft Transaction Server}.
+
+ (1999-03-29)
+
+MTTR
+
+ {Mean Time To Recovery}
+
+MTU
+
+ {Maximum Transmission Unit}
+
+Mu
+
+ <character> (Greek letter).
+
+ 1. <unit> /micro/ prefix denoting division by 10^6, e.g. mu m
+ (micrometre, a millionth part of a metre). Sometimes written
+ as a 'u', the ASCII character nearest in appearance.
+
+ 2. <mathematics> /myoo/ In the theory of functions, mu x . E
+ denotes the least value of x for which E = x, i.e. the {least
+ fixed point} of the function \ x . E. The {recursive}
+ function mu f . H f satisfies (and is defined by) the equation
+
+ mu f . H f = H (mu f . H f)
+
+ An alternative notation for the same function is
+
+ fix H = H (fix H)
+
+ See {fixed point combinator}.
+
+ 3. <database> {multiple value}.
+
+ [{Jargon File}]
+
+ (1995-10-30)
+
+mu
+
+ 1. <networking> The {country code} for Mauritius.
+
+ 2. <philosophy> /moo/ The correct answer to the classic trick
+ question "Have you stopped beating your wife yet?". Assuming
+ that you have no wife or you have never beaten your wife, the
+ answer "yes" is wrong because it implies that you used to beat
+ your wife and then stopped, but "no" is worse because it
+ suggests that you have one and are still beating her.
+ According to various Discordians and Douglas Hofstadter the
+ correct answer is usually "mu", a Japanese word alleged to
+ mean "Your question cannot be answered because it depends on
+ incorrect assumptions".
+
+ Hackers tend to be sensitive to logical inadequacies in
+ language, and many have adopted this suggestion with
+ enthusiasm. The word "mu" is actually from Chinese, meaning
+ "nothing"; it is used in mainstream Japanese in that sense,
+ but native speakers do not recognise the Discordian
+ question-denying use. It almost certainly derives from
+ overgeneralisation of the answer in the following well-known
+ Rinzei Zen teaching riddle:
+
+ A monk asked Joshu, "Does a dog have the Buddha nature?"
+ Joshu retorted, "Mu!"
+
+ See also {has the X nature}, {AI Koan}.
+
+ [Douglas Hofstadter, "Gödel, Escher, Bach: An Eternal Golden
+ Braid"].
+
+ [{Jargon File}]
+
+ (2000-11-22)
+
+MUA
+
+ {Mail User Agent}
+
+MUCAL
+
+ <language, music> A language for playing music on the {PDP-8}.
+
+ (1995-04-16)
+
+MUD
+
+ <games> {Multi-User Dimension} or "Multi-User Domain".
+ Originally "Multi-User Dungeon".
+
+ [{Jargon File}]
+
+ (1995-04-16)
+
+muddie
+
+ <games> Synonym {mudhead}. More common in Great Britain,
+ possibly because system administrators there like to mutter
+ "bloody muddies" when annoyed at the species.
+
+ [{Jargon File}]
+
+Muddle
+
+ Original name of {MDL}.
+
+mudhead
+
+ <games> A {MUD} player who eats, sleeps, and breathes MUD.
+ Mudheads have been known to fail their degrees, drop out,
+ etc. with the consolation, however, that they made wizard
+ level. When encountered in person, on a MUD or in a chat
+ system, all a mudhead will talk about is three topics: the
+ tactic, character, or wizard that is supposedly always
+ unfairly stopping him/her from becoming a wizard or beating a
+ favourite MUD; why the specific game he/she has experience
+ with is so much better than any other; and the MUD he or she
+ is writing or going to write because his/her design ideas are
+ so much better than in any existing MUD. See also {wannabee}.
+
+ To the anthropologically literate, this term may recall the
+ Zuni/Hopi legend of the mudheads or "koyemshi", mythical
+ half-formed children of an unnatural union. Figures
+ representing them act as clowns in Zuni sacred ceremonies.
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+MUD Object Oriented
+
+ <games> (MOO) One of the many {MUD} spin-offs (e.g. {MUSH},
+ {MUSE}, and {MUX}) created to diversify the realm of
+ interactive text-based gaming. A MOO is similar to a MUSH in
+ that the users themselves can create objects, rooms, and code
+ to add to the environment.
+
+ The most frequently used {server} {software} for running a MOO
+ is {LambdaMOO} but alternatives include {WinMOO
+ (http://www-personal.umich.edu/~cunkel/WinMOO/)} and
+ {MacGoesMOO
+ (http://neon.ci.lexington.ma.us/SpamCentral/scaron/mgm.html)}.
+
+ (1999-05-25)
+
+muFP
+
+ A {functional language} for hardware design, a predecessor of
+ {Ruby}.
+
+Muhammad al-Khwarizmi
+
+ {Muhammad ibn Musa al-Khwarizmi}
+
+Muhammad ibn Musa al-Khwarizmi
+
+ <person> An astronomer, geographer and mathematician, born around
+ 780 CE in Khwarizm (modern Khiva), south of the Aral Sea.
+ Khawarizmi founded {algebra} and {algorithms} (named after him),
+ synthesised Greek and Hindu knowledge, introducing the Indian
+ system of numerals (now known as Arabic numerals), developed
+ operations on {fractions}, trigonometric tables containing the
+ {sine functions}, the {calculus of two errors} and the {decimal}
+ system, explained the use of {zero}, perfected the geometric
+ representation of {conic sections}, collaborated in the degree
+ measurements aimed at measuring of volume and circumference of the
+ Earth and produced the first map of the known world in 830 CE. He
+ died around 850 CE.
+
+ {Muslim Heritage.com
+ (http://muslimheritage.com/day_life/default.cfm?ArticleID=317&Oldpage=1])}.
+
+ (2008-07-08)
+
+mu-law
+
+ The North America {standard} for {nonuniform quantising
+ logarithmic compression}.
+
+ [Equation?]
+
+ (1995-02-21)
+
+Mule
+
+ <text, tool> A multi-lingual enhancement of {GNU Emacs}. Mule
+ can handle not only {ASCII} characters (7 bit) and {ISO
+ Latin 1} characters (8 bit), but also {16-bit characters} like
+ Japanese, Chinese, and Korean. Mule can have a mixture of
+ languages in a single buffer.
+
+ Mule runs under the {X window system}, or on a {Hangul
+ terminal}, {mterm} or {exterm}.
+
+ Latest version: 2.3.
+
+ {(ftp://etlport.etl.go.jp/pub/mule)}.
+
+ (1996-01-28)
+
+Mul-T
+
+ An implementation of {Multilisp} built on {T}, for the {Encore
+ Multimax}.
+
+ ["Mul-T: A High-Performance Parallel Lisp", SIGPLAN Notices
+ 24(7):81-90 (Jul 1989)].
+
+ (1995-02-21)
+
+Multi-BinProlog
+
+ <language> A {multi-threaded} {Linda}-style parallel extension
+ to {BinProlog} for {Solaris} 2.3.
+
+ Version: 3.30.
+
+ (1995-04-04)
+
+multiboot
+
+ {dual boot}
+
+multiC
+
+ <language> A {data-parallel} version of {C} from {Wavetracer}.
+
+ (1995-04-04)
+
+MultiCal System
+
+ E-mail: Richard Snodgrass <rts@cs.arizona.edu>.
+
+ {(ftp://ftp.cs.arizona.edu/tsql/multical)}.
+
+ [What is it?]
+
+ (1994-11-11)
+
+multicast addressing
+
+ {Ethernet} addressing scheme used to send {packets} to devices
+ of a certain type or for {broadcast}ing to all nodes. The
+ least significant bit of the most significant byte of a
+ multi-cast address is one.
+
+multicast backbone
+
+ (MBONE) A {virtual network} on top of the {Internet} which
+ supports {routing} of {IP} {multicast} {packets}, intended for
+ {multimedia} transmission. MBONE gives public access {desktop
+ video} communications. The quality is poor with only 3-5
+ frames per second instead of the 30 frames per second of
+ commercial television. Its advantage is that it avoids all
+ telecommunications costs normally associated with
+ teleconferencing. An interesting innovation is the use of
+ MBONE for audio communications and an electronic "whiteboard"
+ where the computer screen becomes a shared workspace where two
+ physically remote parties can draw on and edit shared
+ documents in {real-time}.
+
+ (1994-10-27)
+
+Multi-channel Memorandum Distribution Facility
+
+ <messaging> (MMDF) An {electronic mail} system for Unix(?)
+ which is much easier to configure than {sendmail}. The source
+ is available.
+
+ MMDF is a versatile and configurable mail routing system
+ ({MTA}) which also includes user interface programs ({MUA}).
+ It can be set up to route mail to different {domains} and
+ {hosts} over different channels (e.g. {SMTP}, {UUCP}). On
+ {UNIX} systems, its configuration begins with the
+ /usr/mmdf/mmdftailor file, which defines the machine and
+ domain names, various other configuration tables (alias,
+ domain, channel) and other configuration information.
+
+ [Home?]
+
+ (1997-01-14)
+
+multician
+
+ <jargon, person> /muhl-ti'shn/ A term coined at {Honeywell},
+ ca. 1970 for a competent user of {Multics}. Perhaps oddly, no
+ one has ever promoted the analogous "Unician".
+
+ [{Jargon File}]
+
+ (1996-08-24)
+
+Multi-Color Graphics Array
+
+ <hardware, graphics> (MCGA) One of {IBM}'s less popular
+ hardware video {display standards} for use in the {IBM PS/2}.
+ MCGA can display 80*25 text in {monochrome}, 40*25 text in 256
+ colours or 320*200 pixel graphics in 256 colors. It is now
+ obsolete.
+
+ (2011-03-20)
+
+Multics
+
+ <operating system> /muhl'tiks/ MULTiplexed Information and
+ Computing Service. A {time-sharing} {operating system}
+ co-designed by a consortium including {MIT}, {GE} and {Bell
+ Laboratories} as a successor to MIT's {CTSS}. The system
+ design was presented in a special session of the 1965 Fall
+ Joint Computer Conference and was planned to be operational in
+ two years. It was finally made available in 1969, and took
+ several more years to achieve respectable performance and
+ stability.
+
+ Multics was very innovative for its time - among other things,
+ it was the first major OS to run on a {symmetric
+ multiprocessor}; provided a {hierarchical file system} with
+ {access control} on individual files; mapped files into a
+ paged, segmented {virtual memory}; was written in a
+ {high-level language} ({PL/I}); and provided dynamic
+ inter-procedure linkage and memory (file) sharing as the
+ default mode of operation. Multics was the only
+ general-purpose system to be awarded a B2 {security rating} by
+ the {NSA}.
+
+ Bell Labs left the development effort in 1969. {Honeywell}
+ commercialised Multics in 1972 after buying out GE's computer
+ group, but it was never very successful: at its peak in the
+ 1980s, there were between 75 and 100 Multics sites, each a
+ multi-million dollar {mainframe}.
+
+ One of the former Multics developers from Bell Labs was {Ken
+ Thompson}, a circumstance which led directly to the birth of
+ {Unix}. For this and other reasons, aspects of the Multics
+ design remain a topic of occasional debate among hackers. See
+ also {brain-damaged} and {GCOS}.
+
+ MIT ended its development association with Multics in 1977.
+ Honeywell sold its computer business to {Bull} in the mid
+ 1980s, and development on Multics was stopped in 1988 when
+ Bull scrapped a Boston proposal to port Multics to a
+ {platform} derived from the {DPS-6}.
+
+ A few Multics sites are still in use as late as 1996.
+
+ The last Multics system running, the Canadian Department of
+ National Defence Multics site in Halifax, Nova Scotia, Canada,
+ shut down on 2000-10-30 at 17:08 UTC.
+
+ The {Jargon file} 3.0.0 claims that on some versions of
+ Multics one was required to enter a password to log out but
+ James J. Lippard <lippard@primenet.com>, who was a Multics
+ developer in Phoenix, believes this to be an {urban legend}.
+ He never heard of a version of Multics which required a
+ password to logout. Tom Van Vleck <thvv@multicians.org>
+ agrees. He suggests that some user may have implemented a
+ 'terminal locking' program that required a password before one
+ could type anything, including logout.
+
+ {(http://multicians.org/)}.
+
+ {Usenet} newsgroup: {news:alt.os.multics}.
+
+ [{Jargon File}]
+
+ (2002-04-12)
+
+Multics Relational Data Store
+
+ <database> (MRDS) The first commercial {relational database},
+ implemented as part of {Multics} by Jim Weeldreyer and Oris
+ Friesen of {Honeywell} Phoenix in about 1977. MRDS included a
+ report writer called LINUS written by Jim Falksen.
+
+ (1997-01-29)
+
+Multiflow Computer
+
+ <company> A now-defunct computer company, best known for its
+ work in {Very Long Instruction Word} processors.
+
+ Address: New Haven, Conn. USA.
+
+ (1995-03-01)
+
+Multi-Garnet
+
+ A better constraint system for Garnet. Version 2.1 by Michael
+ Sannella <sannella@cs.washington.edu>.
+
+ {(ftp://a.gp.cs.cmu.edu/usr/garnet/alpha/src/contrib/multi-garnet)}.
+
+ (1992-09-21)
+
+multihomed host
+
+ A {host} which has more than one connection to a {network}.
+ The host may send and receive data over any of the links but
+ will not route traffic for other nodes.
+
+multilayer perceptron
+
+ A network composed of more than one layer of {neurons}, with
+ some or all of the outputs of each layer connected to one or
+ more of the inputs of another layer. The first layer is
+ called the input layer, the last one is the output layer, and
+ in between there may be one or more hidden layers.
+
+MultiLisp
+
+ <language> A {parallel} extension of {Scheme} with explicit
+ {concurrency}. The form (future X) immediately returns a
+ "{future}", and creates a {task} to evaluate X. When the
+ evaluation is complete, the future is resolved to be the
+ value.
+
+ ["MultiLisp: A Language for Concurrent Symbolic Computation",
+ R. Halstead, TOPLAS pp.501-538 (Oct 1985)].
+
+ [Did MultiLisp use {PVM} as its intermediate language?]
+
+ (1998-02-10)
+
+multimedia
+
+ <multimedia> Any collection of data including {text},
+ {graphics}, {images}, {audio} and {video}, or any system for
+ processing or interacting with such data. Often also includes
+ concepts from {hypertext}.
+
+ This term was once almost synonymous with {CD-ROM} in the
+ {personal computer} world because the large amounts of data
+ involved were best supplied on CD-ROM. {DVD}s and {broadband}
+ {Internet} connections have now largely replaced CDs as the
+ means of delivery.
+
+ A "multimedia PC" typically includes software for playing DVD
+ video, {5.1 audio} hardware and can display video on a
+ television. It may also include a television receiver and
+ software to record broadcast television to disk and play it
+ back. The {Multimedia Personal Computer} (MPC) standard was
+ an attempt to improve compatibility between such systems.
+
+ {Usenet} newsgroup: {news:comp.multimedia}.
+
+ (1994-12-02)
+
+Multimedia and Hypermedia information coding Expert Group
+
+ <multimedia, standard> (MHEG) is an {ISO} {standard} encoding
+ for {multimedia} and {hypermedia} information, designed to
+ facilitate use and interchange of such information in varied
+ domains such as games, electronic publishing and medical
+ applications.
+
+ {MHEG Home (http://mheg.org/)}.
+
+ (2002-12-30)
+
+MultiMedia Compact Disc
+
+ <storage> (MMCD) A {CD-ROM} {standard} for storing 4.7 GB of
+ data including video. MMCD is being developed by a large
+ numer of computer manufacturers and is expected to be shipped
+ in late 1996 or early 1997. Initially it will be aimed at the
+ consumer market, then perhaps in {CD-ROM} format for
+ computers, and maybe later on erasble CD.
+
+ (1995-11-23)
+
+MultiMedia Extension
+
+ {Matrix Math eXtensions}
+
+Multimedia Integrated Conferencing for European Researchers
+
+ <communications, project> (MICE) A project which aims to
+ create a pilot (virtual) network between European researchers,
+ and also to connect them to sites in the US. The MICE system
+ currently allows {multimedia} conferencing ({audio}, {video}
+ and shared workspace) between conference rooms and
+ {workstation}-based facilities, hardware and software,
+ {packet-switched} networks and {ISDN}, using both {unicast}
+ (point-to-point) and {multicast} (multi-point) {protocols}.
+
+ {(http://www-mice.cs.ucl.ac.uk/mice)}.
+
+ (1997-12-18)
+
+Multimedia Internet Mail Extensions
+
+ Called {Multipurpose Internet Mail Extensions} in the {RFC}.
+
+ [Is this an old name for it?]
+
+Multimedia Messaging Services
+
+ <messaging> (MMS) A feature of some {mobile telephones} that
+ allows them to send messages including text, sound, images and
+ {video}.
+
+ (2007-06-25)
+
+Multimedia PC
+
+ {multimedia}
+
+Multimedia Personal Computer
+
+ <multimedia> (MPC) A specification published by the Multimedia
+ PC Marketing Council in 1990 to encourage the adoption of a
+ standard {multimedia} computing platform. In May 1993, the
+ MPC Marketing Council published a new specification called
+ {MPC Level 2 Specification} as an enhanced multimedia computer
+ standard. The original MPC specification, now also known as
+ the {MPC Level 1 Specification}, continues in full effect.
+
+ The appearance of the MPC or MPC2 certification mark on a
+ computer system or upgrade kit indicates that the {hardware}
+ meets the corresponding (Level 1 or Level 2) MPC Marketing
+ Council specification. Software bearing the Multimedia PC mark
+ has been designed to work on Multimedia PC licensed hardware.
+
+ By establishing a standard platform, certifying hardware
+ compliance and providing inter-operability between software
+ and hardware for the consumer, the MPC Marketing Council is
+ encouraging widespread use of multimedia applications and
+ hardware.
+
+ (1997-01-19)
+
+multimedia system
+
+ {multimedia}
+
+multi-part key
+
+ {compound key}
+
+Multi-Pascal
+
+ An extension of {Pascal-S} with {multiprocessing} features.
+ Used in "The Art of Parallel Programming", Bruce P. Lester,
+ P-H 1993.
+
+multiple access
+
+ {multiplexing}
+
+Multiple Access with Colision Avoidance
+
+ <networking> (MACA) A {protocol} used as a basis for the IEEE
+ {802.11} {wireless LAN} {standards}.
+
+ [Details?]
+
+ (2004-01-14)
+
+multiple boot
+
+ {dual boot}
+
+Multiple Document Interface
+
+ <programming> (MDI) The ability of an {application program} to
+ show windows giving views of more than one document at a time.
+
+ The opposite is {Single Document Interface} (SDI).
+
+ (1999-03-30)
+
+multiple inheritance
+
+ <programming> In {object-oriented programming}, the possibility
+ that a {class} may have more than one direct {superclass} in the
+ {class hierarchy}.
+
+ The opposite is {single inheritance}.
+
+ (2014-09-06)
+
+Multiple Instruction Multiple Data
+
+ {Multiple Instruction/Multiple Data}
+
+Multiple Instruction/Multiple Data
+
+ (MIMD) The classification under {Flynn's taxonomy} of a
+ {parallel processor} where many {functional units} perform
+ different operations on different data. Examples would be a
+ network of {workstations} or {transputers}. Compare {SIMD}.
+
+ (1994-11-08)
+
+Multiple Master
+
+ <text, tool, software> (Or "Multiple Master Font") A {font}
+ that is a mixture of two or more other fonts.
+
+ A Multiple Master font is a single font containing from two to
+ sixteen master designs (the current implementation limit). A
+ weight factor specifies the contribution of each master design
+ for the creation of a multiple master font {instance}.
+
+ A Multiple Master instance is a single {interpolation} of a
+ multiple master font as created by a user or application.
+
+ {ATM Glossary
+ (http://adobe.com/supportservice/devrelations/typeforum/glossary.html)}.
+
+ {Useable fonts
+ (http://susi.informatik.rwth-aachen.de/Mirror/winsite/win3/fonts_atm.html)}.
+
+ (1998-05-31)
+
+multiple perspective software development
+
+ <programming> A decentralised approach to software development
+ which, instead of adopting a monolithic representation and
+ centralised control, models development in terms of
+ collaboration between autonomous partial systems.
+
+ Software development usually involves people with different
+ goals, expertise, and backgrounds, and the use of a wide range
+ of formalisms, tools, and environments. As information is
+ exchanged between participants, dependencies may be
+ established between information created by them. Multiple
+ perspective software development may be mapped into the
+ transaction model which can be used to prevent uncoordinated
+ access to interdependent information causing inconsistency.
+
+ [Fox Wai-Leung Poon]
+
+ (1995-12-14)
+
+multiple value
+
+ <database> (MU) A one-to-many relationship between entries in
+ a database, for example a person may have an address field
+ which spanned multiple records (with different indexes).
+ Multiple values are a non-{relational} technique.
+
+ MUs have recently been made available in {DB2}, despite the
+ product being so heavily influenced by {Codd's Laws} of
+ {relational databases}.
+
+ [Confirm, clarify?]
+
+ (1995-10-30)
+
+Multiple Virtual Storage
+
+ <operating system> (MVS) Release 2 of {OS/VS2}, called MVS
+ because it had multiple 16 MB virtual address spaces, in
+ contrast to {SVS}. MVS ran on the {IBM 390} series
+ {mainframes}. It became MVS/SP, then MVS/XA (with 31-bit
+ addressing) and then MVS/ESA.
+
+ MVS/Open Edition (MVS/OE), aimed at the growing {open systems}
+ market, added {TCP/IP} and {Unix} support in an MVS address
+ space, allowing users to run IBM, {CICS}-type applications,
+ {batch} applications and Unix.
+
+ MVS/ESA was repackaged as {OS/390} as a marketing exercise but
+ it's basically the same thing.
+
+ Version: 5.1.
+
+ [Features? Dates?]
+
+ (1999-01-20)
+
+multiplexer
+
+ {multiplexor}
+
+multiplexing
+
+ 1. <communications> (Or "multiple access") Combining several
+ signals for transmission on some shared medium (e.g. a
+ telephone wire). The signals are combined at the transmitter
+ by a multiplexor (a "mux") and split up at the receiver by a
+ demultiplexor. The communications channel may be shared
+ between the independent signals in one of several different
+ ways: {time division multiplexing}, {frequency division
+ multiplexing}, or {code division multiplexing}.
+
+ If the inputs take turns to use the output channel ({time
+ division multiplexing}) then the output {bandwidth} need be no
+ greater than the maximum bandwidth of any input.
+
+ If many inputs may be active simultaneously then the output
+ bandwidth must be at least as great as the total bandwidth of
+ all simultaneously active inputs. In this case the
+ multiplexor is also known as a {concentrator}.
+
+ (1995-03-02)
+
+ 2. <storage> Writing multiple {logical} copies of {data}
+ {files}. Placing the copies on totally separate {paths} to
+ {mirror}ed {devices} greatly reduces the probability of all
+ copies being corrupt. Multiplexing differs from mirroring in
+ that mirroring takes one data file and copies it to many
+ devices, thus making it possible to copy a corrupt file many
+ times. Multiplexing writes the data files to many places
+ simultaneously; there is no "original" data file.
+
+ (2001-05-10)
+
+multiplexor
+
+ {multiplexing}
+
+Multiplexor Channel
+
+ (MPX) {mainframe} terminology for a slow peripheral device
+ connection, e.g. for a {printer}, operator console, or card
+ reader.
+
+ (1997-06-30)
+
+multiplex printer
+
+ <hardware> A {duplex} circuit using {time-division
+ multiplexing} to provide multiple duplex channels over one
+ wire.
+
+ For example, channels A, B, C, and D could be used for
+ simultaneous transmission in both directions.
+
+ (2000-04-02)
+
+Multipop-68
+
+ <operating system> An early {time-sharing} {operating system}
+ developed in Edinburgh by Robin Popplestone and others. It
+ was inspired by {MIT}' {Project MAC}, via a "MiniMac" project
+ which was aborted when it became obvious that {Elliot
+ Brothers} Ltd. could not supply the necessary disk storage.
+ Multipop was highly efficient in its use of machine resources
+ to support {symbolic programming}, and effective - e.g. in
+ supporting the development of the {Boyer-Moore theorem prover}
+ and of Burstall and Darlington's transformation work.
+
+ It was not good at supporting the user programs which were
+ then the standard fare of computing, e.g. matrix inversion.
+ This arose from the fact that while the {POP-2} compiler
+ generated good code for function call (which is a lot of what
+ layered systems like operating systems do) it did not generate
+ efficient code for arithmetic or store access, because there
+ was no way to police the generation of illegal objects
+ statically. ({Hindley-Milner type} checking did not exist).
+ Indeed, since many OS features like file-access were performed
+ by function-call (of a {closure}) rather than an OS call
+ requiring a {context switch}, POP-2 actually gained
+ performance.
+
+ Multipop68 was efficient primarily because the one language,
+ POP-2 served all purposes: it was the command language for the
+ operating system as well as being the only available
+ programming language. Thus there was no need to swap in
+ compilers etc. All store management was accomplished
+ uniformly by the {garbage collector}, as opposed to having
+ store management for the OS and store management for each
+ application.
+
+ There was a substantial amount of {assembly language} in
+ Multipop68. This was primarily for interrupt handling, and it
+ is difficult to handle this without a {real-time}
+ garbage-collector.
+
+ [Edited from a posting by Robin Popplestone].
+
+ (1995-03-15)
+
+multiprocessing
+
+ {parallel processing}
+
+multiprocessor
+
+ {parallel processing}
+
+multiprogramming
+
+ {multitasking}
+
+Multiprotocol Label Switching
+
+ <networking> (MPLS) A {packet switching} {protocol} developed
+ by the {IETF}. Initially developed to improve switching
+ speed, other benefits are now seen as being more important.
+
+ MPLS adds a 32-{bit} label to each {packet} to improve
+ {network} efficiency and to enable {routers} to direct
+ {packets} along predefined routes in accordance with the
+ required {quality of service}. The label is added when the
+ {packet} enters the MPLS {network}, and is based on an
+ analysis of the {packet} {header}. The label contains
+ information on the route along which the {packet} may travel,
+ and the {forwarding equivalence class} (FEC) of the {packet}.
+ Packets with the same {FEC} are routed through the {network}
+ in the same way.
+
+ Routers make forwarding decisions based purely on the contents
+ of the label. This simplifies the work done by the {router},
+ leading to an increase in speed. At each {router}, the label
+ is replaced with a new label, which tells the next {router}
+ how to forward the {packet}. The label is removed when the
+ {packet} leaves the MPLS {network}.
+
+ Modern {ASIC}-based routers can look up routes fast enough to
+ make the speed increase less important. However, MPLS still
+ has some benefits. The use of {FECs} allows {QoS} levels to
+ be guaranteed, and MPLS allows {IP} {tunnels} to be created
+ through a {network}, so that {VPNs} can be implemented without
+ {encryption}.
+
+ {MPLS Resource Center (http://mplsrc.com/)}.
+
+ [RFC 3031]
+
+ (2002-04-14)
+
+Multipurpose Internet Mail Extensions
+
+ <file format, multimedia> (MIME) A {standard} for multi-part,
+ {multimedia} {electronic mail} messages and {web}
+ {hypertext} documents on the {Internet}. MIME provides the
+ ability to transfer non-textual data, such as graphics,
+ {audio} and fax. It is defined in {RFC 2045}, {RFC 2046},
+ {RFC 2047}, {RFC 2048}, {RFC 2049}, and {BCP0013}. It uses
+ {mimencode} to encode binary data into {base 64} using a
+ subset of {ASCII}.
+
+ {FAQ
+ (http://cis.ohio-state.edu/hypertext/faq/usenet/mail/mime-faq/top.html)}.
+
+ (1995-04-04)
+
+multiscan
+
+ <hardware> A {monitor} that can synchronise to a variety of
+ {horizontal scan rates} and {refresh rates}, allowing it to
+ display images at different {resolutions}.
+
+ (1996-02-09)
+
+MultiScheme
+
+ An implementation of {Multilisp} built on MIT's {C-Scheme},
+ for the {BBN Butterfly}.
+
+ ["MultiScheme: A Paralled Processing System Based on MIT
+ Scheme", J. Miller, TR-402, MIT LCS, Sept 1987].
+
+ (1995-04-04)
+
+Multistation Access Unit
+
+ {Media Access Unit}
+
+multisync
+
+ <hardware> An {NEC} trademark term for {multiscan}. As NEC
+ was the first to manufacture multiscan {monitors} the term is
+ often used interchangeably with multiscan.
+
+ (1996-02-09)
+
+Multisystem eXtention Interface Bus
+
+ <hardware> (MXIbus) A high performance communication link that
+ interconnects devices using round, flexible cable. MXIbus is
+ used between a {GPIB} card and a {VXI} cage.
+
+ (1999-10-12)
+
+multitasking
+
+ <computer, parallel> (Or "multi-tasking", "multiprogramming",
+ "concurrent processing", "concurrency", "process scheduling")
+ A technique used in an {operating system} for sharing a single
+ processor between several independent jobs. The first
+ multitasking operating systems were designed in the early
+ 1960s.
+
+ Under "{cooperative multitasking}" the running task decides
+ when to give up the CPU and under "{pre-emptive multitasking}"
+ (probably more common) a system process called the
+ "{scheduler}" suspends the currently running task after it has
+ run for a fixed period known as a "{time-slice}". In both
+ cases the scheduler is responsible for selecting the next task
+ to run and (re)starting it.
+
+ The running task may relinquish control voluntarily even in a
+ pre-emptive system if it is waiting for some external {event}.
+ In either system a task may be suspended prematurely if a
+ hardware {interrupt} occurs, especially if a higher priority
+ task was waiting for this event and has therefore become
+ runnable.
+
+ The scheduling {algorithm} used by the scheduler determines
+ which task will run next. Some common examples are
+ {round-robin} scheduling, {priority scheduling}, {shortest job
+ first} and {guaranteed scheduling}.
+
+ Multitasking introduces {overheads} because the processor
+ spends some time in choosing the next job to run and in saving
+ and restoring tasks' state, but it reduces the worst-case time
+ from job submission to completion compared with a simple
+ {batch} system where each job must finish before the next one
+ starts. Multitasking also means that while one task is
+ waiting for some external event, the {CPU} to do useful work
+ on other tasks.
+
+ A multitasking operating system should provide some degree of
+ protection of one task from another to prevent tasks from
+ interacting in unexpected ways such as accidentally modifying
+ the contents of each other's memory areas.
+
+ The jobs in a multitasking system may belong to one or many
+ users. This is distinct from {parallel processing} where one
+ user runs several tasks on several processors. {Time-sharing}
+ is almost synonymous but implies that there is more than one
+ user.
+
+ {Multithreading} is a kind of multitasking with low
+ {overheads} and no protection of tasks from each other, all
+ threads share the same memory.
+
+ (1998-04-24)
+
+Multi-tasking Program for Microcomputers
+
+ <operating system> (MP/M) An {operating system}, written by
+ {Gary Kildal}, very similar to {CP/M}, also written by Kildal.
+ MP/M allowed {virtual terminals}, each of which could execute
+ an {application} while another terminal was called to the
+ screen with a special key combination.
+
+ See also {Control Program for Microcomputers}.
+
+ (1996-09-08)
+
+multithreaded
+
+ {multithreading}
+
+multithreading
+
+ <parallel> Sharing a single {CPU} between multiple tasks (or
+ "threads") in a way designed to minimise the time required to
+ switch threads. This is accomplished by sharing as much as
+ possible of the program execution environment between the
+ different threads so that very little state needs to be saved
+ and restored when changing thread.
+
+ Multithreading differs from {multitasking} in that threads
+ share more of their environment with each other than do tasks
+ under multitasking. Threads may be distinguished only by the
+ value of their {program counters} and {stack pointers} while
+ sharing a single {address space} and set of {global
+ variables}. There is thus very little protection of one
+ thread from another, in contrast to multitasking.
+
+ Multithreading can thus be used for very {fine-grain
+ multitasking}, at the level of a few instructions, and so can hide
+ {latency} by keeping the processor busy after one thread issues a
+ long-latency instruction on which subsequent instructions in that
+ thread depend.
+
+ A {light-weight process} is somewhere between a thread and a
+ full process.
+
+ {TL0} is an example of a threaded machine language.
+ {Dataflow} computation (E.g. {Id} and {SISAL}) is an extreme
+ form of multithreading.
+
+ (1997-12-23)
+
+MultiTOS
+
+ <operating system> (MTOS) A new version of {TOS}. MultiTOS's
+ main advantage was support for {pre-emptive multitasking} and
+ {memory protection}. It also supported the latest (and far
+ superior) versions of {GEM}. MultiTOS was supplied with the
+ Falcon030 range of computers from {Atari}.
+
+ It is a little known fact that the MultiTOS {kernel} was based
+ heavily on the {freeware} OS {MinT} which was developed long
+ before Atari got MultiTOS working.
+
+ (1997-01-10)
+
+multi-user
+
+ <operating system> A term describing an {operating system} or
+ {application program} that can be used by several people
+ concurrently; opposite of {single-user}. {Unix} is an example
+ of a multi-user operating system, whereas most (but not all)
+ versions of {Microsoft Windows} are intended to support only
+ one user at a time.
+
+ A multi-user system, by definition, supports {concurrent
+ processing} of multiple tasks (once known as "{time-sharing}")
+ or true {parallel processing} if it has multiple {CPUs}.
+
+ While {batch processing} systems often ran jobs for serveral
+ users concurrently, the term "multi-user" typically implies
+ {interactive} access.
+
+ Before {Ethernet} networks were commonplace, multi-user
+ systems were accessed from a {terminal} (e.g. a {vt100})
+ connected via a {serial line} (typically {RS-232}). This
+ arrangement was eventually superseded by networked {personal
+ computers}, perhaps sharing files on a {file server}. With
+ the wide-spread availability of Internet connections, the idea
+ of sharing centralised resources is becoming trendy again with
+ {cloud computing} and {managed applications}, though this time
+ it is the overhead of administering the system that is being
+ shared rather than the cost of the hardware.
+
+ In gaming, both on PCs and {games consoles}, the equivalent
+ term is {multi-player}, though the first multi-player games
+ (e.g. {ADVENT}) were on multi-user computers.
+
+ (2009-11-23)
+
+Multi-User Dimension
+
+ <games> (MUD) (Or Multi-User Domain, originally "Multi-User
+ Dungeon") A class of multi-player interactive game, accessible
+ via the {Internet} or a {modem}. A MUD is like a real-time
+ {chat} forum with structure; it has multiple "locations" like
+ an {adventure} game and may include combat, traps, puzzles,
+ magic and a simple economic system. A MUD where characters
+ can build more structure onto the database that represents the
+ existing world is sometimes known as a "{MUSH}". Most MUDs
+ allow you to log in as a guest to look around before you
+ create your own character.
+
+ Historically, MUDs (and their more recent progeny with names
+ of MU- form) derive from a hack by Richard Bartle and Roy
+ Trubshaw on the University of Essex's {DEC-10} in 1979. It
+ was a game similar to the classic {Colossal Cave} adventure,
+ except that it allowed multiple people to play at the same
+ time and interact with each other. Descendants of that game
+ still exist today and are sometimes generically called
+ BartleMUDs. There is a widespread myth that the name MUD was
+ trademarked to the commercial MUD run by Bartle on {British
+ Telecom} (the motto: "You haven't *lived* 'til you've *died*
+ on MUD!"); however, this is false - Richard Bartle
+ explicitly placed "MUD" in the {PD} in 1985. BT was upset at
+ this, as they had already printed trademark claims on some
+ maps and posters, which were released and created the myth.
+
+ Students on the European academic networks quickly improved on
+ the MUD concept, spawning several new MUDs ({VAXMUD},
+ {AberMUD}, {LPMUD}). Many of these had associated
+ {bulletin-board systems} for social interaction. Because
+ these had an image as "research" they often survived
+ administrative hostility to {BBSs} in general. This, together
+ with the fact that {Usenet} feeds have been spotty and
+ difficult to get in the UK, made the MUDs major foci of
+ hackish social interaction there.
+
+ AberMUD and other variants crossed the Atlantic around 1988
+ and quickly gained popularity in the US; they became nuclei
+ for large hacker communities with only loose ties to
+ traditional hackerdom (some observers see parallels with the
+ growth of {Usenet} in the early 1980s). The second wave of
+ MUDs (TinyMUD and variants) tended to emphasise social
+ interaction, puzzles, and cooperative world-building as
+ opposed to combat and competition. In 1991, over 50% of MUD
+ sites are of a third major variety, LPMUD, which synthesises
+ the combat/puzzle aspects of AberMUD and older systems with
+ the extensibility of TinyMud. The trend toward greater
+ programmability and flexibility will doubtless continue.
+
+ The state of the art in MUD design is still moving very
+ rapidly, with new simulation designs appearing (seemingly)
+ every month. There is now a move afoot to deprecate the term
+ {MUD} itself, as newer designs exhibit an exploding variety of
+ names corresponding to the different simulation styles being
+ explored.
+
+ {UMN MUD Gopher page
+ (gopher://spinaltap.micro.umn.edu/11/fun/Games/MUDs/Links)}.
+
+ {U Pennsylvania MUD Web page
+ (http://cis.upenn.edu/~lwl/mudinfo.html)}.
+
+ See also {bonk/oif}, {FOD}, {link-dead}, {mudhead}, {MOO},
+ {MUCK}, {MUG}, {MUSE}, {chat}.
+
+ {Usenet} newsgroups: {news:rec.games.mud.announce},
+ {news:rec.games.mud.admin}, {news:rec.games.mud.diku},
+ {news:rec.games.mud.lp}, {news:rec.games.mud.misc},
+ {news:rec.games.mud.tiny}.
+
+ (1994-08-10)
+
+Multi-User Dungeon
+
+ {Multi-User Dimension}
+
+Multi-User Shared Hallucination
+
+ <communications, application> (MUSH) A user-extendable {MUD}.
+ A MUSH provides commands which the players can use to
+ construct new rooms or make objects and puzzles for other
+ players to explore.
+
+ {(http://cis.upenn.edu/~lwl/muds.html)}.
+
+ (1995-03-16)
+
+Multi-Version Concurrency Control
+
+ <database> (MVCC) An advanced technique for improving
+ multi-user {database} performance.
+
+ The main difference between multiversion and lock models is
+ that in MVCC locks acquired for querying (reading) data don't
+ conflict with locks acquired for writing data and so reading
+ never blocks writing and writing never blocks reading.
+
+ This technique is used in the {free software} database
+ {PostgreSQL}.
+
+ (1999-06-18)
+
+multi-way branch
+
+ {switch statement}
+
+MuMath
+
+ <mathematics, tool> A {symbolic mathematics} package for the
+ {IBM PC}, written in {MuSimp}.
+
+ (1995-04-12)
+
+mumblage
+
+ /muhm'bl*j/ The topic of one's mumbling (see {mumble}). "All
+ that mumblage" is used like "all that stuff" when it is not
+ quite clear how the subject of discussion works, or like "all
+ that crap" when "mumble" is being used as an implicit
+ replacement for pejoratives.
+
+ [{Jargon File}]
+
+mumble
+
+ 1. Said when the correct response is too complicated to
+ enunciate, or the speaker has not thought it out. Often
+ prefaces a longer answer, or indicates a general reluctance to
+ get into a long discussion. "Don't you think that we could
+ improve LISP performance by using a hybrid reference-count
+ transaction garbage collector, if the cache is big enough and
+ there are some extra cache bits for the {microcode} to use?"
+ "Well, mumble ... I'll have to think about it."
+
+ 2. Yet another {metasyntactic variable}, like {foo}.
+
+ 3. Sometimes used in "public" contexts on-line as a
+ placefiller for things one is barred from giving details
+ about. For example, a poster with pre-released hardware in
+ his machine might say "Yup, my machine now has an extra 16M of
+ memory, thanks to the card I'm testing for Mumbleco."
+
+ 4. A conversational wild card used to designate something one
+ doesn't want to bother spelling out, but which can be
+ {glark}ed from context. Compare {blurgle}.
+
+ 5. [XEROX PARC] A colloquialism used to suggest that further
+ discussion would be fruitless.
+
+ (1997-03-27)
+
+mumble mode
+
+ <jargon> The mode a program, piece of hardware, or other
+ system is said to be in when it is still running and perhaps
+ reacting to input and/or occasionally producing output
+ (especially if it shouldn't), but in a way that appears wildly
+ inappropriate to the task it is supposed to perform.
+
+ Compare "{off the trolley}" and "{deep space}".
+
+ (1997-03-27)
+
+MUMPS
+
+ <language> (Or "M") Massachusetts General Hospital Utility
+ Multi-Programming System.
+
+ A programming language with extensive tools for the support of
+ {database management systems}. MUMPS was originally used for
+ medical records and is now widely used where multiple users
+ access the same databases simultaneously, e.g. banks, stock
+ exchanges, travel agencies, hospitals.
+
+ Early MUMPS implementations for {PDP-11} and {IBM PC} were
+ complete {operating systems}, as well as programming
+ languages, but current-day implementations usually run under a
+ normal host {operating system}.
+
+ A MUMPS program hardly ever explicitly performs low-level
+ operations such as opening a file - there are programming
+ constructs in the language that will do so implicitly, and
+ most MUMPS programmers are not even aware of the {operating
+ system} activity that MUMPS performs.
+
+ Syntactically MUMPS has only one data-type: strings.
+ Semantically, the language has many data-types: text strings,
+ {binary strings}, {floating point} values, {integer} values,
+ {Boolean} values. Interpretation of strings is done inside
+ functions, or implicitly while applying mathematical
+ {operators}. Since many operations involve only moving data
+ from one location to another, it is faster to just move
+ uninterpreted strings. Of course, when a value is used
+ multiple times in the context of arithmetical operations,
+ optimised implementations will typically save the numerical
+ value of the string.
+
+ MUMPS was designed for portability. Currently, it is possible
+ to share the same MUMPS database between radically different
+ architectures, because all values are stored as text strings.
+ The worst an implementation may have to do is swap pairs of
+ bytes. Such multi-CPU databases are actually in use, some
+ offices share databases between {VAX}, {DEC Alpha}, {SUN},
+ {IBM PC} and {HP} {workstations}.
+
+ Versions of MUMPS are available on practically all {hardware},
+ from the smallest ({IBM PC}, {Apple Macintosh}, {Acorn}
+ {Archimedes}), to the largest {mainframe}. MSM ({Micronetics
+ Standard MUMPS}) runs on {IBM PC RT} and {R6000}; DSM (Digital
+ Standard Mumps) on the {PDP-11}, {VAX}, {DEC Alpha}, and
+ {Windows-NT}; {Datatree MUMPS} from {InterSystems} runs on
+ {IBM PC}; and {MGlobal MUMPS} on the {Macintosh}.
+ Multi-{platform} versions include {M/SQL}, available from
+ {InterSystems}, {PFCS} <mumps@pfcs.com> and {MSM}.
+
+ {Greystone Technologies}' GT/M runs on {VAX} and {DEC Alpha}.
+ This is a compiler whereas the others are {interpreters}.
+ {GT/SQL} is their {SQL} pre-processor.
+
+ ISO standard 11756 (1991). ANSI standard: "MUMPS Language
+ Standard", X11.1 (1977, 1984, 1990, 1995?).
+
+ The MUMPS User's Group was the {M Technology Association}.
+
+ {Usenet} newsgroups: {news:comp.lang.mumps}.
+
+ (2003-06-04)
+
+munch
+
+ To transform information in a serial fashion, often requiring
+ large amounts of computation. To trace down a data structure.
+ Related to {crunch} and nearly synonymous with {grovel}, but
+ connotes less pain.
+
+ Often confused with {mung}.
+
+ [{Jargon File}]
+
+ (1995-01-10)
+
+munching
+
+ Exploration of security holes of someone else's computer for
+ thrills, notoriety or to annoy the system manager. Compare
+ {cracker}. See also {hacked off}.
+
+ [{Jargon File}]
+
+munching squares
+
+ A {display hack} dating back to the {PDP-1} (ca. 1962,
+ reportedly discovered by Jackson Wright), which employs a
+ trivial computation (repeatedly plotting the graph Y = X XOR T
+ for successive values of T - see {HAKMEM} items 146--148) to
+ produce an impressive display of moving and growing squares
+ that devour the screen. The initial value of T is treated as
+ a parameter, which, when well-chosen, can produce amazing
+ effects. Some of these, later (re)discovered on the {LISP
+ Machine}, have been christened "munching triangles" (try AND
+ for XOR and toggling points instead of plotting them),
+ "munching w's", and "munching mazes". More generally, suppose
+ a graphics program produces an impressive and ever-changing
+ display of some basic form, foo, on a display terminal, and
+ does it using a relatively simple program; then the program
+ (or the resulting display) is likely to be referred to as
+ "munching foos". [This is a good example of the use of the
+ word {foo} as a {metasyntactic variable}.]
+
+munchkin
+
+ /muhnch'kin/ [Squeaky-voiced little people in L. Frank Baum's
+ "The Wizard of Oz"] A teenage-or-younger micro enthusiast
+ hacking BASIC or something else equally constricted. A term
+ of mild derision - munchkins are annoying but some grow up
+ to be hackers after passing through a {larval stage}. The
+ term {urchin} is also used. See also {wannabee}, {bitty box}.
+
+ [{Jargon File}]
+
+mundane
+
+ <jargon> Someone outside some group that is implicit from the
+ context, such as the computer industry or science fiction
+ fandom. The implication is that those in the group are
+ special and those outside are just ordinary.
+
+ (2000-07-22)
+
+mung
+
+ /muhng/ (MIT, 1960) Mash Until No Good.
+
+ Sometime after that the derivation from the {recursive
+ acronym} "Mung Until No Good" became standard. 1. To make
+ changes to a file, especially large-scale and irrevocable
+ changes.
+
+ See {BLT}.
+
+ 2. To destroy, usually accidentally, occasionally maliciously.
+ The system only mungs things maliciously; this is a
+ consequence of {Finagle's Law}.
+
+ See {scribble}, {mangle}, {trash}, {nuke}.
+
+ Reports from {Usenet} suggest that the pronunciation /muhnj/
+ is now usual in speech, but the spelling "mung" is still
+ common in program comments (compare the widespread confusion
+ over the proper spelling of {kluge}).
+
+ 3. The kind of beans of which the sprouts are used in Chinese
+ food. (That's their real name! Mung beans! Really!)
+
+ Like many early hacker terms, this one seems to have
+ originated at {TMRC}; it was already in use there in 1958.
+ Peter Samson (compiler of the original TMRC lexicon) thinks it
+ may originally have been onomatopoeic for the sound of a relay
+ spring (contact) being twanged. However, it is known that
+ during the World Wars, "mung" was army slang for the ersatz
+ creamed chipped beef better known as "SOS".
+
+ [{Jargon File}]
+
+ (1994-12-02)
+
+munge
+
+ /muhnj/ 1. A derogatory term meaning to imperfectly transform
+ information.
+
+ 2. A comprehensive rewrite of a routine, data structure or the
+ whole program.
+
+ This term is often confused with {mung} and may derive from
+ it, or possibly vice-versa. One correspondent believes it
+ derives from the french "mange" /monzh/, eat.
+
+ [{Jargon File}]
+
+ (2002-04-15)
+
+MUP
+
+ {Multiple Universal naming convention Provider}
+
+MU-Prolog
+
+ <language> {Prolog} with "wait" declarations for
+ {coroutining}, developed by L. Naish of the {Univeristy of
+ Melbourne} in 1982.
+
+ ["Negation and Control in Prolog", L. Naish, TR 85/12, U
+ Melbourne (1985)]. See {NU-Prolog}.
+
+ (1998-02-14)
+
+Murphy's Law
+
+ <humour> (Or "Sod's Law") The correct, *original* Murphy's Law
+ reads: "If there are two or more ways to do something, and one
+ of those ways can result in a catastrophe, then someone will
+ do it." This is a principle of defensive design, cited here
+ because it is usually given in mutant forms less descriptive
+ of the challenges of design for {lusers}. For example, you
+ don't make a two-pin plug symmetrical and then label it "THIS
+ WAY UP"; if it matters which way it is plugged in, then you
+ make the design asymmetrical (see also the anecdote under
+ {magic smoke}).
+
+ Edward A. Murphy, Jr. was one of the engineers on the
+ rocket-sled experiments that were done by the US Air Force in
+ 1949 to test human acceleration tolerances (USAF project
+ MX981). One experiment involved a set of 16 accelerometers
+ mounted to different parts of the subject's body. There were
+ two ways each sensor could be glued to its mount, and somebody
+ methodically installed all 16 the wrong way around. Murphy
+ then made the original form of his pronouncement, which the
+ test subject (Major John Paul Stapp) quoted at a news
+ conference a few days later.
+
+ Within months "Murphy's Law' had spread to various technical
+ cultures connected to aerospace engineering. Before too many
+ years had gone by variants had passed into the popular
+ imagination, changing as they went. Most of these are
+ variants on "Anything that can go wrong, will"; this is
+ sometimes referred to as {Finagle's Law}. The memetic drift
+ apparent in these mutants clearly demonstrates Murphy's Law
+ acting on itself!
+
+ [{Jargon File}]
+
+ (1998-02-14)
+
+Muse
+
+ <language> {OR-parallel} {logic programming}.
+
+ [Details?]
+
+ (1995-03-16)
+
+museum
+
+ {Museums on the Web
+ (http://comlab.ox.ac.uk/archive/other/museums.html)}.
+ {(http://galaxy.einet.net/GJ/museums.html)}.
+
+ (1995-03-16)
+
+MUSH
+
+ 1. <games> {Multi-User Shared Hallucination}.
+
+ 2. <messaging> {Mail Users' Shell}.
+
+Music
+
+ <language, music> A series of languages for musical sound
+ synthesis from {Bell Labs}, 1960's. Versions: Music I through
+ Music V.
+
+ ["An Acoustical Compiler for Music and Psychological Stimuli",
+ M.V. Mathews, Bell Sys Tech J 40 (1961)].
+
+ [{Jargon File}]
+
+ (1999-06-04)
+
+Musical Instrument Digital Interface
+
+ <music, hardware, protocol, file format> (MIDI /mi'-dee/,
+ /mee'-dee/) A {hardware} specification and {protocol} used to
+ communicate note and effect information between synthesisers,
+ computers, music keyboards, controllers, and other electronic
+ music devices. It is basically a high-speed {serial}
+ connection with separate connections for MIDI in, MIDI out and
+ MIDI through (to allow devices to be chained).
+
+ The basic unit of information is a "note on/off" event which
+ includes a note number (pitch) and key velocity (loudness).
+ There are many other message types for events such as pitch
+ bend, patch changes and synthesizer-specific events for
+ loading new patches etc.
+
+ There is a file format for expressing MIDI data which is like
+ a dump of data sent over a MIDI port.
+
+ The {MIME} type "audio/midi" isn't actually registered so it
+ should probably be "audio/x-midi".
+
+ {Filename} {extension}: .mid or .midi
+
+ {(http://update.uu.se/~vick/Coordinator.html)}.
+
+ {Usenet} newsgroups: {news:comp.music.midi},
+ {news:alt.music.midi}.
+
+ (1998-06-27)
+
+Musicam
+
+ <audio, compression> A name for {MPEG-1 Layer 2} used for
+ broadcasting. Common data rates are 192, 224, and 256 kbps.
+
+ (2001-12-13)
+
+MuSimp
+
+ <language> A {Lisp} variant used as the programming language
+ for the {IBM PC} {symbolic mathematics} package {MuMath}.
+
+ (1995-04-12)
+
+MUSL
+
+ {Manchester University Systems Language}
+
+mutant
+
+ <programming> {Microsoft}'s term for a {mutex} which is
+ generally used in {user mode} but can also be used in {kernel
+ mode}. According to this terminology a mutex is only used in
+ kernel mode.
+
+ ["Microsoft Windows NT Workstation Resource Kit"].
+
+ (1997-07-30)
+
+Mutation Testing
+
+ <testing> A method to determine {test set thoroughness} by
+ measuring the extent to which a test set can discriminate the
+ program from slight variants of the program.
+
+ (1996-12-27)
+
+MuTeX
+
+ <tool, music> An extension of {TeX} for typesetting music.
+
+ {(ftp://nic.stolaf.edu/pub/mutex/MuTeX.tar.Z)}.
+
+ (1995-02-06)
+
+mutex
+
+ <parallel> A {mutual exclusion} object that allows multiple
+ {threads} to synchronise access to a shared resource. A mutex
+ has two states: locked and unlocked. Once a mutex has been
+ locked by a thread, other threads attempting to lock it will
+ block. When the locking thread unlocks (releases) the mutex,
+ one of the blocked threads will acquire (lock) it and proceed.
+
+ If multiple threads or tasks are blocked on a locked mutex
+ object, the one to take it and proceed when it becomes
+ available is determined by some type of scheduling algorithm.
+ For example, in a priority based system, the highest priority
+ blocked task will acquire the mutex and proceed. Another
+ common set-up is put blocked tasks on a first-in-first-out
+ queue.
+
+ See also: {priority inversion}
+
+ (2002-03-14)
+
+mutter
+
+ To quietly enter a command not meant for the ears, eyes, or
+ fingers of ordinary mortals. Often used in "mutter an
+ {incantation}".
+
+ See also {wizard}.
+
+ [{Jargon File}]
+
+ (1995-02-06)
+
+mutual exclusion
+
+ <parallel, operating system> (Or "mutex", plural: "mutexes") A
+ collection of techniques for sharing resources so that
+ different uses do not conflict and cause unwanted
+ interactions. One of the most commonly used techniques for
+ mutual exclusion is the {semaphore}.
+
+ (1995-04-08)
+
+mutually recursive
+
+ {recursion}
+
+mutual recursion
+
+ {recursion}
+
+mux
+
+ {multiplexing}
+
+mv
+
+ <networking> The {country code} for Maldives.
+
+ (1999-01-27)
+
+MVC
+
+ 1. <programming> {Model View Controller}.
+
+ 2. <filename extension> The {filename extension} of {JPEG}
+ images output by {Sony}'s {Mavica} range of {digital cameras}.
+
+ (2002-05-28)
+
+MVCC
+
+ {Multi-Version Concurrency Control}
+
+MVS
+
+ {Multiple Virtual Storage}
+
+MVS/ESA
+
+ {Multiple Virtual Storage}
+
+MVS/OE
+
+ {Multiple Virtual Storage}
+
+MVS/Open Edition
+
+ {Multiple Virtual Storage}
+
+MVS/SP
+
+ {Multiple Virtual Storage}
+
+MVS/XA
+
+ {Multiple Virtual Storage}
+
+mw
+
+ <networking> The {country code} for Malawi.
+
+ (1999-01-27)
+
+MX
+
+ {Mail Exchange Record}
+
+mx
+
+ <networking> The {country code} for Mexico.
+
+ (1999-01-27)
+
+MXI
+
+ {Multisystem eXtention Interface Bus}
+
+MXIbus
+
+ {Multisystem eXtention Interface Bus}
+
+MX Record
+
+ {Mail Exchange Record}
+
+my
+
+ <networking> The {country code} for Malaysia.
+
+ (1999-01-27)
+
+My Favourite Toy Language
+
+ <jargon, language> (MFTL) Describes a talk on a {programming
+ language} design that is heavy on {syntax} (with lots of
+ {BNF}), sometimes even talks about {semantics} (e.g. {type
+ systems}), but rarely, if ever, has any content (see
+ {content-free}). More broadly applied to talks - even when
+ the topic is not a programming language --- in which the
+ subject matter is gone into in unnecessary and meticulous
+ detail at the sacrifice of any conceptual content. "Well, it
+ was a typical MFTL talk".
+
+ 2. A language about which the developers are passionate (often
+ to the point of prosyletic zeal) but no one else cares about.
+ Applied to the language by those outside the originating
+ group. "He cornered me about type resolution in his MFTL."
+
+ The first great goal in the mind of the designer of an MFTL is
+ usually to write a compiler for it, then bootstrap the design
+ away from contamination by lesser languages by writing a
+ compiler for it in itself. Thus, the standard put-down
+ question at an MFTL talk is "Has it been used for anything
+ besides its own compiler?". On the other hand, a language
+ that *cannot* be used to write its own compiler is beneath
+ contempt.
+
+ {Doug McIlroy} once proposed a test of the generality and
+ utility of a language and the {operating system} under which
+ it is compiled: "Is the output of a {Fortran} program
+ acceptable as input to the Fortran compiler?" In other words,
+ can you write programs that write programs? Alarming numbers
+ of (language, OS) pairs fail this test, particularly when the
+ language is Fortran. Aficionados are quick to point out that
+ {Unix} (even using Fortran) passes it handily. That the test
+ could ever be failed is only surprising to those who have had
+ the good fortune to have worked only under modern systems
+ which lack OS-supported and -imposed "file types".
+
+ See {break-even point}, {toolsmith}.
+
+ (1995-03-07)
+
+MYOB
+
+ <chat> mind your own business.
+
+ (2006-11-22)
+
+MySpace
+
+ <web> A {social networking} website based in
+ Beverly Hills, California, USA.
+
+ {MySpace home (http://myspace.com/)}.
+
+ (2006-11-22)
+
+MySQL
+
+ <database> /mi: S Q L/ The most popular {open source}
+ {relational database management system}. MySQL is developed,
+ distributed, and supported by {MySQL AB}.
+
+ MySQL was named after co-founder Monty Widenius's daughter,
+ My. It was originally written as a backwards compatible
+ replacement for {mSQL}. It is written in {C}, {C++} and
+ {yacc}. It has become popular for use in {web applications}.
+
+ MySQL supports a broad subset of {ANSI SQL 99} and features
+ {views}, {stored procedures}, {triggers}, {cursors},
+ replication, {internationalisation} and {localisation},
+ partitioning, {ACID transactions}. MySQL can be embedded in
+ other systems or run on a {cluster} for fault tolerance. A
+ commercial version, MySQL Enterprise is available.
+
+ Latest version: 6.0, as of 2009-05-11.
+
+ {MySQL Home (http://mysql.com/)}.
+
+ (2009-05-11)
+
+MySQL AB
+
+ <company> The Swedish company that developes, distributes and
+ supports the {MySQL} {open source} {rdbms}. MySQL AB is a
+ subsidiary of {Sun Microsystems}, themselves acquired by
+ {Oracle Corporation} on 2009-04-20.
+
+ (2009-05-11)
+
+MYSTIC
+
+ <language> An early system on the {IBM 704}, {IBM 650}, {IBM
+ 1103} and 1103A.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (1995-03-07)
+
+MZ
+
+ <standard, file format> The file signature of an {MS-DOS}
+ executable (.{EXE}) file (0x4d 5a), always the first two
+ {bytes} of the file. It was reportedly invented by, and named
+ after, a {Microsoft} programmer, Mark Zbikowski.
+
+ In {Unix} systems, the string MZ is the {magic number} that
+ identifies an MS-DOS EXE file.
+
+ (2003-06-10)
+
+mz
+
+ <networking> The {country code} for Mozambique.
+
+ (1999-01-27)
+
+N
+
+ <mathematics, programming, jargon> A {variable} typically used
+ to stand for a number of objects.
+
+ Used unqualified in speech it suggests a large, undetermined
+ number, e.g. "There were N {bugs} in that {crock}!", or a
+ number implied by context, e.g. "Let's get pizza for N + 1".
+
+ [{Jargon File}]
+
+ (2006-04-18)
+
+N10
+
+ Original codename of the {Intel} {i860} {microprocessor}.
+
+na
+
+ <networking> The {country code} for Namibia.
+
+ (1999-01-27)
+
+nadger
+
+ <jargon> /nad'jr/ [Great Britain] To modify software or hardware
+ in a hidden manner, generally so that it conforms better to some
+ format.
+
+ For instance, an {assembly code} {string} printing {subroutine}
+ that takes its string {argument} from the instruction stream would
+ be called like this:
+
+ jsr print:"Hello world"
+
+ The print routine would use the saved {instruction pointer} (its
+ return address) to find its argument and would have to "nadger" it
+ so that the processor returns to the instruction after the string.
+
+ [{Jargon File}]
+
+ (2014-07-09)
+
+NAG
+
+ 1. {Numerical Algorithms Group}.
+
+ 2. The {Linux Network Administrators' Guide}.
+
+Nagling Coalescence
+
+ <networking, algorithm> An algorithm for improving {TCP/IP}
+ network performance by combining small {packets} ("tinygrams")
+ into larger ones, thus reducing the per-packet overhead. The
+ server transmits the packet either when it has reached a
+ preset size or when it receives an acknowledgment of the
+ previous packet.
+
+ [Who was Nagling?]
+
+ (1998-11-06)
+
+nagware
+
+ /nag'weir/ [{Usenet}] The variety of {shareware} that displays
+ a large screen at the beginning or end reminding you to
+ register, typically requiring some sort of keystroke to
+ continue so that you can't use the software in batch mode.
+ Compare {crippleware}.
+
+ [{Jargon File}]
+
+nailed to the wall
+
+ [like a trophy] Said of a {bug} finally eliminated after
+ protracted, and even heroic, effort.
+
+nailing jelly
+
+ {like nailing jelly to a tree}
+
+naive
+
+ Untutored in the perversities of some particular program or
+ system; one who still tries to do things in an intuitive way,
+ rather than the right way (in really good designs these
+ coincide, but most designs aren't "really good" in the
+ appropriate sense). This trait is completely unrelated to
+ general maturity or competence or even competence at any other
+ specific program. It is a sad commentary on the primitive
+ state of computing that the natural opposite of this term is
+ often claimed to be "experienced user" but is really more like
+ "cynical user".
+
+ (1994-11-29)
+
+naive user
+
+ A {luser}. Tends to imply someone who is ignorant mainly
+ owing to inexperience. When this is applied to someone who
+ *has* experience, there is a definite implication of
+ stupidity.
+
+ [{Jargon File}]
+
+NAK
+
+ {Negative Acknowledgement}
+
+name capture
+
+ <reduction> In {beta reduction}, when a term containing a
+ {free} occurrence of a variable v is substituted into another
+ term where v is bound the free v becomes spuriously bound or
+ "captured". E.g.
+
+ (\ x . \ y . x y) y --> \ y . y y (WRONG)
+
+ This problem arises because two distinct variables have the
+ same name. The most common solution is to rename the bound
+ variable using {alpha conversion}:
+
+ (\ x . \ y' . x y') y --> \ y' . y y'
+
+ Another solution is to use {de Bruijn notation}.
+
+ Note that the argument expression, y, contained a {free
+ variable}. The whole expression above must therefore be
+ notionally contained within the body of some {lambda
+ abstraction} which binds y. If we never reduce inside the
+ body of a lambda abstraction (as in reduction to {weak head
+ normal form}) then name capture cannot occur.
+
+ (1995-03-14)
+
+named
+
+ <networking> Name Daemon.
+
+ <networking> A {Unix} {background} process that converts
+ {hostnames} to {Internet addresses} for the {TCP/IP}
+ {protocol}.
+
+ {Unix manual page}: named(8).
+
+ See also {DNS}.
+
+ (1995-03-28)
+
+named pipe
+
+ <operating system> A {Unix} {pipe} with a {filename} created
+ using the "{mknod}" command. Named pipes allow unrelated
+ processes to communicate with each other whereas the normal
+ (un-named) kind can only be used by processes which are parent
+ and child or siblings ({fork}ed from the same parent).
+
+ (1996-12-01)
+
+name resolution
+
+ <networking> The process of mapping a name into its
+ corresponding address.
+
+ The {Domain Name System} is the system which does name
+ resolution on the {Internet}.
+
+ (1997-12-15)
+
+name service switching
+
+ {Domain Name System}
+
+namespace
+
+ <systems> The {set} of all possible identifiers for some kind
+ of object. From the definition of a set, all names in a
+ namespace are unique and there is some rule to determine
+ whether a potential name is an element of the set. For
+ example, the {Domain Name System} includes rules for
+ determining what constitutes a valid host name.
+
+ (2008-12-09)
+
+naming convention
+
+ 1. <programming> {variable naming convention}.
+
+ 2. <networking> {Universal Naming Convention}.
+
+NaN
+
+ {Not-a-Number}
+
+NAND
+
+ <logic> Not AND. The {Boolean} function which is true unless
+ both its arguments are true, the {logical complement} of
+ {AND}:
+
+ A NAND B = NOT (A AND B) = (NOT A) OR (NOT B)
+
+ Its {truth table} is:
+
+ A | B | A NAND B
+ --+---+---------
+ F | F | T
+ F | T | T
+ T | F | T
+ T | T | F
+
+ NAND, like {NOR}, forms a complete set of {Boolean} functions
+ on its own since it can be used to make NOT, AND, OR and any
+ other Boolean function:
+
+ NOT A = A NAND A
+
+ A AND B = NOT (A NAND B)
+
+ A OR B = (NOT A) NAND (NOT B)
+
+ (1995-01-24)
+
+nano-
+
+ /nan'oh/ 1. <unit> A {prefix} meaning 10^-9 or one billionth.
+
+ Used loosely to mean "small", e.g. {nanotechnology}, or
+ (rarely), following "nanosecond", to mean a short time,
+ e.g. "I'll be with you in a nano".
+
+ [{Jargon File}]
+
+ (2002-03-02)
+
+nanoacre
+
+ <unit, humour> /nan'oh-ay"kr/ A unit (about 2 mm square) of
+ real estate on a {VLSI} {integrated circuit}. VLSI nanoacres
+ have costs in the same range as real acres once one allows for
+ design and fabrication setup costs.
+
+ [{Jargon File}]
+
+ (1995-09-20)
+
+nanobot
+
+ <robotics> /nan"oh-bot/ A robot of microscopic proportions,
+ presumably built by means of {nanotechnology}. As yet, only
+ used informally (and speculatively!). Also called a
+ "nanoagent".
+
+ [{Jargon File}]
+
+ (1999-07-19)
+
+nanocomputer
+
+ <architecture> /nan'oh-k*m-pyoo'tr/ A computer with
+ molecular-sized switching elements. Designs for mechanical
+ nanocomputers which use single-molecule sliding rods for their
+ logic have been proposed. The controller for a {nanobot}
+ would be a nanocomputer.
+
+ Some nanocomputers can also be called {quantum computers}
+ because quantum physics plays a major role in calculations.
+ {Richard P. Feynman} is still cited today for his work in this
+ area.
+
+ ["Feynman Lectures on Computation", Richard P. Feynman
+ (Editor, Author), Robin W. Allen (Editor), Tony Hey (Author)]
+
+ [{Jargon File}]
+
+ (2008-01-14)
+
+nanofortnight
+
+ <jargon> ({Adelaide University}) 10^-9 fortnights or about 1.2
+ {milliseconds}. This unit was used largely by students doing
+ undergraduate practicals.
+
+ See {microfortnight}, {attoparsec}, and {micro-}.
+
+ (1996-11-15)
+
+nanometre
+
+ <unit> 10^-9 metres; one thousand millionth part of a metre.
+
+ The wavelength of visible light and dimensions in
+ {nanotechnology} are typically measured in nanometres.
+
+ (2003-05-02)
+
+nanosecond
+
+ <unit> (ns) 10^-9 seconds; one thousand millionth part of a
+ second.
+
+ This is the unit in which the fundamental logical operations
+ of modern digital circuits are typically measured. For
+ example, a {microprocessor} with a {clock} frequency of 100
+ {megahertz} will have a 10 nanosecond clock period.
+
+ (1996-11-15)
+
+nanotechnology
+
+ /nan'-oh-tek-no"l*-jee/ Any fabrication technology in which
+ objects are designed and built by the specification and
+ placement of individual atoms or molecules or where at least
+ one dimension is on a scale of {nanometers}.
+
+ The first unequivocal nanofabrication experiments took place
+ in 1990, for example with the deposition of individual xenon
+ atoms on a nickel substrate to spell the logo of a certain
+ very large computer company.
+
+ {Richard P. Feynman's initial public discussion in 1959-12-29
+ (http://www.zyvex.com/nanotech/feynman.html)} lead to the
+ {Feynman Prize for Nanotechnology
+ (http://www.foresight.org/FI/fi_spons.html)}. Erik Drexler
+ coined the term about 30 years later in his book "Engines of
+ Creation", where he predicted that nanotechnology could give
+ rise to replicating assemblers, permitting an exponential
+ growth of productivity and personal wealth.
+
+ See also {nanobot}.
+
+ {(http://lucifer.com/~sean/Nano.html)}.
+
+ (2008-01-14)
+
+Napier
+
+ Atkinson & Morrison, St Andrews U; design began ca. 1985,
+ first implementation Napier88, 1988. Based on {orthogonal
+ persistence}, permits definition and manipulation of
+ namespaces.
+
+ ["The Napier88 Reference Manual", R. Morrison et al, CS Depts
+ St Andrews U and U Glasgow, Persistent Programming Research
+ Report PPRR-77-89, 1989].
+
+NAPLPS
+
+ North American Presentation-Level-Protocol Syntax. Format for
+ sending text and graphics over communication lines. Used by
+ {videotex} systems.
+
+NAPSS
+
+ Numerical Analysis Problem Solving System. Purdue ca. 1965.
+
+ ["NAPSS - A Numerical Analysis Problem Solving System",
+ J.R. Rice et al, Proc ACM 21st Natl Conf, 1966. Sammet 1969,
+ p.299].
+
+narrowband
+
+ <networking> A communication channel with a low data rate.
+ [More specific?]
+
+ The term is sometimes used for an {Internet} connection via a
+ {dial-up modem}, typically at 56 kbaud, in contrast to
+ {broadband}.
+
+ (2003-10-15)
+
+narrowing
+
+ {Unification} followed by {unfolding}. The left-hand side of
+ a {rule} is unified with some term, resulting in a set of
+ variable bindings. The term is then replaced by the
+ right-hand side of the rule with values substituted for {bound
+ variables}.
+
+NAS
+
+ <networking> 1. {Network Application Support}.
+
+ 2. <storage> {Network Attached Storage}.
+
+ 3. <company> {National Advanced Systems}.
+
+ (2003-07-20)
+
+nasal demons
+
+ Recognised shorthand on the {Usenet} group comp.std.c for any
+ unexpected behaviour of a {C} compiler on encountering an
+ undefined construct. During a discussion on that group in
+ early 1992, a regular remarked "When the compiler encounters
+ [a given undefined construct] it is legal for it to make
+ demons fly out of your nose" (the implication is that the
+ compiler may choose any arbitrarily bizarre way to interpret
+ the code without violating the {ANSI C} {standard}). Someone
+ else followed up with a reference to "nasal demons", which
+ quickly became established.
+
+ [{Jargon File}]
+
+NASI
+
+ {NetWare Asynchronous Services Interface}
+
+ {Novell NetWare}.
+
+nastistical
+
+ <humour, mathematics> A description of a method, thought by
+ the programmer to be correct statistics, but which is not. An
+ example is averaging together several averages of samples of
+ different sizes. The correct way to do this is to average
+ together all of the individual samples.
+
+ (1997-02-12)
+
+NASTRAN
+
+ NAsa STRess ANalysis program. A program for solving large
+ stress analysis problems.
+
+ ["The NASTRAN User's Manual", SP-222(C3), NASA, 1976].
+
+nastygram
+
+ <networking> /nas'tee-gram/ 1. A {network} {packet} or
+ {e-mail} message (the latter is also called a {letterbomb})
+ that takes advantage of misfeatures or security holes on the
+ target system to do untoward things.
+
+ 2. Disapproving e-mail, especially from a {net.god}, pursuant
+ to a violation of {netiquette} or a complaint about failure to
+ correct some mail- or news-transmission problem. Compare
+ {shitogram}, {mailbomb}.
+
+ 3. A status report from an unhappy, and probably picky,
+ customer. "What did Corporate say in today's nastygram?"
+
+ 4. [deprecated] An error reply by mail from a {daemon}; in
+ particular, a {bounce message}.
+
+ [{Jargon File}]
+
+ (2004-02-17)
+
+NAT
+
+ {Network Address Translation}
+
+Nathan Hale
+
+ <character> An {asterisk} ("*", see also {splat}, {ASCII}).
+ Notionally, from "I regret that I have only one asterisk for
+ my country!" ("life to give" -> "ass to risk" -> "asterisk"),
+ a misquote of the famous remark uttered by Nathan Hale just
+ before he was hanged. Hale was a (failed) spy for the rebels
+ in the American War of Independence.
+
+ [{Jargon File}]
+
+ (1996-09-22)
+
+National Advanced Systems
+
+ <company> (NAS) A company, previously known as ITEL, that made
+ {IBM} {plug-compatible} {hardware} and was bought by Hitachi.
+
+ [Is this correct? Dates? US?]
+
+ (2003-07-20)
+
+National Bureau of Standards
+
+ {National Institute of Standards and Technology}
+
+National Center for Supercomputing Applications
+
+ <body, web> (NCSA) The birthplace of the first
+ version of the {Mosaic} {web browser}.
+
+ Address: Urbana, IL, USA.
+
+ {(http://ncsa.uiuc.edu/)}.
+
+ [Summary?]
+
+ (1994-10-27)
+
+national characters
+
+ <character> {Characters} with accents and other diacritical
+ marks that are used in certain written languages (that are
+ based on the Roman alphabet) but not in others, particularly
+ not in English. A standard list is {ISO} {Latin 1}.
+
+ (1996-06-24)
+
+National Database Language
+
+ <database, standard> (NDL) A US {standard} for portability of
+ {database} definitions and {application programs}.
+
+ (1996-06-24)
+
+National Information Infrastructure
+
+ <project> (NII, or "{information superhighway}") Future
+ integrated communications in the USA. The NII will be based
+ on a nationwide network of networks, and will supposedly allow
+ all Americans to take advantage of the country's information,
+ communication, and computing resources.
+
+ The NII will include current and future public and private
+ high-speed, interactive, {narrow-band} and {broadband}
+ networks. It is the satellite, terrestrial, and wireless
+ communications systems that deliver content to homes,
+ businesses, and other public and private institutions. It is
+ the information and content that flows over the infrastructure
+ whether in the form of {databases}, the written word, a film,
+ a piece of music, a sound recording, a picture, or computer
+ software. It is the computers, televisions, telephones,
+ radios, and other products that people will employ to access
+ the infrastructure. It is the people who will provide,
+ manage, and generate new information, and those that will help
+ others do the same. And it is the individual Americans who
+ will use and benefit from the NII. The NII is a term that
+ encompasses all these components and captures the vision of a
+ nationwide, invisible, seamless, dynamic web of transmission
+ mechanisms, information appliances, content, and people.
+
+ {(http://sunsite.unc.edu/nii/NII-Table-of-Contents.html)}.
+
+ (1995-04-08)
+
+National Information Services and Systems
+
+ (NISS) An information archive service at {Bath University},
+ intended primarily for UK eductional institutions.
+
+ {(http://niss.ac.uk/)}.
+
+ (1994-11-23)
+
+National Institute of Standards and Technology
+
+ <body> (NIST, formerly the National Bureau of Standards) A
+ United States governmental body that helps develop
+ {standards} including {FIPS}.
+
+ {NIST Home (http://nist.gov/)}.
+
+ (2003-06-04)
+
+National Research and Education Network
+
+ (NREN) The realisation of an interconnected gigabit computer
+ network devoted to High Performance Computing and
+ Communications.
+
+ See also {HPPC}, {IINREN}.
+
+ (1994-11-23)
+
+National Science Foundation
+
+ <body> (NSF) A US government agency that promotes the
+ advancement of science by funding science researchers,
+ scientific projects and infrastructure to improve the quality
+ of scientific research. The {NSFNET} is funded by NSF.
+
+ {(http://nsf.org/)}.
+
+ (1999-01-15)
+
+National Science Foundation Network
+
+ (NSFNET) A high speed hierarchical "network of networks" in
+ the US, funded by the {National Science Foundation}. At the
+ highest level, it is a {backbone} network comprising 16 nodes
+ connected to a 45Mb/s facility which spans the continental
+ United States. Attached to that are mid-level networks and
+ attached to the mid-levels are campus and local networks.
+ NSFNET also has connections out of the US to Canada, Mexico,
+ Europe, and the Pacific Rim. The NSFNET is part of the
+ {Internet}.
+
+ (1993-01-01)
+
+National Semiconductor
+
+ <company> A {semiconductor} manufacturer, responsible for the
+ {SC/MP}, {National Semiconductor 16000} and {National
+ Semiconductor 32000} series of {microprocessors}.
+
+ (2005-06-09)
+
+National Semiconductor 32000
+
+ <processor> (NS32000) <processor> The first of a series of
+ {microprocessors} from {National Semiconductor}. The 320xx
+ processors have an interface which allows {coprocessors} such
+ as {FPUs} and {MMUs} to be attached in a chain.
+
+ The 320xx was the predecessor of the {Swordfish} processor.
+
+ [Details?]
+
+ (1994-11-17)
+
+National Software Reuse Directory
+
+ (NSRD) A directory of reusable software in the {ASSET} system.
+
+ (1995-02-03)
+
+National Spatial Data Infrastructure
+
+ (NSDI)
+
+ {(http://fgdc.er.usgs.gov/nsdiover.html)}.
+
+ [Summary?]
+
+ (1995-03-06)
+
+National Television Standards Committee
+
+ <electronics> (NTSC) The body defining the television video
+ signal format used in the USA. The UK equivalent is {PAL}.
+
+ Also, humorously, "Never Twice the Same Colour".
+
+ (1997-07-17)
+
+native compiler
+
+ <programming, tool> A {compiler} which runs on the computer
+ for which it is producing {machine code}, in contrast to a
+ {cross-compiler}, which produces code for a different
+ computer.
+
+ (1995-11-04)
+
+Native Language System
+
+ (NLS) A set of interfaces specified by {X/Open} for developing
+ applications to run in different {natural language}
+ environments.
+
+ (1995-02-03)
+
+NATURAL
+
+ An integrated {4GL} from {Software AG}, Germany. The
+ menu-driven version is SUPER/NATURAL.
+
+ Natural 2 is a major upgrade to Natural 1.
+
+ Version 2.1.7 in the MVS environment (June 1995, also
+ available for Unix).
+
+ Natural works with {DB2} and various other {databases}, but
+ Natural and {Adabas} normally go together. There are many
+ products available in the "Natural" family, including
+ SuperNatural, Natural for Windows, Entire Connection (enables
+ up/downloading and interaction with {Excel}) and Esperant.
+
+ (1995-11-14)
+
+natural deduction
+
+ <logic> A set of rules expressing how valid {proofs} may be
+ constructed in {predicate logic}.
+
+ In the traditional notation, a horizontal line separates
+ {premises} (above) from {conclusions} (below). Vertical
+ ellipsis (dots) stand for a series of applications of the
+ rules. "T" is the constant "true" and "F" is the constant
+ "false" (sometimes written with a {LaTeX} {\perp}).
+
+ "^" is the AND ({conjunction}) operator, "v" is the inclusive
+ OR ({disjunction}) operator and "/" is NOT (negation or
+ {complement}, normally written with a {LaTeX} {\neg}).
+
+ P, Q, P1, P2, etc. stand for {propositions} such as "Socrates
+ was a man". P[x] is a proposition possibly containing
+ instances of the variable x, e.g. "x can fly".
+
+ A proof (a sequence of applications of the rules) may be
+ enclosed in a box. A boxed proof produces conclusions that
+ are only valid given the assumptions made inside the box,
+ however, the proof demonstrates certain relationships which
+ are valid outside the box. For example, the box below
+ labelled "Implication introduction" starts by assuming P,
+ which need not be a true {proposition} so long as it can be
+ used to derive Q.
+
+ Truth introduction:
+
+ -
+ T
+
+ (Truth is free).
+
+ Binary AND introduction:
+
+ -----------
+ | . | . |
+ | . | . |
+ | Q1 | Q2 |
+ -----------
+ Q1 ^ Q2
+
+ (If we can derive both Q1 and Q2 then Q1^Q2 is true).
+
+ N-ary AND introduction:
+
+ ----------------
+ | . | .. | . |
+ | . | .. | . |
+ | Q1 | .. | Qn |
+ ----------------
+ Q1^..^Qi^..^Qn
+
+ Other n-ary rules follow the binary versions similarly.
+
+ Quantified AND introduction:
+
+ ---------
+ | x . |
+ | . |
+ | Q[x] |
+ ---------
+ For all x . Q[x]
+
+ (If we can prove Q for arbitrary x then Q is true for all x).
+
+ Falsity elimination:
+
+ F
+ -
+ Q
+
+ (Falsity opens the floodgates).
+
+ OR elimination:
+
+ P1 v P2
+ -----------
+ | P1 | P2 |
+ | . | . |
+ | . | . |
+ | Q | Q |
+ -----------
+ Q
+
+ (Given P1 v P2, if Q follows from both then Q is true).
+
+ Exists elimination:
+
+ Exists x . P[x]
+ -----------
+ | x P[x] |
+ | . |
+ | . |
+ | Q |
+ -----------
+ Q
+
+ (If Q follows from P[x] for arbitrary x and such an x exists
+ then Q is true).
+
+ OR introduction 1:
+
+ P1
+ -------
+ P1 v P2
+
+ (If P1 is true then P1 OR anything is true).
+
+ OR introduction 2:
+
+ P2
+ -------
+ P1 v P2
+
+ (If P2 is true then anything OR P2 is true). Similar
+ symmetries apply to ^ rules.
+
+ Exists introduction:
+
+ P[a]
+ -------------
+ Exists x.P[x]
+
+ (If P is true for "a" then it is true for all x).
+
+ AND elimination 1:
+
+ P1 ^ P2
+ -------
+ P1
+
+ (If P1 and P2 are true then P1 is true).
+
+ For all elimination:
+
+ For all x . P[x]
+ ----------------
+ P[a]
+
+ (If P is true for all x then it is true for "a").
+
+ For all implication introduction:
+
+ -----------
+ | x P[x] |
+ | . |
+ | . |
+ | Q[x] |
+ -----------
+ For all x . P[x] -> Q[x]
+
+ (If Q follows from P for arbitrary x then Q follows from P for
+ all x).
+
+ Implication introduction:
+
+ -----
+ | P |
+ | . |
+ | . |
+ | Q |
+ -----
+ P -> Q
+
+ (If Q follows from P then P implies Q).
+
+ NOT introduction:
+
+ -----
+ | P |
+ | . |
+ | . |
+ | F |
+ -----
+ / P
+
+ (If falsity follows from P then P is false).
+
+ NOT-NOT:
+
+ //P
+ ---
+ P
+
+ (If it is not the case that P is not true then P is true).
+
+ For all implies exists:
+
+ P[a] For all x . P[x] -> Q[x]
+ -------------------------------
+ Q[a]
+
+ (If P is true for given "a" and P implies Q for all x then Q
+ is true for a).
+
+ Implication elimination, modus ponens:
+
+ P P -> Q
+ ----------
+ Q
+
+ (If P and P implies Q then Q).
+
+ NOT elimination, contradiction:
+
+ P /P
+ ------
+ F
+
+ (If P is true and P is not true then false is true).
+
+ (1995-01-16)
+
+Natural English
+
+ Programming in normal, spoken English. [Sammet 1969, p.768].
+
+natural language
+
+ <application> A language spoken or written by humans, as
+ opposed to a language use to program or communicate with
+ computers.
+
+ Natural language understanding is one of the hardest problems
+ of {artificial intelligence} due to the complexity,
+ irregularity and diversity of human language and the
+ philosophical problems of meaning.
+
+ See also {Pleuk grammar development system}, {proof}, {MIT
+ "Start" Project (http://start.csail.mit.edu/)}, {New York U
+ (http://nyu.edu/pages/linguistics/ling.html)}.
+
+ (2011-01-30)
+
+Natural Language Information Analysis Method
+
+ (NIAM, or Nijssen IAM) A method for {data model}ling.
+
+ ["Conceptual Scheme and Relational Database Design", Nijssen
+ and Halpin, Prentice-Hall, 1989].
+
+ (1995-03-31)
+
+natural language processing
+
+ <artificial intelligence> (NLP) Computer understanding,
+ analysis, manipulation, and/or generation of {natural
+ language}.
+
+ This can refer to anything from fairly simple
+ string-manipulation tasks like {stemming}, or building
+ concordances of natural language texts, to higher-level
+ {AI}-like tasks like processing user {queries} in {natural
+ language}.
+
+ (1997-09-12)
+
+natural number
+
+ <mathematics> An {integer} greater than or equal to zero. A
+ natural number is an {isomorphism class} of a finite set.
+
+ (1995-03-25)
+
+nature
+
+ {has the X nature}
+
+NAU
+
+ <networking>
+
+ 1. {Network Addressable Unit}.
+
+ 2. {Network Access Unit}.
+
+ (1997-05-10)
+
+nav bar
+
+ {navigation bar}
+
+navigating
+
+ {navigation}
+
+navigation
+
+ <web> Finding your way around a {website}.
+ Many sites have some kind of {navigation bar}. One of
+ the first {web browsers} was called {Netscape Navigator}.
+
+ (2008-11-17)
+
+navigation bar
+
+ <web> (Always abbreviated "nav bar")
+ On a {website}, a prominently displayed set
+ of {links} to important sections of the site.
+
+ (2008-11-17)
+
+Navigator
+
+ {Netscape Navigator}
+
+Nawk
+
+ New AWK. AT&T. Pattern scanning and processing language. An
+ enhanced version of AWK, with dynamic regular expressions,
+ additional built-ins and operators, and user-defined
+ functions.
+
+NB
+
+ {C}
+
+NBFCP
+
+ {NetBIOS Frames Control Protocol}
+
+NBS
+
+ National Bureau of Standards: part of the US Department of
+ Commerce, now NIST.
+
+NBT
+
+ {NetBios over TCP/IP}
+
+NC
+
+ {Network Computer}
+
+nc
+
+ <networking> The {country code} for New Caledonia.
+
+ (1999-01-27)
+
+NCD
+
+ {Network Computing Devices}
+
+NCP
+
+ <networking>
+
+ 1. {IBM} {Advanced Communication Function/Network Control
+ Program}.
+
+ 2. {Novell, Inc.} {NetWare Core Protocol}.
+
+ (1999-01-20)
+
+NCR Corporation
+
+ <company> Electronics company mainly active in the midrange
+ server market.
+
+ NCR was founded 1884 as National Cash Register Company. It
+ joint the computer industry in th 1950s. In 1991 it was
+ absorbed by {AT&T} (see {dinosaurs mating}), only to be spat
+ out again in 1996.
+
+ NCR {mainframes} of the 1960's are remembered by some for
+ their hardware incompatibility with {IBM} mainframes: NCR
+ punched round holes in their {punched cards} while IBM punched
+ rectangular ones. The codes and machines were not compatible
+ and information could not be easily shared between NCR and IBM
+ customers.
+
+ {(http://ncr.com/)}.
+
+ (1997-03-10)
+
+NCRL
+
+ {Software Writer's Language}
+
+NCR Language
+
+ {Software Writer's Language}
+
+NCS
+
+ Network Computing System: Apollo's RPC system used by DEC and
+ Hewlett-Packard.The protocol has been adopted by {OSF}.
+
+NCSA
+
+ {National Center for Supercomputing Applications}
+
+ND
+
+ {natural deduction}
+
+NDIS
+
+ {Network Device Interface Specification}
+
+NDL
+
+ 1. {National Database Language}.
+
+ 2. {Network Definition Language}.
+
+NDS
+
+ {Netware Directory Services}
+
+ne
+
+ <networking> The {country code} for Niger.
+
+ (1999-01-27)
+
+neat hack
+
+ 1. A clever technique.
+
+ 2. A brilliant practical joke, where neatness is correlated
+ with cleverness, harmlessness, and surprise value. Example:
+ the Caltech Rose Bowl card display switch. See also {hack}.
+
+ [{Jargon File}]
+
+neats vs. scruffies
+
+ <artificial intelligence, jargon> The label used to refer to
+ one of the continuing {holy wars} in {artificial intelligence}
+ research. This conflict tangles together two separate issues.
+ One is the relationship between human reasoning and AI;
+ "neats" tend to try to build systems that "reason" in some way
+ identifiably similar to the way humans report themselves as
+ doing, while "scruffies" profess not to care whether an
+ {algorithm} resembles human reasoning in the least as long as
+ it works. More importantly, neats tend to believe that
+ {logic} is king, while scruffies favour looser, more ad-hoc
+ methods driven by empirical knowledge. To a neat, scruffy
+ methods appear promiscuous, successful only by accident and
+ not productive of insights about how intelligence actually
+ works; to a scruffy, neat methods appear to be hung up on
+ formalism and irrelevant to the hard-to-capture "common sense"
+ of living intelligences.
+
+ (1994-11-29)
+
+Nebula
+
+ An early business-oriented language from {ICL} for the
+ {Ferranti Orion} computer.
+
+ ["NEBULA - A Programming Language for Data Processing", T.G.
+ Braunholtz et al, Computer J 4(3):197-201 (1961)].
+
+ (1994-11-29)
+
+NEC
+
+ {Nippon Electronics Corporation}
+
+NEC 780-C
+
+ <processor> A copy of the {Zilog Z80A} {microprocessor},
+ running at 3.25 MHz.
+
+ The NEC 780-C was the processor used in the Sinclair {ZX-80}.
+
+ (2002-03-11)
+
+needs assessment
+
+ <systems> A systematic process to acquire an accurate,
+ thorough picture of a system's strengths and weaknesses, in
+ order to improve it and meet existing and future challenges.
+
+ (2007-11-24)
+
+neep-neep
+
+ /neep neep/ [onomatopoeic, from New York SF fandom] One who is
+ fascinated by computers. Less specific than {hacker}, as it
+ need not imply more skill than is required to {boot} {games}
+ on a {personal computer}. The derived noun "neeping" applies
+ specifically to the long conversations about computers that
+ tend to develop in the corners at most SF-convention parties
+ (the term "neepery" is also in wide use). Fandom has a
+ related proverb to the effect that "Hacking is a
+ conversational black hole!".
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+negation by failure
+
+ An {extralogical} feature of {Prolog} and other {logic
+ programming} languages in which failure of {unification} is
+ treated as establishing the negation of a {relation}. For
+ example, if Ronald Reagan is not in our {database} and we
+ asked if he was an American, Prolog would answer "no".
+
+ (1994-11-29)
+
+negative acknowledgement
+
+ 1. <character> (NAK) The {mnemonic} for {ASCII} character 21.
+
+ Sometimes used as the response to receipt of a corrupted
+ {packet} of information.
+
+ Opposite of {acknowledgement}.
+
+ 2. <communications> (NAK) Any message transmitted to indicate
+ that some data has been received incorrectly, for example it
+ may have a {checksum} or message length error. A NAK message
+ allows the sender to distinguish a message which has been
+ received in a corrupted state from one which is not received
+ at all.
+
+ An alternative is to use only {ACK} messages, in which case
+ the non-receipt of an ACK after a certain time is counted as a
+ NAK but gives no information about the {integrity} of the
+ communications channel.
+
+ See also {ACK}.
+
+ (1997-01-07)
+
+neighborhood bike code
+
+ <humour, programming> A piece of {code} that every programmer at
+ the company has touched.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ [{Urban Dictionary: neighborhood bike
+ (http://www.urbandictionary.com/define.php?term=neighborhood+bike)}].
+
+ (2014-07-12)
+
+NELIAC
+
+ Navy Electronics Laboratory International ALGOL Compiler.
+
+ An {Algol} variant designed for numeric and logical
+ computations and based on {IAL}. 1958-1959.
+
+ Version: BC NELIAC.
+
+ ["Neliac - A Dialect of Algol", H.D. Huskey et al, CACM
+ 3(8):463-468 (Aug 1960)].
+
+ (1994-11-29)
+
+Neon
+
+ Charles Duff. An object-oriented extension of FORTH, for the
+ Mac. Inheritance, SANE {floating-point}, system classes and
+ objects for Mac interfacing, overlays. Sold by Kriya Systems,
+ 1985-1988. Modified, made PD and renamed Yerk.
+
+neophilia
+
+ /nee"oh-fil"-ee-*/ The trait of being excited and pleased by
+ novelty. Common among most hackers, SF fans, and members of
+ several other connected leading-edge subcultures, including
+ the pro-technology "Whole Earth" wing of the ecology movement,
+ space activists, many members of Mensa, and the
+ Discordian/neo-pagan underground. All these groups overlap
+ heavily and (where evidence is available) seem to share
+ characteristic hacker tropisms for science fiction, music,
+ and oriental food. The opposite tendency is "neophobia".
+
+ [{Jargon File}]
+
+ (1999-06-04)
+
+Neptune
+
+ A hypertext system for computer assisted software engineering,
+ developed at Tektronix.
+
+nerd
+
+ <person> A generally pejortive term for any person who is
+ socially inept and studious or demonstrates obsessive
+ knowledge of something. For example, a computer nerd. The
+ term first appeared in print in "If I Ran the Zoo", 1950 by
+ Dr. Seuss.
+
+ Compare: {geek}.
+
+ (2010-02-28)
+
+Nerd pride
+
+ <body> The Nerd Pride movement, modeled on the Gay Pride
+ movement, was started at {MIT} by Professors {Gerald Sussman}
+ and {Hal Abelson}. Nerd pride paraphernalia includes baseball
+ hats, buttons and - of course - pocket protectors.
+
+ "My idea is to present an image to children that it is good to
+ be intellectual, and not to care about the peer pressures to
+ be anti-intellectual. I want every child to turn into a nerd
+ - where that means someone who prefers studying and learning
+ to competing for social dominance".
+
+ -- {Gerald Sussman}, quoted by Katie Hafner, "New York Times",
+ 1994-08-29.
+
+ (1994-11-11)
+
+NERECO
+
+ NEtwork REmote COmmunications.
+
+ {CSP} with extensions to allow asymmetrical and {asynchronous}
+ communications and fault handling. It is implemented on a
+ network of {Suns}.
+
+ ["A Concurrent Programming Support for Distributed Systems",
+ G. Spezzano et al, in Computing Systems vol 3, pp.423-447, U
+ Cal Press, 1990].
+
+ (1994-11-11)
+
+NESL
+
+ <language> A parallel language loosely based on {ML},
+ developed at {Carnegie Mellon University} by the {SCandAL}
+ project. NESL integrates parallel {algorithms}, {functional
+ languages} and implementation techniques from the system's
+ community.
+
+ Nested {data parallelism} offers concise code that is easy to
+ understand and debug and suits irregular data structures such
+ as {trees}, {graphs} or {sparse matrices}.
+
+ NESL's language based performance model is a formal way to
+ calculate the "work" and "depth" of a program. These measures
+ can be related to running time on a {parallel computer}.
+
+ NESL was designed to make parallel programming easy and
+ portable. Algorithms are typically more concise in NESL than
+ in most other parallel programming languages and the code
+ resembles high-level {pseudocode}. This places more
+ responsibility on the {compiler} and {run-time system} for
+ achieving good efficiency.
+
+ NESL currently runs on {Unix} {workstations}, the {IBM SP-2},
+ the {Thinking Machines} {CM5}, the {Cray} {C90} and {J90}, the
+ {MasPar} {MP2}, and the {Intel} {Paragon}. Work is underway
+ (April 1997) on a portable {MPI} {back end}, and an
+ implementation for {symmetric multiprocessors}, such as the
+ {SGI} {Power Challenge} or the {DEC} {AlphaServer}.
+
+ Latest version: Release 3.1, as of 1995-11-01.
+
+ {Home
+ (http://cs.cmu.edu/afs/cs.cmu.edu/project/scandal/public/www/nesl.html)}.
+
+ ["NESL: A Nested Data-Parallel Language", Guy Blelloch,
+ CMU-CS-93-129, April 1993].
+
+ (1997-04-13)
+
+nested class
+
+ <Java> In {Java}, a {class} defined within an enclosing class
+ definition. A {static} nested class has no direct access to
+ the members of its enclosing class whereas a non-static nested
+ class, known as an "inner class", is associated with an
+ instance of the enclosing class and an instance of the inner
+ class has direct access to the members of its enclosing
+ instance.
+
+ {Java Tutorial
+ (http://java.sun.com/docs/books/tutorial/java/javaOO/nested.html)}.
+
+ [Other languages?]
+
+ (2006-11-19)
+
+net
+
+ 1. <networking> {network}.
+
+ 2. <networking> {network, the}.
+
+ 3. <architecture> {neural network}.
+
+ 4. <networking> The {top-level domain} originally for
+ networks, although it sees heavy use for {vanity domains} of
+ all types.
+
+ [{Jargon File}]
+
+ (1999-01-26)
+
+.NET
+
+ {.NET framework}
+
+net.-
+
+ <convention, networking, messaging> /net dot/ A prefix used to
+ describe people and events related to {Usenet} and the
+ {Internet}. The convention dates from the time before the
+ {Great Renaming}, when most non-local {Usenet} newsgroups had
+ names beginning "net.". Includes {net.gods}, "net.goddesses"
+ (various charismatic net.women with circles of on-line
+ admirers), "net.lurkers" (see {lurker}), "net.person",
+ "net.parties" (a synonym for {boink}), and many similar
+ constructs.
+
+ See also {net.police}.
+
+ [{Jargon File}]
+
+ (1995-03-21)
+
+netaddress
+
+ {Knowbot Information Service}
+
+NetBEUI
+
+ {NetBIOS} Extended User Interface. The network transport
+ {protocol} used by all of {Microsoft}'s network systems and
+ {IBM}'s {LAN Server} based systems.
+
+ NetBEUI is often confused with {NetBIOS}. NetBIOS is the
+ {applications programming interface} and NetBEUI is the
+ transport protocol.
+
+NetBIOS
+
+ An {applications programming interface} (API) which activates
+ {network} operations on {IBM PC} compatibles running under
+ {Microsoft}'s {DOS}. It is a set of network commands that the
+ application program issues in order to transmit and receive
+ data to another {host} on the network. The commands are
+ interpreted by a {network control program} or {network
+ operating system} that is NetBIOS compatible. See
+ {NetBOLLIX}.
+
+NetBIOS Frames Control Protocol
+
+ <protocol> (NBFCP, NBF protocol, originally "NetBEUI
+ protocol")
+
+ [RFC 2097]
+
+ [What is it?]
+
+ (1997-05-10)
+
+NetBios over TCP/IP
+
+ <protocol> (NBT) A protocol supporting {NetBIOS} services in a
+ {TCP/IP} environment, defined by {RFCs} 1001 and 1002.
+
+ (1997-07-04)
+
+NetBOLLIX
+
+ ["bollix": to bungle] {IBM}'s {NetBIOS}, an extremely
+ {brain-damaged} {network} {protocol} that, like {Blue Glue},
+ is used at commercial shops that don't know any better.
+
+ [{Jargon File}]
+
+NetBSD
+
+ <operating system> An {open source} {Unix} {clone} that aims
+ for {platform} independance by a clean separation between the
+ {hardware} and the the {kernel}. It has been ported to many
+ platforms from {embedded systems} to 64-bit computers.
+
+ {NetBSD Home (http://netbsd.org/)}.
+
+ (2004-10-08)
+
+netbui
+
+ <spelling> It's spelled "{NetBEUI}".
+
+ (1996-12-23)
+
+netburp
+
+ <networking, chat> (Or "netsplit") When {netlag} gets really
+ bad, and delays between {IRC} servers exceed a certain
+ threshhold, the network effectively becomes partitioned for a
+ period of time, and large numbers of people seem to be signing
+ off at the same time and then signing back on again when
+ things get better. An instance of this is called a "netburp"
+ (or, sometimes, {netsplit}).
+
+ [{Jargon File}]
+
+ (1996-06-04)
+
+netCDF
+
+ Network Common Data Form. A machine-independent,
+ self-describing file format for scientific data.
+
+Netcom On-line Communication Services, Inc.
+
+ <company> A company providing {Internet} access on {Sun
+ Microsystems} computers running {Unix}. Customers either log
+ in to a {shell} running on a Netcom computer, or rent a {SLIP}
+ or {PPP} connection and run their own net software. Most
+ hosts are in San Jose, California, but they have {Points of
+ Presence} all over the USA.
+
+ {(http://netcom.com/)}.
+
+ Address: 3031 Tisch Way San Jose, CA 95128, USA.
+
+ Telephone: +1 (408) 983 5950, +1 800 353 6600. Fax: +1 (408)
+ 241 9145.
+
+ (1996-04-23)
+
+netdead
+
+ <jargon, chat> The state of someone who signs off {IRC},
+ perhaps during a {netburp}, and doesn't sign back on until
+ later. In the interim, he is "dead to the net".
+
+ [{Jargon File}]
+
+ (2007-09-02)
+
+Netfind
+
+ A research prototype that provides a simple {Internet} "{white
+ pages}" user directory. It runs on {SunOS} 4.0 or more recent
+ systems that are connected to the Internet (however, you can
+ run Netfind on one server at your site, and let the others use
+ Netfind on that server). Given the name of a person on the
+ Internet and a rough description of where the person works,
+ Netfind attempts to locate telephone and electronic mailbox
+ information about the person.
+
+ {(ftp://ftp.cs.colorado.edu/pub/cs/distribs/netfind)}.
+
+.NET framework
+
+ <language, tool, library> A software development and execution
+ environment designed by {Microsoft} as a direct competitor to
+ {Java}. .NET framework should not be confused with
+ {Microsoft}'s past labeling of a line of products as ".NET".
+
+ .NET simplifies interoperability between languages and
+ machines on {Microsoft Windows} especially, although not
+ specifically, for web based services. Essentially the .NET
+ framework consists of the CLR (common language runtime), CTS
+ (common type system), CLS (common language system), and IL
+ (intermediate language).
+
+ The CLR consists of a number of resources provided to .NET
+ applications such as the security model, type system and .NET
+ classes (c.f. Java classes). The CTS is the range of all
+ types that .NET understands although it is not necessarily the
+ case that a .NET program will understand all of these types.
+ The CLS however is a subset of the CTS which all .NET
+ languages must support: any two .NET languages can
+ interoperate via. the CLS.
+
+ All .NET languages are at some stage compiled into the IL, a
+ {byte-code} like language. However unlike a standard Java run
+ time environment, the IL is converted to {machine code} either
+ upon installation of the software or at {run time} by a {just
+ in time compiler} (JIT). The IL is not interpretted.
+
+ .NET's main weakness is that Microsoft have ignored the {Unix}
+ and {mainframe} environments, effectively ruling .NET out of
+ use in many {enterprise} environments. However there is
+ {Mono} - an {open source} .NET framework for Unix}.
+
+ .NET was based on research by Steven Lucco on a product called
+ {OmniVM}, sold by {Colusa software}. Attracted to OmniVM
+ since VB and C/C++ environments were already available,
+ Microsoft bought Colusa in 1996. Microsoft provides .NET
+ compilers for {C#}, {C++}, {VB}, and {Jscript}.
+
+ (2003-09-24)
+
+net.god
+
+ <person> /net god/ Accolade referring to anyone who satisfies
+ some combination of the following conditions: has been visible
+ on {Usenet} for more than 5 years, ran one of the original
+ backbone sites, moderated an important newsgroup, wrote news
+ software, or knows Gene, Mark, Rick, Mel, Henry, Chuq, and
+ Greg personally.
+
+ Net.goddesses such as Rissa or the Slime Sisters have (so far)
+ been distinguished more by personality than by authority.
+
+ See {demigod}.
+
+ [{Jargon File}]
+
+ (1996-01-07)
+
+NetHack
+
+ <games> /net'hak/ (Unix) A dungeon game similar to {rogue} but
+ more elaborate, distributed in {C} source over {Usenet} and
+ very popular at {Unix} sites and on {PC}-class machines
+ (nethack is probably the most widely distributed of the
+ {freeware} dungeon games). The earliest versions, written by
+ Jay Fenlason and later considerably enhanced by Andries
+ Brouwer, were simply called "hack". The name changed when
+ maintenance was taken over by a group of hackers originally
+ organised by Mike Stephenson.
+
+ Version: NetHack 3.2 (Apr 1996?).
+
+ {(http://win.tue.nl/games/roguelike/nethack/)}.
+
+ {FAQ
+ (ftp://rtfm.mit.edu/pub/usenet/rec.games.roguelike.nethack/)}.
+
+ {FTP U Penn (ftp://linc.cis.upenn.edu/pub/NH3.1/)} No large
+ downloads between 9:00 and 18:00 local or the directory will
+ be removed.
+
+ {Usenet} newsgroup: {news:rec.games.roguelike.nethack}.
+
+ E-mail: <nethack-bugs@linc.cis.upenn.edu>.
+
+ (1996-06-13)
+
+netiquette
+
+ <convention, networking> /net'ee-ket/ or /net'i-ket/ Network
+ etiquette.
+
+ The conventions of politeness recognised on {Usenet} and in
+ {mailing lists}, such as not (cross-)posting to inappropriate
+ groups and refraining from commercial advertising outside the
+ biz groups.
+
+ The most important rule of netiquette is "Think before you
+ post". If what you intend to post will not make a positive
+ contribution to the newsgroup and be of interest to several
+ readers, don't post it! Personal messages to one or two
+ individuals should not be posted to newsgroups, use private
+ e-mail instead.
+
+ When following up an article, quote the minimum necessary to
+ give some context to your reply and be careful to attribute
+ the quote to the right person. If the article you are
+ responding to was posted to several groups, edit the
+ distribution ("Newsgroups:") header to contain only those
+ groups which are appropriate to your reply, especially if the
+ original message was posted to one or more inappropriate
+ groups in the first place.
+
+ Re-read and edit your posting carefully before you post.
+ Check the spelling and grammar. Keep your lines to less than
+ 70 characters. Don't post test messages (except to test
+ groups) - wait until you have something to say. When posting
+ humorous or sarcastic comments, it is conventional to append
+ a {smiley}, but don't overuse them.
+
+ Before asking a question, read the messages already in the
+ group and read the group's {FAQ} if it has one. When you do
+ post a question, follow it with "please reply by mail and I
+ will post a summary if requested" and make sure you DO post a
+ summary if requested, or if only a few people were interested,
+ send them a summary by mail. This avoids umpteen people
+ posting the same answer to the group and umpteen others
+ posting "me too"s.
+
+ If you believe someone has violated netiquette, send them a
+ message by __private e-mail__, DO NOT post a follow-up to the
+ news. And be polite, they may not realise their mistake, they
+ might be a beginner or may not even have been responsible for
+ the "crime" - their account may have been used by someone else
+ or their address forged.
+
+ Be proud of your postings but don't post just to see your name
+ in pixels. Remember: your future employer may be reading.
+
+ {Netiquette for Usenet Site Administrators
+ (http://ancho.ucs.indiana.edu/FAQ/USAGN/index.html)}.
+
+ {"net.acceptable"
+ (http://marketing.tenagra.com/net-acceptable.html)}.
+
+ [{Jargon File}]
+
+ (1999-10-18)
+
+NETL
+
+ A {semantic network} language, for {connectionist}
+ architectures.
+
+ ["NETL: A System for Representing and Using Real-World Data",
+ S.E. Fahlman, MIT Press 1979].
+
+ (1995-01-05)
+
+netlag
+
+ <networking> A condition that occurs when the delays in the
+ {IRC} network, a {MUD} connection, a {telnet} connection, or
+ any other networked interactive system, become severe enough
+ that servers briefly lose and then reestablish contact,
+ causing messages to be delivered in bursts, often with delays
+ of up to a minute. (Note that this term has nothing to do
+ with mainstream "jet lag").
+
+ [{Jargon File}]
+
+ (1996-06-21)
+
+NetLingo
+
+ <computing, reference> An on-line dictionary of more than 3000
+ terms, started in 1995 and updated monthly. NetLingo contains
+ simple explanations and comprehensive coverage, including
+ {chat} acronyms and {smilies}. It is also available in {dead
+ tree} form.
+
+ {NetLingo Home (http://netlingo.com/)}.
+
+ (2004-09-12)
+
+netload
+
+ A program to down-load {Excelan} {TCP/IP} software. The
+ host's {Ethernet} address can be specified as
+
+ netload -e aabbccddeeff
+
+ where aabbccddeeff is a 12 {hexadecimal} digit number.
+
+ (1994-12-14)
+
+Netmarq Limited
+
+ A small technical consultancy specialising in the testing of
+ network components. They do performance tests of network
+ interface cards, {routers}, {hubs}, {file servers}, etc. To
+ reflect the marketplace, most tests are carried out in a
+ {Novell NetWare} environment, although they can equally well
+ use {Lan server}, {Banyan Vines}, {NT Advanced Server}, {IBM
+ PC} Support. They claim to be Europe's leading such test lab
+ and compete with US Labs such as {LanQuest} and {NSTL}. They
+ also do some network design, installation, support, and
+ troubleshooting.
+
+ E-mail: <netmarq@cix.compulink.co.uk>.
+
+ (1994-12-14)
+
+netmask
+
+ <networking> A 32-bit {bit mask} which shows how an {Internet
+ address} is to be divided into network, {subnet} and host
+ parts. The netmask has ones in the bit positions in the 32-bit address which are to be used for the network and subnet
+ parts, and zeros for the host part. The mask should contain
+ at least the standard network portion (as determined by the
+ address's {class}), and the subnet field should be contiguous
+ with the network portion.
+
+ If a `+' (plus sign) is given for the netmask value, then the
+ network number is looked up in the {NIS} netmasks.byaddr map
+ (or in the /etc/netmasks) file if not running the NIS service.
+
+ {Unix manual page}: ifconfig(8).
+
+ (1995-01-30)
+
+NetNanny
+
+ <networking> A small program for children to block access to
+ certain sites.
+
+ [Company? Address?]
+
+ (1997-02-12)
+
+netnews
+
+ /net'n[y]ooz/ 1. The software that makes {Usenet} run.
+
+ 2. The content of {Usenet}. "I read netnews right after my
+ mail most mornings."
+
+ [{Jargon File}]
+
+ (1994-12-14)
+
+net.personality
+
+ Someone who has made a name for him or herself on {Usenet},
+ through either longevity or attention-getting posts, but
+ doesn't meet the other requirements of {net.god}hood.
+
+ [{Jargon File}]
+
+netpipes
+
+ <networking> A package by Robert Forsman <thoth@cis.ufl.edu>
+ to manipulate {BSD Unix} {TCP/IP} stream {sockets}. The
+ netpipes package makes TCP/IP streams usable in {shell
+ scripts}. It can also simplify {client-server} code by
+ allowing the programmer to skip all the tedious programming
+ related to sockets and concentrate on writing a
+ filter/service.
+
+ {(http://cis.ufl.edu/~thoth/netpipes/)}.
+
+ (1996-10-03)
+
+net.police
+
+ /net-p*-lees'/ (Or "net police", "net.cops") Those {Usenet}
+ readers who feel it is their responsibility to pounce on and
+ {flame} any posting which they regard as offensive or in
+ violation of their understanding of {netiquette}. Generally
+ used sarcastically or pejoratively.
+
+ See also {net.-}, {code police}.
+
+ [{Jargon File}]
+
+netquette
+
+ <spelling> It's spelled "{netiquette}".
+
+ (1999-09-30)
+
+Netrek
+
+ <games> A 16-player graphical {real-time} battle simulation
+ with a Star Trek theme. The game is divided into two teams of
+ eight (or less), who dogfight each other and attempt to
+ conquer each other's planets. There are several different
+ types of ships, from fast, fragile scouts up to big, slow
+ battleships; this allows a great deal of variance in play
+ styles. Netrek is played using a {client} to connect to one
+ of several Netrek {servers} on the {Internet}. There is a
+ metaserver which distributes details of games in progress on
+ other servers.
+
+ See also {ogg}.
+
+ [Dates? Versions? Authors? Addresses?]
+
+ (1998-02-01)
+
+netrock
+
+ /net'rok/ (IBM) A {flame}; used especially on {VNET}, {IBM}'s
+ internal corporate network.
+
+ [{Jargon File}]
+
+ (1994-11-18)
+
+Netscape
+
+ 1. {Netscape Navigator}.
+
+ 2. {Netscape Communications Corporation}.
+
+Netscape Communications Corporation
+
+ <company> (Formlerly "Mosaic Communications Corporation", MCC)
+ A company set up in April 1994 by {Dr. James H. Clark} and
+ {Marc Andreessen} <marca@netcom.com> (creator of the {NCSA}
+ {Mosaic} program) to market their version of {Mosaic}, known
+ as {Netscape} or {Mozilla}.
+
+ They {changed their name
+ (http://netscape.com/newsref/pr/newsrelease5.html)} on
+ 1994-11-14 to reflect their other activities rather than just
+ their browser based on {Mosaic}.
+
+ {(http://netscape.com/)}.
+
+ Address: 501 East Middlefield Road, Mountain View, CA 94043,
+ USA.
+
+ Telephone: +1 (415) 254 1900. Fax: +1 (415) 254 2601.
+
+ (2000-02-08)
+
+Netscape Navigator
+
+ <networking, tool, product> /Mozilla/ (Often called just
+ "Netscape") A {web browser} from {Netscape
+ Communications Corporation}. The first {beta-test} version
+ was released free to the {Internet} on 13 October 1994.
+ Netscape evolved from {NCSA} {Mosaic} (with which it shares at
+ least one author) and runs on the {X Window System} under
+ various versions of {Unix}, on {Microsoft Windows} and on the
+ {Apple Macintosh}.
+
+ It features integrated support for sending {electronic mail}
+ and reading {Usenet} news, as well as {RSA encryption} to
+ allow secure communications for commercial applications such
+ as exchanging credit card numbers with net retailers. It
+ provides multiple simultaneous interruptible text and image
+ loading; native inline {JPEG} image display; display and
+ interaction with documents as they load; multiple independent
+ windows. Netscape was designed with 14.4 kbps modem links in
+ mind.
+
+ You can download Netscape Navigator for evaluation, or for
+ unlimited use in academic or not-for-profit environments. You
+ can also pay for it.
+
+ Version: 1.0N.
+
+ {(ftp://ftp.netscape.com/netscape/)}.
+
+ E-mail: <sales@netscape.com>.
+
+ (1995-01-25)
+
+Netscape Public License
+
+ {open source license}
+
+netsplit
+
+ {netburp}
+
+netstat
+
+ <networking> (Or "rstat") A {Unix} command to give statistics
+ about the {network} including {socket} status, interfaces that
+ have been auto-configured, memory statistics, {routing}
+ tables.
+
+ {Unix manual pages}: rstat(3), netstat(8).
+
+ (1996-06-04)
+
+netter
+
+ 1. Loosely, anyone with a {network address}.
+
+ 2. More specifically, a {Usenet} regular. Most often found in
+ the plural. "If you post *that* in a technical group, you're
+ going to be flamed by angry netters for the rest of time!"
+
+ [{Jargon File}]
+
+NetWare
+
+ {Novell NetWare}
+
+NetWare Core Protocol
+
+ <networking> (NCP) A {Novell} trademark for the {protocol}
+ used to access {Novell NetWare} file and print service
+ functions. It uses an underlying {IPX} or {IP} {transport
+ protocol}.
+
+ (1995-11-11)
+
+Netware Directory Services
+
+ <networking> (NDS) {Novell, Inc.}'s {directory services} for
+ {Netware}, {Windows NT}, and {Unix}. The NDS directory
+ represents each {network} resource (user, hardware, or
+ application) as an {object} of a certain {class}, where each
+ class has certain properties. For example, User and Print
+ Server are object classes and a user has over 80 properties
+ such as name, login, password, department, and title.
+
+ The directory is hierarchical, divided into branches by {rules
+ of containment}. A given object can only belong to a given
+ container (or branch). The rules governing classes,
+ properties and, {rules of containment} are known as the
+ {schema}.
+
+ (2001-03-20)
+
+Netware Input/Output Subsystem
+
+ <operating system, networking> (NIOS) The lowest {layer} in
+ the {Novell NetWare} {client} architecture. NIOS is the
+ interface layer between the client operating system and the
+ 32-bit client services provided by NetWare.
+
+ {(http://developer.novell.com/research/appnotes/1996/november/01/04.htm)}.
+
+ (1999-04-24)
+
+NetWare Link State Protocol
+
+ <networking, protocol> (NLSP) A companion {protocol} to {IPX}
+ for exchange of {routing} information in a {Novell}
+ {network}. NLSP supersedes Novell's {RIP}.
+
+ (1997-03-04)
+
+network
+
+ <networking> Hardware and software data communication systems.
+
+ The {OSI} seven layer model attempts to provide a way of
+ partitioning any computer network into independent modules
+ from the lowest (physical) layer to the highest (application)
+ layer. Many different specifications exist at each of these
+ layers.
+
+ Networks are often also classified according to their
+ geographical extent: {local area network} (LAN), {metropolitan
+ area network} (MAN), {wide area network} (WAN) and also
+ according to the {protocols} used.
+
+ See {BITNET}, {Ethernet}, {Internet}, {Novell}, {PSTN},
+ {network, the}.
+
+ [Tanenbaum, A., "Computer Networks; 2nd ed.", Prentice Hall,
+ Englewood Cliffs, NJ, 1989.]
+
+ (1995-03-10)
+
+network address
+
+ <networking> 1. The network portion of an {IP address}. For a
+ {class A} network, the network address is the first {byte} of
+ the IP address. For a {class B network}, the network address
+ is the first two bytes of the IP address. For a {class C
+ network}, the network address is the first three bytes of the
+ IP address. In each case, the remainder is the {host
+ address}. In the {Internet}, assigned network addresses are
+ globally unique.
+
+ See also {subnet address}, {Internet Registry}.
+
+ 2. (Or "net address") An {electronic mail} address on {the
+ network}. In the 1980s this might have been a {bang path} but
+ now (1997) it is nearly always a {domain address}. Such an
+ address is essential if one wants to be to be taken seriously
+ by {hackers}; in particular, persons or organisations that
+ claim to understand, work with, sell to, or recruit from among
+ hackers but *don't* display net addresses are quietly presumed
+ to be clueless poseurs and mentally {flush}ed.
+
+ Hackers often put their net addresses on their business cards
+ and wear them prominently in contexts where they expect to
+ meet other hackers face-to-face (e.g. {science-fiction
+ fandom}). This is mostly functional, but is also a signal
+ that one identifies with hackerdom (like lodge pins among
+ Masons or tie-dyed T-shirts among Grateful Dead fans). Net
+ addresses are often used in e-mail text as a more concise
+ substitute for personal names; indeed, hackers may come to
+ know each other quite well by network names without ever
+ learning each others' real monikers.
+
+ See also {sitename}, {domainist}.
+
+ [{Jargon File}]
+
+ (1997-05-10)
+
+Network Addressable Unit
+
+ <networking> (NAU) The {SNA} term for an {addressable entity}.
+ Examples include {PUs}, {LUs}, and {SSCPs}.
+
+ (1997-05-10)
+
+Network Address Translation
+
+ <networking> (NAT, or Network Address Translator, Virtual LAN)
+ A technique in which a {router} or {firewall} rewrites the
+ source and/or destination {Internet addresses} in a packet as
+ it passes through, typically to allow multiple {hosts} to
+ connect to the {Internet} via a single external {IP address}.
+ NAT keeps track of outbound connections and distributes
+ incoming packets to the correct machine.
+
+ NAT is an alternative to adopting {IPv6} (IPng). It allows
+ the same IP addresses (10.x.x.x is the conventional range) to
+ be used on many private local networks while requiring only
+ one of the increasingly scarce public addresses to be
+ allocated to each private network.
+
+ NAT does not however allow an external service to initiate a
+ TCP connection to an internal host, nor does it support
+ stateless protocols based on UDP well unless the router
+ software has extensions to support each specific protocol.
+
+ (2005-09-18)
+
+Network Address Translator
+
+ {Network Address Translation}
+
+Network Administrator
+
+ <job> A person who manages a communications {network} within
+ an organisation. Responsibilities include network {security},
+ installing new applications, distributing software upgrades,
+ monitoring daily activity, enforcing licensing agreements,
+ developing a {storage management} program and providing for
+ routine {backups}.
+
+ (2004-03-20)
+
+Network Application Support
+
+ <networking> (NAS) {DEC}'s approach to {applications
+ integration} across a {distributed} multivendor environment.
+
+ (2003-06-30)
+
+Network Attached Storage
+
+ <networking, storage> (NAS) {Fixed disks}, {RAID} arrays, and
+ {magnetic tape} drives connected directly to a {Storage Area
+ Network} (SAN) or other direct network connection. This is in
+ contrast to a {file server} where the peripherals are
+ connected to the network via a computer (the server).
+
+ (2003-06-30)
+
+network byte order
+
+ <networking> The order in which the {bytes} of a multi-byte
+ number are transmitted on a network - most significant byte
+ first (as in "{big-endian}" storage). This may or may not
+ match the order in which numbers are normally stored in memory
+ for a particular processor.
+
+ {(http://sun.com/realitycheck/headsup980803.html)}.
+ {(http://hp.com/unixwork/whatsnew/fyi/bissue/aug98/article3.htm)}.
+
+ (1998-11-15)
+
+network card
+
+ {network interface controller}
+
+network closet
+
+ <networking> The place where {network} {hardware} (other than
+ cabling) is installed. The space should be used primarily for
+ storage, be dry, and have electricity available. Since
+ network equipment rarely needs attention once installed and
+ tested, the network closet can have limited accessibility.
+
+ (1995-05-05)
+
+Network Computing Devices
+
+ <company> (NCD) Producer of {X terminals}, {PC-Xware} and
+ {Z-Mail}.
+
+ {(http://ncd.com/)}.
+
+ (1998-10-07)
+
+network database
+
+ <database> A kind of {database management system} in which
+ each record type can have multiple owners, e.g. orders are
+ owned by both customers and products. This contrasts with a
+ {hierarchical database} (one owner) or {relational database}
+ (no explicit owner).
+
+ (1998-10-07)
+
+Network Definition Language
+
+ (NDL) The language used to program the DCP (Data
+ Communications Processor) on {Burroughs Large System}.
+
+ Version: NDL II.
+
+ (1994-12-12)
+
+Network Device Interface Specification
+
+ <networking, hardware, standard> (NDIS) A {Microsoft Windows
+ device driver} programming interface allowing multiple
+ {protocols} to share the same {network} {hardware}.
+ E.g. {TCP/IP} and {IPX} on the same {NIC}. NDIS can also be
+ used by some ISDN adapters.
+
+ A protocol manager accepts requests from the {transport layer}
+ and passes them to the {data link layer} (routed to the
+ correct network interface if there is more than one).
+
+ NDIS was developed by {Microsoft} and {3COM}. {Novell} offers
+ a similar device driver for NetWare called Open Data-Link
+ Interface (ODI).
+
+ The NDIS 2.0 specification was 5000 lines.
+
+ Latest version: NDIS 5.0, as of 2000-10-30.
+
+ {(http://microsoft.com/hwdev/devdes/ndis5.htm)}.
+
+ {cdrom.com NDIS archive
+ (ftp://ftp.cdrom.com/pub/os2/network/ndis/)}.
+
+ ["3TECH, The 3COM Technical Journal", Winter 1991].
+
+ (2000-10-30)
+
+network engineer
+
+ <job> A high-level {LAN}/{WAN} technician who plans,
+ implements and supports {network} solutions between multiple
+ {platforms}. A network engineer installs and maintains local
+ area network hardware and software, and troubleshoots network
+ usage and computer {peripherals}. He may have {CNE}
+ certification.
+
+ (2004-03-20)
+
+Network extensible Window System
+
+ (NeWS) An elegant {PostScript}-based windowing environment,
+ invented by James Gosling, the author of {GOSMACS}.
+
+ NeWS would almost certainly have won the {standards} war with
+ the {X Window System} if it hadn't been {proprietary} to {Sun
+ Microsystems}. There is a lesson here that too many software
+ vendors haven't yet heeded. Communication is based on
+ {PostScript} and server functions can be extended.
+
+ See also {HyperNeWS}, {OpenWindows}.
+
+ (1994-12-12)
+
+Network File System
+
+ <networking, operating system> (NFS) A {protocol} developed by
+ {Sun Microsystems}, and defined in {RFC 1094}, which allows a
+ computer to access files over a network as if they were on its
+ local disks. This {protocol} has been incorporated in
+ products by more than two hundred companies, and is now a {de
+ facto} standard. NFS is implemented using a {connectionless
+ protocol} ({UDP}) in order to make it {stateless}.
+
+ See {Nightmare File System}, {WebNFS}.
+
+ (1994-12-12)
+
+Network Filing System
+
+ <spelling> Misnomer for {Network File System}.
+
+Network Information Center
+
+ (NIC) A body that provides information, assistance and
+ services to {network} users. These will typically include
+ telephone and {electronic mail} "help desk" type services for
+ users and network information services such as {hostnames} and
+ addresses which are accessed automatically by computers using
+ some {client-server} protocol (usually Sun's {NIS}).
+
+ See also {Network Operations Center}.
+
+ (1994-12-13)
+
+Network Information Service
+
+ <networking, protocol> (NIS) {Sun Microsystems}' Yellow Pages
+ (yp) {client-server} {protocol} for distributing system
+ configuration data such as user and host names between
+ computers on a network.
+
+ Sun licenses the technology to virtually all other {Unix}
+ vendors.
+
+ The name "Yellow Pages" is a registered trademark in the
+ United Kingdom of British Telecommunications plc for their
+ (paper) commercial telephone directory. Sun changed the name
+ of their system to NIS, though all the commands and functions
+ still start with "yp", e.g. {ypcat}, {ypmatch}, {ypwhich}.
+
+ {Unix manual pages}: yp(3), ypclnt(3), ypcat(1), ypmatch(1).
+
+ (1995-04-08)
+
+Network Information System
+
+ <spelling> A mis-expansion of {NIS}.
+
+ (1995-04-08)
+
+networking
+
+ {network}
+
+network interface card
+
+ {network interface controller}
+
+network interface controller
+
+ <hardware, networking> (NIC or "network interface card") An
+ adapter circuit board installed in a computer to provide a
+ physical connection to a network.
+
+ [Examples? Attributes?]
+
+ (1996-03-04)
+
+network layer
+
+ <networking> (communications subnet layer) The third lowest
+ layer in the {OSI} seven layer model. The network layer
+ determines routing of {packets} of data from sender to
+ receiver via the {data link layer} and is used by the
+ {transport layer}. The most common network layer {protocol}
+ is {IP}.
+
+ (1994-12-13)
+
+network layer reachability information
+
+ <networking> (NLRI) Keywords used for {unicast} and
+ {multicast} {database} forwarding. For example, you would
+ assign a user's NLRI so the user can receive multicast
+ messages regarding hardware down time that will affect a
+ specific user group.
+
+ [Reference?]
+
+ (2002-06-01)
+
+network management
+
+ <networking> The process of controlling a {network} so as to
+ maximise its efficiency and productivity. {ISO}'s model
+ divides network management into five categories: {fault
+ management}, {accounting management}, {configuration
+ management}, {security management} and {performance
+ management}.
+
+ Fault management is the process of identifying and locating
+ faults in the network. This could include discovering the
+ existence of the problem, identifying the source, and possibly
+ repairing (or at least isolating the rest of the network from)
+ the problem.
+
+ Configuration management is the process of identifying,
+ tracking and modifying the setup of devices on the network.
+ This category is extremely important for devices that come
+ with numerous custom settings (e.g. {routers} and {file
+ servers}).
+
+ Security management is the process of controlling (granting,
+ limiting, restricting or denying) access to the network and
+ resources thereon. This could include setting up and managing
+ {access lists} in {routers} (creating "{firewalls}" to keep
+ intruders out), creating and maintaining password access to
+ critical network resources, identifying the points of entry
+ used by intruders and closing them.
+
+ Performance Management is the process of measuring the
+ performance of various network components. This also includes
+ taking measures to optimise the network for maximum system
+ performance (periodically measuring of the use of network
+ resources).
+
+ {Usenet} newsgroup: {news:comp.dcom.net-management}.
+
+ ["Network Management: A Practical Perspective", Allan Leinwand
+ and Karen Fang].
+
+ (1994-11-18)
+
+network meltdown
+
+ <networking> (By analogy with catastrophic failure of a
+ nuclear reactor) An event that causes saturation, or near
+ saturation, of a network. Network meltdown usually results
+ from illegal or misrouted {packets} (see {Chernobyl packet})
+ and typically lasts only a short time. It may also be caused
+ by a {hardware} fault. It is the network equivalent of
+ {thrashing}.
+
+ [{Jargon File}]
+
+ (2004-02-17)
+
+Network News Transfer Protocol
+
+ (NNTP) A {protocol} defined in {RFC} 977 for the distribution,
+ inquiry, retrieval and posting of {Usenet} {news} articles
+ over the {Internet}. It is designed to be used between a
+ {news reader} {client} such as {nn} or {GNUS} and a news
+ {server}. It is normally used on a connection to {TCP} {port}
+ 119 on the news {server}. NNTP is a simple {ASCII} text
+ protocol so even if you don't have a news reader program, you
+ can just connect to the server using {telnet}:
+
+ telnet news 119
+
+ where news is the name of your server
+ (e.g. news.doc.ic.ac.uk). Typing HELP will give a list of
+ other commands.
+
+network node
+
+ <networking> (node) An addressable device attached to a
+ computer {network}. If the node is a computer it is more
+ often called a "host".
+
+ (2004-08-25)
+
+Network Node Interface
+
+ <networking> (NNI) The {ATM Forum}'s specification for
+ connections between network nodes. NNI makes network
+ {routing} possible. It typically refers to {backbone} trunk
+ connections between ATM switching equipment.
+
+ See also: {UNI}.
+
+ (2001-03-26)
+
+network number
+
+ {network address}
+
+Network Operating System
+
+ <operating system> (NOS) The {operating system} on {Control
+ Data Corporation}'s {Cyber Computer}.
+
+ [Details?]
+
+ (2002-11-22)
+
+network operating system
+
+ <networking, operating system> (NOS) An {operating system}
+ which includes {software} to communicate with other computers
+ via a {network}. This allows resources such as files,
+ {application programs}, and {printers} to be shared between
+ computers.
+
+ Examples are {Berkeley Software Distribution} {Unix},
+ {Novell}, {LAntastic}, {MS LAN Manager}.
+
+ [Is there a specific OS called "Network Operating System"?]
+
+ (2001-03-13)
+
+Network Operations Center
+
+ (NOC) A location from which the operation of a {network} or
+ {internet} is monitored. Additionally, this center usually
+ serves as a clearinghouse for connectivity problems and
+ efforts to resolve those problems.
+
+ See also {Network Information Center}.
+
+ (1994-12-01)
+
+network operator
+
+ <job> A person who monitors and maintains the operation of a
+ communications network. A network operator troubleshoots
+ hardware (cables, {routers}, {network switches}, {hubs},
+ {network adaptors}), software, and transmission problems.
+
+ (2004-03-09)
+
+network redirector
+
+ <networking> An {operating system} {driver} that sends data to
+ and receives data from a remote device. A network redirector
+ often provides mechanisms to locate, open, read, write, and
+ delete files and submit print jobs.
+
+ It also makes available application services such as {named
+ pipes} and {mailslots}. When an application needs to send or
+ receive data from a remote device, it sends a call to the
+ redirector. The redirector provides the functionality of the
+ {Application layer} and {Presentation layer} of the {OSI}
+ model.
+
+ In {Microsoft Networking}, the network redirectors are
+ implemented as {installable file systems} (IFS).
+
+ (1999-08-08)
+
+network segment
+
+ <networking> A part of an {Ethernet} or other network, on
+ which all message traffic is common to all nodes, i.e. it is
+ broadcast from one node on the segment and received by all
+ others. This is normally because the segment is a single
+ continuous conductor, though it may include {repeaters}(?).
+
+ Since all nodes share the physical medium, {collision
+ detection} or some other {protocol} is required to determine
+ whether a message was transmitted without interference from
+ other nodes. The receiving node inspects the destination
+ address of a {packet} to tell if it was (one of) the intended
+ recipient(s).
+
+ Communication between nodes on different segments is via one
+ or more {routers}.
+
+ (1996-10-16)
+
+Network Solutions, Inc.
+
+ <company> (NSI) One of the three companies that provide and
+ coordinate {InterNIC} services for the {NSFNet}. NSI is
+ responsible for registration. NSI has been bought by, and is
+ now a wholly-owned subsidiary of, {Science Applications
+ International Corporation} (SAIC).
+
+ (1995-11-09)
+
+network storm
+
+ {broadcast storm}
+
+Network Termination
+
+ (NT, NT1) A device connecting the customer's data or telephone
+ equipment to the local {ISDN} exchange carrier's line. The NT
+ device provides a connection for {terminal equipment} (TE) and
+ {terminal adaptor} (TA) equipment to the {local loop}.
+
+ (1994-11-30)
+
+network, the
+
+ 1. <jargon, networking> (Or "the net") The union of all the
+ major noncommercial, academic and hacker-oriented networks,
+ such as {Internet}, the old {ARPANET}, {NSFnet}, {BITNET}, and
+ the virtual {UUCP} and {Usenet} "networks", plus the corporate
+ in-house networks and commercial {time-sharing} services (such
+ as {CompuServe}) that gateway to them.
+
+ A site was generally considered "on the network" if it could
+ be reached by {electronic mail} through some combination of
+ Internet-style (@-sign) and UUCP ({bang-path}) addresses.
+ Since the explosion of the Internet in the mid 1990s, the term
+ is now synonymous with the Internet.
+
+ See {network address}.
+
+ 2. <body> A fictional conspiracy of libertarian
+ hacker-subversives and anti-authoritarian monkeywrenchers
+ described in Robert Anton Wilson's novel "Schrödinger's Cat",
+ to which many {hackers} have subsequently decided they belong
+ (this is an example of {ha ha only serious}).
+
+ [{Jargon File}]
+
+ (1999-01-26)
+
+Network Time Protocol
+
+ (NTP) A {protocol} built on top of {TCP/IP} that assures
+ accurate local timekeeping with reference to radio, atomic or
+ other clocks located on the {Internet}. This protocol is
+ capable of synchronizing distributed clocks within
+ milliseconds over long time periods. It is defined in {STD}
+ 12, {RFC 1119}.
+
+network topology
+
+ <networking> The "shape" of a network, how the {nodes} are
+ connected to each other. Common topologies are {bus network},
+ {star network} and {ring network}.
+
+ (2009-07-16)
+
+network transparency
+
+ <networking> A feature of an {operating system} or other
+ service which lets the user access a remote resource through a
+ {network} without having to know if the resource is remote or
+ local.
+
+ For example {NFS} allow users to access remote files as if
+ they were local files.
+
+ (1996-12-21)
+
+NetX
+
+ <company> A LukeCo Company that designs {web pages} and web
+ software. Not to be confused with {Net:X}.
+
+ {(http://members.aol.com/netx11/index.html)}.
+
+ (1996-12-15)
+
+Net:X
+
+ <company> A Canadian company. Not to be confused with {NetX}.
+
+ {(http://netx.ca/)}.
+
+ [Summary?]
+
+ (1998-06-25)
+
+neural nets
+
+ {artificial neural network}
+
+neural network
+
+ {artificial neural network}
+
+neuron
+
+ {artificial neural network}
+
+Neutral Interconnect
+
+ Network infrastructure where network service providers can
+ freely exchange traffic without policy restrictions. Examples
+ are the GIX (Global Internet Exchange) at MAE-East (A
+ Metropolitan Area Ethernet around Washington), and the Ebone
+ (European Backbone). There is currently (November 1993) no UK
+ Neutral Interconnect.
+
+neutrosophic
+
+ {Neutrosophy}
+
+neutrosophic logic
+
+ <logic> (Or "Smarandache logic") A generalisation of {fuzzy
+ logic} based on {Neutrosophy}. A {proposition} is t true, i
+ indeterminate, and f false, where t, i, and f are real values
+ from the ranges T, I, F, with no restriction on T, I, F, or
+ the sum n=t+i+f. Neutrosophic logic thus generalises:
+
+ - {intuitionistic logic}, which supports incomplete theories
+ (for 0<n<100 and i=0, 0<=t,i,f<=100);
+
+ - {fuzzy logic} (for n=100 and i=0, and 0<=t,i,f<=100);
+
+ - {Boolean logic} (for n=100 and i=0, with t,f either 0 or
+ 100);
+
+ - {multi-valued logic} (for 0<=t,i,f<=100);
+
+ - {paraconsistent logic} (for n>100 and i=0, with both
+ t,f<100);
+
+ - {dialetheism}, which says that some contradictions are true
+ (for t=f=100 and i=0; some {paradoxes} can be denoted this
+ way).
+
+ Compared with all other logics, neutrosophic logic introduces
+ a percentage of "indeterminacy" - due to unexpected parameters
+ hidden in some propositions. It also allows each component
+ t,i,f to "boil over" 100 or "freeze" under 0. For example, in
+ some {tautologies} t>100, called "overtrue".
+
+ {(http://gallup.unm.edu/~smarandache/NeutLog.txt)}.
+
+ ["Neutrosophy / Neutrosophic probability, set, and logic",
+ F. Smarandache, American Research Press, 1998].
+
+ (1999-10-04)
+
+neutrosophic probability
+
+ <logic> An extended form of probability based on
+ {Neutrosophy}, in which a statement is held to be t true, i
+ indeterminate, and f false, where t, i, f are real values from
+ the ranges T, I, F, with no restriction on T, I, F or the sum
+ n=t+i+f.
+
+ {(http://gallup.unm.edu/~smarandache/NeutProb.txt)}.
+
+ ["Neutrosophy / Neutrosophic Probability, Set, and Logic",
+ Florentin Smarandache, American Research Press, 1998].
+
+ (1999-10-04)
+
+neutrosophic set
+
+ <logic> A generalisation of the {intuitionistic set},
+ classical set, {fuzzy set}, {paraconsistent set}, {dialetheist
+ set}, {paradoxist set}, {tautological set} based on
+ {Neutrosophy}. An element x(T, I, F) belongs to the set in
+ the following way: it is t true in the set, i indeterminate in
+ the set, and f false, where t, i, and f are real numbers taken
+ from the sets T, I, and F with no restriction on T, I, F, nor
+ on their sum n=t+i+f.
+
+ The neutrosophic set generalises:
+
+ - the {intuitionistic set}, which supports incomplete set
+ theories (for 0<n<100 and i=0, 0<=t,i,f<=100);
+
+ - the {fuzzy set} (for n=100 and i=0, and 0<=t,i,f<=100);
+
+ - the classical set (for n=100 and i=0, with t,f either 0 or
+ 100);
+
+ - the {paraconsistent set} (for n>100 and i=0, with both
+ t,f<100);
+
+ - the {dialetheist set}, which says that the intersection of
+ some disjoint sets is not empty (for t=f=100 and i=0; some
+ paradoxist sets can be denoted this way).
+
+ {(http://gallup.unm.edu/~smarandache/NeutSet.txt)}.
+
+ ["Neutrosophy / Neutrosophic Probability, Set, and Logic",
+ Florentin Smarandache, American Research Press, 1998].
+
+ (1999-12-14)
+
+neutrosophic statistics
+
+ <statistics> Analysis of events described by {neutrosophic
+ probability}.
+
+ ["Neutrosophy / Neutrosophic Probability, Set, and Logic",
+ Florentin Smarandache, American Research Press, 1998].
+
+ (1999-07-05)
+
+Neutrosophy
+
+ <philosophy> (From Latin "neuter" - neutral, Greek "sophia" -
+ skill/wisdom) A branch of philosophy, introduced by Florentin
+ Smarandache in 1980, which studies the origin, nature, and
+ scope of neutralities, as well as their interactions with
+ different ideational spectra.
+
+ Neutrosophy considers a {proposition}, theory, event, concept,
+ or entity, "A" in relation to its opposite, "Anti-A" and that
+ which is not A, "Non-A", and that which is neither "A" nor
+ "Anti-A", denoted by "Neut-A". Neutrosophy is the basis of
+ {neutrosophic logic}, {neutrosophic probability},
+ {neutrosophic set}, and {neutrosophic statistics}.
+
+ {(http://gallup.unm.edu/~smarandache/NeutroSo.txt)}.
+
+ ["Neutrosophy / Neutrosophic Probability, Set, and Logic",
+ Florentin Smarandache, American Research Press, 1998].
+
+ (1999-07-29)
+
+Never Offline
+
+ <software> (NOL) /noh-el/ A software service provided by
+ {America's Multimedia Online} that allows {Internet} users to
+ be constantly connected to the Internet.
+
+ {(http://neveroffline.com/)}.
+
+ [But what *is* it?]
+
+ (1999-11-03)
+
+newbie
+
+ <jargon> /n[y]oo'bee/ (Sometimes shorted to "noob") Originally
+ from British public-school and military slang variant of "new
+ boy", an inexperienced user.
+
+ This term surfaced in the {newsgroup} {news:talk.bizarre} but
+ is now in wide use. Criteria for being considered a newbie
+ vary wildly; a person can be called a newbie in one group
+ while remaining a respected regular in another. The label
+ "newbie" is sometimes applied as a serious insult to a person
+ who has been around for a long time but who carefully hides
+ all evidence of having a clue.
+
+ See {BIFF}.
+
+ [{Jargon File}]
+
+ (2007-08-02)
+
+New Flavors
+
+ An {object-oriented} {Lisp} from {Symbolics}, the successor to
+ {Flavors}, it led to {CLOS}.
+
+ ["Reference Guide to Symbolics-Lisp", Symbolics, March 1985].
+
+ (1994-10-10)
+
+newgroup wars
+
+ /n[y]oo'groop worz/ [{Usenet}] The salvos of dueling
+ "newgroup" and "rmgroup" messages sometimes exchanged by
+ persons on opposite sides of a dispute over whether a
+ {newsgroup} should be created net-wide, or (even more
+ frequently) whether an obsolete one should be removed. These
+ usually settle out within a week or two as it becomes clear
+ whether the group has a natural constituency (usually, it
+ doesn't). At times, especially in the completely anarchic alt
+ hierarchy, the names of newsgroups themselves become a form of
+ comment or humour; e.g. the spinoff of
+ alt.swedish.chef.bork.bork.bork from alt.tv.muppets in early
+ 1990, or any number of specialised abuse groups named after
+ particularly notorious {flamers}, e.g. alt.weemba.
+
+ [{Jargon File}]
+
+New Jersey
+
+ [Primarily Stanford/Silicon Valley] Brain-damaged or of poor
+ design. This refers to the allegedly wretched quality of such
+ software as {C}, {C++} and {Unix} (which originated at {Bell
+ Labs} in Murray Hill, New Jersey). "This compiler bites the
+ bag, but what can you expect from a compiler designed in New
+ Jersey?" Compare {Berkeley Quality Software}. See also {Unix
+ conspiracy}.
+
+newline
+
+ <character, jargon> /n[y]oo'li:n/ {Line feed} or other
+ character sequence used to terminate a line of text.
+
+ {Unix} uses {line feed} as its text line terminator - a
+ {Bell-Labs}-ism rather than a {Berkeley}ism. Interestingly
+ (and unusually for Unix jargon), it is said to have originally
+ been an {IBM} usage. Though the term "newline" appears in
+ {ASCII} {standards}, it never caught on in the general
+ computing world before {Unix}. The encoding of line feed as
+ "\n" in {C} and {Unix} strings comes from this name.
+
+ The term has been used more generally for any {end of line}
+ character, character sequence (e.g. {crlf}), or operation
+ (like {Pascal}'s writeln procedure or {Lisp 1.5}'s {terpri})
+ required to terminate a text record or separate lines.
+
+ [{Jargon File}]
+
+ (1997-07-14)
+
+NEWP
+
+ {NEW Programming language}
+
+NEW Programming language
+
+ <language> (NEWP) A language which replaced {ESPOL} on the
+ {Burroughs Large System}.
+
+ (1994-12-13)
+
+NeWS
+
+ /nee'wis/, /n[y]oo'is/ or /n[y]ooz/ {Network extensible Window
+ System}.
+
+ Many hackers insist on the two-syllable pronunciations above
+ as a way of distinguishing NeWS from {news} (the {netnews}
+ software).
+
+ [{Jargon File}]
+
+news
+
+ {netnews}
+
+NewsClip
+
+ A very high level language designed for writing {netnews
+ filters}. It translates into {C}. It includes support for
+ various {newsreaders}. Version 1.01 includes a translator
+ from NewsClip to {C}, examples and documentation.
+
+ NewsClip was written by {Looking Glass Software} Ltd. and is
+ distributed and used by {ClariNet Communications} Corporation It is
+ only supported for ClariNet customers. Output of the filters
+ may not be sold and donation for use of this program is hinted
+ at.
+
+ E-mail: <newsclip@clarinet.com>.
+
+ (1992-10-25)
+
+newsfroup
+
+ <messaging, humour> A silly synonym for {Usenet} {newsgroup},
+ originally a typo but now in regular use on {Usenet}'s
+ {news:talk.bizarre} and other lunatic-fringe groups.
+
+ Compare {hing}, {grilf}, and {filk}.
+
+ [{Jargon File}]
+
+ (1994-12-13)
+
+newsgroup
+
+ <messaging> One of {Usenet}'s huge collection of topic groups
+ or {fora}. {Usenet} groups can be "unmoderated" (anyone can
+ post) or "moderated" (submissions are automatically directed
+ to a {moderator}, who edits or filters and then posts the
+ results). Some newsgroups have parallel {mailing lists} for
+ {Internet} people with no netnews access, with postings to the
+ group automatically propagated to the list and vice versa.
+ Some moderated groups (especially those which are actually
+ gatewayed {Internet} {mailing lists}) are distributed as
+ "{digests}", with groups of postings periodically collected
+ into a single large posting with an index.
+
+ Among the best-known are comp.lang.c (the {C}-language forum),
+ comp.arch (on computer architectures), comp.Unix.wizards (for
+ {Unix wizards}), rec.arts.sf-lovers (for science-fiction
+ fans), and talk.politics.misc (miscellaneous political
+ discussions and {flamage}).
+
+ Barry Shein <bzs@world.std.com> is alleged to have said,
+ "Remember the good old days when you could read all the group
+ names in one day?" This gives a good idea of the growth and
+ size of {Usenet}.
+
+ See also {netiquette}.
+
+ [{Jargon File}]
+
+ (1994-12-13)
+
+newsletter
+
+ <publication> A periodically published work containing news
+ and announcements on some subject, typically with a small
+ circulation. Newsletters are a common application for {DTP}
+ and may be distributed by {electronic mail}.
+
+ (1996-12-10)
+
+Newspeak
+
+ A language inspired by {Scratchpad}.
+
+ [J.K. Foderaro. "The Design of a Language for Algebraic
+ Computation", Ph.D. Thesis, UC Berkeley, 1983].
+
+Newsqueak
+
+ A {concurrent} {applicative} language with {synchronous}
+ channels.
+
+ ["Newsqueak: A Language for Communicating with Mice", R. Pike
+ CSTR143, Bell Labs (March 1989)].
+
+ ["The Implementation of Newsqueak", Rob Pike, Soft Prac & Exp
+ 20(7):649-659 (July 1990)].
+
+.newsrc
+
+ <messaging> (news run commands) The configuration file for the
+ {Unix} {rn} {news reader}.
+
+ See also {rc}.
+
+ (1996-04-09)
+
+news reader
+
+ <messaging> A {browser} program which enables a user to read
+ articles posted to {Usenet}. Articles may be stored in a
+ local (or {NFS}-mounted) {spool} directory, or retrieved via
+ {NNTP}.
+
+ Examples are {rn}, {GNUS}, and {nn}.
+
+ (1996-04-09)
+
+New Storage System
+
+ <storage> (NSS) A major {Multics} implementation project
+ during the 1970s. The initial Multics {file system} design
+ had evolved from the one-huge-disk world of {CTSS}. When
+ multiple disk units were used they were just assigned
+ increasing ranges of disk addresses, so a {segment} could have
+ {pages} scattered over all disks on the system. This provided
+ good {I/O} {parallelism} but made {crash recovery} expensive.
+ NSS redesigned the lower levels of the file system,
+ introducing the concepts of {logical volume} and {physical
+ volume} and a mapping from a Multics directory branch to a
+ {VTOC} entry for each file. The new system had much better
+ recovery performance in exchange for a small space and
+ performance cost.
+
+ (1997-01-29)
+
+new talk
+
+ {ntalk}
+
+New Testament
+
+ [C programmers] The second edition of {K&R}'s "The C
+ Programming Language" (Prentice-Hall, 1988; ISBN
+ 0-13-110362-8), describing {ANSI C}.
+
+ [{Jargon File}]
+
+Newton
+
+ 1. (Named after Isaac Newton (1642-1727)). Rapin et al, Swiss
+ Federal Inst Tech, Lausanne 1981. General purpose expression
+ language, syntactically ALGOL-like, with object-oriented and
+ functional features and a rich set of primitives for
+ concurrency. Used for undergraduate teaching at Lausanne
+ (EPFL).
+
+ Versions: Newton 2.6 for VAX/VMS and Newton 1.2 for
+ DEC-Alpha/{OSF}-1.
+
+ E-mail: J. Hulaas <hulaas@lcodec1.epfl.ch>.
+ {(ftp://ellc4.epfl.ch /pub/languages/Newton)}.
+
+ ["Procedural Objects in Newton", Ch. Rapin, SIGPLAN Notices
+ 24(9) (Sep 1989)].
+
+ ["The Newton Language", Ch. Rapin et al, SIGPLAN Notices
+ 16(8):31-40 (Aug 1981)].
+
+ ["Programming in Newton", Wuetrich and Menu, EPFL 1982].
+
+ 2. {Apple Newton}.
+
+ (2000-08-29)
+
+Newton-Raphson iteration
+
+ <algorithm> An iterative {algorithm} for solving equations.
+ Given an equation,
+
+ f x = 0
+
+ and an initial approximation, x(0), a better approximation is
+ given by:
+
+ x(i+1) = x(i) - f(x(i)) / f'(x(i))
+
+ where f'(x) is the first derivative of f, df/dx.
+
+ Newton-Raphson iteration is an example of an {anytime
+ algorithm} in that each approximation is no worse than the
+ previous one.
+
+ (2007-06-19)
+
+Newton's method
+
+ {Newton-Raphson}
+
+NewWave
+
+ A graphical user interface and object-oriented environment
+ from Hewlett-Packard, based on Windows and available on Unix
+ workstations.
+
+NewYacc
+
+ A {parser generator} by Jack Callahan
+ <callahan@mimsy.cs.umd.edu>. Version 1.0.
+
+ {(ftp://flubber.cs.umd.edu/src/)}.
+
+ [Dec 89 CACM, A brief overview of NewYacc].
+
+ (1992-02-10)
+
+New York State Educational Reasearch ETwork
+
+ (NYSERNET) A New York {Internet} access provider and regional
+ network. NYSERNet has been in the Internet business since
+ about 1985 and have recently upgraded to a {T3} backbone (45
+ megabits per second). They work with {Sprint}, {NYNEX} and
+ Rochester Telephone.
+
+ NYSERNet, Inc., provides Internet Training provided through
+ the NYSERNet Internet Training and Education Center (NITEC), a
+ twenty-four station hands-on facility in Syracuse, NY. The
+ Information Services Group supplies tools for marketing via
+ the {Internet} and NYSERNET also provide Technical Consulting
+ Services.
+
+ {(http://nysernet.org/)}.
+
+ E-mail: <info@nysernet.org>.
+
+ (1995-02-01)
+
+New York University
+
+ (NYU) Established in 1831, New York University today includes
+ thirteen schools, colleges and divisions located in New York
+ City's borough of Manhattan, as well as research centers and
+ programs in the surrounding suburbs and abroad.
+
+ {(http://nyu.edu/)}.
+
+NEXOR
+
+ <company> A technology company that specialises in providing
+ electronic communication software products and services to a
+ worldwide market. It is also the home of {CUSI}.
+
+ {(http://nexor.com/)}.
+
+ (1997-11-10)
+
+Nexpert Object
+
+ An {expert system}.
+
+NeXT, Inc.
+
+ <company> The company founded by {Steve Jobs} [in ?] following
+ his involuntary departure from {Apple Computer, Inc.}. NeXT
+ produced both the hardware and {operating system}
+ ({NEXTSTEP}). They changed their name to "NeXT Software" when
+ they stopped making hardware and released NEXTSTEP For {Intel}
+ processors. The company was bought by Apple in 1997(?).
+
+ (1999-11-25)
+
+Next Program Counter
+
+ <architecture> (nPC) A {register} in a {CPU} that contains the
+ {address} of the {instruction} to be executed next.
+
+ (2000-07-12)
+
+NEXTSTEP
+
+ <operating system> The original {multitasking} {operating
+ system} that {NeXT, Inc.} developed to run on its proprietary
+ {NeXT} computers (informally known as "black boxes").
+ NEXTSTEP includes a specific {graphical user interface}, an
+ interface builder, {object-oriented} application builder, and
+ several "kits" of prebuilt software {objects} such as the
+ Indexing Kit for {databases}. This software runs on top of
+ NeXT's version of the {Mach} operating system on {NeXT},
+ {486}, {Pentium}, {HP-PA}, and {Sun} {SPARC} computers.
+
+ The official spelling changed from "NeXTstep" to "NeXTStep" to
+ "NeXTSTEP", and finally "NEXTSTEP".
+
+ The last release of NEXTSTEP was 3.3, which NeXT then
+ developed into "{OpenStep}".
+
+ {TjL's Pages (http://peak.org/~luomat/)}.
+ {Peanuts (http://peanuts.org/peanuts/NEXTSTEP/)}.
+
+ See also: {GNUStep}.
+
+ (2003-05-23)
+
+nf
+
+ <networking> The {country code} for Norfolk Island.
+
+ (1999-01-27)
+
+NFA
+
+ {Finite State Machine}
+
+NFQL
+
+ ["NFQL: The Natural Forms Query Language", D. Embley, Trans
+ Database Sys 14(2):168-211 (June 1989)].
+
+NFS
+
+ {Network File System}
+
+NFT
+
+ {Network File Transfer}. An INTERLINK command on CERNVM.
+
+ng
+
+ <networking> The {country code} for Nigeria.
+
+ (1999-01-27)
+
+NGL
+
+ A dialect of {IGL}.
+
+NHOH
+
+ <chat> Never heard of him/her. Often used in {initgame}.
+
+ (1998-01-18)
+
+ni
+
+ <networking> The {country code} for Nicaragua.
+
+ (1999-01-27)
+
+NIAL
+
+ Nested Interactive Array Language.
+
+ A high-level {array}-oriented language from {Queen's
+ University}, Canada, based on {Array Theory} as developed by
+ Trenchard More Jr.
+
+ {Q'NIAL} is an implementation in {C}.
+
+ ["Programming Styles in NIAL", M.A. Jenkins et al, IEEE
+ Software 3(1):46-55 (Jan 1986)].
+
+ (1995-01-25)
+
+NIAL Systems Ltd.
+
+ Distributors of {Q'NIAL}.
+
+ Address: Ottawa Canada.
+
+ Telephone: Canada (613) 234 4188.
+
+ (1995-01-25)
+
+NIAM
+
+ {Natural Language Information Analysis Method} (or Nijssen IAM).
+
+nibble
+
+ <data> /nib'l/ (US "nybble", by analogy with "bite" -> "byte")
+ Half a {byte}. Since a byte is nearly always eight {bits}, a
+ nibble is nearly always four bits (and can therefore be
+ represented by one {hex} digit).
+
+ Other size nibbles have existed, for example the {BBC
+ Microcomputer} disk file system used eleven bit sector numbers
+ which were described as one byte (eight bits) and a nibble
+ (three bits).
+
+ Compare {crumb}, {tayste}, {dynner}; see also {bit}, {nickle},
+ {deckle}.
+
+ The spelling "nybble" is uncommon in {Commonwealth Hackish} as
+ British orthography suggests the pronunciation /ni:'bl/.
+
+ (1997-12-03)
+
+Nibble Mode DRAM
+
+ <storage> A standard {DRAM} where four successive {bits} can
+ be clocked out of the single data line by successive pulses on
+ the CAS\ line while RAS\ is active. A column address is only
+ required for the first bit.
+
+ This mode is now unfashionable but can be found on some older
+ 64 kilobit and 256 kilobit chips.
+
+ (1997-12-03)
+
+NIC
+
+ 1. <networking> {Network Information Center}.
+
+ 2. <hardware> {Network Interface Card}.
+
+ (1996-02-13)
+
+NIC.DDN.MIL
+
+ <networking> {Defense Data Network}'s {Network Information
+ Center}.
+
+ (1996-02-13)
+
+NICE
+
+ The {Nonprofit International Consortium for Eiffel}.
+
+nick
+
+ [IRC] nickname. On {IRC}, every user must pick a nick, which
+ is sometimes the user's real name or login name, but is often
+ more fanciful. Compare {handle}.
+
+ [{Jargon File}]
+
+nickle
+
+ /ni'kl/ ["nickel", common name for the US 5-cent coin] A
+ {nibble} + 1; 5 bits. Reported among developers for Mattel's
+ {GI 1600} (the {Intellivision} games processor), a chip with
+ 16 bit-wide {RAM} but 10 bit-wide {ROM}. See also {deckle}.
+
+NICOL I
+
+ 1. Small subset of PL/I by (Massachusetts) Computer Assoc,
+ ca. 1965. Version: NICOL II (1967). Sammet 1969, p.542.
+
+ 2. ICL, 1968. [same as 1?]
+
+NIFOC
+
+ <chat> Naked in front of computer. Possibly also typing with
+ one hand.
+
+ (2001-03-11)
+
+Nightmare File System
+
+ Pejorative hackerism for {Sun}'s {Network File System} (NFS).
+ In any nontrivial network of Suns where there is a lot of NFS
+ {cross-mount}ing, when one Sun goes down, the others often
+ freeze up. Some machine tries to access the down one, and
+ (getting no response) repeats indefinitely. This causes it to
+ appear dead to some messages (what is actually happening is
+ that it is locked up in what should have been a brief
+ excursion to a higher {spl} level). Then another machine
+ tries to reach either the down machine or the pseudo-down
+ machine, and itself becomes pseudo-down. The first machine to
+ discover the down one is now trying both to access the down
+ one and to respond to the pseudo-down one, so it is even
+ harder to reach. This situation snowballs very quickly, and
+ soon the entire network of machines is frozen - worst of
+ all, the user can't even abort the file access that started
+ the problem!
+
+ Many of NFS's problems are excused by partisans as being an
+ inevitable result of its {stateless}ness, which is held to be
+ a great feature (critics, of course, call it a great
+ {misfeature}). {ITS} partisans are apt to cite this as proof
+ of {Unix}'s alleged bogosity; ITS had a working NFS-like
+ shared file system with none of these problems in the early
+ 1970s. See also {broadcast storm}.
+
+ [{Jargon File}]
+
+night mode
+
+ {phase}
+
+NIH
+
+ The United States National Institutes of Health.
+
+NIHCL
+
+ A {class library} for {C++} from the US National Institutes of
+ Health (NIH).
+
+NII
+
+ {National Information Infrastructure}
+
+NIKL
+
+ Frame language.
+
+ ["Recent Developments in NIKL", T.R. Kaczmarek et al, Proc
+ AAAI-86, 1986].
+
+Niklaus Wirth
+
+ <person> The designer of the {Modula-2}, {Modula-3}, and, in
+ around 1970, {Pascal} programming languages.
+
+ [More info?]
+
+ (2001-09-22)
+
+NIL
+
+ /nil/ 1. New Implementation of Lisp. A language intended to
+ be the successor of {MacLisp}. A large {Lisp}, implemented
+ mostly in {VAX} {assembly language}. A forerunner of {Common
+ LISP}.
+
+ ["NIL: A Perspective", Jon L. White, MACSYMA Users' Conf Proc,
+ 1979].
+
+ 2. Network Implementation Language. Strom & Yemini, TJWRC,
+ IBM. Implementation of complex networking protocols in a
+ modular fashion.
+
+ ["NIL: An Integrated Language and System for Distributed
+ Programming", R. Strom et al, SIGPLAN Notices 18(6):73-82
+ (June 1983)].
+
+ 3. Empty list or False. In {Lisp}, the empty list (or "nil
+ list") is used to represent the {Boolean} value False. This
+ is possible because {Lisp} is not typed. True is represented
+ by the special {atom} "t".
+
+ 4. Spoken in reply to a question, particularly one asked using
+ the "-P" convention it means "No". Most hackers assume this
+ derives simply from LISP, but NIL meaning "no" was
+ well-established among radio hams decades before LISP existed.
+ The historical connection between early hackerdom and the ham
+ radio world was strong enough that this may have been an
+ influence.
+
+ [{Jargon File}]
+
+niladic
+
+ <programming> A less common synonym for "{nullary}",
+ presumably following the more common {monadic}, {dyadic}, etc.
+ The term was in use as early as 1976, and probably originated
+ in {APL}.
+
+ [APL: An Interactive Approach, 1976].
+
+ (2001-01-27)
+
+Ninety-Ninety Rule
+
+ <humour> "The first 90% of the code accounts for the first 90%
+ of the development time. The remaining 10% of the code
+ accounts for the other 90% of the development time".
+
+ An aphorism attributed to Tom Cargill of Bell Labs, and
+ popularised by Jon Bentley's September 1985 "Bumper-Sticker
+ Computer Science" column in "Communications of the ACM". It
+ was there called the "Rule of Credibility", a name which seems
+ not to have stuck.
+
+ [{Jargon File}]
+
+ (1995-07-14)
+
+Nintendo
+
+ <company, games> A Japanese {video game} hardware manufacturer
+ and software publisher. Nintendo started by making playing
+ cards, but was later dominant in video games throughout the
+ 1980s and early 1990s worldwide. They make lots of games
+ consoles including the Gameboy, Gameboy Advance SP, DS, DS
+ Lite and the Wii.
+
+ {Nintendo home (http://nintendo.com/)}.
+
+ (2008-03-08)
+
+NIOS
+
+ {Netware Input/Output Subsystem}
+
+nipple
+
+ {Trackpoint}
+
+NIS
+
+ {Network Information Service}
+
+NISO
+
+ National Information Standards Organisation (USA). NISO
+ Standards cover many aspects of library science, publishing,
+ and information services, and address the application of both
+ traditional and new technologies to information services.
+
+NISS
+
+ {National Information Services and Systems}
+
+NIST
+
+ {National Institute of Standards and Technology}
+
+NJCL
+
+ Network Job Control Language.
+
+ ["NJCL - A Network Job Control Language", J. du Masle et al,
+ IFIP Congress 1974].
+
+ (1995-02-03)
+
+nl
+
+ <networking> The {country code} for the Netherlands (Holland).
+
+ (1999-01-27)
+
+NLANR
+
+ {National Laboratory for Applied Network Research}
+
+NLM
+
+ {Netware Loadable Module}
+
+NLP
+
+ 1. <application> {Natural Language Processing}.
+
+ 2. <networking> {Network Layer Protocol}.
+
+NLRI
+
+ {network layer reachability information}
+
+NLS
+
+ {Native Language System}
+
+NLSP
+
+ {NetWare Link State Protocol}
+
+NLX
+
+ <hardware, standard> A low-profile, low {TCO} {motherboard}
+ design created jointly by {Intel Corp.}, {IBM}, {DEC} and
+ other PC vendors. In contrast to the traditional single-board
+ design, NLX uses a {riser} card to carry {PCI}, {ISA} and
+ {AGP} {bus} data (despite {Intel}'s stated intent to rid PC
+ motherboards of the {ISA} {bus} by 2000).
+
+ Version 1.2 of NLX is the final specification, and was frozen
+ in March 1997. Minor modifications appear in the form of
+ "Engineering Change Requests".
+
+ {(http://teleport.com/~nlx/)}.
+
+ {Intel (http://intel.com/design/motherboard/nlx.htm)}.
+
+ ["NLX Motherboard Specification", various, pub. Intel Corp. 1997]
+
+ (1998-09-21)
+
+NMI
+
+ {Non-Maskable Interrupt}
+
+nML
+
+ <language> A specification language for {instruction sets},
+ based on {attribute grammars}, for {back-end generators}.
+
+ ["The nML Machine Description Formalism", M. Freericks
+ <mfx@cs.tu-berlin.de> TR TU Berlin, FB20, Bericht 1991/15].
+
+ (1995-11-28)
+
+NMU
+
+ {Non-Maintainer Upload}
+
+NN
+
+ {neural network}
+
+nn
+
+ <tool, messaging> A {terminal based} program for reading
+ {Usenet} {news} by Kim F. Storm <storm@texas.dk>, Texas
+ Instruments A/S, Denmark.
+
+ nn lets you decide which of the many {news groups} you are
+ interested in, and unsubscribe to those which don't interest
+ you. nn lets you select articles to read from a menu in each
+ of the groups you subscribe. nn sorts and presents new
+ articles very quickly because it uses its own local database
+ to maintain all the necessary information (this database is
+ built and maintained by the nnmaster program).
+
+ The {NNTP} support was designed and implemented by Ren'e
+ Seindal, Institute of Datalogy, University of Copenhagen,
+ Denmark.
+
+ E-mail: <nn-bugs@dkuug.dk> (bugs, fixes, suggestions, etc.)
+
+ {Usenet} newgroup: {news:news.software.nn}.
+
+ (1995-12-04)
+
+NNI
+
+ {Network Node Interface}
+
+NNTP
+
+ <messaging> {Network News Transfer Protocol}.
+
+ (1996-02-26)
+
+no
+
+ <networking> The {country code} for Norway.
+
+ (1999-01-27)
+
+NOC
+
+ {Network Operations Center}
+
+NODAL
+
+ Interpreted language implemented on Norsk Data's NORD-10
+ computers. Used by CERN and DESY high energy physics labs to
+ control their accelerator hardware, PADAC and SEDAC. Included
+ trackball input, graphics.
+
+Nodal Switching System
+
+ (NSS) Main {routing} nodes in the {NSFnet} {backbone}.
+
+noddy
+
+ /nod'ee/ [UK: from the children's books] 1. Small and
+ un-useful, but demonstrating a point. Noddy programs are
+ often written by people learning a new language or system.
+ The archetypal noddy program is {hello, world}. Noddy code
+ may be used to demonstrate a feature or bug of a compiler.
+ May be used of real hardware or software to imply that it
+ isn't worth using. "This editor's a bit noddy."
+
+ 2. A program that is more or less instant to produce. In this
+ use, the term does not necessarily connote uselessness, but
+ describes a {hack} sufficiently trivial that it can be written
+ and debugged while carrying on (and during the space of) a
+ normal conversation. "I'll just throw together a noddy {awk}
+ script to dump all the first fields." In North America this
+ might be called a {mickey mouse program}. See {toy program}.
+
+ 3. A simple (hence the name) language to handle text and
+ interaction on the {Memotech} home computer. Has died with
+ the machine.
+
+ [{Jargon File}]
+
+node
+
+ 1. A point or vertex in a {graph}.
+
+ 2. {network node}.
+
+ 3. A {hypertext} document.
+
+noise
+
+ <communications> Any part of a signal that is not the true or
+ original signal but is introduced by the communication
+ mechanism.
+
+ A common example would be an electrical signal travelling down
+ a wire to which noise is added by inductive and capacitive
+ coupling with other nearby signals (this kind of noise is
+ known as "{crosstalk}").
+
+ A less obvious form of noise is {quantisation} noise, such as
+ the error between the true colour of a point in a scene in the
+ real world and its representation as a {pixel} in a digital
+ image.
+
+ (2003-07-05)
+
+noise margin
+
+ <electronics> The voltage difference between the guaranteed
+ output level and the required input voltage level of a {logic
+ gate}.
+
+ (2007-05-16)
+
+noise shaping
+
+ <communications> {Spectral noise} transformation in a
+ quantisation processes. Noise is "colourised" in the {time
+ domain} an/or {frequency domain} by adding parts of the
+ previous sample. The {SNR bandwidth} and {SNR time integral}
+ stay the same, so some noise decreases, some increases, but
+ overall noise always increases.
+
+ An example of noise shaping in the frequency domain is
+ quantisation of samples on a {Compact Disc} to reduce noise
+ below -98 dB. The are different algorithms with slightly
+ different filters, e.g. {Super Bitmapping}, {4D Recording}.
+
+ A time domain example is {MPEG-4 AAC TNS}, which is a method
+ to enhance quality by temporal forming of the noise in a
+ transform block.
+
+ (2003-07-19)
+
+NOL
+
+ {Never Offline}
+
+NOMAD
+
+ <language, database> A {database} language.
+
+ Version: NOMAD2 from {Must Software} International.
+
+ ["NOMAD Reference Manual", Form 1004, National CSS Inc, Dec
+ 1976].
+
+ (1995-04-01)
+
+NOMEX underwear
+
+ /noh'meks uhn'-der-weir/ [{Usenet}] Synonym {asbestos
+ longjohns}, used mostly in auto-related {mailing lists} and
+ newsgroups. NOMEX underwear is an actual product available on
+ the racing equipment market, used as a fire resistance measure
+ and required in some racing series.
+
+ [{Jargon File}]
+
+Nominal Semidestructor
+
+ <abuse> Slang for "{National Semiconductor}", found among
+ other places in the {4.3BSD} networking sources. During the
+ late 1970s to mid-1980s this company marketed a series of
+ {microprocessors} including the {National Semiconductor 16000}
+ and {National Semiconductor 32000}. At one point early in the
+ great {microprocessor} race, the specs on these chips made
+ them look like serious competition for the rising {Intel
+ 80x86} and {Motorola 680x0} series. Unfortunately, the actual
+ parts were notoriously flaky and never implemented the full
+ {instruction set} promised in their literature, apparently
+ because the company couldn't get any of the {mask steppings}
+ to work as designed. They eventually sank without trace,
+ joining the {Zilog Z8000} and a few even more obscure
+ also-rans in the graveyard of forgotten microprocessors.
+
+ (1994-12-23)
+
+non-algorithmic procedure
+
+ {heuristic}
+
+non-constructive proof
+
+ <logic> (Or "existence proof") A {proof} that something exists
+ that does not provide an example of that thing or a method for
+ finding an example. (A {constructive proof} does provide such an
+ example or method).
+
+ For example, for any pair of finite real numbers n < 0 and p > 0
+ there exists a real number 0 < k < 1 such that
+
+ f(k) = (1-k)*n + k*p = 0.
+
+ A non-constructive proof might proceed by observing that as k
+ changes continuously from 0 to 1, f(k) changes continuously from n
+ to p and, since they lie either side of zero, f(k) must pass
+ through zero for some intermediate value of k. This proof does
+ not tell us what that value of k is, only that it exists.
+
+ {Cantor}'s proof that the {real numbers} are {uncountable} can be
+ thought of as a non-constructive proof that {irrational numbers}
+ exist. There are existence theorems with no known constructive
+ proof.
+
+ (2014-08-23)
+
+nondeterminism
+
+ <algorithm> A property of a computation which may have more
+ than one result.
+
+ One way to implement a nondeterministic {algorithm} is using
+ {backtracking}, another is to explore (all) possible solutions
+ in parallel.
+
+ (1995-04-13)
+
+nondeterministic
+
+ Exhibiting {nondeterminism}.
+
+nondeterministic automaton
+
+ <theory> (Or "probabilistic automaton") An {automaton} in
+ which there are several possible actions (outputs and next
+ states) at each state of the computation such that the overall
+ course of the computation is not completely determined by the
+ program, the starting state, and the initial inputs.
+
+ See also {nondeterministic Turing Machine}.
+
+ (1996-05-07)
+
+nondeterministic polynomial time
+
+ <complexity> (NP) A set or property of computational {decision
+ problems} solvable by a {nondeterministic Turing Machine} in a
+ number of steps that is a {polynomial} function of the size of
+ the input. The word "nondeterministic" suggests a method of
+ generating potential solutions using some form of
+ {nondeterminism} or "trial and error". This may take
+ {exponential time} as long as a potential solution can be
+ verified in {polynomial time}.
+
+ NP is obviously a superset of P ({polynomial time} problems
+ solvable by a deterministic {Turing Machine} in {polynomial
+ time}) since a deterministic algorithm can be considered as a
+ degenerate form of nondeterministic algorithm. The question
+ then arises: is NP equal to P? I.e. can every problem in NP
+ actually be solved in polynomial time? Everyone's first guess
+ is "no", but no one has managed to prove this; and some very
+ clever people think the answer is "yes".
+
+ If a problem A is in NP and a polynomial time algorithm for A
+ could also be used to solve problem B in polynomial time, then
+ B is also in NP.
+
+ See also {Co-NP}, {NP-complete}.
+
+ [Examples?]
+
+ (1995-04-10)
+
+Nondeterministic Turing Machine
+
+ <complexity> A normal (deterministic) {Turing Machine} that
+ has a "guessing head" - a write-only head that writes a guess
+ at a solution on the tape first, based on some arbitrary
+ internal {algorithm}. The regular {Turing Machine} then runs
+ and returns "yes" or "no" to indicate whether the solution is
+ correct.
+
+ A {nondeterministic Turing Machine} can solve
+ {nondeterministic polynomial time} computational {decision
+ problems} in a number of steps that is a {polynomial} function
+ of the size of the input
+
+ (1995-04-27)
+
+non-impact printer
+
+ <printer> Any printer, such as a {laser printer}, {ink-jet
+ printer}, {LED page printer}, that prints without striking the
+ paper, unlike a {dot matrix printer} which hits the paper with
+ small pins. Non-impact printers are quieter than impact
+ printers, and also faster due the lack of moving parts in the
+ print head.
+
+ (1995-11-20)
+
+non-interlaced
+
+ {interlace}
+
+nonintrusive testing
+
+ <testing> Testing that is transparent to the software under
+ test, i.e., does not change its timing or processing
+ characteristics. Nonintrusive testing usually involves
+ additional hardware that collects timing or processing
+ information and processes that information on another
+ platform.
+
+nonlinear
+
+ (Scientific computation) A property of a system whose output
+ is not proportional to its input. For example, a {transistor}
+ has a region of input voltages for which its output voltage is
+ found by multiplying the input voltage by the gain of the
+ transistor. Outside this region though, the transistor
+ behaves non-linearly, meaning that it does not obey this
+ simple equation. The behaviour of a system containing
+ non-linear components is thus harder to model and to predict.
+
+ [{Jargon File}]
+
+Non-Maintainer Upload
+
+ <Debian> (NMU) A {release} of a package by someone other than
+ its usual maintainer.
+
+ <example>The bug was fixed in a recent NMU.</example>
+
+ (2000-05-31)
+
+Non-Maskable Interrupt
+
+ (NMI) An IRQ 7 on the {PDP-11} or {680x0} or the NMI line on
+ an 80x86. In contrast with a {priority interrupt} (which
+ might be ignored, although that is unlikely), an NMI is
+ *never* ignored.
+
+ (1994-12-13)
+
+non-optimal solution
+
+ (Or "sub-optimal solution") An astoundingly stupid way to do
+ something. This term is generally used in deadpan sarcasm, as
+ its impact is greatest when the person speaking looks
+ completely serious.
+
+ See also {Bad Thing}.
+
+ [{Jargon File}]
+
+ (1994-12-13)
+
+Nonpareil
+
+ One of five pedagogical languages based on {Markov
+ algorithms}, used in ["Nonpareil, a Machine Level Machine
+ Independent Language for the Study of Semantics", B. Higman,
+ ULICS Intl Report No ICSI 170, U London (1968)]. The others
+ were {Brilliant}, {Diamond}, {Pearl} and {Ruby}.
+
+non parity
+
+ {parity}
+
+non-polynomial
+
+ <complexity> The set or property of problems for which no
+ {polynomial-time algorithm} is known.
+
+ This includes problems for which the only known {algorithms}
+ require a number of steps which increases exponentially with
+ the size of the problem, and those for which no {algorithm} at
+ all is known. Within these two there are problems which are
+ "{provably difficult}" and "{provably unsolvable}".
+
+ (1995-04-10)
+
+Non Return to Zero Inverted
+
+ <storage> (NRZI) A recording method used for 9-track {magnetic
+ tapes} (200 and 800 BPI) where a zero is represented by a
+ change in the signal and a one by no change.
+
+ NRZI is also used extensively in {SDLC} communications.
+ {VTAM} has a parameter NRZI=YES|NO.
+
+ Compare {Phase Encoded}, {GCR}.
+
+ (1999-01-11)
+
+nontrivial
+
+ Requiring real thought or significant computing power. Often
+ used as an understated way of saying that a problem is quite
+ difficult or impractical, or even entirely unsolvable
+ ("Proving P=NP is nontrivial"). The preferred emphatic form
+ is "decidedly nontrivial".
+
+ See {uninteresting}, {interesting}.
+
+ [{Jargon File}]
+
+ (1995-02-21)
+
+Non-Uniform Memory Access
+
+ <architecture> (NUMA) A memory architecture, used in
+ {multiprocessors}, where the access time depends on the memory
+ location. A processor can access its own local memory faster
+ than non-local memory (memory which is local to another
+ processor or shared between processors).
+
+ (1995-11-12)
+
+non-uniform quantising logarithmic compression
+
+ The kind of {compression} often applied to a sound waveform.
+ {Logarithmic compression} is a good match for the human ear's
+ sensitivity but cannot handle zero amplitude (for which the
+ logarithm is negative infinity). There are two {standard}
+ compression functions which give a smooth transition between
+ the logarithmic function and a linear segment passing through
+ the origin: {mu-law} (North America) and {A-law} ({ITU-T}).
+
+ (1995-02-21)
+
+Non-Uniform Rational B Spline
+
+ <graphics, mathematics> (nurbs) A common term in Mechanical
+ {CAD}. The NURBS has excellent continuity characteristics
+ which make it useful for creating accurate models in 3D
+ geometry generation and computer modelling.
+
+ [What is a nurbs? an rbs? a bs? a s?]
+
+ (1996-08-27)
+
+non-volatile
+
+ {non-volatile storage}
+
+non-volatile memory
+
+ {non-volatile storage}
+
+Non-Volatile Random Access Memory
+
+ <storage> (NVRAM) {Static random-access memory} which is made
+ into {non-volatile storage} either by having a battery
+ permanently connected or by saving its contents to {EEPROM}
+ before turning the power off and reloading it when power is
+ restored.
+
+ (1995-04-22)
+
+non-volatile storage
+
+ <storage> (NVS, persistent storage, memory) A term describing
+ a storage device whose contents are preserved when its power
+ is off. Storage using magnetic media (e.g. {magnetic disks},
+ {magnetic tape} or {bubble memory}) is normally non-volatile
+ by nature whereas {semiconductor} memories ({static RAM} and
+ especially {dynamic RAM}) are normally volatile but can be
+ made into non-volatile storage by having a (rechargable)
+ battery permanently connected.
+
+ {Dynamic RAM} is particularly volatile since it looses its
+ data, even if the power is still on, unless it is {refresh}ed.
+ An acoustic {delay line} is a (very old) example of a volatile
+ storage device.
+
+ Other examples of non-volatile storage are {EEPROM}, {CD-ROM},
+ {paper tape} and {punched cards}.
+
+ (2000-05-22)
+
+noob
+
+ {newbie}
+
+no-op
+
+ /noh'op/ alt. NOP /nop/ [no operation] 1. A machine
+ instruction that does nothing (sometimes used in
+ assembler-level programming as filler for data or patch areas,
+ or to overwrite code to be removed in binaries). See also
+ {JFCL}.
+
+ 2. A person who contributes nothing to a project, or has
+ nothing going on upstairs, or both. As in "He's a no-op."
+
+ 3. Any operation or sequence of operations with no effect,
+ such as circling the block without finding a parking space, or
+ putting money into a vending machine and having it fall
+ immediately into the coin-return box, or asking someone for
+ help and being told to go away. "Oh, well, that was a no-op."
+ Hot-and-sour soup that is insufficiently either is "no-op
+ soup"; so is wonton soup if everybody else is having
+ hot-and-sour.
+
+ [{Jargon File}]
+
+ (1994-12-02)
+
+NOR
+
+ Not OR.
+
+ The {Boolean} function which is true if none of its inputs are
+ true and false otherwise, the {logical complement} of
+ {inclusive OR}. The binary (two-input) NOR function can be
+ defined (written as an {infix} operator):
+
+ A NOR B = NOT (A OR B) = (NOT A) AND (NOT B)
+
+ Its {truth table} is:
+
+ A | B | A NOR B
+ --+---+---------
+ F | F | T
+ F | T | F
+ T | F | F
+ T | T | F
+
+ NOR, like {NAND}, forms a complete set of {Boolean} functions on
+ its own since it can be used to make NOT, AND, OR and any
+ other Boolean function:
+
+ NOT A = A NOR A
+
+ A OR B = NOT (A NOR B)
+
+ A AND B = (NOT A) NOR (NOT B)
+
+ (1995-02-06)
+
+NORC COMPILER
+
+ Early system on NORC machine. Listed in CACM 2(5):16 (May
+ 1959).
+
+NorCroft
+
+ (Contraction of Norman + Mycroft) A company producing {C}
+ compilers, set up by Arthur Norman and Alan Mycroft. Now
+ "sort of" called Codemist. The original Norcroft compiler was
+ written by Alan and Arthur to provide a {platform} for
+ teaching languages and compilers on the {Cambridge University}
+ {mainframe}. They then went on to develop versions for the
+ {transputer}, {ARM} and others.
+
+ [What is the relationship between NorCroft and Codemist?]
+
+ (1994-10-25)
+
+NORD PL
+
+ Intermediate language for {Norsk Data} computers. {Sintran
+ III}, the {operating system} of the ND 10 (late 1970's), was
+ written in NORD PL.
+
+ ["NORD PL User's Guide", ND-60.047.03].
+
+NORDUnet
+
+ <networking, body> (Nordic Universities Network?) A
+ collaboration between the national research networks in
+ Denmark, Finland, Iceland, Norway and Sweden. It provides
+ international access for these countries.
+
+ {(http://info.nordu.net/)}.
+
+ (1998-07-05)
+
+norm
+
+ <mathematics> A real-valued {function} modelling the length of
+ a {vector}. The norm must be {homogeneous} and {symmetric}
+ and fulfil the following condition: the shortest way to reach
+ a point is to go straight toward it. Every {convex} symmetric
+ {closed} surface surrounding point 0 introduces a norm by
+ means of {Minkowski functional}; all vectors that end on the
+ surface have the same norm then.
+
+ The most popular norm is the {Euclidean norm}.
+
+ (2004-02-15)
+
+normal distribution
+
+ <statistics> (Or "Gaussian distribution") The {frequency
+ distribution} of many natural phenomena such as the height or
+ intelligence of people of a certain age and sex. The formula
+ looks something like:
+
+ P(x) = e^(((x-m)/s)^2)
+
+ where P(x) is the probability of a measurement x, m is the
+ mean value of x and s is the {standard deviation}.
+
+ Also known as a "bell curve" because of its shape.
+
+ (2003-10-25)
+
+normal form
+
+ 1. <reduction> In {reduction} systems, the state of a term
+ which contains no reducible expressions. Variants include
+ {head normal form}, {weak head normal form}.
+
+ 2. <database> See {database normalisation}.
+
+normalisation
+
+ 1. <data processing> A transformation applied uniformly to
+ each element in a set of data so that the set has some
+ specific statistical property. For example, monthly
+ measurements of the rainfall in London might be normalised by
+ dividing each one by the total for the year to give a profile
+ of rainfall throughout the year.
+
+ 2. <programming> Representation of a {floating-point} number
+ so that its {mantissa}'s left-most digit is non-zero. If the
+ leftmost fraction digit are zeros, the number is said to be
+ unnormalised. Unnormalised numbers are normalised by shifting
+ the fraction left, one digit at a time, until the leftmost
+ digit is nonzero and reducing the {exponent} by the number of
+ shifts.
+
+ 3. <database> {database normalisation}.
+
+ (1998-04-15)
+
+normalised
+
+ {normalisation}
+
+normal order reduction
+
+ Under this {evaluation strategy} an expression is evaluated by
+ reducing the leftmost outermost {redex} first. This method
+ will terminate for any expression for which termination is
+ possible, whereas {applicative order reduction} may not. This
+ method is equivalent to passing arguments unevaluated because
+ arguments are initially to the right of functions applied to
+ them. See also {computational adequacy theorem}.
+
+normed space
+
+ <mathematics> A {vector space} with a {function}, ||F||, such
+ that
+
+ ||F|| = 0 if and only if F=0
+ ||aF|| = abs(a) * ||F||
+ ||F+G|| <= ||F|| + ||G||
+
+ Roughly, a distance between two elements in the space is
+ defined.
+
+ (2000-03-10)
+
+northbridge
+
+ <architecture> The single {integrated circuit} in a {core
+ logic} {chip set} that connects the {CPU} to the {system
+ memory} and the {AGP} and {PCI} busses. Other functions are
+ provided by the {southbridge} chip.
+
+ {(http://maximumpc.com/terminator/terminator_n.html)}.
+
+ (2000-01-15)
+
+NorthWestNet
+
+ (NWNET) Kochmer, J., and NorthWestNet, "The Internet Passport:
+ NorthWestNets Guide to Our World Online", NorthWestNet,
+ Bellevue, WA, 1992.
+
+NOS
+
+ {Network Operating System}
+
+NOT
+
+ <logic> The {Boolean} function which is true only if its input
+ is false. Its {truth table} is:
+
+ A | NOT A
+ --+----------
+ F | T
+ T | F
+
+ (1996-11-04)
+
+Not-a-Number
+
+ <mathematics> (NaN) An {IEEE floating point} representation
+ for the result of a numerical operation which cannot return a
+ valid number value. A NaN can result from multiplying an
+ infinity by a zero, or from subtracting one infinity from
+ another [what else?].
+
+ NaN is encoded as a special {bit pattern} [what pattern?]
+ which would otherwise represent a {floating-point} number. It
+ is used to signal error returns where other mechanisms are not
+ convenient, e.g. a hardware {floating-point unit} and to allow
+ errors to propagate through a calculation.
+
+ Similar bit patterns represent positive and negative
+ {overflow} and {underflow} and the positive and negative
+ infinities resulting from {division by zero}.
+
+ {Bit patterns
+ (http://psc.edu/general/software/packages/ieee/ieee.html)}.
+
+ [ANSI/IEEE Std 754-1985].
+
+ [Correct?]
+
+ (2001-04-01)
+
+notebook
+
+ 1. <computer> {laptop computer}.
+
+ 2. <tool> {Labtech Notebook}.
+
+ (1998-01-05)
+
+NoteCards
+
+ An ambitious hypertext system developed at Xerox PARC,
+ "designed to support the task of transforming a chaotic
+ collection of unrelated thoughts into an integrated, orderly
+ interpretation of ideas and their interconnections".
+
+Notepad
+
+ <text, tool> The very basic {text editor} supplied with
+ {Microsoft Windows}.
+
+ (1998-01-05)
+
+Notes
+
+ {Lotus Notes}
+
+Nother
+
+ A parallel {symbolic mathematics} system.
+
+ E-mail: <karhu@cs.umu.se>.
+
+not ready for prime time
+
+ Usable, but only just so; not very robust; for internal use
+ only. Said of a program or device. Often connotes that the
+ thing will be made more solid {Real Soon Now}. This term
+ comes from the ensemble name of the original cast of "Saturday
+ Night Live", the "Not Ready for Prime Time Players". It has
+ extra flavour for hackers because of the special (though now
+ semi-obsolescent) meaning of {prime time}. Compare {beta}.
+
+ [{Jargon File}]
+
+notspot
+
+ <networking, humour> In contrast with {wireless hotspot}, a
+ place where there is no means to connect to the {Internet}.
+ While the term "{hotspot}" refers to a {wireless local area
+ network}, "notspot" might also mean a place without decent
+ {DSL} (broadband Internet) connection.
+
+ (2009-05-28)
+
+notwork
+
+ <networking, humour> /not'werk/ A network that is performing
+ badly.
+
+ Said at IBM to have originally referred to a particular period
+ of flakiness on IBM's VNET corporate network ca. 1988; but
+ there are independent reports of the term from elsewhere.
+
+ The joke sounds better in Russian, where "nyet" means "no",
+ hence nyetwork /nyet'werk/.
+
+ (2009-05-28)
+
+Nova
+
+ <processor> A {minicomputer}(?) introduced by {Data General}
+ in 1969, with four 16-bit {accumulators}, AC0 to AC3, and a
+ 15-bit {program counter}. A later model also had a 15-bit
+ {stack pointer} and {frame pointer}. AC2 and AC3 could be
+ used for {indexed addressing} and AC3 was used to store the
+ return address on a {subroutine} call. Apart from the small
+ {register set}, the NOVA was an ordinary {CPU} design.
+
+ Memory could be accessed indirectly through addresses stored
+ in other memory locations. If locations 0 to 3 were used for
+ this purpose, they were auto-incremented after being used. If
+ locations 4 to 7 were used, they were auto-decremented.
+ Memory could be addressed in 16-bit words up to a maximum of
+ 32K words (64K bytes). The instruction cycle time was 500
+ {nanoseconds}(?). The Nova originally used {core memory},
+ then later {dynamic RAM}.
+
+ Like the {PDP-8}, the {Data General} Nova was also copied, not
+ just in one, but two implementations - the {Data General
+ MN601} and {Fairchild 9440}. Luckily, the NOVA was a more
+ mature design than the PDP-8.
+
+ Another CPU, the {PACE}, was based on the NOVA design, but
+ featured 16-bit addresses (instead of the Nova's 15), more
+ {addressing modes}, and a 10-level {stack} (like the {Intel
+ 8008}).
+
+ [Speed, mini?]
+
+ (2003-10-23)
+
+Novell Data Systems
+
+ <company> A small computer {hardware} company building {CP/M}
+ {Z80}-based systems. They later went on to become {Novell,
+ Inc.} and develop {Novell Netware}.
+
+ (1995-09-23)
+
+Novell DOS
+
+ <operating system, product> {Novell}'s fully compatible
+ alternative to {MS-DOS}. It is intended as an {operating
+ system} for {workstations} on {Novell} networks. It features
+ enhanced {memory management} that moves the operating system,
+ {network drivers}, and {memory-resident programs} ({TSRs}) out
+ of conventional memory on all systems with an {Intel 80286} or
+ later processor and {extended memory} or {expanded memory}.
+ It supports {preemptive multitasking} and {peer-to-peer
+ networking} using the same {DOS Requester} and {VLMs} for a
+ "common client" with native {Novell NetWare}.
+
+ A data {compression} utility effectively doubles storage
+ capacity of the hard disk. It supports disk
+ {defragmentation}, a read/write {disk cache} for better
+ performance of both DOS and {Microsoft Windows} {application
+ programs}. An undelete utility recovers erased files, even on
+ network drives. It has a complete on-line reference guide,
+ command help, and menu-driven install and setup utilities for
+ easy configuration changes.
+
+ Novell DOS has internal and external commands like {MS-DOS}.
+ The following commands have been significantly enhanced in
+ Novell DOS: CHKDSK, DISKCOPY, HELP, MEM, REPLACE, UNDELETE,
+ and XCOPY. Novell DOS also includes many new commands such as
+ XDIR, CURSOR, XDEL, TOUCH, SCRIPT, and RENDIR.
+
+ Version: 7.
+
+ (1995-04-14)
+
+Novell, Inc.
+
+ <company, networking> A {software} development company
+ specialising in {network}ing and {workgroup} applications.
+
+ {Novell} started life as {Novell Data Systems}, a computer
+ hardware business. The company was reorganised as Novell,
+ Inc., and began to focus almost entirely on networking in
+ 1983, with the release of {Novell Netware} 1, a {Network
+ Operating System} for {IBM PCs}.
+
+ {Novell Netware}'s success has left Novell in a dominant
+ position in the {network}ing market. The product has evolved
+ and now supports many {hardware} and {software} {platforms}
+ together with {WAN} connectivity.
+
+ The company has diversified in recent years, with the
+ acquisition of several mainstream applications, including
+ {Wordperfect} and {Quattro} Pro. Other products include
+ {UnixWare}, {AppWare}, {Personal NetWare}, {Groupwise} and
+ {Novell Dos 7}.
+
+ {(http://novell.com/)}.
+
+ (21 Sept 1995)
+
+Novell NetWare
+
+ <operating system, networking> {Novell, Inc.}'s proprietary
+ networking {operating system} for the {IBM PC}.
+
+ NetWare uses the {IPX}/{SPX}, {NetBEUI} or {TCP/IP} network
+ {protocols}. It supports {MS-DOS}, {Microsoft Windows},
+ {OS/2}, {Macintosh} and {Unix} {clients}. NetWare for Unix
+ lets users access Unix hosts.
+
+ NetWare 2.2 is a 16-bit operating system, versions 4.x and 3.x
+ are 32-bit operating systems.
+
+ {(http://netware.novell.com/)}.
+
+ {Usenet} newsgroup: {news:comp.sys.novell}.
+
+ ["Netware", K. Siyan, pub. New Riders].
+
+ [LAN Magazine, Sep 1993].
+
+ (1996-01-13)
+
+NOWEB
+
+ <programming> A system of {structured programming} and
+ documentation from M.Speh in {DESY}.
+
+ See {literate programming}.
+
+ (1996-01-13)
+
+no-write allocation
+
+ <memory management> A {cache} policy where only processor
+ reads are cached, thus avoiding the need for {write-back} or
+ {write-through}.
+
+ (1996-06-12)
+
+NP
+
+ <complexity> {nondeterministic polynomial time}.
+
+ [{Jargon File}]
+
+np
+
+ <networking> The {country code} for Nepal.
+
+ (1999-01-27)
+
+NPC
+
+ 1. <complexity> {NP-complete}.
+
+ 2. <architecture> {Next Program Counter}.
+
+ (2000-07-12)
+
+NP-complete
+
+ <complexity> (NPC, Nondeterministic Polynomial time complete)
+ A set or property of computational {decision problems} which
+ is a subset of {NP} (i.e. can be solved by a
+ {nondeterministic} {Turing Machine} in {polynomial} time),
+ with the additional property that it is also {NP-hard}. Thus
+ a solution for one NP-complete problem would solve all
+ problems in NP. Many (but not all) naturally arising problems
+ in class NP are in fact NP-complete.
+
+ There is always a {polynomial-time algorithm} for transforming
+ an instance of any NP-complete problem into an instance of any
+ other NP-complete problem. So if you could solve one you
+ could solve any other by transforming it to the solved one.
+
+ The first problem ever shown to be NP-complete was the
+ {satisfiability problem}. Another example is {Hamilton's
+ problem}.
+
+ See also {computational complexity}, {halting problem},
+ {Co-NP}, {NP-hard}.
+
+ {(http://fi-www.arc.nasa.gov/fia/projects/bayes-group/group/NP/)}.
+
+ [Other examples?]
+
+ (1995-04-10)
+
+NP-hard
+
+ <complexity> A set or property of computational {search
+ problems}. A problem is NP-hard if solving it in {polynomial
+ time} would make it possible to solve all problems in class
+ {NP} in polynomial time.
+
+ Some NP-hard problems are also in {NP} (these are called
+ "{NP-complete}"), some are not. If you could reduce an {NP}
+ problem to an NP-hard problem and then solve it in polynomial
+ time, you could solve all NP problems.
+
+ See also {computational complexity}.
+
+ [Examples?]
+
+ (1995-04-10)
+
+NP-hilarious
+
+ <humour> An {algorithm} whose complexity is a joke, either
+ literally, as in {BogoSort}, or metaphorically.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2014-06-28)
+
+NPL
+
+ 1. New Programming Language. IBM's original (temporary) name
+ for PL/I, changed due to conflict with England's "National
+ Physical Laboratory." MPL and MPPL were considered before
+ settling on PL/I. Sammet 1969, p.542.
+
+ 2. A {functional language} with {pattern matching} designed by
+ Rod Burstall and John Darlington in 1977. The language
+ allowed certain sets and logic constructs to appear on the
+ right hand side of definitions, E.g.
+
+ setofeven(X) <= <:x: x in X & even(x) :>
+
+ The NPL {interpreter} evaluates the list of {generators} from
+ left to right so conditions can mention any bound variables
+ that occur to their left. These were known as {set
+ comprehensions}. NPL eventually evolved into {Hope} but lost
+ set comprehensions which were called {list comprehensions} in
+ later functional languages.
+
+ [John Darlington, "Program Transformation and Synthesis:
+ Present Capabilities", Research Report No. 77/43, Dept. of
+ Computing and Control, Imperial College of Science and
+ Technology, London September 1977.]
+
+ 3. NonProcedural Language. A {relational database} language
+ developed by T.D. Truitt et al in 1980 for {Apple II} and
+ {MS-DOS}.
+
+ ["An Introduction to Nonprocedural Languages Using NPL",
+ T.D. Truitt et al, McGraw-Hill 1983].
+
+NPPL
+
+ Network Picture Processing Language. An interactive language
+ for manipulation of {digraphs}.
+
+ ["A Graph Manipulator for On-line Network Picture Processing",
+ H.A. DiGiulio, Proc FJCC 35 (1969)].
+
+N-Prolog
+
+ {Prolog} extended with explicit negation. Dov Gabbay
+ <dg@doc.ic.ac.uk>.
+
+ [J Logic Programming].
+
+NP time
+
+ {nondeterministic polynomial time}
+
+NP tricky
+
+ <humour> A play on {NP hard} describing an {algorithm} or piece of
+ code that is too complicated for a mere mortal to understand.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2014-06-18)
+
+NQS
+
+ Batch processing software for Unix systems.
+
+Nqthm
+
+ The language used in the {Boyer-Moore} {theorem prover}.
+
+ ["Proving Theorems About LISP Functions", R.S. Boyer et al
+ JACM 22(1):129-144 (Jan 1975)].
+
+nr
+
+ <networking> The {country code} for Nauru.
+
+ (1999-01-27)
+
+NREN
+
+ {National Research and Education Network}
+
+nroff
+
+ <language> /N'rof/ [Unix, from "new {roff}"] A {text formatting
+ language} and interpreter, companion to the Unix typesetter
+ {troff}, accepting identical input but preparing output for
+ terminals and line printers. See also {groff}.
+
+ [{Jargon File}]
+
+ (2012-12-14)
+
+NRZ
+
+ {Non Return to Zero}
+
+NRZI
+
+ {Non Return to Zero Inverted}
+
+ns
+
+ {nanosecond}
+
+NS16000
+
+ {National Semiconductor 16000}
+
+NS32000
+
+ {National Semiconductor 32000}
+
+NSA line eater
+
+ <messaging, tool> The National Security Agency trawling
+ program sometimes assumed to be reading the net for the US
+ Government's spooks. Most hackers describe it as a mythical
+ beast, but some believe it actually exists, more aren't sure,
+ and many believe in acting as though it exists just in case.
+ Some netters put loaded phrases like "KGB", "Uzi", "nuclear
+ materials", "Palestine", "cocaine", and "assassination" in
+ their {sig blocks} to confuse and overload the creature. The
+ {GNU} version of {Emacs} actually has a command that randomly
+ inserts a bunch of insidious anarcho-verbiage into your edited
+ text.
+
+ There is a mainstream variant of this myth involving a "Trunk
+ Line Monitor", which supposedly used speech recognition to
+ extract words from telephone trunks. This one was making the
+ rounds in the late 1970s, spread by people who had no idea of
+ then-current technology or the storage, {signal-processing},
+ or {speech recognition} needs of such a project. On the basis
+ of mass-storage costs alone it would have been cheaper to hire
+ 50 high-school students and just let them listen in.
+ Speech-recognition technology can't do this job even now
+ (1993), and almost certainly won't in this millennium, either.
+
+ The peak of silliness came with a letter to an alternative
+ paper in New Haven, Connecticut, laying out the factoids of
+ this Big Brotherly affair. The letter writer then revealed
+ his actual agenda by offering - at an amazing low price, just
+ this once, we take VISA and MasterCard - a scrambler
+ guaranteed to daunt the Trunk Trawler and presumably allowing
+ the would-be Baader-Meinhof gangs of the world to get on with
+ their business.
+
+ [{Jargon File}]
+
+ (1994-12-13)
+
+NSAPI
+
+ {Netscape Application Programming Interface}
+
+NSDI
+
+ {National Spatial Data Infrastructure}
+
+NSE
+
+ Network Software Environment: a proprietary CASE framework
+ from Sun Microsystems.
+
+NSF
+
+ {National Science Foundation}
+
+NSFIP
+
+ <operating system> {NEXTSTEP} For {Intel} Processor.
+
+ (1999-11-25)
+
+NSFNET
+
+ {National Science Foundation Network}
+
+NSI
+
+ {Network Solutions, Inc.}
+
+nslookup
+
+ <networking> A {Unix} {utility program}, originally by Andrew
+ Cherenson, for querying {Internet} {domain name servers}. The
+ basic use is to find the {IP address} corresponding to a
+ given {hostname} (or vice versa). By changing the query type
+ (e.g. "set type=CNAME") other types of information can be
+ obtained including CNAME - the {canonical name} for an alias;
+ HINFO - the host {CPU} and {operating system} type; MINFO -
+ mailbox or mail list information; {MX} - {mail exchanger}
+ information; NS - the {name server} for the named zone; PTR -
+ the hostname if the query is an IP address, otherwise
+ the pointer to other information; SOA the domain's
+ start-of-authority information; TXT - text information; UINFO
+ - user information; WKS - supported {well-known services}.
+ Other types (ANY, AXFR, MB, MD, MF, NULL) are described in
+ {RFC 1035}.
+
+ {(ftp://src.doc.ic.ac.uk/computing/operating-systems/unix/bsd-sources/usr.sbin/named/tools/nslookup/)}.
+
+ (1994-10-27)
+
+NSRD
+
+ {National Software Reuse Directory}
+
+NSS
+
+ 1. <networking> {Nodal Switching System}.
+
+ 2. <operating system> {New Storage System}.
+
+ (1997-01-29)
+
+NT
+
+ 1. {Network Termination}.
+
+ 2. New Technology, as in {Windows NT}.
+
+NT1
+
+ {Network Termination}
+
+NT5
+
+ {Windows 2000}
+
+ntalk
+
+ <chat> ("new talk") An update of the {Unix} "{talk}" program,
+ old versions of "talk" being referred to as "old talk". New
+ talk and old talk are generally incompatible, and attempts to
+ get them to communicate result in entirely unhelpful error
+ messages.
+
+ On most modern {Unix} systems, the program "talk" is new talk,
+ with some {SunOS} versions being a notable and annoying
+ exception to this.
+
+ (1997-09-11)
+
+NTAS
+
+ {NT Advanced Server}
+
+NT File System
+
+ <file system> (NTFS) The {native} {file system} of {Windows
+ NT}.
+
+ (1995-03-06)
+
+NTFS
+
+ {NT File System}
+
+n-tier
+
+ {three-tier}
+
+NTIS
+
+ {National Technical Information Service}
+
+NTMBS
+
+ <programming> {null-terminated multibyte string}.
+
+ (1995-10-02)
+
+NTP
+
+ {Network Time Protocol}
+
+NTSC
+
+ {National Television Standards Committee}
+
+NTU
+
+ {Network Termination Unit}
+
+nu
+
+ <networking> The {country code} for Niue.
+
+ (1999-01-27)
+
+ Because it sounds like "new", nu is heavily
+ used for {vanity domains}.
+
+ (1999-01-27)
+
+NuBus
+
+ The proprietary {expansion bus} used on Apple {Macintosh}
+ {personal computers}.
+
+ (1995-02-03)
+
+nu-calculus
+
+ An asynchronous version of {pi-calculus}.
+
+NUCLEOL
+
+ List processing language, influenced by EOL. J. Nievergelt,
+ Computer J 13(3) (Aug 1970).
+
+nude
+
+ Said of machines delivered without an operating system
+ (compare {bare metal}). "We ordered 50 systems, but they all
+ arrived nude, so we had to spend a an extra weekend with the
+ installation tapes." This usage is a recent innovation
+ reflecting the fact that most PC clones are now delivered with
+ DOS or Microsoft Windows pre-installed at the factory. Other
+ kinds of hardware are still normally delivered without OS, so
+ this term is particular to PC support groups.
+
+ [{Jargon File}]
+
+ (1994-12-13)
+
+nuke
+
+ /n[y]ook/ 1. To intentionally delete the entire contents of a
+ given directory or storage volume. "On Unix, "rm -r /usr"
+ will nuke everything in the usr file system." Never used for
+ accidental deletion.
+
+ 2. Synonym for {dike}, applied to smaller things such as
+ files, features, or code sections. Often used to express a
+ final verdict. "What do you want me to do with that 80-meg
+ {wallpaper} file?" "Nuke it."
+
+ 3. Used of processes as well as files; nuke is a frequent
+ verbal alias for "kill -9" on Unix.
+
+ 4. On IBM PCs, a bug that results in {fandango on core} can
+ trash the operating system, including the FAT (the in-core
+ copy of the disk block chaining information). This can
+ utterly scramble attached disks, which are then said to have
+ been "nuked". This term is also used of analogous lossages on
+ Macintoshes and other micros without memory protection.
+
+ [{Jargon File}]
+
+null
+
+ <programming> A special value used in several languages to
+ represent the thing referred to by an uninitialised pointer.
+
+ <database> A special value that may be stored in some database
+ columns to represent an unknown, missing, not applicable, or
+ undefined value. Nulls are treated completely differently
+ from ordinary values when evaluating SQL expressions and there
+ are several SQL constructs for dealing with nulls.
+
+ (2003-06-17)
+
+nullary
+
+ <programming> A description of an {operator} or {function}
+ which takes no {arguments}, e.g. a function that returns the
+ current time.
+
+ "Nullary" is part of the {unary}, {binary}, {ternary}
+ sequence, and is more common than its synonym {niladic}.
+
+ (2001-02-25)
+
+null modem
+
+ <communications, hardware> A cable, especially an {EIA-232}
+ cable, for connecting serial ports on two computers directly,
+ rather than via modems. Since, according to the
+ specification, both computers should transmit on pin three of
+ their EIA-232 connectors and receive on pin two, a null modem
+ cable needs to connect one computer's pin two to the other's
+ pin three and vice versa. It also needs to have male
+ connectors at both ends (again, according to the
+ specification).
+
+ (1996-05-17)
+
+null-terminated multibyte string
+
+ <programming> (NTMBS) (Defined in the {ANSI C++} draft)
+
+ [Different from null-terminated string?]
+
+ (1995-10-02)
+
+NUMA
+
+ {Non-Uniform Memory Access}
+
+Number 5 Electronic Switching System
+
+ <communications> (5ESS) An electronic {circuit switching} product
+ sold by {Alcatel Lucent} (formerly {Western Electric}/{AT&T
+ Network Systems}/{Lucent Technologies}), used by many telephone
+ exchange carriers and service providers. Succeeded the Number 4
+ Electronic Switching System (4ESS) and reached widespread use in
+ the 1980s.
+
+ Not to be confused with the {Class 5 Switch}.
+
+ (2013-09-14)
+
+number crunching
+
+ <application, jargon> Computations of a numerical nature,
+ especially those that make extensive use of {floating-point}
+ numbers. The only thing {Fortrash} is good for.
+
+ This term is in widespread informal use outside hackerdom and
+ even in mainstream slang, but has additional hackish
+ connotations: namely, that the computations are mindless and
+ involve massive use of {brute force}. This is not always
+ {evil}, especially if it involves {ray tracing} or {fractals}
+ or some other use that makes {pretty pictures}, especially if
+ such pictures can be used as {wallpaper}.
+
+ See also {crunch}.
+
+ [{Jargon File}]
+
+ (1995-03-17)
+
+number keys
+
+ {keypad}
+
+numbers
+
+ (Scientific computation) Output from a computation that may
+ not be significant but at least indicates that the program is
+ running. Numbers may be used to placate management, grant
+ sponsors, etc. "Making numbers" means running a program
+ because output - any output, not necessarily meaningful output
+ - is needed as a demonstration of progress.
+
+ See {pretty pictures}, {math-out}, {social science number}.
+
+ [{Jargon File}]
+
+ (1995-01-13)
+
+number sign
+
+ <character> {hash}.
+
+numeric keypad
+
+ <hardware> A {keypad} that has become a standard feature of
+ {PC} {keyboards}, consisting of a rectangular array of 17
+ extra keys at the right-hand end: 0-9, {.}, {Num Lock}, {/},
+ {*}, {-}, {+} and {Enter}. Apart from Num Lock, these
+ typically duplicate the function of other keys but are
+ designed to make entering basic numerical calculations as
+ quick as on a {digital calculator}. It is often possible to
+ assign completely different functions to these keys according
+ to the needs of a particular application.
+
+ (2007-01-31)
+
+Numeris
+
+ The name given by France Telecom, the french telephone network
+ operator, to its {ISDN} network.
+
+ (1995-01-31)
+
+Nuprl
+
+ /nyu p*rl/ Nearly Ultimate PRL.
+
+ A system for interactive creation of formal mathematics,
+ including definitions and proofs. It has an extremely rich
+ type system, including dependent functions, products, sets,
+ quotients and universes. Types are first-class citizens.
+ It is built on {Franz Lisp} and {Edinburgh ML}.
+
+ ["Implementing Mathematics in the Nuprl Proof Development
+ System", R.L. Constable et al, P-H 1986].
+
+ (1994-12-13)
+
+NU-Prolog
+
+ L. Naish, U Melbourne. A Prolog with 'when' declarations, the
+ successor to MU-Prolog. Type-checked. "NU-Prolog Reference
+ Manual - Version 1.3", J.A. Thom et al eds, TR 86/10, U
+ Melbourne (1988). Available (but not free). (See
+ PNU-Prolog). E-mail: <jas@mulga.oz.au>.
+
+nurbs
+
+ {Non-Uniform Rational B Spline}
+
+Nu Thena
+
+ A software vendor specialising in rapid prototyping tools for
+ {real-time} hardware and software systems and collaborating
+ with {DAZIX}.
+
+NUXI problem
+
+ <data, architecture> /nuk'see pro'bl*m/ The problem of
+ transferring data between computers with differing {byte
+ order}. The string "Unix" might look like "NUXI" on a machine
+ with a different "byte sex" (e.g. when transferring data from
+ a {little-endian} to a {big-endian}, or vice-versa).
+
+ See also {middle-endian}, {swab}, and {bytesexual}.
+
+ [{Jargon File}]
+
+ (2001-06-12)
+
+NVL
+
+ <database> A {function} in {Oracle} {SQL} called like NVL(X,
+ Y) that returns X unless it is null, in which case it returns
+ Y. This function is useful for supplying a default value
+ where an expression might be null.
+
+ (2010-01-28)
+
+NVRAM
+
+ {Non-Volatile Random Access Memory}
+
+NVS
+
+ {Non-Volatile Storage}
+
+NWNET
+
+ {NorthWestNet}
+
+NYAP
+
+ <language> An early system on the {IBM 704}.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (1997-12-03)
+
+nybble
+
+ {nibble}
+
+nyetwork
+
+ {notwork}
+
+nym
+
+ 1. <tool, networking> /nim/ (From the third syllable of
+ "anonymous"; or "nym server") A {server} that functions as an
+ {anonymous remailer}.
+
+ 2. A popular {hostname} for nym servers.
+
+ 3. A mail-forwarding {account} on a {nym server}.
+
+ (1999-02-26)
+
+nym server
+
+ {nym}
+
+Nyquist frequency
+
+ <DSP> The highest frequency that can be represented in a
+ digital signal of a specified {sampling frequency}. It is
+ equal to one-half of the sampling rate.
+
+ See {Nyquist Theorem}.
+
+ (2001-06-06)
+
+Nyquist Theorem
+
+ <communications> A theorem stating that when an {analogue}
+ waveform is digitised, only the frequencies in the waveform
+ below half the {sampling frequency} will be recorded. In
+ order to reconstruct (interpolate) a signal from a sequence of
+ samples, sufficient samples must be recorded to capture the
+ peaks and troughs of the original waveform. If a waveform is
+ sampled at less than twice its frequency the reconstructed
+ waveform will effectively contribute only {noise}. This
+ phenomenon is called "aliasing" (the high frequencies are
+ "under an alias").
+
+ This is why the best digital audio is sampled at 44,000 Hz -
+ twice the average upper limit of human hearing.
+
+ The Nyquist Theorem is not specific to digitised signals
+ (represented by discrete amplitude levels) but applies to any
+ sampled signal (represented by discrete time values), not just
+ sound.
+
+ {Nyquist
+ (http://geocities.com/bioelectrochemistry/nyquist.htm)}
+ (the man, somewhat inaccurate).
+
+ (2003-10-21)
+
+NYSERNET
+
+ {New York State Educational Reasearch NETwork}
+
+NYU OMNIFAX
+
+ Early system on UNIVAC I or II. Listed in CACM 2(5):16 (May
+ 1959).
+
+nz
+
+ <networking> The {country code} for New Zealand.
+
+ (1999-01-27)
+
+O
+
+ <character> {ASCII} code 79, The letter of the alphabet, not
+ to be confused with 0 ({zero}) the digit.
+
+ (1999-02-07)
+
+O2
+
+ Object-Oriented. {Object-oriented database} language used in
+ the {Altair} project. Implemented as an {interpreter}. GIP
+ Altair, Versailles, France. Francois Bancilhon et al, in
+ Advances in Object-Oriented Database Systems, K.R. Dittrich
+ ed, LNCS 334, Springer 1988. See {CO2}.
+
+Oaklisp
+
+ <language> A portable {object-oriented} {Scheme} by K. Lang
+ and Barak Perlmutter of {Yale}. Oaklisp uses a superset of
+ Scheme {syntax}. It is based on generic operations rather
+ than functions, and features {anonymous classes}, {multiple
+ inheritance}, a strong error system, {setters} and {locators}
+ for operations and a facility for {dynamic binding}.
+
+ Version 1.2 includes an interface, {bytecode compiler},
+ {run-time system} and documentation.
+
+ {(ftp://f.gp.cs.cmu.edu/usr/bap/oak/ftpable/)}, {for Amiga
+ (ftp://ftp.cso.uiuc.edu/pub/amiga/fish/ff519)}.
+
+ ["Oaklisp: An Object-Oriented Scheme with First-Class Types",
+ K. Lang et al, SIGPLAN Notices 21(11):30-37 (Nov 1986) (OOPSLA
+ '86)].
+
+ (1992-05-01)
+
+OAP
+
+ {Outside Awareness Port}
+
+OASIS Open Document Format for Office Applications
+
+ {OpenDocument}
+
+OATH
+
+ Object-oriented Abstract Type Hierarchy, a class library for
+ C++ from {Texas Instruments}.
+
+Ob-
+
+ /ob/ prefix Obligatory. A piece of {netiquette} acknowledging
+ that the author has been straying from the newsgroup's charter
+ topic. For example, if a posting in alt.sex is a response to
+ a part of someone else's posting that has nothing particularly
+ to do with sex, the author may append "ObSex" (or "Obsex") and
+ toss off a question or vignette about some unusual erotic act.
+ It is considered a sign of great {winnitude} when one's Obs
+ are more interesting than other people's whole postings.
+
+ [{Jargon File}]
+
+OBDC
+
+ Do you mean {ODBC}?
+
+ (1996-06-30)
+
+OBE
+
+ {Office By Example}
+
+Oberon
+
+ <language> A {strongly typed} {procedural} programming
+ language and an operating environment evolved from {Modula-2}
+ by {Nicklaus Wirth} in 1988. Oberon adds type extension
+ ({inheritance}), extensible record types, multidimensional
+ open arrays, and {garbage collection}. It eliminates {variant
+ records}, {enumeration types}, {subranges}, lower array
+ indices and {for loops}.
+
+ A successor called Oberon-2 by H. Moessenboeck features a
+ handful of extensions to Oberon including type-bound
+ procedures ({methods}).
+
+ Seneca is a variant of Oberon focussing on numerical
+ programming under development by R. Griesemer in April 1993
+ (to be renamed).
+
+ See also {Ceres workstation Oberon System}.
+
+ {(http://oberon.ethz.ch)}.
+
+ {(http://math.tau.ac.il/~laden/Oberon.html)}.
+
+ {Free ETH Oberon (ftp://ftp.inf.ethz.ch/pub/Oberon)}. {MS-DOS
+ (ftp://ftp.wustl.edu/mirrors/msdos/pgmutl/)}. {Amiga
+ (ftp://ftp.cso.uiuc.edu/pub/amiga/fish/ff380)}.
+
+ ["The Programming Language Oberon", N. Wirth, Soft Prac & Exp
+ 18(7):671-690 July 1988].
+
+ ["Programming in Oberon: Steps Beyond Pascal and Modula",
+ M. Reiser & N. Wirth, A-W 1992].
+
+ ["Project Oberon: the design of an operating system and
+ compiler", N. Wirth & J. Gutknecht, ACM Press 1992].
+
+ ["The Oberon Companion: A Guide to Using and Programming
+ Oberon System 3", André Fischer, Hannes Marais, vdf Verlag der
+ Fachhochschulen, Zurich, 1997, ISBN 3-7281-2493-1. Includes
+ CD-ROM for Windows, Linux, Macintosh and PC Native].
+
+ (1998-03-14)
+
+Oberon-2
+
+ <language> A superset of {Oberon-1}, developed by
+ H. Moessenboeck in 1991 to add {object-orientation}. Oberon-2
+ was a redesign of {Object Oberon}. It included type-bound
+ {procedures} (equivalent to {methods}), read-only export of
+ variables and {record fields}, open {array} variables, and a
+ "{with}" statement with variants. It reintroduced the "{for}"
+ statement.
+
+ There is an Oberon-2 {Lex} scanner and {Yacc} {parser} by
+ Stephen J Bevan of Manchester University, UK, based on the one
+ in the Mo"ssenbo"ck and Wirth reference. Version 1.4.
+
+ {(ftp://neptune.inf.ethz.ch/Oberon/)}.
+
+ {(ftp://ftp.psg.com/pub/oberon/)}.
+
+ ["The Programming Language Oberon-2", H. Mo"ssenbo"ck,
+ N. Wirth, Institut fu"r Computersysteme, ETH Zu"rich, January
+ 1992].
+
+ ["Second International Modula-2 Conference", Sept 1991].
+
+ (1992-07-06)
+
+Oberon-V
+
+ (Formerly Seneca). R. Griesemer, 1990. Descendant of Oberon
+ designed for numerical applications on supercomputers,
+ especially vector or pipelined architectures. Includes array
+ constructors and an ALL statement. "Seneca - A Language for
+ Numerical Applications on Vectorcomputers", Proc CONPAR 90 -
+ VAPP IV Conf. R. Griesemer, Diss Nr. 10277, ETH Zurich.
+
+OBEX
+
+ {Object Exchange}
+
+obfuscated
+
+ <programming> Made unclear, used to describe {source code}
+ that has been transformed or written to make it as hard as
+ possible to read, usually for fun, as in the {Obfuscated C
+ Contest}. A {japh} is a kind of obfuscated {Perl} program.
+
+ The term is not normally used for code that has been
+ transformed for security purposes, e.g. to enforce some kind
+ of licencing mechanism.
+
+ (2009-05-14)
+
+Obfuscated C Contest
+
+ <programming> The International Obfuscated C Code Contest
+ (IOCCC) is an annual contest run since 1984 over {Usenet} by
+ Landon Curt Noll and friends. The overall winner is whoever
+ produces the most unreadable, creative, and bizarre (but
+ working) {C} program. Various other prizes are awarded at the
+ judges' whim. C's terse {syntax} and {macro-preprocessor}
+ facilities give contestants a lot of maneuvering room. The
+ winning programs often manage to be simultaneously funny,
+ breathtaking works of art and horrible examples of how *not*
+ to code in C.
+
+ This relatively short and sweet {hello, world} program
+ demonstrates obfuscated C:
+
+ /* HELLO WORLD program
+ * by Jack Applin and Robert Heckendorn, 1985 */
+
+ main(v,c)char**c;{for(v[c++]="Hello, world!\n)";
+ (!!c)[*c]&&(v--||--c&&execlp(*c,*c,c[!!c]+!!c,!c));
+ **c=!c)write(!!*c,*c,!!**c);}
+
+ Here's another good one:
+
+ /* Program to compute an approximation of pi
+ * by Brian Westley, 1988 */
+
+ #define _ -F<00||--F-OO--;
+ int F=00,OO=00;
+ main(){F_OO();printf("%1.3f\n",4.*-F/OO/OO);}F_OO()
+ {
+ _-_-_-_
+ _-_-_-_-_-_-_-_-_
+ _-_-_-_-_-_-_-_-_-_-_-_
+ _-_-_-_-_-_-_-_-_-_-_-_-_-_
+ _-_-_-_-_-_-_-_-_-_-_-_-_-_-_
+ _-_-_-_-_-_-_-_-_-_-_-_-_-_-_
+ _-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
+ _-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
+ _-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
+ _-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
+ _-_-_-_-_-_-_-_-_-_-_-_-_-_-_
+ _-_-_-_-_-_-_-_-_-_-_-_-_-_-_
+ _-_-_-_-_-_-_-_-_-_-_-_-_-_
+ _-_-_-_-_-_-_-_-_-_-_-_
+ _-_-_-_-_-_-_-_
+ _-_-_-_
+ }
+
+ Note that this program works by computing its own area. For
+ more digits, write a bigger program.
+
+ [{Jargon File}]
+
+obi-wan error
+
+ <programming> /oh'bee-won" er"*r/ (RPI, from "off-by-one" and
+ the Obi-Wan Kenobi character in "Star Wars") A kind
+ of {off-by-one error}.
+
+ (2009-05-14)
+
+OBJ
+
+ Joseph Goguen 1976. A family of declarative "ultra high
+ level" languages. Abstract types, generic modules, subsorts
+ (subtypes with {multiple inheritance}), pattern-matching
+ modulo equations, E-strategies (user control over laziness),
+ module expressions (for combining modules), theories and views
+ (for describing module interfaces). For the massively
+ parallel RRM (Rewrite Rule Machine).
+
+ ["Higher-Order Functions Considered Unnecessary for
+ Higher-Order Programming", J.A. Goguen, in Research Topics in
+ Functional Programming].
+
+OBJ0
+
+ Tardo. Based on unsorted equational logic.
+
+OBJ2
+
+ Clear-like parametrised modules. A functional system based on
+ equations. "Principles of OBJ2", K. Futatsugi et al, 12th
+ POPL, ACM 1985, pp.52-66.
+
+OBJ3
+
+ <language> A version of {OBJ} based on {order-sorted
+ rewriting}. OBJ3 is {agent}-oriented and runs on {AKCL}.
+
+ E-mail: <obj3sys@crl.sri.com>, <obj3dist@csl.sri.com>.
+
+ ["Introducing OBJ3", J. Goguen et al, SRI-CSL-88-9, SRI Intl,
+ 1988].
+
+ (1995-03-16)
+
+object
+
+ <object-oriented> In {object-oriented programming}, an
+ instance of the data structure and behaviour defined by the
+ object's {class}. Each object has its own values for the
+ {instance variables} of its class and can respond to the
+ {methods} defined by its class.
+
+ For example, an object of the "Point" class might have
+ instance variables "x" and "y" and might respond to the "plot"
+ method by drawing a dot on the screen at those coordinates.
+
+ (2004-01-26)
+
+ObjectBroker
+
+ <programming> A distributed {object} system from {DEC} based
+ on the {CORBA} standard.
+
+ (1999-01-14)
+
+ObjectCenter
+
+ A product offering similar facilities to CodeCenter for the
+ C++ language, plus class browsing facilities etc (formerly
+ Saber-C++).
+
+Object CHILL
+
+ ["Object CHILL - An Object Oriented Language for Systems
+ Implementation", J. Winkler et al, ACM Comp Sci Conf 1992,
+ pp. 139-147].
+
+ (1995-01-31)
+
+object code
+
+ The {machine code} generated by a {source code} language
+ processor such as an {assembler} or {compiler}. A file of
+ object code may be immediately executable or it may require
+ {linking} with other object code files, e.g. libraries, to
+ produce a complete executable program.
+
+ (1995-01-31)
+
+Object-code Buffer Overrun Evaluator
+
+ <security, programming, tool> (OBOE) A tool by R. Banfi,
+ D. Bruschi, and E. Rosti for the automatic detection of
+ {buffer overflow} {vulnerabilities} in {object code}. OBOE
+ can be applied to {operating system} components as well as
+ ordinary {application programs}. It was designed for the
+ {system administrator} to identify vulnerable programs before
+ they are exploited. Being automatic, OBOE can be run as a
+ {background process} for the analysis of all potentially
+ insecure programs installed on a {Unix} system. It runs on
+ {HP-UX}, {Linux}, and {Sun} {Solaris}.
+
+ {(http://idea.sec.dsi.unimi.it/research.html)}.
+
+ (2003-10-25)
+
+Object Compatibility Standard
+
+ (OCS) An {88open} standard for compilers and linkers.
+
+Object Constraint Language
+
+ <language> (OCL) A formal specification language extension to
+ {UML}. The Object Constraint Language is a precise text
+ language that provides {constraint} and {object query}
+ expressions on an {object-oriented} model that cannot
+ otherwise be expressed by diagrammatic notation.
+
+ OCL supplements UML by providing expressions that have neither
+ the ambiguities of {natural language} nor the inherent
+ difficulty of using complex mathematics.
+
+ OCL is a descendent of {Syntropy}, a second-generation
+ object-oriented analysis and design method. The OCL 1.4
+ definition specified a constraint language. In OCL 2.0, the
+ definition has been extended to include general object query
+ language definitions.
+
+ {OMG UML Home (http://uml.org/)}.
+
+ {Rational UML Resource Center
+ (http://rational.com/uml/index.jsp)}.
+
+ {OCL 2.0 Submission to UML
+ (http://omg.org/docs/ad/03-01-07.pdf)}.
+
+ (2003-11-15)
+
+Object Database Management Group
+
+ {Object Data Management Group}
+
+Object Data Management Group
+
+ <body, database> (ODMG, previously ".. Database ..") An
+ independent consortium that specifies universal {object}
+ storage {standards}.
+
+ ODMG's members include {object-oriented database} management
+ system (ODBMS) vendors and other interested parties. They aim
+ to increase portability of customer software across products.
+
+ On 1998-04-27 ODMG changed its name from the Object Database
+ Management Group to reflect the expansion of its efforts
+ beyond merely setting storage standards for object databases.
+
+ {(http://odmg.org/)}.
+
+ (2000-05-23)
+
+Objecteering
+
+ <programming, tool> An {object-oriented design} tool from
+ {Softeam}, based on the {Class Relation Methodology}, with
+ {C++} code generation.
+
+ (1997-03-18)
+
+Object Exchange
+
+ <protocol> (OBEX) A {Bluetooth} {protocol} in the {Core
+ Protocol Stack} for {data} exchange.
+
+ (2002-06-28)
+
+objectfuscated code
+
+ <humour, programming> {Object-oriented} code which has been
+ abstracted to so many levels that no-one can understand it
+ anymore. A play on {obfuscated code}.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2014-08-01)
+
+object identifier
+
+ <programming> (OID) Generally an implementation-specific
+ {integer} or {pointer} that uniquely identifies an {object}.
+
+ (1999-07-10)
+
+Objectionable-C
+
+ <abuse, humour, language> A hackish take on "{Objective C}".
+ Objectionable-C uses a {Smalltalk}-like {syntax}, but lacks
+ the flexibility of Smalltalk {method} calls, and (like many
+ such efforts) comes frustratingly close to attaining the
+ {Right Thing} without actually doing so.
+
+ [{Jargon File}]
+
+ (1995-02-15)
+
+Objective C
+
+ <language> An {object-oriented} superset of {ANSI C} by Brad
+ Cox, Productivity Products. Its additions to {C} are few and
+ are mostly based on {Smalltalk}. Objective C is implemented
+ as a {preprocessor} for {C}. Its {syntax} is a superset of
+ standard C syntax, and its {compiler} accepts both C and
+ Objective C {source code} ({filename extension} ".m").
+
+ It has no operator {overloading}, {multiple inheritance}, or
+ {class variables}. It does have {dynamic binding}. It is
+ used as the system programming language on the {NeXT}. As
+ implemented for {NEXTSTEP}, the Objective C language is fully
+ compatible with {ANSI C}.
+
+ Objective C can also be used as an extension to {C++}, which
+ lacks some of the possibilities for {object-oriented design}
+ that {dynamic typing} and {dynamic binding} bring to Objective
+ C. C++ also has features not found in Objective C.
+
+ Versions exist for {MS-DOS}, {Macintosh}, {VAX}/{VMS} and
+ {Unix} {workstations}. Language versions by {Stepstone},
+ {NeXT} and {GNU} are slightly different.
+
+ There is a library of ({GNU}) Objective C {objects} by
+ R. Andrew McCallum <mccallum@cs.rochester.edu> with similar
+ functionality to {Smalltalk}'s Collection objects. It
+ includes: Set, {Bag}, {Array}, LinkedList, LinkList,
+ CircularArray, {Queue}, {Stack}, {Heap}, SortedArray,
+ MappedCollector, GapArray and DelegateList. Version: Alpha
+ Release. {(ftp://iesd.auc.dk/pub/ObjC/)}.
+
+ See also: {Objectionable-C}.
+
+ ["Object-Oriented Programming: An Evolutionary Approach", Brad
+ Cox, A-W 1986].
+
+ (1999-07-10)
+
+Objective CAML
+
+ <language> (Originally "CAML" - Categorical Abstract Machine
+ Language) A version of {ML} by G. Huet, G. Cousineau, Ascander
+ Suarez, Pierre Weis, Michel Mauny and others of {INRIA}. CAML
+ is intermediate between {LCF ML} and {SML} [in what sense?].
+ It has {first-class} functions, {static type inference} with
+ {polymorphic} types, user-defined {variant types} and {product
+ types}, and {pattern matching}. It is built on a proprietary
+ run-time system.
+
+ The CAML V3.1 implementation added {lazy} and {mutable} data
+ structures, a "{grammar}" mechanism for interfacing with the
+ {Yacc} {parser generator}, {pretty-printing} tools,
+ high-performance {arbitrary-precision} arithmetic, and a
+ complete library.
+
+ in 1990 Xavier Leroy and Damien Doligez designed a new
+ implementation called {CAML Light}, freeing the previous
+ implementation from too many experimental high-level features,
+ and more importantly, from the old Le_Lisp back-end.
+
+ Following the addition of a {native-code} compiler and a
+ powerful {module} system in 1995 and of the {object} and
+ {class} layer in 1996, the project's name was changed to
+ Objective CAML. In 2000, Jacques Garrigue added labeled and
+ optional arguments and anonymous variants.
+
+ {Objective CAML Home (http://ocaml.org/)}.
+
+ {Usenet} newsgroup: {news:comp.lang.ml}.
+
+ ["The CAML Reference Manual", P. Weis et al, TR INRIA-ENS,
+ 1989].
+
+ (2002-05-21)
+
+Objective Modula-2
+
+ <language> (Or "ObjM2") An extension to {Modula-2} for {Cocoa}
+ and {GNUstep} software development. Objective Modula-2
+ follows the {Objective-C} {object model} and retains the
+ bracketed {Smalltalk} {message passing} {syntax} used in
+ Objective-C. Classes written in ObjM2 can be used within ObjC
+ and vice versa. ObjM2 also retains Modula-2's {data
+ encapsulation} features, namely {nested modules} with explicit
+ {import} and export lists. Due to the strict {type checking}
+ in Modula-2, ObjM2 can be considered a much safer programming
+ language than is ObjC, yet losing none of the capabilities of
+ ObjC.
+
+ (2005-08-15)
+
+Objective PASCAL
+
+ An extension of the {PASCAL} language which provides the
+ possibility to use {object-oriented} programming constructs.
+
+Object Linking and Embedding
+
+ <operating system> (OLE) A distributed object system and
+ {protocol} from {Microsoft}, also used on the Acorn
+ {Archimedes}. OLE allows an editor to "farm out" part of a
+ document to another editor and then reimport it. For example,
+ a {desk-top publishing} system might send some text to a {word
+ processor} or a picture to a {bitmap} editor using OLE.
+
+ (1998-12-17)
+
+Object Lisp
+
+ <language> An {object-oriented} {Lisp} developed by {Lisp
+ Machines Inc.} (LMI) in about 1987. Object Lisp was based on
+ nested {closures} and {operator shadowing}.
+
+ Several competing object-orientated extensions to Lisp were
+ around at the time, such as {Flavors}, in use by {Symbolics};
+ {Common Objects}, developed by {Hewlett-Packard}; and
+ {CommonLoops} in use by {Xerox}.
+
+ LMI submitted the specification as a candidate for an
+ object-oriented standard for {Common Lisp}, but it was
+ defeated in favour of {CLOS}.
+
+ ["ObjectLISP User Manual", G. Dreschere, LMI 1987].
+
+ (2008-03-19)
+
+ObjectLOGO
+
+ A variant of LOGO with object-oriented extensions. Lexical
+ scope. Version 2.6, for the Mac. Paradigm Software
+ <paradigm@applelink.apple.com> (617)576-7675.
+
+Object Management Group
+
+ <body> (OMG) A consortium aimed at setting {standards} in
+ {object-oriented programming}. In 1989, this consortium,
+ which included {IBM Corporation}, {Apple Computer Inc.} and
+ {Sun Microsystems Inc.}, mobilised to create a
+ cross-compatible distributed object standard. The goal was a
+ common binary object with methods and data that work using all
+ types of development environments on all types of platforms.
+ Using a committee of organisations, OMG set out to create the
+ first {Common Object Request Broker Architecture} (CORBA)
+ standard which appeared in 1991. As of February 1998, the
+ latest standard is CORBA 2.2.
+
+ {(http://omg.org/)}.
+
+ [David S. Linthicum, DBMS, January 1997]
+
+ (1999-02-02)
+
+Object management system
+
+ In an IPSE, the system which maintains information about the
+ system under development.
+
+object method
+
+ <programming> In {object-oriented programming}, a {function} that
+ is called ("invoked") on an {object} ??
+
+ is passed
+
+Object Modelling Technique
+
+ <programming> (OMT) An {object-oriented} methodology.
+
+ [Details?]
+
+ (1996-11-03)
+
+Object Oberon
+
+ {Oberon} plus {class}es and {methods} by H. Moessenboeck &
+ J. Templ, 1989. See {Oberon-2}.
+
+ ["Object Oberon - An Object-Oriented Extension of Oberon", H.
+ Moessenboeck et al, ETH TR 109 (Apr 1990)].
+
+ ["Object Oberon - A Modest Object-Oriented Language",
+ H. Moessenboeck & J. Templ, in Structured Programming 10(4),
+ 1989].
+
+object-orientation
+
+ {object-oriented}
+
+object-oriented
+
+ 1. <programming> (OO) Based on {objects}, {classes} and {methods},
+ as in {object-oriented programming} or {object-oriented design}.
+ An {object-oriented database} applies the same concepts to the
+ storage of objects.
+
+ 2. <graphics> {vector graphics}.
+
+ (2014-01-06)
+
+object-oriented analysis
+
+ <programming> (OOA) The first phase of {object-oriented design}.
+
+ (2014-01-06)
+
+object-oriented database
+
+ <database> (OODB) A system offering {DBMS} facilities in an
+ {object-oriented programming} environment. Data is stored as
+ {objects} and can be interpreted only using the {methods}
+ specified by its {class}. The relationship between similar
+ objects is preserved ({inheritance}) as are references between
+ objects. Queries can be faster because {joins} are often not
+ needed (as in a {relational database}). This is because an
+ object can be retrieved directly without a search, by
+ following its object id.
+
+ The same programming language can be used for both data
+ definition and data manipulation. The full power of the
+ database programming language's {type system} can be used to
+ model {data structures} and the relationship between the
+ different data items.
+
+ {Multimedia} {applications} are facilitated because the
+ {class} {methods} associated with the data are responsible for
+ its correct interpretation.
+
+ OODBs typically provide better support for {versioning}. An
+ object can be viewed as the set of all its versions. Also,
+ object versions can be treated as full fledged objects. OODBs
+ also provide systematic support for {triggers} and
+ {constraints} which are the basis of {active databases}.
+ Most, if not all, object-oriented {application programs} that
+ have database needs will benefit from using an OODB.
+
+ {Ode} is an example of an OODB built on {C++}.
+
+ (1997-12-07)
+
+object-oriented design
+
+ <programming> (OOD) A design method in which a system is modelled
+ as a collection of cooperating {objects} and individual objects
+ are treated as instances of a {class} within a {class hierarchy}.
+ Four stages can be identified: identify the classes and objects,
+ identify their {semantics}, identify their relationships and
+ specify class and object interfaces and implementation.
+ Object-oriented design is one of the stages of {object-oriented
+ programming}.
+
+ {Schlaer-Mellor} is one approach to OOD.
+
+ ["Object-oriented analysis and design with applications",
+ Grady Booch, 2nd ed., pub. Benjamin/Cummings, Redwood CA,
+ 1994].
+
+ (1997-12-07)
+
+Object-Oriented Fortran
+
+ <language> (OOF) An {object-oriented} extension of {Fortran},
+ in which data items can be grouped into objects, which can be
+ instantiated and executed in parallel.
+
+ It was available for {Sun}, {Iris}, {iPSC}, and {nCUBE}, but
+ is no longer supported.
+
+ E-mail: Donna Reese <dreese@cs.msstate.edu>.
+
+ (2001-03-06)
+
+object-oriented language
+
+ {object-oriented programming}
+
+Object-Oriented Pascal
+
+ {Object Pascal}
+
+object-oriented polymorphism
+
+ <programming> The kind of {polymorphism} found in {object-oriented
+ programming} languages where a {variable} can refer to an {object}
+ whose {class} is not known exactly until {run time}. A {method}
+ can use a variable of a given class - call other methods on it,
+ pass it as an argument, etc. - without needing to know to which
+ subclass it refers, as long as its actual class is compatible with
+ those uses.
+
+ (2014-01-05)
+
+object-oriented programming
+
+ <programming> (OOP) The use of a class of programming
+ languages and techniques based on the concept of an "{object}"
+ which is a data structure ({abstract data type}) encapsulated
+ with a set of routines, called "{methods}", which operate on
+ the data. Operations on the data can __only__ be performed via
+ these methods, which are common to all objects that are
+ instances of a particular "{class}". Thus the interface to
+ objects is well defined, and allows the code implementing the
+ methods to be changed so long as the interface remains the
+ same.
+
+ Each class is a separate {module} and has a position in a
+ "{class hierarchy}". Methods or code in one class can be
+ passed down the hierarchy to a {subclass} or inherited from a
+ {superclass}. This is called "{inheritance}".
+
+ A {procedure} call is described as invoking a method on an
+ object (which effectively becomes the procedure's first
+ {argument}), and may optionally include other arguments. The
+ method name is looked up in the object's class to find out how
+ to perform that operation on the given object. If the method
+ is not defined for the object's class, it is looked for in its
+ superclass and so on up the class hierarchy until it is found
+ or there is no higher superclass.
+
+ OOP started with {SIMULA-67} around 1970 and became
+ all-pervasive with the advent of {C++}, and later {Java}.
+ Another popular object-oriented programming language (OOPL) is
+ {Smalltalk}, a seminal example from {Xerox}'s {Palo Alto
+ Research Center} (PARC). Others include {Ada}, {Object
+ Pascal}, {Objective C}, {DRAGOON}, {BETA}, {Emerald}, {POOL},
+ {Eiffel}, {Self}, {Oblog}, {ESP}, {Loops}, {POLKA}, and
+ {Python}. Other languages, such as {Perl} and {VB}, permit,
+ but do not enforce OOP.
+
+ {FAQ (http://iamwww.unibe.ch/~scg/OOinfo/FAQ/)}.
+ {(http://zgdv.igd.fhg.de/papers/se/oop/)}.
+ {(http://cuiwww.unige.ch/Chloe/OOinfo)}.
+
+ {Usenet} newsgroup: {news:comp.object}.
+
+ (2001-10-11)
+
+object-oriented programming language
+
+ {object-oriented programming}
+
+Object-oriented SQL
+
+ <language> (OSQL) A {functional language}, a superset of
+ {SQL}, used in {Hewlett-Packard}'s {OpenODB} {database}
+ system.
+
+ (1994-11-29)
+
+Object-Oriented Turing
+
+ <language> An extension of {Turing} and a replacement for
+ {Turing Plus} by R.C. Holt <holt@csri.toronto.edu>, U Toronto,
+ 1991. Object-Oriented Turing supports {imperative
+ programming}, {object-oriented programming} and {concurrent
+ programming}. It has {modules}, {class}es, {single
+ inheritance}, processes, {exception handling} and optional
+ machine-dependent programming.
+
+ There is an integrated environment under the {X Window System}
+ and {a demo version (ftp://turing.toronto.edu/pub/turing)}.
+ Versions exist for {Sun-4}, {MIPS}, {RS-6000} and others.
+
+ E-mail: <ootinfo@turing.toronto.edu>.
+
+ ["A Conceptual Framework for Software Development", Mancoridis
+ et al, eds, ACM SIGSCE Conference, Feb 1993, Indianapolis].
+ ["Turing Reference Manual", 1992, ISBN 0-921598-15-7].
+
+ (2000-04-21)
+
+Objectory
+
+ <programming> An {object-oriented} {methodology} mostly
+ created by {Ivar Jacobson}.
+
+ (2003-07-11)
+
+ObjectPAL
+
+ {Object-oriented database} language, part of {Borland}'s
+ {MS-Windows} version of {Paradox}.
+
+Object Pascal
+
+ <language> An {object-oriented} {Pascal} developed jointly by
+ {Apple Computer} and {Niklaus Wirth}.
+
+ ["Object Pascal Report", Larry Tesler, Structured Language
+ World 9(3):10-17 (1985)].
+
+ (1994-10-28)
+
+Object Persistence Framework
+
+ <programming> (OPF) Any system for storing {objects} so they
+ can be reloaded into a future session. Typically this will
+ use a {relational database} along with some kind of {object
+ relational mapping}. Another typical solution would store
+ objects in {XML} files (a form of {serialisation}). One of
+ the trickier problems to solve is how to maintain references
+ between objects, e.g. replacing memory pointers with unique
+ names or identifiers.
+
+ Virtually identical considerations apply to transferring
+ objects, or indeed any kind of data structure, from one
+ process to another via some communications channel, e.g. a
+ {TCP/IP} connection.
+
+ {Apple}'s {Enterprise Objects Framework} (EOF) is a mature and
+ powerful example.
+
+ (2009-01-15)
+
+Object Request Broker
+
+ <programming> (ORB) Part of the {OMG} {CORBA} specification,
+ an ORB's basic function is to pass {method} invocation
+ requests to the correct {objects} and return the results to
+ the caller.
+
+ To achieve this the ORB must be able must be able to identify
+ and locate objects, handle connections from invoker and the
+ data returned from methods. Communication between the ORB and
+ applications are achieved through {IDL} stubs and skeletons
+ whilst the OMG has specified {IIOP} as the protocol through
+ which ORBs may communicate with each other. Using IIOP, an
+ ORB may request method invocations from a remote object.
+
+ (2003-11-21)
+
+Object Role Modeling
+
+ <programming> (ORM) A conceptual {model}ling approach that
+ pictures the application world as a set of {objects} that play
+ roles (parts in relationships, which may be unary, binary or
+ higher order). ORM provides both graphical and textual
+ languages that enable models to be expressed naturally. For
+ {data modelling} purposes, its graphical language is more
+ expressive than {ER} or {UML}.
+
+ {(http://orm.net/)}.
+
+ (1999-08-27)
+
+Object Value
+
+ <jargon> In industrial design, a measure of consumers'
+ immediate desire for an object, even before they know or
+ understand what it does. "Gassee may be nuts, but at least
+ the {BeBox} has great object value."
+
+ (1997-03-30)
+
+Objectworks
+
+ An {object-oriented} development environment developed by
+ {ParcPlace}, available under {Smalltalk} and {C++}.
+
+ (1994-10-28)
+
+Object Z
+
+ University of Queensland.
+
+ ["Object Orientation in Z", S. Stepney et al eds, Springer
+ 1992].
+
+Objlog
+
+ A {frame}-based language combining {objects} and {Prolog II}
+ from {CNRS}, Marseille, France.
+
+ ["The Inheritance Processes in Prolog", C. Chouraki et al,
+ GRTC/187bis/Mars 1987 (CNRS)].
+
+ E-mail: <somebody@grtc.cnrs-mrs.fr>.
+
+ (1994-10-28)
+
+OBJT
+
+ {Error algebras} plus an image construct. Tardo.
+
+ObjVlisp
+
+ 1984. An {object-oriented} extension of {Vlisp}.
+ {Reflective} architecture.
+
+ ["Metaclasses are First Class: The ObjVlisp Model", P.
+ Cointe, SIGPLAN Notices 22(121):156-167 (Dec 1987) (OOPSLA
+ '87)].
+
+ObjVProlog
+
+ {Logic programming} and {object-orientation}, an adaptation of
+ the {ObjVlisp} model to {Prolog}.
+
+ ["ObjVProlog: Metaclasses in Logic", J. Malenfant, ECOOP '89,
+ Cambridge U Press 1989, pp.257-269].
+
+Obliq
+
+ A small, statically scoped untyped language by Luca Cardelli,
+ 1993. Obliq is {object-oriented}, higher order, concurrent,
+ and distributed. State is local to an address space, while
+ computation can migrate over the network. The distributed
+ computation mechanism is based on {Modula-3} network objects.
+
+ {(ftp://gatekeeper.dec.com/pub/DEC/Modula-3/contrib)}.
+
+oblique stroke
+
+ <character> "/". Common names include: (forward) slash;
+ stroke; {ITU-T}: slant; oblique stroke. Rare: diagonal;
+ solidus; over; slak; virgule; {INTERCAL}: slat.
+
+ Commonly used as the division {operator} in programming, and
+ to separate the components in {Unix} {pathnames}, and hence
+ also in {URLs}. Also used to delimit {regular expressions} in
+ several languages.
+
+ (1996-09-24)
+
+Oblog
+
+ <language> A small, portable, {Object-oriented} extension to
+ {Prolog} by Margaret McDougall of EdCAAD, Dept Arch,
+ {University of Edinburgh}.
+
+ (1995-12-29)
+OBOE
+
+ {Object-code Buffer Overrun Evaluator}
+
+OBSCURE
+
+ "A Formal Description of the Specification Language OBSCURE",
+ J. Loeckx, TR A85/15, U Saarlandes, Saarbrucken, 1985.
+
+ [{Jargon File}]
+
+observational equivalence
+
+ Two terms M and N are observationally equivalent iff for all
+ contexts C[] where C[M] is a valid term, C[N] is also a valid
+ term with the same value.
+
+Oc
+
+ <language> ("Oh see!") A {parallel} {logic language}.
+
+ ["Self-Description of Oc and its Applications", M. Hirata,
+ Proc 2nd Natl Conf Japan Soc Soft Sci Tech, pp. 153-156,
+ 1984].
+
+ (1995-03-16)
+
+OC-12
+
+ {Optical Carrier 12}
+
+OC-3
+
+ {Optical Carrier 3}
+
+OC-48
+
+ {Optical Carrier 48}
+
+OCAL
+
+ On-Line Cryptanalytic Aid Language.
+
+ ["OCAS: On-line Cryptanalytic Aid System", D.J. Edwards,
+ MAC-TR-27, MIT Project MAC, May 1966. Sammet 1969, p.642].
+
+occam
+
+ <language> (Note lower case) A language based on {Anthony
+ Hoare}'s {CSP} and {David May}'s {EPL}. Named after the
+ English philosopher, William of Occam (1300-1349) who
+ propounded {Occam's Razor}. The occam language was designed
+ by David May of {INMOS} to easily describe {concurrent}
+ processes which communicate via one-way channels. It was
+ developed to run on the {INMOS} {transputer} but {compilers}
+ are available for {VAX}, {Sun} and {Intel} {MDS}, inter alia.
+
+ The basic entity in occam is the process of which there are
+ four fundamental types, {assignment}, input, output, and wait.
+ More complex processes are constructed from these using SEQ to
+ specify sequential execution, PAR to specify parallel
+ execution and ALT where each process is associated with an
+ input from a channel. The process whose channel inputs first
+ is executed. The fourth constructor is IF with a list of
+ conditions and associated processes. The process executed is
+ the one with the first true condition in textual order. There
+ is no {operator precedence}.
+
+ The original occam is now known as "occam 1". It was extended
+ to {occam 2}.
+
+ {Simulator for VAX (ftp://watserv1.waterloo.edu/)}.
+
+ Tahoe mailing list: <occam@sutcase.case.syr.edu>.
+
+ [David May et al, 1982. "Concurrent algorithms"].
+
+ ["Occam", D. May, SIGPLAN Notices 18(4):69-79, 1983].
+
+ (1994-11-18)
+
+occam 2
+
+ <language> An extension of {occam} produced in 1987. Occam 2
+ adds {floating-point}, functions and a type system.
+
+ ["occam 2 Reference Manual", INMOS, P-H 1988, ISBN
+ 0-13-629312-3].
+
+ (1994-11-18)
+
+Occam's Razor
+
+ <philosophy> The English philosopher, William of Occam
+ (1300-1349) propounded Occam's Razor:
+
+ Entia non sunt multiplicanda praeter necessitatem.
+
+ (Latin for "Entities should not be multiplied more than
+ necessary"). That is, the fewer assumptions an explanation of
+ a phenomenon depends on, the better it is.
+
+ For example, some claim that God caused himself to exist and
+ also caused the universe to exist - he was the "first cause" -
+ whereas Occam's Razor suggests that if one accepts the
+ possibility of something causing itself then it is better to
+ assume that it was the universe that caused itself rather than
+ God because this explanation involves fewer entities.
+
+ The negation of Occam's Razor would suggest that an
+ arbitrarily complex explanation is just as good as the
+ simplest one. (E.g. God and his cat created a robot called
+ Sparky who built the universe from parts bought from a shop in
+ another dimension).
+
+ See also {KISS Principle}.
+
+ (1995-11-09)
+
+occlude
+
+ <programming> (Or "shadow") To make a variable inaccessible by
+ declaring another with the same name within the {scope} of the
+ first.
+
+ (1995-12-14)
+
+occurs check
+
+ <programming> A feature of some implementations of
+ {unification} which causes unification of a {logic variable} V
+ and a structure S to fail if S contains V.
+
+ Binding a variable to a structure containing that variable
+ results in a cyclic structure which may subsequently cause
+ unification to loop forever. Some implementations use extra
+ pointer comparisons to avoid this.
+
+ Most implementations of {Prolog} do not perform the occurs
+ check for reasons of efficiency. Without occurs check the
+ {complexity} of {unification} is
+
+ O(min(size(term1), size(term2)))
+
+ with occurs check it's
+
+ O(max(size(term1), size(term2)))
+
+ In {theorem proving} unification without the occurs check can
+ lead to unsound inference. For example, in {Prolog} it is
+ quite valid to write
+
+ X = f(X).
+
+ which will succeed, binding X to a cyclic structure. Clearly
+ however, if f is taken to stand for a function rather than a
+ {constructor}, then the above equality is only valid if f is
+ the {identity function}.
+
+ Weijland calls unification without occur check, "complete
+ unification". The reference below describes a complete
+ unification algorithm in terms of Colmerauer's consistency
+ algorithm.
+
+ ["Semantics for Logic Programs without Occur Check",
+ W.P. Weijland, Theoretical Computer Science 71 (1990) pp
+ 155-174].
+
+ (1996-01-11)
+
+OCL
+
+ <language> 1. {Operator Control Language}.
+
+ 2. {Object Constraint Language}.
+
+ (2003-01-18)
+
+OCLC
+
+ {Online Computer Library Center}
+
+OC-n
+
+ {Optical Carrier n}
+
+OCODE
+
+ An {assembly language} for a {stack}-based {virtual machine},
+ used as the {intermediate language} of the Cambridge {BCPL}
+ compiler.
+
+ ["The Portability of the BCPL Compiler", M. Richards, Soft
+ Prac & Exp 1(2) (1971)].
+
+ (1995-01-30)
+
+OCP
+
+ <processor> {Order Code Processor}.
+
+OCR
+
+ {Optical Character Recognition}
+
+OCS
+
+ {Object Compatibility Standard}
+
+octal
+
+ <mathematics> Base 8. A number representation using the
+ digits 0-7 only, with the right-most digit counting ones, the
+ next counting multiples of 8, then 8^2 = 64, etc. For
+ example, octal 177 is digital 127:
+
+ digit weight value
+ 1 8^2 = 64 1* 64 = 64
+ 7 8^1 = 8 7* 8 = 56
+ 7 8^0 = 1 7* 1 = 7
+ ---
+ 127
+
+ Octal system used to be widespread back when many computers
+ used 6-bit {bytes}, as a 6-bit byte can be conveniently
+ written as a two-digit octal number. Since nowadays a byte is
+ almost always 8-bit long the octal system lost most of its
+ appeal to the {hexadecimal} system.
+
+ For a brief discussion on the word `octal' see {hexadecimal}.
+
+ (1997-06-16)
+
+octal forty
+
+ <jargon> Jargon for "I'm drawing a blank.", I can't work it
+ out.
+
+ {Octal} 40 (decimal 32) is the {ASCII} code for space
+ character. By an odd coincidence, {hex} 40 is the {EBCDIC}
+ space character.
+
+ [{Jargon File}]
+
+ (1995-03-06)
+
+Octave
+
+ <language> A high-level {interactive} language by John
+ W. Eaton, with help from many others, like {MATLAB}, primarily
+ intended for numerical computations. Octave provides a
+ convenient {command line interface} for solving linear and
+ nonlinear problems numerically.
+
+ Octave can do arithmetic for {real} and {complex} {scalars}
+ and {matrices}, solve sets of nonlinear algebraic equations,
+ integrate functions over finite and infinite intervals, and
+ integrate systems of ordinary differential and
+ differential-algebraic equations.
+
+ Octave has been compiled and tested with {g++} and libg++ on a
+ {SPARCstation 2} running {SunOS} 4.1.2, an {IBM} {RS/6000}
+ running {AIX} 3.2.5, {DEC Alpha} systems running {OSF}/1 1.3
+ and 3.0, a {DECstation 5000}/240 running {Ultrix} 4.2a, and
+ {Intel 486} systems running {Linux}. It should work on most
+ other {Unix} systems with {g++} and libg++.
+
+ Octave is distributed under the {GNU} {General Public
+ License}. It requires {gnuplot}, a {C++} compiler and
+ {Fortran} compiler or {f2c} translator.
+
+ Latest version: 2.0.16 (released 2000-01-30), as of 2000-06-26.
+
+ {home (http://che.wisc.edu/octave)}.
+
+ {(ftp://ftp.che.wisc.edu/pub/octave/)} or your nearest {GNU
+ archive site}.
+
+ E-mail: <bug-octave@bevo.che.wisc.edu>.
+
+ (2000-06-27)
+
+octet
+
+ <jargon, networking> Eight bits. This term is used in
+ networking, in preference to {byte}, because some systems use
+ the term "byte" for things that are not 8 bits long.
+
+ (1995-03-03)
+
+octothorpe
+
+ {hash character}
+
+OCX
+
+ {OLE custom controls}
+
+OD390
+
+ <web> A {CICS} Web {interperter} from {IBM} used
+ for application development involving web interfaces to {DB2}
+ tables.
+
+ (1998-06-21)
+
+ODA
+
+ {Open Document Architecture} (formerly Office
+ Document Architecture).
+
+ODBC
+
+ {Open DataBase Connectivity}
+
+ODC
+
+ {Open Distributed Computing}
+
+Ode
+
+ An {Object-Oriented Database} from {AT&T} which extends {C++}
+ and supports fast queries, complex application modelling and
+ {multimedia}.
+
+ Ode uses one integrated data model ({C++} {class}es) for both
+ database and general purpose manipulation. An Ode database is
+ a collection of {persistent} {objects}. It is defined,
+ queried and manipulated using the language {O++}. O++
+ programs can be compiled with C++ programs, thus allowing the
+ use of existing C++ code. O++ provides facilities for
+ specifying transactions, creating and manipulating persistent
+ objects, querying the database and creating and manipulating
+ versions.
+
+ The Ode object database provides four object compatible
+ mechanisms for manipulating and querying the database. As
+ well as O++ there are OdeView - an {X Window System}
+ interface; OdeFS (a file system interface allowing objects to
+ be treated and manipulated like normal Unix files); and CQL++,
+ a {C++} variant of {SQL} for easing the transition from
+ {relational databases} to OODBs such as Ode.
+
+ Ode supports large objects (critical for {multimedia}
+ applications). Ode tracks the relationship between versions
+ of objects and provides facilities for accessing different
+ versions. Transactions can be specified as read-only; such
+ transactions are faster because they are not logged and they
+ are less likely to {deadlock}. 'Hypothetical' transactions
+ allow users to pose "what-if" scenarios (as with
+ {spreadsheets}).
+
+ EOS, the {storage engine} of Ode, is based on a client-server
+ architecture. EOS supports {concurrency} based on
+ {multi-granularity} two-version two-phase locking; it allows
+ many readers and one writer to access the same item
+ simultaneously. Standard two-phase locking is also available.
+ Ode supports both a {client-server} mode for multiple users
+ with concurrent access and a single user mode giving improved
+ performance.
+
+ Ode 3.0 is currently being used as the {multimedia} {database
+ engine} for {AT&T}'s {Interactive TV} project. Ode 2.0 has
+ also been distributed to more than 80 sites within AT&T and
+ more than 340 universities. Ode is available free to
+ universities under a non-disclosure agreement. The current
+ version, 3.0, is available only for {Sun} {SPARCstations}
+ running {SunOS} 4.1.3 and {Solaris} 2.3. Ode is being ported
+ to {Microsoft} {Windows NT}, {Windows 95} and {SGI}
+ {platforms}.
+
+ E-mail: Narain Gehani <nhg@research.att.com>.
+
+ (1994-08-18)
+
+ODI
+
+ 1. {Optical Digital Image}.
+
+ 2. {Open Data-link Interface}.
+
+ODIF
+
+ {Open Document Interchange Format}
+
+ODMA
+
+ {Open Document Management API}
+
+ODMG
+
+ {Object Data Management Group}
+
+odometry
+
+ <robotics> The use of motion sensors to determine a robot's
+ change in position relative to some known position. For
+ example, if a robot is traveling in a straight line and if it
+ knows the diameter of its wheels, then by counting the number
+ of wheel revolutions it can determine how far it has traveled.
+ Robots will often have shaft encoders attached to their drive
+ wheels which emit a fixed number of pulses per revolution. By
+ counting these pulses, the processor can estimate the distance
+ traveled.
+
+ (2006-09-11)
+
+ODP
+
+ {Open Distributed Processing}
+
+ODS
+
+ {Operational Data Store}
+
+ODSA
+
+ {Open Distributed System Architecture}
+
+ODT
+
+ {Open Desktop}
+
+OEM
+
+ {original equipment manufacturer}
+
+OFA
+
+ {Optimal Flexible Architecture}
+
+off-by-one error
+
+ <programming> (Or "Obi-Wan error") An exceedingly common error
+ induced in many ways, such as by starting at zero when you
+ should have started at one or vice-versa, or by writing "< N"
+ instead of "<= N" or vice-versa. Often confounded with
+ {fencepost error}, which is properly a particular subtype of
+ it.
+
+ The term {zeroth} corrects the linguistic off-by-one error of,
+ e.g., referring to the "1st" element of an array whose indexes
+ start from zero.
+
+ [{Jargon File}]
+
+ (1998-09-21)
+
+Office
+
+ {Microsoft Office}
+
+office automation
+
+ <application> The use of computers or related {data
+ processing} technology to do routine clerical work such as
+ writing, filing and distributing documents. The term was used
+ before computers in offices were the norm (1960s?).
+
+ (2007-09-11)
+
+Office By Example
+
+ <language> (OBE) A sequel to {QBE}, described in publications
+ by Moshe Zloof of {IBM} in the early 1980s but apparently
+ never implemented.
+
+ (1998-03-14)
+
+Office Workstations Limited
+
+ <company> (OWL) A UK software company, now a subsidiary of
+ {Matsushita} (Panasonic, etc.). They previously supported the
+ {Guide} {hypertext} system but that support is now provided by
+ US company {InfoAccess}.
+
+ E-mail: <postmaster@owl-uk.owl-uk.co.uk>
+
+ [Correct address?]
+
+ (1996-01-15)
+
+Official Production System
+
+ <language> (OPS) The first {production system} (i.e. rule
+ based) programming language, developed at {CMU} in 1970 and
+ used for building {expert systems}. OPS was originally
+ written in {Franz Lisp} and later ported to other {LISP}
+ dialects.
+
+ (2003-04-05)
+
+off-line
+
+ <jargon> (Or "offline")
+
+ 1. Not directly connected to the computer (e.g., an off-line
+ {tape drive}), or with connection suspended ("take the
+ {printer} off-line").
+
+ Contrast {background}, {on-line}.
+
+ 2. Not now or not here. "Let's take this discussion
+ off-line." Specifically used on {Usenet} to suggest that a
+ discussion be moved off a public {newsgroup} to {e-mail}.
+
+ See also {off-line world}.
+
+ [{Jargon File}]
+
+ (1996-02-02)
+
+off-line world
+
+ <jargon> A die-hard {nethead} term for non-computer-related
+ experience.
+
+ See also {big room}.
+
+ ["Internet", Feb 1996].
+
+ (1996-03-04)
+
+offset
+
+ <programming> An index or position in an {array}, {string}, or
+ block of memory usually a non-negative {integer}.
+
+ E.g. the {Perl} function splice(ARRAY, OFFSET, LENGTH, LIST)
+ replaces LENGTH elements starting at index OFFSET in array
+ with LIST, where offset zero means the start of the array.
+
+ For an {Intel x86} processor with a {segmented address space}
+ the offset is the position of a {byte} relative to the start
+ of the segment.
+
+ (2004-02-27)
+
+offshoring
+
+ <business> Transfer of a business process, e.g. manufacturing
+ or customer service, from a company in one country to the same
+ or another company in a different country. This overlaps
+ partially with outsourcing, in which work is transferred
+ to a different company in the same or a different country.
+
+ (2008-12-12)
+
+off-side rule
+
+ A lexical convention due to Landin, allowing the scope of
+ declarations in a program to be expressed by indentation. Any
+ non-whitespace token to the left of the first such token on
+ the previous line is taken to be the start of a new
+ declaration. Used in, for example, Miranda and Haskell.
+
+ [P.J. Landin "The Next 700 Programming Languages", CACM vol 9
+ pp157-165, March 1966]
+
+off the trolley
+
+ Describes the behaviour of a program that malfunctions and
+ goes catatonic, but doesn't actually {crash} or abort. See
+ {glitch}, {bug}, {deep space}.
+
+ [{Jargon File}]
+
+ogg
+
+ <games> /og/ ({CMU}) 1. In the multi-player space combat game
+ {Netrek}, to execute kamikaze attacks against enemy ships
+ which are carrying armies or occupying strategic positions.
+ Named during a game in which one of the players repeatedly
+ used the tactic while playing Orion ship G, showing up in the
+ player list as "Og". This trick has been roundly denounced by
+ those who would return to the good old days when the tactic of
+ dogfighting was dominant, but as Sun Tzu wrote, "What is of
+ supreme importance in war is to attack the enemy's strategy."
+ However, the traditional answer to the newbie question "What
+ does ogg mean?" is just "Pick up some armies and I'll show
+ you."
+
+ 2. In other games, to forcefully attack an opponent with the
+ expectation that the resources expended will be renewed faster
+ than the opponent will be able to regain his previous
+ advantage. Taken more seriously as a tactic since it has
+ gained a simple name.
+
+ 3. To do anything forcefully, possibly without consideration
+ of the drain on future resources. "I guess I'd better go ogg
+ the problem set that's due tomorrow." "Whoops! I looked down
+ at the map for a sec and almost ogged that oncoming car."
+
+ (1995-01-31)
+
+Ogg Vorbis
+
+ <audio, compression> A patent-free {audio} {compression}
+ {algorithm}.
+
+ {(http://xiph.org/)}.
+
+ (2001-12-17)
+
+OHCI
+
+ {Open Host Controller Interface}
+
+Ohm
+
+ <unit> The {MKS} unit of electrical {resistance}. One Ohm is
+ the resistance of a conductor across which a {potential
+ difference} of one {Volt} produces a {current} of one
+ {Ampere}. Named after {Georg Simon Ohm}.
+
+ (2003-12-02)
+
+Ohm, Georg Simon
+
+ {Georg Simon Ohm}
+
+ohnosecond
+
+ <unit, humour> (Presumably a play on "{nanosecond}") The
+ miniscule time it takes to realize that you've just made a BIG
+ mistake like typing rm -rf * in the wrong directory.
+
+ Seen in Elizabeth P. Crowe's book, "The Electronic Traveller."
+
+ (1998-08-27)
+
+OIC
+
+ <chat> oh, I see.
+
+ (1998-01-18)
+
+OID
+
+ {object identifier}
+
+-oid
+
+ <jargon> (from "android") A suffix used as in mainstream
+ English to indicate a poor imitation, a counterfeit, or some
+ otherwise slightly bogus resemblance. Hackers will happily
+ use it with all sorts of non-Greco/Latin stem words that
+ wouldn't keep company with it in mainstream English. For
+ example, "He's a nerdoid" means that he superficially
+ resembles a {nerd} but can't make the grade; a "modemoid"
+ might be a 300-baud {modem} (Real Modems run at 144000 or up);
+ a "computeroid" might be any {bitty box}.
+
+ "-oid" can also mean "resembling an android", which was once
+ confined to science-fiction fans and hackers. It too has
+ recently (in 1991) started to go mainstream (most notably in
+ the term "trendoid" for victims of terminal hipness). This is
+ probably traceable to the popularisation of the term {droid}
+ in "Star Wars" and its sequels.
+
+ Coinages in both forms have been common in science fiction for
+ at least fifty years, and hackers (who are often SF fans) have
+ probably been making "-oid" jargon for almost that long
+ (though {GLS} and {ESR} can personally confirm only that they
+ were already common in the mid-1970s).
+
+ [{Jargon File}]
+
+ (1999-07-10)
+
+OIL
+
+ 1. ["The Architecture of the FAIM-1 Symbolic Multiprocessing
+ System", A. Davis et al, 9th Intl Joint Conf in Artif Intell,
+ 1985, pp.32-38].
+
+ 2. Operator Identification Language. Used for {overloading}
+ resolution by the {Eli} compiler-writing system.
+
+OLAP
+
+ {On-Line Analytical Processing}
+
+OLAP Council
+
+ <body, standard> A body formed in early 1995 to work on a
+ {cross-product} {API} for {OLAP}. After little success it was
+ replaced by the {Analytical Solutions Forum}.
+
+ (2005-05-28)
+
+OLC
+
+ {On-Line Computer system}
+
+OLDAS
+
+ On-line Digital Analog Simulator. An interactive version of
+ {MIMIC}, for {IBM 360}.
+
+ ["OLDAS: An On-line Continuous System Simulation Language",
+ R.P. Cullen, in Interactive Systems for Experimental Applied
+ Mathematics, A-P 1968].
+
+old fart
+
+ Tribal elder. A title self-assumed with remarkable frequency
+ by (especially) {Usenet}ters who have been programming for
+ more than about 25 years; often appears in {sig blocks}
+ attached to {Jargon File} contributions of great archaeological
+ significance. This is a term of insult in the second or third
+ person but one of pride in first person.
+
+ [{Jargon File}]
+
+old talk
+
+ <chat> The old implementations of {talk}. See "{ntalk}" for
+ details.
+
+ (1997-09-11)
+
+Old Testament
+
+ [C programmers] The first edition of {K&R}, the
+ sacred text describing {Classic C}.
+
+ [{Jargon File}]
+
+OLE
+
+ {Object Linking and Embedding}
+
+OLE custom controls
+
+ <programming> (OCX) An {Object Linking and Embedding}
+ (OLE) custom control allowing infinite extension of the
+ {Microsoft Access} control set. OCX is similar in purpose to
+ {VBX} used in {Visual Basic}. Available OCX's include "Scroll
+ Bar Control", "Calendar Control", and "Data Outline Control".
+
+ [Details?]
+
+ (1995-12-05)
+
+OLE DB
+
+ <database, programming> {Microsoft}'s low-level {application
+ program interface} (API) for access to data sources.
+
+ "OLE" originally stood for {Object Linking and Embedding} and
+ "DB" for database but Microsoft no longer ascribes these
+ meanings.
+
+ (2008-03-19)
+
+OLE for Process Control
+
+ <standard> (OPC) A set of seven open standards for
+ connectivity and interoperability of industrial automation and
+ the enterprise systems.
+
+ Based on fundamental and evolving standards and technology of
+ the general computing market, the OPC Foundation adapts and
+ creates specifications that fill industry-specific needs.
+
+ {OPC Foundation (http://opcfoundation.org/)}.
+
+ (2003-05-21)
+
+OLGA
+
+ Ouf! un Langage pour les Grammaires Attribuees.
+
+ Inria, 1985. Language for specification of attribute
+ grammars, used as the input language of the compiler writing
+ system FNC-2. Applicative, {strongly typed}, polymorphic,
+ pattern-matching, modules.
+
+Olivetti
+
+ <company> A large Italian company producing office machinery,
+ computers and printers.
+
+ Olivetti took a controlling stake in {Acorn Computers} in
+ September 1985.
+
+ Olivetti computers were once marketed in USA with the ATT
+ brand name.
+
+ [Address? Other products?]
+
+ (1995-03-14)
+
+O-Logic
+
+ An {object-oriented} deductive language/database system.
+
+OLTP
+
+ {On-Line Transaction Processing}
+
+OLWM
+
+ {OpenLook Window Manager}
+
+om
+
+ <networking> The {country code} for Oman.
+
+ (1999-01-27)
+
+OMA
+
+ Object Management Architecture.
+
+ A set of standards under study by the {OMG}.
+
+ (1994-11-11)
+
+Omega
+
+ 1. <programming> A {prototype}-based {object-oriented}
+ language from Austria.
+
+ ["Type-Safe Object-Oriented Programming with Prototypes - The
+ Concept of Omega", G. Blaschek, Structured Programming
+ 12:217-225, 1991].
+
+ 2. <text, tool> A successor to {TeX} extended to handle the
+ {Unicode} character set.
+
+ {(http://ens.fr/omega/)}.
+
+ (1997-11-20)
+
+Omega-algebraic
+
+ In domain theory, a complete partial order is algebraic if
+ every element is the lub of some chain of compact elements.
+ If the set of compact elements is countable it is
+ omega-algebraic. Usually written with a Greek letter omega
+ ({LaTeX} \omega).
+
+ (1995-02-03)
+
+Omega test
+
+ The Omega test is a system written by William Pugh
+ <pugh@cs.umd.edu> and others for performing symbolic
+ manipulations of {conjunctions} of {linear constraints} over
+ integer variables. The Omega test dependence analyser is a
+ system built on top of the Omega test to analyse {array} data
+ dependences.
+
+ Version 3.2.2 includes a fortran to tiny translator, a Tiny
+ interpreter(?) and analysis tools.
+
+ {(ftp://ftp.cs.umd.edu/pub/omega)}. E-mail: <omega@cs.umd.edu>.
+
+ (1992-11-13)
+
+OMF
+
+ Object Management Facility.
+
+ Part of the {DAA} proposed by {Hewlett-Packard} and {Sun}.
+
+OMG
+
+ {Object Management Group}
+
+OMNICODE
+
+ Thompson, 1956. Ran on IBM 650.
+
+ [Sammet 1969, p. 5].
+
+OMNIFAX
+
+ Alternate name for NYU OMNIFAX? Early system on UNIVAC I or
+ II. Listed in CACM 2(5):16 (May 1959).
+
+OMNITAB
+
+ Statistical analysis and desk calculator. Version: OMNITAB
+ II.
+
+ ["OMNITAB II User's Reference Manual", NBS Tech Note 552 (Oct
+ 1971). Sammet 1969, pp. 296-299].
+
+OMR
+
+ {Optical Mark Reader}
+
+OMS
+
+ {Opportunity Management System}
+
+OMT
+
+ {Object Modelling Technique}
+
+OMTool
+
+ A graphical tool from General Electric Advanced Concepts
+ Center for design and analysis of systems with the {OMT}
+ methodology. Generates {C++} and {SQL} code.
+
+ONC
+
+ {Open Network Computing}
+
+Ondine
+
+ ["Concurrency Introduction to an Object-Oriented Language
+ System Ondine", T. Ogihara et al, 3rd Natl Conf Record A-5-1,
+ Japan Soc for Soft Sci Tech, Japan 1986].
+
+ (2012-12-31)
+
+one
+
+ <mathematics> The lowest positive {integer} and the basis for
+ counting. Multiplication by one is an {identity operator} and,
+ since one is its own {reciprocal}, so is division by one. One is
+ the result of dividing any non-zero number by itself. One raised
+ to any power is one and raising to the power one is also an
+ identity operator.
+
+ <data> The largest digit in {binary}, related to the value {true}
+ in {Boolean algebra}. {Digital computers} typically represent one
+ by a high voltage and zero by a low voltage.
+
+ (2012-12-31)
+
+one-banana problem
+
+ <jargon, abuse> At computer installations where the computers
+ have operators for routine administrivia, the programmers and
+ hardware people tend to look down on the operators and claim
+ that a trained monkey could do their job. The incentives
+ offered to said monkeys would then describe the difficulty of
+ a task. A one-banana problem is simple; hence, "It's only a
+ one-banana job at the most; what's taking them so long?"
+
+ See also {Infinite-Monkey Theorem}.
+
+ [{Jargon File}]
+
+ (2010-03-20)
+
+one-dimensional array
+
+ <types> An {array} with only one {dimension}; the simplest kind of
+ array, consisting of a sequence of items ("elements"), all of the
+ same type. An element is selected by an integer {index} that
+ normally starts at zero for the first element and increases by
+ one. The index of the last element is thus the length of the
+ array minus one.
+
+ A one-dimensional array is also known as a {vector}. It should
+ not be confused with a {list}. In some languages, e.g. {Perl},
+ all arrays are one-dimensional and higher dimensions are
+ represented as arrays of {pointers} to arrays (which can have
+ different sizes and can themselves contain pointers to arrays and
+ so on).
+
+ A one-dimensional array maps simply to memory: the address of an
+ element with index i is
+
+ A(i) = A0 + i * s
+
+ where A0 is the base address of the array and s is the size of
+ storage used for each element, the "stride". Elements may be
+ padded to certain {address boundaries}, e.g. {machine words}, to
+ increase access speed, in which case the stride will be larger
+ than the amount of data in an element.
+
+ (2014-03-22)
+
+one-line fix
+
+ Used (often sarcastically) of a change to a program that is
+ thought to be trivial or insignificant right up to the moment
+ it crashes the system. Usually "cured" by another one-line
+ fix. See also {I didn't change anything!}
+
+one-liner wars
+
+ <games, programming> A game popular among {hackers} who code
+ in the language {APL} (see {write-only language} and {line
+ noise}). The objective is to see who can code the most
+ interesting and/or useful routine in one line of {operators}
+ chosen from APL's exceedingly {hairy} primitive set. A
+ similar amusement was practiced among {TECO} hackers and is
+ now popular among {Perl} aficionados.
+
+ {Ken Iverson}, the inventor of APL, has been credited with a
+ one-liner that, given a number N, produces a list of the prime
+ numbers from 1 to N inclusive. It looks like this:
+
+ (2 = 0 +.= T o.| T) / T <- iN
+
+ where "o" is the APL null character, the assignment arrow is a
+ single character, and "i" represents the APL iota.
+
+ [{Jargon File}]
+
+ (2000-03-19)
+
+ones complement
+
+ A system used in some computers to represent negative
+ numbers. To negate a number, each bit of the number is
+ inverted (zeros are replaced with ones and vice versa). This
+ has the consequence that there are two reperesentations for
+ zero, either all zeros or all ones.
+
+ ...
+ 000...00011 = +3
+ 000...00010 = +2
+ 000...00001 = +1
+ 000...00000 = +0
+ 111...11111 = -0
+ 111...11110 = -1
+ 111...11101 = -2
+ 111...11100 = -3
+ ...
+
+ Naive logic for ones complement addition might easily conclude
+ that -0 + 1 = +0.
+
+ The {twos complement} avoids this by using all ones to
+ represent -1.
+
+One-Time Password
+
+ <security> (OTP) A security system that requires a new
+ password every time a user authenticates themselves, thus
+ protecting against an intruder replaying an intercepted
+ password. OTP generates passwords using either the {MD4} or
+ {MD5} {hashing} {algorithms}.
+
+ The equivalent term "S/Key", developed by Bellcore, is a
+ trademark of {Telcordia Technologies}, so the name OTP is used
+ increasingly.
+
+ See {RFC 1760} - "The S/KEY One-Time Password System" and {RFC
+ 1938} - "A One-Time Password System".
+
+ {(http://cs.umd.edu/~harry/jotp/)}.
+
+ (2000-01-31)
+
+One Time Programmable Read-Only Memory
+
+ <storage> (OTPROM, EPROM OTP) A kind of storage device like an
+ {EPROM} but with no quartz glass window in the package for
+ erasing the contents. This reduces the packaging cost but
+ means the device cannot be erased with UV and so can only be
+ written once. Erasure is possible, but expensive, with
+ X-rays.
+
+ (1995-04-22)
+
+one-way function
+
+ <cryptography, mathematics> A {function} which is easy to
+ compute but whose {inverse} is very difficult to compute.
+ Such functions have important applications in {cryptography},
+ specifically in {public-key cryptography}.
+
+ See also: {trapdoor function}.
+
+ (2001-05-10)
+
+one-way hash function
+
+ <algorithm> (Or "message digest function") A {one-way
+ function} which takes a variable-length message and produces a
+ fixed-length hash. Given the hash it is computationally
+ infeasible to find a message with that hash; in fact one can't
+ determine any usable information about a message with that
+ hash, not even a single bit. For some one-way hash functions
+ it's also computationally impossible to determine two messages
+ which produce the same hash.
+
+ A one-way hash function can be private or public, just like an
+ {encryption} function. {MD5}, {SHA} and {Snefru} are examples of
+ public one-way hash functions.
+
+ A public one-way hash function can be used to speed up a
+ public-key {digital signature} system. Rather than sign a
+ long message, which can take a long time, compute the one-way
+ hash of the message, and sign the hash.
+
+ {sci.crypt FAQ
+ (ftp://src.doc.ic.ac.uk/usenet/usenet-by-group/sci.crypt/)}.
+
+ (2001-05-10)
+
+on-line
+
+ <jargon> 1. Ready for use. E.g. "The graph plotter's fixed
+ and on-line again".
+
+ 2. {Interactive} as opposed to {batch}. Accessible via a
+ computer (or {terminal}), rather than on paper or other
+ medium.
+
+ 3. Of a user, actively using a computer system, especially the
+ {Internet}. E.g "I haven't been on-line for three days."
+
+ "On-line" should be hyphenated because it is compounded from
+ two words but the hyphen is often omitted in names of
+ organisations or services.
+
+ (1998-12-22)
+
+On-Line Analytical Processing
+
+ <database> (OLAP) A category of {database} software which
+ provides an interface such that users can transform or limit
+ raw data according to user-defined or pre-defined functions,
+ and quickly and interactively examine the results in various
+ dimensions of the data.
+
+ OLAP primarily involves aggregating large amounts of diverse
+ data. OLAP can involve millions of data items with complex
+ relationships. Its objective is to analyze these
+ relationships and look for patterns, trends, and exceptions.
+
+ The term was originally coined by {Dr. Codd} in 1993 with 12
+ "rules". Since then, the {OLAP Council}, many vendors, and
+ Dr. Codd himself have added new requirements and confusion.
+
+ Richard Creeth and Nigel Pendse define OLAP as fast analysis
+ of shared multidimensional information. Their definition
+ requires the system to respond to users within about five
+ seconds. It should support logical and statistical processing
+ of results without the user having to program in a {4GL}. It
+ should implement all the security requirements for
+ confidentiality and concurrent update locking. The system
+ must provide a multidimensional conceptual view of the data,
+ including full support for multiple hierarchies. Other
+ aspects to consider include data duplication, {RAM} and disk
+ space requirements, performance, and integration with {data
+ warehouses}.
+
+ Various bodies have attempted to come up with standards for
+ OLAP, including The {OLAP Council} and the {Analytical
+ Solutions Forum} (ASF), however, the {Microsoft OLE DB for
+ OLAP API} is the most widely adopted and has become the {de
+ facto standard}.
+
+ {(http://access.digex.net/~grimes/olap/)}.
+
+ {Usenet} newsgroup: {news:comp.databases.olap}.
+
+ {(http://arborsoft.com/papers/finkTOC.html)}.
+
+ [What's a "multidimensional conceptual view"?]
+
+ (1996-09-24)
+
+Online Computer Library Center, Inc.
+
+ <library> (OCLC) A nonprofit membership organisation offering
+ computer-based services and research to libraries, educational
+ organisations, and their users. OCLC operates the OCLC
+ Cataloging PRISM service for cataloging and resource sharing,
+ provides on-line reference systems for both librarians and
+ end-users, and distributes on-line electronic journals.
+ OCLC's goals are to increase the availability of library
+ resources and reduce library costs for the fundamental public
+ purpose of furthering access to the world's information. The
+ OCLC library information network connects more than 10,000
+ 36,000 libraries worldwide. Libraries use the OCLC System for
+ cataloguing, interlibrary loan, collection development,
+ bibliographic verification, and reference searching. Their
+ most visible feature is the OCLC Online Union Catalog (OLUC)
+ WorldCat (the OCLC Online Union Catalog).
+
+ {(http://oclc.org/)}.
+
+ (2000-03-23)
+
+On-Line Computer system
+
+ (OLC) A predecessor of the {Culler-Fried System} from {UCSB}
+ ca. 1966.
+
+ [Sammet 1969, p.253].
+
+ (1995-11-25)
+
+Online Media
+
+ {Acorn Online Media}
+
+On-line Process Synthesizer
+
+ <simulation> (OPS) A system for {discrete simulation} under
+ {CTSS} developed by M. Greenberger at {MIT} ca. 1964.
+
+ [Sammet 1969, p.660. Versions: OPS-3, OPS-4. "On- line
+ Computation and Simulation: The OPS-3 System", M. Greenberger
+ et al, MIT Press 1965].
+
+ (2003-04-05)
+
+Online Public Access Catalog
+
+ <library> (OPAC) A computerised system to catalogue and
+ organise materials in a library (the kind that contains
+ books). OPACs have replaced card-based catalogues in many
+ libraries. An OPAC is available to library users (public
+ access).
+
+ (2000-07-17)
+
+On-Line Transaction Processing
+
+ <database> (OLTP) The processing of transactions by computers
+ in real time.
+
+ [Details? Products?]
+
+ (1997-05-14)
+
+Ontic
+
+ <language> {Object-oriented} language for an {inference
+ system} with a {Lisp}-like appearance, but based on set
+ theory.
+
+ ["Ontic: A Knowledge Representation System for Mathematics",
+ D.A. McAllester, MIT Press 1989].
+
+ (1996-06-24)
+
+onto
+
+ {surjection}
+
+ontology
+
+ 1. <philosophy> A systematic account of Existence.
+
+ 2. <artificial intelligence> (From philosophy) An explicit
+ formal specification of how to represent the objects, concepts
+ and other entities that are assumed to exist in some area of
+ interest and the relationships that hold among them.
+
+ For {AI} systems, what "exists" is that which can be
+ represented. When the {knowledge} about a {domain} is
+ represented in a {declarative language}, the set of objects
+ that can be represented is called the {universe of discourse}.
+ We can describe the ontology of a program by defining a set of
+ representational terms. Definitions associate the names of
+ entities in the {universe of discourse} (e.g. classes,
+ relations, functions or other objects) with human-readable
+ text describing what the names mean, and formal {axioms} that
+ constrain the interpretation and well-formed use of these
+ terms. Formally, an ontology is the statement of a {logical
+ theory}.
+
+ A set of {agents} that share the same ontology will be able to
+ communicate about a domain of discourse without necessarily
+ operating on a globally shared theory. We say that an agent
+ commits to an ontology if its observable actions are
+ consistent with the definitions in the ontology. The idea of
+ ontological commitment is based on the {Knowledge-Level}
+ perspective.
+
+ 3. <information science> The hierarchical structuring of
+ knowledge about things by subcategorising them according to
+ their essential (or at least relevant and/or cognitive)
+ qualities. See {subject index}. This is an extension of the
+ previous senses of "ontology" (above) which has become common
+ in discussions about the difficulty of maintaining {subject
+ indices}.
+
+ (1997-04-09)
+
+OnX
+
+ A graphics package from LAL Orsay.
+
+OO
+
+ {object-oriented}
+
+OOA
+
+ {object-oriented analysis}
+
+OOD
+
+ {object-oriented design}
+
+OODB
+
+ {object-oriented database}
+
+OODBMS
+
+ {object-oriented database management system}
+
+OOF
+
+ {Object-Oriented Fortran}
+
+OOGL
+
+ Object-Oriented Graphics Language. 1970's.
+
+OOo
+
+ {OpenOffice.org}
+
+OOP
+
+ {object-oriented programming}
+
+OOPL
+
+ {object-oriented programming language}
+
+OOPS
+
+ "OOPS: A Knowledge Representation Language", D. Vermeir, Proc
+ 19th Intl Hawaii Conf on System Sciences, IEEE (Jan 1986)
+ pp.156-157.
+
+OOPSLA
+
+ Conference on Object-oriented Programming Systems, Languages
+ and Applications.
+
+OOSD
+
+ Object-oriented structured design: a design method elaborated
+ from structured design and incorporating the essential
+ features of the object-oriented approach.
+
+OOZE
+
+ Object oriented extension of Z. "Object Orientation in Z", S.
+ Stepney et al eds, Springer 1992.
+
+op
+
+ <job> /op/ 1. In England and Ireland, a common verbal
+ abbreviation for "operator", as in {system operator}. This is
+ less common in the US, where {sysop} seems to be preferred.
+
+ 2. The general term for an {IRC} {channel op}. Also, as a
+ verb: to give someone {channel op} privileges. Compare
+ {ircop}.
+
+ [{Jargon File}]
+
+ (1997-12-12)
+
+OPAC
+
+ {Online Public Access Catalog}
+
+Opal
+
+ 1. A {DSP} language.
+
+ ["OPAL: A High Level Language and Environment for DSP boards
+ on PC", J.P. Schwartz et al, Proc ICASSP-89, 1989].
+
+ 2. The language of the {object-oriented database} {GemStone}.
+
+ ["Making Smalltalk a Database System", G. Copeland et al, Proc
+ SIGMOD'84, ACM 1984, pp.316- 325].
+
+ 3. A {simulation} language with provision for {stochastic
+ variables}. An extension of {Autostat}.
+
+ ["C-E-I-R OPAL", D. Pilling, Internal Report,
+ C.E.I.R. Ltd. (1963)].
+
+ 4. A language for compiler testing said to be used internally
+ by {DEC}.
+
+ 5. A {functional programming} language designed at the
+ {Technische Universitaet Berlin} as a testbed for the
+ development of {functional programs}. OPAL integrates
+ concepts from Algebraic Specification and Functional
+ Programming, which favour the (formal) development of (large)
+ production-quality software written in a {purely functional}
+ style.
+
+ The core of OPAL is a {strongly typed}, {higher-order},
+ {strict} applicative language which belongs to the tradition
+ of {Hope} and {ML}. The algebraic flavour of OPAL is visible
+ in the syntactical appearance and in the preference of
+ {parameterisation} to {polymorphism}.
+
+ OPAL supports: {information hiding} - each language unit is
+ divided into an interface (signature) and an implementation
+ part; selective import; {parameterised modules}; free
+ constructor {views} on {sorts}, which allow pattern-based
+ function definitions despite quite different implementations;
+ full {overloading} of names; puristic scheme language with no
+ {built-in} data types (except {Booleans} and denotations).
+
+ OPAL and its predecessor OPAL-0 have been used for some time
+ at the Technische Universitaet Berlin in CS courses and for
+ research into optimising compilers for applicative languages.
+ The OPAL compiler itself is writte entirely in OPAL.
+
+ An overview is given in "OPAL: Design And Implementation of an
+ Algebraic Programming Language".
+
+ {(http://cs.tu-berlin.de/~opal/)}.
+
+ {(ftp://ftp.cs.tu-berlin.de/pub/local/uebb/papers/DesignImplOpal.ps.gz)}.
+
+ (1995-02-16)
+
+OPC
+
+ {OLE for Process Control}
+
+op code
+
+ {operation code}
+
+open
+
+ 1. To prepare to read or write a file. This usually involves
+ checking whether the file already exists and that the user has
+ the necessary authorisation to read or write it. The result
+ of a successful open is usually some kind of {capability}
+ (e.g. a {Unix} {file descriptor}) - a token that the user
+ passes back to the system in order to access the file without
+ further checks and finally to close the file.
+
+ 2. Abbreviation for "open (or left) parenthesis" - used when
+ necessary to eliminate oral ambiguity. To read aloud the LISP
+ form (DEFUN FOO (X) (PLUS X 1)) one might say: "Open defun
+ foo, open eks close, open, plus eks one, close close."
+
+ 3. Non-proprietary. An open {standard} is one which can be
+ used without payment.
+
+ [{Jargon File}]
+
+ (1995-01-31)
+
+open box testing
+
+ {white box testing}
+
+OpenBSD
+
+ <operating system> A version of {BSD Unix} with an emphasis on
+ security. A lot of security work that is ported to other free
+ operating systems originates with OpenBSD and a lot of {code
+ review} is done here.
+
+ Sub-projects of OpenBSD include implementations of {SSH
+ (http://openssh.org/)}, {ntpd (http://openntpd.org/)},
+ and {CVS}, to be called OpenCVS.
+
+ {OpenBSD Home (http://openbsd.org/)}.
+
+ (2005-01-17)
+
+open/closed principle
+
+ <programming, theory> A principle used in {OOPL} which states
+ that a {class} must be open and closed where open means it has
+ the ability to be extended and closed means it cannot be
+ modified other than by extension.
+
+ The idea is that once a class has been approved for use having
+ gone through code reviews, unit tests, and other qualifying
+ procedures, you don't want to change the class very much, just
+ extend it. In practice the open/closed principle simply means
+ making good use of {abstraction} and {polymorphism}.
+
+ (1997-09-23)
+
+open-collar worker
+
+ <job> Someone who works at home or telecommutes.
+
+ (1997-04-17)
+
+Open DataBase Connectivity
+
+ <standard, database> (ODBC) A {standard} for accessing
+ different {database} systems. There are interfaces for
+ {Visual Basic}, {Visual C++}, {SQL} and the ODBC driver pack
+ contains drivers for the {Access}, {Paradox}, {dBase}, Text,
+ {Excel} and {Btrieve} databases.
+
+ An application can submit statements to ODBC using the ODBC
+ flavor of SQL. ODBC then translates these to whatever flavor
+ the database understands.
+
+ ODBC 1.0 was released in September 1992.
+
+ ODBC is based on {Call-Level Interface} and was defined by the
+ {SQL Access Group}. {Microsoft} was one member of the group
+ and was the first company to release a commercial product
+ based on its work (under {Microsoft Windows}) but ODBC is not
+ a Microsoft standard (as many people believe).
+
+ ODBC drivers and development tools are available now for
+ {Microsoft Windows}, {Unix}, {OS/2}, and {Macintosh}.
+
+ [On-line document?]
+
+ ["Unix Review", Aug 1995].
+
+ (1996-05-27)
+
+Open Data-link Interface
+
+ <networking, standard> (ODI) A {Novell}-developed {network
+ card} {API} that provides media and {protocol} independence.
+ It allows the sharing of a single card by multiple {transport
+ layer} {protocols} and resolves conflicts.
+
+ (1995-03-13)
+
+Open DeathTrap
+
+ <abuse> An abusive hackerism for the {Santa Cruz Operation}'s
+ {Open DeskTop}. The funniest part is that this was coined by
+ SCO's own developers.
+
+ Compare {AIDX}, {Macintrash} {Nominal Semidestructor},
+ {ScumOS}, {sun-stools}, {HP-SUX}.
+
+ [{Jargon File}]
+
+ (1995-02-02)
+
+Open Desktop
+
+ <operating system, product> A {Motif}-based graphical
+ interface from the {Santa Cruz Operation} (SCO), built over
+ their {Unix} environment, part of the {ACE} initiative.
+
+ Also known as "{Open DeathTrap}".
+
+ (1995-02-02)
+
+Open Distributed Processing
+
+ <standard> (ODP) An attempt to standardise an {OSI}
+ {application layer} communications architecture. ODP is a
+ natural progression from {OSI}, broadening the target of
+ standardisation from the point of interconnection to the end
+ system behaviour. The objective of ODP is to enable the
+ construction of {distributed systems} in a multi-vendor
+ environment through the provision of a general architectural
+ framework that such systems must conform to. One of the
+ cornerstones of this framework is a model of multiple
+ viewpoints which enables different participants to observe a
+ system from a suitable perspective and a suitable level of
+ {abstraction}.
+
+ (1995-03-10)
+
+Open Distributed System Architecture
+
+ (ODSA) A research program sponsored by the UK Department of
+ Trade and Industry and the Engineering and Physical Sciences
+ Research Council.
+
+ [Details?]
+
+ (1995-02-09)
+
+OpenDoc
+
+ <operating system> A compound document architecture from {CIL}
+ based on {CORBA}. It aims to enable embedding of features
+ from different {application programs} into a single working
+ document.
+
+ (1997-02-21)
+
+OpenDocument
+
+ <file format, standard> (ODF, ISO/IEC 26300, OASIS Open
+ Document Format for Office Applications) An {XML} {file
+ format} for {office} documents, such as {spreadsheets},
+ charts, presentations, databases and {word processing}.
+
+ OpenDocument was developed by the Open Office XML technical
+ committee of the Organization for the Advancement of
+ Structured Information Standards ({OASIS}) consortium. It is
+ based on the XML format originally created and implemented by
+ the {OpenOffice.org} {office suite}. OpenDocument is an open
+ standard, i.e. freely available and implementable.
+
+ Compare {OOXML}.
+
+ (2007-09-19)
+
+Open Document Architecture
+
+ <standard> (ODA) {ISO} {standard} (8613) for describing
+ documents. It allows text, graphics, and facsimile documents
+ to be transferred between different systems.
+
+ {ODIF} is part of ODA.
+
+ (1995-03-03)
+
+Open Document Interchange Format
+
+ <standard> (ODIF) Part of the {ODA} standard.
+
+ (1996-10-16)
+
+Open Document Management API
+
+ <text, standard> An open standard allowing desktop
+ applications to interface with {document management systems}.
+
+ {(http://activedoc.com)}.
+
+ (1997-07-04)
+
+OpenGL
+
+ {Open Graphics Library}
+
+Open Graphics Library
+
+ <graphics, library> (OpenGL) A multi-{platform} software
+ interface to graphics hardware, supporting {rendering} and
+ {imaging} operations. The OpenGL interface was developed by
+ {Silicon Graphics}, who license it to other vendors.
+
+ The OpenGL graphics interface consists of several hundred
+ functions operating on 2D and 3D objects, supporting basic
+ techniques, such as {modelling} and {smooth shading}, and
+ advanced techniques, such as {texture mapping} and {motion
+ blur}. Many operations require a {frame buffer}. OpenGL is
+ {network-transparent}, and a common extension to the {X Window
+ System} allows an OpenGL {client} to communicate across a
+ network with a different vendor's OpenGL {server}.
+
+ OpenGL is based on Silicon Graphics' proprietary {IRIS GL}.
+
+ {OpenGL WWW Center (http://sgi.com/Technology/openGL/)}.
+
+ {Mesa GL (http://ssec.wisc.edu/~brianp/Mesa.html)} (PD
+ implementation).
+
+ (1996-09-30)
+
+Open Group
+
+ {The Open Group}
+
+OpenInsight
+
+ <programming, database> The {workflow}-enabled {Windows
+ 95}/{Windows NT} version of {Advanced Revelation}, featuring
+ native support for {Lotus Notes}, {Microsoft SQL Server},
+ {Oracle} and {ODBC}. OpenInsight is available from
+ {Revelation Software}.
+
+ (1997-04-25)
+
+Open Look
+
+ <operating system> A {graphical user interface} and {window
+ manager} from {Sun} and {AT&T}.
+
+ {Usenet} newsgroup: {news:comp.graphics.openlook}.
+
+ (1995-06-11)
+
+Open Network Computing
+
+ (ONC) {Sun}'s {network} {protocols}.
+
+ [more detail?]
+
+OpenOffice.org
+
+ <project> (OOo) The group that produces a {free} ({GPL})
+ {cross-platform} {office suite} that provides much of the same
+ functionality as {Microsoft Office} including {word
+ processing}, {spreadsheet}, presentation and graphics. Each
+ program can read and write both its own and Microsoft formats.
+
+ {OpenOffice Home (http://openoffice.org/)}.
+
+ (2005-01-26)
+
+Open Prolog
+
+ <Prolog, language> {Prolog} for the {Macintosh} by Michael Brady
+ <brady@cs.tcd.ie>.
+
+ {(http://cs.tcd.ie/open-prolog/)}.
+
+ [Details?]
+
+ (2000-12-21)
+
+Open Scripting Architecture
+
+ (OSA) A {CIL} approach to the coexistence of multiple
+ scripting systems.
+
+ (1995-03-10)
+
+Open Shortest-Path First
+
+ {Open Shortest-Path First Interior Gateway Protocol}
+
+Open Shortest-Path First Interior Gateway Protocol
+
+ <networking, protocol, standard> (OSPF) A {link state routing
+ protocol} that is one of the {Internet} standard {Interior
+ Gateway Protocols} defined in {RFC 1247}.
+
+ There is no OSPF {EGP}, OSPF is an IGP only.
+
+ [Relationship to {Internet Protocol} packet routing?]
+
+ {OSPF Design Guide
+ (http://cisco.com/warp/public/104/1.html)}.
+
+ (2002-06-29)
+
+Open Software Foundation
+
+ <body> (OSF) A foundation created by nine computer vendors,
+ ({Apollo}, {DEC}, {Hewlett-Packard}, {IBM}, {Bull}, {Nixdorf},
+ {Philips}, {Siemens} and {Hitachi}) to promote "Open
+ Computing". It is planned that common {operating systems} and
+ interfaces, based on developments of {Unix} and the {X Window
+ System} will be forthcoming for a wide range of different
+ hardware architectures. OSF announced the release of the
+ industry's first open {operating system} - OSF/1 on 23 October
+ 1990.
+
+ (1994-11-23)
+
+open source
+
+ <philosophy, legal> A method and philosophy for software
+ licensing and distribution designed to encourage use and
+ improvement of software written by volunteers by ensuring that
+ anyone can copy the {source code} and modify it freely.
+
+ The term "open source" is now more widely used than the
+ earlier term "{free software}" (promoted by the {Free Software
+ Foundation}) but has broadly the same meaning - free of
+ distribution restrictions, not necessarily free of charge.
+
+ There are various {open source licenses} available.
+ Programmers can choose an appropriate license to use when
+ distributing their programs.
+
+ The {Open Source Initiative} promotes the {Open Source
+ Definition}.
+
+ {The Cathedral and the Bazaar
+ (http://tuxedo.org/~esr/writings/cathedral-bazaar/cathedral-bazaar.html)}.
+ was a seminal paper describing the open source phenomenon.
+
+ {Open Sources - O'Reilly book with full text online
+ (http://oreilly.com/catalog/opensources/book/perens.html)}.
+
+ {Articles from ZDNet
+ (http://zdnet.com/pcmag/features/opensource/)}.
+
+ (1999-12-29)
+
+Open Source Definition
+
+ <standard> (OSD) Definition of distribution terms for {open
+ source} software, promoted by the {Open Source Initiative}.
+
+ {(http://opensource.org/osd.html)}.
+
+ (1999-11-28)
+
+Open Source Initiative
+
+ <body> (OSI) An organisation dedicated to managing and
+ promoting the {Open Source Definition} for the good of the
+ community.
+
+ {(http://opensource.org/)}.
+
+ (1999-11-28)
+
+Open source license
+
+ <legal> Any document that attempts to specify {open source}
+ usage and distribution of software. These licenses are
+ usually drafted by experts and are likely to be more legally
+ sound than one a programmer could write. However, loopholes
+ do exist.
+
+ Here is a non-exhaustive list of open source licenses:
+
+ 1. {Public Domain} - No license.
+
+ 2. {BSD} License - An early open source license
+
+ 3. {General Public License} (GPL) - The {copyleft} license of
+ the {Free Software Foundation}. Used for {GNU} software and
+ much of {Linux}.
+
+ 4. {Artistic License
+ (http://my-opensource.org/Artistic.txt)} Less restrictive
+ than the GPL, permitted by {Perl} in addition to the GPL.
+
+ 5. {Mozilla Public Licenses (http://mozilla.org/MPL/)}.
+ (MPL, MozPL) and Netscape Public License (NPL).
+
+ ["Open Sources", pub. O'Reilly, {full text
+ (http://oreilly.com/catalog/opensources/book/perens.html)}].
+
+ (1999-11-28)
+
+OpenStep
+
+ <operating system> An {object-oriented} {application
+ programming interface} (API) derived from {NEXTSTEP} and
+ proposed as an {open standard} by {NeXT} in 1994.
+
+ OpenStep is the specification of the object kits of NEXTSTEP.
+ OPENSTEP/Mach was an implementation of this specification.
+ The original, OPENSTEP version 4.0, and really was NEXTSTEP 4.
+ {Rhapsody} was the codename for {Apple}'s {Mac OS X} Server,
+ which is really NEXTSTEP 5 (it calls itself "kernel 5.3" at
+ boot time).
+
+ OpenStep was designed to be implemented independently of the
+ computer's operating system, hardware, and user interface.
+ The {API} for {Rhapsody} will be a superset of {OpenStep}'s.
+
+ When the OpenStep {API} is implemented for a specific platform
+ and made into a product, it is written in uppercase,
+ e.g. OPENSTEP Developer 4.2 for Mach, or OPENSTEP Enterprise
+ for {Windows NT} and {Windows 95}. Versions of OPENSTEP exist
+ for Windows 95/NT, Solaris, HP/UX, and Mach.
+
+ (1999-11-25)
+
+open switch
+
+ ({IBM}, probably from railways) An unresolved question, issue,
+ or problem.
+
+ [{Jargon File}]
+
+ (1994-11-11)
+
+Open System Architecture
+
+ <operating system> (OSA) A competitor to {IBM}'s {SNA}.
+
+ (2005-03-07)
+
+Open Systems Interconnect
+
+ {Open Systems Interconnection}
+
+Open Systems Interconnection
+
+ <networking> (OSI-RM, OSI Reference Model, seven layer model)
+ A model of network architecture and a suite of {protocols} (a
+ {protocol stack}) to implement it, developed by {ISO} in 1978
+ as a framework for international {standards} in heterogeneous
+ computer {network} architecture.
+
+ The OSI architecture is split between seven {layers}, from
+ lowest to highest: 1 {physical layer}, 2 {data link layer}, 3
+ {network layer}, 4 {transport layer}, 5 {session layer}, 6
+ {presentation layer}, 7 {application layer}.
+
+ Each layer uses the layer immediately below it and provides a
+ service to the layer above. In some implementations a layer
+ may itself be composed of sub-layers.
+
+ OSI is the umbrella name for a series of non-proprietary
+ protocols and specifications, comprising, among others, the
+ OSI Reference Model, ASN.1 ({Abstract Syntax Notation 1}), BER
+ ({Basic Encoding Rules}), {CMIP} and {CMIS} (Common Management
+ Information Protocol and Services), {X.400} (Message Handling
+ System, or MHS), {X.500} (Directory Service), {Z39.50} (search
+ and retrieval protocol used by {WAIS}), and many others.
+ Apart from its actual application to real protocols, it also
+ serves as a useful teaching model.
+
+ (2004-02-13)
+
+Open Telecom Platform
+
+ <communications, library> (OTP) A set of standard, {open source}
+ {libraries} and tools for use with {Erlang}.
+
+ {(http://erlang.org/faq/t1.html#AEN17)}.
+
+ (2001-08-28)
+
+Open Trading Protocol
+
+ {Internet Open Trading Protocol}
+
+OpenTransport
+
+ <networking> (OT) A complete reimplementation of all levels of
+ the {Macintosh} {networking} code including "Classic"
+ {AppleTalk} and {MacTCP}. It appeared in {MacOS} revision
+ 7.5.3 [or earlier? Date?].
+
+ (2000-08-13)
+
+Open University
+
+ <education, body> (OU) The UK distance-learning organisation,
+ established in 1969. It teaches degree-level courses in many
+ subjects via BBC radio and television broadcasts and summer
+ schools.
+
+ {(http://hcrl.open.ac.uk/ou/ouhome.html)}.
+
+ (1999-07-13)
+
+OpenVMS
+
+ {Virtual Memory System}
+
+OpenWindows
+
+ <operating system> A {graphical user interface} {server} for
+ {Sun} {workstations} which handles {SunView}, {NeWS} and {X
+ Window System} protocols.
+
+ (1995-06-11)
+
+operand
+
+ <programming> An {argument} of an {operator} or of a {machine
+ language} instruction.
+
+ (1995-08-18)
+
+operating system
+
+ <operating system> (OS) The low-level {software} which handles
+ the interface to {peripheral} {hardware}, schedules {tasks},
+ allocates {storage}, and presents a default {interface} to the
+ user when no {application program} is running.
+
+ The OS may be split into a {kernel} which is always present
+ and various system programs which use facilities provided by
+ the kernel to perform higher-level {house-keeping} tasks,
+ often acting as {servers} in a {client-server} relationship.
+
+ Some would include a {graphical user interface} and {window
+ system} as part of the OS, others would not. The {operating
+ system loader}, {BIOS}, or other {firmware} required at {boot
+ time} or when installing the operating system would generally
+ not be considered part of the operating system, though this
+ distinction is unclear in the case of a {rommable operating
+ system} such as {RISC OS}.
+
+ The facilities an operating system provides and its general
+ design philosophy exert an extremely strong influence on
+ programming style and on the technical cultures that grow up
+ around the machines on which it runs.
+
+ Example operating systems include {386BSD}, {AIX}, {AOS},
+ {Amoeba}, {Angel}, {Artemis microkernel}, {BeOS}, {Brazil},
+ {COS}, {CP/M}, {CTSS}, {Chorus}, {DACNOS}, {DOSEXEC 2},
+ {GCOS}, {GEORGE 3}, {GEOS}, {ITS}, {KAOS}, {Linux}, {LynxOS},
+ {MPV}, {MS-DOS}, {MVS}, {Mach}, {Macintosh operating system},
+ {Microsoft Windows}, {MINIX}, {Multics}, {Multipop-68},
+ {Novell NetWare}, {OS-9}, {OS/2}, {Pick}, {Plan 9}, {QNX},
+ {RISC OS}, {STING}, {System V}, {System/360}, {TOPS-10},
+ {TOPS-20}, {TRUSIX}, {TWENEX}, {TYMCOM-X}, {Thoth}, {Unix},
+ {VM/CMS}, {VMS}, {VRTX}, {VSTa}, {VxWorks}, {WAITS}.
+
+ {FAQ
+ (ftp://src.doc.ic.ac.uk/usenet/news-info/comp.os.research)}.
+
+ {Usenet} newsgroup: {news:comp.os.research}.
+
+ [{Jargon File}]
+
+ (1999-06-09)
+
+Operating System/360
+
+ <operating system> (OS/360) An {operating system} developed by
+ {IBM} for their {System/360} computer (announced in 1964).
+
+ After this experience, {Frederick P. Brooks} wrote his famous
+ book, {The Mythical Man-Month}, giving OS/360 as an example of
+ the {second-system effect}.
+
+ [Features? Relatonship to {DOS/360}?]
+
+ (2001-03-23)
+
+Operating System/Multiprogramming of Fixed Tasks
+
+ <operating system> (OS/MFT) One of the {IBM} {operating
+ systems} associated with the {IBM 360}, released in 1966 and
+ targetted at mid-range {IBM 360} users (typically 360/40,
+ 360/50). OS/MFT was the juinior member of the main 'OS'
+ series of IBM operating systems, the other being {OS/MVT}.
+ Smaller 360 mainframes used {DOS}.
+
+ OS/MFT shared {JCL} and utilities with OS/MVT but allocated
+ memory differently. In OS/MFT, partitions of memory were of a
+ fixed number and size, specified by the generation and
+ configuration of the operating system. As this class of
+ mainframe had typically less than 512K of main memory,
+ partitions tended to be about 128K.
+
+ With the advent of {Virtual Storage} and the {System 370}'s
+ {Dynamic Address Translation} (DAT), OS/MFT was improved to
+ become {OS/VS1}, taking account of virtual storage in a single
+ partition up to 16MB.
+
+ (1999-01-22)
+
+operational database
+
+ <database> A {database} containing up-to-date, modifiable
+ data, in contrast to a {decision support database}.
+
+ (1995-02-14)
+
+Operational Data Store
+
+ <database> (ODS) A group of integrated databases designed to
+ support the monitoring of operations. Unlike function
+ oriented databases, an ODS contains subject-oriented, dynamic,
+ current enterprise-wide information that is continually
+ updated to show the current state of operations.
+
+ ["Data Warehousing Architecture and Implementation"].
+
+ (2010-02-28)
+
+operational requirements
+
+ <programming> Qualitative and quantitative parameters that
+ specify the desired capabilities of a system and serve as a
+ basis for determining the operational effectiveness and
+ suitability of a system prior to deployment.
+
+ (1997-01-07)
+
+operational semantics
+
+ <theory> A set of rules specifying how the state of an actual
+ or hypothetical computer changes while executing a program.
+ The overall state is typically divided into a number of
+ components, e.g. {stack}, {heap}, {registers} etc. Each rule
+ specifies certain preconditions on the contents of some
+ components and their new contents after the application of the
+ rule.
+
+ It is similar in spirit to the notion of a {Turing machine},
+ in which actions are precisely described in a mathematical
+ way.
+
+ Compuare {axiomatic semantics}, {denotational semantics}.
+
+ (1996-08-21)
+
+operational test and evaluation
+
+ <testing> (OT&E) Formal testing conducted prior to deployment
+ to evaluate the operational effectiveness and suitability of
+ the system with respect to its mission.
+
+ (1997-01-07)
+
+operational testing
+
+ <testing> A US DoD term for testing performed by the
+ {end-user} on software in its normal operating environment.
+
+ (1997-01-07)
+
+operation code
+
+ <programming> (Always "op code" when spoken) The part or parts
+ of a {machine language} {instruction} which determines what
+ kind of action the computer should take, e.g. add, jump, load,
+ store. In any particular {instruction set} certain fixed bit
+ positions within the instruction word contain the op code,
+ others give {parameters} such as the addresses or {registers}
+ involved. For example, in a 32-bit instruction the most
+ significant eight bits might be the op code giving 256
+ possible operations.
+
+ For some instruction sets, certain values in the fixed bit
+ positions may select a group of operations and the exact
+ operation may depend on other bits within instruction word or
+ subsequent words.
+
+ When programming in {assembly language}, the op code is
+ represented by a readable name called an {instruction
+ mnemonic}.
+
+ (1997-02-14)
+
+operations support technician
+
+ <job> A person who analyses and supports computer operations
+ by controlling production applications, monitoring system
+ resources and response time and providing first-line support
+ for operational problems.
+
+ (2004-03-20)
+
+operator
+
+ <programming> A symbol used as a {function}, with {infix
+ syntax} if it has two arguments (e.g. "+") or {prefix syntax} if
+ it has only one (e.g. {Boolean} NOT). Many languages use
+ operators for built-in functions such as arithmetic and logic.
+
+ (1995-04-30)
+
+Operator Control Language
+
+ <language> (OCL) The {batch language} for the {IBM System/36},
+ used specifically with the {RPG II} {compiler}.
+
+ See also {CL}.
+
+ (1994-11-18)
+
+operator overloading
+
+ {overloading}
+
+OPF
+
+ {Object Persistence Framework}
+
+Opportunity Management System
+
+ <business> (OMS) A system that stores sales opportunities and
+ related information. Each sales lead can be tracked with
+ information such as source, type, worth, status, likelihood of
+ closure etc.
+
+ An OMS can perform other related tasks such as prioritising
+ sales calls and generating analyses that assist the fine-tuning
+ of marketing strategies.
+
+ See also {Customer Relationship Management}.
+
+ (1999-08-20)
+
+OPS
+
+ 1. <simulation> {On-line Process Synthesizer}.
+
+ 2. <language> {Official Production System}.
+
+ 3. <database> {Oracle Parallel Server}.
+
+ (2003-04-05)
+
+OPS5
+
+ <language> A programming language for rule-based {production
+ systems}. A rule consists of pre-condition(s) and a resulting
+ action.
+
+ The system checks its {working memory} to see if there are
+ rules whose pre-conditions are satisfied, if so, the action in
+ one selected satisfied rule is executed.
+
+ There is a {public domain} implementation of an OPS5
+ {interpreter} written by Charles L. Forgy <forgy@cs.cmu.edu>
+ in 1977. It was first implemented in {Lisp} and later in
+ {BLISS}. It was also ported to {Common Lisp} by George Wood
+ and Jim Kowalski.
+
+ {CLIPS} is a language for writing {expert systems}, with some
+ of the capabilities of OPS5.
+
+ See also {C5}, {OPS83}, {OPS4}, {OPS5+}, {OPS83}.
+
+ Inference Engine Tech, Cambridge MA.
+
+ {An OPS5 interpreter in Common LISP
+ (ftp://ftp.wustl.edu/mirrors/Unix-c/languages/ops5)}.
+
+ {A version by Mark Kantrowitz
+ (ftp://ftp.cs.cmu.edu/afs/cs.cmu.edu/user/mkant/Public/Lisp/)}.
+ <mkant+@cs.cmu.edu>.
+
+ ["Programming Expert Systems in OPS5", L. Brownston et al, A-W
+ 1985].
+
+ ["An OPS5 Primer", Sherman et al, comes with OPS5 for DOS].
+
+ ["Rule-Based Programming in the Unix System", G.T. Vesonder,
+ AT&T Tech J 67(1), 1988].
+
+ (1995-08-18)
+
+OPS83
+
+ A commercial version of {OPS5}.
+
+Optical Carrier 12
+
+ <networking> (OC-12) A {SONET} rate of 12 * 51.84 = 622.08
+ {megabits} per second.
+
+ [Matches {STS-12}]?
+
+ (1997-05-26)
+
+Optical Carrier 3
+
+ <networking> (OC-3) A {SONET} rate of 3 * 51.84 = 155.52
+ {megabits} per second, which matches {STS-3}.
+
+ (1997-02-05)
+
+Optical Carrier 48
+
+ <networking> (OC-48) A {SONET} rate of 48 * 51.84 = 2488.32
+ {megabits} per second.
+
+ [Matches {STS-48}]?
+
+ (1997-05-26)
+
+Optical Carrier n
+
+ <networking> (OC-n) A {SONET} rate of n times 51.84 {megabits}
+ per second.
+
+ (1997-02-05)
+
+Optical Character Recognition
+
+ <text> (OCR, sometimes /oh'k*/) Recognition of printed or
+ written characters by computer. Each page of text is
+ converted to a digital using a {scanner} and OCR is then
+ applied to this image to produce a text file. This involves
+ complex {image processing} {algorithms} and rarely achieves
+ 100% accuracy so manual proof reading is recommended.
+
+ (1999-08-26)
+
+optical diff
+
+ {vdiff}
+
+optical disc drive
+
+ {optical disk drive}
+
+optical disk drive
+
+ <hardware> (Or "optical disc drive", "optical storage") A generic
+ term for any device that reads and/or writes {optical media},
+ i.e. {compact discs}, {DVDs} and/or {Blu-ray discs} or future
+ media that uses light (from a small laser) to read data off a
+ removable, rotating disk.
+
+ At least one such drive is commonly installed in most {personal
+ computers} to allow them to play and/or record {audio} and {video}
+ media and load and store data such as program {installers}.
+
+ The {floppy disk} has been replaced by optical media due to its
+ vastly greater capacity, e.g. 50,000 {megabytes} for a dual-layer
+ {blu-ray disc} compared with 1.5 {megabytes} for a floppy (over
+ 30,000 times as much).
+
+ (2014-04-27)
+
+optical drive
+
+ {optical disk drive}
+
+optical fiber
+
+ {optical fibre}
+
+optical fibre
+
+ <communications> (fibre optics, FO, US "fiber", light pipe) A
+ plastic or glass (silicon dioxide) fibre no thicker than a
+ human hair used to transmit information using infra-red or
+ even visible light as the carrier (usually a laser). The
+ light beam is an electromagnetic signal with a frequency in
+ the range of 10^14 to 10^15 Hertz.
+
+ Optical fibre is less susceptible to external noise than other
+ transmission media, and is cheaper to make than copper wire,
+ but it is much more difficult to connect. Optical fibres are
+ difficult to tamper with (to monitor or inject data in the
+ middle of a connection), making them appropriate for secure
+ communications. The light beams do not escape from the medium
+ because the material used provides total internal reflection.
+
+ {AT&T} {Bell Laboratories} in the United States managed to
+ send information at a rate of 420 megabits per second, over
+ 161.5 km through an optical fibre cable. In Japan, 445.8
+ megabits per second was achieved over a shorter distance. At
+ this rate, the entire text of the Encyclopedia Britannica
+ could be transmitted in one second. Currently, AT&T is
+ working on a world network to support high volume data
+ transmission, international computer networking, {electronic
+ mail} and voice communications (a single fibre can transmit
+ 200 million telephone conversations simultaneously).
+
+ See also {FDDI}, {Optical Carrier n}, {SONET}.
+
+ (1997-05-26)
+
+optical grep
+
+ {vgrep}
+
+Optical Mark Reader
+
+ <hardware> (OMR) A special scanning device that can read
+ carefully placed pencil marks on specially designed documents.
+ OMR is frequenty used in forms, questionnaires, and
+ answer-sheets.
+
+ (1995-04-13)
+
+optical mouse
+
+ <hardware> Any kind of {mouse} that uses visible light or
+ infrared to detect changes in its position.
+
+ (1999-07-21)
+
+optical storage
+
+ {optical disk drive}
+
+Optical Storage Technology Association
+
+ <body> (OSTA) An industry consortium concerned with {optical
+ storage}. OSTA wrote and maintains the {UDF} {file system}
+ used on {DVD video} discs.
+
+ {OSTA Home (http://osta.org/)}.
+
+ (2003-07-12)
+
+Optical Time Domain Reflectometer
+
+ <hardware> A device used to perform {Optical Time Domain
+ Reflectometry}.
+
+ (1995-02-01)
+
+Optical Time Domain Reflectometry
+
+ Measurement of the elapsed time and intensity of light
+ reflected on {optical fibre} using an optical time domain
+ reflectometer. The reflectometer can compute the distance to
+ problems on the fibre such as attenuation and breaks, making
+ it a useful tool in optical network trouble-shooting.
+
+ (1995-02-01)
+
+optimal
+
+ 1. <mathematics> Describes a solution to a problem which
+ minimises some {cost function}. {Linear programming} is one
+ technique used to discover the optimal solution to certain
+ problems.
+
+ 2. <programming> Of code: best or most efficient in time,
+ space or code size.
+
+ (1995-10-05)
+
+Optimal Flexible Architecture
+
+ <database> (OFA) Recommendations for logical and physical
+ allocation of {database} files to disks. The OFA principles
+ can be summarised as: isolate redo, rollback, temp, data and
+ index files as much as possible. OFA can be combined with
+ SAME ({Stripe And Mirror Everything}).
+
+ (2007-02-28)
+
+optimise
+
+ To perform {optimisation}.
+
+optimising compiler
+
+ <programming, tool> {compiler} which attempts to analyse the
+ code it produces and to produce more efficient code by
+ performing {program transformation} such as {branch
+ elimination}, {partial evaluation}, or {peep-hole
+ optimisation}.
+
+ Contrast {pessimising compiler}.
+
+ (1995-02-01)
+
+optimism
+
+ What a programmer is full of after fixing the last bug and
+ just before actually discovering the *next* last bug. Fred
+ Brooks's book "{The Mythical Man-Month}" contains the
+ following paragraph that describes this extremely well.
+
+ All programmers are optimists. Perhaps this modern sorcery
+ especially attracts those who believe in happy endings and
+ fairy god-mothers. Perhaps the hundreds of nitty frustrations
+ drive away all but those who habitually focus on the end goal.
+ Perhaps it is merely that computers are young, programmers are
+ younger, and the young are always optimists. But however the
+ selection process works, the result is indisputable: "This
+ time it will surely run," or "I just found the last bug.".
+
+ See also {Lubarsky's Law of Cybernetic Entomology}.
+
+ [{Jargon File}]
+
+optimize
+
+ {optimisation}
+
+option
+
+ {command line option}
+
+OPTRAN
+
+ Specification language for attributed tree transformation
+ writetn by R. Wilhelm, U Saarlandes in the early 1980's.
+
+ ["POPSY and OPTRAN Manual", ESPRIT PROSPECTRA Project Item
+ S.1.6-R.3.0, U Saarlandes (Mar 1986)].
+
+Opus
+
+ <project, product> A {Honeywell} {operating system} promised
+ as a sop to customers after canning {Multics} in 1985. Opus
+ was to provide everything Multics had and more, plus total
+ compatibility with the {Level 6}/{DPS6} operating system.
+
+ "Opus" was a code name, the system was officially named VS3
+ (short for HVS R3 or Honeywell Virtual System Release Three).
+ It was to run on the {DPS6-plus} hardware known internally as
+ the MRX and HRX, and be all things to all people.
+
+ The hardware was a dud (though it did run the native DPS6
+ software just fine), and the goal was, shall we say,
+ ambitious. The effort was cancelled by {Bull} in 1987, in
+ favor of another project going on in France.
+
+OR
+
+ <logic> The {Boolean} function which is true if any of its
+ arguments are true. Its {truth table} is:
+
+ A | B | A OR B
+ --+---+---------
+ F | F | F
+ F | T | T
+ T | F | T
+ T | T | T
+
+ (1996-11-04)
+
+Oracle
+
+ {Oracle Corporation}
+
+Oracle 7
+
+ <database> Version 7 of the {Oracle} {relational database}
+ system software.
+
+ (1996-11-05)
+
+Oracle Card
+
+ <tool> A {Hypercard}-like product from {Oracle} for
+ constructing {database} {applications}. It runs on {IBM PC}
+ and {Macintosh}.
+
+ (1995-03-15)
+
+Oracle*CASE
+
+ A set of {CASE} tools from {Oracle}.
+
+Oracle Co-operative Applications
+
+ <tool, product> Packaged {client/server} software from
+ {Oracle} for accounting, manufacturing, distribution, human
+ resources and project control.
+
+Oracle Corporation
+
+ <company> The world's leading supplier of information
+ management software. The company, worth $2 billion, offers
+ its products, along with related consulting, education and
+ support services in more than 90 countries around the world.
+
+ Oracle is best known for its {database management systems}
+ vendor and {relational DBMS} products. Oracle develops and
+ markets {Oracle Media Server} and the {Oracle7} family of
+ software products for {database} management; {Co-operative
+ Development Environment} and {Oracle Co-operative
+ Applications}
+
+ Oracle software runs on {personal digital assistants},
+ {set-top boxs}, {IBM PCs}, {workstations}, {minicomputers},
+ {mainframes} and {massively parallel computers}.
+
+ Oracle bought {Sun Microsystems} on 2009-04-20.
+
+ See also {Adaptable User Interface}, {Bookviewer},
+ {CASE*Method}, {Component Integration Laboratories}, {DDE
+ Manager}, {Online Media}, {Oracle Card}, {Oracle*CASE},
+ {siod}.
+
+ {(http://oracle.com/)}.
+
+ Address: Redwood Shores, CA, USA.
+
+ (1995-03-15)
+
+Oracle Parallel Server
+
+ <database> (OPS) An {Oracle} configuration that allows for
+ multiple Oracle servers running on seperate computers to
+ access the same database files simultaneously.
+
+ Normally used for {high availability}, running parallel
+ servers can improve performance by spreading out {CPU} load,
+ however, it requires data to be partitioned correctly.
+
+ This feature is enabled with the Parallel Server Option (or
+ "PSO").
+
+ {Oracle Parallel Server Option FAQ
+ (http://orafaq.com/faqops.htm)}.
+
+ (2003-04-05)
+
+Oracle Rdb
+
+ <database> A set of {relational database} products originally
+ known as Rdb from {Digital Equipment Corporation}, but
+ purchased by {Oracle Corporation} in 1994. The current (October
+ 1996) versions are Oracle Rdb V7.0 for {OpenVMS} {VAX}, Oracle
+ Rdb V7.0 for OpenVMS {Alpha}, and Oracle Rdb V7.0 for {Digital
+ UNIX}.
+
+ This release of Oracle Rdb includes advances in {non-stop
+ computing} for {business critical} applications, improvements
+ to {OLTP} performance, and easy {client/server} application
+ development. It also includes an {ODBC} Driver.
+
+ (1996-10-30)
+
+Oracle Toolkit
+
+ {Adaptable User Interface}
+
+Orange Book
+
+ <security, standard> A standard from the US Government
+ {National Computer Security Council} (an arm of the
+ U.S. National Security Agency), "Trusted Computer System
+ Evaluation Criteria, DOD standard 5200.28-STD, December 1985"
+ which defines criteria for trusted computer products. There
+ are four levels, A, B, C, and D. Each level adds more
+ features and requirements.
+
+ D is a non-secure system.
+
+ C1 requires user log-on, but allows {group ID}.
+
+ C2 requires individual log-on with password and an audit
+ mechanism. (Most {Unix} implementations are roughly C1, and
+ can be upgraded to about C2 without excessive pain).
+
+ Levels B and A provide mandatory control. Access is based on
+ standard Department of Defense clearances.
+
+ B1 requires DOD clearance levels.
+
+ B2 guarantees the path between the user and the security
+ system and provides assurances that the system can be tested
+ and clearances cannot be downgraded.
+
+ B3 requires that the system is characterised by a mathematical
+ model that must be viable.
+
+ A1 requires a system characterized by a mathematical model
+ that can be proven.
+
+ See also {crayola books}, {book titles}.
+
+ [{Jargon File}]
+
+ (1997-01-09)
+
+ORB
+
+ {Object Request Broker}
+
+Orbit
+
+ A {Scheme} compiler.
+
+ ["Orbit: An Optimising Compiler for Scheme", D.A. Kranz et al,
+ SIGPLAN Notices 21(7):281-292 (Jul 1986)].
+
+ (1994-10-28)
+
+Orca
+
+ Vrije Universiteit, Amsterdam, 1986. Similar to Modula-2, but
+ with support for distributed programming using shared data
+ objects, like Linda. A 'graph' data type removes the need for
+ pointers. Version for the Amoeba OS, comes with Amoeba.
+ "Orca: A Language for Distributed Processing", H.E. Bal
+ <bal@cs.vu.nl> et al, SIGPLAN Notices 25(5):17-24 (May 1990).
+
+Order Code Processor
+
+ <processor> The {ICL 2900}, {ICL 3900} and above term for
+ "{CPU}".
+
+ (1995-05-06)
+
+order-embedding
+
+ A function f : D -> C is order-embedding iff for all x, y in
+ D,
+
+ f(x) <= f(y) <=> x <= y.
+
+ I.e. arguments and results compare similarly. A function which
+ is order-embedding is {monotonic} and one-to-one and an
+ {injection}.
+
+ ("<=" is written in {LaTeX} as {\sqsubseteq}).
+
+ (1995-02-03)
+
+ordering
+
+ A relation.
+
+ See {partial ordering}, {pre-order}, {total ordering}.
+
+ordinal
+
+ <mathematics> An {isomorphism class} of {well-ordered sets}.
+
+ (1995-03-10)
+
+ordinary differential equation
+
+ <mathematics> (ODE) A {differential equation} that contains
+ functions of only one independent variable, in contrast to a
+ {partial differential equation} (PDE).
+
+ (2009-03-11)
+
+ordinate
+
+ <mathematics> The y-coordinate on an (x,y) graph; the output
+ of a function plotted against its input.
+
+ x is the "{abscissa}".
+
+ See {Cartesian coordinates}.
+
+ (1997-07-08)
+
+OREGANO
+
+ ["On the Design and Specification of the Programming Language
+ OREGANO", D.M. Berry. UCLA-ENG-7388, 1973].
+
+O'Reilly and Associates
+
+ The leading publisher of information on the {Internet},
+ {Unix}, the {X Window System} and other {open} systems. They
+ also provide the {Global Network Navigator} service.
+
+ {Home page(http://ora.com/)}.
+
+ (1995-01-10)
+
+org
+
+ <networking> The {top-level domain} for organisations or
+ individuals that don't fit any other top-level domain
+ (national, com, edu, or gov). Though many have .org domains,
+ it was never intended to be limited to non-profit
+ organisations.
+
+ {RFC 1591}.
+
+ (2001-05-14)
+
+Organic Mode
+
+ <programming> A term used by {COCOMO} to describe a project
+ that is developed in a familiar, stable environment.
+
+ The product is similar to previously developed products. Most
+ people connected with the project have extensive experience in
+ working with related systems and have a thorough understanding
+ of the project. The project contains a minimum of innovative
+ data processing architectures or {algorithms}. The product
+ requires little innovation and is relatively small, rarely
+ greater than 50,000 {DSIs}.
+
+ (1996-05-29)
+
+Orient84/K
+
+ <language>
+
+ ["A Concurrent Object-Oriented Knowledge Representation
+ Language Orient84/K", Y. Ishikawa, Keio U, Yokohama, SIGPLAN
+ Notices 21(11):232-241 OOPSLA '86, Nov 1986].
+
+ (1996-05-29)
+
+Original Equipment Manufacturer
+
+ <company> (OEM) A misleading term for a company which
+ repackages equipment, such as computers, made by other
+ companies. Unlike a {value added reseller}, an OEM does not
+ necessarily add anything except their name to the product. In
+ some cases though they may integrate components into complete
+ systems. OEM arrangements are often made for marketing
+ reasons.
+
+ [Origin?]
+
+ (2001-04-09)
+
+ORKID
+
+ {Open Real-time Kernel Interface Definition}
+
+ORM
+
+ 1. {object relational modelling}.
+
+ 2. {Object Role Modeling}.
+
+orphaned i-node
+
+ /or'f*nd i:'nohd/ [Unix] 1. A file that retains storage but no
+ longer appears in the directories of a file system.
+
+ [{Jargon File}]
+
+orphan process
+
+ <operating system> A {Unix} process whose original parent has
+ terminated and which has become a child of "{init}(1)".
+
+ Compare {zombie}.
+
+ (1996-05-29)
+
+ORTHOCARTAN
+
+ <mathematics, tool> A system for {symbolic mathematics},
+ especially General Relativity, written by A. Krasinski of
+ Warsaw in the early 1980s.
+
+ (1995-04-12)
+
+orthogonal
+
+ <mathematics, jargon> At 90 degrees (right angles).
+
+ N mutually orthogonal {vectors} {span} an N-dimensional
+ {vector space}, meaning that, any vector in the space can be
+ expressed as a {linear combination} of the vectors. This is
+ true of any set of N {linearly independent} vectors.
+
+ The term is used loosely to mean mutually independent or well
+ separated. It is used to describe sets of primitives or
+ capabilities that, like linearly independent vectors in
+ geometry, span the entire "capability space" and are in some
+ sense non-overlapping or mutually independent. For example,
+ in logic, the set of operators "not" and "or" is described as
+ orthogonal, but the set "nand", "or", and "not" is not
+ (because any one of these can be expressed in terms of the
+ others).
+
+ Also used loosely to mean "irrelevant to", e.g. "This may be
+ orthogonal to the discussion, but ...", similar to "going off
+ at a tangent".
+
+ See also {orthogonal instruction set}.
+
+ [{Jargon File}]
+
+ (2002-12-02)
+
+orthogonal instruction set
+
+ <architecture> An {instruction set} where all (or most)
+ instructions have the same format and all {registers} and
+ {addressing modes} can be used interchangeably - the choices
+ of {op code}, register, and addressing mode are mutually
+ independent (loosely speaking, the choices are
+ "{orthogonal}"). This contrasts with some early {Intel}
+ {microprocessors} where only certain registers could be used
+ by certain instructions.
+
+ Examples include the {PDP-11}, {680x0}, {ARM}, {VAX}.
+
+ (2002-06-26)
+
+Orwell
+
+ Lazy functional language, Miranda-like. List comprehensions
+ and pattern matching. "Introduction to Orwell 5.00",
+ P.L. Wadler et al, Programming Research Group, Oxford U, 1988.
+
+OS
+
+ 1. {operating system}.
+
+ 2. [obsolete, {ITS}], an output spy. See "{OS and JEDGAR}".
+
+ 3. <operating system> An {operating system} from {IBM} for
+ their {System/360} line of hardware announced in 1964. OS was
+ planned with several flavours that were supposed to be
+ compatible. OS was late, memory hungry and not able to reach
+ the marketing objectives of IBM for the 360/30, the planned
+ successor of the {IBM 1401}. IBM then decided to design a new
+ operating system for the low end machines which they called
+ {DOS/360}.
+
+ [{Jargon File}]
+
+ (1997-09-22)
+
+OS2
+
+ <spelling> Normally written "{OS/2}".
+
+ [{Jargon File}]
+
+ (1997-05-02)
+
+OS/2
+
+ /O S too/ {IBM} and {Microsoft}'s successor to the {MS-DOS}
+ {operating system} for {Intel 80286} and {Intel 80386}-based
+ {microprocessors}. It is proof that they couldn't get it
+ right the second time either. Often called "Half-an-OS". The
+ design was so {baroque}, and the implementation of 1.x so bad,
+ that 3 years after introduction you could still count the
+ major {application programs} shipping for it on the fingers of
+ two hands, in {unary}. Later versions improved somewhat, and
+ informed hackers now rate them superior to {Microsoft
+ Windows}, which isn't saying much. See {second-system
+ effect}.
+
+ On an {Intel 80386} or better, OS/2 can {multitask} between
+ existing {MS-DOS} {applications}. OS/2 is strong on
+ connectivity and the provision of robust {virtual machines}.
+ It can support {Microsoft Windows} programs in addition to its
+ own {native} applications. It also supports the {Presentation
+ Manager} {graphical user interface}.
+
+ {OS/2} supports {hybrid multiprocessing} (HMP), which provides
+ some elements of {symmetric multiprocessing} (SMP), using
+ add-on IBM software called {MP/2}. OS/2 SMP was planned for
+ release in late 1993.
+
+ After OS/2 1.x the {IBM} and {Microsoft} partnership split.
+ IBM continued to develop OS/2 2.0, while Microsoft developed
+ what was originally intended to be OS/2 3.0 into {Windows NT}.
+ In October 1994, IBM released version OS/2 3.0 (known as
+ "Warp") but it is only distantly related to {Windows NT}.
+ This version raised the limit on RAM from 16MB to 1GB (like
+ Windows NT).
+
+ IBM introduced networking with "OS/2 Warp Connect", the first
+ multi-user version. OS/2 Warp 4.0 ("Merlin") is a {network
+ operating system}.
+
+ {(http://mit.edu:8001/activities/os2/os2world.html)}.
+
+ [Dates?]
+
+ [{Jargon File}]
+
+ (1995-07-20)
+
+OS/360
+
+ {Operating System/360}
+
+OS/390
+
+ <operating system> An {IBM} {mainframe} {operating system},
+ featuring integrated {MVS}, {UNIX}, {LAN}, {distributed
+ computing} and {application enablement services} through its
+ base elements. These base services enable open, distributed
+ processing and offer a foundation for object-ready application
+ development. The OS/390 base includes a {Communication
+ Server} that includes {VTAM}, the {VTAM AnyNet} feature,
+ {TCP/IP} and {TIOC}. It provides {SNA} ({3270}), {APPC},
+ {High Performance Routing}, {ATM} support, {sockets} and
+ {RPC}.
+
+ OS/390 is basically rebranded, repackaged {MVS/OE}, {CMOS}
+ processors, {RAMAC} disk arrays and {open systems} extension
+ to networking in {VTAM}, the principle being that if you can't
+ compete, rebrand what you have and tell everyone it's
+ something new.
+
+ {(http://204.146.133.206/os390/index.html)}.
+
+ (1999-01-20)
+
+OS-9
+
+ <operating system> A {real-time} {operating system} written by
+ {Microware Corporation}. The original version was written
+ about 1978 for the {Motorola 6809} and has since been ported
+ to the {Motorola 68000}, {Intel 80386}, {Intel 486}, and the
+ {PowerPC}. The {kernel} of OS-9 is {ROMable}, modular, with a
+ unified file system, allowing it to easily be scaled up or
+ down as required.
+
+ {FAQ (http://os9archive.rtsi.com/os9faq.html)}.
+
+ {User Group (http://cs.wisc.edu/~pruyne/os9ugfaq.html)}.
+
+ {Usenet} newsgroup: {news:comp.os.os9}.
+
+ (1996-04-03)
+
+OSA
+
+ 1. {Open Scripting Architecture}.
+
+ 2. {Open System Architecture}.
+
+OSA extension
+
+ (OSAX) Any extension to {Macintosh} {OSA}.
+
+ (1999-01-14)
+
+OSAX
+
+ {OSA extension}
+
+Osborne 1
+
+ <computer> A {portable computer} that weighed 11 kg and cost
+ $1795, produced by {Osborne Computer Corporation} in 1981.
+
+ The Osborne 1 came with a five-inch screen, {modem} port, two
+ 5 1/4 {floppy drives} and a {battery pack}. It came with the
+ {CP/M} {operating system}, {SuperCalc} {spreadsheet}
+ application, {WordStar}, {word processing} application,
+ {Microsoft} {MBASIC} programming language and {Digital
+ Research} {CBASIC} programming language.
+
+ {(http://oldcomputers.net/osborne.html)}
+
+ (2007-05-21)
+
+Osborne, Adam
+
+ {Adam Osborne}
+
+Osborne Computer Corporation
+
+ <company> The unsucessful computer manufacturer founded by
+ {Adam Osborne} that produced one of the first {laptop
+ computers}, the {Osborne 1}.
+
+ (2007-05-21)
+
+OSCAR
+
+ 1. Oregon State Conversational Aid to Research. Interactive
+ numerical calculations, vectors, matrices, complex arithmetic,
+ string operations, for CDC 3300. "OSCAR: A User's Manual with
+ Examples", J.A. Baughman et al, CC, Oregon State U.
+
+ 2. Object-oriented language used in the COMANDOS Project.
+ "OSCAR: Programming Language Manual", TR, COMANDOS Project,
+ Nov 1988.
+
+OSD
+
+ {Open Source Definition}
+
+OSE
+
+ {Open Systems Environment}
+
+OSF
+
+ {Open Software Foundation}
+
+OSI
+
+ 1. <networking> {Open Systems Interconnection}.
+
+ 2. {Open Source Initiative}.
+
+ (1999-12-29)
+
+OSI Model
+
+ {Open Systems Interconnect}
+
+OSI Reference Model
+
+ {Open Systems Interconnect}
+
+OSI-RM
+
+ {Open Systems Interconnect}
+
+OSI seven layer model
+
+ {Open Systems Interconnect}
+
+O'small
+
+ <language> A small, concise, formally defined
+ {object-oriented} language intended for teaching, by Andreas
+ Hense <ahense@ahense.de>.
+
+ O'small requires {sml-yacc}, {sml-lex} and {sml-noshare}.
+ Binaries are provided for {SPARC} and it is probably portable
+ to other {Unix} systems. There is also an {interpreter} in
+ {Miranda}.
+
+ {(http://ahense.de/)}.
+
+ [Christoph Boeschen, "Christmas - An abstract machine for
+ O'small". Master's thesis, Universit"at des Saarlandes,
+ Fachbereich, 1993-06-14].
+
+ (2001-02-11)
+
+OS/MFT
+
+ {Operating System/Multiprogramming of Fixed Tasks}
+
+OS/MVT
+
+ <operating system> One of the {IBM} {operating systems}
+ associated with the {IBM 360}, later rereleased with the {IBM
+ S/370} as {OS/VS2}.
+
+ [Details?]
+
+ (1999-01-12)
+
+OSP
+
+ {Optical Signal Processor}
+
+OSPF
+
+ {Open Shortest-Path First Interior Gateway Protocol}
+
+OSQL
+
+ {Object-oriented SQL}
+
+OSSL
+
+ Operating Systems Simulation Language.
+
+ ["OSSL - A Specialized Language for Simulating Computer
+ Systems", P.B. Dewan et al, Proc SJCC 40, AFIPS (Spring
+ 1972)].
+
+OSTA
+
+ {Optical Storage Technology Association}
+
+OS/VS1
+
+ {OS/MFT}
+
+OS/VS2
+
+ <operating system> An {operating system} from {IBM}, released
+ with the {IBM S/370} and originally known as {OS/MVT}. OS/VS2
+ R1 was known as SVS (Single Virtual Storage) as it had a
+ single 16 MB {virtual address space}. OS/VS2 R2 was known as
+ MVS - {Multiple Virtual Storage}.
+
+ (1999-01-13)
+
+OT
+
+ {OpenTransport}
+
+OTDR
+
+ {Optical Time-Domain Reflectometry}
+
+OT&E
+
+ {operational test and evaluation}
+
+OTI
+
+ {Open Tool Interface}
+
+OTOH
+
+ <chat> On the other hand.
+
+ (2000-01-31)
+
+OTP
+
+ 1. <security> {One-Time Password}.
+
+ 2. <protocol> {Open Trading Protocol}.
+
+ 3. <storage, integrated circuit> {One Time Programmable Read
+ Only Memory}.
+
+ 4. <communications, library> {Open Telecom Platform}.
+
+ (2001-08-28)
+
+OTPROM
+
+ {One Time Programmable Read-Only Memory}
+
+OTT
+
+ Over the top.
+
+ Excessive or uncalled for.
+
+ (1995-01-31)
+
+Ottawa Euclid
+
+ {Euclid}
+
+Ousterhout, John K.
+
+ {John Ousterhout}
+
+Ousterhout's dichotomy
+
+ <language> {John Ousterhout}'s division of {high-level
+ languages} into "system programming languages" and "scripting
+ languages". This distinction underlies the design of his
+ language {Tcl}.
+
+ System programming languages (or "applications languages") are
+ {strongly typed}, allow arbitrarily complex {data structures},
+ and programs in them are {compiled}, and are meant to operate
+ largely independently of other programs. Prototypical system
+ programming languages are {C} and {Modula-2}.
+
+ By contrast, scripting languages (or "glue languages") are
+ weakly typed or untyped, have little or no provision for
+ complex data structures, and programs in them ("{scripts}")
+ are {interpreted}. Scripts need to interact either with other
+ programs (often as {glue}) or with a set of functions provided
+ by the interpreter, as with the {file system} functions
+ provided in a {UNIX shell} and with {Tcl}'s {GUI} functions.
+ Prototypical scripting languages are {AppleScript}, {C Shell},
+ {MS-DOS} {batch files} and {Tcl}.
+
+ Many believe that this is a highly arbitrary dichotomy, and
+ refer to it as "Ousterhout's fallacy" or "Ousterhout's false
+ dichotomy". While strong-versus-weak typing, data structure
+ complexity, and independent versus stand-alone might be said
+ to be unrelated features, the usual critique of Ousterhout's
+ dichotomy is of its distinction of compilation versus
+ interpretation, since neither {semantics} nor {syntax} depend
+ significantly on whether code is compiled into
+ {machine-language}, interpreted, {tokenized}, or
+ {byte-compiled} at the start of each run, or any mixture of
+ these. Many languages fall between being interpreted or
+ compiled (e.g. {Lisp}, {Forth}, {UCSD Pascal}, {Perl}, and
+ {Java}). This makes compilation versus interpretation a
+ dubious parameter in a taxonomy of programming languages.
+
+ (2002-05-28)
+
+Ousterhout's fallacy
+
+ {Ousterhout's dichotomy}
+
+Ousterhout's false dichotomy
+
+ {Ousterhout's dichotomy}
+
+out
+
+ <programming> A type or "mode" of {function} {parameter} that
+ passes information in one direction - from the function to the
+ caller. An "out" parameter thus provides an additional
+ {return value}, typically for languages that don't have good
+ support for returning {data structures} like {lists}. Other
+ modes are {in} and {inout}.
+
+ (2010-01-19)
+
+outer join
+
+ <database> A less commonly used variant of the {inner join}
+ {relational database} operation. An inner join selects rows
+ from two {tables} such that the value in one {column} of the
+ first table also appears in a certain column of the second
+ table. For an outer join, the result also includes all rows
+ from the first operand ("left outer join"), or the second
+ operand ("right outer join"), or both ("full outer join"). A
+ field in a result row will be null if the corresponding input
+ table did not contain a matching row.
+
+ For example, if we want to list all employees and their
+ employee number, but not all employees have a number, then we
+ could say (in {SQL-92} syntax, as used by {Microsoft SQL
+ Server}):
+
+ SELECT employee.name, empnum.number
+ FROM employee
+ LEFT JOIN empnum ON employee.id = empnum.id
+
+ or, in {Sybase} syntax:
+
+ SELECT employee.name, empnum.number
+ FROM employee, empnum
+ WHERE employee.id *= empnum.id
+
+ The "*" on the left means "left outer join". "*=*" would be a
+ full outer join.
+
+ In {Oracle} syntax:
+
+ SELECT employee.name, empnum.number
+ FROM employee, empnum
+ WHERE employee.id = empnum.id (+)
+
+ Note that the "(+)" on the right means "left outer join".
+
+ These all mean that all rows from the left-hand "employee"
+ table will appear in the result, even if there is no match for
+ their ID in the empnum table. Where there is no empnum.id
+ equal to a given employee.id, a result row is output anyway
+ but with all result columns from the empnum table null
+ (empnum.number in this case).
+
+ (2004-11-12)
+
+outline font
+
+ <text> (Or "vector font") A {font} defined as a set of lines
+ and curves as opposed to a {bitmap font}. An outline font
+ (e.g. {PostScript}, {TrueType}, {RISC OS}) can be scaled to any
+ size and otherwise transformed more easily than a bitmap font,
+ and with more attractive results, though this requires a lot
+ of numerical processing. The result of transforming a
+ character in an outline font in a particular way is often
+ saved as a bitmap in a {font cache} to avoid repeating the
+ calculations if that character is to be drawn again.
+
+ (1995-03-16)
+
+out-of-band
+
+ 1. <communications> The exchange of {call control} information
+ on a dedicated channel, separate from that used by the
+ telephone call or data transmission.
+
+ 2. Sometimes used to describe what communications people call
+ "shift characters", such as the ESC that leads control
+ sequences for many terminals, or the level shift indicators in
+ the old 5-bit {Baudot} codes.
+
+ 3. In personal communication, using methods other than
+ {electronic mail}, such as telephone or {snail-mail}.
+
+ 4. <software> Values returned by a {function} that are not in
+ its "natural" {range} of return values, but rather signal some
+ kind of {exception}. Many {C} functions that normally return
+ a non-negative integer return -1 to indicate failure.
+
+ This use confuses "out-of-band" with "out-of-range". It is
+ actually a clear example of {in-band} signalling since it uses
+ the same "channel" for control and data.
+
+ Compare {hidden flag}, {green bytes}, {fence}.
+
+ [{Jargon File}]
+
+ (2001-04-08)
+
+output
+
+ <architecture> {Data} transferred from a computer system to
+ the outside world via some kind of {output device}.
+
+ Opposite: {input}.
+
+ (1997-04-28)
+
+output device
+
+ <hardware> Electronic or electromechanical equipment connected
+ to a computer and used to transfer data out of the computer in
+ the form of text, images, sounds or other media to a {display
+ screen}, {printer}, loudspeaker or storage device. Most
+ modern storage devices such as {disk drives} and {magnetic
+ tape drives} act as both input and output devices, others such
+ as {CD-ROM} are input only.
+
+ (1997-03-18)
+
+Outside Awareness Port
+
+ <humour> (OAP) A humorous {IBM} term for a window (the glass
+ kind) rather than the {GUI} kind.
+
+outside-in testing
+
+ <testing> A strategy for {integration testing} where units
+ handling program inputs and outputs are tested first, and
+ units that process the inputs to produce output are
+ incrementally included as the system is integrated. A form of
+ {hybrid testing}.
+
+ (1997-01-07)
+
+outsourcing
+
+ <business> Paying another company to provide services which a
+ company might otherwise have employed its own staff to
+ perform, e.g. software development.
+
+ (1995-03-28)
+
+overclocking
+
+ <hardware> Any adjustments made to {computer} {hardware}, or less
+ commonly {software}, to make its {CPU} run at a higher {clock
+ rate} than intended by the original manufacturers. Typically this
+ involves replacing the {crystal} in the {clock} generation
+ circuitry with a higher frequency one or changing {jumper}
+ settings or software configuration.
+
+ If the {clock rate} is increased too far, eventually some
+ component in the system will not be able to cope and the system
+ will stop working. This failure may be intermittent (it works
+ most of the time but fails more often than usual) continuous (the
+ system never works at the higher frequency) or, in the worst case,
+ irreversible (a component is damaged by overheating). Improved
+ {cooling} may be needed to maintain the same level of reliability.
+
+ (2014-07-12)
+
+Overdrive
+
+ <processor> An {Intel} {Pentium} processor which fits into a
+ socket designed to accomodate an {Intel 486}, or into a
+ special upgrade socket on the {motherboard}.
+
+ (1995-03-27)
+
+overflow
+
+ <programming> The condition that occurs when the result of a
+ calculation is too big to store in the intended format. For
+ example, the result of adding one to 255 cannot be represented
+ as an {unsigned}, eight-bit integer. In a {signed integer}
+ representation, overflow can occur when an integer becomes
+ either too positive or too negative.
+
+ Overflow can also occur in the exponent of a {floating point}
+ number representation. The term "{underflow}" is sometimes
+ used for negative overflow of the exponent.
+
+ Ignoring overflow will result in nonsensicle results such as
+ 255 + 1 = 0. At the hardware level, the {ALU} typically
+ indicates overflow by setting an overflow flag bit which the
+ program can test. Programming languages will typically
+ respond to overflow by raising some kind of {signal} or other
+ error condition to halt normal execution.
+
+ Some languages attempt to avoid overflow by providing
+ (optional) variable length number representation
+ ({multiprecission arithmetic}) so that the maximum number
+ representable is limited only by the amount of storage
+ available.
+
+ (2008-05-30)
+
+overflow bit
+
+ <architecture> A processor {flag bit} set by the {ALU} to
+ indicate {overflow}.
+
+ (2008-05-30)
+
+overflow flag
+
+ {overflow bit}
+
+overflow pdl
+
+ <jargon> The place where you put things when your {pdl} is
+ full. If you don't have one and too many things get pushed,
+ you forget something. The overflow pdl for a person's memory
+ might be a memo pad. This usage inspired the following
+ doggerel:
+
+ Hey, diddle, diddle
+ The overflow pdl
+ To get a little more stack;
+ If that's not enough
+ Then you lose it all,
+ And have to pop all the way back.
+ --The Great Quux
+
+ The term {pdl} seems to be primarily an {MIT}ism; outside MIT
+ this term is replaced by "overflow {stack}".
+
+ (2008-05-30)
+
+overhead
+
+ 1. Resources (in computing usually processing time or storage
+ space) consumed for purposes which are incidental to, but
+ necessary to, the main one. Overheads are usually
+ quantifiable "costs" of some kind.
+
+ Examples: The overheads in running a business include the cost
+ of heating the building. Keeping a program running all the
+ time eliminates the overhead of loading and initialising it
+ for each transaction. Turning a {subroutine} into {inline}
+ code eliminates the call and return time overhead for each
+ execution but introduces space overheads.
+
+ 2. <communications> information, such as control, routing, and
+ error checking characters, that is transmitted along with the
+ user data. It also includes information such as network
+ status or operational instructions, network routing
+ information, and retransmissions of user data received in
+ error.
+
+ 3. Overhead transparencies or "slides" (usually 8-1/2" x 11")
+ that are projected to an audience via an overhead (flatbed)
+ projector.
+
+ (1997-09-01)
+
+overloading
+
+ <language> (Or "Operator overloading"). Use of a single
+ symbol to represent operators with different argument types,
+ e.g. "-", used either, as a {monadic} operator to negate an
+ expression, or as a {dyadic} operator to return the difference
+ between two expressions. Another example is "+" used to add
+ either integers or {floating-point} numbers. Overloading is
+ also known as ad-hoc {polymorphism}.
+
+ User-defined operator overloading is provided by several
+ modern programming languages, e.g. {C++}'s {class} system and
+ the {functional programming} language {Haskell}'s {type
+ class}es.
+
+ Ad-hoc polymorphism (better described as {overloading}) is the
+ ability to use the same syntax for objects of different types,
+ e.g. "+" for addition of reals and integers or "-" for unary
+ negation or diadic subtraction. Parametric polymorphism
+ allows the same object code for a function to handle arguments
+ of many types but overloading only reuses syntax and requires
+ different code to handle different types.
+
+ (2014-01-05)
+
+overriding
+
+ <programming> Redefining in a {child class} a {method} or
+ function member defined in a {parent class}.
+
+ Not to be confused with "{overloading}".
+
+ (1996-12-21)
+
+overrun
+
+ 1. A frequent consequence of data arriving faster than it can
+ be consumed, especially in {serial line} communications. For
+ example, at 9600 baud there is almost exactly one character
+ per millisecond, so if a {silo} can hold only two characters
+ and the machine takes longer than 2 milliseconds to get to
+ service the interrupt, at least one character will be lost.
+
+ 2. Also applied to non-serial-I/O communications. "I forgot
+ to pay my electric bill due to mail overrun." "Sorry, I got
+ four phone calls in 3 minutes last night and lost your message
+ to overrun." When {thrash}ing at tasks, the next person to
+ make a request might be told "Overrun!" Compare {firehose
+ syndrome}.
+
+ 3. More loosely, may refer to a {buffer overflow} not
+ necessarily related to processing time (as in {overrun
+ screw}).
+
+ [{Jargon File}]
+
+overrun screw
+
+ A variety of {fandango on core} produced by a {C} program
+ scribbling past the end of an {array} ({C} implementations
+ typically have no checks for this error). This is relatively
+ benign and easy to spot if the array is static; if it is
+ {auto}, the result may be to {smash the stack} - often
+ resulting in {heisenbugs} of the most diabolical subtlety.
+ The term "overrun screw" is used especially of scribbles
+ beyond the end of arrays allocated with {malloc}; this
+ typically overwrites the allocation header for the next block
+ in the {arena}, producing massive lossage within malloc and
+ often a {core dump} on the next operation to use {stdio} or
+ malloc itself.
+
+ See {spam}, {overrun}; see also {memory leak}, {memory smash},
+ {aliasing bug}, {precedence lossage}, {fandango on core},
+ {secondary damage}.
+
+ (1995-01-19)
+
+overuse strain injury
+
+ <medical> (Or "repetitive strain injury", RSI, "repetitive
+ strain disorder") Any tendon or muscle injury resulting from
+ overuse, usually in the hand, wrist, or arm. Injury may be
+ caused by any combination of repetitive, unacustomed, or
+ prolonged movements, forcefulness, or an awkward position
+ (often due to bad {ergonomics}). The symptoms are pain,
+ tingling, weakness, numbness, swelling, cracking, stiffness,
+ or reduced coordination.
+
+ Common conditions are:
+
+ Carpal tunnel syndrome, where swelling of the membrane linings
+ in your wrist surrounding the tendons that bend your fingers
+ compresses the median nerve. This may result in numbness and
+ pain in the hand, arm, shoulder, and neck.
+
+ Tennis elbow, where rotating your wrist and using force causes
+ a form of epicondylitis.
+
+ Tendinitis, where unacustomed exercise or repeated awkward
+ movements inflame wrist, elbow, or shoulder tendons, often
+ leading to severe stiffness.
+
+ Trigger finger, a popping or catching sensation when you bend
+ your finger, wrist, or shoulder. This form of tenosynovitis
+ is caused by repetitive hand movements.
+
+ To prevent the condition worsening, treat the pain with heat,
+ cold, or aspirin, ibuprofen, or naproxen sodium; rest; or
+ immobilise the injured area with a splint or bandage. See a
+ doctor.
+
+ {Amara's RSI information
+ (http://amara.com/aboutme/rsi.html)}.
+
+ {RSI links from Yahoo
+ (http://dir.yahoo.com/Health/Diseases_and_Conditions/Repetitive_Strain_Disorder/)}.
+
+ {Guide to Carpal Tunnel Syndrome
+ (http://sechrest.com/mmg/cts/)}.
+
+ {CTS from Yahoo
+ (http://dir.yahoo.com/Health/Diseases_and_Conditions/Carpal_Tunnel_Syndrome/)}.
+
+ (1999-10-03)
+
+OWHY
+
+ <language> An early {functional language}(?).
+
+ ["A Type-Theoretical Alternative to CUCH, ISWIM, OWHY", Dana
+ Scott, Oxford U 1969].
+
+ (1995-01-19)
+
+OWL
+
+ 1. <company> {Office Workstations Limited}.
+
+ 2. <language> {Object Windows Language}.
+
+ (1996-01-13)
+
+Owl
+
+ The original name of {Trellis}.
+
+ (1995-01-19)
+
+Ox
+
+ <language, tool> A {preprocessor}, written by Kurt Bischoff of
+ {Iowa State University}, that extends and generalises the
+ {syntax} and {semantics} of {Yacc}, {Lex}, and {C}. Ox's
+ support of {LALR1 grammars} generalises {yacc} in the way that
+ {attribute grammars} generalise {context-free grammars}. It
+ augments Yacc and {Lex} specifications with definitions of
+ synthesised and inherited attributes written in {C} {syntax}.
+ Ox checks these specifications for consistency and
+ completeness, and generates a program that builds and
+ decorates {attributed parse trees}. Ox accepts a most general
+ class of attribute grammars. The user may specify
+ postdecoration traversals for easy ordering of {side effects}
+ such as {code generation}.
+
+ Latest version: G1.01, as of 1993-11-14.
+
+ {(ftp://ftp.cs.iastate.edu/pub/ox/)}.
+
+ Info: <ox-request@cs.iastate.edu>.
+
+ ["User Manual for Ox: An Attribute-Grammar Compiling System
+ based on Yacc, Lex and C", K.M. Bischoff, TR92-30, Iowa State
+ U, Dec 1992].
+
+ (2000-04-03)
+
+Oz
+
+ An {object-oriented} {concurrent} {constraint} language from
+ the {University of Saarbrucken}. Oz is based on {constraint
+ communication}, a new form of {asynchronous} communication
+ using {logic variables}. Partial information about the values
+ of variables is imposed concurrently and incrementally.
+ Supports {higher order} programming and object-orientation
+ including {multiple inheritance}.
+
+ {(ftp:duck.dfki.uni-sb.de/pub/papers)}.
+
+ ["Object-Oriented Concurrent Constraint Programming in Oz",
+ G. Smolka et al].
+
+oz
+
+ An old Australian {top-level domain} and network which got
+ incorporated into the current one. The former Australian
+ {domains} .oz, .edu and .com are now .oz.au, .edu.au and
+ .com.au.
+
+ (1994-10-04)
+
+Oz-Email
+
+ <company> An {Internet} access provider.
+
+ {(http://ozemail.com.au/)}.
+
+ Address: Sydney, Australia.
+
+ (1995-03-02)
+
+P+
+
+ ["Experience with Remote Procedure Calls in a Real-Time
+ Control System", B. Carpenter et al, Soft Prac & Exp
+ 14(9):901-907 (Sep 1984)].
+
+P1754
+
+ <processor, standard> IEEE Std 1754-1994 "A 32-Bit
+ Microprocessor Architecture". The {IEEE} standard defining a
+ version of the {SPARC} {microprocessor} architecture.
+
+ The P1754 standard (the first microprocessor standard) was
+ approved after four years on 1994-03-17. It is compatible
+ with, but distinct from, {SPARC International}'s 32 bit
+ version of the SPARC Architecture, SPARC V8, from which it is
+ largely derived. It is possible for a processor to comply
+ with neither, one, or both specifications.
+
+ {SI article
+ (http://sparc.com/sparc.new/other/sflash/94-03.html)}.
+
+ (1996-12-21)
+
+p2c
+
+ A {Pascal} to {C} translator by Dave Gillespie
+ <daveg@synaptics.com>.
+
+ {Version 1.20 (ftp://csvax.cs.caltech.edu/)}.
+
+ Supports {ANSI}/{ISO} {standard} {Pascal} as well as
+ substantial subsets of {HP Pascal}, {Turbo Pascal}, VAX, and
+ many other dialects.
+
+ (1990-04-13)
+
+P2P
+
+ {peer-to-peer}
+
+P3L
+
+ (Superscript 3). A language with explicit parallelism
+ including constructs for {farms} and {geometric parallelism}.
+ P3L currently uses {C++} as a host language.
+
+ [S. Pelagatti, "A method for the development and the support
+ of massively parallel programs. PhD Thesis - TD 11/93,
+ University of Pisa, Mar 1993].
+
+ (1994-07-15)
+
+P4
+
+ A {macro}/subroutine package for parallel programming by Rusty
+ Lusk <lusk@anta.mcs.anl.gov>. P4 uses {monitors} on shared
+ memory machines and message passing on distributed memory
+ machines. It is implemented as a subroutine library for {C}
+ and {Fortran}. An enhancement of the "Argonne macros",
+ {PARMACS}.
+
+ {(ftp://info.mcs.anl.gov/pub/p4t1.2.tar.Z)}. E-mail:
+ <p4@mcs.anl.gov>.
+
+P6
+
+ <processor> ("P" from {Pentium}, 6 from 686, the successor to
+ 586 which is what the Pentium would have been had it followed
+ the naming scheme its predecessors) The name for the {Pentium
+ Pro} during development.
+
+ (1995-11-15)
+
+pa
+
+ <networking> The {country code} for Panama.
+
+ (1999-01-27)
+
+PABX
+
+ {Private Automatic Branch eXchange}
+
+PACE
+
+ A CPU based on the {Nova} design, but with 16-bit addressing,
+ more {addressing modes} and a 10 level {stack} (like the
+ {Intel 8008}).
+
+ (1994-11-30)
+
+Packard Bell Electronics, Inc.
+
+ <company> A leading US computer vendor.
+
+ As recently as 29 November 1995 the Wall Street Journal
+ reported that the company was having financial difficulties
+ and that one of its major suppliers of CPUs, {Intel}, was
+ about to make a large cash loan, so as to prevent loss of a
+ major customer. Packard Bell is a privately held company and
+ the WSJ also reported that {NEC} has been rumored to have
+ bought a large minority block of shares to help the company
+ stay in business.
+
+ Its computers are sold in major retail outlets in the USA and
+ are available as a bundled package: desktop or {tower} {486}
+ {CPU}, single 3.5 inch {floppy disk drive}, {CD-ROM}, {sound
+ card}, 14 inch colour {monitor}, and 4-8MB of {RAM}.
+
+ 1995 end-of-year prices in Computer Currents magazine (a
+ California Bay Area bi-monthly giveaway publication) are
+ US$1500 (approx. 1000 pounds) for a 486 desktop, with 8MB
+ RAM, 420MB hard disk drive, single 3.5 inch floppy drive, 14
+ inch colour monitor, 2-speed CD-ROM, and 16-bit sound card.
+
+ Headquarters: Sacramento, California, USA.
+
+ (1996-01-02)
+
+packed decimal
+
+ {binary coded decimal}
+
+Packed Encoding Rules
+
+ <protocol, standard> (PER) {ASN.1} encoding rules for
+ producing a compact {transfer syntax} for data structures
+ described in {ASN.1}, defined in 1994.
+
+ PER provides a much more compact encoding then {BER}. It
+ tries to represents the data units using the minimum number of
+ {bits}. The compactness requires that the decoder knows the
+ complete {abstract syntax} of the data structure to be
+ decoded, however.
+
+ Documents: {ITU-T} X.691, {ISO} 8825-2.
+
+ (1998-05-19)
+
+packet
+
+ The unit of data sent across a {network}. "Packet" is a
+ generic term used to describe a unit of data at any layer of
+ the {OSI} {protocol stack}, but it is most correctly used to
+ describe {application layer} data units ("{application
+ protocol data unit}", APDU).
+
+ See also {datagram}, {frame}.
+
+ (1994-11-30)
+
+Packet Assembler/Disassembler
+
+ (PAD) Hardware or software device for splitting a data stream
+ into discrete {packets} for transmission over some medium and
+ then reforming the stream(s) at the receiver.
+
+ The term is most often used for interfaces to {X.25} lines.
+
+ (1995-01-31)
+
+packet driver
+
+ <networking> {IBM PC} {local area network} software that
+ divides data into {packets} which it routes to the network.
+ It also handles incoming data, reassembling the packets so
+ that {application programs} can read the data as a continuous
+ stream.
+
+ {FTP Software} created the specification for {IBM PC} packet
+ drivers but {Crynwr Software} dominate the market and have
+ done the vast majority of the implementations.
+
+ Packet drivers provide a simple, common programming interface
+ that allows multiple {applications} to share a {network
+ interface} at the {data link} layer. Packet drivers
+ demultiplex incoming packets among the applications by using
+ the network media's {standard packet type} or {service access
+ point} field(s).
+
+ The packet driver provides calls to initiate access to a
+ specific packet type, to end access to it, to send a packet,
+ to get statistics on the network interface and to get
+ information about the interface.
+
+ Protocol implementations that use the packet driver can
+ coexist and can make use of one another's services, whereas
+ multiple applications which do not use the driver do not
+ coexist on one machine properly. Through use of the packet
+ driver, a user could run {TCP/IP}, {XNS} and a proprietary
+ protocol implementation such as {DECnet}, {Banyan}'s,
+ {LifeNet}'s, {Novell}'s or {3Com}'s without the difficulties
+ associated with pre-empting the network interface.
+
+ Applications which use the packet driver can also run on new
+ network hardware of the same class without being modified;
+ only a new packet driver need be supplied.
+
+ There are several levels of packet driver. The first is the
+ basic packet driver, which provides minimal functionality but
+ should be simple to implement and which uses very few host
+ resources. The basic driver provides operations to broadcast
+ and receive packets. The second driver is the extended packet
+ driver, which is a superset of the basic driver. The extended
+ driver supports less commonly used functions of the network
+ interface such as {multicast}, and also gathers statistics on
+ use of the interface and makes these available to the
+ application. The third level, the high-performance functions,
+ support performance improvements and tuning.
+
+ {(http://crynwr.com/crynwr/home.html)}.
+
+ (1994-12-05)
+
+Packet in Plastic Grid Array
+
+ <integrated circuit> (PPGA) The package used for
+ {Intel}'s {Celeron} {Socket 370} {CPU}.
+
+ [Description?]
+
+ (1999-06-24)
+
+Packet InterNet Groper
+
+ {ping}
+
+packet radio
+
+ <communications, radio> The use of {packet switched}
+ communications {protocols} in large networks (i.e not
+ {wireless LANs} or {Bluetooth}) having wireless links to
+ terminals at least. Packet radio is split into {amateur
+ packet radio} (AX25) and {General Packet Radio Service}
+ (GRPS).
+
+ (2001-05-12)
+
+packet sniffer
+
+ <networking, tool> A network monitoring tool that captures
+ data {packets} and decodes them using built-in knowledge of
+ common {protocols}. Sniffers are used to debug and monitor
+ networking problems.
+
+ (1995-03-28)
+
+packet switch
+
+ {packet switching}
+
+packet-switched
+
+ {packet switching}
+
+packet switching
+
+ <communications> A communications paradigm in which {packets}
+ (messages or fragments of messages) are individually {routed}
+ between {nodes}, with no previously established communication
+ path. Packets are routed to their destination through the
+ most expedient route (as determined by some routing
+ {algorithm}). Not all packets travelling between the same two
+ hosts, even those from a single message, will necessarily
+ follow the same route.
+
+ The destination computer reassembles the packets into their
+ appropriate sequence. Packet switching is used to optimise
+ the use of the {bandwidth} available in a network and to
+ minimise the {latency}. {X.25} is an international standard
+ packet switching network.
+
+ Also called {connectionless}. Opposite of {circuit switched}
+ or {connection-oriented}. See also {virtual circuit},
+ {wormhole routing}.
+
+ (1999-03-30)
+
+Packet Switch Node
+
+ (PSN) A dedicated computer whose purpose is to accept, {route}
+ and forward {packets} in a {packet-switched} network.
+
+ (1994-11-30)
+
+packet writing
+
+ <storage> A technique for writing {CD-Rs} and {CD-RWs} that is
+ more efficient in both disk space used and the time it takes
+ to write the CD.
+
+ {Adaptec}'s DirectCD is a packet writing recorder for {Windows
+ 95} and {Windows NT} that uses the {UDF} version 1.5 file
+ system.
+
+ [Is this true? How does it work?]
+
+ (1999-09-01)
+
+PackIt
+
+ <file format, tool> A file format used on the {Apple
+ Macintosh} to represent collections of Mac files, possibly
+ {Huffman} compressed. Packing many small related files
+ together before a {MacBinary} transfer or a translation to
+ {BinHex} 4.0 is common practice.
+
+ (1994-11-30)
+
+PACT I
+
+ An early system on the {IBM 701}. Version PACT IA was for the
+ {IBM 704}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1994-11-30)
+
+PACTOLUS
+
+ Digital simulation.
+
+ [Sammet 1969, p. 627].
+
+ (1994-11-30)
+
+PAD
+
+ {Packet Assembler/Disassembler}
+
+padded cell
+
+ Where you put {lusers} so they can't hurt anything. A program
+ that limits a luser to a carefully restricted subset of the
+ capabilities of the host system (for example, the "{rsh}"
+ utility on {USG Unix}). Note that this is different from an
+ {iron box} because it is overt and not aimed at enforcing
+ security so much as protecting others (and the {luser}) from
+ the consequences of the luser's boundless naivet'e (see
+ {naive}). Also "padded cell environment".
+
+ [{Jargon File}]
+
+ (1994-11-30)
+
+Paddle
+
+ A language for transformations leading from specification to
+ program. Used in the {POPART} programming environment
+ generator.
+
+ (1994-11-30)
+
+PAGE
+
+ A typesetting language.
+
+ ["Computer Composition Using PAGE-1", J.L. Pierson, Wiley
+ 1972].
+
+page
+
+ 1. <operating system> {paging}.
+
+ 2. <web> {web page}.
+
+ (1997-04-10)
+
+paged
+
+ {paging}
+
+Page Description Language
+
+ (PDL) A language such as {Adobe Systems, Inc.}'s {PostScript}
+ or {Xerox}'s {Interpress} which allows the appearance of a
+ printed page to be described in a high-level,
+ device-independent way. Printing then becomes a two-stage
+ process: an {application program} produces a description in
+ the language, which is then interpreted by a specific output
+ device. Such a language can therefore serve as an interchange
+ standard for transmission and storage of printable documents.
+
+ (1995-02-20)
+
+Paged Memory Management Unit
+
+ {Memory Management Unit}
+
+page fault
+
+ <memory management> In a {paged virtual memory} system, an
+ access to a page (block) of memory that is not currently
+ mapped to {physical memory}. When a page fault occurs the
+ {operating system} either fetches the page in from {secondary
+ storage} (usually disk) if the access was legitimate or
+ otherwise reports the access as illegal.
+
+ (1995-11-11)
+
+page in
+
+ <storage, architecture> What a {paging} system does when it
+ copies part of a {task}'s {working memory} from {swap space}
+ on disk to {RAM}.
+
+ [{Jargon File}]
+
+ (1995-01-23)
+
+pagelet
+
+ <web> A component of an {HTML} page, that contains
+ directives, layout, and code in a single context. A pagelet
+ may be a separate file or {web page} that contains information
+ you want displayed across several pages. They are similar to
+ {server-side include} files, as implemented in ASP+. Pagelets
+ act like independent HTML frames and provide discrete access
+ to content. They use {Cascading Style Sheets} as templates
+ for defining their layout behavior in a single context.
+
+ [.NET Framework Essentials, 2nd Edition, Thuan L. Thai and Lam
+ Hoang, February 2002, 0-596-00302-1]
+
+ (2004-02-19)
+
+page mode
+
+ 1. <hardware, storage> See {page mode DRAM}.
+
+ 2. <hardware> An operation mode of {video terminals} like the
+ {IBM 3270}, in which the terminal only sends a completed input
+ screen (page) to the host instead of sending each character as
+ the keys are pressed.
+
+ (1995-03-28)
+
+Page Mode DRAM
+
+ {Page Mode Dynamic Random Access Memory}
+
+Page Mode Dynamic Random Access Memory
+
+ <hardware, storage> A technique used to support faster
+ sequential access to {DRAM} by allowing any number of accesses
+ to the currently open row to be made after supplying the {row
+ address} just once.
+
+ The {RAS} signal is kept active, and with each {falling edge}
+ of the {CAS}\ signal a new {column address} can be supplied
+ and the corresponding bits can be accessed. This is faster
+ than a full RAS-CAS cycle because only the shorter Column
+ Access Time needs to be obeyed.
+
+ Note that strictly speaking such a DRAM is not a true {random
+ access memory} since accesses to the open row are faster than
+ to other locations.
+
+ {EDO RAM} is replacing Page Mode DRAM in many new
+ microcomputers.
+
+ [Is "Fast Page Mode" the same as "Page Mode"?]
+
+ (1996-10-06)
+
+page out
+
+ <storage, architecture> What a {paging} system does when it
+ copies part of a {task}'s {working memory} from {RAM} to {swap
+ space} on disk.
+
+ [{Jargon File}]
+
+ (1995-01-23)
+
+pager
+
+ 1. <hardware, communications> (Or "beeper", "bleeper" (UK?))
+ A small wireless receiver that, when triggered (generally via
+ phone), will beep or vibrate (un)pleasantly. The wearer will
+ have been trained to respond to this signal by looking at a
+ small screen on the device for an unimportant message.
+
+ In recent years, pagers have grown more complex, allowing for
+ long {alphanumeric} messages to be received and scrolled
+ though (as opposed to earlier models, which supported only
+ short numeric messages); at the same time as pager functions
+ are integrated into some {PDAs}. If this trend continues, the
+ distinction between {PDAs} and high-end {pagers} will
+ disappear.
+
+ {Short Message Service} allows a mobile phone to display a
+ message, just like an alphanumeric pager.
+
+ 2. <tool> A program for viewing a {text file} a screenful at a
+ time via a text {terminal}, as opposed to scrolling through it
+ in a {GUI} window, or {cat}ting it all at once to the
+ terminal.
+
+ The best known pagers are {more}, {less}, pg and list.com.
+
+ (1997-09-11)
+
+paging
+
+ <operating system> A technique for increasing the memory space
+ available by moving infrequently-used parts of a program's
+ {working memory} from {RAM} to a secondary storage medium,
+ usually {hard {disk}. The unit of transfer is called a page.
+
+ A {memory management unit} (MMU) monitors accesses to memory
+ and splits each address into a page number (the most
+ significant bits) and an offset within that page (the lower
+ bits). It then looks up the page number in its page table.
+ The page may be marked as paged in or paged out. If it is
+ paged in then the memory access can proceed after translating
+ the {virtual address} to a {physical address}. If the
+ requested page is paged out then space must be made for it by
+ paging out some other page, i.e. copying it to disk. The
+ requested page is then located on the area of the disk
+ allocated for "{swap space}" and is read back into {RAM}. The
+ page table is updated to indicate that the page is paged in
+ and its physical address recorded.
+
+ The MMU also records whether a page has been modified since it
+ was last paged in. If it has not been modified then there is
+ no need to copy it back to disk and the space can be reused
+ immediately.
+
+ Paging allows the total memory requirements of all running
+ tasks (possibly just one) to exceed the amount of {physical
+ memory}, whereas {swapping} simply allows multiple processes
+ to run concurrently, so long as each process on its own fits
+ within {physical memory}.
+
+ (1996-11-22)
+
+PaiLisp
+
+ <language> A {parallel} {Lisp} built on {Scheme} in 1986.
+
+ ["A Parallel Lisp Language PaiLisp and its Kernel
+ Specification", T. Ito et al, in Parallel Lisp: Languages and
+ Systems, T. Ito et al eds, LNCS 441, Springer 1989].
+
+ (1995-01-30)
+
+pain in the net
+
+ {flamer}
+
+Paintbrush
+
+ <graphics, tool> A {Microsoft Windows} tool for creating
+ {bitmap} graphics.
+
+ (1996-08-26)
+
+PAISley
+
+ An operational specification language from {Bell Labs}.
+
+ ["An Operational Approach to Requirements Specification for
+ Embedded Systems", P. Zave, IEEE Trans Soft Eng
+ SE-8(3):250-269 (May 1982)].
+
+ (1995-01-30)
+
+Pajek
+
+ <mathematics> A {program} for analysing and visualising large
+ networks. "Pajek" is Slovene for spider. The program runs on
+ {Windows} and is free for noncommercial use. Pajek is developed
+ by Vladimir Batagelj and Andrej Mrvar with contributions from
+ Matjaž Zaveršnik.
+
+ {Pajek home (http://pajek.imfm.si/)}.
+
+ (2014-04-24)
+
+PAL
+
+ 1. <language> {Paradox Application Language}.
+
+ 2. For the {AVANCE} distributed {persistent} {operating
+ system}.
+
+ ["PAL Reference Manual", M. Ahlsen et al, SYSLAB WP-125,
+ Stockholm 1987].
+
+ ["AVANCE: An Object Management System", A. Bjornerstedt et al,
+ SIGPLAN Notices 23(11):206-221 (OOPSLA '88) (Nov 1988)].
+
+ [What is it?]
+
+ 3. <language> An {object-oriented} {Prolog}-like language.
+
+ ["Inheritance Hierarchy Mechanism in Prolog", K. Akama, Proc
+ Logic Prog '86, LNCS 264, Springer 1986, pp. 12-21].
+
+ 4. <language> {PDP Assembly Language}.
+
+ 5. <language> {Pedagogic Algorithmic Language}.
+
+ 6. <hardware, integrated circuit> {Programmable Array Logic}.
+
+ 7. <television> {phase alternating line}.
+
+ (2001-04-02)
+
+Palace
+
+ <virtual reality, chat> A proprietary multi-user {virtual
+ reality}-like {talk} system.
+
+ The Palace is distinguished from most other VR-like systems in
+ that it is only two-dimensional rather than three; rooms,
+ {avatars}, and "props" are made up of relatively small 2D
+ {bitmap} images.
+
+ Palace is a crude {hack}, or lightweight, depending on
+ your point of view.
+
+ {(http://thepalace.com/)}.
+
+ (1997-09-14)
+
+palette
+
+ {colour palette}
+
+palmtop
+
+ <computer> (Or "pocket computer", "Hand-held Personal
+ Computer", H/PC) A small general-purpose, programmable,
+ battery-powered computer cabable of handling both numbers and
+ text (in contrast to most {pocket calculators}) which can be
+ operated comfortably while held in one hand. A palmtop is
+ usually loaded with an {operating system} such as {Windows
+ CE}. Data can be transferred between the palmtop and a
+ desktop {PC}.
+
+ A palmtop is very similar to a {Personal Digital Assistant}
+ though a palmptop may have a larger keyboard and more {RAM}
+ and is possibly more general purpose in concept, if not in
+ practise.
+
+ The {Psion Organiser} is one of the best known examples. [Was
+ it the first?]
+
+ (1998-04-19)
+
+Palo Alto Research Center
+
+ {XEROX PARC}
+
+Palo Alto Research Centre
+
+ {XEROX PARC}
+
+PAM
+
+ {Pluggable Authentication Module}
+
+Pam
+
+ <language> A {toy} {ALGOL}-like language used in "Formal
+ Specification of Programming Languages: A Panoramic Primer",
+ F.G. Pagan, P-H 1981.
+
+ (1996-12-23)
+
+Pandora
+
+ <language> {Parlog} extended to allow {don't-know
+ nondeterminism}.
+
+ ["Pandora: Non-Deterministic Parallel Logic Programming",
+ R. Bahgat et al, Proc 6th Intl Conf Logic Programming, MIT
+ Press 1989 pp. 471-486].
+
+ (1995-04-27)
+
+panic
+
+ 1. <operating system> What {Unix} does when a critical
+ internal consistency checks fails in such a way that Unix
+ cannot continue. The {kernel} attempts to print a short
+ message on the {console} and write an image of memory into the
+ {swap area} on disk. This can be analysed later using {adb}.
+ The kernel will then either wait in a {tight loop} until the
+ machine is rebooted or will initiate an automatic {reboot}.
+
+ {Unix manual page}: panic(8).
+
+ 2. Action taken by software which discovers some fatal problem
+ which prevents it from continuing to run.
+
+ (1995-03-01)
+
+PANON
+
+ A family of pattern-directed string processing languages based
+ on {generalised Markov algorithms}.
+
+ PANON-1 is based on {simple generalised Markov algorithms} and
+ PANON-2 on {conditional functional generalised Markov
+ algorithms}.
+
+ ["String Processing Languages and Generalized Markov
+ Algorithms", A. C. Forino, Proc IFIP Working Conf on Symb
+ Manip Languages, pp.141-206, Amsterdam 1968].
+
+PANS
+
+ {Pretty Amazing New Stuff}.
+
+Pansophic
+
+ A US Software Engineering company.
+
+Pantone
+
+ <graphics> A set of standard colours for printing, each of
+ which is specified by a single number. You can buy a Pantone
+ swatch book containing samples of each colour. Some computer
+ graphics software allows colours to be specified as Pantone
+ numbers. Even though a computer {monitor} can only show an
+ approximation to some of the colours, the software can output
+ a {colour separation} for each different Pantone colour,
+ enabling a print shop to exactly reproduce the original
+ desired colour.
+
+ (1996-03-23)
+
+PAP
+
+ 1. <networking, protocol, security> {Password Authentication
+ Protocol}.
+
+ 2. <networking, protocol, printer> {Printer Access Protocol}.
+
+ (1996-03-23)
+
+Paper Feed Control Character
+
+ (PFCC) An obscure mechanism used in Fortran run-time systems
+ whereby the first character of a line of output to a
+ line-printer caused various actions after the line was
+ printed:
+
+ space return newline
+ 0 return newline return newline
+ 1 form-feed
+ + return
+
+papermail
+
+ {snail mail}
+
+paper-net
+
+ {snail mail}
+
+paper tape
+
+ <hardware, history> Punched paper tape. An early
+ {input/output} and storage medium borrowed from {telegraph}
+ and {teletype} systems.
+
+ Data entered at the keyboard of the teletype could be directed
+ to a perforator or punch which punched a pattern of holes
+ across the width of a paper tape to represent the characters
+ typed. The paper tape could be read by a tape reader feeding
+ the computer. Computer output could be similarly punched onto
+ tape and printed off-line.
+
+ As well as storage of the program and data, use of paper tape
+ enabled {batch processing}.
+
+ The first units had five data hole positions plus a sprocket hole
+ (for the driving wheel) across the width of the tape. These used
+ commercial telegraph code ({ITA2} also known as {Murray}), {Baudot
+ code} or proprietary codes such as {Elliott} which were more
+ programmer-friendly. Later systems had eight data holes and used
+ {ASCII} coding.
+
+ (2003-12-02)
+
+paraconsistent probability
+
+ <logic> A notion introduced by Florentin Smarandache: The
+ probability (T, I, F) that an event occurs is calculated from
+ different sources which may be contradictory or may overlap
+ information; here T, I, F are real subsets representing the
+ truth, indeterminacy, and falsity percentages respectively,
+ and n_sup = sup(T)+sup(I)+sup(F) > 100.
+
+ ["Neutrosophy / Neutrosophic probability, set, and logic",
+ F. Smarandache, American Research Press, 1998].
+
+ See {neutrosophic probability}
+
+ (2001-01-20)
+
+PARADE
+
+ PARallel Applicative Database Engine. A project at Glasgow
+ University to construct a transaction-processor in the
+ parallel {functional programming} language {Haskell} to run on
+ an {ICL} {EDS+} database machine.
+
+PARADIGM PLUS
+
+ A configurable {object-oriented} {CASE} tool from {Proto
+ Soft}.
+
+Paradigms of AI Programming
+
+ A book by Peter Norvig with {Scheme} and {Prolog}
+ {interpreters} and {compilers} in {Common Lisp}.
+
+ {(ftp://Unix.sri.com/pub/norvig/)}.
+
+ ["Paradigms of AI Programming", Peter Norvig].
+
+Paradise
+
+ Paradise is a subsystem (a set of packages) developed to
+ implement inter-processes, inter-tasks and inter-machine
+ communication for {Ada} programs under {Unix}. This subsystem
+ gives the user full access to files, {pipes}, {sockets} (both
+ Unix and {Internet}) and {pseudo-devices}.
+
+ Paradise has been ported to {Sun}, {DEC}, {Sony MIPS},
+ {Verdex} compiler, DEC compiler, {Alsys}/{Systeam} compiler.
+
+ {Version 2.0 of the library
+ (ftp://cnam.cnam.fr/pub/Ada/Paradise)}. E-mail:
+ <paradise-info@cnam.cnam.fr>.
+
+ (1992-09-30)
+
+Paradox
+
+ <database> A {relational database} for {Microsoft Windows},
+ originally from {Borland}.
+
+ Paradox 5 ran on {Microsoft Windows} [version?] and provided a
+ graphical environment, a debugger, a {data modelling} tool,
+ and many "ObjectPAL" commands.
+
+ Paradox 7 ran under {Windows 95} and {Windows NT}.
+
+ Latest version: Paradox 9, as of 2000-02-10 (a {Corel}
+ product).
+
+ {(http://corel.com/paradox9/index.htm)}.
+
+ [Update?]
+
+ (1996-05-27)
+
+paradox
+
+ <logic> An apparently sound argument leading to a
+ {contradiction}.
+
+ Some famous examples are {Russell's paradox} and the {liar
+ paradox}. Most paradoxes stem from some kind of
+ {self-reference}.
+
+ {Smarandache Linguistic Paradox
+ (http://gallup.unm.edu/~smarandache/Paradox.htm)}.
+
+ (1999-11-05)
+
+Paradox Application Language
+
+ (PAL) The programming language for {Paradox}, {Borland}'s
+ {relational database}.
+
+ (1995-01-26)
+
+Paragon
+
+ Mark Sherman. IEEE Software (Nov 1991).
+
+Paralation
+
+ PARALlel reLATION. Sabot, MIT 1987. A framework for parallel
+ programming. A "field" is an array of objects, placed at
+ different sites. A paralation is a group of fields, defining
+ nearness between field elements. Operations can be performed
+ in parallel on every site of a paralation.
+
+ ["The Paralation Model: Architecture Independent Programming",
+ G.W. Sabot <gary@think.com>, MIT Press 1988].
+
+Paralation C
+
+ Paralation embedded in C. Under development.
+
+Paralation LISP
+
+ Embeds the paralation model in Common LISP. Available
+ from MIT Press, (800)356-0343.
+
+ParAlfl
+
+ Hudak, Yale. Parallel functional language, a superset of
+ Alfl. Used by the Alfalfa system on Intel iPSC and Encore
+ Multimax.
+
+ ["Para-Functional Programming", P. Hudak, Computer 19(8):60-70
+ (Aug 1986)].
+
+ ["Alfalfa: Distributed Graph Reduction on a Hypercube
+ Multiprocessor", B. Goldberg & P. Hudak, TR, Yale U, Nov
+ 1986].
+
+Parallaxis
+
+ <language> A {procedural} programming language developed by
+ Thomas Braeunl <braunl@ee.uwa.edu.au> at the {University of
+ Stuttgart}. It is based on {Modula-2}, but extended for {data
+ parallel} ({SIMD}) programming. The main approach for machine
+ independent parallel programming is to include a description
+ of the virtual parallel machine with each parallel
+ {algorithm}.
+
+ There is a simulator and {X Window System}-based profiler for
+ {workstations}, {Macintosh}, and {IBM PC}.
+
+ Version 2.0 runs on {MP-1}, {CM-2}, {Sun-3}, {Sun-4},
+ {DECstation}, {HP 700}, {RS/6000}.
+
+ {(http://ee.uwa.edu.au/~braunl/parallaxis/)}.
+
+ ["User Manual for Parallaxis Version 2.0", T. Braunl, U
+ Stuttgart].
+
+ (2000-05-31)
+
+parallel
+
+ {parallel processing}
+
+Parallel Advanced Technology Attachment
+
+ <storage, standard> (PATA, Parallel ATA) A back-formation
+ introduced around 2003 to distinguish the original {Advanced
+ Technology Attachment} (ATA) standards from the new {Serial
+ Advanced Technology Attachment} (Serial ATA, SATA).
+
+ (2010-02-20)
+
+Parallel ATA
+
+ {Parallel Advanced Technology Attachment}
+
+Parallel C
+
+ 1. <language, parallel> Never implemented, but influenced the
+ design of {C*}. [Details?]
+
+ 2. {C} for the {transputer} by {3L}.
+
+ 3. (PC) Extensions to {C} developed at the {University of
+ Houston} providing a {shared memory} {SIMD} model on {message
+ passing} computers.
+
+ {(ftp://karazm.math.uh.edu/pub/Parallel/Tools/pc.1.1.1.tar.Z)}.
+
+ E-mail: Ridgway Scott <scott@uh.edu>.
+
+ (1995-03-21)
+
+parallel computer
+
+ {parallel processor}
+
+parallel computing
+
+ {parallel processing}
+
+Parallel FORTH
+
+ {Forth} For the {MPP}.
+
+Parallel Fortran
+
+ <language> (Pfortran) Extensions to {Fortran} by Ridgway Scott
+ <scott@uh.edu> of Houston University. Pfortran provides a
+ {shared memory} {SIMD} model on {message passing} computers.
+
+ It was under development in 1994.
+
+ ["Pfortran: A Parallel Dialect of Fortran", L.R. Scott,
+ Fortran Forum 11(3):20-31, Sep 1992].
+
+ (1994-11-08)
+
+Parallel Haskell
+
+ <language, parallel> (pH) A parallel variant of {Haskell}
+ incorporating ideas from {Id} and {Sisal}. pH is under
+ development.
+
+ Mailing list: pH@abp.lcs.mit.edu.
+
+ (1995-03-31)
+
+parallelism
+
+ 1. {parallel processing}.
+
+ 2. <parallel> The maximum number of independent subtasks in a
+ given task at a given point in its execution. E.g. in
+ computing the expression
+
+ (a + b) *
+
+ (c + d) the expressions a, b, c and d can all be calculated in
+ parallel giving a degree of parallelism of (at least) four.
+ Once they have been evaluated then the expressions a + b and c
+ + d can be calculated as two independent parallel processes.
+
+ The {Bernstein condition} states that processes P and Q can be
+ executed in parallel (or in either sequential order) only if:
+
+ (i) there is no overlap between the inputs of P and the
+ outputs of Q and vice versa and
+
+ (ii) there is no overlap between the outputs of P, the outputs
+ of Q and the inputs of any other task.
+
+ If process P outputs value v which process Q reads then P must
+ be executed before Q. If both processes write to some
+ variable then its final value will depend on their execution
+ order so they cannot be executed in parallel if any other
+ process depends on that variable's value.
+
+ (1995-05-07)
+
+Parallel Pascal
+
+ <language> A {data-parallel} language, similar to {Actus} and
+ {Glypnir}.
+
+ ["Parallel Pascal: An Extended Pascal for Parallel Computers",
+ A. Reeves, J Parallel Dist Computing 1:64-80 (1984)].
+
+ (1995-05-07)
+
+parallel port
+
+ <hardware> An interface from a computer system where data is
+ transferred in or out in parallel, that is, on more than one
+ wire. A parallel port carries one {bit} on each wire thus
+ multiplying the transfer rate obtainable over a single wire.
+ There will usually be some control signals on the port as well
+ to say when data is ready to be sent or received.
+
+ The commonest kind of parallel port is a {printer port}, e.g. a
+ {Centronics} port which transfers eight bits at a time. Disks
+ are also connected via special parallel ports, e.g. {SCSI} or
+ {IDE}.
+
+ (1995-01-24)
+
+Parallel Presence Detect
+
+ {presence detect}
+
+parallel processing
+
+ <parallel> (Or "multiprocessing") The simultaneous use of more
+ than one computer to solve a problem. There are many
+ different kinds of parallel computer (or "parallel
+ processor"). They are distinguished by the kind of
+ interconnection between processors (known as "processing
+ elements" or PEs) and between processors and memory. {Flynn's
+ taxonomy} also classifies parallel (and serial) computers
+ according to whether all processors execute the same
+ instructions at the same time ("{single instruction/multiple
+ data}" - SIMD) or each processor executes different
+ instructions ("{multiple instruction/multiple data}" - MIMD).
+
+ The processors may either communicate in order to be able to
+ cooperate in solving a problem or they may run completely
+ independently, possibly under the control of another processor
+ which distributes work to the others and collects results from
+ them (a "{processor farm}"). The difficulty of cooperative
+ problem solving is aptly demonstrated by the following dubious
+ reasoning:
+
+ If it takes one man one minute to dig a post-hole
+ then sixty men can dig it in one second.
+
+ {Amdahl's Law} states this more formally.
+
+ Processors communicate via some kind of network or bus or a
+ combination of both. Memory may be either {shared memory}
+ (all processors have equal access to all memory) or private
+ (each processor has its own memory - "{distributed memory}")
+ or a combination of both.
+
+ Many different software systems have been designed for
+ programming parallel computers, both at the {operating system}
+ and programming language level. These systems must provide
+ mechanisms for partitioning the overall problem into separate
+ tasks and allocating tasks to processors. Such mechanisms may
+ provide either {implicit parallelism} - the system (the
+ {compiler} or some other program) partitions the problem and
+ allocates tasks to processors automatically or {explicit
+ parallelism} where the programmer must annotate his program to
+ show how it is to be partitioned. It is also usual to provide
+ synchronisation primitives such as {semaphores} and {monitors}
+ to allow processes to share resources without conflict.
+
+ {Load balancing} attempts to keep all processors busy by
+ allocating new tasks, or by moving existing tasks between
+ processors, according to some {algorithm}.
+
+ Communication between tasks may be either via {shared memory}
+ or {message passing}. Either may be implemented in terms of
+ the other and in fact, at the lowest level, shared memory uses
+ message passing since the address and data signals which flow
+ between processor and memory may be considered as messages.
+
+ The terms "parallel processing" and "multiprocessing" imply
+ multiple processors working on one task whereas "{concurrent
+ processing}" and "{multitasking}" imply a single processor
+ sharing its time between several tasks.
+
+ See also {cellular automaton},{symmetric multi-processing}.
+
+ {Usenet} newsgroup: {news:comp.parallel}.
+
+ {Institutions (http://ccsf.caltech.edu/other_sites.html)},
+ {research groups
+ (http://cs.cmu.edu/~scandal/research-groups.html)}.
+
+ (2004-11-07)
+
+parallel processor
+
+ <parallel> A computer with more than one {central processing
+ unit}, used for {parallel processing}.
+
+ (1996-04-23)
+
+parallel random-access machine
+
+ <parallel> (PRAM) An idealised {parallel processor} consisting
+ of P processors, unbounded {shared memory}, and a common
+ {clock}. Each processor is a random-access machine (RAM)
+ consisting of R {registers}, a {program counter}, and a
+ read-only signature register. Each RAM has an identical
+ program, but the RAMs can branch to different parts of the
+ program. The RAMs execute the program synchronously one
+ instruction in one clock cycle.
+
+ See also {pm2}.
+
+ (1997-06-04)
+
+parallel reduction
+
+ A form of {applicative order reduction} in which all {redex}es
+ in an expression are reduced simultaneously. Variants include
+ {parallel outermost reduction} and {lenient reduction}. See
+ {normal order reduction}.
+
+Parallel Server Option
+
+ {Oracle Parallel Server}
+
+Parallel SML
+
+ ["Parallel SML: A Functional Language and its Implementation
+ in Dactl", Kevin Hammond, Pitman Press 1990].
+
+Parallel Sysplex
+
+ <operating system> A {Sysplex} that uses one or more {coupling
+ facilities}.
+
+ {(http://s390.ibm.com/products/pso/psohp.html)}.
+
+ (1996-11-21)
+
+Parallel Virtual Machine
+
+ <parallel, networking, tool> (PVM) 1. A {software} system
+ designed to allow a network of {heterogeneous} machines to be
+ used as a single {distributed} {parallel processor}.
+
+ PVM was developed by the {University of Tennessee}, The {Oak
+ Ridge National Laboratory} and the {Emory University}.
+
+ {(http://epm.ornl.gov/pvm/)}.
+
+ {Usenet} newsgroup: {news:comp.parallel.pvm}.
+
+ 2. The {intermediate language} used by the {Gambit} compiler for
+ {Scheme}.
+
+ [And Multilisp?]
+
+ (1995-01-30)
+
+param
+
+ {formal argument}
+
+parameter
+
+ {formal argument}
+
+parameter RAM
+
+ (PRAM) A small memory in a {Macintosh} with a battery power
+ supply which stores system parameters (desktop pattern,
+ selectable memory configuration, etc.) when the computer is
+ turned off.
+
+ (1995-10-08)
+
+parametric polymorphism
+
+ Polymorphism was first identified by {Christopher Strachey} in
+ 1967 and developed by Hindley and Milner.
+
+ For example we could specify that the argument of the "head"
+ {function} was a list without specifying a type for the elements
+ of the list. In {Haskell} we would write:
+
+ head :: [a] -> a
+
+ meaning head has type function from "list of a" to "a" where "a"
+ is a {type variable}). This is known as parametric polymorphism.
+ Polymorphic typing allows strong type checking as well as generic
+ functions. {ML} in 1976 was the first language with polymorphic
+ typing.
+
+ See also {generic type variable}.
+
+ (2014-01-05)
+
+paraML
+
+ An extension of {Standard ML} which supports {coarse-grained
+ parallelism}. Peter Bailey, while at the Edinburgh Parallel
+ Computing Centre at {University of Edinburgh}, has implemented of
+ Murray Cole's original four {skeletons} in paraML.
+
+ See also {Skel-ML}.
+
+paranoid programming
+
+ <programming> A programming style that tries to prepare for
+ the worst external conditions, including incorrect input,
+ resource limitations, hardware and software failure and even
+ {can't happen} errors, to the fullest possible extent. While
+ some believe in the motto "professional programming is
+ paranoid programming", the expression usually has the
+ connotation that the efforts are unnecessary or too costly
+ ("Maybe this code is just paranoid programming, but I think it
+ is necessary to avoid a possible overflow condition".)
+
+ (2001-01-27)
+
+ParaSoft Corp
+
+ Distributors of the {message passing} system {Express}.
+
+ {(ftp://ftp.parasoft.com/)}. Telephone: +1 (818) 792-9941.
+ E-mail: <support@parasoft.com>.
+
+ (1994-10-19)
+
+Parasol
+
+ Parallel Systems Object Language.
+
+ An {object-oriented} language which supports network and
+ parallel computing. It has {modules} and {exceptions}.
+
+ ["The Parasol Programming Language", R. Jervis
+ <hjervis!rbj@uunet.uu.net>, Dr Dobbs J, Oct 1993, pp. 34-41].
+
+ (1995-01-26)
+
+PARC
+
+ {XEROX PARC}
+
+ParcPlace Systems
+
+ <company> A company spun-off from {Xerox PARC} that developed
+ the original version of {VisualWorks}.
+
+ (2002-04-15)
+
+parent
+
+ <mathematics, data> The {ancestor} {node} in a {tree} that
+ points to the current node (one of its child nodes).
+
+ (2005-09-15)
+
+parentheses
+
+ See {left parenthesis}, {right parenthesis}.
+
+ (1997-12-03)
+
+parent message
+
+ <messaging> What a {followup} follows up.
+
+ [{Jargon File}]
+
+ (1997-12-03)
+
+parent process
+
+ <operating system> The {Unix} {process} that created one or
+ more other processes.
+
+ Every process except process 0 is created when another process
+ executes the {fork} {system call}. The process that invoked
+ fork is the parent process, and the newly created process is
+ the {child process}. Every process has one parent process,
+ but can have many child processes.
+
+ The {kernel} identifies each process by its {process
+ identifier} (PID). Process 0 is a special process that is
+ created when the system boots; after forking a child process
+ (process 1), process 0 becomes the {swapper} process. Process
+ 1, known as {init}, is the ancestor of every other process in
+ the system and enjoys a special relationship with them.
+
+ (1997-12-03)
+
+Pari
+
+ <mathematics, tool> A system for {symbolic mathematics},
+ especially {number theory}.
+
+ Version 1.37 for {Unix}, {Macintosh}, {MS-DOS}, {Amiga}.
+
+ E-mail: <pari@alioth.greco-prog.fr>.
+
+ {(ftp://math.ucla.edu/pub/pari)}.
+
+ (1995-04-12)
+
+Paris
+
+ PARallel Instruction Set.
+
+ A low-level language for the {Connection Machine}.
+
+ (1995-02-16)
+
+parity
+
+ <storage, communications> An extra bit added to a {byte} or
+ {word} to reveal errors in storage (in {RAM} or {disk}) or
+ transmission. Even (odd) parity means that the parity bit is
+ set so that there are an even (odd) number of one bits in the
+ word, including the parity bit. A single parity bit can only
+ reveal single bit errors since if an even number of bits are
+ wrong then the parity bit will not change. Moreover, it is
+ not possible to tell which bit is wrong, as it is with more
+ sophisticated {error detection and correction} systems.
+
+ See also {longitudinal parity}, {checksum}, {cyclic redundancy
+ check}.
+
+ (1996-03-01)
+
+parity bit
+
+ <storage, communications> An extra bit added to a {byte} or
+ {word} to reveal errors.
+
+ See {parity}.
+
+ (1996-03-01)
+
+parity error
+
+ <storage, communications> An error discovered by the inclusion
+ of a {parity} bit.
+
+ (1996-03-01)
+
+Parkinson's Law of Data
+
+ "Data expands to fill the space available for storage"; buying
+ more memory encourages the use of more memory-intensive
+ techniques. It has been observed over the last 10 years that
+ the memory usage of evolving systems tends to double roughly
+ once every 18 months. Fortunately, memory density available
+ for constant dollars also tends to double about once every 12
+ months (see {Moore's Law}); unfortunately, the laws of physics
+ guarantee that the latter cannot continue indefinitely.
+
+ [{Jargon File}]
+
+Park-Miller
+
+ A {pseudorandom} number generation {algorithm} which was
+ discredited by Marsaglia and Steve Sullivanin in the July 1993
+ CACM.
+
+ [CACM Oct 1988].
+
+Parlance
+
+ A {concurrent} language.
+
+ ["Parallel Processing Structures: Languages, Schedules, and
+ Performance Results", P.F. Reynolds, PhD Thesis, UT Austin
+ 1979].
+
+ (1994-12-12)
+
+Parlog
+
+ Clark & Gregory, Imperial College 1983. An {AND-parallel}
+ {Prolog}, with {guards} and {committed choice nondeterminism}
+ ({don't care nondeterminism}). {Shallow backtracking} only.
+
+ Implementations: MacParlog and PC-Parlog from Parallel Logic
+ Programming Ltd., Box 49 Twickenham TW2 5PH, UK.
+
+ See also {SPM}.
+
+ {(ftp://ftp.inria.fr/lang/Parlog.tar.Z)}. E-mail:
+ <parlog@doc.ic.ac.uk>.
+
+ ["Parlog: A Parallel Logic Programming Language", K.L. Clark
+ and S. Gregory, Imperial College, London, May 1983].
+ ("Parlog83", in which the ouput mechanism was assignment).
+
+ ["Parallel Logic Programming in PARLOG, The Language and Its
+ Implementation", S. Gregory, A-W 1987]. ("Parlog86", in which
+ the output mechanism was unification, as in {GHC}). (See
+ {Strand}).
+
+Parlog++
+
+ An object-oriented extension to MacParlog. It combines
+ object-oriented and parallel logic programming, giving the
+ benefits of both paradigms within a single coherent
+ development environment.
+
+ Andrew Davison <ad@cs.mu.oz.au>, then Imperial College now U
+ Melbourne. Object orientation plus parallel logic, built on
+ top of MacParlog.
+
+ "Parlog++: A Parlog Object-Oriented Language", A. Davison,
+ Parlog Group, Imperial College 1988. Sold by PLP Ltd.
+ E-mail: <parlog@doc.ic.ac.uk>.
+
+parm
+
+ /parm/ Further-compressed form of {param}. This term is an
+ {IBM}ism, and written use is almost unknown outside IBM shops;
+ spoken /parm/ is more widely distributed, but the synonym
+ {arg} is favoured among hackers. Compare {var}.
+
+ [{Jargon File}]
+
+PARMACS
+
+ The "Argonne macros" from {Argonne National Laboratory}. A
+ package of {macros} written in {m4} for portable {parallel
+ programming}, using {monitors} on {shared memory} machines,
+ and {message passing} on {distributed memory} machines.
+
+ [E. Lusk et al, "Portable Programs for Parallel Processors",
+ HRW 1987. p4].
+
+ {(ftp://research.att.com/netlib/parmacs)}.
+
+ParMod
+
+ "Parallel Programming with ParMod", S. Eichholz, Proc 1987
+ Intl Conf on Parallel Proc, pp.377-380.
+
+PARS
+
+ {Programmable Airline Reservation System}
+
+parse
+
+ {parser}
+
+PARSEC
+
+ <language> An extensible language with {PL/I}-like {syntax},
+ derived from {PROTEUS}.
+
+ ["PARSEC User's Manual", Bolt Beranek & Newman, Dec 1972].
+
+ (2009-06-26)
+
+parser
+
+ <language> An {algorithm} or program to determine the
+ syntactic structure of ("parse") a {sentence} or string of
+ symbols in some language. A parser normally takes as input a
+ sequence of {tokens} output by a {lexical analyser}. It may
+ produce some kind of {abstract syntax tree} as output. A
+ parser may be produced automatically from a grammar by a
+ {parser generators} such as {yacc}.
+
+ A parser is normally part of some larger program, like a
+ {compiler}, which takes the output of the parser and attempts
+ to extract meaning from it in some way, e.g. translating it
+ into another language.
+
+ (2009-06-26)
+
+parser generator
+
+ A program which takes a formal description of a {grammar}
+ (e.g. in {BNF}) and outputs source code for a parser which will
+ recognise valid strings obeying that grammar and perform
+ associated actions. {Unix}'s {yacc} is a well known example.
+
+parsing
+
+ {parser}
+
+Parsley
+
+ A {Pascal} extension for construction of {parse trees}, by
+ Barber of {Summit Software}. It features {Iterators}.
+
+ ["PARSLEY: A New Compiler-Compiler", in Software Development
+ Tools, Techniques and Alternatives, Arlington VA, Jul 1983,
+ pp.232-241].
+
+ (1995-02-22)
+
+Partial Differential Equation LANguage
+
+ (PDELAN)
+
+ ["An Extension of Fortran Containing Finite Difference
+ Operators", J. Gary et al, Soft Prac & Exp 2(4) (Oct 1972)].
+
+partial equivalence relation
+
+ (PER) A relation R on a set S where R is symmetric (x R y => y
+ R x) and transitive (x R y R z => x R z) and where there may
+ exist elements in S for which the relation is not defined. A
+ PER is an equivalence relation on the subset for which it is
+ defined, i.e. it is also reflexive (x R x).
+
+partial evaluation
+
+ <compiler, algorithm> (Or "specialisation") An {optimisation}
+ technique where the {compiler} evaluates some subexpressions
+ at {compile-time}. For example,
+
+ pow x 0 = 1
+ pow x n = if even n
+ then pxn2 * pxn2
+ else x * pow x (n-1)
+ where pxn2 = pow x (n/2)
+ f x = pow x 5
+
+ Since n is known we can specialise pow in its second argument
+ and unfold the recursive calls:
+
+ pow5 x = x * x4 where x4 = x2 * x2
+ x2 = x * x
+ f x = pow5 x
+
+ pow5 is known as the residual. We could now also unfold pow5
+ giving:
+
+ f x = x * x4 where x4 = x2 * x2
+ x2 = x * x
+
+ It is important that the partial evaluation algorithm should
+ terminate. This is not guaranteed in the presence of
+ recursive function definitions. For example, if partial
+ evaluation were applied to the right hand side of the second
+ clause for pow above, it would never terminate because the
+ value of n is not known.
+
+ Partial evaluation might change the termination properties of
+ the program if, for example, the expression (x * 0) was
+ reduced to 0 it would terminate even if x (and thus x * 0) did
+ not.
+
+ It may be necessary to reorder an expression to partially
+ evaluate it, e.g.
+
+ f x y = (x + y) + 1
+ g z = f 3 z
+
+ If we rewrite f:
+
+ f x y = (x + 1) + y
+
+ then the expression x+1 becomes a constant for the function g
+ and we can say
+
+ g z = f 3 z = (3 + 1) + z = 4 + z
+
+ Partial evaluation of {built-in functions} applied to constant
+ arguments is known as {constant folding}.
+
+ See also {full laziness}.
+
+ (1999-05-25)
+
+partial function
+
+ A function which is not defined for all arguments of its input
+ type. E.g.
+
+ f(x) = 1/x if x /= 0.
+
+ The opposite of a {total function}. In {denotational
+ semantics}, a partial function
+
+ f : D -> C
+
+ may be represented as a total function
+
+ ft : D' -> lift(C)
+
+ where D' is a superset of D and
+
+ ft x = f x if x in D
+ ft x = bottom otherwise
+
+ where lift(C) = C U {bottom}. Bottom ({LaTeX} {\perp})
+ denotes "undefined".
+
+ (1995-02-03)
+
+partial key
+
+ <database> A {key} which identifies a subset of a set of
+ information items (e.g. database "{records}"), and which could
+ narrow the subset to one item if other partial key(s) were
+ combined with it.
+
+ (1997-04-26)
+
+partially ordered set
+
+ A {set} with a {partial ordering}.
+
+partial ordering
+
+ A {relation} R is a partial ordering if it is a {pre-order}
+ (i.e. it is {reflexive} (x R x) and {transitive} (x R y R z =>
+ x R z)) and it is also {antisymmetric} (x R y R x => x = y).
+ The ordering is partial, rather than total, because there may
+ exist elements x and y for which neither x R y nor y R x.
+
+ In {domain theory}, if D is a set of values including the
+ undefined value ({bottom}) then we can define a partial
+ ordering relation <= on D by
+
+ x <= y if x = bottom or x = y.
+
+ The constructed set D x D contains the very undefined element,
+ (bottom, bottom) and the not so undefined elements, (x,
+ bottom) and (bottom, x). The partial ordering on D x D is
+ then
+
+ (x1,y1) <= (x2,y2) if x1 <= x2 and y1 <= y2.
+
+ The partial ordering on D -> D is defined by
+
+ f <= g if f(x) <= g(x) for all x in D.
+
+ (No f x is more defined than g x.)
+
+ A {lattice} is a partial ordering where all finite subsets
+ have a {least upper bound} and a {greatest lower bound}.
+
+ ("<=" is written in {LaTeX} as {\sqsubseteq}).
+
+ (1995-02-03)
+
+Partial Response Maximum Likelihood
+
+ <storage> (PRML) A method for converting the weak {analog}
+ signal from the head of a {magnetic disk} drive into a digital
+ signal. PRML attempts to correctly interpret even small
+ changes in the analog signal, whereas {peak detection} relies
+ on fixed thresholds. Because PRML can correctly decode a
+ weaker signal it allows higher density recording.
+
+ For example, PRML would read the magnetic flux density pattern
+ 70, 60, 55, 60, 70 as binary "101", and the same for 45, 40,
+ 30, 40, 45. A peak detector would decode everything above,
+ say, 50 as high, and below 50 as low, so the first pattern
+ would read "111" and the second as "000".
+
+ (1996-12-27)
+
+partition
+
+ 1. <storage> A {logical} section of a {disk}. Each partition
+ normally has its own {file system}. {Unix} tends to treat
+ partitions as though they were separate physical entities.
+
+ 2. <mathematics> A division of a set into subsets so that each
+ of its elements is in exactly one subset.
+
+ (1996-12-09)
+
+partitioned data set
+
+ <file format> (PDS) A {data set} on an {IBM} {mainframe} that
+ contains members, each of which acts like a separate data set.
+ Partitioned data sets are more space-efficient than individual
+ data sets, because they can put more than one data set on a
+ track. They are also used to hold libraries, with one
+ function per member. The syntax for a member is
+ NAME.OF.PDS(MEMBER) although some systems (such as {Phoenix})
+ could use NAME.OF.PDS:MEMBER
+
+ Original PDSes were of fixed size, and needed frequent
+ {compression} to recover space after deleting or changing
+ members. Newer PDS/E Extended PDSes do not have this problem.
+
+ (2003-12-05)
+
+PARTS
+
+ {Digitalk}. {Visual language} for {OS/2} 2.0.
+
+@-party
+
+ <event, history> /at'par-tee/ (Or "@-sign party") An antiquated
+ term for a gathering of {hackers} at a science-fiction convention
+ (especially the annual Worldcon) to which only people who had an
+ {electronic mail address} were admitted.
+
+ The term refers to the {commercial at} symbol, "@", in an e-mail
+ address and dates back to the era when having an e-mail address
+ was a distinguishing characteristic of the select few who worked
+ with computers.
+
+ Compare {boink}.
+
+ [{Jargon File}]
+
+ (2012-11-17)
+
+PARULEL
+
+ "The PARULEL Parallel Rule Language", S. Stolfo et al, Proc
+ 1991 Intl Conf Parallel Proc, CRC Press 1991, pp.36-45.
+
+PASC
+
+ {Perceptional Adaptive Subband Coding}
+
+Pascal
+
+ <language> (After the French mathematician {Blaise Pascal}
+ (1623-1662)) A programming language designed by {Niklaus
+ Wirth} around 1970. Pascal was designed for simplicity and
+ for teaching programming, in reaction to the complexity of
+ {ALGOL 68}. It emphasises {structured programming}
+ constructs, data structures and {strong typing}. Innovations
+ included {enumeration types}, {subranges}, sets, {variant
+ records}, and the {case statement}. Pascal has been extremely
+ influential in programming language design and has a great
+ number of variants and descendants.
+
+ ANSI/IEEE770X3.97-1993 is very similar to {ISO Pascal} but
+ does not include {conformant arrays}.
+
+ ISO 7185-1983(E). Level 0 and Level 1. Changes from Jensen &
+ Wirth's Pascal include name equivalence; names must be bound
+ before they are used; loop index must be local to the
+ procedure; formal procedure parameters must include their
+ arguments; {conformant array schemas}.
+
+ An ALGOL-descended language designed by Niklaus Wirth on the
+ CDC 6600 around 1967--68 as an instructional tool for
+ elementary programming. This language, designed primarily to
+ keep students from shooting themselves in the foot and thus
+ extremely restrictive from a general-purpose-programming point
+ of view, was later promoted as a general-purpose tool and, in
+ fact, became the ancestor of a large family of languages
+ including Modula-2 and {Ada} (see also {bondage-and-discipline
+ language}). The hackish point of view on Pascal was probably
+ best summed up by a devastating (and, in its deadpan way,
+ screamingly funny) 1981 paper by Brian Kernighan (of {K&R}
+ fame) entitled "Why Pascal is Not My Favourite Programming
+ Language", which was turned down by the technical journals but
+ circulated widely via photocopies. It was eventually
+ published in "Comparing and Assessing Programming Languages",
+ edited by Alan Feuer and Narain Gehani (Prentice-Hall, 1984).
+ Part of his discussion is worth repeating here, because its
+ criticisms are still apposite to Pascal itself after ten years
+ of improvement and could also stand as an indictment of many
+ other bondage-and-discipline languages. At the end of a
+ summary of the case against Pascal, Kernighan wrote:
+
+ 9. There is no escape
+
+ This last point is perhaps the most important. The language
+ is inadequate but circumscribed, because there is no way to
+ escape its limitations. There are no casts to disable the
+ type-checking when necessary. There is no way to replace the
+ defective run-time environment with a sensible one, unless one
+ controls the compiler that defines the "standard procedures".
+ The language is closed.
+
+ People who use Pascal for serious programming fall into a
+ fatal trap. Because the language is impotent, it must be
+ extended. But each group extends Pascal in its own direction,
+ to make it look like whatever language they really want.
+ Extensions for {separate compilation}, Fortran-like COMMON,
+ string data types, internal static variables, initialisation,
+ {octal} numbers, bit operators, etc., all add to the utility
+ of the language for one group but destroy its portability to
+ others.
+
+ I feel that it is a mistake to use Pascal for anything much
+ beyond its original target. In its pure form, Pascal is a toy
+ language, suitable for teaching but not for real programming.
+
+ Pascal has since been almost entirely displaced (by {C}) from
+ the niches it had acquired in serious applications and systems
+ programming, but retains some popularity as a hobbyist
+ language in the {MS-DOS} and {Macintosh} worlds.
+
+ See also {Kamin's interpreters}, {p2c}.
+
+ ["The Programming Language Pascal", N. Wirth, Acta Informatica
+ 1:35-63, 1971].
+
+ ["PASCAL User Manual and Report", K. Jensen & N. Wirth,
+ Springer 1975] made significant revisions to the language.
+
+ [BS 6192, "Specification for Computer Programming Language
+ Pascal", {British Standards Institute} 1982].
+
+ [{Jargon File}]
+
+ (1996-06-12)
+
+Pascal-
+
+ Pascal subset used in Brinch Hansen on Pascal Compilers, P.
+ Brinch Hansen, P-H 1985.
+
+ [{Jargon File}]
+
+Pascal-80
+
+ A successor of Platon. Developed at RC International for
+ systems programming. Later it was renamed Real-Time Pascal.
+ "PASCAL80 Report", J. Staunstrup, RC Intl, Denmark Jan 1980.
+
+Pascal+CSP
+
+ "Pascal+CSP, Merging Pascal and CSP in a Parallel Processing
+ Oriented Language", J. Adamo, Proc 3rd Intl Conf Distrib Comp
+ Sys, IEEE 1982, pp.542-547.
+
+Pascal-F
+
+ Pascal extended to include fixed-point arithmetic. E. Nelson,
+ "Pascal-F: Programming Language for Real-Time Automotive
+ Control", IEEE ElectroTechnol. Rev. (USA), 2:39, 1968.
+
+Pascal-FC
+
+ A {Pascal} derived from {Pascal-S} which provides several
+ types of {concurrency}: {semaphores}, {monitors}, both
+ {occam}/{CSP}-style and {Ada}-style {rendezvous}.
+
+ ["The Teaching Language Pascal-FC", G.L. Davies et al,
+ Computer J 33(2):147-154 (Apr 1990)].
+
+ (1994-11-02)
+
+Pascal/L
+
+ A {SIMD} parallel extension of {Pascal}.
+
+ ["Implementation of an Array and Vector Processing Language",
+ C. Fernstrom, Intl Conf Parallel Proc, IEEE, pp.113-127
+ (1982)].
+
+ (1994-11-02)
+
+Pascal-Linda
+
+ Ian Flockhart, U Edinburgh, 1991. Under development.
+
+Pascal-m
+
+ ["Pascal-m: A Language for Loosely Coupled Distributed
+ Systems", S. Abramsky et al in Distributed Computing Systems,
+ Y. Paker et al eds, Academic Press 1986, pp. 163-189].
+
+ (1994-11-02)
+
+Pascal-P
+
+ <language> The variant of {Pascal} used by the {UCSD}
+ {p-system} environment. Pascal-P has extended {string} and
+ {array} operations, {random-access files} and {separate
+ compilation}. It uses {P-code} intermediate code and is
+ available from {Pecan}.
+
+ (1994-11-02)
+
+Pascal P4
+
+ compiler and interpreter
+
+ Version ? 1
+
+ compiler, assembler/interpreter, documentation
+
+ Urs Ammann, Kesav Nori, Christian Jacobi
+
+ {(ftp://ftp.cwi.nl/pascal/)}.
+
+ A compiler for Pascal written in Pascal, producing an
+ intermediate code, with an assembler and interpreter for the
+ code.
+
+ reference: Pascal Implementation, by Steven Pemberton and
+ Martin Daniels, published by Ellis Horwood, Chichester, UK (an
+ imprint of Prentice Hall), ISBN: 0-13-653-0311. Also
+ available in Japanese.
+
+ E-mail: <Steven.Pemberton@cwi.nl>.
+
+ (1993-07-05)
+
+Pascal Plus
+
+ <language> {Pascal} with extensions for {object-oriented}
+ {multiprogramming} by Jim Welsh and D. Bustard of {Queens
+ University, Belfast}, UK. Pascal Plus uses an "envelope"
+ construct for both {packages} and {classes}.
+
+ ["Pascal Plus - Another Language for Modular
+ Multiprogramming", J. Welsh et al, Soft Prac & Exp 9:947
+ (1979)].
+
+ ["Sequential Program Structures", J. Welsh et al, P-H 1984,
+ ISBN 0-13806828-3].
+
+ (1997-12-09)
+
+Pascal/R
+
+ {Pascal} with {relational database} constructs added. The
+ first successful integrated {database} language.
+
+ ["Pascal/R Report", J.W. Schmidt et al, U Hamburg, Fachbereich
+ Informatik, Report 66, Jan 1980].
+
+ (1994-10-19)
+
+Pascal-S
+
+ Simplified Pascal. June, 1975. A strict subset of Pascal,
+ omits scalar types, subranges, sets, files, pointers, packed
+ structures, 'with' and 'goto. Source for a complete Pascal-S
+ compiler is in "Pascal-S: A Subset and Its Implementation",
+ N. Wirth in Pascal - The Language and Its Implementation, by
+ D.W. Barron, Wiley 1979.
+
+ {(ftp://csseq.cs.tamu.edu/mcguire/pascal-s)}.
+
+Pascal-SC
+
+ ESPRIT DIAMOND Project. An extension of Pascal for numerical
+ analysis, with controlled rounding, overloading, dynamic
+ arrays and modules. "PASCAL-SC, A Computer Language for
+ Scientific Computation", G. Bohlender et al, Academic Press
+ 1987.
+
+pasos2
+
+ version: Alpha
+
+ parts: Compiler, run-time library
+
+ author: Willem Jan Withagen <wjw@eb.ele.tue.nl>
+
+ how to get: {(ftp://ftp.eb.ele.tue.nl/pub/src/pascal/pasos2*)}.
+
+ A PASCAL/i386 compiler which generates code for OS/2 and
+ DOS. It uses EMX as DOS extender and GNU/GAS, MASM or TASM as
+ assembler.
+
+ 1993-12-17
+
+Pasqual
+
+ ["Pasqual: A Proposed Generalization of Pascal", R.D. Tennent,
+ TR75-32, Queen's U, Canada, 1975].
+
+PASRO
+
+ <robotics> {PAScal} for RObots.
+
+ ["PASRO - Pascal for Robots", C. Blume et al, Springer 1985].
+
+ (1999-07-19)
+
+PASSIM
+
+ A {simulation} language based on {Pascal}.
+
+ ["PASSIM: A Discrete-Event Simulation Package for Pascal", D.H
+ Uyeno et al, Simulation 35(6):183-190 (Dec 1980)].
+
+passive matrix display
+
+ <hardware> A type of {liquid crystal display} which relies on
+ {persistence} to maintain the state of each display element
+ ({pixel}) between refresh scans. The {resolution} of such
+ displays is limited by the ratio between the time to set a
+ pixel and the time it takes to fade.
+
+ Contrast {active matrix display}.
+
+ (1995-12-09)
+
+passphrase
+
+ <operating system> A string of words and characters that you
+ type in to authenticate yourself. Passphrases differ from
+ passwords only in length. Passwords are usually short - six
+ to ten characters. Passphrases are usually much longer - up
+ to 100 characters or more.
+
+ Modern passphrases were invented by Sigmund N. Porter in 1982.
+
+ Their greater length makes passphrases more secure.
+
+ Phil Zimmermann's popular encryption program {PGP}, for
+ example, requires you to make up a passphrase that you then
+ must enter whenever you sign or decrypt messages.
+
+ {(http://world.std.com/~reinhold/diceware.page.html)}.
+
+ (1996-12-21)
+
+passw0rd
+
+ <security> A common default {password}, often given out by
+ {system administrtors} to new users, the hope being that they
+ will change it immediately.
+
+ (2011-11-22)
+
+password
+
+ <security> An arbitrary string of characters chosen by a user
+ or {system administrator} and used to authenticate the user
+ when he attempts to log on, in order to prevent unauthorised
+ access to his account.
+
+ A favourite activity among unimaginative {computer nerds} and
+ {crackers} is writing programs which attempt to discover
+ passwords by using lists of commonly chosen passwords such as
+ people's names (spelled forward or backward). It is
+ recommended that to defeat such methods passwords use a
+ mixture of upper and lower case letters or digits and avoid
+ proper names and real words. If you have trouble remembering
+ random strings of characters, make up an acronym like
+ "ihGr8trmP" ("I have great trouble remembering my password").
+
+ (1994-10-27)
+
+Password Authentication Protocol
+
+ <networking> (PAP) An {authentication} scheme used by {PPP}
+ servers to validate the identity of the originator of the
+ connection.
+
+ PAP applies a two-way {handshaking} procedure. After the link
+ is established the originator sends an id-password pair to the
+ server. If authentication succeeds the server sends back an
+ acknowledgement; otherwise it either terminates the connection
+ or gives the originator another chance.
+
+ PAP is not a strong authentication method. Passwords are sent
+ over the circuit "in the clear" and there is no protection
+ against playback or repeated "trial and error" attacks. The
+ originator is in total control of the frequency and timing of
+ the attempts. Therefore, any server that can use a stronger
+ authentication method, such as {CHAP}, will offer to negotiate
+ that method prior to PAP. The use of PAP is appropriate,
+ however, if a {plaintext} password must be available to
+ simulate a login at a remote host.
+
+ PAP is defined in {RFC} 1334.
+
+ (1996-03-23)
+
+paste
+
+ {copy and paste}
+
+pastie
+
+ /pay'stee/ An adhesive label designed to be attached to a key
+ on a keyboard to indicate some non-standard character which
+ can be accessed through that key. Pasties are likely to be
+ used in APL environments, where almost every key is associated
+ with a special character. A pastie on the R key, for example,
+ might remind the user that it is used to generate the rho
+ character. The term properly refers to nipple-concealing
+ devices formerly worn by strippers in concession to
+ indecent-exposure laws; compare {tits on a keyboard}.
+
+ [{Jargon File}]
+
+PAT
+
+ 1. <language> {Personalized Array Translator}.
+
+ 2. <networking> {Port Address Translation}.
+
+ (1998-05-09)
+
+PATA
+
+ 1. <storage> {Parallel Advanced Technology Attachment}.
+
+ 2. {Pooling Agreement for Technical Assistance}.
+
+patch
+
+ <software> 1. A temporary addition to a piece of code, usually
+ as a {quick-and-dirty} remedy to an existing {bug} or
+ {misfeature}. A patch may or may not work, and may or may not
+ eventually be incorporated permanently into the program.
+ Distinguished from a {diff} or {mod} by the fact that a patch
+ is generated by more primitive means than the rest of the
+ program; the classical examples are instructions modified by
+ using the front panel switches, and changes made directly to
+ the binary executable of a program originally written in an
+ {HLL}. Compare {one-line fix}.
+
+ 2. To insert a patch into a piece of code.
+
+ 3. [in the Unix world] A {diff}.
+
+ 4. A set of modifications to binaries to be applied by a
+ patching program. {IBM} systems often receive updates to the
+ {operating system} in the form of absolute {hexadecimal}
+ patches. If you have modified your OS, you have to
+ disassemble these back to the {source code}. The patches
+ might later be corrected by other patches on top of them
+ (patches were said to "grow scar tissue"). The result was
+ often a convoluted {patch space} and headaches galore.
+
+ There is a classic story of a {tiger team} penetrating a
+ secure military computer that illustrates the danger inherent
+ in binary patches (or, indeed, any patches that you can't - or
+ don't - inspect and examine before installing). They couldn't
+ find any {trap doors} or any way to penetrate security of
+ IBM's OS, so they made a site visit to an IBM office
+ (remember, these were official military types who were
+ purportedly on official business), swiped some IBM stationery,
+ and created a fake patch. The patch was actually the trapdoor
+ they needed. The patch was distributed at about the right
+ time for an IBM patch, had official stationery and all
+ accompanying documentation, and was dutifully installed. The
+ installation manager very shortly thereafter learned something
+ about proper procedures.
+
+ 5. {Larry Wall}'s "patch" {utility program}, which
+ automatically applies a patch to a set of {source code} or
+ other text files. Patch accepts input in any of the four
+ forms output by the {Unix} {diff} utility. When the files
+ being patched are not identical to those on which the diffs
+ were based, patch uses {heuristics} to determine how to
+ proceed.
+
+ Diff and patch are the standard way of producing and applying
+ updates under {Unix}. Both have been ported to other
+ {operating systems}.
+
+ {Patch Home (http://gnu.org/software/patch/patch.html)}.
+
+ [{Jargon File}]
+
+ (2005-05-16)
+
+patch pumpkin
+
+ {pumpkin}
+
+patch space
+
+ An unused block of bits left in a binary so that it can later
+ be modified by insertion of machine-language instructions
+ there (typically, the patch space is modified to contain new
+ code, and the superseded code is patched to contain a jump or
+ call to the patch space). The widening use of HLLs has made
+ this term rare; it is now primarily historical outside {IBM}
+ shops. See {patch}, {zap}, {hook}.
+
+ [{Jargon File}]
+
+PATCHY
+
+ A {Fortran} {code management} program written at {CERN}.
+
+path
+
+ 1. <file system> {pathname}.
+
+ 2. <networking> A {bang path} or explicitly routed {Internet
+ address}; a node-by-node specification of a link between two
+ machines.
+
+ 3. <operating system> The list of directories the kernel
+ (under {Unix}) or the command interpreter (under {MS-DOS})
+ searches for {executables}. It is stored as part of the
+ {environment} in both operating systems.
+
+ Other, similar constructs abound under Unix; the {C}
+ {preprocessor}, for example, uses such a search path to
+ locate "#include" files.
+
+ [{Jargon File}]
+
+ (1996-11-21)
+
+path coverage testing
+
+ <testing> Testing a program by examining which lines of
+ {executable code} are visited (as in {code coverage testing})
+ and also the ways of getting to each line of code and the
+ subsequent sequence of execution.
+
+ Path coverage testing is the most comprehensive type of
+ testing that a {test suite} can provide. It can find more
+ {bugs}, especially those that are caused by {data coupling}.
+ However, path coverage is hard and usually only used for small
+ and/or critical sections of code.
+
+ (2005-01-25)
+
+pathname
+
+ <file system> (Or "path") The specification of a node (file or
+ directory) in a {hierarchical file system}. The path is usually
+ specified by listing the nodes top-down, separating the
+ directories by the {pathname separator} ("/" in {Unix}, "\" in
+ {MS-DOS}).
+
+ A pathname may be an {absolute pathname} (starting from the {root
+ directory}, "/") or a {relative pathname} (starting from the
+ {current working directory}).
+
+ The part of the pathname of a file after the last separator is
+ called the {basename}.
+
+ (1997-03-10)
+
+pathname separator
+
+ <file system> The character used to separate elements of a
+ {path} or {pathname}. Under {Unix} and {POSIX.1} compliant
+ systems the pathname separator is the (forward) {slash}, in
+ {MS-DOS} {backslash} serves the same purpose. For obvious
+ reasons the no directory or file name can contain this
+ character.
+
+ (1996-11-21)
+
+pathological
+
+ 1. [scientific computation] Used of a data set that is grossly
+ atypical of normal expected input, especially one that exposes
+ a weakness or bug in whatever algorithm one is using. An
+ algorithm that can be broken by pathological inputs may still
+ be useful if such inputs are very unlikely to occur in
+ practice.
+
+ 2. When used of test input, implies that it was purposefully
+ engineered as a worst case. The implication in both senses is
+ that the data is spectacularly ill-conditioned or that someone
+ had to explicitly set out to break the algorithm in order to
+ come up with such a crazy example.
+
+ 3. Also said of an unlikely collection of circumstances. "If
+ the network is down and comes up halfway through the execution
+ of that command by root, the system may just crash." "Yes,
+ but that's a pathological case." Often used to dismiss the
+ case from discussion, with the implication that the
+ consequences are acceptable, since they will happen so
+ infrequently (if at all) that it doesn't seem worth going to
+ the extra trouble to handle that case (see sense 1).
+
+ [{Jargon File}]
+
+Path Pascal
+
+ Parallel extension of Pascal. Processes have shared access to
+ data objects. Constraints on their synchronisation are
+ specified in a path expression.
+
+ ["An Overview of Path Pascal's Design", R.H. Campbell, SIGPLAN
+ Notices 15(9):13-24 (Sep 1980)].
+
+pathspec
+
+ {pathname}
+
+pattern matching
+
+ 1. A function is defined to take arguments of a particular
+ type, form or value. When applying the function to its actual
+ arguments it is necessary to match the type, form or value of
+ the actual arguments against the formal arguments in some
+ definition. For example, the function
+
+ length [] = 0
+ length (x:xs) = 1 + length xs
+
+ uses pattern matching in its argument to distinguish a null
+ list from a non-null one.
+
+ There are well known {algorithm} for translating pattern
+ matching into conditional expressions such as "if" or "case".
+ E.g. the above function could be transformed to
+
+ length l = case l of
+ [] -> 0
+ x:xs -> 1 : length xs
+
+ Pattern matching is usually performed in textual order though
+ there are languages which match more specific patterns before
+ less specific ones.
+
+ 2. Descriptive of a type of language or utility such as {awk}
+ or {Perl} which is suited to searching for strings or patterns
+ in input data, usually using some kind of {regular
+ expression}.
+
+ (1994-11-28)
+
+pattern recognition
+
+ <artificial intelligence, data processing> A branch of
+ {artificial intelligence} concerned with the classification or
+ description of observations.
+
+ Pattern recognition aims to classify {data} (patterns) based
+ on either a priori knowledge or on statistical information
+ extracted from the patterns. The patterns to be classified
+ are usually groups of measurements or observations, defining
+ points in an appropriate multidimensional space.
+
+ A complete pattern recognition system consists of a sensor
+ that gathers the observations to be classified or described; a
+ {feature extraction} mechanism that computes numeric or
+ {symbolic} information from the observations; and a
+ classification or description scheme that does the actual job
+ of classifying or describing observations, relying on the
+ extracted features.
+
+ The classification or description scheme is usually based on
+ the availability of a set of patterns that have already been
+ classified or described. This set of patterns is termed the
+ {training set} and the resulting learning strategy is
+ characterised as {supervised}. Learning can also be
+ {unsupervised}, in the sense that the system is not given an a
+ priori labelling of patterns, instead it establishes the
+ classes itself based on the statistical regularities of the
+ patterns.
+
+ The classification or description scheme usually uses one of
+ the following approaches: statistical (or {decision
+ theoretic}), syntactic (or structural), or neural.
+ Statistical pattern recognition is based on statistical
+ characterisations of patterns, assuming that the patterns are
+ generated by a {probabilistic} system. Structural pattern
+ recognition is based on the structural interrelationships of
+ features. Neural pattern recognition employs the neural
+ computing paradigm that has emerged with {neural networks}.
+
+ (1995-09-22)
+
+PAW
+
+ <tool> {Physics Analysis Workbench}.
+
+PAW++
+
+ An extended version of PAW with a Motif human interface.
+
+payware
+
+ /pay'weir/ Commercial software. Opposite: {shareware}
+ or {freeware}.
+
+ [{Jargon File}]
+
+PB Cache
+
+ {Pipeline Burst Cache}
+
+PBCAK
+
+ {PEBCAK}
+
+PBD
+
+ {Programmer Brain Damage}
+
+PBEM
+
+ {play by electronic mail}
+
+PBKAC
+
+ {PEBCAK}
+
+PBM
+
+ play by mail. See {play by electronic mail}.
+
+PBX
+
+ {Private Branch Exchange}
+
+PC
+
+ 1. <computer> {personal computer}.
+
+ 2. <computer> {IBM PC}.
+
+ 3. <hardware> {program counter}.
+
+ 4. <hardware> {printed circuit}.
+
+ 5. <language> {Parallel C}.
+
+pC++
+
+ {Data parallel} extension to {C++}. {Class}es and {methods}
+ for managing distributed collections.
+
+ E-mail: Dennis Gannon <gannon@cs.indiana.edu>.
+
+ ["Distributed pC++: Basic Ideas for an Object Parallel
+ Language", F. Bodin et al, Proc Supercomput 91, ACM SIGARCH,
+ pp. 273-282].
+
+ (2001-02-22)
+
+PC-1834
+
+ <computer> An {IBM PC}-like computer, using a {K1810 WM 86}
+ {Intel 8086} {clone} from the formerly known Eastern bloc,
+ introduced in 1988.
+
+ (2004-03-24)
+
+PC200
+
+ {Sinclair PC200}
+
+PC-7150
+
+ <hardware> An {IBM PC}-like computer, using a {K1810 WM 86}
+ {Intel 8086} {clone} from the formerly known Eastern bloc,
+ introduced in 1988.
+
+ (2004-03-24)
+
+PCA
+
+ <tool, programming> A dynamic analyser from {DEC} giving
+ information on {run-time} performance and code use.
+
+ (2004-03-24)
+
+P-CAD
+
+ <application> A {CAE} system marketed by {CADAM}, an {IBM}
+ company.
+
+ (2004-03-24)
+
+PC AT
+
+ {IBM PC AT}
+
+PCB
+
+ 1. <hardware> {Power Circuit Breaker}.
+
+ 2. <hardware> {Power Control Box}.
+
+ 3. <hardware> {Printed Circuit Board}.
+
+ 4. {Process Control Block}.
+
+ 5. {Product Configuration Baseline}.
+
+ 6. {Program Control Block}.
+
+ 7. <networking> {Protocol Control Block}.
+
+ ({TCP}).
+
+PC Card
+
+ {Personal Computer Memory Card International Association}
+
+PCCTS
+
+ {Purdue Compiler-Construction Tool Set}
+
+PCF
+
+ A simply typed, {functional language}.
+
+ ["Fully Abstract Translations Between Functional Languages",
+ J. Riecke, 18th POPL, pp. 245-254 (1991)].
+
+ ["LCF Considered as a Programming Language", Theor CS 5:223,
+ 1977].
+
+ (1996-01-18)
+
+PCI
+
+ {Peripheral Component Interconnect}
+
+PCI bus
+
+ {Peripheral Component Interconnect}
+
+PCI Configuration Utility
+
+ <tool> (PCU) A piece of {software} for configuring a specific
+ {PCI} {hardware} device.
+
+ [What software? What hardware?]
+
+ (1998-11-22)
+
+PCI Mezzanine Card
+
+ <hardware> (PMC) A family of low profile {mezzanine} cards for
+ {VMEbus}, {Futurebus+}, desktop computers and other computer
+ systems with logical and electrical layers based on the
+ {Peripheral Component Interconnect} (PCI) specification. PMC
+ is defined in {IEEE} P1386.1 and follows the {Common Mezzanine
+ Card} (CMC) mechanical specification.
+
+ PCI2.0 defines a 4.2 inch by 12.3 inch board that plugs
+ perpendicularly into a {mother board}.
+
+ (1994-10-06)
+
+PCI slot
+
+ <hardware> A connector on {Peripheral Component Interconnect}
+ and the associated physical space occupied by the installed
+ PCI card.
+
+ (1997-12-07)
+
+PC-ism
+
+ /P-C-izm/ A piece of code or coding technique that takes
+ advantage of the unprotected single-tasking environment in
+ {IBM PCs} and the like, e.g. by {busy-wait}ing on a {hardware
+ register}, direct diddling of {screen memory} or using hard
+ timing loops. Compare {ill-behaved}, {vaxism}, {Unixism}.
+
+ [{Jargon File}]
+
+PCjr
+
+ {IBM PCjr}
+
+PCL
+
+ 1. Printer Control Language. A {Document description
+ language} used by {Hewlett-Packard} {Laserjet} printers, a
+ superset of {HP-GL/2}.
+
+ [PCL 5 Printer Language Printer Technical Reference Manual, HP
+ 33459-90903. Versions: PCL 3, PCL 5].
+
+ 2. {Portable CommonLoops}.
+
+ 3. Peripheral Conversion Language. A {Honeywell} command
+ language for {file transfer} between I/O devices on the {CP-V}
+ and {CP-6} {operating systems}.
+
+ 4. ["PCL - A Process Oriented Job Control Language", V. Lesser
+ et al, Proc 1st Intl Conf Distrib Comp Sys, IEEE 1979,
+ pp.315-329].
+
+PCLIPS
+
+ Parallel CLIPS - U Lowell. Concurrent independent CLIPS
+ expert systems. They use 'rassert' (remote assert) to enter
+ facts into each other's database. "PCLIPS: A Distributed
+ Expert System Environment", R. Miller, CLIPS Users Group
+ Conf, Aug 1990. E-mail: <pclips@dragon.ulowell.edu>(?).
+
+PCM
+
+ 1. <data> {Pulse Code Modulation}.
+
+ 2. <company> {Plug Compatible Manufacturer}.
+
+ (2003-06-24)
+
+PCMCIA
+
+ <body, standard> {Personal Computer Memory Card International
+ Association}. (Or People Can't Memorise Computer Industry
+ Acronyms).
+
+PCMIA
+
+ {Personal Computer Manufacturer Interface Adaptor}
+
+PCN
+
+ 1. {Program Composition Notation}.
+
+ 2. <communications> {Personal Communication Network}.
+
+PC-NFS
+
+ {Personal Computer Network File System}
+
+P-code
+
+ <language> The {intermediate language} produced by the
+ {Pascal-P} {compiler}. P-code is the {assembly language} for
+ a hypothetical {stack machine}, the P-machine, said to imitate
+ the {instruction set} of the {Burroughs 6700}.
+
+ The term was first used in the Wirth reference below. {Byte}
+ articles on writing a Pascal Compiler in {Northstar BASIC} (ca
+ Aug 1978) also used the term.
+
+ P-code was initially the intermediate code generated by the P2
+ compiler from ETH Zurich. P-code was later used as the
+ intermediate language in the {UCSD Pascal System}, and in its
+ two main derivatives, {Apple Pascal} and the {UCSD P-system}.
+
+ Variants: P2 P-code, P4 P-code, UCSD P-code, LASL P-code.
+
+ [Algorithms + Data Structures = Programs, N. Wirth, P-H 1976].
+
+ ["A Comparison of PASCAL Intermediate Languages", P.A. Nelson,
+ SIGPLAN Notices 14(8):208-213, Aug 1979].
+
+ (2004-11-08)
+
+PC Pursuit
+
+ A {TELENET} service which enabled people to dial up {BBS}es in
+ other cities for less than normal long-distance rates. PC
+ Pursuit died because TELENET were too mean to upgrade beyond
+ 2400 bits per second.
+
+ (1994-10-17)
+
+PC-RT
+
+ <computer> An incorrect name for the {RT-PC}.
+
+ (1995-04-06)
+
+PCS
+
+ 1. {Personal Communication Services}.
+
+ 2. {PC-Scheme}.
+
+PC-Scheme
+
+ Version 3.03
+
+ compiler, debugger, profiler, editor, libraries
+
+ {(ftp://altdorf.ai.mit.edu/archive/pc-scheme/)}.
+
+ Written at {Texas Instruments}. Runs on {MS-DOS} 286/386 IBM
+ PCs and compatibles. Includes an optimising compiler, an
+ emacs-like editor, inspector, debugger, performance testing,
+ foreign function interface, window system and an
+ object-oriented subsystem. Also supports the dialect used in
+ {Hal Abelson} and {Gerald Sussman}'s {SICP}.
+
+ Conformance: Revised^3 Report, also supports dialect used in
+ SICP.
+
+ restriction: official version is $95, contact <rww@ibuki.com>
+
+ ports: MS-DOS
+
+ See also {PCS/Geneva}.
+
+ (1992-02-23)
+
+PCS/Geneva
+
+ A cleaned-up version of {Texas Instrument}'s {PC Scheme}
+ developed at the {University of Geneva}. The main extensions
+ to PC Scheme are {486} support, {BGI} graphics, {LIM-EMS}
+ pagination support, line editing and {assembly code}-level
+ interfacing.
+
+ Version 4.02PL1.
+
+ E-mail: <schemege@uni2a.unige.ch>.
+
+ (1994-01-11)
+
+PC support
+
+ <job> (Or "PC analyst", end user support) A person who works
+ with {microcomputer} applications including {word processors},
+ {spreadsheets}, {presentation graphics}, {database management
+ systems}, {electronic mail}, and communications. He also
+ evaluates, installs and supports PCs, {Macintoshes}, and
+ associated {peripherals}.
+
+ (2004-03-20)
+
+PC-TALK III
+
+ <communications, tool> An {MS-DOS} communications program by
+ {Andrew Fluegelman}.
+
+ (1997-08-25)
+
+PCTE
+
+ {Portable Common Tool Environment}
+
+PCTE+
+
+ A European NATO specification based on {PCTE} with security
+ enhancements.
+
+PC-TILES
+
+ <language> A {visual programming language}.
+
+ (1997-08-25)
+
+PCU
+
+ {PCI Configuration Utility}
+
+PC-ware
+
+ Pejorative term for software full of {PC-isms} on a machine
+ with a more capable {operating system}.
+
+pcx
+
+ <filename extension> A {filename extension} for {images}
+ created with the {IBM PC} {Paintbrush} tool.
+
+ [Format?]
+
+ (1995-12-10)
+
+PD
+
+ {public domain}
+
+PDA
+
+ {Personal Digital Assistant}
+
+PDC
+
+ {Primary Domain Controller}
+
+PDC Prolog
+
+ Prolog Development Centre Prolog. A {Prolog} evolved from
+ {Turbo Prolog} by the original authors.
+
+PDEL
+
+ Partial Differential Equation Language. A {preprocessor} for
+ {PL/I}.
+
+ ["PDEL - A Language for Partial Differential Equations",
+ A.F. Cardenas, CACM 13(3):184-191 (Mar 1970)].
+
+PDELAN
+
+ {Partial Differential Equation LANguage}
+
+PDES
+
+ {Product Data Exchange using STEP}
+
+PDF
+
+ {Portable Document Format}
+
+PDFTeX
+
+ <tool, TeX> A modification of {TeX} to produce {PDF} output
+ instead of the {canonical} {DVI}.
+
+ {pdftexlib.tar.gz (ftp://ftp.tug.org/pub/tex/pdftexlib.tar.gz)}.
+
+ {Thanh's source of pdfTeX
+ (ftp://ftp.muni.cz/pub/tex/local/cstug/thanh/pdftex/)}.
+
+ {User Manual
+ (http://tug.cs.umb.edu/applications/pdftex/pdftex-s.pdf)}.
+
+ {FAQ
+ (http://tug.cs.umb.edu/applications/pdftex/pdfTeX-FAQ-scr.pdf)}.
+
+ (2000-12-21)
+
+PDH
+
+ {Plesiochronous Digital Hierarchy}
+
+PDIL
+
+ <language> A language developed at Agence d'Informatique,
+ France in the 1970s for description of communication
+ {protocols}. It was part of the {RHIN} project.
+
+ (1995-02-28)
+
+pdksh
+
+ Version 4.9
+
+ interpreter
+
+ Simon J. Gerraty <sjg@zen.void.oz.au>
+
+ comp.sources.misc volume 4
+
+ It is not intended to be the ultimate shell but rather a
+ usable ksh work alike.
+
+ conformance: Almost identical to ksh88, but missing arrays
+
+ E-mail: Simon J Gerraty <sjg@melb.bull.oz.au> (zen.void.oz.au
+ is down)
+
+ ports: Sun, 386bsd, ?
+
+ 1993-10-11
+
+PDL
+
+ 1. {Page Description Language}.
+
+ 2. {Program Design Language}.
+
+ 3. {Push Down List}.
+
+ 4. Dave Lebling, one of the co-authors of {Zork}. His
+ {network address} on the {ITS} machines was at one time
+ <pdl@dms>.
+
+ 5. {Propositional Dynamic Logic}.
+
+ [{Jargon File}]
+
+PDL2
+
+ <language> {Process Design Language 2}.
+
+PDM
+
+ 1. {Product Development Management}.
+
+ 2. {Product Data Management}.
+
+ (1997-02-11)
+
+PDP
+
+ {Programmed Data Processor}
+
+PDP-10
+
+ <computer> Programmed Data Processor model 10.
+
+ The series of {mainframes} from {DEC} that made {time-sharing}
+ real. It looms large in hacker folklore because of its
+ adoption in the mid-1970s by many university computing
+ facilities and research labs, including the {MIT} {AI Lab},
+ {Stanford}, and {CMU}. Some aspects of the {instruction set}
+ (most notably the bit-field instructions) are still considered
+ unsurpassed.
+
+ The PDP-10 was eventually eclipsed by the {VAX} machines
+ (descendants of the {PDP-11}) when DEC recognised that the
+ PDP-10 and VAX product lines were competing with each other
+ and decided to concentrate its software development effort on
+ the more profitable VAX. The machine was finally dropped from
+ DEC's line in 1983, following the failure of the {Jupiter}
+ Project at DEC to build a viable new model. (Some attempts by
+ other companies to market clones came to nothing; see {Foonly}
+ and {Mars}.) This event spelled the doom of {ITS} and the
+ technical cultures that had spawned the original {Jargon
+ File}, but by mid-1991 it had become something of a badge of
+ honourable old-timerhood among hackers to have cut one's teeth
+ on a PDP-10.
+
+ See {TOPS-10}, {AOS}, {BLT}, {DDT}, {DPB}, {EXCH}, {HAKMEM},
+ {JFCL}, {LDB}, {pop}, {push}.
+
+ {news:alt.sys.pdp10}
+
+ [Was the PDP-10 a mini or a mainframe?]
+
+ (2001-01-05)
+
+PDP-11
+
+ Programmed Data Processor model 11.
+
+ A series of {minicomputers} based on an {instruction set}
+ designed by C. Gordon Bell at {DEC} in the early 1970s (late
+ 60s?). The PDP-11 family, which came after, but was not
+ derived from, the {PDP-10}, was the most successful computer
+ of its time until it was itself succeeded by the {VAX}.
+
+ Models included the 11/23 and 11/24 (based on the F11
+ chipset); 11/44, 11/04, 11/34, 11/05, 11/10, 11/15, 11/20,
+ 11/35, 11/40, 11/45, 11/70, 11/60 ({MSI} and {SSI}); LSI-11/2
+ and LSI-11 (LSI-11 chipset). In addition there were the 11/8x
+ (J11 chipset) and SBC-11/21 (T11 chip) and then there was
+ compatibility mode in the early {VAX} processors.
+
+ The {B} and {C} languages were both used initially to
+ implement {Unix} on the PDP-11. The {microprocessor} design
+ tradition owes a heavy debt to the PDP-11 {instruction set}.
+
+ See also {SEX}.
+
+ (1994-12-21)
+
+PDP-20
+
+ The most famous computer that never was. {PDP-10} computers
+ running the {TOPS-10} operating system were labelled
+ "DECsystem-10" as a way of differentiating them from the
+ {PDP-11}. Later on, those systems running {TOPS-20} were
+ labelled "DECSYSTEM-20" (the block capitals being the result
+ of a lawsuit brought against DEC by Singer, which once made a
+ computer called "system-10"), but contrary to popular lore
+ there was never a "PDP-20"; the only difference between a 10
+ and a 20 was the {operating system} and the colour of the
+ paint. Most (but not all) machines sold to run {TOPS-10} were
+ painted "Basil Blue", whereas most TOPS-20 machines were
+ painted "Chinese Red" (often mistakenly called orange).
+
+ [{Jargon File}]
+
+ (1994-12-21)
+
+PDP-6
+
+ <computer> Programmed Data Processor model 6. A computer
+ designed around 1960 with more or less exactly the same
+ hardware architecture as the {PDP-10}. It already had
+ multi-user {time sharing} and {batch processing} and
+ multi-level priority {interrupts}
+
+ (1996-12-21)
+
+PDP-7
+
+ <computer> A minicomputer sold by DEC in 1964. It had a
+ memory cycle time of 1.75 microseconds and add time of 4
+ microseconds. I/O included a keyboard, printer, {paper-tape}
+ and dual transport DECtape drives (type 555).
+
+ DEC provided an "advanced" {Fortran II} {compiler}, a Symbolic
+ {Assembler}, Editor, {DDT} Debugging System, Maintenance
+ routines and a library of arithmetic, utility and programming
+ aids developed on the program-compatible {PDP-4}.
+
+ [DEC sales brochure].
+
+ The PDP-7 was considered reliable enough (when properly
+ programmed) to be used for control of nuclear reactors and
+ such.
+
+ Around 1970 {Ken Thompson} built the {operating system} that
+ became {Unix} on a scavenged {PDP-7} so he could play a
+ descendant of the {SPACEWAR} game.
+
+ (1995-03-10)
+
+PDP Assembly Language
+
+ <language> (PAL) The {assembly language} for the {PDP-8} and
+ {PDP-11}.
+
+ [Description?]
+
+ (1995-01-26)
+
+PDS
+
+ 1. <hardware> {Processor Direct Slot}.
+
+ 2. {partitioned data set}.
+
+PDSA cycle
+
+ Plan, Do, See, Approve (from Japan).
+
+PDS/MaGen
+
+ Problem Descriptor System. A system for generating matrices
+ and reports for mathematical programming and {operations
+ research}.
+
+ ["PDS MaGen User Information Manual", Haverly Systems (Dec
+ 1977)].
+
+ (1994-10-27)
+
+PDU
+
+ {Protocol Data Unit}
+
+PE
+
+ 1. <database> {periodic group}
+
+ 2. <storage> {Phase Encoded}.
+
+ 3. <architecture> {processing element}.
+
+ (1995-10-30)
+
+pe
+
+ <networking> The {country code} for Peru.
+
+ (1999-01-27)
+
+PeaceNet
+
+ One of the {IGC} networks. PeaceNet serves peace and social
+ justice advocates around the world in such areas as human
+ rights, disarmament, and international relations. A number of
+ alternative news services provide a range of information about
+ these and other topics from around the world.
+
+ E-mail: <peacenet@igc.apc.org>. {(ftp://igc.apc.org/)}.
+
+peak envelope power
+
+ <communications> (PEP) The maximum power output by a radio
+ transmitter over one complete RF cycle at any modulation.
+
+ (2008-02-11)
+
+Peano
+
+ {Giuseppe Peano}
+
+Peano arithmetic
+
+ <mathematics> {Giuseppe Peano}'s system for representing {natural
+ numbers} {inductively (induction)} using only two symbols, "0"
+ (zero) and "S" (successor).
+
+ This system could be expressed as a {recursive} data type with the
+ following {Haskell} definition:
+
+ data Peano = Zero | Succ Peano
+
+ The number three, usually written "SSS0", would be Succ (Succ
+ (Succ Zero)). Addition of Peano numbers can be expressed as a
+ simple syntactic transformation:
+
+ plus Zero n = n
+ plus (Succ m) n = Succ (plus m n)
+
+ (1995-03-28)
+
+PEARL
+
+ 1. <language, mathematics> A language for {constructive
+ mathematics} developed by Constable at {Cornell University} in
+ the 1980s.
+
+ 2. <language, real-time> {Process and Experiment Automation
+ Real-Time Language}.
+
+ 3. <language, education> One of five pedagogical languages
+ based on {Markov} {algorithms}, used in "Nonpareil, a Machine
+ Level Machine Independent Language for the Study of
+ Semantics", B. Higman, ULICS Intl Report No ICSI 170, U London
+ (1968). Compare {Brilliant}, {Diamond}, {Nonpareil}, {Ruby}.
+
+ 4. <language> A multilevel language developed by Brian Randell
+ ca 1970 and mentioned in "Machine Oriented Higher Level
+ Languages", W. van der Poel, N-H 1974.
+
+ 5. <language, tool, history> An obsolete term for {Larry
+ Wall}'s {PERL} programming language, which never fell into
+ common usage other than in typographical errors. The missing
+ 'a' remains as an atrophied remnant in the expansion
+ "Practical Extraction and Report Language".
+
+ ["Programming Perl", Larry Wall and Randal L. Schwartz,
+ O'Reilly & Associates, Inc. Sebastopol, CA. ISBN
+ 0-93715-64-1].
+
+ (2000-08-16)
+
+Pebble
+
+ A {polymorphic} language.
+
+ ["A Kernel Language for Abstract Data Types and Modules",
+ R.M. Burstall & B. Lampson, in Semantics of Data Types, LNCS
+ 173, Springer 1984].
+
+ (1995-01-26)
+
+Pebbleman
+
+ {DoD} requirements that led to {APSE}. They were written in
+ Jul 1978 and revised Jan 1979.
+
+ (1995-01-26)
+
+PEBCAK
+
+ <humour> (Or "PEBKAC", "PBCAK", "PBKAC") Tech support
+ shorthand for "Problem (Exists) between Chair and Keyboard".
+
+ An alternative is "PICNIC" - "Problem In Chair, Not In
+ Computer".
+
+ An acronym commonly used by helpdesk technicians to indicate
+ that a problem is due to the user rather than the system.
+
+ See also {UBD}.
+
+ (2012-08-26)
+
+PEBKAC
+
+ {PEBCAK}
+
+PECOS
+
+ A {constraint}-based language, built on the {object-oriented}
+ module of {Le-Lisp}.
+
+ ["Pecos Reference Manual", ILOG, 1990. ILOG, 12 av Raspail,
+ BP 7, F94251 Gentilly, France].
+
+ (1995-01-26)
+
+Pedagogic Algorithmic Language
+
+ ["PAL - A Language for Teaching Programming Linguistics",
+ A. Evans Jr, Proc ACM 23rd Natl Conf, Brandon/Systems Press
+ (1968)].
+
+ (1995-01-26)
+
+PEEK
+
+ The command in most {microcomputer} {BASICs} for reading
+ memory contents (a byte) at an absolute address. POKE is the
+ corresponding command to write a value to an absolute address.
+
+ This is often extended to mean the corresponding constructs in
+ any {High Level Language}.
+
+ Much hacking on small {microcomputers} without {MMUs} consists
+ of "peek"ing around memory, more or less at random, to find
+ the location where the system keeps interesting stuff. Long
+ (and variably accurate) lists of such addresses for various
+ computers circulate (see {interrupt list}). The results of
+ "poke"s at these addresses may be highly useful, mildly
+ amusing, useless but neat, or total {lossage} (see {killer
+ poke}).
+
+ Since a {real operating system} provides useful, higher-level
+ services for the tasks commonly performed with peeks and pokes
+ on micros, and real languages tend not to encourage low-level
+ memory groveling, a question like "How do I do a peek in C?"
+ is diagnostic of the {newbie}. Of course, {operating system}
+ {kernels} often have to do exactly this; a real {C} hacker
+ would unhesitatingly, if unportably, assign an absolute
+ address to a pointer variable and indirect through it.
+
+ [{Jargon File}]
+
+ (1995-01-31)
+
+PEEL
+
+ Used to implement version of {Emacs} on {PRIME} computers.
+
+peephole optimisation
+
+ <compiler> A kind of low-level {code optimisation} that
+ considers only a few adjacent {machine code} instructions at a
+ time and looks for certain combinations which can be replaced
+ with more efficient sequences. E.g.
+
+ ADD R0, #1
+ ADD R0, #1
+
+ (add one to register R0) could be replaced by
+
+ ADD R0, #2
+
+ as long as there were no jumps to the second instruction.
+
+ (2008-11-17)
+
+peephole optimization
+
+ {peephole optimisation}
+
+peer
+
+ <networking> A unit of communications hardware or software
+ that is on the same {protocol layer} of a network as another.
+ A common way of viewing a communications link is as two
+ {protocol stacks}, which are actually connected only at the
+ very lowest (physical) layer, but can be regarded as being
+ connected at each higher layer by virtue of the services
+ provided by the lower layers. Peer-to-peer communication
+ refers to these real or virtual connections between
+ corresponding systems in each layer.
+
+ To give a simple example, when two people talk to each other,
+ the lowest layer is the physical layer which concerns the
+ sound pressure waves travelling from mouth to ear (so mouths
+ and ears are peers) the next layer might be the speech and
+ hearing centres in the people's brains and the top layer their
+ cerebellums or minds. Although, barring telepathy, nothing
+ passes directly between the two minds, there is a peer-to-peer
+ communication between them.
+
+ (2007-03-27)
+
+peer-to-peer
+
+ <networking> 1. The kind of communication found in a system
+ using layered {protocols}. Each software or hardware
+ component can be considered to communicate only with its
+ {peer} in the same layer via the connection provided by the
+ lower layers.
+
+ (1994-12-14)
+
+ 2. A decentralised {file sharing} system like {BitTorrent},
+ {Gnutella} or {Kazaa} where computers that download data also
+ store that data and serve it to other downloaders. This
+ increases the total bandwidth available in proportion to the
+ number of users and so reduces download time. It also
+ improves resilience by providing multiple redundant sources
+ for the same data. This contrasts with {client-server} where
+ all clients download the data from a single server (or
+ {mirror}), sharing its fixed bandwidth.
+
+ Peer-to-peer networks are typically ad-hoc and rely on users
+ sharing the content they have downloaded for the benefit of
+ other users. Users who fail to do this are called "leaches".
+ A "seed" is a node on a peer-to-peer network that is
+ sharing a complete copy of a file, as opposed to other nodes
+ that may only have some of the parts into which the file has
+ been split.
+
+ (2010-02-20)
+
+peer-to-peer network
+
+ {peer-to-peer}
+
+Pegasus
+
+ 1. <networking, product> A product to support {Internet}
+ searches, {electronic mail}, and {Usenet news}.
+
+ [Details? Addesss?]
+
+ (1997-07-14)
+
+ 2. <project> An {open source} project run by {The Open Group}
+ which implements a {Common Information Model} (CIM) Object
+ Manager.
+
+ {Pegasus Home (http://openpegasus.org/)}.
+
+ (2003-06-07)
+
+PEIPA
+
+ {Pilot European Image Processing Archive}
+
+PEM
+
+ {Privacy Enhanced Mail}
+
+PENCIL
+
+ Pictorial ENCodIng Language. On-line system to display line
+ structures. Sammet 1969, 675.
+
+pencil and paper
+
+ An archaic information storage and transmission device that
+ works by depositing smears of graphite on bleached wood pulp.
+ More recent developments in paper-based technology include
+ improved "write-once" update devices which use tiny rolling
+ heads similar to mouse balls to deposit coloured pigment. All
+ these devices require an operator skilled at so-called
+ "handwriting" technique. These technologies are ubiquitous
+ outside hackerdom, but nearly forgotten inside it. Most
+ hackers had terrible handwriting to begin with, and years of
+ keyboarding tend to have encouraged it to degrade further.
+ Perhaps for this reason, hackers deprecate pencil-and-paper
+ technology and often resist using it in any but the most
+ trivial contexts.
+
+ [{Jargon File}]
+
+ (1994-12-06)
+
+penis war
+
+ <jargon, abuse> (Or "Dick Size War", "DSW") Any argument which
+ has degenerated into quantitative boasting of the sort "My
+ [program|bot|etc.] is [faster|meaner|etc.] than yours!".
+ Generally as unconstructive (and with as little emphasis on
+ empirical proof) as men debating who has the biggest penis.
+
+ The term is often used on {IRC}, {news:alt.sysadmin.recovery},
+ and sometimes applied to IRC {botwars}, because of their
+ equally pointless nature.
+
+ (1999-07-14)
+
+Pentium
+
+ <processor> {Intel}'s {superscalar} successor to the {486}.
+ It has two 32-bit 486-type integer {pipelines} with dependency
+ checking. It can execute a maximum of two instructions per
+ cycle. It does pipelined {floating-point} and performs
+ {branch prediction}. It has 16 {kilobytes} of on-chip
+ {cache}, a 64-bit memory interface, 8 32-bit general-purpose
+ {registers} and 8 80-bit {floating-point} registers. It is
+ built from 3.1 million transistors on a 262.4 mm^2 die with
+ ~2.3 million transistors in the core logic. Its {clock rate}
+ is 66MHz, heat dissipation is 16W, integer performance is 64.5
+ {SPECint92}, {floating-point} performance 56.9 {SPECfp92}.
+
+ It is called "Pentium" because it is the fifth in the 80x86
+ line. It would have been called the 80586 had a US court not
+ ruled that you can't trademark a number.
+
+ The successors are the {Pentium Pro} and {Pentium II}.
+
+ The following Pentium variants all belong to "x86 Family 6",
+ as reported by "Microsoft Windows" when identifying the CPU:
+
+ Model Name
+ 1 Pentium Pro
+ 2 ?
+ 3 Pentium II
+ 4 ?
+ 5, 6 Celeron or Pentium II
+ 7 Pentium III
+ 8 Celeron uPGA2 or Mobile Pentium III
+
+ A {floating-point division bug
+ (ftp://ftp.isi.edu/pub/carlton/pentium/FAQ)} was discovered in
+ October 1994.
+
+ [Internal implementation, "Microprocessor Report" newsletter,
+ 1993-03-29, volume 7, number 4].
+
+ [Pentium based computers, PC Magazine, 1994-01-25].
+
+ (2003-09-30)
+
+Pentium 2
+
+ {Pentium II}
+
+Pentium 3
+
+ {Pentium III}
+
+Pentium II
+
+ <processor> {Intel Corporation}'s successor to the {Pentium
+ Pro}.
+
+ The Pentium II can execute all the instructions of all the
+ earlier members of the {Intel 80x86} processor family. There
+ are four versions targetted at different user markets. The
+ {Celeron} is the simplest and cheapest. The standard Pentium
+ II is aimed at mainstream home and business users. The
+ {Pentium II Xeon} is intended for higher performance business
+ {servers}. There is also a mobile version of the Pentium II
+ for use in portable computers.
+
+ All versions of the Pentium II are packaged on a special
+ {daughterboard} that plugs into a card-edge processor slot on
+ the {motherboard}. The daughterboard is enclosed within a
+ rectangular black box called a {Single Edge Contact} (SEC)
+ cartridge. The budget {Celeron} may be sold as a card only
+ without the box. Consumer line Pentium II's require a 242-pin
+ slot called {Slot 1}. The {Xeon} uses a 330-pin slot called
+ Slot 2. Intel refers to Slot 1 and Slot 2 as SEC-242 and
+ SEC-330 in some of their technical documentation. The
+ daughterboard has mounting points for the Pentium II {CPU}
+ itself plus various support chips and {cache} memory chips.
+ All components on the daughterboard are normally permanently
+ soldered in place. Previous generation {Socket 7}
+ motherboards cannot normally be upgraded to accept the Pentium
+ II, so it is necessary to install a new motherboard.
+
+ All Pentium II processors have {Multimedia Extensions} (MMX)
+ and integrated Level One and Level Two cache controllers.
+ Additional features include {Dynamic Execution} and Dual
+ Independent Bus Architecture, with separate 64 bit system and
+ cache busses. Pentium II is a {superscalar} CPU having about
+ 7.5 million {transistors}.
+
+ The first Pentium II's produced were code named {Klamath}.
+ They were manufactured using a 0.35 micron process and
+ supported {clock rates} of 233, 266, 300 and 333 {MHz} at a
+ {bus} speed of 66 MHz. Second generation Pentium II's, code
+ named Deschutes, are made with a 0.25 micron process and
+ support rates of 350, 400 and 450 MHz at a bus speed of 100
+ MHz.
+
+ {(http://intel.com/PentiumII/)}.
+
+ (1998-10-06)
+
+Pentium III
+
+ <processor> The {microprocessor} that was {Intel Corporation}'s
+ successor to the {Pentium II}, introduced in 1999 with a 500 {MHz}
+ {clock rate}. The Pentim III is very similar to the Pentium II in
+ architecture. Its {external bus} can be clocked at 100 or 133
+ {MHz}, it can have up to 512 {KB} of {secondary cache}, and it
+ comes in various packages including {SECC2} and {FC-PGA}.
+
+ The Pentium III has a {P6} {Dynamic Execution}
+ {microarchitecture}, a {multi-transaction system bus}, and {MMX},
+ like the Pentium II. It adds {Dual Independent Bus} (DIB)
+ Architecture, the {Intel Processor Serial Number}, Internet
+ {Streaming SIMD Extensions} and 70 new {instructions}. Some
+ versions also include an {Advanced Transfer Cache} and {Advanced
+ System Buffering}.
+
+ When Intel released a 1.13 {GHz} version of the Pentium III
+ processor using a 0.18 {micron} fabrication process on
+ 2000-07-31, it was the world's highest performance
+ microprocessor for {PC}s.
+
+ {(http://intel.com/PentiumIII)}.
+
+ (2000-10-05)
+
+Pentium II Xeon
+
+ <processor> The successor to {Intel Corporation}'s {Pentium
+ II} processor.
+
+ The Xeon has the same {P6} core as existing {Pentium
+ Pro}/{Pentium II} units, but it supports a 100 {MHz} system
+ {bus} and offers as much as 2 {MB} of {level 2 cache}.
+
+ {(http://intel.com/PentiumII/xeon/home.htm)}.
+
+ (1998-09-09)
+
+Pentium Pro
+
+ <processor> (Known as "P6" during development) {Intel}'s
+ successor to the {Pentium} processor, in development Jan 1995,
+ generally available 1995-11-01. The P6 has an internal
+ {RISC} architecture with a {CISC}-{RISC} translator, 3-way
+ {superscalar} execution, and {out-of order execution} (or
+ "{speculative execution}", which Intel calls "{Dynamic
+ Execution}"). It also features {branch prediction} and
+ {register renaming}, and is superpipelined (14 stages).
+
+ The P6 is made as a two-chip assembly: the first chip is the
+ {CPU} and 16 kilobyte {first-level cache} (5.5 million
+ {transistors}) and the other is a 256 (or 512) kilobyte
+ {second-level cache} (15 million transistors). The first
+ version has a {clock rate} of 133 Mhz and consumes about 20W
+ of power. It is about twice as fast as the 100 MHz Pentium.
+ The original 0.35 micron versions of the Pentium Pro released
+ on 1995-11-01 run at 150 and 166 Mhz for desktop machines and
+ up to 200 Mhz for {servers}. Heat disspation is about 20
+ Watts.
+
+ The Pentium Pro is optimised for 32-bit software and runs
+ 16-bit software slower than the original Pentium. The
+ successor was the {Pentium II}.
+
+ [Performance?]
+
+ (1996-03-01)
+
+peon
+
+ <jargon> A person with no special ({root} or {wheel})
+ privileges on a computer system. "I can't create an account
+ on foovax for you; I'm only a peon there."
+
+ [{Jargon File}]
+
+ (2001-12-23)
+
+PeopleSoft
+
+ <application, company> A company selling {web-based} {ERP}
+ systems. Originally PeopleSoft supplied human resource
+ management systems, they now provide financial data
+ management, {customer relationship management}, {supply chain
+ management}, {workforce management}, and {data analytics}
+ systems.
+
+ {(http://peoplesoft.com/)}.
+
+ (2003-06-01)
+
+PEP
+
+ {peak envelope power}
+
+Pepper
+
+ <language> A variant of {POP-11} by Chris Dollin
+ <kers@hplb.hpl.hp.com>.
+
+ (2002-05-26)
+
+PEPsy
+
+ {Prolog} extended with parallel modules within which explicit
+ {OR-parallelism} can be used.
+
+ ["PEPsy: A Prolog for Parallel Processing", M. Ratcliffe et
+ al, ECRC TR CA-17, 1986].
+
+PER
+
+ 1. <networking> {Packed Encoding Rules}.
+
+ 2. <mathematics> {partial equivalence relation}.
+
+ (1998-05-27)
+
+percent
+
+ %
+
+ Common: {ITU-T}: percent sign; mod; grapes. {INTERCAL}:
+ double-oh-seven.
+
+ (1995-03-06)
+
+Perceptional Adaptive Subband Coding
+
+ <audio, compression> (PASC) A version of {MPEG-1 Layer 1} used
+ for the {Philips} {Digital Compact Cassette DCC}.
+
+ (2001-12-13)
+
+perceptron
+
+ 1. A single {McCulloch-Pitts neuron}.
+
+ 2. A network of {neurons} in which the output(s) of some
+ neurons are connected through weighted connections to the
+ input(s) of other neurons. A {multilayer perceptron} is a
+ specific instance of this.
+
+percussive maintenance
+
+ <jargon> The fine art of whacking a device to get it working,
+ possibly using a {fine adjuster}.
+
+ (1999-01-15)
+
+perf
+
+ {chad}
+
+perfect programmer syndrome
+
+ Arrogance; the egotistical conviction that one is above normal
+ human error. Most frequently found among programmers of some
+ native ability but relatively little experience (especially
+ new graduates; their perceptions may be distorted by a history
+ of excellent performance at solving {toy problems}). "Of
+ course my program is correct, there is no need to test it."
+ "Yes, I can see there may be a problem here, but *I'll* never
+ type "rm -r /" while in {root mode}."
+
+ [{Jargon File}]
+
+PERFORM
+
+ <programming> A {COBOL} statement used for executing
+ "paragraphs".
+
+ [What's a paragraph?]
+
+ (1997-06-10)
+
+period
+
+ 1. <data> The time between repetitions of any cyclic event
+ or phenomenon such as an {electromagnetic wave} or planetary
+ orbit. Period is the {reciprocal} of {frequency}.
+
+ 2. <character> American for {full stop}.
+
+ (2010-07-25)
+
+periodic group
+
+ <database> (PE) Groups of logically related fields which occur
+ multiple times within a group.
+
+ Periodic groups are a non-{relational} technique. An example
+ of a PE would be for storing the history of a person's name
+ changes, where name was kept in logically related fields such
+ as surname, first name and middle name - with the person
+ having changed their name more than once.
+
+ [Clarification?]
+
+ (1995-10-30)
+
+peripheral
+
+ <hardware> (Or "peripheral device", "device") Any part of a
+ computer other than the {CPU} or {working memory},
+ i.e. {disks}, {keyboards}, {monitors}, {mice}, {printers},
+ {scanners}, {tape drives}, {microphones}, {speakers},
+ {cameras}, to list just the less exotic ones.
+
+ High speed working {memory}, such as {RAM}, {ROM} or, in the
+ old days, {core} would not normally be referred to as
+ peripherals. The more modern term "device" is also more
+ general in that it is used for things such as a {pseudo-tty},
+ a {RAM drive}, or a {network adaptor}.
+
+ Some argue that, since the advent of the {personal computer},
+ the {motherboard}, {hard disk}, keyboard, mouse, and monitor
+ are all parts of the base system, and only use the term
+ "peripheral" for optional additional components.
+
+ (2002-09-03)
+
+Peripheral Component Interconnect
+
+ <hardware> (PCI) A standard for connecting {peripherals} to a
+ {personal computer}, designed by {Intel} and released around
+ Autumn 1993. PCI is supported by most major manufacturers
+ including {Apple Computer}. It is technically far superior to
+ {VESA}'s {local bus}. It runs at 20 - 33 MHz and carries 32
+ bits at a time over a 124-pin connector or 64 bits over a
+ 188-pin connector. An address is sent in one cycle followed
+ by one word of data (or several in burst mode).
+
+ PCI is used in systems based on {Pentium}, {Pentium Pro}, {AMD
+ 5x86}, {AMD K5} and {AMD K6} processors, in some {DEC Alpha}
+ and {PowerPC} systems, and probably {Cyrix 586} and {Cyrix
+ 686} systems. However, it is processor independent and so can
+ work with other processor architectures as well.
+
+ Technically, PCI is not a bus but a {bridge} or {mezzanine}.
+ It includes buffers to decouple the {CPU} from relatively slow
+ peripherals and allow them to operate asynchronously.
+
+ (1997-12-07)
+
+peripheral device
+
+ {peripheral}
+
+Peripheral Technology Group
+
+ <company> A national and international distributor of {IBM
+ PC}-to-{Unix} and {Internet} connectivity products. They
+ cater for resellers, dealers and {VARs} and are one of the top
+ {Seagate} and {Micropolis} distributors in the US.
+
+ {(http://ptgs.com/)}.
+
+ Address: Eden Prairie, MN, USA (a suburb of Minneapolis).
+
+ Eden Prairie ("Silicon Prairie") is the home of Digi
+ International, Ontrack, Open Systems, LaserMaster, Best Buy,
+ and others.
+
+ (1995-11-29)
+
+Perl
+
+ <language, tool> A {high-level} programming language, started
+ by {Larry Wall} in 1987 and developed as an {open source}
+ project. It has an eclectic heritage, deriving from the
+ ubiquitous {C} programming language and to a lesser extent
+ from {sed}, {awk}, various {Unix} {shell} languages, {Lisp},
+ and at least a dozen other tools and languages. Originally
+ developed for {Unix}, it is now available for many
+ {platforms}.
+
+ Perl's elaborate support for {regular expression} matching and
+ substitution has made it the {language of choice} for tasks
+ involving {string manipulation}, whether for text or binary
+ data. It is particularly popular for writing {CGI scripts}.
+
+ The language's highly flexible syntax and concise regular
+ expression operators, make densely written Perl code
+ indecipherable to the uninitiated. The syntax is, however,
+ really quite simple and powerful and, once the basics have
+ been mastered, a joy to write.
+
+ Perl's only {primitive} data type is the "scalar", which can
+ hold a number, a string, the undefined value, or a typed
+ reference. Perl's {aggregate} data types are {arrays}, which
+ are ordered lists of {scalars} indexed by {natural numbers},
+ and hashes (or "{associative arrays}") which are unordered
+ lists of scalars indexed by strings. A reference can point to
+ a scalar, array, hash, {function}, or {filehandle}. {Objects}
+ are implemented as references "{blessed}" with a {class} name.
+ Strings in Perl are {eight-bit clean}, including {nulls}, and
+ so can contain {binary data}.
+
+ Unlike C but like most Lisp dialects, Perl internally and
+ dynamically handles all memory allocation, {garbage
+ collection}, and type {coercion}.
+
+ Perl supports {closures}, {recursive functions}, {symbols}
+ with either {lexical scope} or {dynamic scope}, nested {data
+ structures} of arbitrary content and complexity (as lists or
+ hashes of references), and packages (which can serve as
+ classes, optionally inheriting {methods} from one or more
+ other classes). There is ongoing work on {threads},
+ {Unicode}, {exceptions}, and {backtracking}. Perl program
+ files can contain embedded documentation in {POD} (Plain Old
+ Documentation), a simple markup language.
+
+ The normal Perl distribution contains documentation for the
+ language, as well as over a hundred modules (program
+ libraries). Hundreds more are available from The
+ {Comprehensive Perl Archive Network}. Modules are themselves
+ generally written in Perl, but can be implemented as
+ interfaces to code in other languages, typically compiled C.
+
+ The free availability of modules for almost any conceivable
+ task, as well as the fact that Perl offers direct access to
+ almost all {system calls} and places no arbitrary limits on
+ data structure size or complexity, has led some to describe
+ Perl, in a parody of a famous remark about {lex}, as the
+ "Swiss Army chainsaw" of programming.
+
+ The use of Perl has grown significantly since its adoption as
+ the language of choice of many {web} developers.
+ {CGI} interfaces and libraries for Perl exist for several
+ {platforms} and Perl's speed and flexibility make it well
+ suited for form processing and on-the-fly {web page} creation.
+
+ Perl programs are generally stored as {text} {source} files,
+ which are compiled into {virtual machine} code at run time;
+ this, in combination with its rich variety of data types and
+ its common use as a glue language, makes Perl somewhat hard to
+ classify as either a "{scripting language}" or an
+ "{applications language}" -- see {Ousterhout's dichotomy}.
+ Perl programs are usually called "Perl scripts", if only for
+ historical reasons.
+
+ Version 5 was a major rewrite and enhancement of version 4,
+ released sometime before November 1993. It added real {data
+ structures} by way of "references", un-adorned {subroutine}
+ calls, and {method} {inheritance}.
+
+ The spelling "Perl" is preferred over the older "PERL" (even
+ though some explain the language's name as originating in the
+ acronym for "Practical Extraction and Report Language"). The
+ program that interprets/compiles Perl code is called
+ "perl", typically "/usr/local/bin/perl" or "/usr/bin/perl".
+
+ Latest version: 5.005_03 stable, 5.005_62 in development, as
+ of 1999-12-04.
+
+ {(http://perl.com/)}.
+
+ {Usenet} newsgroups: {news:comp.lang.perl.announce},
+ {news:comp.lang.perl.misc}.
+
+ ["Programming Perl", Larry Wall and Randal L. Schwartz,
+ O'Reilly & Associates, Inc. Sebastopol, CA. ISBN
+ 0-93715-64-1].
+
+ ["Learning Perl" by Randal L. Schwartz, O'Reilly & Associates,
+ Inc., Sebastopol, CA].
+
+ [{Jargon File}]
+
+ (1999-12-04)
+
+Perl5
+
+ <language, tool> A commonly used but unofficial term for 5.*
+ versions of {Perl}.
+
+ (1999-12-04)
+
+perl-byacc
+
+ A modified version of {byacc} that generates a {parser} in
+ {Perl} code, by Rick Ohnemus <rick@imd.sterling.com>. It has
+ a "-p" switch so multiple parsers can be used in one program
+ ({C} or Perl). Version 1.8.2 should work on most {Unix}
+ systems. It also works with {SAS/C} 6.x on {Amiga}.
+
+ (1993-01-24)
+
+Perl profiler
+
+ <tool> (pprof) A tool by Anthony Iano-Fletcher of Nottingham
+ University, UK to profile, and collate data from, {Perl}
+ scripts.
+
+ Version: 1?
+
+ Source posted on comp.lang.perl in mid-June 1993.
+
+ (1993-06-17)
+
+permanent link
+
+ <web> A {URL} that always points to the same piece
+ of {web content}. {Web pages} that appear for a limited time
+ at their main URL, such as {web logs} or news sites, often
+ display an alternative, permanent link. Readers can quote,
+ bookmark, or link to this URL in order to refer to a
+ particular item, rather than the page displaying the latest
+ item.
+
+ For example, the URL http://news.bbc.co.uk/ points to the
+ latest news from the BBC whereas
+ http://news.bbc.co.uk/1/2614839.stm is a permanent link to a
+ particular news story.
+
+ (2003-12-27)
+
+Permanent Virtual Circuit
+
+ <networking> (PVC, or in {ATM} terminology, "Permanent Virtual
+ Connection") A {virtual circuit} that is permanently
+ established, saving the time associated with circuit
+ establishment and tear-down.
+
+ (1997-10-06)
+
+Permanent Virtual Connection
+
+ {Permanent Virtual Circuit}
+
+permission
+
+ <file system> (Or "file mode") The ability to access (read,
+ write, execute, traverse, etc.) a {file} or {directory}.
+ Depending on the {operating system}, each file may have
+ different permissions for different kinds of access and
+ different users or groups of users.
+
+ {chmod} ("change mode") is the {UNIX} command to change
+ permissions.
+
+ (2000-12-07)
+
+permutation
+
+ <mathematics> 1. An ordering of a certain number of elements
+ of a given set.
+
+ For instance, the permutations of (1,2,3) are (1,2,3) (2,3,1)
+ (3,1,2) (3,2,1) (1,3,2) (2,1,3).
+
+ Permutations form one of the canonical examples of a "{group}"
+ - they can be composed and you can find an inverse permutation
+ that reverses the action of any given permutation.
+
+ The number of permutations of r things taken from a set of n
+ is
+
+ n P r = n! / (n-r)!
+
+ where "n P r" is usually written with n and r as subscripts
+ and n! is the {factorial} of n.
+
+ What the football pools call a "permutation" is not a
+ permutation but a {combination} - the order does not matter.
+
+ 2. A {bijection} for which the {domain} and {range} are the
+ same set and so
+
+ f(f'(x)) = f'(f(x)) = x.
+
+ (2001-05-10)
+
+\perp
+
+ {LaTeX} inverted T. Used in {domain theory} to represent
+ {bottom}.
+
+ (1995-02-03)
+
+perplexity
+
+ The {geometric mean} of the number of words which may follow
+ any given word for a certain {lexicon} and {grammar}.
+
+persistence
+
+ 1. <programming> A property of a programming language where
+ created objects and variables continue to exist and retain
+ their values between runs of the program.
+
+ 2. <hardware> The length of time a phosphor dot on the screen
+ of a {cathode ray tube} will remain illuminated after it has
+ been energised by the electron beam. Long-persistence
+ phosphors reduce flicker, but generate ghost-like images that
+ linger on screen for a fraction of a second.
+
+ (1994-11-09)
+
+persistent
+
+ {persistence}
+
+Persistent Functional Language
+
+ <language, database> (PFL) A {functional database} language
+ developed by Carol Small at Birkbeck College, London, UK and
+ Alexandra Poulovassilis (now at {King's College London}).
+
+ In PFL, functions are defined equationally and bulk data is
+ stored using a special class of functions called selectors.
+ PFL is a {lazy} language, supports {higher-order functions},
+ has a strong {polymorphic} {type inference} system, and allows
+ new user-defined data types and values. All functions, types
+ and values persist in a {database}. Functions can be written
+ which update all aspects of the database: by adding data to
+ selectors, by defining new equations, and by introducing new
+ data types and values.
+
+ PFL is "semi-{referentially transparent}", in the sense that
+ whilst updates are referentially opaque and are executed
+ {destructive}ly, all evaluation is referentially transparent.
+ Similarly, {type checking} is "semi-static" in the sense that
+ whilst updates are dynamically type checked at run time,
+ expressions are type checked before they are evaluated and no
+ type errors can occur during their evaluation.
+
+ ["{A Functional Approach to Database Updates
+ (http://web.dcs.bbk.ac.uk/CS/Research/DBPL/papers/INFSYS93.abs.html)}",
+ C. Small, Information Systems 18(8), 1993, pp. 581-95].
+
+ (1995-04-27)
+
+persistent memory
+
+ {non-volatile storage}
+
+Personal Communication Network
+
+ <networking> (PCN) Any {network} supporting {Personal
+ Communication Service} (PCS). Also, sometimes used to refer
+ to the specific implementation (using the {GSM}-derivative
+ {DCS-1800}) of initial PCS capabilities in the United Kingdom.
+
+ (1996-08-23)
+
+Personal Communication Services
+
+ <communications> (PCS) Telecommunications services that bundle
+ voice communications, numeric and text messaging, {voice-mail}
+ and various other features into one device, service contract
+ and bill. PCS are carried over {cellular} links, most often
+ digital.
+
+ (1996-08-01)
+
+personal computer
+
+ <computer> (PC) A general-purpose single-user {microcomputer}
+ designed to be operated by one person at a time.
+
+ This term and the concept has been successfully hijacked by
+ {IBM} due to the huge market share of the {IBM PC}, despite
+ its many obvious weaknesses when compared to other equally
+ valid claimants to the term, e.g. the {Acorn} {Archimedes},
+ {Amiga}, {Atari}, {Macintosh}.
+
+ (1994-11-02)
+
+Personal Computer Memory Card International Association
+
+ <body, hardware, standard> (PCMCIA, or "PC Card") An
+ international trade association and the {standards} they have
+ developed for devicies, such as {modems} and external {hard
+ disk} drives, that can be plugged into {notebook computers}.
+ A PCMCIA card is about the size of a credit card.
+
+ For some unfathomable reason, around 1995(?) they decided to
+ rename PCMCIA cards "PC Cards", perhaps to encourage sales to
+ confused purchasers.
+
+ {(ftp://ftp.sidewinder.com/pub/Portables/PCMCIA)}.
+
+ Address: PCMCIA Administration, 1030 East Duane Avenue, Suite
+ G, Sunnyvale, CA 94086 USA.
+
+ Telephone: +1 (408) 720 0107. Fax: +1 (408) 720 9416. BBS:
+ +1 (408) 720 9388.
+
+ (1996-10-16)
+
+Personal Digital Assistant
+
+ <computer> (PDA) A small hand-held computer typically
+ providing calendar, contacts, and note-taking applications but
+ may include other applications, for example a {web browser}
+ and {media player}. Small keyboards and pen-based input
+ systems are most commonly used for user input.
+
+ The {Apple Newton} was a fairly early example.
+
+ [First? Notable examples? Current Best?]
+
+ (2002-09-03)
+
+Personal Identification Number
+
+ <security> (PIN, "PIN number") A {password}, typically four
+ digits entered through a telephone keypad or automatic teller
+ machine.
+
+ (1996-11-03)
+
+Personalized Array Translator
+
+ <language> (PAT) A small subset of {APL}.
+
+ E-mail: <oed@watsol.uwaterloo.ca>.
+
+ [Sammet 1969, p. 252].
+
+ (1998-05-09)
+
+person of no account
+
+ (University of California at Santa Cruz) Used when referring
+ to a person with no {network address}, frequently to forestall
+ confusion. Most often as part of an introduction: "This is
+ Bill, a person of no account, but he used to be
+ bill@random.com".
+
+ Compare {return from the dead}.
+
+ [{Jargon File}]
+
+ (1994-11-22)
+
+perspective
+
+ <games> In computer games, the {virtual} position from which
+ the human player views the playing area. There are three
+ different perspectives: first person, second person, and third
+ person.
+
+ First person perspective: Viewing the world through the eyes
+ of the primary character in three dimensions. e.g. Doom,
+ Quake.
+
+ Second person perspective: Viewing the game through a
+ spectator's eyes, in two or three dimensions. Depending on
+ the game, the main character is always in view. e.g. Super
+ Mario Bros., Tomb Raider.
+
+ Third person perspective: a point of view which is independent
+ of where characters or playing units are. The gaming world is
+ viewed much as a satellite would view a battlefield.
+ E.g. Warcraft, Command & Conquer.
+
+ (1997-06-19)
+
+PERT
+
+ {Program Evaluation and Review Technique}
+
+pessimal
+
+ /pes'im-l/ (Latin-based antonym for "optimal") Maximally bad.
+ "This is a pessimal situation." Also "pessimise" To make as
+ bad as possible. These words are the obvious Latin-based
+ antonyms for "optimal" and "optimise", but for some reason
+ they do not appear in most English dictionaries, although
+ "pessimise" is listed in the OED.
+
+ [{Jargon File}]
+
+ (1995-02-01)
+
+pessimising compiler
+
+ /pes'*-mi:z"ing k*m-pi:l"r/ (Antonym of "{optimising
+ compiler}") A {compiler} that produces {object code} that is
+ worse than the straightforward or obvious hand translation.
+ The implication is that the compiler is actually trying to
+ optimise the program, but through excessive cleverness is
+ doing the opposite. A few pessimizing compilers have been
+ written on purpose, however, as pranks or burlesques.
+
+ (1995-02-01)
+
+peta-
+
+ {prefix}
+
+petabyte
+
+ <unit, data> (PB) A unit of data equal to one quadrillion {bytes}
+ but see {binary prefix} for other definitions. A petabyte is
+ 10^15 bytes or 1000^5 bytes or 1000 {terabytes}.
+
+ As of 2013-11-05, the {Internet Archive} {Wayback Machine}
+ contains almost two petabytes of data.
+
+ A petabyte is the amount of data that would be required to store a
+ 2000 by 1600 pixel image of every one of the 314 million people
+ living in the USA in 2012.
+
+ 1000 petabytes are one {exabyte}.
+
+ See {prefix}.
+
+ (2007-09-13)
+
+petaflops
+
+ <unit> 10^15 {flops} or 1000 {teraflops}.
+
+ As with {flops}, the term ends in S in both the singular and
+ plural as the S stands for seconds.
+
+ The first computer to perform one petaflops was recorded in {June
+ 2008 (http://top500.org/list/2008/06/100)}. By {June 2012
+ (http://top500.org/list/2012/06/100)} there were 20.
+
+ (2013-04-27)
+
+petdingo
+
+ <tool> An {Estelle} to {C++} translator.
+
+ (1997-01-24)
+
+Peter Chen
+
+ <person> The developer of the {Entity-Relationship model}.
+
+ (1995-02-07)
+
+Petri net
+
+ <parallel, simulation> A {directed}, {bipartite graph} in
+ which nodes are either "places" (represented by circles) or
+ "transitions" (represented by rectangles), invented by Carl
+ Adam Petri. A Petri net is marked by placing "tokens" on
+ places. When all the places with arcs to a transition (its
+ input places) have a token, the transition "fires", removing a
+ token from each input place and adding a token to each place
+ pointed to by the transition (its output places).
+
+ Petri nets are used to model {concurrent} systems,
+ particularly {network} {protocols}.
+
+ Variants on the basic idea include the {coloured Petri Net},
+ {Time Petri Net}, {Timed Petri Net}, {Stochastic Petri Net},
+ and {Predicate Transition Net}.
+
+ {FAQ (http://daimi.aau.dk/PetriNets/faq/answers.htm)}.
+
+ (1996-09-10)
+
+PETSCII
+
+ <character> /pet'skee/ {PET} {ASCII}. The variation (many
+ would say perversion) of the ASCII {character set} used by the
+ {Commodore Business Machines}' {PET} series of {personal
+ computers} and the later {Commodore 64}, {Commodore 16}, and
+ {Commodore 128} computers. The PETSCII set used left-arrow
+ and up-arrow (as in old-style ASCII) instead of underscore and
+ caret, placed the unshifted alphabet at positions 65--90, put
+ the shifted alphabet at positions 193--218, and added {graphic
+ characters}.
+
+ [{Jargon File}]
+
+ (1995-10-29)
+
+PEX
+
+ (PHIGS Extension to X) Extension to the {X Window System}
+ providing 3d graphics support.
+
+pf
+
+ <networking> The {country code} for French Polynesia.
+
+ (1999-01-27)
+
+PFE
+
+ 1. <text, editor> {Programmer's File Editor}.
+
+ 2. <language> {Portable Forth Environment}.
+
+ (2000-12-07)
+
+PFL
+
+ 1. <language> A concurrent extension of {ML} by Holmstrom and
+ Matthews, using {CCS}.
+
+ ["PFL: A Functional Language for Parallel Programming",
+ S. Holmstrom in Proc Declarative Language Workshop, London
+ 1983].
+
+ 2. <language, database> {Persistent Functional Language}.
+
+pfm
+
+ {program file manager}
+
+pForth
+
+ <language> A portable (hence the "p") {ANS}-standard {Forth}
+ implemented in {ANSI C}. {Phil Burk
+ (http://softsynth.com/philburk.html)} initially began
+ developing pForth in 1994 to support ASIC development at
+ {3DO}.
+
+ (1998-06-30)
+
+Pfortran
+
+ {Parallel Fortran}
+
+PFP
+
+ {Plastic Flat Package}
+
+pg
+
+ <networking> The {country code} for Papua New Guinea.
+
+ (1999-01-27)
+
+PGA
+
+ 1. <graphics, specification> {Professional Graphics Adapter}.
+
+ 2. <hardware> {Pin Grid Array}.
+
+ (1999-08-04)
+
+PGA370
+
+ {Socket 370}
+
+PGP
+
+ {Pretty Good Privacy}
+
+PH
+
+ <tool> The tool for looking up people in Eudora on the
+ {Macintosh}. Equivalent to {Unix}'s {finger} service.
+
+ (1995-03-31)
+
+pH
+
+ {Parallel Haskell}
+
+ph
+
+ <networking> The {country code} for the Philippines.
+
+ (1999-01-27)
+
+phacker
+
+ <communications, security> A telephone system {cracker}. A
+ phacker may attempt to gain unauthorised access to a phone
+ system in order to make free or untraceable calls or he may
+ disrupt, alter or illegally tap phone systems via computer.
+
+ The disruptions may include causing a phone line to be engaged
+ so no calls go in or out, redirecting outgoing or incoming
+ calls, as well as listening to actual calls made.
+
+ Phackers are frequently confidence tricksters or phone freaks
+ (nuisance callers who can only relate to other people by
+ phone). Phackers are sometimes employed by illegal
+ enterprises to conduct business using untraceable calls, or to
+ disrupt, or follow legal authorities' investigations.
+ Phackers interventions may be lethal to the person being
+ phacked.
+
+ A phacker may be a phone company employee, or usually,
+ ex-employee who specialises in illegal phone system
+ disruption, alteration or tapping via physically altering
+ installations. A phacker is generally considered to be a
+ socially and intellectually retarded cracker.
+
+ See {Captain Crunch}.
+
+ (1998-08-09)
+
+phage
+
+ A program that modifies other programs or databases in
+ unauthorised ways; especially one that propagates a {virus} or
+ {Trojan horse}. See also {worm}, {mockingbird}. The
+ analogy, of course, is with phage viruses in biology.
+
+ [{Jargon File}]
+
+phase
+
+ 1. The offset of one's waking-sleeping schedule with respect
+ to the standard 24-hour cycle; a useful concept among people
+ who often work at night and/or according to no fixed schedule.
+ It is not uncommon to change one's phase by as much as 6 hours
+ per day on a regular basis. "What's your phase?" "I've been
+ getting in about 8 P.M. lately, but I'm going to {wrap around}
+ to the day schedule by Friday." A person who is roughly 12
+ hours out of phase is sometimes said to be in "night mode".
+ (The term "day mode" is also (but less frequently) used,
+ meaning you're working 9 to 5 (or, more likely, 10 to 6).)
+ The act of altering one's cycle is called "changing phase";
+ "phase shifting" has also been recently reported from Caltech.
+
+ 2. "change phase the hard way": To stay awake for a very long
+ time in order to get into a different phase.
+
+ 3. "change phase the easy way": To stay asleep, etc. However,
+ some claim that either staying awake longer or sleeping longer
+ is easy, and that it is *shortening* your day or night that is
+ really hard (see {wrap around}). The "jet lag" that afflicts
+ travelers who cross many time-zone boundaries may be
+ attributed to two distinct causes: the strain of travel per
+ se, and the strain of changing phase. Hackers who suddenly
+ find that they must change phase drastically in a short period
+ of time, particularly the hard way, experience something very
+ like jet lag without travelling.
+
+phase alternating line
+
+ <television> (PAL) The {video} signal format used in the UK
+ [where else?].
+
+ PAL uses {Amplitude Modulation} for the video information, and
+ {Frequency Modulation} for the {audio} information. The phase
+ of the {colour subcarrier} is reversed on alternate lines
+ which (together with the use of a delay line) allows the
+ receiver to cancel any phase errors introduced in the path
+ between the studio and the end-user's receiver. Such phase
+ errors are quite common and would cause the displayed colours
+ to shift in {hue}.
+
+ The US equivalent, {NTSC}, does not have this feature and thus
+ requires a user control to correct for transmission phase
+ errors, hence the mis-expansion "Never Twice the Same Colour".
+
+ (2001-06-08)
+
+Phase Encoded
+
+ <storage> (PE) A recording method used for 1600 BPI {magnetic
+ tapes}.
+
+ Compare {NRZI}, {GCR}.
+
+ (1996-02-03)
+
+phase of the moon
+
+ Used humorously as a random parameter on which something is
+ said to depend. Sometimes implies unreliability of whatever
+ is dependent, or that reliability seems to be dependent on
+ conditions nobody has been able to determine. "This feature
+ depends on having the channel open in mumble mode, having the
+ foo switch set, and on the phase of the moon."
+
+ See also {heisenbug}.
+
+ True story: Once upon a time there was a {bug} that really did
+ depend on the phase of the moon. There was a little
+ subroutine that had traditionally been used in various
+ programs at {MIT} to calculate an approximation to the moon's
+ true phase. {GLS} incorporated this routine into a {Lisp}
+ program that, when it wrote out a file, would print a
+ timestamp line almost 80 characters long. Very occasionally
+ the first line of the message would be too long and would
+ overflow onto the next line, and when the file was later read
+ back in the program would {barf}. The length of the first
+ line depended on both the precise date and time and the length
+ of the phase specification when the timestamp was printed, and
+ so the bug literally depended on the phase of the moon!
+
+ The first paper edition of the {Jargon File} (Steele-1983)
+ included an example of one of the timestamp lines that
+ exhibited this bug, but the typesetter "corrected" it. This
+ has since been described as the phase-of-the-moon-bug bug.
+
+ [{Jargon File}]
+
+ (1995-02-22)
+
+phase-shift keying
+
+ <communications> (PSK) A {digital modulation} scheme that
+ conveys data by changing the {phase} of a {carrier} wave. The
+ data can either determine the absolute phase relative to the
+ unmodulated carrier or reference signal ("coherent phase-shift
+ keying", CPSK) or the change in phase ("differential
+ phase-shift keying", DPSK). The number of different phases
+ used determines the amount of data that can be transmitted in
+ each cycle. Each cycle can be considered to constitute one
+ "symbol", e.g. with two possible phases, each cycle carries
+ one {bit}. The more phases that are used, the less tollerant
+ to noise the transmissions becomes.
+
+ Alternatives to PSK are {amplitude-shift keying} (ASK) and
+ {frequency-shift keying} (FSK).
+
+ (2010-01-26)
+
+phase space
+
+ <mathematics> The 2n-dimensional space consisting of the
+ possible values of (x1, x1., x2, x2., ..., xn, xn.) for a
+ system of n first-order {ordinary differential equations} (or
+ more generally, {Pfaffian forms}).
+
+ If n=1, the phase space is known as a phase plane.
+
+ {(http://mathworld.wolfram.com/PhaseSpace.html)}.
+
+ (2008-05-02)
+
+phase-wrapping
+
+ ({MIT}) {wrap around}.
+
+ [{Jargon File}]
+
+ (1995-02-22)
+
+PHIGS
+
+ {Programmers Hierarchical Interactive Graphics System}
+
+Philip R. Bagley
+
+ <person> A pioneer of computer document retrieval. See
+ {metadata}.
+
+ (2010-05-15)
+
+Philips
+
+ <company> A Dutch multinational electronics company. It
+ produces washing machines, consumer electronics, {integrated
+ circuits} and light bulbs. Together with {Sony} they set the
+ {Compact Disc} standard, especially {Green Book CD-ROM}. They
+ are members of the {Open Software Foundation}. Philips
+ Research Labs developed the {POOL} and {SPL} languages.
+
+ Address: Philips Research Labs, Eindhoven, Netherlands.
+
+ (1995-02-07)
+
+Philips SCC68070
+
+ <processor> A {microprocessor} which is {object code}
+ compatible with the {Motorola 68000}. It is not a performance
+ improvement over the 68060; it's performance rather resembles
+ that of the 68000.
+
+ (1995-04-22)
+
+philosophy
+
+ See {computer ethics}, {liar paradox}, {netiquette}, {proof}.
+
+phishing
+
+ <security> ("brand spoofing", "carding", after "fishing")
+ /fishing/ Sending {e-mail} that claims to be from some
+ well-known organisation, e.g. a bank, to trick the recipient
+ into revealing information for use in {identity theft}. The
+ user is told to visit a {website} where they are asked to
+ enter information such as passwords, credit card details,
+ social security or bank account numbers. The website usually
+ looks like it belongs to the organisation in question and may
+ silently redirect the user to the real website after
+ collecting their data.
+
+ For example, a scam started in 2003 claimed that the user's
+ eBay account would be suspended unless he updated his credit
+ card information on a given website.
+
+ (2006-01-19)
+
+PHOCUS
+
+ An {object-oriented} {Prolog}-like language.
+
+ ["PHOCUS: Production Rules, Horn Clauses, Objects and Contexts
+ in a Unification Based System", D. Chan et al, Actes du Sem
+ Prog et Logique, Tregastel (May 1987), pp. 77-108].
+
+ (1994-11-09)
+
+Phoenix
+
+ <operating system> An {operating system}, built in {BCPL} on
+ top of {IBM} {MVT} and later {MVS} by {Cambridge University}
+ Computing Service from 1973 to 1995, which ran on the
+ university central {mainframe}. All parts of the system were
+ named after birds, including Eagle (the {job scheduler}, also
+ the nearest pub), Pigeon (the mailer), {GCAL} (the text
+ processor) and Wren (the command language), leading to Wren
+ Libraries (a local pun).
+
+ Phoenix was much used by {chemists} in daytime and by the rest
+ of the university in the evenings, and was only abandoned in
+ favour of {Unix} in 1995; it is one reason Cambridge
+ made little contribution to Unix until then.
+
+ {Computing Service Phoenix closure memo
+ (http://cam.ac.uk/cs/newsletter/1995/nl183/phoenix.html)}
+
+ (2003-12-05)
+
+phone mail
+
+ {voice mail}
+
+Phonetastic
+
+ <communications> A {CTI} product from {Callware}. Phonetastic
+ employs if-then rules and customer records to tell those
+ receiving calls who is calling (based on {ANI} and {DNIS}) and
+ to determine how the call should be routed, e.g. to a certain
+ sales representative or to the general sales department;
+ receive high-priority treatment; receive a fax-back, etc.
+
+ (1996-12-08)
+
+Phong shading
+
+ <graphics> A model of how light is reflected from surfaces
+ used extensively in three dimensional graphics to generate
+ visually realistic images.
+
+ [Details?]
+
+ (1994-11-09)
+
+phosphor fatigue
+
+ {screen saver}
+
+photo CD
+
+ <multimedia, specification, standard, storage, graphics> A
+ {standard} for storing photographic images on {CD-ROM},
+ produced by {Kodak}.
+
+ {Kodak Photo CD page
+ (http://kodak.com/digitalImaging/aboutPhotoCD/aboutPCD.shtml)}.
+
+ (1995-12-12)
+
+Photoshop
+
+ <graphics, tool> An image manipulation program by {Adobe
+ Systems, Inc.}.
+
+ {(http://adobe.com/Apps/Photoshop.html)}.
+
+ [Summary?]
+
+ (1995-07-05)
+
+PHP
+
+ {PHP: Hypertext Preprocessor}
+
+PHP: Hypertext Preprocessor
+
+ <web, programming> (PHP) An {Open Source},
+ {server-side}, {cross-platform}, {scripting language} used to
+ create dynamic {web pages}.
+
+ PHP can be embedded in {HTML} using special tags like:
+
+ <?php echo '<p>Hello World</p>'; ?>
+
+ This is stored in a file with a ".php" extension. The {web
+ server} passes the file to the PHP {interpreter} which
+ executes the code in the <?php ... ?> tags. The tagged code
+ is then replaced with its output, typically ordinary HTML, in
+ the response sent to the {web browser}.
+
+ PHP is a {recursive acronym}.
+
+ Latest version: 5.3.2 2010-03-04, as of 2010-03-20.
+
+ {PHP Home (http://php.net/)}.
+
+ {Cheat sheet
+ (http://addedbytes.com/cheat-sheets/php-cheat-sheet/)}.
+
+ (2010-03-20)
+
+phreaking
+
+ <jargon> /freek'ing/ "phone phreak" 1. The art and science of
+ {cracking} the telephone network so as, for example, to make
+ free long-distance calls.
+
+ 2. By extension, security-{cracking} in any other context
+ (especially, but not exclusively, on communications networks).
+
+ At one time phreaking was a semi-respectable activity among
+ hackers; there was a gentleman's agreement that phreaking as
+ an intellectual game and a form of exploration was OK, but
+ serious theft of services was taboo. There was significant
+ crossover between the hacker community and the hard-core phone
+ phreaks who ran semi-underground networks of their own through
+ such media as the legendary "TAP Newsletter".
+
+ This ethos began to break down in the mid-1980s as wider
+ dissemination of the techniques put them in the hands of less
+ responsible phreaks. Around the same time, changes in the
+ phone network made old-style technical ingenuity less
+ effective as a way of hacking it, so phreaking came to depend
+ more on overtly criminal acts such as stealing phone-card
+ numbers.
+
+ The crimes and punishments of gangs like the "414 group"
+ turned that game very ugly. A few old-time hackers still
+ phreak casually just to keep their hand in, but most these
+ days have hardly even heard of "blue boxes" or any of the
+ other paraphernalia of the great phreaks of yore.
+
+ [{Jargon File}]
+
+ (1994-11-09)
+
+physical
+
+ <jargon> The opposite of {logical} in its jargon sense.
+ Compare {real}, {virtual}, and {transparent}.
+
+ It is said that what you can touch and see is real; what you
+ can see but not touch is virtual; what you can touch but not
+ see is transparent; and what you can neither touch nor see is
+ probably imaginary.
+
+ (2001-10-26)
+
+physical address
+
+ <memory management> The address presented to a computer's main
+ memory in a {virtual memory} system, in contrast to the
+ {virtual address} which is the address generated by the {CPU}.
+ A {memory management unit} translates virtual addresses into
+ physical addresses.
+
+ (1995-03-31)
+
+physical addressing
+
+ <networking> The low level addressing scheme used on
+ {Ethernet}. The 48-bit destination {Ethernet address} in a
+ {packet} is compared with the receiving node's Ethernet
+ address.
+
+ Compare {IP address}.
+
+ (1994-12-23)
+
+physical file
+
+ <file system> A low-level view of the physical characteristics
+ of a {file}, such as its location on a {disk} or its physical
+ structure, for example, whether indexed or sequential.
+
+ (2004-12-23)
+
+physical layer
+
+ <networking> Layer one, the lowest layer in the {OSI} seven
+ layer model. The physical layer encompasses details such as
+ electrical and mechanical connections to the network,
+ transmission of {binary} data as changing voltage levels on
+ wires or similar concepts on other connectors, and {data
+ rates}.
+
+ The physical layer is used by the {data link layer}.
+
+ Example physical layer {protocols} are {CSMA/CD}, {token ring}
+ and bus.
+
+ (2004-06-29)
+
+physical memory
+
+ <memory management> The memory hardware (normally {RAM})
+ installed in a computer. The term is only used in contrast to
+ {virtual memory}.
+
+ (1996-03-23)
+
+physical memory address
+
+ {physical address}
+
+Physical Sequential
+
+ <file format> (PS, QSAM, Queued Sequential Access Method) The
+ simplest {data set} on an {IBM} {mainframe}. Sequential files
+ can only be read or written from the beginning: they do not
+ support {random access}.
+
+ [Why "Queued"?]
+
+ (2003-12-05)
+
+Physical Transport Network
+
+ <communications> (PTN) The actual {hardware} through which
+ data transfer devices are connected.
+
+ {Virtual Circuits} may be leased by the owner of the physical
+ network to organisations which cannot afford the high costs of
+ laying long distance cable.
+
+ (2003-11-23)
+
+Physics Analysis Workbench
+
+ <tool> (PAW) A general purpose portable tool for analysis and
+ presentation of physics data.
+
+ (1994-11-28)
+
+PI
+
+ <programming> An {interface} between {Prolog} {application
+ programs} and the {X Window System} that aims to be independent
+ from the {Prolog} {engine}, provided that it has a {Quintus}
+ {foreign function} interface (e.g. {SICStus} and {YAP}). PI is
+ mostly written in {Prolog} and is divided in two libraries: Edipo
+ - the lower level interface to the {Xlib} functions; and Ytoolkit
+ - the higher level user interface toolkit.
+
+ {(ftp://ftp.ncc.up.pt/pub/prolog/ytoolkit.tar.Z)}.
+
+ E-mail: Ze' Paulo Leal <zp@ncc.up.pt>.
+
+ (1993-03-02)
+
+pi
+
+ 1. <character> The greek lower-case letter P.
+
+ 2. <mathematics> The mathematical constant that is the
+ circumference of a circle divided by its diameter. Pi is written
+ as the greek character pi.
+
+ Some have suggested that pi is the wrong choice and a better
+ constant to describe the geometry of circles would have been 2*pi,
+ for which they have proposed the name {tau}. Most practising
+ mathematicians think this is silly. The {xkcd} comic strip
+ {proposed (http://xkcd.com/1292/)} a compromise between pi and
+ tau, namely 1.5*pi or "pau".
+
+ (2013-12-09)
+
+PIC
+
+ 1. <hardware> {programmable interrupt controller}.
+
+ 2. A graphics language by {Brian Kernighan}, for textually
+ describing pictures with {troff}.
+
+ [Featured in "More Programming Pearls", Jon Bentley].
+
+ ["PIC - A Language for Typesetting Graphics", B.W. Kernighan,
+ Soft Prac & Exp 12(1):1-21 (Jan 1982)].
+
+ ["PIC - A Graphics Language for Typesetting, Revised User
+ Manual", Bell Labs TR 116, Dec 1984].
+
+ (1994-10-28)
+
+ 3. {personal intelligent communicator}.
+
+ (2001-04-30)
+
+pi-calculus
+
+ <theory> A {process algebra} in which channel names can act
+ both as transmission medium and as transmitted data. Its
+ basic atomic actions are individual point to point
+ communications which are {nondeterministic}ally selected and
+ globally sequentialised.
+
+ [Details? Examples?]
+
+ (1995-03-20)
+
+Pick BASIC
+
+ {Data/BASIC}
+
+PICL
+
+ Language on {Ncube} or {iPSC} machines?
+
+PICNIC
+
+ {PEBCAK}
+
+pico-
+
+ {prefix}
+
+picosecond
+
+ <unit> 10^-12 seconds.
+
+ (1997-04-26)
+
+PICS
+
+ {Platform for Internet Content Selection}
+
+PICT
+
+ <file format> An {Apple} graphics format.
+
+ [Details?]
+
+ (1997-06-06)
+
+PicTeX
+
+ A version of {TeX} for pictures.
+
+ {(ftp://june.cs.washington.edu/tex/PiCTeX.tar.Z)}.
+
+pictogram
+
+ <text> (Or "pictograph") A {symbol} which is a picture that
+ represents an object or concept, e.g. a picture of an envelope
+ used to represent an {e-mail message}.
+
+ Pictograms are common in everyday life, e.g. signs in public
+ places or roads, whereas the term "{icon}" is specific to
+ interfaces on computers or other electronic devices.
+
+ Pictograms are the most common kind of {ideogram} (symbols
+ representing concepts), the other kind are not pictures but are
+ conventions.
+
+ (2014-07-30)
+
+pictograph
+
+ {pictogram}
+
+Pictorial Janus
+
+ K. Kahn, Xerox. Visual extension of Janus. Requires
+ Strand88 and a PostScript interpreter.
+
+picture
+
+ {image}
+
+picture element
+
+ <graphics> (pixel) The smallest resolvable rectangular area of
+ an {image}, either on a screen or stored in memory. Each
+ pixel in a {monochrome} image has its own brightness, from 0
+ for black to the maximum value (e.g. 255 for an eight-bit
+ pixel) for white. In a colour image, each pixel has its own
+ brightness and colour, usually represented as a triple of red,
+ green and blue intensities (see {RGB}).
+
+ Compare {voxel}.
+
+ (1998-05-08)
+
+Picture Quality Scale
+
+ <graphics> (PQS) A system for rating image quality based upon
+ features of images that affect their perception by the human
+ eye, rather than the traditional {signal-to-noise ratio} which
+ examines differences for every single {pixel}.
+
+ [Details?]
+
+ (1995-01-12)
+
+PID
+
+ {process identifier}
+
+pidgen+
+
+ <language> A language for the {Apple II}.
+
+ {(ftp://ftp.wustl.edu/system/apple2/Lang/pidgen/)}.
+
+ [Published in Dr. Dobbs Journal?]
+
+ (1994-11-29)
+
+Pidgin
+
+ <software, communications> A {text chat} {application} that
+ work with many different chat systems at the same time.
+ Systems it works with include {AOL} Instant Messenger, Yahoo!
+ Messenger, Windows Live Messenger, {IRC} and {Facebook}.
+ There are {plug-ins} to add even more systems, e.g. {Skype}
+ and to add features.
+
+ Pidgin was first released in 1998. The name "Pidgin" was
+ applied in 2007. It is available for several {operating
+ systems}. It is licensed under the {GNU General Public
+ License}.
+
+ The name "Pidgin" comes from the term for a simplified human
+ language that evolves from two or more languages.
+
+ {Pidgin Home (http://pidgin.im/)}.
+
+ (2012-04-15)
+
+PIE
+
+ A language from {CMU} similar to {Actus}.
+
+ (1994-11-29)
+
+pif
+
+ {Program Information File}
+
+piggybacking
+
+ 1. A method for passing {acknowledgement frames} and {data
+ frames} in the same direction along a line.
+
+ 2. The practice of increasing memory capacity by soldering
+ chips on top of other chips. The chip-enable or high address
+ pins would be connected to the {address bus} by a flying lead.
+ Many {Ohio Superboards} were expanded to a massive 8K of {RAM}
+ in this way.
+
+ (1994-11-29)
+
+pig, run like a
+
+ To run very slowly on given hardware, said of software.
+ Distinct from {hog}.
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+PIGUI
+
+ {Platform Independent Graphical User Interface}
+
+PIL
+
+ Procedure Implementation Language.
+
+ A subsystem of {DOCUS}.
+
+ [Sammet 1969, p.678].
+
+ (1994-11-29)
+
+PILE
+
+ 1. Polytechnic's Instructional Language for Educators.
+ Similar in use to an enhanced PILOT, but structurally more
+ like Pascal with Awk-like associative arrays (optionally
+ stored on disk). Distributed to about 50 sites by Initial
+ Teaching Alphabet Foundation for Apple II and CP/M.
+
+ ["A Universal Computer Aided Instruction System," Henry
+ G. Dietz & Ronald J Juels, Proc Natl Educ Computing Conf '83,
+ pp.279-282].
+
+ 2. <language, music> ["PILE _ A Language for Sound Synthesis",
+ P. Berg, Computer Music Journal 3.1, 1979].
+
+ (1999-06-04)
+
+PIL/I
+
+ Variant of JOSS. Sammet 1969, p.217.
+
+PILOT
+
+ Programmed Inquiry Learning Or Teaching. CAI language, many
+ versions. "Guide to 8080 PILOT", J. Starkweather, Dr Dobb's J
+ (Apr 1977).
+
+pilot error
+
+ <jargon> ({Sun}, from aviation) A user's misconfiguration or
+ misuse of a piece of software, producing apparently {bug}-like
+ results.
+
+ E.g. "Joe Luser reported a bug in sendmail that causes it to
+ generate bogus headers." "That's not a bug, that's pilot
+ error. His "sendmail.cf" is hosed."
+
+ Compare {UBD}.
+
+ [{Jargon File}]
+
+ (1994-12-05)
+
+Pilot European Image Processing Archive
+
+ (PEIPA) An archive devoted to {image processing}, {computer
+ vision}, and {computer graphics}. It includes software,
+ images, reference material, and miscellaneous goodies.
+
+ The archive is funded by the {British Machine Vision
+ Association} (BMVA) and the {University of Essex} and is
+ closely associated with the {Pixel} {mailing list} and
+ Technical Committee 5 (Benchmarking and Software) of the
+ {IAPR}.
+
+ {(http://peipa.essex.ac.uk/)}.
+
+PIM
+
+ 1. {Personal Information Manager}.
+
+ 2. {Product Information Management}.
+
+ (1997-02-11)
+
+PIN
+
+ {Personal Identification Number}
+
+PINBOL
+
+ <language, games> A {decision table} language for controlling
+ pinball machines used at Atari. PINBOL included a
+ {multitasking} executive and an {interpreter} that worked on
+ data structures compiled from condition:action lists.
+
+ (1996-11-03)
+
+Pine
+
+ Program for Internet News & Email. A tool for reading,
+ sending, and managing electronic messages. It was designed
+ specifically with novice computer users in mind, but can be
+ tailored to accommodate the needs of "power users" as well.
+ Pine uses {Internet} message {protocols} (e.g. {RFC 822},
+ {SMTP}, {MIME}, {IMAP}, {NNTP}) and runs under {Unix} and
+ {MS-DOS}.
+
+ The guiding principles for Pine's user-interface were: careful
+ limitation of features, one-character mnemonic commands,
+ always-present command menus, immediate user feedback, and
+ high tolerance for user mistakes. It is intended that Pine
+ can be learned by exploration rather than reading manuals.
+ Feedback from the {University of Washington} community and a
+ growing number of {Internet} sites has been encouraging.
+
+ Pine's message composition editor, {Pico}, is also available
+ as a separate stand-alone program. Pico is a very simple and
+ easy-to-use {text editor} offering paragraph justification,
+ cut/paste, and a spelling checker.
+
+ Pine features on-line help; a message index showing a message
+ summary which includes the status, sender, size, date and
+ subject of messages; commands to view and process messages; a
+ message composer with easy-to-use editor and spelling checker;
+ an address book for saving long complex addresses and personal
+ distribution lists under a nickname; message attachments via
+ {Multipurpose Internet Mail Extensions}; {folder} management
+ commands for creating, deleting, listing, or renaming message
+ folders; access to remote message folders and archives via the
+ {Interactive Mail Access Protocol} as defined in {RFC 1176};
+ access to {Usenet} news via {NNTP} or {IMAP}.
+
+ Pine, {Pico} and {UW}'s {IMAP} {server} are copyrighted but
+ freely available.
+
+ {Unix} Pine runs on {Ultrix}, {AIX}, {SunOS}, {SVR4} and
+ {PTX}. PC-Pine is available for {Packet Driver}, {Novell
+ LWP}, {FTP PC/TCP} and {Sun} {PC/NFS}. A {Microsoft
+ Windows}/{WinSock} version is planned, as are extensions for
+ off-line use.
+
+ Pine was originally based on {Elm} but has evolved much since
+ ("Pine Is No-longer Elm"). Pine is the work of Mike Seibel,
+ Mark Crispin, Steve Hubert, Sheryl Erez, David Miller and
+ Laurence Lundblade (now at Virginia Tech) at the University of
+ Washington Office of Computing and Communications.
+
+ {(ftp://ftp.cac.washington.edu/mail/pine.tar.Z)}.
+ {(telnet://demo.cac.washington.edu/)} (login as "pinedemo").
+
+ E-mail: <pine@cac.washington.edu>,
+ <pine-info-request@cac.washington.edu>,
+ <pine-announce-request@cac.washington.edu>.
+
+ (21 Sep 93)
+
+pin feed
+
+ {sprocket feed}
+
+ping
+
+ <networking, tool> (ping, originally contrived to match
+ submariners' term for the sound of a returned sonar pulse) A
+ program written in 1983 by Mike Muuss (who also wrote {TTCP})
+ used to test reachability of destinations by sending them one,
+ or repeated, {ICMP} echo requests and waiting for replies.
+ Since ping works at the {IP} level its server-side is often
+ implemented entirely within the {operating system} {kernel}
+ and is thus the lowest level test of whether a remote host is
+ alive. Ping will often respond even when higher level,
+ {TCP}-based services cannot.
+
+ Sadly, Mike Muuss was killed in a road accident on 2000-11-20.
+
+ The term is also used as a verb: "Ping host X to see if it is
+ up."
+
+ The {Unix} command "ping" can be used to do this and to
+ measure round-trip delays.
+
+ The funniest use of "ping" was described in January 1991 by
+ Steve Hayman on the {Usenet} group comp.sys.next. He was
+ trying to isolate a faulty cable segment on a {TCP/IP}
+ {Ethernet} hooked up to a {NeXT} machine. Using the sound
+ recording feature on the NeXT, he wrote a {script} that
+ repeatedly invoked ping, listened for an echo, and played back
+ the recording on each returned {packet}. This caused the
+ machine to repeat, over and over, "Ping ... ping ... ping ..."
+ as long as the network was up. He turned the volume to
+ maximum, ferreted through the building with one ear cocked,
+ and found a faulty tee connector in no time.
+
+ Ping did not stand for "Packet InterNet Groper", Dave Mills
+ offered this {backronym} expansion some time later.
+
+ See also {ACK}, {ENQ}, {traceroute}, {spray}.
+
+ {The Story of the Ping Program
+ (http://ftp.arl.mil/~mike/ping.html)}.
+
+ {Unix manual page}: ping(8).
+
+ (2005-06-22)
+
+ping command
+
+ {ping}
+
+ping-flood
+
+ <networking> To {flood} another user with {ping} requests.
+
+ (1997-04-07)
+
+pinging
+
+ {ping}
+
+ping-pong
+
+ <architecture> A phenomenon which can occur in a
+ {multi-processor} system with {private caches} where two
+ processors are alternately caching a shared location. Each
+ time one writes to it, it invalidates the other's copy.
+
+ (1995-12-29)
+
+Pin Grid Array
+
+ <hardware> (PGA) A style of {integrated circuit} socket or
+ pin-out with pins laid out on a square or rectangular grid
+ with a separation of 0.1 inch in each direction. The pins
+ near the centre of the array are often missing.
+
+ PGA is often used on {motherboards} for {processors}, e.g.
+ {Socket 6} and {Socket 8}.
+
+ PPGA is "plastic PGA" (as opposed to ceramic?).
+
+ See also {SPGA}.
+
+ (2000-03-09)
+
+Pink-Shirt Book
+
+ <publication> "The Peter Norton Programmer's Guide to the IBM
+ PC".
+
+ The original cover featured a picture of Peter Norton with a
+ silly smirk on his face, wearing a pink shirt. Perhaps in
+ recognition of this usage, the current edition has a different
+ picture of Norton wearing a pink shirt.
+
+ See also {book titles}.
+
+ [{Jargon File}]
+
+ (1995-03-28)
+
+pin-out
+
+ <hardware> (Or "pinout") The allocation of logical functions
+ or signals to the electrical connection points (pins) of an
+ {integrated circuit} or other component or connector.
+
+ (1996-04-04)
+
+PIO mode
+
+ {programmed input/output mode}
+
+PIP
+
+ <tool> Peripheral Interchange Program.
+
+ A program on {CP/M}, {RSX-11}, {RSTS/E}, {TOPS-10}, and {OS/8}
+ (derived from a utility on the {PDP-6}) that was used for file
+ copying (and in OS/8 and RT-11 for just about every other file
+ operation you might want to do). It is said that when the
+ program was written, during the development of the PDP-6 in
+ 1963, it was called ATLATL ("Anything, Lord, to Anything,
+ Lord"; this played on the Nahuatl word "atlatl" for a
+ spear-thrower, with connotations of utility and primitivity
+ that were no doubt quite intentional).
+
+ See also {BLT}, {dd}, {cat}.
+
+ [{Jargon File}]
+
+ (1995-03-28)
+
+pipe
+
+ 1. <operating system> One of {Unix}'s buffers which can be
+ written to by one {asynchronous} process and read by another,
+ with the {kernel} suspending and waking up the sender and
+ receiver according to how full the pipe is. In later versions
+ of Unix, rather than using an anonymous kernel-managed
+ temporary file to implement a pipe, it can be named and is
+ implemented as a local {socket} pair.
+
+ 2. <character> "|" {ASCII} character 124. Used to represent a
+ pipe between two processes in a {shell} command line. E.g.
+
+ grep foo log | more
+
+ which feeds the output of grep into the input of more without
+ requiring a named temporary file and without waiting for the
+ first process to finish.
+
+ 3. <jargon, networking> A connection to a {network}.
+
+ See also {light pipe}.
+
+ (1996-09-24)
+
+pipeline
+
+ <architecture> A sequence of {functional units} ("stages")
+ which performs a task in several steps, like an assembly line
+ in a factory. Each functional unit takes inputs and produces
+ outputs which are stored in its output {buffer}. One stage's
+ output buffer is the next stage's input buffer. This
+ arrangement allows all the stages to work in parallel thus
+ giving greater throughput than if each input had to pass
+ through the whole pipeline before the next input could enter.
+
+ The costs are greater latency and complexity due to the need
+ to synchronise the stages in some way so that different inputs
+ do not interfere. The pipeline will only work at full
+ efficiency if it can be filled and emptied at the same rate
+ that it can process.
+
+ Pipelines may be synchronous or asynchronous. A synchronous
+ pipeline has a master clock and each stage must complete its
+ work within one cycle. The minimum clock period is thus
+ determined by the slowest stage. An asynchronous pipeline
+ requires {handshaking} between stages so that a new output is
+ not written to the interstage buffer before the previous one
+ has been used.
+
+ Many {CPUs} are arranged as one or more pipelines, with
+ different stages performing tasks such as fetch instruction,
+ decode instruction, fetch arguments, arithmetic operations,
+ store results. For maximum performance, these rely on a
+ continuous stream of instructions fetched from sequential
+ locations in memory. Pipelining is often combined with
+ {instruction prefetch} in an attempt to keep the pipeline
+ busy.
+
+ When a {branch} is taken, the contents of early stages will
+ contain instructions from locations after the branch which
+ should not be executed. The pipeline then has to be flushed
+ and reloaded. This is known as a {pipeline break}.
+
+ (1996-10-13)
+
+pipeline break
+
+ <architecture> (Or "pipeline stall") The delay caused on a
+ processor using {pipelines} when a {transfer of control} is
+ taken. Normally when a control-transfer instruction (a
+ branch, conditional branch, call or trap) is taken, any
+ following instructions which have been loaded into the
+ processor's {pipeline} must be discarded or "flushed" and new
+ instructions loaded from the branch destination. This
+ introduces a delay before the processor can resume execution.
+
+ "{Delayed control-transfer}" is a technique used to reduce
+ this effect.
+
+ (1996-10-13)
+
+Pipeline Burst Cache
+
+ <hardware, storage> (PB Cache) A {synchronous cache} built
+ from {pipelined} {SRAM}.
+
+ A {cache} in which reading or writing a new location takes
+ multiple {cycles} but subsequent locations can be accessed in
+ a single {cycle}. On {Pentium} systems in 1996, pipeline burst
+ caches are frequently used as {secondary caches}. The first 8
+ {bytes} of data are transferred in 3 {CPU} {cycles}, and the
+ next 3 8-{byte} pieces of data are transferred in one {cycle}
+ each.
+
+ (1996-10-13)
+
+pipelined
+
+ {pipeline}
+
+Pipelined Burst Cache
+
+ {Pipeline Burst Cache}
+
+pipeline stall
+
+ {pipeline break}
+
+pipelining
+
+ {pipeline}
+
+PIPEX Ltd.
+
+ {UUNET PIPEX}
+
+piping
+
+ {pipe}
+
+piracy
+
+ {software piracy}
+
+pirate
+
+ {software pirate}
+
+PIRL
+
+ Pattern Information Retrieval Language.
+
+ A language for {digraph} manipulation, embeddable in {Fortran}
+ or {ALGOL}, for {IBM 7094}.
+
+ ["PIRL - Pattern Information Retrieval Language",
+ S. Berkowitz, Naval Ship Res Dev Ctr, Wash DC].
+
+ (1994-11-29)
+
+pistol
+
+ [IBM] A tool that makes it all too easy for you to shoot
+ yourself in the foot. "Unix "rm *" makes such a nice pistol!"
+
+ [{Jargon File}]
+
+PIT
+
+ Language for IBM 650. (See {IT}).
+
+PITA
+
+ Pain in the arse/ass.
+
+pixel
+
+ {picture element}
+
+pixels per inch
+
+ <unit, graphics> (ppi) The unit used to measure {resolution}
+ of a {bitmap display} or video input device.
+
+ (2010-02-28)
+
+pixmap
+
+ (Contraction of "pixel map"). A 3 dimensional {array} of bits
+ corresponding to a 2 dimensional array of {pixels}. It is
+ used, for example, in the {X Window System} to describe a
+ memory region where graphics can be drawn without affecting
+ the screen. Typically this is used for the efficient handling
+ of {expose} events, {icon} images or for animation. Compare
+ {bitmap}.
+
+ [Xlib Guide].
+
+pizza box
+
+ [Sun] The largish thin box housing the electronics in
+ (especially {Sun}) desktop {workstations}, so named because of
+ its size and shape and the dimpled pattern that looks like air
+ holes.
+
+ Two megabyte single-platter removable disk packs used to be
+ called pizzas, and the huge drive they were stuck into was
+ referred to as a pizza oven. It's an index of progress that
+ in the old days just the disk was pizza-sized, while now the
+ entire computer is.
+
+ [{Jargon File}]
+
+PJPEG
+
+ {Progressive JPEG}
+
+pk
+
+ <networking> The {country code} for Pakistan.
+
+ (1999-01-27)
+
+PKE
+
+ {public-key encryption}
+
+PKI
+
+ {Public Key Infrastructure}
+
+PKLITE
+
+ <compression, tool> An executable file {compression} utility
+ for {MS-DOS} from {PKWARE, Inc.}. PKLITE compresses the body
+ of the executable and adds a small, fast decompress routine in
+ the header. In many cases it performs better than {lzexe}.
+ With {headpack} the output is smaller and cannot be
+ decompressed.
+
+ (1999-01-07)
+
+PKUNZIP
+
+ <tool, compression> A program to unpack {archives} created by
+ {PKZIP}, written by {PKWARE, Inc.} and released as
+ {shareware}. Versions exist for {MS-DOS}, {Microsoft Windows}
+ and {Open VMS}. PKUNZIP is no longer distributed, its
+ functions having been incorporated into PKZIP.
+
+ (1999-01-07)
+
+PKWARE, Inc.
+
+ <company, compression> The company which produces the {PKZIP}
+ and {PKUNZIP} compression tools and libraries for many
+ {platforms}.
+
+ {(http://pkware.com/)}.
+
+ E-mail: info@pkware.com.
+
+ Telephone: +1 (414) 354 8699.
+
+ Address: 9025 N. Deerwood Drive, Brown Deer, WI 53223-2480,
+ USA.
+
+ (1999-01-07)
+
+PKZIP
+
+ <tool> A file {compression} and archiver utility for {MS-DOS}
+ and {Microsoft Windows} from {PKWARE, Inc.}. PKZIP uses a
+ variation on the {sliding window} compression {algorithm}. It
+ comes with {pkunzip} and {pklite} and is available as
+ {shareware} from most {FTP archives} in a self-expanding
+ {MS-DOS} executable.
+
+ Current versions as of 1999-10-07: PKZIP 2.60 GUI for
+ {Microsoft Windows 3.1}x, {Windows 9x}, {Windows NT}; PKZIP
+ 2.50 Command Line for Windows 9x NT; PKZIP 2.04g for {MS-DOS};
+ PKZIP 2.51 for {Unix}, ({Linux}, {SPARC} {Solaris}, {Digital},
+ {HP-UX}, {IBM AIX} and {SCO} Unix); PKZIP 2.50 for {OS/2};
+ PKZIP for {Open VMS}/{VAX}.
+
+ {WINZIP} is a version with a {GUI} for {Microsoft Windows}.
+
+ A distribution in about 1995-06-22 claiming to be "PKZIP 3"
+ was actually a {Trojan horse} which attempted to reformat the
+ hard disk and delete all files on it.
+
+ {(http://pkware.com/catalog/pkzip_win.html)}.
+
+ [Status, history of WINZIP, PKLITE?]
+
+ (1999-01-16)
+
+pl
+
+ <networking> The {country code} for Poland.
+
+ (1999-01-27)
+
+PL1
+
+ <spelling> It's spelled "{PL/I}".
+
+ (1996-12-13)
+
+PL/1
+
+ <spelling> It's spelled "{PL/I}".
+
+ (1996-12-13)
+
+PL-11
+
+ <language> A high-level machine-oriented language for the
+ {PDP-11} developed by R.D. Russell of CERN in Nov 1971. It is
+ similar to {PL360} and is written in {Fortran IV} and
+ {cross-compile}d on other machines.
+
+ (1995-01-05)
+
+PL360
+
+ {Structured assembly language} for the {IBM 360} and {IBM
+ 370}, with a few high-level constructs. Syntactically it
+ resembles {ALGOL 60}. Its grammar is defined entirely by
+ operator precedence.
+
+ ["PL/360, A Programming Language for the 360 Computers",
+ N. Wirth, J ACM 15(1):37-74 (Jan 1968)].
+
+ (1995-01-05)
+
+PL516
+
+ An {ALGOL}-like {assembly language} for the {DDP-516}, similar
+ to {PL360}.
+
+ ["PL 516, An ALGOL-like Assembly Language for the DDP-516",
+ B.A. Wichmann, Natl Phys Lab UK, Report CCU 9, 1970].
+
+ (1995-01-05)
+
+PL-6
+
+ <language> A {PL/I}-like system language for the {Honeywell}
+ {operating system}, {CP-6}.
+
+ (1995-01-05)
+
+PL.8
+
+ A systems dialect of {PL/I}, developed originally for the {IBM
+ 801} {RISC} {minicomputer}, later used internally for {IBM RT}
+ and {R/6000} development.
+
+ ["An Overview of the PL.8 Compiler", M. Auslander et al, Proc
+ SIGPLAN '82 Symp on Compiler Writing].
+
+ (1995-01-05)
+
+Pla
+
+ <language, music> A high-level music programming language,
+ written in {SAIL}. Pla includes {concurrency} based on
+ {message passing}.
+
+ ["Pla: A Composer's Idea of a Language", B. Schottstaedt,
+ Computer Music J 7(1):11-20, Winter 1983].
+
+ (1999-06-04)
+
+PLACE
+
+ Programming Language for Automatic Checkout Equipment.
+
+ ["The Compiler for the Programming Language for Automatic
+ Checkout Equipment (PLACE)", AFAPL TR-68-27, Battelle Inst,
+ Columbus, May 1968].
+
+PLAGO
+
+ A translator-interpreter for a PL/I subset. "PLAGO/360 User's
+ Manual, Poly Inst Brooklyn.
+
+plaid screen
+
+ [XEROX PARC] A "special effect" that occurs when certain kinds
+ of {memory smash}es overwrite the control blocks or image
+ memory of a bit-mapped display. The term "salt and pepper"
+ may refer to a different pattern of similar origin. Though
+ the term as coined at PARC refers to the result of an error,
+ some of the {X} demos induce plaid-screen effects deliberately
+ as a {display hack}.
+
+ [{Jargon File}]
+
+PLAIN
+
+ Programming LAnguage for INteraction. Pascal-like, with
+ extensions for database, string handling, exceptions and
+ pattern matching. "Revised Report on the Programming Language
+ PLAIN", A. Wasserman, SIGPLAN Notices 6(5):59-80 (May 1981).
+
+plain ASCII
+
+ /playn-as'kee/ {flat ASCII}.
+
+ [{Jargon File}]
+
+Plain Old Documentation
+
+ <text> (pod, occasionally "POD") A simple {markup language}
+ used to embed {documentation}, {literate programming}-style,
+ in {Perl} programs. Pod readers and converters are part of
+ the standard Perl distribution and the documentation provided
+ with Perl is all in pod format.
+
+ {The Pod Specification
+ (http://perl.com/CPAN-local/doc/manual/html/pod/perlpod.html)}.
+
+ (1998-12-18)
+
+Plain Old Telephone Service
+
+ <communications> (POTS) The traditional voice service provided
+ by phone companies, especially when opposed to data services.
+
+ Note that the acronym POTS is sometimes expanded as "Plain Old
+ Telephone System" in which sense it is synonymous to {Public
+ Switched Telephone Network} but used somewhat derogatively.
+
+ (1998-05-18)
+
+Plain Old Telephone System
+
+ {Public Switched Telephone Network}
+
+plain TeX
+
+ <publication> {Donald Knuth}'s original set of user-level
+ {macros} for interaction with his {TeX} formatter. Dedicated
+ TeX fans still prefer these over the more {user-friendly}
+ {LaTeX} macros used by the majority of the TeX community.
+
+ (1997-11-20)
+
+plaintext
+
+ <cryptography> A message before {encryption} or after
+ decryption, i.e. in its usual form which anyone can read, as
+ opposed to its encrypted form ("{ciphertext}").
+
+ (1995-05-10)
+
+PLAN
+
+ <language> Programming LANguage Nineteen hundred.
+
+ The {assembly language} for {ICL 1900} series computers.
+
+ (1995-03-21)
+
+.plan
+
+ <operating system> See {plan file}.
+
+Plan 9
+
+ <operating system> (Named after the classically bad,
+ exceptionally low-budget SF film "Plan 9 from Outer Space") An
+ {operating system} developed at {Bell Labs} by many
+ researchers previously intimately involved with {Unix}.
+
+ Plan 9 is superficially Unix-like but features far finer
+ control over the {name-space} (on a per-process basis) and is
+ inherently distributed and scalable.
+
+ Plan 9 is divided according to service functions. {CPU}
+ servers concentrate computing power into large
+ {multiprocessors}; {file servers} provide repositories for
+ storage and terminals give each user of the system a dedicated
+ computer with {bitmap screen} and {mouse} on which to run a
+ window system. The sharing of computing and file storage
+ services provides a sense of community for a group of
+ programmers, amortises costs and centralises and hence
+ simplifies management and administration.
+
+ The pieces communicate by a single {protocol}, built above a
+ reliable {data transport layer} offered by an appropriate
+ network, that defines each service as a rooted tree of files.
+ Even for services not usually considered as files, the unified
+ design permits some simplification. Each process has a local
+ file name space that contains attachments to all services the
+ process is using and thereby to the files in those services.
+ One of the most important jobs of a terminal is to support its
+ user's customised view of the entire system as represented by
+ the services visible in the name space.
+
+ {(http://plan9.bell-labs.com/plan9dist/)}.
+
+ (2005-02-15)
+
+Planet
+
+ ["An Experiment in Language Design for Distributed Systems",
+ D. Crookes et al, Soft Prac & Exp 14(10):957-971 (Oct 1984)].
+
+plan file
+
+ <operating system> On {Unix} systems that support {finger},
+ the ".plan" file in a user's {home directory} is displayed
+ when the user is fingered. This feature was originally
+ intended to be used to keep potential fingerers apprised of
+ one's location and near-future plans, but has been turned
+ almost universally to humorous and self-expressive purposes
+ (like a {sig block}). See also {Hacking X for Y}.
+
+ A later innovation in plan files was the introduction of
+ "scrolling plan files" which are one-dimensional animations
+ made using only the printable {ASCII} character set, {carriage
+ return} and {line feed}, avoiding terminal specific {escape
+ sequences}, since the {finger} command will (for security
+ reasons; see {letterbomb}) not pass the {escape} character.
+
+ Scrolling .plan files have become art forms in miniature, and
+ some sites have started competitions to find who can create
+ the longest running, funniest, and most original animations.
+ A compiler (ASP) is available on {Usenet} for producing them.
+ Typical animation components include:
+
+ Centipede: mmmmme
+ Lorry/Truck: oo-oP
+ Andalusian Video Snail: _@/
+
+ In the mid-1990s {WWW} {home pages} largely supplanted .plan
+ files, providing a much richer forum for the publication of
+ personal minutiae and digital creativity.
+
+ See also {twirling baton}.
+
+ [{Jargon File}]
+
+ (1998-01-16)
+
+PLANIT
+
+ Programming LANguage for Interaction and Teaching. CAI
+ language. "PLANIT - A Flexible Language Designed for
+ Computer-Human Interaction", S.L. Feingold, Proc FJCC 31,
+ AFIPS (Fall 1967) Sammet 1969, p.706.
+
+Plankalkül
+
+ <language, history> (Or "Plankalkuel" if you don't have
+ umlauts). The first programming language, designed by {Konrad
+ Zuse}, ca. 1945. Zuse wrote "Rechenplan allgemeiner Struktur"
+ in 1944 which developed into Plankalkül. Plankalkül included
+ {arrays} and {records} and used a style of {assignment} in
+ which the new value appears on the right.
+
+ Zuse wrote Plankalkül for his {Z3} computer (finished before
+ 1945) and implemented it on there as well. Much of his work
+ may have been either lost or confiscated in the aftermath of
+ World War II.
+
+ {ESR Plankalkül
+ (http://tuxedo.org/~esr/retro/plankalkuel/)}.
+
+ ["The Plankalkül of Konrad Zuse", F.L. Bauer et al, CACM
+ 15(7):678-685, Jul 1972].
+
+ (2002-05-28)
+
+PLANNER
+
+ A language for writing {theorem provers} by {Carl Hewitt}
+ <hewitt@ai.mit.edu> {MIT} 1967. Never fully implemented.
+
+ {CONNIVER} was an outgrowth of {PLANNER} and {microPLANNER} a
+ subset. {PLASMA} is a PLANNER-like system modelled on
+ {Actors}. See also {POPLER}, {QLISP}, {Scheme}.
+
+ ["PLANNER: A Language for Proving Theorems in Robots", Carl
+ Hewitt, Proc IJCAI-69, Wash DC, May 1969].
+
+Planner-73
+
+ The original name for {PLASMA}.
+
+PLANS
+
+ Programming Language for Allocation and Network Scheduling. A
+ PL/I preprocessor, used for developing scheduling algorithms.
+ "A User's Guide to the Programming Language for Allocation and
+ Network Scheduling", H.R. Ramsey et al, TR SAI-77-068-DEN,
+ Science Applications Inc (Jun 1977).
+
+plants
+
+ ["The Algorithmic Beauty of Plants", Przemyslaw Prusinkiewicz,
+ Aristid Lindenmayer. New York: Springer-Verlag, 1990.
+ 3-54097297-8].
+
+PLASMA
+
+ PLAnner-like System Modelled on Actors. {Carl Hewitt}, 1975.
+ The first {actor} language. Originally called Planner-73, and
+ implemented in MacLisp. Lisp-like syntax, but with several
+ kinds of parentheses and brackets.
+
+ ["A PLASMA Primer", B. Smith et al, AI Lab Working Paper 92,
+ MIT Oct 1975].
+
+ ["Viewing Control Structures as Patterns of Passing Messages",
+ C. Hewitt, AI Lab Memo 410, MIT 1976].
+
+Plastic Pin Grid Array
+
+ <hardware, processor> (PPGA) The package used for certain
+ {Intel} {Celeron} {processors}. PPGA processors fit into
+ {Socket 370} {motherboard} sockets.
+
+ The Plastic {Pin Grid Array} packaging is similar to that used
+ on {Pentium} processors. The {silicon} {core} is covered by a
+ {heat slug} that faces down toward the {motherboard}.
+
+ The Celeron 300A to the 533 use a PPGA package. The Celeron
+ 566 onward use a {FC-PGA} package.
+
+ Celeron processors are also available in {Slot 1} {SEPP}
+ packaging.
+
+ (2000-08-26)
+
+platform
+
+ Specific computer hardware, as in the phrase
+ "platform-independent". It may also refer to a specific
+ combination of hardware and {operating system} and/or
+ {compiler}, as in "this program has been ported to several
+ platforms". It is also used to refer to support software for
+ a particular activity, as in "This program provides a platform
+ for research into routing protocols".
+
+ (1994-12-07)
+
+Platform for Internet Content Selection
+
+ <web> (PICS) A standard for {meta-data} associated
+ with {web} content, originally designed to help
+ parents and teachers control what children access on the
+ Internet, but also used for {code signing} and privacy. The
+ PICS platform is one on which other rating services and
+ filtering software have been built.
+
+ {(http://w3.org/PICS}).
+
+ (2001-03-29)
+
+Platform Independent Graphical User Interface
+
+ (PIGUI) {The PIGUI FAQ
+ (ftp://rtfm.mit.edu/pub/usenet/news.answers/portable-GUI-software/)}.
+
+ [Summary?]
+
+ (1994-11-22)
+
+platinum-iridium
+
+ <standard> A standard, against which all others of the same
+ category are measured. Usage: silly.
+
+ The notion is that one of whatever it is has actually been
+ cast in platinum-iridium alloy and placed in the vault beside
+ the Standard Kilogram at the International Bureau of Weights
+ and Measures near Paris, as the bar defining the standard
+ {metre} once was.
+
+ "This {garbage collection} {algorithm} has been tested against
+ the platinum-iridium cons cell in Paris."
+
+ Compare {golden}.
+
+ [{Jargon File}]
+
+ (1997-02-20)
+
+Platon
+
+ Distributed language based on asynchronous message passing.
+
+ ["Message Passing Communication Versus Procedure Call
+ Communication", J. Staunstrup, Soft Prac & Exp 12(3):223-234
+ (Mar 1982)].
+
+ ["Platon Reference Manual", S. Soerensen et al, RECAU, U
+ Aarhus, Denmark].
+
+PLAY
+
+ <language, music> A language for {real-time} music synthesis.
+ 1977.
+
+ ["An Introduction to the Play Program", J. Chadabe ete al,
+ Computer Music J 2,1 (1978)].
+
+ (1999-06-04)
+
+play by electronic mail
+
+ <games> A kind of game where the players use {electronic mail}
+ to communicate. This may be done via a human {moderator} or
+ an automatic {mailing list} {exploder} on some central machine
+ or it may be fully distributed with each player just
+ addressing his mail to all other players.
+
+ This is a natural extension of "play by mail" games conducted
+ via {snail mail}.
+
+ {(http://fermi.clas.virginia.edu/~gl8f/pbm.html)}. {Usenet}
+ newsgroup: {news:rec.games.pbm}.
+
+ (1994-10-27)
+
+Playground
+
+ A visual language for children, developed for Apple's Vivarium
+ Project. OOPSLA 89 or 90?
+
+Play, Inc.
+
+ <company> The company which designed and markets {Snappy Video
+ Snapshot}.
+
+ {(http://play.com)}.
+
+ (1997-07-11)
+
+playpen
+
+ (IBM) A room where programmers work.
+
+ Compare {salt mines}.
+
+ [{Jargon File}]
+
+Playstation
+
+ <games, hardware> The leading family of {games consoles}, from
+ {Sony Corporation} consisting of the original Playstation
+ (PS1) and the Playstation 2 (PS2).
+
+ The basic Playstations consist of a small box containing the
+ processor and a {DVD} reader, with video outputs to connect to
+ a TV, sockets for two game controllers, and a socket for one
+ or two memory cards. The PS2 also has {USB} sockets.
+
+ The PS2 can run PS1 software because the PS2's I/O processor
+ is the same as the PS1's CPU.
+
+ {(http://scea.sony.com/playstation/)}.
+
+ {FAQ
+ (http://flex.net/users/cjayc/vgfa/system/sony_psx.txt)}.
+
+ [Dates? Features?]
+
+ (2003-07-29)
+
+playte
+
+ <data, jargon> /playt/ 16 {bits}, by analogy with {byte}.
+ Usage: rare and extremely silly.
+
+ See also {dynner}, {crumb}.
+
+ [{Jargon File}]
+
+ (1997-12-03)
+
+PLC
+
+ {Programmable Logic Controller}
+
+PL/C
+
+ {Programming Language/Cornell}
+
+PL Cornell
+
+ {Programming Language/Cornell}
+
+PLD
+
+ {Programmable Logic Device}
+
+plenum cable
+
+ <hardware> Cable that can be (legally) installed in the plenum
+ (the space between a ceiling and the floor above it). Such
+ cable is (usually) teflon-coated so that it will not give off
+ toxic fumes when burned. In some parts of the world such
+ cable is required by law.
+
+ (1996-08-25)
+
+pleonasm
+
+ Redundancy of expression; tautology.
+
+ (1995-03-25)
+
+plesiochronous
+
+ <communications> Nearly synchronised, a term describing a
+ communication system where transmitted signals have the same
+ nominal digital rate but are synchronised on different clocks.
+
+ According to {ITU-T} {standards}, corresponding signals are
+ plesiochronous if their significant instants occur at
+ nominally the same rate, with any variation in rate being
+ constrained within specified limits.
+
+ [Pronunciation? /ples'ee-oh-kroh'nus/?]
+
+ (1995-03-02)
+
+Plesiochronous Digital Hierarchy
+
+ <communications> (PDH) A transmission system for voice
+ communication using {plesiochronous} synchronisation.
+
+ PDH is the conventional {multiplexing} technology for network
+ transmission systems. The transmitter adds dummy information
+ bits to allow multiple channels to be bit interleaved. The
+ receiver discards these bits once the signals have been
+ demultiplexed.
+
+ PDH combines multiple 2 Mb/s ({E1}) channels in Europe and
+ 1.544 Mb/s ({DS1}) channels in the US and Japan.
+
+ PDH is being replaced by {SONET} and other SDH ({Synchronous
+ Digital Hierarchy}) schemes.
+
+ (2003-09-30)
+
+Pleuk grammar development system
+
+ <grammar, tool> A {shell} for {grammar} development by Jo
+ Calder <jcalder@cs.sfu.ca>, Kevin Humphreys
+ <kwh@cogsci.ed.ac.uk>, Chris Brew
+ <Chris.Brew@edinburgh.ac.uk>, and Mike Reape
+ <mreape@cs.tcd.ie>. It handles various grammatical formalisms
+ and requires {SICStus Prolog} version 2.1#6 or later.
+
+ Latest version: 1.0, as of 1993-06-18.
+
+ {(ftp://ai.uga.edu/ai.natural.language/)}.
+
+ E-mail: <pleuk@cogsci.ed.ac.uk>.
+
+ (2000-07-22)
+
+Plexus
+
+ A modular {web server} written in {Perl} by Tony
+ Sanders <sanders@earth.com>. Comes with interfaces to allow
+ many other information services to be served via the Web.
+
+ {Version 3.0m 1994-07-22 (ftp://ftp.earth.com/plexus/)}.
+
+ (1994-07-22)
+
+PL/I
+
+ <language> Programming Language One.
+
+ An attempt to combine the best features of {Fortran}, {COBOL}
+ and {ALGOL 60}. Developed by George Radin of {IBM} in 1964.
+ Originally named NPL and Fortran VI. The result is large but
+ elegant. PL/I was one of the first languages to have a formal
+ {semantic} definition, using the {Vienna Definition Language}.
+ {EPL}, a dialect of PL/I, was used to write almost all of the
+ {Multics} {operating system}. PL/I is still widely used
+ internally at {IBM}. The PL/I standard is ANS X3.53-1976.
+
+ PL/I has no {reserved words}. Types are fixed, float,
+ complex, character strings with maximum length, bit strings,
+ and label variables. {Arrays} have lower bounds and may be
+ dynamic. It also has summation, multi-level structures,
+ {structure assignment}, untyped pointers, {side effects} and
+ {aliasing}. {Control flow} constructs include goto; do-end
+ groups; do-to-by-while-end loops; external procedures;
+ internal nested procedures and blocks; {generic procedures}
+ and {exception handling}. Procedures may be declared
+ {recursive}. Many implementations support {concurrency}
+ ('call task' and 'wait(event)' are equivalent to {fork}/join)
+ and compile-time statements.
+
+ {LPI} is a PL/I {interpreter}.
+
+ ["A Structural View of PL/I", D. Beech, Computing Surveys, 2,1
+ 33-64 (1970)].
+
+ (1994-10-25)
+
+PL/I-FORMAC
+
+ <language> A variant of {FORMAC}.
+
+ ["The PL/I-FORMAC Interpreter", J. Xenakis, Proc 2nd Symp
+ Symbolic and Algebraic Manip, ACM, Mar 1971].
+
+ [Sammet 1969, p. 486].
+
+ [Details? Relatonship to {PL/I}?]
+
+ (1994-10-25)
+
+pling
+
+ <character> {exclamation mark}.
+
+ [Does anyone call {vertical bar} ("|", broken or unbroken)
+ "pling"?]
+
+ (1998-09-20)
+
+plingnet
+
+ {UUCPNET}. See also {pling}.
+
+ [{Jargon File}]
+
+PLisp
+
+ 1. PostScript Lisp? A {Common Lisp} translator and
+ programming environment in {PostScript} by John Peterson
+ <peterson-john@cs.yale.edu>.
+
+ 2. Pattern LISP. 1990. A {pattern-matching} rewrite-rule
+ language, optimised for describing syntax translation rules.
+ (See {LISP70}).
+
+PL/I SUBSET
+
+ An early 70's version of {PL/I} for {minicomputers}.
+
+PL/I Subset G
+
+ ("General Purpose") The commercial {PL/I} subset, i.e. what was
+ actually implemented by most vendors. ANS X3.74-1981.
+
+PLITS
+
+ Programming Language In The Sky. A computational model for
+ concurrency with communication via {asynchronous
+ message-passing}.
+
+ ["High Level Programming for Distributed Computing",
+ J.A. Feldman, CACM 22(6):353- 368 (Jun 1979)].
+
+PLL
+
+ {phase-locked loop}
+
+PL/M
+
+ Programming Language/Microcomputers. MAA (later Digital
+ Research) for Intel, 1972. A very low level language
+ incorporating ideas from PL/I, ALGOL and XPL. Integrated
+ macro processor. Originally the implementation language for
+ CP/M. "PL/M-80 Programming Manual", Doc 98-268B, Intel 1976.
+ "A Guide to PL/M Programming for Microcomputer Applications",
+ D. McCracken, A-W 1978. Versions: PL/M-80, PL/M-86, PL/M-286.
+
+PLMK
+
+ <chat> please let me know.
+
+ (1999-09-27)
+
+plokta
+
+ /plok't*/ Press Lots Of Keys To Abort. To press random keys
+ in an attempt to get some response from the system. One might
+ plokta when the abort procedure for a program is not known, or
+ when trying to figure out if the system is just sluggish or
+ really hung. Plokta can also be used while trying to figure
+ out any unknown key sequence for a particular operation.
+ Someone going into "plokta mode" usually places both hands
+ flat on the keyboard and mashes them down, hoping for some
+ useful response.
+
+ A slightly more directed form of plokta can often be seen in
+ mail messages or {Usenet} articles from new users - the text
+ might end with
+
+ ^X^C
+ q
+ quit
+ :q
+ ^C
+ end
+ x
+ exit
+ ZZ
+ ^D
+ ?
+ help
+
+ as the user vainly tries to find the right exit sequence, with
+ the incorrect tries piling up at the end of the message.
+
+ [{Jargon File}]
+
+plonk
+
+ <networking, abuse> (Usually written "*plonk*") The sound a
+ {newbie} makes as he falls to the bottom of a {kill file}.
+
+ In the first of a series of humourous books by Stephen Potter,
+ "One-Upmanship" (published in 1952) a "plonk" - a pompous bit
+ of misinformation said in a "plonking" tone - was a key
+ feature of his advice on how to "creatively intimidate"
+ someone by making them feel inferior and thereby gain the
+ status of being "one-up" on them. Since these efforts are
+ usually transparently pathetic, the term became widely applied
+ to any idiotic statement.
+
+ The term appeared on-line in the {Usenet} {newsgroup}
+ {news:talk.bizarre} and, by 1994, was widespread on {Usenet}
+ and {mailing} lists as a form of public ridicule.
+
+ The term may have been influenced by British slang "plonker"
+ for someone behaving stupidly. The expansion "Person with
+ Little Or No Knowledge" may be a {backronym}.
+
+ (2012-05-27)
+
+plotter
+
+ <hardware> A device that uses one or more pens that can be
+ raised, lowered and moved over the printing media to draw
+ graphics or text.
+
+ The heart of the plotter is the printer head assembly,
+ consisting of a horizontal bar and, attached to it, the head
+ assembly holding the pen in use. The pen can be positioned
+ horizontally by moving the pen assembly along the bar.
+ Vertical positioning is achieved by either moving the bar
+ (stationary page plotter) or the paper (rolling page plotter).
+ Combinations of horizontal and vertical movement are used to
+ draw arbitrary lines and curves in a single action, in
+ contrast to {printers} which usually scan horizontally across
+ the page.
+
+ Colour plots can be made by using more than one pen. Older
+ plotters required a separate pen for each colour and the pens
+ had to be changed by hand. Modern colour plotters usually use
+ only four pens (cyan, magenta, yellow, and black, see {CMYK})
+ and need no human intervention to change them.
+
+ Monochromatic plotters have been largely phased out by {laser
+ printers} except when large paper size is needed, e.g. in
+ {CAD}.
+
+ (1996-01-10)
+
+PL/P
+
+ Programming Language, Prime. Russ Barbour, PRIME Computer,
+ late 70's. Subset of PL/I used internally for implementation
+ of PRIMOS. (See SPL[4]).
+
+PL/PROPHET
+
+ PL/I-like language for the PROPHET system, used by
+ pharmacologists. "The Implementation of the PROPHET System",
+ P.A. Castleman et al, NCC 43, AFIPS (1974).
+
+PL/S
+
+ {Programming Language/Systems}
+
+PL/Seq
+
+ Programming Language for Sequences. A DSP language. "A
+ General High Level Language for Signal Processors", J. Skytta
+ & O. Hyvarinen, Digital Signal Processing 84, Proc Intl Conf,
+ Fiorence, Italy, Sep 1984, pp.217-221.
+
+PL/SQL
+
+ {Procedural Language/SQL}
+
+PLTL
+
+ {Propositional Linear Temporal Logic}
+
+plug and play
+
+ <jargon> 1. Hardware or software that, after being installed
+ ("plugged in"), can immediately be used ("played with"), as
+ opposed to hardware or software which requires configuration.
+
+ See also {turnkey}, {plug and pray}.
+
+ 2. A new recruit who needs no training. "The new guy, John,
+ is great. He's totally plug-and-play."
+
+ (1997-03-30)
+
+plug and pray
+
+ <humour> The {Windows 95} equivalent of the {Macintosh}'s
+ {plug and play}, referring to difficulties encountered when
+ setting up new {hardware} under Windows 95.
+
+ (1997-10-11)
+
+Plug Compatible Manufacturer
+
+ <company> (PCM) A manufacturer of equipment that some other
+ manufacturer's system can identify and work with. The PCM's
+ device replaces the original manufacturer's.
+
+ Most PCMs competed with {IBM}. PCM devices normally offer a
+ cost-performance benefit over the original device. For
+ example, several PCM versions of the {Direct-Access Storage
+ Device} {IBM 3350} offered twice the storage and improved data
+ access (dual port).
+
+ Plug compatible devices include replacement {CPUs}, such as
+ the {Hitachi 7/90} series (which could be substituted for {IBM
+ 3090} series processors), {I/O} subsystems, and {dumb
+ terminals} like the {IBM 3270}.
+
+ [Used outside mainframe market?]
+
+ (2003-06-24)
+
+Pluggable Authentication Module
+
+ <security> (PAM) The new industry standard integrated {login}
+ {framework}. PAM is used by system entry components, such as
+ the {Common Desktop Environment}'s dtlogin, to authenticate
+ users logging into a {Unix} system. It provides pluggability
+ for a variety of system-entry services. PAM's ability to
+ {stack} authentication {modules} can be used to integrate
+ {login} with different authentication mechanisms such as
+ {RSA}, {DCE} and {Kerberos}, and thus unify login mechanisms.
+ PAM can also integrate {smart card} authentication.
+
+ {White paper (http://gr.osf.org/book/psm-wppr.htm)}.
+
+ [OSF-RFC 86.0 V. Samar, R. Schemers, "Unified Login with
+ Pluggable Authentication Modules (PAM)", Oct 1995].
+
+ (1997-07-18)
+
+plugh
+
+ <games> /ploogh/ A magic word from the {ADVENT} game.
+
+ [{Jargon File}]
+
+ (1996-04-01)
+
+plug-in
+
+ <tool> A file containing data used to alter, enhance, or
+ extend the operation of a parent {application program}. One
+ of the first uses of this term was in {Silicon Beach}'s
+ {SuperPaint} application (late 1980s?) for the {Macintosh}.
+ It had a Plug-ins {folder} containing different tools and
+ effects.
+
+ The {Netscape Navigator} {web browser} supports
+ plug-ins which display or interpret a particular file format
+ or {protocol} such as {Shockwave}, {RealAudio}, {Adobe
+ Systems, Inc.} {PDF}, {Corel CMX} ({vector graphics}). The
+ file to be displayed is included in a {web page} using an
+ EMBED {HTML} {tag}.
+
+ Plug-ins, both commercially and indepently authored, can
+ usually be downloaded for free and are stored locally.
+ Plug-ins come in different versions specific to particular
+ {operating systems} ({Microsoft Windows 3.1}, 3.2, and
+ {Macintosh} are available).
+
+ Compare {applet}.
+
+ {Plug-in Plaza (http://browserwatch.com/plug-in.html)}.
+
+ {PC Mag Plug-ins
+ (http://zdnet.com/pcmag/IU/plugins/plugins.htm)}.
+
+ (1996-05-25)
+
+PLUM
+
+ A {compiler} for a substantial subset of {PL/I} for the
+ {Univac 1100}, from the {University of Maryland}.
+
+ ["PL/I Programming with PLUM", M.V. Zelkowitz, Paladin House,
+ 1978].
+
+ (1995-02-23)
+
+Plumber
+
+ <programming, tool> A system for obtaining information about
+ {memory leaks} in {Ada} and {C} programs.
+
+ {(http://home.earthlink.net/~owenomalley/plumber.html)}.
+
+ (17 Feb 1999)
+
+plumbing
+
+ (Unix) Term used for {shell} code, so called because of the
+ prevalence of "{pipelines}" that feed the output of one
+ program to the input of another. Under {Unix}, user utilities
+ can often be implemented or at least prototyped by a suitable
+ collection of pipelines and temporary file {grind}ing
+ encapsulated in a {shell script}. This is much less effort
+ than writing {C} every time, and the capability is considered
+ one of Unix's major winning features. A few other {operating
+ systems} such as {IBM}'s {VM/CMS} support similar facilities.
+
+ The {tee} utility is specifically designed for plumbing.
+
+ [{Jargon File}]
+
+ (1995-02-23)
+
+Plural EuLisp
+
+ EuLisp with parallel extensions. "Collections and Garbage
+ Collection", S.C. Merall et al, in Memory Management - IWMM92,
+ Springer 1992, pp.473-489.
+
+PLUS
+
+ Late 60's. Machine-oriented systems language used internally
+ by Univac.
+
+plus
+
+ <character> "+", {ASCII} character 43, 0x2B. The mathematical
+ symbol for the {addition} {operator}, also used with the same
+ meaning in arithmetic expressions in nearly all {programming
+ languages}.
+
+ Common names: {ITU-T}: plus; add. Rare: cross; {INTERCAL}:
+ intersection.
+
+ In programming, the operator is sometimes {overloaded} to
+ perform other tasks like concatenating strings. In the {C}
+ language and its many imitators, the symbol is doubled, as in
+ "x++" or "++x" to give an increment operator that adds one to
+ its operand ("x" in this case) and also returns x's previous
+ or resulting value respectively.
+
+ In a {regular expression}, "+" means match one or more
+ instances of the previous pattern. Thus /b(an)+a/ would match
+ any of "bana", "banana", "bananana", etc. (see {banana
+ problem}).
+
+ (2010-03-20)
+
+PLUSS
+
+ {Proposition of a Language Useable for Structured
+ Specifications}
+
+ply
+
+ <mathematics, data> 1. Of a {node} in a {tree}, the number of
+ {branches} between that node and the {root}.
+
+ 2. Of a tree, the maximum ply of any of its nodes.
+
+ (1998-12-29)
+
+PM
+
+ 1. {preventive maintenance}.
+
+ 2. {Presentation Manager}
+
+ 3. ["PM, A System for Polynomial Manipulations", G.E. Collins,
+ CACM 9(8):578-589 (Aug 1966)].
+
+ [{Jargon File}]
+
+pm
+
+ <networking> The {country code} for St. Pierre and Miquelon.
+
+ (1999-01-27)
+
+pm2
+
+ <language, compiler> A software emulator for parallel random
+ access machine (PRAM) and a parallel {Modula-2} compiler for
+ the emulator. pm2 programming language is Modula-2/Pascal
+ mixture having extensions for parallel execution in a PRAM.
+ Parallelism is expressed by pardo-loop-structure. Additional
+ features include private/shared variables, two synchronisation
+ strategies, load balancing and parallel dynamic memory
+ allocation.
+
+ {(ftp://cs.joensuu.fi/pub/Software/pram/)}.
+
+ E-mail: Simo Juvaste <sjuva@cs.joensuu.fi>.
+
+ (1997-06-04)
+
+P-mail
+
+ Physical mail, as opposed to {e-mail}. Synonymous
+ with {snail-mail}.
+
+ [{Jargon File}]
+
+PMBX
+
+ {Private Manual Branch EXchange}
+
+PMC
+
+ {PCI Mezzanine Card}
+
+PML
+
+ Parallel {ML}.
+
+ ["Synchronous Operations as First-Class Values", J.H. Reppy
+ <jhr@research.att.com>, Proc SIGPLAN 88 Conf Prog Lang Design
+ and Impl, June 1988, pp. 250-259].
+
+PMP
+
+ {Portable Media Player}
+
+pn
+
+ <networking> The {country code} for Pitcairn Island.
+
+ (1999-01-27)
+
+pnambic
+
+ <jargon> /p*-nam'bik/ (From the scene in the film, "The Wizard
+ of Oz" in which the true nature of the wizard is first
+ discovered: "Pay no attention to the man behind the curtain").
+ A term coined by Daniel Klein <dvk@lonewolf.com> for a stage
+ of development of a process or function that, owing to
+ incomplete implementation or to the complexity of the system,
+ requires human interaction to simulate or replace some or all
+ of its actions, inputs or outputs. The term may also be
+ applied to a process or function whose apparent operations are
+ wholly or partially falsified or one requiring
+ {prestidigitization}.
+
+ The ultimate pnambic product was "Dan Bricklin's Demo", a
+ program which supported flashy user-interface design
+ prototyping.
+
+ There is a related maxim among hackers: "Any sufficiently
+ advanced technology is indistinguishable from a rigged demo."
+ See {magic} for illumination of this point.
+
+ ["Open Channel", IEEE "Computer", November 1981].
+
+ [{Jargon File}]
+
+ (1994-11-01)
+
+PNG
+
+ {Portable Network Graphics}
+
+PNP
+
+ 1. <electronics> A type of {bipolar transistor} consisting of
+ a layer of N-doped {semiconductor} (the "base") between two
+ P-doped layers (the "collector" and "emitter"). PNP
+ transistors are commonly operated with the emitter at {ground}
+ and the collector at a negative {voltage}.
+
+ In the 1960s, the germanium PNP transistor was the cheapest
+ and best for use at ordinary temperatures. The {leakage
+ current} from collector to base in this type of device is
+ larger than for the silicon transistor, and also varies more
+ with temperature. The effect of these deficiencies can be
+ lessened by proper biasing and feedback, which can make the
+ circuit both serviceable and reliable. Neither germanium nor
+ PNP transistors are as common today.
+
+ The voltages used on a PNP transistor are inverted when
+ compared with {vacuum tubes}. Further, the behaviour of
+ vacuum tubes is usually described in terms of {voltages}
+ whereas transistors are better described in terms of
+ {current}.
+
+ 2. <architecture> {plug and play}.
+
+ (1997-05-05)
+
+PNU-Prolog
+
+ A parallel extension of NU-Prolog, implemented as a
+ preproccessor.
+
+ {(ftp://munnari.oz.au/pub/bebop.tar.Z)}.
+
+POA
+
+ {Portable Object Adapter}
+
+PoB
+
+ {Prisoner of Bill}
+
+POC
+
+ {Point Of Contact}
+
+POCAL
+
+ PETRA Operator's CommAnd Language.
+
+pocket calculator
+
+ <computer> A small battery-powered digital electronic device
+ for performing simple arithmetic operations on data input on a
+ keypad and outputting the result (usually a single number) to
+ a simple {LCD} or other display.
+
+ The most sophisticated programmable calculators are really
+ {pocket computers} which are limited to handling numerical
+ data only.
+
+ (1996-12-23)
+
+pocket computer
+
+ {palmtop}
+
+pod
+
+ Not to be confused with {P.O.D.}.
+
+ 1. <printer> (Allegedly from abbreviation POD for "Prince Of
+ Darkness") A {Diablo} 630 (or, latterly, any {letter-quality}
+ {impact printer}). From the {DEC-10} {PODTYPE} program used
+ to feed formatted text to it.
+
+ 2. <text> {Plain Old Documentation}.
+
+ [{Jargon File}]
+
+ (1998-12-18)
+
+P.O.D.
+
+ <data> Piece Of Data (as opposed to {code}).
+
+ [{Jargon File}]
+
+ (2000-04-08)
+
+podcast
+
+ <networking> Any series of {audio} files that can be
+ downloaded from the {Internet}, often released on some regular
+ schedule, e.g. daily or weekly.
+
+ Podcasts are named after {Apple Computer, Inc.}'s {iPod}
+ portable audio players, though most podcasts are in {MP3}
+ format and so can be played on virtually any modern audio
+ player.
+
+ (2009-12-16)
+
+POE
+
+ {PowerOpen Environment}
+
+POFAC
+
+ A subset of {Fortran}.
+
+ [Mentioned in Machine Oriented Higher Level Languages, W. van
+ der Poel, N-H 1974, p. 273].
+
+ ["POFAC Description", R. Haentjens, Report 19, Cenre
+ d'Information, Ecole Royale Militaire, Brussels, 1973].
+
+ (1994-10-20)
+
+POFOD
+
+ {Probability of Failure on Demand}
+
+POGO
+
+ Early system on G-15. Listed in CACM 2(5):16 (May 1959).
+
+point
+
+ 1. <unit, text> (Sometimes abbreviated "pt") The unit of
+ length used in {typography} to specify text character height,
+ {rule} width, and other small measurements.
+
+ There are six slightly different definitions: {Truchet point},
+ {Didot point}, {ATA point}, {TeX point}, {Postscript point},
+ and {IN point}.
+
+ In Europe, the most commonly used is Didot and in the US, the
+ formerly standard ATA point has essentially been replaced by
+ the PostScript point due to the demise of traditional
+ typesetting systems and rise of desktop computer based systems
+ running software such as {QuarkXPress}, {Adobe InDesign} and
+ {Adobe Pagemaker}.
+
+ There are 20 {twips} in a point and 12 points in a {pica}
+ (known as a "Cicero" in the Didot system).
+
+ {Different point systems
+ (http://vakcer.com/oberon/dtp/fonts/point.htm)}.
+
+ (2004-12-23)
+
+ 2. <hardware> To move a {pointing device} so that the
+ on-screen pointer is positioned over a certain object on the
+ screen such as a {button} in a {graphical user interface}. In
+ most {window systems} it is then necessary to {click} a
+ (physical) button on the pointing device to activate or select
+ the object. In some systems, just pointing to an object is
+ known as "mouse-over" {event} which may cause some help text
+ (called a "tool tip" in {Windows}) to be displayed.
+
+ (2001-05-21)
+
+point-and-drool interface
+
+ <abuse> (Or "point-and-grunt interface") A parody of
+ "{point-and-shoot interface}", describing a windows, icons,
+ and mouse-based ({WIMP}) {graphical user interface}. The
+ implication, of course, is that such an interface is only
+ suitable for idiots.
+
+ See {for the rest of us}, {WIMP}, {drool-proof paper}.
+
+ [{Jargon File}]
+
+ (2000-08-08)
+
+point-and-grunt interface
+
+ {point-and-drool interface}
+
+pointed domain
+
+ <theory> In most formulations of {domain theory}, a {domain}
+ is defined to have a {bottom} element and {algebraic} {CPOs}
+ without bottoms are called "{predomains}". David Schmidt's
+ domains do not have this requirement and he calls a domain
+ with a bottom "pointed".
+
+ (1999-07-07)
+
+pointer
+
+ 1. <programming> An {address}, from the point of view of a
+ programming language. A pointer may be typed, with its {type}
+ indicating the type of data to which it points.
+
+ The terms "pointer" and "reference" are generally
+ interchangeable although particular programming languages often
+ differentiate these two in subtle ways. For example, {Perl}
+ always calls them references, never pointers. Conversely, in
+ C, "pointer" is used, although "a reference" is often used to
+ denote the concept that a pointer implements.
+
+ {Anthony Hoare} once said:
+
+ Pointers are like jumps, leading wildly from one part of the
+ data structure to another. Their introduction into high-level
+ languages has been a step backward from which we may never
+ recover.
+
+ [C.A.R.Hoare "Hints on Programming Language Design", 1973,
+ Prentice-Hall collection of essays and papers by Tony Hoare].
+
+ 2. <operating system> (Or "mouse pointer") An {icon}, usually
+ a small arrow, that moves on the screen in response to
+ movement of a {pointing device}, typically a {mouse}. The
+ pointer shows the user which object on the screen will be
+ selected etc. when a mouse button is clicked.
+
+ (1999-07-07)
+
+pointer swizzling
+
+ {swizzle}
+
+pointing device
+
+ <hardware> Any hardware component that allows a user to input
+ spatial data to a computer. {CAD} systems and {Graphical User
+ Interfaces} (GUI) allow the user to control and provide data
+ to the computer using physical "gestures" - {point}, {click},
+ and {drag} - typically by moving a hand-held {mouse} across
+ the surface of the physical desktop and activating switches on
+ the mouse. Movements of the pointing device are echoed on a
+ graphical representation of a desktop on the screen by
+ movements of the {mouse pointer} and other visual changes.
+
+ While the most common pointing device by far is a mouse, other
+ kinds include {tracker ball}, {trackpad}, {lightpen}, various
+ kinds of {digitising tablets} which use a stylus, and even a
+ special "{data glove}" that translates the user's movements to
+ computer gestures.
+
+ (1997-02-03)
+
+pointing stick
+
+ {TrackPoint}
+
+Point Of Contact
+
+ <networking> (POC) An individual associated with a particular
+ {Internet} entity ({IP network}, {domain}, {ASN}).
+
+ (1998-09-07)
+
+point of presence
+
+ (PoP) A site where there exists a collection of
+ telecommunications equipment, usually {modems}, digital leased
+ lines and {multi-protocol routers}. An {Internet access
+ provider} may operate several PoPs distributed throughout
+ their area of operation to increase the chance that their
+ subscribers will be able to reach one with a local telephone
+ call. The alternative is for them to use {virtual PoPs}
+ (virtual points of presence) via some third party.
+
+ (1994-12-13)
+
+point of sale terminal
+
+ <hardware> (Or "POS") A computer, probably with a {bar code}
+ reader, serving as a glorified cash register.
+
+ (1997-11-23)
+
+Point-to-Point Protocol
+
+ <communications, protocol> (PPP) The {protocol} defined in
+ {RFC 1661}, the {Internet} standard for transmitting {network
+ layer} {datagrams} (e.g. {IP} packets) over serial
+ point-to-point links.
+
+ PPP has a number of advantages over {SLIP}; it is designed to
+ operate both over {asynchronous} connections and bit-oriented
+ {synchronous} systems, it can configure connections to a
+ remote network dynamically, and test that the link is usable.
+ PPP can be configured to encapsulate different network layer
+ protocols (such as {IP}, {IPX}, or {AppleTalk}) by using the
+ appropriate {Network Control Protocol} (NCP).
+
+ {RFC 1220} describes how PPP can be used with remote bridging.
+
+ {Usenet} newsgroup: {news:comp.protocols.ppp}.
+
+ {A paper on PPP
+ (ftp://ftp.uu.net/vendor/MorningStar/papers/sug91-cheapIP.ps.Z)}.
+
+ (1994-12-13)
+
+Point-to-Point Protocol over ATM
+
+ <networking> (PPPoA) A network {protocol} for encapsulating
+ {PPP} {frames} in {ATM} {AAL5}. It is used mainly with {cable
+ modem}, {DSL} and {ADSL} services.
+
+ PPPoA offers standard PPP features such as {authentication},
+ {encryption}, and {compression}. It is very slightly more
+ efficient than {PPPoE} and, like PPPoE, supports {VC-MUX} and
+ {LLC} encapsulation.
+
+ PPPoA is specified in {RFC 2364}.
+
+ (2007-06-15)
+
+Point-to-Point Protocol over Ethernet
+
+ <communications, protocol> (PPPoE) The {protocol} defined in
+ {RFC 2516} that allows one or more computers to connect to the
+ {Internet} via a shared {modem}. The computers connect to the
+ modem via a {local area network} such as {Ethernet} and the
+ modem connects to an {Internet Service Provider} (ISP) via a
+ {serial} connection such as {PPP} over {ADSL}.
+
+ PPPoE provides each user with a connection that looks and
+ behaves like a point-to-point {dial-up} connection even though
+ they are actually sharing an Ethernet or {wireless} network.
+ At the same time, the ISP only needs to provide a single
+ Internet connection, with the same kind of accounting as for
+ {PPP}. Also, the {IP address} is only assigned when the PPPoE
+ connection is open, allowing the dynamic reuse of IP addresses
+ via {DHCP}.
+
+ PPPoE works by {encapsulating} PPP {frames} in Ethernet
+ frames.
+
+ (2006-09-20)
+
+Point-to-Point Tunneling Protocol
+
+ <communications, protocol> (PPTP) A {tunneling protocol} for
+ connecting {Windows NT} {clients} and {servers} over {Remote
+ Access Services} (RAS). PPTP can be used to create a {Virtual
+ Private Network} between computers running NT. It is an
+ extension of {PPP} sponsored by {Microsoft}.
+
+ {Microsoft Point to Point Encryption} may be used with PPTP to
+ provide an encrypted connection but PPTP itself does not use
+ encryption.
+
+ Compare: {Layer Two Tunneling Protocol}.
+
+ [Origin? Standard? Document?]
+
+ (1998-09-23)
+
+Poisson distribution
+
+ <mathematics> A {probability distribution} used to describe
+ the occurrence of unlikely events in a large number of
+ independent trials.
+
+ Poisson distributions are often used in building simulated
+ user loads.
+
+ [Formula?]
+
+ (2003-03-18)
+
+POJO
+
+ {Plain Old Java Object}
+
+ [As opposed to?]
+
+poke
+
+ The {BASIC} command to write a value to an absolute address.
+
+ See {peek}.
+
+ [{Jargon File}]
+
+ (1995-01-31)
+
+Pokémon exception handling
+
+ <programming, humour> A humourous term for a {try-catch}
+ exception handling construct with no constraint on which
+ exceptions will be caught, for when you just "Gotta Catch 'Em
+ All." (a slogan used in the Pokémon media empire).
+
+ Pokémon is a trademark of the Pokémon Company of Japan.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2012-07-10)
+
+Polka
+
+ <language> An {object-oriented} parallel {logic programming}
+ language, built on top of {Parlog}.
+
+ ["Polka: A Parlog Object-Oriented Language", Andrew Davison,
+ TR, Parlog Group, Imperial College, London 1988].
+
+ (1995-01-31)
+
+poll
+
+ To check the status of an input line, sensor, or memory
+ location to see if a particular external event has been
+ registered.
+
+ Contrast {interrupt}.
+
+ [{Jargon File}]
+
+ (1995-01-31)
+
+polling
+
+ {poll}
+
+Poly
+
+ <language> 1. A {polymorphic}, {block-structured} language
+ developed by D.C.J. Matthews at Cambridge in the early 1980s.
+
+ ["An Overview of the Poly Programming Language", D.C.J.
+ Matthews, in Data Types and Persistence,
+ M.P. Atkinson et al eds, Springer 1988].
+
+ 2. A language developed at St Andrews University, Scotland.
+
+ [Software Practice & Exp, Oct 1986].
+
+ 3. A {polymorphic} language used in the referenced book.
+
+ ["Polymorphic Programming Languages", David M. Harland, Ellis
+ Horwood 1984].
+
+ (2000-11-07)
+
+polygon pusher
+
+ (Or "rectangle slinger"). A chip designer who spends most of
+ his or her time at the physical layout level (which requires
+ drawing *lots* of multi-coloured polygons).
+
+ [{Jargon File}]
+
+POLYGOTH
+
+ <language> A distributed language integrating {class}es with a
+ parallel block structure, including {multiprocedures} and
+ {fragments}.
+
+ ["Operational Semantics of a Distributed Object-Oriented
+ Language and its Z Formal Specification", M. Benveniste
+ <mbenveni@irisa.irisa.fr>, TR532, IRISA/INRIA-Rennes].
+
+ (1995-10-17)
+
+polylithism
+
+ <programming> A property of a data-object that can exist in
+ many shapes and sizes, but not simultaneously; which
+ distinguishes it from a {union}. It is often implemented as a
+ set of {classes} (or structs) derived from a common {base
+ class} (or with a common header, as in the case of structs),
+ typically without any {methods}.
+
+ It has been loosely described as {polymorphic} data.
+
+ [Clarification?]
+
+ (1996-01-07)
+
+Poly/ML
+
+ <language> {SML} implemented in D.C.J. Matthews's {Poly}, for
+ {Motorola 68020} and {SPARC} by Abstract Hardware Ltd.
+
+ (1999-11-23)
+
+polymorphic
+
+ {polymorphism}
+
+polymorphic lambda-calculus
+
+ <language, types> (Or "second order typed lambda-calculus",
+ "System F", "Lambda-2"). An extension of {typed
+ lambda-calculus} allowing functions which take types as
+ parameters. E.g. the {polymorphic} function "twice" may be
+ written:
+
+ twice = /\ t . \ (f :: t -> t) . \ (x :: t) . f (f x)
+
+ (where "/\" is an upper case Greek lambda and "(v :: T)" is
+ usually written as v with subscript T). The parameter t will
+ be bound to the type to which twice is applied, e.g.:
+
+ twice Int
+
+ takes and returns a function of type Int -> Int. (Actual type
+ arguments are often written in square brackets [ ]). Function
+ twice itself has a higher type:
+
+ twice :: Delta t . (t -> t) -> (t -> t)
+
+ (where Delta is an upper case Greek delta). Thus /\
+ introduces an object which is a function of a type and Delta
+ introduces a type which is a function of a type.
+
+ Polymorphic lambda-calculus was invented by Jean-Yves Girard
+ in 1971 and independently by John C. Reynolds in 1974.
+
+ ["Proofs and Types", J-Y. Girard, Cambridge U Press 1989].
+
+ (2005-03-07)
+
+polymorphism
+
+ <theory, programming> The ability to leave parts of a {type} in a
+ {typed language} unspecified. The term has three distinct uses:
+
+ * {Parametric polymorphism} refers to the use of type variables in
+ a {strongly typed} language.
+
+ * {Overloading}, sometimes called {ad-hoc polymorphism}, means
+ using the same {syntax} for different types.
+
+ * {object-orientated polymorphism} allows a {variable} to refer to
+ objects whose {class} is not known at compile time.
+
+ (2014-01-05)
+
+polynomial
+
+ 1. <mathematics> An arithmetic expression composed by summing
+ multiples of powers of some variable.
+
+ P(x) = sum a_i x^i for i = 0 .. N
+
+ The multipliers, a_i, are known as "{coefficients}" and N, the
+ highest power of x with a non-zero coefficient, is known as
+ the "degree" of the polynomial. If N=0 then P(x) is constant,
+ if N=1, P(x) is linear in x. N=2 gives a "{quadratic}" and
+ N=3, a "cubic".
+
+ 2. <complexity> {polynomial-time}.
+
+polynomial-time
+
+ <complexity> (P) The set or property of problems which can be
+ solved by a known {polynomial-time algorithm}.
+
+ (1995-04-10)
+
+polynomial-time algorithm
+
+ <complexity> A known {algorithm} (or {Turing Machine}) that is
+ guaranteed to terminate within a number of steps which is a
+ {polynomial} function of the size of the problem.
+
+ See also {computational complexity}, {exponential time},
+ {nondeterministic polynomial-time} (NP), {NP-complete}.
+
+ (1995-04-13)
+
+polyvinyl chloride
+
+ <hardware> (PVC) A common plastic used for insulating and
+ jacketing many wire and cable products.
+
+ (2001-03-26)
+
+POM
+
+ {phase of the moon}
+
+ Usually used in the phrase "POM-dependent", which means
+ {flaky}.
+
+ (1995-04-10)
+
+Ponder
+
+ A {non-strict} {polymorphic}, {functional language} by Jon
+ Fairbairn <jf@cl.cam.ac.uk>.
+
+ Ponder's type system is unusual. It is more powerful than the
+ {Hindley-Milner type} system used by {ML} and {Miranda} and
+ extended by {Haskell}. Ponder adds extra recursive 'mu' types
+ to those of Girard's {System F}, allowing more general
+ {recursion}. Surprisingly, the type system and {type
+ inference} {algorithm} are still not completely understood.
+
+ ["Ponder and its Type System", J. Fairbairn, TR 31, Cambridge
+ U Computer Lab, Nov 1982].
+
+ [J. Fairbairn, "Design and Implementation of a Simple Typed
+ Language based on the Lambda-Calculus", Technical Report
+ No. 75, Computer Laboratory, University of Cambridge, May
+ 1985].
+
+ [J. Fairbairn, "A New Type-Checker for a Functional Language",
+ Technical Report No. 53, Computer Laboratory, University of
+ Cambridge, 1984].
+
+ [J. Fairbairn, "Some Types with Inclusion Properties in
+ \forall, \rightarrow, \mu", Technical Report No. 171, Computer
+ Laboratory, University of Cambridge, Jun 1989].
+
+ [Valeria C. V. de Paiva, "Subtyping in Ponder (Preliminary
+ Report)", Technical Report No. 203, Computer Laboratory,
+ University of Cambridge, Aug 1990].
+
+Pong
+
+ <games> A computer game invented in 1972 by {Atari}'s Nolan
+ Bushnell. The game is a minimalist rendering of table tennis.
+ Each of the two players are represented as a white slab,
+ controllable by a knob, which deflects a bouncing ball. The
+ goal of the game is to "AVOID MISSING BALL FOR HIGH SCORE".
+
+ {Yahoo
+ (http://yahoo.com/Recreation/Games/Video_Games/Classic_Arcade_Games/Titles/Pong/)}.
+
+ (1997-11-23)
+
+POOL
+
+ Parallel Object-Oriented Language.
+
+ A series of languages from {Philips Research Labs}.
+
+ See {POOL2}, {POOL-I}, {POOL-T}.
+
+ (1995-02-07)
+
+POOL2
+
+ Parallel Object-Oriented Language 2.
+
+ Philips Research Labs, 1987.
+
+ Strongly typed, synchronous message passing, designed to run
+ on {DOOM} (DOOM = Decentralised Object-Oriented Machine).
+
+ ["POOL and DOOM: The Object- Oriented Approach", J.K. Annot,
+ PAM den Haan, in Parallel Computers, Object-Oriented,
+ Functional and Logic, P. Treleaven ed].
+
+ ["Issues in the Design of a Parallel Object-Oriented
+ Language", P. America, Formal Aspects of Computing
+ 1(4):366-411 (1989)].
+
+ (1995-02-07)
+
+POOL-I
+
+ One of the {POOL} languages.
+
+ ["A Parallel Object-Oriented Language with Inheritance and
+ Subtyping", P. America et al, SIGPLAN Notices 25(10):161-168
+ (OOPSLA/ECOOP '90) (Oct 1990)].
+
+ (1995-02-07)
+
+Pooling Agreement for Technical Assistance
+
+ <business> (PATA) Written limitations on what types of
+ technical information is shared when two companies (or
+ departments) work together on a common project. Often
+ because of security concerns rather than marketing concerns.
+
+ (2010-02-20)
+
+POOL-T
+
+ Object-oriented, concurrent, synchronous. Predecessor of
+ POOL2.
+
+ ["Definition of the Programming Language POOL-T", Esprit
+ Project 415, Doc. 0091, Philips Research Labs, Eindhoven,
+ Netherlands, June 1985].
+
+ (1995-02-07)
+
+POP
+
+ 1. <language> A family of programming languages, {POP-1},
+ {POP-2}, {POP-10}, {Pop-11}, {POP++}, {POP-9X}, {POPLOG}.
+
+ 2. {Post Office Protocol}.
+
+ See also {pop}, {PoP}.
+
+ [{Jargon File}]
+
+ (1996-02-18)
+
+PoP
+
+ {Point Of Presence}
+
+pop
+
+ <programming> To remove something from the top of a {stack}.
+
+ Opposite of {push}.
+
+ (Not to be confused with {Post Office Protocol} or {POP-1} the
+ language).
+
+ [{Jargon File}]
+
+ (1996-02-18)
+
+POP++
+
+ An object-oriented extension of {POPLOG}. Available from
+ Integral Solutions.
+
+ [{Jargon File}]
+
+POP-1
+
+ Package for Online Programming. Edinburgh, 1966. First of
+ the POP family of languages. Used reverse Polish notation.
+ Implemented as a threaded interpreter. EPU-R-17, U Edinburgh
+ (Jul 1966). "POP-1: An Online Language", R. Popplestone, Mach
+ Intell 2, E. Dale et al eds, Oliver and Boyd, Edinburgh 1968.
+
+POP-10
+
+ Descendant of {POP}-2, for the {PDP-10} by Julian Davies,
+ 1973. ["POP-10 User's Manual", D.J.M. Davies, CS R25, U West
+ Ontario, 1976].
+
+Pop-11
+
+ <language> A programming language created by Robin Popplestone
+ in 1975, originally for the {PDP-11}. Pop-11 is
+ {stack-oriented}, extensible, and efficient like {FORTH}. It
+ is also {functional}, {dynamically typed}, {interactive}, with
+ {garbage collection} like {LISP}, and the {syntax} is {block
+ structured} like {Pascal}.
+
+ ["Programming in POP-11", J. Laventhol <jcl@deshaw.com>,
+ Blackwell 1987].
+
+ AlphaPop is an implementation for the {Macintosh} from
+ Computable Functions Inc. PopTalk and POPLOG from the
+ University of Sussex are available for {VAX/VMS} and most
+ {workstations}.
+
+ E-mail: Robin Popplestone <pop@cs.umass.edu>
+
+ (2003-03-25)
+
+POP-2
+
+ Robin POPplestone, Edinburgh, 1967. An innovative language
+ incorporating many of Landin's ideas, including streams,
+ closures, and functions as first-class citizens. ALGOL-like
+ syntax. The first implementation was named Multi-POP, based
+ on a REVPOL function written in POP-1, producing the
+ reverse-polish form as output. "POP-2 Papers", R.M. Burstall
+ et al, Oliver & Boyd 1968. "Programming in POP-2",
+ R.M. Burstall et al, Edinburgh U Press 1971. "POP-2 User's
+ Manual", R. Popplestone, Mach Intell 2, E. Dale et al eds,
+ Oliver and Boyd, Edinburgh 1968.
+
+POP3
+
+ <messaging, protocol> Version 3 of the {Post Office Protocol}.
+ POP3 is defined in {RFC 1081}, written in November 1988 by
+ Marshall Rose, which is based on RFC 918 (since revised as RFC
+ 937). POP3 allows a {client} computer to retrieve {electronic
+ mail} from a POP3 {server} via a (temporary) {TCP/IP} or
+ other[?] connection. It does not provide for sending mail,
+ which is assumed to be done via {SMTP} or some other method.
+
+ POP is useful for computers, e.g. mobile or home computers,
+ without a permanent network connection which therefore require
+ a "post office" (the POP server) to hold their mail until they
+ can retrieve it.
+
+ Although similar in form to the original POP proposed for the
+ {Internet} community, POP3 is similar in spirit to the ideas
+ investigated by the {MZnet} project at the University of
+ California, Irvine, and is incompatible with earlier versions
+ of POP.
+
+ Substantial work was done on examining POP in a {PC}-based
+ environment. This work, which resulted in additional
+ functionality in this protocol, was performed by the {ACIS}
+ Networking Systems Group at {Stanford University}.
+
+ RFC 1082 (POP3 Extended Service) extends POP3 to deal with
+ accessing mailboxes for {mailing lists}.
+
+ (1997-01-09)
+
+POP-9X
+
+ Proposed {BSI} standard for {Pop-11}.
+
+POPART
+
+ A {grammar}-driven programming environment generator. Uses
+ {Paddle}.
+
+ ["POPART: Producer of Paddles and Related Tools, System
+ Builders' Manual", D.S. Wile TR RR-82-21, ISI, Marina del Rey,
+ CA 1982].
+
+ (1994-11-30)
+
+POPCORN
+
+ AI system built on POP-2. "The POPCORN Reference Manual", S.
+ Hardy, Essex U, Colchester, 1973.
+
+pop-down menu
+
+ {pull-down menu}
+
+POPJ
+
+ /pop'J/ [{PDP-10} return-from-subroutine instruction]. To
+ return from a digression. By verb doubling, "Popj, popj"
+ means roughly "Now let's see, where were we?" See {RTI}.
+
+ [{Jargon File}]
+
+Poplar
+
+ Morris, 1978. A blend of LISP with SNOBOL4 pattern matching
+ and APL-like {postfix syntax}. Implicit iteration over lists,
+ sorting primitive. "Experience with an Applicative
+ String-Processing Language", J.H. Morris et al, 7th POPL, ACM
+ 1980, pp.32-46.
+
+POPLER
+
+ A PLANNER-type language for the POP-2 environment.
+
+ ["Popler 1.6 Reference Manual", D. Davies et al, U Edinburgh,
+ TPU Report No 1 (May 1973)].
+
+POPLOG
+
+ A multi-language programming environment, which includes the
+ languages {Pop-11}, {ML}, {Common Lisp} and {Prolog}. It
+ supports mixed-language programming and {incremental
+ compilation} and includes a comprehensive {X Window System}
+ interface. It is built on top of a two-stack {virtual
+ machine}, PVM. POPLOG was developed at the University of
+ Sussex, Brighton, UK.
+
+ ["POPLOG's Two-Level Virtual Machine Support for Interactive
+ Languages", R. Smith et al, in Research Directions in
+ Cognitive Science, v.5 (1992)].
+
+POPLOG ML
+
+ {SML} for the {Poplog} system from the University of Sussex,
+ UK.
+
+POP server
+
+ {Post Office Protocol}
+
+PopTalk
+
+ <language, product> A commercial {object-oriented} derivative
+ of {POP}, from {Cambridge Consultants}, used in the {expert
+ system} {MUSE}.
+
+ (1995-02-27)
+
+POR
+
+ {power-on reset}
+
+porn
+
+ {pornography}
+
+porno
+
+ {pornography}
+
+pornography
+
+ <application> Still and moving images, usually of women, in
+ varying states of nudity, posing or performing erotic acts
+ with men, women, animals, machines, or other props. Some say
+ it degrades women, some say it corrupts young boys (who
+ down-load it from the {web} or exchange it on
+ {floppy disks}). Most of it is in the form of {JPEG} images.
+ Many websites offer porn of all sorts, almost always for a
+ subscription. It is said that these are a driving force in
+ the evolution of new technology and techniques for the web.
+ Advertisments for them certainly constitute a significant
+ proportion of all {spam}. There are even pornographic
+ computer games, an early example being {Mac Playmate}.
+
+ Beware - many institutions, particularly universities, have
+ strict rules against their computers and networks being used
+ to transfer or store such things, and you might get corrupted.
+
+ (2002-03-08)
+
+port
+
+ 1. <networking> A logical channel or channel endpoint in a
+ communications system. The {Transmission Control Protocol}
+ and {User Datagram Protocol} {transport layer} protocols used
+ on {Ethernet} use port numbers to distinguish between
+ (demultiplex) different logical channels on the same {network
+ interface} on a computer.
+
+ Each {application program} has a unique port number associated
+ with it, defined in /etc/services or the {Network Information
+ Service} "services" database. Some {protocols}, e.g. {telnet}
+ and {HTTP} (which is actually a special form of telnet) have
+ default ports specified as above but can use other ports as
+ well.
+
+ Some port numbers are defined in {RFC 3232} (which replaces
+ RFC 1700). Ports are now divided into: "Well Known" or
+ "Privileged", and "Ephemeral" or "Unprivileged" (comprising
+ "Registered", "Dynamic", "Private").
+
+ (2004-12-30)
+
+ 2. <operating system, programming> To translate or modify
+ {software} to run on a different {platform}, or the results of
+ doing so. The {portability} of the software determines how
+ easy it is to port.
+
+ 3. <language> An {imperative language} descended from {Zed}
+ from {Waterloo Microsystems} (now {Hayes} Canada) ca. 1979.
+
+ ["Port Language" document in the Waterloo Port Development
+ System].
+
+ (2002-06-19)
+
+portability
+
+ <operating system, programming> The ease with which a piece of
+ software (or {file format}) can be "ported", i.e. made to run
+ on a new {platform} and/or compile with a new {compiler}.
+
+ The most important factor is the language in which the
+ software is written and the most portable language is almost
+ certainly {C} (though see {Vaxocentrism} for counterexamples).
+ This is true in the sense that C compilers are available for
+ most systems and are often the first compiler provided for a
+ new system. This has led several compiler writers to compile
+ other languages to C code in order to benefit from its
+ portability (as well as the quality of compilers available for
+ it).
+
+ The least portable type of language is obviously {assembly
+ code} since it is specific to one particular (family of)
+ {processor}(s). It may be possible to translate mechanically
+ from one assembly code (or even {machine code}) into another
+ but this is not really portability. At the other end of the
+ scale would come {interpreted} or {semi-compiled} languages
+ such as {LISP} or {Java} which rely on the availability of a
+ portable {interpreter} or {virtual machine} written in a lower
+ level language (often C for the reasons outlined above).
+
+ The act or result of porting a program is called a "port".
+ E.g. "I've nearly finished the {Pentium} port of my big bang
+ simulation."
+
+ Portability is also an attribute of {file formats} and depends
+ on their adherence to {standards} (e.g. {ISO 8859}) or the
+ availability of the relevant "viewing" software for different
+ {platforms} (e.g. {PDF}).
+
+ (1997-06-18)
+
+portable
+
+ {portability}
+
+Portable AIRTIME
+
+ <communications, wireless> A wireless, digital communications
+ system enabling user-to-user voice communication,
+ "{quicknotes}", and {alphanumeric messaging}.
+
+ [Details?]
+
+ (2000-12-07)
+
+Portable Commodore 64
+
+ <computer> A version of the {Commodore 64} modelled after the
+ original Osborne portable PCs, with a flip-down keyboard that
+ revealed a 5-inch colour monitor, and a built-in {1541} {floppy
+ disk} drive. It is thought that few were made but that they
+ did go on sale, at least in Canada.
+
+ [Relationship to {Commodore 65}?]
+
+ (1997-09-14)
+
+Portable Common Loops
+
+ (PCL) A language which started out as an implementation of
+ {CommonLoops} and turned into a portable {CLOS}
+ implementation. Version 1992-08-28. It runs under {Lucid
+ Common LISP} 4.0.1 and {CMU Common LISP} 16e.
+
+ {(ftp://parcftp.xerox.com/pcl)}.
+
+ (1992-09-02)
+
+ [Was it developed by Richard Harris
+ <rharris@ptolemy2.rdrc.rpi.edu>?]
+
+Portable Common Tool Environment
+
+ <tool> (PCTE) An {ECMA} standard framework for software tools
+ developed in the {Esprit} programme. It is based on an
+ {entity-relationship} {Object Management System} and defines
+ the way in which tools access this.
+
+ (2001-03-03)
+
+portable computer
+
+ <computer> (Commonly, "laptop") A portable {personal computer}
+ you can carry with one hand. Some laptops run so hot that it
+ would be quite uncomforable to actually use them on your lap
+ for long. The term "notebook" is often used to describe
+ these, though it also implies a low weight (less than 2kg). A
+ "{luggable}" is one you could carry in one hand but is so
+ heavy you wouldn't want to. One that can by easily operated
+ while held in one hand is a "{palmtop}".
+
+ The computer considered by most historians to be the first
+ true portable computer was the {Osborne 1} but see the link
+ below for other contenders.
+
+ {History of laptop computers
+ (http://inventors.about.com/library/inventors/bllaptop.htm)}.
+
+ (2007-05-21)
+
+Portable Document Format
+
+ <file format> (PDF) The native file format for {Adobe
+ Systems}' {Acrobat}. PDF is the file format for representing
+ documents in a manner that is independent of the original
+ application software, hardware, and operating system used to
+ create those documents. A PDF file can describe documents
+ containing any combination of text, graphics, and images in a
+ device-independent and {resolution} independent format. These
+ documents can be one page or thousands of pages, very simple
+ or extremely complex with a rich use of {fonts}, graphics,
+ colour, and {images}.
+
+ {(http://adobe.com/products/acrobat/adobepdf.html)}.
+
+ ["The Portable Document Format Reference Manual", Adobe
+ systems, Inc. Addison-Wesley Publ. Co., ISBN: 0-201-62628-4].
+
+ (2000-09-08)
+
+Portable Forth Environment
+
+ <language> (PFE) A highly {portable} {Forth} development
+ system based on the {ANSI} standard for Forth, by Dirk-Uwe
+ Zoller of FHT, Mannheim, Germany. PFE aims to be correct,
+ complete, usable, and simple but it isn't optimised for speed.
+ It supports all {dpANS} {word sets}. It runs on {Linux},
+ {RS/6000}, and {HP-UX}.
+
+ {Tektronix} adopted PFE in 1998 and added {modules} and
+ {multithreading}. You can load additional {C} objects at
+ {run time} to extend the Forth {dictionary}. It can be
+ targeted at different embedded environments by changing the
+ terminal driver and initilisation routines.
+
+ Latest version: 0.30.27 preview, as of 2000-11-23.
+
+ {(http://pfe.sourceforge.net/)}.
+
+ E-mail: Guido Draheim <guidod@gmx.de>.
+
+ (2000-12-07)
+
+Portable Network Graphics
+
+ <file format> /ping/ (PNG) An extensible {file format} for the
+ {lossless}, {portable}, well-compressed storage of {raster
+ images}. PNG provides a patent-free replacement for {GIF} and
+ can also replace many common uses of {TIFF}.
+ {Indexed-colour}, {greyscale} and {truecolour} images are
+ supported, plus an optional {alpha channel}. Sample depths
+ range from 1 to 16 bits.
+
+ PNG is designed for on-line viewing applications, such as the
+ {World Wide Web}, so it is fully {streamable} with a
+ {progressive display} option. PNG is robust, providing both
+ full file {integrity checking} and simple detection of common
+ transmission errors. Also, PNG can store {gamma correction}
+ and {chromaticity} data for improved colour matching on
+ heterogeneous {platforms}.
+
+ {Filename extension}: .png.
+
+ {RFC 2083}. {W3C PNG pages
+ (http://w3.org/Graphics/PNG/)}. {PNG home page
+ (http://wco.com/~png/)}.
+
+ (1997-08-07)
+
+Portable Object Adapter
+
+ <architecture> (POA) Part of the {CORBA} architecture.
+
+ [Details?]
+
+ (2004-06-23)
+
+Portable Operating System Interface
+
+ <operating system, standard> (POSIX) A set of {IEEE} standards
+ designed to provide {application} {portability} between {Unix}
+ variants. IEEE 1003.1 defines a Unix-like operating system
+ interface, IEEE 1003.2 defines the {shell} and utilities and
+ IEEE 1003.4 defines {real-time} extensions.
+
+ ["More UNIX For Dummies", ISBN: 1-56884-361-5] says it stands
+ for "Portable Operating System Interface with an X thrown in
+ to make it sound cooler."
+
+ (1997-12-04)
+
+Portable Pixmap
+
+ <file format> (PPM) A colour {image} {file format}.
+
+ A PPM file contains the following:
+
+ a two character "{magic number}" - "P3",
+ the width in pixels,
+ the height in pixels,
+ the maximum colour component value,
+ HEIGHT rows of WIDTH {pixels}.
+
+ The rows are ordered from top to bottom with the pixels in
+ each row ordered from left to right. Each pixel is
+ represented as three values for red, green, and blue.
+
+ All parts are separated by {whitespace} and numbers are in
+ decimal {ASCIII} representation. A zero pixel component means
+ that colour is absent. Characters from a "#" to the next
+ end-of-line are ignored and no line should be longer than 70
+ characters.
+
+ Here is an example of a small pixmap in this format:
+
+ P3
+ # feep.ppm
+ 4 4
+ 15
+ 0 0 0 0 0 0 0 0 0 15 0 15
+ 0 0 0 0 15 7 0 0 0 0 0 0
+ 0 0 0 0 0 0 0 15 7 0 0 0
+ 15 0 15 0 0 0 0 0 0 0 0 0
+
+ A "RAWBITS" variant has magic number "P6", pixel values are
+ stored as plain binary bytes, instead of ASCII decimal and no
+ whitespace is allowed after a single whitespace character
+ after the maximum colour component value which must be less
+ than or equal to 255.
+
+ (1998-02-06)
+
+Portable Scheme Debugger
+
+ (PSD) A package for source code debugging of {R4RS}-compliant
+ {Scheme} under {GNU Emacs} by Kellom ?ki Pertti
+ <pk@cs.tut.fi>. Version 1.1. Distributed under {GNU} {GPL}.
+ It works with {scm}, {Elk} and {Scheme->C}.
+
+ {(ftp://ftp.cs.tut.fi/pub/src/languages/schemes/psd.tar.Z)}.
+
+ (1992-10-08)
+
+Portable Scheme Interpreter
+
+ (PSI) A portable scheme interpreter by Ozan Yigit
+ <oz@ursa.sis.yorku.ca>, David Keldsen and Pontus Hedman that
+ includes a simple {DAG} compiler and a {virtual machine}. It
+ can be used as an integrated extension {interpreter} in other
+ systems and allows easy addition of new primitives. There are
+ some unique debugging and tracing facilities. Acceptable
+ performance results from a fairly straight-forward
+ implementation. {Continuations} are fully and portably
+ supported and perform well. PSI is based on the simple
+ compilers and {virtual machine} in Kent Dbyvig's thesis.
+
+ The pre-release version conforms to {R4RS} with a number of
+ useful extensions.
+
+ (1993-02-19)
+
+Portable Standard Lisp
+
+ <language> (PSL) A dialect of {Lisp} from {Utah University}.
+ PSL is available as a kit for {68000} and also runs on {VAX}.
+ It compiles {Lisp} to {C}-code {virtual machine} language.
+
+ ["The Portable Standard LISP Users Manual", TR-10, CS Dept, U
+ Utah, Jan 1982].
+
+ ["A Portable Lisp System", M.L. Griss et al, Proc 1982 ACM
+ Symp on Lisp and Functional Prog, Aug 1982].
+
+ (2000-09-25)
+
+Portable Tool Interface
+
+ <programming, standard> (PTI) A standard such as {PCTE},
+ allowing interworking between different software tools via
+ defined interfaces to the user and to the {repository} or
+ {object management system}.
+
+ (2000-09-25)
+
+Port Address Translation
+
+ <networking> (PAT) A function provided by some {routers} which
+ allows {hosts} on a {LAN} to communicate with the rest of a
+ network (such as the {Internet}) without revealing their own
+ private {IP address}. All outbound {packets} have their IP
+ address translated to the routers external IP address.
+ Replies come back to the router which then translates them
+ back into the private IP address of the original host for
+ final delivery.
+
+ Compare {SOCKS}.
+
+ (1998-05-08)
+
+PORTAL
+
+ Process-Oriented Real-Time Algorithmic Language.
+
+ ["PORTAL - A Pascal-based Real-Time Programming Language",
+ R. Schild in Algorithmic Languages, J.W. deBakker et al eds,
+ N-H 1981].
+
+portal
+
+ <web> A {website} that aims to be an entry point
+ to the {web}, typically offering a {search engine}
+ and/or links to useful pages, and possibly news or other
+ services. These services are usually provided for free in the
+ hope that users will make the site their default {home page}
+ or at least visit it often. Popular examples are {Yahoo} and
+ {MSN}. Most portals on the {Internet} exist to generate
+ advertising income for their owners, others may be focused on
+ a specific group of users and may be part of an {intranet} or
+ {extranet}. Some may just concentrate on one particular
+ subject, say technology or medicine, and are known as a
+ {vertical portals}.
+
+ (2001-07-07)
+
+porting
+
+ Translating software to run on a different computer and/or
+ {operating system}.
+
+ (1995-01-06)
+
+Port Language
+
+ ["Communicating Parallel Processes", J. Kerridge et al, Soft
+ Prac & Exp 16(1):63-86 (Jan 1986)].
+
+portmapper
+
+ <networking> A {server} that converts {TCP/IP} {protocol}
+ {port} numbers into {RPC} program numbers. It must be running
+ in order to make RPC calls.
+
+ When an RPC server starts, it tells portmap the port number it
+ is listening on and what RPC program numbers it serves.
+ Before a client can call a given RPC program number, it must
+ contacts portmap on the server machine to determine the port
+ number to which RPC packets should be sent.
+
+ (1996-12-09)
+
+port number
+
+ {port}
+
+POS
+
+ {point of sale}
+
+POSE
+
+ <language A {query language} written in 1967.
+
+ ["POSE: A Language for Posing Problems to Computers",
+ S. Schlesinger et al, CACM 10:279-285, May 1967].
+
+ (1996-12-09)
+
+poset
+
+ {partially ordered set}
+
+positional representation
+
+ <mathematics> The conventional way of writing numbers as a
+ string of digits in which each digit, D, has value D * R^I,
+ where R is the {radix} or (number) base and I is the digit's
+ position counting leftward from zero at the least significant
+ (right-hand) end. Each digit can be zero to R-1. Each
+ position has a weight or significance R times greater than the
+ position to its right and the right-most place has a weight of
+ one.
+
+ Decimal numbers are radix ten, {binary} numbers are radix two,
+ {octal} radix eight and {hexadecimal} radix 16.
+
+ Positional representation makes arithmetic operations on large
+ numbers much easier than, say, {roman numerals}. It is
+ fundamental to the binary representation used by {digital
+ computers}.
+
+ (2006-11-10)
+
+POSIX
+
+ {Portable Operating System Interface}
+
+POSIX Threads
+
+ <programming> (Pthreads) A {POSIX} {standard} {API} that
+ defines a set of {C} programming language {types}, {functions}
+ and {constants} for creating and manipulating {pre-emptive
+ threads}.
+
+ The standard's full name is "POSIX.1c, Threads extensions
+ (IEEE Std 1003.1c-1995)". Implementations are available on
+ many {Unix}-like POSIX-conformant {operating systems} such as
+ {FreeBSD}, {NetBSD}, {OpenBSD}, {GNU/Linux}, {Mac OS X} and
+ {Solaris} as well as {DR-DOS} and {Microsoft Windows}.
+
+ Pthreads was designed and implemented in the {PART} Project
+ (POSIX / Ada-Runtime Project).
+
+ (2012-04-18)
+
+POST
+
+ {power-on self-test}
+
+post
+
+ <messaging> To send a message to a {mailing list} or
+ {newsgroup}. Usually implies that the message is sent
+ indiscriminately to multiple users, in contrast to "mail"
+ which implies one or more deliberately selected individual
+ recipients.
+
+ You should only post a message if you think it will be of
+ interest to a significant proportion of the readers of the
+ group or list, otherwise you should use private {electronic
+ mail} instead. See {netiquette}.
+
+ [{Jargon File}]
+
+ (1997-12-04)
+
+postcardware
+
+ {Shareware} that borders on {freeware}, in that the author
+ requests only that satisfied users send a postcard of their
+ home town or something. (This practice, silly as it might
+ seem, serves to remind users that they are otherwise getting
+ something for nothing, and may also be psychologically related
+ to real estate "sales" in which $1 changes hands just to keep
+ the transaction from being a gift.)
+
+ [{Jargon File}]
+
+posted write-through
+
+ A {cache} with a posted write-through policy (e.g. Intel 80386)
+ delays the write-back to main memory until the bus is not in
+ use.
+
+Postel, Jon
+
+ {Jon Postel}
+
+postfix notation
+
+ <language> (Or "Reverse Polish Notation", RPN) One of the
+ possible orderings of {functions} and {operands}: in postfix
+ notation the functions are preceded by all their operands.
+ For example, what may normally be written as "1+2" becomes "1
+ 2 +". Postfix notation is well suited for {stack} based
+ {architectures} but modern {compilers} reduced this advantage
+ considerably.
+
+ The best-known language with postfix syntax is {FORTH}. Some
+ {Hewlett-Packard} calculators use it, e.g. HP-25, HP-29C,
+ HP-41C, HP-23SII.
+
+ Compare: {infix notation}, {prefix notation}.
+
+ (2003-06-23)
+
+postfix syntax
+
+ {postfix notation}
+
+POSTGRES
+
+ <database> An {active DBMS} developed at the {University of
+ California at Berkeley} by a team led by Michael Stonebraker
+ (1986-1994). Postgres was later taken by {Illustra} and
+ developed into a commercial product, which in turn was bought
+ by {Informix} and integrated into their product, {Universal
+ Server}.
+
+ {PostgreSQL} is a further development of the original POSTGRES
+ code as a {free software} alternative to commercial {DBMS}
+ vendor offerings.
+
+ [Details? Reference? Relationship to {Ingres}?]
+
+ (1999-07-04)
+
+PostgreSQL
+
+ <database> /'post-gres-kyu-el/ An enhancement of the
+ {POSTGRES} {database} system.
+
+ PostgreSQL is an advanced {relational database management
+ system} with some {object oriented} approaches. PostgreSQL is
+ developed and distributed as {free software}, and while
+ retaining its freedom it remains technically and featurewise a
+ worthy competitor to even the most advanced commercial
+ alternatives.
+
+ It was also one of the first databases to offer {MVCC} as
+ opposed to {row-level locking} or {table locking}, thereby
+ greatly improving multi-user performance.
+
+ PostgreSQL implements an extended subset of {ANSI} {SQL} and
+ runs on many {platforms}. It also has {interfaces} to many
+ different {programming languages} and database {protocols},
+ like {ODBC} and {JDBC}.
+
+ {(http://postgresql.org/)}.
+
+ (1999-09-18)
+
+posting
+
+ A message sent to a {newsgroup} or {mailing list} (may also be
+ called "a post") or the act of sending it. Distinguished from
+ a "letter" or ordinary {electronic mail} message by the fact
+ that it is broadcast rather than point-to-point. It is not
+ clear whether messages sent to a small mailing list are
+ postings or e-mail; perhaps the best dividing line is that if
+ you don't know the names of all the potential recipients, it
+ is a posting.
+
+ [{Jargon File}]
+
+postmaster
+
+ The {electronic mail} contact and maintenance person at a site
+ connected to the {Internet} or {UUCPNET}. Often, but not
+ always, the same as the {admin}. The Internet standard for
+ electronic mail ({RFC} 822) requires each machine to have a
+ "postmaster" address; usually it is aliased to this person.
+ See also {webmaster}.
+
+post office problem
+
+ <algorithm> Given a set of points (in N dimensions), find
+ another point which minimises the sum of the distances from
+ that point to each of the others.
+
+ (2007-03-07)
+
+Post Office Protocol
+
+ <messaging, protocol> (POP) A {protocol} designed to allow
+ single-user computers to retrieve {electronic mail} from a POP
+ {server} via {TCP/IP}. The default {port} is 110.
+
+ The POP server might be a computer with a permanent {Internet}
+ connection whereas its clients might only connect to it
+ occasionally, e.g. by {modem}.
+
+ There are (in 1994) three versions: POP, POP2, and {POP3}.
+ Later versions are NOT compatible with earlier ones.
+
+ [Details?]
+
+ (2007-03-07)
+
+post-order traversal
+
+ {traversal}
+
+POSTQUEL
+
+ POSTGRES QUERy Language. The language used by the {POSTGRES}
+ {database} system.
+
+ ["The Design of POSTGRES", M. Stonebraker et al, Proc ACM
+ SIGMOD Conf, June 1986].
+
+ {Version 4.0
+ (ftp://postgres.berkeley.edu/pub/postgresv4r0.tar.Z)}.
+
+PostScript
+
+ <language, text, graphics> A {page description language} based
+ on work originally done by John Gaffney at Evans and
+ Sutherland in 1976, evolving through "JaM" ("John and Martin",
+ Martin Newell) at {XEROX PARC}, and finally implemented in its
+ current form by John Warnock et al. after he and Chuck Geschke
+ founded {Adobe Systems, Inc.} in 1982.
+
+ PostScript is an {interpreted}, {stack-based language} (like
+ {FORTH}). It was used as a page description language by the
+ {Apple LaserWriter}, and now many {laser printers} and
+ on-screen graphics systems. Its primary application is to
+ describe the appearance of text, graphical shapes, and sampled
+ {images} on printed or displayed pages.
+
+ A program in PostScript can communicate a document description
+ from a composition system to a printing system in a
+ device-independent way.
+
+ PostScript is an unusually powerful printer language because
+ it is a full programming language, rather than a series of
+ low-level escape sequences. (In this it parallels {Emacs},
+ which exploited a similar insight about editing tasks). It is
+ also noteworthy for implementing on-the fly {rasterisation},
+ from {Bezier curve} descriptions, of high-quality {fonts} at
+ low (e.g. 300 dpi) resolution (it was formerly believed that
+ hand-tuned {bitmap fonts} were required for this task).
+
+ PostScript's combination of technical merits and widespread
+ availability made it the language of choice for graphical
+ output until {PDF} appeared.
+
+ The {Postscript point}, 1/72 inch, is slightly different from
+ other {point} units.
+
+ {An introduction
+ (http://cs.indiana.edu/docproject/programming/postscript/postscript.html)}.
+
+ ["PostScript Language Reference Manual" ("The Red Book"),
+ Adobe Systems, A-W 1985].
+
+ [{Jargon File}]
+
+ (2002-03-11)
+
+Postscript point
+
+ <unit, text> The variant of the {point} used by {Postscript},
+ equal to 0.3527777778 mm, or 1/72 inch.
+
+ (2002-03-11)
+
+Post, Telephone and Telegraph administration
+
+ <communications, company> (PTT) One of the many national
+ bodies responsible for providing communications services in a
+ particular country. Traditionally, PTTs had monopolies in
+ their respective countries. This monopoly was first broken in
+ the USA, with the UK joining somewhat later. Currently the
+ markets are being deregulated in Europe as well as other parts
+ of the world.
+
+ Well-known PTTs include {MCI}, {AT&T}, and {British Telecom}.
+
+ Compare: {telco}.
+
+ (1998-05-18)
+
+POSYBL
+
+ Programming system for distributed applications. A {Linda}
+ implementation for {Unix} networks by Ioannis Schoinas
+ <sxoinas@csd.uch.gr>.
+
+ {(ftp://ariadne.csi.forth.gr/pub/POSYBL.TAR.Z)}.
+
+ (1995-12-04)
+
+potential difference
+
+ {voltage}
+
+POTS
+
+ {Plain Old Telephone Service}
+
+pound
+
+ <character> A British {pound sign} or Americal {hash character}.
+
+ (2013-08-15)
+
+pound on
+
+ {bang on}
+
+pound sign
+
+ <character> "£", {ASCII} character 163, 0xA3. A stylised capital
+ "L" used to prefix amounts in British pounds sterling (GBP).
+
+ Americans call the {hash character} ("#") "pound" but that is an
+ antiquated reference to pounds weight (lb).
+
+ (2013-08-15)
+
+POWER
+
+ Performance Optimization with Enhanced RISC. The {IBM}
+ processor architecture on which {PowerPC} was based.
+
+PowerBuilder
+
+ <tool, database> A {graphical user interface} development tool
+ from {Powersoft} for developing {client-server} {database}
+ {applications}. It runs under {MS-DOS}(?) and {Microsoft
+ Windows}. There are also versions for {Microsoft Windows},
+ {Windows NT}, {Macintosh}, and {Unix}.
+
+ Applications can be built by creating {windows}, controls
+ (such as {listboxes} and {buttons}), and {menus} within the
+ PowerBuilder development environment. The language used to
+ program PowerBuilder, {PowerScript}, is loosely based on
+ {BASIC}.
+
+ PowerBuilder supports programming on many database backends
+ including {Sybase} and {Oracle}. It also has added support
+ for {ODBC} database drivers. PowerBuilder also comes with a
+ built-in database backend ({WATCOM} {SQL} 32-bit {relational
+ database}).
+
+ {Product information
+ (http://powersoft.com/mktg/prodinfo/prodintr.html)}.
+
+ {FAQ (ftp://ftp.oar.net/pub/psoft/pb01.faq)}.
+
+ {Usenet} newsgroup: {news:comp.soft-sys.powerbuilder}.
+
+ [Correct list of platforms?]
+
+ (2001-03-23)
+
+power cycle
+
+ <hardware> (Or "cycle power", "cycle") To turn a machine's
+ power off and on, with the intention of clearing some kind of
+ {hung} or {gronk}ed state. Synonym {120 reset}; see also {Big
+ Red Switch}. Compare {Vulcan nerve pinch}, {bounce} and
+ {boot}, and see the {AI Koan} about Tom Knight and the novice.
+
+ [{Jargon File}]
+
+ (2012-02-09)
+
+powerdomain
+
+ <theory> The powerdomain of a {domain} D is a domain
+ containing some of the {subsets} of D. Due to the asymmetry
+ condition in the definition of a {partial order} (and
+ therefore of a domain) the powerdomain cannot contain all the
+ subsets of D. This is because there may be different sets X
+ and Y such that X <= Y and Y <= X which, by the asymmetry
+ condition would have to be considered equal.
+
+ There are at least three possible orderings of the subsets of
+ a powerdomain:
+
+ Egli-Milner:
+
+ X <= Y iff for all x in X, exists y in Y: x <= y
+ and for all y in Y, exists x in X: x <= y
+
+ ("The other domain always contains a related element").
+
+ Hoare or Partial Correctness or Safety:
+
+ X <= Y iff for all x in X, exists y in Y: x <= y
+
+ ("The bigger domain always contains a bigger element").
+
+ Smyth or Total Correctness or Liveness:
+
+ X <= Y iff for all y in Y, exists x in X: x <= y
+
+ ("The smaller domain always contains a smaller element").
+
+ If a powerdomain represents the result of an {abstract
+ interpretation} in which a bigger value is a safe
+ approximation to a smaller value then the Hoare powerdomain is
+ appropriate because the safe approximation Y to the
+ powerdomain X contains a safe approximation to each point in
+ X.
+
+ ("<=" is written in {LaTeX} as {\sqsubseteq}).
+
+ (1995-02-03)
+
+PowerFuL
+
+ <language> A language combining {functional programming} and
+ {logic programming}, using "angelic Powerdomains".
+
+ (1998-06-30)
+
+power hit
+
+ (Or "power {glitch}") A sudden increase (spike) or decrease
+ (drop-out) in the mains electricity supply. These can cause
+ crashes and even permanent damage to computers. Computers and
+ other electronic equipment should really include some kind of
+ over-voltage protection in its mains input to prevent such
+ damamge.
+
+ [{Jargon File}]
+
+Power Mac
+
+ <computer> {Apple Computer}'s {personal computer} based on the
+ {PowerPC}, introduced on 1994-03-14.
+
+ The Power Mac G4 (Quicksilver 2002) was the first Power Mac to
+ clock at 1 GHz. In mid-2003, the Power Mac G5 was released,
+ the first Mac to be based on a 64-bit architecture. IBM
+ manufactured the CPU for this new model. The clock speed was
+ initially 1.6 GHz but a dual 2 GHz system was available in
+ September. Existing {680x0} code (both applications and
+ device drivers) run on Power Mac systems without modification
+ via a {Motorola 68LC040} {emulator}. The performance of these
+ unmodified applications is equivalent to a fast {68040}-based
+ {Macintosh}, e.g. a fast {Macintosh Quadra}.
+
+ The Power Mac runs {Macintosh operating system} from {System
+ 7.5} to {Mac OS} 8.5.
+
+ Latest version, as of 2003-11-26: Power Mac G5.
+
+ {Power Mac Home (http://apple.com/powermac/)}.
+
+ (2003-11-26)
+
+Power Macintosh
+
+ {Power Mac}
+
+power-on reset
+
+ <hardware>(POR) The processes that take place when a
+ {hardware} device is turned on. This may include running
+ {power-on self-test} or reloading {software} from
+ {non-volatile storage}. The term implies that the device
+ has some reasonably complex internal state that will be
+ set back to a "normal" initial condition. This state may
+ include the physical state of the device (e.g. a {printer})
+ as well as data in the memory of an {embedded system}.
+
+ If a device has no reset button, and sometimes even
+ if it does, turning it off and on again ({power
+ cycling}) may be the only way to clear a fault.
+
+ (2012-02-09)
+
+power-on self-test
+
+ <hardware, testing> (POST) A sequence of diagnostic tests that
+ are run automatically by a device when the power is turned on.
+
+ In a {personal computer} a typical POST sequence does the
+ following:
+
+ - checks that the {system board} is working
+
+ - checks that the {memory} is working
+
+ - compares the current system configuration with that
+ recorded by the PC's configuration program to see if
+ anything has been added or removed or broken
+
+ - starts the video operation
+
+ - checks that the {diskette} drive, {hard disk drive},
+ {CD-ROM} drive, and any other drives that may be installed
+ are working.
+
+ When POST is finished, typically it will {beep}, and then
+ let your {operating system} start to {boot}. If POST finds
+ an error, it may beep more than once (or possibly not at all
+ if it is your PC speaker that is broken) and display a POST
+ error message. These messages are often nothing more than a
+ single ominous number. Some common numbers and their
+ meanings are:
+
+ 161 Dead battery
+ (get a new battery for the system board)
+
+ 162 Configuration changed
+ (you added some memory or a new card to the PC)
+
+ 301 Keyboard error
+ (take the book off the corner of the keyboard)
+
+ Because a successful POST indicates that the system is
+ restored to known state, turning the power off and on is a
+ standard way to reset a system whose software has {hung}.
+ Compare {120 reset}, {Big Red Switch}, {power cycle}.
+
+ (2001-03-30)
+
+PowerOpen
+
+ The {PowerOpen Association} defines and promotes the
+ {PowerOpen Environment} (POE).
+
+PowerOpen Association
+
+ An independent body established to promote, and test
+ conformance with, the {PowerOpen Environment} (POE).
+
+ (1994-11-08)
+
+PowerOpen Environment
+
+ <operating system> (POE) A definition containing {API} and
+ {ABI} specifications based on the {PowerPC} architecture. It
+ is not an {operating system}. The presence of the ABI
+ specification in the POE distinguishes it from other open
+ systems (POSIX, XPG4, etc.) since it allows {platform}
+ independent binary compatibility which is otherwise typically
+ limited to particular hardware.
+
+ The POE is an {open standard}, derived from {AIX} and
+ conforming to industry open standards including {POSIX},
+ {XPG4} and {Motif}. The POE specification will be publicly
+ available to anyone wishing to produce either {application
+ programs} or hardware {platforms}. The {PowerOpen
+ Association} will provide the necessary {conformance test}ing
+ and POE branding.
+
+ The POE is hardware {bus} independent. System implementations
+ can range from {laptop computers} to {supercomputers}. It
+ requires a multi-user, {multitasking} {operating system}. It
+ provides networking support, an {X Window System} extension, a
+ {Macintosh} Application Services extension and {Motif}. It is
+ {conformance test}ed and certified by an independent party
+ (the {PowerOpen Association}).
+
+ The POE specification is targeted for availability in the
+ first quarter of 1994. The {PowerOpen Association} will soon
+ have some of the information material available on-line.
+
+ (1994-11-08)
+
+PowerPC
+
+ <processor, standard> (PPC) A {RISC} {microprocessor} designed
+ to meet a {standard} which was jointly designed by {Motorola},
+ {IBM}, and {Apple Computer} (the PowerPC Alliance). The
+ PowerPC standard specifies a common {instruction set
+ architecture} (ISA), allowing anyone to design and fabricate
+ PowerPC processors, which will run the same code. The PowerPC
+ architecture is based on the IBM {POWER} architecture, used in
+ IBM's {RS/6000} {workstations}. Currently {IBM} and
+ {Motorola} are working on PowerPC chips.
+
+ The PowerPC standard specifies both 32-bit and 64-bit data
+ paths. Early implementations were 32-bit (e.g. {PowerPC
+ 601}); later higher-performance implementations were 64-bit
+ (e.g. PowerPC 620). A PowerPC has 32 integer {registers} (32-
+ or 64 bit) and 32 {floating-point} (IEEE standard 64 bit)
+ {floating-point} registers.
+
+ The POWER CPU chip and PowerPC have a (large) common core, but
+ both have instructions that the other doesn't. The PowerPC
+ offers the following features that POWER does not:
+
+ Support for running in {little-endian} mode.
+
+ Addition of single precision {floating-point} operations.
+
+ Control of branch prediction direction.
+
+ A hardware coherency model (not in Book I).
+
+ Some other {floating-point} instructions (some optional).
+
+ The real time clock (upper and lower) was replaced with the
+ time base registers (upper and lower), which don't count in
+ sec/ns (the decrementer also changed).
+
+ 64-bit instruction operands, registers, etc. (in 64 bit
+ processors).
+
+ See also {PowerOpen}, {PowerPC Platform} (PReP).
+
+ {IBM PPC info
+ (http://fnctsrv0.chips.ibm.com/products/ppc/index.html)}.
+
+ {(gopher://info.hed.apple.com/)}, "Apple Corporate News/"
+ (press releases), "Apple Technologies/" and "Product
+ Information/". {(gopher://ike.engr.washington.edu/)}, "IBM
+ General News/", "IBM Product Announcements/", "IBM Detailed
+ Product Announcements/", "IBM Hardware Catalog/".
+
+ {Usenet} newsgroups: {news:comp.sys.powerpc},
+ {news:comp.sys.mac.hardware}.
+
+ ["Microprocessor Report", 16 October 1991].
+
+ (1994-09-30)
+
+PowerPC 601
+
+ <processor> A 32-bit {RISC} processor with 2.8 million
+ transistors (~1.2 million in the core logic) and 32 kilobytes
+ of on-chip {cache}. Die size: 118.8 mm2. Heat dissipation at
+ 66MHz: 9W. Performance at 66MHz: integer >60 {SPECint92},
+ {floating-point} >80 {SPECfp92}. Estimated manufacturing
+ cost: $76. Maximum instructions per cycle: 3. 32 32-bit
+ general-purpose registers. 32 64-bit {floating-point}
+ registers. Successors: PowerPC 603, 604, 620.
+
+ (2000-01-12)
+
+PowerPC G3
+
+ <processor> A {processor} chip from {Apple Computer, Inc.}.
+
+ Described by Apple as "the third generation in the development
+ of advanced processor technology" the first PowerPC G3
+ products were launched in 1997. It is specifically optimised
+ for the {Macintosh Operating System} and uses {backside cache}
+ to improve performance. The PowerPC G3 has been used by Apple
+ in {notebook}, {desktop} and {server} products.
+
+ {(http://apple.com/powermac/technologies/g3.html)}.
+
+ (1998-10-03)
+
+PowerPC Platform
+
+ <architecture, standard> (PPCP, PReP - PowerPC Reference
+ Platform, formerly CHRP - Common Hardware Reference Platform)
+ An open system standard, designed by {IBM}, intended to ensure
+ compatibility among {PowerPC}-based systems built by different
+ companies. The PReP standard specifies the {PCI} bus, but
+ will also support {ISA}, {MicroChannel} and {PCMCIA}.
+
+ PReP-compliant systems will be able to run the {Macintosh} OS,
+ {OS/2}, {WorkplaceOS}, {AIX}, {Solaris}, {Taligent} and
+ {Windows NT}. IBM systems will (of course) be PReP-compliant.
+ Apple's first {PowerPC} {Macintosh}es will not be compliant,
+ but future ones may be.
+
+ {IBM info
+ (http://fnctsrv0.chips.ibm.com/products/ppc/L3ppcp.html)}.
+
+ {(http://billboard.emedia.com.au/chipster/computers/CHRP/whatsCHRP.html)}.
+
+ [Current OS statuses?]
+
+ (1997-03-23)
+
+PowerPC Reference Platform
+
+ {PowerPC Platform}
+
+Powerpoint
+
+ <graphics, tool> A {Microsoft} application for creating
+ presentations, speeches, slides, etc.
+
+ (1996-08-26)
+
+power save mode
+
+ <architecture> A feature of a component or subsystem designed
+ to actively reduce its power consumption when not in use.
+ Almost any electronic device might benefit from having a power
+ save mode but the most common application is for portable
+ computers which attempt to conserve battery life by
+ incorporating power saving modes in the {CPU}, display, disks,
+ printer, or other units.
+
+ (1995-10-14)
+
+powerset
+
+ <mathematics> The powerset of a set S is the set of possible
+ subsets of S, usually written PS.
+
+ (1994-11-08)
+
+Powersoft Corporation
+
+ <company> A leading vendor of {client/server} application
+ development tools.
+
+ In February 1994, {Watcom} became a wholly-owned subsidiary of
+ Powersoft Corporation which merged with {Sybase} on 13
+ February 1995. In April 1995, the new company is the fastest
+ growing top-ten software company and the seventh largest
+ software company in the world.
+
+ {(http://powersoft.com/)}.
+
+ Headquarters: Concord, Massachusetts, USA.
+
+ (1995-12-27)
+
+power supply
+
+ {power supply unit}
+
+power supply unit
+
+ <hardware> (PSU) An electronic module that converts high
+ voltage (110 or 240 VAC) {alternating current} mains
+ electricity into smoothed {direct current} at the various
+ differnt voltages required by the {motherboard}; internal
+ {peripheral} devices, cheifly storage devices: {hard disks},
+ {CD} or {DVD}, {floppy disks} and external connections such as
+ {USB}. A PSU needs a high enough power output rating to
+ supply all the devices connected to it and should output as
+ little as possible electrical noise, both on the output wires
+ and as {electromagnetic radiation}.
+
+ See also {uninterruptable power supply}.
+
+ (2007-09-20)
+
+PP96
+
+ <language> A parallel {Pascal} extension.
+
+ [Details? Any relation to {Parallel Pascal}?]
+
+ (1998-04-29)
+
+PPC
+
+ {PowerPC}
+
+PPCP
+
+ {PowerPC Platform}
+
+PPD
+
+ {Parallel Presence Detect}
+
+PPGA
+
+ {Plastic Pin Grid Array}
+
+ppi
+
+ {pixels per inch}
+
+PPL
+
+ Polymorphic Programming Language. An interactive, extensible
+ language, based on {APL}, from {Harvard University}.
+
+ ["Some Features of PPL - A Polymorphic Programming Language",
+ T.A. Standish, SIGPLAN Notices 4(8) (Aug 1969)].
+
+ (1994-10-06)
+
+PPLambda
+
+ <language> essentially the {first-order predicate calculus}
+ superposed upon the {simply-typed} {polymorphic
+ lambda-calculus}. PPLambda is the {object language} for
+ {LCF}.
+
+ ["Logic and Computation: Interactive Proof with Cambridge
+ LCF", L. Paulson, Cambridge U Press, 1987].
+
+ (1995-05-01)
+
+PPM
+
+ {Portable Pixmap}
+
+PPN
+
+ Project-Programmer Number.
+
+ A user-ID under {TOPS-10} and its various mutant progeny at
+ {SAIL}, {BBN}, {CompuServe} and elsewhere. Old-time hackers
+ from the {PDP-10} era sometimes use this to refer to user IDs
+ on other systems as well.
+
+ [{Jargon File}]
+
+ (1994-11-18)
+
+PPP
+
+ {Point-to-Point Protocol}
+
+PPPoA
+
+ {Point-to-Point Protocol over ATM}
+
+PPPoE
+
+ {Point-to-Point Protocol over Ethernet}
+
+P-Prolog
+
+ <language> A parallel {logic language}.
+
+ ["P-Prolog: A Parallel Logic Language Based on Exclusive
+ Relation", R. Yang et al, Third Intl Conf on Logic Prog, 1986,
+ pp. 255-269].
+
+ (1994-11-18)
+
+PPTP
+
+ {Point-to-Point Tunneling Protocol}
+
+PQS
+
+ {Picture Quality Scale}
+
+PR
+
+ {Packet Radio}
+
+pr
+
+ <networking> The {country code} for Puerto Rico.
+
+ (1999-01-27)
+
+pr0n
+
+ {pron}
+
+PRA
+
+ PRAgmatics.
+
+ The language used by {COPS} for specification of {code
+ generators}.
+
+ ["Metalanguages of the Compiler Production System COPS", J.
+ Borowiec, in GI Fachgesprach "Compiler-Compiler", ed
+ W. Henhapl, Tech Hochs Darmstadt 1978, pp. 122-159].
+
+ (1994-11-18)
+
+pragma
+
+ <programming> (pragmatic information) A standardised form of
+ {comment} which has meaning to the {compiler} or some other
+ program. It may use a special {syntax} or a specific form
+ within the normal comment syntax. A pragma usually conveys
+ non-essential information, often intended to help the compiler
+ to {optimise} the program or to generate formatted
+ {documentation}.
+
+ (2010-01-19)
+
+PRAM
+
+ <hardware> 1. {parallel random-access machine}.
+
+ 2. {parameter RAM}.
+
+Praxis Critical Systems
+
+ <company> The company that supplies {SPARK}.
+
+ (2001-07-12)
+
+pre\box
+
+ <computer> {Phase 5}'s Amiga clone, announced on 1998-03-10.
+ The pre\box will have a processor card with four {PowerPC}
+ processors running in parallel. The processors will range
+ from four 200 MHz {PPC604e} chips to four 300MHz {PPC750}
+ chips. It will have a {Voodoo2} {video graphics card}, as
+ well as a custom video chip working in concert, with 8 MB of
+ {video ram}. It will run {Amiga OS} 3.1 (or higher if
+ {Gateway 2000} delivers the next upgrade before its release)
+ and have {Motorola 68000} {CPU} {emulation} in software.
+
+ Other features include {EIDE}, {Ultra Wide SCSI-II}, {PCI},
+ {Ethernet} and {DIMM} sockets. Extra RAM, hard disks and
+ {CD-ROM} will be available. The initial specification will
+ probably be 32MB RAM, 32-speed CD and 4GB hard disk in an {ATX
+ minitower}. Systems should start at about $2000 for four
+ parallel 200 MHZ CPUs and be available at the end of 1998.
+
+ {Full press release
+ (http://cucug.org/amiga/aminews/1998/980310-phase5.html)}.
+
+ (1998-07-29)
+
+PRE-CC
+
+ PREttier Compiler-Compiler.
+
+ An earlier version of {PRECCX}.
+
+ (1995-01-24)
+
+PRECCX
+
+ <tool> (Pre-C-Compiler eXtended) An infinite-{lookahead}
+ {compiler-compiler} by Peter Breuer <ptb@comlab.ox.ac.uk> for
+ {context dependent grammars}. PRECCX generates {ANSI C}.
+ Specification scripts are in very {EBNF} with {inherited
+ attributes} and {synthetic attributes} allowed. Scripts can
+ be compiled in separate {modules} and linked later.
+ {Meta-production rules} are allowed. Grammars can be
+ essentially LL(oo) with optimisations. A converter for {yacc}
+ scripts is available.
+
+ Versions 1.xx were known as "PRECC" and only had unbounded
+ lookahead. The 2.xx series added the "X" for "extended" and
+ featured higher order parameterisation (inherited attributes).
+
+ Version 2.42 integrates inherited and synthesized attributes
+ by using a "monadic" model for parsing. You can now synthsize
+ attributes during the pass and inherit them in the remainder,
+ e.g.
+
+ @ foo = bar\x gum(x)
+
+ synthesises an x in bar and passes it down into gum as a
+ parameter. Useful for @ what = ?\x did_you_say(x), for
+ example. It now compiles into {C} instead of running an
+ {interpreter} at parse-time.
+
+ Version 2.42 runs under {Unix} and {MS-DOS}.
+
+ {(http://comlab.ox.ac.uk/archive/redo/precc.html)}.
+
+ E-mail: Peter Breuer <ptb@comlab.ox.ac.uk>, Jonathan Bowen
+ <J.P.Bowen@reading.ac.uk>.
+
+ ["The PRECC Compiler-Compiler" by P.T. Breuer and J.P. Bowen.
+ In E. Davies and A. Findlay (eds.), Proc. UKUUG/SUKUG Joint
+ New Year 1993 Conference, St. Cross Centre, Oxford, UK, 6-8
+ January 1993, ISBN 1 873611 06 4 ({UKUUG}), 0 9520700 0 6
+ (SUKUG) UKUUG/SUKUG Secretariat, Owles Hall, Buntingford,
+ Herts SG9 9PL, UK, pp 167-182, 1993].
+
+ (2000-04-24)
+
+precedence
+
+ {operator precedence}
+
+precedence lossage
+
+ /pre's*-dens los'*j/ A misunderstanding of {operator
+ precedence} resulting in unintended grouping of arithmetic or
+ logical {operators} when coding an {expression}. Used
+ especially of mistakes in {C} code due to the nonintuitively
+ low precedence of "&", "|", "^", "<<" and ">>". For example,
+ the following C expression, intended to test the least
+ significant bit of x,
+
+ x & 1 == 0
+
+ is parsed as
+
+ x & (1 == 0)
+
+ which is always zero (false).
+
+ Some lazy programmers ignore precedence and parenthesise
+ everything. {Lisp} fans enjoy pointing out that this can't
+ happen in *their* favourite language, which eschews precedence
+ entirely, requiring one to use explicit parentheses
+ everywhere.
+
+ [{Jargon File}]
+
+ (1994-12-16)
+
+precharge
+
+ <storage> The phase in the access cycle of {DRAM} during which
+ the storage capacitors are charged to the appropriate value.
+
+ (1997-02-23)
+
+precision
+
+ <mathematics> The number of decimal places to which a number
+ is computed.
+
+ Compare {accuracy}.
+
+ (1998-04-19)
+
+predecessor
+
+ {parent}
+
+predicate calculus
+
+ {predicate logic}
+
+predicate logic
+
+ <logic> (Or "predicate calculus") An extension of
+ {propositional logic} with separate symbols for {predicates},
+ {subjects}, and {quantifiers}.
+
+ For example, where propositional logic might assign a single
+ symbol P to the proposition "All men are mortal", predicate
+ logic can define the predicate M(x) which asserts that the
+ subject, x, is mortal and bind x with the {universal
+ quantifier} ("For all"):
+
+ All x . M(x)
+
+ Higher-order predicate logic allows predicates to be the
+ subjects of other predicates.
+
+ (2002-05-21)
+
+predict
+
+ 1. <simulation> {simulation}, {predictive analytics}.
+
+ 2. <architecture> {branch prediction}.
+
+ 3. <audio, compression> {predictive audio compression}.
+
+predomain
+
+ <theory> A {domain} with no {bottom} element.
+
+ (1995-05-04)
+
+pre-emptive multitasking
+
+ <operating system, parallel> A type of {multitasking} where
+ the {scheduler} can interrupt and suspend ("swap out") the
+ currently running task in order to start or continue running
+ ("swap in") another task. The tasks under pre-emptive
+ multitasking can be written as though they were the only task
+ and the {scheduler} decides when to swap them. The scheduler
+ must ensure that when swapping tasks, sufficient state is
+ saved and restored that tasks do not interfere.
+
+ The length of time for which a process runs is known as its
+ "{time slice}" and may depend on the task's priority or its
+ use of resources such as memory and I/O.
+
+ {OS/2}, {Unix} and the {Amiga} use pre-emptive multitasking.
+
+ This contrasts with {cooperative multitasking} where each task
+ must include calls to allow it to be {deschedule}d
+ periodically.
+
+ (1995-03-20)
+
+prefetch
+
+ {instruction prefetch}
+
+prefix
+
+ 1. <unit> An {SI prefix} used to multiply the value of an {SI
+ (Système International)} unit by some power of ten.
+
+ 2. <programming, mathematics> In mathematics or programming, a
+ {prefix operator} is one that is written before its {operand}. In
+ a {programming language} using {prefix notation}, all operators
+ are prefix operators.
+
+ (2014-07-08)
+
+prefix notation
+
+ <language> (Or "prefix syntax") One of the possible orderings
+ of {functions} and {operands}: in prefix notation the function
+ precedes all its operands. For example, what may normally be
+ written as "1+2" becomes "(+ 1 2)". A few languages (e.g.,
+ {lisp}) have strictly prefix syntax, many more employ prefix
+ notation in combination with {infix notation}.
+
+ The opposite, {postfix notation}, is somewhat rarer.
+
+ (2014-07-08)
+
+prefix syntax
+
+ {prefix notation}
+
+pre-order
+
+ <theory>
+
+ 1. {traversal}.
+
+ 2. A {relation} R is a pre-order if it is {reflexive}
+ (x R x) and {transitive} (x R y R z => x R z). If it is also
+ {antisymmetric} (x R y R x => x = y) then it is a {partial
+ ordering}.
+
+ (2001-10-01)
+
+pre-order traversal
+
+ {traversal}
+
+PREP
+
+ 1. (PReP) {PowerPC Reference Platform}.
+
+ 2. (PREP) PRogrammed Electronics Patterns. Language for
+ designing {integrated circuits}. ["Computer Assisted Mask
+ Production", R.L. Rosenfeld, Proc IEEE 57(9) Sep 1969].
+
+prepaging
+
+ <architecture> (Or "working set model") A technique whereby
+ the {operating system} in a {paging} {virtual memory}
+ {multitasking} environment loads all pages of a process's
+ {working set} into memory before the process is restarted.
+
+ Under {demand paging} a process accesses its working set by
+ {page faults} every time it is restarted. Under prepaging the
+ system remembers the pages in each process's working set and
+ loads them into physical memory before restarting the process.
+ Prepaging reduces the {page fault} rate of reloaded processes
+ and hence generally improves CPU efficiency.
+
+ ["Modern Operating Systems", Andrew S. Tanenbaum,
+ pub. Prentice Hall, Inc. 1992].
+
+ (1998-04-23)
+
+prepend
+
+ <jargon> /pree'pend'/ (by analogy with "append") To prefix or
+ add to the beginning.
+
+ [{Jargon File}]
+
+ (1998-04-23)
+
+preprocessor
+
+ <programming> A program that transforms input data in some way
+ before it is read by the main program. In the case of a
+ {compiler}, the input is {source code}. The main advantage of
+ using a preprocessor is that it is possible to change the
+ specification of the input data without changing the main
+ program. The separation can also help to make the system's
+ overall behaviour easier to understand. The disadvantage is
+ that performance may be reduced by the extra input and output
+ performed between the two programs.
+
+ For example, the {C} preprocessor, {cpp}, handles textual
+ {macro} substitution (it acts as a "macro preprocessor"),
+ {conditional compilation} and inclusion of other files.
+
+ A preprocessor may be used to transform a program into a
+ simpler language, e.g. to transform {C++} into {C}.
+
+ (2007-04-05)
+
+pre-sales support rep
+
+ <job> A person who supports sales by analysing customer
+ requirements, proposing and demonstrating technical solutions,
+ ensuring acceptable product installations, training users and
+ providing initial technical support.
+
+ (2004-03-20)
+
+presence detect
+
+ <storage> A means of identifying a {memory chip} to the
+ {memory controller} logic. The original scheme, Parallel
+ Presence Detect (PPD) used a separate pin for each bit of
+ information. The limited number of pins available only gave
+ the density and the speed of the chips. To pass more
+ information, the Serial Presence Detect (SPD) scheme was
+ introduced, storing the information in {serial EEPROM} with
+ one pin to enable it and one for data.
+
+ (2012-06-25)
+
+presentation layer
+
+ <networking> The second highest layer (layer 6) in the {OSI}
+ seven layer model. Performs functions such as text
+ {compression}, code or format conversion to try to smooth out
+ differences between {hosts}. Allows incompatible processes in
+ the {application layer} to communicate via the {session
+ layer}.
+
+ Documents: {ITU} Rec. X.226 ({ISO} 8823), ITU Rec. X.216 (ISO
+ 8822).
+
+ (1996-07-20)
+
+Presentation Manager
+
+ The {elephantine} graphical user interface to the {OS/2}
+ {operating system}.
+
+prestidigitization
+
+ /pres`t*-di"j*-ti:-zay"sh*n/ 1. A term coined by Daniel Klein
+ <dvk@lonewolf.com> for the act of putting something into
+ digital notation via sleight of hand.
+
+ ["Open Channel", IEEE "Computer", November 1981].
+
+ 2. Data entry through legerdemain.
+
+ [{Jargon File}]
+
+ (1994-11-01)
+
+PRESTO
+
+ A parallel language for shared-memory multiprocessors, built
+ on top of C++ by Bershad et al, U Washington 1987. PRESTO
+ provides {class}es for {threads} and {spinlocks} as well as
+ {Mesa}-style {monitors} and {condition variables}.
+
+ {(ftp://cs.washington.edu/pub/presto1.0.tar.Z)}. E-mail:
+ <presto@cs.washington.edu>.
+
+ ["PRESTO: A Kernel for Parallel Programming Environments",
+ B.N. Bershad et al, U Wash CS TR, Jan 1987].
+
+Pretty Amazing New Stuff
+
+ <humour, communications> (PANS) What {PSTN} is evolving into.
+
+ (1996-10-16)
+
+Pretty Good Privacy
+
+ <tool, cryptography> (PGP) A high security {RSA} {public-key
+ encryption} application for {MS-DOS}, {Unix}, {VAX/VMS}, and
+ other computers. It was written by {Philip R. Zimmermann}
+ <pkz@acm.org> of Phil's Pretty Good(tm) Software and later
+ augmented by a cast of thousands, especially including Hal
+ Finney, Branko Lankester, and Peter Gutmann.
+
+ PGP was distributed as "{guerrilla freeware}". The authors
+ don't mind if it is distributed widely, just don't ask Philip
+ Zimmermann to send you a copy. PGP uses a {public-key
+ encryption} {algorithm} claimed by US patent #4,405,829. The
+ exclusive rights to this patent are held by a California
+ company called {Public Key Partners}, and you may be
+ infringing this patent if you use PGP in the USA. This is
+ explained in the PGP User's Guide, Volume II.
+
+ PGP allows people to exchange files or messages with {privacy}
+ and {authentication}. Privacy and authentication are provided
+ without managing the keys associated with conventional
+ cryptographic software. No secure channels are needed to
+ exchange keys between users, which makes PGP much easier to
+ use. This is because PGP is based on {public-key
+ cryptography}.
+
+ PGP encrypts data using the {International Data Encryption
+ Algorithm} with a random {session key}, and uses the {RSA}
+ algorithm to encrypt the session key.
+
+ In December 1994 Philip Zimmermann faced prosecution for
+ "exporting" PGP out of the United States but in January 1996
+ the US Goverment dropped the case. A US law prohibits the
+ export of {encryption} software out of the country.
+ Zimmermann did not do this, but the US government hoped to
+ establish the proposition that posting an encryption program
+ on a {BBS} or on the {Internet} constitutes exporting it - in
+ effect, stretching export control into domestic censorship.
+ If the government had won it would have had a chilling effect
+ on the free flow of information on the global network, as well
+ as on everyone's privacy from government snooping.
+
+ {FAQ (ftp://ftp.netcom.com/pub/mp/mpj/getpgp.asc)}. {UK FTP
+ (ftp://src.doc.ic.ac.uk/packages/pgp/)}. {USA FTP
+ (http://web.mit.edu/network/pgp-form.html)}.
+ {(http://pegasus.esprit.ec.org/people/arne/pgp.html)}.
+
+ {Justice Dept. announcement
+ (http://eff.org/pub/Alerts/usatty_pgp_011196.announce)}.
+
+ ["Protect Your Privacy: A Guide for PGP Users", William
+ Stallings, Prentice-Hall, ISBN 0-13-185596-4].
+
+ (1996-04-07)
+
+pretty pictures
+
+ (scientific computation) The next step up from {numbers}.
+ Interesting graphical output from a program that may not have
+ any sensible relationship to the system the program is
+ intended to model, but good for showing to {management}.
+
+ [{Jargon File}]
+
+ (1995-02-15)
+
+prettyprint
+
+ /prit'ee-print/ (Or "pretty-print") To generate "pretty"
+ human-readable output from a {hairy} internal representation;
+ especially used for the process of {grind}ing program code.
+
+ [{Jargon File}]
+
+ (1995-02-15)
+
+pretzel key
+
+ {feature key}
+
+preventive maintenance
+
+ (PM) To bring down a machine for inspection or test purposes.
+
+ See {provocative maintenance}, {scratch monkey}.
+
+ (1995-02-15)
+
+PRI
+
+ {ISDN} {Primary Rate Interface}.
+
+ See also {BRI}
+
+ (1994-12-08)
+
+primary cache
+
+ <hardware, architecture> (L1 cache, level one cache) A small,
+ fast {cache} memory inside or close to the {CPU} chip.
+
+ For example, an {Intel 80486} has an eight-{kilobyte} on-chip
+ cache, and most {Pentiums} have a 16-KB on-chip level one
+ cache that consists of an 8-KB {instruction cache} and an 8-KB
+ {data cache}.
+
+ The larger, slower {secondary cache} is normally connected to
+ the CPU via its external {bus}.
+
+ (1997-06-25)
+
+Primary Domain Controller
+
+ <networking> (PDC) Each {Windows NT} {domain} has a Primary
+ Domain Controller and zero or more {Backup Domain
+ Controllers}. The PDC holds the {SAM} database and
+ authenticates access requests from {workstations} and
+ {servers} in the domain.
+
+ (2003-07-16)
+
+primary key
+
+ <database> A unique {identifier}, often an {integer}, that
+ labels a certain row in a table of a {relational database}.
+
+ When this value occurs in other tables as a reference to a
+ particular row in the first table it is called a "foreign
+ key".
+
+ Some {RDBMS}es can generate a new unique identifier each time
+ a new row is inserted, others merely allow a column to be
+ constrained to contain unique values.
+
+ A table may have multiple {candidate keys}, from which the
+ primary key is chosen. The primary key should be an arbitrary
+ value, such as an {autoincrementing} integer. This avoids
+ dependence on uniqueness, permanence and format of existing
+ columns with real-world meaning (e.g. a person's name) or
+ other external identifier (e.g. social security number).
+
+ There should be enough possible primary key values to cater
+ for the current and expected number of rows, bearing in mind
+ that a wider column will generally be slower to process.
+
+ (2006-05-29)
+
+primary management domain
+
+ <messaging> (PRMD) The component of an {X.400} {electronic
+ mail address} that gives the organisation name, usually
+ abbreviated to p= in written addresses.
+
+ See also {ADMD}.
+
+ (2003-05-15)
+
+Primary Rate Interface
+
+ (PRI) A type of {ISDN} connection. In North America and
+ Japan, this consists of 24 channels, usually divided into 23 B
+ channels and 1 D channel, and runs over the same physical
+ interface as {T1}. Elsewhere the PRI has 31 user channels,
+ usually divided into 30 B channels and 1 D channel and is
+ based on the {E1} interface.
+
+ PRI is typically used for connections such as one between a
+ PBX (private branch exchange, a telephone exchange operated by
+ the customer of a telephone company) and a CO (central office,
+ of the telephone company) or IXC (inter exchange carrier, a
+ long distance telephone company).
+
+ (1995-01-18)
+
+primary storage
+
+ {main memory}
+
+Prime Computer
+
+ <company> (Or "Pr1ME") A {minicomputer} manufacturer.
+
+ [Dates? Status? Products? Addresses?]
+
+ (1996-09-28)
+
+Primenet, Inc.
+
+ Arizona's {Internet provider}.
+
+ (1994-12-08)
+
+prime number theorem
+
+ <mathematics> The number of {prime numbers} less than x is
+ about x/log(x). Here "is about" means that the ratio of the
+ two things tends to 1 as x tends to infinity. This was first
+ conjectured by {Gauss} in the early 19th century, and was
+ proved (independently) by Hadamard and de la Vall'ee Poussin
+ in 1896. Their proofs relied on {complex analysis}, but Erdös
+ and Selberg later found an "elementary" proof.
+
+ (1995-04-10)
+
+prime time
+
+ (From TV programming) Normal high-usage hours on a
+ {time-sharing} system; the day shift. Avoidance of prime time
+ was traditionally given as a major reason for {night mode}
+ hacking. The rise of the personal workstation has rendered
+ this term, along with {time-sharing} itself, almost obsolete.
+ The hackish tendency to late-night {hacking runs} has changed
+ not a bit.
+
+ [{Jargon File}]
+
+ (1995-01-18)
+
+primitive
+
+ <programming> A {function}, {operator}, or {type} which is
+ built into a programming language (or {operating system}),
+ either for speed of execution or because it would be
+ impossible to write it in the language. Primitives typically
+ include the arithmetic and logical operations (plus, minus,
+ and, or, etc.) and are implemented by a small number of
+ {machine language} instructions.
+
+ (1995-05-01)
+
+Princeton University
+
+ <body, education> Chartered in 1746 as the College of New
+ Jersey, Princeton was British North America's fourth college.
+ First located in Elizabeth, then in Newark, the College moved
+ to Princeton in 1756. The College was housed in Nassau Hall,
+ newly built on land donated by Nathaniel and Rebeckah
+ FitzRandolph. Nassau Hall contained the entire College for
+ nearly half a century. The College was officially renamed
+ Princeton University in 1896; five years later in 1900 the
+ Graduate School was established.
+
+ Fully coeducational since 1969, Princeton now enrolls
+ approximately 6,400 students (4,535 undergraduates and 1,866
+ graduate students). The ratio of full-time students to
+ faculty members (in full-time equivalents) is eight to one.
+
+ Today Princeton's main campus in Princeton Borough and
+ Princeton Township consists of more than 5.5 million square
+ feet of space in 160 buildings on 600 acres. The University's
+ James Forrestal Campus in Plainsboro consists of one million
+ square feet of space in four complexes on 340 acres.
+
+ As Mercer County's largest private employer and one of the
+ largest in the Mercer/Middlesex/Somerset County region, with
+ approximately 4,830 permanent employees - including more than
+ 1,000 faculty members - the University plays a major role in
+ the educational, cultural, and economic life of the region.
+
+ {(http://princeton.edu/index.html)}.
+
+ (1994-01-19)
+
+principal type
+
+ The most general {type} of an expression. For example, the
+ following are all valid types for the {lambda abstraction}
+ (\ x . x):
+
+ Int -> Int
+ Bool -> Bool
+ (a->b) -> (a->b)
+
+ but any valid type will be an instance of the principal type:
+ a -> a. An instance is derived by substituting the same type
+ expression for all occurences of some {type variable}. The
+ principal type of an expression can be computed from those of
+ its subexpressions by Robinson's {unification} {algorithm}.
+
+ (1994-12-16)
+
+PRINT
+
+ <language> PRe-edited INTerpreter.
+
+ An early mathematics language for the {IBM 705}.
+
+ [Sammet 1969, p. 134].
+
+ (1995-05-01)
+
+printed circuit board
+
+ <hardware> (PCB) A thin board to which electronic components
+ are fixed by solder. Component leads and {integrated circuit}
+ pins may pass through holes ("vias") in the board or they may
+ be {surface mounted}, in which case no holes are required
+ (though they may still be used to connect different layers).
+
+ The simplest kind of PCB has components and wires on one side
+ and interconnections (the printed circuit) on the other. PCBs
+ may have components mounted on both sides and may have many
+ internal layers, allowing more connections to fit in the same
+ board area. Boards with internal conductor layers usually
+ have "plated-through holes" to improve the electrical
+ connection to the internal layers.
+
+ The connections are metal strips (usually copper). The
+ pattern of connections is often produced using photo-resist
+ and acid etching. Boards, especially those for high frequency
+ circuits such as modern {microprocessors}, usually have one or
+ more "{ground planes}" and "power planes" which are large
+ areas of copper for greater current carrying ability.
+
+ A computer or other electronic system might be built from
+ several PCBs, e.g. processor, memory, graphics controller, disk
+ controller etc. These boards might all plug into a
+ {motherboard} or {backplane} or be connected by a {ribbon
+ cable}.
+
+ (1995-05-01)
+
+printer
+
+ <printer> A {peripheral} device for producing text and images
+ on paper. There are many different types, broadly grouped
+ into "{impact printers}" and "{non-impact printers}".
+
+ Compare {plotter}. See also {Braille printer}, {tree-killer}.
+
+ (1996-01-13)
+
+Printer Access Protocol
+
+ <networking, protocol, printer> (PAP) A {protocol} used in
+ {Mac OS} {Appletalk} to provide bi-directional communication
+ between {PostScript} printers and the client computer.
+
+ (1999-03-02)
+
+printer port
+
+ <hardware, printer> A connector found on many {microcomputers}
+ intended for attaching a printer. This may be a
+ general-purpose input/output {parallel port} or may be a
+ special {Centronics} interface.
+
+ Most printers can also be connected to a {serial port} but
+ that is unlikely to be described as a "printer port".
+
+ (1996-01-07)
+
+printf
+
+ <library> The standard function in the {C} programming
+ language library for printing formatted output.
+
+ The first argument is a format string which may contain
+ ordinary characters which are just printed and "conversion
+ specifications" - sequences beginning with '%' such as %6d
+ which describe how the other arguments should be printed, in
+ this case as a six-character decimal integer padded on the
+ right with spaces.
+
+ Possible conversion specifications are d, i or u (decimal
+ integer), o ({octal}), x, X or p ({hexadecimal}), f
+ ({floating-point}), e or E ({mantissa} and {exponent},
+ e.g. 1.23E-22), g or G (f or e format as appropriate to the
+ value printed), c (a single character), s (a string), %
+ (i.e. %% - print a % character). d, i, f, e, g are signed,
+ the rest are unsigned.
+
+ The variant {fprintf} prints to a given output stream and
+ sprintf stores what would be printed in a string variable.
+
+ {Unix manual page}: printf(3).
+
+ (1996-12-08)
+
+PRINT I
+
+ An early system on {IBM 705}.
+
+ [CACM 2(5):16 (May 1959)].
+
+printing discussion
+
+ [XEROX PARC] A protracted, low-level, time-consuming,
+ generally pointless discussion of something
+ only peripherally interesting to all.
+
+ [{Jargon File}]
+
+print server
+
+ <printer> A {server} device that is set up on a {network} to
+ route print requests and status information between computers
+ and {printers} connected by a network. A typical print server
+ routes print requests for multiple computers and printers on a
+ network.
+
+ For example, a networked {workstation} user submits a print
+ command that includes a {print file} and information about the
+ printer to be used, usually a nearby printer for convenience.
+ The print server sends the print file to the requested
+ printer. The printer {spools} the print file and provides job
+ status. The print server relays the status of the printer
+ back to the workstation and makes this status information
+ available to other devices on the network.
+
+ (1999-02-18)
+
+Print Services Facility
+
+ <printer> (PSF) {IBM}'s system software which generates
+ {native} IBM printer language, {IPDS} and, depending on the
+ version, {PostScript} and LaserJet {PCL}.
+
+ See also: {Advanced Function Presentation}.
+
+ (1998-06-28)
+
+priority inheritance
+
+ <parallel> A technique for avoiding {priority inversion} by
+ temporarily raising the prioriry of all processes that want to
+ access a shared resource to the highest priority level of any
+ of them. Priority inversion occurs where a low priority
+ process, L is holding a resource required by a high priority
+ process, H, but L is not running because a medium priority
+ process, M is running. Under priority inheritance, L
+ temporarily inherits H's priority, allowing L to run and
+ release the resource H is waiting for.
+
+ For example, an ambulance (H) is stuck behind a lorry (L)
+ waiting at a junction (the shared resource) for a gap in a
+ line of cars (M) using the junction. Applying priority
+ inheritance, the cars give way to the lorry as they would to
+ the ambulance, thus allowing the lorry and then the ambulance
+ to use the junction.
+
+ (2005-02-11)
+
+priority interrupt
+
+ <jargon> Any stimulus compelling enough to yank one right out
+ of {hack mode}. Classically used to describe being dragged
+ away by an {SO} for immediate sex, but may also refer to more
+ mundane interruptions such as a fire alarm going off in the
+ near vicinity. Also called an {NMI} (non-maskable interrupt),
+ especially in PC-land.
+
+ [{Jargon File}]
+
+ (2005-02-13)
+
+priority inversion
+
+ <parallel> The state of a concurrent system where a high
+ priority task is waiting for a low priority task which is
+ waiting for a medium priority task. The system may become
+ unstable and {crash} under these circumstances.
+
+ In an {operating system} that uses multiple tasks, each task
+ (or {context}) may be given a priority. These priorities help
+ the {scheduler} decide which task to run next. Consider
+ tasks, L, M, and H, with priorities Low, Medium, and High. M
+ is running and H is blocked waiting for some resource that is
+ held by L. So long as any task with a priority higher than L
+ is runable, it will prevent task L, and thus task H, from
+ running.
+
+ Priority inversion is generally considered either as a
+ high-level design failure or an implementation issue to be
+ taken into account depending on who is talking. Most
+ operating systems have methods in place to prevent or take
+ inversion into account. {Priority inheritance} is one method.
+
+ The most public instance of priority inversion is the repeated
+ 'fail-safe' rebooting of the {Mars Pathfinder
+ (http://research.microsoft.com/~mbj/Mars_Pathfinder/Mars_Pathfinder.html)}.
+ base station ('Sagan Memorial Station').
+
+ (2003-06-04)
+
+priority queue
+
+ <programming> A data structure with three operations: insert a
+ new item, return the highest priority item, and remove the
+ highest priority item. The obvious way to represent priority
+ queues is by maintaining a sorted list but this can make the
+ insert operation very slow. Greater efficiency can be
+ achieved by using {heaps}.
+
+ (1996-03-12)
+
+priority scheduling
+
+ <operating system> {Processes scheduling} in which the
+ {scheduler} selects tasks to run based on their priority as
+ opposed to, say, a simple {round-robin}.
+
+ Priorities may be static or dynamic. Static priorities are
+ assigned at the time of creation, while dynamic priorities are
+ based on the processes' behaviour while in the system. For
+ example, the scheduler may favour {I/O}-intensive tasks so
+ that expensive requests can be issued as early as possible.
+
+ A danger of priority scheduling is {starvation}, in which
+ processes with lower priorities are not given the opportunity
+ to run. In order to avoid starvation, in preemptive
+ scheduling, the priority of a process is gradually reduced
+ while it is running. Eventually, the priority of the running
+ process will no longer be the highest, and the next process
+ will start running. This method is called {aging}.
+
+PRISM
+
+ A distributed {logic language}.
+
+ ["PRISM: A Parallel Inference System for Problem Solving",
+ S. Kasif et al, Proc 1983 Logic Prog Workshop, pp. 123-152].
+
+Prisoner of Bill
+
+ <humour> (PoB) A derisory term, in use generally among {Unix}
+ users, for anyone who uses {Microsoft} products either because
+ they don't know there is anything better (i.e. Unix) or
+ because they would be incapable of working anything more
+ complex (i.e. Unix).
+
+ The interesting and widespread presumption among users of the
+ term is that (at least at the time of writing, 1998) using
+ anything other than Unix or a Microsoft OS (whether {VMS},
+ {Macintosh}, {Amiga}) is so eccentric a choice as to be at
+ least somewhat praiseworthy.
+
+ (1998-09-07)
+
+privacy
+
+ <security> An attribute of a system's {security} that ensures
+ that only intended or desired people or bodies can read a
+ message or piece of stored data. Privacy is often enforced by
+ some kind of {access control} or {encryption}.
+
+ (2011-06-03)
+
+Privacy Enhanced Mail
+
+ <messaging< (PEM) {Internet} {electronic mail} which provides
+ {confidentiality}, {authentication} and message {integrity}
+ using various {encryption} methods.
+
+ See also {Pretty Good Privacy}.
+
+ (2009-06-03)
+
+private
+
+ {privacy}
+
+Private Automatic Branch eXchange
+
+ <communications> (PABX) A telephone exchange operated within
+ an organisation, used for switching calls between internal
+ lines and between internal and {PSTN} lines. In contrast to a
+ {PMBX}, a PABX can route calls without manual intervention,
+ based entirely on the number dialed. Not all PABXs can route
+ external calls to internal numbers automatically however.
+
+ (1998-08-07)
+
+Private Branch Exchange
+
+ <communications> (PBX) A telephone exchange local to a
+ particular organisation who use, rather than provide,
+ telephone services. The earliest PBXs were manual ({Private
+ Manual Branch EXchange}, PMBX) but are now more likely to be
+ automatic ({Private Automatic Branch eXchange}).
+
+ (1997-06-25)
+
+private key
+
+ <cryptography> A piece of data used in {private-key
+ cryptography} and {public-key cryptography}. In the former
+ the private key is known by both sender and recipient whereas
+ in the latter it is known only to the sender.
+
+ (2008-02-07)
+
+private-key cryptography
+
+ <cryptography> As opposed to {public-key cryptography}, a
+ cryptographic method in which the same key is used to encrypt
+ and decrypt the message. Private-key algorithms include the
+ obsolescent {Data Encryption Standard} (DES), triple-DES
+ (3DES), the {Advanced Encryption Standard} (AES), also known
+ as Rijndael, Blowfish, Twofish RC2, {RC4}, RC5 and RC6.
+
+ A problem with private-key cryptography is that the sender and
+ the recipient of the message must agree on a common key via
+ some alternative secure channel.
+
+ {Public-key cryptography} gives an answer to this problem.
+
+ (2008-02-07)
+
+Private Manual Branch eXchange
+
+ <communications> (PMBX) The original manual equivalent of a
+ {PABX}; a PMBX involves company employed operators manually
+ switching each call using a manual switchboard.
+
+ (1998-08-07)
+
+privileged instruction
+
+ A {machine code} instruction that may only be executed when
+ the processor is running in {supervisor mode}. Privileged
+ instructions include operations such as I/O and {memory
+ management}.
+
+ (1995-02-15)
+
+PRL
+
+ Proof Refinement Logic.
+
+ Versions: {micro-PRL}, {lambda-PRL}, {nu-PRL}.
+
+ ["PRL: Proof Refinement Logic Programmer's Manual", CS Dept,
+ Cornell, 1983].
+
+ (1995-01-24)
+
+PRMD
+
+ {primary management domain}
+
+PRML
+
+ {Partial Response Maximum Likelihood}
+
+probabilistic
+
+ <probability> Relating to, or governed by, probability. The
+ behaviour of a probabilistic system cannot be predicted
+ exactly but the probability of certain behaviours is known.
+ Such systems may be simulated using {pseudorandom} numbers.
+ {Evolutionary computation} uses probabilistic processes to
+ generate new (potential) solutions to a problem.
+
+ See also {deterministic}, {non-probabilistic}.
+
+ (1995-09-22)
+
+probabilistic automaton
+
+ {nondeterministic automaton}
+
+Probability of Failure on Demand
+
+ <systems> (POFOD) The likelihood that some system will fail
+ when a service request is made.
+
+ (2010-09-26)
+
+Probe
+
+ An {object-oriented} {logic language} based on {ObjVlisp}.
+
+ ["Proposition d'une Extension Objet Minimale pour Prolog",
+ Actes du Sem Prog en Logique, Tregastel (May 1987),
+ pp. 483-506].
+
+problem state
+
+ {IBM} jargon for {user mode}, the opposite of "supervisor
+ state".
+
+ On IBM {System 360}, 370 and 390 {mainframes} {privileged
+ instructions} may only be executed in "supervisor state".
+ {Application programs} request the {operating system} to
+ perform these operations by using the Supervisor Call (SVC)
+ instruction.
+
+ (1995-02-15)
+
+Problem Statement Language/Problem Statement Analyser
+
+ <language> (PSL/PSA) A {CASE} system developed by
+ D. Teichroew that allows computer-based development
+ and analysis of a statement of {requirements},
+ and assistance during the design phase.
+
+ (2010-01-26)
+
+PROC
+
+ <language> The {job control language} used in the {Pick}
+ {operating system}.
+
+ ["Exploring the Pick Operating System", J.E. Sisk et al,
+ Hayden 1986].
+
+ (1998-10-13)
+
+procedural
+
+ {procedural language}
+
+procedural language
+
+ <language> Any {programming language} in which the programmer
+ specifies an explicit sequences of steps to follow to produce
+ a result (an {algorithm}).
+
+ The term should not be confused with "{imperative language}" -
+ a language that specifies explicit manipulation of state. An
+ example (non-imperative) procedural language is {LOGO}, which
+ specifies sequences of steps to perform but does not have an
+ internal state.
+
+ Other procedural languages include {Basic}, {Pascal}, {C}, and
+ {Modula-2}.
+
+ Both procedural and imperative languages are in contrast to
+ {declarative languages}, in which the programmer specifies
+ neither explicit steps nor explicit state manipulation.
+
+ (2004-05-17)
+
+Procedural Language/SQL
+
+ <language> (PL/SQL) {Oracle Corporation}'s proprietary
+ {procedural language} extension of industry-standard {SQL}.
+
+ [Features? Reference? Any relation to {PL/I}?]
+
+ (1999-09-14)
+
+procedure
+
+ {subroutine}
+
+proceedings
+
+ <publication> (Proc.) A printed collection of papers presented
+ at a conference or meeting, e.g. "The Proceedings of the Fifth
+ International Conference on Microelectronics for Neural
+ Networks and Fuzzy Systems". Along with learned journals,
+ conference proceedings are a major repository of peer-reviewed
+ research results.
+
+ (2008-07-16)
+
+process
+
+ 1. <operating system, software> The sequence of states of an
+ executing {program}. A process consists of the program {code}
+ (which may be shared with other processes which are executing
+ the same program), private data, and the state of the
+ {processor}, particularly the values in its {registers}. It
+ may have other associated resources such as a {process
+ identifier}, open files, {CPU time} limits, {shared memory},
+ {child processes}, and {signal handlers}.
+
+ One process may, on some {platforms}, consist of many
+ {threads}. A {multitasking} {operating system} can run
+ multiple processes {concurrently} or in {parallel}, and allows
+ a process to spawn "child" processes.
+
+ (2001-06-16)
+
+ 2. <business> The sequence of activities, people, and systems
+ involved in carrying out some business or achieving some
+ desired result. E.g. software development process, project
+ management process, configuration management process.
+
+ (2001-06-16)
+
+Process and Experiment Automation Real-Time Language
+
+ <language> (PEARL) A {real-time} language for programming
+ {process control} systems, widely used in Europe. Size and
+ complexity exceeds {Ada}. Defined in {DIN} 66253 Teil 2.
+
+ ["Programmiersprache PEARL", Beuth-Verlag, Nov 1980].
+
+ (2000-08-16)
+
+process data
+
+ {data processing}
+
+Process Design Language 2
+
+ <language> (PDL2) A language developed for the {Texas
+ Instruments} {ASC} computer.
+
+ ["Texas Instruments Process Design Methodology - Design
+ Specification: Process Design Language", Volume I (Sep 1976)].
+
+ [Mentioned in "An Overview of Ada" J.G.P. Barnes, Soft Prac &
+ Exp 10:851-887 (1980)].
+
+ (1995-08-13)
+
+process ID
+
+ {process identifier}
+
+process identifier
+
+ <operating system> (PID) An integer used by the {Unix}
+ {kernel} to uniquely identify a process. PIDs are returned by
+ the {fork} {system call} and can be passed to wait() or
+ kill() to perform actions on the given process.
+
+ (1996-12-09)
+
+processing
+
+ <data> Performing some predefined sequence of operations on an
+ input to produce an output or change of internal state; activity
+ specifically involving the computer's {CPU}.
+
+ The term is often qualified: "{data processing}" treats
+ {digital} data, "{signal processing}" treats {analog} data
+ (possibly in digital form), "{word processing}" takes in typed
+ human language input and produces digital documents, {image
+ processing} transforms digital {images}.
+
+ (2003-10-23)
+
+processor
+
+ {central processing unit}
+
+Processor Direct Slot
+
+ <hardware> (PDS) {Apple Computer}'s name for a {local bus}
+ connection. Most {Macintosh}es have only one PDS connector.
+ Different Apple computers have different PDS specifications.
+
+ (1995-05-02)
+
+processor farm
+
+ <computer, parallel> A {parallel processor} where tasks are
+ distributed, or "farmed out", by one "farmer" processor to
+ several "worker" processors, and results are sent back to the
+ farmer. This arrangement is suitable for {applications} which
+ can be partitioned into many separate, independent tasks, the
+ canonical examples being {ray tracing} and the {Mandelbrot
+ set}. In order to be efficient, the extra time spent on
+ communications must be small compared to the time spent
+ processing each task.
+
+ (2001-05-28)
+
+Processor System Modeling Language
+
+ <language> (PSML) A language for simulating computer systems
+ designs, implemented as a {preprocessor} to {SIMSCRIPT}.
+
+ ["Processor System Modeling - A Language and Simulation
+ System", F. Pfisterer, Proc Symp on Simulation of Computer
+ Systems, Aug 1976].
+
+ (2009-05-11)
+
+processor time
+
+ <software> The amount of time a {process} takes to run, given
+ that it has exclusive and uninterrupted use of the {CPU}.
+ Note that in a modern computer, this would be very unusual,
+ and so the processor time calculation for most processes
+ involves adding up all the small amounts of time the CPU
+ actually spends on the process.
+
+ Some systems break processor time down into {user time} and
+ {system time}.
+
+ Compare {wall clock time}.
+
+ (1998-03-13)
+
+process scheduling
+
+ {multitasking}
+
+process table
+
+ <operating system, process> A table containing all of the
+ information that must be saved when the {CPU} switches from
+ running one {process} to another in a {multitasking} system.
+
+ The information in the process table allows the suspended
+ process to be restarted at a later time as if it had never
+ been stopped. Every process has an entry in the table. These
+ entries are known as {process control blocks} and contain the
+ following information:
+
+ process state - information needed so that the process can be
+ loaded into memory and run, such as the {program counter}, the
+ {stack pointer}, and the values of {registers}.
+
+ memory state - details of the memory allocation such as
+ pointers to the various memory areas used by the program
+
+ resource state - information regarding the status of files
+ being used by the process such as {user ID}.
+
+ Accounting and scheduling information.
+
+ An example of a UNIX process table is shown below.
+
+ SLOT ST PID PGRP UID PRI CPU EVENT NAME FLAGS
+ 0 s 0 0 0 95 0 runout sched load sys
+ 1 s 1 0 0 66 1 u init load
+ 2 s 2 0 0 95 0 10bbdc vhand load sys
+
+ SLOT is the entry number of the process.
+
+ ST shows whether the process is paused or sleeping (s), ready
+ to run (r), or running on a {CPU} (o).
+
+ PID is the {process ID}.
+
+ PGRP is the {process Group}.
+
+ UID is the {user ID}.
+
+ PRI is the priority of the process from 127 (highest) to 0
+ (lowest).
+
+ EVENT is the {event} on which a process is paused or
+ sleeping.
+
+ NAME is the name of the process.
+
+ FLAGS are the process {flags}.
+
+ A process that has died but still has an entry in the process
+ table is called a {zombie process}.
+
+ (1998-04-24)
+
+PROCOL
+
+ <language> A parallel {object language} with {protocols},
+ {constraints} and distributed delegation by J. Van Den Bos of
+ Erasmus University, Rotterdam.
+
+ ["PROCOL: A Parallel Object Language with Protocols", J. Van
+ Den Bos et al, SIGPLAN Notices 24(10):95-102 (OOPSLA '89), Oct
+ 1989].
+
+ (1998-03-23)
+
+Procomm
+
+ <communications, product> A {terminal emulator} program,
+ originally from {Datastorm Technologies}, used for connection
+ to {BBS}es etc.
+
+ Procomm Plus for Windows incorporates automatic {modem}
+ detection, a custom log-on script generator and sophisticated
+ {off-line} message managers for {CompuServe} and {MCI Mail}.
+ It also has a fax send and receive capability.
+
+ Version 2.0 was chosen as the Editors Choice in PC Magazine
+ 1995-03-14.
+
+ Procomm Plus is now distributed by {Symantec, Inc.}.
+
+ {Procomm Home (http://symantec.com/procomm/)}.
+
+ {Version 2.4.3 1989-01-01
+ (http://ftp.bauru.unesp.br/comunicacao/procomm/PRCM243.NEW)}.
+
+ Current Version: Procomm Plus 4.8, as of 2004-06-29.
+
+ (2004-06-29)
+
+Procrustean string
+
+ <programming> A fixed-length {string}. If a string value is
+ too long for the allocated space, it is truncated to fit; and
+ if it is shorter, the empty space is padded, usually with
+ space characters.
+
+ This is an allusion to Procrustes, a legendary robber of ancient
+ Attica. He bound his victims to a bed, and if they were shorter
+ than the bed, he stretched their limbs until they would fit; if
+ their limbs were longer, he lopped them off.
+
+ (1997-09-12)
+
+Prodigy
+
+ <networking> A commercial on-line conferencing service,
+ co-developed by {IBM} and Sears, Roebuck, Inc.
+
+ Prodigy's main competitors are {AOL} and {Compuserve}.
+
+ (1995-03-01)
+
+ProDoc
+
+ <documentation> A set of tools for software {documentation}
+ from {SPC}.
+
+ (2006-10-12)
+
+product
+
+ <mathematics, programming> An {expression} in mathematics or
+ computer programming consisting of two other expressions
+ multiplied together. In mathematics, multiplication is
+ usually represented by {juxtaposition}, e.g. "x y", whereas in
+ programming, "*" is used as an {infix} operator, e.g. "salary
+ * tax_rate.
+
+ In the most common type of product, each {operand} is a number
+ ({integer}, {real number}, {fraction} or {imaginary number})
+ but the term extends naturally to cover more complex
+ operations like multiplying a string by an integer (e.g., in
+ {Perl}, "foo" x 2) or multiplying {vectors} and {matrices} or
+ more than two operands.
+
+ In {type systems}, a {tuple} is sometimes known as a "product
+ type".
+
+ (2006-10-12)
+
+production system
+
+ <programming> A production system consists of a collection of
+ productions (rules), a {working memory} of {facts} and an
+ {algorithm}, known as {forward chaining}, for producing new
+ facts from old. A rule becomes eligible to "fire" when its
+ conditions match some set of elements currently in working
+ memory. A {conflict resolution strategy} determines which of
+ several eligible rules (the {conflict set}) fires next. A
+ condition is a list of symbols which represent constants,
+ which must be matched exactly; variables which bind to the
+ thing they match and "<> symbol" which matches a field not
+ equal to symbol.
+
+ Example production systems are {OPS5}, {CLIPS}, {flex}.
+
+ (2005-06-17)
+
+Professional Graphics Adapter
+
+ <graphics, specification> (PGA) A computer video {display
+ standard} produced by {IBM} for early {CAD} applications. It
+ had a resolution of 640x400 {pixels}.
+
+ (1997-04-25)
+
+Professional Office System
+
+ <messaging> (PROFS) An office messaging system from {IBM},
+ used worldwide, mainly on IBM {mainframes}.
+
+ (1996-03-23)
+
+professional programming
+
+ {paranoid programming}
+
+professional services
+
+ <job> A department of a supplier providing consultancy and
+ programming manpower for the supplier's products.
+
+ (2004-03-09)
+
+PROFILE
+
+ Simple language for matching and scoring data. "User's Manual
+ for the PROFILE System", Cambridge Computer Assoc (May 1974).
+
+ [{Jargon File}]
+
+profile
+
+ 1. A control file for a program, especially a text file
+ automatically read from each user's home directory and
+ intended to be easily modified by the user in order to
+ customise the program's behaviour. Used to avoid {hard-coded}
+ choices (see also {dot file}, {rc file}).
+
+ 2. A report on the amounts of time spent in each routine of a
+ program, used to find and {tune} away the {hot spots} in it.
+ This sense is often verbed. Some profiling modes report units
+ other than time (such as call counts) and/or report at
+ granularities other than per-routine, but the idea is similar.
+
+PROFS
+
+ {Professional Office System}
+
+PROGENY
+
+ 1961. Report generator for UNIVAX SS90.
+
+proglet
+
+ /prog'let/ [UK] A short extempore program written to meet an
+ immediate, transient need. Often written in BASIC, rarely
+ more than a dozen lines long and containing no subroutines.
+ The largest amount of code that can be written off the top of
+ one's head, that does not need any editing, and that runs
+ correctly the first time (this amount varies significantly
+ according to one's skill and the language one is using).
+ Compare {toy program}, {noddy}, {one-liner wars}.
+
+ [{Jargon File}]
+
+program
+
+ {software}
+
+Program Composition Notation
+
+ (PCN) A specification language for parallelism between {C} and
+ {Fortran} {modules}. PCN provides a simple language for
+ specifying {concurrent} {algorithms}, interfaces to {Fortran}
+ and {C}, a portable toolkit that allows applications to be
+ developed on a {workstation} or small parallel computer and
+ run unchanged on {supercomputers} and integrated debugging and
+ performance analysis tools. PCN was developed at {Argonne
+ National Laboratory} and the {California Institute of
+ Technology}. It has been used to develop a wide variety of
+ applications, in areas such as climate modelling, fluid
+ dynamics, computational biology, chemistry, and circuit
+ simulation.
+
+ Version 2.0 runs on networks of workstations: {Sun-4}, {NeXT},
+ {RS/6000}, {SGI}; {multicomputers}: {iPSC}/860, {Touchstone
+ DELTA}; and {shared memory} multiprocessors:
+ {Symmetry}/{Dynix}.
+
+ {(ftp://info.mcs.anl.gov/pub/pcn)}.
+
+ E-mail: Ian Foster <pcn@mcs.anl.gov>, Steve Tuecke
+ <tuecke@mcs.anl.gov>.
+
+ ["Productive Parallel Programming: The PCN Approach",
+ I. Foster et al, Sci Prog 1(1):51-66 (1992)].
+
+ (1993-02-12)
+
+program counter
+
+ <hardware> (PC) A {register} in the {central processing unit}
+ that contains the addresss of the next {instruction} to be
+ executed. After each instruction is fetched, the PC is
+ automatically incremented to point to the following
+ instruction. It is not normally manipulated like an ordinary
+ {register} but instead, special instructions are provided to
+ alter the {flow of control} by writing a new value to the PC,
+ e.g. JUMP, CALL, {RTS}.
+
+ {IBM} call it the {Instruction Address Register}.
+
+ (1995-03-21)
+
+Program Design Language
+
+ Any of a large class of formal and profoundly useless
+ pseudo-languages in which {management} forces one to design
+ programs. Too often, management expects PDL descriptions to
+ be maintained in parallel with the code, imposing massive
+ overhead of little or no benefit.
+
+ See also {flow chart}.
+
+ (1995-04-01)
+
+Program Evaluation and Review Technique
+
+ <programming> (PERT) A method used to size a software product
+ and calculate the Standard Deviation (SD) for risk assessment.
+ The PERT equation (beta distribution) estimates the Equivalent
+ {Delivered Source Instructions} (EDSIs) and the SD based on
+ the analyst's estimates of the lowest possible size, the most
+ likely size, and the highest possible size of each computer
+ program component (CPC).
+
+ (1996-05-29)
+
+Program Information File
+
+ <file format> Under {Windows}, a file providing information on
+ how a non-Windows {application program} should be run,
+ including how much {memory} should be allocated to it and what
+ graphics interface it requires.
+
+ {Filename extension}: .pif
+
+ (1997-10-11)
+
+Programmable Airline Reservation System
+
+ <application> (PARS) An {IBM} proprietary large scale airline
+ reservation application, executing under the control of IBM's
+ {ACP} (and later its successor, {TPF}).
+
+ In the early days of automated reservations systems in the
+ 1960s and 1970s the combination of ACP and PARS provided
+ unprecendented scale and performance from an on-line
+ {real-time} system, and for a considerable period ranked among
+ the largest networks and systems of the era.
+
+ {IPARS} was the international version.
+
+ (1999-01-18)
+
+Programmable Array Logic
+
+ <hardware> (PAL) A family of fuse-programmable logic
+ {integrated circuits} originally developed by {MMI}.
+ Registered or {combinatorial} output functions are modelled in
+ a {sum of products} form. Each output is a sum (logical or)
+ of a fixed number of products (logical and) of the input
+ signals. This structure is well suited for automatic
+ generation of programming patterns by logic compilers.
+
+ PAL devices are programmed by blowing the fuses permanently
+ using overvoltage.
+
+ Today, more complex devices based on the same original
+ architecture are available (CPLD's for Complex PLD's) that
+ incorporate the equivalent of several original PAL chips. PAL
+ chips are, however, still popular due to their high speed.
+
+ {Generic Array Logic} devices are reprogrammable and contain
+ more {logic gates}.
+
+ (1995-12-09)
+
+Programmable Interrupt Controller
+
+ <integrated circuit> {PIC} A special-purpose {integrated
+ circuit} that functions as an overall manager in an
+ {interrupt} driven system. It accepts requests from the
+ {peripheral} equipment, determines which of the incoming
+ requests is of the highest priority, ascertains whether the
+ incoming request has a higher priority value than the level
+ currently being serviced, and issues an interrupt to the {CPU}
+ based on this determination.
+
+ PICs typically have eight interrupt lines, and two PICs are
+ often cascaded to provide 15 available interrupt lines.
+
+ See also: {Advanced Programmable Interrupt Controller}.
+
+ (2003-03-18)
+
+Programmable Logic Controller
+
+ <hardware> (PLC) A device used to automate monitoring and
+ control of industrial plant. Can be used stand-alone or in
+ conjunction with a {SCADA} or other system.
+
+ (1997-02-11)
+
+Programmable Read-Only Memory
+
+ <storage> (PROM) A kind of {ROM} which can be written using a
+ PROM programmer. The contents of each bit is determined by a
+ {fuse} or {antifuse}. The memory can be programmed once after
+ manufacturing by "blowing" the fuses, which is an irreversible
+ process. Blowing a fuse opens a connection while blowing an
+ antifuse closes a connection (hence the name). Programming is
+ done by applying high-voltage pulses which are not encountered
+ during normal operation.
+
+ (1995-04-22)
+
+Programmed Data Processor
+
+ <computer> (PDP) Early (1960's?) {Digital Equipment
+ Corporation} family of {minicomputers}. The best known ranges
+ were the {PDP-10} and {PDP-11}. {PAL} was the {assembly
+ language}.
+
+ (1997-11-21)
+
+PROgrammed Graph REwriting Systems
+
+ <language> (PROGRES) A very high level language based on
+ {graph grammars}, developed by Andy Scheurr
+ <andy@i3.informatik.rwth-aachen.de> and Albert Zuendorf
+ <albert@i3.informatik.rwth-aachen.de> of {RWTH}, Aachen in
+ 1991.
+
+ PROGRES supports structurally {object-oriented specification}
+ of {attributed graph} structures with {multiple inheritance}
+ hierarchies and types of types (for {parametric
+ polymorphism}). It also supports declarative/relational
+ specification of derived attributes, node sets, binary
+ relationships (directed edges) and {Boolean} {constraints},
+ rule-oriented/visual specification of parameterised graph
+ rewrite rules with complex application conditions,
+ {nondeterministic} and {imperative programming} of composite
+ graph transformations (with built-in {backtracking} and
+ cancelling arbitrary sequences of failing graph
+ modifications).
+
+ It is used for implementing {abstract data types} with
+ graph-like internal structure, as a visual language for the
+ {graph-oriented database} {GRAS}, and as a rule-oriented
+ language for prototyping {nondeterministic}ally specified
+ data/rule base transformations.
+
+ PROGRES has a formally defined {semantics} based on
+ "PROgrammed Graph Rewriting Systems". It is an almost
+ {statically typed} language which additionally offers "down
+ casting" operators for run time checked type
+ casting/conversion (in order to avoid severe restrictions
+ concerning the language's expressiveness).
+
+ Version RWTH 5.10 includes an integrated environment.
+
+ [A. Scheurr, "Introduction to PROGRES, an Attribute Graph
+ Grammar Based Specification Language", in Proc WG89 Workshop
+ on Graphtheoretic Concepts in Computer Science", LNCS 411,
+ Springer 1991].
+
+ {(ftp://ftp.informatik.rwth-aachen.de/pub/Unix/PROGRES/)} for
+ {Sun-4}.
+
+ (1993-11-02)
+
+programmer
+
+ <job> (Or "computer programmer", "developer") Someone who
+ writes or debugs {computer programs}, for a living or for fun.
+ "Analyst/developer" is a common equivalent job title, implying
+ the added role of {system analysis}. The term may be
+ qualified according to the type of software - "{application}
+ programmer", "{system programmer}", etc.
+
+ (2000-01-24)
+
+Programmer Brain Damage
+
+ <humour> (PBD) A classification of a {bug} which was obviously
+ introduced by an incompetent or short-sighted programmer.
+
+ Compare {UBD}. See also {brain-damaged}.
+
+ (1996-10-13)
+
+Programmer's Cheer
+
+ <humour>
+
+ "Shift to the left!
+ Shift to the right!
+ Pop up, push down!
+ Byte! Byte! Byte!"
+
+ [Origin?]
+
+ [{Jargon File}]
+
+ (1996-10-13)
+
+Programmers Hierarchical Interactive Graphics System
+
+ (PHIGS) An {ANSI}/{ISO} {standard}. Worked on by the
+ {ISO}/{IEC} group {JTC1/SC24}.
+
+ [More detail?]
+
+ (1995-01-04)
+
+PROgrammer's Microapplication Language
+
+ <language> (PROMAL) An interpreted {C}-like language from
+ {Systems Management Associates} for {MS-DOS}, {Commodore 64},
+ and {Apple II}.
+
+ [Computer Language, Mar 1986, pp. 128-134].
+
+ (1996-03-21)
+
+Programmer's Switch
+
+ <hardware> A button on the front of some {Apple Macintosh}
+ computers which, when pressed, causes a command line prompt to
+ appear. This gives access to the built-in mini-{debugger},
+ which has commands to dump memory, return to the application
+ that was broken out, and others. A more sophisticated
+ debugger must be installed in order to inspect {breakpoints},
+ etc.
+
+ (2000-11-01)
+
+programming
+
+ 1. The art of debugging a blank sheet of paper (or, in these
+ days of on-line editing, the art of {debugging an empty
+ file}).
+
+ 2. A pastime similar to banging one's head against a wall, but
+ with fewer opportunities for reward.
+
+ 3. The most fun you can have with your clothes on (although
+ clothes are not mandatory).
+
+ [{Jargon File}]
+
+ (2003-02-12)
+
+programming fluid
+
+ <jargon> (Or "{wirewater}") Coffee, unleaded coffee
+ (decaffeinated), Cola, or any caffeinacious stimulant. Many
+ hackers consider these essential for those all-night {hacking
+ runs}.
+
+ (1996-05-01)
+
+programming language
+
+ <language> A formal language in which computer programs are
+ written. The definition of a particular language consists of
+ both {syntax} (how the various symbols of the language may be
+ combined) and {semantics} (the meaning of the language
+ constructs).
+
+ Languages are classified as low level if they are close to
+ {machine code} and high level if each language statement
+ corresponds to many machine code instructions (though this
+ could also apply to a low level language with extensive use of
+ {macros}, in which case it would be debatable whether it still
+ counted as low level). A roughly parallel classification is
+ the description as {first generation language} through to
+ {fifth generation language}.
+
+ The other major classification of languages distinguishes
+ between {imperative languages}, {procedural language} and
+ {declarative languages}.
+
+ {Programming languages in this dictionary
+ (/contents/language.html)}.
+
+ {Programming languages time-line/family tree
+ (http://levenez.com/lang/history.html)}.
+
+ (2004-05-17)
+
+Programming Language/Cornell
+
+ <language> (PL/C) A large subset of {PL/I} from {Cornell
+ University}, aimed at novice programmers.
+
+ ["Introduction to PL/1 and PL/C programming", Kochenburger,
+ Ralph J., Santa Barbara, Hamilton, c1974].
+
+ ["User's Guide to PL/C", S. Worona et al, Cornell, June 1974].
+
+ ["PL/C - A High Performance Compiler" H.L. Morgan et al, Proc
+ SJCC, AFIPS 38:503-510 (1971)].
+
+ (1999-05-26)
+
+Programming Language/Systems
+
+ <language> (PL/S) An {IBM} machine-oriented language derived
+ from {PL/I}, in the late 1960s, for the {IBM 360} and {IBM
+ 370}. PL/S permitted {inline} {assembly language} and control
+ over {register} usage.
+
+ Previous IBM 360 operating systems such as {OS/MFT} and
+ {OS/MVT} had been written entirely in {assembly language}.
+ The first IBM OS that had any significant portion written in
+ PL/S was {MVS}, followed by {OS/VS1}, {OS/VS2} and {OS/SVS}.
+
+ PL/S was part of IBM's {OCO
+ (http://www.landley.net/history/mirror/ibm/oco.html)} (object
+ code only) effort, started in 1983. PL/S was used internally
+ and never released to the public. It is documented in various
+ IBM internal ZZ-? publications.
+
+ Versions: PLS1, PLSII.
+
+ ["PL/S, Programming Language/Systems", W.R. Brittenham, Proc
+ GUIDE Intl, GUIDE 34, May 14, 1972, pp. 540-556].
+
+ (2012-01-20)
+
+Program Temporary Fix
+
+ <programming> (PTF) (Colloquially: Probably This Fixes) An
+ {IBM} sanctioned {patch}, often implemented using {ZAP} or
+ {SUPERZAP}.
+
+ (1998-07-08)
+
+program transformation
+
+ The systematic development of efficient programs from
+ high-level specifications by meaning-preserving program
+ manipulations. Also known as optimisation. See {fusion},
+ {loop combination}, {peephole optimisation}, {register
+ allocation}, {tupling}, {unfold/fold}.
+
+Prograph
+
+ <language>
+
+ A visual {dataflow} programming language and environment from
+ the {Technical University of Halifax}.
+
+ Prograph is an entirely graphical {visual programming}
+ language, other than for the text of {method} names, and
+ supports the program development process in a
+ highly-interactive fashion. Operation icons are connected by
+ data links through which information flows. It supports
+ {object orientation} via {class}-based {data abstraction} with
+ {single inheritance}.
+
+ Prograph is available for the {Macintosh}, and soon for
+ Windows and Unix, from {TGS Systems}.
+
+ (1995-03-31)
+
+PROGRES
+
+ <language> {PROgrammed Graph REwriting Systems}.
+
+progressive coding
+
+ <graphics, file format, algorithm> (Or "interlacing") An
+ aspect of a {graphics} storage format or transmission
+ {algorithm} that treats {bitmap} {image} data non-sequentially
+ in such a way that later data adds progressively greater
+ {resolution} to an already full-size image. This contrasts
+ with {sequential coding}.
+
+ Progressive coding is useful when an image is being sent
+ across a slow communications channel, such as the {Internet},
+ as the low-resolution image may be sufficient to allow the
+ user to decide not to wait for the rest of the file to be
+ received.
+
+ In an interlaced {GIF89} image, the {pixels} in a row are
+ stored sequentially but the rows are stored in interlaced
+ order, e.g. 0, 8, 4, 12, 2, 6, 8, 10, 14, 1, 3, 5, 7, 9, 11,
+ 13, 15. Each vertical scan adds rows in the middle of the
+ gaps left by the previous one.
+
+ {PNG} interlaces both horizontally and vertically using the
+ "{Adam7}" method, a seven pass process named after Adam
+ M. Costello.
+
+ Interlacing is also supported by other formats. {JPEG}
+ supports a functionally similar concept known as {Progressive
+ JPEG}. [How does the algorithm differ?]
+
+ {JBIG} uses {progressive coding}.
+
+ See also {progressive/sequential coding}.
+
+ ["Progressive Bi-level Image Compression, Revision 4.1",
+ ISO/IEC JTC1/SC2/WG9, CD 11544, 1991-09-16].
+
+ (2000-09-12)
+
+Progressive JPEG
+
+ <graphics, file format> (PJPEG) An implementation of {JPEG}
+ that supports {progressive coding}.
+
+ [Standards documents?]
+
+ (1998-02-10)
+
+progressive/sequential coding
+
+ <compression, algorithm> The kind of image {compression}
+ {algorithm} used in {JBIG} where an image coded using
+ {progressive coding} can be decoded sequentially, and vice
+ versa.
+
+ (1995-03-01)
+
+PROJECT
+
+ Subsystem of ICES. Sammet 1969, p.616.
+
+project assurance
+
+ The process of specifying the support system: techniques,
+ internal standards, measurements, tools, and training for a
+ project; counselling the project team in the application of
+ these elements and monitoring the adherence to the standards.
+
+Project Athena
+
+ <project> A {distributed system} project for support of
+ educational and research computing at {MIT}. Much of the
+ software developed is now in wider use, especially the {X
+ Window System}.
+
+ (2000-02-24)
+
+Project Guardian
+
+ <project, security> A project which grew out of the {ARPA}
+ support for {Multics} and the sale of Multics systems to the
+ US Air Force. The USAF wanted a system that could be used to
+ handle more than one security classification of data at a
+ time. They contracted with {Honeywell} and {MITRE
+ Corporation} to figure out how to do this. Project Guardian
+ led to the creation of the {Access Isolation Mechanism}, the
+ forerunner of the {B2} labeling and star property support in
+ Multics. The {DoD Orange Book} was influenced by the
+ experience in building secure systems gained in Project
+ Guardian.
+
+ (1997-01-29)
+
+projection
+
+ <theory> In domain theory, a {function}, f, which is (a)
+ {idempotent}, i.e. f(f(x))=f(x) and (b) whose result is no
+ more defined than its argument. E.g. F(x)=bottom or F(x)=x.
+
+ In {reduction} systems, a function which returns some
+ {component} of its argument. E.g. head, tail, \ (x,y) . x.
+ In a {graph reduction} system the function can just return a
+ pointer to part of its argument and does not need to build any
+ new graph.
+
+ (1997-01-29)
+
+projective plane
+
+ <mathematics> The space of {equivalence classes} of {vectors}
+ under non-zero {scalar} multiplication. Elements are sets of
+ the form
+
+ {kv: k != 0, k scalar, v != O, v a vector}
+
+ where O is the origin. v is a representative member of this
+ equivalence class.
+
+ The projective plane of a {vector space} is the collection of
+ its 1-dimensional {subspaces}. The properties of the vector
+ space induce a {topology} and notions of {smoothness} on the
+ projective plane.
+
+ A projective plane is in no meaningful sense a plane and would
+ therefore be (but isn't) better described as a "projective
+ space".
+
+ (1996-09-28)
+
+Project MAC
+
+ <project> A project suggested by J C R Licklider; its founding
+ director was {MIT} Prof. Robert M Fano. MAC stood for
+ Multiple Access Computers on the 5th floor of Tech Square, and
+ Man and Computer on the 9th floor. The major efforts were
+ Corbato's {Multics} development and {Marvin Minsky}'s
+ {Artificial Intelligence} Laboratory. In 1963 Project MAC
+ hosted a summer study, which brought many well-known computer
+ scientists to Cambridge to use {CTSS} and to discuss the
+ future of computing.
+
+ Funding for Project MAC was provided by the Information
+ Processing Techniques Office of the {Advanced Research
+ Projects Agency} (ARPA) of the US Department of Defense.
+
+ See also {Early PL/I}, {MacLisp}, {MACSYMA}, {MDL},
+ {Multipop-68}, {OCAL}.
+
+ (1997-01-29)
+
+project management
+
+ <project, job> The process of planning, organising, staffing,
+ directing and controlling the production of a system.
+ Software tools are available to help with this, e.g. {PERT}
+ chart editors.
+
+ (1998-12-12)
+
+project planning
+
+ {project management}
+
+Prolog
+
+ <programming> Programming in Logic or (French) Programmation
+ en Logique. The first of the huge family of {logic
+ programming} languages.
+
+ Prolog was invented by Alain Colmerauer and Phillipe Roussel
+ at the University of Aix-Marseille in 1971. It was first
+ implemented 1972 in {ALGOL-W}. It was designed originally for
+ {natural-language processing} but has become one of the most
+ widely used languages for {artificial intelligence}.
+
+ It is based on {LUSH} (or {SLD}) {resolution} {theorem
+ proving} and {unification}. The first versions had no
+ user-defined functions and no control structure other than the
+ built-in {depth-first search} with {backtracking}. Early
+ collaboration between Marseille and Robert Kowalski at
+ {University of Edinburgh} continued until about 1975.
+
+ Early implementations included {C-Prolog}, {ESLPDPRO},
+ {Frolic}, {LM-Prolog}, {Open Prolog}, {SB-Prolog}, {UPMAIL
+ Tricia Prolog}. In 1998, the most common Prologs in use are
+ {Quintus Prolog}, {SICSTUS Prolog}, {LPA Prolog}, {SWI
+ Prolog}, {AMZI Prolog}, {SNI Prolog}.
+
+ {ISO} draft standard at {Darmstadt, Germany
+ (ftp://ftp.th-darmstadt.de/pub/programming/languages/prolog/standard/)}.
+ or {UGA, USA (ftp://ai.uga.edu/ai.prolog.standard)}.
+
+ See also {negation by failure}, {Kamin's interpreters},
+ {Paradigms of AI Programming}, {Aditi}.
+
+ A Prolog {interpreter} in {Scheme}.
+ {(ftp://cpsc.ucalgary.ca/pub/prolog1.1)}.
+
+ {A Prolog package
+ (ftp://cpsc.ucalgary.ca/pub/prolog1.1/prolog11.tar.Z)} from
+ the {University of Calgary} features {delayed goals} and
+ {interval arithmetic}. It requires {Scheme} with
+ {continuations}.
+
+ ["Programming in Prolog", W.F. Clocksin & C.S. Mellish,
+ Springer, 1985].
+
+ (2001-04-01)
+
+Prolog++
+
+ (After {C++}) {Prolog} with {object-oriented} features added
+ by Phil Vasey of {Logic Programming Associates}. Prolog++ is
+ available for {MS-DOS} and the {X Window System}. It is
+ distributed by {AI International} Ltd. in England and by
+ {Quintus}.
+
+Prolog-2
+
+ An implementation of Edinburgh Prolog by Nick Henfrey, {ESL}.
+
+ ["An Advanced Logic Programming Language", Anthony Dodd].
+
+Prolog-D-Linda
+
+ Embeds the {Linda} parallel paradigm into {SISCtus Prolog}.
+
+ {(ftp://ftp.cs.uwa.au/)}. E-mail: <geoff@cs.uwa.edu.au>.
+
+Prolog-II
+
+ Prolog with two new predicates: "dif" for coroutines and
+ "freeze" for delayed evaluation.
+
+ Available from ExperIntelligence, Santa Barbara CA.
+
+ ["Prolog II Reference Manual and Theoretical Model",
+ A. Colmerauer, Internal Report, GroupeIA, U Aix-Marseille (Oct
+ 1982)].
+
+Prolog-III
+
+ A. Colmerauer, U Aix-Marseille, ca 1984. Marseille Prolog,
+ with unification replaced by constraint resolution. [deferred
+ goals too?] (Not to be confused with Prolog 3, a commercial
+ product?)
+
+ Version 1.2 for MS-DOS.
+
+ ["Opening the Prolog-III Universe", BYTE 12(9):177-182 (Aug
+ 1987)].
+
+ ["An Introduction to Prolog III", A. Colmerauer, CACM
+ 33(7):69-90 (1990)].
+
+Prolog-Linda
+
+ 1. Prolog extended with Linda-style parallelism. Proc 4th
+ Australian Conf on Artif Intell.
+
+ {(ftp://bison.cs.uwa.oz.au/)}.
+
+ 2. Neil MacDonald, U Edinburgh 1989. Another Prolog extended
+ with Linda, implemented on a Computing Surface.
+
+Prolog/Mali
+
+ <language> (PM) {Lambda-Prolog} for the {MALI}-V06 abstract
+ memory system, developed by Pascal Brisset at IRISA, France.
+ There is a compiler which compiles to {C}, a linker,
+ libraries, {run-time system}, and documentation. It runs
+ under {Unix}.
+
+ {(ftp://ftp.irisa.fr/pm/)}.
+
+ Mailing list: prolog-mali-request@irisa.fr. E-mail:
+ <pm@irisa.fr>.
+
+ (1992-07-06)
+
+PROM
+
+ {Programmable Read-Only Memory}
+
+PROMAL
+
+ {PROgrammer's Microapplication Language}
+
+Prometheus
+
+ <language> A programmaing language geared for logic,
+ mathematics, {AI}, and string, list and database processing.
+ Prometheus runs on a variety of {platforms} from {Macintosh}
+ to {MS-DOS}
+
+ {(http://aard.tracor.com/Jason/Prometheus/)}.
+
+ (1996-03-04)
+
+promiscuous mode
+
+ <networking> Where a node on a network accepts all {packets},
+ regardless of their destination address.
+
+ (1996-03-04)
+
+PROM monitor
+
+ <operating system> a small program stored in {PROM} (or
+ {ROM}), responsible for both loading the {OS} and providing
+ some means to analyse OS {crashes}. It may also have some
+ sort of {user interface} which can be used to examine and
+ change the contents of memory, control the boot process
+ (specifying arguments to the {kernel}, or changing where to
+ look for the it), and so forth.
+
+ The main difference between a PROM monitor and a {bootstrap
+ loader} is that the PROM monitor regains control when the OS
+ terminates. This may enable a {wizard} to find out what went
+ wrong if the OS crashed, although it is usually of little help
+ for the average {sysadmin}.
+
+ (1996-12-03)
+
+pron
+
+ <jargon> (Or "pr0n") {B1FF}-speak for pornography. Often seen
+ on {IRC} in such desperate cries for help as "I WNAT
+ PRON!!!!!"
+
+ (1997-09-14)
+
+Pronet
+
+ <language>
+
+ ["The Design of a Programming Language Based on Connectivity
+ Networks", R. LeBlanc et al, Proc 3rd Intl Conf Distrib Comp
+ Sys, IEEE 1982, pp. 532-541].
+
+ (1997-09-14)
+
+Pronunciation
+
+ In this dictionary slashes (/../) bracket phonetic
+ pronunciations of words not found in a standard English
+ dictionary. The notation, and many of the pronunciations,
+ were adapted from the Hacker's {Jargon File}.
+
+ Syllables are separated by {dash} or followed {single quote}
+ or {back quote}. Single quote means the preceding syllable is
+ stressed (louder), back quote follows a syllable with
+ intermediate stress (slightly louder), otherwise all syllables
+ are equally stressed.
+
+ Consonants are pronounced as in English but note:
+
+ ch soft, as in "church"
+ g hard, as in "got"
+ gh aspirated g+h of "bughouse" or "ragheap"
+ j voiced, as in "judge"
+ kh guttural of "loch" or "l'chaim"
+ s unvoiced, as in "pass"
+ zh as "s" in "pleasure"
+
+ Uppercase letters are pronounced as their English letter
+ names; thus (for example) /H-L-L/ is equivalent to /aych el
+ el/. /Z/ is pronounced /zee/ in the US and /zed/ in the UK
+ (elsewhere?).
+
+ Vowels are represented as follows:
+
+ a back, that
+ ah father, palm (see note)
+ ar far, mark
+ aw flaw, caught
+ ay bake, rain
+ e less, men
+ ee easy, ski
+ eir their, software
+ i trip, hit
+ i: life, sky
+ o block, stock (see note)
+ oh flow, sew
+ oo loot, through
+ or more, door
+ ow out, how
+ oy boy, coin
+ uh but, some
+ u put, foot
+ *r fur, insert (only in stressed
+ syllables; otherwise use just "r")
+ y yet, young
+ yoo few, chew
+ [y]oo /oo/ with optional fronting as
+ in `news' (/nooz/ or /nyooz/)
+
+ A /*/ is used for the `schwa' sound of unstressed or occluded
+ vowels (often written with an upside-down `e'). The schwa
+ vowel is omitted in unstressed syllables containing vocalic l,
+ m, n or r; that is, "kitten" and "colour" would be rendered
+ /kit'n/ and /kuhl'r/, not /kit'*n/ and /kuhl'*r/.
+
+ The above table reflects mainly distinctions found in standard
+ American English (that is, the neutral dialect spoken by TV
+ network announcers and typical of educated speech in the Upper
+ Midwest, Chicago, Minneapolis/St.Paul and Philadelphia).
+ However, we separate /o/ from /ah/, which tend to merge in
+ standard American. This may help readers accustomed to
+ accents resembling British Received Pronunciation.
+
+ Entries with a pronunciation of `//' are written-only.
+
+ (1997-12-10)
+
+proof
+
+ 1. <logic> A {finite} sequence of {well-formed formulas}, F1,
+ F2, ... Fn, where each Fi either is an {axiom}, or follows by
+ some rule of inference from some of the previous F's, and Fn
+ is the statement being proved.
+
+ See also {proof theory}.
+
+ 2. A left-associative {natural language} {parser} by Craig
+ R. Latta <latta@xcf.berkeley.edu>. Ported to {Decstation
+ 3100}, {Sun-4}.
+
+ {(ftp://scam.berkeley.edu/pub/src/local/proof/)}.
+
+ E-mail: <proof@xcf.berkeley.edu>. Mailing list:
+ proof-requestf@xcf.berkeley.edu (Subject: add me).
+
+ (1994-11-29)
+
+PROOF/L
+
+ A {functional}, {object-oriented language} with {implicit
+ parallelism}.
+
+ [J Parallel Dist Comp 12:202-212 (1991)].
+
+ [Forthcoming Technical Report from {RADC}].
+
+ (1994-10-31)
+
+proof theory
+
+ <logic> The branch of {logic} describing procedures for
+ combining logical statements to show, by a series of
+ truth-preserving transformations, that one statement is a
+ consequence of some other statement or group of statements.
+
+ (1994-10-31)
+
+propeller head
+
+ <jargon> Used by hackers, this is synonym with {computer
+ geek}. Non-hackers sometimes use it to describe all techies.
+ Probably derives from SF fandom's tradition (originally
+ invented by old-time fan Ray Faraday Nelson) of propeller
+ beanies as fannish insignia (though nobody actually wears them
+ except as a joke).
+
+ [{Jargon File}]
+
+ (1995-01-18)
+
+propeller key
+
+ {feature key}
+
+proportionally spaced font
+
+ {proportional font}
+
+Proposal Writing
+
+ Extension of {Fortran} for proposal writing.
+
+ [Sammet 1969, p. 170].
+
+ (1995-01-18)
+
+proposition
+
+ <logic> A statement in {propositional logic} which may be
+ either true or false. Each proposition is typically
+ represented by a letter in a {formula} such as "p => q",
+ meaning proposition p implies proposition q.
+
+ (2006-03-14)
+
+propositional calculus
+
+ {propositional logic}
+
+propositional logic
+
+ <logic> (or "propositional calculus") A system of {symbolic
+ logic} using symbols to stand for whole {propositions} and
+ {logical connectives}. Propositional logic only considers
+ whether a proposition is true or false. In contrast to
+ {predicate logic}, it does not consider the internal structure
+ of propositions.
+
+ (2002-05-21)
+
+Proposition of a Language Useable for Structured Specifications
+
+ <language> (PLUSS)
+ An {algebraic specification language}, built on top of {ASL}.
+
+ ["A First Introduction to PLUSS", M.C. Gaudel, TR, U Paris
+ Sud, Orsay 1984].
+
+ (2006-03-14)
+
+proprietary
+
+ 1. In {marketroid}-speak, superior; implies a product imbued
+ with exclusive magic by the unmatched brilliance of the
+ company's own hardware or software designers.
+
+ 2. In the language of hackers and users, inferior; implies a
+ product not conforming to {open-systems} {standards}, and thus
+ one that puts the customer at the mercy of a vendor who can
+ inflate service and upgrade charges after the initial sale has
+ locked the customer in.
+
+ [{Jargon File}]
+
+PROSE
+
+ 1. PROblem Solution Engineering. Numerical problems including
+ differentiation and integration. "Computing in Calculus",
+ J. Thames, Research/Development 26(5) (May 1975).
+
+ 2. A constraints-and-sequencing system similar to
+ Kaleidoscope. "Reflexive Constraints for Dynamic Knowledge
+ Bases", P. Berlandier et al in Proc First Intl CS Conf '88:
+ AI: Theory and Appls, Dec 1988.
+
+ProSet
+
+ A derivative of {SETL} with {Ada}-like {syntax} developed at
+ the {University of Essen} in 1990. Formerly known as SETL/E.
+
+ ["SETL/E, A Prototyping System Based on Sets", E.E. Doberkat
+ et al, in Tagungsband TOOL90, W. Zorn ed, pp. 109-118, U
+ Karlsruhe, Nov 1990].
+
+ ["ProSet - A Language for Prototyping with Sets",
+ E.-E. Doberkat et al, in Proc Third Intl Workshop on Rapid
+ System Prototyping, N. Kanopoulos ed, IEEE Comp Soc Press,
+ June 1992, pp. 235-248].
+
+PROSPER
+
+ ["PROSPER: A Language for Specification by Prototyping", J.
+ Leszczylowski, Comp Langs 14(3):165-180 (1989)].
+
+Prospero
+
+ A tool for organising {Internet} resources. Prospero allows
+ each user to organise the contents of remote file servers into
+ his own virtual file system with his own hierarchical name
+ space consisting of links to remote objects. Remote indexing
+ services are made available by treating the results as a
+ virtual directory. A "union link" allows the contents of the
+ link's target directory to appear as part of the directory
+ containing the link. Arbitrary filters can be associated with
+ links to modify the representation of the target directory as
+ desired. Prospero directories can be shared between users.
+ The Prospero protocol is used for communication between
+ clients and servers in the archie system.
+
+ A prototype of Prospero has been available since December
+ 1990. It interfaces with Sun {NFS}, the {Andrew File System}
+ and {FTP} (with local caching) and {Archie}. Support for
+ {web} and {WAIS} is planned (1992).
+
+ E-mail: <info-prospero@isi.edu>.
+ {(ftp://prospero.isi.edu/pub/prospero)}.
+
+ProTalk
+
+ {Quintus}. An {object-oriented} {Prolog}.
+
+protected mode
+
+ An operating mode of {Intel 80x86} processors. The opposite
+ of real mode. The {Intel 8088}, {Intel 8086}, {Intel 80188}
+ and {Intel 80186} had only real mode, processors beginning
+ with the {Intel 80286} feature a second mode called protected
+ mode.
+
+ In real mode, addresses are generated by adding an address
+ offset to the value of a {segment register} shifted left four
+ bits. As the segment register and address offset are 16 bits
+ long this results in a 20-bit address. This is the origin of
+ the one megabyte (2^20) limit in real mode.
+
+ There are 4 segment registers on processors before the {Intel
+ 80386}. The 80386 introduced two more segment registers.
+ Which segment register is used depends on the instruction, on
+ the {addressing mode} and of an optional instruction prefix
+ which selects the segment register explicitly.
+
+ In protected mode, the segment registers contain an index into
+ a table of {segment descriptors}. Each segment descriptor
+ contains the start address of the segment, to which the offset
+ is added to generate the address. In addition, the segment
+ descriptor contains {memory protection} information. This
+ includes an offset limit and bits for write and read
+ permission. This allows the processor to prevent memory
+ accesses to certain data. The {operating system} can use this
+ to protect different processes' memory from each other, hence
+ the name "protected mode".
+
+ While the standard {register set} belongs to the {CPU}, the
+ segment registers lie "at the boundary" between the CPU and
+ MMU. Each time a new value is loaded into a segment register
+ while in protected mode, the corresponding descriptor is
+ loaded into a descriptor cache in the (Segment-)MMU. On
+ processors before the {Pentium} this takes longer than just
+ loading the segment register in real mode. Addresses
+ generated by the CPU (which are segment offsets) are passed to
+ the MMU to be checked against the limit in the segment
+ descriptor and are there added to the segment base address in
+ the descriptor to form a {linear address}.
+
+ On a 80386 or later, the linear address is further processed
+ by the paged MMU before the result (the physical address)
+ appears on the chip's address pins. The 80286 doesn't have a
+ paged MMU so the linear address is output directly as the
+ physical address.
+
+ The paged MMU allows for arbitrary remapping of four klilobyte
+ memory blocks ({pages}) through a translation table stored in
+ memory. A few entries of this table are cached in the MMU's
+ {Translation Lookaside Buffer} to avoid excessive memory
+ accesses.
+
+ After processor reset, all processors start in real mode.
+ Protected mode has to be enabled by software. On the 80286
+ there exists no documented way back to real mode apart from
+ resetting the processor. Later processors allow switching
+ back to real mode by software.
+
+ Software which has been written or compiled to run in
+ protected mode must only use segment register values given to
+ it by the operating system. Unfortunately, most application
+ code for {MS-DOS}, written before the 286, will fail in
+ protected mode because it assumes real mode addressing and
+ writes arbitrary values to segment registers, e.g. in order to
+ perform address calculations.
+
+ Such use of segment registers is only really necessary with
+ data structures that are larger than 64 kilobytes and thus
+ don't fit into a single segment. This is usually dealt with
+ by the {huge memory model} in compilers. In this model,
+ compilers generate address arithmetic involving segment
+ registers. A solution which is portable to protected mode
+ with almost the same efficiency would involve using a table of
+ segments instead of calculating new segment register values ad
+ hoc.
+
+ To ease the transition to protected mode, {Intel 80386} and
+ later processors provide "{virtual 86 mode}".
+
+ (1995-03-29)
+
+PROTEUS
+
+ An extensible language, the core of {PARSEC}.
+
+ ["The Design of a Minimal Expandable Computer Language",
+ J.R. Bell, PhD Thesis, CS, {Stanford University} (Dec 1968)].
+
+protocal
+
+ <spelling> It's spelled "{protocol}".
+
+protocol
+
+ A set of formal rules describing how to transmit data,
+ especially across a {network}. Low level protocols define the
+ electrical and physical standards to be observed, bit- and
+ byte-ordering and the transmission and {error detection and
+ correction} of the bit stream. High level protocols deal with
+ the data formatting, including the {syntax} of messages, the
+ terminal to computer dialogue, {character sets}, sequencing of
+ messages etc.
+
+ Many protocols are defined by {RFCs} or by {OSI}.
+
+ See also {handshaking}.
+
+ [{Jargon File}]
+
+ (1995-01-12)
+
+protocol analyser
+
+ <communications, hardware, networking, testing, tool> Any
+ device that captures and interprets the {network traffic}
+ between two or more connected computer systems. The traffic
+ can then be {decoded} so that it is possible to see what
+ {processes} are occurring.
+
+ By examining the flow of traffic, protocol analysers can be
+ used to find out where problems (such as {bottlenecks} or the
+ failure of a network device) are on a {LAN}.
+
+ Advanced protocol analysers can also provide statistics on
+ the traffic that can help to identify trends that may in
+ future lead to further problems with the network.
+
+ (2000-07-24)
+
+protocol converter
+
+ <networking> A device or program to translate between
+ different {protocols} which serve similar functions
+ (e.g. {TCP} and {TP4}).
+
+ Some call this a "{gateway}", though others use that term for
+ other kinds of {internetworking} device.
+
+ (1996-03-07)
+
+Protocol Data Unit
+
+ (PDU) A {packet} of data passed across a {network}. The term
+ implies a specific layer of the {OSI} seven layer model and a
+ specific {protocol}.
+
+ (1994-10-13)
+
+protocol layer
+
+ <networking> The {software} and/or {hardware} environment of
+ two or more communications devices or computers in which a
+ particular {network} {protocol} operates. A network
+ connection may be thought of as a set of more or less
+ independent protocols, each in a different layer or level.
+ The lowest layer governs direct host-to-host communication
+ between the hardware at different hosts; the highest consists
+ of user {application programs}. Each layer uses the layer
+ beneath it and provides a service for the layer above. Each
+ networking component {hardware or software} on one host uses
+ {protocols} appropriate to its layer to communicate with the
+ corresponding component (its "peer") on another host. Such
+ layered protocols are sometimes known as peer-to-peer
+ protocols.
+
+ The advantages of layered {protocols} is that the methods of
+ passing information from one layer to another are specified
+ clearly as part of the {protocol} suite, and changes within a
+ protocol layer are prevented from affecting the other layers.
+ This greatly simplifies the task of designing and maintaining
+ communication systems.
+
+ Examples of layered protocols are {TCP/IP}'s five layer
+ {protocol stack} and the {OSI} seven layer model.
+
+ (1997-05-05)
+
+protocol stack
+
+ <protocol> A layered set of {protocols} which work together to
+ provide a set of network functions. Each intermediate
+ {protocol layer} uses the layer below it to provide a service
+ to the layer above.
+
+ The {OSI} seven layer model is an attempt to provide a
+ standard framework within which to describe protocol stacks.
+
+ (1997-12-07)
+
+PROTON
+
+ 1. A home computer made by {Acorn Computers} under a contract
+ won from the {BBC} in April 1981.
+
+ [Details?]
+
+ 2. Something to do with {Microsoft} {SoftLib}?
+
+ (1994-11-28)
+
+Protosynthex
+
+ A query system for English text.
+
+ [Sammet 1969, p. 669].
+
+prototype
+
+ 1. <systems> An early version of a product, designed to
+ demonstrate feasability and elicit feedback. A prototype
+ usually has some subset of the functions, behaviour and
+ appearance of the finished product. It is usually made using
+ a method suitable for producing a one-off rather than mass
+ production.
+
+ 2. <programming> In {prototype-based programming}, an {object}
+ that is intended to be cloned to create similar objects which
+ may then be modified independantly and/or cloned themselves.
+
+ (2010-03-02)
+
+Prototyper
+
+ An {interface builder} for the {Macintosh} from Smethers
+ Barnes.
+
+ (1994-11-28)
+
+prototyping
+
+ The creation of a model and the {simulation} of all aspects of
+ a product. {CASE} tools support different degrees of
+ prototyping. Some offer the end-user the ability to review
+ all aspects of the {user interface} and the structure of
+ documentation and reports before code is generated.
+
+provably difficult
+
+ The set or property of problems for which it can be proven
+ that no {polynomial-time} {algorithm} exists, only
+ {exponential-time} {algorithms}.
+
+provably unsolvable
+
+ The set or property of problems for which no {algorithm} at
+ all exists. E.g. the {Halting Problem}. See also {provably
+ difficult}.
+
+provider
+
+ {Internet Access Provider}
+
+provocative maintenance
+
+ [Common ironic mutation of "preventive maintenance"] Actions
+ performed upon a machine at regularly scheduled intervals to
+ ensure that the system remains in a usable state. So called
+ because it is all too often performed by a {field servoid} who
+ doesn't know what he is doing; such "maintenance" often
+ *induces* problems, or otherwise results in the machine's
+ remaining in an *un*usable state for an indeterminate amount
+ of time. See also {scratch monkey}.
+
+ [{Jargon File}]
+
+prowler
+
+ ({Unix}) A {daemon} that is run periodically (typically once a
+ week) to seek out and erase {core} files, truncate
+ administrative logfiles, nuke "lost+found" directories, and
+ otherwise clean up the {cruft} that tends to pile up in the
+ corners of a file system.
+
+ See also {GFR}, {reaper}, {skulker}.
+
+ (1995-02-14)
+
+proxy
+
+ <networking> A process that accepts requests for some service
+ and passes them on to the real {server}. A proxy may run on
+ dedicated {hardware} or may be purely {software}. It may
+ transform the request in some way or provide some additional
+ layer of functionality such as {caching} or remote access. A
+ proxy may be intended to increase security, e.g. a {web proxy}
+ that allows multiple clients inside an organisation to access
+ the {Internet} through a single secure, shared connection.
+
+ (2007-09-03)
+
+proxy ARP
+
+ <networking> The technique in which one {host}, usually a
+ {router}, answers {Address Resolution Protocol} (ARP) requests
+ intended for another machine. By "faking" its identity, the
+ router accepts responsibility for routing {packets} to the
+ "real" destination. Proxy ARP allows a site to use a single
+ {IP address} with two physical networks. {Subnet}ting would
+ normally be a better solution.
+
+ (2007-09-03)
+
+proxy gateway
+
+ {proxy server}
+
+Proxy Server
+
+ <software, security> (Capitalised) {Microsoft}'s {proxy
+ server} and {proxy gateway}, designed to provide extensible
+ {firewall} and network security. Proxy Server is part of
+ {BackOffice}.
+
+ (1999-09-17)
+
+proxy server
+
+ <networking> A {server} process that intercepts requests from
+ a client, passes them to an {origin server} and returns the
+ response to the client while performing various other
+ operations in the process. An {HTTP proxy server} is a common
+ example.
+
+ A proxy may be used for purposes of {security}, performance
+ ({caching}) or anonymity. It may be purely software or may
+ run on its own hardware, either a standard {PC} or server
+ machine or a custom hardware appliance. A software proxy may
+ be on the same computer as the client or the origin server,
+ separate hardware may be anywhere on the network in between.
+
+ The proxy may filter requests, rejecting some if the request
+ or response matches certain conditions (e.g. an {antivirus}
+ proxy). It may cache requests and responses to reduce load on
+ the origin server or data volume on the network or to provide
+ quicker response to the client for common requests. The proxy
+ may modify the request or response, e.g. to convert between
+ different protocols or interfaces.
+
+ Proxy servers are often used in large companies as part of a
+ {firewall} so that users within the company need have no
+ direct connection to the Internet (and can use a {private IP
+ address} range) but can still access the {web},
+ {instant messenger}, etc via the proxy. Usually this requires
+ each client to be configured to use the proxy.
+
+ The term "proxy gateway" may more imply transparency (less
+ intervention) in the request-response process, though is often
+ used as a synonym for proxy server.
+
+ (2008-07-01)
+
+PS
+
+ 1. <language, text, graphics> {PostScript}.
+
+ 2. <file format> {Physical Sequential}.
+
+PS1
+
+ {Sony Playstation}
+
+PS2
+
+ {Sony Playstation}
+
+PS/2
+
+ <computer> {IBM}'s second generation of {personal computers}.
+ The PS/2 series introduced three advances over the PC series:
+ 3.5" 1.44 megabyte {microfloppy} disks, {VGA} and {8514}
+ graphics {display standards}, and the {Micro Channel} bus
+ architecture. The 3.5" disks and VGA can be easily installed
+ on other PCs and will become the standard for new compatible
+ computers. The Micro Channel bus allows for multiprocessing
+ and less aggravation, but cannot be retrofitted to older PCs.
+
+ PS/2 models 25 and 30 are {ISA}, other models have Micro
+ Channel and {ESDI}.
+
+ (1995-11-27)
+
+PS 440
+
+ <language> The system implementation language for the
+ {Telefunken TR 440} computer, developed by K. Lagally in about
+ 1974.
+
+ (2003-07-29)
+
+PSA
+
+ Problem Statement Analizer. See {PSL/PSA}.
+
+PS-ALGOL
+
+ Persistent ALGOL. ca 1981, released 1985. A derivative of
+ S-ALGOL. Database capability derived from the longevity of
+ data. "The PS- Algol Reference Manual", TR PPR-12-85, CS
+ Dept, U Glasgow 1985. IBM PC version available from CS Dept,
+ U Strathclyde, Glasgow.
+
+pSather
+
+ <language> A parallel extension of {Sather} for a clustered
+ {shared memory} model. It features {threads} synchronised by
+ {monitor} objects ("gates"); {locality} {assertions} and
+ placement operators.
+
+ There is an implementation for the {CM-5}.
+
+ ["pSather Monitors: Design, Tutorial, Rationale and
+ Implementation", J.A. Feldman et al, TR-91-031 and TR-93-028,
+ ICSI, Berkeley, CA].
+
+ (1995-03-13)
+
+PSD
+
+ <tool> {Portable Scheme Debugger}.
+
+PSDN
+
+ <communications> {Public Switched Data Network}.
+
+pseudo
+
+ <jargon> /soo'doh/ ({Usenet}) Pseudonym.
+
+ 1. An {electronic-mail} or {Usenet} persona adopted by a human
+ for amusement value or as a means of avoiding negative
+ repercussions of one's net.behaviour; a "nom de {Usenet}",
+ often associated with forged postings designed to conceal
+ message origins. Perhaps the best-known and funniest hoax of
+ this type is {BIFF}.
+
+ 2. Notionally, a {flamage}-generating {AI} program simulating
+ a {Usenet} user. Many flamers have been accused of actually
+ being such entities, despite the fact that no AI program of
+ the required sophistication yet exists. However, in 1989
+ there was a famous series of forged postings that used a
+ phrase-frequency-based travesty generator to simulate the
+ styles of several well-known flamers; it was based on large
+ samples of their back postings (compare {Dissociated Press}).
+ A significant number of people were fooled by the forgeries,
+ and the debate over their authenticity was settled only when
+ the perpetrator came forward to publicly admit the hoax.
+
+ [{Jargon File}]
+
+ (1995-03-13)
+
+pseudocode
+
+ <programming> A notation resembling a {programming language}
+ but not intended for actual {compilation}. It usually
+ combines some of the structure of a programming language with
+ an informal {natural language} description of the computations
+ to be carried out. Some {CASE} systems produce it as a basis
+ for later {hand coding}.
+
+ (2011-01-29)
+
+pseudoprime
+
+ A backgammon prime (six consecutive occupied points) with one
+ point missing. This term is an esoteric pun derived from a
+ mathematical method that, rather than determining precisely
+ whether a number is prime (has no divisors), uses a
+ statistical technique to decide whether the number is
+ "probably" prime. A number that passes this test is called a
+ pseudoprime. The hacker backgammon usage stems from the idea
+ that a pseudoprime is almost as good as a prime: it does the
+ job of a prime until proven otherwise, and that probably won't
+ happen.
+
+ [{Jargon File}]
+
+pseudorandom number
+
+ <programming> One of a sequence of numbers generated by some
+ {algorithm} so as to have an even distribution over some range
+ of values and minimal {correlation} between successive
+ values.
+
+ Pseudorandom numbers are used in {simulation} and
+ {encryption}. They are pseudorandom not random because the
+ sequence eventually repeats exactly and is entirely determined
+ by the initial conditions.
+
+ One of the simplest algorithms is
+
+ x[i+1] = (a * x[i] + c) mod m
+
+ but this repeats after at most m numbers and successive
+ numbers are closely related. Better algorithms generally use
+ more previous numbers to calculate the next number.
+
+ {(http://random.mat.sbg.ac.at/)}.
+
+ (2007-06-29)
+
+PseudoScheme
+
+ A translator from {Scheme} to {Common Lisp} by Jonathan Rees
+ <jar@cs.cornell.edu>. Version 2.8. It conforms to all of
+ {R3RS} except {call/cc} and requires {Common Lisp}. Runs on
+ {Lucid}, {Symbolics CL}, {VAX Lisp}, {Explorer CL}.
+
+ Mailing list: info-clscheme-request@mc.lcs.mit.edu.
+
+ (1994-10-28)
+
+pseudosuit
+
+ /soo'doh-s[y]oot"/ A {suit} wannabee; a hacker who has decided
+ that he wants to be in management or administration and begins
+ wearing ties, sport coats, and (shudder!) suits voluntarily.
+ It's his funeral. See also {lobotomy}.
+
+ [{Jargon File}]
+
+pseudo-tty
+
+ {Berkeley} {Unix} networking device which appears to an
+ {application program} as an ordinary terminal but which is in
+ fact connected via the network to a process running on a
+ different {host} or a windowing system. Pseudo-ttys have a
+ slave half and a control half. The slave tty (/dev/ttyp*) is
+ the device that user programs use and the control tty
+ (/dev/ptyp*) is used by {daemons} to talk to the net.
+
+ (1994-11-08)
+
+PSF
+
+ {Print Services Facility}
+
+PSI
+
+ {Portable Scheme Interpreter}
+
+Psion
+
+ <company> The UK company that produced the {Psion Organiser}.
+ They also wrote software for the {Sinclair} {QL}.
+
+ {Psion Home (http://psionteklogix.com/)}.
+
+ (2009-05-27)
+
+Psion Organiser
+
+ <computer> A popular {pocket computer} from the UK Company
+ {Psion} plc. The organiser uses a {graphical user interface}
+ with windows, menus, icons and {dialog box}es. There have
+ been several versions so far: Series3a, Series3, HC, MC,
+ OrgII.
+
+ {Usenet} newsgroups: {news:comp.sys.psion},
+ {news:comp.binaries.psion}.
+
+ (1995-03-03)
+
+PSK
+
+ 1. <communications> {Phase-Shift Keying}.
+
+ 2. <cryptography, networking> {Pre-Shared Key}.
+
+PSL
+
+ <language>
+
+ 1. {Portable Standard Lisp}.
+
+ 2. {Problem Statement Language}.
+
+PSL/PSA
+
+ {Problem Statement Language/Problem Statement Analyser}
+
+PSML
+
+ {Processor System Modeling Language}.
+
+PSN
+
+ {Packet Switch Node}
+
+PSO
+
+ {Oracle Parallel Server}
+
+PSPP
+
+ <statistics> A {GNU} version of {SPSS}.
+
+ [URL? Features?]
+
+ (2010-03-21)
+
+PSTN
+
+ {Public Switched Telephone Network}
+
+PSU
+
+ {power supply unit}
+
+psychedelicware
+
+ /si:"k*-del"-ik-weir/ [UK] Synonym {display hack}. See also
+ {smoking clover}.
+
+ [{Jargon File}]
+
+psyton
+
+ <humour> /si:'ton/ (From {TMRC}) The elementary particle
+ carrying the sinister force. The probability of a process
+ losing is proportional to the number of psytons falling on it.
+ Psytons are generated by observers, which is why demos are
+ more likely to fail when lots of people are watching. This
+ term appears to have been largely superseded by {bogon}; see
+ also {quantum bogodynamics}.
+
+ (1997-04-26)
+
+pt
+
+ 1. <text, unit> {point}.
+
+ 2. <networking> The {country code} for Portugal.
+
+ (1999-01-27)
+
+P-TAC
+
+ Parallel Three Address Code.
+
+ {Kid} is a refinement of {P-TAC}, used as an intermediate
+ language for {Id}.
+
+ ["P-TAC: A Parallel Intermediate Language", Z. Ariola et al,
+ Fourth Intl Conf Func Prog Langs and Comp Arch, ACM Sept
+ 1989].
+
+ptc
+
+ A {Pascal} to {C} translator.
+
+ {(ftp://uxc.sco.uiuc.edu/languages/ptc)}.
+
+PTF
+
+ {Program Temporary Fix}
+
+Pthreads
+
+ {POSIX Threads}
+
+PTI
+
+ {Portable Tool Interface}
+
+PTN
+
+ {Physical Transport Network}
+
+Ptolemy
+
+ A flexible foundation for the specification, simulation, and
+ rapid prototyping of systems. It is an {object-oriented}
+ framework within which diverse models of computation can
+ co-exist and interact. For example, using Ptolemy a
+ {data-flow} system can be easily connected to a hardware
+ simulator which in turn may be connected to a discrete-event
+ system. Because of this, Ptolemy can be used to model entire
+ systems. In addition, Ptolemy now has code generation
+ capabilities. From a {flow graph} description, Ptolemy can
+ generate both {C} code and {DSP} {assembly code} for rapid
+ prototyping. Note that code generation is not yet complete,
+ and is included in the current release for demonstration
+ purposes only.
+
+ Version 0.4.1 includes a graphical algorithm layout, code
+ generator and simulator. It requires {C++}, {C} and has been
+ ported to {Sun-4}, {MIPS}/{Ultrix}; {DSP56001}, {DSP96002}.
+ Ptolemy is an active research project.
+
+ {(ftp://ptolemy.bekeley.edu/pub/ptolemy/)}. Mailing list:
+ ptolemy-hackers-request@ohm.berkeley.edu. E-mail:
+ <ptolemy@ohm.berkeley.edu>.
+
+ (1993-04-22)
+
+PTT
+
+ {Post, Telephone and Telegraph administration}
+
+PUB
+
+ 1. PUBlishing. A 1972 text-formatting language for {TOPS-10},
+ with syntax based on {SAIL}. Influenced {TeX} and {Scribe}.
+ ["PUB: The Document Compiler", Larry Tesler, Stanford AI Proj
+ Op Note, Sept 1972].
+
+ 2. /pub, the top-level, publicly accessible directory on most
+ {anonymous FTP} archives. This is usually where the
+ interesting files are. See {pubic directory}.
+
+pubic directory
+
+ [NYU] (also "pube directory" /pyoob' d*-rek't*-ree/) The "pub"
+ (public) directory on a machine that allows {FTP} access. So
+ called because it is the default location for {SEX} (software
+ exchange).
+
+ [{Jargon File}]
+
+public domain
+
+ (PD) The total absence of {copyright} protection. If
+ something is "in the public domain" then anyone can copy it or
+ use it in any way they wish. The author has none of the
+ exclusive rights which apply to a copyright work.
+
+ The phrase "public domain" is often used incorrectly to refer
+ to {freeware} or {shareware} (software which is copyrighted
+ but is distributed without (advance) payment). Public domain
+ means no copyright -- no exclusive rights. In fact the phrase
+ "public domain" has no legal status at all in the UK.
+
+ See also {archive site}, {careware}, {charityware},
+ {copyleft}, {crippleware}, {guiltware}, {postcardware} and
+ {-ware}. Compare {payware}.
+
+public domain software
+
+ {public domain}
+
+public-key cryptography
+
+ {public-key encryption}
+
+Public-Key Cryptography Standards
+
+ <cryptography, standard> (PKCS) A set of {standards} for
+ {public-key cryptography}, developed by {RSA Data Security,
+ Inc.} in cooperation with an informal consortium, originally
+ including {Apple}, {Microsoft}, {DEC}, {Lotus}, {Sun} and
+ {MIT}. The PKCS have been cited by the {OSI Implementers'
+ Workshop} (OIW) as a method for implementation of {OSI}
+ standards.
+
+ PKCS includes both {algorithm}-specific and
+ algorithm-independent implementation standards. Many
+ algorithms are supported, including {RSA} and {Diffie-Hellman}
+ key exchange, however, only the latter two are specifically
+ detailed. PKCS also defines an algorithm-independent {syntax}
+ for {digital signatures}, {digital envelopes}, and extended
+ {digital certificates}; this enables someone implementing any
+ cryptographic algorithm whatsoever to conform to a standard
+ syntax, and thus achieve interoperability.
+
+ E-mail: pkcs@rsa.com.
+
+ (1999-02-16)
+
+public-key encryption
+
+ <cryptography> (PKE, Or "public-key cryptography") An
+ {encryption} scheme, introduced by Diffie and Hellman in 1976,
+ where each person gets a pair of keys, called the public key
+ and the private key. Each person's public key is published
+ while the private key is kept secret. Messages are encrypted
+ using the intended recipient's public key and can only be
+ decrypted using his private key. This is often used in
+ conjunction with a {digital signature}.
+
+ The need for sender and receiver to share secret information
+ (keys) via some secure channel is eliminated: all
+ communications involve only public keys, and no private key is
+ ever transmitted or shared.
+
+ Public-key encryption can be used for {authentication},
+ {confidentiality}, {integrity} and {non-repudiation}.
+
+ {RSA encryption} is an example of a public-key cryptosystem.
+
+ {alt.security FAQ
+ (http://cis.ohio-state.edu/hypertext/faq/bngusenet/alt/security/top.html)}.
+
+ See also {knapsack problem}.
+
+ (1995-03-27)
+
+Public Key Infrastructure
+
+ <cryptography, communications> (PKI) A system of {public key
+ encryption} using {digital certificates} from {Certificate
+ Authorities} and other registration authorities that verify
+ and authenticate the validity of each party involved in an
+ electronic transaction.
+
+ PKIs are currently evolving and there is no single PKI nor
+ even a single agreed-upon standard for setting up a PKI.
+ However, nearly everyone agrees that reliable PKIs are
+ necessary before {electronic commerce} can become widespread.
+
+ {US DOD PKI (http://www-pki.itsi.disa.mil/)}.
+
+ {US NIST PKI (http://csrc.ncsl.nist.gov/pki/)}.
+
+ {IETF PKIX Working Group (http://imc.org/ietf-pkix/)}.
+
+ (1999-11-30)
+
+Public Switched Telephone Network
+
+ <communications> (PSTN, T.70) The collection of interconnected
+ systems operated by the various telephone companies and
+ administrations ({telcos} and {PTTs}) around the world. Also
+ known as the Plain Old Telephone System (POTS) in contrast to
+ {xDSL} and {ISDN} (not to mention other forms of {PANS}).
+
+ The PSTN started as human-operated analogue circuit switching
+ systems (plugboards), progressed through electromechanical
+ switches. By now this has almost completely been made
+ digital, except for the final connection to the subscriber
+ (the "last mile"): The signal coming out of the phone set is
+ analogue. It is usually transmitted over a {twisted pair
+ cable} still as an analogue signal. At the {telco} office
+ this analogue signal is usually digitised, using 8000 samples
+ per second and 8 bits per sample, yielding a 64 kb/s data
+ stream ({DS0}). Several such data streams are usually
+ combined into a fatter stream: in the US 24 channels are
+ combined into a {T1}, in Europe 31 DS0 channels are combined
+ into an {E1} line. This can later be further combined into
+ larger chunks for transmission over high-bandwidth core
+ trunks. At the receiving end the channels are separated, the
+ digital signals are converted back to analogue and delivered
+ to the received phone.
+
+ While all these conversions are inaudible when voice is
+ transmitted over the phone lines it can make digital
+ communication difficult. Items of interest include {A-law} to
+ {mu-law} conversion (and vice versa) on international calls;
+ {robbed bit} signalling in North America (56 kbps <--> 64
+ kbps); data {compression} to save {bandwidth} on long-haul
+ trunks; signal processing such as echo suppression and voice
+ signal enhancement such as AT&T TrueVoice.
+
+ (2000-07-09)
+
+puff
+
+ <algorithm> To decompress data that has been crunched by
+ {Huffman coding}. At least one widely distributed Huffman
+ decoder program was actually *named* "PUFF", but these days it
+ is usually packaged with the encoder.
+
+ Opposite: {huff}.
+
+ [{Jargon File}]
+
+ (1996-10-16)
+
+PUFFT
+
+ ["The Purdue University Fast Fortran Translator", Saul Rosen
+ et al, CACM 8(11):661-666 (Nov 1965)].
+
+ (1995-01-05)
+
+pull
+
+ {pull media}
+
+pull-down list
+
+ <operating system> (Or "drop-down list") A {graphical user
+ interface} component that allows the user to choose one (or
+ sometimes more than one) item from a list. The current choice
+ is visible in a small rectangle and when the user clicks on
+ it, a list of items is revealed below it. The user can then
+ click on one of these to make it the current choice and the
+ list disappears. In some cases, by holding down a modifier
+ key such as Ctrl when clicking, the selection is added to (or
+ removed from) the set of current choices rather than replacing
+ it.
+
+ (1999-09-25)
+
+pull-down menu
+
+ <operating system> (Or "drop-down menu", "pop-down menu") A
+ {menu} in a {graphical user interface}, whose title is
+ normally visible but whose contents are revealed only when the
+ user activates it, normally by pressing the {mouse} button
+ while the {pointer} is over the title, whereupon the menu
+ items appear below the title. The user may then select an
+ item from the menu or click elsewhere, in either case the menu
+ contents are hidden again. A menu item is selected either by
+ dragging the mouse from the menu title to the item and
+ releasing or by clicking the title and then the item.
+
+ When a pull-down menu appears in the main area of a window, as
+ opposed to the {menu bar}, it may have a small,
+ downward-pointing triangle to the right.
+
+ Compare: {scrollable list}.
+
+ (1999-09-22)
+
+pull media
+
+ <messaging> A model of media distribution were the bits of
+ content have to be requested by the user, e.g. normal use of
+ {HTTP} on the {web}.
+
+ Opposite: "{push media}".
+
+ (1997-04-10)
+
+Pulse Code Modulation
+
+ <data> (PCM) A method by which an audio signal is represented
+ as digital data.
+
+ Virtually all digital audio systems use PCM, including, {CD},
+ {DAT}, F1 format, 1630 format, DASH, DCC, and MD. Many people
+ get confused because "PCM" is also slang for Sony's F1 format
+ which stores PCM digital audio on videotape.
+
+ (1995-02-09)
+
+pumpkin
+
+ <jargon> A humourous term for the {token} - the object
+ (notional or real) that gives its possessor (the "pumpking" or
+ the "pumpkineer") exclusive access to something, e.g. applying
+ {patches} to a master copy of {source} (for which the pumpkin
+ is called a "patch pumpkin").
+
+ Chip Salzenberg <chip@perl.com> wrote:
+
+ David Croy once told me once that at a previous job, there was
+ one tape drive and multiple systems that used it for backups.
+ But instead of some high-tech exclusion software, they used a
+ low-tech method to prevent multiple simultaneous backups: a
+ stuffed pumpkin. No one was allowed to make backups unless
+ they had the "backup pumpkin".
+
+ (1999-02-23)
+
+pumpkineer
+
+ {pumpkin}
+
+pumpking
+
+ {pumpkin}
+
+punch card
+
+ {punched card}
+
+punched card
+
+ <storage, history> (Or "punch card") The signature medium of
+ computing's Stone Age, now long obsolete outside of a few
+ {legacy systems}. The punched card actually predates
+ computers considerably, originating in 1801 as a control
+ device for {Jacquard looms}. {Charles Babbage} used them as a
+ data and program storage medium for his {Analytical Engine}:
+
+ "To those who are acquainted with the principles of the
+ Jacquard loom, and who are also familiar with analytical
+ formulæ, a general idea of the means by which the Engine
+ executes its operations may be obtained without much
+ difficulty. In the Exhibition of 1862 there were many
+ splendid examples of such looms. [...] These patterns are then
+ sent to a peculiar artist, who, by means of a certain machine,
+ punches holes in a set of pasteboard cards in such a manner
+ that when those cards are placed in a Jacquard loom, it will
+ then weave upon its produce the exact pattern designed by the
+ artist. [...] The analogy of the Analytical Engine with this
+ well-known process is nearly perfect. There are therefore two
+ sets of cards, the first to direct the nature of the
+ operations to be performed -- these are called operation
+ cards: the other to direct the particular variables on which
+ those cards are required to operate -- these latter are called
+ variable cards. Now the symbol of each variable or constant,
+ is placed at the top of a column capable of containing any
+ required number of digits."
+
+ -- from Chapter 8 of Charles Babbage's "Passages from the Life
+ of a Philosopher", 1864.
+
+ The version patented by {Herman Hollerith} and used with
+ mechanical tabulating machines in the 1890 US Census was a
+ piece of cardboard about 90 mm by 215 mm. There is a
+ widespread myth that it was designed to fit in the currency
+ trays used for that era's larger dollar bills, but recent
+ investigations have falsified this.
+
+ {IBM} (which originated as a tabulating-machine manufacturer)
+ married the punched card to computers, encoding binary
+ information as patterns of small rectangular holes; one
+ character per column, 80 columns per card. Other coding
+ schemes, sizes of card, and hole shapes were tried at various
+ times.
+
+ The 80-column width of most character terminals is a legacy of
+ the IBM punched card; so is the size of the quick-reference
+ cards distributed with many varieties of computers even today.
+
+ See {chad}, {chad box}, {eighty-column mind}, {green card},
+ {dusty deck}, {lace card}, {card walloper}.
+
+ [{Jargon File}]
+
+ (1998-10-19)
+
+punt
+
+ (From the punch line of an old joke referring to American
+ football: "Drop back 15 yards and punt!") 1. To give up,
+ typically without any intention of retrying. "Let's punt the
+ movie tonight." "I was going to hack all night to get this
+ feature in, but I decided to punt" may mean that you've
+ decided not to stay up all night, and may also mean you're not
+ ever even going to put in the feature.
+
+ 2. More specifically, to give up on figuring out what the
+ {Right Thing} is and resort to an inefficient hack.
+
+ 3. A design decision to defer solving a problem, typically
+ because one cannot define what is desirable sufficiently well
+ to frame an algorithmic solution. "No way to know what the
+ right form to dump the graph in is - we'll punt that for
+ now."
+
+ 4. To hand a tricky implementation problem off to some other
+ section of the design. "It's too hard to get the compiler to
+ do that; let's punt to the run-time system."
+
+ [{Jargon File}]
+
+Purdue Compiler-Construction Tool Set
+
+ <tool> (PCCTS) A highly integrated {lexical analser generator}
+ and {parser generator} by Terence J. Parr <parrt@acm.org>,
+ Will E. Cohen and Henry G. Dietz <hankd@ecn.purdue.edu>, both
+ of {Purdue University}.
+
+ ANTLR (ANother Tool for Language Recognition) corresponds to
+ YACC and DLG (DFA-based Lexical analyser Generator) functions
+ like {LEX}. PCCTS has many additional features which make it
+ easier to use for a wide range of translation problems. PCCTS
+ {grammars} contain specifications for lexical and syntactic
+ analysis with selective {backtracking} ("infinite lookahead"),
+ {semantic predicates}, intermediate-form construction and
+ error reporting. Rules may employ {Extended BNF} (EBNF)
+ grammar constructs and may define parameters, return values,
+ and have {local variables}.
+
+ Languages described in PCCTS are recognised via {LLk} parsers
+ constructed in pure, human-readable, {C} code. Selective
+ backtracking is available to handle non-LL(k) constructs.
+ PCCTS {parsers} may be compiled with a {C++} compiler. PCCTS
+ also includes the {SORCERER} tree parser generator.
+
+ Latest version: 1.10, runs under {Unix}, {MS-DOS}, {OS/2}, and
+ {Macintosh} and is very portable.
+
+ {(ftp://marvin.ecn.purdue.edu/pub/pccts/1.10)}.
+
+ {UK FTP (ftp://src.doc.ic.ac.uk/
+ computing/programming/languages/tools/pccts/)}. {Macintosh
+ FTP (ftp://maya.dei.unipd.it/pub/mac/)}.
+
+ Mailing list: pccts-users-request@ahpcrc.umn.edu ("subscribe
+ pccts-users your_name" in the message body).
+
+ E-mail: Terence J. Parr <parrt@acm.org>, Roberto Avanzi
+ <mocenigo@maya.dei.unipd.it> (Mac port).
+
+ (2000-10-30)
+
+Purdue University
+
+ {(http://purdue.edu/)}.
+
+ (1995-01-05)
+
+pure functional language
+
+ {purely functional language}
+
+pure lambda-calculus
+
+ {Lambda-calculus} with no constants, only functions expressed
+ as {lambda abstractions}.
+
+ (1994-10-27)
+
+PureLink
+
+ An incremental linker from {Pure Software}.
+
+Pure Lisp
+
+ A {purely functional language} derived from {Lisp} by
+ excluding any feature which causes {side-effects}.
+
+purely functional language
+
+ <language> A language that supports only {functional
+ programming} and does not allow functions to have
+ {side-effects}. Program execution consists of evaluation of
+ an expression and all subexpressions are {referentially
+ transparent}.
+
+ (2003-03-25)
+
+Purify
+
+ A debugging tool from Pure Software.
+
+Purple Book
+
+ 1. <publication> The "System V Interface Definition". The
+ covers of the first editions were an amazingly nauseating
+ shade of off-lavender.
+
+ 2. <publication> The {Wizard Book}.
+
+ See also {book titles}.
+
+ [{Jargon File}]
+
+purple wire
+
+ <jargon, hardware> Wire installed by {IBM} Field Engineers to
+ work around problems discovered during testing or debugging.
+ These are called "purple wires" even when (as is frequently
+ the case) they are yellow.
+
+ Compare {blue wire}, {yellow wire}, and {red wire}.
+
+ (1995-04-11)
+
+Purveyor
+
+ <web> A {web server} for {Windows NT}
+ and {Windows 95} (when available).
+
+ {(http://process.com/)}.
+
+ E-mail: <info@process.com>.
+
+ (1995-04-11)
+
+push
+
+ 1. <programming> To put something onto a {stack} or {pdl}.
+
+ Opposite: "{pop}".
+
+ 2. <communications> {push media}.
+
+ [{Jargon File}]
+
+ (1997-04-10)
+
+push-button
+
+ <electronics> A roughly fingertip-sized plastic cover attached
+ to a spring-loaded, normally-open switch, which, when pressed,
+ closes the switch. Typical examples are the keys on a
+ computer or calculator keyboard and {mouse} buttons.
+
+ (1997-07-07)
+
+Push Down List
+
+ <programming> (PDL) In {ITS} days, the preferred {MIT}ism for
+ {stack}.
+
+ See {overflow pdl}.
+
+ (1995-12-21)
+
+push media
+
+ <messaging> A model of media distribution where items of
+ content are sent to the user (viewer, listener, etc.) in a
+ sequence, and at a rate, determined by a {server} to which the
+ user has connected. This contrasts with {pull media} where
+ the user requests each item individually. Push media usually
+ entail some notion of a "channel" which the user selects and
+ which delivers a particular kind of content.
+
+ Broadcast television is (for the most part) the prototypical
+ example of push media: you turn on the TV set, select a
+ channel and shows and commercials stream out until you turn
+ the set off.
+
+ By contrast, the {web} is (mostly) the prototypical
+ example of pull media: each "page", each bit of content, comes
+ to the user only if he requests it; put down the keyboard and
+ the mouse, and everything stops.
+
+ At the time of writing (April 1997), much effort is being put
+ into blurring the line between push media and pull media.
+ Most of this is aimed at bringing more push media to the
+ {Internet}, mainly as a way to disseminate advertising, since
+ telling people about products they didn't know they wanted is
+ very difficult in a strict pull media model.
+
+ These emergent forms of push media are generally variations on
+ targeted advertising mixed in with bits of useful content.
+ "At home on your computer, the same system will run soothing
+ {screensavers} underneath regular news flashes, all while
+ keeping track, in one corner, of press releases from companies
+ whose stocks you own. With frequent commercial messages, of
+ course." (Wired, March 1997, page 12).
+
+ {Pointcast (http://pointcast.com)} is probably the best
+ known push system on the Internet at the time of writing.
+
+ As part of the eternal desire to apply a fun new words to
+ boring old things, "push" is occasionally used to mean nothing
+ more than email {spam}.
+
+ (1997-04-10)
+
+PVC
+
+ 1. <networking> {Permanent Virtual Circuit}.
+
+ 2. <hardware> {polyvinyl chloride}.
+
+ (2001-03-26)
+
+PVM
+
+ {Parallel Virtual Machine}
+
+PV-WAVE
+
+ <graphics, tool> (Precision Visuals' Workstation Analysis and
+ Visualization Environment) Interactive scientific
+ {visualisation} software originally from Precision Visuals,
+ Inc., but now owned by Visual Numerics, Inc. (VNI).
+
+ (1999-07-18)
+
+pw
+
+ <networking> The {country code} for Palau.
+
+ (1999-01-27)
+
+PWM
+
+ {pulse width modulation}
+
+py
+
+ <networking> The {country code} for Paraguay.
+
+ (1999-01-27)
+
+Pythagoras
+
+ <person> (Pythagoras of Samos, Ionia; about 569-475 BC) The
+ Greek mathematician who founded a philosophical and religious
+ school in Croton (now Crotone) in southern Italy.
+
+ Pythagoras is most famous for {Pythagoras's Theorem} but other
+ important postulates are attributed to him, e.g. the sum of
+ the angles of a triangle is equal to two right angles.
+
+ (2004-02-12)
+
+Pythagoras's Theorem
+
+ <mathematics> The theorem of geometry, named after
+ {Pythagoras}, of Samos, Ionia, stating that, for a
+ right-angled triangle, the square of the length of the
+ {hypotenuse} is equal to the sum of the squares of the lengths
+ of the other two sides. I.e. if the longest side has
+ length A and the other sides have lengths B and C (in any
+ units),
+
+ A^2 = B^2 + C^2
+
+ (2004-02-12)
+
+Pythagoras' Theorem
+
+ <spelling> It's {Pythagoras's Theorem}.
+
+ (2007-06-07)
+
+Pythagorean Theorem
+
+ {Pythagoras's Theorem}
+
+Python
+
+ 1. <language> A simple, high-level interpreted language
+ invented by Guido van Rossum <guido@cwi.nl> in 1991. Python
+ combines ideas from {ABC}, {C}, {Modula-3} and {Icon}. It
+ bridges the gap between {C} and {shell} programming, making it
+ suitable for {rapid prototyping} or as an extension language
+ for C applications. It is {object-oriented} and supports
+ packages, {modules}, {classes}, user-defined exceptions, a
+ good C interface, dynamic loading of C modules and has no
+ arbitrary restrictions.
+
+ Python is available for many {platforms}, including {Unix},
+ {Windows}, {DOS}, {OS/2}, {Macintosh} and {Amoeba}.
+
+ Latest version: 2.5, as of 2007-02-21.
+
+ {(http://python.org/)}.
+
+ {Usenet} newsgroup: {news:comp.lang.python}.
+
+ (2007-02-21)
+
+ 2. <compiler> A {compiler} for {CMU Common LISP}. Python is
+ more sophisticated than other {Common Lisp} compilers. It
+ produces better code and is easier to use. The programming
+ environment based on the {Hemlock} editor is better integrated
+ than {GNU} {Emacs} based environments.
+
+ (1997-02-27)
+
+Q
+
+ <language> A very {high level language} by Per Bothner based
+ on {lazy} generalised sequences. Q has {lexical scope}, and
+ some support for {logic programming}[?] and {constraint}
+ programming. The language includes small subsets of {Common
+ Lisp} and {Scheme}.
+
+ Q was a test-bed for programming language ideas. Where {APL}
+ uses {arrays} for looping, Q uses generalised sequences which
+ may be infinite and may be stored or calculated on demand. It
+ has {macros}, {primitives} to run programs, and an
+ {interactive} command language.
+
+ Q is implemented in {C++}, and comes with an {interpreter},
+ {compiler} framework, libraries, and documentation. It runs
+ on {Linux} and {SUN-4} and should work on any 32-bit {Unix}.
+
+ Latest version: 1, as of 1993-06-07. Development stopped in
+ 1994.
+
+ {(http://kelso.bothner.com/~per/software/#Q )}.
+
+ E-mail: Per Bothner <per@bothner.com>.
+
+ (2000-05-22)
+
+QA
+
+ {Quality Assurance}
+
+qa
+
+ <networking> The {country code} for Qatar.
+
+ (1999-01-27)
+
+QA4
+
+ Question-answering language. A procedural calculus for
+ intuitive reasoning. A LISP-based pattern-matching language
+ for theorem proving. "QA4, A Language for Writing
+ Problem-Solving Programs", J.F. Rulifson et al, Proc IFIP
+ Congress 1968.
+
+QAM
+
+ 1. {Quadrature Amplitude Modulation}.
+
+ 2. {Quality Assurance Management}.
+
+Qbasic
+
+ <language> Quick basic.
+
+ A version of {BASIC} from {Microsoft}, later known as
+ {MS-BASIC}.
+
+ (1995-03-16)
+
+QBE
+
+ {Query By Example}
+
+QCA
+
+ {Quantum-dot Cellular Automata}
+
+QCIF
+
+ {Quarter CIF}
+
+qdjanus
+
+ A {Janus}-to-{Prolog} compiler by Saumya Debray
+ <debray@cs.arizona.edu>. It is meant to be used with {Sicstus
+ Prolog} and is mostly compliant with "Programming in Janus" by
+ Saraswat, Kahn, and Levy.
+
+ Latest version: 1.3.
+
+ {(ftp://cs.arizona.edu/janus/qdjanus/)}.
+
+ (1992-05-18)
+
+QDOS
+
+ <operating system> The Sinclair {QL}'s proprietary {operating
+ system}. The origin of the name is uncertain (a weak pun on
+ kudos, perhaps, as {Unix} was on {Multics}). There was
+ another OS around from the birth of personal computers called
+ Q.D.O.S. - Quick And Dirty Operating System. QDOS might also
+ stand for QL Data/Disk/Drive/Device Operating System.
+
+ QDOS did the usual OS sorts of things, as well as
+ multitasking. It was unusual in several ways. It treated all
+ devices (serial ports, mouse ports, screen, {microdrive},
+ {disk drive}, keyboard, etc.) uniformly, so you could print a
+ text file direct to disk or save a binary to the screen for
+ example.
+
+ Also logical channels could be assigned to particular physical
+ devices. Output directed to a channel would go to the
+ appropriate in/output. This also meant you could have many
+ windows on screen (the QL booted up from internal ROMs with 3
+ windows - command line, output and program listing) all
+ independent to some extent. Channels could be redirected
+ without affecting the way the process sent or received the
+ data.
+
+ (1996-07-22)
+
+QEMM386
+
+ <software, storage> A combined {expanded memory manager} and
+ {extended memory manager} for {IBM PCs} with an {Intel 80386}
+ or higher processor from {Quarterdeck Office Systems}.
+ QEMM386 can also act as an {UMB} provider and an {A20
+ handler}.
+
+ (1996-01-10)
+
+QIC
+
+ {Quarter-Inch Cartridge}
+
+QL
+
+ <computer> (Quantum Leap) Sir {Clive Sinclair}'s first
+ {Motorola 68008}-based {personal computer}, developed from
+ around 1981 and released about 1983. The QL ran Sinclair's
+ {QDOS} {operating system} which was the first {multitasking}
+ OS on a home computer, though few programmers used this
+ feature. It had a structured, extended {BASIC} and a suite of
+ integrated {application programs} written by {Psion}. It
+ featured innovative "{microdrives}" which were random-access
+ tape drives. It was not a success.
+
+ The microdrives were innovative but probably a mistake.
+ Though reliable and quite quick, they sounded like they were
+ going to jam and explode, releasing a shower of plastic
+ shavings and tape into your face.
+
+ The QL and QDOS only supported two graphics modes - ominously
+ named high res and low res. High res had four (fixed) colours
+ at a resolution of 512 by 256 {pixels}. Low res had 8 colours
+ (black, blue, red, magenta, green, cyan, yellow, white) plus a
+ flash mode with 256 by 256 pixels. The sound was next to
+ useless - single channel single oscillator with various
+ parameters for fuzz, pitch change. There was one internal
+ {font}, scalable to 2 heights and 3 widths.
+
+ Peripherals and enhancements included a {GUI} on a plug-in
+ {ROM}, accelerator cards ({Motorola 68020}, 4 MB RAM), {floppy
+ disks} and {hard disks}.
+
+ In 1996 there is still some interest in the QL, spread by the
+ Internet of course. {Emulation} software, {source code}, "The
+ QL Hackers Journal" and similar are still available, and many
+ QLs are on the net.
+
+ {(http://imaginet.fr/~godefroy/english)}.
+
+ (1996-08-01)
+
+Qlambda
+
+ <language> A {LISP} by {Richard Gabriel} and {John McCarthy}.
+
+ ["Queue-based Multi-processing Lisp", R. Gabriel &
+ J. McCarthy, Proc 1984 Symp Lisp and Functional Prog,
+ pp. 25-44].
+
+ (1999-10-12)
+
+QLISP
+
+ 1. SRI 1973. General problem solving, influenced by PLANNER.
+ QA4 features merged with INTERLISP.
+
+ ["QLISP - A Language for the Interactive Development of
+ Complex Systems", E. Sacerdoti et al, NCC 45:349-356, AFIPS,
+ 1976].
+
+ 2. A parallel LISP.
+
+ ["Qlisp", R. Gabriel et al in Parallel Computation and
+ Computers for AI, J. Kowalik ed, 1988, pp.63-89].
+
+ (1999-10-12)
+
+QLOG
+
+ A version of {Prolog} implemented in {Lisp} which allows
+ Prolog programs to call Lisp and vice versa.
+
+ ["QLOG - The Programming Environment for Prolog in LISP",
+ H.J. Komorowski in Logic Prgramming, K.L. Clark et al eds,
+ Academic Press 1982].
+
+ (1995-01-25)
+
+QMQP
+
+ {Quick Mail Queueing Protocol}
+
+QMTP
+
+ {Quick Mail Transfer Protocol}
+
+QMW
+
+ {Queen Mary and Westfield College}
+
+Q'NIAL
+
+ A portable {incremental compiler} for {NIAL}, written in {C}
+ at {Queen's University}, Canada.
+
+ There aree versions for {Unix} and {MS-DOS}, from {NIAL
+ Systems} Ltd.
+
+ ["The Q'NIAL Reference Manual", M.A. Jenkins, Queen's U
+ Report, Dec 1983].
+
+ (1995-01-25)
+
+QNX
+
+ <operating system> A {realtime}, network distributed,
+ {POSIX}-certified, {microkernel}, multi-user, {multitasking},
+ {ROMable}, {fault-tolerant}, embeddable {operating system}
+ that supports {TCP/IP}, {NFS}, {FTP}, the {X Window System},
+ {Microsoft Windows} as a guest process, {Ethernet}, {Token
+ Ring}, {Arcnet} and {Watcom} {ANSI C}/{C++}. Support for
+ {Pentium}, {486}, {386}, {286}, {80x87}. Developed and
+ distributed by QNX Software Systems, Ltd.
+
+ Latest version: 6.1, as of 2001-09-02.
+
+ {QNX Home (http://qnx.com/)}.
+
+ {OpenQNX: The QNX community portal (http://openqnx.com)}.
+
+ {Papers (ftp://ftp.cse.ucsc.edu/pub/qnx/qnx-paper.ps.Z)}.
+ (128.114.134.19).
+
+ {Usenet} newsgroup: {news:comp.os.qnx}.
+
+ E-mail: <info@qnx.com>.
+
+ (2003-07-27)
+
+QoS
+
+ {Quality of service}
+
+QPE
+
+ <language> 1. A two-dimensional pictorial {query language}.
+
+ ["Pictorial Information Systems", S.K. Chang et al eds,
+ Springer 1980].
+
+ [Q-systems. A. Colmerauer, 1969].
+
+ 2. A {rewrite system} with {one-way unification}, used for
+ English-French translation. It led to {Prolog}.
+
+ ["The Birth of Prolog" A. Colmerauer et al, SIGPLAN Notices
+ 28(3):37-52 March 1993].
+
+ (2003-12-25)
+
+QSAM
+
+ {Physical Sequential}
+
+QT-OBJECTS
+
+ A library by Michael Travers <mt@media.mit.edu> and others
+ providing an interface between {MCL} and {QuickTime}.
+
+ (1992-12-20)
+
+QTRADER
+
+ <application> Analytical software for stock and commodity
+ trading, released in July 1995 by {Caribou CodeWorks}.
+
+ QTRADER allows dynamic automated analysis of current trends
+ and features "Paper Trade" plotting, as well as "TradeSignal
+ Bands" and "StudyMatrix" filter to screen potential trades.
+ Projected ranges are handled with a "Tomorrow's Bar".
+
+ QTRADER version 3.0 runs on {IBM PC}-compatibles, a
+ {Macintosh} version is not available until late 1996.
+
+ {Demo copy (http://winternet.com/~jottis)}.
+ {(ftp://ftp.winternet.com/users/jottis)}.
+
+ (1995-11-05)
+
+quad
+
+ <character> The rectangle or box {glyph} used in the {APL}
+ language for various arcane purposes mostly related to {I/O}.
+
+ [{Jargon File}]
+
+ (2007-05-31)
+
+Quadralay Corporation
+
+ <company> The developers of {GWHIS}.
+
+ {(http://quadralay.com/)}.
+
+ Telephone: +1 512-346-9199.
+ Fax: +1 512-346-8990.
+
+ (2000-08-12)
+
+Quadrature Amplitude Modulation
+
+ (QAM) A method for encoding digital data in an analog signal
+ in which each combination of phase and amplitude represents
+ one of sixteen four bit patterns. This is required for fax
+ transmission at 9600 bits per second.
+
+ (1995-02-02)
+
+quadruple bucky
+
+ Obsolete. 1. On an MIT {space-cadet keyboard}, use of all four
+ of the shifting keys (control, meta, hyper, and super) while
+ typing a character key.
+
+ 2. On a Stanford or MIT keyboard in {raw mode}, use of four
+ shift keys while typing a fifth character, where the four
+ shift keys are the control and meta keys on *both* sides of
+ the keyboard. This was very difficult to do! One accepted
+ technique was to press the left-control and left-meta keys
+ with your left hand, the right-control and right-meta keys
+ with your right hand, and the fifth key with your nose.
+
+ Quadruple-bucky combinations were very seldom used in
+ practice, because when one invented a new command one usually
+ assigned it to some character that was easier to type. If you
+ want to imply that a program has ridiculously many commands or
+ features, you can say something like: "Oh, the command that
+ makes it spin the tapes while whistling Beethoven's Fifth
+ Symphony is quadruple-bucky-cokebottle." See {double bucky},
+ {bucky bits}, {cokebottle}.
+
+ [{Jargon File}]
+
+quadruplex
+
+ <communications> A kind of telegraphy system developed by
+ Thomas A. Edison in the 1870s combining {diplex} and {duplex}
+ communications to support simultaneous transmission of two
+ messages in each direction.
+
+ (2000-04-02)
+
+Quake
+
+ A string-oriented language designed to support the
+ construction of {Modula-3} programs from {modules}, interfaces
+ and libraries. Written by Stephen Harrison of DEC SRC, 1993.
+
+Qualcomm
+
+ <company> A California-based technology company; their primary
+ product is the {OMNITRACS} tractor-trailer-tracking system.
+ They also develop the free and commercial versions of
+ {Eudora} for {Macintosh} and {IBM PC}.
+
+ (1995-10-05)
+
+quality
+
+ The totality of features and characteristics of a product or
+ service that bear on its ability to satisfy stated or implied
+ needs. Not to be mistaken for "degree of excellence" or
+ "fitness for use" which meet only part of the definition.
+
+ [{ISO8402}].
+
+ (1995-11-10)
+
+quality assurance
+
+ <testing> (QA) A planned and systematic pattern of all actions
+ necessary to provide adequate confidence that the product
+ optimally fulfils customers' expectations, i.e. that it is
+ problem-free and well able to perform the task it was designed
+ for.
+
+ The QA of a commercial product usually involves {alpha
+ testing}, where an early version of the product is tested at
+ the developer's site, and is then improved accordingly. Then,
+ an almost complete version of the product is made available
+ for {beta testing} by (selected) real users. Faults
+ identified during beta testing should be fixed before the
+ product is released for full scale manufacturing and
+ distribution.
+
+ (2001-04-21)
+
+quality control
+
+ <testing> The assessment of product compliance with stated
+ requirements. Quality control should be independent from
+ production.
+
+ (2001-05-20)
+
+quality of service
+
+ <communications, networking> (QoS) The performance properties
+ of a network service, possibly including {throughput},
+ {transit delay}, {priority}. Some {protocols} allow {packets}
+ or {streams} to include QoS requirements.
+
+ (1998-07-30)
+
+Quality Systems & Software Ltd.
+
+ <company> The company which produced the {DOORS} requirements
+ engineering tool. They also provide consultancy as
+ Requirements Engineering Ltd.
+
+ {(http://qss.co.uk/)}.
+
+ E-mail: Ian Alexander <iany@easynet.co.uk>, Amanda
+ Haisman-Baker <100023.44@compuserve.com>.
+
+ (1995-11-11)
+
+quantifier
+
+ <logic> An operator in {predicate logic} specifying for which
+ values of a variable a formula is true. Universally
+ quantified means "for all values" (written with an inverted A,
+ {LaTeX} \forall) and existentially quantified means "there
+ exists some value" (written with a reversed E, {LaTeX}
+ \exists). To be unambiguous, the set to which the values of
+ the variable belong should be specified, though this is often
+ omitted when it is clear from the context (the "universe of
+ discourse"). E.g.
+
+ Forall x . P(x) <=> not (Exists x . not P(x))
+
+ meaning that any x (in some unspecified set) has property P
+ which is equivalent to saying that there does not exist any x
+ which does not have the property.
+
+ If a variable is not quantified then it is a {free variable}.
+ In {logic programming} this usually means that it is actually
+ universally quantified.
+
+ See also {first order logic}.
+
+ (2002-05-21)
+
+Quantify
+
+ A performance analysis tool from {Pure Software}.
+
+quantum
+
+ {time slice}
+
+quantum bogodynamics
+
+ /kwon'tm boh"goh-di:-nam"iks/ A theory that characterises the
+ universe in terms of {bogon} sources (such as politicians,
+ used-car salesmen, TV evangelists, and {suits} in general),
+ bogon sinks (such as taxpayers and computers), and bogosity
+ potential fields. Bogon absorption causes human beings to
+ behave mindlessly and machines to fail (and may also cause
+ both to emit secondary bogons); however, the precise mechanics
+ of bogon-{computron} interaction are not yet understood.
+
+ Quantum bogodynamics is most often invoked to explain the
+ sharp increase in hardware and software failures in the
+ presence of suits; the latter emit bogons, which the former
+ absorb.
+
+ [{Jargon File}]
+
+ (1994-11-02)
+
+quantum cell
+
+ <electronics, computing> (Or "quantum dot cell") A structure
+ comprising four {quantum dots} arranged in a square, with two
+ diagonally opposed dots containing electron charges. One
+ diagonal containing charges is arbitrarily defined as
+ representing a value of '1', the other as '0'. In a five-dot
+ cell, the fifth, central dot contains no charge.
+
+ See also: {quantum cell wire}, {quantum-dot cellular}
+ automata.
+
+ {(http://mitre.org/research/nanotech/quantum_dot_cell.html)}.
+
+ ["Quantum Dot Heterostructures", D. Bimberg, et al, John Wiley
+ & Sons Ltd., Dec 1998].
+
+ [Implementations?]
+
+ (2001-07-17)
+
+quantum cell wire
+
+ <electronics, computing> (Or "quantum wire", "binary wire")
+ {Quantum cells} arranged in a line to carry signals. Adjacent
+ cells with the same orientation are at a low energy state and
+ a change of orientation at one end of a quantum wire
+ propagates along the wire, transmitting a signal. However,
+ unlike conventional wire, since only the orientation of charge
+ pairs changes, no current flows.
+
+ Circuits created using quantum cell wires are referred to as
+ Quantum-dot Wireless Digital Circuits, see {quantum dot},
+ {Quantum-dot Cellular Automata}.
+
+ {(http://mitre.org/research/nanotech/quantum_dot_cell.html)}.
+
+ ["Quantum Dot Heterostructures", D. Bimberg, et al, John Wiley
+ & Sons Ltd., Dec 1998]
+
+ (2001-07-17)
+
+quantum computer
+
+ <computer> A type of computer which uses the ability of
+ quantum systems, such as a collection of atoms, to be in many
+ different states at once. In theory, such superpositions
+ allow the computer to perform many different computations
+ simultaneously. This capability is combined with interference
+ among the states to produce answers to some problems, such as
+ factoring integers, much more rapidly than is possible with
+ conventional computers. In practice, such machines have not
+ yet been built due to their extreme sensitivity to noise.
+
+ {Oxford University (http://eve.physics.ox.ac.uk/QChome.html)},
+ {Stanford University (http://feynman.stanford.edu/qcomp/)}.
+
+ A {quantum search algorithm
+ (ftp://parcftp.xerox.com/pub/dynamics/quantum.html)} for
+ {constraint satisfaction} problems exhibits the phase
+ transition for {NP-complete} problems.
+
+ (1997-02-11)
+
+quantum computing
+
+ {quantum computer}
+
+quantum dot
+
+ <physics> (Or "single-electron transistor") A location capable
+ of containing a single electrical charge; i.e., a single
+ electron of {Coulomb} charge. Physically, quantum dots are
+ nanometer-size {semiconductor} structures in which the
+ presence or absence of a quantum electron can be used to store
+ information.
+
+ See also: {quantum cell}, {quantum cell wire}, {quantum-dot
+ cellular automata}.
+
+ {(http://www-mtl.mit.edu/MTL/bulletin/v6n2/Kumar.html)}.
+
+ ["Quantum Dot Heterostructures", D. Bimberg, et al, John
+ Wiley & Sons Ltd., Dec 1998].
+
+ (2001-07-17)
+
+Quantum-dot Cellular Automata
+
+ <electronics, computing> (QCA) Quantum logic circuits created
+ by orientating pairs of {quantum cells} so that their relative
+ positions determine their affect on each other. This is
+ functionally analogous but structurally different from how
+ individual {gates} in {integrated circuits} are combined to
+ create logical and memory circuitry.
+
+ The advantages of quantum-dot cellular automata over
+ conventional circuitry are extremely small size/high density,
+ low power requirements, and potentially high processing
+ speeds. Disadvantages (in 2000) are difficulty of fabrication
+ and low yield.
+
+ See also: {quantum cell wire}.
+
+ {(http://nd.edu/~qcahome/)}.
+
+ {(http://mitre.org/research/nanotech/quantum_dot_cell.html)}.
+
+ ["Quantum Dot Heterostructures", D. Bimberg, et al, John Wiley
+ & Sons Ltd., Dec 1998].
+
+ (2001-07-17)
+
+quarter
+
+ {crumb}
+
+Quarter CIF
+
+ <communications, standard> (QCIF), a {video} format standard
+ used in videoconferencing, that transfers one fourth as much
+ data as {Common Intermediate Format} (CIF).
+
+ QCIF is defined in ITU H.261 as having 144 lines and 176
+ pixels per line, with half as many {chrominance} pixels in
+ each direction. QCIF is suitable for {videoconferencing}
+ systems that use telephone lines. The {codec} standard
+ specifies that QCIF compatibility is mandatory, and CIF
+ compatibility is optional.
+
+ (1999-04-22)
+
+Quarter Inch Cartridge
+
+ <storage> /kwik/ (QIC) a type of {magnetic tape} and {tape
+ drive}. Development standards for QIC make it possible for
+ tapes written on one QIC drive to be read on another. QIC
+ drives are made to work with different lengths of tape. The
+ model number of the drive consists of QIC followed by a number
+ which indicates the drives tape capacity in {megabytes} (MB).
+
+ (1996-12-09)
+
+Quay Financial Software
+
+ {CSK Software}
+
+QUEASY
+
+ An early system on the {IBM 701}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1995-01-25)
+
+Queen Mary and Westfield College
+
+ (QMW) One of the largest of the multi-faculty schools of the
+ {University of London}. QMW has some 6000 students and over
+ 600 teaching and research staff organised into seven
+ faculties.
+
+ QMW was one of the first colleges in the University of London
+ to develop fully the course-unit, or modular, approach to
+ degree programmes. Cross faculty courses are encouraged and
+ the physical proximity of all the College buildings is a major
+ factor in enabling students to adopt an interdisciplinary
+ approach to their studies.
+
+ {(http://qmw.ac.uk/)}.
+
+ (1995-01-25)
+
+Queens Problem
+
+ {Eight Queens Puzzle}
+
+Queens Puzzle
+
+ {Eight Queens Puzzle}
+
+Queen's University
+
+ A Canadian University. Source of {GVL}, {NIAL}, {Pasqual},
+ {Q'NIAL} and {TXL}.
+
+ {(ftp://ftp.qucis.queensu.ca/pub/)}.
+
+ (1994-10-20)
+
+QUEL
+
+ The {query language} used by the {database management system}
+ {INGRES}.
+
+ (1995-01-31)
+
+query
+
+ 1. <database, information science> A user's (or {agent}'s)
+ request for information, generally as a formal request to a
+ {database} or {search engine}.
+
+ {SQL} is the most common {database query language}.
+
+ 2. <character> {question mark}.
+
+ (1997-04-09)
+
+Query By Example
+
+ <database, language> (QBE) A {user-friendly} {query language}
+ developed by Moshé Zloof of {IBM} in 1975.
+
+ {(http://informatik.uni-trier.de/~ley/db/indices/a-tree/z/Zloof:Mosh=eacute=_M=.html)}.
+
+ [Moshé M. Zloof, "Query By Example", AFIPS NCC 1975: 431-438].
+
+ [Moshé M. Zloof, "Query-by-Example: A Data Base Language", IBM
+ Systems Journal 16(4): 324-343, 1977].
+
+ ["QBE/OBE: A Language for Office and Business Automation",
+ M.M. Zloof, Computer pp.13-22, May 1981].
+
+ (2001-03-25)
+
+query expansion
+
+ <information science> Adding {search terms} to a user's
+ search. Query expansion is the process of a {search engine}
+ adding {search terms} to a user's {weighted search}. The
+ intent is to improve {precision} and/or {recall}. The
+ additional terms may be taken from a {thesaurus}. For example
+ a search for "car" may be expanded to: car cars auto autos
+ automobile automobiles.
+
+ The additional terms may also be taken from documents
+ that the user has specified as being relevant; this is the
+ basis for the "more like this" feature of some search engines.
+
+ The extra terms can have positive or negative weights.
+
+ (1999-08-27)
+
+ques
+
+ {question mark}
+
+Quest
+
+ 1. A language designed for its simple denotational semantics.
+ "The Denotational Semantics of Programming Languages",
+ R. Tennent, CACM 19(8):437-453 (Aug 1976).
+
+ 2. QUantifiers and SubTypes. Language with a sophisticated
+ type system. Just as types classify values, "kinds" classify
+ types and type operators. Explicit universal and existential
+ quantification over types, type operators, and subtypes.
+ Subtyping is defined inductively on all type constructions,
+ including higher-order functions and abstract types.
+ User-definable higher-order type operators.
+
+ "Typeful Programming", Luca Cardelli <luca@src.dec.com>, RR
+ 45, DEC SRC 1989.
+
+ Implemented in Modula-3.
+
+ {(ftp://gatekeeper.dec.com/pub/DEC/Quest/quest12A.tar.Z)}.
+
+ 3. <tool, text> A {multimedia} {authoring} system. Quest has
+ been available for {MS-DOS} for some time. Version 3.5 for
+ {Microsoft Windows} was released around March 1995. It
+ features an {Authorware}-style {flowchart} system with an
+ {ANSI-C} {script language}.
+
+ (1995-04-02)
+
+question mark
+
+ <character> "?", {ASCII} character 63.
+
+ Common names: query; {ITU-T}: question mark; {ques}. Rare:
+ whatmark; {INTERCAL}: what; wildchar; huh; hook; buttonhook;
+ hunchback.
+
+ Question mark is used, along with {colon} for {C}'s {lazy}
+ triadic "if" {operator} (similar to the {IIF} function in
+ {Visual Basic}). The expression x?y:z evaluates x, then if x
+ is true it returns y else it returns z.
+
+ In {Unix} {shell} file name patterns, question mark matches
+ any single character.
+
+ (2003-06-17)
+
+queue
+
+ <programming> A {first-in first-out} data structure used to
+ sequence objects. Objects are added to the tail of the queue
+ ("enqueued") and taken off the head ("dequeued").
+
+ For example, an {operating system} might use a queue to
+ serialise {concurrent} demands for a resource such as a
+ {printer}, {processor} or communications channel. Users might
+ place files on a print queue and a {background} process or
+ "{demon}" would take them off and print them. Another common
+ use is to pass data between an {interrupt handler} and a user
+ process.
+
+ (2007-05-18)
+
+Queued Sequential Access Method
+
+ {Physical Sequential}
+
+QUICK
+
+ <language> An early system on the {IBM 701}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1995-05-11)
+
+quick-and-dirty
+
+ <jargon, programming> Describes a {crock} put together under
+ time or user pressure. Used especially when you want to
+ convey that you think the fast way might lead to trouble
+ further down the road. "I can have a quick-and-dirty fix in
+ place tonight, but I'll have to rewrite the whole module to
+ solve the underlying design problem."
+
+ See also {kluge}.
+
+ [{Jargon File}]
+
+ (1995-05-11)
+
+QuickDraw
+
+ <library, graphics> Part of the software in the {Apple
+ Macintosh}'s {ROM} that performs graphics operations.
+
+ (1995-05-11)
+
+Quick Mail Queueing Protocol
+
+ <communications> (QMQP) A {protocol} that provides a central
+ {e-mail} queue for a {cluster} of {hosts}. QMOP is supposed
+ to provide fast transfers of messages with many recipients as
+ it can batch them up as a single transaction. It listens on
+ port 628.
+
+ {(http://cr.yp.to/mail.html)}
+
+ (2007-05-25)
+
+Quick Mail Transfer Protocol
+
+ <communications> (QMTP) An {SMTP} replacement that works
+ better over high {latency} links as it doesn't require as much
+ interaction as SMTP. QMTP listens on port 209 and is used by
+ {qmail}.
+
+ {(http://cr.yp.to/mail.html)}
+
+ (2007-05-25)
+
+Quicksilver
+
+ <database> A {dBASE}-like compiler for {MS-DOS} from
+ {WordTech}.
+
+ (1995-05-11)
+
+Quicksort
+
+ A sorting {algorithm} with O(n log n) average time
+ {complexity}.
+
+ One element, x of the list to be sorted is chosen and the
+ other elements are split into those elements less than x and
+ those greater than or equal to x. These two lists are then
+ sorted {recursive}ly using the same algorithm until there is
+ only one element in each list, at which point the sublists are
+ recursively recombined in order yielding the sorted list.
+
+ This can be written in {Haskell}:
+
+ qsort :: Ord a => [a] -> [a]
+ qsort [] = []
+ qsort (x:xs) = qsort [ u | u<-xs, u<x ] ++
+ [ x ] ++
+ qsort [ u | u<-xs, u>=x ]
+
+ [Mark Jones, Gofer prelude.]
+
+QuickTime
+
+ <graphics, standard, file format, product> {Apple Computer}'s
+ software for playing {audio} and {video}. The QuickTime
+ {application} is a free {media player}. QuickTime Pro is a
+ paid-for version with editing ability. QuickTime's native
+ format for audio and video is .mov but it can handle many
+ others.
+
+ {(http://apple.com/quicktime/what-is)}
+
+ (2011-01-04)
+
+quiesce
+
+ <networking> To render quiescent, i.e. temporarily inactive or
+ disabled. For example to quiesce a device (such as a digital
+ modem). It is also a system command in MAX TNT software which
+ is used to "Temporarily disable a modem or DS0 channel".
+
+ Also used as an adjective, in the expression "{quiesce time}".
+
+ (2000-03-05)
+
+quiesce time
+
+ <jargon> The length of time taken to {quiesce} a system (to
+ render it inactive), or the length of time between periods of
+ inactivity.
+
+ (2000-03-05)
+
+QUIKSCRIPT
+
+ Simulation language derived from {SIMSCRIPT}, based on
+ {20-GATE}.
+
+ ["Quikscript - A Simpscript-like Language for the G-20",
+ F.M. Tonge et al, CACM 8(6):350-354 (June 1965)].
+
+QUIKTRAN
+
+ Fortran-like, interactive with debugging facilities. Sammet
+ 1969, p.226.
+
+QUIN
+
+ Pyle 1965. Interactive language. Sammet 1969, p.691.
+
+quine
+
+ <programming> /kwi:n/ (After the logician Willard V. Quine,
+ via Douglas Hofstadter) A program that generates a copy of its
+ own source text as its complete output. Devising the shortest
+ possible quine in some given programming language is a common
+ hackish amusement.
+
+ In most interpreted languages, any constant, e.g. 42, is a
+ quine because it "evaluates to itself". In certain {Lisp}
+ dialects (e.g. {Emacs Lisp}), the symbols "nil" and "t" are
+ "self-quoting", i.e. they are both a symbol and also the value
+ of that symbol. In some dialects, the function-forming
+ function symbol, "lambda" is self-quoting so that, when
+ applied to some arguments, it returns itself applied to those
+ arguments. Here is a quine in {Lisp} using this idea:
+
+ ((lambda (x) (list x x)) (lambda (x) (list x x)))
+
+ Compare this to the {lambda expression}:
+
+ (\ x . x x) (\ x . x x)
+
+ which reproduces itself after one step of {beta reduction}.
+ This is simply the result of applying the {combinator} {fix}
+ to the {identity function}. In fact any quine can be
+ considered as a {fixed point} of the language's evaluation
+ mechanism.
+
+ We can write this in {Lisp}:
+
+ ((lambda (x) (funcall x x)) (lambda (x) (funcall x x)))
+
+ where "funcall" applies its first argument to the rest of its
+ arguments, but evaluation of this expression will never
+ terminate so it cannot be called a quine.
+
+ Here is a more complex version of the above Lisp quine, which
+ will work in Scheme and other Lisps where "lambda" is not
+ self-quoting:
+
+ ((lambda (x)
+ (list x (list (quote quote) x)))
+ (quote
+ (lambda (x)
+ (list x (list (quote quote) x)))))
+
+ It's relatively easy to write quines in other languages such
+ as {PostScript} which readily handle programs as data; much
+ harder (and thus more challenging!) in languages like {C}
+ which do not. Here is a classic {C} quine for {ASCII}
+ machines:
+
+ char*f="char*f=%c%s%c;main() {printf(f,34,f,34,10);}%c";
+ main(){printf(f,34,f,34,10);}
+
+ For excruciatingly exact quinishness, remove the interior line
+ break. Some infamous {Obfuscated C Contest} entries have been
+ quines that reproduced in exotic ways.
+
+ {Ken Thompson}'s {back door} involved an interesting variant
+ of a quine - a compiler which reproduced part of itself when
+ compiling (a version of) itself.
+
+ [{Jargon File}]
+
+ (1995-04-25)
+
+Quintec-Objects
+
+ Based on {Quintec Prolog} (not {Quintus}). British.
+
+quintillion
+
+ 10^30 in Europe (this is called a {nonillion} in the United
+ States and Canada).
+
+ 10^18 in the United States and Canada (this is called a
+ trillion in Europe).
+
+ [Collins dictionary].
+
+Quintus Prolog
+
+ <language, product> A version of {Prolog} developed by
+ {Quintus}. Development of Quintus Prolog had transferred to
+ the {Swedish Institute of Computer Science} by December 1998.
+
+ {(ftp://ftp.quintus.com/)}.
+
+ Telephone: +1 (800) 542 1283.
+
+ [More details? Features?]
+
+ (1998-12-12)
+
+quote chapter and verse
+
+ [by analogy with the mainstream phrase] To cite a relevant
+ excerpt from an appropriate {bible}. "I don't care if "rn"
+ gets it wrong; "Followup-To: poster" is explicitly permitted
+ by {RFC} 1036. I'll quote chapter and verse if you don't
+ believe me." See also {legalese}, {language lawyer}, {RTFS}
+ (sense 2).
+
+ [{Jargon File}]
+
+quotient
+
+ The number obtained by dividing one number (the "numerator")
+ by another (the "denominator"). If both numbers are
+ {rational} then the result will also be rational.
+
+Qu-Prolog
+
+ An extension of {Prolog} which performs {meta-level
+ computations} over {object languages}, such as {predicate
+ calculi} and {lambda-calculi}, which have object-level
+ variables, and {quantifiers} that create local {scopes} for
+ those variables. Qu-Prolog is well suited as an implementation
+ language for {theorem provers} and support notations typically
+ found in texts on mathematics and logic.
+
+Quty
+
+ A functional plus logic language. "Quty: A Functional
+ Language Based on Unification", M. Sato et al, in Conf. Fifth
+ Gen. Computer Systems, ICOT 1984, pp.157-165.
+
+quux
+
+ /kwuhks/ [Mythically, from the Latin semi-deponent verb quuxo,
+ quuxare, quuxandum iri; noun form variously "quux" (plural
+ "quuces", anglicised to "quuxes") and "quuxu" (genitive plural
+ is "quuxuum", for four u-letters out of seven in all, using up
+ all the "u" letters in Scrabble).] 1. Originally, a
+ {metasyntactic variable} like {foo} and {foobar}. Invented by
+ {Guy Steele} for precisely this purpose when he was young and
+ naive and not yet interacting with the real computing
+ community. Many people invent such words; this one seems
+ simply to have been lucky enough to have spread a little. In
+ an eloquent display of poetic justice, it has returned to the
+ originator in the form of a nickname.
+
+ 2. See {foo}; however, denotes very little disgust, and is
+ uttered mostly for the sake of the sound of it.
+
+ 3. {Guy Steele} in his persona as "The Great Quux", which is
+ somewhat infamous for light verse and for the "Crunchly"
+ cartoons.
+
+ 4. In some circles, used as a punning opposite of "crux".
+ "Ah, that's the quux of the matter!" implies that the point is
+ *not* crucial (compare {tip of the ice-cube}).
+
+ [{Jargon File}]
+
+qux
+
+ /kwuhks/ The fourth of the standard {metasyntactic variable},
+ after {baz} and before the quu(u...)x series. See {foo},
+ {bar}, {baz}, {quux}. This appears to be a recent mutation
+ from {quux}, and many versions (especially older versions) of
+ the standard series just run {foo}, {bar}, {baz}, {quux}, ...
+
+QWERTY
+
+ <hardware> /kwer'tee/ (From the top left row of letter keys of
+ most keyboards) Pertaining to a standard English-language
+ typewriter keyboard (sometimes called the Sholes keyboard
+ after its inventor), as opposed to {Dvorak} or
+ foreign-language layouts (e.g. "keyboard AZERTY" in
+ french-speaking countries) or a {space-cadet keyboard} or {APL
+ keyboard}.
+
+ The QWERTY layout is a fine example of a {fossil}. It is
+ sometimes said that it was designed to slow down the typist,
+ but this is wrong; it was designed to allow *faster* typing -
+ under a constraint now long obsolete. In early typewriters,
+ fast typing using nearby type-bars jammed the mechanism. So
+ Sholes fiddled the layout to separate the letters of many
+ common digraphs (he did a far from perfect job, though; "th",
+ "tr", "ed", and "er", for example, each use two nearby keys).
+ Also, putting the letters of "typewriter" on one line allowed
+ it to be typed with particular speed and accuracy for {demos}.
+ The jamming problem was essentially solved soon afterward by a
+ suitable use of springs, but the keyboard layout lives on.
+
+ [{Jargon File}]
+
+ (1998-01-15)
+
+QX
+
+ (Meaning "OK", from E.E. Smith SF books) A language for
+ {digital signal processing} of digitised speech, by Richard
+ Gillmann of {SDC}, Santa Monica. QX was part of SDC's {speech
+ recognition} project.
+
+ (1995-02-09)
+
+R2000
+
+ {MIPS R2000}
+
+R2RS
+
+ A revision of {RRS}, itself revised in {R3RS}.
+
+ ["The Revised Revised Report on the Algorithmic Language
+ Scheme", Clinger, AI Memo 848, MIT Aug 1985].
+
+ (1995-02-09)
+
+R3.99RS
+
+ {R4RS} without the {macros}.
+
+R3RS
+
+ A revision of {R2RS}, revised in {R4RS}.
+
+ ["The Revised^3 Report on the Algorithmic Language Scheme",
+ J. Rees et al, SIGPLAN Notices 21(12):37-79 (Dec 1986)].
+
+R4RS
+
+ A revision of {R3RS}, revised in {R3.99RS}.
+
+ {(ftp://altdorf.ai.mit.edu/)}.
+
+ ["The Revised^4 Report on the Algorithmic Language Scheme", W.
+ Clinger et al, MIT (Nov 1991)].
+
+ (1994-10-28)
+
+ [Later revisions?]
+
+rabbit job
+
+ (Cambridge) A batch job that does little, if any, real work,
+ but creates one or more copies of itself, breeding like
+ rabbits.
+
+ Compare {wabbit}, {fork bomb}.
+
+ [{Jargon File}]
+
+ (1994-11-09)
+
+RACE
+
+ <programming> {Requirements Acquisition and
+ Controlled Evolution}.
+
+ (1995-11-21)
+
+race condition
+
+ Anomalous behavior due to unexpected critical dependence on
+ the relative timing of events.
+
+ For example, if one process writes to a file while another is
+ reading from the same location then the data read may be the
+ old contents, the new contents or some mixture of the two
+ depending on the relative timing of the read and write
+ operations.
+
+ A common remedy in this kind of race condition is {file
+ locking}; a more cumbersome remedy is to reorganize the system
+ such that a certain processes (running a {daemon} or the like)
+ is the only process that has access to the file, and all other
+ processes that need to access the data in that file do so only
+ via interprocess communication with that one process.
+
+ As an example of a more subtle kind of race condition,
+ consider a {distributed} {chat} {network} like {IRC}, where a
+ {user} is granted channel-operator {privileges} in any channel
+ he starts. If two users on different {servers}, on different
+ ends of the same network, try to start the same-named channel
+ at the same time, each user's respective server will grant
+ channel-operator privileges to each user, since neither will
+ yet have received the other's signal that that channel has
+ been started.
+
+ In this case of a race condition, the "shared resource" is the
+ conception of the {state} of the network (what channels exist,
+ as well as what users started them and therefore have what
+ privileges), which each server is free to change as long as it
+ signals the other servers on the network about the changes so
+ that they can update their conception of the state of the
+ network. However, the {latency} across the network makes
+ possible the kind of race condition described. In this case,
+ heading off race conditions by imposing a form of control over
+ access to the shared resource -- say, appointing one server to
+ be in charge of who holds what privileges -- would mean
+ turning the distributed network into a centralized one (at
+ least for that one part of the network operation). Where this
+ is not acceptable, the more pragmatic solution is to have the
+ system recognize when a race condition has occurred and to
+ repair the ill effects.
+
+ Race conditions also affect electronic circuits where the
+ value output by a {logic gate} depends on the exact timing of
+ two or more input signals. For example, consider a two input
+ AND gate fed with a logic signal X on input A and its
+ negation, NOT X, on input B. In theory, the output (X AND NOT
+ X) should never be high. However, if changes in the value of
+ X take longer to propagate to input B than to input A then
+ when X changes from false to true, there will be a brief
+ period during which both inputs are true, and so the gate's
+ output will also be true. If this output is fed to an
+ edge-sensitive component such as a counter or flip-flop then
+ the temporary effect ("{glitch}") will become permanent.
+
+ (2002-08-03)
+
+RACF
+
+ {Resource Access Control Facility}
+
+RAD
+
+ <programming> {Rapid Application Development}.
+
+Raddle
+
+ <parallel>
+
+ ["On the Design of Large Distributed Systems", I.R. Forman,
+ Proc 1st IEEE Intl Conf Comp Langs, pp.25-27 (Oct 1986)].
+
+ (2008-07-30)
+
+Radio-frequency identification
+
+ <hardware> (RFID) Small {radio} {transponders} or "tags"
+ designed to be attached to items like products in a
+ supermarket to allow the items to be identified and tracked by
+ a remote system. Typically an RFID tag includes an
+ {integrated circuit} that stores data and interfaces to the
+ antenna, allowing the stored data to be retrieved by the
+ remote system.
+
+ (2008-07-30)
+
+Radio Frequency Interference
+
+ <hardware, testing> (RFI) Electromagnetic radiation which is
+ emitted by electrical circuits carrying rapidly changing
+ signals, as a by-product of their normal operation, and which
+ causes unwanted signals (interference or noise) to be induced
+ in other circuits.
+
+ The most important means of reducing RFI are: use of bypass or
+ "decoupling" {capacitors} on each active device (connected
+ across the power supply, as close to the device as possible),
+ risetime control of high speed signals using series resistors
+ and {VCC filtering}. Shielding is usually a last resort after
+ other techniques have failed because of the added expense of
+ RF gaskets and the like.
+
+ The efficiency of the radiation is dependant on the height
+ above the ground or power plane (at RF one is as good as the
+ other) and the length of the conductor in relationship to the
+ wavelength of the signal component (fundamental, harmonic or
+ transient (overshoot, undershoot or ringing)). At lower
+ frequencies, such as 133 MHz, radiation is almost exclusively
+ via I/O cables; RF noise gets onto the power planes and is
+ coupled to the line drivers via the VCC and ground pins. The
+ Rf is then coupled to the cable through the line driver as
+ common node noise. Since the noise is common mode, shielding
+ has very little effect, even with differential pairs. The RF
+ energy is capacitively coupled from the signal pair to the
+ shield and the shield itself does the radiating.
+
+ At higher frequencies, usually above 500 Mhz, traces get
+ electrically longer and higher above the plane. Two
+ techniques are used at these frequencies: wave shaping with
+ series resistors and embedding the traces between the two
+ planes. If all these measures still leave too much RFI,
+ sheilding such as RF gaskets and copper tape can be used.
+ Most digital equipment is designed with metal, or coated
+ plastic, cases.
+
+ Switching power supplies can be a source of RFI, but have
+ become less of a problem as design techniques have improved.
+
+ Most countries have legal requirements that electronic and
+ electrical hardware must still work correctly when subjected
+ to certain amounts of RFI, and should not emit RFI which could
+ interfere with other equipment (such as radios).
+
+ See also {Electrostatic Discharge}, {Electromagnetic
+ Compatibility}.
+
+ (1998-01-26)
+
+radio in the loop
+
+ {Wireless Local Loop}
+
+radiosity
+
+ <graphics> A method for rendering a view of a
+ three-dimensional scene that provides realistic lighting
+ effects, such as interobject reflections and {color bleeding}.
+ Radiosity methods are computationally intense, due to the use
+ of linear systems of equations and the spatial complexity of
+ large scenes.
+
+ {Usenet} newsgroup: {news:comp.graphics}.
+
+ [Is radiosity more accurate than {ray tracing}? Does it take
+ more computing power? How does compute time scale with scene
+ complexity?]
+
+ (2003-06-01)
+
+RADIUS
+
+ {Remote Authentication Dial-In User Service}
+
+radix
+
+ <mathematics> The ratio, R, between the weights of adjacent
+ digits in {positional representation} of numbers. The
+ right-most digit has weight one, the digit to its left has
+ weight R, the next R^2, R^3, etc. The radix also determines
+ the set of digits which is zero to R-1. E.g. decimal (radix
+ ten) uses 0-9 and each digit is worth ten times as much as you
+ move left along the number.
+
+ (2006-11-10)
+
+RAID
+
+ {Redundant Arrays of Independent Disks}
+
+RAIL
+
+ <robotics> Automatix. High-level language for industrial
+ robots.
+
+ (2006-11-10)
+
+rainbow series
+
+ <publication> Any of several series of technical manuals
+ distinguished by cover colour. The original rainbow series
+ was the NCSC security manuals (see {Orange Book}, {crayola
+ books}); the term has also been commonly applied to the
+ PostScript reference set (see {Red Book}, {Green Book}, {Blue
+ Book}, {White Book}). Which books are meant by ""the" rainbow
+ series" unqualified is thus dependent on one's local technical
+ culture.
+
+ [{Jargon File}]
+
+ (1996-12-03)
+
+rain dance
+
+ 1. Any ceremonial action taken to correct a hardware problem,
+ with the expectation that nothing will be accomplished. This
+ especially applies to reseating {printed circuit boards},
+ reconnecting cables, etc. "I can't boot up the machine.
+ We'll have to wait for Greg to do his rain dance."
+
+ 2. Any arcane sequence of actions performed with computers or
+ software in order to achieve some goal; the term is usually
+ restricted to rituals that include both an {incantation} or
+ two and physical activity or motion.
+
+ Compare {magic}, {voodoo programming}, {black art}, {cargo
+ cult programming}, {wave a dead chicken}.
+
+ [{Jargon File}]
+
+ (1995-02-09)
+
+RAIS
+
+ {Redundant Array of Inexpensive Servers}
+
+RAISE
+
+ {Rigorous Approach to Industrial Software Engineering}
+
+RAISE Specification Language
+
+ <language> (RSL) (RAISE = Rigorous Approach to Industrial
+ Software Engineering). A wide-spectrum specification and
+ design language developed by {ESPRIT} Project 315 at {CRI}
+ A/S, Denmark. Systems may be modular, {concurrent} and
+ {nondeterministic}. Specifications may be {applicative} or
+ {imperative}, explicit or implicit, abstract or concrete.
+
+ ["The RAISE Specification Language", RAISE Language Group, P-H
+ 1992, ISBN 0-13-752833-7].
+
+ (2007-10-02)
+
+RAL
+
+ 1. Rutherford Appleton Laboratory (UK).
+
+ 2. An {expert system}.
+
+RAM
+
+ {Random Access Memory}
+
+Rambus DRAM
+
+ <storage> (RDRAM) A high bandwidth {DRAM}, designed by
+ {Rambus, Inc.} of Mountain View, CA.
+
+ RDRAM is used mainly for {video accelerators}, and also in the
+ {Ultra 64} from {Nintendo}. It offers sustained {transfer
+ rates} of around 1000 Mbps, compared to 200 Mbps for ordinary
+ DRAM. Although it cannot be used as a direct replacement for
+ existing memory, it is likely that it will replace DRAM and
+ {SDRAM} as the main memory system in {personal computers} as
+ the {bus} speeds required by these machines increase. SDRAM
+ can operate up to around 100MHz, but RDRAM has been
+ demonstrated by the manufacturers running at 600MHz.
+
+ The memory is also only 8 or 9 {bits} wide, so the bandwidth
+ would increase enormously if it were used in parallel to give
+ 32 or 64-bit memory.
+
+ {RDRAM Installation
+ (http://www.cheapestrdram.com/rdram_install.php)}.
+
+ (2007-06-13)
+
+Rambus, Inc.
+
+ <company> The company which designed {Rambus DRAM}.
+
+ {(http://rambus.com/)}.
+
+ Address: Mountain View, CA., USA.
+
+ (1996-12-15)
+
+RAMDAC
+
+ {Random Access Memory Digital-to-Analog Converter}
+
+RAM disk
+
+ <operating system, storage> A memory-resident program which
+ mimics a {hard disk} drive. It uses part of computer's {RAM}
+ to store data which can be accessed as files. Unlike a real
+ disk drive, this drive forgets all stored data when the
+ computer is turned off.
+
+ (1995-03-14)
+
+RAM drive
+
+ {RAM disk}
+
+RAMIS II
+
+ Rapid Access {Management Information System}.
+
+ A {database} from {On-Line Software International}.
+
+ (1994-11-14)
+
+RAMTRON
+
+ <company> The company which holds the patents for {FRAM} and
+ licenses the technology to other companies.
+
+ The licensees are currently (Feb 1997) {Hitachi}, {Rohm},
+ {Samsung}, {SGS-Thomson} and {Toshiba}, none of who offer FRAM
+ products of their own yet.
+
+ {(http://csn.net/ramtron/)}.
+
+ (1997-02-19)
+
+random
+
+ 1. Unpredictable (closest to mathematical definition); weird.
+ "The system's been behaving pretty randomly."
+
+ 2. Assorted; undistinguished. "Who was at the conference?"
+ "Just a bunch of random business types."
+
+ 3. (pejorative) Frivolous; unproductive; undirected. "He's
+ just a random loser."
+
+ 4. Incoherent or inelegant; poorly chosen; not well organised.
+ "The program has a random set of misfeatures." "That's a
+ random name for that function." "Well, all the names were
+ chosen pretty randomly."
+
+ 5. In no particular order, though {deterministic}. "The I/O
+ channels are in a pool, and when a file is opened one is
+ chosen randomly."
+
+ 6. Arbitrary. "It generates a random name for the scratch
+ file."
+
+ 7. Gratuitously wrong, i.e. poorly done and for no good
+ apparent reason. For example, a program that handles file
+ name defaulting in a particularly useless way, or an assembler
+ routine that could easily have been coded using only three
+ registers, but redundantly uses seven for values with
+ non-overlapping lifetimes, so that no one else can invoke it
+ without first saving four extra registers. What {randomness}!
+
+ 8. A random hacker; used particularly of high-school students
+ who soak up computer time and generally get in the way.
+
+ 9. Anyone who is not a hacker (or, sometimes, anyone not
+ known to the hacker speaking). "I went to the talk, but the
+ audience was full of randoms asking bogus questions".
+
+ 10. (occasional MIT usage) One who lives at Random Hall. See
+ also {J. Random}, {some random X}.
+
+ [{Jargon File}]
+
+ (1995-12-05)
+
+random-access memory
+
+ <storage> (RAM) (Previously "direct-access memory"). A data
+ storage device for which the order of access to different
+ locations does not affect the speed of access. This is in
+ contrast to, say, a {magnetic disk}, {magnetic tape} or a
+ {mercury delay line} where it is very much quicker to access
+ data sequentially because accessing a non-sequential location
+ requires physical movement of the storage medium rather than
+ just electronic switching.
+
+ In the 1970s {magnetic core} memory was used and some
+ old-timers still call RAM "core". The most common form of RAM
+ in use today is {semiconductor} {integrated circuits}, which
+ can be either {static random-access memory} (SRAM) or {dynamic
+ random-access memory} (DRAM).
+
+ The term "RAM" has gained the additional meaning of
+ read-write. Most kinds of semiconductor {read-only memory}
+ (ROM) are actually "random access" in the above sense but are
+ never referred to as RAM. Furthermore, memory referred to as
+ RAM can usually be read and written equally quickly
+ (approximately), in contrast to the various kinds of
+ {programmable read-only memory}. Finally, RAM is usually
+ volatile though {non-volatile random-access memory} is also
+ used.
+
+ Interestingly, some {DRAM} devices are not truly random access
+ because various kinds of "{page mode}" or "column mode" mean
+ that sequential access is faster than random access.
+
+ The humorous expansion "Rarely Adequate Memory" refers to the
+ fact that programs and data always seem to expand to fill the
+ memory available.
+
+ (2007-10-12)
+
+Random Access Memory Digital-to-Analog Converter
+
+ <hardware> (RAMDAC) A combination of three fast {DACs} with a
+ small {SRAM} used in graphics {display adapters} to store the
+ {colour palette} and to generate the analog signals to drive a
+ colour {monitor}. The logical colour number from the display
+ memory is fed into the address inputs of the SRAM to select a
+ palette entry to appear on the output of the SRAM. This entry
+ is composed of three separate values corresponding to the
+ three components (red, green, and blue) of the desired
+ physical colour. Each component value is fed to a separate
+ DAC, whose analog output goes to the monitor, and ultimately
+ to one of its three {electron guns} (or equivalent in
+ non-{CRT} displays).
+
+ DAC word lengths range usually from 6 to 10 bits. The SRAM's
+ wordlength is three times the DAC's word length. The SRAM
+ acts as a {colour lookup table}. It usually has 256 entries
+ (and thus an 8-bit address). If the DAC's word length is also
+ 8 bits, we have a 256 x 24-bit SRAM which allows a selection
+ of 256 out of 16777216 possible colours for the display. The
+ contents of the SRAM can be changed while the display is not
+ active (during {display blanking} times). The SRAM can
+ usually be bypassed and the DACs can be fed directly by
+ display data (for {true colour} modes).
+
+ (1996-03-24)
+
+randomness
+
+ 1. An inexplicable misfeature; gratuitous inelegance.
+
+ 2. A {hack} or {crock} that depends on a complex combination
+ of coincidences (or, possibly, the combination upon which the
+ crock depends for its accidental failure to malfunction).
+ "This hack can output characters 40--57 by putting the
+ character in the four bit accumulator field of an XCT and then
+ extracting six bits - the low 2 bits of the XCT opcode are
+ the right thing." "What randomness!"
+
+ 3. Of people, synonymous with "flakiness". The connotation is
+ that the person so described is behaving weirdly,
+ incompetently, or inappropriately for reasons which are (a)
+ too tiresome to bother inquiring into, (b) are probably as
+ inscrutable as quantum phenomena anyway, and (c) are likely to
+ pass with time. "Maybe he has a real complaint, or maybe it's
+ just randomness. See if he calls back."
+
+ [{Jargon File}]
+
+random number
+
+ {pseudorandom number}
+
+random testing
+
+ <programming, testing> A {black-box testing} approach in which
+ {software} is tested by choosing an arbitrary subset of all
+ possible input values. Random testing helps to avoid the
+ problem of only testing what you know will work.
+
+ (2001-04-30)
+
+range
+
+ {image}
+
+Rapid Application Development
+
+ <programming> (RAD) A loose term for any {software life-cycle}
+ designed to give faster development and better results and to
+ take maximum advantage of recent advances in development
+ software.
+
+ RAD is associated with a wide range of approaches to software
+ development: from hacking away in a {GUI builder} with little
+ in the way of analysis and design to complete {methodologies}
+ expanding on an {information engineering} framework.
+
+ Some of the current RAD techniques are: {CASE} tools,
+ {iterative life-cycles}, {prototyping}, {workshops}, {SWAT
+ teams}, {timebox development}, and {Re-use} of applications,
+ templates and code.
+
+ {RAD at BSO/Den Haag
+ (http://riv.nl/origin/company/denhaag/RAD.HTM)}.
+
+ ["Rapid Application Development", James Martin].
+
+ (1995-09-23)
+
+RapidCAD
+
+ <processor> A specially packaged {Intel 486DX} and a dummy
+ {floating point unit} (FPU) designed as pin-compatible
+ replacements for an {Intel 80386} processor and {80387} FPU.
+ Since the DX variant has a working on-chip FPU, a dummy FPU
+ package is supplied to go in the {387} FPU socket.
+
+ (1995-05-10)
+
+Rapidly Extensible Language, English
+
+ <language> (REL English) A {formal language} based on English.
+
+ ["Practical Natural Language Processing: The REL System as
+ Prototype", Adv in Computers 13, Academic Press 1975].
+
+ (1997-04-09)
+
+rapid prototyping
+
+ <programming> The creation of a working model of a software module
+ to demonstrate the feasibility and suitability of the function.
+ The prototype is expected to be replaced or refined before
+ inclusion in the final product.
+
+ Rapid prototyping contrasts with a {DIRFT} approach which
+ emphasises careful design and implementation to avoid the
+ overheads of debugging and testing prototype code. Rapid
+ prototyping is appropriate when the requirements are unclear or
+ likely to change (which is most of the time).
+
+ (2012-11-17)
+
+Rapidwrite
+
+ <language, tool> A method for translating set of abbreviations
+ into the much more verbose {COBOL} code.
+
+ [Sammet 1969, p. 338].
+
+ (1995-05-10)
+
+RAPT
+
+ ["An Interpreter for a Language for Describing Assemblies",
+ R.J. Popplestone et al, Artif Intell 14:79-107 (1980)].
+
+ (1995-05-10)
+
+RARE
+
+ {Réseaux Associés pour la Recherche Européenne}
+
+rare mode
+
+ <operating system> {Unix} CBREAK mode (character-by-character
+ with keyboard {interrupts} enabled). Distinguished from {raw
+ mode} and {cooked mode}; the phrase "a sort of half-cooked
+ (rare?) mode" is used in the V7/BSD manuals to describe the
+ mode. Usage: rare.
+
+ [{Jargon File}]
+
+ (1995-05-10)
+
+RARP
+
+ {Reverse Address Resolution Protocol}
+
+RAS
+
+ 1. <hardware, storage> {Row Address Strobe}.
+
+ 2. <communications> {Remote Access Services}.
+
+ 3. <systems> {Reliability, Availability, Serviceability}.
+
+ (2000-08-13)
+
+RASP
+
+ <language> ["RASP - A Language with Operations on Fuzzy Sets",
+ D.D. Djakovic, Comp Langs 13(3):143-148 (1988)].
+
+ (1995-05-10)
+
+raster
+
+ <hardware> The area of a video display that is covered by
+ sweeping the electron beam of the display in a series of
+ horizontal lines from top to bottom. The beam then returns to
+ the top during the vertical flyback interval.
+
+ See also {CRT}, {frame buffer}.
+
+ (1995-03-22)
+
+raster blaster
+
+ <hardware, jargon> (Cambridge) Specialised hardware for
+ {bitblt} operations (a {blitter}). Allegedly inspired by
+ "Rasta Blasta", British slang for the sort of portable stereo
+ Americans call a "boom box" or "ghetto blaster".
+
+ [{Jargon File}]
+
+ (1995-03-22)
+
+raster burn
+
+ 1. (Or terminal illness) Eyestrain brought on by too many
+ hours of looking at low-resolution, poorly tuned, or
+ glare-ridden monitors, especially graphics monitors.
+
+ 2. The "burn-in" condition your {CRT} tends to get if you
+ don't use a {screen saver}.
+
+ [{Jargon File}]
+
+raster font
+
+ {bitmap font}
+
+rastergram
+
+ {Single Image Random Dot Stereogram}
+
+raster graphics
+
+ <graphics> Computer graphics in which an {image} is composed
+ of an array of pixels arranged in rows and columns.
+
+ Opposite: {vector graphics}.
+
+ (1995-03-22)
+
+Raster Image Processor
+
+ <application, printer> (RIP) A device (usually {hardware} but
+ can be {software}) that takes a {Page Description Language}
+ description of a page and converts it into a {bitmap} for
+ printing.
+
+ (2003-09-10)
+
+rasterising
+
+ <algorithm> A transformation that can be applied to an image
+ to prepare it for printing. Rasterising reduces resolution by
+ a factor of typically four to eight. It also reduces
+ sensitivity to paper properties. Rasterising can be combined
+ with {dithering}.
+
+ [How does it work?]
+
+ (2003-07-20)
+
+rasterizing
+
+ {rasterising}
+
+raster subsystem
+
+ <graphics> The part of a graphics system concerned with an
+ {image} after it has been transformed and scaled to screen
+ coordinates. It includes scan conversion and display.
+
+ (1995-03-22)
+
+Ratatosk
+
+ An {SLR parser} generator written in {Gofer} (a {Haskell}
+ variant) by Torben AEgidius Mogensen <torbenm@diku.dk>.
+ Ratatosk generates {purely functional} {backtracking} {LR0
+ grammar} {parsers} (also in Gofer).
+
+ Even though the {sematic} value of a {production} is a
+ function of the attributes of its right-hand side (and thus
+ apparently purely synthesised), inherited attributes are
+ easily simulated by using {higher-order functions}.
+
+ {(ftp://ftp.diku.dk/pub/diku/dists/Ratatosk.tar.Z)}.
+
+rat belt
+
+ A cable tie, especially the sawtoothed, self-locking plastic
+ kind that you can remove only by cutting (as opposed to a
+ random twist of wire or a twist tie or one of those humongous
+ metal clip frobs). Small cable ties are "mouse belts".
+
+ [{Jargon File}]
+
+RatC
+
+ {Rationalized C}
+
+RATEL
+
+ Raytheon Automatic Test Equipment Language. For analog and
+ digital computer controlled test centres. "Automatic Testing
+ via a Distributed Intelligence Processing System", S.J. Ring,
+ IEEE AUTOTESTCON 77 (Nov 1977).
+
+Rate monotonic scheduling
+
+ <algorithm> A means of {scheduling} the time allocated to
+ periodic {hard-deadline} {real-time} users of a resource. The
+ users are assigned priorities such that a shorter fixed period
+ between deadlines is associated with a higher priority.
+
+ Rate monotonic scheduling provides a low-overhead, reasonably
+ resource-efficient means of guaranteeing that all users will
+ meet their deadlines provided that certain analytical
+ equations are satisfied during the system design. It avoids
+ the design complexity of {time-line scheduling} and the
+ overhead of dynamic approaches such as {earliest-deadline
+ scheduling}.
+
+ [D. R. Wilcox, Naval Ocean Systems Center Technical Report
+ 1310, August 1989, "Periodic Phase Adjustment Distributed
+ Clock Synchronization in the Hard Realtime Environment",
+ p. 9].
+
+ (1996-03-23)
+
+RATFIV
+
+ <language> An enhancement to the {RATFOR} programming
+ language, developed by Bill Wood while at the Institute for
+ Cancer Research (Philadelphia PA, now the Fox Chase Cancer
+ Center) in 1980-1981. RATFIV was released on several {DECUS}
+ (Digital Equipment Corporation User's Group) tapes for
+ {VAX/VMS}. Among its enhancements were: optional {Fortan 77}
+ output, an enhanced Format statement and enhanced {macros}.
+
+ (2007-05-16)
+
+RATFOR
+
+ {RATional Fortran}
+
+rational
+
+ [Mathematics] a fractional number n/d, where n and d are
+ integers, n is the numerator and d is the denominator. The
+ set of all rational numbers is usually called Q.
+ Computers do not usually deal with rational numbers but
+ instead convert them to {real} numbers which are represented
+ (approximately in some cases) as {floating-point} numbers.
+ Compare {irrational}.
+
+RATional Fortran
+
+ <language> (RATFOR) {Brian Kernighan}'s {Fortran}
+ {preprocessor} that allows programming with {C}-like {control
+ flow}. RATFOR is mainly of historical significance.
+
+ A translator from Ratfor to Fortran IV was posted to
+ comp.sources.Unix volume 13.
+
+ {(ftp://ftp.wustl.edu/mirrors/Unix-c/languages/ratfor.tar-z)}.
+
+ ["Ratfor - A Preprocessor for a Rational Fortran",
+ B.W. Kernighan, Soft Prac & Exp 5:395-406, Oct 1975].
+
+ ["Software Tools", B.W. Kernighan & P.J. Plauger, A-W, 1976].
+
+ (2001-07-31)
+
+Rationalized C
+
+ <language> (RatC, after "{RATFOR}") A version of Ron Cain's
+ original {Small-C} {compiler}.
+
+ ["A Book on C", R.E. Berry and B.A. Meekings, 1984, ISBN
+ 0-333-36821-5].
+
+ [In what way was it "rationalized"?]
+
+ (1999-06-28)
+
+rave
+
+ [WPI] 1. To persist in discussing a specific subject.
+
+ 2. To speak authoritatively on a subject about which one knows
+ very little.
+
+ 3. To complain to a person who is not in a position to correct
+ the difficulty.
+
+ 4. To purposely annoy another person verbally.
+
+ 5. To evangelise. See {flame}.
+
+ 6. Also used to describe a less negative form of blather, such
+ as friendly bullshitting. "Rave" differs slightly from
+ {flame} in that "rave" implies that it is the persistence or
+ obliviousness of the person speaking that is annoying, while
+ {flame} implies somewhat more strongly that the tone or
+ content is offensive as well.
+
+ [{Jargon File}]
+
+rave on!
+
+ Sarcastic invitation to continue a {rave}, often by someone
+ who wishes the raver would get a clue but realises this is
+ unlikely.
+
+ravioli code
+
+ <jargon, humour> {Object-oriented} code consisting of a number of
+ small and {loosely-coupled} software components. Presumably, the
+ term is a compliment, contrasting the code with {spaghetti code}.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2013-10-28)
+
+raw data
+
+ {data}
+
+raw mode
+
+ <operating system> A mode that allows a program to transfer
+ {bits} directly to or from an {I/O} device without any
+ processing, abstraction, or interpretation by the {operating
+ system}.
+
+ Systems that make this distinction for a disk file are
+ generally regarded as broken.
+
+ Compare {rare mode}, {cooked mode}.
+
+ [{Jargon File}]
+
+ (2002-04-14)
+
+RAWOOP-SNAP
+
+ <language> An early system on the {IBM 1130}.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (1996-05-29)
+
+ray casting
+
+ <graphics> A simplified form of {ray tracing}. A ray is fired
+ from each {pixel} in the view plane, and information is
+ accumulated from all the {voxels} in the volume data it
+ intersects.
+
+ Each voxel is first given an associated colour and opacity.
+ The ray is sampled at a fixed number of evenly spaced
+ locations and the colour and opacity are trilinearly
+ interpolated from the eight nearest voxels. These are then
+ composed linearly back to front to give a single colour for
+ the pixel.
+
+ Ray casting was invented by John Carmack for the game
+ {Wolfenstein 3D}. It is faster and lower quality than ray
+ tracing, and is ideal for interactive applications. It
+ parallelises well, although random access is needed to the
+ voxels.
+
+ (2004-01-06)
+
+Rayleigh distribution
+
+ <mathematics> A curve that yields a good approximation to the
+ actual labour curves on software projects.
+
+ [Details? Equation?]
+
+ (1996-05-29)
+
+Ray Tomlinson
+
+ <person> An engineer at {Bolt Beranek and Newman} who, in July
+ 1972 while designing the first[?] {electronic mail} program,
+ chose the {commercial at} symbol "@" to separate the user name
+ from the computer name.
+
+ (2004-08-22)
+
+ray tracing
+
+ <graphics> A technique used in {computer graphics} to create
+ realistic {images} by calculating the paths taken by rays of
+ light entering the observer's eye at different angles. The
+ paths are traced backward from the viewpoint, through a point
+ (a {pixel}) in the image plane until they hit some object in
+ the scene or go off to infinity. Objects are modelled as
+ collections of abutting surfaces which may be rectangles,
+ triangles, or more complicated shapes such as 3D {splines}.
+ The optical properties of different surfaces (colour,
+ reflectance, transmitance, refraction, texture) also affect
+ how it will contribute to the colour and brightness of the
+ ray. The position, colour, and brightness of light sources,
+ including ambient lighting, is also taken into account.
+
+ Ray tracing is an ideal application for {parallel processing}
+ since there are many pixels, each of whose values is
+ independent and can thus be calculated in parallel.
+
+ Compare: {radiosity}.
+
+ {Usenet} newsgroup: {news:comp.graphics.raytracing}.
+
+ {(http://directory.google.com/Top/Computers/Software/Graphics/3D/Ray_Tracing/)}.
+
+ (2003-09-11)
+
+R:BASE
+
+ <database> An {MS-DOS} {4GL} from {Microrim} based on the
+ {minicomputer} {DBMS} {RIM}.
+
+ [Was Wayne Erickson the author?]
+
+ (2004-09-01)
+
+RBASIC
+
+ Database language for Revelation, by Cosmos, Inc. Combines
+ features of BASIC, Pascal and Fortran.
+
+RBCSP
+
+ Roper and Barter's CSP.
+
+ ["A Communicating Sequential Process Language and
+ Implementation", T. Roper & J. Barter, Soft Prac & Exp
+ 11(11):1215-1234 (Nov 1981)].
+
+RBOC
+
+ {Regional Bell Operating Company}
+
+rc
+
+ 1. <filename extension> (run commands) The {filename
+ extension} common to many {Unix} configuration files, e.g.
+ {.newsrc}, {.cshrc}, {.twmrc}, elmrc, etc.
+
+ The suffix "rc" derives from a script-creation utility in
+ {CTSS} called "{runcom}" (for "run commands").
+
+ {Unix FAQ
+ (http://cis.ohio-state.edu/hypertext/faq/usenet/unix-faq/faq/top.html)}.
+
+ 2. A {shell} from {AT&T}'s {Plan 9}, by Tom Duff. rc offers
+ much the same capabilities as a traditional {Bourne shell},
+ but with a much cleaner {syntax}.
+
+ An open source reimplementation was made by Byron Rakitzis,
+ and is now maintained by Tim Goodwin <tjg@star.le.ac.uk>.
+
+ Latest version: 1.6, as of 2000-06-15.
+
+ {(http://star.le.ac.uk/~tjg/rc)}.
+
+ (2000-06-17)
+
+RC4
+
+ <cryptography> A {cipher} designed by {RSA Data Security,
+ Inc.} which can accept {keys} of arbitrary length, and is
+ essentially a {pseudo random number generator} with the output
+ of the generator being {XOR}ed with the data stream to produce
+ the encrypted data. For this reason, it is very important
+ that the same RC4 key never be used to encrypt two different
+ data streams. The encryption mechanism used to be a trade
+ secret, until someone posted source code for an {algorithm}
+ onto {Usenet News}, claiming it to be equivalent to RC4. The
+ algorithm is very fast, its security is unknown, but breaking
+ it does not seem trivial either. There is very strong
+ evidence that the posted algorithm is indeed equivalent to
+ RC4.
+
+ The United States government routinely approves RC4 with
+ 40-bit keys for export. Keys this small can be easily broken
+ by governments, criminals, and amateurs. The exportable
+ version of {Netscape}'s {Secure Socket Layer}, which uses
+ RC4-40, was broken by at least two independent groups.
+ Breaking it took about eight days; in many universities or
+ companies the same computing power is available to any
+ computer science student.
+
+ See also {Damien Doligez's SSL cracking page
+ (http://pauillac.inria.fr/~doligez/ssl/)}, {RC4 Source and
+ Information (http://cs.hut.fi/crypto/rc4)}, {SSLeay
+ (http://cs.hut.fi/crypto/software.html#ssleay)}, {Crypto++
+ (http://cs.hut.fi/crypto/software.html#crypto++)}, {Ssh
+ (http://cs.hut.fi/crypto/software.html#ssh)}, {A
+ collection of articles
+ (http://cs.hut.fi/crypto/rc4-breaking)}.
+
+ (1996-10-28)
+
+RCA 1802
+
+ <processor> An extremely simple {microprocessor} fabricated in
+ {CMOS}, running at 6.4 MHz at 10V (very fast for 1974). It
+ could be suspended with the clock stopped. It was an 8-bit
+ processor, with 16-bit addressing. Simplicity was the primary
+ design goal, and in that sense it was one of the first {RISC}
+ chips. It had sixteen 16-bit {registers}, which could be
+ accessed as thirty-two 8-bit registers, and an {accumulator} D
+ used for arithmetic and memory access - memory to D, then D to
+ registers and vice versa, using one 16-bit register as an
+ address. This led to one person describing the 1802 as having
+ 32 bytes of {RAM} and 65535 I/O ports. A 4-bit control
+ register P selected any one general register as the {program
+ counter}, while control registers X and N selected registers
+ for I/O Index and the operand for the current instruction.
+ All instructions were 8 bits - a 4-bit {op code} (total of 16
+ operations) and 4-bit {operand register} stored in N. There
+ was no real {conditional branching}, no {subroutine} support
+ and no actual {stack} but these could be implemented by clever
+ use of registers, e.g. changing P to another register allowed
+ jump to a subroutine. Similarly, on an interrupt P and X were
+ saved, then R1 and R2 were selected for P and X until an {RTI}
+ restored them.
+
+ The {RCA 1805} was an enhanced version.
+
+ The 1802 was used in the {COSMAC} (VIP?) {microcomputer} kit,
+ some video games from {RCA} and {Radio Shack}, and the
+ {ETI-660} computer. It was chosen for the Voyager, Viking and
+ Galileo space probes as it was also fabricated in {Silicon on
+ Sapphire}, giving radiation and static resistance, ideal for
+ space operation.
+
+ {More history (http://cosmacelf.com)}.
+
+ (2002-04-09)
+
+RCA 1805
+
+ A later, enhanced version of the {RCA 1802}. It added several
+ {Forth} language primitives.
+
+ (1994-11-16)
+
+RCC
+
+ An extensible language.
+
+ [More detail?]
+
+rc file
+
+ /R C fi:l/ [Unix: from the startup script "/etc/rc", but this
+ is commonly believed to have been named after older scripts to
+ "run commands"] Script file containing startup instructions
+ for an application program (or an entire operating system),
+ usually a text file containing commands of the sort that might
+ have been invoked manually once the system was running but are
+ to be executed automatically each time the system starts up.
+ See also {dot file}, {profile} (sense 1).
+
+ [{Jargon File}]
+
+RCL
+
+ Reduced Control Language. A simplified job control language
+ for OS360, translated to IBM JCL. "Reduced Control Language
+ for Non- Professional Users", K. Appel in Command Languages,
+ C. Unger ed, N-H 1973.
+
+rcp
+
+ <networking, tool> (Remote copy) The {Unix} utility for
+ copying files over {Ethernet}. Rcp is similar to {FTP} but
+ uses the {hosts.equiv} user authentication method.
+
+ {Unix manual page}: rcp(1).
+
+ (1997-01-12)
+
+RCS
+
+ {Revision Control System}
+
+Rdb
+
+ {Oracle Rdb}
+
+rdb
+
+ A roll-your-own {database}, created in the {Unix} toolkit
+ philosophy. It appears to be written in the {awk} language,
+ and is very compatible with awk. It uses awk's syntax and can
+ be combined with awk commands.
+
+ The definitive introduction is "Unix Relational Database
+ Management: Application Development in the Unix Environment",
+ by Rod Manis, Evan Schaeffer, and Robert Jorgensen, published
+ by Prentice Hall. The book tells how to use rdb to create
+ database/spreadsheets in the awk tradition, only easier. It's
+ a good way to get into programming for novices. It's also a
+ good way to learn DB theory and construction quite painlessly.
+
+RDBA
+
+ {Remote Database Access}
+
+RDBMS
+
+ {relational database}
+
+RDF
+
+ {Resource Description Framework}
+
+RDI
+
+ {Receiver Data Interface}
+
+RDL
+
+ Requirements and Development Language.
+
+ ["RDL: A Language for Software Development", H.C. Heacox,
+ SIGPLAN Notices 14(9):71-79 (Sep 1979)].
+
+RDOS
+
+ {Realtime Disk Operating System}
+
+RDP
+
+ <protocol>
+
+ 1. {Reliable Data Protocol}.
+
+ 2. {Remote Desktop Protocol}.
+
+ (2004-09-14)
+
+RDRAM
+
+ {Rambus DRAM}
+
+RDS
+
+ {Random Dot Stereogram}
+
+RE
+
+ {regular expression}
+
+re
+
+ 1. <networking> The {country code} for Reunion.
+
+ 2. <chat> /re-/ (From "rehi") Hello again. A greeting
+ originating in, and most often heard on, {Internet}
+ interactive conversation services.
+
+ [{Jargon File}]
+
+ (1999-02-08)
+
+read-eval-print loop
+
+ <language, LISP, programming> (REPL) A programming {structure}
+ within {LISP} which repeatedly reads a {form} from the {user},
+ evaluates it, and displays the result.
+
+ A read-eval-print {loop} forms the basis of the {Top-Level}
+ {shell} that programmers of the LISP family of languages
+ interact with.
+
+ In many dialects of LISP a very simple REPL could be
+ implemented as:
+
+ (loop (print (eval (read)))).
+
+ (2003-06-23)
+
+README file
+
+ <convention, documentation> A {text file} traditionally included
+ in the top-level {directory} of a {software} distribution,
+ containing pointers to {documentation}, credits, revision history,
+ notes, etc. Originally found in {Unix} source distributions, the
+ convention has spread to many other products. The file may be
+ named README, READ.ME, ReadMe or readme.txt or some other variant.
+
+ In the {Macintosh} and {IBM PC} worlds, software is not
+ usually distributed in source form, and the README is more
+ likely to contain user-oriented material like last-minute
+ documentation changes, error workarounds, and restrictions.
+
+ The README convention probably follows the famous scene in Lewis
+ Carroll's "Alice's Adventures In Wonderland" in which Alice
+ confronts magic munchies labeled "Eat Me" and "Drink Me".
+
+ [{Jargon File}]
+
+ (1995-02-28)
+
+Read-Only Memory
+
+ <storage> (ROM) A type of data storage device which is
+ manufactured with fixed contents. In its most general sense,
+ the term might be used for any storage system whose contents
+ cannot be altered, such as a gramophone record or a printed
+ book; however, the term is most often applied to
+ {semiconductor} {integrated circuit} memories, of which there
+ are several types, and {CD-ROM}.
+
+ ROM is inherently {non-volatile storage} - it retains its
+ contents even when the power is switched off, in contrast to
+ {RAM}.
+
+ ROM is often used to hold programs for {embedded systems}
+ since these usually have a fixed purpose. ROM is also used
+ for storage of the lowest level {bootstrap} software
+ (firmware) in a computer.
+
+ See also {Programmable Read-Only Memory}.
+
+ (1995-05-09)
+
+read-only user
+
+ <jargon> Describes a {luser} who uses computers almost
+ exclusively for reading {Usenet}, {bulletin boards}, and/or
+ {electronic mail}, rather than writing code or purveying
+ useful information.
+
+ See {twink}, {terminal junkie}, {lurker}.
+
+ [{Jargon File}]
+
+ (1995-02-28)
+
+real
+
+ 1. Not simulated. Often used as a specific antonym to
+ {virtual} in any of its jargon senses.
+
+ 2. <mathematics> {real number}.
+
+ [{Jargon File}]
+
+ (1997-03-12)
+
+RealAudio
+
+ <tool, communications> A program from {Real Media} for playing
+ {audio} over the {Internet}, and the {lossy} audio compression
+ format it uses.
+
+ The system is implemented as a {client/server} architecture.
+ The RealAudio server incorporates an {encoder} which
+ compresses sound into RealAudio files. The client side is a
+ {web browser} {plug-in} or {add-on} (a recent version of
+ {Internet Explorer} apparently has built-in support for
+ RealAudio) which allows the stream of data sent from the
+ server to be uncompressed and output using the normal sound
+ facilities of the computer, such as a {sound card}.
+
+ A 14.4 {KBps} or better {modem} is required, and a 28.8 KBps
+ connection is recommended for music-quality sound.
+
+ {(http://realaudio.com/)}.
+
+ (2001-12-13)
+
+real estate
+
+ <jargon> May be used for any critical resource measured in
+ units of area. Most frequently used of "chip real estate",
+ the area available for logic on the surface of an {integrated
+ circuit} (see also {nanoacre}). May also be used of floor
+ space in a {dinosaur pen}, or even space on a crowded desktop
+ (whether physical or electronic).
+
+ [{Jargon File}]
+
+ (1996-11-06)
+
+real hack
+
+ A {crock}. This is sometimes used affectionately; see {hack}.
+
+ [{Jargon File}]
+
+reality check
+
+ <testing> The simplest kind of {functional test} of {software} or
+ {hardware}; doing the equivalent of asking it what 2 + 2 is and
+ seeing if it says four. The software equivalent of a {smoke
+ test}. A reality check may include letting a {real user} try out
+ {prototype} software.
+
+ A {sanity check} is even more basic, the equivalent of checking
+ that the above addition was implemented with an addition operator
+ rather than subtraction.
+
+ (2007-03-15)
+
+realization
+
+ <specification> A {UML} {semantic} relationship between a
+ {classifier} that specifies a contract and another classifier
+ that guarantees to carry it out.
+
+ [Handout by Mr. David Gillibrand].
+
+ (2007-03-15)
+
+Really Simple Syndication
+
+ {Rich Site Summary}
+
+real mode
+
+ An operating mode of {Intel 80x86} processors. The opposite
+ of {protected mode}.
+
+ (1995-03-29)
+
+real number
+
+ <mathematics> One of the infinitely divisible range of values
+ between positive and negative {infinity}, used to represent
+ continuous physical quantities such as distance, time and
+ temperature.
+
+ Between any two real numbers there are infinitely many more
+ real numbers. The {integers} ("counting numbers") are real
+ numbers with no fractional part and real numbers ("measuring
+ numbers") are {complex numbers} with no imaginary part. Real
+ numbers can be divided into {rational numbers} and {irrational
+ numbers}.
+
+ Real numbers are usually represented (approximately) by
+ computers as {floating point} numbers.
+
+ Strictly, real numbers are the {equivalence classes} of the
+ {Cauchy sequences} of {rationals} under the {equivalence
+ relation} "~", where a ~ b if and only if a-b is {Cauchy} with
+ limit 0.
+
+ The real numbers are the minimal {topologically closed}
+ {field} containing the rational field.
+
+ A sequence, r, of rationals (i.e. a function, r, from the
+ {natural numbers} to the rationals) is said to be Cauchy
+ precisely if, for any tolerance delta there is a size, N,
+ beyond which: for any n, m exceeding N,
+
+ | r[n] - r[m] | < delta
+
+ A Cauchy sequence, r, has limit x precisely if, for any
+ tolerance delta there is a size, N, beyond which: for any n
+ exceeding N,
+
+ | r[n] - x | < delta
+
+ (i.e. r would remain Cauchy if any of its elements, no matter
+ how late, were replaced by x).
+
+ It is possible to perform addition on the reals, because the
+ equivalence class of a sum of two sequences can be shown to be
+ the equivalence class of the sum of any two sequences
+ equivalent to the given originals: ie, a~b and c~d implies
+ a+c~b+d; likewise a.c~b.d so we can perform multiplication.
+ Indeed, there is a natural {embedding} of the rationals in the
+ reals (via, for any rational, the sequence which takes no
+ other value than that rational) which suffices, when extended
+ via continuity, to import most of the algebraic properties of
+ the rationals to the reals.
+
+ (1997-03-12)
+
+real operating system
+
+ <operating system, abuse> The sort the speaker is used to.
+ People from the {BSD}ophilic academic community are likely to
+ issue comments like "{System V}? Why don't you use a *real*
+ operating system?", people from the commercial/industrial
+ {Unix} sector are known to complain "BSD? Why don't you use a
+ *real* operating system?", and people from {IBM} object "Unix?
+ Why don't you use a *real* operating system?"
+
+ See {holy wars}, {religious issues}, {proprietary}, {Get a
+ real computer!}.
+
+ [{Jargon File}]
+
+ (1997-03-12)
+
+Real Programmer
+
+ <job, humour> (From the book "Real Men Don't Eat Quiche") A
+ variety of hacker possessed of a flippant attitude toward
+ complexity that is arrogant even when justified by experience.
+ The archetypal "Real Programmer" likes to program on the {bare
+ metal} and is very good at it, remembers the binary {op codes}
+ for every machine he has ever programmed, thinks that
+ {high-level languages} are sissy, and uses a {debugger} to
+ edit his code because full-screen editors are for wimps. Real
+ Programmers aren't satisfied with code that hasn't been
+ {bum}med into a state of {tense}ness just short of rupture.
+
+ Real Programmers never use {comments} or write
+ {documentation}: "If it was hard to write", says the Real
+ Programmer, "it should be hard to understand." Real
+ Programmers can make machines do things that were never in
+ their spec sheets; in fact, they are seldom really happy
+ unless doing so. A Real Programmer's code can awe with its
+ fiendish brilliance, even as its crockishness appals.
+
+ Real Programmers live on junk food and coffee, hang
+ line-printer art on their walls, and terrify the crap out of
+ other programmers - because someday, somebody else might have
+ to try to understand their code in order to change it. Their
+ successors generally consider it a {Good Thing} that there
+ aren't many Real Programmers around any more.
+
+ For a famous (and somewhat more positive) portrait of a Real
+ Programmer, see "{The Story of Mel}". The term itself was
+ popularised by a 1983 Datamation article "{Real Programmers
+ Don't Use Pascal}" by Ed Post, still circulating on {Usenet}
+ and Internet in on-line form.
+
+ [{Jargon File}]
+
+ (1997-08-29)
+
+Real Programmers Don't Use Pascal
+
+ <humour> Back in the good old days - the "Golden Era" of
+ computers, it was easy to separate the men from the boys
+ (sometimes called "Real Men" and "Quiche Eaters" in the
+ literature). During this period, the Real Men were the ones
+ that understood computer programming, and the Quiche Eaters
+ were the ones that didn't. A real computer programmer said
+ things like "DO 10 I=1,10" and "ABEND" (they actually talked
+ in capital letters, you understand), and the rest of the world
+ said things like "computers are too complicated for me" and "I
+ can't relate to computers - they're so impersonal". (A
+ previous work [1] points out that Real Men don't "relate" to
+ anything, and aren't afraid of being impersonal.)
+
+ But, as usual, times change. We are faced today with a world
+ in which little old ladies can get computers in their
+ microwave ovens, 12-year-old kids can blow Real Men out of the
+ water playing Asteroids and Pac-Man, and anyone can buy and
+ even understand their very own Personal Computer. The Real
+ Programmer is in danger of becoming extinct, of being replaced
+ by high-school students with {TRASH-80s}.
+
+ There is a clear need to point out the differences between the
+ typical high-school junior Pac-Man player and a Real
+ Programmer. If this difference is made clear, it will give
+ these kids something to aspire to -- a role model, a Father
+ Figure. It will also help explain to the employers of Real
+ Programmers why it would be a mistake to replace the Real
+ Programmers on their staff with 12-year-old Pac-Man players
+ (at a considerable salary savings).
+
+ LANGUAGES
+
+ The easiest way to tell a Real Programmer from the crowd is by
+ the programming language he (or she) uses. Real Programmers
+ use {Fortran}. Quiche Eaters use {Pascal}. Nicklaus Wirth,
+ the designer of Pascal, gave a talk once at which he was asked
+ how to pronounce his name. He replied, "You can either call
+ me by name, pronouncing it 'Veert', or call me by value,
+ 'Worth'." One can tell immediately from this comment that
+ Nicklaus Wirth is a Quiche Eater. The only parameter passing
+ mechanism endorsed by Real Programmers is
+ call-by-value-return, as implemented in the {IBM 370}
+ {Fortran-G} and H compilers. Real programmers don't need all
+ these abstract concepts to get their jobs done - they are
+ perfectly happy with a {keypunch}, a {Fortran IV} {compiler},
+ and a beer.
+
+ Real Programmers do List Processing in Fortran.
+
+ Real Programmers do String Manipulation in Fortran.
+
+ Real Programmers do Accounting (if they do it at all) in
+ Fortran.
+
+ Real Programmers do {Artificial Intelligence} programs in
+ Fortran.
+
+ If you can't do it in Fortran, do it in {assembly language}.
+ If you can't do it in assembly language, it isn't worth doing.
+
+ STRUCTURED PROGRAMMING
+
+ The academics in computer science have gotten into the
+ "structured programming" rut over the past several years.
+ They claim that programs are more easily understood if the
+ programmer uses some special language constructs and
+ techniques. They don't all agree on exactly which constructs,
+ of course, and the examples they use to show their particular
+ point of view invariably fit on a single page of some obscure
+ journal or another - clearly not enough of an example to
+ convince anyone. When I got out of school, I thought I was
+ the best programmer in the world. I could write an unbeatable
+ tic-tac-toe program, use five different computer languages,
+ and create 1000-line programs that WORKED. (Really!) Then I
+ got out into the Real World. My first task in the Real World
+ was to read and understand a 200,000-line Fortran program,
+ then speed it up by a factor of two. Any Real Programmer will
+ tell you that all the Structured Coding in the world won't
+ help you solve a problem like that - it takes actual talent.
+ Some quick observations on Real Programmers and Structured
+ Programming:
+
+ Real Programmers aren't afraid to use {GOTOs}.
+
+ Real Programmers can write five-page-long DO loops without
+ getting confused.
+
+ Real Programmers like Arithmetic IF statements - they make the
+ code more interesting.
+
+ Real Programmers write self-modifying code, especially if they
+ can save 20 {nanoseconds} in the middle of a tight loop.
+
+ Real Programmers don't need comments - the code is obvious.
+
+ Since Fortran doesn't have a structured IF, REPEAT ... UNTIL,
+ or CASE statement, Real Programmers don't have to worry about
+ not using them. Besides, they can be simulated when necessary
+ using {assigned GOTOs}.
+
+ Data Structures have also gotten a lot of press lately.
+ Abstract Data Types, Structures, Pointers, Lists, and Strings
+ have become popular in certain circles. Wirth (the
+ above-mentioned Quiche Eater) actually wrote an entire book
+ [2] contending that you could write a program based on data
+ structures, instead of the other way around. As all Real
+ Programmers know, the only useful data structure is the Array.
+ Strings, lists, structures, sets - these are all special cases
+ of arrays and can be treated that way just as easily without
+ messing up your programing language with all sorts of
+ complications. The worst thing about fancy data types is that
+ you have to declare them, and Real Programming Languages, as
+ we all know, have implicit typing based on the first letter of
+ the (six character) variable name.
+
+ OPERATING SYSTEMS
+
+ What kind of operating system is used by a Real Programmer?
+ CP/M? God forbid - CP/M, after all, is basically a toy
+ operating system. Even little old ladies and grade school
+ students can understand and use CP/M.
+
+ Unix is a lot more complicated of course - the typical Unix
+ hacker never can remember what the PRINT command is called
+ this week - but when it gets right down to it, Unix is a
+ glorified video game. People don't do Serious Work on Unix
+ systems: they send jokes around the world on {UUCP}-net and
+ write adventure games and research papers.
+
+ No, your Real Programmer uses OS 370. A good programmer can
+ find and understand the description of the IJK305I error he
+ just got in his JCL manual. A great programmer can write JCL
+ without referring to the manual at all. A truly outstanding
+ programmer can find bugs buried in a 6 megabyte {core dump}
+ without using a hex calculator. (I have actually seen this
+ done.)
+
+ OS is a truly remarkable operating system. It's possible to
+ destroy days of work with a single misplaced space, so
+ alertness in the programming staff is encouraged. The best
+ way to approach the system is through a keypunch. Some people
+ claim there is a Time Sharing system that runs on OS 370, but
+ after careful study I have come to the conclusion that they
+ were mistaken.
+
+ PROGRAMMING TOOLS
+
+ What kind of tools does a Real Programmer use? In theory, a
+ Real Programmer could run his programs by keying them into the
+ front panel of the computer. Back in the days when computers
+ had front panels, this was actually done occasionally. Your
+ typical Real Programmer knew the entire bootstrap loader by
+ memory in hex, and toggled it in whenever it got destroyed by
+ his program. (Back then, memory was memory - it didn't go
+ away when the power went off. Today, memory either forgets
+ things when you don't want it to, or remembers things long
+ after they're better forgotten.) Legend has it that {Seymore
+ Cray}, inventor of the Cray I supercomputer and most of
+ Control Data's computers, actually toggled the first operating
+ system for the CDC7600 in on the front panel from memory when
+ it was first powered on. Seymore, needless to say, is a Real
+ Programmer.
+
+ One of my favorite Real Programmers was a systems programmer
+ for Texas Instruments. One day he got a long distance call
+ from a user whose system had crashed in the middle of saving
+ some important work. Jim was able to repair the damage over
+ the phone, getting the user to toggle in disk I/O instructions
+ at the front panel, repairing system tables in hex, reading
+ register contents back over the phone. The moral of this
+ story: while a Real Programmer usually includes a keypunch and
+ lineprinter in his toolkit, he can get along with just a front
+ panel and a telephone in emergencies.
+
+ In some companies, text editing no longer consists of ten
+ engineers standing in line to use an 029 keypunch. In fact,
+ the building I work in doesn't contain a single keypunch. The
+ Real Programmer in this situation has to do his work with a
+ "text editor" program. Most systems supply several text
+ editors to select from, and the Real Programmer must be
+ careful to pick one that reflects his personal style. Many
+ people believe that the best text editors in the world were
+ written at Xerox Palo Alto Research Center for use on their
+ Alto and Dorado computers [3]. Unfortunately, no Real
+ Programmer would ever use a computer whose operating system is
+ called SmallTalk, and would certainly not talk to the computer
+ with a mouse.
+
+ Some of the concepts in these Xerox editors have been
+ incorporated into editors running on more reasonably named
+ operating systems - {Emacs} and {VI} being two. The problem
+ with these editors is that Real Programmers consider "what you
+ see is what you get" to be just as bad a concept in Text
+ Editors as it is in women. No the Real Programmer wants a
+ "you asked for it, you got it" text editor - complicated,
+ cryptic, powerful, unforgiving, dangerous. TECO, to be
+ precise.
+
+ It has been observed that a TECO command sequence more closely
+ resembles transmission line noise than readable text [4]. One
+ of the more entertaining games to play with TECO is to type
+ your name in as a command line and try to guess what it does.
+ Just about any possible typing error while talking with TECO
+ will probably destroy your program, or even worse - introduce
+ subtle and mysterious bugs in a once working subroutine.
+
+ For this reason, Real Programmers are reluctant to actually
+ edit a program that is close to working. They find it much
+ easier to just patch the binary {object code} directly, using
+ a wonderful program called SUPERZAP (or its equivalent on
+ non-IBM machines). This works so well that many working
+ programs on IBM systems bear no relation to the original
+ Fortran code. In many cases, the original source code is no
+ longer available. When it comes time to fix a program like
+ this, no manager would even think of sending anything less
+ than a Real Programmer to do the job - no Quiche Eating
+ structured programmer would even know where to start. This is
+ called "job security".
+
+ Some programming tools NOT used by Real Programmers:
+
+ Fortran preprocessors like {MORTRAN} and {RATFOR}. The
+ Cuisinarts of programming - great for making Quiche. See
+ comments above on structured programming.
+
+ Source language debuggers. Real Programmers can read core
+ dumps.
+
+ Compilers with array bounds checking. They stifle creativity,
+ destroy most of the interesting uses for EQUIVALENCE, and make
+ it impossible to modify the operating system code with
+ negative subscripts. Worst of all, bounds checking is
+ inefficient.
+
+ Source code maintenance systems. A Real Programmer keeps his
+ code locked up in a card file, because it implies that its
+ owner cannot leave his important programs unguarded [5].
+
+ THE REAL PROGRAMMER AT WORK
+
+ Where does the typical Real Programmer work? What kind of
+ programs are worthy of the efforts of so talented an
+ individual? You can be sure that no Real Programmer would be
+ caught dead writing accounts-receivable programs in {COBOL},
+ or sorting {mailing lists} for People magazine. A Real
+ Programmer wants tasks of earth-shaking importance
+ (literally!).
+
+ Real Programmers work for Los Alamos National Laboratory,
+ writing atomic bomb simulations to run on Cray I
+ supercomputers.
+
+ Real Programmers work for the National Security Agency,
+ decoding Russian transmissions.
+
+ It was largely due to the efforts of thousands of Real
+ Programmers working for NASA that our boys got to the moon and
+ back before the Russkies.
+
+ Real Programmers are at work for Boeing designing the
+ operating systems for cruise missiles.
+
+ Some of the most awesome Real Programmers of all work at the
+ Jet Propulsion Laboratory in California. Many of them know
+ the entire operating system of the Pioneer and Voyager
+ spacecraft by heart. With a combination of large ground-based
+ Fortran programs and small spacecraft-based assembly language
+ programs, they are able to do incredible feats of navigation
+ and improvisation - hitting ten-kilometer wide windows at
+ Saturn after six years in space, repairing or bypassing
+ damaged sensor platforms, radios, and batteries. Allegedly,
+ one Real Programmer managed to tuck a pattern-matching program
+ into a few hundred bytes of unused memory in a Voyager
+ spacecraft that searched for, located, and photographed a new
+ moon of Jupiter.
+
+ The current plan for the Galileo spacecraft is to use a
+ gravity assist trajectory past Mars on the way to Jupiter.
+ This trajectory passes within 80 +/-3 kilometers of the
+ surface of Mars. Nobody is going to trust a Pascal program
+ (or a Pascal programmer) for navigation to these tolerances.
+
+ As you can tell, many of the world's Real Programmers work for
+ the U.S. Government - mainly the Defense Department. This is
+ as it should be. Recently, however, a black cloud has formed
+ on the Real Programmer horizon. It seems that some highly
+ placed Quiche Eaters at the Defense Department decided that
+ all Defense programs should be written in some grand unified
+ language called "ADA" ((C), DoD). For a while, it seemed that
+ ADA was destined to become a language that went against all
+ the precepts of Real Programming - a language with structure,
+ a language with data types, {strong typing}, and semicolons.
+ In short, a language designed to cripple the creativity of the
+ typical Real Programmer. Fortunately, the language adopted by
+ DoD has enough interesting features to make it approachable --
+ it's incredibly complex, includes methods for messing with the
+ operating system and rearranging memory, and Edsgar Dijkstra
+ doesn't like it [6]. (Dijkstra, as I'm sure you know, was the
+ author of "GoTos Considered Harmful" - a landmark work in
+ programming methodology, applauded by Pascal programmers and
+ Quiche Eaters alike.) Besides, the determined Real Programmer
+ can write Fortran programs in any language.
+
+ The Real Programmer might compromise his principles and work
+ on something slightly more trivial than the destruction of
+ life as we know it, providing there's enough money in it.
+ There are several Real Programmers building video games at
+ Atari, for example. (But not playing them - a Real Programmer
+ knows how to beat the machine every time: no challenge in
+ that.) Everyone working at LucasFilm is a Real Programmer.
+ (It would be crazy to turn down the money of fifty million
+ Star Trek fans.) The proportion of Real Programmers in
+ Computer Graphics is somewhat lower than the norm, mostly
+ because nobody has found a use for computer graphics yet. On
+ the other hand, all computer graphics is done in Fortran, so
+ there are a fair number of people doing graphics in order to
+ avoid having to write COBOL programs.
+
+ THE REAL PROGRAMMER AT PLAY
+
+ Generally, the Real Programmer plays the same way he works -
+ with computers. He is constantly amazed that his employer
+ actually pays him to do what he would be doing for fun anyway
+ (although he is careful not to express this opinion out loud).
+ Occasionally, the Real Programmer does step out of the office
+ for a breath of fresh air and a beer or two. Some tips on
+ recognizing Real Programmers away from the computer room:
+
+ At a party, the Real Programmers are the ones in the corner
+ talking about operating system security and how to get around
+ it.
+
+ At a football game, the Real Programmer is the one comparing
+ the plays against his simulations printed on 11 by 14 fanfold
+ paper.
+
+ At the beach, the Real Programmer is the one drawing
+ flowcharts in the sand.
+
+ At a funeral, the Real Programmer is the one saying "Poor
+ George, he almost had the sort routine working before the
+ coronary."
+
+ In a grocery store, the Real Programmer is the one who insists
+ on running the cans past the laser checkout scanner himself,
+ because he never could trust keypunch operators to get it
+ right the first time.
+
+ THE REAL PROGRAMMER'S NATURAL HABITAT
+
+ What sort of environment does the Real Programmer function
+ best in? This is an important question for the managers of
+ Real Programmers. Considering the amount of money it costs to
+ keep one on the staff, it's best to put him (or her) in an
+ environment where he can get his work done.
+
+ The typical Real Programmer lives in front of a computer
+ terminal. Surrounding this terminal are:
+
+ Listings of all programs the Real Programmer has ever worked
+ on, piled in roughly chronological order on every flat surface
+ in the office.
+
+ Some half-dozen or so partly filled cups of cold coffee.
+ Occasionally, there will be cigarette butts floating in the
+ coffee. In some cases, the cups will contain Orange Crush.
+
+ Unless he is very good, there will be copies of the OS JCL
+ manual and the Principles of Operation open to some
+ particularly interesting pages.
+
+ Taped to the wall is a line-printer Snoopy calendar for the
+ year 1969.
+
+ Strewn about the floor are several wrappers for peanut butter
+ filled cheese bars - the type that are made pre-stale at the
+ bakery so they can't get any worse while waiting in the
+ vending machine.
+
+ Hiding in the top left-hand drawer of the desk is a stash of
+ double-stuff Oreos for special occasions.
+
+ Underneath the Oreos is a flowcharting template, left there by
+ the previous occupant of the office. (Real Programmers write
+ programs, not documentation. Leave that to the maintenance
+ people.)
+
+ The Real Programmer is capable of working 30, 40, even 50
+ hours at a stretch, under intense pressure. In fact, he
+ prefers it that way. Bad response time doesn't bother the
+ Real Programmer - it gives him a chance to catch a little
+ sleep between compiles. If there is not enough schedule
+ pressure on the Real Programmer, he tends to make things more
+ challenging by working on some small but interesting part of
+ the problem for the first nine weeks, then finishing the rest
+ in the last week, in two or three 50-hour marathons. This not
+ only impresses the hell out of his manager, who was despairing
+ of ever getting the project done on time, but creates a
+ convenient excuse for not doing the documentation. In
+ general:
+
+ No Real Programmer works 9 to 5 (unless it's the ones at
+ night).
+
+ Real Programmers don't wear neckties.
+
+ Real Programmers don't wear high-heeled shoes.
+
+ Real Programmers arrive at work in time for lunch [9].
+
+ A Real Programmer might or might not know his wife's name. He
+ does, however, know the entire {ASCII} (or EBCDIC) code table.
+
+ Real Programmers don't know how to cook. Grocery stores
+ aren't open at three in the morning. Real Programmers survive
+ on Twinkies and coffee.
+
+ THE FUTURE
+
+ What of the future? It is a matter of some concern to Real
+ Programmers that the latest generation of computer programmers
+ are not being brought up with the same outlook on life as
+ their elders. Many of them have never seen a computer with a
+ front panel. Hardly anyone graduating from school these days
+ can do hex arithmetic without a calculator. College graduates
+ these days are soft - protected from the realities of
+ programming by source level debuggers, text editors that count
+ parentheses, and "user friendly" operating systems. Worst of
+ all, some of these alleged "computer scientists" manage to get
+ degrees without ever learning Fortran! Are we destined to
+ become an industry of Unix hackers and Pascal programmers?
+
+ From my experience, I can only report that the future is
+ bright for Real Programmers everywhere. Neither OS 370 nor
+ Fortran show any signs of dying out, despite all the efforts
+ of Pascal programmers the world over. Even more subtle
+ tricks, like adding structured coding constructs to Fortran
+ have failed. Oh sure, some computer vendors have come out
+ with Fortran 77 compilers, but every one of them has a way of
+ converting itself back into a Fortran 66 compiler at the drop
+ of an option card - to compile DO loops like God meant them to
+ be.
+
+ Even Unix might not be as bad on Real Programmers as it once
+ was. The latest release of Unix has the potential of an
+ operating system worthy of any Real Programmer - two different
+ and subtly incompatible user interfaces, an arcane and
+ complicated teletype driver, virtual memory. If you ignore
+ the fact that it's "structured", even 'C' programming can be
+ appreciated by the Real Programmer: after all, there's no type
+ checking, variable names are seven (ten? eight?) characters
+ long, and the added bonus of the Pointer data type is thrown
+ in - like having the best parts of Fortran and assembly
+ language in one place. (Not to mention some of the more
+ creative uses for #define.)
+
+ No, the future isn't all that bad. Why, in the past few
+ years, the popular press has even commented on the bright new
+ crop of {computer nerds} and hackers ([7] and [8]) leaving
+ places like Stanford and M.I.T. for the Real World. From all
+ evidence, the spirit of Real Programming lives on in these
+ young men and women. As long as there are ill-defined goals,
+ bizarre bugs, and unrealistic schedules, there will be Real
+ Programmers willing to jump in and Solve The Problem, saving
+ the documentation for later. Long live Fortran!
+
+ ACKNOWLEGEMENT
+
+ I would like to thank Jan E., Dave S., Rich G., Rich E., for
+ their help in characterizing the Real Programmer, Heather
+ B. for the illustration, Kathy E. for putting up with it, and
+ atd!avsdS:mark for the initial inspiration.
+
+ REFERENCES
+
+ [1] Feirstein, B., "Real Men don't Eat Quiche", New York,
+ Pocket Books, 1982.
+
+ [2] Wirth, N., "Algorithms + Data Structures Programs",
+ Prentice Hall, 1976.
+
+ [3] Ilson, R., "Recent Research in Text Processing", IEEE
+ Trans. Prof. Commun., Vol. PC-23, No. 4, Dec. 4, 1980.
+
+ [4] Finseth, C., "Theory and Practice of Text Editors - or - a
+ Cookbook for an EMACS", B.S. Thesis, MIT/LCS/TM-165,
+ Massachusetts Institute of Technology, May 1980.
+
+ [5] Weinberg, G., "The Psychology of Computer Programming",
+ New York, Van Nostrand Reinhold, 1971, p. 110.
+
+ [6] Dijkstra, E., "On the GREEN language submitted to the
+ DoD", Sigplan notices, Vol. 3 No. 10, Oct 1978.
+
+ [7] Rose, Frank, "Joy of Hacking", Science 82, Vol. 3 No. 9,
+ Nov 82, pp. 58-66.
+
+ [8] "The Hacker Papers", Psychology Today, August 1980.
+
+ [9] sdcarl!lin, "Real Programmers", UUCP-net, Thu Oct 21
+ 16:55:16 1982.
+
+ Ed Post, "Real Programmers Don't Use Pascal", DATAMATION, July
+ 1983, pp. 263-265 (Readers' Forum).
+
+ (1997-08-29)
+
+Real Simple Syndication
+
+ <spelling> Illiterate form of {Really Simple Syndication}.
+
+ (2013-08-15)
+
+Real Soon Now
+
+ <jargon, humour> (RSN) A phrase used ironically when you believe
+ an event will take a long or unknown time to occur. The term
+ originated in SF's fanzine community, popularised by Jerry
+ Pournelle's column in {BYTE}.
+
+ The phrase can be used, for example, when a manager asks how long
+ it will take you to {debug} some {software} and you have no idea.
+ "I'll have it working Real Soon Now."
+
+ [{Jargon File}]
+
+ (2013-08-22)
+
+real-time
+
+ 1. Describes an application which requires a program to
+ respond to stimuli within some small upper limit of response
+ time (typically milli- or microseconds). Process control at a
+ chemical plant is the classic example. Such applications
+ often require special operating systems (because everything
+ else must take a back seat to response time) and speed-tuned
+ hardware.
+
+ 2. In jargon, refers to doing something while people are
+ watching or waiting. "I asked her how to find the calling
+ procedure's program counter on the stack and she came up with
+ an algorithm in real time."
+
+ Used to describe a system that must guarantee a response to an
+ external event within a given time.
+
+ (1997-11-23)
+
+Real-Time Common Design Language
+
+ <language> (RT-CDL) A {real-time} language for the design of
+ reliable {reactive systems}.
+
+ ["RT-CDL: A Real-Time Description Language and Its Semantics",
+ L.Y. Lin et al, 11th World Computer Congress IFIP '89 pp.19-26
+ Sep 1989].
+
+ (2003-06-07)
+
+Realtime Disk Operating System
+
+ <operating system> A {Data General} {operating system}
+ developed in the 1970s or 1980s. When used in conjuction with
+ a {BASIC} (e.g. {Business Basic}) it could support 16
+ concurrent users at the {record locking} level and two
+ printers all on 128K memory.
+
+ Reputedly {IBM} wanted to license this for the first {IBM PC}
+ but DG turned them down so they went to {Microsoft} instead.
+ How different the world could have been.
+
+ [Before or after IBM wanted {CP/M}?]
+
+ (1997-11-23)
+
+Real-Time Euclid
+
+ Real-time language, restriction to time-bounded constructs.
+ ["Real-Time Euclid: A Language for Reliable Real-Time
+ Systems", E. Kligerman et al, IEEE Trans Software Eng
+ SE-12(9):941-1986-09-949].
+
+Real-Time Mentat
+
+ An extension of C++. "Real-Time Mentat: A Data-Driven
+ Object-Oriented System", A.S. Grimshaw et al, Proc IEEE
+ Globecom, Nov 1989 pp.232-241.
+
+Real-Time Object-Oriented Modeling
+
+ <programming> (ROOM Methodology)
+
+ {(http://objectime.on.ca/ROOM.HTML)}.
+
+ [Summary?]
+
+ (1997-02-17)
+
+Real-Time Operating System
+
+ <operating system> (RTOS) Any {operating system} where
+ interrupts are guaranteed to be handled within a certain
+ specified maximum time, thereby making it suitable for control
+ of hardware in {embedded systems} and other time-critical
+ applications. RTOS is not a specific product but a class of
+ operating systems.
+
+ [Other criteria?]
+
+ (1998-02-27)
+
+Real-Time Operating System Nucleus
+
+ {The Real-Time Operating System Nucleus}
+
+Real-Time Pascal
+
+ <language> A later name for {Pascal-80} by {RC International},
+ Denmark.
+
+ (1995-05-09)
+
+Real Time Streaming Protocol
+
+ <multimedia, networking, protocol> (RTSP) An {application
+ layer} {protocol} for controlling delivery of a {stream} of
+ {real-time} {multimedia} content. RTSP allows users to start
+ playing from a certain position. It does not actually deliver
+ the data, but works alongside existing delivery channels such
+ as {UDP}, {TCP}, or IP {multicast}.
+
+ RTSP was developed by {RealNetworks}, {Netscape
+ Communications}, and {Columbia University}, and is described
+ in {RFC 2326}, April 1998. RTSP is an {IETF} proposed
+ {standard}.
+
+ {FAQ
+ (http://real.com/devzone/library/fireprot/rtsp/faq.html)}.
+
+ (1999-08-26)
+
+real-time structured analysis
+
+ <programming> (RTSA) Any version of {structured analysis}
+ capable of modelling {real-time} aspects of software.
+
+ (1995-04-06)
+
+Real-Time Transport Protocol
+
+ <protocol> (RTP) An {Internet} {protocol} for transmitting
+ {real-time} data such as {audio} and {video}. RTP itself does
+ not guarantee real-time delivery of data, but it does provide
+ mechanisms for the sending and receiving applications to
+ support {streaming} data. Typically, RTP runs on top of the
+ {UDP} protocol, although the specification is general enough
+ to support other {transport protocols}.
+
+ RTP has received wide industry support. {Netscape} intends to
+ base its {LiveMedia} technology on RTP, and {Microsoft} claims
+ that its {NetMeeting} product supports RTP.
+
+ (2003-07-06)
+
+real user
+
+ 1. A commercial user. One who is paying *real* money for his
+ computer usage.
+
+ 2. A non-hacker. Someone using the system for an explicit
+ purpose (a research project, a course, etc.) other than pure
+ exploration. See {user}. Hackers who are also students may
+ also be real users. "I need this fixed so I can do a problem
+ set. I'm not complaining out of randomness, but as a real
+ user." See also {luser}.
+
+ [{Jargon File}]
+
+Real Video
+
+ <video, compression> A {lossy} video compression format from
+ {Real Media}.
+
+ (2001-12-13)
+
+Real World
+
+ 1. Those institutions at which "programming" may be used in
+ the same sentence as "Fortran", "{COBOL}", "RPG", "{IBM}",
+ "DBASE", etc. Places where programs do such commercially
+ necessary but intellectually uninspiring things as generating
+ payroll checks and invoices.
+
+ 2. The location of non-programmers and activities not related
+ to programming.
+
+ 3. A bizarre dimension in which the standard dress is shirt
+ and tie and in which a person's working hours are defined as 9
+ to 5 (see {code grinder}).
+
+ 4. Anywhere outside a university. "Poor fellow, he's left MIT
+ and gone into the Real World." Used pejoratively by those not
+ in residence there. In conversation, talking of someone who
+ has entered the Real World is not unlike speaking of a
+ deceased person. It is also noteworthy that on the campus of
+ Cambridge University in England, there is a gaily-painted
+ lamp-post which bears the label "REALITY CHECKPOINT". It
+ marks the boundary between university and the Real World;
+ check your notions of reality before passing. This joke is
+ funnier because the Cambridge "campus" is actually coextensive
+ with the centre of Cambridge.
+
+ See also {fear and loathing}, {mundane}, {uninteresting}.
+
+reaper
+
+ A {prowler} that {GFRs} files. A file removed in this way is
+ said to have been "reaped".
+
+ [{Jargon File}]
+
+reassembly
+
+ {segmentation}
+
+reboot
+
+ <operating system> (From {boot}) A {boot} with the implication
+ that the computer has not been down for long, or that the
+ {boot} is a {bounce} intended to clear some state of
+ {wedgitude}.
+
+ See {warm boot}.
+
+ (1995-11-27)
+
+REC
+
+ {CONVERT}
+
+recent changes
+
+ {Recent changes to FOLDOC (/new.html)}.
+
+recipe
+
+ {suspension}
+
+recipient
+
+ <communications> One who receives; receiver. E.g. "No
+ recipient of the {e-mail} message will know about the other
+ {addressees} who were listed in the {BCC} header."
+
+ (2000-03-22)
+
+Recital
+
+ {dBASE}-like language and {DBMS} from Recital Corporation.
+ Versions include {Vax} {VMS}.
+
+RECOL
+
+ REtrieval COmmand Language. CACM 6(3):117-122 (Mar 1963).
+
+Recommended Standard
+
+ <standard> (RS) A series of {EIA} {standards} including
+ {EIA-232}.
+
+ (1995-03-28)
+
+record
+
+ <data, database, programming> An {ordered set} of {fields},
+ usually stored contiguously. The term is used with similar
+ meaning in several different contexts. In a file, a "record"
+ probably has some fixed length, in contrast to a "line" which
+ may have any length and is terminated by some {End Of Line}
+ sequence). A {database} record is also called a "row". In a
+ {spreadsheet} it is always called a "row". Some programming
+ languages use the term to mean a type composed of fields of
+ several other types ({C} calls this a "{struct}").
+
+ In all these cases, a record represents an entity with certain
+ field values.
+
+ Fields may be of a fixed width ({bits} or {characters}) or
+ they may be separated by a {delimiter} character, often
+ {comma} ({CSV}) or {HT} ({TSV}).
+
+ In a database the list of values of a given field from all
+ records is called a column.
+
+ (2002-03-22)
+
+Record Management Services
+
+ <operating system> (RMS) Procedures in the {VMS} {operating
+ system} that {programs} call to process {files} and {records}
+ within files. RMS allows programs to issue GET and PUT
+ requests at the record level (record I/O) as well as read and
+ write {blocks} (block I/O). VMS RMS is an integral part of
+ the system software; its procedures run in {executive mode}.
+
+ (2003-11-11)
+
+records
+
+ {record}
+
+Record Separator
+
+ <character> (RS) {ASCII} character 30.
+
+rectangle slinger
+
+ {polygon pusher}
+
+recurrence relation
+
+ <mathematics> An {equation} that defines each element of a
+ {sequence} in terms of one or more earlier elements. E.g. The
+ {Fibonacci sequence},
+
+ X[1] = 1
+ X[2] = 1
+ X[n] = X[n-1] + X[n-2]
+
+ Some recurrence relations can be converted to "closed form"
+ where X[n] is defined purely in terms of n, without reference
+ to earlier elements.
+
+ (2008-01-14)
+
+recurse
+
+ {recursion}
+
+recursion
+
+ <mathematics, programming> When a {function} (or {procedure})
+ calls itself. Such a function is called "recursive". If the
+ call is via one or more other functions then this group of
+ functions are called "mutually recursive".
+
+ If a function will always call itself, however it is called,
+ then it will never terminate. Usually however, it first
+ performs some test on its arguments to check for a "base case"
+ - a condition under which it can return a value without
+ calling itself.
+
+ The {canonical} example of a recursive function is
+ {factorial}:
+
+ factorial 0 = 1
+ factorial n = n * factorial (n-1)
+
+ {Functional programming languages} rely heavily on recursion,
+ using it where a {procedural language} would use {iteration}.
+
+ See also {recursion}, {recursive definition}, {tail recursion}.
+
+ [{Jargon File}]
+
+ (1996-05-11)
+
+recursion theory
+
+ <theory> The study of problems that, in principle, cannot be
+ solved by either computers or humans.
+
+ [Proper definition?]
+
+ (1999-03-01)
+
+recursive
+
+ {recursion}
+
+recursive acronym
+
+ <convention> A hackish (and especially {MIT}) tradition is to
+ choose acronyms and abbreviations that refer humorously to
+ themselves or to other acronyms or abbreviations. The classic
+ examples were two MIT editors called {EINE} ("EINE Is Not
+ {Emacs}") and {ZWEI} ("ZWEI Was EINE Initially"). More
+ recently, there is a {Scheme} compiler called {LIAR} (Liar
+ Imitates Apply Recursively), and {GNU} stands for "GNU's Not
+ Unix!" - and a company with the name {CYGNUS}, which expands
+ to "Cygnus, Your GNU Support".
+
+ See also {mung}.
+
+ [{Jargon File}]
+
+ (1995-04-28)
+
+recursive definition
+
+ See {recursive definition}.
+
+recursive descent parser
+
+ <grammar> A "top-down" {parser} built from a set of
+ {mutually-recursive} procedures or a non-recursive equivalent
+ where each such procedure usually implements one of the
+ {productions} of the {grammar}. Thus the structure of the
+ resulting program closely mirrors that of the grammar it
+ recognises.
+
+ ["Recursive Programming Techniques", W.H. Burge, 1975, ISBN
+ 0-201-14450-6].
+
+ (1995-04-28)
+
+Recursive Functional Algorithmic Language
+
+ <language> (REFAL) A language developed by V.F. Turchin (later
+ at {CUNY}?) in Moscow in about 1972.
+
+ See also {supercompilation}.
+
+ [V.F. Turchin, "An algorithm of generalisation in the
+ supercompiler", Workshop on partial evaluation and mixed
+ computations, Oct 1987, Denmark, Eds. D. Bjorner, A.P. Ershov,
+ N.D. Jones].
+
+ [V. Turchin, "Supercompiler System Based on the Language
+ Refal", V. Turchin, SIGPLAN Notices 14(2):46-54 (Feb 1979)].
+
+ (1998-06-29)
+
+Recursive Macro Actuated Generator
+
+ <tool> (RMAG) Robert A. Magnuson, NIH ca 1970.
+
+ A stand-alone macroprocessor for IBM 360/370 under VS or
+ OS. Many built-in features and a library of several hundred
+ macros. Several large systems were written in RMAG to
+ generate source code for languages such as IBM JCL, IBM
+ assembly language, COBOL.
+
+ There was also a system (SLANG: Structured LANGuage compiler)
+ which would generate 370 assembly language from a
+ pseudo-structured-programming language, based on Michael
+ Kessler's structure programming macros developed at IBM.
+
+ ["Project RMAG--RMAG22 User's Guide", R.A. Magnuson,
+ NIH-DCRT-DMB-SSS-UG103, NIH, DHEW, Bethesda, MD 20205 (1977)].
+
+ (1995-11-23)
+
+recursive type
+
+ A data type which contains itself. The commonest example is
+ the list type, in {Haskell}:
+
+ data List a = Nil | Cons a (List a)
+
+ which says a list of a's is either an empty list or a {cons
+ cell} containing an 'a' (the "head" of the list) and another
+ list (the "tail").
+
+ Recursion is not allowed in {Miranda} or Haskell {synonym
+ types}, so the following {Haskell} types are illegal:
+
+ type Bad = (Int, Bad)
+ type Evil = Bool -> Evil
+
+ whereas the seeminly equivalent {algebraic data types} are
+ acceptable:
+
+ data Good = Pair Int Good
+ data Fine = Fun (Bool->Fine)
+
+Red
+
+ (Or "REDL") A language proposed by {Intermetrics} to meet the
+ {Ironman} requirements which led to {Ada}.
+
+ ["On the RED Language Submitted to the DoD", E.W. Dijkstra,
+ SIGPLAN Notices 13(10):27 (Oct 1978)].
+
+ ["RED Language Reference Manual", J. Nestor and M. van Deusen,
+ Intermetrics 1979].
+
+ (1995-01-19)
+
+Red Book
+
+ 1. <publication> Informal name for one of the four standard
+ references on {PostScript}. The other three official guides
+ are known as the {Blue Book}, the {Green Book}, and the {White
+ Book}.
+
+ ["PostScript Language Reference Manual", Adobe Systems,
+ Addison-Wesley, 1985 (ISBN 0-201-10174-2); second edition
+ 1990 (ISBN 0-201-18127-4)].
+
+ 2. <publication> Informal name for one of the three standard
+ references on Smalltalk. This book also has blue and green
+ siblings.
+
+ ["Smalltalk-80: The Interactive Programming Environment",
+ Adele Goldberg, Addison-Wesley, 1984; (ISBN 0-201-11372-4)].
+
+ 3. <publication> Any of the 1984 standards issued by the
+ {ITU-T} eighth plenary assembly. These include, among other
+ things, the {X.400} {electronic mail} specification, the Group
+ 1 through 4 fax standards, {ISDN}, the R2 signalling system
+ (Q.400 series recommendations), data communication via the
+ {PSTN} (the V series recommendations) and tariffs and metering
+ principles (the D series).
+
+ 4. <publication> The new version of the {Green Book} - IEEE
+ 1003.1-1990, also known as ISO 9945-1 - is (because of the
+ colour and the fact that it is printed on A4 paper) known in
+ the USA. as "the Ugly Red Book That Won't Fit On The Shelf"
+ and in Europe as "the Ugly Red Book That's A Sensible Size".
+
+ 5. <publication> The NSA "Trusted Network Interpretation"
+ companion to the {Orange Book}.
+
+ See also {book titles}.
+
+ [{Jargon File}]
+
+Red Brick Intelligent SQL
+
+ <database> (RISQL) A vendor-specific extension to {SQL}
+ designed specifically for business managers. It augments SQL
+ with a variety of operations appropriate to data analysis and
+ {decision support} applications such as ranking, moving
+ averages, comparisons, market share, this year vs. last year,
+ etc. It was developed to simplify the creation of complex
+ business queries.
+
+ {Home
+ (http://redbrick.com/products/white/papers/risql/risql.html)}.
+
+ (1998-10-15)
+
+Redcode
+
+ <language> The {ICWS} standard language for {Core War} "battle
+ programs".
+
+ [Spec?]
+
+ (1998-10-30)
+
+redex
+
+ Reducible Expression. An expression matching the left hand
+ side of a {reduction rule} or definition.
+
+Red Hat
+
+ <operating system> A distribution of {Linux}.
+
+ {(http://redhat.com/)}.
+
+ (1996-12-21)
+
+RediLisp
+
+ R.M. Keller, U Utah. Dialect of Lisp used on the Rediflow
+ machine, a derivative of FEL.
+
+redirection
+
+ 1. <operating system> {input/output redirection}.
+
+ 2. <web> {URL redirection}.
+
+ (1997-07-15)
+
+redirector
+
+ {network redirector}
+
+RedNet Ltd.
+
+ <company> A systems integration company who also provide
+ "onLine", an {Internet} service aimed at both hobbyists and
+ corporate end-users. The service offers {dial-in} with {slip}
+ or {PPP}, {POP3} {electronic mail}.
+
+ {(http://rednet.co.uk)}.
+
+ E-mail: <info@rednet.co.uk> (with INFO in the body).
+
+ {Snail mail}: RedNet Ltd., 6 Cliveden Office Village, Lancaser
+ Road, High Wycombe, Bucks, HP12 3YZ, UK. Telephone: +44
+ (1494) 513 333. Fax: +44 (494) 443 374.
+
+ (1994-11-08)
+
+redocumentation
+
+ The creation or revision of a semantically equivalent
+ representation within the same relative abstraction level.
+ The resulting forms of representation are usually considered
+ alternate views intended for a human audience.
+
+REDUCE
+
+ <language, mathematics> A {symbolic mathematics} language with
+ {ALGOL}-like {syntax}, written in {Lisp} by Anthony Hearn in
+ 1963.
+
+ Reduce 2 is a version based on {Portable Standard LISP}.
+
+ {(http://rrz.uni-koeln.de/REDUCE/)}.
+
+ E-mail: <reduce@rand.org>.
+
+ Server: reduce-netlib@rand.org.
+
+ ["REDUCE, Software for Algebraic Computation", G. Rayna,
+ Springer 1987].
+
+ (1994-10-31)
+
+Reduced Instruction Set Computer
+
+ <processor> (RISC) A {processor} whose design is based on the
+ rapid execution of a sequence of simple instructions rather
+ than on the provision of a large variety of complex
+ instructions (as in a {Complex Instruction Set Computer}).
+
+ Features which are generally found in RISC designs are uniform
+ instruction encoding (e.g. the {op-code} is always in the same
+ bit positions in each instruction which is always one word
+ long), which allows faster decoding; a homogenous {register
+ set}, allowing any register to be used in any context and
+ simplifying {compiler} design; and simple {addressing modes}
+ with more complex modes replaced by sequences of simple
+ arithmetic instructions.
+
+ Examples of (more or less) RISC processors are the {Berkeley
+ RISC}, {HP-PA}, {Clipper}, {i960}, {AMD 29000}, {MIPS R2000}
+ and {DEC Alpha}. {IBM}'s first RISC computer was the {RT/PC}
+ ({IBM 801}), they now produce the RISC-based {RISC
+ System/6000} and {SP/2} lines.
+
+ Despite {Apple Computer}'s bogus claims for their
+ {PowerPC}-based {Macintosh}es, the first RISC processor used
+ in a {personal computer} was the {Advanced RISC Machine} (ARM)
+ used in the {Acorn} {Archimedes}.
+
+ (1997-06-03)
+
+reduction
+
+ (Or "contraction") The process of transforming an expression
+ according to certain reduction rules. The most important
+ forms are {beta reduction} (application of a {lambda
+ abstraction} to one or more argument expressions) and {delta
+ reduction} (application of a mathematical function to the
+ required number of arguments).
+
+ An {evaluation strategy} (or {reduction strategy}), determines
+ which part of an expression (which redex) to reduce first.
+ There are many such strategies.
+
+ See {graph reduction}, {string reduction}, {normal order
+ reduction}, {applicative order reduction}, {parallel
+ reduction}, {alpha conversion}, {beta conversion}, {delta
+ conversion}, {eta conversion}.
+
+ (1995-02-21)
+
+reduction strategy
+
+ <theory> An {algorithm} for deciding which {redex}(es) to
+ reduce next. Different strategies have different termination
+ properties in the presence of {recursive} functions or values.
+
+ See {string reduction}, {normal order reduction}, {applicative
+ order reduction}, {parallel reduction}
+
+ (1995-05-09)
+
+redundancy
+
+ 1. <architecture, parallel> The provision of multiple
+ interchangeable components to perform a single function in
+ order to provide resilience (to cope with failures and
+ errors). Redundancy normally applies primarily to hardware.
+ For example, a {cluster} may contain two or three computers
+ doing the same job. They could all be active all the time
+ thus giving extra performance through {parallel processing}
+ and {load balancing}; one could be active and the others
+ simply monitoring its activity so as to be ready to take over
+ if it failed ("warm standby"); the "spares" could be kept
+ turned off and only switched on when needed ("cold standby").
+ Another common form of hardware redundancy is {disk
+ mirroring}.
+
+ 2. <data, communications, storage> {data redundancy}.
+
+ (1995-05-09)
+
+Redundant Array of Independent Disks
+
+ <storage, architecture> (RAID) A standard naming convention
+ for various ways of using multiple disk drives to provide
+ redundancy and distributed I/O.
+
+ The original ("..Inexpensive..") term referred to the 3.5 and
+ 5.25 inch disks used for the first RAID system but no longer
+ applies. As {solid state drives} are becoming a practical
+ repacement for magnetic disks, "RAID" is sometimes expanded as
+ "Redundant Array of Independent Drives".
+
+ The following standard RAID specifications exist:
+
+ RAID 0 Non-redundant striped array
+ RAID 1 Mirrored arrays
+ RAID 2 Parallel array with ECC
+ RAID 3 Parallel array with parity
+ RAID 4 Striped array with parity
+ RAID 5 Striped array with rotating parity
+
+ RAID originated in a project at the computer science
+ department of the {University of California at Berkeley},
+ under the direction of Professor Katz, in conjunction with
+ Professor {John Ousterhout} and Professor {David Patterson}.
+ A prototype disk array file server with a capacity of 40
+ GBytes and a sustained bandwidth of 80 MBytes/second was
+ interfaced to a 1 Gb/s {local area network}. It was planned
+ to extend the storage array to include automated {optical
+ disks} and {magnetic tapes}.
+
+ {(ftp://wuarchive.wustl.edu/doc/techreports/berkeley.edu/raid/raidPapers)}.
+ {(http://HTTP.CS.Berkeley.EDU/projects/parallel/research_summaries/14-Computer-Architecture/)}.
+
+ ["A Case for Redundant Arrays of Inexpensive Disks (RAID)",
+ "D. A. Patterson and G. Gibson and R. H. Katz", Proc ACM
+ SIGMOD Conf, Chicago, IL, Jun 1988].
+
+ ["Introduction to Redundant Arrays of Inexpensive Disks
+ (RAID)", "D. A. Patterson and P. Chen and G. Gibson and
+ R. H. Katz", IEEE COMPCON 89, San Francisco, Feb-Mar 1989].
+
+ (2012-08-26)
+
+Redundant Array of Independent Drives
+
+ {Redundant Arrays of Independent Disks}
+
+Redundant Array of Inexpensive Disks
+
+ {Redundant Arrays of Independent Disks}
+
+Redundant Array of Inexpensive Servers
+
+ <architecture> (RAIS) The use of multiple {servers} to provide
+ the same service in such a way that service will still be
+ available if one or more of the servers fails. The term may
+ or may not imply some kind of {load balancing} between the
+ servers. See {cluster}.
+
+ The term "RAIS" follows {RAID}, which describes schemes for
+ resilient disk storage.
+
+ (2007-02-28)
+
+Redundant Arrays of Inexpensive Disks
+
+ {Redundant Arrays of Independent Disks}
+
+red wire
+
+ <jargon, hardware> (IBM) Patch wires installed by programmers
+ who have no business mucking with the hardware. It is said
+ that the only thing more dangerous than a hardware guy with a
+ code patch is a {softy} with a soldering iron.
+
+ Compare {blue wire}, {yellow wire}, {purple wire}.
+
+ [{Jargon File}]
+
+ (1994-12-23)
+
+red zone
+
+ <networking> An environment located between internal and
+ external {firewalls} where software and hardware are deployed
+ to enable access to {extranet} applications.
+
+ Compare {De-Militarised Zone}.
+
+ (1997-11-05)
+
+re-engineering
+
+ The examination and modification of a system to reconstitute
+ it in a new form and the subsequent implementation of the new
+ form.
+
+ {(http://erg.abdn.ac.uk/users/brant/sre)}.
+
+ (1994-12-23)
+
+re-entrant
+
+ <programming> Used to describe code which can have multiple
+ simultaneous, interleaved, or nested invocations which will
+ not interfere with each other. This is important for
+ {parallel processing}, {recursive} functions or subroutines,
+ and {interrupt handling}.
+
+ It is usually easy to arrange for multiple invocations
+ (e.g. calls to a subroutine) to share one copy of the code and
+ any read-only data but, for the code to be re-entrant, each
+ invocation must use its own copy of any modifiable data (or
+ synchronised access to shared data). This is most often
+ achieved using a {stack} and allocating local variables in a
+ new {stack frame} for each invocation. Alternatively, the
+ caller may pass in a pointer to a block of memory which that
+ invocation can use (usually for outputting the result) or the
+ code may allocate some memory on a {heap}, especially if the
+ data must survive after the routine returns.
+
+ Re-entrant code is often found in system software, such as
+ {operating systems} and {teleprocessing monitors}. It is also
+ a crucial component of {multithreaded} programs where the term
+ "thread-safe" is often used instead of "re-entrant".
+
+ (1996-12-21)
+
+refactoring
+
+ <object-oriented, programming> Improving a computer {program}
+ by reorganising its internal structure without altering its
+ external behaviour.
+
+ When software developers add new features to a program, the
+ code degrades because the original program was not designed
+ with the extra features in mind.
+
+ This problem could be solved by either rewriting the existing
+ code or working around the problems which arise when adding
+ the new features. Redesigning a program is extra work, but
+ not doing so would create a program which is more complicated
+ than it needs to be. Refactoring is a collection of
+ techniques which have been designed to provide an alternative
+ to the two situations mentioned above.
+
+ The techniques enable programmers to restructure code so
+ that the design of a program is clearer. It also allows
+ programmers to extract {reusable components}, streamline a
+ program, and make additions to the program easier to
+ implement.
+
+ Refactoring is usually done by renaming {methods}, moving
+ {fields} from one {class} to another, and moving code into a
+ separate method.
+
+ Although it is done using small and simple steps,
+ refactoring a program will vastly improve its design and
+ structure, making it easier to maintain and leading to
+ more robust code.
+
+ {"Refactoring, Reuse & Reality" by Bill Opdyke
+ (http://st-www.cs.uiuc.edu/users/opdyke/wfo.990201.refac.html)}.
+
+ {"Refactoring, a first example" by Martin Fowler
+ (http://aw.com/cseng/titles/0-201-89542-0/vidrefact/vidrefact.html)}.
+
+ (2001-05-02)
+
+REFAL
+
+ {Recursive Functional Algorithmic Language}
+
+REF-ARF
+
+ ["REF-ARF: A System for Solving Problems Stated as
+ Procedures", R.E. Fikes, Artif Intell J 1(1), Spring 1970].
+
+ (1998-06-29)
+
+reference
+
+ {pointer}
+
+reference counting
+
+ <programming> A {garbage collection} technique where each
+ {memory cell} contains a count of the number of other cells
+ which point to it. If this count reaches zero the cell is
+ freed and its {pointers} to other cells are followed to
+ decrement their counts, and so on {recursively}.
+
+ This technique cannot cope with {circular data structures}.
+ Cells in such structures refer (indirectly) to themselves and
+ so will never have a zero reference count. This means they
+ would never be reclaimed, even when there are no references
+ from outside the structure.
+
+ (1995-02-22)
+
+referential integrity
+
+ <database> A collection of properties which should be
+ possessed by data in a {relational database}.
+
+ For example, in a database of family members, if we enter A as
+ a spouse of B, we should also enter B as a spouse of A.
+ Similarly, if we remove one end of the relationship we should
+ also remove the other.
+
+ (1998-02-18)
+
+referentially transparent
+
+ {referential transparency}
+
+referential transparency
+
+ <programming> An expression E is referentially transparent if
+ any subexpression and its value (the result of evaluating it)
+ can be interchanged without changing the value of E. This is
+ not the case if the value of an expression depends on global
+ state which can change value. The most common example of
+ changing global state is assignment to a global variable. For
+ example, if y is a global variable in:
+
+ f(x)
+ { return x+y; }
+
+ g(z)
+ {
+ a = f(1);
+ y = y + z;
+ return a + f(1);
+ }
+
+ function g has the "{side-effect}" that it alters the value of
+ y. Since f's result depends on y, the two calls to f(1) will
+ return different results even though the argument is the same.
+ Thus f is not referentially transparent. Changing the order
+ of evaluation of the statements in g will change its result.
+
+ {Pure functional languages} achieve referential transparency
+ by forbidding {assignment} to global variables. Each
+ expression is a constant or a function application whose
+ evaluation has no side-effect, it only returns a value and
+ that value depends only on the definition of the function and
+ the values of its arguments.
+
+ We could make f above referentially transparent by passing in
+ y as an argument:
+
+ f(x, y) = x+y
+
+ Similarly, g would need to take y as an argument and return
+ its new value as part of the result:
+
+ g(z, y)
+ {
+ a = f(1, y);
+ y' = y+z;
+ return (a + f(1, y'), y');
+ }
+
+ Referentially transparent programs are more amenable to
+ {formal methods} and easier to reason about because the
+ meaning of an expression depends only on the meaning of its
+ subexpressions and not on the order of evaluation or
+ side-effects of other expressions.
+
+ We can stretch the concept of referential transparency to
+ include input and output if we consider the whole program to
+ be a function from its input to its output. The program as a
+ whole is referentially transparent because it will always
+ produce the same output when given the same input. This is
+ stretching the concept because the program's input may include
+ what the user types, the content of certain files or even the
+ time of day. If we do not consider global state like the
+ contents of files as input, then writing to a file and reading
+ what was written behaves just like assignment to a global
+ variable. However, if we must consider the state of the
+ universe as an input rather than global state then any
+ {deterministic} system would be referentially transparent!
+
+ See also {extensional equality}, {observational equivalence}.
+
+ (1997-03-25)
+
+referer
+
+ <web> A misspelling of "referrer" which somehow
+ made it into the {HTTP} standard. A given {web page}'s
+ referer (sic) is the {URL} of whatever web page contains the
+ link that the user followed to the current page. Most
+ browsers pass this information as part of a request.
+
+ (1998-10-19)
+
+referrer
+
+ {referer}
+
+REFINE
+
+ 1. "Research on Knowledge-Based Software Environments at
+ Kestrel Institute", D.R. Smith et al, IEEE Trans Soft Eng,
+ SE-11(11) (1985). E-mail: <maria@kestrel.edu>.
+
+ 2. Cordell Green et al, Stanford U. Uses logic to specify and
+ evolve programs. [same as 1?] Reasoning Systems, Inc.
+ E-mail: <help@reasoning.com>.
+
+Refined C
+
+ (RC) An extension of C to directly specify data access rights
+ so that flow analysis, and hence automatic parallelisation, is
+ more effective. Research implementations only. "Refining A
+ Conventional Language For Race-Free Specification Of Parallel
+ Algorithms," H.G. Dietz et al, Proc 1984 Intl Conf Parallel
+ Proc, pp.380-382.
+
+Refined Fortran
+
+ (RF) Similar to Refined C. Research implementations only.
+ "Refined Fortran: Another Sequential Language for Parallel
+ Programming," H.G. Dietz et al, Proc 1986 Intl Conf Parallel
+ Proc, pp.184-191.
+
+reflexive
+
+ <theory> A {relation} R is reflexive if, for all x, x R x.
+
+ {Equivalence relations}, {pre-orders}, {partial orders} and
+ {total orders} are all reflexive.
+
+ (1999-01-28)
+
+reflexive domain
+
+ A domain satisfying a recursive domain equation.
+ E.g. D = D -> D.
+
+Reflexive transitive closure
+
+ Two elements, x and y, are related by the reflexive transitive
+ closure, R+, of a relation, R, if they are related by the
+ transitive closure, R*, or they are the same element.
+
+RefLisp
+
+ <language> A small {Lisp} {interpreter} written in {C++} by
+ Bill Birch of {Bull}, UK. RefLisp has a built-in {web
+ server}, {Wiki}, {LISP server pages}, {SQL Databases}, {XML
+ parser}, {MD5} hashing, {regular expressions}, {reference
+ counting} and {mark-sweep garbage collection}.
+
+ RefLisp has {shallow-binding} and {dynamic scope} with
+ optional support for {lexical scope}, {Common Lisp}
+ compatibility and for {indefinite extent} {Scheme} programs.
+
+ RefLisp is distributed under the {GPL}.
+
+ Latest version: 5.0 Beta, as of 2005-01-19.
+
+ {RefLisp Home (http://sourceforge.net/projects/reflisp/)}.
+
+ (2005-02-08)
+
+refresh
+
+ 1. <storage> {DRAM refresh}.
+
+ 2. <hardware> {screen refresh}.
+
+ (1998-10-19)
+
+refreshable braille display
+
+ {braille display}
+
+refreshable display
+
+ {braille display}
+
+refresh rate
+
+ <hardware> (Or "vertical refresh rate", "vertical scan rate")
+ The maximum number of {frames} that can be displayed on a
+ {monitor} in a second, expressed in {Hertz}.
+
+ The scan rate is controlled by the vertical sync signal
+ generated by the {video controller}, ordering the monitor to
+ position the {electron gun} at the upper left corner of the
+ {raster}, ready to paint another frame. It is limited by the
+ monitor's maximum {horizontal scan rate} and the {resolution},
+ since higher resolution means more {scan lines}. Increasing
+ the refresh rate decreases flickering, reducing eye strain,
+ but few people notice any change above 60-72 Hz.
+
+ (1999-08-01)
+
+refuctoring
+
+ <humour, programming> Taking a well-designed piece of {code} and,
+ through a series of small, reversible changes, making it
+ completely unmaintainable by anyone except yourself. The term is
+ a humourous play on the term {refactoring} and was coined by Jason
+ Gorman in a pub in 2002.
+
+ Refuctoring techniques include:
+
+ Using Pig Latin as a naming convention.
+
+ Stating The Bleeding Obvious - writing comments that paraphrase
+ the code (e.g., "declare an integer called I with an initial value
+ of zero").
+
+ Module Gravity Well - adding all new code to the biggest module.
+
+ Unique Modeling Language - inventing your own visual notation.
+
+ Treasure Hunt - Writing code consisting mostly of references to
+ other code and documents that reference other documents.
+
+ Rainy Day Module - writing spare code just in case somebody needs
+ it later.
+
+ {Waterfall 2006 presentation
+ (http://www.waterfall2006.com/gorman.html)}.
+
+ (2013-12-01)
+
+refutable
+
+ <programming> In {lazy functional languages}, a refutable pattern
+ is one which may fail to match. An expression being matched
+ against a refutable pattern is first evaluated to {head normal
+ form} (which may fail to terminate) and then the top-level
+ constructor of the result is compared with that of the pattern.
+ If they are the same then any arguments are matched against the
+ pattern's arguments otherwise the match fails.
+
+ An irrefutable pattern is one which always matches. An attempt to
+ evaluate any {variable} in the pattern forces the pattern to be
+ matched as though it were refutable which may fail to match
+ (resulting in an error) or fail to terminate.
+
+ Patterns in {Haskell} are normally refutable but may be made
+ irrefutable by prefixing them with a tilde (~). For example,
+
+ (\ (x,y) -> 1) undefined ==> undefined
+ (\ ~(x,y) -> 1) undefined ==> 1
+
+ Patterns in {Miranda} are refutable, except for {tuples} which are
+ irrefutable. Thus
+
+ g [x] = 2
+ g undefined ==> undefined
+
+ f (x,y) = 1
+ f undefined ==> 1
+
+ Pattern bindings in local definitions are irrefutable in both
+ languages:
+
+ h = 1 where [x] = undefined ==> 1
+
+ Irrefutable patterns can be used to simulate {unlifted products}
+ because they effectively ignore the top-level constructor of the
+ expression being matched and consider only its components.
+
+ (2013-11-03)
+
+regex
+
+ The {GNU} {regular expression} matching library. See also
+ {Rx}.
+
+regexp
+
+ 1. {regular expression}.
+
+ 2. Name of a well-known PD regexp-handling package in portable
+ C, written by revered {Usenet}ter Henry Spencer
+ <henry@zoo.toronto.edu>.
+
+ [{Jargon File}]
+
+Regina
+
+ <standard> A widely-used {open source} {Rexx} {interpreter} by
+ Anders Christensen <anders@pvv.unit.no>, ported to many
+ {platforms} including {Unix}, {Windows 95}, {Windows NT},
+ {OS/2}. Regina is currently maintained by Mark Hessling.
+
+ Regina conforms almost completely to Rexx Language Level 4.00,
+ with some Rexx SAA API extensions. It is distributed under
+ the GNU {General Public License}.
+
+ Latest version: 2.0+, as of 2001-03-30.
+
+ {Home {http://lightlink.com/hessling/)}.
+
+ {Usenet} newsgroup: {news:comp.lang.rexx}.
+
+ (2001-03-30)
+
+regional network
+
+ {mid-level network}
+
+register
+
+ 1. One of a small number of high-speed memory locations in a
+ computer's {CPU}. Registers differ from ordinary
+ {random-access memory} in several respects:
+
+ There are only a small number of registers (the "register
+ set"), typically 32 in a modern processor though some,
+ e.g. {SPARC}, have as many as 144. A register may be directly
+ addressed with a few bits. In contrast, there are usually
+ millions of words of main memory (RAM), requiring at least
+ twenty bits to specify a memory location. Main memory
+ locations are often specified indirectly, using an {indirect
+ addressing} mode where the actual memory address is held in a
+ register.
+
+ Registers are fast; typically, two registers can be read and a
+ third written -- all in a single cycle. Memory is slower; a
+ single access can require several cycles.
+
+ The limited size and high speed of the register set makes it
+ one of the critical resources in most computer architectures.
+ {Register allocation}, typically one phase of the {back-end},
+ controls the use of registers by a compiled program.
+
+ See also {accumulator}, {FUBAR}, {orthogonal}, {register
+ dancing}, {register allocation}, {register spilling}.
+
+ 2. An addressable location in a {memory-mapped} peripheral
+ device. E.g. the transmit data register in a {UART}.
+
+register allocation
+
+ <compiler, algorithm> The phase of a {compiler} that
+ determines which values will be placed in {registers}.
+ Register allocation may be combined with {register
+ assignment}.
+
+ This problem can be shown to be isomorphic to {graph
+ colouring} by relating values to nodes in the graph and
+ registers to colours. Values (nodes) which must be valid
+ simultaneously are linked by edges and cannot be stored in the
+ same register (coloured the same).
+
+ See also {register dancing} and {register spilling}.
+
+ [Preston Briggs, PhD thesis, Rice University, April 1992
+ {"Register Allocation via Graph Coloring"
+ (ftp://ftp.cs.rice.edu/public/preston/thesis.ps.gz)}].
+
+ (2000-12-04)
+
+register assignment
+
+ <compiler, algorithm> The phase of a {compiler} that
+ determines which {register} to use for each program value
+ selected during {register allocation}.
+
+ (2000-12-04)
+
+register dancing
+
+ Many older processor architectures suffer from a serious
+ shortage of general-purpose registers. This is especially a
+ problem for compiler-writers, because their generated code
+ needs places to store temporaries for things like intermediate
+ values in expression evaluation. Some designs with this
+ problem, like the Intel 80x86, do have a handful of
+ special-purpose registers that can be pressed into service,
+ providing suitable care is taken to avoid unpleasant side
+ effects on the state of the processor: while the
+ special-purpose register is being used to hold an intermediate
+ value, a delicate minuet is required in which the previous
+ value of the register is saved and then restored just before
+ the official function (and value) of the special-purpose
+ register is again needed.
+
+ [{Jargon File}]
+
+registered port
+
+ <networking> Any {TCP} or {UDP} {port} with a number in the
+ range 1025 to 65535 (i.e. not a {well-known port}) that is
+ registered with {IANA}.
+
+register set
+
+ All a processor's {registers}. The size and arrangement of a
+ processor's register set is one of the crucial factors in its
+ performance.
+
+register spilling
+
+ <programming, compiler> (By analogy with spilling the contents of
+ an overfull container) When a {compiler} is performing the
+ {register allocation} phase of generating {machine code} and there
+ are more {live variables} than the machine has {registers} and it
+ has to transfer or "spill" some variables from registers to
+ memory.
+
+ (2014-08-02)
+
+Register Transfer Language
+
+ (RTL) 1. A kind of {hardware description language} (HDL) used
+ in describing the {registers} of a computer or digital
+ electronic system, and the way in which data is transferred
+ between them.
+
+ 2. An intermediate code for a machine with an infinite number
+ of {registers}, used for machine-independent optimisation.
+ RTL was developed by Chris Fraser <cwf@research.att.com> and
+ J. Davidson <jwd@virginia.edu> at the {University of Arizona}
+ in the early 1980s. RTL is used by the {GNU} C compiler,
+ {gcc} and by Davidson's {VPCC} (Very Portable C compiler).
+
+ ["Quick Compilers Using Peephole Optimisation", Davidson et
+ al, Soft. Prac. & Exp. 19(1):79-97 (Jan 1989)].
+
+ (1994-11-16)
+
+registry
+
+ {Windows Registry}
+
+regression
+
+ 1. <mathematics> A mathematical method where an {empirical
+ function} is derived from a set of experimental data.
+
+ 2. {regression testing}.
+
+ (1995-03-14)
+
+regression testing
+
+ <programming> Part of the test phase of software development
+ where, as new {modules} are integrated into the system and the
+ added functionality is tested, previously tested functionality
+ is re-tested to assure that no new module has corrupted the
+ system.
+
+ [Bennatan, E.M., "Software Project Management", 2nd edition,
+ McGraw-Hill International, 1992].
+
+ (1995-12-04)
+
+REG-SYMBOLIC
+
+ An early system on the {IBM 704}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1994-12-02)
+
+REGTRAL
+
+ Mentioned in Attribute Grammars, LNCS 323, p.108.
+
+ Relational Language. Clark & Gregory. First parallel logic
+ language to use the concept of committed choice. Forerunner
+ of PARLOG. "A Relational Language for Parallel Programming",
+ K.L. Clark et al, Proc ACM Conf on Functional Prog Langs and
+ Comp Arch, pp.171-178, ACM 1981.
+
+regular expression
+
+ 1. <text, operating system> (regexp, RE) One of the {wild
+ card} patterns used by {Perl} and other languages, following
+ {Unix} utilities such as {grep}, {sed}, and {awk} and editors
+ such as {vi} and {Emacs}. Regular expressions use conventions
+ similar to but more elaborate than those described under
+ {glob}. A regular expression is a sequence of characters with
+ the following meanings (in Perl, other flavours vary):
+
+ An ordinary character (not one of the special characters
+ discussed below) matches that character.
+
+ A backslash (\) followed by any special character matches the
+ special character itself. The special characters are:
+
+ "." matches any character except {newline}; "RE*" (where the
+ "*" is called the "{Kleene star}") matches zero or more
+ occurrences of RE. If there is any choice, the longest
+ leftmost matching string is chosen.
+
+ "^" at the beginning of an RE matches the start of a line and
+ "$" at the end of an RE matches the end of a line.
+
+ [CHARS] matches any one of the characters in CHARS. If the
+ first character of the string is a "^" it matches any
+ character except the remaining characters in the string (and
+ also usually excluding newline). "-" may be used to indicate
+ a range of consecutive {ASCII} characters.
+
+ (RE) matches whatever RE matches and \N, where N is a digit,
+ matches whatever was matched by the RE between the Nth "(" and
+ its corresponding ")" earlier in the same RE. Many flavours
+ use \(RE\) instead of just (RE).
+
+ The concatenation of REs is a RE that matches the
+ concatenation of the strings matched by each RE. RE1 | RE2
+ matches whatever RE1 or RE2 matches.
+
+ \< matches the beginning of a word and \> matches the end of a
+ word. Many flavours use "\b" instead as the special character
+ for "word boundary".
+
+ RE\{M\} matches M occurences of RE. RE\{M,\} matches M or more
+ occurences of RE. RE\{M,N\} matches between M and N occurences.
+ Other flavours use RE\\{M\\} etc.
+
+ Perl provides several "quote-like" {operators} for writing
+ REs, including the common // form and less common {??}.
+
+ A comprehensive survey of regexp flavours is found in Friedl
+ 1997 (see below).
+
+ [Jeffrey E.F. Friedl, "{Mastering Regular Expressions
+ (http://enterprise.ic.gc.ca/~jfriedl/regex/index.html)},
+ O'Reilly, 1997].
+
+ 2. Any description of a {pattern} composed from combinations
+ of {symbols} and the three {operators}:
+
+ Concatenation - pattern A concatenated with B matches a match
+ for A followed by a match for B.
+
+ Or - pattern A-or-B matches either a match for A or a match
+ for B.
+
+ Closure - zero or more matches for a pattern.
+
+ The earliest form of regular expressions (and the term itself)
+ were invented by mathematician {Stephen Cole Kleene} in the
+ mid-1950s, as a notation to easily manipulate "regular sets",
+ formal descriptions of the behaviour of {finite state
+ machines}, in {regular algebra}.
+
+ [S.C. Kleene, "Representation of events in nerve nets and
+ finite automata", 1956, Automata Studies. Princeton].
+
+ [J.H. Conway, "Regular algebra and finite machines", 1971, Eds
+ Chapman & Hall].
+
+ [Sedgewick, "Algorithms in C", page 294].
+
+ (2004-02-01)
+
+Regular Expression Converter
+
+ {CONVERT}
+
+regular graph
+
+ <mathematics> A {graph} in which all {nodes} have the same
+ {degree}.
+
+ (1995-03-07)
+
+rehi
+
+ <chat> Hello again.
+
+ (1995-02-28)
+
+Reid, Brian
+
+ {Brian Reid}
+
+reify
+
+ To regard (something abstract) as a material thing.
+
+ (1995-03-07)
+
+re-image
+
+ <system administration> To re-install a computer's {operating
+ system}, and possibly other software, by writing a {disk
+ image} to the {hard disk}, replacing the entire contents.
+ Re-imaging is quicker, easier and more reliable than going
+ through a complete install but it relies on having a disk
+ image available.
+
+ "Sometimes if your {PC} has a {virus}, the only cure is to
+ re-image it."
+
+ (2007-06-26)
+
+reincarnation, cycle of
+
+ {cycle of reincarnation}
+
+reinvent the wheel
+
+ <jargon> To design or implement a tool equivalent to an
+ existing one or part of one, with the implication that doing
+ so is silly or a waste of time. This is often a valid
+ criticism. On the other hand, automobiles don't use wooden
+ rollers, and some kinds of wheel have to be reinvented many
+ times before you get them right. On the third hand, people
+ reinventing the wheel do tend to come up with the moral
+ equivalent of a trapezoid with an offset axle.
+
+ [{Jargon File}]
+
+ (1997-04-12)
+
+relation
+
+ 1. <mathematics> A subset of the {product} of two sets, R : A
+ x B. If (a, b) is an element of R then we write a R b,
+ meaning a is related to b by R. A relation may be:
+ {reflexive} (a R a), {symmetric} (a R b => b R a),
+ {transitive} (a R b & b R c => a R c), {antisymmetric} (a R b
+ & b R a => a = b) or {total} (a R b or b R a).
+
+ See {equivalence relation}, {partial ordering}, {pre-order},
+ {total ordering}.
+
+ 2. <database> A {table} in a {relational database}.
+
+ (1995-02-28)
+
+relational algebra
+
+ <database, theory> A family of {algebra} with a {well-founded}
+ {semantics} used for modelling the data stored in {relational
+ databases}, and defining queries on it. The main operations
+ of the relational algebra are the {set} operations (such as
+ {union}, {intersection}, and {cartesian product}), selection
+ (keeping only some lines of a {table}) and the {projection}
+ (keeping only some columns).
+
+ The {relational data model} describes how the data is
+ structured.
+
+ {Codd's reduction algorithm} can convert from {relational
+ calculus} to {relational algebra}.
+
+ (1997-02-17)
+
+relational calculus
+
+ <database> An operational methodolgy, founded on {predicate
+ calculus}, dealing with descripitive expressions that are
+ equivalent to the operations of {relational algebra}. {Codd's
+ reduction algorithm} can convert from {relational calculus} to
+ {relational algebra}.
+
+ Two forms of the relational calculus exist: the {tuple
+ calculus} and the {domain calculus}.
+
+ ["An Introduction To Database Systems" (6th ed), C. J. Date,
+ Addison Wesley].
+
+ (1998-10-05)
+
+relational database
+
+ <database> (RDBMS - relational database management system) A
+ {database} based on the {relational model} developed by
+ {E.F. Codd}. A relational database allows the definition of
+ data structures, storage and retrieval operations and
+ {integrity constraints}. In such a database the data and
+ relations between them are organised in {tables}. A table is
+ a collection of rows or {records} and each row in a table
+ contains the same {fields}. Certain fields may be designated
+ as {keys}, which means that searches for specific values of
+ that field will use indexing to speed them up.
+
+ Where fields in two different tables take values from the same
+ set, a {join} operation can be performed to select related
+ records in the two tables by matching values in those fields.
+ Often, but not always, the fields will have the same name in
+ both tables. For example, an "orders" table might contain
+ (customer_id, product_code) pairs and a "products" table might
+ contain (product_code, price) pairs so to calculate a given
+ customer's bill you would sum the prices of all products
+ ordered by that customer by joining on the product-code fields
+ of the two tables. This can be extended to joining multiple
+ tables on multiple fields. Because these relationships are
+ only specified at retreival time, relational databases are
+ classed as {dynamic database management system}.
+
+ The first commercial RDBMS was the {Multics Relational Data
+ Store}, first sold in 1978.
+
+ {INGRES}, {Oracle}, {Sybase, Inc.}, {Microsoft Access}, and
+ {Microsoft SQL Server} are well-known database products and
+ companies. Others include {PostgreSQL}, {SQL/DS}, and {RDB}.
+
+ ["Managing Data Bases, Four Critical Factors" Michael
+ M. Gorman, QED Information Sciences, Inc.].
+
+ ["An Introduction To Database Systems" (6th ed) C. J. Date,
+ Addison Wesley (an excellent source of detailed info)].
+
+ ["An End-User's Guide to Data Base" James Martin, Prentice
+ Hall (excellent place to begin learning about DBMS)].
+
+ (2002-06-10)
+
+relational database management system
+
+ {relational database}
+
+relational data model
+
+ <database> (Or "relational model") A {data model} introduced
+ by {E.F. Codd} in 1970, particularly well suited for business
+ data management. In this model, data are organised in
+ {tables}. The set of names of the columns is called the
+ "schema" of the table.
+
+ Here is an example table with the schema (account number,
+ amount) and 3 lines.
+
+ account number amount
+ -------------- ---------
+ 12343243546456 +30000.00
+ 23149875245824 +2345.33
+ 18479827492874 -123.25
+
+ The data can be manipulated using a {relational algebra}.
+ {SQL} is a standard language for talking to a database built
+ on the relational model (a "{relational database}").
+
+ ["A relational model for large shared data banks"
+ Communications of ACM 13:6, pp 377-387].
+
+ (1998-10-05)
+
+relational DBMS
+
+ {relational database}
+
+relational language
+
+ <language> Any kind of {programming language} that specifies
+ output in terms of some property and some arguments. For
+ example, if Tom has two brothers, Dick and Harry, a relational
+ language will respond to the query "Who is Tom's brother?"
+ with either Dick or Harry. Notice that unlike {functional
+ languages}, relational languages do not require a unique
+ output for each {predicate}/argument pair. {Prolog} is the
+ best known relational language.
+
+ (2004-05-17)
+
+relational model
+
+ {relational data model}
+
+RELATIVE
+
+ Early system on IBM 650. Listed in CACM 2(5):16 (May 1959).
+
+relatively prime
+
+ <mathematics> Having no common divisors (greater than 1).
+
+ Two numbers are said to be relativey prime if there is no
+ number greater than unity that divides both of them evenly.
+
+ For example, 10 and 33 are relativly prime. 15 and 33 are not
+ relatively prime, since 3 is a {divisor} of both.
+
+ (1997-03-11)
+
+relative pathname
+
+ <file system> A {path} relative to the {working directory}.
+ Its first character can be anything but the {pathname
+ separator}.
+
+ (1996-11-21)
+
+Relative Record Data Set
+
+ <database> (RRDS) One of the access methods used by {IBM}'s
+ {VSAM}.
+
+ [What is it?]
+
+ (1999-01-12)
+
+RELCODE
+
+ Early system on UNIVAC I or II. Listed in CACM 2(5):16 (May
+ 1959).
+
+release
+
+ <programming> (Or "released version", "baseline") A version of
+ a piece of software which has been made public (as opposed to
+ a version that is in development, or otherwise unreleased).
+
+ A release is either a {major release}, a {revision}, or a
+ {bugfix}.
+
+ Pre-release versions may be called {alpha test}, or {beta
+ test} versions.
+
+ See {change management}.
+
+ (1996-08-04)
+
+released version
+
+ {release}
+
+REL English
+
+ {Rapidly Extensible Language, English}
+
+relevance
+
+ <information science> A measure of how closely a given object
+ (file, {web page}, database {record}, etc.) matches a user's
+ search for information.
+
+ The relevance {algorithms} used in most large web {search
+ engines} today are based on fairly simple word-occurence
+ measurement: if the word "daffodil" occurs on a given page,
+ then that page is considered relevant to a {query} on the word
+ "daffodil"; and its relevance is quantised as a factor of the
+ number of times the word occurs in the page, on whether
+ "daffodil" occurs in title of the page or in its META
+ keywords, in the first {N} words of the page, in a heading,
+ and so on; and similarly for words that a {stemmer} says are
+ based on "daffodil".
+
+ More elaborate (and resource-expensive) relevance algorithms
+ may involve thesaurus (or {synonym ring}) lookup; e.g. it
+ might rank a document about narcissuses (but which may not
+ mention the word "daffodil" anywhere) as relevant to a query
+ on "daffodil", since narcissuses and daffodils are basically
+ the same thing. Ditto for queries on "jail" and "gaol", etc.
+
+ More elaborate forms of thesaurus lookup may involve
+ multilingual thesauri (e.g. knowing that documents in Japanese
+ which mention the Japanese word for "narcissus" are relevant
+ to your search on "narcissus"), or may involve thesauri (often
+ auto-generated) based not on equivalence of meaning, but on
+ word-proximity, such that "bulb" or "bloom" may be in the
+ thesaurus entry for "daffodil".
+
+ {Word spamming} essentially attempts to falsely increase a web
+ page's relevance to certain common searches.
+
+ See also {subject index}.
+
+ (1997-04-09)
+
+reliability
+
+ <systems> An attribute of any system that consistently produces
+ the same results, preferably meeting or exceeding its
+ specifications. The term may be qualified, e.g {software
+ reliability}, {reliable communication}.
+
+ Reliability is one component of {RAS}.
+
+ (2000-08-13)
+
+Reliability, Availability, Serviceability
+
+ <systems, design, hardware, software> (RAS) Three key attributes
+ of a computing system design. See {reliability}, {availability},
+ and {serviceability}.
+
+ The term "RAS" is fairly common in the computing industry
+ (particularly computers and storage) as computing becomes more
+ fundamental. For example, a vehicle may depend on dozens of
+ computers, and the consequences of the failure can be
+ significant (e.g., an ambulance's engine won't start).
+
+ (2000-08-13)
+
+reliable communication
+
+ <communications> Communication where messages are guaranteed
+ to reach their destination complete and uncorrupted and in the
+ order they were sent. This reliability can be built on top of
+ an unreliable {protocol} by adding sequencing information and
+ some kind of {checksum} or {cyclic redundancy check} to each
+ message or {packet}. If the communication fails, the sender
+ will be notified. {Transmission Control Protocol} is a
+ reliable protocol used on {Ethernet}.
+
+ (2004-09-14)
+
+Reliable Data Protocol
+
+ <protocol> (RDP) A {protocol} designed to provide a reliable
+ data transport service for {packet}-based applications such as
+ remote loading and {debugging}. RDP is intended to be simple
+ to implement but still be efficient in environments where
+ there may be long transmission delays and loss or
+ non-sequential delivery of message segments.
+
+ RDP is defined in {RFC 908}.
+
+ (2004-09-14)
+
+religion of CHI
+
+ /ki:/ [Case Western Reserve University] Yet another hackish
+ parody religion (see also {Church of the SubGenius},
+ {Discordianism}). In the mid-70s, the canonical "Introduction
+ to Programming" courses at CWRU were taught in {ALGOL}, and
+ student exercises were punched on cards and run on a Univac
+ 1108 system using a homebrew operating system named CHI. The
+ religion had no doctrines and but one ritual: whenever the
+ worshipper noted that a digital clock read 11:08, he or she
+ would recite the phrase "It is 11:08; ABS, ALPHABETIC, ARCSIN,
+ ARCCOS, ARCTAN." The last five words were the first five
+ functions in the appropriate chapter of the ALGOL manual; note
+ the special pronunciations /obz/ and /ark'sin/ rather than the
+ more common /ahbz/ and /ark'si:n/. Using an alarm clock to
+ warn of 11:08's arrival was {considered harmful}.
+
+ [{Jargon File}]
+
+religious issues
+
+ Questions which seemingly cannot be raised without touching
+ off {holy wars}, such as "What is the best operating system
+ (or editor, language, architecture, shell, mail reader, news
+ reader)?", "What about that Heinlein guy, eh?", "What should
+ we add to the new Jargon File?" See {holy wars}; see also
+ {theology}, {bigot}.
+
+ This term is a prime example of {ha ha only serious}. People
+ actually develop the most amazing and religiously intense
+ attachments to their tools, even when the tools are
+ intangible. The most constructive thing one can do when one
+ stumbles into the crossfire is mumble {Get a life!} and leave
+ - unless, of course, one's *own* unassailably rational and
+ obviously correct choices are being slammed.
+
+ (1996-08-16)
+
+REM
+
+ <programming> (From "remark") The {keyword} used in {BASIC} to
+ introduce a {comment} (which continues to the end of the
+ line). {MS-DOS} probably borrowed it from {BASIC}. Might be
+ used in the form "REM out" meaning to {comment out}.
+
+ (1998-04-27)
+
+remailer
+
+ {anonymous remailer}
+
+Remote Access Services
+
+ <communications> (RAS) A service provided by {Windows NT}
+ which allows most of the services which would be available on
+ a {network} to be accessed over a {modem} link. The service
+ includes support for {dialup} and {logon}, and then presents
+ the same network interface as the normal network drivers
+ (albeit slightly slower!). It is not necessary to run Windows
+ NT on the {client} - there are client versions for other
+ {Windows} {operating systems}.
+
+ [What services?]
+
+ (1996-08-14)
+
+Remote Database Access
+
+ <database, standard> (RDBA) A standard permitting the exchange
+ of information between different {DBMS} systems.
+
+ (1998-09-23)
+
+Remote Desktop Protocol
+
+ <protocol> (RDP) A {Microsoft} {protocol} that provides remote
+ display and input for {Windows}.
+
+ RDP's {video driver} renders display output by sending packets
+ to the client which translates them into corresponding
+ Microsoft Win32 graphics device interface API calls. Client
+ mouse and keyboard events are redirected from the client to
+ virtual keyboard and mouse drivers on the server.
+
+ RDP 4.0 was introduced with {Windows NT} Server 4.0, Terminal
+ Server Edition. Windows 2000 Terminal Services included RDP
+ 5.0. The Terminal Services Advanced Client (TSAC), an RDP
+ client based on an {ActiveX control}, also supports RDP 5.0.
+ RDP 5.0 provides enhanced performance over low-speed
+ connections. Windows XP uses RDP 5.1 and includes Remote
+ Desktop Web Connection, which is an updated version of the
+ TSAC.
+
+ RDP extends the {ITU T.120} protocols, allowing separate
+ virtual channels for device communication and presentation
+ data from the server, as well as encrypted mouse and keyboard
+ data.
+
+ Compare: {VNC}.
+
+ {MSDN RDP
+ (http://msdn.microsoft.com/library/en-us/termserv/termserv/remote_desktop_protocol.asp)}.
+
+ {thinclient.net
+ (http://thinclient.net/technology/RDP_Features_and_Performance.htm)}.
+
+ (2004-09-14)
+
+remote echo
+
+ <communications> (Obsolete: "full-duplex") A mode of operation
+ of communicating programs or devices in which the sending
+ system does not display the characters the user enters, but
+ only sends them to the remote system which then "echoes" them
+ back to be displayed to the user. This lets the operator see
+ not only typing errors, but also transmission errors. This is
+ now the usual mode of most systems with remote users.
+
+ Contrast: {local echo}.
+
+ (2000-03-30)
+
+Remote Job Entry
+
+ <operating system> (RJE) A system, widely used in the mid/late
+ 1960s, for submitting {jobs} to {mainframes} like the {IBM
+ 360} under {OS/MFT}. Communication with the {computer
+ operator} was via the keyboard and later via {CRTs}.
+
+ (1999-03-26)
+
+remote login
+
+ <networking> A {client-server} program and {protocol} that
+ provides an interactivel {command line interface} to a remote
+ computer, using a {protocol} over a computer network,
+ simulating a locally attached {terminal}.
+
+ {rlogin} is the {BSD Unix} program and protocol for this,
+ {telnet} is an earlier, more widely implemented protocol.
+
+ (1999-03-26)
+
+Remote Method Invocation
+
+ <programming> (RMI) Part of the {Java} {programming language}
+ {library} which enables a Java program running on one computer
+ to access the {objects} and {methods} of another Java program
+ running on a different computer.
+
+ {Home
+ (http://java.sun.com/products/jdk/1.1/docs/guide/rmi/index.html)}.
+
+ (1997-09-04)
+
+remote monitoring
+
+ <protocol> (RMON) A {network management} {protocol} that
+ allows network information to be gathered at a single
+ computer. Whereas {SNMP} gathers network data from a single
+ type of {Management Information Base} (MIB), RMON 1 defines
+ nine additional MIBs that provide a much richer set of data
+ about network usage. For RMON to work, network devices, such
+ as {hubs} and {switches}, must be designed to support it.
+
+ The newest version of RMON, RMON 2, provides data about
+ {traffic} at the {network layer} in addition to the {physical
+ layer}. This allows administrators to analyse traffic by
+ protocol.
+
+ (2003-09-15)
+
+Remote Operations Service Element
+
+ <networking> (ROSE) A sub-layer of {protocol layer} six
+ ({presentation layer}) in the {OSI} seven layer model which
+ provides {SASE} for remote operations.
+
+ Documents: {ITU} Rec. X.229 ({ISO} 9072-2), ITU Rec. X.219
+ (ISO 9072-1).
+
+ (1997-12-07)
+
+Remote Procedure Call
+
+ <networking, programming> (RPC) A {protocol} which allows a
+ program running on one {host} to cause code to be executed on
+ another host without the programmer needing to explicitly code
+ for this. RPC is an easy and popular paradigm for
+ implementing the {client-server} model of {distributed
+ computing}. An RPC is initiated by the caller (client)
+ sending request message to a remote system (the server) to
+ execute a certain procedure using arguments supplied. A
+ result message is returned to the caller. There are many
+ variations and subtleties in various implementations,
+ resulting in a variety of different (incompatible) RPC
+ {protocols}.
+
+ {Sun} RPC is defined in {RFC 1057} and {ONC} RPC in {RFC
+ 1831}.
+
+ (2003-06-04)
+
+Remote Reference Layer
+
+ <protocol> (RRL) Part of {Java}'s {Remote Method Invocation}
+ protocol. RRL exists in both the RMI {client} and {server}.
+ It is used by the {stub} or {skeleton} {protocol layer} and
+ uses the {transport layer}. RRL is reponsible for
+ transport-independent functioning of RMI, such as {connection
+ management} or {unicast}/{multicast} {object invocation}.
+
+ [Specification URL?]
+
+ (1997-12-03)
+
+Remote Spooling Communication Subsystem
+
+ <communications> (RSCS) A {networking} {protocol} used
+ primarily on {Bitnet}.
+
+ [Details?]
+
+ (1996-02-04)
+
+Remote Write Protocol
+
+ <chat, protocol> (RWP) A proposed {Internet} {protocol} for
+ exchanging short messages between terminals.
+
+ The RWP proposal is detailed in {RFC 1756}.
+
+ (1996-09-08)
+
+removable disk
+
+ {removable hard disk}
+
+removable hard disk
+
+ <storage> A type of {magnetic disk}, or possibly
+ {magneto-optical disk} which is not permanently attached to
+ the {disk drive} (not a {fixed disk}) but which can be taken
+ out and replaced, allowing many disks to be used in the same
+ drive.
+
+ The term "removable disk" would seem to be applicable to
+ {floppy disks} but is generally reserved for {hard disks} in
+ suitable cartridges such as those made by {Syquest}, {Iomega}
+ and others.
+
+ Removable disk packs were common on {minicomputers} such as
+ the {PDP-11} in use in the 1970s except that the drives were
+ the size of {washing machines} and the disk packs as big as
+ car wheels. Removable disks became popular on
+ {microcomputers} in the 1990s as a cheap way of expanding disk
+ space, transporting large amounts of data between computers
+ and storing {backups}. Large, cheap fixed hard disks and {USB
+ memory sticks} have made removable disks less attractive.
+
+ (2007-06-14)
+
+rendering
+
+ <graphics, text> The conversion of a high-level object-based
+ description into a graphical image for display.
+
+ For example, {ray-tracing} takes a mathematical model of a
+ three-dimensional object or scene and converts it into a
+ {bitmap} image. Another example is the process of converting
+ {HTML} into an image for display to the user.
+
+ (2001-02-06)
+
+RenderMan Shading Language
+
+ ["The RenderMan Companion", S. Upstill, A-W 1989, chaps
+ 13-15].
+
+rendezvous
+
+ 1. In {Ada}, the method of synchronising the activity of
+ different tasks.
+
+ 2. Query language, close to natural English.
+
+ ["Seven Steps to Rendezvous with the Casual User", E. Codd in
+ Data Base Management, J.W. Klimbie et al eds, N-H 1974,
+ pp.179-199].
+
+REP
+
+ <programming> A directive used in {IBM} {object code} {card
+ decks} (and later {PTF Tapes}) to REPlace fragments of already
+ assembled or compiled object code prior to {link edit}.
+ Recompiling or reassembling the {source code} to produce a
+ whole new object module was only possible if the {source code}
+ was available, which it rarely was (if you had the object you
+ were lucky!) It was also quicker to apply incremental changes
+ with REP cards and they also circumvented the {checksums} and
+ {card sequence numbers} present in the object code.
+
+ (1998-07-16)
+
+repeat
+
+ {repeat loop}
+
+repeater
+
+ <networking, communications> A network or communications
+ device which propagates electrical signals from one cable to
+ another, amplifying them to restore them to full strength in
+ the process. Repeaters are used to counter the attenuation
+ which occurs when signals travel long distances (e.g. across
+ an ocean).
+
+ A network repeater is less intelligent than a {bridge},
+ {gateway} or {router} since it works at the {physical layer}.
+
+ (1998-07-16)
+
+repeating group
+
+ <database> Any {attribute} that can have multiple values
+ associated with a single instance of some {entity}. For
+ example, a book might have multiple authors.
+
+ Such a "-to-many" relationship might be represented in an
+ unnormalised {relational database} as multiple author columns
+ in the book table or a single author(s) column containing a
+ string which was a list of authors. Converting this to "first
+ normal form" is the first step in {database normalisation}.
+ Each author of the book would appear in a separate {row} along
+ with the book's {primary key}. Later nomalisation stages
+ would move the book-author relationship into a separate table
+ to avoid repeating other book attibutes (e.g. title,
+ publisher) for each author.
+
+ (2005-07-28)
+
+repeat loop
+
+ <programming> (Or "do loop") A {loop} construct found in many
+ {procedural languages} which repeatedly executes some
+ instructions while a {condition} is true.
+
+ Repeat loops are found in {Perl}, {Pascal}, {BASIC} and {C}.
+ The initial {keyword} may be "repeat" or "do" and the
+ condition may be introduced with a "while" or "until" keyword.
+
+ In constrast to a {while} loop, the "loop body" is executed
+ once before the condition is tested. This is useful when the
+ condition depends on the action of the loop body. In the
+ following BASIC loop "Hello" is printed once despite the fact
+ that the condition is false;
+
+ i = 2
+ repeat
+ print "Hello"
+ i = i+1
+ until i>0
+
+ See also {while loop} and {for loop}.
+
+ (1999-05-06)
+
+repetitive strain disorder
+
+ {overuse strain injury}
+
+repetitive strain injury
+
+ {overuse strain injury}
+
+REPL
+
+ 1. <language, LISP, programming> {read-eval-print loop}.
+
+ 2. <language> {Restricted EPL}.
+
+ (2003-06-23)
+
+replacement algorithm
+
+ The method used to determine which entry in an associative
+ {cache} to flush to main memory when it is desired to cache a
+ new block of data. The "least recently used" algorithm
+ flushed the block which has not been accessed for the longest
+ time. A random replacement algorithm picks any block with
+ equal probability.
+
+Replay
+
+ {Acorn Computers}' {full-motion video} system written by Roger
+ Wilson. Video and sound information are stored in compressed
+ form. Compression is relatively slow but decompression is
+ done in {real-time} with quality and {frame-rate} varying with
+ the processing power available, the size of the picture and
+ whether it appears in a {window} or uses the whole screen.
+
+ (1994-11-09)
+
+replication
+
+ <database, networking> Creating and maintaining a duplicate
+ copy of a database or file system on a different computer,
+ typically a {server}. The term usually implies the
+ intelligent copying of parts of the source database which have
+ changed since the last replication with the destination.
+
+ Replication may be one-way or two-way. Two-way replication is
+ much more complicated because of the possibility that a
+ replicated object may have been updated differently in the two
+ locations in which case some method is needed to reconcile the
+ different versions.
+
+ For example, {Lotus Notes} can automatically distribute
+ document databases across telecommunications networks. Notes
+ supports a wide range of network {protocols} including {X25}
+ and {Internet} {TCP/IP}.
+
+ Compare {mirror}. See also {rdist}.
+
+ (1997-12-12)
+
+replicator
+
+ Any construct that acts to produce copies of itself; this
+ could be a living organism, an idea (see {meme}), a program
+ (see {quine}, {worm}, {wabbit}, {fork bomb}, and {virus}), a
+ pattern in a {cellular automaton} (see {life}), or
+ (speculatively) a robot or {nanobot}. It is even claimed by
+ some that {Unix} and {C} are the symbiotic halves of an
+ extremely successful replicator; see {Unix conspiracy}.
+
+ [{Jargon File}]
+
+reply
+
+ {followup}
+
+Repondez s'il vous plait
+
+ {Répondez s'il vous plait}
+
+Report Program Generator
+
+ <tool> (RPG) An {IBM} programming language developed by {Wilf
+ Hey} at {IBM} in 1965 for easy production of sophisticated
+ large system reports.
+
+ RPG is a {3GL} similar to {COBOL}, but more concise and
+ supposedly easier for non-programmers to use. It processes
+ its input one line at a time and does not treat tables as
+ {conceptual entities}.
+
+ It was popular on {System 34}/36 {minicomputers}.
+
+ Versions: RPG II, RPG III, RPG/400 for IBM {AS/400}. {MS-DOS}
+ versions by {California Software} and {Lattice}. {Unix}
+ version by {Unibol}. {Cross-platform} version by {J & C
+ Migrations} runs on {MS-DOS}, {Windows}, {AIX}, {HP-UX}, and
+ {OS/390}.
+
+ See also {CL}, {OCL}.
+
+ (2004-08-24)
+
+repository
+
+ 1. <database> See {data dictionary}.
+
+ 2. <programming> The core of a {CASE} tool, typically a {DBMS}
+ where all development documents are stored.
+
+ (1999-04-27)
+
+Representation Language Language
+
+ <language> (RLL) A {frame language}.
+
+ ["A Representation Language Language", R. Greiner and
+ D.B. Lenat, Proc AAAI-80, 1980].
+
+ (2003-06-02)
+
+Request For Comments
+
+ <standard> (RFC) One of a series, begun in 1969, of numbered
+ {Internet} informational documents and {standards} widely
+ followed by commercial software and {freeware} in the
+ {Internet} and {Unix} communities. Few RFCs are standards but
+ all Internet standards are recorded in RFCs. Perhaps the
+ single most influential RFC has been {RFC 822}, the Internet
+ {electronic mail} format standard.
+
+ The RFCs are unusual in that they are floated by technical
+ experts acting on their own initiative and reviewed by the
+ Internet at large, rather than formally promulgated through an
+ institution such as {ANSI}. For this reason, they remain
+ known as RFCs even once adopted as standards.
+
+ The RFC tradition of pragmatic, experience-driven,
+ after-the-fact standard writing done by individuals or small
+ working groups has important advantages over the more formal,
+ committee-driven process typical of {ANSI} or {ISO}.
+
+ Emblematic of some of these advantages is the existence of a
+ flourishing tradition of "joke" RFCs; usually at least one a
+ year is published, usually on April 1st. Well-known joke RFCs
+ have included 527 ("ARPAWOCKY", R. Merryman, UCSD; 22 June
+ 1973), 748 ("Telnet Randomly-Lose Option", Mark R. Crispin; 1
+ April 1978), and 1149 ("A Standard for the Transmission of IP
+ Datagrams on Avian Carriers", D. Waitzman, BBN STC; 1 April
+ 1990). The first was a Lewis Carroll pastiche; the second a
+ parody of the {TCP/IP} documentation style, and the third a
+ deadpan skewering of standards-document legalese, describing
+ protocols for transmitting Internet data packets by carrier
+ pigeon.
+
+ The RFCs are most remarkable for how well they work - they
+ manage to have neither the ambiguities that are usually rife
+ in informal specifications, nor the committee-perpetrated
+ {misfeatures} that often haunt formal standards, and they
+ define a network that has grown to truly worldwide
+ proportions.
+
+ {rfc.net (http://rfc.net/)}.
+ {W3
+ (http://w3.org/hypertext/DataSources/Archives/RFC_sites.html)}.
+ {JANET UK FTP (ftp://nic.ja.net/pub/newsfiles/JIPS/rfc)}.
+ {Imperial College, UK FTP (ftp://src.doc.ic.ac.uk/rfc/)}.
+ {Nexor UK (http://nexor.com/public/rfc/index/rfc.html)}.
+ {Ohio State U
+ (http://cis.ohio-state.edu/hypertext/faq/usenet/top.html)}.
+
+ See also {For Your Information}, {STD}.
+
+ (1997-11-10)
+
+request for proposal
+
+ <programming> (RFP) The publication by a prospective software
+ purchaser of details of the required system in order to
+ attract offers by software developers to supply it. Software
+ development under contract starts with the selection of the
+ software developer by the customer. A request for proposal
+ (also called in Britain an "invitation to tender") is the
+ beginning of the selection process.
+
+ [Bennatan, E.M., "Software Project Management", 2nd edition,
+ McGraw-Hill International, 1992].
+
+ (1995-12-04)
+
+Request For Technology
+
+ (RFT) The process established by the {OSF} to get proposals
+ for new standards.
+
+ (1994-11-30)
+
+Required-COBOL
+
+ A minimal subset of {COBOL} developed in 1961. It was later
+ dropped entirely.
+
+ [Sammet 1969, p. 339].
+
+ (1994-11-30)
+
+requirements
+
+ <programming> The first stage of software development which
+ defines what the potential users want the system to do. In
+ modern methods these requirements should be testable, and will
+ usually be traceable in later development stages. A common
+ feature of nearly all software is that the requirements change
+ during its lifetime.
+
+ See {software life-cycle}.
+
+ (1995-11-11)
+
+Requirements Acquisition and Controlled Evolution
+
+ <programming, project> (RACE) A "back to basics" approach to
+ {requirements engineering}. The method, is being pieced
+ together through a series of intermediate research studies.
+ In essence, the approach has been to establish requirements
+ for RACE, identify individual techniques that meet those
+ requirements, experiment with the combined use of the
+ techniques, and finally assemble the method. In practice,
+ RACE has been influenced significantly by Checkland and
+ Wilson's {Soft Systems Methodology} (SSM) and this forms the
+ core of the method.
+
+ (1995-11-21)
+
+requirements analysis
+
+ <project> The process of reviewing a business's processes to
+ determine the business needs and {functional requirements}
+ that a system must meet.
+
+ (1996-08-01)
+
+Requirements Engineering
+
+ <programming> The task of capturing, structuring, and
+ accurately representing the user's {requirements} so that they
+ can be correctly embodied in systems which meet those
+ requirements (i.e. are of good quality).
+
+ {DOORS} is one product to help with this task.
+
+ (1995-11-11)
+
+Research Systems, Inc.
+
+ (RSI) Distributors of {Interactive Data Language} (IDL).
+
+ {(ftp://gateway.rs.inc.com/pub/)}. E-mail: <info@rsinc.com>.
+
+ (1994-10-07)
+
+ResEdit
+
+ <programming, tool> A free {resource editor} for {Win32}
+ programs. ResEdit can create {dialogs}, {icon}, {version
+ information} or other types of resources. Output files can be
+ compiled by any Win32 {compiler} like {MinGW} and Microsoft
+ {Visual C++}.
+
+ Latest version: 1.3.5, as of 2007-03-24.
+
+ {(http://www.resedit.net/)}.
+
+ (2007-03-24)
+
+reserved memory
+
+ <storage> The address range 640-1024 {kilobytes} on an {IBM
+ PC}, reserved for {BIOS}, {video cards}, and add-on cards.
+ Depending on the configuration some of the address space may
+ be unused in which case it can be used by {EMS} or {UMB}.
+
+ (1996-01-10)
+
+resolution
+
+ 1. <hardware> the maximum number of {pixels} that can be
+ displayed on a {monitor}, expressed as (number of horizontal
+ pixels) x (number of vertical pixels), i.e., 1024x768. The
+ ratio of horizontal to vertical resolution is usually 4:3, the
+ same as that of conventional television sets.
+
+ 2. <logic> A mechanical method for proving statements of
+ {first order logic}, introduced by J. A. Robinson in 1965.
+ Resolution is applied to two {clauses} in a {sentence}. It
+ eliminates, by {unification}, a {literal} that occurs
+ "positive" in one and "negative" in the other to produce a new
+ clause, the {resolvent}.
+
+ For example, given the sentence:
+
+ (man(X) => mortal(X)) AND man(socrates).
+
+ The literal "man(X)" is "negative". The literal
+ "man(socrates)" could be considered to be on the right hand
+ side of the degenerate implication
+
+ True => man(socrates)
+
+ and is therefore "positive". The two literals can be unified
+ by the binding X = socrates.
+
+ The {truth table} for the implication function is
+
+ A | B | A => B
+ --+---+-------
+ F | F | T
+ F | T | T
+ T | F | F
+ T | T | T
+
+ (The implication only fails if its premise is true but its
+ conclusion is false). From this we can see that
+
+ A => B == (NOT A) OR B
+
+ Which is why the left hand side of the implication is said to
+ be negative and the right positive. The sentence above could
+ thus be written
+
+ ((NOT man(socrates)) OR mortal(socrates))
+ AND
+ man(socrates)
+
+ Distributing the AND over the OR gives
+
+ ((NOT man(socrates)) AND man(socrates))
+ OR
+ mortal(socrates) AND man(socrates)
+
+ And since (NOT A) AND A == False, and False OR A == A we can
+ simplify to just
+
+ mortal(socrates) AND man(socrates)
+
+ So we have proved the new literal, mortal(socrates).
+
+ Resolution with {backtracking} is the basic control mechanism
+ of {Prolog}.
+
+ See also {modus ponens}, {SLD Resolution}.
+
+ 3. <networking> {address resolution}.
+
+ (1996-02-09)
+
+resolver
+
+ <networking> The {TCP/IP} {protocol} library software that
+ formats requests to be sent to the {Domain Name Server} for
+ {hostname} to {IP address} conversion.
+
+ (1995-03-28)
+
+Resource Access Control Facility
+
+ (RACF) {IBM}'s large system security product. It originally
+ ran only under {MVS} but has since been ported to run under
+ {VM}.
+
+ (1995-02-07)
+
+Resource Description Framework
+
+ <web, specification, data> (RDF) A specification
+ being developed in 2000 by the {W3C} as a foundation for
+ processing {meta-data} regarding resources on the {Internet},
+ including the {web}.
+
+ Resource Description Framework data consists of resources
+ ({nodes}), and property/value pairs describing the resource.
+ A node is any object which can be pointed to by a {URI},
+ properties are attributes of the node, and values can be
+ either atomic values for the attribute, or other nodes. For
+ example, information about a particular {web page} (a node),
+ might include the property "Author". The value for the Author
+ property could be either a string giving the name of the
+ author, or a {link} to a resource describing the author.
+
+ Resource Description Framework only specifies a mechanism for
+ encoding and transferring meta-data. It does not specify what
+ that meta-data should, or can be. RDF does not, for example,
+ define an "Author" attribute. Sets of properties are defined
+ within RDF Vocabularies (or Schemas). Anynone can create an
+ RDF schema, describing a specialized set of properties, by
+ creating a resource, referenced by the Schema URI, which
+ provides a human- and machine-understandable definition of the
+ schema's properties. The description of a node may include
+ properties defined in different schemas. The properties
+ within a resource description are associated with a certain
+ schema definition using the {XML} {namespace} mechanism.
+ Schemas currently being developed include a content screening
+ system modeled after {PICS}, and a bibliographic vocabulary,
+ such as the {Dublin Core Initiative}.
+
+ {(http://w3c.org/RDF/)}.
+
+ {W3C Resource Description Framework-RDF Model and Syntax
+ Specification (http://w3.org/TR/REC-rdf-syntax/)}.
+
+ (2000-03-25)
+
+resource fork
+
+ {Macintosh file system}
+
+Resource Reservation Protocol
+
+ <protocol> (RSVP) A {protocol} that supports {quality of
+ service}.
+
+ {(http://zdnet.com/pcweek/stories/news/0,4153,389107,00.html)}.
+
+ (2001-03-18)
+
+Restricted EPL
+
+ <language> (REPL) The efficient {subset} of {EPL} used to
+ write the core of {Multics}.
+
+ (2003-06-23)
+
+restriction
+
+ A {bug} or design error that limits a program's capabilities,
+ and which is sufficiently egregious that nobody can quite work
+ up enough nerve to describe it as a {feature}. Often used
+ (especially by {marketroid} types) to make it sound as though
+ some crippling bogosity had been intended by the designers all
+ along, or was forced upon them by arcane technical constraints
+ of a nature no mere user could possibly comprehend (these
+ claims are almost invariably false).
+
+ Old-time hacker Joseph M. Newcomer advises that whenever
+ choosing a quantifiable but arbitrary restriction, you should
+ make it either a power of 2 or a power of 2 minus 1. If you
+ impose a limit of 17 items in a list, everyone will know it is
+ a random number - on the other hand, a limit of 15 or 16
+ suggests some deep reason (involving 0- or 1-based indexing in
+ binary) and you will get less {flamage} for it. Limits which
+ are round numbers in base 10 are always especially suspect.
+
+ [{Jargon File}]
+
+Restructured EXtended eXecutor
+
+ <language> (REXX, or "System Product Interpreter", originally
+ known as "REX") A {script}ing language for {IBM VM} and {MVS}
+ systems, developed by M. Cowlishaw at {IBM} ca. 1979,
+ replacing {EXEC2}.
+
+ Versions: PC-Rexx for {MS-DOS}, {AREXX} for the {Amiga}, the
+ {OS/2} implementation from IBM, WINREXX (Rexx for Windows,
+ from {Quercus systems}) and Personal Rexx (Rexx for MS-DOS,
+ from Quercus systems).
+
+ See also {Regina}, {freerexx}, {imc}.
+
+ {REXXWARE} is an implementation of {REXX} for {Novell
+ NetWare}.
+
+ {Usenet} newsgroup: {news:comp.lang.rexx}.
+
+ ["The REXX Language: A Practical Approach to Programming",
+ M.F. Cowlishaw, 1985].
+
+ (1992-05-13)
+
+restructuring
+
+ The transformation from one representation form to another at
+ the same relative abstraction level, while preserving the
+ subject system's external behaviour (functionality and
+ semantics).
+
+retcon
+
+ /ret'kon/ retroactive continuity.
+
+ The common situation in fiction where a new story "reveals"
+ things about events in previous stories, usually leaving the
+ "facts" the same (thus preserving continuity) while completely
+ changing their interpretation. For example, revealing that a
+ whole season of "Dallas" was a dream was a retcon.
+
+ This term was once thought to have originated on the {Usenet}
+ newsgroup {news:rec.arts.comics} but is now believed to have
+ been used earlier in comic fandom.
+
+ [{Jargon File}]
+
+ (1994-12-08)
+
+rete
+
+ <artificial intelligence> /Re'te/ (From Latin "net") A net or
+ network; a plexus; particularly, a network of blood vessels or
+ nerves, or a part resembling a network.
+
+ [How is it used in AI? What is a "rete procedure "?]
+
+ (2002-03-14)
+
+RETI
+
+ {RTI}
+
+Retrieve
+
+ <language> A {query language} inspired {JPLDIS} which led to
+ {Vulcan} and then to {dBASE II}, developed by {Tymshare Corp}
+ in the 1960s.
+
+ (1998-04-29)
+
+retrocomputing
+
+ /ret'-roh-k*m-pyoo'ting/ Refers to emulations of
+ way-behind-the-state-of-the-art hardware or software, or
+ implementations of never-was-state-of-the-art; especially if
+ such implementations are elaborate practical jokes and/or
+ parodies, written mostly for {hack value}, of more "serious"
+ designs. Perhaps the most widely distributed retrocomputing
+ utility was the "pnch(6)" or "bcd(6)" program on V7 and other
+ early Unix versions, which would accept up to 80 characters of
+ text argument and display the corresponding pattern in
+ {punched card} code. Other well-known retrocomputing hacks
+ have included the programming language {INTERCAL}, a
+ {JCL}-emulating shell for Unix, the card-punch-emulating
+ editor named 029, and various elaborate {PDP-11} hardware
+ emulators and RT-11 OS emulators written just to keep an old,
+ sourceless {Zork} binary running.
+
+ [{Jargon File}]
+
+retronym
+
+ <jargon> A term invented to distinguish a subclass of things
+ from new members of the superclass, where the distinction was
+ previously not necessary, since the old subclass had been all
+ there was of the superclass.
+
+ For example, the retronyms "{snail mail}" and "{paper mail}"
+ were coined by those for who "mail" was likely to mean
+ {electronic mail}.
+
+ While the English language in general has a few retronyms
+ ("whole milk", "snow skiing", "acoustic guitar"), hacker
+ jargon is necessarily (at points capriciously) rich in
+ retronyms, e.g. {plaintext}, {natural language}, {impact
+ printer}, {eyeball search}, biological {virus}.
+
+ [More examples?]
+
+ (2001-02-25)
+
+return from interrupt
+
+ <programming> (RTI) An instruction {mnemonic} on many
+ computers including the {6502} and {6800}. The variant "RETI"
+ is found among former {Zilog Z80} hackers (almost nobody
+ programs these things in {assembly code} anymore). The {Intel
+ 80x86} equivalent is "IRET".
+
+ (1994-10-31)
+
+return from the dead
+
+ <jargon> To regain access to the net after a long absence.
+
+ Compare {person of no account}.
+
+ [{Jargon File}]
+
+ (1999-01-14)
+
+Return To Zero
+
+ <communications> A class of encoding methods for physical
+ circuits in which the carrier (current, voltage) returns to
+ zero after each transmitted bit, i.e. the data is carried in
+ pulse width or polarity, not in the level of the signal.
+
+ Contrast {NRZ}.
+
+ (1995-11-11)
+
+reusability
+
+ {reuse}
+
+reuse
+
+ Using code developed for one {application program} in another
+ application. Traditionally achieved using program libraries.
+ {Object-oriented programming} offers reusability of code via
+ its techniques of {inheritance} and {genericity}. {Class}
+ libraries with {intelligent browsers} and {application
+ generators} are under development to help in this process.
+ {Polymorphic} {functional languages} also support reusability
+ while retaining the benefits of {strong typing}.
+
+ See also {DRAGOON}, {National Software Reuse Directory},
+ {RLF}.
+
+Reverse Address Resolution Protocol
+
+ <networking, protocol> (RARP) A {protocol} defined in {RFC
+ 903} which provides the reverse function of {ARP}. RARP maps
+ a hardware address ({MAC address}) to an {IP address}.
+ It is used primarily by {diskless nodes}, when they first
+ initialise, to find their {IP address}.
+
+ See also {BOOTP}.
+
+ (1994-12-08)
+
+Reverse ARP
+
+ {Reverse Address Resolution Protocol}
+
+reverse engineering
+
+ <systems, product, design> The process of analysing an existing
+ system to identify its components and their interrelationships and
+ create representations of the system in another form or at a
+ higher level of {abstraction}. Reverse engineering is usually
+ undertaken in order to redesign the system for better
+ maintainability or to produce a copy of a system without access to
+ the design from which it was originally produced.
+
+ For example, one might take the {executable code} of a computer
+ program, run it to study how it behaved with different inputs and
+ then attempt to write a program which behaved identically (or
+ better). An {integrated circuit} might also be reverse engineered
+ by an unscrupulous company wishing to make unlicensed copies of a
+ popular chip.
+
+ (1995-10-06)
+
+Reverse Polish Notation
+
+ {postfix notation}
+
+reverse polish syntax
+
+ {postfix notation}
+
+Revised ALGOL 60
+
+ {ALGOL 60 Revised}
+
+revision
+
+ <programming> A {release} of a piece of software which is not
+ a {major release} or a {bugfix}, but only introduces small
+ changes or new features.
+
+ (1996-08-04)
+
+Revision Control System
+
+ <software, tool> (RCS) A {version control} system that
+ automates the storing, retrieval, logging, identification, and
+ merging of revisions. RCS is useful for text that is revised
+ frequently, for example programs, documentation, graphics,
+ papers, and form letters.
+
+ {Unix manual page}: rcs(1).
+
+ ["RCS -- A System for Version Control", Walter F. Tichy,
+ Software--Practice & Experience 15, 7, July 1985, 637-654].
+
+ [Features? Availability? URL?]
+
+ (1994-12-23)
+
+Revolutionary Surrealist Vandal Party
+
+ <body> (RSVP)
+ {(http://impropaganda.com/kultcha.html#bullet21)}.
+
+ (1996-12-01)
+
+revolutions per minute
+
+ <unit> (rpm, rarely: rotations per minute) A unit of {angular
+ velocity}.
+
+ (2004-04-18)
+
+REX
+
+ The original name for {Restructured EXtended eXecutor}.
+
+REXX
+
+ {Restructured EXtended eXecutor}
+
+REXXWARE
+
+ An implementation of {REXX} for {Novell NetWare} produced by
+ {Simware, Inc.} in January 1994. It is used by {LAN} managers
+ to automate LAN administration chores on a Novell NetWare
+ {server}.
+
+ As a scripting language, REXXWARE is an NLM ({NetWare Loadable
+ Module}) that runs on {Novell NetWare} servers. It includes
+ more than 275 NetWare-specific functions, plus the standard
+ {REXX} {keywords}, instructions, built-in functions,
+ {flow-control}, tracing, and error trapping and recovery
+ features.
+
+ REXXWARE is certified by Novell for use with NetWare.
+
+ E-mail: <rexxware@simware.com>.
+
+ (1995-01-11)
+
+RF
+
+ {radio frequency}
+
+RFC
+
+ {Request For Comments}
+
+RFC 1014
+
+ <programming, networking, standard> The {RFC} defining
+ {eXternal Data Representation}.
+
+ {(rfc:1014)}.
+
+ (1994-12-13)
+
+RFC 1034
+
+ <networking, standard> One of the {RFCs} defining the {Domain
+ Name System}.
+
+ {(rfc:1034)}.
+
+ (1997-12-15)
+
+RFC 1035
+
+ <networking, standard> One of the {RFCs} defining the {Domain
+ Name System}.
+
+ {(rfc:1035)}.
+
+ (1997-12-15)
+
+RFC 1057
+
+ <networking, standard> The {RFC} defining {Sun} {RPC}.
+
+ {(rfc:1057)}.
+
+ (2003-06-04)
+
+RFC 1058
+
+ <networking, standard> The {RFC} defining {Routing Information
+ Protocol}. Updated by {RFC 1388}.
+
+ {(rfc:1058)}.
+
+ (1994-11-30)
+
+RFC 1081
+
+ <messaging, standard> The {RFC} defining {POP3}, {Post Office
+ Protocol} version 3.
+
+ {(rfc:1081)}.
+
+ (1994-12-12)
+
+RFC 1094
+
+ <standard, networking, storage> The {RFC} defining {Sun
+ Microsystems}'s {Network File System} (NFS).
+
+ {(rfc:1094)}.
+
+ (1994-12-12)
+
+RFC 1112
+
+ <networking, standard> The {RFC} describing {MBONE}.
+
+ {(rfc:1112)}.
+
+ (1994-11-11)
+
+RFC 1119
+
+ <networking, standard> The {RFC} defining {Network Time
+ Protocol}.
+
+ {(rfc:1119)}.
+
+ (1994-11-30)
+
+RFC 1123
+
+ <networking, standard> The {RFC} "Requirements for Internet
+ Hosts Application and Support" which clarifies or changes the
+ specification of protocols given in earlier RFCs.
+
+ RFC 1123 defines the terms "MUST", "SHOULD", "MAY",
+ "unconditionally compliant", "conditionally compliant".
+ Capitals are used to emphasise that the official definition of
+ the word is being used.
+
+ MUST or REQUIRED means an absolute requirement for
+ conformance.
+
+ SHOULD or RECOMMENDED means the item can be ignored under
+ certain circumstances, although the full implications should
+ be understood.
+
+ MAY or OPTIONAL means the implementor can choose, usually
+ depending on whether it is needed or not.
+
+ Something "unconditionally compliant" meets all the MUST and
+ SHOULD requirements, "conditionally compliant" meets all the
+ MUST requirements and "not compliant" - does not meet some
+ MUST requirement.
+
+ For example, RFC 1123 amends RFC952 to say software MUST
+ handle either a letter or a digit as the first character of a
+ {hostname}.
+
+ {(rfc:1123)}.
+
+ (1996-01-13)
+
+RFC 1156
+
+ <standard> The {RFC} which established the MIB I {Management
+ Information Base} standard.
+
+ {(rfc:1156)}.
+
+ (1994-11-14)
+
+RFC 1157
+
+ <networking, standard> The {RFC} defining {Simple Network
+ Management Protocol}.
+
+ {(rfc:1157)}.
+
+ (1994-11-14)
+
+RFC 1171
+
+ <protocol, standard> The {RFC} defining the {Point-to-Point
+ Protocol}.
+
+ {(rfc:1171)}.
+
+ (1994-12-13)
+
+RFC 1208
+
+ <networking, standard> The {RFC} defining many of the
+ network-related terms in this dictionary.
+
+ {(rfc:1208)}.
+
+ ["A Glossary of Networking Terms", Jacobsen, O., and D. Lynch,
+ RFC 1208, Interop, Inc., March 1991.]
+
+ (1996-08-06)
+
+RFC 1213
+
+ <networking, standard> The {RFC} which definied the MIB II
+ {Management Information Base}.
+
+ {(rfc:1213)}.
+
+ (1994-11-14)
+
+RFC 1267
+
+ <networking, standard> One of the {RFCs} describing {Border
+ Gateway Protocol}.
+
+ {(rfc:1267)}.
+
+RFC 1268
+
+ <networking, standard> One of the {RFCs} describing {Border
+ Gateway Protocol}.
+
+ {(rfc:1268)}.
+
+RFC 1304
+
+ <networking, standard> One of the {RFCs} describing {SMDS
+ Interface Protocol}.
+
+ {(rfc:1304)}.
+
+ (2000-09-02)
+
+RFC 1321
+
+ <messaging, standard> The {RFC} defining the {Message Digest
+ 5} {algorithm}.
+
+ {(rfc:1321)}.
+
+ (1996-08-04)
+
+RFC 1334
+
+ <networking, security, standard, protocol> The {RFC} defining
+ {Challenge-Handshake Authentication Protocol} and {Password
+ Authentication Protocol}.
+
+ {(rfc:1334)}.
+
+ (1996-03-23)
+
+RFC 1341
+
+ <messaging, standard> The June 1992 {RFC} defining
+ {Multipurpose Internet Mail Extensions} (MIME). This {RFC}
+ has been obsoleted by {RFC 2045}, {RFC 2046}, {RFC 2047}, {RFC
+ 2048}, {RFC 2049}, and {BCP0013}.
+
+ {(rfc:1341)}.
+
+ (1997-08-30)
+
+RFC 1347
+
+ <networking, protocol> One of the {RFCs} describing the {TUBA}
+ {protocol}.
+
+ {(rfc:1347)}.
+
+ (1997-08-30)
+
+RFC 1350
+
+ <networking, protocol> The {RFC} defining {TFTP}.
+
+ {(rfc:1350)}.
+
+ (1997-08-30)
+
+RFC 1388
+
+ <networking, standard> An update to {RFC 1058}, the {RFC}
+ defining {Routing Information Protocol}.
+
+ {(rfc:1388)}.
+
+ (1994-11-30)
+
+RFC 1436
+
+ <networking, standard> The {RFC} defining the {Internet}
+ {Gopher} {protocol}.
+
+ {(rfc:1436)}.
+
+ (1995-11-16)
+
+RFC 1441
+
+ <networking, standard> The {RFC} introducing {SNMP v2}.
+
+ {(rfc:1441)}.
+
+ (1997-11-23)
+
+RFC 1442
+
+ <networking, standard> The {RFC} defining {SMI} for {SNMP v2}.
+
+ {(rfc:1442)}.
+
+ (1997-11-23)
+
+RFC 1443
+
+ <networking, standard> The {RFC} defining textual conventions
+ for {SNMP v2}.
+
+ {(rfc:1443)}.
+
+ (1997-11-23)
+
+RFC 1444
+
+ <networking, standard> The {RFC} defining conformance
+ statements for {SNMP v2}.
+
+ {(rfc:1444)}.
+
+ (1997-11-23)
+
+RFC 1445
+
+ <networking, standard> The {RFC} defining the administrative
+ model for {SNMP v2}.
+
+ {(rfc:1445)}.
+
+ (1997-11-23)
+
+RFC 1446
+
+ <networking, standard> The {RFC} defining security protocols
+ for {SNMP v2}.
+
+ {(rfc:1446)}.
+
+ (1997-11-23)
+
+RFC 1447
+
+ <networking, standard> The {RFC} defining {Party MIB} for
+ {SNMP v2}.
+
+ {(rfc:1447)}.
+
+ (1997-11-23)
+
+RFC 1448
+
+ <networking, standard> The {RFC} defining protocol operations
+ for {SNMP v2}.
+
+ {(rfc:1448)}.
+
+ (1997-11-23)
+
+RFC 1449
+
+ <networking, standard> The {RFC} defining {transport mappings}
+ for {SNMP v2}.
+
+ {(rfc:1449)}.
+
+ (1997-11-23)
+
+RFC 1450
+
+ <networking, standard> The {RFC} defining {MIB} for {SNMP v2}.
+
+ {(rfc:1450)}.
+
+ (1997-11-23)
+
+RFC 1451
+
+ <networking, standard> The {RFC} defining {Manager to Manger
+ MIB}.
+
+ {(rfc:1451)}.
+
+ (1997-11-23)
+
+RFC 1452
+
+ <networking, standard> The {RFC} describing coexistance
+ between {SNMP} v1 and {SNMP v2}.
+
+ {(rfc:1452)}.
+
+ (1995-02-15)
+
+RFC 1475
+
+ <networking, protocol> The {RFC} describing the {TP/IX}
+ {protocol}.
+
+ {(rfc:1475)}.
+
+ (1995-04-03)
+
+RFC 1508
+
+ <security, standard> One of the {RFCs} defining {GSS-API}.
+
+ {(rfc:1508)}.
+
+ (1996-05-19)
+
+RFC 1509
+
+ <security, standard> One of the {RFCs} defining {GSS-API}.
+
+ {(rfc:1509)}.
+
+ (1996-05-19)
+
+RFC 1520
+
+ <networking, standard> The {RFC} defining {Classless
+ Inter-Domain Routing}.
+
+ {(rfc:1520)}.
+
+ (1996-10-01)
+
+RFC 1521
+
+ <messaging, standard> An {RFC} defining {Multipurpose Internet
+ Mail Extensions} (MIME). This {RFC} has been obsoleted by
+ {RFC 2045}, {RFC 2046}, {RFC 2047}, {RFC 2048}, {RFC 2049},
+ and {BCP0013}.
+
+ {(rfc:1521)}.
+
+ (1997-11-23)
+
+RFC 1526
+
+ <networking, protocol> One of the {RFCs} describing the {TUBA}
+ {protocol}.
+
+ {(rfc:1526)}.
+
+ (1997-11-23)
+
+RFC 1531
+
+ <networking, protocol> The original {RFC} defining {DHCP},
+ obsoleted by {RFC 2131}.
+
+ {(rfc:1531)}.
+
+ (1998-11-20)
+
+RFC 1550
+
+ <networking, protocol> An {RFC} {white paper} on {IPng}.
+
+ {(rfc:1550)}.
+
+ (1995-04-03)
+
+RFC 1561
+
+ <networking, protocol> One of the {RFCs} describing the {TUBA}
+ {protocol}.
+
+ {(rfc:1561)}.
+
+ (1997-11-23)
+
+RFC 1568
+
+ <messaging, standard> An {RFC} defining the {Simple Network
+ Paging Protocol} (SNPP) which is designed to support
+ {Internet} access to {paging} services such as those based on
+ the {Telocator Alphanumeric Protocol}. See also {RFC 1861}.
+
+ {(rfc:1568)}.
+
+ (1996-06-24)
+
+RFC 1591
+
+ <networking, standard> The {RFC} defining the {Domain Name
+ System}. Written by J. Postel in March 1994.
+
+ (2001-05-14)
+
+RFC 1630
+
+ <networking, standard> The {RFC} defining the {Universal
+ Resource Identifier}.
+
+ {(rfc:1630)}.
+
+ (1995-01-13)
+
+RFC 1661
+
+ <networking, standard> The {RFC} defining {Point-to-Point
+ Protocol}.
+
+ {(rfc:1661)}.
+
+ (1997-02-05)
+
+RFC 1700
+
+ <networking, standard> The original {RFC} defining "Assigned
+ Numbers" such as standard "well-known" {TCP} and {UDP} {port}
+ numbers, now superseded by {RFC 3232}.
+
+ {(rfc:1700)}.
+
+ (2001-04-08)
+
+RFC 1701
+
+ <networking, standard> The {RFC} defining {Generic Routing
+ Encapsulation}.
+
+ See also {RFC 1702}.
+
+ {(rfc:1701)}.
+
+ (1997-04-02)
+
+RFC 1702
+
+ <networking, standard> The {RFC} defining {Generic Routing
+ Encapsulation} over {IP}.
+
+ {(rfc:1702)}.
+
+ (1997-04-02)
+
+RFC 1707
+
+ <networking, standard> The {RFC} defining {CATNIP}.
+
+ {(rfc:1707)}.
+
+ (1996-03-23)
+
+RFC 1730
+
+ <messaging, standard> An old {RFC} defining {IMAP}, obsoleted
+ by {RFC 2060}, {RFC 2061} and others.
+
+ {(rfc:1730)}.
+
+ (1996-03-11)
+
+RFC 1756
+
+ <messaging> The {RFC} describing {Remote Write Protocol}.
+
+ {(rfc:1756)}.
+
+ (1996-09-08)
+
+RFC 1760
+
+ <security> The {RFC} describing the S/KEY {One-Time Password}
+ system.
+
+ {(rfc:1760)}.
+
+ (2000-01-31)
+
+RFC 1777
+
+ <networking, standard> The {RFC} defining {Lightweight
+ Directory Access Protocol}.
+
+ {(rfc:1777)}.
+
+ (1996-08-23)
+
+RFC 1778
+
+ <networking, standard> The {RFC} that defines the requirements
+ that must be satisfied by encoding rules used to render {X.500}
+ Directory attribute syntaxes into a form suitable for use in
+ {LDAP}.
+
+ {(rfc:1778)}.
+
+ (2002-03-02)
+
+RFC 1795
+
+ <networking, standard> The {RFC} that defines {Data Link
+ Switching}.
+
+ {(rfc:1795)}.
+
+ (2008-01-11)
+
+RFC 1823
+
+ <networking, standard> The {RFC} defining the {C} language
+ {application program interface} to the {Lightweight Directory
+ Access Protocol}.
+
+ {(rfc:1823)}.
+
+ (1996-11-28)
+
+RFC 1825
+
+ <networking, standard> The {RFC} describing security
+ mechanisms for {Internet Protocol} version 4 and {IP version
+ 6} and the services that they provide.
+
+ {(rfc:1825)}.
+
+ (1997-07-09)
+
+RFC 1831
+
+ <networking, standard> The {RFC} describing {ONC} {RPC}.
+
+ (2003-06-04)
+
+RFC 1861
+
+ <networking, standard> The {RFC} defining {Simple Network
+ Paging Protocol}. See also {RFC 1568}.
+
+ {(rfc:1861)}.
+
+ (1997-04-25)
+
+RFC 1938
+
+ <security, standard> The {RFC} describing a proposed
+ {standard} for a {One-Time Password} system, obsoleted by {RFC
+ 2289}.
+
+ ["A One-Time Password System.", N. Haller & C. Metz].
+
+ {(rfc:1938)}.
+
+ (2000-03-05)
+
+RFC 1951
+
+ <standard> The {RFC} describing {deflate} {compression}.
+
+ {(rfc:1951)}.
+
+ (1997-06-21)
+
+RFC 1959
+
+ <networking, standard> The {RFC} defining a {URL} format for
+ the {Lightweight Directory Access Protocol}.
+
+ {(rfc:1959)}.
+
+ (1996-11-28)
+
+RFC 1960
+
+ <networking, standard> The {RFC} defining the human-readable
+ format of search filters used with the {Lightweight Directory
+ Access Protocol}.
+
+ {(rfc:1960)}.
+
+ (2002-03-02)
+
+RFC 2045
+
+ <messaging, standard> One of the {RFCs} defining {MIME}.
+
+ {(rfc:2045)}.
+
+ (1999-10-29)
+
+RFC 2046
+
+ <messaging, standard> One of the {RFCs} defining {MIME}.
+
+ {(rfc:2046)}.
+
+ (1999-10-29)
+
+RFC 2047
+
+ <messaging, standard> One of the {RFCs} defining {MIME}.
+
+ {(rfc:2047)}.
+
+ (1999-10-29)
+
+RFC 2048
+
+ <messaging, file format, standard> The {RFC} explaining
+ registration of {MIME types}.
+
+ {(rfc:2048)}.
+
+ (1998-02-11)
+
+RFC 2049
+
+ <messaging, standard> One of the {RFCs} defining {MIME}.
+
+ {(rfc:2049)}.
+
+ (1999-10-29)
+
+RFC 2060
+
+ <messaging> One of the {RFCs} describing {IMAP}.
+
+ {(rfc:2060)}.
+
+ (1999-03-14)
+
+RFC 2061
+
+ <messaging> One of the {RFCs} describing {IMAP}.
+
+ {(rfc:2061)}.
+
+ (1999-03-14)
+
+RFC 2068
+
+ <networking, standard> The {RFC} defining {HTTP} version 1.1.
+
+ {(rfc:2068)}.
+
+ (1997-05-03)
+
+RFC 2093
+
+ <networking, standard> The {RFC} specifying the {Inverse
+ Address Resolution Protocol}.
+
+ {(rfc:2093)}.
+
+ (2000-01-15)
+
+RFC 2131
+
+ <networking, protocol> The {RFC} defining {DHCP}. Obsoletes
+ {RFC 1531}.
+
+ {(rfc:2131)}.
+
+ (1998-11-22)
+
+RFC 2234
+
+ <standard> The {RFC} defining {Augmented Backus-Naur Form}.
+
+ {(rfc:2234)}.
+
+ (1997-11-23)
+
+RFC 2236
+
+ <networking, standard> The {RFC} describing {IGMP} version 2.
+
+ {(rfc:2236)}.
+
+ (1999-11-08)
+
+RFC 2246
+
+ <networking, standard> The {RFC} that defines {TLS} protocol
+ Version 1.0. Written by T. Dierks and C. Allen in January
+ 1999.
+
+ {(rfc:2246)}.
+
+ (2003-10-25)
+
+RFC 2279
+
+ <standard> The {RFC} defining {UTF-8}.
+
+ {(rfc:2279)}.
+
+ (1998-07-29)
+
+RFC 2281
+
+ <networking, standard> The {RFC} describing {CISCO} {Hot
+ Standby Routing Protocol}.
+
+ {(rfc:2281)}.
+
+ (2005-01-26)
+
+RFC 2298
+
+ <security, standard> The {RFC} proposing a {standard}
+ {One-Time Password} system.
+
+ {(rfc:2298)}.
+
+ (2000-03-05)
+
+RFC 2326
+
+ <standard> The {RFC} defining {RTSP}.
+
+ {(rfc:2326)}.
+
+ (1999-10-12)
+
+RFC 2364
+
+ The {RFC} defining {PPPoA}.
+
+ {(rfc:2364)}.
+
+ (2007-06-15)
+
+RFC 2408
+
+ <standard, security> The {RFC} proposing {ISAKMP}.
+
+ {(rfc:2408)}.
+
+ (2000-02-08)
+
+RFC 2516
+
+ <standard, security> The {RFC} defining {Point-to-Point
+ Protocol over Ethernet} (PPPoE).
+
+ {(rfc:2516)}.
+
+ (2006-09-20)
+
+RFC 2543
+
+ <networking, standard> One of the {RFCs} describing {Session
+ Initiation Protocol}.
+
+ {(rfc:2543)}.
+
+ (2000-07-08)
+
+RFC 2795
+
+ <networking, standard> The {RFC} describing The {Infinite
+ Monkey Protocol Suite }.
+
+ {(rfc:2795)}.
+
+RFC 2821
+
+ <networking, standard> The {RFC} describing {SMTP}. RFC 2821
+ supersedes {RFC 821}.
+
+ {(rfc:2821)}.
+
+ (2007-06-01)
+
+RFC 3232
+
+ <networking, standard> The {RFC} describing {TCP} {port}
+ numbers. RFC 3232 supersedes RFC 1700.
+
+ {(rfc:3232)}.
+
+ See also {IANA}, {STD 2}.
+
+ (2004-12-30)
+
+RFC 4213
+
+ <networking, standard> The {RFC} defining mechanisms for
+ transitioning to {IPv6}, such as {dual-stack} versus {tunnelling}.
+
+ {(rfc:4213)}.
+
+ (2013-11-12)
+
+RFC 792
+
+ <networking, standard> The {RFC} defining {Internet Control
+ Message Protocol}.
+
+ {(rfc:792)}.
+
+ (1996-08-23)
+
+RFC 821
+
+ <messaging, standard> The original {RFC} defining {SMTP}.
+ Updated by {RFC 2821}.
+
+ {(rfc:821)}.
+
+ (2007-06-01)
+
+RFC 822
+
+ <messaging, standard> The {RFC} defining the {Internet}
+ standard format for {electronic mail} message headers. Also
+ {STD 11}, evolved from RFC 733.
+
+ {(rfc:822)}.
+
+ (1997-03-08)
+
+RFC 826
+
+ <networking, standard> The {RFC} defining the {Address
+ Resolution Protocol}.
+
+ {(rfc:826)}.
+
+ (1997-11-21)
+
+RFC 854
+
+ <networking, standard> The {RFC} defining the {telnet}
+ protocol.
+
+ ["Telnet Protocol specification", J. Postel, J.K. Reynolds,
+ 1983-05-01].
+
+ {(rfc:854)}.
+
+ (2000-03-18)
+
+RFC 903
+
+ <networking, standard> The {RFC} defining {Reverse Address
+ Resolution Protocol}.
+
+ {(rfc:903)}.
+
+ (1994-12-08)
+
+RFC 908
+
+ <networking, standard> The July 1984 {RFC} defining {Reliable
+ Data Protocol} (RDP).
+
+ {(rfc:908)}.
+
+ (2004-09-14)
+
+RFC 959
+
+ <networking, standard> The {RFC} containing the official
+ specification of {File Transfer Protocol} (FTP).
+
+ {(rfc:959)}.
+
+ (1995-01-12)
+
+RFCOMM
+
+ <protocol> (RS232 Serial Cable Emulation Profile) A
+ {Bluetooth} transport {protocol} in the {Core Protocol Stack}
+ based on the {ETSI} standard.
+
+ {RFCOMM Layer Tutorial
+ (http://palowireless.com/infotooth/tutorial/rfcomm.asp)}.
+
+ (2002-06-28)
+
+RFE
+
+ 1. {Request For Enhancement} (compare {RFC}).
+
+ 2. (From "Radio Free Europe", {Bellcore} and {Sun}) Radio Free
+ Ethernet.
+
+ A system originated by Peter Langston for broadcasting audio
+ among Sun {SPARCstations} over the {Ethernet}.
+
+ [{Jargon File}]
+
+ (1994-12-06)
+
+RFI
+
+ {radio frequency interference}
+
+RFID
+
+ {Radio-frequency identification}
+
+RFP
+
+ 1. <business> {Request for Proposal}.
+
+ 2. <Debian> {Request for Package}.
+
+ (2001-01-15)
+
+RFT
+
+ {Request For Technology}
+
+RG58
+
+ <networking, hardware> A common, low-impedance (52 ohm),
+ quarter-inch diameter {coaxial cable} with {BNC} connectors,
+ used for {10base2} {Ethernet} wiring, sometimes called
+ "{cheapernet}" in comparison with "full spec" {RG8} cabling.
+ A member of the "Radio Guide" series.
+
+ (2002-06-17)
+
+RG8
+
+ <networking, hardware> The original "full spec" cable used for
+ {10base5} {Ethernet} networks. RG8 is stiff, large diameter
+ {coaxial} cable with an {impedance} of 50 ohms, a member of the
+ "Radio Guide" series. The outer sheath is usually yellow, to
+ indicate double shielding, so it is often just called "yellow
+ cable".
+
+ 10base5 cable is designed to allow transceivers to be added
+ while existing connections are live. This is achieved using a
+ "{vampire tap}".
+
+ RG8 is sometimes called "thicknet" or "thick Ethernet" in contrast
+ to {RG58}, a cheaper, thinner, more flexible alternative.
+
+ (2014-09-06)
+
+RGB
+
+ Red, Green, Blue. The three colours of light which can be
+ mixed to produce any other colour. Coloured images are often
+ stored as a sequence of RGB triplets or as separate red, green
+ and blue overlays though this is not the only possible
+ representation (see {CMYK} and {HSV}). These colours
+ correspond to the three "guns" in a colour {cathode ray tube}
+ and to the colour receptors in the human eye.
+
+ Often used as a synonym for colour, as in "RGB monitor" as
+ opposed to {monochrome} (black and white).
+
+Rhapsody
+
+ <operating system> {Apple Computer, Inc.}'s next-generation
+ {operating system} for {PowerPC} processor-based systems
+ capable of running {Mac OS}. Rhapsody includes four
+ components: the Core OS, the {Blue Box} (the implementation of
+ the Mac OS within Rhapsody), the {Yellow Box}, and the Advanced
+ Mac Look and Feel.
+
+ "Rhapsody for Intel" runs on {Intel} processors [which ones?].
+ It includes the Core OS, the {Yellow Box}, and the Advanced
+ Mac Look and Feel, but lacks the {Blue Box} and therefore is
+ unable to run Mac OS software.
+
+ "Rhapsody Developer Release" is a developer-only release of
+ {Rhapsody}, scheduled for release in late 1997. It will go to
+ all members of the Macintosh Developer Program and the Apple
+ Media Program worldwide who have signed nondisclosure
+ agreements.
+
+ "Rhapsody Premier Release" will be the second release of
+ {Rhapsody}, scheduled for early 1998. It is meant for early
+ adopters and will include a partially finished human interface
+ and a partial implementation of the {Blue Box}.
+
+ "Rhapsody Unified Release" will be the third release,
+ scheduled for mid-1998. It will be the first public release,
+ and it will include the first full implementation of the
+ {Rhapsody} human interface and the {Blue Box}.
+
+ {FAQ (http://devworld.euro.apple.com/rhapsody/faqsec1.html)}.
+
+ (1997-10-15)
+
+ribbon cable
+
+ <hardware> A type of flat multicore cable with cores
+ positioned side-by-side, making it quick and relatively easy
+ to clamp an {Insulation Displacement Connector} (IDC) across
+ all cores.
+
+ Ribbon cables typically have grey insulation with cores on a
+ 0.050" pitch and a red stripe marking Pin 1. They are less
+ resilient than screened, multicore cable and are usually used
+ inside equipment where little movement or plugging and
+ unplugging are expected. A common use is connecting a {disk
+ drive} to the {motherboard} in a {PC}.
+
+ (2007-07-21)
+
+rib site
+
+ <networking> (By analogy with {backbone site}) A {host} with
+ an on-demand high-speed link to a {backbone site} that serves
+ as a regional distribution point for lots of third-party
+ traffic in {electronic mail} and {Usenet} news.
+
+ Compare {leaf site}.
+
+ [{Jargon File}]
+
+ (1994-11-30)
+
+rice box
+
+ <jargon> (From ham radio slang) Any Asian-made commodity
+ computer, especially an {80x86}-based machine built to {IBM
+ PC}-compatible {ISA} or {EISA}-bus standards.
+
+ [{Jargon File}]
+
+ (1994-11-30)
+
+Richard Gabriel
+
+ <person> (Dick, RPG) Dr. Richard P. Gabriel. A noted {SAIL}
+ {LISP} {hacker} and volleyball fanatic.
+
+ Consulting Professor of Computer Science at {Stanford
+ University}. Richard Gabriel is a leader in the {Lisp} and
+ {OOP} community, with years of contributions to
+ {standardisation}. He founded the successful company, {Lucid
+ Technologies, Inc.}.
+
+ In 1996 he was Distinguished Computer Scientist at
+ ParcPlace-Digitalk, Inc. (later renamed {ObjectShare, Inc.}).
+
+ See also {gabriel}, {Qlambda}, {QLISP}, {saga}.
+
+ (1999-10-12)
+
+Richard Hamming
+
+ <person> Professor Richard Wesley Hamming (1915-02-11 -
+ 1998-01-07). An American mathematician known for his work in
+ {information theory} (notably {error detection and
+ correction}), having invented the concepts of {Hamming code},
+ {Hamming distance}, and {Hamming window}.
+
+ Richard Hamming received his B.S. from the University of
+ Chicago in 1937, his M.A. from the University of Nebraska in
+ 1939, and his Ph.D. in mathematics from the University of
+ Illinois at Urbana-Champaign in 1942. In 1945 Hamming joined
+ the Manhattan Project at Los Alamos.
+
+ In 1946, after World War II, Hamming joined the {Bell
+ Telephone Laboratories} where he worked with both {Shannon}
+ and {John Tukey}. He worked there until 1976 when he accepted
+ a chair of computer science at the Naval Postgraduate School
+ at Monterey, California.
+
+ Hamming's fundamental paper on error-detecting and
+ error-correcting codes ("{Hamming codes}") appeared in 1950.
+
+ His work on the {IBM 650} leading to the development in 1956
+ of the {L2} programming language. This never displaced the
+ workhorse language {L1} devised by Michael V Wolontis. By
+ 1958 the 650 had been elbowed aside by the 704.
+
+ Although best known for error-correcting codes, Hamming was
+ primarily a numerical analyst, working on integrating
+ {differential equations} and the {Hamming spectral window}
+ used for smoothing data before {Fourier analysis}. He wrote
+ textbooks, propounded aphorisms ("the purpose of computing is
+ insight, not numbers"), and was a founder of the {ACM} and a
+ proponent of {open-shop} computing ("better to solve the right
+ problem the wrong way than the wrong problem the right way.").
+
+ In 1968 he was made a fellow of the {Institute of Electrical
+ and Electronics Engineers} and awarded the {Turing Prize} from
+ the {Association for Computing Machinery}. The Institute of
+ Electrical and Electronics Engineers awarded Hamming the
+ Emanuel R Piore Award in 1979 and a medal in 1988.
+
+ {(http://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Hamming.html)}.
+
+ {(http://zapata.seas.smu.edu/~gorsak/hamming.html)}.
+
+ {(http://webtechniques.com/archives/1998/03/homepage/)}.
+
+ [Richard Hamming. Coding and Information Theory.
+ Prentice-Hall, 1980. ISBN 0-13-139139-9].
+
+ (2003-06-07)
+
+Richard Korf
+
+ <person> A Professor of computer science at the University of
+ California, Los Angeles. Richard Korf received his B.S. from
+ {MIT} in 1977, and his M.S. and Ph.D. in computer science from
+ Carnegie-Mellon University in 1980 and 1983. From 1983 to
+ 1985 he served as Herbert M. Singer Assistant Professor of
+ Computer Science at Columbia University.
+
+ Dr. Korf studies problem-solving, {heuristic search} and
+ {planning} in {artificial intelligence}. He wrote "Learning
+ to Solve Problems by Searching for Macro-Operators" (Pitman,
+ 1985). He serves on the editorial boards of Artificial
+ Intelligence, and the Journal of Applied Intelligence.
+ Dr. Korf is the recipient of several awards and is a Fellow of
+ the {American Association for Artificial Intelligence}.
+
+ {Richard Korf home page (http://www.cs.ucla.edu/~korf/)}.
+
+ (2007-05-01)
+
+Richard P. Feynman
+
+ <person, computing, architecture> /fayn'mn/ 1918-1988. A US
+ physicist, computer scientist and author who graduated from
+ {Massachusetts Institute of Technology} and {Princeton}.
+ Feynmane was a key figure in helping Oppenheimer and team
+ develop atomic bomb. In 1950 he became a professor at
+ {Caltech} and in 1965 became Nobel Prize Laureate in Physics
+ for QED (quantum electrodynamics). He was a primary figure in
+ "solving" the Challenger disaster O-ring problem. He
+ "rediscovered" the former Soviet Socialist Republic of Tuva.
+ The 2001 film "Infinity" about Feynman's early life featured
+ Matthew Broderick and Patricia Arquette. In 2001, "QED", a
+ play about Feynman's life featuring Alan Alda opened.
+
+ {(http://www.feynman.com/)}.
+
+ (2008-01-14)
+
+Richard P. Gabriel
+
+ {Richard Gabriel}
+
+Richard Stallman
+
+ <person> Richard M. Stallman. Founder of the {GNU} project.
+ He resigned from the {AI lab} at {MIT} so he would be free to
+ produce {free software} which he could then distribute on his
+ own terms. He went on to establish the {Free Software
+ Foundation} to support the production of free software and
+ ensure its free distribution.
+
+ E-mail: <rms@gnu.ai.mit.edu>.
+
+ (1994-10-28)
+
+rich object
+
+ In {artificial intelligence}, an object which cannot be
+ completely described or represented but about which assertions
+ can be made.
+
+ (1994-12-14)
+
+Rich Site Summary
+
+ <web, standard> (RSS, blog, feed) A family of
+ {standard} {web} document types containing regularly
+ updated, short articles or news items.
+
+ RSS documents (generally called "RSS feeds", "news feeds" or just
+ "feeds") can be read with an RSS reader like {BottomFeeder} or
+ {Feedly}. These are sometimes called "{aggregators}" because they
+ combine multiple RSS feeds which the user can browse as a single
+ list. The RSS reader tracks which articles the use has read, and
+ is typically set to show only new articles, hence the idea of a
+ "feed" or flow of new items.
+
+ Most RSS feeds are based on {RDF}. {RDF} is a structured document
+ format for describing textual resources such as news articles
+ available on the web. RSS originally stood for "RDF Site Summary"
+ as it was designed to provide short descriptions of (changes to) a
+ {website}.
+
+ Because it provides a standard way to deliver, or "syndicate",
+ news or updates from one site to another, RSS is sometimes
+ expanded as "Really Simple Syndication". It is closely associated
+ with {blogs}, most of which provide an RSS feed of articles.
+
+ (2013-08-15)
+
+Rich Text Format
+
+ (RTF) An interchange format from {Microsoft} for exchange of
+ documents between {Word} and other document preparation
+ systems.
+
+ (1994-12-08)
+
+RIFF
+
+ <file format> {Microsoft}'s equivalent to the {Amiga}'s {IFF}
+ files format. RIFF is used for {WAV} and {AVI} files.
+
+ (1995-04-21)
+
+RIGAL
+
+ A language for compiler writing. Data strucures are atoms,
+ lists/trees. Control is based on {pattern matching}.
+
+ ["Programming Language RIGAL as a Compiler Writing Tool",
+ M.I. Augustson, Inst of Math and CS of Latvia U, 1987].
+
+ (1994-10-28)
+
+Rigel
+
+ A {database} language? Based on {Pascal}. Listed by
+ M.P. Atkinson & J.W. Schmidt in a tutorial presented in
+ Zurich, 1989.
+
+ (1994-10-28)
+
+right brace
+
+ <character> "}". {ASCII} character 125.
+
+ Common names: close brace; right brace; right squiggly; right
+ squiggly bracket/brace; right curly bracket/brace; {ITU-T}:
+ closing brace. Rare: unbrace; uncurly; rytit ("{" = leftit);
+ right squirrelly; {INTERCAL}: bracelet ("{" = embrace).
+
+ Paired with {left brace}
+
+ (1995-03-30)
+
+right bracket
+
+ <character> "]". {ASCII} character 93.
+
+ Common names: right square bracket; {ITU-T}: closing bracket;
+ unbracket. Rare: unsquare; {INTERCAL}: U turn back.
+
+ Paired with {left bracket}.
+
+ (1997-11-23)
+
+right-click
+
+ <hardware> To {click} the right-most {mouse} button on a mouse
+ with more than one button. This usually performs a different
+ function from the left button, e.g. displaying a
+ {context-sensitive menu} ({Microsoft Windows}), extending the
+ {selection} ({X}).
+
+ When used as a verb it is often written as two words with a
+ space instead of a hyphen.
+
+ (2006-07-09)
+
+right join
+
+ {outer join}
+
+right outer join
+
+ {outer join}
+
+right parenthesis
+
+ <character> ")". {ASCII} character 41.
+
+ Common names: right paren; right parenthesis; right; close;
+ thesis ("(" = paren); close paren; close parenthesis; right
+ parenthesis; right banana. Rare: already ("(" = so); rparen;
+ {ITU-T}: closing parenthesis; close round bracket, right round
+ bracket, {INTERCAL}: wane ("(" = wax); unparenthisey ("(" =
+ parenthisey); right ear.
+
+ Paired with {left parenthesis}.
+
+ (1995-03-06)
+
+Right Thing
+
+ That which is *compellingly* the correct or appropriate thing
+ to use, do, say, etc. Always capitalised, always emphasised
+ in speech as though capitalised. Use of this term often
+ implies that in fact reasonable people may disagree. "What's
+ the Right Thing for {Lisp} to do when it sees "(mod a 0)"?
+ Should it return "a", or give a divide-by-0 error?"
+
+ Opposite: {Wrong Thing}.
+
+ [{Jargon File}]
+
+ (1994-10-28)
+
+Rijndael
+
+ {Advanced Encryption Standard}
+
+ring network
+
+ <networking, topology> A network topology in which all {nodes}
+ are connected to a single wire in a ring or {point-to-point}.
+ There are no endpoints. This topology is used by {token ring}
+ networks.
+
+ Compare: {bus network}, {star network}.
+
+ (2000-11-16)
+
+ring topology
+
+ {ring network}
+
+Riordan's Internet Privacy Enhanced Mail
+
+ <messaging> (RIPEM) A (not yet complete, but useful)
+ implementation of {Privacy Enhanced Mail} (PEM). RIPEM allows
+ your {electronic mail} to have the four security facilities
+ provided by PEM: {disclosure protection} (optional),
+ originator authenticity, message {integrity} measures and
+ {non-repudiation} of origin (always).
+
+ RIPEM was written primarily by Mark Riordan
+ <mrr@scss3.cl.msu.edu>. Most of the code is in the {public
+ domain}, except for the {RSA} routines, which are a library
+ called RSAREF licensed from {RSA Data Security, Inc}.
+
+ The current (November 1993) version of RIPEM is 1.1a; the
+ current version of the {Macintosh} {port} of RIPEM is 0.8b1.
+
+ (1998-07-03)
+
+RIP
+
+ 1. <networking> {Routing Information Protocol}.
+
+ 2. <application, printer> {Raster Image Processor}.
+
+ (2003-09-10)
+
+rip
+
+ <audio, video, legal> (From "rip off" - to steal) To copy
+ audio or video, typically from a {compact disc} or {DVD}, to a
+ {file} on a {computer} {hard disk}. A dedicated program to do
+ this is called a "ripper" though it is often a function of
+ player software.
+
+ Ripping usually includes converting the data to a format that
+ is more suitable for computer playback, e.g. {MP3} {digital
+ audio} or {DivX} video. The process is entirely digital so it
+ is possible to make a perfect copy of the data. However the
+ resulting files are large (a few {megabytes} for an audio
+ track, a few {gigabytes} for a film) so the conversion often
+ includes {compression} to reduce the file size at the cost of
+ some loss of quality.
+
+ While it may be legal to do this for personal use,
+ distributing a ripped copyright work to others could result in
+ prosecution.
+
+ See also {ripcording}.
+
+ (2008-01-21)
+
+ripcording
+
+ <audio> (From "{ripping}" and "recording") Encoding
+ {streaming} {digital audio} from the {Internet} to an {MP3}
+ file or similar. Ripcording is commononly used to copy
+ commercial music from a free stream instead of paying to
+ download.
+
+ (2006-01-27)
+
+RIPE
+
+ {Réseaux IP Européens}
+
+RIPEM
+
+ {Riordan's Internet Privacy Enhanced Mail}
+
+ripper
+
+ {rip}
+
+RISC
+
+ {Reduced Instruction Set Computer}
+
+RISCiX
+
+ <operating system> /risk-icks/ (Or "RISC iX") {BSD}-based
+ {Unix} developed by {Acorn Computers Ltd.} (Cambridge, UK) to
+ run on 32-bit {ARM} {RISC} processors.
+
+ RISCiX was launched circa 1989 for three production machines -
+ the R140, R260, the discless R225; and other prototypes.
+
+ (2003-09-24)
+
+RISC OS
+
+ <operating system> (Reduced Instruction Set Computer Operating
+ System) The {operating system} originally developed by {Acorn
+ Computers} for their {Archimedes} family of {personal
+ computers}.
+
+ RISC OS replaced the {Arthur} operating system used on the
+ first Archimedeses.
+
+ It is written in {ARM} {assembly code} and distributed on
+ {ROM} so it takes up no disk space and takes no time to load.
+ It supports {cooperative multitasking} with memory management
+ and includes a {graphical user interface} or "WIMP". It is
+ written in a highly modular style and makes extensive use of
+ {vectors} so it is easy to modify and extend by loading new
+ modules in {RAM}. Many {system calls} (called "SWIs" -
+ software interrupts) are available to application programmers
+ and some of these are available as user comands via a built-in
+ {command-line interpreter}. RISC OS also supported {outline
+ fonts} when only {bitmap fonts} were available on most other
+ {platforms}.
+
+ Following the virtual demise of Acorn, development of RISC OS
+ 4 was taken over by {RISCOS Ltd} on 1999-03-05 and released on
+ 1999-07-01.
+
+ Latest version: 4.39, as of 2004-09-21.
+
+ (2004-09-21)
+
+RiscPC
+
+ <computer> The final addition to {Acorn}'s {Archimedes} family
+ of {personal computers}, released in April 1994. The RiscPC
+ allowed a second processor, e.g. an {Intel 486} or a second
+ {ARM}, to share the {bus}, memory and {peripherals} with the
+ main processor. It also had full 24-bit colour graphics
+ support.
+
+ The Risc PC 600 (the first to be launched) had the new
+ {ARM600} processor and {RISC OS} 3.5. The RiscPC 700 had an
+ {ARM710} processor and RISC OS 3.6, and the SA had the
+ {StrongARM} processor and RISC OS 3.7.
+
+ {Castle Technology Ltd} later introduced the {IYONIX pc} with
+ the 32-bit {X-Scale} processor and {USB} sockets. USB and
+ StrongArm can also be retrofitted to earlier RiscPCs.
+
+ RiscPCs are among the most energy efficient home computers.
+
+ {Acorn Computer Museum
+ (http://pages.zoom.co.uk/acorn.computer/riscpc.html)}.
+
+ (2004-09-21)
+
+RISC System/6000
+
+ <computer> (Or "RS/6000") {IBM}'s current {RISC}-based {Unix}
+ computer. The RS/6000, announced in 1990, replaced the
+ {RT-PC}. It runs {AIX} 3.x and 4.x. Most models have an
+ {MCA} bus. A wide range of models are available.
+
+ (1995-04-06)
+
+Risk Based Testing
+
+ <testing> Testing based on identification of potential risks
+ (or "candidate risks"), which should be analysed by the
+ project stakeholder or which might appear during the project's
+ development.
+
+ (2006-09-07)
+
+RISQL
+
+ {Red Brick Intelligent SQL}
+
+RITL
+
+ {Wireless Local Loop}
+
+RJ-11
+
+ <hardware, communications> An American-style telephone jack
+ with six possible connections. A telephone normally uses two
+ pairs of wires. Often found on the back of US-manufactured
+ {modems} or for connection to a {leased line}.
+
+ (1998-06-30)
+
+RJ-45
+
+ <hardware> A {serial} connector which looks very much like a
+ standard telephone connector, except it houses eight wires
+ instead of four.
+
+ RJ-45s are typically found on {computers} either integrated
+ into the {mother board} or on a {NIC}. Because they are so
+ small they are often used on devices such as {terminal
+ servers} that have many {ports}.
+
+ {Ethernet} ({10baseT}) and {Token Ring} sometimes use four
+ wires of an RJ-45 plug, {100baseVG} uses all eight.
+ {100BaseTX} uses the same four wires of the RJ-45 connector as
+ 10baseT but the wire must be {category 5} instead of {category
+ 3}.
+
+ [Would the cable normally be {shielded twisted pair} or
+ {unshielded twisted pair}?]
+
+ (2004-05-22)
+
+RJE
+
+ {Remote Job Entry}
+
+RKM
+
+ {Rom Kernel Manual}
+
+RL
+
+ (MUD community) Real Life.
+
+ "Firiss laughs in RL" means that Firiss's player is laughing.
+
+ Opposite: {VR}.
+
+ [{Jargon File}]
+
+ (1995-05-09)
+
+rl
+
+ Kent Wittenburg <kentw@bellcore.com>.
+
+ The RL files contain code for defining {relational grammars}
+ and using them in a bottom-up parser to recognise and/or parse
+ expressions in Relational Languages.
+
+ The approach is a simplification of that described in
+ Wittenburg, Weitzman, and Talley (1991), Unification-Based
+ Grammars and Tabular Parsing for Graphical Languages, Journal
+ of Visual Languages and Computing 2:347-370. This code is
+ designed to support the definition and parsing of Relational
+ Languages, which are characterised as sets of objects standing
+ in user-defined relations.
+
+ Correctness and completeness is independent of the order in
+ which the input is given to the parser. Data to be parsed can
+ be in many forms as long as an interface is supported for
+ queries and predicates for the relations used in grammar
+ productions.
+
+ To date, this software has been used to parse recursive
+ pen-based input such as math expressions and {flow charts}; to
+ check for {data integrity} and design conformance in
+ databases; to automatically generate constraints in
+ drag-and-drop style graphical interfaces; and to generate
+ graphical displays by parsing relational data and generating
+ output code.
+
+ requires: Common Lisp
+
+ ports: Allegro Common Lisp 4.1, Macintosh Common Lisp 2.0
+
+ {(ftp://flash.bellcore.com/rl/)}.
+
+ (1992-10-31)
+
+RLaB
+
+ A {MATLAB}-like matrix-oriented programming language/toolbox.
+ RLaB focusses on creating a good experimental environment (or
+ laboratory) in which to do matrix mathematics. Currently RLaB
+ has numeric scalars and matrices (real and complex), and
+ string scalars, and matrices. RLaB also contains a list
+ variable type, which is a heterogeneous associative array.
+
+ Version 0.95 includes an interpreter, libraries and
+ documentation. E-mail: Ian Searle <ians@eskimo.com>.
+ {(ftp://evans.ee.adfa.oz.au)}. Requires {GNUPLOT},
+ lib[IF]77.a (from f2c). Ported to many {platforms} including
+ {Unix}, {OS/2}, {Amiga}.
+
+ (1993-10-27)
+
+RLDRAM
+
+ <storage> (Reduced Latency DRAM) A kind of {dynamic random
+ access memory}. RLDRAM comes in "common IO" and "separate IO"
+ configurations. It supports {broadside addressing}. It is
+ typically used in networking gear and set-top boxes that
+ require high {bandwidth} memory.
+
+ [What is the latency, and how does it compare to ordinary DRAM?]
+
+ (2007-03-20)
+
+RLE
+
+ {run-length encoding}
+
+RLF
+
+ {Reuse Library Framework} of the {DoD}.
+
+RLL
+
+ 1. <language> {Representation Language Language}.
+
+ 2. <storage> {Run Length Limited}.
+
+ (2003-07-24)
+
+rlogin
+
+ <networking, tool> (Remote login) The {4.2BSD} {Unix} utility
+ to allow a user to log in on another {host} via a network.
+ Rlogin communicates with a {daemon} on the remote host.
+
+ {Unix manual page}: rlogin(1).
+
+ See also {telnet}.
+
+ (1997-01-12)
+
+RMAG
+
+ {Recursive Macro Actuated Generator}
+
+RMAIL
+
+ <messaging> A {MUA} written in {Emacs Lisp} to run within
+ {Emacs}.
+
+ (1996-03-21)
+
+RMI
+
+ {Remote Method Invocation}
+
+RM-ODP
+
+ <programming> The {ISO Reference Model} for {Open
+ Distributed Environments}.
+
+ {(http://pepper.open.ac.uk/~armsarms/sa.html)}.
+
+ (1995-11-23)
+
+RMON
+
+ 1. <networking> {remote monitoring}.
+
+ 2. {Remote Monitor}.
+
+ (2003-09-15)
+
+RMS
+
+ 1. {Record Management Services}.
+
+ 2. {Richard Stallman}.
+
+RNF
+
+ {root normal form}
+
+ro
+
+ <networking> The {country code} for Romania.
+
+ (1999-01-27)
+
+roach
+
+ <jargon> A {Bell Labs} term meaning destroy, especially of a
+ data structure. Hardware gets {toast}ed or {fried}, software
+ gets roached.
+
+ [Why?]
+
+ [{Jargon File}]
+
+ (1999-02-08)
+
+ROADS
+
+ Subsystem of ICES. Sammet 1969, p.616.
+
+Robert T. Morris
+
+ The creator of the "{Internet Worm}" that wreaked havoc on
+ many {Internet} systems for a day or two.
+
+ Morris, the son of an NSA spook, did some jail time for
+ releasing the worm.
+
+ (1995-01-12)
+
+ROBEX
+
+ ROBot EXapt. Aachen Tech College. Based on EXAPT. Version:
+ ROBEX-M for micros.
+
+RoboHELP
+
+ <tool> A {Microsoft} {Windows} Help authoring tool from {Blue
+ Sky Software}. Used with {Microsoft Word} to create Help
+ files for inclusion in a Windows application or for stand
+ alone use.
+
+ (1997-01-19)
+
+robot
+
+ 1. <robotics> A mechanical device for performing a task which
+ might otherwise be done by a human, e.g. spraying paint on
+ cars.
+
+ See also {cybernetics}.
+
+ 2. <chat> An {IRC} or {MUD} user who is actually a program.
+ On IRC, typically the robot provides some useful service.
+ Examples are {NickServ}, which tries to prevent random users
+ from adopting {nicks} already claimed by others, and MsgServ,
+ which allows one to send {asynchronous} messages to be
+ delivered when the recipient signs on. Also common are
+ "annoybots", such as KissServ, which perform no useful
+ function except to send cute messages to other people.
+ Service robots are less common on {MUDs}; but some others,
+ such as the "Julia" robot active in 1990--91, have been
+ remarkably impressive {Turing test} experiments, able to pass
+ as human for as long as ten or fifteen minutes of
+ conversation.
+
+ 3. <web> {spider}.
+
+ [{Jargon File}]
+
+ (1996-03-23)
+
+robot exclusion standard
+
+ {standard for robot exclusion}
+
+robots.txt
+
+ {standard for robot exclusion}
+
+robust
+
+ Said of a system that has demonstrated an ability to recover
+ gracefully from the whole range of exceptional inputs and
+ situations in a given environment. One step below
+ {bulletproof}. Carries the additional connotation of elegance
+ in addition to just careful attention to detail. Compare
+ {smart}, opposite: {brittle}.
+
+ [{Jargon File}]
+
+Rockwell Protocol Interface
+
+ (RPI) A cost-cutting feature of some {modems} allowing data
+ {compression} and {error correction} (e.g. {ITU-T} {V.42bis},
+ {V.42}) to be provided in software instead of hardware.
+
+ Usually an RPI modem comes with RPI-aware software (e.g. the
+ low-end RPI models of Supra come with the {COMit} which
+ supports RPI, providing {MNP} 2,4,5,7, V.42 and V.42bis). RPI
+ is not supported by many commercial packages nor by current
+ releases of popular {shareware} communication programs
+ ({Telix} v3.22 and {Telemate} v4.12). {ProComm Plus} for
+ {Windows 2.0} will support RPI.
+
+ Currently {Rockwell} produce two classes of RPI chip set. The
+ original is capable of 2400 bit/s data, 9600 bit/s class
+ 1-only fax. The newer one is capable of 14400 bit/s data/fax.
+ Currently there are no RPI chipset from Rockwell supporting
+ speeds higher than 14400 bit/s.
+
+ (1994-07-01)
+
+Rocky Mountain Basic
+
+ <language> The {BASIC} language used by {Hewlett Packard} on
+ their {680x0}-based computers. Rocky Mountain Basic is good
+ for interfaces to {IEEE 488} controls and contains many
+ mathematical and matrix functions. It has about 600 commands.
+ Typical applications include automatic test stations.
+
+ (1996-04-28)
+
+rococo
+
+ <jargon, abuse> {Baroque} in the extreme. Used to imply that
+ a program has become so encrusted with the software equivalent
+ of gold leaf and curlicues that they have completely swamped
+ the underlying design. Called after the later and more
+ extreme forms of Baroque architecture and decoration prevalent
+ during the mid-1700s in Europe. Alan Perlis said: "Every
+ program eventually becomes rococo, and then rubble."
+
+ Compare {critical mass}.
+
+ [{Jargon File}]
+
+ (1996-04-06)
+
+ROCOF
+
+ {Rate of Occurrence of Failures}
+
+roff
+
+ <text, tool> A text formatting language associated with
+ {Unix}. See {groff}, {nroff}, {troff}.
+
+ [Was roff the original? Platform(s)?]
+
+ (1998-11-14)
+
+ROFL
+
+ {ROTFL}
+
+ROFLMAO
+
+ {ROTFLMAO}
+
+rogue
+
+ <games> [Unix] A Dungeons-and-Dragons-like game using
+ character graphics, written under BSD Unix and subsequently
+ ported to other Unix systems. The original BSD "curses(3)"
+ screen-handling package was hacked together by Ken Arnold to
+ support "rogue(6)" and has since become one of Unix's most
+ important and heavily used application libraries. Nethack,
+ Omega, Larn, and an entire subgenre of computer dungeon games
+ all took off from the inspiration provided by "rogue(6)". See
+ also {nethack}.
+
+ [{Jargon File}]
+
+rollback
+
+ <database> Reverting data in a {database} to an earlier state,
+ usually in response to an error or aborted operation.
+
+ In a {transaction} based database system, transactions are
+ considered {atomic}. If an error occurs while performing a
+ transaction, the database is automatically rolled back
+ to the state at the previous {commit}.
+
+ Rollback may also be performed by an explicit rollback
+ transaction.
+
+ (2000-01-15)
+
+ROM
+
+ {Read-Only Memory}
+
+ROM BIOS
+
+ {Basic Input/Output System}
+
+ROME
+
+ An experimental {object-oriented} language.
+
+ ["The Point of View Notion for {Multiple Inheritance}",
+ B. Carre et al, SIGPLAN Notices 25(10):312-321 (OOPSLA/ECOOP
+ '90) (Oct 1990)].
+
+ (1994-11-30)
+
+Rom Kernel Manual
+
+ <publication> (RKM) A series of books or files for developers
+ for the {Amiga} computer, containing information about the
+ {operating system} {kernel} stored in {ROM}.
+
+ (1996-04-06)
+
+room
+
+ {channel}
+
+ROOM Methodology
+
+ {Real-Time Object-Oriented Modeling}
+
+room-temperature IQ
+
+ <abuse> (IBM) 80 or below. Used in describing the expected
+ intelligence range of the {luser}. "Well, but how's this
+ interface going to play with the room-temperature IQ crowd?"
+ This is a much more insulting phrase in countries that use
+ Celsius thermometers.
+
+ See {drool-proof paper}.
+
+ [{Jargon File}]
+
+ (1996-04-06)
+
+root
+
+ 1. <operating system> The {Unix} {superuser} account (with
+ user name "root" and user ID 0) that overrides file
+ permissions. The term {avatar} is also used. By extension,
+ the privileged system-maintenance login on any {operating
+ system}.
+
+ See {root mode}, {go root}, {wheel}.
+
+ [{Jargon File}]
+
+ (1994-10-27)
+
+ 2. <operating system> {root directory}.
+
+ (1996-11-21)
+
+ 3. <data> {root node}.
+
+ (1998-11-14)
+
+root bridge
+
+ <communications, hardware, networking> A {bridge} which
+ continuously transmits {network} {topology} information to
+ other bridges, using the {spanning tree protocol}, in order to
+ notify all other bridges on the network when topology changes
+ are required.
+
+ This means that a network is able to reconfigure itself
+ whenever a network link (e.g. another bridge) fails, so an
+ alternative path can be found. The presence of a root
+ bridge also prevents {loops} from forming in the network.
+
+ The root bridge is where the paths that {frames} take through
+ the network they are assigned. It should be located centrally
+ on the network to provide the shortest path to other links on
+ the network. Unlike other bridges, the root bridge always
+ forwards frames out over all of its {ports}.
+
+ Every network should only have one root bridge. It should
+ have the lowest bridge ID number.
+
+ (2000-11-26)
+
+root directory
+
+ <file system> The topmost node of a {hierarchical file
+ system}.
+
+ (1996-11-21)
+
+root mode
+
+ Synonym with {wizard mode} or "wheel mode". Like these, it is
+ often generalised to describe privileged states in systems
+ other than {operating systems}.
+
+ [{Jargon File}]
+
+root node
+
+ <mathematics, data> In a {tree}, a node with no {parents}, but
+ which typically has {daughters}.
+
+ (1998-11-14)
+
+Root Normal Form
+
+ (RNF) {Head Normal Form} in {graph rewriting}.
+
+root version
+
+ The initial value of an object in a {change management}
+ system.
+
+ROSE
+
+ {Remote Operations Service Element}
+
+Rosette
+
+ <language> A {concurrent} {object-oriented language} from
+ {MCC}.
+
+ [Details?]
+
+ (1997-11-26)
+
+Roskind grammars
+
+ <tool> {Yacc}-based {parsers} for {C} and {C++} by Jim
+ Roskind. It does not use the %prec and %assoc YACC features
+ so conflicts are never hidden. The C {grammar} has only one
+ {shift-reduce conflict}, the C++ grammar has a few more. With
+ {byacc} it can produce graphical {parse trees} automatically.
+ The C grammar conforms to {ANSI C} and the C++ grammar
+ supports {cfront} 2.0 constructs.
+
+ Latest version: cpp5 (cf2.0).
+
+ {(ftp://ftp.infoseek.com/pub/c++grammar/)}.
+
+ (2003-10-09)
+
+rot13
+
+ /rot ther'teen/ [{Usenet}: from "rotate alphabet 13 places"],
+ v. The simple Caesar-cypher encryption that replaces each
+ English letter with the one 13 places forward or back along
+ the alphabet, so that "The butler did it!" becomes "Gur ohgyre
+ qvq vg!" Most {Usenet} news reading and posting programs
+ include a rot13 feature. It is used to enclose the text in a
+ sealed wrapper that the reader must choose to open - e.g. for
+ posting things that might offend some readers, or {spoilers}.
+ A major advantage of rot13 over rot(N) for other N is that it
+ is self-inverse, so the same code can be used for encoding and
+ decoding.
+
+ [{Jargon File}]
+
+rotary debugger
+
+ (Commodore) Essential equipment for those late-night or
+ early-morning debugging sessions. Mainly used as sustenance
+ for the hacker. Comes in many decorator colours, such as
+ Sausage, Pepperoni, and Garbage.
+
+ (1995-01-11)
+
+rotational latency
+
+ <storage, hardware> The time for the start of the required
+ {sector} on a {disk} to appear underneath the {read/write
+ head}. The worst case is where it has just passed the head
+ when the request is received. For a {disk drive} with N heads
+ per surface, rotating at R revolutions per minute, the average
+ rotational latency will be
+
+ L = 30/NR seconds.
+
+ Rotational latency is one component of {access time}.
+
+ (2009-11-06)
+
+rotations per minute
+
+ {revolutions per minute}
+
+ROTFL
+
+ <chat> (Or "ROFL") Rolling on the floor laughing (or rolls...).
+
+ Used in {chat}, {MUD}, {news}.
+
+ See also {ROTFLMAO}, {ROTFLOL}.
+
+ (1996-02-22)
+
+ROTFLMAO
+
+ <chat> Rolling on the floor laughing my ass (arse) off. An
+ extreme form of {ROTFL}.
+
+ (2000-11-12)
+
+ROTFLMAOASTC
+
+ <chat> Rolling on the floor laughing my ass (or arse) off and scaring
+ the cat. The superlative form of {ROTFL}.
+
+ (2004-04-06)
+
+ROTFLOL
+
+ <chat> Rolling on the floor laughing out loud. See {ROTFL}.
+
+ (1997-03-06)
+
+round-robin
+
+ <algorithm> A {scheduling} {algorithm} in which processes are
+ activated in a fixed cyclic order. Those which cannot proceed
+ because they are waiting for some event (e.g. termination of a
+ {child process} or an input/output operation) simply return
+ control to the scheduler. The virtue of round-robin
+ scheduling is its simplicity - only the processes themselves
+ need to know what they are waiting for or how to tell if it
+ has happened. However, if a process goes back to sleep just
+ before the event for which it is waiting occurs then the event
+ will not get handled until all the other processes have been
+ activated.
+
+ Compare {priority scheduling}.
+
+ (1996-02-10)
+
+round tape
+
+ <storage, jargon> Industry-standard 1/2-inch {magnetic tape}
+ (7- or 9-track) on traditional circular reels.
+
+ See {macrotape}, opposite: {square tape}.
+
+ [{Jargon File}]
+
+ (1996-02-03)
+
+round-trip time
+
+ (RTT) A measure of the current delay on a network, found by
+ timing a packet bounced off some remote host. This can be
+ done with {ping} -s.
+
+ (1994-11-30)
+
+route
+
+ <networking> /root/ The sequence of {hosts}, {routers},
+ {bridges}, {gateways}, and other devices that network traffic
+ takes, or could take, from its source to its destination. As
+ a verb, to determine the link down which to send a {packet},
+ that will minimise its total journey time according to some
+ {routeing algorithm}.
+
+ You can find the route from your computer to another using the
+ program {traceroute} on {Unix} or tracert on {Microsoft
+ Windows}.
+
+ (2001-05-26)
+
+routed
+
+ <networking> /root dee/ Route Daemon. A program which runs
+ under {4.2BSD} {Unix} systems and derivatives to propagate
+ routes among machines on a {local area network}, using the
+ {Routing Information Protocol}. See also {gated}.
+
+ (2002-07-31)
+
+route flapping
+
+ {flapping router}
+
+routeing
+
+ <networking> (US "routing") /roo'ting/ The process, performed
+ by a {router}, of selecting the correct interface and next
+ {hop} for a {packet} being forwarded.
+
+ This is the British and international standard spelling.
+
+ See also {Exterior Gateway Protocol}, {Interior Gateway
+ Protocol}.
+
+ (2001-05-28)
+
+routeing domain
+
+ <networking> (US "routing") A set of {routers} that exchange
+ routeing information within an {administrative domain}.
+
+ (1994-12-14)
+
+router
+
+ <networking> /roo't*/ A device which forwards {packets}
+ between {networks}. The forwarding decision is based on
+ {network layer} information and routing tables, often
+ constructed by routing {protocols}.
+
+ {Unix manual page}: route(8).
+
+ See also {bridge}, {gateway}, {Exterior Gateway Protocol},
+ {Interior Gateway Protocol}, {flapping router}.
+
+ (1999-08-24)
+
+routine
+
+ {subroutine}
+
+routing
+
+ <tool> /row'ting/ Using a kind of rotating cutting tool called
+ a router, pronounced /row't*/. In the USA a {router},
+ pronounced /row't*/, is also a network device that performs
+ "routing". In the UK, the network device is pronounced
+ /roo't*/ and what it does is spelled "{routeing}".
+
+ (2002-07-31)
+
+Routing Information Protocol
+
+ 1. <networking> (RIP) A {distance vector}, as opposed to {link
+ state}, {routing} {protocol}. RIP is an {Internet} {standard}
+ {Interior Gateway Protocol} defined in {STD} 34, {RFC 1058}
+ and updated by {RFC 1388}.
+
+ See also {Open Shortest Path First}.
+
+ 2. <networking> (RIP) A companion {protocol} to {IPX} for
+ exchange of {routing} information in a {Novell} {network}.
+ RIP has been partly superseded by {NLSP}. It is not related
+ to the {Internet} protocol of the same name.
+
+ (1997-03-04)
+
+routing policy
+
+ <networking> Rules implemented on a {router} or other network
+ device to select routes from peers, customers, and upstream
+ providers; select and modify routes you send to peers,
+ customers and upstream providers and identify routes within
+ your own {Autonomous System}.
+
+ {(http://www.nanog.org/mtg-0202/ppt/golding/sld005.htm)}.
+
+ (2008-12-12)
+
+Routing Table Maintenance Protocol
+
+ <protocol> (RTMP) A {protocol} used by {AppleTalk} to ensure
+ that all {routers} on the network have consistent routing
+ information.
+
+ (1997-05-11)
+
+row
+
+ {record}
+
+Row Address Strobe
+
+ <storage> (RAS) An input to a {dynamic random-access memory}
+ (DRAM) to indicate that the row address lines are valid.
+
+ (2004-02-15)
+
+row-level locking
+
+ <database> A technique used in {database management systems},
+ where a {row} is locked for writing to prevent other users
+ from accessing data being while it is being updated.
+
+ Other techniques are {table locking} and {MVCC}.
+
+ (1999-06-18)
+
+Royal Veterinary and Agricultural University
+
+ Address: Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
+
+ (1994-12-12)
+
+RPC
+
+ {Remote Procedure Call}
+
+RPG
+
+ 1. <games> {Role-Playing Game}.
+
+ 2. <tool> {Report Program Generator}.
+
+ 3. <person> {Richard Gabriel}.
+
+ (1999-10-12)
+
+RPG-II
+
+ {Report Program Generator}
+
+RPI
+
+ {Rockwell Protocol Interface}
+
+RPL
+
+ Reverse Polish LISP. Language used by HP-28 and HP-48
+ calculators.
+
+RPL-1
+
+ Data reduction language. Proc SJCC 30:571-575, AFIPS (Spring
+ 1967).
+
+RPM
+
+ <operating system, tool> A {Unix} {package}-management system
+ that helps installation of software packages; similar to an
+ install program.
+
+ [More details? Reference? Expansion?]
+
+ (1996-03-07)
+
+rpm
+
+ {rotation per minute}
+
+RPN
+
+ {postfix notation}
+
+Répondez s'il vous plait
+
+ <chat> (RSVP) French for "please reply", commonly found
+ (abbreviated) on invitations.
+
+ (1996-12-02)
+
+RPT
+
+ Unify. Report Writer Language.
+
+RRL
+
+ {Remote Reference Layer}
+
+RRS
+
+ An early definition of {Scheme}. Revised in {R2RS}.
+
+ ["The Revised Report on Scheme", G.L. Steele et al, AI Memo
+ 452, MIT, Jan 1978].
+
+ (1994-10-28)
+
+ [Was the original "Report on Scheme" published?]
+
+RS
+
+ 1. <character> {Record Separator}
+
+ 2. <standard> Recommended Standard, a series of {EIA}
+ {standards} including {EIA-232}.
+
+RS-232
+
+ {EIA-232}
+
+RS-232C
+
+ Renamed {EIA-232C}
+
+ (2004-08-02)
+
+RS-232D
+
+ <communications, standard> The {EIA} equivalent of {ITU-T}
+ {standard} {V.28}.
+
+ [Difference from EIA-232/EIA-232C?]
+
+ (1995-03-02)
+
+RS-422
+
+ {EIA-422}
+
+RS-423
+
+ {EIA-423}
+
+RS-449
+
+ {EIA-449}
+
+RS-485
+
+ {EIA-485}
+
+RS6000
+
+ {RISC System/6000}
+
+RS/6000
+
+ {RISC System/6000}
+
+RS6K
+
+ {RISC System/6000}
+
+RSA
+
+ <cryptography, company> (The initials of the authors)
+
+ 1. {RSA Data Security, Inc.}
+
+ 2. Their {cryptography} systems, especially {RSA encryption}.
+
+ The RSA {algorithm} was first described in the paper:
+
+ [R. Rivest, A. Shamir, L. Adleman, "A Method for Obtaining
+ Digital Signatures and Public-key Cryptosystems". CACM 21,2;
+ 1978]
+
+ (1995-03-21)
+
+RSA Data Security, Inc.
+
+ <cryptography, company> (After Rivest, Shamir, Adleman - see
+ {RSA}) A recognised world leader in {cryptography}, with
+ millions of copies of its software encryption and
+ authentication installed and in use worldwide. RSA's
+ technologies are the global {de facto standard} for {public
+ key cryptography} and {digital signatures}, and are part of
+ existing and proposed {standards} for the {Internet}, {ITU-T},
+ {ISO}, {ANSI}, {PKCS}, {IEEE} and business and financial
+ networks around the world.
+
+ {(http://rsa.com/)}.
+
+ (1994-12-08)
+
+RSA encryption
+
+ <cryptography, algorithm> A {public-key cryptosystem} for both
+ {encryption} and {authentication}, invented in 1977 by Ron
+ Rivest, Adi Shamir, and Leonard Adleman. Its name comes from
+ their initials.
+
+ The RSA {algorithm} works as follows. Take two large {prime
+ numbers}, p and q, and find their product n = pq; n is called
+ the modulus. Choose a number, e, less than n and {relatively
+ prime} to (p-1)(q-1), and find its reciprocal mod (p-1)(q-1),
+ and call this d. Thus ed = 1 mod (p-1)(q-1); e and d are
+ called the public and private exponents, respectively. The
+ public key is the pair (n, e); the private key is d. The
+ factors p and q must be kept secret, or destroyed. It is
+ difficult (presumably) to obtain the private key d from the
+ public key (n, e). If one could factor n into p and q,
+ however, then one could obtain the private key d. Thus the
+ entire security of RSA depends on the difficulty of factoring;
+ an easy method for factoring products of large prime numbers
+ would break RSA.
+
+ {RSA FAQ (http://rsa.com/rsalabs/faq/faq_home.html)}.
+
+ (2004-07-14)
+
+RSCS
+
+ <communications> {Remote Spooling Communication
+ Subsystem}.
+
+ (1996-02-04)
+
+Réseaux Associés pour la Recherche Européenne
+
+ (RARE) An association of national and international European
+ networks and users.
+
+ See also {CCIRN}.
+
+ (1994-11-30)
+
+Réseaux IP Européens
+
+ (RIPE) A collaboration between European networks which use the
+ {TCP/IP} {protocol} suite to provide {Internet} services.
+
+ (1994-11-30)
+
+RS flip-flop
+
+ {SR flip-flop}
+
+rsh
+
+ Remote shell.
+
+ A {Berkeley Unix} networking command to execute a given
+ command on a remote {host}, passing it input and receiving its
+ output. Rsh communicates with a {daemon} on the remote host.
+ It is sometimes called remsh to avoid confusion with the
+ {restricted shell}, also called "rsh".
+
+ {Unix manual page}: rsh(1).
+
+ (1994-12-08)
+
+RSI
+
+ 1. <medical> {overuse strain injury}.
+
+ 2. <company> {Research Systems, Inc.}.
+
+ (1999-01-08)
+
+RSL
+
+ {RAISE Specification Language}
+
+RSN
+
+ {Real Soon Now}
+
+RSS
+
+ {Rich Site Summary}
+
+RSS feed
+
+ {Rich Site Summary}
+
+rstat
+
+ {netstat}
+
+RSTS/E
+
+ <operating system> A {multi-user}, general purpose
+ {timesharing} {operating system} produced by {Mentec, Inc.}
+ and licensed bu {Digital Equipment Corporation}.
+
+ RSTS/E can be used for interactive timesharing, {batch
+ processing}, indirect command file processing, program
+ development using a variety of languages and tools, and a wide
+ variety of special purpose applications. Up to 127 concurrent
+ {terminal} users in both local and remote locations through
+ multi-terminal services can interact with application tasks.
+ Without multi-terminal services, 63 users are the maximum.
+ Tasks can share computational, storage, and input/output
+ services provided by the RSTS/E system.
+
+ {Full description
+ (http://pyrfect.ico.olivetti.com/SPD/13-01-37.txt)}.
+
+ (1996-06-04)
+
+RSVP
+
+ 1. <chat> {Répondez s'il vous plait}.
+
+ 2. <protocol> {Resource Reservation Protocol}.
+
+ 3. <body> {Revolutionary Surrealist Vandal Party}.
+
+ (2001-03-18)
+
+RT-11
+
+ <operating system> A {real time} {operating system} for the
+ {DEC} {PDP-11} computers, used in the early 1980s and still in
+ 2005 found occasionally in old {embedded systems}.
+
+ (2005-01-26)
+
+RTBM
+
+ ({Unix}) Read The Bloody Manual.
+
+ {Commonwealth Hackish} variant of {RTFM}. RTBM is often the
+ entire text of the first reply to a question from a {newbie};
+ the *second* would escalate to "RTFM".
+
+ [{Jargon File}]
+
+ (1994-12-08)
+
+RTC++
+
+ A {real-time} extension of {C++}.
+
+ ["Object-Oriented Real-Time Language Design: Constructs for
+ Timing Constraints", Y. Ishikawa et al, SIGPLAN Notices
+ 25(10):289-298 (OOPSLA/ECOOP '90) (Oct 1990)].
+
+ (1994-12-08)
+
+RT-CDL
+
+ {Real-Time Common Design Language}
+
+RTEE
+
+ Real Time Engineering Environment: a set of CASE tools
+ produced by Westmount Technology B.V.
+
+RTF
+
+ {Rich Text Format}
+
+RTFAQ
+
+ ({Usenet}, primarily written, by analogy with {RTFM}) Read the
+ FAQ!
+
+ An exhortation that the person addressed ought to read the
+ newsgroup's {FAQ list} before posting questions.
+
+ [{Jargon File}]
+
+ (1994-12-08)
+
+RTFB
+
+ <jargon> (By analogy with {RTFM}) Read The Fucking
+ Binary.
+
+ Used when neither {documentation} nor {source} for the problem
+ at hand exists, and the only thing to do is use some
+ {debugger} or {monitor} and directly analyse the {assembler}
+ or even the {machine code}.
+
+ "RTFB" is the least pejorative of the RTF? forms, the anger is
+ directed at the absence of both source *and* adequate
+ documentation rather than at the person asking a question.
+
+ [{Jargon File}]
+
+ (1995-08-20)
+
+RTFM
+
+ <jargon> /R T F M/ Read The Fucking Manual (always
+ abbreviated, sometimes bowdlerised to "Fine" or "Friendly") An
+ (unhelpful) {guru}'s traditional response when someone asks a
+ question in a {newsgroup} or {mailing list} which he could
+ have easily answered for himself had he bothered to RTFM.
+
+ The term may also be used to indicate that you couldn't find
+ the answer in the manual. E.g. "How do I interface Unix to my
+ toaster? And yes, I did RTFM but the {FM} didn't help and I
+ can't {RTFS}."
+
+ Other derived forms include {RTFAQ}, {RTFB}, {RTM}, {RYFM}
+ and, more recently, {STFW}. Compare: {UTSL}.
+
+ [Earliest use?]
+
+ [{Jargon File}]
+
+ (2003-06-07)
+
+RTFS
+
+ <jargon> 1. Read The Fucking Source. Variant form of {RTFM},
+ used when the problem at hand is not necessarily obvious and
+ not answerable from the manuals - or the manuals are not yet
+ written and maybe never will be. For even trickier
+ situations, see {RTFB}. Unlike RTFM, the anger inherent in
+ RTFS is not usually directed at the person asking the
+ question, but rather at the people who failed to provide
+ adequate documentation.
+
+ 2. Read The Fucking Standard; this oath can only be used when
+ the problem area (e.g. a language or operating system
+ interface) has actually been codified in a ratified standards
+ document. The existence of these standards documents (and the
+ technically inappropriate but politically mandated compromises
+ that they inevitably contain, and the impenetrable {legalese}
+ in which they are invariably written, and the unbelievably
+ tedious bureaucratic process by which they are produced) can
+ be unnerving to hackers, who are used to a certain amount of
+ ambiguity in the specifications of the systems they use.
+ (Hackers feel that such ambiguities are acceptable as long as
+ the {Right Thing} to do is obvious to any thinking observer;
+ sadly, this casual attitude toward specifications becomes
+ unworkable when a system becomes popular in the {Real World}.)
+ Since a hacker is likely to feel that a standards document is
+ both unnecessary and technically deficient, the deprecation
+ inherent in this term may be directed as much against the
+ standard as against the person who ought to read it.
+
+ [{Jargon File}]
+
+RTI
+
+ {Return from interrupt}
+
+RTL
+
+ 1. <hardware> {Resistor-Transistor Logic}.
+
+ 2. <language> {Register Transfer Language}.
+
+RTL/1
+
+ <language> Real Time Language.
+
+ A {real-time} language written by J.G.P. Barnes of {ICI} in
+ 1971. It was the predecessor of {RTL/2}.
+
+ ["Real Time Languages for Process Control", J.G.P. Barnes,
+ Computer J 15(1):15-17, Feb 1972].
+
+ (1994-11-09)
+
+RTL/2
+
+ Real Time Language.
+
+ A small {real-time} language based on {ALGOL 68}, with
+ {separate compilation} designed by J.G.P. Barnes of ICI in
+ 1972 as a successor to {RTL/1}.
+
+ A program is composed of separately compilable modules called
+ "bricks" which may be datablocks, procedures or stack. A
+ stack is a storage area for use as a workspace by a task. The
+ language is {block-structured} and {weakly typed}. Simple
+ types are byte, int, frac and real. There are no {Booleans}.
+ Compound types may be formed from {arrays}, {records} and
+ {refs} (pointers). There are no user-defined types. Control
+ statements are if-then-elseif-else-end, for-to-by-do-rep,
+ block-endblock, switch, goto, and label variables.
+
+ ["RTL/2: Design and Philosophy", J.G.P. Barnes, Hayden & Son,
+ 1976].
+
+RTM
+
+ 1. [{Usenet}] Read The Manual. Politer variant of {RTFM}.
+
+ 2. Robert T. Morris Jr.
+
+ The perpetrator of the great Internet worm of 1988 (see {Great
+ Worm}); villain to many, naive hacker gone wrong to a few.
+ Morris claimed that the worm that brought the Internet to its
+ knees was a benign experiment that got out of control as the
+ result of a coding error. After the storm of negative
+ publicity that followed this blunder, Morris's user name on ITS
+ was hacked from RTM to {RTFM}.
+
+ [{Jargon File}]
+
+ (1995-03-31)
+
+RTMP
+
+ {Routing Table Maintenance Protocol}
+
+RTOS
+
+ {Real-Time Operating System}
+
+RTP
+
+ {Real-Time Transport Protocol}
+
+RT-PC
+
+ <computer> RISC Technology Personal Computer.
+
+ (Commonly, but incorrectly, known as the "PC-RT", later
+ changed to just "RT") {IBM}'s first {RISC}-based {Unix}
+ computer. The RT-PC was the predecessor to IBM's {RS/6000}.
+ It ran {AIX} 1.x and 2.x and had a {PC-AT} bus and IBM's
+ {ROMP} {microprocessor}. It was withdrawn from the marketing
+ around 1989 or 1990.
+
+ (1995-04-06)
+
+RTS
+
+ 1. <operating system> {run-time system}.
+
+ 2. <programming> {return from subroutine}.
+
+ (1999-07-26)
+
+RTSA
+
+ {real-time structured analysis}
+
+RTSP
+
+ {Real Time Streaming Protocol}
+
+RTT
+
+ {Round-Trip Time}
+
+RTTI
+
+ {Run Time Type Information}
+
+RTTY
+
+ {radio teletypewriter}
+
+ru
+
+ <networking> The {country code} for the Russian Federation.
+
+ (1999-01-27)
+
+rubi
+
+ {furigana}
+
+Ruby
+
+ <language>
+
+ 1. A {relational language} designed by Jones and M. Sheeran in
+ 1986 for describing and designing circuits (a {hardware
+ description language}). Ruby programs denote {binary
+ relations} and programs are built-up inductively from
+ primitive relations using a pre-defined set of {relational
+ operators}. Ruby programs also have a geometric
+ interpretation as networks of primitive relations connected by
+ wires, which is important when layout is considered in circuit
+ design.
+
+ Ruby has been continually developed since 1986, and has been
+ used to design many different kinds of circuits, including
+ {systolic arrays}, {butterfly networks} and arithmetic
+ circuits.
+
+ {(ftp://ftp.cs.chalmers.se/pub/misc/ruby/)}.
+
+ E-mail: <graham@cs.chalmers.se>.
+
+ ["Ruby - A Language of Relations and Higher-Order Functions",
+ M. Sheeran, Proc 3rd Banff Workshop on Hardware Verification,
+ Springer 1990].
+
+ (1994-10-27)
+
+ 2. One of five pedagogical languages based on {Markov
+ algorithms}, used in Higman's report (below). The other
+ languages are {Brilliant}, {Diamond}, {Nonpareil}, and
+ {Pearl}.
+
+ ["Nonpareil, a Machine Level Machine Independent Language for
+ the Study of Semantics", B. Higman, ULICS Intl Report No ICSI
+ 170, U London (1968)].
+
+ (1994-10-27)
+
+ 3. A fully {object oriented} {interpreted} {scripting
+ language} by Yukihiro Matsumoto <matz@netlab.co.jp>.
+
+ Similar in scope to {Perl} and {Python}, Ruby has high-level
+ {data types}, automatic {memory management}, {dynamic typing},
+ a {module} system, {exceptions}, and a rich standard library.
+ Other features are {CLU}-style {iterators} for {loop
+ abstraction}, {singleton classes}/{methods} and {lexical
+ closures}.
+
+ In Ruby, everything is an {object}, including the basic data
+ types. For example, the number 1 is an instance of {class}
+ Fixnum.
+
+ Current version (stable): 1.6.7, as of 2002-03-01.
+
+ {Ruby Home (http://ruby-lang.org/)}.
+
+ {Ruby Central (http://rubycentral.com/)}.
+
+ ["Programming Ruby - The Pragmatic Programmer's Guide", David
+ Thomas, Andrew Hunt, Yukihiro Matsumoto pub. Addison Wesley
+ 2000].
+
+ (2002-06-19)
+
+rude
+
+ [WPI] 1. Badly written or functionally poor, e.g. a program
+ that is very difficult to use because of gratuitously poor
+ design decisions. Opposite: {cuspy}.
+
+ 2. Anything that manipulates a shared resource without regard
+ for its other users in such a way as to cause a (non-fatal)
+ problem. Examples: programs that change tty modes without
+ resetting them on exit, or windowing programs that keep
+ forcing themselves to the top of the window stack. Compare
+ {all-elbows}.
+
+ [{Jargon File}]
+
+ (1994-10-27)
+
+RUFL
+
+ Rhodes University Functional Language. A {Miranda}-like
+ functional language from Rhodes University, Grahamstown, South
+ Africa with a {SPARC} {code generator}.
+
+ (1994-10-27)
+
+run
+
+ {execution}
+
+RUNCIBLE
+
+ Early system for mathematics on {IBM 650}.
+
+ See also {FORTRUNCIBLE}, {IT}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1994-10-27)
+
+runes
+
+ 1. Anything that requires {heavy wizardry} or {black art} to
+ {parse}: core dumps, {JCL} commands, {APL} or code in a
+ language you haven't a clue how to read. Not quite as bad as
+ {line noise}, but close.
+
+ Compare {casting the runes}, {Great Runes}.
+
+ 2. Special display characters (for example, the high-half
+ graphics on an {IBM PC}).
+
+ [{Jargon File}]
+
+runic
+
+ <jargon> Obscure, consisting of {runes}.
+
+ {VMS} fans sometimes refer to {Unix} as "RUnix". Unix fans
+ return the compliment by expanding VMS to "Very Messy Syntax"
+ or "Vachement Mauvais Systeme" (French; literally "Cowlike Bad
+ System", idiomatically "Bitchy Bad System").
+
+ (1996-09-17)
+
+run-length encoding
+
+ A kind of {compression} {algorithm} which replaces sequences
+ ("runs") of consecutive repeated characters (or other units of
+ data) with a single character and the length of the run. This
+ can either be applied to all input characters, including runs
+ of length one, or a special character can be used to introduce
+ a run-length encoded group. The longer and more frequent the
+ runs are, the greater the compression that will be achieved.
+ This technique is particularly useful for encoding black and
+ white {images} where the data units would be single bit
+ {pixels}.
+
+ (1994-10-27)
+
+Run Length Limited
+
+ <storage> (RLL) The most popular scheme for encoding data on
+ {magnetic disks}. RLL packs up to 50% more data on a disk
+ than {MFM}.
+
+ {IBM} invented RLL encoding and used it in {mainframe} disk
+ drives. During the late 1980s, {PC} hard disks began using
+ RLL. Today, virtually every drive on the market uses some
+ form of RLL.
+
+ Groups of bits are mapped to specific patterns of flux. The
+ density of flux transitions is limited by the spatial
+ resolution of the disk and frequency response of the head and
+ electronics. However, transitions must be close enough to
+ allow reliable {clock recovery}. RLL implementations vary
+ according to the minimum and maximum allowed numbers of
+ {transition cells} between transitions. For example, the most
+ common variant today, RLL 1,7, can have a transition in every
+ other cell and must have at least one transition every seven
+ cells. The exact mapping from bits to transitions is
+ essentially arbitrary.
+
+ Other schemes include {GCR}, {FM}, {Modified Frequency
+ Modulation} (MFM). See also: {PRML}.
+
+ {(http://cma.zdnet.com/book/upgraderepair/ch14/ch14.htm)}.
+
+ (2003-08-12)
+
+run time
+
+ 1. The elapsed time to perform a computation on a particular
+ computer.
+
+ 2. The amount of time a processor actually spent on a
+ particular process and not on other processes or overhead (see
+ {time-sharing}).
+
+ 3. The period of time during which a program is being
+ executed, as opposed to {compile-time} or load time. The term
+ should be hyphenated when used as an adjective.
+
+ 4. {run-time support}.
+
+ (2001-09-14)
+
+run-time environment
+
+ <operating system> A collection of subroutines and
+ {environment variables} that provide commonly used functions
+ and data for a program while it is running.
+
+ Compare {run-time support}.
+
+ (1995-03-22)
+
+run-time error
+
+ <programming> An {error} in the execution of a program which
+ occurs at {run time}, as opposed to a {compile-time error}.
+
+ A good programming language should, among other things, aim to
+ replace run-time errors by compile-time errors. Language
+ features such as {strong typing} help.
+
+ A good program should attempt to avoid run-time errors by, for
+ example, checking that their input data is sensible. Where
+ this is not possible, the program should attempt to detect the
+ error and handle it gracefully rather than just exiting via
+ the language or operating system's default handler. Here
+ again, a good language will make this easy to do (or at least
+ possible).
+
+ See also {abort}, {core dump}, {GPF}.
+
+ (1997-01-13)
+
+run-time library
+
+ <operating system, programming, library> A file containing
+ routines which are linked with a program at {run time} rather
+ than at {compile-time}. The advantage of such {dynamic
+ linking} is that only one copy of the library needs to be
+ stored, rather than a copy being included with each
+ {executable} that refers to it. This can greatly reduce the
+ disk space occupied by programs. Furthermore, it means that
+ all programs immediately benefit from changes (e.g. {bug}
+ fixes) to the single copy of the library without requiring
+ recompilation. Since the library code is normally classified
+ as read-only to the {memory management} system, it is possible
+ for a single copy of the library to be loaded into memory and
+ shared by all active programs, thus reducing {RAM} and
+ {virtual memory} requirements and program load time.
+
+ (1997-07-16)
+
+run-time support
+
+ {run-time system}
+
+run-time system
+
+ <programming> (RTS, run-time support, run-time) Library code
+ and processes which support software written in a particular
+ language running on a particular {platform}. The RTS
+ typically deals with details of the interface between the
+ program and the {operating system} such as {system calls},
+ program start-up and termination, and {memory management}.
+
+ (1999-07-26)
+
+Run-Time Type Information
+
+ <compiler> (RTTI) Facilities included in {C++} {compilers} to
+ allow the {type} of an object to be determined at {run time}.
+
+ This facility, found in good C++ compilers and some other
+ {high level languages}, adds type information to memory
+ resident objects (i.e. type name or unique type-id). This
+ allows the {run-time system} to determine if an object is of a
+ specific type, for example, to ensure that a {cast} of an
+ object is valid.
+
+ (1996-04-15)
+
+ruptime
+
+ {Unix} {Berkeley networking} command to report the status of
+ all hosts on the net. See also rwho. See ruptime(1N).
+
+RUSH
+
+ 1. <language> An interactive dialect of {PL/I}, related to
+ {CPS}, dated about 1966. The name is the abbreviation of
+ "Remote Use of Shared Hardware".
+
+ ["Introduction to RUSH", Allen-Babcock Computing 1969. Sammet
+ 1969, p.309.]
+
+ 2. <language> A {high-level language} that closely resembles
+ {Tcl} but aimed to provide substantially faster execution.
+ See {An Introduction to the Rush Language
+ (ftp://ginsberg.cs.berkeley.edu/pub/papers/asah/rush-tcl94.ps.gz)}.
+ by Adam Sah, Jon Blow, and Brian Dennis (1994).
+
+ (1996-12-17)
+
+Russell
+
+ <language> (After {Bertrand Russell}) A compact,
+ {polymorphical}ly typed {functional language} by A. Demers &
+ J. Donahue with {bignums} and {continuations}. {Types} are
+ themselves {first-class} values and may be passed as
+ {arguments}.
+
+ {(ftp://parcftp.xerox.com/pub/russell/russell.tar.Z)}.
+
+ ["An Informal Description of Russell", H. Boehm et al, Cornell
+ CS TR 80-430, 1980].
+
+ ["Understanding Russell: A First Attempt", J.G. Hook in LNCS
+ 173, Springer].
+
+ (1995-03-27)
+
+Russell, Bertrand
+
+ {Bertrand Russell}
+
+Russell's Attic
+
+ <mathematics> An imaginary room containing {countably many}
+ pairs of shoes (i.e. a pair for each {natural number}), and
+ countably many pairs of socks. How many shoes are there?
+ Answer: countably many (map the left shoes to even numbers and
+ the right shoes to odd numbers, say). How many socks are
+ there? Also countably many, we want to say, but we can't
+ prove it without the {Axiom of Choice}, because in each pair,
+ the socks are indistinguishable (there's no such thing as a
+ left sock). Although for any single pair it is easy to select
+ one, we cannot specify a general method for doing this.
+
+ (1995-03-29)
+
+Russell's Paradox
+
+ <mathematics> A {paradox} (logical contradiction) in {set
+ theory} discovered by {Bertrand Russell}. If R is the set of
+ all sets which don't contain themselves, does R contain
+ itself? If it does then it doesn't and vice versa.
+
+ The paradox stems from the acceptance of the following
+ {axiom}: If P(x) is a property then
+
+ {x : P}
+
+ is a set. This is the {Axiom of Comprehension} (actually an
+ {axiom schema}). By applying it in the case where P is the
+ property "x is not an element of x", we generate the paradox,
+ i.e. something clearly false. Thus any theory built on this
+ axiom must be inconsistent.
+
+ In {lambda-calculus} Russell's Paradox can be formulated by
+ representing each set by its {characteristic function} - the
+ property which is true for members and false for non-members.
+ The set R becomes a function r which is the negation of its
+ argument applied to itself:
+
+ r = \ x . not (x x)
+
+ If we now apply r to itself,
+
+ r r = (\ x . not (x x)) (\ x . not (x x))
+ = not ((\ x . not (x x))(\ x . not (x x)))
+ = not (r r)
+
+ So if (r r) is true then it is false and vice versa.
+
+ An alternative formulation is: "if the barber of Seville is a
+ man who shaves all men in Seville who don't shave themselves,
+ and only those men, who shaves the barber?" This can be taken
+ simply as a proof that no such barber can exist whereas
+ seemingly obvious axioms of {set theory} suggest the existence
+ of the paradoxical set R.
+
+ {Zermelo Fränkel set theory} is one "solution" to this
+ paradox. Another, {type theory}, restricts sets to contain
+ only elements of a single type, (e.g. {integers} or sets of
+ integers) and no type is allowed to refer to itself so no set
+ can contain itself.
+
+ A message from Russell induced {Frege} to put a note in his
+ life's work, just before it went to press, to the effect that
+ he now knew it was inconsistent but he hoped it would be
+ useful anyway.
+
+ (2000-11-01)
+
+rusty iron
+
+ <jargon, hardware> Synonym {tired iron}. It has been claimed
+ that this is the inevitable fate of {water MIPS}.
+
+ [{Jargon File}]
+
+ (1995-03-25)
+
+rusty memory
+
+ <storage, humour> {Mass-storage} that uses iron-oxide-based
+ magnetic media (especially {magnetic tape} and the
+ pre-{Winchester} {removable disk packs} used in {washing
+ machines}).
+
+ Compare {donuts}.
+
+ [{Jargon File}]
+
+ (1997-07-20)
+
+RUTH
+
+ D.A. Harrison at Newcastle University. Real-time language
+ based on LispKit. Uses timestamps and real-time clocks.
+
+ ["RUTH: A Functional Language for Real-Time Programming",
+ D. Harrison in PARLE: Parallel Architectures and Languages
+ Europe, LNCS 259, Springer 1987, pp.297-314].
+
+rw
+
+ <networking> The {country code} for Rwanda.
+
+ (1999-01-27)
+
+rwho
+
+ <networking> The {Berkeley Unix} networking command to report
+ who is logged in on all {hosts} on the local {network
+ segment}.
+
+ {Unix manual page}: rwho(1).
+
+ (1996-09-08)
+
+RWP
+
+ {Remote Write Protocol}
+
+Rx
+
+ A pattern matcher compatible with {GNU} {regex}, but generally
+ faster.
+
+ Version 0.05, released 1994-05-18, contained substantial
+ changes from the version last distributed with GNU {sed}.
+ These changes provide low-level support for searching across
+ arbitrarily fragmented strings and suspendable searches.
+
+RYFM
+
+ <abuse> 1. "Read Your Fucking Manual". Uncommon variant of
+ {RTFM}.
+
+ 2. "Read Your Fucking Mail". A gentle reminder to someone to
+ check their corresponence and, who knows, maybe even respond.
+
+ (2012-10-27)
+
+S
+
+ <language> A statistical analysis language from {AT&T}.
+
+ ["S: An Interactive Environment for Data Analysis and
+ Graphics", Richard A. Becker, Wadsworth 1984].
+
+ (1997-01-21)
+
+s///
+
+ <chat> s/{foo}/{bar}/ is an idiom which means "I didn't mean
+ to type 'foo', I meant to type 'bar'".
+
+ Its use in {talk} systems, especially {irc}, comes from the
+ use of s/// as a substitution operator in {Perl}, {sed} and
+ {ed}. In these languages and tools, s/foo/bar/ would replace
+ any substring matching the {regular expression} "foo" with the
+ string "bar".
+
+ (1997-03-16)
+
+S3
+
+ 1. <language> An {ALGOL 68}-like system language for the {ICL
+ 2900} computer.
+
+ 2. <graphics, hardware> A video chipset.
+
+ 3. <graphics> An {X Window System} {screen server}.
+
+ (2003-02-28)
+
+SA
+
+ {Structured Analysis}
+
+sa
+
+ <networking> The {country code} for Saudi Arabia.
+
+ (1999-01-27)
+
+SA-110
+
+ <processor> The first member of the {StrongARM} family
+ resulting from the architecture license agreement between
+ {Digital Equipment Corporation} and {Advanced RISC Machines}
+ Ltd. (ARM), developer of the {ARM} 32-bit {RISC} architecture.
+
+ The SA-110 combines ARM's low-power architecture with
+ Digital's processor design and {CMOS} process expertise, and
+ is targetted at {embedded} consumer electronics products.
+
+ (1996-02-06)
+
+SAA
+
+ {Systems Application Architecture}
+
+Saber-C
+
+ Renamed to {CodeCenter}.
+
+Saber-C++
+
+ Renamed to {ObjectCenter}.
+
+SAC
+
+ 1. An early system on the {Datatron 200} series.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1995-04-12)
+
+ 2. {Service Access Controller}.
+
+ (2002-12-30)
+
+SAC-1
+
+ <mathematics, tool> An early {symbolic mathematics} system,
+ written in {Fortran} by G.E. Collins.
+
+ [Proc 2nd Symp Symb Alg Manip pp.144-152 (1971)].
+
+ (1995-04-12)
+
+SAC2
+
+ <mathematics, tool> A {symbolic mathematics} system which
+ compiles to {Fortran} or {Common Lisp}.
+
+ E-mail: <jma@poly.polytechnique.fr>.
+
+ (1995-04-12)
+
+sacadm
+
+ <operating system> (Service Access Controller Administration)
+ A {Unix} (Solaris?) command for administering both {ttymon}
+ and {listen}. It can be used to add and remove, start and
+ stop, and enable and disable {port monitors}.
+
+ (2002-12-30)
+
+sacred
+
+ <jargon> Reserved for exclusive use by something. The term
+ might mean only writable by whatever it is sacred to.
+
+ For example, "Register 7 is sacred to the interrupt handler"
+ would mean that if any other code changed the contents of
+ register 7, dire consequences would ensue.
+
+ [{Jargon File}]
+
+ (2002-12-30)
+
+SAD
+
+ {Systems Analysis Definition}
+
+SAD SAM
+
+ Query language by Lindsay. Sammet 1969, p.669.
+
+SADT
+
+ {Structured Analysis and Design Technique}
+
+SAFARI
+
+ ON-line text editing system by {MITRE Corporation}.
+
+ Sammet 1969, p.685.
+
+safe
+
+ A safe program analysis is one which will not reach invalid
+ conclusions about the behaviour of the program. This may
+ involve making safe approximations to properties of parts of
+ the program. A safe approximation is one which gives less
+ information.
+
+ For example, strictness analysis aims to answer the question
+ "will this function evaluate its argument"?. The two possible
+ results are "definitely" and "don't know". A safe
+ approximation for "definitely" is "don't know". The two
+ possible results correspond to the two sets: "the set of all
+ functions which evaluate their argument" and "all functions".
+ A set can be safely approximated by another which contains it.
+
+safe mode
+
+ <operating system> An alternative way to start {Microsoft
+ Windows} such that only a minimal set of software components
+ ({drivers} and {background processes}) are loaded, making it
+ easier to diagnose problems. Safe mode loads a standard low
+ {resolution} {video driver} and does not support connection to
+ the {Internet}.
+
+ Windows will sometimes restart in safe mode automatically
+ following a {crash}. All Windows versions except {Windows
+ 3.1} can be started in safe mode, usually by holding the Ctrl
+ or F8 key while the computer is restarting. To start {Windows
+ NT} in safe mode you need to edit C:\boot.ini.
+
+ Once the problem is fixed you need to restart Windows normally
+ to load all the installed components.
+
+ (2004-12-31)
+
+safety
+
+ See {safe}, {safety-critical system}.
+
+safety-critical system
+
+ A computer, electronic or electromechanical system whose
+ failure may cause injury or death to human beings. E.g. an
+ aircraft or nuclear power station control system. Common
+ tools used in the design of safety-critical systems are
+ {redundancy} and {formal methods}.
+
+ See also {aeroplane rule}.
+
+saga
+
+ <jargon> (WPI) A {cuspy} but bogus raving story about N
+ {random} broken people.
+
+ Here is a classic example of the saga form, as told by {Guy
+ Steele} (GLS):
+
+ Jon L. White (login name JONL) and I (GLS) were office mates
+ at {MIT} for many years. One April, we both flew from Boston
+ to California for a week on research business, to consult
+ face-to-face with some people at {Stanford}, particularly our
+ mutual friend {Richard Gabriel} (RPG).
+
+ RPG picked us up at the San Francisco airport and drove us
+ back to {Palo Alto} (going {logical} south on route 101,
+ parallel to {El Camino Bignum}). Palo Alto is adjacent to
+ Stanford University and about 40 miles south of San Francisco.
+ We ate at The Good Earth, a "health food" restaurant, very
+ popular, the sort whose milkshakes all contain honey and
+ protein powder. JONL ordered such a shake - the waitress
+ claimed the flavour of the day was "lalaberry". I still have
+ no idea what that might be, but it became a running joke. It
+ was the colour of raspberry, and JONL said it tasted rather
+ bitter. I ate a better tostada there than I have ever had in
+ a Mexican restaurant.
+
+ After this we went to the local Uncle Gaylord's Old Fashioned
+ Ice Cream Parlor. They make ice cream fresh daily, in a
+ variety of intriguing flavours. It's a chain, and they have a
+ slogan: "If you don't live near an Uncle Gaylord's - MOVE!"
+ Also, Uncle Gaylord (a real person) wages a constant battle to
+ force big-name ice cream makers to print their ingredients on
+ the package (like air and plastic and other non-natural
+ garbage). JONL and I had first discovered Uncle Gaylord's the
+ previous August, when we had flown to a computer-science
+ conference in {Berkeley}, California, the first time either of
+ us had been on the West Coast. When not in the conference
+ sessions, we had spent our time wandering the length of
+ Telegraph Avenue, which (like Harvard Square in Cambridge) was
+ lined with picturesque street vendors and interesting little
+ shops. On that street we discovered Uncle Gaylord's Berkeley
+ store. The ice cream there was very good. During that August
+ visit JONL went absolutely bananas (so to speak) over one
+ particular flavour, ginger honey.
+
+ Therefore, after eating at The Good Earth - indeed, after
+ every lunch and dinner and before bed during our April visit
+ --- a trip to Uncle Gaylord's (the one in Palo Alto) was
+ mandatory. We had arrived on a Wednesday, and by Thursday
+ evening we had been there at least four times. Each time,
+ JONL would get ginger honey ice cream, and proclaim to all
+ bystanders that "Ginger was the spice that drove the Europeans
+ mad! That's why they sought a route to the East! They used
+ it to preserve their otherwise off-taste meat." After the
+ third or fourth repetition RPG and I were getting a little
+ tired of this spiel, and began to paraphrase him: "Wow!
+ Ginger! The spice that makes rotten meat taste good!" "Say!
+ Why don't we find some dog that's been run over and sat in the
+ sun for a week and put some *ginger* on it for dinner?!"
+ "Right! With a lalaberry shake!" And so on. This failed to
+ faze JONL; he took it in good humour, as long as we kept
+ returning to Uncle Gaylord's. He loves ginger honey ice
+ cream.
+
+ Now RPG and his then-wife KBT (Kathy Tracy) were putting us up
+ (putting up with us?) in their home for our visit, so to thank
+ them JONL and I took them out to a nice French restaurant of
+ their choosing. I unadventurously chose the filet mignon, and
+ KBT had je ne sais quoi du jour, but RPG and JONL had lapin
+ (rabbit). (Waitress: "Oui, we have fresh rabbit, fresh
+ today." RPG: "Well, JONL, I guess we won't need any
+ *ginger*!")
+
+ We finished the meal late, about 11 P.M., which is 2 A.M
+ Boston time, so JONL and I were rather droopy. But it wasn't
+ yet midnight. Off to Uncle Gaylord's!
+
+ Now the French restaurant was in Redwood City, north of Palo
+ Alto. In leaving Redwood City, we somehow got onto route 101
+ going north instead of south. JONL and I wouldn't have known
+ the difference had RPG not mentioned it. We still knew very
+ little of the local geography. I did figure out, however,
+ that we were headed in the direction of Berkeley, and
+ half-jokingly suggested that we continue north and go to Uncle
+ Gaylord's in Berkeley.
+
+ RPG said "Fine!" and we drove on for a while and talked. I
+ was drowsy, and JONL actually dropped off to sleep for 5
+ minutes. When he awoke, RPG said, "Gee, JONL, you must have
+ slept all the way over the bridge!", referring to the one
+ spanning San Francisco Bay. Just then we came to a sign that
+ said "University Avenue". I mumbled something about working
+ our way over to Telegraph Avenue; RPG said "Right!" and
+ maneuvered some more. Eventually we pulled up in front of an
+ Uncle Gaylord's.
+
+ Now, I hadn't really been paying attention because I was so
+ sleepy, and I didn't really understand what was happening
+ until RPG let me in on it a few moments later, but I was just
+ alert enough to notice that we had somehow come to the Palo
+ Alto Uncle Gaylord's after all.
+
+ JONL noticed the resemblance to the Palo Alto store, but
+ hadn't caught on. (The place is lit with red and yellow
+ lights at night, and looks much different from the way it does
+ in daylight.) He said, "This isn't the Uncle Gaylord's I went
+ to in Berkeley! It looked like a barn! But this place looks
+ *just like* the one back in Palo Alto!"
+
+ RPG deadpanned, "Well, this is the one *I* always come to when
+ I'm in Berkeley. They've got two in San Francisco, too.
+ Remember, they're a chain."
+
+ JONL accepted this bit of wisdom. And he was not totally
+ ignorant - he knew perfectly well that University Avenue was
+ in Berkeley, not far from Telegraph Avenue. What he didn't
+ know was that there is a completely different University
+ Avenue in Palo Alto.
+
+ JONL went up to the counter and asked for ginger honey. The
+ guy at the counter asked whether JONL would like to taste it
+ first, evidently their standard procedure with that flavour,
+ as not too many people like it.
+
+ JONL said, "I'm sure I like it. Just give me a cone." The
+ guy behind the counter insisted that JONL try just a taste
+ first. "Some people think it tastes like soap." JONL
+ insisted, "Look, I *love* ginger. I eat Chinese food. I eat
+ raw ginger roots. I already went through this hassle with the
+ guy back in Palo Alto. I *know* I like that flavour!"
+
+ At the words "back in Palo Alto" the guy behind the counter
+ got a very strange look on his face, but said nothing. KBT
+ caught his eye and winked. Through my stupor I still hadn't
+ quite grasped what was going on, and thought RPG was rolling
+ on the floor laughing and clutching his stomach just because
+ JONL had launched into his spiel ("makes rotten meat a dish
+ for princes") for the forty-third time. At this point, RPG
+ clued me in fully.
+
+ RPG, KBT, and I retreated to a table, trying to stifle our
+ chuckles. JONL remained at the counter, talking about ice
+ cream with the guy b.t.c., comparing Uncle Gaylord's to other
+ ice cream shops and generally having a good old time.
+
+ At length the g.b.t.c. said, "How's the ginger honey?" JONL
+ said, "Fine! I wonder what exactly is in it?" Now Uncle
+ Gaylord publishes all his recipes and even teaches classes on
+ how to make his ice cream at home. So the g.b.t.c. got out
+ the recipe, and he and JONL pored over it for a while. But
+ the g.b.t.c. could contain his curiosity no longer, and asked
+ again, "You really like that stuff, huh?" JONL said, "Yeah,
+ I've been eating it constantly back in Palo Alto for the past
+ two days. In fact, I think this batch is about as good as the
+ cones I got back in Palo Alto!"
+
+ G.b.t.c. looked him straight in the eye and said, "You're *in*
+ Palo Alto!"
+
+ JONL turned slowly around, and saw the three of us collapse in
+ a fit of giggles. He clapped a hand to his forehead and
+ exclaimed, "I've been hacked!"
+
+ [My spies on the West Coast inform me that there is a close
+ relative of the raspberry found out there called an
+ "ollalieberry" - ESR]
+
+ [Ironic footnote: it appears that the {meme} about ginger vs.
+ rotting meat may be an urban legend. It's not borne out by an
+ examination of mediaeval recipes or period purchase records
+ for spices, and appears full-blown in the works of Samuel
+ Pegge, a gourmand and notorious flake case who originated
+ numerous food myths. - ESR]
+
+ [{Jargon File}]
+
+ (1994-12-08)
+
+sagan
+
+ <jargon> /say'gn/ (From Carl Sagan's TV series "Cosmos")
+ Billions and billions. A large quantity of anything.
+
+ "There's a sagan different ways to tweak Emacs." "The US
+ Government spends sagans on bombs and welfare - hard to say
+ which is more destructive."
+
+ [{Jargon File}]
+
+ (1999-10-12)
+
+SAGE
+
+ 1. <body, job> {Systems Administrators Guild}.
+
+ 2. <project> {Semi-Automatic Ground Environment}.
+
+ (2001-01-27)
+
+SAIC
+
+ {(http://saic.com)}.
+
+ (1996-03-21)
+
+SAID
+
+ {Security Association ID}
+
+SAIL
+
+ 1. <body, education> {Stanford Artificial Intelligence
+ Laboratory}.
+
+ 2. <language> {Stanford Artificial Intelligence Language}.
+
+ 3. <language> An early system on the {Larc} computer.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ [{Jargon File}]
+
+ (2001-06-22)
+
+SAINT
+
+ 1. <language> {Symbolic Automatic INTegrator}.
+
+ 2. <networking, security, tool> {Security Administrator's
+ Integrated Network Tool}.
+
+Saint Andrews Static Language
+
+ {St Andrews Static Language}
+
+SAL
+
+ <language>
+
+ 1. {Simple Actor Language}.
+
+ 2. {SPARK Annotation Language}.
+
+SALEM
+
+ ["SALEM - A Programming System for the Simulation of Systems
+ Described by Partial Differential Equations", S.M. Morris et
+ al, Proc SJCC 33(1), 1968].
+
+ (1994-12-08)
+
+Sales Automation
+
+ {Sales Force Automation}
+
+salescritter
+
+ /sayls'kri"tr/ Pejorative hackerism for a computer
+ salesperson. Hackers tell the following joke:
+
+ Q. What's the difference between a used-car dealer and a
+ computer salesman?
+
+ A. The used-car dealer knows he's lying. [Some versions add:
+ ...and probably knows how to drive.]
+
+ This reflects the widespread hacker belief that salescritters
+ are self-selected for stupidity (after all, if they had brains
+ and the inclination to use them, they'd be in programming).
+ The terms "salesthing" and "salesdroid" are also common.
+
+ Compare {marketroid}, {suit}.
+
+ [{Jargon File}]
+
+ (1994-12-08)
+
+Sales Force Automation
+
+ <business> (Sales Automation, SFA, SFFA, Sales & Field Force
+ Automation) Software to support sales reps. The software
+ gives sales representitives access to contacts, appointments
+ and e-mail. It is likely to be integrated with {Customer
+ Relationship Management} systems and {Opportunity Management
+ Systems}.
+
+ (1999-08-20)
+
+S-ALGOL
+
+ Orthogonal data structures on ALGOL 60. "S-Algol Language
+ Reference Manual", R. Morrison, TR CS/79/1 U St Andrews, 1979.
+ "An Introduction to Programming with S-Algol", A.J. Cole &
+ R. Morrison, Cambridge U Press 1982.
+
+SALT
+
+ 1. Symbolic Assembly Language Trainer. Assembly-like language
+ implemented in BASIC by Kevin Stock, now at Encore in France.
+
+ 2. Sam And Lincoln Threaded language. A threaded extensible
+ variant of BASIC. "SALT", S.D. Fenster et al, BYTE (Jun 1985)
+ p.147.
+
+ [{Jargon File}]
+
+salt
+
+ A tiny bit of near-random data inserted where too much
+ regularity would be undesirable; a data {frob} (sense 1). For
+ example, the Unix crypt(3) manual page mentions that "the salt
+ string is used to perturb the DES algorithm in one of 4096
+ different ways."
+
+salt mines
+
+ Dense quarters housing large numbers of programmers working
+ long hours on grungy projects, with some hope of seeing the
+ end of the tunnel in N years. Noted for their absence of
+ sunshine. Compare {playpen}, {sandbox}.
+
+ [{Jargon File}]
+
+salt substrate
+
+ [MIT] Collective noun used to refer to potato chips, pretzels,
+ saltines, or any other form of snack food designed primarily
+ as a carrier for sodium chloride. From the technical term
+ "chip substrate", used to refer to the silicon on the top of
+ which the active parts of integrated circuits are deposited.
+
+SAM
+
+ {System Account Manager}
+
+sam
+
+ <tool> A multi-file {screen editor} with structural {regular
+ expressions}. Sam runs under the {X Window System}.
+
+ (2000-07-16)
+
+SAM76
+
+ A {macro} language by Claude Kagan descended from {TRAC}.
+ There is a version for {CP/M}.
+
+ [Dr Dobbs J ca 1977].
+
+Samba
+
+ <networking> A free suite of programs which implement the
+ {Server Message Block} (SMB) protocol.
+
+ Originally developed for {Unix} by Andrew Tridgell at the
+ {Australian National University}, the Samba {server} allows
+ files and printers on the {host} {operating system} to be
+ shared with {clients} such as {Windows for Workgroups}, {DOS},
+ {OS/2}, {Windows NT} and others.
+
+ For example, instead of using {telnet} to log in to a Unix
+ machine to edit a file there, a {Windows 95} user might
+ connect a drive in the Windows {Explorer} to a Samba server on
+ the Unix machine and edit the file in a Windows editor.
+
+ A Unix client called smbclient, built from the same {source
+ code}, allows {ftp}-like access to SMB resources.
+
+ Samba is available for many Unix variants, OS/2, and {VMS}.
+ Porting to {Novell Netware} is in progress (August 1996).
+
+ smblib is a {portable} generic library for making SMB calls
+ for implementing {client/server} functions from within any
+ program. {Linux} implements a complete file system (based on
+ smbclient) so by default Linux users have full access to
+ resources on {LAN Server}, Windows NT and {LAN Manager}
+ networks.
+
+ {(http://samba.org/samba/samba.html)}.
+
+ (1998-11-22)
+
+SAME
+
+ 1. {Standard ANSI Module language with Extensions}.
+
+ 2. <architecture> {Stripe And Mirror Everything}.
+
+same-day service
+
+ <humour, operating system> An ironic term used to describe
+ long response time, particularly with respect to {MS-DOS}
+ {system calls} (which ought to require only a tiny fraction of
+ a second to execute). Such response time is a major incentive
+ for programmers to write programs that are not {well-behaved}.
+
+ See also {PC-ism}.
+
+ [{Jargon File}]
+
+ (1996-12-17)
+
+SAMeDL
+
+ {SQL} {Ada} Module Description Language. Used to interface
+ {Ada} {application programs} to {SQL}-based {DBMSs}.
+
+ E-mail: Marc Graham <marc@sei.cmu.edu>.
+ {(ftp://ajpo.sei.cmu.edu/public/atip/samedl/)}.
+
+ ["Rationale for SQL Ada Module Description Language SAMeDL",
+ SEI-92-TR-016].
+
+samizdat
+
+ <publication> (Russian, literally "self publishing") The
+ process of disseminating documentation via underground
+ channels. Originally referred to photocopy duplication and
+ distribution of banned books in the former Soviet Union; now
+ refers by obvious extension to any less-than-official
+ promulgation of textual material, especially rare, obsolete,
+ or never-formally-published computer documentation. Samizdat
+ is obviously much easier when one has access to
+ high-{bandwidth} {networks} and high-quality {laser printers}.
+
+ Strictly, "samizdat" only applies to distribution of needed
+ documents that are otherwise unavailable, and not to
+ duplication of material that is available for sale under
+ {copyright}.
+
+ See {Lions Book} for a historical example.
+
+ See also: {hacker ethic}.
+
+ [{Jargon File}]
+
+ (2000-03-23)
+
+SAML
+
+ <security> An {XML} framework for communicating user
+ {authentication}, {entitlement}, and attribute information,
+ developed by the Security Services Technical Committee of
+ {OASIS}.
+
+ SAML supports {federation}, allowing business entities to make
+ assertions regarding the identity, attributes and entitlements
+ of a subject (an entity that is often a human user) to other
+ entities, such as a partner company or another enterprise
+ application.
+
+ (2011-05-12)
+
+Sammet, Jean E.
+
+ {Jean E. Sammet}
+
+sample
+
+ <digital signal processing> The result of measuring the
+ amplitude of an analog signal at a specified time. In
+ {digital signal processing} a sample is a signed or unsigned
+ number and the number of samples per second is called the
+ {sample rate}.
+
+ (2001-06-06)
+
+sample rate
+
+ <digital signal processing> The number of times an analog
+ signal is measured (sampled) per second. The unit of sample
+ rate is "samples per second". This is often expressed in
+ {kiloHertz} (kHz). For example, "CD quality" sound has a
+ sample rate of 44 kHz.
+
+ Compare {data rate}. See {Nyquist frequency}.
+
+ [Is it correct to use Hertz for things other than the
+ frequency of a sine wave?]
+
+ (2001-06-06)
+
+sampling
+
+ <DSP> The process of taking a {sample} of a signal at evenly
+ spaced intervals of time. This is the first step in {Digital
+ Signal Processing}.
+
+ (2001-06-06)
+
+sampling frequency
+
+ {sample rate}
+
+samurai
+
+ A hacker who hires out for legal cracking jobs, snooping for
+ factions in corporate political fights, lawyers pursuing
+ privacy-rights and First Amendment cases, and other parties
+ with legitimate reasons to need an electronic locksmith. In
+ 1991, mainstream media reported the existence of a loose-knit
+ culture of samurai that meets electronically on BBS systems,
+ mostly bright teenagers with personal micros; they have
+ modelled themselves explicitly on the historical samurai of
+ Japan and on the "net cowboys" of William Gibson's {cyberpunk}
+ novels. Those interviewed claim to adhere to a rigid ethic of
+ loyalty to their employers and to disdain the vandalism and
+ theft practiced by criminal crackers as beneath them and
+ contrary to the hacker ethic; some quote Miyamoto Musashi's
+ "Book of Five Rings", a classic of historical samurai
+ doctrine, in support of these principles.
+
+ See also {Stupids}, {social engineering}, {cracker}, {hacker
+ ethic}, and {dark-side hacker}.
+
+ [{Jargon File}]
+
+SAN
+
+ {Storage Area Network}
+
+sandbender
+
+ [IBM] A person involved with silicon lithography and the
+ physical design of {integrated circuits}. Compare
+ {ironmonger}, {polygon pusher}.
+
+sandbox
+
+ (UK: "sandpit")
+
+ 1. <operating system> A protected, limited environment where
+ applications (e.g. {Java} programs downloaded from the
+ {Internet}) are allowed to "play" without risking damage to
+ the rest of the system.
+
+ 2. <jargon> A term for the R&D department at many software and
+ computer companies (where hackers in commercial environments
+ are likely to be found). The term is half-derisive, but
+ reflects the truth that research is a form of creative play.
+
+ Compare {playpen}.
+
+ 3. <operating system> {link farm}.
+
+ [{Jargon File}]
+
+ (2001-02-08)
+
+Sandman
+
+ The {DoD} requirements that led to {APSE}.
+
+San Francisco
+
+ <project, library> {IBM}'s {Java} component {framework}
+ application template.
+
+ The San Francisco Project, started in 1998(?), aims to create
+ a generic set of {java} building blocks to provide the core
+ functions of general business processes such as sales order
+ processing, general ledger, inventory management and product
+ distribution.
+
+ The project aims to use component based design allowing easy
+ vendor customisation and Java code generation allowing
+ applications to be built and run across multiple platforms.
+ It also aims to be compatible with third party development
+ tools.
+
+ {(http://ibm.com/Java/Sanfrancisco/)}.
+
+ (1998-08-16)
+
+sanity check
+
+ <programming> 1. Checking {code} (or anything else, e.g. a
+ {Usenet} posting) for completely stupid mistakes. Implies
+ that the check is to make sure the author was sane when it was
+ written; e.g. if a piece of scientific software relied on a
+ particular formula and was giving unexpected results, one
+ might first look at the nesting of parentheses or the coding
+ of the formula, as a "sanity check", before looking at the
+ more complex I/O or data structure manipulation routines, much
+ less the {algorithm} itself.
+
+ Compare {reality check}.
+
+ 2. A run-time test, either validating input or ensuring that
+ the program hasn't screwed up internally (producing an
+ inconsistent value or state).
+
+ [{Jargon File}]
+
+ (1998-08-29)
+
+Santa Cruz Operation
+
+ (SCO) A supplier of {Unix} systems for {Intel}
+ {microprocessors}. They supply {Xenix} and {Open Desktop}.
+
+ Founded in 1979, SCO became a public company in May, 1993 and
+ trades on the Nasdaq National Market System under the symbol
+ SCOC. SCO maintains its world headquarters in Santa Cruz,
+ California, USA; a European headquarters in Watford, England;
+ a Government Systems Group in Reston, Virginia; and offices in
+ Asia, Australia, Canada, Latin America, and throughout Europe
+ and the United States. In February 1993, SCO acquired {IXI}
+ Limited of Cambridge, England, the leading supplier of {Unix}
+ System windowing software.
+
+ {(http://websco.sco.com/)}.
+
+ (1994-10-28)
+
+ [Addresses?]
+
+SAP
+
+ 1. <company> {SAP AG} (Systems, Applications and Products in
+ Data Processing).
+
+ 2. <protocol> {Service Advertising Protocol}.
+
+ 3. <networking> {Service Access Point}.
+
+ 4. <language> {Symbolic Assembler Program}.
+
+ (1999-05-26)
+
+SAP AG
+
+ <company> (Systeme, Anwendungen, Produkte in der
+ Datenverarbeitung - German for "Systems, Applications and
+ Products in Data Processing") A company from Germany that
+ sells the leading suite of {client-server} business software.
+ The US branch is called SAP America.
+
+ {(http://sap.com/)}.
+
+ [Details?]
+
+ (1998-07-28)
+
+SAPI
+
+ 1. <programming> {Speech Application Programming Interface}.
+
+ 2. <programming> {Scheduling Application Programming
+ Interface}.
+
+ 3. <networking> {Service Access Point Identifier}.
+
+ (1996-10-03)
+
+SAR
+
+ {segmentation and reassembly}
+
+SAS
+
+ 1. <language> {Statistical Analysis System}.
+
+ 2. <tool> {SAS System}.
+
+ (1998-11-06)
+
+SASD
+
+ {Structured Analysis, Structured Design}
+
+SASE
+
+ {Specific Application Service Element}. Opposite: {CASE}.
+
+SASI
+
+ {Small Computer System Interface}
+
+SASL
+
+ 1. <language> {St Andrews Static Language}.
+
+ 2. <networking> {Simple Authentication and Security Layer}.
+
+SASL+LV
+
+ Unifies logic and functional programming. A more complete
+ version of FGL+LV, in SASL syntax. "Combinator Evaluations of
+ Functional Programs with Logical Variables", G. Bage et al, TR
+ UUCS-87-027, U Utah, Oct 1987.
+
+SASL-YACC
+
+ A version of {Yacc} written in {SASL} by Simon Peyton-Jones.
+
+SAS System
+
+ <tool> (SAS) Integrated software to access, manage, analyze,
+ and present data. The SAS System can be used to perform data
+ entry, retrieval and management; report writing and graphics
+ design; statistical and mathematical analysis; business
+ forecasting and decision support; operations research; project
+ management and applications development.
+
+ (1998-11-06)
+
+SATA
+
+ {Serial Advanced Technology Attachment}
+
+SATAN
+
+ {Security Administrator's Integrated Network Tool}
+
+Sather
+
+ <language> /Say-ther/ (Named after the Sather Tower at {UCB},
+ as opposed to the Eiffel Tower).
+
+ An interactive {object-oriented} language designed by Steve
+ M. Omohundro at {ICSI} in 1991. Sather has simple {syntax},
+ similar to {Eiffel}, but it is non-proprietary and faster.
+
+ Sather 0.2 was nearly a subset of Eiffel 2.0, but Sather 1.0
+ adds many distinctive features: parameterised {class}es,
+ {multiple inheritance}, statically-checked {strong typing},
+ {garbage collection}. The compiler generates {C} as an
+ {intermediate language}. There are versions for most
+ {workstations}.
+
+ Sather attempts to retain much of {Eiffel}'s theoretical
+ cleanliness and simplicity while achieving the efficiency of
+ {C++}. The compiler generates efficient and portable C code
+ which is easily integrated with existing code.
+
+ A variety of development tools including a debugger and
+ {browser} based on {gdb} and a {GNU Emacs} development
+ environment have also been written. There is also a {class
+ library} with several hundred classes that implement a variety
+ of basic data structures and numerical, geometric,
+ connectionist, statistical, and graphical abstractions. The
+ authors would like to encourage contributions to the library
+ and hope to build a large collection of efficient,
+ well-written, well-tested classes in a variety of areas of
+ computer science.
+
+ Sather runs on {Sun-4}, {HP9000}/300, {Decstation} 5000,
+ {MIPS}, {Sony News} 3000, {Sequent}/{Dynix}, {SCO} {SysV}R3.2,
+ {NeXT}, {Linux}.
+
+ See also {dpSather}, {pSather}, {Sather-K}.
+
+ {(ftp://ftp.icsi.berkeley.edu/pub/sather)}.
+
+ E-mail: <sather-admin@icsi.berkeley.edu>.
+
+ Mailing list: sather-request@icsi.berkeley.edu.
+
+ (1995-04-26)
+
+Sather-K
+
+ <language> Karlsruhe Sather.
+
+ A sublanguage of {Sather} used for introductory courses in
+ {object-oriented design} and {typesafe programming}.
+
+ E-mail: <trapp@karlsruhe.gmd.de>.
+
+ (1994-11-11)
+
+satisfiability problem
+
+ A problem used as an example in {complexity theory}. It can
+ be stated thus:
+
+ Given a Boolean expression E, decide if there is some
+ assignment to the variables in E such that E is true.
+
+ A {Boolean} expression is composed of Boolean variables,
+ (logical) negation (NOT), (logical) {conjunction} (AND) and
+ parentheses for grouping. The satisfiability problem was the
+ first problem to be proved to be {NP-complete} (by Cook).
+
+ ["Introduction to Automata Theory, Languages, and Computation"
+ by Hopcroft and Ullman, pub. Addison-Wesley].
+
+ (1994-11-11)
+
+saturation
+
+ 1. <graphics> In colour theory, the "colourfulness" of a
+ stimulus relative to its {brightness}, the amount of the
+ dominant wavelength relative to other wavelengths in the
+ colour, one of the three coordinates in the {hue, saturation,
+ value} (HSV) and {hue, saturation, brightness} (HSB) {colour
+ models}.
+
+ White, black and grey contain equal amounts of red, green and
+ blue light and are completely unsaturated. A pure colour with
+ very little gray in it is highly saturated. The amount of
+ saturation does not affect the {hue} of a colour and is
+ unrelated to the {value} (total amount of light in a colour).
+
+ There are several competing mathematical definitions of
+ saturation.
+
+ {(http://www.ncsu.edu/scivis/lessons/colormodels/color_models2.html#saturation)}.
+
+ {(http://www.pomona.edu/academics/courserelated/classprojects/visual-lit/saturation/saturation.html)}.
+
+ 2. The state of any system that is operating at its maximum
+ capacity, e.g. a network connection that is carry a continuous
+ stream of data with no idle time. {Capacity planning} aims to
+ monitor load and increase resources before saturation is
+ reached.
+
+ (2008-05-09)
+
+Saturday-night special
+
+ <jargon> (From police slang for a cheap handgun) A
+ {quick-and-dirty} program or feature {kluge}d together during off
+ hours, under a deadline, and in response to pressure from a
+ {salescritter}. Such hacks are dangerously unreliable, but all
+ too often sneak into a production release after insufficient
+ review.
+
+ [{Jargon File}]
+
+ (1994-11-11)
+
+sausage code
+
+ <humour, programming> Code which, once you know the details of how
+ it's made, you'll never want to use again.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2013-11-22)
+
+SAVE
+
+ An {assembler} for the {Burroughs 220} by Melvin Conway (see
+ {Conway's Law}). The name "SAVE" didn't stand for anything,
+ it was just that you lost fewer card decks and listings
+ because they all had SAVE written on them.
+
+ (1995-01-16)
+
+save
+
+ <editor, programming, storage> To copy {data} to a more
+ permanent form of storage. The term is commonly used for when
+ some kind of document editing {application program} writes the
+ current document from {RAM} to a {file} on {hard disk} at the
+ request of the user. The implication is that the user might
+ later {load} the file back into the editor again to view it,
+ print it, or continue editing it. Saving a document makes it
+ safe from the effects of power failure.
+
+ The "document" might actually be anything, e.g. a {word
+ processor} document, the current state of a game, a piece of
+ music, a {website}, or a memory image of some program being
+ executed (though the term "dump" would probably be more common
+ here).
+
+ Data can be saved to any kind of (writable) storage: hard
+ disk, {floppy disk}, {CD-R}; either locally or via a
+ {network}.
+
+ A program might save its data without any explicit user
+ request, e.g. periodically as a precaution ("auto save"), or
+ if it forms part of a {pipeline} of processes which pass data
+ via intermediate files. In the latter case the term suggests
+ all data is written in a single operation whereas "output"
+ might be a continuous flow, in true pipeline fashion.
+
+ When copying several files from one storage medium to another,
+ the terms "backup", "dump", or "archive" would be used rather
+ than "save". The term "store" is similar to "save" but
+ typically applies to copying a single item of data, e.g. a
+ number, from a {processor}'s {register} to {RAM}.
+
+ A "save" operation saves the document in its native format,
+ e.g. a proprietary word processor format, whereas "save as"
+ (or "export") saves the same data in a different format,
+ e.g. a {plain text} file.
+
+ (2002-06-07)
+
+save as
+
+ <editor, programming, storage> A variant of {save} that saves
+ the current document in an alternative format.
+
+ (2005-02-15)
+
+say
+
+ A human may "say" things to a computer by typing them on a
+ terminal. "To list a directory verbosely, say "ls -l"."
+ Tends to imply a {newline}-terminated command (a "sentence").
+
+ A computer may "say" things to you, even if it doesn't have a
+ speech synthesiser, by displaying them on a terminal in
+ response to your commands. This usage often confuses
+ {mundanes}.
+
+ [{Jargon File}]
+
+sb
+
+ <networking> The {country code} for the Solomon Islands.
+
+ (1999-01-27)
+
+SB AWE32
+
+ <multimedia, music, hardware> A standard {SB16 MultiCD} {sound
+ card} with the {EMU8000} "Advanced WavEffect" music
+ synthesizer {integrated circuit}. The card includes all the
+ standard SB16 features as well as the {Advanced Signal
+ Processor} and multiple interfaces supporting {Creative},
+ {Mitsumi} and {Sony} {CD-ROM} drives.
+
+ The EMU8000 comes integrated with 1MB of {General MIDI}
+ samples and 512kB of {DRAM} for additional sample downloading.
+ It can address up to 28 MB of external DRAM. The SB AWE32
+ supports General MIDI, Roland GS, and Sound Canvas MT-32
+ {emulation}.
+
+ (1996-12-16)
+
+SBCS
+
+ <character> (IBM) single-byte character set.
+
+ A {character set} that uses 8 bits to represent a character.
+
+ (1995-03-21)
+
+SBD
+
+ {Smart Battery Data}
+
+SBE
+
+ {Microsoft Office Small Business Edition}
+
+SBM
+
+ {Solution Based Modelling}
+
+SB-Prolog
+
+ Stony Brook Prolog. A {public domain} {Prolog} {interpreter}
+ for {Unix}. Version 3.1. Distributed under the {GNU}
+ {General Public License}.
+
+ {(ftp://sbcs.sunysb.edu/pub/sbprolog/)}.
+
+ {Amiga version 2.3.2
+ (ftp://ftp.cso.uiuc.edu/amiga/fish/f1/ff140)} and
+ {(ftp://ftp.cso.uiuc.edu/amiga/fish/f1/ff141)}.
+
+ E-mail: <warren@sbcs.sunysb.edu>.
+
+ (1995-01-16)
+
+SBR
+
+ {Spectral Band Replication}
+
+SBus
+
+ <hardware> The hardware interface for add-in boards in later
+ {Sun-3} (and {Sun-4}?) {workstations}.
+
+ [Reference?]
+
+ (2001-09-07)
+
+SC
+
+ <body> Subcommittee (of {ISO}, {JTC}?).
+
+sc
+
+ <networking> The {country code} for the Seychelles.
+
+ (1999-01-27)
+
+SCA
+
+ {Single Connection Attach}
+
+SCADA
+
+ {Supervisory Control and Data Acquisition}
+
+scag
+
+ To destroy the data on a disk, either by corrupting the
+ file system or by causing media damage.
+
+ Compare {scrog}, {roach}.
+
+ [{Jargon File}]
+
+ (1995-01-16)
+
+scalability
+
+ How well a solution to some problem will work when the size of
+ the problem increases.
+
+ For example, a central {server} of some kind with ten
+ {clients} may perform adequately but with a thousand clients
+ it might fail to meet response time requirements. In this
+ case, the average response time probably scales linearly with
+ the number of clients, we say it has a {complexity} of O(N)
+ ("order N") but there are problems with other complexities.
+ E.g. if we want N nodes in a network to be able to communicate
+ with each other, we could connect each one to a central
+ exchange, requiring O(N) wires or we could provide a direct
+ connection between each pair, requiring O(N^2) wires (the
+ exact number or formula is not usually so important as the
+ highest power of N involved).
+
+ (1995-03-29)
+
+Scalable Coherent Interface
+
+ <hardware, protocol> (SCI) The {ANSI}/{IEEE} 1596-1992
+ {standard} that defines a point-to-point {interface} and a set
+ of {packet} {protocols}. The SCI protocols use packets with a
+ 16-byte {header} and 16, 64, or 256 data bytes. Each packet
+ is protected by a 16-bit {CRC} code.
+
+ The standard defines 1 Gbit/second {serial} {fiber-optic}
+ links and 1 Gbyte/second {parallel} copper links. SCI has two
+ unidirectional links that operate concurrently.
+
+ The SCI protocols support {shared memory} by encapsulating
+ {bus} requests and responses into SCI request and response
+ packets. Packet-based {handshake} protocols guarantee
+ reliable data delivery. A set of {cache coherence} protocols
+ are defined to maintain cache coherence in a {shared memory
+ system}.
+
+ {Message passing} is supported by a compatible subset of the
+ SCI protocols. This protocol subset does not invoke SCI cache
+ coherency protocols.
+
+ SCI uses 64-bit {addressing} and the most significant 16 bits
+ are used for addressing up to 64K {nodes}.
+
+ {http://uni-paderborn.de/pc2/systems/sci/}.
+
+ [Applications?]
+
+ (1999-03-22)
+
+Scalable Processor ARChitecture
+
+ <computer> (SPARC) An {instruction set architecture} designed
+ by {Sun Microsystems} for their own use in 1985. Sun was a
+ maker of {680x0}-based {Unix} {workstations}. Research
+ versions of {RISC} processors had promised a major step
+ forward in speed but existing manufacturers were slow to
+ introduce a RISC type processor, so Sun went ahead and
+ developed its own, based on the {University of California at
+ Berkley}'s {RISC I} and {RISC II} 1980-2. In keeping with
+ their open philosophy, they licenced it to other companies,
+ rather than manufacture it themselves. The evolution and
+ standardisation of SPARC is now directed by the non-profit
+ consortium {SPARC International, Inc.}
+
+ SPARC was not the first {RISC} processor. The {AMD 29000}
+ came before it, as did the {MIPS R2000} (based on {Stanford}'s
+ design) and {Hewlett-Packard} {Precision Architecture} {CPU},
+ among others. The SPARC design was radical at the time, even
+ omitting multiple cycle multiply and divide instructions (like
+ a few others), while most RISC CPUs are more conventional.
+
+ SPARC implementations usually contain 128 or 144 {registers},
+ ({CISC} designs typically had 16 or less). At each time 32
+ registers are available - 8 are global, the rest are allocated
+ in a "window" from a stack of registers. The window is moved
+ 16 registers down the stack during a function call, so that
+ the upper and lower 8 registers are shared between functions,
+ to pass and return values, and 8 are local. The window is
+ moved up on return, so registers are loaded or saved only at
+ the top or bottom of the register stack. This allows
+ functions to be called in as little as 1 cycle. Like some
+ other RISC processors, reading global register zero always
+ returns zero and writing it has no effect. SPARC is
+ {pipelined} for performance, and like previous processors, a
+ dedicated {condition code register} holds comparison results.
+
+ SPARC is "scalable" mainly because the register stack can be
+ expanded (up to 512, or 32 windows), to reduce loads and saves
+ between functions, or scaled down to reduce {interrupt} or
+ {context switch} time, when the entire register set has to be
+ saved. Function calls are usually much more frequent, so the
+ large register set is usually a plus.
+
+ SPARC is not a chip, but a specification, and so there are
+ various implementations of it. It has undergone revisions,
+ and now has multiply and divide instructions. Most versions
+ are 32 bits, but there are designs for 64-bit and
+ {superscalar} versions. SPARC was submitted to the {IEEE}
+ society to be considered for the {P1754} microprocessor
+ standard.
+
+ SPARC(R) is a registered trademark of SPARC International,
+ Inc. in the United States and other countries.
+
+ [The SPARC Architecture Manual, v8, ISBN 0-13-825001-4].
+
+ (1994-11-01)
+
+Scalable Sampling Rate
+
+ <compression, standard, algorithm> (SSR) See, e.g., {MPEG-4
+ AAC SSR}.
+
+ (2001-12-08)
+
+Scalable Vector Graphics
+
+ <graphics, web> A {W3C} standard for {vector
+ graphics}, based on {XML}.
+
+ {(http://w3.org/Graphics/SVG/)}.
+
+ (2001-02-06)
+
+scalar
+
+ 1. <mathematics> A single number, as opposed to a {vector} or
+ {matrix} of numbers. Thus, for example, "scalar
+ multiplication" refers to the operation of multiplying one
+ number (one scalar) by another and is used to contrast this
+ with "matrix multiplication" etc.
+
+ 2. <architecture> In a {parallel processor} or {vector
+ processor}, the "scalar processor" handles all the sequential
+ operations - those which cannot be parallelised or vectorised.
+
+ See also {superscalar}.
+
+ 3. <programming> Any data type that stores a single value
+ (e.g. a number or {Boolean}), as opposed to an {aggregate}
+ data type that has many elements. A {string} is regarded as a
+ scalar in some languages (e.g. {Perl}) and a vector of
+ {characters} in others (e.g. {C}).
+
+ (2002-06-12)
+
+SCALLOP
+
+ <language, history> A medium-level language for {CDC}
+ computers, used to {bootstrap} the first {Pascal} {compiler}.
+
+ (1994-11-01)
+
+SCAN
+
+ 1. ["A Parallel Implementation of the SCAN Language",
+ N.G. Bourbakis, Comp Langs 14(4):239-254 (1989)].
+
+ 2. A {real-time} language from {DEC}.
+
+ [Are these the same language?]
+
+ (1994-11-01)
+
+scan
+
+ 1. (computer peripheral) See {scanner}.
+
+ 2. (circuit design) See {scan design}.
+
+ 3. ({functional programming}) See {scanl}, {scanr}.
+
+ 4. <storage, algorithm> An algorithm for scheduling multiple
+ accesses to a disk. A number of requests are ordered
+ according to the data's position on the storage device. This
+ reduces the disk arm movement to one "scan" or sweep across
+ the whole disk in the worst case. The serivce time can be
+ estimated from the disk's track-to-track {seek} time, maximum
+ seek time (one scan), and maximum {rotational latency}.
+
+ {Scan-EDF} is a variation on this.
+
+ (1995-11-15)
+
+scan design
+
+ <electronics> (Or "Scan-In, Scan-Out") A electronic circuit
+ design technique which aims to increase the controllability
+ and observability of a digital {logic circuit} by
+ incorporating special "{scan registers}" into the circuit so
+ that they form a {scan path}.
+
+ Some of the more common types of scan design include the
+ {multiplexed register} designs and {level-sensitive scan
+ design} (LSSD) used extensively by {IBM}. {Boundary scan} can
+ be used alone or in combination with either of the above
+ techniques.
+
+ ["Digital Systems Testing and Testable Design" by Abramovici,
+ Breuer, and Friedman, ISBN 0-7167-8179-4].
+
+ ["Design of Testable Logic Circuits" by R.G. Bennetts,
+ (Brunel/Southhampton Universities), ISBN 0-201-14403-4].
+
+ (1995-02-23)
+
+SCANDISK
+
+ <operating system, storage> An {MS-DOS} command to check for
+ faults on a disk and provide a graphical representation the
+ results. Scandisk was introduced with MS-DOS version 6 to
+ replace CHKDSK.
+
+ [What kinds of disk? What faults?]
+
+ (1997-07-16)
+
+Scan-EDF
+
+ <storage, algorithm> A variation of the {Scan} disk aceess
+ algorithm for use in a {real-time} environment where, in
+ general, requests are served according to {Earliest Deadline
+ First}. If two requests share the same deadline, they may be
+ reorganised according to Scan.
+
+ A typical example is a video server that retrieves video data
+ from a hard disk. The playback of a video impose tight
+ real-time constraints but if the server retrieves data once
+ every second for each video channel, Scan-EDF can be applied,
+ reducing the {seek} {overhead}.
+
+ (1995-11-15)
+
+scanf
+
+ The {C} library routine that reads data from the {standard
+ input} {stream} {stdin} into the locations given by each entry
+ in its argument list. The first argument is a format string
+ which controls interpretation of the input and each subsequent
+ argument points to a variable with a type that corresponds to
+ a type specifier in the format-string.
+
+ {Unix manual page}: scanf(3).
+
+ (1995-02-23)
+
+Scan-In, Scan-Out
+
+ {scan design}
+
+scan line
+
+ <hardware> A horizontal line of {pixels} generated by a single
+ horizontal sweep of the beam from a {monitor}'s {electron
+ gun}. The number of scanlines that make up a {frame} is the
+ vertical {resolution}.
+
+ (1996-02-09)
+
+scanner
+
+ 1. An input device that takes in an optical image and
+ digitises it into an electronic image represented as binary
+ data. This can be used to create a computerised version of a
+ photo or illustration.
+
+ A scanner may be linked to {optical character recognition}
+ software allowing printed documents to be converted to
+ electronic text without having to type them in at a keyboard.
+
+ 2. {lexical analyser}.
+
+ (1995-02-14)
+
+scanno
+
+ /skan'oh/ An error in a document caused by a {scanner} glitch,
+ analogous to a typo or {thinko}.
+
+ [{Jargon File}]
+
+ (1995-02-14)
+
+scan path
+
+ (circuit design) A technique used to increase the
+ controllability and observability of a {logic circuit} by
+ incorporating "{scan registers}" into the circuit. Normally
+ these act like {flip-flops} but they can be switched into a
+ "test" mode where they all become one long {shift register}.
+ This allows data to be clocked serially through all the scan
+ registers and out of an output pin at the same time as new
+ data is clocked in from an input pin.
+
+ Using this technique, the state of certain points in the
+ circuit can be examined and modified at any time by suspending
+ normal operation and switching to test mode. If the scan path
+ is placed adjacent to the circuit's input and output pins then
+ this is known as "{boundary scan}".
+
+ (1995-02-14)
+
+scan register
+
+ <electronics, testing> A {digital logic} circuit which can
+ act either as a {flip-flop} or as a serial {shift register}
+ and which is used to form a {scan path} for testing.
+
+ The most common design is a multiplexed {flip-flop}:
+
+ ___ ____
+ normal in --| \ | |
+ |mux |------|D Q|---- normal/scan
+ scan in ----|___/ | | output
+ | |flip|
+ test mode ----+ |flop|
+ | |
+ clk --------------------|> |
+ |____|
+
+ The addition of a {multiplexor} (mux) to each {flip-flop}'s
+ input allows operation in either normal or test mode. The
+ output of each flip-flop goes to the normal functional logic
+ as well as to the scan input of the next multiplexor in the
+ scan path.
+
+ The other common design is {level-sensitive scan design}
+ (LSSD).
+
+ (2011-12-16)
+
+scar tissue code
+
+ <humour, programming> Old {code} that is {commented out} but still
+ included in the current {release}.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2014-01-04)
+
+SCC
+
+ {strongly connected component}
+
+SCCS
+
+ <software> Source Code Control System: a popular {source code
+ management} system found on {Unix} since early versions.
+
+ {Unix manual page}: sccs(1).
+
+ (2011-12-16)
+
+SCEPTRE
+
+ Designing and analysing circuits.
+
+ ["SCEPTRE: A Computer Program for Circuit and Systems
+ Analysis", J.C. Bowers et al, P-H 1971].
+
+Schachter's Hypothesis
+
+ <web> The observation that "Given two unrelated
+ technical terms, an {Internet} {search engine} will retrieve
+ only résumés". This was first formulated by {Joshua Eli
+ Schachter (http://burri.to/~joshua/)} in about 1998, while
+ poring over the uniformly irrelevant pages that resulted from
+ a search he'd run on "+{Perl} +{MAPI}" in {Altavista}.
+
+ (2002-02-04)
+
+scheduler
+
+ {scheduling}
+
+scheduling
+
+ <algorithm> The arrangement of a number of related operations
+ in time.
+
+ There are several kinds of scheduling related to computers:
+
+ {instruction scheduling} - sequencing the instructions
+ executed by the {CPU}
+
+ {multitasking} ("process scheduling") - sharing a CPU between
+ several processes
+
+ {application} {software} to help organise your daily meetings
+ etc.
+
+ {task scheduling} - {algorithms} to solve the general problem
+ of satisfying time and resource {constraints} between a number
+ of tasks.
+
+ Compare {planning}.
+
+ (1998-04-25)
+
+Scheduling API
+
+ {Scheduling Application Programming Interface}
+
+Scheduling Application Programming Interface
+
+ (SAPI, Scheduling API) An {API} aimed at {software} which aids
+ humans in arranging their (business) activities.
+
+ {Microsoft} has defined a SAPI for its {Schedule+}
+ application.
+
+ (1995-01-11)
+
+Schelog
+
+ <language, Scheme, Prolog> (Previously "slog"?) A {Prolog} to
+ {Chez Scheme} {macro} translator by <dorai@cs.rice.edu>.
+ Schelog relies on continuations.
+
+ {(http://cs.rice.edu/CS/PLT/packages/schelog)}.
+
+ (2000-11-20)
+
+schema
+
+ 1. <database> {database schema}.
+
+ 2. <logic> {axiom schema}.
+
+ 3. <data> {XML schema}.
+
+Schema Definition Set
+
+ (SDS) Something in {Portable Common Tool Environment}.
+
+ [What?]
+
+ (2001-03-03)
+
+Schema Representation language
+
+ (SRL)
+
+ ["SRL/2 Users Manual", J.M. Wright et al, Robotics Inst, CMU,
+ 1984].
+
+schematic capture
+
+ The process of entering the logical design of an electronic
+ circuit into a CAE system by creating a schematic
+ representation of components and interconnections.
+
+schematic type variable
+
+ {generic type variable}
+
+Schematik
+
+ A {NeXT} front-end to {MIT Scheme} for the NeXT by Chris Kane
+ and Max Hailperin <max@nic.gac.edu>. Schematik provides
+ syntax-knowledgeable text editing, graphics windows and a
+ user-interface to an underlying MIT Scheme process. It comes
+ with MIT Scheme 7.1.3 ready to install on the NeXT and
+ requires {NEXTSTEP}.
+
+ Version: 1.1.5.2.
+
+ {USA FTP (ftp://ftp.gac.edu/pub/next/scheme/)}. {Germany
+ (ftp://ftp.informatik.uni-muenchen.de/pub/next/ProgLang)}.
+
+ E-mail: <schematik@gac.edu>.
+
+ (1993-03-11)
+
+Scheme
+
+ <programming> (Originally "Schemer", by analogy with {Planner}
+ and {Conniver}). A small, uniform {Lisp} dialect with clean
+ {semantics}, developed initially by {Guy Steele} and {Gerald
+ Sussman} in 1975. Scheme uses {applicative order reduction}
+ and {lexical scope}. It treats both {functions} and
+ {continuations} as {first-class} objects.
+
+ One of the most used implementations is {DrScheme}, others
+ include {Bigloo}, {Elk}, {Liar}, {Orbit}, {Scheme86} (Indiana
+ U), {SCM}, {MacScheme} (Semantic Microsystems), {PC Scheme}
+ (TI), {MIT Scheme}, and {T}.
+
+ See also {Kamin's interpreters}, {PSD}, {PseudoScheme},
+ {Schematik}, {Scheme Repository}, {STk}, {syntax-case}, {Tiny
+ Clos}, {Paradigms of AI Programming}.
+
+ There have been a series of revisions of the report defining
+ Scheme, known as {RRS} (Revised Report on Scheme), {R2RS}
+ (Revised Revised Report ..), {R3RS}, {R3.99RS}, {R4RS}.
+
+ {Scheme resources (http://schemers.org/)}.
+
+ Mailing list: scheme@mc.lcs.mit.edu.
+
+ [IEEE P1178-1990, "IEEE Standard for the Scheme Programming
+ Language", ISBN 1-55937-125-0].
+
+ (2003-09-14)
+
+Scheme84
+
+ {Scheme} from {Indiana University}. It requires {Franz Lisp}
+ on a {VAX} under {VMS} or {BSD}.
+
+ E-mail: Nancy Garrett <nlg@indiana.edu>.
+
+ Send a tape with return postage to Scheme84 Distribution,
+ Nancy Garrett, c/o Dan Friedman, Department of Computer
+ Science, Indiana University, Bloomington, Indiana. Telephone:
+ +1 (812) 335 9770.
+
+Scheme88
+
+ {(ftp://nexus.yorku.ca/pub/scheme/)}.
+
+ [Description?]
+
+Scheme->C
+
+ {Scheme-to-C}
+
+Scheme Library
+
+ <library> (SLIB) A portable {Scheme} library providing
+ compatibiliy and utility functions for all standard Scheme
+ implementations.
+
+ Version 2c5 supports {Bigloo}, {Chez}, {ELK}, {GAMBIT},
+ {MacScheme}, {MITScheme}, {PocketScheme}, {RScheme},
+ {Scheme->C}, {Scheme48}, {SCM}, {SCSH}, {T3.1}, {UMB-Scheme},
+ and {VSCM}.
+
+ {(http://swissnet.ai.mit.edu/~jaffer/SLIB.html)}.
+
+ (1999-06-07)
+
+Scheme-Linda
+
+ A {Scheme} interface to {Linda} written by Ulf Dahlen of
+ {University of Edinburgh} in 1990. It runs on the {Computing
+ Surface} and the {Symmetry}.
+
+ ["Scheme-Linda", U. Dahlen et al, EPCC-TN-90-01 Edinburgh
+ 1990].
+
+ (1994-12-15)
+
+Scheme Object System
+
+ (SOS) Chris Hanson?
+
+ {(ftp://altdorf.ai.mit.edu/archive/cph/sos.tar.gz)}.
+
+ [Description?]
+
+Scheme Repository
+
+ A collection of free {Scheme} programs.
+
+ {(ftp://nexus.yorku.ca/pub/scheme/)}.
+
+Scheme-to-C
+
+ <language> A {Scheme} {compiler} written in {C} that emits C
+ and is embeddable in C. Scheme-to-C was written by Joel
+ Bartlett of {Digital Western Research Laboratory}. Version
+ 15mar93 translates a superset of Revised**4 Scheme to C that
+ is then compiled by the {native} {C} compiler for the {target
+ machine}. This design results in a portable system that
+ allows either stand-alone Scheme programs or programs written
+ in both compiled and interpreted Scheme and other languages.
+ It supports "{expansion passing style}" {macros}, {foreign
+ function} calls, {records}, and interfaces to {Xlib} ({Ezd}
+ and {Scix}).
+
+ Scheme-to-C runs on {VAX}, {ULTRIX}, {DECstation}, {Alpha AXP}
+ {OSF}/1, {Windows 3.1}, {Apple Macintosh} 7.1, {HP 9000/300},
+ {HP 9000/700}, {Sony News}, {SGI} {Iris} and {Harris}
+ {Nighthawk}, and other {Unix}-like {88000} systems. The
+ earlier 01nov91 version runs on {Amiga}, {SunOS}, {NeXT}, and
+ {Apollo} systems.
+
+ {(ftp://gatekeeper.dec.com/pub/DEC/Scheme-to-C/)}.
+
+ (2000-05-24)
+
+Schlaer-Mellor
+
+ An {object-oriented analysis} (OOA), design and modelling
+ method that addresses the integration of structural and
+ behavioural properties. It also allows an animation of the
+ design.
+
+ {I-OOA} is a tool that supports the Schlaer Mellor Design
+ Method.
+
+ (1995-01-31)
+
+Schoonschip
+
+ <mathematics, tool> (From the Dutch for "beautiful ship" or
+ "clean ship") A program for {symbolic mathematics}, especially
+ High Energy Physics, written by M. Veltman of CERN in 1964.
+ Schoonschip only does algebra, no derivatives. It was
+ implemented originally in {CDC 6600} and {CDC 7600} {assembly
+ language} and currently in {680x0} {assembly language}.
+ Latest versions run on {Amiga}, {Atari ST}, {Sun-3} and
+ {NeXT}.
+
+ It was once maintained by David Williams at the {University of
+ Michigan} Physics Department.
+
+ {(ftp://archive.umich.edu/physics/schip)}.
+
+ (2000-11-14)
+
+schrödinbug
+
+ <jargon, programming> /shroh'din-buhg/ ({MIT}, from the
+ Schrödinger's Cat thought-experiment in quantum physics) A design
+ or implementation {bug} that doesn't manifest until someone
+ reading the {source code} or using the program in an unusual way
+ notices that it never should have worked, at which point it stops
+ working until fixed.
+
+ Though (like {bit rot}) this sounds impossible, it happens; some
+ programs have harboured schrödinbugs for years.
+
+ Compare {heisenbug}, {Bohr bug}, {mandelbug}.
+
+ [{Jargon File}]
+
+ (1995-02-28)
+
+SCI
+
+ <hardware> 1. {Scalable Coherent Interface}.
+
+ 2. {UART}.
+
+ (1998-02-14)
+
+Science and Engineering Research Council
+
+ <body> (SERC) Formerly the largest of the five research
+ councils funded by the British Government through the Office
+ of Science and Technology. SERC funded higher education
+ research in science and engineering, including computing and
+ was responsible for the Rutherford Appleton Laboratory, near
+ Oxford; the Daresbury Laboratory, near Warrington; the Royal
+ Greenwich Observatory at Cambridge and the Royal Observatory,
+ Edinburgh.
+
+ In April 1994 SERC was split into the Engineering and Physical
+ Sciences Research Council and the Particle Physics and
+ Astronomy Research Council. SERC's remote sensing efforts
+ have been transferred to the Natural Environment RC and its
+ biotechnology efforts merged with the Agriculture and Food RC
+ to make the new Biotechnology and Biological Sciences RC. The
+ two major SERC laboratories - {Rutherford Appleton Laboratory}
+ and Daresbury Laboratory are now independent.
+
+ {(http://unixfe.rl.ac.uk/serc/serc.html)}.
+
+ (1994-12-15)
+
+Scientific Data Systems
+
+ <company> (SDS) The company that produced the SDS 940 (later
+ renamed {XDS 940}). Around 1968 {Xerox} bought out SDS and
+ renamed the SDS machines to XDS.
+
+ [What else?]
+
+ (2001-03-03)
+
+SCL
+
+ <language> 1. {System Control Language}.
+
+ 2. Symbolic Communication Language. Designed primarily for
+ the manipulation of symbolic formulas. Featured pattern
+ matching (which was partly the inspiration for SNOBOL), string
+ operations in buffers, and automatic storage management. "A
+ Language for Symbolic Communication", C.Y. Lee et al, Tech Mem
+ 62-3344-4, Bell Labs, Sept 1962.
+
+SCM
+
+ 1. <business> {Supply Chain Management}.
+
+ (2003-10-09)
+
+ 2. <language> A {Scheme} {interpreter} in {C} by Aubrey Jaffer
+ and others. SCM conforms to {R4RS} and {IEEE} {P1178} and
+ includes a {conformance test}. It is distributed under {GPL}.
+ Version 5d0 runs under {Amiga}, {Atari-ST}, {MacOS}, {MS-DOS},
+ {OS/2}, {NOS/VE}, {Unicos}, {VMS}, {Unix}, and similar
+ systems.
+
+ {x-scm} provides an {X Window System} interface for SCM
+ programs.
+
+ {(http://swissnet.ai.mit.edu/~jaffer/SCM.html)}.
+
+ (1999-06-07)
+
+SC/MP
+
+ <processor> (Nicknamed "Scamp") A typical 8-bit
+ {microprocessor} from {National Semiconductor} released in
+ April 1976. It was intended for control applications (a
+ simple {BASIC} in a 2.5K {ROM} was added to one version). It
+ featured 16 bit addressing, with 12 address lines and 4 lines
+ borrowed from the data bus (it was common to borrow lines from
+ the data bus for addressing). Internally, it included three
+ {index registers} (P1 to P3) and two 8-bit general-purpose
+ {registers}. It had a {PC}, but no {stack pointer} or
+ {subroutine} instructions (though they could be emulated with
+ index registers). During {interrupts}, the {PC} was saved in
+ P3. It was meant for embedded control, and these features
+ were omitted for cost reasons. It was also {bit serial}
+ internally to keep it cheap.
+
+ The unique feature was the ability to completely share a
+ system bus with other processors. Most processors of the time
+ assumed they were the only ones accessing memory or I/O
+ devices. Multiple SC/MPs could be hooked up to the bus, as
+ well as other intelligent devices, such as {DMA controllers}.
+ A control line (ENOUT (Enable Out) to ENIN) could be chained
+ along the processors to allow cooperative processing. This
+ was very advanced for the time, compared to other {CPUs}.
+
+ In addition to I/O ports like the {Intel 8080}, the SC/MP also
+ had instructions and one pin for serial input and one for
+ output.
+
+ (1994-11-16)
+
+SCO
+
+ {Santa Cruz Operation}
+
+Scode
+
+ The internal representation used by the {Liar} compiler for
+ {MIT Scheme}.
+
+ (1994-11-01)
+
+SCOOP
+
+ Structured Concurrent Object-Oriented Prolog.
+
+ ["SCOOP, Structured Concurrent Object-Oriented Prolog",
+ J. Vaucher et al, in ECOOP '88, S. Gjessing et al eds, LNCS
+ 322, Springer 1988, pp.191-211].
+
+SCOOPS
+
+ Scheme Object-Oriented Programming System. Developed at
+ {Texas Instruments} in 1986. It supports {multiple
+ inheritance} and {class variables}.
+
+ {(ftp://altdorf.ai.mit.edu/archive/scheme-library/unsupported/CScheme)}.
+
+ (1994-11-01)
+
+SCOPE
+
+ <project> Software Evaluation and Certification Programme
+ Europe.
+
+ An {ESPRIT} project.
+
+ (1995-04-12)
+
+scope
+
+ <programming> The scope of an identifier is the region of a
+ program source within which it represents a certain thing.
+ This usually extends from the place where it is declared to
+ the end of the smallest enclosing block (begin/end or
+ procedure/function body). An inner block may contain a
+ redeclaration of the same identifier in which case the scope
+ of the outer declaration does not include (is "shadowed" or
+ "{occlude}d" by) the scope of the inner.
+
+ See also {activation record}, {dynamic scope}, {lexical
+ scope}.
+
+ (1994-11-01)
+
+Scorpion
+
+ Twenty tools that can be used to construct specialised
+ programming environments. The Scorpion Project was started by
+ Prof. Richard Snodgrass <rts@cs.arizona.edu> as an outgrowth
+ of the {SoftLab} Project (which produced the {IDL Toolkit})
+ that he started when he was at the {University of North
+ Carolina}. The Scorpion Project is directed by him at the
+ {University of Arizona} and by Karen Shannon at the
+ {University of North Carolina} at Chapel Hill.
+
+ Version 6.0 runs on {Sun-3}, {Sun-4}, {VAX}, {Decstation},
+ {Iris}, {Sequent}, {HP9000}.
+
+ See also {Candle}.
+
+ {(ftp://cs.arizona.edu/scorpion/)}.
+
+ Mailing list: info-scorpion-request@cs.arizona.edu.
+
+ E-mail: <scorpion-project@cs.arizona.edu>.
+
+ (1993-11-04)
+
+Scott-closed
+
+ A set S, a subset of D, is Scott-closed if
+
+ (1) If Y is a subset of S and Y is {directed} then lub Y is in
+ S and
+
+ (2) If y <= s in S then y is in S.
+
+ I.e. a Scott-closed set contains the {lubs} of its {directed}
+ subsets and anything less than any element. (2) says that S
+ is downward {closed} (or left closed).
+
+ ("<=" is written in {LaTeX} as {\sqsubseteq}).
+
+ (1995-02-03)
+
+Scott domain
+
+ An {algebraic}, {boundedly complete}, {complete partial
+ order}. Often simply called a {domain}.
+
+ (1994-11-01)
+
+SCPI
+
+ {Standard Commands for Programmable Instruments}
+
+SCPI Consortium
+
+ <body> A body established to promote {Standard Commands for
+ Programmable Instruments}.
+
+ Address: 8380 Hercules Drive, Suite P3, La Mesa, CA 91942,
+ USA.
+
+ {SCPI in Europe
+ (http://ourworld.compuserve.com/homepages/acea/scpi_uk.htm)}.
+ Address: ACEA, P.O. Box 134, 7640 AC Wierden The Netherlands.
+ Telephone: +31 546 577 994. E-mail: <ACEA@compuserve.com>.
+
+ (1999-01-05)
+
+scram switch
+
+ <jargon> (From the nuclear power industry) An emergency
+ power-off switch (see {Big Red Switch}), especially one
+ positioned to be easily hit by evacuating personnel. In
+ general, this is *not* something you {frob} lightly; these
+ often initiate expensive events (such as Halon dumps) and are
+ installed in a {dinosaur pen} for use in case of electrical
+ fire or in case some luckless {field servoid} should put 120
+ volts across himself while {Easter egging}.
+
+ SCRAM stands for Safety Control Rod Ax Man. In the early days
+ of nuclear power, boron moderator rods were raised and lowered
+ on ropes. In the event of a runaway chain reaction, a man
+ with an axe would chop the rope and drop the rods into the
+ nuclear pile to stop the reaction.
+
+ See also {molly-guard}, {TMRC}.
+
+ [{Jargon File}]
+
+ (2003-05-17)
+
+SCRAP
+
+ Something written at {CSIR}, Pretoria, South Africa in the
+ late 1970s. It ran on {Interdata} and {Perkin-Elmer}
+ computers and was in use until the late 1980s.
+
+ [But what was it?]
+
+ (1994-12-15)
+
+scratch
+
+ 1. (From "scratchpad") Describes a data structure or recording
+ medium attached to a machine for testing or temporary-use
+ purposes; one that can be {scribble}d on without loss.
+ Usually in the combining forms "scratch memory", "scratch
+ register", "scratch disk", "scratch tape", "scratch volume".
+
+ See also {scratch monkey}.
+
+ 2. (primarily {IBM}) To delete (as in a file).
+
+ [{Jargon File}]
+
+ (1994-12-15)
+
+scratch disk
+
+ 1. <storage> See {scratch}.
+
+ 2. <operating system> Unallocated space on {Windows 95}'s
+ primary {hard disk} {partition}, used for {virtual memory}.
+
+ Shortage of space on this partition can result in the error
+ "scratch disk full".
+
+ (2000-03-07)
+
+scratch monkey
+
+ <humour> As in "Before testing or reconfiguring, always mount
+ a {scratch monkey}", a proverb used to advise caution when
+ dealing with irreplaceable data or devices. Used to refer to
+ any scratch volume hooked to a computer during any risky
+ operation as a replacement for some precious resource or data
+ that might otherwise get trashed.
+
+ This term preserves the memory of Mabel, the Swimming Wonder
+ Monkey, star of a biological research program at the
+ University of Toronto. Mabel was not (so the legend goes)
+ your ordinary monkey; the university had spent years teaching
+ her how to swim, breathing through a regulator, in order to
+ study the effects of different gas mixtures on her physiology.
+ Mabel suffered an untimely demise one day when a DEC engineer
+ troubleshooting a crash on the program's VAX inadvertently
+ interfered with some custom hardware that was wired to Mabel.
+
+ It is reported that, after calming down an understandably
+ irate customer sufficiently to ascertain the facts of the
+ matter, a DEC troubleshooter called up the {field circus}
+ manager responsible and asked him sweetly, "Can you swim?"
+
+ Not all the consequences to humans were so amusing; the sysop
+ of the machine in question was nearly thrown in jail at the
+ behest of certain clueless droids at the local "humane"
+ society. The moral is clear: When in doubt, always mount a
+ scratch monkey.
+
+ {ESR} notes: There is a version of this story, complete with
+ reported dialogue between one of the project people and DEC
+ field service, that has been circulating on Internet since
+ 1986. It is hilarious and mythic, but gets some facts wrong.
+ For example, it reports the machine as a {PDP-11} and alleges
+ that Mabel's demise occurred when DEC {PM}ed the machine.
+ Earlier versions of this entry were based on that story; this
+ one has been corrected from an interview with the hapless
+ sysop.
+
+ A corespondent adds: The details you give are somewhat
+ consistent with the version I recall from the Digital "War
+ Stories" notesfile, but the name "Mabel" and the swimming bit
+ were not mentioned, IIRC. Also, there's {a very detailed
+ account (http://mv.com/ipusers/arcade/monkey.htm)} that
+ claims that three monkies died in the incident, not just one.
+ I believe Eric Postpischil wrote the original story at DEC, so
+ his coming back with a different version leads me to wonder
+ whether there ever was a real Scratch Monkey incident.
+
+ [{Jargon File}]
+
+ (2004-08-22)
+
+Scratchpad I
+
+ <language> A general-purpose language originally for
+ interactive {symbolic mathematics} by Richard Jenks, Barry
+ Trager, Stephen M. Watt and Robert S. Sutor of {IBM Research},
+ ca 1971. It features abstract parametrised data types,
+ {multiple inheritance} and {polymorphism}. There were
+ implementations for {VM/CMS} and {AIX}.
+
+ ["Scratchpad User's Manual", RA 70, IBM (June 1975)].
+
+ (1994-12-15)
+
+Scratchpad II
+
+ See {Scratchpad I}, {AXIOM}.
+
+ ["Scratchpad II Programming Language Manual", R.D. Jenks et
+ al, IBM, 1985].
+
+ [Scratchpad II Newsletter: Computer Algebra Group, TJWRC, Box
+ 218, Yorktown Hts, NY 10598].
+
+scream and die
+
+ Synonym {cough and die}, but connotes that an error message
+ was printed or displayed before the program crashed.
+
+ [{Jargon File}]
+
+Screamer
+
+ An extension of {Common Lisp} providing {nondeterministic}
+ {backtracking} and {constraint} programming.
+
+ {(ftp://ftp.ai.mit.edu/pub/screamer.tar.Z)}.
+
+ [Isn't all backtracking nondeterministic by definition?]
+
+screaming tty
+
+ [Unix] A terminal line which spews an infinite number of
+ random characters at the operating system. This can happen if
+ the terminal is either disconnected or connected to a
+ powered-off terminal but still enabled for login;
+ misconfiguration, misimplementation, or simple bad luck can
+ start such a terminal screaming. A screaming tty or two can
+ seriously degrade the performance of a vanilla Unix system;
+ the arriving "characters" are treated as userid/password pairs
+ and tested as such. The Unix password encryption algorithm is
+ designed to be computationally intensive in order to foil
+ brute-force crack attacks, so although none of the logins
+ succeeds; the overhead of rejecting them all can be
+ substantial.
+
+ [{Jargon File}]
+
+screen
+
+ 1. <hardware> A generic term for a {display device} that shows
+ text and/or images on a roughly flat rectangular surface. The
+ most common type is usually refered to as a "{monitor}" and is
+ based on a {cathode-ray tube}, though {flat panel} displays
+ have, since around 2000, become increasingly competitive in
+ price and performance.
+
+ (2005-07-28)
+
+ 2. A {screen multiplexer} utility which lets you run multiple
+ {interactive} {terminal sessions} (and {curses} programs)
+ through a single terminal connection (on one {virtual
+ console}, one terminal, through one {modem} link, {telnet}
+ session or {xterm}).
+
+ Screen can detach processes from one terminal and attach them
+ to another. "Auto-detach" lets you continue working after
+ being disconnected and reconnected. It supports keyboard
+ driven cut and paste from any text and/or curses application
+ (like {Lynx}) to any other (like {xemacs}).
+
+ Screen comes with many {Linux} distributions and is available
+ (free) on many other {Unix} {platforms}.
+
+ (2005-07-29)
+
+screen blanker
+
+ {screen saver}
+
+screen dump
+
+ <graphics> (Or "screen shot") An {image}, often stored in a
+ file, of what was displayed on a computer's screen at some
+ time. Sending someone a screen dump can be very useful for
+ remote support and diagnosis because it may show important
+ details that the user didn't realise were significant,
+ e.g. which {web browser} they were using.
+
+ (2009-01-05)
+
+Screen Peace
+
+ <tool> A {screen saver} for {Microsoft Windows} by Anthony
+ Andersen. Released as {charityware}. It can load extension
+ modules with {filename extension} ".SPX".
+
+ {Some modules
+ (ftp://src.doc.ic.ac.uk/computing/systems/ibmpc/windows3/desktop/spx2.zip)}.
+
+ (1997-11-23)
+
+screen popping
+
+ <communications> The use of {CTI} to make customer data appear
+ on a call centre terminal at the same time as the customer
+ call is transferred.
+
+ (2003-12-04)
+
+screen reader
+
+ <application> A {text-to-speech} system, intended for use by
+ blind or low-vision users, that speaks the text content of a
+ computer display.
+
+ (1998-10-19)
+
+screen refresh
+
+ {refresh rate}
+
+screen saver
+
+ <tool> A program which displays either a completely black
+ image or a constantly changing image on a computer monitor to
+ prevent a stationary image from "burning" into the phosphor of
+ the screen. Screen savers usually start automatically after
+ the computer has had no user input for a preset time. Some
+ screen savers come with many different modules, each giving a
+ different effect.
+
+ Approximately pre-1990, many {cathode ray tubes}, in TVs,
+ computer {monitors} or elsewhere, were prone to "burn-in";
+ that is, if the same pattern (e.g., the {WordPerfect} status
+ line; the {Pong} score readout; or a TV channel-number
+ display) were shown at the same position on the screen for
+ very long periods of time, the phosphor on the screen would
+ "fatigue" and that part of the screen would seem greyed out,
+ even when the CRT was off.
+
+ Eventually CRTs were developed which were resistant to burn-in
+ (and which sometimes went into {sleep} mode after a period of
+ inactivity); but in the meantime, solutions were developed:
+ home video game systems of the era (e.g., Atari 2600s) would,
+ when not being played, change the screen every few seconds, to
+ avoid burn-in; and computer screen saver programs were
+ developed.
+
+ The first screen savers were simple screen blankers - they
+ just set the screen to all black, but, in the best case of
+ {creeping featurism} ever recorded, these tiny (often under 1K
+ long) programs grew without regard to efficiency or even basic
+ usefulness. At first, small, innocuous {display hacks}
+ (generally on an almost-black screen) were added. Later, more
+ complex effects appeared, including {animations} (often with
+ sound effects!) of arbitrary length and complexity.
+
+ Along the way, avoiding repetitive patterns and burn-in was
+ completely forgotten and "screen savers" such as {Pointcast}
+ were developed, which make no claim to save your monitor, but
+ are simply bloated {browsers} for {push media} which
+ self-start after the machine has been inactive for a few
+ minutes.
+
+ (1997-11-23)
+
+screen scraper
+
+ <tool> A piece of software used to automate interaction
+ between two computer systems through the terminal interface
+ (designed for human use) of one of those systems.
+
+ Typically, the screen scraper interacts with {terminal
+ emulation} software to generate input to and process output
+ from the "host" system through terminal screens. Screen
+ scrapers are advantageous when modifications to the host
+ system are undesireable, when it is desireable to make use of
+ the existing business and data integrity logic on the host,
+ and when no other (peer-to-peer) interface method is
+ available.
+
+ Some products employ screen scraping combined with additional
+ functionality which provides a {DBMS}-like or other
+ specialised interface to the host. The host system is often
+ called a "{legacy} system" because it usually the older of the
+ systems involved and based on older technology.
+
+ (1995-04-19)
+
+screen server
+
+ <spelling> Do you mean "{screen saver}"?
+
+ (2004-08-21)
+
+screen sharing
+
+ {Audiographic Teleconferencing}
+
+Screenwrite
+
+ <language> A columnar format {third generation programming
+ language} similar in layout to {assembler} and used for
+ {transaction processing}, solely on the {Honeywell} {Bull}
+ {TPS6} {database}/transaction management system on their Level
+ 6 {DPS6} {minicomputers} running under the {GCOS6} {operating
+ system}. In the UK it was mainly used by local authorities
+ and the Ministry of Defense. Being proprietary technology,
+ its popularity waned with the introduction of {open systems}
+ standards, {relational databases} and {fourth generation
+ languages} but it is believed that some systems made it
+ through {Y2K}.
+
+ [Dates?]
+
+ (2003-05-15)
+
+screw
+
+ <jargon> (MIT) A failure, usually in software. Especially
+ used for user-visible misbehaviour caused by a {bug} or
+ {misfeature}. This use has become quite widespread outside
+ {MIT}.
+
+ [{Jargon File}]
+
+ (1994-12-01)
+
+screwage
+
+ /skroo'*j/ Like {lossage} but connotes that the failure is due
+ to a designed-in misfeature rather than a simple inadequacy or
+ a mere bug.
+
+ [{Jargon File}]
+
+ (1994-12-01)
+
+scribble
+
+ To modify a data structure in a random and unintentionally
+ destructive way. "Bletch! Somebody's disk-compactor program
+ went berserk and scribbled on the i-node table." "It was
+ working fine until one of the allocation routines scribbled on
+ low core." Synonymous with {trash}; compare {mung}, which
+ conveys a bit more intention, and {mangle}, which is more
+ violent and final.
+
+ [{Jargon File}]
+
+Scribe
+
+ A text-formatting language by Brian Reid.
+
+ (1994-12-01)
+
+SCRIPT
+
+ 1. An early system on the {IBM 702}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ 2. A {real-time} language.
+
+ ["A Communication Abstraction Mechanism and its Verification",
+ N. Francez et al, Sci Comp Prog 6(1):35-88 (1986)].
+
+ (1994-12-01)
+
+script
+
+ <language> A program written in a {scripting language}, but
+ see {Ousterhout's dichotomy}.
+
+ (1999-02-22)
+
+Scriptics
+
+ <company> {John Ousterhout}'s company that is the home of
+ {Tcl} development and the {TclPro} tool suite.
+
+ {(http://scriptics.com/)}.
+
+ (1998-11-27)
+
+scripting language
+
+ <language> (Or "glue language") A loose term for any language
+ that is {weakly typed} or {untyped} and has little or no
+ provision for complex {data structures}. A program in a
+ scripting language (a "{script}") is often {interpreted} (but
+ see {Ousterhout's dichotomy}).
+
+ Scripts typically interact either with other programs (often
+ as {glue}) or with a set of functions provided by the
+ interpreter, as with the {file system} functions provided in a
+ {UNIX shell} and with {Tcl}'s {GUI} functions. Prototypical
+ scripting languages are {AppleScript}, {C Shell}, {MS-DOS}
+ {batch files} and {Tcl}.
+
+ (2001-03-06)
+
+scrog
+
+ /skrog/ [Bell Labs] To damage, trash, or corrupt a data
+ structure. "The list header got scrogged." Also reported as
+ "skrog", and ascribed to the comic strip "The Wizard of Id".
+ Compare {scag}; possibly the two are related. Equivalent to
+ {scribble} or {mangle}.
+
+ [{Jargon File}]
+
+SCROLL
+
+ String and Character Recording Oriented Logogrammatic
+ Language.
+
+ ["SCROLL - A Pattern Recording Language", M. Sargent, Proc
+ SJCC 36 (1970)].
+
+ (1994-12-01)
+
+scroll
+
+ <interface> (From a scroll of paper) To change the portion of
+ a document displayed in a window or on a {VDU} screen. In a
+ {graphical user interface}, scrolling is usually controlled by
+ the user via {scroll bars}, whereas on a VDU the text scrolls
+ up automatically as lines of data are output at the bottom of
+ the screen.
+
+ (2001-04-27)
+
+scrollable list
+
+ <operating system> A list of information in a {graphical user
+ interface} with a {scroll bar}, often used to present a list
+ of choices.
+
+ (1999-10-03)
+
+scroll bar
+
+ <graphics> A {widget} found in {graphical user interfaces} and
+ used to show and control ("scroll") which portion of a
+ document is currently visible in a window. A window may have
+ a horizontal or, most often, vertical scroll bar or both.
+
+ A vertical scroll bar is a narrow strip drawn up the side of
+ the window containing a "bubble" whose position in the scroll
+ bar represents the position of the visible part within the
+ whole document. By dragging the bubble with the mouse the
+ user can scroll the view over the entire document. Arrow
+ buttons are usually provided at the end(s) of the scroll bar
+ to allow the window to be scrolled by a small amount, e.g. one
+ line of text, in either direction by clicking them with the
+ mouse. Some programs provide a second pair of buttons for
+ scrolling a page at a time or some other unit. Clicking on
+ the scroll bar outside the bubble will either, depending on
+ the particular {WIMP}, move the bubble to that point or move
+ it some amount (typically a screenful) in that direction.
+
+ Different {WIMP} systems define different standards for
+ whether scroll bars appear on the left or right, top or bottom
+ of the window, and for their behaviour.
+
+ To reduce mouse movement, the up and down scroll buttons
+ should either be next to each other at one end of the scroll
+ bar (as in {NEXTSTEP}) or should reverse their effect when
+ clicked with the right-hand mouse button (as in the {X Window
+ System} and {RISC OS}). The fraction of the scroll bar filled
+ by the bubble should indicate the fraction of the document
+ visible in the window.
+
+ (1998-06-26)
+
+scrolling
+
+ <chat, games> To flood a {chat room} or {Internet game} with
+ text or {macros} in an attempt to annoy the occupants. This
+ can often cause the chat room to be "uninhabitable" due to the
+ "noise" created by the scroller. Compare {spam}.
+
+ (2001-03-27)
+
+scrool
+
+ /skrool/ [The pioneering Roundtable chat system in Houston
+ ca. 1984; probably originated as a typo for "scroll"] The log
+ of old messages, available for later perusal or to help one
+ get back in synch with the conversation. It was originally
+ called the "scrool monster", because an early version of the
+ roundtable software had a bug where it would dump all 8K of
+ scrool on a user's terminal.
+
+ [{Jargon File}]
+
+scrozzle
+
+ /skroz'l/ Used when a {self-modifying code} segment runs
+ incorrectly and corrupts the running program or vital data.
+
+ (1994-11-24)
+
+scruffies
+
+ {neats vs. scruffies}
+
+SCSI
+
+ {Small Computer System Interface}
+
+SCSI-1
+
+ <hardware> The original {SCSI}, as opposed to
+ {SCSI-2} or {SCSI-3}.
+
+ (1995-04-20)
+
+SCSI-2
+
+ <hardware> A version of the {SCSI} command
+ specification.
+
+ SCSI-2 shares the original SCSI's {asynchronous} and
+ {synchronous} modes and adds a "{Fast SCSI}" mode (<10MB/s)
+ and "{Wide SCSI}" (16 bit, <20MB/s or rarely 32 bit).
+
+ Another major enhancement was the definition of command sets
+ for different device classes. SCSI-1 was rather minimalistic
+ in this respect which led to various incompatibilities
+ especially for devices other than {hard-disks}. SCSI-2
+ addresses that problem. allowing {scanners}, {hard disk
+ drives}, {CD-ROM} drives, tapes and many other devices to be
+ connected.
+
+ Normal SCSI-2 equipment (not wide or {differential}) can be
+ connected to a SCSI-1 bus and vice versa.
+
+ (1995-04-19)
+
+SCSI-3
+
+ <hardware> An ongoing standardisation effort to
+ extend the capabilities of {SCSI-2}. SCSI-3's goals are more
+ devices on a bus (up to 32); faster data transfer; greater
+ distances between devices (longer cables); more device classes
+ and command sets; structured documentation; and a structured
+ {protocol} model.
+
+ In SCSI-2, data transmission is parallel (8, 16 or 32 bit
+ wide). This gets increasingly difficult with higher data
+ rates and longer cables because of varying signal delays on
+ different wires. Furthermore, wiring cost and drive power
+ increases with wider data words and higher speed. This has
+ triggered the move to serial interfacing in SCSI-3. By
+ embedding clock information into a serial data stream signal
+ delay problems are eliminated. Driving a single signal also
+ consumes less driving power and reduces connector cost and
+ size.
+
+ To allow for backward compatibility and for added flexibility
+ SCSI-3 allows the use of several different transport
+ mechanisms, some serial and some parallel. The software
+ {protocol} and command set is the same for each transport.
+ This leads to a layered protocol definition similar to
+ definitions found in networking.
+
+ SCSI-3 is therefore in fact the sum of a number of separate
+ standards which are defined by separate groups. These
+ standards and groups are currently:
+
+ X3T9.2/91-13R2 SCSI-3 Generic Packetized Protocol
+ X3T9.2/92-141 SCSI-3 Queuing Model
+ X3T9.2/92-079 SCSI-3 Architecture Model
+ IEEE P1394 High Performance Serial Bus
+ X3T9.2/92-106 SCSI-3 Block Commands
+ X3T9.2/91-189 SCSI-3 Serial Bus Protocol
+ X3T9.2/92-105 SCSI-3 SCSI-3 Core Commands
+ SCSI-3 Common Command Set
+ X3T9.2/92-108 SCSI-3 Graphic Commands
+ X3T9.2/92-109 SCSI-3 Medium Changer Commands
+ X3T9.2/91-11 SCSI-3 Interlocked Protocol
+ X3T9.2/91-10 SCSI-3 Parallel Interface
+ X3T9.2/92-107 SCSI-3 Stream Commands
+ SCSI-3 Scanner Commands
+
+ Additional Documents for the Fibre Channel are also meant to
+ be included in the SCSI-3 framework, i.e.:
+
+ Fibre Channel SCSI Mapping
+ Fibre Channel Fabric Requirements
+ Fibre Channel Low Cost Topologies
+ X3T9.3/92-007 Fibre Channel Physical and Signalling Interface
+ Fibre Channel Single Byte Commands
+ Fibre Channel Cross Point Switch Topology
+ X3T9.2/92-103 SCSI-3 Fibre Channel Protocol (GPP & SBP)
+
+ As all of this is an ongoing effort of considerable
+ complexity, document structure and workgroups may change. No
+ final standard is issued yet.
+
+ In the meantime a group of manufacturers have proposed an
+ extension of {SCSI-2} called {Ultra-SCSI} which doubles the
+ transfer speed of {Fast-SCSI} to give 20MByte/s on an 8 bit
+ connection and 40MByte/s on a 16-bit connection.
+
+ [Hermann Strass: "SCSI-Bus erfolgreich anwenden",
+ Franzis-Verlag Muenchen 1993].
+
+ (1995-04-19)
+
+SCSI adaptor
+
+ <hardware> (Or "host adaptor") A device that communicates
+ between a computer and its {SCSI} {peripherals}. The SCSI
+ adaptor is usually assigned {SCSI ID} 7. It is often a
+ separate card that is connected to the computer's {bus}
+ (e.g. {PCI}, {ISA}, {PCMCIA}) though increasinly, SCSI
+ adaptors are built in to the {motherboard}. Apart from being
+ cheaper, busses like PCI are too slow to keep up with the
+ newer SCSI standards like {Ultra SCSI} and {Ultra-Wide SCSI}.
+
+ There are several varieties of SCSI (and their connectors) and
+ an adaptor will not support them all.
+
+ The performance of SCSI devices is limited by the speed of the
+ SCSI adaptor and its connection to the computer. An adaptor
+ that plugs into a parallel port is unlikely to be as fast as
+ one incorporated into a motherboard. Fast adaptors use {DMA}
+ or {bus mastering}.
+
+ Some SCSI adaptors include a {BIOS} to allow PCs to {boot}
+ from a SCSI hard disk, if their own BIOS supports it.
+
+ {Adaptec} make the majority of SCSI {chipsets} and many of the
+ best-selling adaptors.
+
+ Note that it is not a "SCSI controller" - it does not control
+ the devices, and "SCSI interface" is redundant - the "I" of
+ "SCSI" stands for "interface".
+
+ (1999-11-24)
+
+SCSI controller
+
+ {SCSI adaptor}
+
+SCSI ID
+
+ <hardware> The unique address of a {SCSI} device. SCSI IDs
+ range from 0 to 7 for 8-bit SCSI systems, 0 to 15 for 16-bit
+ and 0 to 31 for 32-bit systems. The {SCSI adaptor} is
+ usually assigned ID 7. A device's SCSI ID is often set by
+ switches on the device.
+
+ (1999-09-01)
+
+SCSI initiator
+
+ <hardware> A device that begins a {SCSI} transaction by
+ issuing a command to another device (the {SCSI target}),
+ giving it a task to perform. Typically a SCSI host adapter is
+ the initiator but targets may also become initiators.
+
+ (1999-02-10)
+
+SCSI interface
+
+ {SCSI adaptor}
+
+SCSI reconnect
+
+ <hardware> The ability of a {SCSI initiator} to initiate new
+ transactions before earlier ones have completed. A target or
+ initiator can disconnect from the bus when it experiences a
+ delay in completing a task so that another device can use the
+ bus. It can reconnect later and complete the task.
+
+ (1999-02-16)
+
+SCSI target
+
+ <hardware> A {SCSI} device that executes a command from a
+ {SCSI initiator} to perform some task. Typically the target
+ is a SCSI peripheral device but the {host adapter} can also be
+ a target.
+
+ (1999-02-10)
+
+ScumOS
+
+ <abuse, operating system> /skuhm'os/ or /skuhm'O-S/ An
+ Unflattering hackerism for {SunOS}, the {Unix} variant once
+ supported on {Sun Microsystems}'s Unix {workstations}.
+
+ Despite what this term might suggest, Sun was founded by
+ hackers and still enjoys excellent relations with hackerdom;
+ usage is more often in exasperation than outright loathing.
+
+ See also {sun-stools}. Compare {AIDX}, {Macintrash}, {Nominal
+ Semidestructor}, {Open DeathTrap}, {HP-SUX}.
+
+ [{Jargon File}]
+
+ (1995-04-19)
+
+scuzzy
+
+ The usual pronunciation of {SCSI}.
+
+SD
+
+ {Structured Design}
+
+sd
+
+ <networking> The {country code} for the Sudan.
+
+ (1999-01-27)
+
+SDDI
+
+ {Sony Digital Data Interface}
+
+SDE
+
+ Software Development Environment: equivalent to SEE.
+
+SDF
+
+ Syntax Definition Formalism. A language for lexical and
+ syntactic specification.
+
+ ["The Syntax Definition Formalism SDF - Reference Manual",
+ J. Heering et al, Centre for Math & CS, Amsterdam].
+
+ ["Algebraic Specification", J.A. Bergstra et al eds, ACM Press
+ 1989, Chap 6. To appear].
+
+ (1994-10-27)
+
+SDH
+
+ {Synchronous Digital Hierarchy}
+
+SDI
+
+ 1. <library> {Selective Dissemination of Information}.
+
+ 2. <programming> {Single Document Interface}.
+
+ (1999-03-30)
+
+SDK
+
+ {Software Developers Kit} (or "Software Development Kit").
+
+SDL
+
+ Specification and Design Language.
+
+ Defined by the {ITU-T} (recommendation Z100) to provide a tool
+ for unambiguous specification and description of the behaviour
+ of telecommunications systems. The area of application also
+ includes process control and real-time applications. SDL
+ provides a Graphic Representation (SDL/GR) and a textual
+ Phrase Representation (SDL/PR), which are equivalent
+ representations of the same semantics. A system is specified
+ as a set of interconnected {abstract machines} which are
+ extensions of the {Finite State Machine} (FSM).
+
+ 1. System Software Development Language. System software for
+ the B1700. "System Software Development Language Reference
+ Manual", 1081346, Burroughs Corp (Dec 1974).
+
+ 2. Specification and Description Language. {ITU-T}.
+ Specification language with both graphical and character-based
+ syntaxes for defining interacting extended finite state
+ machines. Used to specify discrete interactive systems such
+ as industrial process control, traffic control, and
+ telecommunication systems. Proc Plenary Assembly, Melbourne
+ 14-1988-11-25, Fasc X.1, CCITT. "Telecommunications Systems
+ Engineering Using SDL", R. Saracco et al, N-H 1989. Available
+ from Verilog, MD. (See XDL).
+
+ 3. Shared Dataspace Language. "A Shared Dataspace Language
+ Supporting Large-Scale Concurrency", G. Roman et al, Proc 8th
+ Intl Conf Distrib Comp Sys, IEEE 1988, pp.265-272.
+
+ 4. Structure Definition Language. Used internally by DEC to
+ define and generate the symbols used for VAX/VMS internal data
+ structures in various languages.
+
+ 5. System Description Language. language used by the Eiffel/S
+ implementation of Eiffel to assemble clusters into a system.
+ (see Lace).
+
+SDL 92
+
+ SDL[2] with object-orientation.
+
+SDLC
+
+ 1. <communications> {Synchronous Data Link Control}.
+
+ 2. <programming> {Systems Development Life Cycle}.
+
+ (2000-12-24)
+
+SDM
+
+ {Schematic Data Model}
+
+SDMS
+
+ A {query language}.
+
+SDP
+
+ {Service Discovery Protocol}
+
+SDRAM
+
+ {Synchronous Dynamic Random Access Memory}
+
+SDRC
+
+ <company> The company behind {VGX}.
+
+ {(http://sdrc.com/)}.
+
+ [More details?]
+
+ (1998-02-06)
+
+SDR-RAM
+
+ {Single Data Rate Random Access Memory}
+
+SDR-SDRAM
+
+ {Single Data Rate Random Access Memory}
+
+SDS
+
+ 1. <company> {Scientific Data Systems}.
+
+ 2. <tool> {Schema Definition Set}.
+
+ (2001-03-03)
+
+SDS 92
+
+ <computer> A 12-bit computer from {Scientific Data Systems}
+ which preceded the {Xerox Data Systems Model 940}.
+
+ (2001-03-03)
+
+SDS 940
+
+ {Xerox Data Systems Model 940}
+
+SDSL
+
+ {Single-line Digital Subscriber Line}
+
+SE
+
+ 1. <software> {software engineering}.
+
+ 2. {IBM Systems Engineer}.
+
+ (1998-07-08)
+
+se
+
+ <networking> The {country code} for Sweden.
+
+ (1999-01-27)
+
+SEA
+
+ {Self Extracting Archive}
+
+Seagate Technology
+
+ <company> A major manufacturer of {hard disk drives}, founded
+ in 1979 as "Shugart Technology" by {Alan F. Shugart} and
+ {Finis Conner}. That name is on the original patents for the
+ 5.25" hard disk drive. They changed the name to Seagate
+ Technology soon after to avoid confusion, and also to avoid
+ friction with {Xerox}, which had since purchased Alan's
+ earlier company, {Shugart Associates}.
+
+ {(http://seagate.com/)}.
+
+ {Technical information at Impediment
+ (http://impediment.com/seagate/)}.
+
+ Address: 920 Disc Drive, Scotts Valley, CA 95066, USA.
+
+ Fax: +1 (408) 438 3320.
+
+ (2000-02-09)
+
+SEAL
+
+ Semantics-directed Environment Adaptation Language.
+
+ {(ftp://ftp.cwi.nl/pub/gipe/0092b.ps.Z)}.
+
+search
+
+ 1. <web> {web search}.
+
+ 2. <computability> {search problem}.
+
+ 3. <theory> {search algorithm}.
+
+search algorithm
+
+ <theory> Any {algorithm} for identifying a solution to a
+ problem (a {search problem}) out of a {space} of potential
+ solutions by considering several potential solutions until one
+ is found that meets certain criteria.
+
+ See {A* search}, {beam search}, {best-first search},
+ {breadth-first search}, {depth-first search}.
+
+ (2007-11-03)
+
+search-and-destroy mode
+
+ Hackerism for a noninteractive search-and-replace facility in
+ an editor, so called because an incautiously chosen match
+ pattern can cause {infinite} damage.
+
+ [{Jargon File}]
+
+search engine
+
+ <web, tool, information science> A remotely
+ accessible program that lets you do keyword searches for
+ information on the {Internet}. There are several types of
+ search engine; the search may cover titles of documents,
+ {URLs}, headers, or the {full text}.
+
+ {A list of search engines
+ (http://cuiwww.unige.ch/meta-index.html#MISC)}, Centre
+ Universitaire d'Informatique at the University of Geneva
+
+ (1995-11-28)
+
+search problem
+
+ <computability> A computational problem that requires
+ identifying a solution from some, possibly infinite, solution
+ {space} (set of possible solutions). E.g. "What is the
+ millionth {prime number}?". This contrasts with a {decision
+ problem} which merely asks whether a given answer is a
+ solution or not.
+
+ (1999-02-15)
+
+search term
+
+ <information science> An element of a search or query. A
+ search term is the basic building block of a {boolean search}
+ or a {weighted search}. In a search engine a search term is
+ typically a word, phrase, or pattern match expression. For
+ example: cosmonaut or "space travel" or astronaut*
+
+ In a {database} a term is typically the comparison of a column
+ with a constant or with another column. For example:
+ last_name like 'Smith%'
+
+ (1999-08-27)
+
+{searchTerms}
+
+ <web> The placeholder or {variable} used in the <Url> element of
+ an {OpenSearchDescription} {XML} file to show where the user's
+ actual {search terms} should go. For example, this dictionary's
+ Open Search description (published in file {(/search.xml)})
+ includes the following element:
+
+ <Url type="text/html" template="http://foldoc.org/{searchTerms}" />
+
+ meaning that to search for, say, "foo", you should go to
+ http://foldoc.org/foo.
+
+ You may have reached this page because you were trying to use some
+ system based on {Open Search} and failed to supply any search term
+ to substitute into the URL.
+
+ {Open Search reference (http://www.opensearch.org/Specifications/OpenSearch/1.1#The_.22Url.22_element)}.
+
+ (2014-08-22)
+
+Search The Fucking Web
+
+ <web, jargon> (Always abbreviated STFW) A response implying that
+ an inquirer could have easily found an answer to his question
+ using {Google} or some other {web} {search engine}. It
+ is now often quicker and more productive to search the {World-Wide
+ Web} than to {RTFM}.
+
+ {JFGI}, {GIYF} and {lmgtfy.com} convey the same message.
+
+ (2014-05-23)
+
+SEC
+
+ {Single Edge Contact Cartridge}
+
+SECC
+
+ {Single Edge Contact Cartridge}
+
+SECD machine
+
+ {Stack Environment Control Dump machine}
+
+secondary cache
+
+ <memory management> (Or "second level cache", "level two
+ cache", "L2 cache") A larger, slower {cache} between the
+ {primary cache} and main memory. Whereas the {primary cache}
+ is often on the same {integrated circuit} as the {central
+ processing unit} (CPU), a secondary cache is usually external.
+
+ (1997-06-25)
+
+secondary damage
+
+ When a fatal error occurs (especially a {segfault}) the
+ immediate cause may be that a pointer has been trashed due to
+ a previous {fandango on core}. However, this fandango may
+ have been due to an *earlier* fandango, so no amount of
+ analysis will reveal (directly) how the damage occurred. "The
+ data structure was clobbered, but it was secondary damage."
+
+ By extension, the corruption resulting from N cascaded
+ fandangoes on core is "Nth-level damage". There is at least
+ one case on record in which 17 hours of {grovel}ling with
+ "adb" actually dug up the underlying bug behind an instance of
+ seventh-level damage! The hacker who accomplished this
+ near-superhuman feat was presented with an award by his
+ fellows.
+
+ [{Jargon File}]
+
+secondary key
+
+ <database> A {candidate key} which is not selected as a
+ {primary key}.
+
+ (1997-04-26)
+
+secondary storage
+
+ <storage> Any {non-volatile} storage medium that is not
+ directly accessible to the {processor}. Memory directly
+ accessible to the processor includes {main memory}, {cache}
+ and the {CPU} {registers}. Secondary storage includes {hard
+ drives}, {magnetic tape}, {CD-ROM}, {DVD drives}, {floppy
+ disks}, {punch cards} and {paper tape}.
+
+ Secondary storage devices are usually accessed via some kind
+ of controller. This contains registers that can be directly
+ accessed by the CPU like main memory ("{memory mapped}").
+ Reading and writing these registers can cause the device to
+ perform actions like reading a block of data off a disk or
+ rewinding a tape. See also {DMA}.
+
+ Programs and data stored in secondary storage must first be
+ loaded into main memory before the processor can use them.
+
+ (1997-11-05)
+
+second generation
+
+ 1. <language> {second generation language}.
+
+ 2. <architecture> {second generation computer}.
+
+second generation computer
+
+ <architecture> A computer built from {transistors}, designed
+ between the mid-1950s and mid-1960s.
+
+ {Ferrite core memory} and {magnetic drums} replaced {cathode
+ ray tubes} and {delay-line storage} for main {memory}. {Index
+ registers} and {floating point} arithmetic hardware became
+ widespread. Machine-independent {high level programming
+ languages} such as {ALGOL}, {COBOL} and {Fortran} were
+ introduced to simplify programming.
+
+ {I/O processors} were introduced to supervise input-output
+ operations independently of the {CPU} thus freeing the CPU
+ from time-consuming housekeeping functions. The CPU would
+ send the I/O processor an initial instruction to start
+ operating and the I/O processor would then continue
+ independently of the CPU. When completed, or in the event of
+ an error, the I/O processor sent an {interrupt} to the CPU.
+
+ {Batch} processing became feasible with the improvement in I/O
+ and storage technology in that a batch of jobs could be
+ prepared in advance, stored on magnetic tape and processed on
+ the computer in one continuous operation placing the results
+ on another magnetic tape. It became commonplace for
+ auxiliary, small computers to be used to process the input and
+ output tapes off-line thus leaving the main computer free to
+ process user programs. Computer manufacturers began to
+ provide system software such as {compilers}, {subroutine}
+ libraries and batch monitors.
+
+ With the advent of second generation computers it became
+ necessary to talk about computer systems, since the number of
+ memory units, processors, I/O devices, and other system
+ components could vary between different installations, even
+ though the same basic computer was used.
+
+ The instruction repertoire of the {IBM 7094} (a typical second
+ generation machine) had over 200 instructions including data
+ transfer instructions for transferring a {word} of information
+ between the CPU and memory or between two CPU registers;
+ fixed-point and floating point arithmetic instructions;
+ {logic} instructions (AND, OR etc.); instructions for
+ modifying {index registers}; conditional and unconditional
+ branching; {subroutines}; input-output operations for
+ transferring data between I/O devices and main memory.
+
+ (1996-11-25)
+
+second generation language
+
+ {assembly language}
+
+ See also {first generation language}, {third generation
+ language}.
+
+second level cache
+
+ {secondary cache}
+
+second normal form
+
+ {database normalisation}
+
+Second-Order Lambda-calculus
+
+ <language> (SOL) A {typed lambda-calculus}.
+
+ ["Abstract Types have Existential Type", J. Mitchell et al,
+ 12th POPL, ACM 1985, pp. 37-51].
+
+ (1995-07-29)
+
+second-system effect
+
+ (Sometimes, more euphoniously, "second-system syndrome") When
+ one is designing the successor to a relatively small, elegant,
+ and successful system, there is a tendency to become grandiose
+ in one's success and design an {elephantine} feature-laden
+ monstrosity. The term was first used by Fred Brooks in his
+ classic "{The Mythical Man-Month}. It described the jump from
+ a set of nice, simple operating systems on the {IBM 70xx}
+ series to {OS/360} on the 360 series. A similar effect can
+ also happen in an evolving system; see {Brooks's Law},
+ {creeping elegance}, {creeping featurism}. See also
+ {Multics}, {OS/2}, {X}, {software bloat}.
+
+ [{Jargon File}]
+
+sector interleave
+
+ (Or sector map) The mapping from logical to physical sector
+ numbers on a {magnetic disk} designed to optimise sequential
+ reads and writes. Data is usually transferred to and from the
+ disk in {blocks} or {sectors} where one sector lies within a
+ continuous range of rotational angle of the disk. If logical
+ sectors are assigned sequentially to physical sectors
+ (0,1,2,...) then by the time one sector has been read and
+ processed (e.g. writen to main memory) the start of the next
+ logical sector will have passed the read/write head and will
+ not be accessible until the disk's rotation brings it back
+ under the head.
+
+ Staggering the physical sectors (e.g. 0,3,6,1,4,7,2,5,8) aims
+ to allow just enough time deal with one sector before the next
+ is accessible. This obviously depends on the relative speed
+ of the rotation of the disk, sector size, sectors per track
+ and the speed of transfer of sectors to main memory.
+
+sector interleaving
+
+ {sector interleave}
+
+sector map
+
+ {sector interleave}
+
+sector mapping
+
+ In this scheme the memory and {cache} are divided into blocks
+ of 2^m bytes (the {cache line} size). A sector consists of
+ 2^n consecutive blocks.
+
+ When a block is cached, it is read into the correct position
+ in any sector of the cache, given by discarding the bottom m
+ address bits and taking the next n as the block number within
+ the sector.
+
+ That whole sector is then tagged with the remaining upper
+ address bits and the other blocks in the sector are marked as
+ invalid. This scheme takes advantage of locality of reference
+ to consecutive blocks and needs fewer tags thus reducing the
+ cost of associative access to the tags.
+
+Secure File Transfer Protocol
+
+ {SSH File Transfer Protocol}
+
+Secure Hash Algorithm
+
+ <algorithm, cryptography} (SHA) A {one-way hash function}
+ developped by {NIST} and defined in standard {FIPS} 180.
+ SHA-1 is a revision published in 1994; it is also described
+ in {ANSI} standard X9.30 (part 2).
+
+ (2003-04-12)
+
+Secure Multipurpose Internet Mail Extensions
+
+ <messaging, standard> (S-MIME) A specification for secure
+ {electronic mail}. S-MIME was designed to add security to
+ e-mail messages in {MIME} format. The security services
+ offered are {authentication} (using {digital signatures}) and
+ {privacy} (using {encryption}).
+
+ {(http://rsa.com/rsa/S-MIME/)}.
+
+ (1997-05-10)
+
+Secure Shell
+
+ <operating system> (ssh) A {Unix} {shell} program for logging
+ into, and executing commands on, a remote computer. ssh is
+ intended to replace {rlogin} and {rsh}, and provide secure
+ encrypted communications between two untrusted hosts over an
+ insecure network. {X11} connections and arbitrary {TCP/IP}
+ {ports} can also be forwarded over the secure channel.
+
+ {(http://cs.hut.fi/ssh/)}.
+
+ (1997-01-07)
+
+Secure Sockets Layer
+
+ <networking, security> (SSL) A {protocol} designed by
+ {Netscape Communications Corporation} to provide secure
+ communications over the {Internet} using {asymmetric key
+ encryption}. SSL is layered beneath application {protocols}
+ such as {HTTP}, {SMTP}, {Telnet}, {FTP}, {Gopher} and {NNTP}
+ and is layered above the connection protocol {TCP/IP}. It is
+ used by the {HTTPS} {access method}.
+
+ (2007-05-25)
+
+security
+
+ <security> Protection against unauthorized access to, or
+ alteration of, information and system resources including
+ {CPUs}, {storage devices} and programs.
+
+ Security includes:
+
+ * {confidentiality} - preventing unauthorized access;
+ {integrity} - preventing or detecting unauthorized
+ modification of information.
+
+ * {authentication} - determining whether a user is who they
+ claim to be.
+
+ * {access control} - ensuring that users can access the
+ resources, and only the resources, that they are authorised
+ to.
+
+ * {nonrepudiation} - proof that a message came from a certain
+ source.
+
+ * availability - ensuring that a system is operational and
+ accessible to authorised users despite hardware or software
+ failures or attack.
+
+ * privacy - allowing people to know and control how
+ information is collected about them and how it is used.
+
+ Security can also be considered in the following terms:
+
+ * physical security - who can touch the system to operate or
+ modify it, protection against the physical environment - heat,
+ earthquake, etc.
+
+ * operational/procedural security - who is authorised to do or
+ responsible for doing what and when, who can authorise others
+ to do what and who has to report what to who.
+
+ * personnel security - hiring employees, background screening,
+ training, security briefings, monitoring and handling
+ departures.
+
+ * System security - User access and authentication controls,
+ assignment of privilege, maintaining file and {filesystem}
+ integrity, {backup}, monitoring processes, log-keeping, and
+ {auditing}.
+
+ * {network security} - protecting network and
+ telecommunications equipment, protecting network servers and
+ transmissions, combatting eavesdropping, controlling access
+ from untrusted networks, firewalls, and intrusion detection.
+
+ {Encryption} is one important technique used to improve data
+ security.
+
+ {OWASP} is the {free} and {open} application security
+ community.
+
+ (2007-10-05)
+
+Security Administrator's Integrated Network Tool
+
+ <networking, security, tool> (SAINT, originally "Security
+ Administrator Tool for Analyzing Networks", SATAN) A tool
+ written by Dan Farmer and Wietse Venema which remotely probes
+ systems via the {network} and stores its findings in a
+ {database}. The results can be viewed with an {web browser}.
+ SAINT requires {Perl} 5.000 or better.
+
+ In its simplest mode, SAINT gathers as much information about
+ remote hosts and networks as possible by examining such
+ network services as {finger}, {NFS}, {NIS}, {FTP}, {TFTP},
+ {rexd}, and other services. The information gathered includes
+ the presence of various network information services as well
+ as potential security flaws - usually in the form of
+ incorrectly setup or configured network services, well-known
+ {bugs} in system or network utilities, or poor or ignorant
+ policy decisions. It can then either report on this data or
+ use a simple rule-based system to investigate any potential
+ security problems. Users can then examine, query, and analyze
+ the output with a {web browser}. While the program is
+ primarily geared toward analysing the security implications
+ of the results, a great deal of general network information
+ can be gained when using the tool - network topology, network
+ services running, and types of hardware and software being
+ used on the network.
+
+ SAINT can also be used in exploratory mode. Based on the
+ initial data collection and a user configurable ruleset, it
+ will examine the avenues of trust and dependency and iterate
+ further data collection runs over secondary hosts. This not
+ only allows the user to analyse his own network, but also to
+ examine the real implications inherent in network trust and
+ services and help them make reasonably educated decisions
+ about the security level of the systems involved.
+
+ {(http://wwdsi.com/saint/)}.
+
+ {Old SATAN page (http://fish.com/satan/)}.
+
+ {Mailing list (http://wwdsi.com/saint/list_server.html)}.
+
+ (2000-08-12)
+
+Security Association
+
+ <networking> The relationship between two or more entities
+ (typically, a computer, but could be a user on a computer, or
+ software component) which describes how the entities will use
+ security services, such as {encryption}, to communicate.
+
+ See {RFC 1825}.
+
+ (1997-07-09)
+
+Security Association ID
+
+ <networking> (SAID) A 32-bit field added to {packet} headers
+ for {encryption} and {authentication} in the proposed
+ {Internet Protocol Version 6}.
+
+ (1997-07-09)
+
+security through obscurity
+
+ <security> Or "security by obscurity". A term applied by
+ hackers to most {operating system} vendors' favourite way of
+ coping with security holes - namely, ignoring them,
+ documenting neither any known holes nor the underlying
+ security {algorithms}, trusting that nobody will find out
+ about them and that people who do find out about them won't
+ exploit them. This never works for long and occasionally sets
+ the world up for debacles like the {RTM} worm of 1988 (see
+ {Great Worm}), but once the brief moments of panic created by
+ such events subside most vendors are all too willing to turn
+ over and go back to sleep. After all, actually fixing the
+ bugs would siphon off the resources needed to implement the
+ next user-interface frill on marketing's wish list - and
+ besides, if they started fixing security bugs customers might
+ begin to *expect* it and imagine that their warranties of
+ merchantability gave them some sort of rights.
+
+ Historical note: There are conflicting stories about the
+ origin of this term. It has been claimed that it was first
+ used in the {Usenet} newsgroup in {news:comp.sys.apollo}
+ during a campaign to get {HP}/{Apollo} to fix security
+ problems in its {Unix}-{clone} {Aegis}/{DomainOS} (they didn't
+ change a thing). {ITS} fans, on the other hand, say it was
+ coined years earlier in opposition to the incredibly paranoid
+ {Multics} people down the hall, for whom security was
+ everything. In the ITS culture it referred to (1) the fact
+ that by the time a {tourist} figured out how to make trouble
+ he'd generally got over the urge to make it, because he felt
+ part of the community; and (2) (self-mockingly) the poor
+ coverage of the documentation and obscurity of many commands.
+ One instance of *deliberate* security through obscurity is
+ recorded; the command to allow patching the running ITS system
+ ({altmode} altmode control-R) echoed as $$^D. If you actually
+ typed alt alt ^D, that set a flag that would prevent patching
+ the system even if you later got it right.
+
+ [{Jargon File}]
+
+ (1994-12-15)
+
+SED
+
+ {smoke-emitting diode}
+
+Sed
+
+ <tool, text> Stream editor.
+
+ The {Unix} stream editor. It has a powerful but cryptic
+ command language and is based on {regular expressions}.
+
+ There is a {GNU} version called {GNU Sed}.
+
+ [{Jargon File}]
+
+ (1994-11-03)
+
+SEE
+
+ 1. {Simultaneous Engineering Environment}.
+
+ 2. {Software Engineering Environment}.
+
+ (1999-04-26)
+
+seed
+
+ {BitTorrent}
+
+seek
+
+ 1. <storage> To move the head of a {disk drive} radially,
+ i.e., to move from one {track} to another.
+
+ 2. <storage> To wind the {tape} to a given location.
+
+ 3. <programming> To move the pointer that marks the next {byte}
+ to be read from or written to a {file}.
+
+ (1997-07-15)
+
+seeking
+
+ {seek}
+
+seek time
+
+ <storage> The time it takes for a {disk drive} to move its
+ head(s) from one {track} to another. The seek time depends on
+ the power of the servo, the mass of the heads, the number of
+ tracks traversed and the time taken to position the heads over
+ the target track accurately enough to start data transfer.
+
+ See also: {average seek time}, {minimum seek time}, {maximum
+ seek time}.
+
+ (1997-07-15)
+
+SEESAW
+
+ <language> An early system on the {IBM 701}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1994-12-15)
+
+see u see me
+
+ {CU-SeeMe}
+
+SEGA
+
+ <company, games> manufacturer of video game hardware and
+ software.
+
+ {Usenet} newsgroup: {news:rec.games.video.sega}.
+
+ (1995-03-01)
+
+Sega Genesis/MegaDrive
+
+ <games> A {games console} made by {SEGA}.
+
+ The Genesis used a {Zilog Z80} for its sound generator. This
+ made the Genesis compatible with {Sega Master System} games
+ through a device called a "Power Base Converter" which
+ basically shut down the Genesis/MegaDrive's {68000} {CPU} and
+ made the Z80 the CPU.
+
+ (2008-07-28)
+
+segfault
+
+ {segmentation fault}
+
+seggie
+
+ /seg'ee/ British shorthand for a {Unix} {segmentation fault}.
+
+ [{Jargon File}]
+
+ (1994-12-15)
+
+segment
+
+ /seg'ment/ 1. <architecture> A collection of {pages} in a
+ {memory management} system.
+
+ 2. <programming> A separately relocatable section of an
+ executable program. {Unix} executables have a {text segment}
+ (executable {machine instructions}), a {data segment}
+ (initialised data) and a {bss segment} (uninitialised data).
+
+ 3. <networking> {network segment}.
+
+ 4. To experience a {segmentation fault}. Confusingly, the stress
+ is often put on the first syllable, like the noun "segment",
+ rather than the second like mainstream verb "segment". This
+ is because it is actually a noun shorthand that has been
+ verbed.
+
+ 5. A block of memory in a {segmented address space}.
+
+ [{Jargon File}]
+
+ (2004-02-27)
+
+segmentation
+
+ <networking> (Or "segmentation and reassembly", SAR) Breaking
+ an arbitrary size {packet} into smaller pieces at the
+ transmitter. This may be necessary because of restrictions in
+ the communications channel or to reduce {latency}. The pieces
+ are joined back together in the right order at the receiver
+ ("reassembly"). Segmentation may be performed by a {router}
+ when routing a packet to a network with a smaller maximum
+ packet size.
+
+ The term "segmentation" is used in {ATM}, in {TCP/IP}, it is
+ called "fragmentation" an is performed at the {IP} layer
+ before the "fragments" are passed to the {transport layer}.
+
+ See for example {ATM forum} {UNI} 4.0 specification.
+
+ [Better reasons?]
+
+ (1999-06-14)
+
+segmentation and reassembly
+
+ {segmentation}
+
+segmentation fault
+
+ An error in which a running {Unix} program attempts to access
+ memory not allocated to it and terminates with a segmentation
+ violation error and usually a {core dump}.
+
+ [{Jargon File}]
+
+ (1994-12-15)
+
+segmented address space
+
+ <architecture> An addressing scheme where all memory
+ references are formed by adding an offset to a base address
+ held in a segment {register}.
+
+ The effect is to segment memory into blocks, which may overlap
+ either partially or completely, depending on the contents of
+ the segment registers but normally they would be distinct to
+ give access to the maximum total range of addresses. In this
+ case the scheme does provide some degree of {memory
+ protection} within a single process since, for example, a data
+ reference cannot affect an area of memory containing code.
+ However, compilers must either generate slower code or code
+ with artificial limits on the size of {data structures}.
+
+ The best known implementation is that used on the {Intel 8086}
+ and later Intel {microprocessors}, where a 16-bit {offset} is
+ added to a 16-bit base address held in one of four segment
+ base registers. Each instruction has a default segment (code
+ (CS), data (DS), stack (SS), ? (ES)) which determines which
+ segment register is used. Special prefix instructions allow
+ this default to be overridden.
+
+ Other computers, such as {GE-645}/{Honeywell Multics},
+ {Burroughs} large systems ({B-5500}, {B-6600}), and others,
+ have used segmentation to good effect.
+
+ Opposite: {flat address space}. See also {addressing mode}.
+
+ [In what way were the others better than Intel's {brain
+ damaged} implementation?].
+
+ (2004-06-01)
+
+segv
+
+ /seg'vee/ segmentation violation.
+
+ {segmentation fault}
+
+ (1994-12-15)
+
+SEI
+
+ Software Engineering Institute.
+
+ (Carnegie Mellon University).
+
+Seiko RC-4000
+
+ A wristwatch with an {EIA-232} interface. A clip fitted round
+ the watch and made electrical contact. This clip had a socket
+ for a stereo style jack lead the other end of which was a
+ 25-way {D-type} connector. The lead allowed you to enter
+ phone numbers etc. into the watch without having to play with
+ tiny buttons. It also meant if the battery on your watch ran
+ out you could restore the data without having to type it all
+ in again.
+
+ It was around the era of the 8-bit home computers like the
+ {Spectrum}, {BBC Microcomputer}, {Apple II}, {C64} - the
+ 1980s.
+
+ (1995-01-30)
+
+SEL
+
+ 1. {Self-Extensible Language}.
+
+ 2. {Subset-Equational Language}.
+
+Selective Dissemination of Information
+
+ <library> (SDI) (From Library Science) SDI is a current
+ awareness system which alerts you to the latest publications
+ in your specified field(s) of interest.
+
+ A user registers at such a system with keywords representing
+ his or her fields of interest, called a search profile. When
+ new publications matching the search profile appear, the
+ system informs the user of them instantly, periodically or
+ upon request. Some systems may also be able to inform the
+ user if changes in already notified publications occur.
+
+ {Health Science Library SDI
+ (http://www-hsl.mcmaster.ca/sdi.html)}. {FIZ Karlsruhe
+ Scientific Service Institution
+ (http://fiz-karlsruhe.de/mc-sdi.html)}.
+
+ (1997-03-10)
+
+selector
+
+ <programming> 1. In {Smalltalk} or {Objective C}, the {syntax}
+ of a message which selects a particular {method} in the target
+ {object}.
+
+ 2. An operation that returns the state of an object but does
+ not alter that state. Selector {functions} or {methods} often
+ have names which begin with "get" and corresponding {modifier}
+ methods or {procedures} whose names begin with "set".
+
+ (1998-01-12)
+
+Self
+
+ <language> A small, {dynamically typed} {object-oriented
+ language}, based purely on {prototypes} and {delegation}.
+ Self was developed by the Self Group at {Sun Microsystems
+ Laboratories, Inc.} and {Stanford University}. It is an
+ experimental {exploratory programming} language.
+
+ Release 2.0 introduces full {source-level debugging} of
+ optimised code, adaptive optimisation to shorten compile
+ pauses, {lightweight threads} within Self, support for
+ dynamically linking {foreign functions}, changing programs
+ within Self and the ability to run the experimental Self
+ graphical browser under {OpenWindows}. Designed for
+ expressive power and malleability, Self combines a pure,
+ {prototype}-based object model with uniform access to state
+ and behaviour. Unlike other languages, Self allows objects to
+ inherit state and to change their patterns of inheritance
+ dynamically. Self's customising compiler can generate very
+ efficient code compared to other dynamically-typed
+ object-oriented languages.
+
+ Version: 3.0 runs on {Sun-3} (no optimiser) and {Sun-4}.
+
+ {(http://sunlabs.com/research/self/)}.
+
+ ["Self: The Power of Simplicity", David Ungar
+ <ungar@sun.eng.com> et al, SIGPLAN Notices 22(12):227-242,
+ OOPSLA '87, Dec 1987].
+
+ (1999-06-09)
+
+Self-Extensible Language
+
+ ["SEL - A Self-Extensible Programming Language", G. Molnar,
+ Computer J 14(3):238-242 (Aug 1971)].
+
+ (1994-12-15)
+
+Self Extracting Archive
+
+ <file format> (SEA) An {archive} format used on the {Apple
+ Macintosh}. {Double-click}ing a file of this type should
+ extract its contents.
+
+ (1995-05-02)
+
+self-reference
+
+ See {self-reference}.
+
+ [{Jargon File}]
+
+selvage
+
+ {chad}
+
+SEM
+
+ The semantic specification language for {COPS}.
+
+ ["Metalanguages of the Compiler Production System COPS",
+ J. Borowiec, in GI Fachgesprach "Compiler-Compiler", ed
+ W. Henhapl, Tech Hochs Darmstadt 1978, pp. 122-159].
+
+semantic gap
+
+ The difference between the complex operations performed by
+ {high-level language} constructs and the simple ones provided
+ by computer {instruction sets}. It was in an attempt to try
+ to close this gap that computer architects designed
+ increasingly {complex instruction set computers}.
+
+ (1994-10-10)
+
+semantic network
+
+ <data> A {graph} consisting of {nodes} that represent physical
+ or conceptual objects and arcs that describe the relationship
+ between the nodes, resulting in something like a data flow
+ diagram. Semantic nets are an effective way to represent data
+ as they incorporate the inheritance mechanism that prevents
+ duplication of data. That is, the meaning of a concept comes
+ from its relationship to other concepts and the information is
+ stored by interconnecting nodes with labelled arcs.
+
+ (1999-01-07)
+
+semantics
+
+ <theory> The meaning of a string in some language, as opposed
+ to {syntax} which describes how symbols may be combined
+ independent of their meaning.
+
+ The semantics of a programming language is a function from
+ programs to answers. A program is a {closed term} and, in
+ practical languages, an answer is a member of the syntactic
+ category of values. The two main kinds are {denotational
+ semantics} and {operational semantics}.
+
+ (1995-06-21)
+
+semaphore
+
+ <programming, operating system> The classic method for
+ restricting access to shared resources (e.g. storage) in a
+ {multi-processing} environment. They were invented by
+ {Dijkstra} and first used in {T.H.E} {operating system}.
+
+ A semaphore is a {protected variable} (or {abstract data
+ type}) which can only be accessed using the following
+ operations:
+
+ P(s)
+ Semaphore s;
+ {
+ while (s == 0) ; /* wait until s>0 */
+ s = s-1;
+ }
+
+ V(s)
+ Semaphore s;
+ {
+ s = s+1;
+ }
+
+ Init(s, v)
+ Semaphore s;
+ Int v;
+ {
+ s = v;
+ }
+
+ P and V stand for Dutch "Proberen", to test, and "Verhogen",
+ to increment. The value of a semaphore is the number of units
+ of the resource which are free (if there is only one resource
+ a "binary semaphore" with values 0 or 1 is used). The P
+ operation {busy-waits} (or maybe {sleeps}) until a resource is
+ available whereupon it immediately claims one. V is the
+ inverse, it simply makes a resource available again after the
+ process has finished using it. Init is only used to
+ initialise the semaphore before any requests are made. The P
+ and V operations must be {indivisible}, i.e. no other process
+ can access the semaphore during the their execution.
+
+ To avoid {busy-wait}ing, a semaphore may have an associated
+ {queue} of processes (usually a {FIFO}). If a process does a
+ P on a semaphore which is zero the process is added to the
+ semaphore's queue. When another process increments the
+ semaphore by doing a V and there are tasks on the queue, one
+ is taken off and resumed.
+
+ (1995-02-01)
+
+semi
+
+ /se'mee/ or /se'mi:/ A spoken abbreviation for semicolon.
+
+ "Commands to {grind} are prefixed by semi semi star" means
+ that the prefix is ";;*", not 1/4 of a star.
+
+ [{Jargon File}]
+
+ (1995-01-31)
+
+Semi-Automatic Ground Environment
+
+ <project> (SAGE) The computer system of the old US Norad air
+ defence system. SAGE was ground-breaking in many ways, such
+ as being one of the first very large software projects and the
+ first {real-time} system.
+
+ {MIT Lincoln Laboratory} developed SAGE and {MITRE
+ Corporation} was responsible for system engineering and
+ implementation oversight.
+
+ {(http://togger.com/)},
+ {(http://jps.net/ethelen/sage.html)},
+ {(http://eskimo.com/%7Ewow-ray/sage28.html)}.
+
+ [Confirm? Dates? Connection with MIT Research Laboratory for
+ Electronics?]
+
+ (1999-12-16)
+
+semicolon
+
+ ;
+
+ Common: {ITU-T}: semicolon; {semi}. Rare: weenie; {INTERCAL}:
+ hybrid, pit-thwong.
+
+semiconductor
+
+ <electronics> A material, typically crystaline, which allows
+ {current} to flow under certain circumstances. Common
+ semiconductors are silicon, germanium, gallium arsenide.
+ Semiconductors are used to make {diodes}, {transistors} and
+ other basic "solid state" electronic components.
+
+ As crystals of these materials are grown, they are "doped"
+ with traces of other elements called {donors} or {acceptors}
+ to make regions which are n- or p-type respectively for the
+ {electron model} or p- or n-type under the {hole model}.
+ Where n and p type regions adjoin, a junction is formed which
+ will pass {current} in one direction (from p to n) but not the
+ other, giving a {diode}.
+
+ One {model} of semiconductor behaviour describes the doping
+ elements as having either {free electrons} or {holes} dangling
+ at the points in the crystal lattice where the doping elements
+ replace one of the atoms of the foundation material. When
+ external electrons are applied to n-type material (which
+ already has free electrons present) the repulsive force of
+ like charges causes the free electrons to migrate toward the
+ junction, where they are attracted to the holes in the p-type
+ material. Thus the junction conducts current.
+
+ In contrast, when external electrons are applied to p-type
+ material, the attraction of unlike charges causes the holes to
+ migrate away from the junction and toward the source of
+ external electrons. The junction thus becomes "depleted" of
+ its charge carriers and is non-conducting.
+
+ (1995-10-04)
+
+Semidetached Mode
+
+ <programming> A term used by {COCOMO} to describe a project
+ development somewhere between organic and embedded. The team
+ members have a mixture of experienced and inexperienced
+ personnel. The software to be developed has some
+ characteristics of both organic and embedded modes.
+ Semidetached software can be as large as 300K {DSIs}.
+
+ (1996-05-29)
+
+SENDIT
+
+ Systems Engineering for Network Debugging, Integration and
+ Test. A two-year European Commission funded project to
+ produce software tools for distributed applications running on
+ networks of microcontrollers.
+
+ (1994-07-21)
+
+sendmail
+
+ <messaging> The {BSD} Unix {Message Transfer Agent} supporting
+ mail transport via {TCP/IP} using {SMTP}. Sendmail is
+ normally invoked in the {background} via a {Mail User Agent}
+ such as the {mail} command.
+
+ Sendmail was written by {Eric Allman} at the {University of
+ California at Berkeley} during the late 1970s. He now has his
+ own company, {Sendmail Inc.}
+
+ Sendmail was one of the first programs to route messages
+ between {networks} and today is still the dominant e-mail
+ transfer software. It thrived despite the awkward {ARPAnet}
+ transition between {NCP} to TCP protocols in the early 1980s
+ and the adoption of the new SMTP Simple Mail Transport
+ Protocol, all of which made the business of mail routing a
+ complex challenge of backward and forward compatibility for
+ several years. There are now over one million copies of
+ Sendmail installed, representing over 75% of all Internet mail
+ servers.
+
+ Simultaneously with the announcement of the company in
+ November 1997, Sendmail 8.9 was launched, featuring new tools
+ designed to limit {junk e-mail}. SendMail 8.9 is still
+ distributed as {source code} with the rights to modify and
+ distribute.
+
+ Latest version: 8.9.1, as of 1998-08-25.
+
+ The command
+
+ sendmail -bv ADDRESS
+
+ can be used to learn what the local mail system thinks of
+ ADDRESS. You can also talk to the Sendmail {daemon} on a
+ remote host FOO with the command
+
+ telnet FOO 25
+
+ (1998-08-25)
+
+sendmail.cf
+
+ <messaging> {sendmail}'s configuration file, which it reads
+ once when starting up, usually found in the /etc directory.
+
+ Only real {Unix Gurus} can understand, let alone modify, this
+ file since it consists moslty of {header} {rewrite rules}
+ written as {M4} {macros}, as well as various other one- or
+ two-character commands.
+
+ (1996-12-09)
+
+Sendmail Inc.
+
+ <company> The company, announced in November 1997 and launched
+ in March 1998, created by {Eric Allman}, the original author
+ of {Sendmail}. Allman is Chief Technology Officer, {Greg
+ Olson} is President and CEO.
+
+ Sendmail Inc. will sell commercial upgrades, service and
+ support to {Internet Service Providers} and corporations
+ running critical {e-mail} applications, while still continuing
+ {freeware} development.
+
+ {Sun Microsystems} founders {Bill Joy} and Andy Bechtolscheim
+ are among the investors in the company, along with Tim
+ O'Reilly of publishers O'Reilly & Associates and John Funk of
+ e-mail company {InfoBeat Inc.}.
+
+ Allman said that he devoted the fist six months of the life of
+ Sendmail Inc. to finalising the freeware release. A
+ commercial version was due in summer 1998, at around $1000 per
+ server. The company is expected to reach $40m annual sales
+ within three years. Funding is in the region of $1.25m.
+
+ {(http://sendmail.com/)}.
+
+ Address: Emeryville, California, USA.
+
+ (1998-08-25)
+
+Seneca
+
+ {Oberon-V}
+
+senior bit
+
+ [IBM] Synonym {meta bit}.
+
+ [{Jargon File}]
+
+sense
+
+ <human language> A meaning of a word.
+
+ (2007-05-03)
+
+sensor
+
+ <hardware> An electronic device used to measure a physical
+ quantity such as temperature, pressure or loudness and convert
+ it into an electronic signal of some kind (e.g a voltage).
+ Sensors are normally components of some larger electronic
+ system such as a computer control and/or measurement system.
+
+ Analog sensors most often produce a voltage proportional to
+ the measured quantity. The signal must be converted to
+ digital form with a {ADC} before the CPU can process it.
+
+ Digital sensors most often use serial communication such as
+ {EIA-232} to return information directly to the controller or
+ computer through a {serial port}.
+
+ (1997-04-15)
+
+sentence
+
+ <logic> A collection of {clauses}.
+
+ See also {definite sentence}.
+
+ (2003-12-04)
+
+SE-ODP
+
+ Support Environment for Open Distributed Processing. An
+ {ECMA} {standard}.
+
+SEP
+
+ 1. Someone Else's Problem.
+
+ 2. <tool> A {SASD} tool from {IDE}.
+
+ (1995-10-12)
+
+separate compilation
+
+ <programming> A feature of most modern programming languages
+ that allows each program {module} to be compiled on its own to
+ produce an {object file} which the {linker} can later combine
+ with other object files and {libraries} to produce the final
+ {executable}. Separate compilation avoids processing all the
+ source code every time the program is built, thus saving
+ development time. The object files are designed to require
+ minimal processing at {link time}. They can also be collected
+ together into {libraries} and distributed commercially without
+ giving away source code (though they can be disassembled).
+
+ Examples of the output of separate compilation are {C} object
+ files (extension ".o") and {Java} ".class" files.
+
+ (2005-02-19)
+
+SEPIA
+
+ Standard ECRC Prolog Integrating Applications. Prolog with
+ many extensions including attributed variables ("metaterms")
+ and declarative coroutining. "SEPIA", Micha Meier
+ <micha@ecrc.de> et al, TR-LP-36 ECRC, March 1988. Version 3.1
+ available for Suns and VAX. (See ECRC-Prolog). E-mail:
+ <sepia-request@ecrc.de>.
+
+SEPP
+
+ {Single Edge Processor Package}
+
+Seque
+
+ "Seque: A Programming Language for Manipulating Sequences",
+ R.E. Griswold et al, Comp Langs 13(1):13-22 (1988).
+
+Sequel
+
+ 1. Precursor to SQL.
+
+ ["System R: Relational Approach to Database Management", IBM
+ Res Lab, San Jose, reprinted in Readings in Database Systems].
+
+ 2. U Leeds. Theorem prover specification language. Pattern
+ matching notation similar to Prolog. Compiled into Lisp.
+
+ [Proc ICJAI 13].
+
+ {(ftp://agora.leeds.ac.uk/scs/logic/)}.
+
+Sequenced Packet Exchange
+
+ <networking, protocol> (SPX) A {transport layer} {protocol}
+ built on top of {IPX}. SPX is used in {Novell NetWare}
+ systems for communications in {client/server} {application
+ programs}, e.g. {BTRIEVE} ({ISAM} manager).
+
+ SPX is not used for connections to the {file server} itself;
+ this uses {NCP}. It has been extended as SPX-II. SPX/IPX
+ perform equivalent functions to {TCP/IP}.
+
+ {(http://developer.novell.com/research/appnotes/1995/december/03/04.htm)}.
+
+ [Better reference?]
+
+ (1999-05-27)
+
+sequencer
+
+ <music> Any system for recording and/or playback of music via
+ a programmable memory which stores music not as audio data,
+ but as some representation of notes. The most common modern
+ usage of "sequencer" is to refer to systems (whether in
+ software, or as a feature of devices like synthesizers or drum
+ machines) that deal with {MIDI} data.
+
+ (1999-06-04)
+
+Sequent
+
+ <company> A computer manufacturer.
+
+ Quarterly sales $109M, profits $7M (Aug 1994).
+
+ Sequent computers was acquired by {IBM} in 1999.
+
+ [History?]
+
+ (2003-10-21)
+
+sequential coding
+
+ <graphics, file format, algorithm> The usual {bitmap} {image}
+ data storage format or transmission {algorithm} where the
+ resoluton is constant and later data adds only more area.
+ This contrasts with {progressive coding}.
+
+ (2000-09-12)
+
+sequential file matching
+
+ A programming technique that matches records in one sequential
+ file with records in another sequential file. The records are
+ accessed in the physical order in which they are stored.
+
+ (1994-11-02)
+
+Sequential Parlog Machine
+
+ (SPM) The {virtual machine} (and its machine code) for the
+ {Parlog} {logic programming} language.
+
+ {(ftp://nuri.inria.fr/lang/Parlog.tar.Z)}.
+
+ ["Parallel Logic Programming in PARLOG", Steve Gregory,
+ Addison-Wesely, UK, 1987].
+
+sequential processing
+
+ <architecture> (Or "serial processing") Running a single
+ {task} to completion on a single {processor}, in contrast to
+ {parallel processing} or {multitasking}.
+
+ (1995-04-23)
+
+SERC
+
+ {Science and Engineering Research Council}
+
+SERCOS
+
+ {serial real-time communications system}
+
+ [What is it?]
+
+ ["More choices link motors and drives to controls", by
+ L. Langnau. Power Transmission Design, vol. 37, no. 7,
+ pp. 33-36].
+
+ (1996-01-23)
+
+serial
+
+ 1. <communications> {serial communications}
+
+ 2. <architecture> {serial processor}.
+
+Serial Advanced Technology Attachment
+
+ <storage> (SATA, Serial ATA) A computer {bus} technology
+ primarily designed for transfer of data to and from a {hard
+ disk}. SATA is the successor to {Advanced Technology
+ Attachment} (ATA), which was given the {retronym} Parallel ATA
+ (PATA) to distinguish it from Serial ATA.
+
+ Serial ATA is designed to be scalable. The original SATA/150
+ or "SATA 1" can transfer up to 150 {MBps} and "SATA 3.0
+ Gbit/s" has a maximum data rate of 300 {MBps}.
+
+ Both SATA and PATA drives have built-in low level control
+ electronics but the term {IDE} is usually restricted to
+ parallel ATA drives.
+
+ {(http://www.serialata.org/)}.
+
+ (2007-02-23)
+
+Serial ATA
+
+ {Serial Advanced Technology Attachment}
+
+serial communications
+
+ <communications> Communication via a single channel that
+ delivers one bit of data at a time, in contrast to {parallel}
+ communications where multiple serial channels are combined,
+ either physically (e.g. multiple cores in a cable) or by
+ {multiplexing}.
+
+Serial Communications Interface
+
+ {UART}
+
+Serial Interface Adaptor
+
+ (SIA) The {Ethernet} driver chip used on a {Filtabyte}
+ Ethernet card.
+
+serial IO chip
+
+ {UART}
+
+serialise
+
+ <programming> To represent an arbitrarily complex {data
+ structure} in a location-independent way so that it can be
+ communicated or stored elsewhere.
+
+ For example, an {object} representing a time, with
+ {attributes} for year, month, timezone, etc., could be
+ serialised as the {string} "2002-02-24T14:33:52-0800", or an
+ {XML} element "<dateobj year='2002' month='02' day='24'
+ hour='14' minute='33' second='52' timezone='-0800' />", or as
+ a {binary} string.
+
+ As well as providing an external data representation
+ (e.g. representing an {integer} as a string of {ASCII}
+ digits) and {marshalling} components into a single block of
+ data, a serialisation {algorithm} needs to follow {pointers}
+ to include objects referred to by the initial object. This is
+ further complicated by the possible presence of cycles in the
+ {object graph}.
+
+ It should be possible to store the serialised representation
+ on disk, or transmit it across a network, and then restore it
+ as an object (graph) that is the same as the original.
+
+ (2001-09-28)
+
+serialize
+
+ {serialise}
+
+serial line
+
+ <communications> Wires which connect two {serial ports}
+ carrying serial data consisting of sequential bits represented
+ by one of two voltages.
+
+ A common electrical specification for the signals on a serial
+ line is {RS-423}.
+
+ {(ftp://ftp.acorn.co.uk/pub/documents/appnotes/231-245/234.ps)}.
+
+ (1995-02-02)
+
+Serial Line Internet Protocol
+
+ <communications, protocol> (SLIP) Software allowing the
+ {Internet Protocol} (IP), normally used on {Ethernet}, to be
+ used over a {serial line}, e.g. an {EIA-232} {serial port}
+ connected to a {modem}. It is defined in {RFC} 1055.
+
+ SLIP modifies a standard {Internet} {datagram} by appending a
+ special SLIP END character to it, which allows datagrams to be
+ distinguished as separate. SLIP requires a port configuration
+ of 8 data bits, no {parity}, and {EIA} or {hardware flow
+ control}. SLIP does not provide {error detection}, being
+ reliant on other high-layer protocols for this. Over a
+ particularly error-prone {dial-up} link therefore, SLIP on its
+ own would not be satisfactory.
+
+ A SLIP connection needs to have its {IP address} configuration
+ set each time before it is established whereas {Point-to-Point
+ Protocol} (PPP) can determine it automatically once it has
+ started.
+
+ See also {SLiRP}.
+
+ (1995-04-30)
+
+Serial Line IP
+
+ (SLIP) {Serial Line Internet Protocol}.
+
+Serial Peripheral Interface
+
+ <communications, hardware> (SPI) A {serial interface} in which
+ a master device supplies {clock} pulses to exchanges data
+ serially with a slave over two data wires (Master-Slave and
+ Slave-Master). This term probably originated with Motorola in
+ about 1979 with their first all-in-one {microcontroller}.
+
+ (2003-07-13)
+
+serial port
+
+ <hardware, communications> (Or "com port") A connector on a
+ computer to which you can attach a {serial line} connected to
+ peripherals which communicate using a serial (bit-stream)
+ {protocol}. The most common type of serial port is a 25-pin
+ D-type connector carrying {EIA-232} signals. Smaller
+ connectors (e.g. 9-pin {D-type}) carrying a subset of EIA-232
+ are often used on {personal computers}. The serial port is
+ usually connected to an {integrated circuit} called a {UART}
+ which handles the conversion between serial and parallel data.
+
+ In the days before bit-mapped displays, and today on
+ {multi-user} systems, the serial port was used to connect one
+ or more terminals ({teletypewriters} or {VDUs}), printers,
+ {modems} and other serial peripherals. Two computers
+ connected together via their serial ports, possibly via
+ {modems}, can communicate using a {protocol} such as {UUCP} or
+ {CU} or {SLIP}.
+
+ (1995-01-12)
+
+Serial Presence Detect
+
+ {presence detect}
+
+serial processing
+
+ {sequential processing}
+
+serial processor
+
+ <architecture> A computer whose {central processing unit}
+ performs a single machine-level operation at a time. This
+ term would be used mostly in contrast to a {parallel
+ processor}.
+
+ (2008-03-14)
+
+Serial Storage Architecture
+
+ <storage> (SSA) IBM's proposed ANSI standard for a standard
+ high-speed interface to disk clusters and arrays. SSA allows
+ {full-duplex} {packet multiplexed} serial data transfers at
+ rates of 20Mb/sec in each direction.
+
+ According to John Taylor, programme manager at IBM's Storage
+ Division at Havant, SSA will be used in arrays of discs
+ working with high-end computers ranging from mainframes down
+ to LAN servers. Taylor said that SSA differs from the {IEEE}
+ proposed {P1394} serial interface specification in its ability
+ to offer simultaneous multiplexed transfers from more than one
+ disk or array. IBM also supports the P1394 standard which
+ will be used primarily by desktop PCs for {multimedia}
+ applications.
+
+ SSA has received backing from a number of companies including
+ connector makers Molex, ITT Cannon and AMP, disk drive makers
+ Conner and Western Digital and RAID array suppliers like
+ Dynatech and NCR. IBM expects to see the first SSA products
+ released at Comdex in Autumn 1994 but it will be 1995 before
+ the products ship in volume.
+
+ Under an agreement signed with {ASIC} maker and {ARM} licencee
+ {VLSI Technology}, IBM will use ARM-based chips made by VLSI
+ to implement the SSA interface and VLSI will make these cores
+ available to third parties as one of its Functional System
+ Blocks.
+
+serve
+
+ <networking> To be a {server}, to provide a {service}.
+
+ E.g., "The {shttpd} serves requested documents to clients over
+ a secure link."
+
+ (1997-09-11)
+
+servelet
+
+ {Java servlet}
+
+server
+
+ 1. A program which provides some service to other ({client})
+ programs. The connection between client and server is
+ normally by means of {message passing}, often over a
+ {network}, and uses some {protocol} to encode the client's
+ requests and the server's responses. The server may run
+ continuously (as a {daemon}), waiting for requests to arrive
+ or it may be invoked by some higher level daemon which
+ controls a number of specific servers ({inetd} on {Unix}).
+
+ There are many servers associated with the {Internet}, such as
+ those for {HTTP}, {Network File System}, {Network Information
+ Service} (NIS), {Domain Name System} (DNS), {FTP}, {news},
+ {finger}, {Network Time Protocol}. On Unix, a long list can
+ be found in /etc/services or in the {NIS} database "services".
+ See {client-server}.
+
+ 2. A computer which provides some service for other computers
+ connected to it via a network. The most common example is a
+ {file server} which has a local disk and services requests
+ from remote clients to read and write files on that disk,
+ often using {Sun}'s {Network File System} (NFS) {protocol} or
+ {Novell Netware} on {PCs}. Another common example is a {web
+ server}.
+
+ [{Jargon File}]
+
+ (2003-12-29)
+
+serverlet
+
+ {Java Servlet}
+
+Server Message Block
+
+ <protocol> (SMB) A {client/server} {protocol} that provides
+ file and printer sharing between computers. In addition SMB
+ can share {serial ports} and communications abstractions such
+ as {named pipes} and {mail slots}. SMB is similar to {remote
+ procedure call} (RPC) specialised for file system access.
+
+ SMB was developed by {Intel}, {Microsoft}, and {IBM} in the
+ early 1980s. It has also had input from {Xerox} and {3Com}.
+ It is the native method of file and print sharing for
+ Microsoft {operating systems}; where it is called {Microsoft
+ Networking}. {Windows for Workgroups}, {Windows 95}, and
+ {Windows NT} all include SMB clients and servers. SMB is also
+ used by {OS/2}, {Lan Manager} and {Banyan} {Vines}. There are
+ SMB servers and clients for {Unix}, for example {Samba} and
+ {smbclient}.
+
+ SMB is a {presentation layer} protocol structured as a large
+ set of commands (Server Message Blocks). There are commands
+ to support file sharing, printer sharing, {user
+ authentication}, resource browsing, and other miscellaneous
+ functions. As clients and servers may implement different
+ versions ("dialects") of the protocol they negotiate before
+ starting a session.
+
+ The {redirector} packages SMB requests into a {network control
+ block} (NBC) structure that can be sent across the network to
+ a remote device.
+
+ SMB originally ran on top of the lower level protocols
+ {NetBEUI} and {NetBIOS}, but now typically runs over {TCP/IP}.
+
+ Microsoft have developed an extended version of SMB for the
+ {Internet}, the {Common Internet File System} (CIFS), which in
+ most cases replaces SMB. {CIFS} runs only runs over TCP/IP.
+
+ {Just what is SMB?
+ (http://samba.anu.edu.au/cifs/docs/what-is-smb.html)}.
+
+ {IBM protocols
+ (http://protocols.com/pbook/ibm.htm)}.
+
+ {Microsoft SMB/CIFS documents
+ (ftp://ftp.microsoft.com/developr/drg/CIFS/)}.
+
+ (1999-08-08)
+
+server-parsed HTML
+
+ <file format, web> (SPML, SHTML) A kind of {HTML}
+ file containing server-specific, non-standard commands which
+ are interpreted by the {HTTP server} and replaced by standard
+ HTML or text before the data is returned to the client.
+
+ Different servers use different command syntax and support
+ different sets of commands. The most common example is a
+ {server-side include} command which simply expands to the
+ contents of some given file and allows bits of HTML or text to
+ be shared between pages for ease of updating. Other commands
+ insert the value of an {environment variable} or the output of
+ a {shell command}. These allow pages to be different each
+ time they are served without requiring a {CGI} script.
+
+ Some servers distinguish SPML from HTML with a different
+ {filename extension}, others use the execute bit of the file's
+ {permissions}.
+
+ (1996-09-29)
+
+server room
+
+ <hardware> The room where all the {server} computers are
+ housed. The {workstations} at which people sit and program
+ are usually located elsewhere.
+
+ Compare: {sun lounge}, {dinosaur pen}, {play pen}, {salt
+ mines}, {disk farm}.
+
+ (1998-07-06)
+
+servers
+
+ {server}
+
+server-side
+
+ <web> Processing or content generation that is done
+ on the {web server} or other server, as opposed to on the
+ {client} computer where the {web browser} is running.
+
+ An example is {server-side include} where one file is inserted
+ in another before it is served, rather than, say, having the
+ browser request the files separately and combine them using an
+ {iframe}. A very common kind of server-side processing is the
+ inclusion of data from a {database} in a web page.
+
+ There are many software environments and technologies designed
+ for server-side processing, e.g. {CGI}, {ISAPI}, {WebObjects}
+ and {ASP}.
+
+ The greatest advantage of server-side processing is that it is
+ independent of the many different client software environments
+ that exist on the {Internet}, chiefly different {web browsers}
+ and {operating systems}. The disadvantage is that the user
+ must wait for a response from the server which is a much
+ slower form of interaction than is possible with client-side
+ processing using, e.g., {JavaScript}.
+
+ (2003-12-29)
+
+server-side include
+
+ <web> (SSI) The facility provided by most {web
+ servers}, e.g. {NCSA httpd}, to replace special {tags} in an
+ {HTML} file with the contents of another file before the file
+ is sent out by the server, i.e. an {HTML} {macro}.
+
+ {NCSA httpd tutorial
+ (http://hoohoo.ncsa.uiuc.edu/docs/tutorials/includes.html)}.
+
+ (1996-09-08)
+
+service
+
+ <networking, programming> Work performed (or offered) by a
+ {server}. This may mean simply serving simple requests for
+ data to be sent or stored (as with {file servers}, {gopher} or
+ {http} servers, {e-mail} servers, {finger} servers, {SQL}
+ servers, etc.); or it may be more complex work, such as that
+ of {irc} servers, print servers, {X Windows} servers, or
+ process servers.
+
+ E.g. "Access to the finger {service} is restricted to the
+ local {subnet}, for security reasons".
+
+ (1997-09-11)
+
+serviceability
+
+ <systems> The ease with which {corrective maintenance} or
+ {preventative maintenance} can be performed on a system (e.g. by a
+ {hardware} service technician). Higher serviceability improves
+ {availability} and reduces service cost.
+
+ Serviceability is one component of {RAS}.
+
+ (2000-08-13)
+
+Service Access Point
+
+ <networking> (SAP) The {OSI} term for the component of a
+ network address which identifies the individual application on
+ a host which is sending or receiving a {packet}.
+
+ {TCP/IP}'s equivalent term is "{port}".
+
+ Different SAPs distinguish between different services or
+ applications on a host, e.g. {electronic mail}, {FTP}, {HTTP}.
+
+ (1996-12-23)
+
+Service Advertising Protocol
+
+ <networking> (SAP) A {Novell NetWare} {protocol}. SAP follows
+ the spirit of the {Xerox} {Clearinghouse} protocol, it permits
+ file, print, and gateway servers to advertise their services
+ and addresses.
+
+ (1996-01-13)
+
+Service Discovery Protocol
+
+ <protocol> (SDP) A {Bluetooth} {protocol} in the {Core
+ Protocol Stack} that allows {devices} to connect to
+ other {services}.
+
+ {Bluetooth SDP
+ (http://bluetooth.org/assigned-numbers/sdp.htm)}.
+
+ (2002-06-28)
+
+service-oriented architecture
+
+ <software, architecture> (SOA) Systems built from
+ loosely-coupled {software} modules deployed as {services},
+ typically communicating via a {network}. This allows
+ different modules to be implemented and deployed in different
+ ways, e.g. owned by different organisations, developed by
+ different teams, written in different {programming languages},
+ running on different {hardware} and {operating systems}. The
+ key to making it work is {interoperability} and {standards} so
+ that modules can exchange data.
+
+ SOAs often support {service discovery}, allowing a service to
+ be changed without having to explicitly reconnect all its
+ clients.
+
+ Many different frameworks have been developed for SOA,
+ including {SOAP}, {REST}, {RPC}, {DCOM}, {CORBA}, {web
+ services} and {WCF}.
+
+ (2009-01-23)
+
+service provider
+
+ <communications> An organisation that provides a service by
+ telephone, such as an 0800 (toll free) number. The service
+ provider buys the services of a telecom supplier (e.g. BT) but
+ advertises the service and deals with the calls itself.
+ Increasingly, service providers are now also managing their
+ advanced {call-routing}.
+
+ (1996-08-27)
+
+Service Set Identifier
+
+ <networking> (SSID) A 32-{character} unique identifier that
+ distinguishes one wireless network from another. All devices
+ attempting to connect to a specific network use the same SSID,
+ which appears in the header of {packets}. Because an SSID can
+ be intercepted, it does not supply any security to the
+ network.
+
+ (2009-01-23)
+
+servlet
+
+ {Java servlet}
+
+session
+
+ <networking> 1. A lasting connection between a user (or user
+ agent) and a {peer}, typically a {server}, usually involving
+ the exchange of many packets between the user's computer and
+ the server. A session is typically implemented as a layer in
+ a network {protocol} (e.g. {telnet}, {FTP}).
+
+ In the case of protocols where there is no concept of a
+ session layer (e.g. {UDP}) or where sessions at the {session
+ layer} are generally very short-lived (e.g. {HTTP}), {virtual}
+ sessions are implemented by having each exchange between the
+ user and the remote host include some form of {cookie} which
+ stores state (e.g. a unique session ID, information about the
+ user's preferences or authorisation level, etc.).
+
+ See also {login}.
+
+ 2. A lasting connection using the {session layer} of a
+ networking protocol.
+
+ (1997-08-03)
+
+Session Initiation Protocol
+
+ <protocol> (SIP) A very simple text-based application-layer
+ control {protocol}. It creates, modifies, and terminates
+ {sessions} with one or more participants. Such sessions
+ include {Internet telephony} and {multimedia} conferences.
+
+ It is described in {RFC 2543}.
+
+ (2000-05-31)
+
+session layer
+
+ <networking> The third highest {protocol layer} (layer 5) in the {OSI}
+ seven layer model. The session layer uses the {transport
+ layer} to establish a {connection} between processes on
+ different {hosts}. It handles {security} and creation of the
+ session. It is used by the {presentation layer}.
+
+ Documents: {ITU} Rec. X.225 ({ISO} 8327), ITU Rec. X.215 (ISO
+ 8326).
+
+ [Examples?]
+
+ (1997-12-07)
+
+SES/workbench
+
+ <tool, simulation> An iconic {simulation} and design tool,
+ linked to some of the major {CASE} systems now available or in
+ development.
+
+ (1996-03-28)
+
+SET
+
+ 1. <security> {Secure Electronic Transaction}.
+
+ 2. <electronics> {Single Electron Tunneling}.
+
+ 3. <standard> {Standard d'Echange et de Transfert}.
+
+ (1999-03-26)
+
+set
+
+ A collection of objects, known as the elements of the set,
+ specified in such a way that we can tell in principle whether
+ or not a given object belongs to it. E.g. the set of all prime
+ numbers, the set of zeros of the cosine function.
+
+ For each set there is a {predicate} (or property) which is
+ true for (possessed by) exactly those objects which are
+ elements of the set. The predicate may be defined by the set
+ or vice versa. Order and repetition of elements within the
+ set are irrelevant so, for example, {1, 2, 3} = {3, 2, 1} =
+ {1, 3, 1, 2, 2}.
+
+ Some common set of numbers are given the following names:
+
+ N = the {natural numbers} 0, 1, 2, ...
+
+ Z = the {integers} ..., -2, -1, 0, 1, 2, ...
+
+ Q = the {rational numbers} p/q where p, q are in Z and q /= 0.
+
+ R = the {real numbers}
+
+ C = the {complex numbers}.
+
+ The empty set is the set with no elements. The intersection
+ of two sets X and Y is the set containing all the elements x
+ such that x is in X and x is in Y. The union of two sets is
+ the set containing all the elements x such that x is in X or x
+ is in Y.
+
+ See also {set complement}.
+
+ (1995-01-24)
+
+set abstraction
+
+ {list comprehension}
+
+set associative cache
+
+ <architecture> A compromise between a {direct mapped cache}
+ and a {fully associative cache} where each address is mapped
+ to a certain set of cache locations. The address space is
+ divided into blocks of 2^m bytes (the {cache line} size),
+ discarding the bottom m address bits. An "n-way set
+ associative" cache with S sets has n cache locations in each
+ set. Block b is mapped to set "b mod S" and may be stored in
+ any of the n locations in that set with its upper address bits
+ as a tag. To determine whether block b is in the cache, set
+ "b mod S" is searched associatively for the tag.
+
+ A direct mapped cache could be described as "one-way set
+ associative", i.e. one location in each set whereas a fully
+ associative cache is N-way associative (where N is the total
+ number of blocks in the cache). Performance studies have
+ shown that it is generally more effective to increase the
+ number of entries rather than associativity and that 2- to
+ 16-way set associative caches perform almost as well as fully
+ associative caches at little extra cost over direct mapping.
+
+ (2004-10-18)
+
+set complement
+
+ <theory> The complement of set A in set U is all elements of U
+ which are not elements of A.
+
+ (1995-01-24)
+
+set comprehension
+
+ {list comprehension}
+
+Setext
+
+ A markup scheme intended for documents that are both human-
+ and computer-readable.
+
+SETL
+
+ SET Language. A very high level language based on sets,
+ designed by Jack Schwartz at the {Courant Institute} in the
+ early 1970s. It was possibly the first use of {list
+ comprehension} notation.
+
+ Data types include sets (unordered collections), {tuples}
+ (ordered collections) and maps (collections of ordered pairs).
+ Expressions may include {quantifiers} ('for each' and
+ 'exists'). The first {Ada} translator was written in SETL.
+
+ See also {ISETL}, {ProSet}, {SETL2}.
+
+ ["Programming With Sets - An Introduction to SETL", Jacob
+ T. Schwartz et al, Springer 1986].
+
+SETL2
+
+ {SETL} with more conventional {Ada}-like syntax, {lexical
+ scope}, full block structure, {first-class functions} and a
+ package and library system. Ported to {OS/2}, {MS-DOS} (3.1
+ up), Extended {MS-DOS} (80286 and higher processors with
+ extended memory), {Macintosh} (with the {MPW} environment),
+ Sun-3 (SunOS 4), Sun-4 (SunOS 4), IBM RS/6000 (AIX 3.1), DEC
+ RISC product line (Ultrix 4.0), DEC Vaxen (Mt. Xinu Unix or
+ VMS).
+
+ {(ftp://cs.nyu.edu/pub/languages/setl2)}. Please e-mail Kirk
+ Snyder <snyder@spunky.cs.nyu.edu> if you take a copy.
+
+ ["The SETL2 Programming Language", W. Kirk Snyder, Courant
+ Inst TR 490, Jan 1990].
+
+SETL/E
+
+ {ProSet}
+
+Set Priority Level
+
+ (SPL) The way traditional {Unix} {kernels} implement {mutual
+ exclusion} by running code at high {interrupt priority levels}
+ and thus blocking lower level interrupts.
+
+ (1994-11-23)
+
+SETS
+
+ Set Equation Transformation System.
+
+ Symbolic manipulation of Boolean equations. "Efficient
+ Ordering of Set Expressions for Symbolic Expansion",
+ R.G. Worrell et al, J ACM 20(3):482-488 (Jul 1973).
+
+set theory
+
+ <mathematics> A mathematical formalisation of the theory of
+ "sets" (aggregates or collections) of objects ("elements" or
+ "members"). Many mathematicians use set theory as the basis
+ for all other mathematics.
+
+ Mathematicians began to realise toward the end of the 19th
+ century that just doing "the obvious thing" with sets led to
+ embarrassing {paradox}es, the most famous being {Russell's
+ Paradox}. As a result, they acknowledged the need for a
+ suitable {axiomatisation} for talking about sets. Numerous
+ such axiomatisations exist; the most popular among ordinary
+ mathematicians is {Zermelo Fränkel set theory}.
+
+ {The beginnings of set theory
+ (http://www-groups.dcs.st-and.ac.uk/~history/HistoryTopics.html)}.
+
+ (1995-05-10)
+
+set-top box
+
+ <communications, networking> (STB) Any electronic device
+ designed to produce output on a conventional televesion set
+ (on top of which it nominally sits) and connected to some
+ other communications channels such as telephone, {ISDN},
+ {optical fibre} or cable. The STB usually runs software to
+ allow the user to interact with the programmes shown on the
+ television in some way.
+
+ {Online Media} are one STB manufacturer.
+
+ (1997-05-16)
+
+SEUS
+
+ R. Weyrauch et al. Language allowing functions to return
+ multiple values. Implemented but never published. Mentioned
+ in "Evolution of Lisp", G.L. Steele et al, SIGPLAN Notices
+ 28(3):231-270 (March 1993).
+
+seven layer model
+
+ {Open Systems Interconnect}
+
+Seven-Segment Display
+
+ <electronics> (SSD) A kind of display element consisting of seven
+ independently controllable lines arranged as a rectangular figure
+ eight. A seven-segment display is the simplest device that can
+ display any of the digits zero to nine (and some other characters)
+ by lighting different combinations of lines. They are often seen
+ in electronic calculators or measuring equipment.
+
+ (2013-04-27)
+
+SEX
+
+ /seks/ [Sun Users' Group & elsewhere] 1. Software EXchange. A
+ technique invented by the blue-green algae hundreds of
+ millions of years ago to speed up their evolution, which had
+ been terribly slow up until then. Today, SEX parties are
+ popular among hackers and others (of course, these are no
+ longer limited to exchanges of genetic software). In general,
+ SEX parties are a {Good Thing}, but unprotected SEX can
+ propagate a {virus}. See also {pubic directory}.
+
+ 2. The {mnemonic} often used for Sign EXtend, a machine
+ instruction found in the {PDP-11} and many other
+ architectures. The {RCA 1802} chip used in the early {Elf}
+ and SuperElf {personal computers} had a "SEt X register" SEX
+ instruction, but this seems to have had little folkloric
+ impact.
+
+ DEC's engineers nearly got a {PDP-11} {assembler} that used
+ the "SEX" mnemonic out the door at one time, but (for once)
+ marketing wasn't asleep and forced a change. That wasn't the
+ last time this happened, either. The author of "The Intel
+ 8086 Primer", who was one of the original designers of the
+ {Intel 8086}, noted that there was originally a "SEX"
+ instruction on that processor, too. He says that Intel
+ management got cold feet and decreed that it be changed, and
+ thus the instruction was renamed "CBW" and "CWD" (depending on
+ what was being extended). The {Intel 8048} (the
+ {microcontroller} used in {IBM PC} keyboards) is also missing
+ straight "SEX" but has logical-or and logical-and instructions
+ "ORL" and "ANL".
+
+ The {Motorola 6809}, used in the UK's "{Dragon 32}" {personal
+ computer}, actually had an official "SEX" instruction; the
+ {6502} in the {Apple II} with which it competed did not.
+ British hackers thought this made perfect mythic sense; after
+ all, it was commonly observed, you could (on some theoretical
+ level) have sex with a dragon, but you can't have sex with an
+ apple.
+
+ [{Jargon File}]
+
+ (1998-03-03)
+
+sexadecimal
+
+ {hexadecimal}
+
+sex changer
+
+ {gender mender}
+
+SEXI
+
+ {SNOBOL}
+
+Seymour Cray
+
+ <person> The founder of {Cray Research} and designer of
+ several of their {supercomputers}.
+
+ Cray has been a charismatic yet somewhat reclusive figure. He
+ began Cray Research in Minnesota in 1972. In 1988, Cray moved
+ his {Cray-3} project to Colorado Springs. The next year, Cray
+ Research spun it off to create {Cray Computer}. In 1989, Cray
+ left Cray Research and started Cray Computer Corporation in Colorado
+ Springs.
+
+ His quest to build a faster computer using new-generation
+ materials failed in 1995, and his bankruptcy cost half a
+ billion dollars and more than 400 jobs. The company was
+ unable to raise $20 million needed to finish the {Cray-4} and
+ filed for bankruptcy in March 1995.
+
+ In the summer of 1996, Cray started a Colorado Springs-based
+ company called {SRC Computers, Inc.} "We think we'll build
+ computers, but who knows what kind or how," Cray said at the
+ time. "We'll talk it over and see if we can come up with a
+ plan."
+
+ On 1996-09-22, aged 70, Cray broke his neck in a car
+ accident. Surgery for massive head injuries and swelling of
+ the brain leaving him in a critical and unstable condition.
+
+ (1997-03-02)
+
+SFA
+
+ {Sales Force Automation}
+
+SFBI
+
+ Shared Frame Buffer Interconnect (Intel)
+
+SFD-ALGOL
+
+ System Function Description-ALGOL. Extension of ALGOL for
+ synchronous systems. Sammet 1969, p.625.
+
+SFFA
+
+ {Sales Force Automation}
+
+SFL
+
+ System Function Language. Assembly language for the ICL2900.
+ "SFL Language Definition Manual", TR 6413, Intl Computers Ltd.
+
+SFLV
+
+ Unifies logic and functional programming. SASL+LV with
+ unification moved from actual/formal parameter matching to
+ equational clauses. "Static Analysis of Functional Programs
+ with Logical Variables", G. Lindstrom in Programming Languages
+ Implementation and Logic Programming, P. Deransart et al eds,
+ LNCS 348, Springer 1988.
+
+sFTP
+
+ {Secure File Transfer Protocol}
+
+sg
+
+ <networking> The {country code} for Singapore.
+
+ (1999-01-27)
+
+SGCP
+
+ {Simple Gateway Control Protocol}
+
+SGI
+
+ {Silicon Graphics, Inc.}
+
+SGML
+
+ {Standard Generalized Markup Language}
+
+sgmls
+
+ <language, tool> Sgmls is an {SGML} {parser} derived from the
+ {ARCSGML} parser materials which were written by Charles
+ Goldfarb. It outputs a simple, easily parsed, line oriented,
+ {ASCII} representation of an SGML document's Element Structure
+ Information Set (see pp 588-593 of "The SGML Handbook"). It
+ is intended to be used as the front end for
+ structure-controlled SGML {application programs}.
+
+ Version 1.1 for {Unix} and {MS-DOS} by James J. Clark
+ <jjc@jclark.com> and Charles Goldfarb.
+
+ {(ftp://ftp.uu.net/pub/text-processing/sgml/sgmls-1.0.tar.Z)},
+ {(ftp://ftp.jclark.com/sgmls/sgmls-1.1.tar.Z)}.
+
+ E-mail: James Clark <jjc@jclark.com>.
+
+ (1993-02-22)
+
+SGML Tagger
+
+ <tool> A tool to assist with adding {SGML} to a piece of text.
+ The Tagger only lets the user insert a mark-up tag which is
+ correct in that particular context.
+
+ {(http://www1.oup.co.uk/cite/oup/E-P/Humanities/The_SGML_Tagger/)}.
+
+ (1997-03-18)
+
+SGRAM
+
+ {Synchronous Graphics Random Access Memory}
+
+sh
+
+ 1. <operating system> {Bourne shell}.
+
+ 2. <networking> The {country code} for St. Helena.
+
+ (1999-01-27)
+
+SHA
+
+ {Secure Hash Algorithm}
+
+SHACO
+
+ An early system on the {IBM 701}.
+
+ [Listed in CACM 2(5):1959-05-16].
+
+ (1995-10-25)
+
+SHADOW
+
+ <language> A {syntax}-directed {compiler} written by Barnett
+ and Futrelle in 1962. It was the predecessor to {SNOBOL}(?)
+
+ [Sammet 1969, p. 448, 605].
+
+ (1995-01-16)
+
+shadowing
+
+ {aliasing}
+
+shadow ram
+
+ <operating system> A memory area in {PC-AT} compatibles used
+ to store frequently accessed {ROM} code to speed up operation.
+
+ (1995-01-16)
+
+shallow binding
+
+ A method of storing variable bindings where the current value
+ of a variable can be found at a known location rather than by
+ searching an environment or association list. When a new
+ binding is made, the old value is copied into the environment.
+
+shambolic link
+
+ /sham-bol'ik link/ A Unix symbolic link, particularly when it
+ confuses you, points to nothing at all, or results in your
+ ending up in some completely unexpected part of the
+ file system.
+
+ [{Jargon File}]
+
+Shape_VC
+
+ A {code management} system which offers version control
+ functionality similar to systems like {RCS} or {SCCS} with
+ some extensions and a more {Unix}-like command interface.
+
+ (1994-11-04)
+
+ShapeTools
+
+ <tool, programming> A {code management} system for {Unix} from
+ The {Technical University of Berlin}.
+
+ (1995-05-11)
+
+shar
+
+ <tool, file format> ("Shell archive", after {ar} and {tar})
+ Any of the many {Unix} programs that creates a {flatten}ed
+ representation of one or more files, with the unique property
+ that it can be unflattened (the original files extracted)
+ merely by feeding it through a standard {Unix} {shell}. The
+ output of shar, known as a "shar file" or "sharchive", can be
+ distributed to anyone running {Unix}, and no special unpacking
+ software is required.
+
+ Sharchives are intriguing in that they are typically created
+ by shell scripts; the script that produces sharchives is thus
+ a script which produces self-unpacking scripts, which may
+ themselves contain scripts. The disadvantage of sharchives
+ are that they are an ideal venue for {Trojan horse} attacks
+ and that, for recipients not running Unix, no simple
+ un-sharchiving program is possible; sharchives can and do make
+ use of arbitrarily-powerful shell features and other Unix
+ commands.
+
+ Different implementations of shar vary in sophistication.
+ Some just {uuencode} each input file and output commands to
+ {uudecode} the result, others include extensive checking to
+ make sure the files have been transferred without corruption
+ and that all parts of a multi-file sharchive have been
+ unpacked.
+
+ The {unshar} utility strips off mail and news headers before
+ passing the remainder of its input to sh.
+
+ (1996-10-18)
+
+sharchive
+
+ {shar}
+
+sharding
+
+ <database> A form of {data partitioning} in which a large
+ {database} {table} is split over multiple {servers} in order
+ to {balance load (load balancing)}. Some property of the data
+ is used to select which server should handle a given row,
+ e.g. the {primary id} {modulo} the number of servers.
+
+ Sharding should be a last resort in database performance
+ optimisation because of the difficulty of changing the
+ allocation of data to servers, e.g. if the number of servers
+ changes or the distribution is found to be uneven.
+
+ {Sharding Your Database, Ovid, perl.org
+ (http://blogs.perl.org/users/ovid/2010/05/sharding-your-database.html)}.
+
+ (2010-05-16)
+
+Share and enjoy!
+
+ 1. Commonly found at the end of software release announcements
+ and {README files}, this phrase indicates allegiance to the
+ hacker ethic of free information sharing (see {hacker ethic}).
+
+ 2. The motto of the Sirius Cybernetics Corporation (the
+ ultimate gaggle of incompetent {suits}) in Douglas Adams's
+ "Hitch Hiker's Guide to the Galaxy". The irony of using this
+ as a cultural recognition signal appeals to {freeware}
+ hackers.
+
+ [{Jargon File}]
+
+shared memory
+
+ 1. Memory in a {parallel computer}, usually {RAM}, which can
+ be accessed by more than one processor, usually via a shared
+ {bus} or network.
+
+ It usually takes longer for a processor to access shared
+ memory than to access its own private memory because of
+ contention for the processor-to-memory connections and because
+ of other overheads associated with ensuring synchronised
+ access. Computers using shared memory usually have some kind
+ of local {cache} on each processor to reduce the number of
+ accesses to shared memory. This requires a {cache
+ consistency} {protocol} to ensure that one processor's cached
+ copy of a shared memory location is invalidated when another
+ processor writes to that location.
+
+ The alternative to shared memory is {message passing} where
+ all memory is private to some particular processor and
+ processors communicate by sending messages down special
+ links. This is usually slower than shared memory but it
+ avoids the problems of contention for memory and can be
+ implemented more cheaply.
+
+ 2. Memory which can be access by more than one process in a
+ {multitasking} {operating system} with memory protection.
+ Some {Unix} variants, e.g. {SunOS} provide this kind of shared
+ memory.
+
+ {Unix manual pages}: shmop(2), shmctl(2), shmget(2).
+
+ (1994-10-20)
+
+Shared Time Repair of Big Electronic Systems
+
+ <language> (STROBES) A language for computer testing.
+
+ [Sammet 1969, p. 699].
+
+ (1995-02-06)
+
+shareware
+
+ <software> /sheir'weir/ {Software} that, like {freeware}, can
+ be usually obtained ({download}ed) and redistributed for free,
+ but most often is under {copyright} and does legally require a
+ payment in the {EULA}, at least beyond the {evaluation} period
+ or for commercial applications. This payment, as well as
+ fulfilling the {user}'s legal obligations, may buy additional
+ support, documentation, or functionality. Generally, {source
+ code} for shareware programs is not available. Shareware is
+ sometimes also {nagware} and/or {crippleware}, which muddles
+ the term and is frowned upon in the community.
+
+ See also {careware}, {charityware}, {guiltware},
+ {postcardware}, and {-ware}; compare {payware}.
+
+ [{Jargon File}]
+
+ (2002-01-30)
+
+shar file
+
+ {shar}
+
+sharp
+
+ <character> {hash}.
+
+Sharp APL
+
+ <language> (Or "Dictionary APL")
+
+ ["A Dictionary of the APL Language", K. Iverson, Pub 0402,
+ Sharp Assocs, Toronto, 1985].
+
+ {(ftp://watserv1.waterloo.edu/languages/apl/sharp.apl)}.
+
+ (1997-09-02)
+
+S-HDSL
+
+ {Single-pair High Speed Digital Subscriber Line}
+
+shebang
+
+ <operating system> (Or "shebang line", "{bang path}")
+ /sh*-bang'/ (From "{sharp}" and "{bang}") The {magic cookie}
+ "#!" used in {Unix} to mark the start of a {script}, e.g. a
+ {shell script} or {Perl script}.
+
+ Under {Unix}, if the first two bytes of an {executable} file
+ are "#!", the {kernel} treats the file as a script rather than
+ a {machine code} program. The word following the "!" (i.e.,
+ everything up to the first {whitespace}) is used as the
+ {pathname} of the {interpreter}. For example, if the first
+ line of an executable is
+
+ #!/usr/local/bin/perl
+
+ the script will be treated as a {Perl} script and passed as an
+ argument to /usr/local/bin/perl to be interpreted. Some
+ variants of Unix also allow one or more parameters to be
+ passed to the interpreter, for example, you can write
+
+ #!/usr/bin/perl -w
+
+ and the script will be started as if you typed
+
+ /usr/bin/perl -w <filename>
+
+ on the command line. Also, most modern kernels ignore any
+ whitespace between the "!" and the interpreter pathname. Even
+ some modern kernels have fairly small limits (e.g. 32) on the
+ length of line they will accept, making long pathnames and
+ arguments somewhat unportable.
+
+ [Does anyone call this a "magic string"?]
+
+ (1998-05-06)
+
+SHEEP
+
+ <mathematics, tool> A package for {symbolic mathematics},
+ especially {tensor analysis} and General Relativity, developed
+ by Inge Frick in Stockholm in the late 1970s to early 1980s.
+ SHEEP was implemented in {DEC-10} {assembly language}, then in
+ several {LISPs}. The current version runs on {Sun}-3 and is
+ based on {Portable Standard LISP}.
+
+ ["Sheep, a Computer Algebra System for General Relativity",
+ J.E.F. Skea et al in Proc First Brazilian School on Comp Alg,
+ W. Roque et al eds, Oxford U Press 1993, v2].
+
+ {(http://riaca.win.tue.nl/archive/can/SystemsOverview/Special/Tensoranalysis/SHEEP/index.html)}.
+
+ (2002-12-28)
+
+shelf
+
+ A public library of {class}es for the {Eiffel} language.
+
+shelfware
+
+ <jargon> /shelfweir/ {Software} which is never used and so
+ ends up on the shelf. Shelfware may be purchased on a whim by
+ an individual, or in accordance with corporate policy, but not
+ actually required for any particular use. Alternatively, it
+ may be software that has been developed (unlike {vaporware}),
+ but is never released as a product -- a common occurrence at
+ {DEC}.
+
+ [{Jargon File}]
+
+ (1997-07-20)
+
+SHELL
+
+ <language> An early system on the {Datatron 200} series.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ [{Jargon File}]
+
+ (1995-05-11)
+
+shell
+
+ 1. <operating system> (Originally from {Multics}, widely
+ propagated via {Unix}) The {command interpreter} used to pass
+ commands to an {operating system}; so called because it is the
+ part of the operating system that interfaces with the outside
+ world.
+
+ The commonest Unix shells are the c shell ({csh}) and the
+ Bourne shell ({sh}).
+
+ 2. (Or "wrapper") Any interface program that mediates access
+ to a special resource or {server} for convenience, efficiency,
+ or security reasons; for this meaning, the usage is usually "a
+ shell around" whatever.
+
+ [{Jargon File}]
+
+ (1995-05-11)
+
+shell out
+
+ [Unix] To spawn an interactive subshell from within a program
+ (e.g. a mailer or editor). "Bang foo runs foo in a subshell,
+ while bang alone shells out."
+
+ [{Jargon File}]
+
+ (1995-05-11)
+
+shell script
+
+ <programming, operating system> A {program} written to be
+ interpreted by the {shell} of an {operating system},
+ especially {Unix}.
+
+ Compare: {script}, {glue language}.
+
+ (1999-02-22)
+
+shell variable
+
+ <programming, operating system> One of the {variables}
+ accessible to a {Unix} {shell} process, including {environment
+ variables} (e.g. $HOME), {command line arguments} (e.g. $1)
+ and local variables (e.g. $input_file). Other {operating
+ systems} have similar variables.
+
+ (1999-01-26)
+
+shielded twisted pair
+
+ <hardware> (STP) A kind of cable {used} for most {Ethernet}
+ cabling, especially fast ethernet connections such as 100
+ {Mbps}.
+
+ Compare: {unshielded twisted pair}.
+
+ (1999-11-15)
+
+SHIFT
+
+ Scalable Heterogeneous Integrated Facility Testbed. A
+ parallel processing project at CERN.
+
+Shift In
+
+ <character> (SI, Control-O, {ASCII} 15) The character used on
+ some ancient {teletypes} to start using an alternative
+ {character set}.
+
+ (1996-06-24)
+
+shift left logical
+
+ {logical shift}
+
+Shift Out
+
+ <character> (SO, Control-N, {ASCII} 14) The character which
+ was used to "shift out" of an alternate character set on some
+ ancient {teletypes}, reversing the effect of the {Shift In}
+ (SI, ASCII 15) character.
+
+ (1996-06-24)
+
+shift right logical
+
+ {logical shift}
+
+shim
+
+ <jargon, memory management> A small piece of data inserted in
+ order to achieve a desired {memory alignment} or other
+ addressing property.
+
+ For example, the {PDP-11} {Unix} {linker}, in split I&D
+ (instructions and data) mode, inserts a two-{byte} shim at
+ location 0 in data space so that no data object will have an
+ address of 0 (and be confused with the {C} null pointer).
+
+ See also {loose bytes}.
+
+ [{Jargon File}]
+
+ (1994-12-21)
+
+shit hit the fan
+
+ <chat> (SHTF) A slang expression for a chaotic or otherwise
+ unfavourable outcome.
+
+ (2000-11-07)
+
+shitogram
+
+ /shit'oh-gram/ A *really* nasty piece of e-mail.
+
+ Compare {nastygram}, {flame}.
+
+ [{Jargon File}]
+
+ (1994-12-21)
+
+Shockwave
+
+ <tool> A program from {Macromedia} for viewing files created
+ with {Macromedia Director}. Shockwave is freely available as
+ a {plug-in} for the {Netscape Navigator} web {browser}.
+
+ "Shocked" pages that incorporate documents created in Director
+ can usually only be enjoyed by users with an {ISDN} or faster
+ connection.
+
+ {(http://macromedia.com/shockwave/)}.
+
+ [Filetypes? More detail?]
+
+ (1998-07-07)
+
+shockwave
+
+ <networking> The propagation of failure, shutdown, {meltdown},
+ net overload, or a {virus} from one network node to another,
+ resulting in a wave of inactivity across the net.
+
+ (1997-05-16)
+
+Shockwave Flash
+
+ {Flash}
+
+shopbot
+
+ <web> A kind of {bot} that searches the {World-Wide
+ Web} to find the best price for a product you're looking for.
+
+ [Examples?]
+
+ (1999-06-19)
+
+short card
+
+ <hardware> A half-length {IBM PC expansion card} or adaptor
+ that will fit in one of the two short slots located toward
+ the right rear of a standard chassis (tucked behind the
+ {floppy disk} drives).
+
+ See also: {tall card}.
+
+ [What bus?]
+
+ [{Jargon File}]
+
+ (1998-07-08)
+
+Short Code
+
+ <language> (SHORTCODE) A {pseudocode} {interpreter} for
+ mathematics problems, designed by {John Mauchly} in 1949 to
+ execute on Eckert and Mauchly's {BINAC} and later on {UNIVAC
+ I} and II. Short Code was possibly the first attempt at a
+ {high level language}.
+
+ [Sammet 1969, p. 129].
+
+ (1996-11-01)
+
+shortcut
+
+ <file system> {Microsoft Corporation}'s term for a {symbolic
+ link}, stored as a file with extension ".lnk". Shortcuts
+ first appeared in 1996 in the {Windows 95} {operating system}.
+ Windows shortcuts can link to any file or directory
+ ("folder"), including those on remote computers, using {UNC}
+ paths. Each shortcut can also have its own {icon}. A
+ shortcut that links to an executable file can pass {arguments}
+ and specify the directory in which the command should run.
+ Unlike a {Unix} {symbolic link}, a shortcut does not always
+ behave exactly like the target file or directory.
+
+ Compare {pif}.
+
+ (2001-12-18)
+
+Shorten
+
+ <audio, compression> A form of {lossless} {audio}
+ {compression}.
+
+ [Details?]
+
+ (2001-12-17)
+
+shortest job first
+
+ <algorithm> A scheduling {algorithm} used in {multitasking}
+ {operating systems} that favours processes with the shortest
+ estimated running time.
+
+ (1998-04-25)
+
+Short Message Service
+
+ <messaging> (SMS) A message service offered by the {GSM}
+ digital {cellular telephone} system.
+
+ Using SMS, a short alphanumeric message (160 alphanumeric
+ characters) can be sent to a mobile phone to be displayed
+ there, much like in an {alphanumeric pager} system. The
+ message is buffered by the GSM network until the phone becomes
+ active.
+
+ (1996-02-18)
+
+shotgun debugging
+
+ The software equivalent of {Easter egging}; the making of
+ relatively undirected changes to software in the hope that a
+ bug will be perturbed out of existence. This almost never
+ works, and usually introduces more bugs.
+
+ [{Jargon File}]
+
+shoulder surfing
+
+ <security> Secretly watching someone perform some supposedly
+ secure action; looking over their shoulder. The canonical example
+ is watching what keys someone presses when they enter a password.
+ Other examples include using binoculars to watch someone across
+ the street enter their PIN in a cash machine or simply reading
+ sensitive information off somebody's screen without them
+ realising.
+
+ (2013-11-06)
+
+shovelware
+
+ /shuh'v*l-weir"/ Extra software dumped onto a CD-ROM or tape
+ to fill up the remaining space on the medium after the
+ software distribution it's intended to carry, but not
+ integrated with the distribution.
+
+Show-And-Tell
+
+ A visual {dataflow} language designed for use by elementary
+ school children.
+
+ ["A Visual Language for Keyboardless Programming", T. Kimura
+ et al, TR WUCS-86-6, CS Dept Washington U, Mar 1986].
+
+ ["Show and Tell: A Visual Language", T.D. Kimura et al in
+ Visual Programming Environments: Paradigms and Systems,
+ E.P. Glinert ed, IEEE Comp Sci Press, 1990, pp. 397-404].
+
+ (1995-01-31)
+
+showstopper
+
+ A hardware or (especially) software {bug} that makes an
+ implementation effectively unusable; one that absolutely has
+ to be fixed before development can go on. Opposite in
+ connotation from its original theatrical use, which refers to
+ something stunningly *good*.
+
+ [{Jargon File}]
+
+ (1995-01-31)
+
+shriek
+
+ {exclamation mark}
+
+shrug report
+
+ <humour> A {bug report} with no error message or reproduction
+ steps and only a vague description of the problem. Usually
+ contains the phrase "doesn't work."
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}]
+
+ (2012-02-04)
+
+sht
+
+ {server-parsed HTML}
+
+SHTF
+
+ {shit hit the fan}
+
+shtml
+
+ {server-parsed HTML}
+
+Shub-Internet
+
+ /shuhb in't*r-net/ (MUD, from H. P. Lovecraft's evil fictional
+ deity "Shub-Niggurath", the Black Goat with a Thousand Young)
+ The harsh personification of the {Internet}, Beast of a
+ Thousand Processes, Eater of Characters, Avatar of Line Noise,
+ and Imp of Call Waiting; the hideous multi-tendriled entity
+ formed of all the manifold connections of the net. A sect of
+ {MUD}ders worships Shub-Internet, sacrificing objects and
+ praying for good connections. To no avail - its purpose is
+ malign and evil, and is the cause of all network slowdown.
+ Often heard as in "Freela casts a tac nuke at Shub-Internet
+ for slowing her down." (A forged response often follows along
+ the lines of: "Shub-Internet gulps down the tac nuke and burps
+ happily.") Also cursed by users of {FTP} and {telnet} when
+ the system slows down. The dread name of Shub-Internet is
+ seldom spoken aloud, as it is said that repeating it three
+ times will cause the being to wake, deep within its lair
+ beneath the Pentagon.
+
+ [{Jargon File}]
+
+ (1994-11-04)
+
+SHUG
+
+ {Scottish Hypermedia Users' Group}
+
+Shugart, Alan F.
+
+ {Alan F. Shugart}
+
+Shugart Associates
+
+ <company> The {disk drive} company, founded by Alan
+ F. Shugart, which developed {SCSI}. Alan left Shugart
+ Associates in 1974 [did he quit or was he fired?]. Shugart
+ Associates was bought, and eventually shut down by {Xerox}.
+
+ (2000-02-09)
+
+Shugart Technology
+
+ {Seagate Technology}
+
+SI
+
+ 1. <unit> {Système International}.
+
+ 2. <character> {Shift In}.
+
+si
+
+ <networking> The {country code} for Slovenia.
+
+ (1999-01-27)
+
+SIA
+
+ {Serial Interface Adaptor}
+
+SIBO
+
+ {SIxteen Bit Organisers}
+
+SICL
+
+ {Standard Instrument Control Library}
+
+SICS
+
+ {Swedish Institute for Computer Science}
+
+SICStus Prolog
+
+ A {Prolog} from the SICS (Swedish Inst of Comp Sci).
+
+ E-mail: <sicstus-request@sics.se>.
+ Mailing list: sicstus-users@sics.se.
+
+ (1995-01-05)
+
+sidecar
+
+ 1. Synonym {slap on the side}. Especially used of add-ons for
+ the late and unlamented {IBM PCjr}.
+
+ 2. The {IBM PC} compatibility box that could be bolted onto
+ the side of an {Amiga}. Designed and produced by {Commodore},
+ it broke all of the company's own design rules. If it worked
+ with any other peripherals, it was by {magic}.
+
+ [{Jargon File}]
+
+side-effect
+
+ A language construct that modifies the state of the system.
+ The most common side-effects are {assignment}, input and
+ output. A language without side-effects is
+ {purely-functional} - execution consists of the evaluation of
+ an expression and all subexpressions are {referentially
+ transparent}.
+
+ (1995-02-16)
+
+Siemens
+
+ A German semiconductor and electronics manufacturer.
+
+ {(http://siemens.de/)}.
+
+ [Summary?]
+
+ (1995-07-26)
+
+Siemens Nixdorf Informationssteme, AG
+
+ <company> (SNI) A separate company within {Siemens}, the
+ largest {IT} company in Europe. SNI sells the {BS2000}
+ {operating system}, a wide variety of {databases}, {servers}
+ and other products.
+
+ (1997-06-13)
+
+Sierra
+
+ <company, games> (Or "Sierra On-Line") A computer game
+ developer founded in the early 1980s by Ken and Roberta
+ Willams in the small mountain town of Oakhurst California.
+ Sierra was named after the local mountian range, 15 miles from
+ the famous Yosemite National Park.
+
+ In 1997 Sierra was purchased by {CUC} and its main office is
+ now in Seattle, WA, USA.
+
+ Products include Kings Quest, Space Quest, Police Quest, Quest
+ for Glory, Robin Hood, Phantasmagoria, Leisure Suit Larry, Eco
+ Quest and many more.
+
+ {(http://sierra.com /)}.
+
+ (1997-11-23)
+
+SIFT
+
+ SHARE Internal Fortran Translator. Translation utility
+ designed for converting Fortran II to Fortran IV. The word
+ "sift" was often used as a verb to describe converting code
+ from one language to another. Sammet 1969, p.153.
+
+SIG
+
+ {Special Interest Group}
+
+Sig
+
+ Signal Processing, Analysis, and Display program. An
+ environment with an associated programming language by Jan
+ Carter of {Argonne National Lab}. Telephone +1 (312) 972
+ 7250.
+
+ [{Jargon File}]
+
+sig
+
+ {signature}
+
+sig block
+
+ /sig blok/ [Unix; often written ".sig" there]. See
+ {signature}.
+
+ [{Jargon File}]
+
+SIGBUS
+
+ {bus error}
+
+SIGhyper
+
+ Special Interest Group on Hypertext and Multimedia of the
+ {SGML} Users' Group.
+
+SIGLA
+
+ <robotics> SIGma LAnguage. A language for industrial robots
+ from {Olivetti}.
+
+ ["SIGLA: The Olivetti Sigma Robot Programming Language",
+ M. Salmon, Proc 8th Intl Symp on Industrial Robots, 1978,
+ pp. 358-363].
+
+SIGMA
+
+ A scientific {visual programming} environment from NASA.
+
+ {(http://fi-www.arc.nasa.gov/fia/projects/sigma/)}.
+
+SIGNAL
+
+ <language> A synchronous language by Le Guernic et al of
+ {INRIA}.
+
+ ["SIGNAL - A Data Flow-Oriented Language for Signal
+ Processing," P. le Guernic, IEEE Trans Acoustics Speech &
+ Signal Proc, ASSP-34(2):362-1986-04-374].
+
+ (1996-12-10)
+
+signal
+
+ <operating system> A predefined message sent between two
+ {Unix} {processes} or from the {kernel} to a process. Signals
+ communicate the occurrence of unexpected external events such
+ as the forced termination of a process by the user. Each
+ signal has a unique number associated with it and each process
+ has a signal handler set for each signal. Signals can be sent
+ using the {kill} {system call}.
+
+ (1996-12-10)
+
+signalling rate
+
+ <communications> The number of times per second the
+ {amplitude}, {frequency} or {phase} of the signal transmitted
+ down a communications channel changes each second. The
+ signalling rate is measured in {baud}.
+
+ (1998-02-14)
+
+Signalling System 7
+
+ <protocol> (SS7) A {protocol} suite used for communication
+ with, and control of, telephone central office switches and
+ their attached processors.
+
+ (1995-03-01)
+
+signal-to-noise ratio
+
+ 1. <communications> (SNR, "s/n ratio", "s:n ratio") "Signal"
+ refers to useful information conveyed by some communications
+ medium, and "noise" to anything else on that medium. The
+ ratio of these is usually expressed logarithmically, in
+ {decibels}.
+
+ 2. <networking> The term is often applied to {Usenet}
+ newsgroups though figures are never given. Here it is quite
+ common to have more noise (inappropriate postings which
+ contribute nothing) than signal (relevant, useful or
+ interesting postings). The signal gets {lost in the noise}
+ when it becomes too much effort to try to find interesting
+ articles among all the crud. Posting "noise" is probably the
+ worst breach of {netiquette} and is a waste of {bandwidth}.
+
+ [{Jargon File}]
+
+ (1996-01-29)
+
+signature
+
+ 1. A set of function symbols with {arities}.
+
+ 2. <messaging> (Or sig) A few lines of information about the
+ sender of an {electronic mail} message or {news} {posting}.
+ Most {Unix} mail and news software will {automagically} append
+ a signature from a file called .signature in the user's {home
+ directory} to outgoing mail and news.
+
+ A signature should give your real name and your {e-mail
+ address} since, though these appear in the {headers} of your
+ messages, they may be {munged} by intervening software. It is
+ currently (1994) hip to include the {URL} of your {home page}
+ on the {web} in your sig.
+
+ The composition of one's sig can be quite an art form,
+ including an {ASCII} logo or one's choice of witty sayings
+ (see {sig quote}, {fool file}). However, large sigs are a
+ waste of {bandwidth}, and it has been observed that the size
+ of one's sig block is usually inversely proportional to one's
+ prestige on the net.
+
+ See also {doubled sig}, {sig virus}.
+
+ 2. <programming> A concept very similar to {abstract base
+ classes} except that they have their own {hierarchy} and can
+ be applied to compiled {classes}. Signatures provide a means
+ of separating {subtyping} and {inheritance}. They are
+ implemented in {C++} as patches to {GCC} 2.5.2 by Gerald
+ Baumgartner <gb@cs.purdue.edu>.
+
+ {(ftp://ftp.cs.purdue.edu/pub/gb/)}.
+
+ (2001-01-05)
+
+sig quote
+
+ <messaging> /sig kwoht/ A maxim, quote, proverb, joke, or slogan
+ embedded in one's {sig block} (as used in {Usenet} news) and
+ intended to convey something of one's philosophical stance,
+ pet peeves, or sense of humour. "Calm down, it's only ones
+ and zeroes."
+
+ [{Jargon File}]
+
+ (1994-11-04)
+
+sig virus
+
+ A parasitic {meme} embedded in a {sig block}. There was a
+ {meme plague} or fad for these on {Usenet} in late 1991. Most
+ were equivalents of "I am a .sig virus. Please reproduce me
+ in your .sig block.". Of course, the .sig virus's memetic
+ hook is the giggle value of going along with the gag; this,
+ however, was a self-limiting phenomenon as more and more
+ people picked up on the idea. There were creative variants on
+ it; some people stuck "sig virus antibody" texts in their
+ sigs, and there was at least one instance of a sig virus
+ eater.
+
+ [{Jargon File}]
+
+SIL
+
+ 1. "SIL - A Simulation Language", N. Houbak, LNCS 426,
+ Springer 1990.
+
+ 2. SNOBOL Implementation Language. Intermediate language
+ forming a virtual machine for the implementation of portable
+ interpreters.
+
+ ["The Design of Transportable Interpreters", F. Druseikis,
+ SNOBOL4 Project Document S4D49, U Arizona (Feb 1975)].
+
+ Version 3.11. {(ftp://cs.arizona.edu/snobol4/)}. E-mail:
+ <snobol4@arizona.edu>.
+
+ (1986-07-29)
+
+Silage
+
+ Synchronous DSP specification language.
+
+ ["Silage Reference Manual, Draft 1.0", D.R. Genin &
+ P.N. Hilfinger, Silvar-Lisco, Leuven 1989].
+
+silicon
+
+ 1. <electronics> The material used as the base (or
+ "substrate") for most {integrated circuits}.
+
+ 2. <jargon> {Hardware}, especially {integrated circuits} or
+ {microprocessor}-based computer systems (compare {iron}).
+
+ Contrast: {software}. See also {sandbender}.
+
+ [{Jargon File}]
+
+ (1996-05-28)
+
+silicon chip
+
+ {integrated circuit}
+
+Silicon Graphics, Inc.
+
+ <company> (SGI) Manufacturer of {workstations} and {software}
+ for {graphics} and {image processing}. SGI was founded by
+ {Dr. James H. Clark}, who left some time before May 1994 to
+ head {Mosaic Communications Corporation}.
+
+ Quarterly sales $433M, profits $44M (Aug 1994).
+
+ {(http://sgi.com/)}.
+
+ (1994-09-26)
+
+Siliwood
+
+ <jargon> (Or "Hollywired") The coming convergence of film,
+ {interactive TV} and computers.
+
+ (1999-01-15)
+
+silly walk
+
+ [Monty Python's Flying Circus] 1. A ridiculous procedure
+ required to accomplish a task. Like {grovel}, but more
+ {random} and humorous. "I had to silly-walk through half the
+ /usr directories to find the maps file."
+
+ 2. Synonym {fandango on core}.
+
+ [{Jargon File}]
+
+silo
+
+ The {FIFO} input-character buffer in an {EIA-232} serial line
+ card. So called from {DEC} terminology used on DH and DZ line
+ cards for the {VAX} and {PDP-11}, presumably because it was a
+ storage space for fungible stuff that went in at the top and
+ came out at the bottom.
+
+Silver Book
+
+ <publication> Jensen and Wirth's infamous "Pascal User Manual
+ and Report", so called because of the silver cover of the
+ widely distributed Springer-Verlag second edition of 1978
+ (ISBN 0-387-90144-2).
+
+ See also {book titles}, {Pascal}.
+
+ [{Jargon File}]
+
+ (1996-12-03)
+
+silver bullet
+
+ {magic bullet}
+
+SIM
+
+ {Subscriber Identity Module}
+
+SIMAN
+
+ {SIMulation ANalysis}
+
+SimCity
+
+ <games> {Maxis Software}'s simulation game which lets you
+ design and build your own city, which must be administered
+ well if it is to thrive. Land must be zoned, transportation
+ systems built, and police and fire protection provided. Once
+ you've zoned some land, and provided electrical power, the
+ simulation takes over, and simcitizens move in. If you
+ perform your mayoral duties poorly, however, they will move
+ out again. If you don't provide enough police, crime will
+ rise and sims will vote with their feet. Try to save money on
+ fire protection, and your city may burn to the ground. There
+ is no predefined way to win the game, building the largest
+ city you can is just one possible strategy.
+
+ SimCity runs on {Archimedes}, {Amiga}, {Atari ST}, {IBM PC}
+ and {Macintosh}. There was also a {NeWS} version for {Sun}
+ {SPARC} {workstations} running {OpenWindows}.
+
+ {SimCity 2000} is an upgrade of SimCity.
+
+ (1995-06-11)
+
+SimCity 2000
+
+ <games> An upgraded version of the game/simulation {SimCity}
+ by {Maxis Software}. In the new version you can raise, lower
+ and level terrain; build roads and railways at 45-degree
+ angles; name things in your city by planting "signs"; build
+ raised highways, subways, and train and bus stations, schools,
+ colleges, hospitals, electricity, water, recreational marinas
+ and zoos.
+
+ There are three levels of zoom, and the view may be rotated to
+ look at your city from any of the four directions. A query
+ feature which will tell you the zoning, land value, etc. of
+ any square. You get newspapers, advice from council members,
+ graphs, and charts.
+
+ (1995-02-08)
+
+SIMD
+
+ {Single Instruction/Multiple Data}
+
+Similix
+
+ An autoprojector (self-applicable partial evaluator) for a
+ higher order subset of the strict functional language Scheme.
+ Similix handles programs with user defined primitive abstract
+ data type operators which may process global variables (such
+ as input/output operators).
+
+ Version 5.0.
+
+ Anders Bondorf <anders@diku.dk>
+
+ conformance: extension of large subset of R4RS Scheme.
+
+ requires: Scheme
+
+ ports: Scm, Chez Scheme
+
+ portability: high
+
+ E-mail: Anders Bondorf <anders@diku.dk>
+
+ {(ftp://ftp.diku.dk/pub/diku/dists/Similix.tar.Z)}.
+
+ (1993-05-18)
+
+SIML/I
+
+ Simulation language, descendant of ASPOL.
+
+ ["The Simulation Language SIML/I", M.H. MacDougall, Proc NCC
+ 1979, pp. 39-44].
+
+SIMM
+
+ {Single in-line memory module}
+
+Simone
+
+ <language> A {simulation} language by A. Hoare et al. based on
+ {Pascal}.
+
+ ["Quasiparallel Programming", W.H. Kaubisch et al, Soft Prac &
+ Exp 6:341-356 1976].
+
+ [C.A.R. Hoare?]
+
+ (1996-01-18)
+
+Simonyi, Charles
+
+ {Charles Simonyi}
+
+SIMPAC
+
+ Early simulation language with fixed time steps.
+
+ "Simpac User's Manual", R.P. Bennett et al, TM-602/000/000,
+ Sys Devel Corp, Apr 1962.
+
+SIMPAS
+
+ Event scheduling language, implemented as Pascal preprocessor.
+
+ "SIMPAS - A Simulation Language Based on Pascal", R.M. Bryant
+ in Proc 1980 Winter Sim Conf, T.I Oren et al eds, pp.559-572.
+
+SIMPL
+
+ Simulation language, descendant of OPS-4, compiled into PL/I
+ on Multics.
+
+ "The SIMPL Primer", M.W. Jones et al, Oct 1971.
+
+SIMPLE
+
+ 1. Early system on Datatron 200 series. Listed in CACM
+ 2(5):16 (May 1959).
+
+ 2. Simulation of Industrial Management Problems with Lots of
+ Equations. R.K. Bennett, 1958. Predecessor to DYNAMO, for
+ IBM 704.
+
+Simple Actor Language
+
+ <language> (SAL) A minimal {actor language}, used for teaching
+ in:
+
+ ["Actors, A Model of Concurrent Computation in Distributed
+ Systems", G. Agha, MIT Press 1986].
+
+ (1994-12-08)
+
+Simple Authentication and Security Layer
+
+ <networking> (SASL)
+
+ {(http://asg2.web.cmu.edu/sasl/)}.
+
+ [Summary?]
+
+ (2001-08-24)
+
+Simple Gateway Control Protocol
+
+ <communications, protocol> (SGCP) An {IETF} work in progress,
+ superseded by {MGCP}.
+
+ (1999-04-26)
+
+Simple Mail Transfer Protocol
+
+ <messaging> (SMTP) A {protocol} defined in {STD} 10, {RFC}
+ 821, used to transfer {electronic mail} between computers,
+ usually over {Ethernet}. It is a server to server protocol,
+ so other protocols are used to access the messages. The SMTP
+ dialog usually happens in the background under the control of
+ the {message transfer agent}, e.g. {sendmail} but it is
+ possible to interact with an SMTP server using {telnet} to
+ connect to the normal SMTP {port}, 25. E.g.
+
+ telnet mhs-relay.ac.uk 25
+
+ You should normally start by identifying the local {host}:
+
+ HELO wombat.doc.ic.ac.uk
+
+ You can then issue commands to verify an address or expand an
+ alias:
+
+ VRFY fred@doc.ic.ac.uk
+ VRFY postmaster
+
+ or expand a {mailing list}:
+
+ EXPN c-help
+
+ You can even send a message:
+
+ MAIL From:<fred@doc.ic.ac.uk>
+ RCPT To:<fred@mailway.doc.ic.ac.uk>
+ DATA
+ What is the point?
+ .
+ QUIT
+
+ This is useful if you want to find out exactly what is
+ happening to your message at a certain point.
+
+ See also {Post Office Protocol}, {RFC 822}, {sendmail}.
+
+ (1995-10-17)
+
+simple multicast protocol
+
+ <communications, protocol> A proposed {mulitcast} {protocol}
+ that would ease the requirements for {IP} Multicast, such as
+ no longer mandating that routers be able to calculate the
+ source of a multicast stream. This has not been adopted by
+ the {IETF}.
+
+ {(http://infoworld.com/cgi-bin/displayStory.pl?981125.whmulti.htm)}.
+
+ [Reference?]
+
+ (2001-07-02)
+
+Simple Network Management Protocol
+
+ <protocol> (SNMP) The {Internet} {standard} {protocol},
+ defined in {STD 15}, {RFC 1157}, developed to manage {nodes}
+ on an {IP} {network}. SNMP is not limited to {TCP/IP}. It
+ can be used to manage and monitor all sorts of equipment
+ including computers, {routers}, {wiring hubs}, {toasters} and
+ {jukeboxes}.
+
+ See also {Management Information Base}, {Simple Network
+ Management Protocol version 2}.
+
+ (1995-02-15)
+
+Simple Network Management Protocol version 2
+
+ <protocol> (SNMP v2) A revision of {Simple Network Management
+ Protocol} (not just a new {MIB}) which includes improvements
+ in the areas of performance, security, confidentiality, and
+ manager-to-manager communications.
+
+ The major components of SNMPv2 are defined in the following
+ {RFCs}:
+
+ {RFC 1089} - SNMP over Ethernet
+ {RFC 1140} - IAB Official Protocol Standards
+ {RFC 1155} - Structure and Identification of Management
+ Information for TCP/IP based internets
+ {RFC 1156} (H) - Management Information Base Network
+ Management of TCP/IP based internets
+ {RFC 1157} - A Simple Network Management Protocol
+ {RFC 1158} - Management Information Base Network
+ Management of TCP/IP based internets: MIB-II
+ {RFC 1161} (H) - SNMP over OSI
+ {RFC 1187} - Bulk Table Retrieval with the SNMP
+ {RFC 1212} - Concise MIB Definitions
+ {RFC 1213} - Management Information Base for Network
+ Management of TCP/IP-based internets: MIB-II
+ {RFC 1215} (I) - A Convention for Defining
+ Traps for use with the SNMP
+ {RFC 1224} - Techniques for Managing
+ Asynchronously Generated Alerts
+ {RFC 1270} (I) - SNMP Communication Services
+ {RFC 1303} (I) - A Convention for Describing
+ SNMP-based Agents
+ {RFC 1470} (I) - A Network Management Tool Catalog
+ {RFC 1298} - SNMP over IPX
+ {RFC 1418} - SNMP over OSI
+ {RFC 1419} - SNMP over IPX
+ {RFC 1441} - Introduction to SNMP v2
+ {RFC 1442} - SMI For SNMP v2
+ {RFC 1443} - Textual Conventions for SNMP v2
+ {RFC 1444} - Conformance Statements for SNMP v2
+ {RFC 1445} - Administrative Model for SNMP v2
+ {RFC 1446} - Security Protocols for SNMP v2
+ {RFC 1447} - Party MIB for SNMP v2
+ {RFC 1448} - Protocol Operations for SNMP v2
+ {RFC 1449} - Transport Mappings for SNMP v2
+ {RFC 1450} - {MIB} for SNMP v2
+ {RFC 1451} - Manager to Manger MIB
+ {RFC 1452} - Coexistance between SNMP v1 and SNMP v2
+
+ {FAQ
+ (http://cis.ohio-state.edu/hypertext/faq/usenet/snmp-faq)}.
+
+ {Introduction
+ (http://gt-er.cg.org.br/documentacao/buffer/gerencia/faq1.html)}.
+
+ {Cisco
+ (http://cisco.com/cpropub/univ-src/ccdcp/data/doc/software/11_1/mib/mover.htm)}.
+
+ (1997-12-02)
+
+Simple Network Paging Protocol
+
+ <protocol> (SNPP) A standard for sending one- and two-way
+ wireless messages to {pagers}. In its simplest form, SNPP
+ provides a simple way to make a link between the {Internet}
+ and a {Telocator Alphanumeric input Protocol} (TAP) paging
+ terminal. SNPP is defined in {RFC 1861}.
+
+ (1997-04-25)
+
+Simple Object Access Protocol
+
+ <protocol> (SOAP) A minimal set of conventions for invoking
+ {code} using {XML} over {HTTP}.
+
+ {DevelopMentor}, {Microsoft Corporation}, and {UserLand
+ Software} submitted SOAP to the {IETF} as an internal draft in
+ December 1999.
+
+ Latest version: SOAP 1.1 defined by {World Wide Web
+ Consortium}.
+
+ {(http://w3.org/TR/SOAP/)}.
+
+ (2000-01-08)
+
+simplex
+
+ 1. <communications> Used to describe a communications channel
+ that can only ever carry a signal in one direction, like a
+ one-way street. Television is an example of ({broadcast})
+ simplex communication.
+
+ Opposite: {duplex}.
+
+ 2. <algorithm> The {simplex method}.
+
+ (2001-07-21)
+
+simplex method
+
+ <algorithm> An {algorithm} for solving the classical {linear
+ programming} problem; developed by George B. Dantzig in 1947.
+
+ The simplex method is an {iterative} procedure, solving a
+ system of {linear equations} in each of its steps, and
+ stopping when either the optimum is reached, or the solution
+ proves infeasible. The basic method remained pretty much the
+ same over the years, though there were many refinements
+ targeted at improving performance (eg. using {sparse matrix}
+ techniques), numerical {accuracy} and stability, as well as
+ solving special classes of problems, such as {mixed-integer}
+ programming.
+
+ (2003-07-09)
+
+simplex printer
+
+ <communications> A term applied by Western Union Telegraph
+ Company to {teletypewriters} that are not part of a
+ {multiplex} system. They usually provided for alternate
+ transmission in both directions. If working {simplex} or
+ {half-duplex}, what was keyed in at the keyboard would be
+ typed out at the printing portion. If working {full-duplex},
+ sending would be blind as the printing portion was being used
+ only for reception.
+
+ (2000-04-02)
+
+SIMPL/I
+
+ A {simulation} language implemented as a {PL/I}
+ {preprocessor}.
+
+ ["SIMPL/I (Simulation Language Based on PL/I). Program
+ Reference Manual", IBM SH19- 5060-0 (June 1972)].
+
+ (1994-12-07)
+
+Simplified Multicast Routing Protocol
+
+ <communications, protocol> (SMRP) A {transport-layer}
+ {protocol} to route {multimedia} data streams over {AppleTalk}
+ networks. SMRP supports {Apple}'s {QuickTime Conferencing}
+ (QTC).
+
+ {Documentation
+ (http://cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/smrp.htm)}.
+
+ (2001-07-02)
+
+SIMPL-T
+
+ The base language for a family of languages and compilers.
+
+ ["SIMPL-T, A Structured Programming Language", V.R. Basili,
+ Paladin House 1976].
+
+ (1994-12-07)
+
+SIMSCRIPT
+
+ A free-form, English-like general-purpose {simulation}
+ language produced by Harry Markowitz et al of {Rand} Corp in
+ 1963. It was implemented as a {Fortran} {preprocessor} on
+ {IBM 7090} and was designed for large discrete simulations.
+ It influenced {Simula}. Later versions included {SIMSCRIPT
+ I.5} and {SIMSCRIPT II.5}.
+
+SIMSCRIPT I.5
+
+ A version of {SIMSCRIPT} developed at {CACI} in 1965. It
+ produced {assembly language}.
+
+SIMSCRIPT II.5
+
+ Another version of {SIMSCRIPT} from {CACI}.
+
+ ["SIMSCRIPT: A Simulation Programming Language", P.J. Kiviat
+ et al, CACI, 1973].
+
+simship
+
+ {simultaneous shipment}
+
+SIMULA
+
+ <language> SIMUlation LAnguage.
+
+ See {Lund Simula}, {SIMULA 67}, {SIMULA I}. See also
+ {Association for SIMULA Users}, {C++SIM}, {FLEX}, {MODSIM},
+ {SIMSCRIPT}.
+
+ A simula-to-{C} {compiler} project is underway. E-mail:
+ Harald Thingelstad <harald.thingelstad@basalmed.uio.no>.
+
+ {Usenet} newsgroup: {news:bit.listserv.simula}.
+
+ (1995-03-29)
+
+SIMULA 67
+
+ <language> A version of {SIMULA I}?
+
+ {Association for SIMULA Users}
+
+ Simula a.s., Postboks 4403 - Torshov, N-0402 Oslo 4, Norway,
+ versions for almost every computer.
+
+ E-mail: Henry Islo <hio@helios.sunet.se>.
+
+ {(ftp:/lund.se:/mac/misc/simula/)},
+ {(ftp://ftp.fenk.wau.nl/pub/simula/compilers)},
+ {(ftp://ftp.ifi.uio.no/cim/)}.
+
+ ["Object-Oriented Programming with SIMULA", Bjorn Kirkerud,
+ A-W 1989].
+
+ ["Data Processing - Programming Languages - SIMULA", Swedish
+ Standard SS 63 61 14 (1987), available through ANSI].
+
+ [Difference from SIMULA I?]
+
+ (1995-03-29)
+
+SIMULA I
+
+ <language> SIMUlation LAnguage.
+
+ An extension to {ALGOL 60} for the {Univac 1107} designed in
+ 1962 by Kristen Nygaard and Ole-Johan Dahl and implemented in
+ 1964. SIMULA I was designed for {discrete simulation}. It
+ introduced the {record} {class}, leading the way to {data
+ abstraction} and {object-oriented programming} languages like
+ {Smalltalk}. It also featured {coroutines}.
+
+ SIMULA's philosophy was the result of addressing the problems
+ of describing complex systems for the purpose of simulating
+ them. This philosophy proved to be applicable for describing
+ complex systems generally (not just for simulation) and so
+ SIMULA is a general-purpose object-oriented application
+ programming language which also has very good discrete event
+ simulation capability. Virtually all OOP products are derived
+ in some manner from SIMULA.
+
+ For a description of the evolution of SIMULA and therefore the
+ fundamental concepts of OOP, see Dahl and Nygaard in ["History
+ of Programming Languages". Ed. R. W. Wexelblat.
+ Addison-Wesley, 1981].
+
+ (1995-03-29)
+
+simulate
+
+ {simulation}
+
+simulated annealing
+
+ A technique which can be applied to any minimisation or
+ learning process based on successive update steps (either
+ random or {deterministic}) where the update step length is
+ proportional to an arbitrarily set parameter which can play
+ the role of a temperature. Then, in analogy with the
+ annealing of metals, the temperature is made high in the early
+ stages of the process for faster minimisation or learning,
+ then is reduced for greater stability.
+
+Simulating Digital Systems
+
+ Fortran-like language for describing computer
+ logic design. Sammet 1969, p.622.
+
+simulation
+
+ <simulation, systems> Attempting to predict aspects of the
+ behaviour of some system by creating an approximate (mathematical)
+ model of it. This can be done by physical modelling, by writing a
+ special-purpose computer program or using a more general
+ simulation package, probably still aimed at a particular kind of
+ simulation (e.g. structural engineering, fluid flow). Typical
+ examples are aircraft flight simlators or electronic circuit
+ simulators.
+
+ A great many {simulation languages} exist, e.g. {Simula}.
+
+ See also {emulation}, {Markov chain}.
+
+ (1995-02-23)
+
+SIMulation ANalysis
+
+ <language, simulation> (SIMAN) A {simulation} language,
+ especially for manufacturing systems, developed by C. Dennis
+ Pegden in 1983.
+
+ ["Introduction to Simulation using SIMAN", C.D. Pegden et al,
+ McGraw-Hill 1990].
+
+ (1999-01-13)
+
+Simulation Language for Alternative Modeling
+
+ <language> (SLAM) A {simulation} language descended from
+ {GASP}. Implemented as a {Fortran} {preprocessor}.
+
+Simulation Oriented Language
+
+ <language> (SOL) An {ALGOL} extension for {discrete
+ simulation} by {Donald Knuth} and McNeley.
+
+ ["SOL - A Symbolic Language for General Purpose System
+ Simulation", D.E. Knuth et al, IEEE Trans Elec Comp,
+ EC-13(4):401-408 (Aug 1964)].
+
+ [Sammet 1969, p. 656].
+
+ (1995-07-26)
+
+Simultaneous Engineering Environment
+
+ (SEE) A {CAE} framework from {DAZIX}.
+
+ (1994-11-03)
+
+Simultaneous Peripheral Operation On-Line
+
+ <operating system, history> (SPOOL) Accessing {peripheral}
+ devices with the help of an {off-line} {tape drive}. The term
+ was derived by {IBM} for use with the {IBM 360} {operating
+ systems}.
+
+ In the early days of computing (early 1960s), before
+ {multitasking} was invented, computers (e.g. {IBM 704}) could
+ run only one job at a time. As peripheral devices such as
+ {printers} or {card readers} were much slower than the {CPU},
+ devoting the computer (the only computer in many cases) to
+ controlling such devices was impractical.
+
+ To free the CPU for useful work, the output was sent to a
+ {magnetic tape} drive, which was much faster than a printer
+ and much cheaper than a computer. After the job was finished
+ the tape was removed from the tape drive attached to the
+ computer and mounted on a tape drive connected to a printer
+ (such as the {IBM 1403}). The printer could then print the
+ data without holding up the computer. Similarly, instead of
+ inputting the program from the card reader it was first copied
+ to a tape and the tape was read by the computer.
+
+ (1999-01-12)
+
+simultaneous shipment
+
+ <programming> (simship) The release of international,
+ {localised} versions of software at the same time, or within a
+ short period of time of the original release.
+
+ Major software publishers can release as many as 30 different
+ localised versions within a month or two of the original
+ version. These products may have thousands of pages of
+ {documentation}.
+
+ (1999-06-09)
+
+Simware, Inc.
+
+ <company> The producers of {REXXWARE}.
+
+ E-mail: <rexxware@simware.com>.
+
+ Address: Ottawa, Canada.
+
+ (1995-01-11)
+
+SINA
+
+ ["An Implementation of the Object-Oriented Concurrent
+ Programming Language SINA", A. Tripathi et al, Soft Prac & Exp
+ 19(3):235-256 (1989)].
+
+since time T equals minus infinity
+
+ A long time ago; for as long as anyone can remember; at the
+ time that some particular frob was first designed. Usually
+ the word "time" is omitted. See also {time T}; contrast
+ {epoch}.
+
+ [{Jargon File}]
+
+Sinclair, Clive
+
+ {Clive Sinclair}
+
+Sinclair PC200
+
+ <computer>
+
+ {(http://nonowt.demon.co.uk/magfold/articfol/the_miss.htm)}.
+
+ [Summary?]
+
+ 1998-07-28
+
+Sinclair Radionics
+
+ {Sinclair Research}
+
+Sinclair Research
+
+ <company> A British microelectronics developer and
+ manufacturer. Evolving from Sinclair Radionics in 1979,
+ Sinclair Research was owned by Sir {Clive Sinclair}. Sinclair
+ Radionics produced electronic components and devices (such as
+ calculators and pocket radios and televisions), but Sinclair
+ Research began by producing some of the first {8-bit} home
+ {microcomputers}.
+
+ Sinclair produced five microcomputers from 1980 to 1987, all
+ based on the {Zilog Z80} {microprocessor} (except for the
+ {QL}, which used the {Motorola 68008} - a variant on the
+ {68000}). The 1K kit-build {ZX80}, introduced in 1980, was
+ followed by the 1K {ZX81} (expandable to 16K) in 1981, the 16K
+ (expandable to 48K) {ZX Spectrum} in 1982 (then superseded by
+ two distinct 48K models and a 128K model in 1986) and the {QL}
+ (Quantum Leap) in 1984. A portable {laptop computer}, the
+ {Z88}, was released in 1987 under the {Cambridge Computers}
+ banner.
+
+ Of them all, the ZX Spectrum was the best known, and it went
+ on to become the most popular microcomputer of its time in the
+ United Kingdom and in many other territories. This was partly
+ due to its ease of use, and also due to its enormous
+ {software} catalogue, covering games, {word processing},
+ music, {programming} and {graphics}. Glorious
+ "mine's-better-than-yours" battles were fought (and still are
+ today) between owners of Spectrums and {Commodore 64s} over
+ who had the best machine.
+
+ Sir Clive's financial problems in the mid-80s led him to sell
+ the rights to the Sinclair brand to {Amstrad} in April 1986.
+ This led to further models of the Spectrum being released from
+ 1986 to 1988 and also an {IBM} {PC}-compatible based
+ internally on Amstrad's own PC range. Sir Clive was not
+ involved with the production of these computers, and no
+ computer with the Sinclair name has been produced since.
+
+ {(http://sinclair-research.co.uk/)}.
+ {Planet Sinclair (http://nvg.ntnu.no/sinclair/)}.
+ {comp.sys.sinclair FAQ
+ (http://kendalls.demon.co.uk/cssfaq/)}.
+
+ (1998-12-09)
+
+sine wave
+
+ <mathematics> A waveform of a single constant frequency and
+ amplitude that continues for all time.
+
+ Compare {wavelet}.
+
+ (1994-11-09)
+
+single assignment
+
+ <programming> A property of {variables} in a {functional
+ language}. If a {variable} is only assigned a value once then
+ an instance of that variable is thereafter semantically
+ equivalent to the value. {SISAL} is an example of a language
+ with this property.
+
+ See also {zero assignment}.
+
+ (2003-12-22)
+
+single assignment language
+
+ <language> Any programming language with the {single
+ assignment} property.
+
+ (2007-03-21)
+
+single-attached
+
+ Connected to only one of the two rings of an {FDDI} network.
+ This is the kind of connection normally used for a {host}
+ computer, as opposed to {routers} and {concentrators} which
+ are normally "{dual-attached}".
+
+ (1994-12-13)
+
+Single Connection Attach
+
+ <hardware> (SCA, "Single Connector Attachment") A non-standard
+ type of {SCSI} connector, used mostly by {OEMs}, which carries
+ both power and data on one 80-pin connector. SCA SCSI drives
+ tend to be cheaper but use with standard SCSI cables requires
+ an adaptor and external termination.
+
+ {(http://pcmech.com/show/harddrive/152/)}.
+
+ (2003-06-21)
+
+Single Connector Attachment
+
+ {Single Connection Attach}
+
+Single Data Rate Random Access Memory
+
+ <storage> (SDR-RAM, SDR-SDRAM, Single Data Rate Synchronous
+ Dynamic Random Access Memory) {RAM} or {SDRAM} that transfers
+ data on only one {clock} transition (0-1 or 1-0), in contrast
+ to {DDR-RAM}.
+
+ (2001-05-24)
+
+Single Data Rate Synchronous Dynamic Random Access Memory
+
+ {Single Data Rate Random Access Memory}
+
+Single Document Interface
+
+ <programming> (SDI) A limitation applying to an {application
+ program} that only shows a single windows giving a view of one
+ document at a time.
+
+ The opposite is {Multiple Document Interface} (MDI).
+
+ (1999-03-30)
+
+single-duplex
+
+ <communications> (From {telegraphy}) A {full-duplex} link with
+ one telegrapher at each end, transmitting alternately in each
+ direction.
+
+ (2000-03-30)
+
+Single Edge Contact
+
+ <hardware> (SEC) The type of cartridge in which a {Pentium II}
+ is packaged.
+
+ [Other uses?]
+
+ (1999-02-15)
+
+Single Edge Contact Cartridge
+
+ <hardware> (SEC, SECC) The cased {daughterboard} housing
+ {Intel}'s {Pentium II}, {Pentium III}, and {Xeon}
+ {microprocessors}.
+
+ A SECC fits into a {Slot 1} or {Slot 2} connector.
+
+ [SECC 2?]
+
+ (1999-08-05)
+
+Single Edge Processor Package
+
+ <hardware> (SEPP) The caseless {daughterboard} containing
+ {Intel}'s {Celeron} {processor}. A SEPP fits into a {Slot 1}
+ connector.
+
+ (1999-08-04)
+
+single-electron transistor
+
+ {quantum dot}
+
+Single Electron Tunneling
+
+ <electronics> (SET) A New electrical standard for capacitance.
+
+ SET devices can be used to construct circuits which process
+ information by manipulating individual electrons. SET devices
+ are small, dissipate little power, and can detect exquisitely
+ small quantities of charge. The small size and low power
+ dissipation of SET circuits makes them potentially useful for
+ the {Information Technology} industry.
+
+ (1999-01-06)
+
+Single Electron Tunneling Technology
+
+ <hardware> A {neural network} hardware concept based on
+ {single electron tunneling}. {Single electron tunneling
+ transistors} have some properties which make them attractive
+ for neural networks, among which their small size, low power
+ consumption and potentially high speed.
+
+ Simulations have been performed on some small circuits of SET
+ transistors that exhibit functional properties similar to
+ those required for neural networks.
+
+ {(http://computer.org/conferen/proceed/mn96/ABSTRACT.HTM#125)}.
+
+ [Proceedings of the Fifth International Conference on
+ Microelectronics for Neural Networks and Fuzzy Systems
+ (MicroNeuro '96). Martijn J. Goossens, Chris J.M. Verhoeven,
+ and Arthur H.M. van Roermund].
+
+ (1999-01-06)
+
+single ended
+
+ <hardware> An electrical connection where one wire carries the
+ signal and another wire or shield is connected to electrical
+ ground. This is in contrast to a {differential} connection
+ where the second wire carries an inverted signal.
+
+Single Image Random Dot Stereogram
+
+ <graphics> (SIRDS, originally "autostereogram") A {stereogram}
+ composed of (coloured) dots which when viewed correctly
+ appears three-dimensional. SIRDs were invented by
+ Dr. Christoper Tyler, Associate Director of the
+ Smith-Kettlewell Eye Research Institute in San Francisco
+ (1999).
+
+ {FAQ (http://cs.waikato.ac.nz/~singlis/sirds.html)}.
+ {Nice pictures
+ (http://eleves.ens.fr:8080/home/massimin/index.ang.html)}.
+ {Picture Gallery (http://h2.ph.man.ac.uk/gareth/sirds.html)}.
+ {Vern Hart's SIRDS Gallery (http://vern.com/)}. {SGI
+ Gallery (http://sgi.com/free/gallery.html)}.
+
+ (1996-11-06)
+
+single inheritance
+
+ <programming> In {object-oriented programming}, the restriction
+ that a {class} can have only one superclass in the {class
+ hierarchy}.
+
+ The opposite is {multiple inheritance}.
+
+ (2014-09-06)
+
+Single In-line Memory Module
+
+ <storage> (SIMM) A small circuit board or substrate, typically
+ about 10cm x 2cm, with {RAM} {integrated circuits} or die on
+ one or both sides and a single row of pins along one long
+ edge. Several SIMMs are mounted with their substrates at
+ right-angles to the main circuit board (the {motherboard}).
+ This configuration allows greater packing density than direct
+ mounting of, e.g. DIL ({dual in-line}) RAM packages on the
+ motherboard. In 1993 one SIMM typically held one or four
+ megabytes, by early 1997 one could hold 8, 16, or 32 MB.
+
+ (1997-01-05)
+
+Single Inline Pin Package
+
+ <hardware> (SIPP) An {integrated circuit} package with a
+ single line of pins.
+
+ Compare {Dual Inline Package}, {Single In-line Memory Module}.
+
+ (1995-03-01)
+
+Single Instruction Multiple Data
+
+ {Single Instruction/Multiple Data}
+
+Single Instruction/Multiple Data
+
+ (SIMD) (Or "data parallel") The classification under {Flynn's
+ taxonomy} for a {parallel processor} where many processing
+ elements ({functional units}) perform the same operations on
+ different data. There is often a central controller which
+ broadcasts the instruction stream to all the processing
+ elements.
+
+ Contrast {Multiple Instruction/Multiple Data}.
+
+ (1994-11-04)
+
+Single-line Digital Subscriber Line
+
+ <communications, protocol> (SDSL, or Single-pair High Speed
+ Digital Subscriber Line, S-HDSL) A form of {Digital Subscriber
+ Line} similar to {HDSL} but providing {T1} or {E1} connections
+ over a single {twisted-pair} copper line.
+
+ (1998-05-18)
+
+Single-pair High Speed Digital Subscriber Line
+
+ {Single-line Digital Subscriber Line}
+
+single program/multiple data
+
+ <parallel, architecture> (SPMD) A kind of {parallel
+ processing} where the same program is run on multiple
+ processors. Every instance of the program knows which part of
+ the computation it should perform and the results of the
+ computation are combined somehow.
+
+ (2002-04-21)
+
+single quote
+
+ <character> "'" {ASCII} character 39.
+
+ Common names include single quote; quote; {ITU-T}: apostrophe.
+ Rare: prime; glitch; tick; irk; pop; {INTERCAL}: spark;
+ {ITU-T}: closing single quotation mark; {ITU-T}: acute accent.
+
+ Single quote is used in {C} and derived languages to introduce
+ a single character {literal value} which is represented
+ internally by its ASCII code. In the {Unix} {shells} and
+ {Perl} single quote is used to delimit strings in which
+ variable substitution is not performed (in contrast to
+ {double-quote}-delimited strings).
+
+ Single quote is often used in text for both open and close
+ single quotation mark and apostrophe. Typesetters use two
+ different symbols - open has a tail going up, close and
+ apostrophe have tails hanging down (like a raised {comma}).
+ Some people use {back quote} (`) for open single quotation
+ mark.
+
+ (1998-04-04)
+
+single sign-on
+
+ <security> (SSO) Any user authentication system permiting
+ users to access multiple data sources through a single point
+ of entry. Part of an integrated access management framework.
+
+ (2003-12-31)
+
+single sourcing
+
+ <publication> Using a single original document set to generate
+ {dead tree} and on-line {documentation}, and usually also
+ on-line help. In practice, it most often refers to a
+ {FrameMaker} file set with {conditional text} which, when the
+ conditions are set appropriately, allows you to create
+ variants of the original document (e.g., for a product that
+ runs on different {Unix} {platforms}) as well as for different
+ media -- typically task-oriented on-line help to be accessed
+ under {Microsoft Windows} or from a {web browser}, linear
+ printed document, and {HTML} delivered via the {WWW} and/or
+ {CD-ROM}.
+
+single static assignment
+
+ <compiler> (Also known as SSA form) A special form of code
+ where each variable has only one single definition in the
+ program code. "Static" comes from the fact that the definition
+ site may be in a loop, thus dynamically executed several
+ times.
+
+ SSA form is used for program optimization or {static analysis}
+ and {optimisation}.
+
+ (2003-04-12)
+
+singleton variable
+
+ <programming> A {variable} which is only referred to once in a
+ piece of code, probably because of a programming mistake. To
+ be useful, a variable must be set and read from, in that
+ order. If it is only referred to once then it cannot be both
+ set and read.
+
+ There are various exceptions. {C}-like {assignment
+ operators}, e.g. "x += y", read and set x and return its new
+ value (they are abbreviations for "x = x+y", etc). A
+ {function} {argument} may be passed only for the sake of
+ uniformity or to support future enhancements. A good
+ {compiler} or a {syntax} checker like {lint} should report
+ singleton variables but also allow specific instances to be
+ marked as deliberate by the programmer.
+
+ (1997-12-20)
+
+Single Virtual Storage
+
+ {OS/VS2}
+
+siod
+
+ <language> (Scheme In One Defun or Scheme In One Day)
+ A small {Scheme} implementation in {C} by George Carrette
+ <gjc@world.std.com>, <gjc@mitech.com>. SIOD is arranged as a
+ set of subroutines that can be called from any main program
+ for the purpose of introducing an interpreted extension
+ language. It compiles to 20 kbytes of executable
+ ({VAX}/{VMS}). {Lisp} calls {C} and C calls Lisp
+ transparently.
+
+ SIOD supports symbols, strings, {arrays}, {hash coding}, file
+ i/o (binary, text, seek), data save/restore in binary and
+ text, interface to commercial {databases} such {Oracle} and
+ {Digital} {RDB}.
+
+ Version 3.0 runs on {VAX}/{VMS},{Unix}, {Sun-3}, {Sun-4},
+ {Amiga}, {Macintosh}, {MIPS}, {Cray}, {ALPHA}/{VMS}, {Windows
+ NT} and {OS/2}. It can be compiled by most {ANSI C} compilers
+ and {C++} compilers, e.g. {gcc} -Wall.
+
+ {(ftp://world.std.com/pub/gjc/)},
+ {(ftp://world.std.com/src/lisp/)}.
+
+ {Usenet} newsgroup: {news:comp.lang.scheme}.
+
+ (1994-02-18)
+
+SIP
+
+ 1. <protocol> {Session Initiation Protocol}.
+
+ 2. <text, standard> {Supplementary Ideographic Plane}.
+
+ (2003-12-26)
+
+SIPB
+
+ Student Information Processing Board, {MIT}.
+
+ {(http://mit.edu:8001/afs/athena.mit.edu/user/r/e/rei/WWW/GAME/sipbroom.html)}.
+
+SIPLAN
+
+ SIte PLANning computer language. Interactive language for
+ space planning. "Formal Languages for Site Planning",
+ C.I. Yessios in Spatial Synthesis for Computer-Aided Design,
+ C. Eastman ed, Applied Science Publ 1976.
+
+SIPP
+
+ {Single Inline Pin Package}
+
+SI prefix
+
+ <unit, standard> The {standard} metric prefixes used in the
+ {Système International d'Unités} (SI) conventions for
+ scientific measurement.
+
+ Here are the SI magnifying prefixes, along with the
+ corresponding binary interpretations in common use:
+
+ prefix abr decimal binary
+
+ yocto- 1000^-8
+ zepto- 1000^-7
+ atto- 1000^-6
+ femto- f 1000^-5
+ pico- p 1000^-4
+ nano- n 1000^-3
+ micro- * 1000^-2 * Abbreviation: Greek mu
+ milli- m 1000^-1
+
+ kilo- k 1000^1 1024^1 = 2^10 = 1,024
+ mega- M 1000^2 1024^2 = 2^20 = 1,048,576
+ giga- G 1000^3 1024^3 = 2^30 = 1,073,741,824
+ tera- T 1000^4 1024^4 = 2^40 = 1,099,511,627,776
+ peta- 1000^5 1024^5 = 2^50 = 1,125,899,906,842,624
+ exa- 1000^6 1024^6 = 2^60 = 1,152,921,504,606,846,976
+ zetta- 1000^7 1024^7 = 2^70 = 1,180,591,620,717,411,303,424
+ yotta- 1000^8 1024^8 = 2^80 = 1,208,925,819,614,629,174,706,176
+
+ "Femto" and "atto" derive not from Greek but from Danish.
+
+ The abbreviated forms of these prefixes are common in
+ electronics and physics.
+
+ When used with bytes of storage, these prefixes usually denote
+ multiplication by powers of 1024 = 2^10 (K, M, G and T are
+ common in computing). Thus "MB" stands for megabytes (2^20
+ bytes). This common practice goes against the edicts of the
+ {BIPM} who deprecate the use of these prefixes for powers of
+ two. The formal SI prefix for 1000 is lower case "k"; some,
+ including this dictionary, use this strictly, reserving upper
+ case "K" for multiplication by 1024 (KB is thus "kilobytes").
+
+ Also, in data transfer rates the prefixes stand for powers of
+ ten so, for example, 28.8 kb/s means 28,800 bits per second.
+
+ The unit is often dropped so one may talk of "a 40K salary"
+ (40000 dollars) or "2 meg of disk space" (2*2^20 bytes).
+
+ The accepted pronunciation of the initial G of "giga-" is
+ hard, /gi'ga/.
+
+ Confusing 1000 and 1024 (or other powers of 2 and 10 close in
+ magnitude) - for example, describing a memory in units of 500K
+ or 524K instead of 512K - is a sure sign of the {marketroid}.
+ For example, 3.5" {microfloppies} are often described as
+ storing "1.44 MB". In fact, this is completely specious. The
+ correct size is 1440 KB = 1440 * 1024 = 1474560 bytes. Alas,
+ this point is probably lost on the world forever.
+
+ In 1993, hacker Morgan Burke proposed, to general approval on
+ {Usenet}, the following additional prefixes: groucho (10^-30),
+ harpo (10^-27), harpi (10^27), grouchi (10^30). This would
+ leave the prefixes zeppo-, gummo-, and chico- available for
+ future expansion. Sadly, there is little immediate prospect
+ that Mr. Burke's eminently sensible proposal will be ratified.
+
+ (2009-09-01)
+
+Siprol
+
+ Signal Processing Language. A DSP language.
+
+ ["SIPROL: A High Level Language for Digital Signal
+ Processing", H. Gethoffer, Proc ICASSP-80, 1980,
+ pp.1056-1059].
+
+SIR
+
+ 1. <language> An early system on the {IBM 650}.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ 2. <standard> Serial Infrared. An {infrared} {standard} from
+ {IrDA}, part of {IrDA Data}. SIR supports {asynchronous}
+ communications at 9600 bps - 115.2 Kbps, at a distance of up
+ to 1 metre.
+
+ [Reference?]
+
+ (1999-10-14)
+
+SIRDS
+
+ {Single Image Random Dot Stereogram}
+
+Siri
+
+ An {object-oriented} {constraint language} using a single
+ abstraction mechanism developed by Bruce Horn of {CMU} in
+ 1991. Siri is a conceptual blend of {BETA} and {Bertrand}.
+ It is similar to {Kaleidoscope}.
+
+ ["Constraint Patterns as a Basis for Object-Oriented
+ Constraint Programming", B. Horn, OOPSLA '92 (Sept 1992)].
+
+ (1994-11-04)
+
+SIRTS
+
+ {Single Image Random Text Stereogram}. (Or {ASCII}
+ {stereogram}).
+
+SISAL
+
+ <language> (Streams and Iteration in a Single Assignment
+ Language) A general-purpose {single assignment} {functional
+ programming language} with {strict} semantics, automatic
+ parallelisation and efficient {arrays}. Outputs a dataflow
+ graph in {IF1} (Intermediary Form 1). Derived from {VAL},
+ adds {recursion} and finite {streams}. {Pascal}-like syntax.
+ Designed to be a common high-level language for numerical
+ programs on a variety of {multiprocessors}.
+
+ Implementations exist for {Cray X-MP}, {Cray Y-MP}, {Cray-2},
+ {Sequent}, {Encore Alliant}, {dataflow} architectures,
+ {transputers} and {systolic arrays}.
+
+ Defined in 1983 by James McGraw et al, {Manchester
+ University}, {Lawrence Livermore National Laboratory},
+ {Colorado State University} and {DEC}. Revised in 1985.
+ First compiled implementation in 1986. Performance superior
+ to {C} and competitive with {Fortran}, combined with efficient
+ and automatic parallelisation.
+
+ Not to be confused with {SASL}.
+
+ E-mail: John Feo <feo@llnl.gov>, Rod Oldehoeft
+ <rro@cs.colostate.edu>.
+
+ David C. Cann has written an {Optimising SISAL Compiler
+ (ftp://sisal.llnl.gov/pub/sisal)} (OSC) which attempts to make
+ efficient use of {parallel processors} such as {Crays}.
+
+ Latest version: 12.0, SISAL 1.2.
+
+ ["A Report on the SISAL Language Project", J.T. Feo et al, J
+ Parallel and Distrib Computing 10(4):349-366 (Dec 1990)].
+
+ (2000-07-07)
+
+sit
+
+ {Stuffit}
+
+SITBOL
+
+ <language> A {SNOBOL4} {interpreter} for the {PDP-10}.
+
+ ["SITBOL Version 3.0", J.F. Gimpel, TRS4D30b, Bell Labs,
+ 1973].
+
+ (1997-09-14)
+
+site map
+
+ <web> A {web page} listing the other main pages on
+ a {website} to help users find pages they want and see what
+ areas are available.
+
+ FOLDOC doesn't really have a site map but it does have a
+ {contents page (/contents.html)}.
+
+ (2009-03-07)
+
+sitename
+
+ {hostname}
+
+SIxteen Bit Organisers
+
+ <communications> (SIBO) {Psion}'s family of {PDA}s running
+ {EPOC}, including the MC200, MC400, Series 3 (1991-1998),
+ Series 3a, Series 3c, Series 3mx, Siena, Workabout and
+ Workabout mx.
+
+ (2009-05-26)
+
+sj
+
+ <networking> The {country code} for Svalbard and Jan Mayen
+ Islands.
+
+ (1999-01-27)
+
+sk
+
+ <networking> The {country code} for Slovakia.
+
+ (1999-01-27)
+
+Skel-ML
+
+ A parallel variant of {ML} using {skeletons} being developed
+ (April 1994) as part of Tore Bratvold's PhD in the Department
+ of Computing and Electronic Engineering, Heriot-Watt
+ University, Edinburgh, UK. Programs are written in a subset
+ of {Standard ML}, and parallelism is extracted from the use of
+ certain {higher-order functions}. The SkelML compiler uses
+ profiling information together with skeleton performance
+ models to distinguish useful from non-useful parallelism. An
+ important feature is the ability to perform transformations
+ between skeletons to improve performance. Skeletons currently
+ supported are map, filter, fold, pipe (implicitly extracted
+ from function application) and various combinations of these.
+
+ See also {paraML}.
+
+ E-mail: Tore A Bratvold <tore@cee.hw.ac.uk>.
+
+Sketchpad
+
+ A program that allowed users to draw on a screen with a {light
+ pen}. It supported constraints (e.g. drawing a constrained
+ ellipse produced a circle). It also had some {computer aided
+ design} features (e.g. computing loads on beams).
+
+ Sketchpad was the subject of {Ivan E. Sutherland}'s 1963 {MIT}
+ PhD thesis, which opened the field of {computer graphics}. It
+ was the progenitor of computer drawing packages like {MacDraw}
+ or {Adobe Illustrator}. There is a film of Sketchpad in
+ action.
+
+ It solved {constraints} using {value inference} and introduced
+ the "{ring}" list structure.
+
+ ["Sketchpad: A Man-Machine Graphical Communication System",
+ I.e. Sutherland, MIT Lincoln Lab, TR 296 (Jan 1963)].
+
+ [Sammet 1969, p. 678].
+
+ (1995-02-14)
+
+S/Key
+
+ {One-Time Password}
+
+Skill
+
+ A somewhat peculiar blend between {Franz-Lisp} and {C}, with a
+ large set of various {CAD} primitives. It is owned by
+ {Cadence Design Systems} and has been used in their CAD
+ frameworks since 1985. It's an {extension language} to the
+ CAD framework (in the same way that {Emacs-Lisp} extends {GNU
+ Emacs}), enabling you to automate virtually everything that
+ you can do manually in for example the graphic editor. Skill
+ accepts {C}-syntax, fun(a b), as well as {Lisp} syntax, (fun a
+ b), but most users (including Cadence themselves) use the
+ C-style.
+
+ [Jonas Jarnestrom <etxjojm@eua.ericsson.se>].
+
+ (1995-02-14)
+
+Skim
+
+ <language> A {Scheme} implementation with {packages} and other
+ enhancements, by Alain Deutsch et al, France.
+
+ (2000-11-02)
+
+SkipJack
+
+ <cryptography> An {encryption} {algorithm} created by the NSA
+ (National Security Agency) which encrypts 64-bit blocks of
+ data with an 80-bit key. It is used in the {Clipper} chip, a
+ {VLSI} device with an {ARM} processor core, which is intended
+ to perform cryptographic operations while allowing the
+ security agencies listen in.
+
+ There are (apparently) two agencies, both of whom have to
+ agree that there is a valid reason to decode a message. Don't
+ laugh, they are serious.
+
+ [Algorithm?]
+
+ (1995-12-07)
+
+SKOL
+
+ {Fortran} pre-processor for {COS} (Cray Operating System).
+
+skolemisation
+
+ A means of removing {quantifiers} from {first order logic}
+ formulas.
+
+ [Details?]
+
+S-K reduction machine
+
+ An {abstract machine} defined by Professor {David Turner} to
+ evaluate {combinator} expressions represented as {binary
+ graphs}. Named after the two basic combinators, S and K.
+
+skrog
+
+ {scrog}
+
+SKsh
+
+ Steve Koren/Korn shell. A {Unix} {ksh}-like {shell} which
+ runs under {AmigaDos} by Steve Koren
+ <koren@hpfcogv.fc.hp.com>. SKsh provides a {Unix}-like
+ environment but supports many {AmigaDos} features such as
+ {resident commands} and {ARexx}. Scripts can be written to
+ run under either {ksh} or SKsh and many of the useful {Unix}
+ commands such as {xargs}, {grep} and {find} are provided.
+
+ Latest version: 2.1.
+
+ {(ftp://hubcap.clemson.edu/pub/amiga/incom*/utils/SKsh021.lzh)}.
+
+ (1992-12-16)
+
+SKU
+
+ {stock-keeping unit}
+
+skulker
+
+ {prowler}
+
+SL
+
+ <processor> Features of some {Intel} processors, including the
+ {Pentium}, for reducing power consumption. These features
+ operate at two levels: the {microprocessor} and the system.
+ The processor can enter a low power state during
+ non-{processor intensive} tasks (such as {word processing}),
+ or a very low-power state when the computer is not in use
+ ("sleep" mode). At the system level, {system management mode}
+ can slow down, suspend, or completely shut down various system
+ components to save energy.
+
+ (1995-05-06)
+
+sl
+
+ <networking> The {country code} for Sierra Leone.
+
+ (1999-01-27)
+
+SL5
+
+ String and list processing language with expression-oriented
+ syntax. Coroutines.
+
+ ["An Overview of SL5", Ralph E. Griswold, SIGPLAN Notices
+ 12(4):40-50 (Apr 1977)].
+
+slack
+
+ 1. <operating system> Internal fragmentation. Space allocated
+ to a disk file but not actually used to store useful
+ information.
+
+ 2. <jargon> In the theology of the {Church of the SubGenius},
+ a mystical substance or quality that is the prerequisite of
+ all human happiness.
+
+ Since {Unix} files are stored compactly, except for the
+ unavoidable wastage in the last block or fragment, it might be
+ said that "Unix has no slack".
+
+ See {ha ha only serious}.
+
+ [{Jargon File}]
+
+ (1995-03-01)
+
+slackware
+
+ <operating system> A distribution of the {Linux} {operating
+ system} by Patrick Volkerding
+ <volkerdi@mhd1.moorhead.msus.edu>, <volkerdi@ftp.cdrom.com>.
+
+ {cdrom.com (ftp://ftp.cdrom.com/pub/linux/)}.
+
+ {FAQ
+ (ftp://sunsite.unc.edu/pub/Linux/distributions/slackware/SLAKWARE.FAQ)}.
+
+ {Sunsite Linux archives
+ (http://sunsite.unc.edu/pub/Linux/distributions/slackware/)}.
+
+ {Sunsite mirrors
+ (http://sunsite.unc.edu/pub/Linux/MIRRORS.html)}.
+
+ (1995-03-01)
+
+SLAM
+
+ 1. <language> {Simulation Language for Alternative
+ Modeling}.
+
+ 2. A continuous simulation language.
+
+ ["SLAM - A New Continuous Simulation Language",
+ N.A. Wallington et al, in SCS Simulation Council Proc Series:
+ Toward Real-Time Simulation (Languages, Models and Systems),
+ R.E. Crosbie et al eds, 6(1):85-89 (Dec 1976)].
+
+ (1995-03-03)
+
+SLANG
+
+ 1. R.A. Sibley. CACM 4(1):75-84 (Jan 1961).
+
+ 2. Set LANGuage. Jastrzebowski, ca 1990. C extension with
+ set-theoretic data types and garbage collection. "The SLANG
+ Programming Language Reference Manual, Version 3.3",
+ W. Jastrzebowski <wojtek@loml.math.yale.edu>, 1990.
+
+ 3. Structured LANGuage. Michael Kessler, IBM. A language
+ based on structured programming macros for IBM 370 assembly
+ language. "Project RMAG: SLANG (Structured Language)
+ Compiler", R.A. Magnuson, NIH-DCRT-DMB-SSS-UG105, NIH, DHEW,
+ Bethesda, MD 20205 (1980).
+
+ 4. "SLANG: A Problem Solving Language for Continuous-Model
+ Simulation and Optimisation", J.M. Thames, Proc 24th ACM Natl
+ Conf 1969.
+
+S-Lang
+
+ <language> A small but highly functional {embedded}
+ {interpreter}. S-Lang was a stack-based {postfix} language
+ resembling {Forth} and {BC}/{DC} with limited support for
+ {infix notation}. Now it has a {C}-like infix syntax.
+ {Arrays}, stings, integers, {floating-point} and {autoloading}
+ are all suported. The editor {JED} embeds S-lang.
+
+ S-Lang is available under the {GNU Library General Public
+ License}. It runs on {MS-DOS}, {Unix}, and {VMS}.
+
+ Latest version: 0.94, as of 1993-06-12.
+
+ {(ftp://amy.tch.harvard.edu/)}.
+
+ E-mail: John E. Davis <davis@tch.harvard.edu>.
+
+ (2000-10-30)
+
+slap on the side
+
+ (Also called a {sidecar}, or abbreviated "SOTS"). A type of
+ external expansion hardware marketed by computer manufacturers
+ (e.g. {Commodore} for the {Amiga} 500/1000 series and {IBM} for
+ the hideous failure called {IBM PCjr}). Various SOTS boxes
+ provided necessities such as memory, hard drive controllers,
+ and conventional expansion slots.
+
+ [{Jargon File}]
+
+slash
+
+ {oblique stroke}
+
+slashdot effect
+
+ <jargon> An effect where a document on a {WWW} {server} is
+ linked to from another, popular, site, with the resultant
+ traffic overloading the server so that a connection cannot be
+ made to it. This is especially likely if the server is
+ running {Microsoft IIS}.
+
+ The term was coined by readers of the {Unix} advocacy {web
+ site} {slashdot.org (http://slashdot.org/)}.
+
+ (1998-10-24)
+
+slave tty
+
+ (/dev/ttyp*) The half of a {pseudo-tty} which programs
+ (e.g. getty) read from and write to as though it was an
+ ordinary {serial line}.
+
+SLD resolution
+
+ <logic, programming> (Selected, Linear, Definite) {Linear
+ resolution} with a {selection function} for {definite
+ sentences}.
+
+ A definite sentence has exactly one {positive literal} in each
+ {clause} and this literal is selected to be resolved upon,
+ i.e. replaced in the {goal} clause by the {conjunction} of
+ {negative literals} which form the body of the clause.
+
+ [Why is SLD resolution important?]
+
+ (2003-12-04)
+
+sleep
+
+ 1. <operating system, multitasking> (Or "{block}") When a
+ {process} on a {multitasking} system asks the {scheduler} to
+ deactivate it until some given external event (e.g. an
+ {interrupt} or a specified time delay) occurs.
+
+ The alternative is to {poll} or "{busy wait}" for the event
+ but this uses processing power.
+
+ Also used in the phrase "sleep on" (or "block on") some
+ external event, meaning to wait for it.
+
+ E.g. the {Unix} command of the same name which pauses the
+ current process for a given number of seconds.
+
+ 2. <hardware> To go into partial deactivation to save power.
+
+ [{Jargon File}]
+
+ (2000-09-25)
+
+SLIB
+
+ {Scheme Library}
+
+Slide
+
+ <project> A now-retired {Jakarta} project to develop a
+ repository for content management. Slide is no longer in
+ development. It featured {WebDAV}, DeltaV WebDAV versioning,
+ different databases and file system storage, transactions and
+ locking, flexible permissions per file and more.
+
+ {Slide home (http://jakarta.apache.org/slide/)}.
+
+ (2008-06-04)
+
+sliding-window
+
+ <networking> A method of {flow control} in which a {receiver}
+ gives a {transmitter} permission to transmit {data} until a
+ {window} is full. When the window is full, the transmitter
+ must stop transmitting until the receiver advertises a larger
+ window.
+
+ {TCP}, other transport {protocols}, and several {link-layer
+ protocols} use this method of flow control.
+
+ (2002-12-02)
+
+SLIM
+
+ A VLSI language for translating DFA's into circuits.
+ J.L. Hennessy, "SLIM: A Simulation and Implementation Language
+ for VLSI Microcode", Lambda, Apr 1981, pp.20-28.
+
+ [{Jargon File}]
+
+slim
+
+ <jargon> A small, derivative change (e.g. to code).
+
+ (2003-05-13)
+
+Slingshot
+
+ <networking, business, tool, product, protocol> {CSK
+ Software}'s {real time} financial server for the {Internet}.
+
+ Slingshot allows the delivery of real time market data across
+ the {Internet} and private {intranets} quickly, cheaply and
+ securely. The first beta-test version was released free to
+ the Internet on 6 August 1996. Slingshot allows any financial
+ institution, regardless of size, to publish their rates and
+ associated information to a global audience using standard
+ Internet protocols and software. The {real-time} data can be
+ seamlessly integrated into any standard {web}
+ application and thus combined with static text, database
+ queries and even audio and video objects, to create services.
+
+ The Slingshot protocol enables the delivery of other forms of
+ real time data over the Internet, thus making Slingshot useful
+ in industries as varied as manufacturing, betting, telemetry,
+ weather, transport and medicine.
+
+ Version 2's improved protocol minimises the required
+ {bandwidth} and can go through {firewalls}, {proxies}, and
+ {virus scanners}, making Slingshot real-time data accessible
+ everywhere where normal web access is possible.
+
+ (2003-05-13)
+
+SLIP
+
+ 1. {Serial Line Internet Protocol}.
+
+ 2. Symmetric LIst Processsor. Early 1960's list processing
+ subroutine package for {Fortran} by J. Weizenbaum. Later also
+ embedded in {MAD} and {ALGOL}. ["Symmetric List Processor",
+ J. Weizenbaum CACM 6:524-544(1963). Sammet 1969, p.387].
+
+SlipKnot
+
+ <web> A graphical {web browser} specifically
+ designed for {Microsoft Windows} users who have {Unix} {shell
+ accounts} with their service providers. Its primary feature
+ is that it does not require {SLIP} or {PPP} or {TCP/IP}
+ services. SlipKnot is distributed as restricted shareware.
+
+ Version: 1.0.
+
+ {SlipKnot home (http://micromind.com/slipknot.htm)}.
+
+ E-mail: <slipknot@micromind.com>.
+
+ (2003-03-25)
+
+SLIPS
+
+ "An Interpreter for SLIPS - An Applicative Language Based on
+ Lambda-Calculus", V. Gehot et al, Comp Langs 11(1):1-14
+ (1986).
+
+SLiRP
+
+ <networking, tool> A {SLIP emulator} by Danny Gasparovski,
+ faster than {TIA}.
+
+ Version: 0.95H 12 Sep 95.
+
+ {(http://webcom.com/~llarrow/slirp.html)}.
+
+ (1995-09-15)
+
+SLLIC
+
+ <language> An intermediate language developed at {HP}. An
+ infinite-register version of the {Precision Architecture}
+ {instruction set}?
+
+ (1995-05-28)
+
+slog
+
+ {Schelog}
+
+Sloop
+
+ "Parallel Programming in a Virtual Object Space", S. Lucco,
+ SIGPLAN Notices 22(12):26-34 (OOPSLA '87) (Dec 1987).
+
+slop
+
+ <jargon> 1. A one-sided {fudge factor}, that is, an allowance
+ for error but in only one of two directions. For example, if
+ you need a piece of wire 10 feet long and have to guess when
+ you cut it, you make very sure to cut it too long, by a large
+ amount if necessary, rather than too short by even a little
+ bit, because you can always cut off the slop but you can't
+ paste it back on again. When discrete quantities are
+ involved, slop is often introduced to avoid the possibility of
+ being on the losing side of a {fencepost error}.
+
+ 2. The percentage of "extra" code generated by a compiler over
+ the size of equivalent {assembly code} produced by
+ {hand-hacking}; i.e. the space (or maybe time) you lose because
+ you didn't do it yourself. This number is often used as a
+ measure of the quality of a compiler; slop below 5% is very
+ good, and 10% is usually acceptable. Modern compilers,
+ especially on {RISCs}, may actually have *negative* slop; that
+ is, they may generate better code than humans. This is one of
+ the reasons assembler programming is becoming less common.
+
+ [{Jargon File}]
+
+ (1995-05-28)
+
+slopsucker
+
+ /slop'suhk-r/ A lowest-{priority} task that only runs when the
+ computer would otherwise be idle. Also called a "hungry
+ puppy" or "bottom feeder" (after the fishermen's and
+ naturalists' term for finny creatures who subsist on the
+ primordial ooze).
+
+ One common variety of slopsucker hunts for large {prime
+ numbers}.
+
+ Compare {background}.
+
+ [{Jargon File}]
+
+ (2003-09-29)
+
+slosh
+
+ {backslash}
+
+Slot 1
+
+ <hardware, standard> The physical and electrical specification
+ for the connector used by some of {Intel}'s {microprocessor}
+ cards, currently (August 1999) the {SEPP} {Celeron} and the
+ {SECC} {Pentium II}.
+
+ Slot 1 is a departure from the square {ZIF} {PGA}/{SPGA}
+ sockets used by {Pentium} and earlier processors, the
+ processor being mounted on a card, with a 242-lead
+ edge-connector.
+
+ The Slot 1 specification allows for higher {bus rates} than
+ {Socket 7}. Slot 1 motherboards use the {GTL+} {bus
+ protocol}.
+
+ See also {Slot 2}, {Slot A}.
+
+ [bus rates?]
+
+ (1999-08-04)
+
+Slot 2
+
+ <hardware, standard> A physical and electrical specification
+ for the 330-lead edge-connector used by some of {Intel}'s
+ {microprocessor} cards, currently (August 1999) the {SECC}
+ {Pentium III}/{Xeon}.
+
+ Slot 2 is intended for use in high end multi-processor
+ {workstations} and {servers}.
+
+ See also {Slot A}, {Slot 1}.
+
+ [Multi processor support?]
+
+ (1999-08-04)
+
+Slot A
+
+ <hardware> The physical and electrical specification for the
+ edge-connector used by {AMD}'s {Athlon} processor.
+
+ The connector allows for a higher {bus rate} than {Socket 7}
+ or {Super 7}. Slot A motherboards use {Compaq}'s {EV6} {bus
+ protocol}. Slot A is mechanically compatible but electrically
+ incompatible with {Intel}'s {Slot 1}.
+
+ (1999-08-05)
+
+slurp
+
+ To read a large data file entirely into {core} before working
+ on it. This may be contrasted with the strategy of reading a
+ small piece at a time, processing it, and then reading the
+ next piece. "This program slurps in a 1K-by-1K matrix and
+ does an FFT." See also {sponge}.
+
+ [{Jargon File}]
+
+sm
+
+ <networking> The {country code} for San Marino.
+
+ (1999-01-27)
+
+smail
+
+ {snail-mail}
+
+SMALGOL
+
+ SMall ALGOL.
+
+ A subset of {ALGOL 60}.
+
+ ["SMALGOL-61", G.A. Bachelor et al CACM 4(11):499-502 (Nov
+ 1961)].
+
+ [Sammet 1969].
+
+ (1995-01-31)
+
+SMALL
+
+ 1. Functional, lazy, untyped.
+
+ ["SMALL - A Small Interactive Functional System",
+ L. Augustsson, TR 28, U Goteborg and Chalmers U, 1986].
+
+ 2. A {toy language} used to illustrate {denotational
+ semantics}.
+
+ ["The Denotational Description of Programming Languages",
+ M.J.C. Gordon, Springer 1979].
+
+Small Business Edition
+
+ {Microsoft Office Small Business Edition}
+
+Small-C
+
+ A subset of {C}. The original compiler, written in {C} by Ron
+ Cain, appeared in Dr. Dobb's Journal. James E. Hendrix
+ improved and extended the original compiler and published "The
+ Small-C Handbook". Both these compilers produced {8080}
+ {assembly code}.
+
+ A Small-C compiler based on {RatC} produced {6502} {assembly
+ code} for the {BBC Microcomputer}. It was written in Small-C
+ and {bootstrap}ped using {Zorland C} on an {Amstrad PC1512}
+ under {MS-DOS} 3.2, then transferred onto a {BBC Micro} using
+ {Kermit}. The compiler can be used to cross-compile {6502}
+ code from an {MS-DOS} host, or as a {resident} Small-C
+ compiler on a BBC Micro. It runs on {68000}, {6809}, {VAX},
+ {8080}, {BBC Micro} and {Zilog Z80}.
+
+ Posted to comp.sources.unix volume 5.
+
+ {(ftp://apple.com/ArchiveVol1/Unix_lang)}.
+
+ ["Small-C"?, Ron Cain, Dr. Dobb's Journal, May 1980, Dec
+ 1982?]
+
+ ["The Small-C Handbook," James Hendrix, Reston 1984, ISBN
+ 0-8359-7012-4].
+
+ (1989-01-05)
+
+Small Computer System Interface
+
+ <hardware, standard> (SCSI) /skuh'zee/, /sek'si/ The most
+ popular processor-independent standard, via a parallel bus,
+ for system-level interfacing between a computer and
+ intelligent devices including {hard disks}, {floppy disks},
+ {CD-ROM}, {printers}, {scanners}, and many more.
+
+ SCSI can connect multiple devices to a single {SCSI adaptor}
+ (or "host adaptor") on the computer's bus. SCSI transfers bits
+ in parallel and can operate in either {asynchronous} or
+ {synchronous} modes. The synchronous transfer rate is up to
+ 5MB/s. There must be at least one {target} and one
+ {initiator} on the SCSI {bus}.
+
+ SCSI connections normally use "{single ended}" drivers as
+ opposed to {differential drivers}. Single ended SCSI can
+ suport up to six metres of cable. Differential ended SCSI can
+ support up to 25 metres of cable.
+
+ SCSI was developed by {Shugart Associates}, which later became
+ {Seagate}. SCSI was originally called SASI for "Shugart
+ Associates System Interface" before it became a standard.
+
+ Due to SCSI's inherent protocol flexibility, large support
+ infrastructure, continued speed increases and the acceptance
+ of SCSI Expanders in applications it is expected to hold its
+ market.
+
+ The original standard is now called "SCSI-1" to distinguish it
+ from {SCSI-2} and {SCSI-3} which include specifications of
+ {Wide SCSI} (a 16-bit bus) and {Fast SCSI} (10 MB/s transfer).
+
+ SCSI-1 has been standardised as {ANSI} X3.131-1986 and
+ {ISO}/{IEC} 9316.
+
+ A problem with SCSI is the large number of different
+ connectors allowed. Nowadays the trend is toward a 68-pin
+ {miniature D-type} or "high density" connector (HD68) for
+ {Wide SCSI} and a 50-pin version of the same connector (HD50)
+ for 8-bit SCSI (Type 1-4, pin pitch 1.27 mm x 2.45 mm).
+ 50-pin {ribbon cable} connectors are also popular for internal
+ wiring (Type 5, pin pitch 2.54 mm x 2.54 mm). {Apple
+ Computer} used a 25-pin connector on the {Macintosh} computer
+ but this connector causes problems with high-speed equipment.
+ Original SCSI implementations were highly incompatible with
+ each other.
+
+ {ASPI} is a standard {Microsoft Windows} interface to SCSI
+ devices.
+
+ {Usenet} newsgroup: {news:comp.periphs.scsi}.
+
+ {(news:comp.periphs.scsi)}.
+ SCSI Trade Association & FAQ {(http://scsita.org/)}.
+
+ ["System" or "Systems"?]
+
+ (1999-03-30)
+
+small-office/home-office
+
+ (SoHo) A term describing the market for certain computer goods.
+
+ (1995-01-11)
+
+Small Outline DIMM
+
+ <storage> (SO-DIMM) A smaller kind of {DIMM} with 72 pins
+ (supporting 32-bit transfers) or 144 pins (64-bit transfers).
+ Regular DIMMs have 168 pins and support 64-bit transfers.
+ Being roughly half the size of the regular DIMM, SO-DIMMs are
+ often used in {notebook computers}.
+
+ {Kingston Memory Guide
+ (http://kingston.com/tools/umg/newumg05a.asp)}.
+
+ (2001-02-16)
+
+Smalltalk
+
+ <language> The pioneering {object-oriented programming} system
+ developed in 1972 by the Software Concepts Group, led by {Alan
+ Kay}, at {Xerox PARC} between 1971 and 1983. It includes a
+ language, a programming environment, and an extensive object
+ library.
+
+ Smalltalk took the concepts of {class} and {message} from
+ {Simula-67} and made them all-pervasive. Innovations included
+ the {bitmap display}, windowing system, and use of a {mouse}.
+
+ The {syntax} is very simple. The fundamental construction is
+ to send a message to an {object}:
+
+ object message
+
+ or with extra parameters
+
+ object message: param1 secondArg: param2 .. nthArg: paramN
+
+ where "secondArg:" etc. are considered to be part of the
+ message name.
+
+ Five pseudo-variables are defined: "self", "super", "nil",
+ "true", "false". "self" is the receiver of the current
+ message. "super" is used to delegate processing of a message
+ to the {superclass} of the receiver. "nil" is a reference to
+ "nothing" (an instance of UndefinedObject). All variables
+ initially contain a reference to nil. "true" and "false" are
+ {Booleans}.
+
+ In Smalltalk, any message can be sent to any object. The
+ recipient object itself decides (based on the message name,
+ also called the "message selector") how to respond to the
+ message. Because of that, the {multiple inheritance} system
+ included in the early versions of Smalltalk-80 appeared to be
+ unused in practice. All modern implementations have single
+ inheritance, so each class can have at most one superclass.
+
+ Early implementations were {interpreted} but all modern ones
+ use {dynamic translation} (JIT).
+
+ Early versions were Smalltalk-72, Smalltalk-74, Smalltalk-76
+ (inheritance taken from Simula, and concurrency), and
+ Smalltalk-78, {Smalltalk-80}. Other versions include {Little
+ Smalltalk}, {Smalltalk/V}, {Kamin's interpreters}. Current
+ versions are {VisualWorks}, {Squeak}, {VisualAge}, {Dolphin
+ Smalltalk}, {Object Studio}, {GNU Smalltalk}.
+
+ See also: {International Smalltalk Association}.
+
+ {UIUC Smalltalk archive (http://st-www.cs.uiuc.edu/)}.
+ {FAQ (http://XCF.Berkeley.EDU/pub/misc/smalltalk/FAQ/)}.
+
+ {Usenet} newsgroup: {news:comp.lang.smalltalk}.
+
+ ["The Smalltalk-76 Programming System Design and
+ Implementation", D.H. Ingalls, 5th POPL, ACM 1978, pp. 9-16].
+
+ (2001-09-11)
+
+Smalltalk-80
+
+ <language> The classic standard {Smalltalk} dialect, described
+ in Adele's book, cited below, commonly known as "The Blue
+ Book".
+
+ ["Smalltalk-80: The Language and Its Implementation", Adele
+ Goldberg et al, A-W 1983].
+
+ [BYTE 6(8), Aug 1981].
+
+ {(ftp://st.cs.uiuc.edu/pub/ISA)},
+ {(ftp://st.cs.uiuc.edu/pub/Smalltalk/MANCHESTER)},
+ {(ftp://gnu.org/pub/gnu)}.
+
+ Mail server: goodies-lib@r5.cs.man.ac.uk.
+
+ (2004-12-14)
+
+Smalltalk/V
+
+ The first widely available version of {Smalltalk}, developed
+ by {Digitalk} in 1986 for {IBM PC} and {Macintosh}.
+
+ (1995-02-14)
+
+SmallVDM
+
+ <tool>
+
+ ["SmallVDM: An Environment for Formal Specification and
+ Prototyping in Smalltalk", in Object Oriented Specification
+ Case Studies, K. Lano et al eds, P-H 1993].
+
+ (1996-04-20)
+
+SMALLWORLD
+
+ <legal> A trademark of {Smallworldwide
+ Plc. (http://smallworld.co.uk/)}.
+
+ (1999-08-26)
+
+SmallWorld
+
+ <language> An {object-oriented} language.
+
+ ["SW 2 - An Object-based Programming Environment", M.R. Laff
+ et al, IBM TJWRC, 1985].
+
+ (1996-04-20)
+
+Smarandache logic
+
+ {neutrosophic logic}
+
+SMART
+
+ For {MS-DOS}?
+
+ [{Jargon File}]
+
+smart
+
+ 1. <programming> Said of a program that does the {Right Thing}
+ in a wide variety of complicated circumstances. There is a
+ difference between calling a program smart and calling it
+ intelligent; in particular, there do not exist any intelligent
+ programs (yet - see {AI-complete}).
+
+ Compare {robust} (smart programs can be {brittle}).
+
+ 2. <hardware> Incorporating some kind of digital electronics.
+
+ (1995-03-28)
+
+Smart Battery Data
+
+ <hardware, protocol> (SBD) A method to monitor a rechargeable
+ battery pack, initiated by {Duracell} and {Intel}. An special
+ {IC} in the battery pack monitors the battery and reports
+ information to the {SMBus}. This information might include:
+ type, model number, manufacturer, characteristics, discharge
+ rate, predicted remaining capacity, almost-discharged alarm so
+ that the PC can shut down gracefully; temperature and voltage
+ to provide safe fast-charging.
+
+ {Smart Battery System Implementers Forum
+ (http://sbs-forum.org/)}.
+
+ (1999-08-08)
+
+smart card
+
+ Any plastic card (like a credit card) with an embedded
+ {integrated circuit} for storing information.
+
+ Smart cards are being incorporated into soldier's dog-tags and
+ used to store hospital patients' medical records. This way
+ they are always instantly accessible.
+
+ Other uses are as a form of token in banking systems. You
+ could store electronic money on the card or less valuable
+ tokens such as those given away by petrol companies which you
+ collect to exchange for free gifts at a later date. The idea
+ being that one smart card is easier to carry around than a
+ multitude of paper tokens.
+
+ {news:alt.technology.smartcards}
+
+ (1995-01-06)
+
+Smartdrive
+
+ <storage, product> A {Microsoft} {MS DOS} {disk cache} program
+ to speed up disk access.
+
+ For most users, a 1MB cache is sufficient. Devoting more
+ memory to the cache offers diminishing returns, since the
+ additional cache hits become fewer (and the extra memory could
+ be better used to reduce {swapping}).
+
+ Typing SMARTDRV /S at a DOS prompt shows the cache size, a
+ hit-and-miss report, and information about which drives are
+ being cached. The hit-and-miss statistics are crucial for
+ gauging the effectiveness of SmartDrive settings. A score in
+ the high 80s shows that SmartDrive is well configured. Run
+ SMARTDRV /S several times during a Windows session and note
+ the-hit-and-miss figures each time. If your percentage
+ usually falls below 80 percent, you should consider increasing
+ the cache size. You can edit the SMARTDRV line in your
+ {AUTOEXEC.BAT} file to increase both the InitCacheSize and the
+ WinCacheSize parameters.
+
+ SmartDrive Monitor is an undocumented Windows program that
+ comes with DOS 6.0 for logging and controling the cache.
+
+ (1995-11-22)
+
+SMARTdrv
+
+ {Smartdrive}
+
+smart terminal
+
+ {intelligent terminal}
+
+smash case
+
+ {case sensitivity}
+
+smash sum
+
+ {coalesced sum}
+
+smash the stack
+
+ <jargon> In {C} programming, to corrupt the execution stack by
+ writing past the end of a local array or other data structure.
+ Code that smashes the stack can cause a return from the
+ routine to jump to a random address, resulting in insidious
+ data-dependent {bugs}.
+
+ Variants include "trash" the stack, {scribble} the stack,
+ {mangle} the stack.
+
+ See {spam}; see also {aliasing bug}, {fandango on core},
+ {memory leak}, {memory smash}, {precedence lossage}, {overrun
+ screw}.
+
+ [{Jargon File}]
+
+ (1995-03-16)
+
+SMB
+
+ 1. <protocol> {Server Message Block}.
+
+ 2. <hardware, protocol> {System Management Bus}.
+
+ (1999-08-08)
+
+smbclient
+
+ {Samba}
+
+smblib
+
+ {Samba}
+
+SMBus
+
+ {System Management Bus}
+
+SMCC
+
+ {Sun Microsystems} Computer Corporation.
+
+SMDS
+
+ {Switched Multimegabit Data Service}
+
+SMG
+
+ Screen Management Guidelines. A {VMS} package of run-time
+ library routines providing windows on {DEC} {VT100} terminals.
+
+SMI
+
+ {Structure of Management Information}
+
+SMIL
+
+ 1. <language> The {machine language} for a Swedish computer.
+
+ {(ftp://ftp.wustl.edu/mirrors/info-mac/lang/smil-emulator.hqx)}.
+
+ 2. <hypertext, language, multimedia, text, web>
+ {Synchronized Multimedia Integration Language}.
+
+ (2000-04-21)
+
+smiley
+
+ {emoticon}
+
+smilies
+
+ {emoticon}
+
+S-MIME
+
+ {Secure Multipurpose Internet Mail Extensions}
+
+SML
+
+ 1. {Standard ML}.
+
+ 2. Small Machine Language. Barnes, ICI 1969. Real-time
+ language, an ALGOL variant, and the predecessor of RTL. "SML
+ User's Guide", J.G.P. Barnes, ICI, TR JGPB/69/35 (1969).
+
+SML#
+
+ An extension of SML/NJ with polymorphic field selection and
+ nondestructive field update. "A Compilation Method for
+ ML-style Polymorphic Record Calculi", A. Ohori, POPL 1992.
+
+ {(ftp://ftp.cis.upenn.edu/pub/sml#/)}.
+
+sml2c
+
+ A Standard ML to C compiler. sml2c is a batch compiler and
+ compiles only module-level declarations, i.e. signatures,
+ structures and functors. It provides the same pervasive
+ environment for the compilation of these programs as SML/NJ.
+ As a result, module-level programs that run on SML/NJ can be
+ compiled by sml2c without any changes. Based on SML/NJ
+ version 0.67 and shares front end and most of its run-time
+ system, but does not support SML/NJ style debugging and
+ profiling.
+
+ School of Computer Science, Carnegie Mellon University
+
+ {(ftp://dravido.soar.cs.cmu.edu/usr/nemo/sml2c/sml2c.tar.Z)}.
+ {Linux
+ (ftp://ftp.dcs.glasgow.ac.uk/pub/linux/smlnj-0.82-linux.tar.Z)}.
+
+ conformance: superset
+ + first-class continuations,
+ + asynchronous signal handling
+ + separate compilation
+ + freeze and restart programs
+
+ ports: IBM-RT Decstation3100 Omron-Luna-88k Sun-3 Sun-4
+ 386(Mach)
+
+ portability: easy, easier than SML/NJ
+
+ E-mail: <david.tarditi@cs.cmu.edu>, <peter.lee@cs.cmu.edu>
+
+ (1991-06-27)
+
+SML/NJ
+
+ {Standard ML of New Jersey}
+
+SMM
+
+ {System Management Mode}
+
+SMNP
+
+ Do you mean "{SNMP}"? If not, please tell me.
+
+smoke
+
+ 1. To {crash} or blow up, usually spectacularly. "The new
+ version smoked, just like the last one." Used for both
+ hardware (where it often describes an actual physical event),
+ and software (where it's merely colourful).
+
+ 2. [Automotive slang] To be conspicuously fast. "That
+ processor really smokes." Compare {magic smoke}.
+
+ [{Jargon File}]
+
+smoke and mirrors
+
+ Marketing deceptions. The term is mainstream in this general
+ sense. Among hackers it's strongly associated with bogus
+ demos and crocked {benchmarks} (see also {MIPS},
+ {machoflops}). "They claim their new box cranks 50 MIPS for
+ under $5000, but didn't specify the instruction mix - sounds
+ like smoke and mirrors to me." The phrase has been said to
+ derive from carnie slang for magic acts and "freak show"
+ displays that depend on "trompe l"oeil' effects, but also
+ calls to mind the fierce Aztec god Tezcatlipoca (lit. "Smoking
+ Mirror") for whom the hearts of huge numbers of human
+ sacrificial victims were regularly cut out. Upon hearing
+ about a rigged demo or yet another round of fantasy-based
+ marketing promises, hackers often feel analogously
+ disheartened.
+
+smoke-emitting diode
+
+ <humour, electronics> (From "{light-emitting diode}") An
+ incorrectly connected {diode}, probably a {light-emitting
+ diode}, in the process of losing its {magic smoke} and
+ becoming a {friode}.
+
+ See also {LER}.
+
+ (1996-04-28)
+
+smoke test
+
+ 1. A rudimentary form of testing applied to electronic
+ equipment following repair or reconfiguration, in which power
+ is applied and the tester checks for sparks, smoke, or other
+ dramatic signs of fundamental failure. See {magic smoke}.
+
+ 2. By extension, the first run of a piece of software after
+ construction or a critical change. See and compare {reality
+ check}.
+
+ There is an interesting semi-parallel to this term among
+ typographers and printers: When new typefaces are being
+ punch-cut by hand, a "smoke test" (hold the letter in candle
+ smoke, then press it onto paper) is used to check out new
+ dies.
+
+ [{Jargon File}]
+
+smoking clover
+
+ [ITS] A {display hack} originally due to Bill Gosper. Many
+ convergent lines are drawn on a colour monitor in {AOS} mode
+ (so that every pixel struck has its colour incremented). The
+ lines all have one endpoint in the middle of the screen; the
+ other endpoints are spaced one pixel apart around the
+ perimeter of a large square. The colour map is then
+ repeatedly rotated. This results in a striking, rainbow-hued,
+ shimmering four-leaf clover. Gosper joked about keeping it
+ hidden from the FDA (the US's Food and Drug Administration)
+ lest its hallucinogenic properties cause it to be banned.
+
+SMoLCS
+
+ Specification metalanguage used for a formal definition of
+ Ada. "An Introduction to the SMoLCS Methodology",
+ E. Astesiano, U Genova 1986.
+
+SMOP
+
+ /S-M-O-P/ [Simple (or Small) Matter of Programming] 1. A piece
+ of code, not yet written, whose anticipated length is
+ significantly greater than its complexity. Used to refer to a
+ program that could obviously be written, but is not worth the
+ trouble. Also used ironically to imply that a difficult
+ problem can be easily solved because a program can be written
+ to do it; the irony is that it is very clear that writing such
+ a program will be a great deal of work. "It's easy to enhance
+ a Fortran compiler to compile COBOL as well; it's just an
+ SMOP." 2. Often used ironically by the intended victim when a
+ suggestion for a program is made which seems easy to the
+ suggester, but is obviously (to the victim) a lot of work.
+
+ [{Jargon File}]
+
+SMP
+
+ 1. {Symbol Manipulation Program}.
+
+ 2. <computer, parallel> {symmetric multiprocessing}.
+
+ (1995-03-19)
+SMPS
+
+ {switch mode power supply}
+
+SMPT
+
+ <spelling> Do you mean {SMTP}?
+
+ (2003-11-24)
+
+SMRP
+
+ {Simplified Multicast Routing Protocol}
+
+SMS
+
+ 1. <messaging> {Short Message Service}.
+
+ 2. <storage> {Storage Management Services}.
+
+ 3. <operating system> {System Management Server}.
+
+ (1999-05-02)
+
+SMT
+
+ {Station Management}
+
+SMTP
+
+ {Simple Mail Transfer Protocol}
+
+smug report
+
+ <humour> A {bug report} submitted by a user who thinks he
+ knows more about the system's design than he really does,
+ filled with irrelevant technical details and (incorrect)
+ suggestions about the cause and solution of the problem.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2011-11-30)
+
+smurf
+
+ <jargon> /smerf/ (From the {news:soc.motss} {Usenet}
+ newsgroup, after some obnoxiously gooey cartoon characters) A
+ newsgroup regular with a habitual style that is irreverent,
+ silly, and cute. Like many other hackish terms for people,
+ this one may be praise or insult depending on who uses it. In
+ general, being referred to as a smurf is probably not going to
+ make your day unless you've previously adopted the label
+ yourself in a spirit of irony.
+
+ Compare {old fart}.
+
+ [{Jargon File}]
+
+ (1995-10-25)
+
+sn
+
+ <networking> The {country code} for Senegal.
+
+ (1999-01-27)
+
+SNA
+
+ {Systems Network Architecture}
+
+snacc
+
+ <tool> (Sample Neufeld {ASN.1} to {C/C++} Compiler) A program
+ by Mike Sample <msample@opentext.com> which compiles 1990
+ {ASN.1} data structures (including some {macros}) into {C},
+ {C++} or type tables. The generated {C/C++} includes a .h
+ file with the equivalent data struct and a .c/.C file for the
+ {BER} encode and decode, print and free routines.
+
+ snacc includes the compiler, run-time BER libraries, and
+ utility programs. snacc is compiled under {GNU} {General
+ Public License}. It requires {yacc} or {bison}, {lex} or
+ {flex}, and {cc} (ANSI or non-ANSI).
+
+ ITU TS X.208/ISO 8824.
+
+ Latest version: 1.1, as of 1993-07-12.
+
+ {Home
+ (http://fokus.gmd.de/ovma/freeware/snacc/entry.html)}.
+
+ E-mail: <snacc-bugs@cs.ubc.ca>.
+
+ [Michael Sample and Gerald Neufeld, "Implementing Efficient
+ Encoders and Decoders for Network Data Representations", IEEE
+ INFOCOM '93 Proceedings, Vol 3, pp. 1143-1153, Mar 1993].
+
+ [Michael Sample, "How Fast Can ASN.1 Encoding Rules Go?",
+ M.Sc. Thesis, University of British Columbia, Apr 1993].
+
+ (1998-08-09)
+
+snaf
+
+ {chad}
+
+SNAFU principle
+
+ /sna'foo prin'si-pl/ [WWII Army acronym for "Situation Normal:
+ All Fucked Up"] "True communication is possible only between
+ equals, because inferiors are more consistently rewarded for
+ telling their superiors pleasant lies than for telling the
+ truth." - a central tenet of {Discordianism}, often invoked
+ by hackers to explain why authoritarian hierarchies screw up
+ so reliably and systematically. The effect of the SNAFU
+ principle is a progressive disconnection of decision-makers
+ from reality. This lightly adapted version of a fable dating
+ back to the early 1960s illustrates the phenomenon perfectly:
+
+ In the beginning was the plan,
+ and then the specification;
+ And the plan was without form,
+ and the specification was void.
+
+ And darkness
+ was on the faces of the implementors thereof;
+ And they spake unto their leader,
+ saying:
+ "It is a crock of shit,
+ and smells as of a sewer."
+
+ And the leader took pity on them,
+ and spoke to the project leader:
+ "It is a crock of excrement,
+ and none may abide the odor thereof."
+
+ And the project leader
+ spake unto his section head, saying:
+ "It is a container of excrement,
+ and it is very strong, such that none may abide it."
+
+ The section head then hurried to his department manager,
+ and informed him thus:
+ "It is a vessel of fertilizer,
+ and none may abide its strength."
+
+ The department manager carried these words
+ to his general manager,
+ and spoke unto him
+ saying:
+ "It containeth that which aideth the growth of plants,
+ and it is very strong."
+
+ And so it was that the general manager rejoiced
+ and delivered the good news unto the Vice President.
+ "It promoteth growth,
+ and it is very powerful."
+
+ The Vice President rushed to the President's side,
+ and joyously exclaimed:
+ "This powerful new software product
+ will promote the growth of the company!"
+
+ And the President looked upon the product,
+ and saw that it was very good.
+
+ After the subsequent disaster, the {suits} protect themselves
+ by saying "I was misinformed!", and the implementors are
+ demoted or fired.
+
+ [{Jargon File}]
+
+snag
+
+ {bug}
+
+snail mail
+
+ <messaging> (Or "snailmail", "smail" from "US Mail" via
+ "USnail"; "paper mail"). Bits of {dead tree} sent via the
+ postal service as opposed to {electronic mail}. One's postal
+ address is, correspondingly, a "snail (mail) address". There
+ have even been parody USnail posters and stamps made.
+
+ The variant "paper-net" is a hackish way of referring to the
+ postal service, comparing it to a very slow, low-reliability
+ {network}. {Sig blocks} sometimes include a "Paper-Net:"
+ header just before the sender's postal address; common
+ variants of this are "Papernet" and "P-Net". Note that the
+ standard {netiquette} guidelines discourage this practice as a
+ waste of bandwidth, since netters are quite unlikely to
+ casually use postal addresses and if they really wanted your
+ {snail mail} address they could always ask for it by e-mail.
+
+ Compare {voice-net}, {sneakernet}, {P-mail}.
+
+ (1995-01-31)
+
+SNAP
+
+ <language> 1. An early ({IBM 360}?) interpreted
+ text-processing language for beginners, close to basic
+ English.
+
+ ["Computer Programming in English", M.P. Barnett, Harcourt
+ Brace 1969].
+
+ 2. ["Some Proposals for SNAP, A Language with Formal Macro
+ Facilities", R.B. Napper, Computer J 10(3):231-243, 1967].
+
+ [Same as 1?]
+
+ (2006-05-27)
+
+snap
+
+ 1. <programming> To remove indirection, e.g. by replacing a
+ {pointer} to a pointer with a pointer to the final target (see
+ {chase pointers}).
+
+ The underlying metaphor may be a rubber band stretched through
+ a number of points; if you release it from the intermediate
+ points, it snaps to a straight line from first to last.
+
+ Often a {trampoline} performs an error check once and then
+ snaps the pointer that invoked it so subsequent calls will
+ bypass the trampoline (and its one-shot error check). In this
+ context one also speaks of "snapping links". For example, in
+ a {Lisp} implementation, a function interface trampoline might
+ check to make sure that the caller is passing the correct
+ number of arguments; if it is, and if the caller and the
+ callee are both compiled, then snapping the link allows that
+ particular path to use a direct procedure-call instruction
+ with no further overhead.
+
+ [{Jargon File}]
+
+ (2006-05-27)
+
+ 2. <operating system> {snap dump}.
+
+ (2006-05-27)
+
+snap dump
+
+ <operating system> A {memory dump}, often partial, requested
+ by a program to display its current status for debugging.
+ Program execution often continues normally following a snap
+ dump, as opposed to a {crash dump}.
+
+ [Short for "snapshot"?]
+
+ (2006-05-27)
+
+Snappy
+
+ {Snappy Video Snapshot}
+
+Snappy Video Snapshot
+
+ <hardware> (registered trademark) A {frame grabber} for the
+ {IBM PC} designed and marketed by {Play, Inc.}.
+
+ (1997-07-11)
+
+snarf
+
+ /snarf/ 1. To grab, especially to grab a large document or
+ file for the purpose of using it with or without the author's
+ permission.
+
+ See also {BLT}.
+
+ 2. ({Unix}) To fetch a file or set of files across a network.
+
+ See also {blast}.
+
+ 3. To acquire, with little concern for legal forms or
+ politesse (but not quite by stealing). "They were giving away
+ samples, so I snarfed a bunch of them."
+
+ 4. Synonym for {slurp}. "This program starts by snarfing the
+ entire database into core."
+
+ 5. ({GEnie}) To spray food or {programming fluids} due to
+ laughing at the wrong moment. This sense appears to be
+ widespread among mundane teenagers - ESR.
+
+ 6. This term was mainstream in the late 1960s, meaning "to eat
+ piggishly". It may still have this connotation in context.
+
+ 7. A creature on the Thundercats, fond of eating, usually
+ covertly.
+
+ [{Jargon File}]
+
+ (1995-02-21)
+
+snarf & barf
+
+ /snarf'n-barf`/ Under a {WIMP} environment, the act of
+ grabbing a region of text and then stuffing the contents of
+ that region into another region (or the same one) to avoid
+ retyping a command line. In the late 1960s, this was a
+ mainstream expression for an "eat now, regret it later" cheap
+ restaurant expedition.
+
+ [{Jargon File}]
+
+ (1994-11-04)
+
+snarf down
+
+ To {snarf}, with the connotation of absorbing, processing, or
+ understanding. "I'll snarf down the latest version of the
+ {nethack} user's guide - it's been a while since I last
+ played."
+
+ [{Jargon File}]
+
+ (1994-11-04)
+
+snark
+
+ [Lewis Carroll, via the Michigan Terminal System] 1. A system
+ failure. When a user's process bombed, the operator would get
+ the message "Help, Help, Snark in MTS!"
+
+ 2. More generally, any kind of unexplained or threatening
+ event on a computer (especially if it might be a boojum).
+ Often used to refer to an event or a log file entry that might
+ indicate an attempted security violation. See {snivitz}.
+
+ 3. UUCP name of snark.thyrsus.com, home site of the Hacker
+ {Jargon File} versions 2.*.*.
+
+ [{Jargon File}]
+
+sneakernet
+
+ /snee'ker-net/ Term used (generally with ironic intent) for
+ transfer of electronic information by physically carrying
+ tape, disks, or other media from one machine to another.
+
+ "Never underestimate the bandwidth of a station wagon filled
+ with magtape, or a 747 filled with CD-ROMs."
+
+ Also called tennis-net, armpit-net, floppy-net, shoe-net,
+ walk-net, foot-net.
+
+ (2003-07-02)
+
+sneck
+
+ <jargon> The sound made by {deboursification}, according to
+ Sam Spade anti-{spam} software.
+
+ (1999-09-15)
+
+snert
+
+ <abuse> A derogatory term commonly used on the {Internet}
+ {ECHO} {BBS}, echonyc.com, meaning to "make overtures of a
+ sexual nature". It implies terminal cluelessness.
+
+ (1995-03-01)
+
+SNI
+
+ {Siemens Nixdorf Informationssteme, AG}
+
+Sniff
+
+ A {C++}/{C} programming environment providing browsing,
+ cross-referencing, design visualisation, documentation and
+ editing support. Developed by UBS Switzerland and marketed by
+ takeFive Salzburg.
+
+ [{Jargon File}]
+
+sniff
+
+ {poll}
+
+sniffer
+
+ {packet sniffer}
+
+snivitz
+
+ <jargon> /sniv'itz/ A hiccup in hardware or software; a small,
+ transient problem of unknown origin (less serious than a
+ {snark}).
+
+ Compare {glitch}.
+
+ [{Jargon File}]
+
+ (1995-03-28)
+
+SNMP
+
+ {Simple Network Management Protocol}
+
+SNMP agent
+
+ <networking> A software process that responds to queries using
+ the {Simple Network Management Protocol} to provide status and
+ statistics about a network {node}.
+
+ (1995-11-11)
+
+SNMPv2
+
+ {Simple Network Management Protocol version 2}
+
+SNOBOL
+
+ {String Oriented Symbolic Language}
+
+SNOBOL2
+
+ A {SNOBOL} variant which existed only briefly. It featured
+ built-in functions, but not programmer-defined ones.
+
+ ["SNOBOL2", D.J. Farber, R.E. Griswold and I.P. Polonsky, TR
+ Bell Labs, Apr 1964].
+
+SNOBOL3
+
+ {SNOBOL} with user-defined functions. Written in 1965. The
+ SNOBOL 6.3 compiler for the {PDP-6} and {PDP-10} was written
+ in SNOBOL.
+
+ ["The SNOBOL3 Programming Language", D.J. Farber et al, Bell
+ Sys Tech J 45(6):895-944 (Jul 1966)].
+
+ (1994-11-04)
+
+SNOBOL4
+
+ <language> A quite distinct descendant of {SNOBOL}, developed
+ by Griswold et al in 1967. SNOBOL4 is {declarative} with
+ {dynamic scope}. Patterns are {first-class} data objects that
+ can be constructed by concatenation and alternation. Success
+ and failure are used for {flow control}. Delayed
+ (unevaluated) expressions can be used to implement
+ {recursion}. It has a table data type. Strings generated at
+ run time can be treated as programs and executed.
+
+ See also {vanilla}.
+
+ {SNOBOL 4 (http://snobol4.org/)}.
+
+ {(ftp://apple.com/ArchiveVol1/Unix_lang)}.
+
+ {A FOLDOC parser in SNOBOL4
+ (http://www.topcat.hypermart.net/foldoc.html)}!
+
+ ["The SNOBOL4 Programming Language", Ralph E. Griswold et al,
+ P-H 1971].
+
+ (2011-01-05)
+
+SNOOPS
+
+ Craske, 1988. An extension of SCOOPS with meta-objects that
+ can redirect messages to other objects. "SNOOPS: An
+ Object-Oriented language Enhancement Supporting Dynamic
+ Program Reeconfiguration", N. Craske, SIGPLAN Notices 26(10):
+ 53-62 (Oct 1991).
+
+'Snooze
+
+ /snooz/ [FidoNet] Fidonews, the weekly official on-line
+ newsletter of FidoNet. As the editorial policy of Fidonews is
+ "anything that arrives, we print", there are often large
+ articles completely unrelated to FidoNet, which in turn tend
+ to elicit {flamage} in subsequent issues.
+
+ [{Jargon File}]
+
+SNPP
+
+ {Simple Network Paging Protocol}
+
+SNR
+
+ {signal-to-noise ratio}
+
+S/N ratio
+
+ {signal-to-noise ratio}
+
+SNR bandwidth product
+
+ <communications> The {integral} of the {SNR} over {frequency}.
+ The SNR bandwidth product is an important limit in the
+ capacity of a communication channel.
+
+ (2003-07-20)
+
+SO
+
+ 1. <character> {Shift Out}
+
+ 2. Significant Other, almost invariably written abbreviated
+ and pronounced /S-O/ by hackers. Used to refer to one's
+ primary relationship, especially a live-in to whom one is not
+ married.
+
+ [{Jargon File}]
+
+so
+
+ <networking> The {country code} for Somalia.
+
+ (1999-01-27)
+
+SO 2
+
+ An early system on {IBM 701}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1994-11-04)
+
+SOA
+
+ 1. <architecture> {service-oriented architecture}.
+
+ 2. <networking> {start of authority}.
+
+SOAP
+
+ 1. <protocol> {Simple Object Access Protocol}.
+
+ 2. <language> {Symbolic Optimal Assembly Program}.
+
+ (2001-03-23)
+
+SOAR
+
+ 1. State, Operator And Result. A general problem-solving
+ {production system} architecture, intended as a model of human
+ intelligence. Developed by A. Newell in the early 1980s.
+ SOAR was originally implemented in {Lisp} and {OPS5} and is
+ currently implemented in {Common Lisp}. Version: Soar6.
+
+ E-mail: <soar@cs.cmu.edu>.
+
+ ["The SOAR Papers", P.S. Rosenbloom et al eds, MIT Press
+ 1993].
+
+ (1994-11-04)
+
+ 2. Smalltalk On A RISC. A {RISC} {microprocessor} designed by
+ David Patterson's at Berekeley.
+
+ (1994-11-04)
+
+social engineering
+
+ <jargon, security> A term used among {crackers} and {samurai}
+ for cracking techniques that rely on weaknesses in {wetware}
+ rather than software; the aim is to trick people into
+ revealing passwords or other information that compromises a
+ target system's security. Classic scams include phoning up a
+ mark who has the required information and posing as a field
+ service tech or a fellow employee with an urgent access
+ problem. See also the {tiger team} story in the {patch}
+ entry.
+
+ [{Jargon File}]
+
+ (2006-11-22)
+
+social network
+
+ <communications> Any {website} designed to allow multiple
+ users to publish content themselves. The information may be
+ on any subject and may be for consumption by (potential)
+ friends, mates, employers, employees, etc. The sites
+ typically allow users to create a "profile" describing
+ themselves and to exchange public or private messages and list
+ other users or groups they are connected to in some way.
+ There may be editorial content or the site may be entirely
+ user-driven. Content may include text, images
+ (e.g. {(http://flickr.com/)}), video
+ (e.g. {(http://youtube.com/)}) or any other media.
+
+ Social networks on the the web are a natural extension of
+ {mailing lists} and {buletin boards}. They are related to
+ {wikis} like {(http://wikipedia.org/)} but typically do not
+ allow users to modify content once it has been submitted,
+ though usually you can publish comments on others'
+ submissions.
+
+ Different sites have different emphasis. For example,
+ {(http://friendsreunited.co.uk/)} (one of the earliest such
+ sites) focusses on listing former acquaintances;
+ {(http://myspace.com/)} is music-oriented;
+ {(http://linkedin.com/)} aims to connect business partners;
+ {(http://del.icio.us/)}, {(http://stumbleupon.com/)} and
+ {(http://digg.com/)} are for exchanging links to favouirite
+ websites. There are many more.
+
+ Sometimes the social aspects are a side-effect of bringing
+ together people with shared interests,
+ e.g. {(http://slashdot.org/)} (IT), other times they become
+ more important than the original purpose,
+ e.g. {(http://worldofwarcraft.com/)} (fantasy gaming).
+
+ (2006-12-05)
+
+social networking
+
+ {social network}
+
+social science number
+
+ (IBM) A statistic that is {content-free}, or nearly so. A
+ measure derived via methods of questionable validity from data
+ of a dubious and vague nature. Predictively, having a social
+ science number in hand is seldom much better than nothing, and
+ can be considerably worse. {Management} loves them.
+
+ See also {numbers}, {math-out}, {pretty pictures}.
+
+ (1994-11-04)
+
+socket
+
+ <networking> The {Berkeley Unix} mechansim for creating a
+ virtual connection between processes. Sockets interface
+ {Unix}'s {standard I/O} with its {network} communication
+ facilities. They can be of two types, stream (bi-directional)
+ or {datagram} (fixed length destination-addressed messages).
+ The socket library function socket() creates a communications
+ end-point or socket and returns a {file descriptor} with which
+ to access that socket. The socket has associated with it a
+ socket address, consisting of a {port} number and the local
+ host's network address.
+
+ {Unix manual page}: socket(2).
+
+ (1995-01-31)
+
+Socket 1
+
+ {x86 processor socket}
+
+Socket 2
+
+ {x86 processor socket}
+
+Socket 3
+
+ {x86 processor socket}
+
+Socket 370
+
+ <hardware, standard, processor> (PGA370) A physical and
+ electrical specification for a {motherboard} {processor}
+ socket. Socket 370 uses a square {SPGA} {ZIF} socket with 370
+ pins, arranged 37x37 (sometimes described as 19x19).
+
+ {Intel} originally designed Socket 370 for {PPGA} Celeron
+ processors. Newer Socket 370 motherboards additionally
+ support {FC-PGA} Celeron and {Pentium III} processors.
+
+ The difference between the two versions is electrical;
+ some pins are used differently and voltage requirements have
+ been changed from Intel's {VRM 8.2} to {VRM 8.4}. In
+ addition, Celeron processors require a 66 MHz front side bus
+ ({FSB}), and Pentium III processors require a 100/133 MHz FSB.
+
+ Some older Socket 370 motherboards support VRM 8.4 and
+ variable bus speeds, so adapters are available that convert
+ the socket pinout to allow FC-PGA processors to work.
+
+ {VIA}'s {Cyrix III} processor was designed to work with
+ Socket 370 motherboards.
+
+ {Intel Celeron Processor in PPGA form factor - Integration
+ (http://pentium.com/design/quality/celeron/ppga/integration.htm)}.
+
+ {Pentium III Processors - Design Guidelines
+ (http://intel.com/design/PentiumIII/designgd/)}.
+
+ (2000-08-26)
+
+Socket 4
+
+ {x86 processor socket}
+
+Socket 5
+
+ {x86 processor socket}
+
+Socket 6
+
+ {x86 processor socket}
+
+Socket 7
+
+ <hardware, standard> A physical and electrical specification
+ for the {x86 processor socket} matching the pins on {Pentium}
+ {microprocessors} manufactured by {Intel}, and compatibles
+ made by {Cyrix}, {AMD} and others. Any {CPU} chip conforming
+ to this specification can be plugged into any conforming
+ {motherboard}.
+
+ Supported processors include: 2.5V - 3.5V {Pentiums} 75-233
+ MHz, AMD {K5} through {K6}, Cyrix {6x86} (and MX) P120 - P233.
+
+ Socket 7 uses a {SPGA} socket, either a 296 pin {LIF} or a 321
+ pin {ZIF} arranged as 37x37 or 19x19 (depending on who you
+ speak to!).
+
+ See also {Super 7}.
+
+ Intel's {Pentium II} processor uses {Slot 1} mounting.
+
+ [Pin-out?]
+
+ (1999-08-29)
+
+Socket 8
+
+ <hardware, standard> A physical and electrical specification
+ for the {x86 processor socket} matching the pins on a {Pentium
+ Pro} {microprocessor}.
+
+ Socket 8 uses a {dual pattern} {PGA}/{SPGA} {LIF}/{ZIF} socket
+ with 387 pins, arranged 24x26.
+
+ (1999-08-04)
+
+SOCKS
+
+ <security> A security package that allows a {host} behind a
+ {firewall} to use {finger}, {FTP}, {telnet}, {Gopher}, and
+ {Mosaic} to access resources outside the firewall while
+ maintaining the security requirements.
+
+ [The Security FAQ, {Usenet} newsgroups
+ {news:comp.security.misc}, {news:comp.security.unix},
+ {news:alt.security}].
+
+ (1995-01-31)
+
+SOCRATIC
+
+ An early interactive learning system (not a language(?))
+ developed at {Bolt, Beranek & Newman}.
+
+ [Sammet 1969, p. 702].
+
+ (1994-11-04)
+
+SODA
+
+ {Symbolic Optimum DEUCE Assembly Program}
+
+SODAS
+
+ [D.L. Parnas & J.A. Darringer. Proc FJCC 31:449-474, AFIPS
+ (Fall 1967)].
+
+ (1994-11-04)
+
+SO-DIMM
+
+ {Small Outline DIMM}
+
+Sod's Law
+
+ <humour> {Murphy's Law}.
+
+ [Or is it "Sodd"?]
+
+ (1995-12-29)
+
+SOE
+
+ {Standard Operating Environment}
+
+SoftBench
+
+ An {IPSE} from {Hewlett-Packard}.
+
+soft boot
+
+ <operating system> A {boot} which resets only part of the
+ {system}.
+
+ For example, "If you're running the {mess-dos} {emulator},
+ control-alt-insert will cause a soft boot of the emulator,
+ while leaving the rest of the system running".
+
+ Contrast {hard boot}.
+
+ [{Jargon File}]
+
+ (1995-11-27)
+
+softcopy
+
+ /soft'kop-ee/ (by analogy with "hardcopy") A machine-readable
+ ("{machinable}") form of corresponding {hardcopy}.
+
+ [{Jargon File}]
+
+ (1994-11-04)
+
+Softlab
+
+ <company> A {software engineering} company strong in the UK
+ and Germany.
+
+ [Details?]
+
+soft link
+
+ {symbolic link}
+
+SoftModem
+
+ The integration of {modem} controller and {data pump}
+ {algorithms} into a single {RAM}-based {DSP} hardware
+ architecture. These integrated algorithms are stored on the
+ computer's hard disk, from which they are downloaded into the
+ DSP board's random-access memory (RAM). This downloading, or
+ "booting" process of the PC-installed software algorithms
+ occurs as part of the computer's power-up initialisation
+ process in less than 100 milliseconds, making it transparent
+ to the user.
+
+ [Digicom Modem FAQ version 2.03].
+
+SoftVelocity Inc.
+
+ <company> The distributors of the {Clarion} family of
+ application development systems.
+
+ {SoftVelocity, Inc. (http://softvelocity.com)}.
+
+ (2003-10-15)
+
+software
+
+ <programming> (Or "computer program", "program", "code") The
+ instructions executed by a computer, as opposed to the
+ physical device on which they run (the "{hardware}").
+
+ The term was coined by the eminent statistician, {John Tukey}.
+
+ Programs stored on {non-volatile storage} built from
+ {integrated circuits} (e.g. {ROM} or {PROM}) are usually
+ called {firmware}.
+
+ Software can be split into two main types - {system software}
+ and application software or {application programs}. System
+ software is any software required to support the production or
+ execution of application programs but which is not specific to
+ any particular application. Examples of system software would
+ include the {operating system}, {compilers}, editors and
+ sorting programs.
+
+ Examples of application programs would include an accounts
+ package or a {CAD} program. Other broad classes of
+ application software include {real-time} software, {business
+ software}, scientific and engineering software, {embedded
+ software}, personal computer software and {artificial
+ intelligence} software.
+
+ Software includes both {source code} written by humans and
+ executable {machine code} produced by {assemblers} or
+ {compilers}. It does not usually include the data processed
+ by programs unless this is in a format such as {multimedia}
+ which depends on the use of computers for its presentation.
+ This distinction becomes unclear in cases such as {spread
+ sheets} which can contain both instructions (formulae and
+ {macros}) and data. There are also various intermediate
+ compiled or {semi-compiled}, forms of software such as
+ {library} files and {byte-code}.
+
+ Some claim that {documentation} (both paper and electronic) is
+ also software. Others go further and define software to be
+ programs plus documentation though this does not correspond
+ with common usage.
+
+ The noun "program" describes a single, complete and
+ more-or-less self-contained list of instructions, often stored
+ in a single {file}, whereas "code" and "software" are
+ uncountable nouns describing some number of instructions which
+ may constitute one or more programs or part thereof. Most
+ programs, however, rely heavily on various kinds of {operating
+ system} software for their execution. The nounds "code" and
+ "software" both refer to the same thing but "code" tends to
+ suggest an interest in the implementation details whereas
+ "software" is more of a user's term.
+
+ (2002-07-21)
+
+Software AG
+
+ <company> A German {software engineering} company that started
+ with the {ADABAS} {database}. {Natural} is their {4GL}
+ development environment, {EntireX} is their {DCOM} for {Unix}
+ and {IBM}. {BOLERO}, is an {object-oriented} development
+ environment and {application server} specially made for
+ Electronic Business applications.
+
+ {(http://softwareag.com/)}.
+
+ Mailing-list: <sag-l@uafsysb.uark.edu>.
+
+ (1999-03-06)
+
+software audit
+
+ <legal> A regular investigation of the software installed on
+ all computers in an organisation to ensure that it is
+ authorised or licensed.
+
+ Software audits minimise the risk of prosecution for {software
+ theft}, minimise the risk of {viruses} through uncontrolled
+ software copying, and ensure technical support is available to
+ all users.
+
+ The {Business Software Alliance} {Guide To Software Management
+ (http://bsa.org/bsa)}.
+
+ (1996-05-19)
+
+Software BackPlane
+
+ <programming, tool> A {CASE} framework from {Atherton}.
+
+ (1996-05-19)
+
+software bloat
+
+ <jargon, abuse> The result of adding new features to a program
+ or system to the point where the benefit of the new features
+ is outweighed by the extra resources consumed ({RAM}, disk
+ space or performance) and complexity of use. Software bloat
+ is an instance of Parkinson's Law: resource requirements
+ expand to consume the resources available. Causes of software
+ bloat include {second-system effect} and {creeping
+ featuritis}. Commonly cited examples include Unix's "{ls}(1)"
+ command, the {X Window System}, {BSD}, {Missed'em-five},
+ {OS/2} and any {Microsoft} product.
+
+ [{Jargon File}]
+
+ (1995-10-16)
+
+Software bus
+
+ A support environment for heterogeneous distributed
+ processing, such as the ANSA Testbench.
+
+software copyright
+
+ <legal> {Copyright} on a piece of {software}. Software raises
+ interesting questions in relation to copyright, such as what
+ constitutes a "performance" of a piece of software and which
+ aspects of software are restricted.
+
+ (2008-05-22)
+
+Software Description Database
+
+ <networking> {Archie}'s database of names and short
+ descriptions of many of the software packages, documents (like
+ {RFCs} and educational material), and data files that are
+ available via the {Internet}.
+
+ (1995-11-12)
+
+Software Developers Kit
+
+ <jargon, product> (SDK, or "Software Development Kit")
+ Software provided by a software vendor to allow their products
+ to be used with those of other software vendors.
+
+ (1995-03-01)
+
+software development life cycle
+
+ {software life cycle}
+
+software enabling
+
+ <programming> (Or "enabling") Modification of the design or
+ implementation of software to allow {internationalisation} to
+ take place.
+
+ In particular, enabling may refer to the modification of
+ software to support double-byte character sets, hence
+ "{Unicode} enabling" and "double-byte enabling".
+
+ (1999-06-28)
+
+software engineering
+
+ <programming> (SE) A systematic approach to the analysis,
+ design, implementation and maintenance of {software}. It
+ often involves the use of {CASE} tools. There are various
+ models of the {software life-cycle}, and many {methodologies}
+ for the different phases.
+
+ (1994-11-03)
+
+Software Engineering Environment
+
+ (SEE) A set of management and technical tools to support
+ software development, usually integrated in a coherent
+ framework; equivalent to an {IPSE}.
+
+ (1994-11-03)
+
+software handshaking
+
+ <communications> The transmission of extra data on a channel
+ in order to control the device sending data in the other
+ direction on that channel. For an {EIA-232} connection, this
+ means sending {Control-S} and {Control-Q} characters to stop
+ and start transmission.
+
+ Since software handshaking requires the transmission and
+ processing of extra data it can be less efficient than
+ {hardware handshaking}.
+
+ (1996-10-16)
+
+software interrupt
+
+ An {interrupt} caused by a specific {machine language}
+ operation code (e.g. the {Motorola 68000}'s TRAP, the {IBM
+ System/390}'s SVC or the {ARM}'s SWI) rather than by a
+ hardware event.
+
+ As with a hardware interrupt, this causes the processor to
+ store the current state, store identifying information about
+ the particular interrupt, and pass control to a first level
+ {interrupt handler}.
+
+ A {trap} is similar except that it is caused by an unexpected
+ software condition or error (e.g. divide by zero, undefined
+ instruction) rather than a deliberate instruction.
+
+ (1995-02-14)
+
+Software in the Public Interest, Inc.
+
+ <company> (SPI) A non-profit corporation which helps
+ organisations develop and distribute {open hardware} and {open
+ software}. SPI's goals are:
+
+ * to create, form and establish an organization to formulate
+ and provide software systems for use by the general public
+ without charge;
+
+ * to teach and train individuals regarding the use and
+ application of such systems;
+
+ * to hold classes, seminars and workshops concerning the
+ proper use and application of computers and computer systems;
+
+ * to endeavor to monitor and improve the quality of currently
+ existing publicly available software;
+
+ * to support, encourage and promote the creation and
+ development of software available to the general public;
+
+ * to provide information and education regarding the proper
+ use of the Internet;
+
+ * to organize, hold and conduct meetings, discussions and
+ forums on contemporary issues concerning the use of computers
+ and computer software;
+
+ * to foster, promote and increase access to software systems
+ available to the general public;
+
+ * to solicit, collect and otherwise raise money and to expend
+ such funds in furtherance of the goals and activities of the
+ corporation;
+
+ * to aid, assist, cooperate, co-sponsor and otherwise
+ engage in concerted action with private, educational and
+ governmental organisations and associations on all issues
+ and matters concerning the use of computers and computer
+ software and;
+
+ * generally to endeavor to promote, foster and advance
+ interest in computers and computer software by all available
+ means and methods.
+
+ SPI currently supports {Berlin}, {Debian}, {GNOME}, {LSB},
+ {Open Source}.
+
+ {SPI Home (http://spi-inc.org/)}.
+
+ (2002-04-14)
+
+software laser
+
+ An optical laser works by bouncing photons back and forth
+ between two mirrors, one totally reflective and one partially
+ reflective. If the lasing material (usually a crystal) has
+ the right properties, photons scattering off the atoms in the
+ crystal will excite cascades of more photons, all in lockstep.
+ Eventually the beam will escape through the partially
+ reflective mirror.
+
+ One kind of {sorcerer's apprentice mode} involving {bounce
+ messages} can produce closely analogous results, with a
+ {cascade} of messages escaping to flood nearby systems. By
+ mid-1993 there had been at least two publicised incidents of
+ this kind.
+
+ [{Jargon File}]
+
+software law
+
+ <legal> Software may, under various circumstances and in
+ various countries, be restricted by patent or {copyright} or
+ both. Most commercial software is sold under some kind of
+ {software license}.
+
+ A patent normally covers the design of something with a
+ function such as a machine or process. Copyright restricts
+ the right to make and distribute copies of something written
+ or recorded, such as a song or a book of recipies. Software
+ has both these aspects - it embodies functional design in the
+ {algorithms} and data structures it uses and it could also be
+ considered as a recording which can be copied and "performed"
+ (run).
+
+ "{Look and feel}" lawsuits attempt to monopolize well-known
+ command languages; some have succeeded. {Copyrights} on
+ command languages enforce gratuitous incompatibility, close
+ opportunities for competition, and stifle incremental
+ improvements.
+
+ {Software patents} are even more dangerous; they make every
+ design decision in the development of a program carry a risk
+ of a lawsuit, with draconian pretrial seizure. It is
+ difficult and expensive to find out whether the techniques you
+ consider using are patented; it is impossible to find out
+ whether they will be patented in the future.
+
+ The proper use of {copyright} is to prevent {software piracy}
+ - unauthorised duplication of software. This is completely
+ different from copying the idea behind the program in the same
+ way that photocopying a book differs from writing another book
+ on the same subject.
+
+ {Usenet} newsgroup: {news:misc.legal.computing}.
+
+ ["The Software Developer's and Marketer's Legal Companion",
+ Gene K. Landy, 1993, AW, 0-201-62276-9].
+
+ (1994-11-16)
+
+software life-cycle
+
+ <programming> The phases a software product goes through
+ between when it is conceived and when it is no longer
+ available for use. The software life-cycle typically includes
+ the following: {requirements analysis}, {design},
+ construction, testing ({validation}), installation, operation,
+ maintenance, and retirement.
+
+ The development process tends to run iteratively through these
+ phases rather than linearly; several models (spiral, waterfall
+ etc.) have been proposed to describe this process.
+
+ Other processes associated with a software product are:
+ quality assurance, marketing, sales and support.
+
+ (1996-12-27)
+
+Software Method
+
+ {Software Methodology}
+
+Software Methodology
+
+ <programming> The study of how to navigate through each phase
+ of the software process model (determining data, control, or
+ uses hierarchies, partitioning functions, and allocating
+ requirements) and how to represent phase products (structure
+ charts, stimulus-response threads, and {state transition
+ diagrams}).
+
+ (1996-05-29)
+
+software metric
+
+ <programming> A measure of software quality which indicates
+ the complexity, understandability, testability, description
+ and intricacy of code.
+
+ (1994-11-16)
+
+software patent
+
+ <legal> A patent intended to prevent others from using some
+ programming technique.
+
+ There have been several infamous patents for software
+ techniques which most experienced programmers would consider
+ fundamental or trivial, such as the idea of using
+ {exclusive-or} to plot a cursor on a {bitmap display}. The
+ spread of software patents could stifle innovation and make
+ programming much harder because programmers would have to
+ worry about patents when designing or choosing {algorithms}.
+
+ There are over ten thousand software patents in the US, and
+ several thousand more are issued each year. Each one may be
+ owned by, or could be bought by, a grasping company whose
+ lawyers carefully plan to attack people at their most
+ vulnerable moments. Of course, they couch the threat as a
+ "reasonable offer" to save you miserable years in court.
+ "Divide and conquer" is the watchword: pursue one group at a
+ time, while advising the rest of us to relax because we are in
+ no danger today.
+
+ Compuserve developed the {GIF} format for graphical images
+ many years ago, not knowing about {Unisys}'s 1985 patent
+ covering the {LZW} data compression {algorithm} used in GIF.
+ GIF was subsequently adopted widely on the {Internet}. In
+ 1994 Unisys threatened to sue Compuserve, forcing them to
+ impose a sublicensing agreement for GIF on their users.
+ Compuserve users can accept this agreement now, or face Unisys
+ later on their own. The rest of us don't have a choice -- we
+ get to face Unisys when they decide it's our turn. So much
+ trouble from just one software patent.
+
+ Patents in the UK can't describe {algorithms} or mathematical
+ methods.
+
+ See also {LPF}, {software law}.
+
+ {patent search
+ (http://sunsite.unc.edu/patents/intropat.html)}.
+
+ (1995-01-06)
+
+software piracy
+
+ <software> Making or distributing unauthorised copies of
+ {software}, either for kudos or for profit. See {software
+ theft}.
+
+ (2010-02-03)
+
+software pirate
+
+ <software, legal> Someone engaged in {software piracy}.
+
+ (2010-02-03)
+
+Software Practice and Experience
+
+ <publication> (SPE) A journal about {software}.
+
+ {(http://columbus.cs.nott.ac.uk/compsci/spe/)}.
+
+ [Publisher? UK?]
+
+ (1997-12-12)
+
+Software Productivity Centre
+
+ <body> (SPC) A non-profit organisation based in Vancouver, BC,
+ Canada with the mandate to assist software developers to
+ improve their {software engineering} process.
+
+ (1998-10-13)
+
+Software Publishing Certificate
+
+ <security> (SPC) A {public key certification standard} (PKCS)
+ #7 signed data object containing {X.509} {certificates}. SPCs
+ are used for {digital signatures} as applicable to computer
+ software.
+
+ (2007-05-16)
+
+Software Publishing Corporation
+
+ <company> (SPC) The company that produces {Harvard Graphics}.
+
+ {(http://spco.com/)}.
+
+ (1998-10-13)
+
+software reliability
+
+ See also {formal methods}, {safety-critical system}.
+
+ {(ftp://ftp.sei.cmu.edu/pub/depend-sw)}. Mailing list:
+ depend-sw@sei.cmu.edu.
+
+ [Summary?]
+
+software rot
+
+ <programming> The tendency of software that has not been used
+ in a while to fail; such failure may be semi-humorously
+ ascribed to {bit rot}. More commonly, "software rot" strikes
+ when a program's assumptions become out of date. If the
+ design was insufficiently {robust}, this may cause it to fail
+ in mysterious ways.
+
+ For example, owing to shortsightedness in the design of some
+ COBOL programs, many would have succumbed to software rot when
+ their 2-digit year counters wrapped around at the beginning of
+ the year 2000. A related incident made the news in 1990, when
+ a gentleman born in 1889 applied for a driver's licence
+ renewal in Raleigh, North Carolina. The system refused to
+ issue the card, probably because with 2-digit years the ages
+ 101 and 1 cannot be distinguished.
+
+ Historical note: Software rot in an even funnier sense than
+ the mythical one was a real problem on early research
+ computers (e.g. the {R1}; see {grind crank}). If a program
+ that depended on a peculiar instruction hadn't been run in
+ quite a while, the user might discover that the {opcodes} no
+ longer did the same things they once did. ("Hey, so-and-so
+ needs an instruction to do such-and-such. We can {snarf} this
+ opcode, right? No one uses it.")
+
+ Another classic example of this sprang from the time an {MIT}
+ hacker found a simple way to double the speed of the
+ unconditional jump instruction on a {PDP-6}, so he patched the
+ hardware. Unfortunately, this broke some fragile timing
+ software in a music-playing program, throwing its output out
+ of tune. This was fixed by adding a defensive initialisation
+ routine to compare the speed of a timing loop with the
+ real-time clock; in other words, it figured out how fast the
+ PDP-6 was that day, and corrected appropriately.
+
+ [{Jargon File}]
+
+ (2002-02-22)
+
+software theft
+
+ <legal> Unauthorised duplication and/or use of computer
+ {software}. This usually means unauthorised copying, either
+ by individuals for use by themselves or their friends or by
+ companies who then sell the illegal copies to users. Many
+ kinds of {software protection} have been invented to try to
+ reduce software theft but, with sufficient effort, it is
+ always possible to bypass or "crack" the protection, and
+ {software protection} is often annoying for legitimate users.
+
+ Software theft in 1994 was estimated to have cost $15 billion
+ in worldwide lost revenues to software publishers. It is an
+ offence in the UK under the Copyright, Designs and Patents Act
+ 1988, which states that "The owner of the copyright has the
+ exclusive right to copy the work."
+
+ It is estimated that European software houses alone lose $6
+ billion per year through the unlawful copying and distribution
+ of software, with much of this loss being through business
+ users rather than "basement hackers". One Italian pirating
+ operation employed over 100 staff and had a turnover of $10M.
+
+ It is illegal to: 1. Copy or distribute software or its
+ documentation without the permission or licence of the
+ copyright owner. 2. Run purchased software on two or more
+ computers simultaneously unless the licence specifically
+ allows it. 3. Knowingly or unknowingly allow, encourage or
+ pressure employees to make or use illegal copies sources
+ within the organisation. 4. Infringe laws against
+ unauthorised software copying because someone compels or
+ requests it. 5. Loan software in order that a copy be made of
+ it.
+
+ When software is upgraded it is generally the case that the
+ licence accompanying the new version revokes the old version.
+ This means that it is illegal to run both the old and new
+ versions as only the new version is licensed.
+
+ Both individuals and companies may be convicted of piracy
+ offences. Officers of a company are also liable to conviction
+ if the offences were carried out by the company with their
+ consent. On conviction, the guilty party can face
+ imprisonment for up to two years (five in USA), an unlimited
+ fine or both as well as being sued for copyright infringement
+ (with no limit) by the copyright owner.
+
+ Because copying software is easy, some think that it is less
+ wrong than, say, stealing it from a shop. In fact, both
+ deprive software producers of income.
+
+ Software theft should be reported to the {Federation Against
+ Software Theft} (FAST).
+
+ See also {Business Software Alliance}, {software audit},
+ {software law}.
+
+ (2003-06-17)
+
+Software through Pictures
+
+ <programming, tool> (StP) A set of {CASE} tools distributed by
+ {Aonix (http://aonix.com/)}.
+
+ (1999-05-21)
+
+software tool
+
+ <programming> A program that aids in the development of other
+ programs. It may assist the programmer in the design, code,
+ compile, link, edit, or debug phases.
+
+ (1996-05-28)
+
+Software Verification Research Centre
+
+ <body> (SVRC) A Special Research Centre of the Australian
+ Research Council. Its mission is to create improved methods
+ and tools, of industrial significance, for developing
+ {verified software}. Two of the SVRC's core projects are the
+ {Cogito} methodology and the {Ergo} {proof tool}.
+
+ (1995-11-14)
+
+Software Writer's Language
+
+ <language> (SWL) /swil/ An industrial strength dialect of
+ {Pascal} that allowed multiple {source code} files, originally
+ developed at {Control Data Corporation} (CDC) prior to 1973.
+ Development continued at the {Integrated Systems Laboratory}.
+ SWL was adopted by NCR as its corporate {operating system} and
+ {compiler} implementation language (1978-1982+). The NCR SWL
+ dialect was renamed NCRL (NCR Language) in 1981 and continued
+ development [until ?].
+
+ (2003-12-31)
+
+softwarily
+
+ /soft-weir'i-lee/ In a way pertaining to software. "The
+ system is softwarily unreliable." The adjective "softwary" is
+ *not* used. See {hardwarily}.
+
+ [{Jargon File}]
+
+softy
+
+ (IBM) {Hardware} hackers' term for a {software} expert who is
+ largely ignorant of the mysteries of hardware.
+
+ (1995-01-11)
+
+SOH
+
+ {Start Of Header}
+
+SOHIO
+
+ An early system on the {IBM 705}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1995-01-11)
+
+SoHo
+
+ {small-office/home-office.}
+
+SOIF
+
+ {Summary Object Interchange Format}
+
+SOJ
+
+ {Small Outline J}
+
+SOL
+
+ 1. <language> {Simulation Oriented Language}.
+
+ 2. {Second-Order lambda-calculus}.
+
+ 3. Semantic Operating Language. Language for manipulating
+ semantic networks for building cognitive models, particularly
+ for natural language understanding. "Explorations in
+ Cognition", D.A. Norman et al, W.H. Freeman 1974.
+
+ 4. Shit Outta Luck.
+
+Solaris
+
+ <operating system> {Sun Microsystems, Inc.}'s version of the
+ {Unix} {operating system}. As well as the core operating
+ system, Solaris inludes networking software, the {Java Virtual
+ Machine}, the {CDE}/Desktop that includes an {X11}-based
+ {windowing environment} and {graphical user interface}.
+
+ Sun claim that Solaris is not just an operating system but an
+ "operating environment".
+
+ Solaris 1.x was a retroactive (marketing?) name for {SunOS}
+ 4.1.x (where x>=1).
+
+ Solaris 2.x (which is the first version most people call
+ "Solaris") includes SunOS5.x, which is an SVR4-derived Unix,
+ {OpenWindows} 3.x, and {tooltalk}.
+
+ Version 2.7 ("Solaris 7") was around in 1999-03-02. Version
+ 2.8 was released in June 2000. Latest version: 9, as of
+ 2002-07-15.
+
+ {(http://sun.com/solaris/)}.
+
+ (2002-07-15)
+
+solid state
+
+ <electronics> (Often hyphenated when used as an adjective) A
+ term describing any device that uses {semiconductor}
+ components rather than {electron tubes} or {relays}.
+ Semiconductors are "solid" in that they contain no gas
+ ("vacuum" tubes contain a small amount as the vacuum is not
+ perfect) or moving parts (like relays), but probably more
+ important is the connotation of reliability and durability
+ that made possible things like portable radios.
+
+ (2007-09-21)
+
+Solid State Disk
+
+ (SSD) <storage> Any kind of {solid-state storage device} that
+ appears to the system as a disk drive. SSDs are more expensive
+ that the same capacity of magnetic disk but have much shorter
+ {access time}.
+
+ (2013-04-27)
+
+solid-state storage device
+
+ <storage> Any memory component with no moving parts, typically
+ built around some kind of semiconductor {integrated circuit}.
+ An example is {bubble memory}.
+
+ See also: {RAM disk}.
+
+ (2001-12-31)
+
+SOLO
+
+ [SOL (Semantic Operating Language) + LOGO]. A variant of
+ {LOGO} with primitives for dealing with {semantic networks}
+ and {pattern matching} rather than lists.
+
+ ["A User-Friendly Software Environment for the Novice
+ Programmer", M. Eisenstadt <marc@open.ac.uk>, CACM
+ 27(12):1056-1064 (1983)].
+
+solution
+
+ <jargon> A {marketroid} term for something he wants to sell
+ you without bothering you with the often dizzying distinctions
+ between {hardware}, {software}, {services}, {applications},
+ {file formats}, companies, brand names and {operating
+ systems}.
+
+ "{Flash} is a perfect image-streaming solution." "What is
+ it?" "Um... about a thousand dollars."
+
+ See also: {technology}.
+
+ (1998-07-07)
+
+Solution Based Modelling
+
+ (SBM) A software development process described in the book
+ "Developing Object-Oriented Software for the Macintosh"
+ written by Neal Goldstein and Jeff Alger, published by Addison
+ Wesley in 1992.
+
+Solve
+
+ Parallel object-oriented language. "Message Pattern
+ Specifications: A New Technique for Handling Errors in
+ Parallel Object- Oriented Systems", J.A. Purchase et al,
+ SIGPLAN Notices 25(10):116-125 (OOPSLA/ECOOP '90) (Oct 1990).
+
+SOM
+
+ System Object Model. An implementation of CORBA by IBM.
+
+Somar DumpAcl
+
+ <tool> A utilty which provides a concise report of {Windows
+ NT} file system permissions, to help find holes in system
+ security.
+
+ (1995-04-10)
+
+Somar Software
+
+ <company> The distributors of {Somar DumpAcl} and other
+ utilities for {Windows NT}.
+
+ {(http://somar.com/)}.
+
+ Address: Washington, DC, USA.
+
+ (1995-04-10)
+
+some random X
+
+ <jargon> Used to indicate a member of class X, with the
+ implication that Xs are interchangeable. "I think some random
+ cracker tripped over the guest timeout last night."
+
+ See also {J. Random}.
+
+ [{Jargon File}]
+
+ (1995-03-03)
+
+Sonata
+
+ <operating system> The code name for the major {Mac OS}
+ release due in mid-1999.
+
+ {(http://devworld.apple.com/mkt/informed/appledirections/mar97/roadmap.html)}.
+
+ (1997-10-15)
+
+SONET
+
+ {Synchronous Optical NETwork}
+
+Sony Playstation
+
+ {Playstation}
+
+SORCERER
+
+ <tool> A simple tree {parser generator} by Terence Parr
+ <parrt@s1.arc.umn.edu>.
+
+ SORCERER is suitable for translation problems lying between
+ those solved by {code generator} generators and by full
+ source-to-source translator generators. SORCERER generates
+ simple, flexible, top-down, tree {parsers} that, in contrast
+ to code generators, may execute actions at any point during a
+ tree walk. SORCERER accepts {extended BNF} notation, allows
+ {predicates} to direct the tree walk with {semantic} and
+ {syntactic} context information, and does not rely on any
+ particular intermediate form, parser generator, or other
+ pre-existing application.
+
+ SORCERER is included in the {Purdue Compiler-Construction Tool
+ Set}.
+
+ Version: 1.00B
+
+ {(ftp://marvin.ecn.purdue.edu/pub/pccts/sorcerer/)}.
+
+ E-mail: <parrt@acm.org> ("e-mail sor.tar.Z.uu" in subject).
+
+ Mailing list: pccts-users-request@ahpcrc.umn.edu (message
+ body: "subscribe pccts-users YOUR-NAME", where YOUR-NAME can
+ be your name or e-mail address).
+
+ (1994-02-15)
+
+sorcerer's apprentice mode
+
+ <networking> (From Johann Wolfgang von Goethe's "Der
+ Zauberlehrling", via the Walt Disney film "Fantasia") A {bug}
+ in a {protocol} where, under some circumstances, the receipt
+ of a message causes multiple messages to be sent, each of
+ which, when received, triggers the same bug. Used especially
+ of such behaviour caused by {bounce message} loops in
+ {electronic mail} software.
+
+ Compare {broadcast storm}, {network meltdown}, {software
+ laser}, {ARMM}.
+
+ {Der Zauberlehrling
+ (http://unix-ag.uni-kl.de/~conrad/lyrics/zauber.html)}.
+
+ [{Jargon File}]
+
+ (1999-10-08)
+
+sort
+
+ 1. <application, algorithm> To arrange a collection of items
+ in some specified order. The items - {records} in a file or
+ data structures in memory - consist of one or more {fields} or
+ members. One of these fields is designated as the "sort key"
+ which means the records will be ordered according to the value
+ of that field. Sometimes a sequence of key fields is
+ specified such that if all earlier keys are equal then the
+ later keys will be compared. Within each field some ordering
+ is imposed, e.g. ascending or descending numerical, {lexical
+ ordering}, or date.
+
+ Sorting is the subject of a great deal of study since it is a
+ common operation which can consume a lot of computer time.
+ There are many well-known sorting {algorithms} with different
+ time and space behaviour and programming {complexity}.
+
+ Examples are {quicksort}, {insertion sort}, {bubble sort},
+ {heap sort}, and {tree sort}. These employ many different
+ data structures to store sorted data, such as {arrays},
+ {linked lists}, and {binary trees}.
+
+ 2. <tool> The {Unix} utility program for sorting lines of
+ files.
+
+ {Unix manual page}: sort(1).
+
+ (1997-02-12)
+
+sorting
+
+ {sort}
+
+SOS
+
+ 1. {Scheme Object System}.
+
+ 2. An infamously {losing} text editor. Once, back in the
+ 1960s, when a text editor was needed for the {PDP-6}, a hacker
+ {crufted} together a {quick-and-dirty} "stopgap editor" to be
+ used until a better one was written. Unfortunately, the old
+ one was never really discarded when new ones (in particular,
+ {TECO}) came along. SOS is a descendant ("Son of Stopgap") of
+ that editor, and many {PDP-10} users gained the dubious
+ pleasure of its acquaintance. Since then other programs
+ similar in style to SOS have been written, notably the early
+ font editor BILOS /bye'lohs/, the Brother-In-Law Of Stopgap
+ (the alternate expansion "Bastard Issue, Loins of Stopgap" has
+ been proposed).
+
+ 3. The {PDP-10} instruction to decrease a value. Oppose
+ {AOS}.
+
+ [{Jargon File}]
+
+sound
+
+ 1. {audio}.
+
+ 2. <logic> An {inference system} A is sound with respect to
+ another system B if A can only reach conclusions which are
+ true in B. A {type inference} system is considered sound with
+ respect to a {semantics} if the type inferred for an
+ expression is the same as the type inferred for the meaning of
+ that expression under the semantics.
+
+ The dual to soundness is {complete}ness.
+
+ (1995-03-01)
+
+Sound Blaster
+
+ <hardware> The best known family of {sound cards} for the {IBM
+ PC} from {Creative Labs}.
+
+ [Features? Models? Reference?]
+
+ (1998-04-28)
+
+sound card
+
+ A plug-in optional circuit card for an {IBM PC}. It provides
+ high-quality stereo sound output under program control. A
+ "{multimedia}" PC usually includes a sound card. One of the
+ best known is the {Sound Blaster}.
+
+ [Other kinds?]
+
+ (1995-03-01)
+
+soundex
+
+ <algorithm, text> An {algorithm} for encoding a word so that
+ similar sounding words encode the same. The first letter is
+ copied unchanged then subsequent letters are encoded as
+ follows:
+
+ bfpv -> "1"
+ cgjkqsxz -> "2"
+ dt -> "3"
+ l -> "4"
+ mn -> "5"
+ r -> "6"
+
+ Other characters are ignored and repeated characters are
+ encoded as though they were a single character. Encoding
+ stops when the resulting string is four characters long,
+ adding trailing "0"s if it is shorter. For example, "SMITH"
+ or "SMYTHE" would both be encoded as "S530".
+
+ (1995-01-05)
+
+soundness
+
+ The quality of being {sound} (2).
+
+source
+
+ {source code}
+
+source code
+
+ <language, programming> (Or "source", or rarely "source language")
+ The form in which a {computer program} ({software}) is written by
+ the {programmer}. Source code is written in some formal
+ {programming language} which can be {compiled} automatically into
+ {object code} or {machine code} or executed by an {interpreter}.
+
+ Source code might be stored in a {source code management} system.
+
+ If you have the source code for a program rather than just its
+ compiled, executable form, then you can, with the right tools,
+ modify it to fix {bugs} or add new {features}. This is the basis
+ of the {open source} philosophy - empowering people to improve the
+ software they use for the benefit of themselves and others.
+
+ The {Jargon File} would have us believe that an old-time hacker
+ might refer to source code informally as "English", with the
+ implication that to him his favourite {programming language} is at
+ least as readable as English.
+
+ (2014-06-27)
+
+source code control
+
+ {source code management}
+
+source code escrow
+
+ <software> An arrangement where some {source code} is held in
+ {escrow} by a third party as long as it is supported by the
+ vendors, but should they cease to support it, it becomes the
+ property of the purchasers so that they can arrange for its
+ continued maintenance.
+
+ (1999-12-14)
+
+source code management
+
+ <software> The use of software systems to help program
+ developers keep track of version history of {source code}
+ {modules} as well as {releases}, parallel versions ({code
+ branches}), etc. The free {CVS} was an early example, mostly
+ replaced by {Subversion} and {git}. {Perforce} is a powerful
+ commercial product. {SCCS} was once popular on {Unix} and
+ {VSS} is {Microsoft}'s offering.
+
+ (2011-12-16)
+
+source language
+
+ {source code}
+
+source-level debugger
+
+ <programming, tool> A {debugger} that shows the programmer the
+ line or {expression} in the {source code} that resulted in a
+ particular {machine code} instruction of a running program
+ loaded in memory. This helps the programmer to analyse a
+ program's behaviour in the high-level terms like source-level
+ {flow control} constructs, {procedure} calls, named
+ {variables}, etc instead of {machine instructions} and memory
+ locations. Source-level debugging also makes it possible to
+ step through execution a line at a time and set source-level
+ {breakpoints}.
+
+ In order to support source-level debugging, the program must
+ be compiled with this option enabled so that extra information
+ is included in the executable code to identify the
+ corresponding positions in the source code.
+
+ A {symbolic debugger} is one level lower - it displays symbols
+ (procedure and variable names) stored in the executable but
+ not individual source code lines.
+
+ {GDB} is a widely used example of a source-level debugger.
+
+ (2007-04-03)
+
+source of all good bits
+
+ <jargon, job> A person from whom (or a place from which)
+ useful information may be obtained. If you need to know about
+ a program, a {guru} might be the source of all good bits. The
+ title is often applied to a particularly competent secretary.
+
+ [{Jargon File}]
+
+ (2001-01-27)
+
+source package
+
+ <software> A collection (usually an {archive} file) containing
+ all the files necessary to build and modify a piece of
+ software.
+
+ A {Debian} source package includes the original source archive
+ (.orig.tar.gz), Debianisation diffs
+ (-<debian-version>.diff.gz) and a Debian source control file
+ (-<debian-version>.dsc).
+
+ (2000-05-31)
+
+source route
+
+ <messaging> An {electronic mail address} which specifies the
+ route the message should take as a sequence of {hostnames}.
+ It is called a source route because the route is determined at
+ the source of the message rather than at each stage as is now
+ more common. The most common kind of source route is a {UUCP}
+ style {bang path}, "foo!bar!baz!fred'. The {RFC 822} syntax,
+ "@foo:@bar:fred@baz", is seldom seen because most systems
+ which understand RFC 822 also perform automatic routing based
+ on the destination hostname. A third, intermediate, form is
+ sometimes seen: "fred%baz%bar@foo.com".
+
+source routing
+
+ {source route}
+
+southbridge
+
+ <architecture> The {integrated circuit} in a {core logic}
+ {chip set} that controls the {IDE} bus, {USB}, {plug-n-play}
+ support, the {PCI}-{ISA} bridge, keyboard/mouse controller,
+ {power management}, and various other features. One brand
+ provides {sound card} functions.
+
+ Other functions are provided by the {northbridge} chip.
+
+ {(http://maximumpc.com/terminator/terminator_s.html)}.
+
+ (2000-01-15)
+
+SP
+
+ Simplicity and Power.
+
+ A {Prolog}-like language.
+
+ ["Simplicity and Power - Simplifying Ideas in Computing",
+ J.G. Wolff, Computer J 33(6):518-534 (Dec 1990)].
+
+ (1994-12-01)
+
+SP2
+
+ {SP/2}
+
+ [Which is correct?]
+
+SP/2
+
+ Scalable POWERparallel 2.
+
+ A line of {RISC}-based processors from {IBM} using {symmetric
+ multi-processing}. SP/2 replaced SP/1.
+
+ The SP2 is a classical {MPP} design, based on a {Shared
+ Nothing} architecture. The SP2 is an example of the
+ {Distributed Memory Processor} (DMP) parallel model, with
+ individual nodes interconnected over a {LAN}, or a
+ High-Performance Switch (HPS). SP2 systems can have from 2 to
+ 512 nodes. Each node is a {RISC system/6000} running {IBM}'s
+ {AIX} {operating system}.
+
+ The SP2 supports applications in both technical and commercial
+ environments. In terms of commercial applications, the SP2 is
+ typically being used in support of, {MIS}/{DSS} including
+ {data mining}, {business applications} e.g. {SAP}, {Alternative
+ Mainframe}/{Mainframe Offload}, {LAN Server Consolidation}.
+
+ (1995-03-07)
+
+space
+
+ <character> The space character, {ASCII} 32.
+
+ See {octal forty}.
+
+ (2007-01-29)
+
+space bar
+
+ <hardware> (Or "space key") The extra-wide {key} at the near
+ edge of every {keyboard} that is used to enter a {space}
+ character.
+
+ In some {Graphical User Interfaces}, the space bar can be used
+ to select the current item where the context does not allow
+ text entry, e.g. when the {input focus} is on a {push button}
+ or {tick box}.
+
+ (2007-01-29)
+
+space-cadet keyboard
+
+ A now-legendary device used on {MIT} {Lisp} machines, which
+ inspired several still-current jargon terms and influenced the
+ design of {Emacs}. It was equipped with no fewer than *seven*
+ shift keys: four keys for {bucky bits} ("control", "meta",
+ "hyper", and "super") and three like regular shift keys,
+ called "shift", "top", and "front". Many keys had three
+ symbols on them: a letter and a symbol on the top, and a Greek
+ letter on the front. For example, the "L" key had an "L" and
+ a two-way arrow on the top, and the Greek letter lambda on the
+ front. By pressing this key with the right hand while playing
+ an appropriate "chord" with the left hand on the shift keys,
+ you could get the following results:
+
+ L lowercase l
+
+ shift-L uppercase L
+
+ front-L lowercase lambda
+
+ front-shift-L uppercase lambda
+
+ top-L two-way arrow
+
+ (front and shift are ignored) And of course each of these
+ might also be typed with any combination of the control, meta,
+ hyper, and super keys. On this keyboard, you could type over
+ 8000 different characters! This allowed the user to type very
+ complicated mathematical text, and also to have thousands of
+ single-character commands at his disposal. Many hackers were
+ actually willing to memorise the command meanings of that many
+ characters if it reduced typing time (this attitude obviously
+ shaped the interface of {Emacs}). Other hackers, however,
+ thought that many {bucky bits} was overkill, and objected that
+ such a keyboard can require three or four hands to operate.
+
+ See {cokebottle}, {double bucky}, {meta bit}, {quadruple
+ bucky}.
+
+ Note: early versions of this entry incorrectly identified the
+ space-cadet keyboard with the "Knight keyboard". Though both
+ were designed by Tom Knight, the latter term was properly
+ applied only to a keyboard used for {ITS} on the {PDP-10} and
+ modelled on the Stanford keyboard (as described under {bucky
+ bits}). The true space-cadet keyboard evolved from the Knight
+ keyboard.
+
+ [{Jargon File}]
+
+ (1994-12-05)
+
+space complexity
+
+ <complexity> The way in which the amount of storage space
+ required by an {algorithm} varies with the size of the problem
+ it is solving. Space complexity is normally expressed as an
+ order of magnitude, e.g. O(N^2) means that if the size of the
+ problem (N) doubles then four times as much working storage
+ will be needed.
+
+ See also {computational complexity}, {time complexity}.
+
+ (1996-05-08)
+
+space key
+
+ {space bar}
+
+space leak
+
+ A data structure which grows bigger, or lives longer, than
+ might be expected. Such unexpected memory use can cause a
+ program to require more {garbage collections} or to run out of
+ {heap}. Space leaks in {functional programs} usually result
+ from excessive laziness. For example, the {Haskell} function
+
+ sum [] = 0
+ sum (x:xs) = x + sum xs
+
+ when applied to a list will build a chain of closures for the
+ additions and only when it reaches the end of the list will it
+ perform the additions and free the storage. Another example
+ is the function
+
+ mean l = sum l / length l
+
+ The sum function forces the entire list l to be evaluated and
+ built in the heap. None of it can be garbage collected until
+ the length function has consumed it.
+
+SPACEWAR
+
+ <games> A space-combat simulation game for the {PDP-1} written
+ in 1960-61 by Steve Russell, an employee at {MIT}. SPACEWAR
+ was inspired by E. E. "Doc" Smith's "Lensman" books, in which
+ two spaceships duel around a central sun, shooting torpedoes
+ at each other and jumping through hyperspace. MIT were
+ wondering what to do with a new {vector video display} so
+ Steve wrote the world's first video game. Steve now lives in
+ California and still writes software for {HC12} {emulators}.
+
+ SPACEWAR aficionados formed the core of the early hacker
+ culture at {MIT}. Nine years later, a descendant of the game
+ motivated {Ken Thompson} to build, in his spare time on a
+ scavenged {PDP-7}, the {operating system} that became {Unix}.
+ Less than nine years after that, SPACEWAR was commercialised
+ as one of the first video games; descendants are still
+ {feep}ing in video arcades everywhere.
+
+ ["SPACEWAR" or "Space Travel"?]
+
+ [{Jargon File}]
+
+ (2004-07-19)
+
+SPADE
+
+ Specification Processing And Dependency Extraction.
+ Specification language. G.S. Boddy, ICL Mainframes Div,
+ FLAG/UD/3DR.003
+
+spaghetti code
+
+ <programming> A pejorative term for code with a complex and
+ tangled {control structure}, especially one using many
+ {GOTOs}, {exceptions}, or other "unstructured" branching
+ constructs. The synonym "kangaroo code" has been reported,
+ doubtless because such code has so many jumps in it.
+
+ {Object-oriented programming} may also feature {spaghetti
+ inheritance} or {spaghetti with meatballs code}.
+
+ [{Jargon File}]
+
+ (2013-07-31)
+
+spaghetti inheritance
+
+ <humour, programming> A term used by users of {object-oriented}
+ languages with inheritance, such as {Smalltalk} for a convoluted
+ {class}-subclass graph, often resulting from carelessly deriving
+ subclasses from other classes just for the sake of reusing their
+ code. Coined to discourage such practice, through
+ guilt-by-association with {spaghetti code}.
+
+ [{Jargon File}]
+
+ (2013-07-31)
+
+spaghetti with meatballs code
+
+ <humour, programming> {Object-oriented code} that depends on messy
+ procedural {spaghetti code}. May also feature {spaghetti
+ inheritance}.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2013-07-31)
+
+spam
+
+ 1. <messaging> (From Hormel's Spiced Ham, via the Monty Python
+ "Spam" song) To post irrelevant or inappropriate messages to
+ one or more {Usenet} {newsgroups}, {mailing lists}, or other
+ messaging system in deliberate or accidental violation of
+ {netiquette}.
+
+ It is possible to spam a newsgroup with one well- (or ill-)
+ planned message, e.g. asking "What do you think of abortion?"
+ on soc.women. This can be done by {cross-post}ing, e.g. any
+ message which is crossposted to alt.rush-limbaugh and
+ alt.politics.homosexuality will almost inevitably spam both
+ groups. (Compare {troll} and {flame bait}).
+
+ Posting a message to a significant proportion of all
+ newsgroups is a sure way to spam Usenet and become an object
+ of almost universal hatred. Canter and Siegel spammed the net
+ with their Green card post.
+
+ If you see an article which you think is a deliberate spam, DO
+ NOT post a {follow-up} - doing so will only contribute to the
+ general annoyance. Send a polite message to the poster by
+ private e-mail and CC it to "postmaster" at the same address.
+ Bear in mind that the posting's origin might have been forged
+ or the apparent sender's account might have been used by
+ someone else without his permission.
+
+ The word was coined as the winning entry in a 1937 competition
+ to choose a name for Hormel Foods Corporation's "spiced meat"
+ (now officially known as "SPAM luncheon meat"). Correspondant
+ Bob White claims the modern use of the term predates Monty
+ Python by at least ten years. He cites an editor for the
+ Dallas Times Herald describing Public Relations as "throwing a
+ can of spam into an electric fan just to see if any of it
+ would stick to the unwary passersby."
+
+ {Usenet} newsgroup: {news:news.admin.net-abuse}.
+
+ See also {netiquette}.
+
+ 2. (A narrowing of sense 1, above) To indiscriminately send
+ large amounts of unsolicited {e-mail} meant to promote a
+ product or service. Spam in this sense is sort of like the
+ electronic equivalent of junk mail sent to "Occupant".
+
+ In the 1990s, with the rise in commercial awareness of the
+ net, there are actually scumbags who offer spamming as a
+ "service" to companies wishing to advertise on the net. They
+ do this by mailing to collections of {e-mail} addresses,
+ Usenet news, or mailing lists. Such practises have caused
+ outrage and aggressive reaction by many net users against the
+ individuals concerned.
+
+ 3. (Apparently a generalisation of sense 2, above) To abuse
+ any network service or tool by for promotional purposes.
+
+ "AltaVista is an {index}, not a promotional tool. Attempts to
+ fill it with promotional material lower the value of the index
+ for everyone. [...] We will disallow {URL} submissions from
+ those who spam the index. In extreme cases, we will exclude
+ all their pages from the index." -- {Altavista}.
+
+ 4. <jargon, programming> To crash a program by overrunning a
+ fixed-size {buffer} with excessively large input data.
+
+ See also {buffer overflow}, {overrun screw}, {smash the stack}.
+
+ 5. <chat, games> (A narrowing of sense 1, above) To flood any
+ {chat} forum or {Internet game} with purposefully annoying
+ text or macros. Compare {Scrolling}.
+
+ (2003-09-21)
+
+spamdex
+
+ <web> (Presumably from "{spam}", "index") {word
+ spamming}.
+
+ "Spamdexing has come a long way from the halcyon days of the
+ summer of 1995. Back then, all one needed to do was add the
+ word 'sex' a thousand times at the end of a Web page to
+ attract attention from the likes of Lycos. The search-engine
+ operators caught on fast" -- {Andrew Leonard, Hotwired 1996
+ (http://packet.com/packet/leonard/96/32/index3a.html)}.
+
+ (1997-04-09)
+
+spamming
+
+ {spam}
+
+spanning tree algorithm
+
+ <networking, standard> An {IEEE 802.1} standard providing
+ distributed {routing} over multiple {LAN}s connected by
+ {bridges}.
+
+ (2010-09-26)
+
+SPAR
+
+ Early system on Datatron 200 series. Listed in CACM 2(5):16
+ (May 1959).
+
+SPARC
+
+ 1. <processor> {Scalable Processor ARChitecture}.
+
+ 2. <database> {ANSI/SPARC Architecture}.
+
+ (1999-02-27)
+
+SPARC International, Inc.
+
+ <body> An organisation established to promote the {Scalable
+ Processor ARChitecture} (SPARC). Their main service is
+ conformance testing. They also produce the "SPARC flash"
+ newsletter and publish lists of SPARC compliant machines
+ tested by SPARC International to be {binary compatible} with
+ other compliant machines.
+
+ {(http://sparc.com/)}.
+
+ SPARC(R) is a registered trademark of SPARC International,
+ Inc. in the United States and other countries.
+
+ (1995-01-04)
+
+SPARCStation
+
+ <computer> A family of {workstations} from {Sun Microsystems}
+ based on the {SPARC} architecture. Models include the
+ {SPARCStation 1}, 1+, SLC, {SPARCStation ELC}, IPX,
+ {SPARCStation 5}, {SPARCStation 10} and {SPARCStation 20}.
+
+ (1994-11-23)
+
+SPARCstation 10
+
+ <computer> A {SPARCStation} with a 4-way associative {data
+ cache} and a five-way associative {instruction cache}. The
+ 10/31, 10/41 and 10/51 also have a {secondary cache} not
+ present on earlier {SPARCStations}.
+
+ (1994-12-02)
+
+SPARCstation 20
+
+ <computer> A {SPARCStation} based on the {HyperSPARC}
+ processor. The 20 is compatible with the earlier
+ {SPARCstation 10}. It has a {clock rate} of 100MHz and
+ delivers a {SPECfp92} of 127.6.
+
+ The SPARCstation 20 Model 71 and 712MP uses the 75MHz
+ {SuperSPARC} processors that give a 35% and 14% boost to
+ SPECint92 and SPECfp92 respectively compared to the 61/612MP.
+
+ (1994-12-02)
+
+SPARCsystem 4
+
+ <computer> A computer built with the {MicroSPARC ii} 70MHz
+ {CPU} as used in the {SPARC 5} Model 70. The SPARCsystem 4 is
+ basically a cheaper, cut-down SPARC 5. It has an 8-bit {pixel
+ accelerator} instead of the SBus Turbo GX card. Memory
+ expansion is limited to 160 MB. Availability was planned for
+ March/April 1995.
+
+ (1995-02-07)
+
+SPARC Xterminal 1
+
+ <computer> {Sun}'s lowest cost networked {Unix} desktop, it is
+ board-upgradeable to a {SPARC 4}. It comes with a choice of
+ {frame buffers}: 8-bit colour, {Turbo GX}, or Turbo GX plus.
+ This product was expected to replace the {SPARCclassic X}. UK
+ availability was planned for March 1995.
+
+ (1995-02-08)
+
+SPARK
+
+ <language> An annotated subset of {Ada} supported by tools
+ supplied by {Praxis Critical Systems} (originally by PVL).
+
+ {(http://sparkada.com)}.
+
+ (2001-07-12)
+
+SPARK Annotation Language
+
+ <language> (SAL) {ICL}, Ltd. Used in the verification of
+ {SPARK} programs against {Z} specifications.
+
+ (1994-12-08)
+
+SPARKS
+
+ <language> Fortran superset, used in Fundamentals of Data
+ Structures, E. Horowitz & S. Sahni, Computer Science Press
+ 1976.
+
+ (2007-03-21)
+
+sparse
+
+ A sparse {matrix} (or {vector}, or {array}) is one in which
+ most of the elements are zero. If storage space is more
+ important than access speed, it may be preferable to store a
+ sparse matrix as a list of (index, value) pairs or use some
+ kind of {hash} scheme or {associative memory}.
+
+ (1995-01-16)
+
+Spatial Technologies
+
+ <company> Distributors of the {ACIS} {solid modelling} engine.
+
+ [More info?]
+
+ (1999-06-29)
+
+spawn
+
+ <operating system> To create a {child process} in a
+ {multitasking} {operating system}. E.g. {Unix}'s {fork}
+ {system call} or one of the spawn() library routines provided
+ by most {MS-DOS}, {Novell NetWare} and {OS/2} {C} compilers -
+ spawnl(), spawnle(), etc.
+
+ (1995-03-28)
+
+SPC
+
+ 1. <business> {Statistical Process Control}. Something to do
+ with {quality management}.
+
+ [What is it?]
+
+ 2. <body> {Software Productivity Centre}.
+
+ 3. <company> {Software Publishing Corporation}.
+
+ 4. <security> {Software Publishing Certificate}.
+
+SPD
+
+ {Serial Presence Detect}
+
+SPDL
+
+ Standard Page Description Language
+
+ A draft within the ODA standard.
+
+ (1995-03-28)
+
+SPE
+
+ {Software Practice and Experience}
+
+Speakeasy
+
+ Simple array-oriented language with numerical integration and
+ differentiation, graphical output, aimed at statistical
+ analysis.
+
+ ["Speakeasy", S. Cohen, SIGPLAN Notices 9(4), (Apr 1974)].
+
+ ["Speakeasy-3 Reference Manual", S. Cohen et al. 1976].
+
+speaker
+
+ 1. <audio, hardware> {loudspeaker}.
+
+ 2. The person who is (assumed to be) talking.
+
+ (1996-12-01)
+
+SPEC
+
+ <benchmark, body> Standard Performance Evaluation Corporation.
+
+ A non-profit corporation registered in California formed to
+ "establish, maintain and endorse a standardized set of
+ relevant {benchmarks} that can be applied to the newest
+ generation of high-performance computers" (from SPEC's
+ bylaws). The founders believe that the user community will
+ benefit greatly from an objective series of
+ applications-oriented tests, which can serve as common
+ reference points and be considered during the evaluation
+ process.
+
+ SPEC develops suites of {benchmarks} intended to measure
+ computer performance. These are available to the public for a
+ fee covering development and administration costs.
+
+ The current (14 Nov 94) SPEC benchmark suites are: {CINT92}
+ (CPU intensive integer benchmarks); {CFP92} (CPU intensive
+ floating-point benchmarks); SDM (UNIX Software Development
+ Workloads); SFS (System level file server (NFS) workload).
+
+ {Results (ftp://ftp.cdf.toronto.edu/pub/spectable)}.
+
+ SPEC also publishes a quarterly report of SPEC news and
+ results, The SPEC Newsletter. Some issues are {here
+ (http://performance.netlib.org/performance/html/spec.html)}.
+
+ There is a {FAQ} about SPEC {here
+ (http://performance.netlib.org/performance/html/specfaq.html)}.
+
+ (1994-11-14)
+
+Spec
+
+ A specification language. It expresses {black box} interface
+ specifications for large distributed systems with {real-time}
+ constraints. It incorporates conceptual models, {inheritance}
+ and the event model. It is a descendant of {MSG.84}.
+
+ ["An Introduction to the Specification Language Spec",
+ V. Berzins et al, IEEE Software 7(2):74-84 (Mar 1990)].
+
+spec
+
+ {specification}
+
+SPECbase_fp92
+
+ A variant of {SPECfp92} that reports "baseline" results, using
+ stricter run rules.
+
+ (1994-11-14)
+
+SPECbase_int92
+
+ A variant of {SPECint92} that reports "baseline" results,
+ using stricter run rules.
+
+ (1994-11-14)
+
+SPECbaserate
+
+ A variant of {SPECrate} that reports "baseline" results, using
+ stricter run rules.
+
+ See {SPECrate_base_fp92}, {SPECrate_base_int92}.
+
+ (1994-11-14)
+
+SPEC CFP92
+
+ <benchmark> A {benchmark} suite from {SPEC} containing 14
+ programs performing {floating-point} computations. 12 are
+ written in {Fortran} and two in {C}. They can be used to
+ estimate the performance of CPU, memory system, and compiler
+ code generation.
+
+ The individual programs are Circuit Design, Simulation (2x),
+ Quantum Chemistry (3x), Electromagnetism, Geometric
+ Translation, Optics, Robotics, Medical Simulation, Quantum
+ Physics, Astrophysics, NASA Kernels.
+
+ The benchmark suite can be used either for speed measurement,
+ resulting in {SPEC ratios}, or for throughput measurement,
+ resulting in {SPEC rates}
+
+ (1994-11-15)
+
+SPEC CINT92
+
+ <benchmark> A {benchmark} suite from {SPEC}, which contains
+ six benchmarks in {C} performing integer computations. They
+ can be used to estimate the performance of CPU, memory system,
+ and compiler code generation.
+
+ The individual programs are Logic Design (2x), Interpreter,
+ Data Compression, Spreadsheet. The approximate size of the
+ suite is 85500 lines of source code without comments.
+
+ The benchmark suite can be used either for speed measurement,
+ resulting in {SPEC ratios}, or for throughput measurement,
+ resulting in {SPEC rates}
+
+ (1994-11-15)
+
+SPECfp92
+
+ <benchmark> A {benchmark} result derived from the results of a
+ set of CPU intensive floating-point benchmarks from {SPEC}
+ (the {geometric mean} of the 14 {SPEC ratios} of {CFP92}).
+ SPECfp92 can be used to estimate a machine's single-tasking
+ performance on {floating-point} code.
+
+ {Results (ftp://ftp.nosc.mil/pub/aburto/specfp92.tbl)}.
+
+ (1994-11-14)
+
+SPECIAL
+
+ <language, specification> A specification language, developed
+ at {SRI} around 1976, used to specify the {abstract machines}
+ in {Hierarchical Design Methodology} (HDM).
+
+ ["SPECIAL - A Specification and Assertion Language",
+ L. Robinson et al, TR CSL-46, SRI, Jan 1977].
+
+ (2012-07-08)
+
+special-case
+
+ To write unique code to handle input to or situations arising
+ in a program that are somehow distinguished from normal
+ processing. This would be used for processing of mode
+ switches or interrupt characters in an interactive interface
+ (as opposed, say, to text entry or normal commands), or for
+ processing of {hidden flags} in the input of a batch program
+ or {filter}.
+
+ [{Jargon File}]
+
+Special Interest Group
+
+ (SIG) One of several technical areas, sponsored by the
+ {Association for Computing Machinery}. Well-known SIGs
+ include SIGPLAN (the Special Interest Group on Programming
+ Languages), SIGARCH (the Special Interest Group for Computer
+ Architecture) and SIGGRAPH (the Special Interest Group for
+ Computer Graphics).
+
+ (1994-10-27)
+
+specialisation
+
+ A reduction in generality, usually for the sake of increased
+ efficiency. If a piece of code is specialised for certain
+ values of certain variables (usually function arguments), this
+ is known as "{partial evaluation}". In a language with
+ {overloading} (e.g. {Haskell}), an overloaded function might be
+ specialised to a non-overloaded instance at compile-time if
+ the types of its arguments are known.
+
+specification
+
+ <jargon> (spec) A document describing how some system should
+ work.
+
+ (2001-02-06)
+
+specific markup
+
+ In computerised document preparation, a method of adding
+ formatting commands to the text to control layout, such as new
+ line, new page, centre text etc.
+
+ Compare {generic markup}.
+
+ (2001-02-06)
+
+SPECint92
+
+ <benchmark> A {benchmark} result derived from the results of a
+ set of integer benchmarks from {SPEC} (geometric mean of the 6
+ {SPEC ratios} of {CINT92}) which can be used to estimate a
+ machine's single-tasking performance on integer code.
+
+ SPECint92 obsoletes SPECint89.
+
+ {Results (ftp://ftp.nosc.mil/pub/aburto/specin92.tbl)}.
+
+ See also {SPECbase_int92}.
+
+ (1994-11-14)
+
+SPECmark
+
+ <benchmark> The average of a set of {floating-point} and
+ integer {SPEC} {benchmark} results.
+
+ While the old average {SPECmark89} has been popular with the
+ industry and the press, {SPEC} has intentionally *not* defined
+ an average "SPECmark92" over all {CPU} {benchmarks} of the
+ 1992 suites ({CINT92} and {CFP92}), for the following reasons:
+ With 6 integer ({CINT92}) and 14 {floating-point} ({CFP92})
+ benchmarks, the average would be biased too much toward
+ floating-point. Customers' workloads are different, some
+ integer-only, some floating-point intensive, some mixed.
+ Current processors have developed their strengths in a more
+ diverse way (some more emphasizing integer performance, some
+ more floating-point performance) than in 1989.
+
+ Some SPECmark results are available {here
+ (ftp://ftp.cdf.toronto.edu/pub/spectable)}.
+
+ See also {SPECint92}, {SPECfp92}, {SPECrate_int92},
+ {SPECrate_fp92}.
+
+ (1994-11-15)
+
+SPECmark89
+
+ <benchmark> An old {SPECmark} {benchmark} result derived from
+ a set of {floating-point} and integer {benchmarks}. It is the
+ {geometric mean} of ten {SPEC ratios} of the outdated 1989
+ {SPEC} benchmark suite. The use of SPECmark89 is strongly
+ discouraged, having been superseded by {CINT92} and {CFP92}.
+
+ (1994-11-29)
+
+SPECOL
+
+ ["SPECOL - A Computer Enquiry Language for the
+ Non-Programmer", B.T. Smith, Computer J 11:121 (1968)].
+
+SPEC rate
+
+ <benchmark> Results of the throughput measurement using {SPEC}
+ {benchmark} suites {CINT92} and {CFP92}. With the throughput
+ measurement method, several copies of a given benchmark are
+ executed. The method is particularly suitable for
+ {multiprocessor} systems.
+
+ The results, called SPEC rate, express how many jobs of a
+ particular type (characterised by the individual benchmark)
+ can be executed in a given time (The SPEC reference time
+ happens to be a week, the execution times are normalized with
+ respect to a {VAX 11/780}). The SPEC rates therefore
+ characterise the capacity of a system for compute-intensive
+ jobs of similar characteristics.
+
+ See also {SPEC ratio}.
+
+ (1994-11-14)
+
+SPECrate_base_fp92
+
+ <benchmark> A variant of {SPECrate_fp92} that reports
+ "baseline" results, using stricter run rules.
+
+ (1994-11-15)
+
+SPECrate_fp92
+
+ <benchmark> A {benchmark} result derived from the results of a
+ set of {floating-point} benchmarks (the {geometric mean} of 14
+ {SPEC rates} from {CFP92}) run multiple times simultaneously,
+ which can be used to estimate a machine's overall
+ {multi-tasking} throughput for {floating-point} code. It is
+ typically used on {multiprocessor} machines.
+
+ SPECrate_fp92 obsoletes SPECfpThruput89.
+
+ (1994-11-14)
+
+SPECrate_int92
+
+ <benchmark> The integer {SPECrate} derived from the results of
+ a set of integer benchmarks (the {geometric mean} of six {SPEC
+ rates} from {CINT92}) run multiple times simultaneously, and
+ can be used to estimate a machine's overall {multi-tasking}
+ throughput for integer code. It is typically used on
+ {multiprocessor} machines.
+
+ SPECrate_int92 obsoletes SPECintThruput89.
+
+ See also {SPECbaserate}.
+
+ (1994-11-14)
+
+SPEC ratio
+
+ <benchmark> Results for each individual {benchmark} of the
+ {SPEC} benchmark suites, for example {CINT92} and {CFP92},
+ expressed as the ratio of the wall clock time to execute one
+ single copy of the benchmark, compared to a fixed "SPEC
+ reference time", which was chosen early-on as the execution
+ time on a {VAX 11/780}.
+
+ See also {SPEC rate}.
+
+ (1994-11-14)
+
+Spectral Band Replication
+
+ <audio, compression> (SBR) Guessing the nontransmitted higher
+ frequency range of a compressed audio file by some helper bits
+ (transmiited with the stream) and the transmitted base band.
+ SBR allows a restoration (not reconstruction) of the upper
+ frequency range without lots of bits. It was developed by
+ {Coding Technology (http://codingtechnology.com/)}, and is
+ useful for medium and high quality coding at low and medium
+ data rates. It is used by {Digital Radio Mondiale} and {MP3
+ Pro}.
+
+ (2004-12-10)
+
+Spectrum
+
+ {ZX Spectrum}
+
+speculative evaluation
+
+ <parallel> A technique used in {parallel processing} where
+ some evaluation may be started before it is known whether it
+ is needed (Eager evaluation). This may result in some wasted
+ processing and may introduce unnecessary non-terminating
+ processes but it can reduce the overall run time by making
+ some needed results available earlier than they would be
+ otherwise.
+
+ Opposite: {conservative evaluation}.
+
+ (1995-05-05)
+
+speculative execution
+
+ <processor> A technique allows a {superscalar} processor to
+ keep its {functional units} as busy as possible by executing
+ instructions before it is known that they will be needed.
+
+ The {Intel P6} uses speculative execution.
+
+ Compare {branch prediction}, {speculative evaluation}.
+
+ (1995-05-05)
+
+Speech Application Programming Interface
+
+ <programming, standard> (SAPI) {Microsoft}'s standard {API}
+ for speech synthesis and {speech recognition} in {Windows 95}.
+ The idea is to let developers try out and use various
+ low-level speech software from any number of verndors, while
+ retaining the same API.
+
+ Mike Rozak is the lead of the SAPI project at Microsoft.
+ Numerous major speech vendors have announced SAPI-support
+ plans. {SRAPI}, the competing speech recognition API by
+ {Lotus}/WordPerfect, is fast becoming obsolete.
+
+ (1996-03-04)
+
+speech recognition
+
+ <application> (Or voice recognition) The identification of
+ spoken words by a machine. The spoken words are digitised
+ (turned into sequence of numbers) and matched against coded
+ dictionaries in order to identify the words.
+
+ Most systems must be "trained," requiring samples of all the
+ actual words that will be spoken by the user of the system.
+ The sample words are digitised, stored in the computer and
+ used to match against future words. More sophisticated
+ systems require voice samples, but not of every word. The
+ system uses the voice samples in conjunction with dictionaries
+ of larger vocabularies to match the incoming words. Yet other
+ systems aim to be "speaker-independent", i.e. they will
+ recognise words in their vocabulary from any speaker without
+ training.
+
+ Another variation is the degree with which systems can cope
+ with connected speech. People tend to run words together,
+ e.g. "next week" becomes "neksweek" (the "t" is dropped). For
+ a voice recognition system to identify words in connected
+ speech it must take into account the way words are modified by
+ the preceding and following words.
+
+ It has been said (in 1994) that computers will need to be
+ something like 1000 times faster before large vocabulary (a
+ few thousand words), speaker-independent, connected speech
+ voice recognition will be feasible.
+
+ (1995-05-05)
+
+Speech Recognition Application Program Interface
+
+ <programming> (SRAPI) {Novell, Inc.}'s high level {API} for
+ {speech recognition} which will be rolled out with
+ {WordPerfect} 7.0 and {Perfect Office} 7.0. SRAPI is in
+ competition with {SAPI} from {Microsoft}, a high level API
+ which currently addresses command and control (but not yet
+ dictation).
+
+ [Byte; March 1996; page 30; "Battle of the Dictaion APIs"].
+
+ (1996-03-12)
+
+speech synthesis
+
+ The generation of an sound waveform of human speech from a
+ textual or phonetic description. See also {speech
+ recognition}.
+
+ There are demonstrations which {say a number
+ (http://cs.yale.edu/cgi-bin/saynumber.au)} or {say a
+ phrase (http://wwwtios.cs.utwente.nl/say/form/)}.
+
+SPEED
+
+ Early system on LGP-30. Listed in CACM 2(5):16 (May 1959).
+
+Speedcoding
+
+ <language> A {pseudocode} {interpreter} for mathematics on
+ {IBM 701} and {IBM 650} written by John Backus in 1953.
+
+ [Sammet 1969, p. 130].
+
+ (2000-03-27)
+
+Speedcoding 3
+
+ <language> [Listed in CACM 2(5):16, May 1959].
+
+ (2000-03-27)
+
+SPEEDEX
+
+ Early system on {IBM 701}. Listed in CACM 2(5):16 (May 1959).
+
+speedometer
+
+ A pattern of lights displayed on a linear set of LEDs (today)
+ or nixie tubes (yesterday, on ancient mainframes). The
+ pattern is shifted left every N times the operating system
+ goes through its {main loop}. A swiftly moving pattern
+ indicates that the system is mostly idle; the speedometer
+ slows down as the system becomes overloaded. The speedometer
+ on Sun Microsystems hardware bounces back and forth like the
+ eyes on one of the Cylons from the wretched "Battlestar
+ Galactica" TV series.
+
+ Historical note: One computer, the GE 600 (later Honeywell
+ 6000) actually had an *analog* speedometer on the front panel,
+ calibrated in instructions executed per second.
+
+ [{Jargon File}]
+
+spell
+
+ {incantation}
+
+spelling flame
+
+ <messaging> A {Usenet} posting ostentatiously correcting a
+ previous article's spelling, possibly as a way of casting
+ scorn on the point the article was trying to make, instead of
+ actually responding to that point (compare {dictionary
+ flame}). Of course, people who are more than usually slovenly
+ spellers are prone to think *any* correction is a spelling
+ flame. It's an amusing comment on human nature that spelling
+ flames themselves often contain spelling errors.
+
+ [{Jargon File}]
+
+ (1994-11-22)
+
+Sperry Corporation
+
+ <company> The company which merged with the {Burroughs
+ Corporation} to form {Unisys Corporation}. Divisions included
+ {Sperry Univac}, Sperry Flight Systems, and others. Some of
+ these were sold off after the merger.
+
+ (1995-03-27)
+
+Sperry Univac
+
+ <company> One of the divisions of {Sperry Corporation} at the
+ time that company merged with the {Burroughs Corporation} to
+ form {Unisys Corporation}.
+
+ [Connection with the {Univac} computer?]
+
+ (1994-11-22)
+
+SPG
+
+ System Program Generator. A compiler-writing language.
+
+ ["A System Program Generator", D. Morris et al, Computer J
+ 13(3) (1970)].
+
+SPGA
+
+ {Staggered Pin Grid Array}
+
+SPI
+
+ 1. <company> {Software in the Public Interest, Inc.}.
+
+ 2. <hardware> {Serial Peripheral Interface}.
+
+ (2003-07-13)
+
+Spice Lisp
+
+ <language> A flavour of {Lisp}, the sources of which (in Lisp)
+ are available from {CMU}.
+
+ (1998-03-14)
+
+SPID
+
+ Service Provider ID
+
+spider
+
+ <web> (Or "robot", "crawler") A program that
+ automatically explores the {web} by retrieving a
+ document and recursively retrieving some or all the documents
+ that are referenced in it. This is in contrast with a normal
+ {web browser} operated by a human that doesn't automatically
+ follow links other than {inline images} and {URL redirection}.
+
+ The {algorithm} used to pick which references to follow
+ strongly depends on the program's purpose. {Index}-building
+ spiders usually retrieve a significant proportion of the
+ references. The other extreme is spiders that try to validate
+ the references in a set of documents; these usually do not
+ retrieve any of the links apart from redirections.
+
+ The {standard for robot exclusion} is designed to avoid some
+ problems with spiders.
+
+ Early examples were {Lycos} and {WebCrawler}.
+
+ {Home
+ (http://info.webcrawler.com/mak/projects/robots/robots.html)}.
+
+ (2001-04-30)
+
+Spiderweb
+
+ <tool> A program for creating versions of {Knuth}'s {WEB}
+ self-documenting programs ("{literate programming}").
+
+ {(ftp://princeton.edu/)}.
+
+ (1999-08-26)
+
+spiffy
+
+ /spi'fee/ 1. Said of programs having a pretty, clever, or
+ exceptionally well-designed interface. "Have you seen the
+ spiffy {X} version of {empire} yet?" This was common
+ mainstream slang during the 1940s.
+
+ 2. Said sarcastically of a program that is perceived to have
+ little more than a flashy interface going for it. Which
+ meaning should be drawn depends delicately on tone of voice
+ and context.
+
+ [{Jargon File}]
+
+spike
+
+ <jargon> To defeat a selection mechanism by introducing a
+ (sometimes temporary) device that forces a specific result.
+ The word is used in several industries; telephone engineers
+ refer to spiking a relay by inserting a pin to hold the relay
+ in either the closed or open state, and railroaders refer to
+ spiking a track switch so that it cannot be moved. In
+ programming environments it normally refers to a temporary
+ change, usually for testing purposes (as opposed to a
+ permanent change, which would be called {hard-coded}).
+
+ (1999-10-18)
+
+spill
+
+ {register spilling}
+
+spim
+
+ <messaging> (From {spam} and {IM}) Unsolicited commercial
+ messages sent via an {instant messaging} system, instant
+ messenger spam.
+
+ (2008-01-21)
+
+spin
+
+ <programming, jargon> Equivalent to {buzz}. More common among
+ {C} and {Unix} programmers.
+
+ [{Jargon File}]
+
+ (2008-01-21)
+
+spin control
+
+ <interface> A type of input {control} available on most {graphical
+ user interfaces}, consisting of a {text box} or {list control}
+ with associated up and down {buttons}. The user can either type
+ in the text box or select an item from the list by clicking on it
+ directly, or they can repeatedly select the next or previous value
+ by clicking the up or down button.
+
+ (2008-09-26)
+
+spinner
+
+ {spin control}
+
+spiral model
+
+ <programming> A {software life-cycle} model which supposes
+ incremental development, using the {waterfall model} for each
+ step, with the aim of managing risk. In the spiral model,
+ developers define and implement features in order of
+ decreasing priority.
+
+ [Barry Boehm, "A Spiral Model of Software Development and
+ Enhancement", ACM SIGSOFT Software Engineering Notes, August
+ 1986].
+
+ [Barry Boehm "A Spiral Model of Software Development and
+ Enhancement" IEEE Computer, vol.21, #5, May 1988, pp 61-72].
+
+ [Better explanation?]
+
+ (1997-11-23)
+
+SPIT
+
+ Language for IBM 650. (See IT).
+
+SPITBOL
+
+ SPeedy ImplemenTation of snoBOL. "Macro SPITBOL - A SNOBOL4
+ Compiler", R.B.K. Dewar et al, Soft Prac & Exp 7:95-113, 1971.
+
+ Current versions: SPITBOL-68000, Sparc SPITBOL from Catspaw
+ Inc, (719)539-3884.
+
+spiware
+
+ <spelling> Misspelling of {spyware}.
+
+ (2008-10-07)
+
+SP/k
+
+ <language> (Subset PL/I, k=1..8) A series of {PL/I} subsets,
+ simplified for student use.
+
+ ["SP/k: A System for Teaching Computer Programming", R.C. Holt
+ et al, CACM 20(5):301-309, May 1977].
+
+ (1997-12-27)
+
+SPL
+
+ 1. Synchronous Programming Language. A DSP language.
+ "Introduction to the SPL Compiler", Computalker Consultants,
+ 1986.
+
+ 2. Space Programming Language. Realtime language used by the
+ US Air Force for aerospace software. Aka SPL/J6. Similar to
+ JOVIAL. "Space Programming Language Development", SAMSO TP
+ 70-325, System Development Corp (Sep 1970). (See CLASP).
+
+ 3. System Programming Language. HP, 1977. An ALGOL-like
+ language for the HP3000 computer allowing inline assembly
+ code. MPE, the OS for the HP3000 was written in SPL.
+ Pub.No.30000-90024, HP. See also {SPLash!}.
+
+ 4. Systems Programming Language.
+
+ PRIME Computer, 80's. A variant of PL/I used on PRIME
+ computers. PL/I subset G, less I/O plus a few extensions.
+ SPL User's Reference Guide, Prime. (See PL/P.)
+
+ 5. Systems Programming Language.
+
+ A PL/I subset/extension for the P1000.
+
+ D.B. Wortman, U Toronto.
+
+ Philips Data Sys, Netherlands, 1971.
+
+ Symbolic constants, pointer arithmetic, inline assembly code.
+ Used to implement compilers, operating systems, and database.
+
+ ["Experiences With SPL", J. Klunder in Machine Oriented Higher
+ Level Languages, W. van der Poel, N-H 1974, pp. 385-393].
+
+ [Can 4 and 5 be the same?]
+
+ 6. Student Programming Language.
+
+ A translator-interpreter for a dialect of {PL/I}.
+
+ 7. {Set Priority Level}
+
+ [{Jargon File}]
+
+ (1995-02-07)
+
+SPL/1
+
+ {SPL/I}
+
+SPLash!
+
+ 1. Software Research Northwest, 1987. Compiler for SPL[3].
+
+ 2. Systems Programming LAnguage for Software Hackers.
+ Mentioned in TeX for the Impatient, Paul W. Abrahams, A-W
+ 1990.
+
+splash screen
+
+ <programming> An initial screen displayed by interactive
+ software, usually containing a logo, version information,
+ author credits and/or a {copyright} notice.
+
+ The term originated among {Macintosh} users and spread, the
+ synonym {banner} was once also used.
+
+ [{Jargon File}]
+
+ (1998-04-28)
+
+splat
+
+ 1. Name used in many places (DEC, IBM, and others) for the
+ asterisk ("*") character (ASCII 0101010). This may derive
+ from the "squashed-bug" appearance of the asterisk on many
+ early line printers.
+
+ 2. Name used by some {MIT} people for the "#" character (ASCII
+ 35).
+
+ 3. (Rochester Institute of Technology) The {feature key} on a
+ Mac (same as {alt}).
+
+ 4. An obsolete name used by some people for the
+ {Stanford}/{ITS} {extended ASCII} circle-x character. This
+ character is also called "blobby" and "frob", among other
+ names; it is sometimes used by mathematicians as a notation
+ for "tensor product".
+
+ 5. An obsolete name for the semi-mythical {Stanford} {extended
+ ASCII} circle-plus character.
+
+ See also {ASCII}.
+
+ [{Jargon File}]
+
+ (1995-01-19)
+
+SPL/I
+
+ Signal Processing Language One.
+
+ (Or "SPL/1") A language designed by {Intermetrics} for
+ acoustic {signal processing}. It has graphics and
+ multiprocessing features.
+
+ ["SPL/I Language Reference Manual", M.S. Kosinski,
+ Intermetrics Report 172-1 (July 1976)].
+
+ (1995-01-19)
+
+SPLINTER
+
+ A {PL/I} {interpreter} with debugging features.
+
+ [Sammet 1969, p.600].
+
+ (1995-01-19)
+
+split
+
+ {chunker}
+
+Split-C
+
+ Parallel extension of {C} for distributed memory
+ multiprocessors. Aims to provide efficient low-level access
+ to the underlying machine.
+
+ {CM5 (ftp://ftp.cs.berkeley.edu/ucb/CASTLE/Split-C)}.
+ Mail-list: split-c@boing.cs.berkeley.edu.
+
+splot
+
+ <graphics, tool> A graph plotting package from {Stanford
+ University} which produces {encapsulated PostScript}.
+
+ splot is more flexible than {gnuplot} in producing histograms,
+ and you can set {font} and symbol sizes individually.
+
+ (1997-09-26)
+
+SPLX
+
+ <language> Specification Language for Parallel cross-product
+ of processes and sequential modules.
+
+ ["Parallel Module Specification on SPLX", C.F. Nourani,
+ SIGPLAN Notices 27(1):114-115, Jan 1992].
+
+ (1997-09-26)
+
+SPM
+
+ {Sequential Parlog Machine}
+
+SPMD
+
+ {single processor/multiple data}
+
+SPML
+
+ {server-parsed HTML}
+
+spod
+
+ <chat> (Great Britain) A lower form of life found on {chat}
+ systems and {MUDs}. The spod has few friends in {RL} and uses
+ chat instead, finding communication easier and preferable over
+ the {net}. He has all the negative traits of the {computer
+ geek} without having any interest in computers per se.
+ Lacking any knowledge of, or interest in, how networks work,
+ and considering his access a God-given right, he is a major
+ irritant to {sysadmins}, clogging up lines in order to reach
+ new {MUDs}, following passed-on instructions on how to sneak
+ his way onto {Internet} ("Wow! It's in America!") and
+ complaining when he is not allowed to use busy routes. A true
+ spod will start any conversation with "Are you male or
+ female?" (and follow it up with "Got any good
+ numbers/IDs/passwords?") and will not talk to someone
+ physically present in the same terminal room until they log
+ onto the same computer that he is using and enter {chat}.
+
+ Compare {newbie}, {tourist}, {weenie}, {twink}, {terminal
+ junkie}, {dweeb}.
+
+ [{Jargon File}]
+
+ (1998-01-18)
+
+spoiler
+
+ 1. A remark which reveals important plot elements
+ from books or movies, thus denying the reader (of the article)
+ the proper suspense when reading the book or watching the
+ movie.
+
+ 2. Any remark which telegraphs the solution of a problem or
+ puzzle, thus denying the reader the pleasure of working out
+ the correct answer (see also {interesting}). Either sense
+ readily forms compounds like "total spoiler", "quasi-spoiler"
+ and even "pseudo-spoiler".
+
+ By convention, {Usenet} news articles which are spoilers in
+ either sense should contain the word "spoiler" in the Subject:
+ line, or guarantee via various tricks that the answer appears
+ only after several screens-full of warning, or conceal the
+ sensitive information via {rot13}, or some combination of
+ these techniques.
+
+ [{Jargon File}]
+
+ (1995-01-18)
+
+sponge
+
+ <tool> A kind of {Unix} {filter} that reads its entire input
+ before writing any output, e.g. {sort}. Unlike most filters, a
+ sponge can safely overwrite the input file with the output data.
+
+ On a file system with {file versioning} (like {ITS} or {VMS}) the
+ distinction is less significant because output would be written to
+ a new version of the input file anyway.
+
+ See also {slurp}.
+
+ [{Jargon File}]
+
+ (2014-06-21)
+
+spoo
+
+ Variant of {spooge}, sense 1.
+
+ [{Jargon File}]
+
+spoof
+
+ {spoofing}
+
+spoofing
+
+ A technique used to reduce network overhead, especially in
+ {wide area networks} (WAN).
+
+ Some network {protocols} send frequent packets for management
+ purposes. These can be {routing} updates or {keep-alive}
+ messages. In a {WAN} this can introduce significant overhead,
+ due to the typically smaller {bandwidth} of WAN connections.
+
+ Spoofing reduces the required bandwidth by having devices,
+ such as {bridges} or {routers}, answer for the remote devices.
+ This fools (spoofs) the {LAN} device into thinking the remote
+ LAN is still connected, even though it's not. The spoofing
+ saves the WAN bandwidth, because no packet is ever sent out on
+ the WAN.
+
+ LAN {protocols} today do not yet accommodate spoofing easily.
+
+ ["Network Spoofing" by Jeffrey Fritz, BYTE, December 1994,
+ pages 221 - 224].
+
+ (1995-01-13)
+
+spooge
+
+ /spooj/ Inexplicable or arcane code, or random and probably
+ incorrect output from a computer program.
+
+ [{Jargon File}]
+
+ (1995-01-12)
+
+SPOOL
+
+ <operating system> Acronym for {Simultaneous Peripheral
+ Operation On-Line}; but see also {spool}.
+
+ [{Jargon File}]
+
+ (1996-05-20)
+
+Spool
+
+ <language> An {object-oriented} {logic programming} language.
+
+ ["An Experience with a Prolog Based Language", K. Fukunaga et
+ al, SIGPLAN Notices 21(11):224-231 (Nov 1986) (OOPSLA '86)].
+
+ [{Jargon File}]
+
+ (1995-03-25)
+
+spool
+
+ <operating system> To send files to some device or program (a
+ "{spooler}" or {demon}) that puts them in a {queue} for later
+ processing of some kind. Without qualification, the spooler
+ is the "print spooler" controlling output of jobs to a
+ {printer}; but the term has been used in connection with other
+ {peripherals} (especially {plotters} and graphics devices) and
+ occasionally even for input devices.
+
+ The term "SPOOL" has been attributed to {IBM} as an acronym
+ for {Simultaneous Peripheral Operation On-Line} but it's
+ widely thought to have been contrived for effect.
+
+ [No connection with "spool of magnetic tape"?]
+
+ [{Jargon File}]
+
+ (1996-05-20)
+
+spooler
+
+ <operating system, tool> Software or hardware to which data is
+ {spool}ed and which processes that data (e.g. prints it) in the
+ {background}.
+
+ (1995-03-25)
+
+spool file
+
+ Any file to which data is {spool}ed to await the next stage of
+ processing. Especially used in circumstances where spooling
+ the data copes with a mismatch between speeds in two devices
+ or pieces of software. For example, when you send mail under
+ Unix, it's typically copied to a spool file to await a
+ transport {demon}'s attentions.
+
+ [{Jargon File}]
+
+SpoolView
+
+ <tool> A printing system for {Unix}. SpoolView can control
+ several {printers} connected to a {TCP/IP} network. Different
+ printers can be loaded with different paper and forms.
+
+ After submitting a print request, the user can change the
+ printer, form, number of copies or priority.
+
+ Administrators can register new printers, change paper forms
+ on printers, cancel requests, suspend printers.
+
+ {Light Infocon S.A. (http://light.com.br/)}.
+
+ (1998-12-21)
+
+spray
+
+ <networking> A {Unix} command that sends {packets} to a {host}
+ and reports performance statistics. The number of packets,
+ delay between packets and packet length can all be specified.
+ The spray command uses the {Remote Procedure Call} (RPC)
+ {protocol} to send a one-way stream of packets to the sprayd
+ {daemon} on the given host. With the "-i" option, spray uses
+ the {Internet Control Message Protocol} (ICMP) instead of RPC.
+ Normally these will be echoed automatically, creating a return
+ stream.
+
+ {Unix manual page}: spray(1M).
+
+ (2007-03-12)
+
+spreadsheet
+
+ <application, tool> (Or rarely "worksheet") A type of
+ {application program} which manipulates numerical and string
+ data in rows and columns of cells. The value in a cell can be
+ calculated from a formula which can involve other cells. A
+ value is recalculated automatically whenever a value on which
+ it depends changes. Different cells may be displayed with
+ different formats.
+
+ Some spreadsheet support three-dimensional matrices and cyclic
+ references which lead to iterative calculation.
+
+ An essential feature of a spreadsheet is the copy function
+ (often using {drag-and-drop}). A rectangular area may be
+ copied to another which is a multiple of its size. References
+ between cells may be either absolute or relative in either
+ their horizontal or vertical index. All copies of an absolute
+ reference will refer to the same row, column or cell whereas a
+ relative reference refers to a cell with a given offset from
+ the current cell.
+
+ Many spreadsheets have a "What-if" feature. The user gives
+ desired end conditions and assigns several input cells to be
+ automatically varied. An area of the spreadsheet is assigned
+ to show the result of various combinations of input values.
+
+ Spreadsheets usually incorporate a {macro language}, which
+ enables third-party writing of worksheet applications for
+ commercial purposes.
+
+ In the 1970s, a {screen editor} based calculation program
+ called {Visi-Calc} was introduced. It was probably the first
+ commercial spreadsheet program. Soon {Lotus Development
+ Corporation} released the more sophisticated {Lotus 1-2-3}.
+ Clones appeared, (for example {VP-Planner} from {Paperback
+ Software} with {CGA} graphics, {Quattro} from {Borland}) but
+ Lotus maintained its position with world-wide marketing and
+ support - and lawyers! For example, Borland was forced to
+ abandon its Lotus-like {pop-up menu}.
+
+ While still developing 1-2-3, Lotus introduced {Symphony},
+ which had simultaneously active windows for the spreadsheet,
+ graphs and a {word processor}.
+
+ {Microsoft} produced {MultiPlan} for the {Macintosh}, which
+ was followed by {Excel} for Macintosh, long before {Microsoft
+ Windows} was developed.
+
+ When {Microsoft Windows} arrived Lotus was still producing the
+ {text-based} 1-2-3 and Symphony. Meanwhile, {Microsoft}
+ launched its {Excel} spreadsheet with interactive graphics,
+ graphic charcters, mouse support and {cut-and-paste} to and
+ from other Windows applications. To compete with Windows
+ spreadsheets, Lotus launched its {Allways} add-on for 1-2-3 -
+ a post-processor that produced Windows-quality graphic
+ characters on screen and printer. The release of Lotus 1-2-3
+ for Windows was late, slow and buggy.
+
+ Today, Microsoft, Lotus, Borland and many other companies offer
+ Windows-based spreadsheet programs.
+
+ The main end-users of spreadsheets are business and science.
+
+ Spreadsheets are an example of a non-algorithmic programming
+ language.
+
+ [Dates?]
+
+ (1995-03-28)
+
+spread spectrum communications
+
+ <communications> (Or "spread spectrum") A technique by which a
+ signal to be transmitted is modulated onto a {pseudorandom},
+ noise-like, wideband {carrier signal}, producing a
+ transmission with a much larger {bandwidth} than that of the
+ data {modulation}.
+
+ Reception is accomplished by {cross correlation} of the
+ received wide band signal with a synchronously generated
+ replica of the carrier.
+
+ Spread-spectrum communications offers many important benefits:
+
+ Low probability of detection, interception or determination of
+ the transmitter's location. To an observer who does not
+ possess information about the carrier, the transmission is
+ indistinguishable from other sources of noise.
+
+ High immunity against interference and jamming (intentional
+ interference). The presence of (narrowband) interference
+ signals only decreases the channel's {signal-to noise ratio}
+ and therefore its {error rate}, which can be dealt with by
+ using {error correcting codes}. A jammer would have to use
+ wideband interference signals, which would require very high
+ power (again assuming that the jammer does not know the
+ characteristics of the carrier).
+
+ High immunity against adverse effects of multipath
+ transmission. In the presence of multiple paths between
+ transmitter and receiver (e.g. by reflected signals), signals
+ of certain frequencies can be cancelled at certain locations
+ when the difference in path delays between multiple
+ propagation paths cause the signals to arrive out of phase.
+ This effect is particularly troublesome in narrowband mobile
+ communications, where it causes "blind spots" - locations
+ where no signal can be received.
+
+ Transmitter/receiver pairs using independent random carriers
+ can operate in the same frequency range with minimal
+ interference. These are called {Code Division Multiple
+ Access} (CDMA) systems. Increasing the number of T/R pairs
+ again only gradually increases each channel's error rate. In
+ contrast, narrowband systems can only accomodate a fixed
+ number of channels determined by available bandwidth and
+ channel width (data rate).
+
+ When the data modulation cannot be distinguished from the
+ carrier modulation, and the carrier modulation is random to an
+ unwanted observer, the spread spectrum system assumes
+ cryptographic capabilities, with the carrier modulation taking
+ on the function of a key in a {cipher} system.
+
+ The most important practical modes of spread spectrum coding
+ are Direct Sequence (DS) and {Frequency-Hopping Spread
+ Spectrum} (FH).
+
+ In DS, a pseudo random sequence is phase-shift-keyed (PSK)
+ onto the carrier.
+
+ Spread Spectrum development began during World War II, with
+ the earliest studies dating from the 1920s. Most papers
+ remained classified until the 1980s.
+
+ Direct sequence spread spectrum was invented by Paul Kotowski
+ and Kurt Dannehl at Telefunken.
+
+ The technique is used extensively in military communications
+ today. Commercial applications include {cellular telephony}
+ and mobile networking.
+
+ ["Spread Spectrum Communications", Charles E. Cook et al
+ (Ed.), IEEE Press, New York, 1983. ISBN 0-87942-170-3].
+
+ {Hedy Lamarr (http://sirius.be/lamarr.htm)},
+ {(http://ncafe.com/chris/pat2/)}.
+
+ (2001-08-08)
+
+SPRING
+
+ {String PRocessING language}
+
+SPRINT
+
+ List processing language involving stack operations. "SPRINT
+ - A Direct Approach to List Processing Languages", C.A. Kapps,
+ Proc SJCC 30 (1967). Sammet 1969, p 462.
+
+Sprintnet
+
+ A public {packet-switched} network using the {ITU-T} {X.25}
+ {protocols}, that provides {dial-up} access to services like
+ {Delphi}, {Portal}, {GEnie} and {Compuserve}.
+
+ (1994-10-17)
+
+Sprite
+
+ <operating system> An {operating system} from {Berkeley}
+ supporting {multiprocessing} and distributed files.
+
+ [Details? References?]
+
+ (1994-10-17)
+
+sprite
+
+ <graphics, file format> A small {bitmap} image, often used in
+ animated games but also sometimes used as a synonym for
+ {icon}.
+
+ (1997-06-29)
+
+sprocket feed
+
+ <printer> (Or "tractor feed", "pin feed") A method some
+ {printers} use to move paper by rotating wheels with pins or
+ studs (tractors) that engage holes along the sides of the
+ (usually fanfold) paper. A sprocket feed printer does not
+ slip unless the paper jams, but cannot feed standard typing
+ paper or work with a {sheet feeder} like {friction feed}.
+
+ Some paper for sprocket feed printers has the edge strips with
+ the holes in detachable from the rest of the paper. These
+ strips are known as {chad} (and other names).
+
+ (1997-06-29)
+
+SPS
+
+ Symbolic Programming System. Assembly language for IBM 1620.
+
+SPSS
+
+ {Statistical Package for the Social Sciences}
+
+SPSS, Inc.
+
+ <company> A company selling a variety of {software} under the
+ general description of "Statistical Product and Service
+ Solutions".
+
+ The company was founded to distribute and support the
+ {Statistical Package for the Social Sciences}, but now
+ supplies software or four broad markets: {data mining},
+ survey/market research, quality improvement, and scientific
+ research.
+
+ {(http://spss.com/)}.
+
+ (1999-07-20)
+
+SPUR
+
+ An early system on the {IBM 650}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1994-12-01)
+
+SPX
+
+ 1. <networking> {Sequenced Packet Exchange}.
+
+ 2. <application> A graphics program for the {Atari} microcomputer.
+
+ {(ftp://src.doc.ic.ac.uk/computing/systems/atari/umich/Graphics/spx_v18.lzh)}.
+
+ 3. {Simplex}.
+
+ (1997-03-04)
+
+spx
+
+ <filename extension> The {filename extension} for {Screen
+ Peace} eXtension files.
+
+ (1995-03-14)
+
+spyware
+
+ <software> (Or "adware") Any type of software that transmits
+ information without the user's knowledge.
+
+ Information is sent via the {Internet} to a server somewhere,
+ normally as a hidden side effect of using a program.
+ Gathering this information may benefit the user indirectly,
+ e.g. by helping to improve the software he is using. It may
+ be collected for advertising purposes or, worst of all, to
+ steal security information such as passwords to online
+ accounts or credit card details.
+
+ Spyware may be installed along with other software or as the
+ result of a {virus} infection. There are many tools available
+ to locate and remove various forms of spyware from a computer.
+
+ Some {HTTP cookies} could be considered as spyware as their
+ use is generally not made explicit to users. It is however
+ possible to disallow them, either totally or individually, and
+ some are actually useful, e.g. recording the fact that a user
+ has logged in.
+
+ {(http://spychecker.com/spyware.html)}.
+
+ (2004-05-23)
+
+\sqcap
+
+ {LaTeX} inverted square U. The symbol for {greatest lower
+ bound}.
+
+ (1994-12-01)
+
+\sqcup
+
+ {LaTeX} square U. The symbol for {least upper bound}.
+
+ (1994-12-01)
+
+SQE
+
+ {Signal Quality Error}
+
+ {IEEE 802.3}, {Ethernet}. Equivalent to {D/I/X} "{Collision
+ Presence Test}".
+
+ (1995-04-14)
+
+SQL
+
+ <language, database, standard> /S Q L/ An industry-standard
+ language for creating, updating and, querying {relational
+ database management systems}.
+
+ SQL was developed by {IBM} in the 1970s for use in {System R}.
+ It is the {de facto standard} as well as being an {ISO} and
+ {ANSI} {standard}. It is often embedded in general purpose
+ programming languages.
+
+ The first SQL standard, in 1986, provided basic language
+ constructs for defining and manipulating {tables} of data; a
+ revision in 1989 added language extensions for {referential
+ integrity} and generalised {integrity} {constraints}. Another
+ revision in 1992 provided facilities for {schema} manipulation
+ and {data administration}, as well as substantial enhancements
+ for data definition and data manipulation.
+
+ Development is currently underway to enhance SQL into a
+ computationally complete language for the definition and
+ management of {persistent}, complex objects. This includes:
+ generalisation and specialisation hierarchies, {multiple
+ inheritance}, user defined {data types}, {triggers} and
+ {assertions}, support for {knowledge based systems},
+ {recursive query expressions}, and additional data
+ administration tools. It also includes the specification of
+ {abstract data types} (ADTs), object identifiers, {methods},
+ {inheritance}, {polymorphism}, {encapsulation}, and all of the
+ other facilities normally associated with object data
+ management.
+
+ The emerging {SQL3} standard is expected to be complete in
+ 1998.
+
+ According to Allen G. Taylor, SQL does __not__ stand for
+ "Structured Query Language". That, like "SEQUEL" (and its
+ pronunciation /see'kw*l/), was just another unofficial name
+ for a precursor of SQL. However, the IBM SQL Reference manual
+ for DB2 and Craig Mullins's "DB2 Developer's Guide" say SQL
+ __does__ stand for "Structured Query Language".
+
+ {SQL Standards (http://jcc.com/sql_stnd.html)}.
+
+ {An SQL parser
+ (ftp://ftp.ora.com/published/oreilly/nutshell/lexyacc/)} is
+ described in "Lex & Yacc", by Levine, Mason & Brown published
+ by O'Reilly.
+
+ {The 1995 SQL Reunion: People, Projects, and Politics
+ (http://mcjones.org/System_R/SQL_Reunion_95/)}.
+
+ ["A Guide to the SQL Standard", C.J. Date, A-W 1987].
+
+ ["SQL for Dummies", Allen G. Taylor, IDG Books Worldwide].
+
+ (2005-11-17)
+
+SQL2
+
+ <database, standard, language> An extended version of the
+ {SQL} {standard}.
+
+ (1995-03-20)
+
+SQL3
+
+ <database, standard, language> A draft {standard} for another
+ extension of {SQL}. The latest SQL3 Working Draft addresses
+ the requirement for {objects} and "object identifiers" in SQL
+ and also specifies supporting features such as
+ {encapsulation}, {subtypes}, {inheritance}, and
+ {polymorphism}.
+
+ In the USA, SQL3 is being processed as both an {ANSI} Domestic
+ ("D") project and as an {ISO} project. It is expected to be
+ complete in 1998.
+
+ {November 1992 paper
+ (ftp://speckle.ncsl.nist.gov/isowg3/dbl/BASEdocs/sql3overview.txt)}.
+
+ {Working draft (ftp://gatekeeper.dec.com/pub/standards/sql/)}.
+
+ [ISO/IEC SQL Revision. ISO-ANSI Working Draft Database
+ Language SQL (SQL3), Jim Melton - Editor, document ISO/IEC
+ JTC1/SC21 N6931, {ANSI}, July 1992].
+
+ [Current Status?]
+
+ (2002-04-21)
+
+SQL Access Group
+
+ <body> The origanisaton which defined {Call-Level Interface},
+ on which {ODBC} is based. It is now part of {X/Open}.
+
+ [Address, details?]
+
+ (1995-11-05)
+
+SQL/DS
+
+ A database package from IBM including a relational DBMS.
+
+SQL Module Language
+
+ A language used to interface other languages ({Ada}, {C},
+ {COBOL}) to {SQL}-based {DBMS}es. It is an {ANSI} {standard}.
+
+ Version: Ada/{SAME} by {Informix}.
+
+ (1994-11-23)
+
+SQL Server
+
+ <database> (Note capitalised)
+
+ 1. Sybase {Adaptive Server Enterprise}.
+
+ 2. {Microsoft SQL Server}.
+
+ (2003-07-02)
+
+SQL server
+
+ <database> (Note not capitalised) Any {database management
+ system} (DBMS) that can respond to queries from {clients}
+ formatted in the {SQL} language.
+
+ Two popular examples are {Microsoft SQL Server} and {Sybase
+ SQL Server}.
+
+ (1997-12-07)
+
+SQLWindows
+
+ <programming, product> A package used to graphically develop
+ {MS-Windows} {client-server} applications. Sold by {Gupta}
+ Corporation.
+
+ {(http://wji.com/gupta/w1000030.html)}.
+ {Demos FTP (ftp://wji.com/gupta/sqlw.demodisk/)}.
+
+ (1995-07-05)
+
+SQR
+
+ <database, language> A {fourth generation language} for the
+ creation of reports from {databases}. SQR is interpreted to
+ dynamically generate {SQL} queries and format the results.
+
+ Originally a {Sybase} product, it was then sold to MITI, who
+ subsequently changed their name to {SQRIBE}.
+
+ SQR Server supports {native} database access for all major
+ {DBMSs} and the use of {platform} independent {Java} code.
+
+ (1998-09-19)
+
+SQRIBE
+
+ <company> The company formerly known as MITI which bought
+ {SQR} from {Sybase}.
+
+ {(http://sqribe.com/)}.
+
+ (1998-09-24)
+
+\sqsubseteq
+
+ {LaTeX} name for a symbol like a capital E without the bottom
+ half of its vertical line.
+
+ In {domain theory},
+
+ x \sqsubseteq y
+
+ means x is no more defined that y. This expression only has
+ meaning if x and y are {comparable} elements of some
+ {partially ordered set}.
+
+ (1994-11-24)
+
+Square
+
+ <language> A {query language}, a precursor to {SQL}.
+
+ ["Specifying Queries as Relational Expressions: The SQUARE
+ Data Sublanguage", R.E. Boyce et al, CACM 18(11):621-628 (Nov
+ 1975)].
+
+ (1995-05-02)
+
+square-headed boyfriend
+
+ {square-headed girlfriend}
+
+square-headed girlfriend
+
+ <humour> A computer.
+
+ (1999-01-15)
+
+square tape
+
+ <storage> {Mainframe} magnetic tape cartridges for use with
+ {IBM 3480} or compatible tape drives; or {QIC} tapes used on
+ {workstations} and {microcomputers}. The term comes from the
+ square (actually rectangular) shape of the cartridges;
+ contrast {round tape}.
+
+ [{Jargon File}]
+
+Squeak
+
+ <language> 1. <graphics>
+
+ ["Squeak: A Language for Communicating with Mice", L. Cardelli
+ et al, Comp Graphics 19(3):199-204, July 1985].
+
+ See {Newsqueak}.
+
+ 2. A {Smalltalk} implementation and a media {authoring} tool
+ by members of the original {Xerox PARC} team which created
+ Smalltalk ({Alan Kay}, Dan Ingalls, et al). Squeak is an
+ {open-source} implementation, with a highly portable {virtual
+ machine} implemented in a subset of Smalltalk (translated into
+ {C} and compiled by a C {compiler} of the target {platform}).
+
+ {Squeak Home (http://squeak.org/)}.
+
+ {SqueakCentral (http://squeakland.org/)}.
+
+ (2002-11-03)
+
+Squiggol
+
+ {Bird-Meertens Formalism}
+
+squirt the bird
+
+ <jargon, communications> To transmit a signal up to a
+ satellite. "Crew and talent are ready, what time do we squirt
+ the bird?"
+
+ (1997-04-29)
+
+SR
+
+ <language> Synchronizing Resources.
+
+ A language for concurrent programming.
+
+ "Resources" encapsulate processes and variables they share.
+ Each Resource can be separately compiled. "Operations"
+ provide the primary mechanism for process interaction.
+
+ SR provides a novel integration of the mechanisms for invoking
+ and servicing operations. Consequently, it supports local and
+ {remote procedure call}, {rendezvous}, {message passing},
+ {dynamic process creation}, {multicast}, {semaphores} and
+ {shared memory}.
+
+ Version 2.2 has been ported to {Sun-3}, {Sun-4}, {Decstation},
+ {SGI Iris}, {HP PA}, {HP 9000/300}, {NeXT}, {Sequent
+ Symmetry}, {DG AViiON}, {RS/6000}, {Multimax}, {Apollo} and
+ others.
+
+ {(ftp://cs.arizona.edu/sr/sr.tar.Z)}.
+
+ E-mail: <sr-project@cs.arizona.edu>. Mailing list:
+ info-sr-request@cs.arizona.edu.
+
+ ["An Overview of the SR Language and Implementation", G.
+ Andrews, ACM TOPLAS 10:51-86 (Jan 1988)].
+
+ ["The SR Programming Language: Concurrency in Practice",
+ G.R. Andrews et al, Benjamin/Cummings 1993, ISBN
+ 0-8053-0088-0].
+
+ (1992-09-01)
+
+sr
+
+ <networking> The {country code} for Suriname.
+
+ (1999-01-27)
+
+SRAM
+
+ {static random-access memory}
+
+SRAPI
+
+ {Speech Recognition Application Program Interface}
+
+SRC Modula-3
+
+ Version 2.11
+
+ compiler(->C), run-time, library, documentation
+
+ The goal of Modula-3 is to be as simple and safe as it
+ can be while meeting the needs of modern systems
+ programmers. Instead of exploring new features, we
+ studied the features of the Modula family of languages
+ that have proven themselves in practice and tried to
+ simplify them into a harmonious language. We found
+ that most of the successful features were aimed at one
+ of two main goals: greater robustness, and a simpler,
+ more systematic type system. Modula-3 retains one of
+ Modula-2's most successful features, the provision for
+ explicit interfaces between modules. It adds objects
+ and classes, exception handling, garbage collection,
+ lightweight processes (or threads), and the isolation
+ of unsafe features.
+
+ conformance: implements the language defined in SPwM3.
+
+ ports: i386/AIX 68020/DomainOS Acorn/RISCiX MIPS/Ultrix
+ 68020/HP-UX RS/6000/AIX IBMRT/4.3 68000/NEXTSTEP i860/SVR4
+ SPARC/SunOS 68020/SunOS sun386/SunOS Multimax/4.3 VAX/Ultrix
+
+ Mailing list: comp.lang.modula3
+
+ E-mail: Bill Kalsow <kalsow@src.dec.com>
+
+ From DEC/SRC, Palo Alto, CA. "Modula-3 Report (revised)"
+ Luca Cardelli et al.
+
+ {(ftp://gatekeeper.dec.com/DEC/Modula-3/)}.
+
+ (1992-02-09)
+
+SRDL
+
+ Small {algebraic specification language}, allows {distfix
+ operators}.
+
+ ["A Constructive Method for Abstract Algebraic Software
+ Specification", H. Klaeren, Theor Computer Sci 30,
+ pp.134-204, 1984].
+
+SR flip-flop
+
+ <hardware> (Or "RS flip-flop") A "set/reset" {flip-flop} in
+ which activating the "S" input will switch it to one stable
+ state and activating the "R" input will switch it to the other
+ state.
+
+ The outputs of a basic SR flip-flop change whenever its R or S
+ inputs change appropriately. A clocked SR flip-flop has an
+ extra clock input which enables or disables the other two
+ inputs. When they are disabled the outputs remain constant.
+
+ If we connect two clocked SR flip-flops so that the Q and /Q
+ outputs of the first, "master" flip-flop drive the S and R
+ inputs of the second, "slave" flip-flop, and we drive the
+ slave's clock input with an inverted version of the master's
+ clock, then we have an {edge-triggered} RS flip-flop. The
+ external R and S inputs of this device are latched on one edge
+ (transition) of the clock (e.g. the falling edge) and the
+ outputs will only change on the next opposite (rising) edge.
+
+ If both R and S inputs are active (when enabled), a {race
+ condition} occurs and the outputs will be in an indeterminate
+ state. A {JK flip-flop} avoids this possibility.
+
+ {(http://play-hookey.com/digital/logic4.html)}.
+
+ (1997-05-15)
+
+SRI
+
+ {SRI International}
+
+SRI International
+
+ <company> One of the world's largest contract research firms.
+ Founded in 1946 in conjuction with {Stanford University} as
+ the Stanford Research Institute, they later became fully
+ independent and were incorporated as a non-profit organisation
+ under U.S. and California laws.
+
+ SRI does research and development in many areas, independently
+ and for hire. They produce and sell reports on the
+ independent research.
+
+ {(http://sri.com/)}.
+
+ Address: Menlo Park, California, USA; Cambridge, UK.
+
+ (2003-04-12)
+
+SRL
+
+ 1. Bharat Jayaraman.
+
+ ["Towards a Broader Basis for Logic Programming",
+ B. Jayaraman, TR CS Dept, SUNY Buffalo, 1990].
+
+ 2. {Schema Representation language}.
+
+ 3. {Structured Robot Language}.
+
+ C. Blume & W. Jacob, U Karlsruhe.
+
+ (1995-01-26)
+
+SRP
+
+ A {data link layer} {protocol}.
+
+SS7
+
+ {Signalling System 7}
+
+SSA
+
+ {Single Static Assignment}
+ {Serial Storage Architecture}
+
+SSADM
+
+ A software engineering method and toolset required by some UK
+ government agencies.
+
+SSBA
+
+ {Suite Synthetique des Benchmarks de l'AFUU}
+
+SSD
+
+ 1. {Solid State Disk}
+
+ 2. {Seven-Segment Display}
+
+SSE
+
+ {Streaming SIMD Extensions}
+
+SSE-2
+
+ <architecture> {Intel Corporation}'s extention of their {SSE}
+ {floating point} {SIMD} instructions to handle 64-bit floating
+ point numbers. SSE-2 was introduced with the {Pentium 4}.
+
+ (2001-12-23)
+
+ssh
+
+ <operating system> 1. {Steve's Shell}.
+
+ 2. {Secure Shell}.
+
+ (1997-01-07)
+
+SSH File Transfer Protocol
+
+ <networking> (SFTP) A version of {File Transfer Protocol}
+ (FTP) using an {encrypted} network connection provided by
+ {Secure Shell} (SSH), usually SSH 2.
+
+ The SFTP {protocol} allows for a range of operations on remote
+ files, making it more like a {remote file system} protocol.
+ SFTP clients can resume interrupted transfers, get directory
+ listings and remove remote files. SFTP has largely replaced
+ {Secure Copy} (SCP).
+
+ {IETF spec
+ (http://ietf.org/internet-drafts/draft-ietf-secsh-filexfer-13.txt)}.
+
+ (2006-09-28)
+
+SSI
+
+ 1. <electronics> {small scale integration}.
+
+ 2. <computer> A kind of {PDP-11}(?).
+
+ [What kind?]
+
+ 3. <web> {server-side include}.
+
+ (1996-09-08)
+
+SSID
+
+ {Service Set Identifier}
+
+SSII
+
+ {Societe de Service en Ingenierie Informatique}
+
+SSL
+
+ 1. <language> {Synthesizer Specification Language}.
+
+ 2. <language> {Syntax/Semantic Language} (S/SL).
+
+ 3. <networking, web> {Secure Sockets Layer}.
+
+ (1996-09-08)
+
+S/SL
+
+ {Syntax/Semantic Language}
+
+SSLeay
+
+ <networking, security, protocol> A free implementation of
+ {Netscape}'s {Secure Socket Layer} {protocol}, coded from
+ scratch, using only the publically available documentation of
+ the various protocols, by Eric Young in Australia.
+
+ SSLeay supports the {DES}, {RSA}, {RC4}, and {IDEA}
+ {encryption} {algorithms}.
+
+ [Home?]
+
+ (2000-12-07)
+
+SSMA
+
+ <chat> some such meaningless acronym.
+
+ (1998-10-30)
+
+SSO
+
+ {single sign-on}
+
+SSR
+
+ {Scalable Sampling Rate}
+
+st
+
+ <networking> The {country code} for Sao Tome and Principe.
+
+ (1999-01-27)
+
+ST-506
+
+ <storage> The first full-height 5.25 inch {hard disk drive}
+ for {personal computers}, introduced in 1980 by Shugart
+ Technology (now {Seagate Technology}). The ST-506 stored up
+ to 5 {megabtyes} after {formatting} using {MFM encoding}. It
+ transferred data at 625 {kilobytes per second}.
+
+ The ST-506 (like the {ST-412}) was interfaced to a computer
+ via a {disk controller}. The interface was a faster version
+ of the Shugart Associates {SA1000} interface, which was in
+ turn based upon the {floppy disk drive} interface. Two cables
+ connected the controller to the disk. The 34-pin control
+ cable controlled mechanical motion and data was read or
+ written serially using two pins of the 20-pin data cable.
+
+ Other companies copied the interface, creating a universal {de
+ facto standard} that was further strengthened by its revision
+ to support Seagate's 10 MB ST-412 drive that was adopted for
+ the {IBM PC XT}.
+
+ Around 1990, {SCSI} and {ATA} superseded ST-506. These
+ eliminated the problems of matching controllers to drives by
+ physically integrating a controller with the drive, allowing
+ {interleave ratios} and other disk parameters to be optimised
+ by the manufacturer rather than the system integrator.
+
+ {Connector pin-out (http://www.gamesx.com/hwb/co_ST506.html)}.
+
+ (2007-03-06)
+
+STAB
+
+ <language> A descendent of {BCPL}.
+
+ (1996-08-25)
+
+STAB-11
+
+ ["The Translation and Interpretation of STAB-11", A.J.T. Colin
+ et al, Soft Prac & Exp 5(2):123-138, Apr 1975].
+
+ (1996-08-25)
+
+STAC
+
+ 1. <language> {Storage Allocation and Coding Program}.
+
+ 2. <company> The company responsible for {Stacker} and {stac
+ compression}.
+
+ {(http://stac.com/)}.
+
+ (1998-06-08)
+
+stac compression
+
+ <communications> A {data compression} technique from {STAC},
+ used with {modems}. Stac compression is capable of
+ compressing data by a factor of about four.
+
+ [Details?]
+
+ (1998-06-08)
+
+stack
+
+ <programming> (See below for synonyms) A data structure for
+ storing items which are to be accessed in last-in first-out
+ order.
+
+ The operations on a stack are to create a new stack, to "push"
+ a new item onto the top of a stack and to "pop" the top item
+ off. Error conditions are raised by attempts to pop an empty
+ stack or to push an item onto a stack which has no room for
+ further items (because of its implementation).
+
+ Most processors include support for stacks in their
+ {instruction set architectures}. Perhaps the most common use
+ of stacks is to store {subroutine} arguments and return
+ addresses. This is usually supported at the {machine code}
+ level either directly by "jump to subroutine" and "return from
+ subroutine" instructions or by {auto-increment} and
+ auto-decrement {addressing modes}, or both. These allow a
+ contiguous area of memory to be set aside for use as a stack
+ and use either a special-purpose {register} or a general
+ purpose register, chosen by the user, as a {stack pointer}.
+
+ The use of a stack allows subroutines to be {recursive} since
+ each call can have its own calling context, represented by a
+ stack frame or {activation record}. There are many other
+ uses. The programming language {Forth} uses a data stack in
+ place of variables when possible.
+
+ Although a stack may be considered an {object} by users,
+ implementations of the object and its access details differ.
+ For example, a stack may be either ascending (top of stack is
+ at highest address) or descending. It may also be "full" (the
+ stack pointer points at the top of stack) or "empty" (the
+ stack pointer points just past the top of stack, where the
+ next element would be pushed). The full/empty terminology is
+ used in the {Acorn Risc Machine} and possibly elsewhere.
+
+ In a list-based or {functional language}, a stack might be
+ implemented as a {linked list} where a new stack is an empty
+ list, push adds a new element to the head of the list and pop
+ splits the list into its head (the popped element) and tail
+ (the stack in its modified form).
+
+ At {MIT}, {pdl} used to be a more common synonym for stack,
+ and this may still be true. {Knuth} ("The Art of Computer
+ Programming", second edition, vol. 1, p. 236) says:
+
+ Many people who realised the importance of stacks and queues
+ independently have given other names to these structures:
+ stacks have been called push-down lists, reversion storages,
+ cellars, dumps, nesting stores, piles, last-in first-out
+ ("LIFO") lists, and even yo-yo lists!
+
+ [{Jargon File}]
+
+ (1995-04-10)
+
+Stack Environment Control Dump machine
+
+ (SECD machine) The first {abstract machine} for reducing
+ {lambda-calculus} expressions, invented by P. J. Landin. The
+ machine has four {registers} holding pointers to {linked
+ lists} operated as push-down {stacks} which hold the
+ information required for the evaluation of an expression. The
+ registers point to (1) Stack which holds the arguments of
+ partially evaluated expressions and results of completely
+ evaluated ones, (2) Environment where the current expression
+ being evaluated is stored, (3) Control which holds the machine
+ instructions that manipulate the contents of the four
+ registers that represent the expression being evaluated, (4)
+ Dump on which the state of the machine is temporarily saved
+ during the evaluation of expressions. See also {Lispkit}.
+
+stack frame
+
+ {activation record}
+
+stacking order
+
+ <graphics> The relationship between {windows} that (partially)
+ obscure each other. A {window manager} will include commands
+ to alter the stacking order by bringing a chosen window to the
+ front (top) or back (bottom) of the stack.
+
+ (1995-03-21)
+
+stack loader
+
+ <hardware, storage> (Or "autoloader") A {magnetic tape} drive
+ that can automatically fetch tapes from a stack and load them.
+
+ Compare {jukebox}.
+
+ [Sequential or random access?]
+
+ (1996-12-12)
+
+stack overflow
+
+ <programming> An error condition which results from attempting
+ to {push} more items onto a {stack} than space has been
+ allocated for. Often, this will simply overwrite the adjacent
+ memory locations causing hard-to-trace {bugs}.
+
+ Stack overflow can result, for example, from an insufficient
+ number of stack frames to handle hardware {interrupts}.
+
+ (1995-03-21)
+
+stack pointer
+
+ <architecture, programming> (SP) A {register} or {variable}
+ pointing to the top of a {stack}.
+
+ (2004-11-08)
+
+stack puke
+
+ Some processor architectures are said to "puke their guts onto
+ the stack" to save their internal state during {exception}
+ processing. The {Motorola 68020}, for example, regurgitates
+ up to 92 bytes on a {bus fault}. On a {pipeline}d machine,
+ this can take a while.
+
+ [{Jargon File}]
+
+ (1994-11-01)
+
+stack traceback
+
+ <programming> (The results of) determining the sequence of
+ nested procedure calls a program has made up to a certain
+ point in its execution. A traceback may also show values of
+ procedure arguments and {local variables} stored on the stack.
+
+ (1995-03-21)
+
+STAGE2
+
+ A {macro} language.
+
+ ["The Mobile Programming System: STAGE2", W.M. Waite, CACM
+ 13:415 (1970)].
+
+ (1994-10-27)
+
+Staggered Pin Grid Array
+
+ <hardware> (SPGA) A style of {integrated circuit} socket or
+ pin-out with a staggered grid of pins around the edge of the
+ socket, positioned as several squares, one inside the other.
+
+ SPGA is commonly used on {motherboards} for {processors},
+ e.g. {Socket 5}, {Socket 7} and {Socket 8}.
+
+ See also {PGA}.
+
+ [Better description?]
+
+ (1999-08-04)
+
+staircase
+
+ {jaggies}
+
+staircasing
+
+ {jaggies}
+
+@stake
+
+ <security, software> A computer security development group and
+ consultancy dedicated to researching and documenting security
+ flaws that exist in {operating systems}, {network}
+ {protocols}, or software.
+
+ @stake publishes information about security flaws through
+ advisories, research reports, and tools. They release the
+ information and tools to help system administrators, users,
+ and software and hardware vendors better secure their
+ systems.
+
+ L0pht merged with @stake in January 2000.
+
+ {@stake home (http://atstake.com/research/redirect.html)}.
+
+ (2003-06-12)
+
+stale pointer bug
+
+ <programming> (Or "aliasing bug") A class of subtle
+ programming errors that can arise in code that does {dynamic
+ allocation}, especially via {malloc} or equivalent.
+
+ If several {pointers} address (are "aliases for") a given hunk
+ of storage, it may happen that the storage is freed or
+ reallocated (and thus moved) through one alias and then
+ referenced through another, which may lead to subtle (and
+ possibly intermittent) lossage depending on the state and the
+ allocation history of the malloc {arena}. This bug can be
+ avoided by never creating aliases for allocated memory, or by
+ use of a {higher-level language}, such as {Lisp}, which
+ employs a {garbage collector}.
+
+ The term "aliasing bug" is nowadays associated with {C}
+ programming, it was already in use in a very similar sense in
+ the {ALGOL 60} and {Fortran} communities in the 1960s.
+
+ See also {smash the stack}, {fandango on core}, {memory leak},
+ {memory smash}, {spam}.
+
+ [{Jargon File}]
+
+ (1995-05-09)
+
+Stallman, Richard M.
+
+ {Richard Stallman}
+
+stand-alone
+
+ <jargon> Capable of operating without other programs,
+ libraries, computers, hardware, networks, etc. Exactly what
+ is absent is presumed to be obvious from context.
+
+ "We only run Windows on stand-alone PCs because it's too
+ dangerous to run it on networked ones."
+
+ (1998-02-11)
+
+standard
+
+ <standard> Standards are necessary for {interworking},
+ {portability}, and {reusability}. They may be {de facto
+ standards} for various communities, or officially recognised
+ national or international standards.
+
+ {Andrew Tanenbaum}, in his Computer Networks book, once said,
+ "The nice thing about standards is that there are so many of
+ them to choose from", a reference to the fact that competing
+ standards become a source of confusion, division,
+ obsolescence, and duplication of effort instead of an
+ enhancement to the usefulness of products.
+
+ Some bodies concerned in one way or another with computing
+ standards are {IAB} ({RFC} and {STD}), {ISO}, {ANSI}, {DoD},
+ {ECMA}, {IEEE}, {IETF}, {OSF}, {W3C}.
+
+ (1999-07-06)
+
+Standard Commands for Programmable Instruments
+
+ <standard> (SCPI) A standard complementing {IEEE 488},
+ developed by {Hewlett-Packard} and promoted by the {SCPI
+ Consortium}.
+
+ (1994-11-01)
+
+Standard d'Echange et de Transfert
+
+ <standard> (SET) A French {standard} for exchange of {CAD}
+ data.
+
+ (1998-03-07)
+
+standard deviation
+
+ <statistics> (SD) A measure of the range of values in a set of
+ numbers. Standard deviation is a statistic used as a measure
+ of the dispersion or variation in a distribution, equal to the
+ square root of the {arithmetic mean} of the squares of the
+ deviations from the arithmetic mean.
+
+ The standard deviation of a random variable or list of numbers
+ (the lowercase greek sigma) is the square of the {variance}.
+ The standard deviation of the list x1, x2, x3...xn is given by
+ the formula:
+
+ sigma = sqrt(((x1-(avg(x)))^2 + (x1-(avg(x)))^2 +
+ ... + (xn(avg(x)))^2)/n)
+
+ The formula is used when all of the values in the population
+ are known. If the values x1...xn are a random sample chosen
+ from the population, then the sample Standard Deviation is
+ calculated with same formula, except that (n-1) is used as the
+ {denominator}.
+
+ [{dictionary.com (http://dictionary.com/)}].
+
+ ["Barrons Dictionary of Mathematical Terms, second edition"].
+
+ (2003-05-06)
+
+standard for robot exclusion
+
+ <web> A proposal to try to prevent the havoc
+ wreaked by many of the early {web} {robots} when
+ they retrieved documents too rapidly or retrieved documents
+ that had side effects (such as voting). The proposed standard
+ for robot exclusion offers a solution to these problems in the
+ form of a file called "robots.txt" placed in the {document
+ root} of the {website}.
+
+ {W3C standard
+ (http://w3.org/TR/html4/appendix/notes.html#h-B.4.1.1)}.
+
+ (2006-10-17)
+
+Standard for the exchange of product model data
+
+ (STEP) A draft {ISO} {standard} for the exchange of {CAD}
+ data.
+
+ See also {PDES}.
+
+ (1995-02-22)
+
+Standard Generalised Markup Language
+
+ <spelling> {ISO} spell it "{Standard Generalized Markup
+ Language}".
+
+ (1996-12-13)
+
+Standard Generalized Markup Language
+
+ <language, text> (SGML) A generic {markup} language for
+ representing documents. SGML is an International Standard
+ that describes the relationship between a document's content
+ and its structure. SGML allows document-based information to
+ be shared and re-used across applications and computer
+ {platforms} in an open, vendor-neutral format. SGML is
+ sometimes compared to {SQL}, in that it enables companies to
+ structure information in documents in an open fashion, so that
+ it can be accessed or re-used by any SGML-aware application
+ across multiple platforms.
+
+ SGML is defined in "ISO 8879:1986 Information processing --
+ Text and office systems -- Standard Generalized Markup
+ Language (SGML)", an {ISO} standard produced by {JTC} 1/SC 18
+ and amended by "Amendment 1:1988".
+
+ Unlike other common document file formats that represent both
+ content and presentation, SGML represents a document's content
+ {data} and structure (interrelationships among the data).
+ Removing the presentation from content establishes a neutral
+ format. SGML documents and the information in them can easily
+ be re-used by publishing and non-publishing {applications}.
+
+ SGML identifies document elements such as titles, paragraphs,
+ tables, and chapters as distinct objects, allowing users to
+ define the relationships between the objects for structuring
+ data in documents. The relationships between document
+ elements are defined in a {Document Type Definition} (DTD).
+ This is roughly analogous to a collection of {field}
+ definitions in a {database}. Once a document is converted
+ into SGML and the information has been 'tagged', it becomes a
+ database-like document. It can be searched, printed or even
+ programmatically manipulated by SGML-aware applications.
+
+ Companies are moving their documents into SGML for several
+ reasons:
+
+ Reuse - separation of content from presentation facilitates
+ multiple delivery formats like {CD-ROM} and {electronic
+ publishing}.
+
+ Portability - SGML is an international, platform-independent,
+ standard based on {ASCII} text, so companies can safely store
+ their documents in SGML without being tied to any one vendor.
+
+ Interchange - SGML is a core data standard that enables
+ SGML-aware applications to inter-operate and share data
+ seamlessly.
+
+ A central SGML document store can feed multiple processes in a
+ company, so managing and updating information is greatly
+ simplified. For example, when an aeroplane is delivered to a
+ customer, it comes with thousands of pages of documentation.
+ Distributing these on paper is expensive, so companies are
+ investigating publishing on CD-ROM. If a maintenance person
+ needs a guide for adjusting a plane's flight surfaces, a
+ viewing tool automatically assembles the relevant information
+ from the document {repository} as a complete document. SGML
+ can be used to define attributes to information stored in
+ documents such as security levels.
+
+ There are few clear leaders in the SGML industry which, in
+ 1993, was estimated to be worth US $520 million and is
+ projected to grow to over US $1.46 billion by 1998.
+
+ A wide variety tools can be used to create SGML systems. The
+ SGML industry can be separated into the following categories:
+
+ Mainstream Authoring consists of the key {word processing}
+ vendors like {Lotus}, {WordPerfect} and {Microsoft}.
+
+ SGML Editing and Publishing includes traditional SGML
+ authoring tools like {ArborText}, {Interleaf}, {FrameBuilder}
+ and {SoftQuad Author}/Editor.
+
+ SGML Conversions is one of the largest sectors in the market
+ today because many companies are converting legacy data from
+ mainframes, or documents created with mainstream word
+ processors, into SGML.
+
+ Electronic Delivery is widely regarded as the most compelling
+ reason companies are moving to SGML. Electronic delivery
+ enables users to retrieve information on-line using an
+ intelligent document viewer.
+
+ Document Management may one day drive a major part of the
+ overall SGML industry.
+
+ SGML Document Repositories is one of the cornerstone
+ technologies that will affect the progress of SGML as a data
+ standard.
+
+ Since 1998, almost all development in SGML has been focussed
+ on {XML} - a simple (and therefore easier to understand and
+ implement) subset of SGML.
+
+ {"ISO 8879:1986//ENTITIES Added Latin 1//EN"
+ (http://ucc.ie/info/net/isolat1.html)} defines some
+ characters. [How are these related to {ISO 8859}-1?].
+
+ {ISO catalogue entry (http://iso.ch/cate/d16387.html)}.
+
+ SGML parsers are available from
+ {VU, NL (ftp://star.cs.vu.nl/Sgml)},
+ {FSU (ftp://mailer.cc.fsu.edu/pub/sgml)},
+ {UIO, Norway (ftp://ifi.uio.no/pub/SGML/SGMLS)}.
+
+ See also {sgmls}.
+
+ {Usenet} newsgroup: {news:comp.text.sgml}.
+
+ ["The SGML Handbook", Charles F. Goldfarb, Clarendon Press,
+ 1991, ISBN 0198537379. (Full text of the ISO standard plus
+ extensive commentary and cross-referencing. Somewhat cheaper
+ than the ISO document)].
+
+ ["SGML - The User's Guide to ISO 8879", J.M. Smith et al,
+ Ellis Harwood, 1988].
+
+ [Example of some SGML?]
+
+ (2000-05-31)
+
+standard input/output
+
+ <programming, operating system> The predefined input/output
+ channels which every {Unix} process is initialised with.
+ Standard input is by default from the terminal, and standard
+ output and standard error are to the terminal. Each of these
+ channels (controlled via a {file descriptor} 0, 1, or 2 -
+ stdin, stdout, stderr) can be redirected to a file, another
+ device or a {pipe} connecting its process to another process.
+ The process is normally unaware of such {I/O redirection},
+ thus simplifying prototyping of combinations of commands.
+
+ The {C} programming language library includes routines to
+ perform basic operations on standard I/O. Examples are
+ "printf", allowing text to be sent to standard output, and
+ "scanf", allowing the program to read from standard input.
+
+ (1996-06-07)
+
+Standard Instrument Control Library
+
+ (SICL) A {platform}-independent {API} for software to control
+ and test electronic instruments conforming to {IEEE 488}.
+
+ (1995-01-05)
+
+standard interpretation
+
+ {standard semantics}
+
+standard I/O
+
+ {standard input/output}
+
+Standard Lisp
+
+ A subset of {Lisp 1.5} developed by A. Hearn primarily for
+ implementing {REDUCE}. It was replaced by {Portable Sandard
+ LISP}.
+
+ ["Standard LISP Report", J. Marti et al, SIGPLAN Notices
+ 14(10):48-58 (Oct 1979)].
+
+ (1994-11-04)
+
+Standard ML
+
+ <language> (SML) Originally an attempt by Robin Milner
+ <rm@lfcs.edinburgh.ac.uk> ca. 1984 to unify the dialects of
+ {ML}, SML has evolved into a robust general-purpose language.
+ Later versions have been maintained by D. B. MacQueen, Lal
+ George <george@research.att.com>, and J. H. Reppy
+ <jhr@research.att.com> at AT&T, and A. W. Appel
+ <appel@princeton.edu>.
+
+ SML is {functional}, with {imperative programming} features.
+ It is environment based and {strict}. It adds to ML the
+ {call-by-pattern} of {Hope}, {recursive data types},
+ {reference types}, typed {exceptions}, and {modules}. (The
+ "core" language excludes the modules).
+
+ Standard ML is {polymorphic}ally typed and its module system
+ supports flexible yet secure large-scale programming.
+ {Standard ML of New Jersey} is an optimising {native-code
+ compiler} for Standard ML that is written in Standard ML. It
+ runs on a wide range of architectures. The distribution also
+ contains: an extensive library - The Standard ML of New Jersey
+ Library, including detailed documentation; {Concurrent ML}
+ (CML); {eXene} - an elegant interface to {X11} (based on
+ {CML}); {SourceGroup} - a {separate compilation} and "{make}"
+ facility.
+
+ Implementations: {SML/NJ}, {POPLOG ML}, {Poly/ML}, {Edinburgh
+ SML}, {ANU ML}, {Micro ML}, {lazy sml2c}.
+
+ {sml2c} compiles to {C}. See also {ML Kit}.
+
+ Version 0.93 runs on {68000}, {SPARC}, {MIPS}, {HPPA},
+ {RS/6000}, {Intel 386}, {Intel 486} and {Macintosh}.
+
+ {Manual
+ (http://dcs.napier.ac.uk/course-notes/sml/manual.html)}.
+
+ {FTP from ATT (ftp://research.att.com/dist/ml/)}.
+ {FTP from Suny SB (ftp://sbcs.sunysb.edu/)}.
+
+ Mailing list: sml-request@cs.cmu.edu.
+
+ ["A Proposal for Standard ML", R. Milner, ACM Symp on LISP and
+ Functional Prog 1984, pp. 184-197].
+
+ (1995-12-24)
+
+Standard ML of New Jersey
+
+ (SML/NJ) An implementation of {SML} by {Andrew Appel} at
+ {Princeton} <Appel@princeton.edu> and {Dave MacQueen} at
+ {AT&T}. Version 0.93.
+
+ ["Standard ML of New Jersey", A. Appel et al, "Proc Third Intl
+ Symp on Prog Lang Impl and Logic Programming", LNCS Springer
+ 1991].
+
+ Versions for Unix, Mac. {(ftp://cs.yale.edu/pub/ml)},
+ {(ftp://research.att.com/dist/ml)}. Mailing list:
+ sml@cs.cmu.edu.
+
+Standard Operating Environment
+
+ <standard> (SOE) A specification of the {architecture},
+ {operating systems}, {application set} and configuration of
+ computers within an organisation.
+
+ (2007-06-11)
+
+standard semantics
+
+ The standard interpretation of a term in some language yields
+ the term's standard denotational semantics, i.e. its "meaning".
+ This is usually given by a semantic function which maps a term
+ in the abstract syntax to a point in some domain. The domain
+ is the interpretation of the term's type. The semantic
+ function also takes an environment - a function which maps the
+ free variables of the term to their meaning. We say that a
+ domain point "denotes", or "is the denotation of", a term. A
+ non-standard semantics results from some other interpretation,
+ e.g. an abstract interpretation.
+
+Standard Widget Toolkit
+
+ <graphics, programming, standard> (SWT) The {Eclipse Foundation}'s
+ {framework} for developing {graphical user interfaces} in {Java}.
+ SWT is written in explicitly standard Java but uses the {Java
+ Native Interface} to talk to a {platform}-native GUI library. SWT
+ is the third major attempt to give Java a decent GUI framework,
+ following {AWT} and {Swing}. Of the three, SWT is the most
+ consistent with the native GUIs but its programming model is hard
+ to port to non-{Windows} platforms.
+
+ {Wikipedia (http://en.wikipedia.org/wiki/SWT)}.
+
+ (2004-12-21)
+
+St Andrews Static Language
+
+ <language> (SASL) A {functional programming} language designed
+ by Professor {David Turner} in 1976 whilst at St. Andrews
+ University. SASL is a derivative of {ISWIM} with {infinite
+ data structures}. It is fully {lazy} but {weakly typed}. It
+ was designed for teaching functional programming, with very
+ simple {syntax}.
+
+ Example syntax:
+
+ def fac n =
+ n = 0 -> 1 ; n x fac(n-1)
+
+ A version of the {expert system} {EMYCIN} has been written in
+ SASL.
+
+ SASL was originally known as "St Andrews Standard Language".
+ Not to be confused with {SISAL}.
+
+ {(ftp://a.cs.uiuc.edu/uiuc/kamin.distr/distr/sasl.p)}.
+ See also {Kamin's interpreters}.
+
+ ["A New Implementation Technique for Applicative Languages",
+ D.A. Turner, Soft Prac & Exp 8:31-49 (1979)].
+
+ (2007-03-21)
+
+Stanford Artificial Intelligence Laboratory
+
+ <body, education> (SAIL) /sayl/, not /S-A-I-L/ An important
+ site in the early development of {LISP}; with the {MIT AI
+ Lab}, {BBN}, {CMU}, {XEROX PARC}, and the {Unix} community,
+ one of the major wellsprings of technical innovation and
+ hacker-culture traditions (see the {WAITS} entry for details).
+ The SAIL machines were shut down in late May 1990, scant weeks
+ after the MIT AI Lab's ITS cluster was officially
+ decommissioned.
+
+ [{Jargon File}]
+
+ (2001-06-22)
+
+Stanford Artificial Intelligence Language
+
+ <language> (SAIL) Dan Swinehart & Bob Sproull, Stanford AI
+ Project, 1970. A large ALGOL 60-like language for the DEC-10
+ and DEC-20. Its main feature is a symbolic data system based
+ upon an associative store (originally called LEAP). Items may
+ be stored as unordered sets or as associations (triples).
+ Processes, events and interrupts, contexts, backtracking and
+ record garbage collection. Block- structured macros. "Recent
+ Developments in SAIL - An ALGOL-based Language for Artificial
+ Intelligence", J. Feldman et al, Proc FJCC 41(2), AFIPS (Fall
+ 1972). (See MAINSAIL).
+
+ The Stanford Artificial Intelligence Language used at {SAIL}
+ (the place). It was an ALGOL 60 derivative with a coroutining
+ facility and some new data types intended for building search
+ trees and association lists.
+
+ A number of interesting software systems were coded in SAIL,
+ including early versions of {FTP} and {TeX} and a document
+ formatting system called {PUB}.
+
+ In 1978, there were half a dozen different operating systems
+ for the PDP-10: WAITS (Stanford), ITS (MIT), TOPS-10 (DEC),
+ CMU TOPS-10 (CMU), TENEX (BBN), and TOPS-20 (DEC, after
+ TENEX).
+
+ SAIL was ported from {WAITS} to {ITS} so that {MIT}
+ researchers could make use of software developed at {Stanford
+ University}. Every port usually required the rewriting of I/O
+ code in each application.
+
+ [{Jargon File}]
+
+ (2001-06-22)
+
+Stanford Research Institute
+
+ Former name of {SRI International}.
+
+Stanford University
+
+ <education> A University in the city of Palo Alto, California,
+ noted for work in computing, especially {artificial
+ intelligence}. See {SAIL}.
+
+ (2003-02-28)
+
+STAPLE
+
+ <language> A programming language written at Manchester
+ (University?) and used at {ICL} in the early 1970s for writing
+ the test suites. STAPLE was based on {Algol 68} and had a
+ very advanced {optimising compiler}.
+
+ (2003-02-28)
+
+Staple
+
+ <language> St Andrews Applicative Persistent Language.
+ Language combining functional programming with persistent
+ storage, developed at St. Andrews University in Scotland.
+ Tony Davie, <ad@cs.st-andrews.ac.uk>.
+
+ (2007-03-22)
+
+STAR 0
+
+ Early system on Datatron 200 series. Listed in CACM 2(5):16
+ (May 1959).
+
+StarBurst
+
+ An active DBMS from IBM Almaden Research Center.
+
+StarLISP
+
+ {*LISP}
+
+StarMOD
+
+ {*MOD}
+
+star network
+
+ <networking> A {network} topology where every {node} has a
+ direct connection (only) to the central node, which might be a
+ {hub}, {switch}, or {server}.
+
+ (1999-10-29)
+
+Starset
+
+ Portable storage/retrieval language for distributed databases.
+ "Starset programming Language", M.M. Gilula et al, Nauka,
+ Moscow 1991, ISBN 5-02-006831-4.
+
+STARSYS
+
+ {Convergent Technologies Operating System}
+
+start bit
+
+ <protocol> A {bit} which signals the start of transmission of
+ a character on a {serial line}. For an {RS-423} signal, the
+ line is normally at logical zero which there is no data and
+ the start bit is a logical one. The zero-one transition tells
+ the receiver when to start sampling the signal to extract the
+ data bits.
+
+ [Is this upside-down?]
+
+ (1995-02-02)
+
+start of authority
+
+ <networking> (SOA) A type of {resource record} used by the
+ {Domain Name System} (DNS) to give meta-data about a set of
+ domain name data (the contents of a "zone file"). An SOA
+ record has the following parameters:
+
+ Serial: the zone serial number - a version number for the zone
+ file.
+
+ Refresh: the number of seconds between update requests from
+ secondary and slave name servers.
+
+ Retry: the number of seconds the secondary or slave will wait
+ before retrying when an attempt fails.
+
+ Expire: (time to live - TTL) the number of seconds a master or
+ slave will wait before considering cached data out-of-date.
+
+ Minimum: previously used to determine the minimum TTL, this
+ offers negative caching.
+
+ (2007-05-11)
+
+Start Of Header
+
+ <character> (SOH) {mnemonic} for {ASCII} 1.
+
+ [What header?]
+
+ (1996-05-31)
+
+Start Of Text
+
+ <character> (STX) {Mnemonic} for {ASCII} 2.
+
+ (1996-05-31)
+
+start tag
+
+ {tag}
+
+state
+
+ <storage, architecture, jargon, theory> How something is; its
+ configuration, attributes, condition, or information content.
+ The state of a system is usually temporary (i.e. it changes
+ with time) and volatile (i.e. it will be lost or reset to some
+ initial state if the system is switched off).
+
+ A state may be considered to be a point in some {space} of all
+ possible states. A simple example is a light, which is either
+ on or off. A complex example is the electrical activation in
+ a human brain while solving a problem.
+
+ In computing and related fields, states, as in the light
+ example, are often modelled as being {discrete} (rather than
+ continuous) and the transition from one state to another is
+ considered to be instantaneous. Another (related) property of
+ a system is the number of possible states it may exhibit.
+ This may be finite or infinite. A common model for a system
+ with a finite number of discrete state is a {finite state
+ machine}.
+
+ [{Jargon File}]
+
+ (1996-10-13)
+
+state diagram
+
+ {state transition diagram}
+
+stateless
+
+ A stateless {server} is one which treats each request as an
+ independent transaction, unrelated to any previous request.
+ This simplifies the server design because it does not need to
+ allocate storage to deal with conversations in progress or
+ worry about freeing it if a client dies in mid-transaction. A
+ disadvantage is that it may be necessary to include more
+ information in each request and this extra information will
+ need to be interpreted by the server each time.
+
+ An example of a stateless server is a {web} server.
+ These take in requests ({URLs}) which completely specify the
+ required document and do not require any context or memory of
+ previous requests.
+
+ Contrast this with a traditional {FTP} server which conducts
+ an interactive session with the user. A request to the server
+ for a file can assume that the user has been authenticated and
+ that the current directory and transfer mode have been set.
+
+state machine
+
+ {finite state machine}
+
+statement
+
+ <programming> A single instruction in a {computer program}
+ written in a {procedural language}. Typical examples are an
+ {assignment statement}, an {if statement} (conditional), a
+ {loop} statement ("while", "for", "repeat", "until", etc.), a
+ {procedure call}, a procedure {exit}, {function} {return
+ statement}, {switch statement} or {goto statement}.
+
+ In many languages, one or more simple statements can be
+ executed sequentially as a {compound statement},
+ e.g. bracketed between "begin" and "end" or "{" and "}" which
+ can then appear in place of a simple statement in an "if" or
+ loop.
+
+ Each statement in a {high-level language} will typically be
+ translated into several {machine code} instructions by a
+ {compiler} or, alternatively, executed by an {interpreter}.
+
+ (2009-10-23)
+
+state transition diagram
+
+ A diagram consisting of circles to represent states and
+ directed line segments to represent transitions between the
+ states. One or more actions (outputs) may be associated with
+ each transition. The diagram represents a {finite state
+ machine}.
+
+State University of New York
+
+ <body> (SUNY) The public university system of New York State,
+ USA, with campuses throughout the state.
+
+ (1995-03-01)
+
+static
+
+ <programming> {static typing}, {static variable}.
+
+ <storage> {static random-access memory}.
+
+ <web> {static content}.
+
+ <theory, programming> {static analysis}.
+
+statically typed
+
+ {static typing}
+
+static analysis
+
+ <theory, programming> A family of techniques of program
+ analysis where the program is not actually executed (as
+ opposed to dynamic analysis), but is analyzed by tools to
+ produce useful information.
+
+ Static analysis techniques range from the most mundane
+ (statistics on the density of comments, for instance) to the
+ more complex, {semantics}-based techniques.
+
+ Qualities sought in static analysis techniques are {soundness}
+ and {completeness}.
+
+ (2003-04-12)
+
+static database management system
+
+ <database> (static DBMS) A {database} consisting of
+ "information-based relationships", one that is rigorously
+ structured to facilitate retrieval and update in terms of
+ inherent relationships. This creates a static environment
+ wherein the locations of the related records are already
+ known. Typical static DBMS are either hierarchical ({IMS},
+ {System 2000}) or a {CODACYL} (network or plex) DBMS (such as
+ {TOTAL}, {IDMS}, {IDS}, {DMS-2}). These environments
+ facilitate rapid, high volume processing of data.
+
+ The opposite is a {dynamic database management system}.
+
+ (1998-10-07)
+
+static DBMS
+
+ {static database management system}
+
+static link
+
+ <compiler> (Or "access link" or "environment link") A pointer
+ from an {activation record} to the activation record for the
+ textually enclosing {scope}. A static link is only required
+ in a statically (lexically) scoped language.
+
+ The number of static links to follow may be determined
+ statically (at compile time). It is simply the difference in
+ {lexical nesting depth} between the declaration and the
+ reference.
+
+ See also {display}.
+
+ (1995-03-07)
+
+static method
+
+ <programming> In {object-oriented programming}, a {function}
+ packaged along with a given {class}; not really a {method} at all.
+
+ For example, a String class might include a static method,
+ concatenate(), which returns its arguments joined into one
+ string. It might be called like this:
+
+ print String.concatenate("FOL", "DOC");
+
+ which would print "FOLDOC".
+
+ The same result might be achieved with a real {object method},
+ append(), which returns its argument string appended to the object
+ it is invoked on, e.g.:
+
+ String s = "FOL";
+ print s.append("DOC");
+
+ While the {syntax} looks similar, the two are completely
+ different. The static method is just a function called
+ "String.concatenate" which can be resolved to the address of some
+ code at compile time (or load time if the String class is
+ dynamically loaded). When invoking an object method, the class of
+ the object is not generally known until {run time} so method
+ lookup is a run-time process.
+
+ (2014-09-06)
+
+static nested scope
+
+ <programming> Where the {scope} of an {identifier} is fixed at
+ {compile-time} to be the smallest {block} ({begin}/end,
+ {function}, or {procedure} body) containing the identifier's
+ {declaration}. This means that an identifier declared in some
+ block is only accessible within that block and from procedures
+ declared within it.
+
+ This term is used in the {Python} community.
+
+ Compare {lexical scope}.
+
+ (2002-02-18)
+
+static nested scoping
+
+ {static nested scope}
+
+static RAM
+
+ {static random-access memory}
+
+static random-access memory
+
+ <storage> (SRAM) {Random-access memory} in which each bit of
+ storage is a bistable {flip-flop}, commonly consisting of
+ cross-coupled {inverters}. It is called "static" because it
+ will retain a value as long as power is supplied, unlike
+ {dynamic random-access memory} (DRAM) which must be regularly
+ refreshed. It is however, still {volatile}, i.e. it will lose
+ its contents when the power is switched off, in contrast to
+ {ROM}.
+
+ SRAM is usually faster than DRAM but since each bit requires
+ several transistors (about six) you can get less bits of SRAM
+ in the same area. It usually costs more per bit than DRAM and
+ so is used for the most speed-critical parts of a computer
+ (e.g. {cache} memory) or other circuit.
+
+ (1995-04-22)
+
+static scope
+
+ {lexical scope}
+
+static typing
+
+ <programming> Enforcement of type rules at {compile time}
+ rather than at {run time}. Static typing catches more errors
+ at compile time than {dynamic typing}.
+
+ {Ada}, {C}, {C++}, {Haskell}, {Java}, and {ML} are examples of
+ statically typed languages.
+
+ Statically typed languages may have {strong typing} or {weak
+ typing}.
+
+ (2004-07-20)
+
+static variable
+
+ <programming> A kind of {local variable} in certain
+ {programming languages} that retains its value even when
+ program execution moves outside its {scope}. This contrasts
+ with an ordinary, {automatic variable}, which is reinitialised
+ (possibly to an undefined value) every time the block is
+ entered.
+
+ Static variables have a fixed location in the data section of
+ the program's {address space} whereas automatic variables are
+ typically allocated on the {stack}.
+
+ (2009-12-14)
+
+Station Management
+
+ <networking> (SMT) Station Management One of the 4 key {FDDI}
+ component layers. SMT is an overlay function that handles the
+ management of the FDDI ring. It handles neighbor
+ identification, fault detection and reconfiguration, insertion
+ and de-insertion from the ring, and traffic statistics
+ monitoring.
+
+ (1997-05-11)
+
+Statistical Analysis System
+
+ <language> (SAS) A statistical and matrix handling language
+ with {PL/I}-like {syntax}.
+
+ ["A User's Guide to SAS", A.J. Barr, SAS Inst 1976].
+
+ (1994-12-12)
+
+Statistical Package for the Social Sciences
+
+ <statistics, tool> (SPSS) The flagship program of {SPSS,
+ Inc.}, written in the late 1960s.
+
+ ["SPSS X User's Guide", SPSS, Inc. 1986].
+
+ [Details?]
+
+ (1999-07-20)
+
+statistical time division multiplexing
+
+ <communications> (STDM, StatMUX) A system developed to
+ overcome some inefficiencies of standard {time division
+ multiplexing}, where {time slices} are still allocated to
+ channels, even if they have no information to transmit.
+
+ STDM uses a variable time slot length and by allowing channels
+ to vie for any free slot space. It employs a buffer memory
+ which temporarily stores the data during periods of peak
+ traffic. This scheme allows STDM to waste no high-speed line
+ time with inactive channels. STDM requires each transmission
+ to carry identification information (i.e. a channel
+ identifier). To reduce the cost of this overhead, a number of
+ characters for each channel are grouped together for
+ transmission.
+
+ ["Data Communications, Computer Networks and Open Systems",
+ Halsall & Fred, Addison Wesley, p160-161, 1995].
+
+ ["Digital, Analog, and Data Communication", Sinnema &
+ McGovern, Prentice Hall, p245, 1986].
+
+ (1997-03-05)
+
+statistics
+
+ <statistics, mathematics> The practice, study or result of the
+ application of mathematical {functions} to collections of
+ {data} in order to summarise or {extrapolate} that data.
+
+ The subject of statistics can be divided into descriptive
+ statistics - describing data, and analytical statistics -
+ drawing conclusions from data.
+
+ (1997-07-16)
+
+StatMUX
+
+ {statistical time division multiplexing}
+
+STB
+
+ {set-top box}
+
+STD
+
+ 1. {state transition diagram}.
+
+ 2. {Internet} standard.
+
+ A subseries of {Request For Comments} (RFC) that specify
+ {Internet} {standards}. The official list of Internet
+ standards is {STD 1}.
+
+ See also {For Your Information}.
+
+ {rfc.net (http://rfc.net/)}.
+
+ (1994-11-30)
+
+STD 1
+
+ <standard> The {Internet Architecture Board} official list of
+ {Internet} {standards}.
+
+ [Postel, J., "IAB Official Protocol Standards", STD 1, RFC
+ 1360, Internet Architecture Board, September 1992].
+
+ (1995-02-07)
+
+STD 13
+
+ <networking, standard> One of the {STDs} defining the {Domain
+ Name System}.
+
+ (1997-12-15)
+
+STD 15
+
+ The {STD} defining {Simple Network Management Protocol}.
+
+ (1994-11-14)
+
+STD 2
+
+ <networking, standard> The document listing the current
+ {Internet} {Assigned Numbers}.
+
+ [Reynolds, J., and J. Postel, "Assigned Numbers", STD 2, RFC
+ 1340, USC/Information Sciences Institute, July 1992].
+
+ (2001-04-08)
+
+STD 9
+
+ The {STD} defining {File Transfer Protocol} (FTP).
+
+ (1995-02-07)
+
+stderr
+
+ {standard input/output}
+
+stdin
+
+ {standard input/output}
+
+stdio
+
+ {standard input/output}
+
+stdio.h
+
+ <programming> {standard input/output} {header file}.
+
+ (1996-01-28)
+
+STDM
+
+ {statistical time division multiplexing}
+
+stdout
+
+ {standard input/output}
+
+STDWIN
+
+ A windowing interface from {CWI} with windows, menus, modal
+ dialogs, mouse and keyboard input, scroll bars, drawing
+ primitives, etc that is portable between {platforms}. STDWIN
+ is available for {Macintosh} and the {X Window System}.
+
+steam-powered
+
+ Old-fashioned or underpowered; archaic. This term does not
+ have a strong negative loading and may even be used
+ semi-affectionately for something that clanks and wheezes a
+ lot but hangs in there doing the job.
+
+ [{Jargon File}]
+
+Steelman
+
+ DoD, June 1978. Fifth and last of the series of DoD
+ requirements that led to Ada. "Steelman Requirements for High
+ Order Programming Languages", US Dept of Defense, June 1978.
+ SIGPLAN Notices 13(12) (Dec 1978). (See Strawman, Woodenman,
+ Tinman, Ironman).
+
+steganography
+
+ <security> Hiding a secret message within a larger one in such
+ a way that others can not discern the presence or contents of
+ the hidden message. For example, a message might be hidden
+ within an {image} by changing the {least significant bits} to
+ be the message bits.
+
+ [{Chaffing and Winnowing: Confidentiality without Encryption,
+ Ronald L. Rivest, MIT Lab for Computer Science, 1998-03-22
+ (http://theory.lcs.mit.edu/~rivest/chaffing.txt)}].
+
+ (1998-07-13)
+
+stemmer
+
+ <information science, human language> A program or {algorithm}
+ which determines the morphological root of a given inflected
+ (or, sometimes, derived) word form -- generally a written word
+ form.
+
+ A stemmer for English, for example, should identify the
+ {string} "cats" (and possibly "catlike", "catty" etc.) as
+ based on the root "cat", and "stemmer", "stemming", "stemmed"
+ as based on "stem".
+
+ English stemmers are fairly {trivial} (with only occasional
+ problems, such as "dries" being the third-person singular
+ present form of the verb "dry", "axes" being the plural of
+ "ax" as well as "axis"); but stemmers become harder to design
+ as the morphology, orthography, and {character encoding} of
+ the target language becomes more complex. For example, an
+ Italian stemmer is more complex than an English one (because
+ of more possible verb inflections), a Russian one is more
+ complex (more possible noun declensions), a Hebrew one is even
+ more complex (a {hairy} writing system), and so on.
+
+ Stemmers are common elements in {query} systems, since a user
+ who runs a query on "daffodils" probably cares about documents
+ that contain the word "daffodil" (without the s).
+
+ ({This dictionary} has a rudimentary stemmer which currently
+ (April 1997) handles only conversion of plurals to singulars).
+
+ (1997-04-09)
+
+stemming
+
+ {stemmer}
+
+STENSOR
+
+ L. Hornfeldt, Stockholm, mid-80's. Symbolic math, especially
+ General Relativity. Implemented on top of SHEEP and MACSYMA.
+
+STEP
+
+ {Standard for the exchange of product model data}
+
+Stephen Cole Kleene
+
+ {Stephen Kleene}
+
+Stephen Jobs
+
+ <person> Stephen P. Jobs (born 24 February 1955). The
+ co-founder and ex-president of {Apple Computer}, leader of the
+ team that produced the {Macintosh}.
+
+ In 1979, when he was president of Apple, Steven Jobs saw a
+ demonstration of {Smalltalk} at {Xerox}'s {Palo Alto Research
+ Center}. He and other Apple employees were "very impressed
+ with the unique and revolutionary user-friendly design".
+
+ The first {Macintosh} was released in January 1984. Jobs
+ described it as {insanely great}.
+
+ Jobs was ousted from Apple in 1985 and founded {Next, Inc.}.
+ In December 1996 he was re-employed by Apple when they bought
+ NeXT.
+
+ See also {lithium lick}, {Mathematica}.
+
+ (1997-03-18)
+
+Stephen Kleene
+
+ <person> Professor Stephen Cole Kleene (1909-01-05 -
+ 1994-01-26) /steev'n (kohl) klay'nee/ An American
+ mathematician whose work at the {University of
+ Wisconsin-Madison} helped lay the foundations for modern
+ computer science. Kleene was best known for founding the
+ branch of {mathematical logic} known as {recursion theory} and
+ for inventing {regular expressions}. The {Kleene star} and
+ {Ascending Kleene Chain} are named after him.
+
+ Kleene was born in Hartford, Conneticut, USA. He received his
+ Bachelor of Arts degree from Amherst College in 1930. From
+ 1930 to 1935, he was a graduate student and research assistant
+ at {Princeton University} where he received his doctorate in
+ mathematics in 1934. In 1935, he joined UW-Madison
+ mathematics department as an instructor. He became an
+ assistant professor in 1937.
+
+ From 1939 to 1940, he was a visiting scholar at Princeton's
+ {Institute for Advanced Study} where he laid the foundation
+ for recursive function theory, an area that would be his
+ lifelong research interest. In 1941 he returned to Amherst as
+ an associate professor of mathematics.
+
+ During World War II Kleene was a lieutenant commander in the
+ United States Navy. He was an instructor of navigation at the
+ U.S. Naval Reserve's Midshipmen's School in New York, and then
+ a project director at the Naval Research Laboratory in
+ Washington, D.C.
+
+ In 1946, he returned to Wisconsin, eventually becoming a full
+ professor. He was chair of mathematics, and computer sciences
+ in 1962 and 1963 and dean of the College of Letters and
+ Science from 1969 to 1974. In 1964 he was named the Cyrus
+ C. MacDuffee professor of mathematics.
+
+ An avid mountain climber, Kleene had a strong interest in
+ nature and the environment and was active in many conservation
+ causes. He led several professional organisations, serving as
+ president of the {Association of Symbolic Logic} from 1956 to
+ 1958. In 1961, he served as president of the International
+ Union of the History and the Philosophy of Science.
+
+ Kleene pronounced his last name /klay'nee/. /klee'nee/ and
+ /kleen/ are extremely common mispronunciations. His first
+ name is /steev'n/, not /stef'n/. His son, Ken Kleene
+ <kenneth.kleene@umb.edu>, wrote: "As far as I am aware this
+ pronunciation is incorrect in all known languages. I believe
+ that this novel pronunciation was invented by my father."
+
+ {(gopher://gopher.adp.wisc.edu/00/.data/.news-rel/.9401/.940126a)}.
+
+ (1999-03-03)
+
+stepper motor
+
+ <hardware> An electric motor that rotates in small, fixed
+ increments and is used, among other things, to control the
+ radial position (seeking) of the heads on a {disk drive}.
+
+ (2006-12-24)
+
+Stepstone Corp
+
+ <company> A company founded by Brad Cox, responsible for
+ {Objective C}.
+
+ Telephone: +1 (203) 426-1875.
+
+ (1996-08-04)
+
+stepwise refinement
+
+ {top-down design}
+
+stereogram
+
+ A two-dimensional image which, when viewed correctly appears
+ three-dimensional. E.g. {SIRDS} or {SIRTS}.
+
+ {(ftp://katz.anu.edu.au/pub/stereograms)}.
+
+ (1994-11-03)
+
+Sterling Software, Inc.
+
+ <company> A software company which was bought out by {Computer
+ Associates International, Inc.}
+
+ {Acquisition (http://ca.com/acq/sterling/)}.
+
+ (2002-04-20)
+
+Steve Jobs
+
+ {Stephen Jobs}
+
+Steve's Shell
+
+ <operating system> (ssh) A {Unix} {shell} with many {csh}- and
+ {ksh}-like features, by Steve Baker <ice@judy.indstate.edu>
+ and Thomas Moore.
+
+ Version 1.7 has been ported to {Sequent}, {Sun}, {NeXT},
+ {Ultrix}, {BSDI} and is available from {comp.sources.unix}
+ volume 26.
+
+ (1993-04-15)
+
+Steve Wozniak
+
+ <person> Co-founder of {Apple Computer} with {Steve Jobs} on
+ 01 April 1976 and the inventor of the {Apple II} {personal
+ computer}.
+
+ (1998-04-05)
+
+STFT
+
+ {Short Term Fourier Transform}
+
+STFU
+
+ <chat> Shut the fuck up.
+
+ (2008-03-04)
+
+STFW
+
+ {Search The Fucking Web}
+
+Sticks&Stones
+
+ <language, functional programming> A {functional},
+ {polymorphic} {hardware description language} loosely based on
+ {ML} by Lucca Cardelli.
+
+ ["An Algebraic Approach to Hardware Description and
+ Verification", L. Cardelli, Thesis, Edinburgh U, 1982].
+
+ ["Sticks&Stones II: A Functional Language VLSI Layout
+ Generation Tool", Andrew Butterfield <butrfeld@cs.tcd.ie>,
+ Thesis, Trinity College, 1990].
+
+ (2008-03-04)
+
+sticky analysis
+
+ <theory> A kind of program analysis that uses information from
+ all the call sites of a function or procedure.
+
+ (1999-06-15)
+
+sticky bit
+
+ <operating system> The {bit} in the mode of a {Unix} file
+ which, if set for an executable, tells the {kernel} to keep
+ the code loaded in {swap space} even after it has finished
+ executing on the assumption that it is likely to be used again
+ soon. This performance optimisation was included in some
+ early (and recent?) versions of {Unix} to save reloading
+ frequently used programs such as the {shell} or {vi} from
+ disk.
+
+ If the sticky bit is set on a directory, an unprivileged user
+ may not delete or rename files of other users in that
+ directory even if he has write access to the directory.
+
+ The Unix "ls" command displays a set sticky bit as a "t" in
+ the permissions of a file or directory.
+
+ (1997-02-26)
+
+sticky content
+
+ <web> {web} pages that refer only or
+ mostly to pages on the same {website}. This is important to
+ some commercial sites who want users to keep accessing pages
+ from their site because they receive advertising income from
+ each hit. It does however somewhat miss the point of the
+ web which is to link useful information across the
+ whole {Internet}.
+
+ (1999-06-15)
+
+stiffy
+
+ <storage, jargon> ({University of Lowell}, Massachusetts) A
+ 3.5-inch {microfloppy}, so called because their jackets are
+ more rigid than those of the 5.25-inch and the (obsolete)
+ 8-inch {floppy disk}. Elsewhere this might be called a
+ "firmy".
+
+ [{Jargon File}]
+
+ (1994-11-03)
+
+STIL
+
+ STatistical Interpretive Language.
+
+ ["STIL User's Manual", C.F. Donaghey et al, Indust Eng Dept,
+ U Houston (Aug 1969)].
+
+STING
+
+ A parallel dialect of {Scheme} intended to serve as a
+ high-level {operating system} for symbolic programming
+ languages. {First-class} {threads} and processors and
+ customisable {scheduling} policies.
+
+ E-mail: <suresh@research.nj.dec.com>.
+
+ ["A Customizable Substrate for Concurrent Languages",
+ S. Jagannathan et al, ACM SIGPLAN Notices, 1992].
+
+ (1994-11-03)
+
+STk
+
+ <language, LISP, graphics> A {Scheme} {interpreter} blended
+ with Ousterhout's {Tk} package by Erick Gallesio
+ <eg@unice.fr>. STk expresses all of Tk as Scheme objects.
+ STk includes a slow {CLOS}/{Dylan}-like {object-oriented}
+ extension.
+
+ STk almost conforms to {R4RS} and runs on {SunOS} 4.1.x and
+ {Ultrix}/{MIPS}.
+
+ Latest version: 4.0.1, as of 2000-09-24.
+
+ {(ftp://kaolin.unice.fr/pub/STk-1.00.tar.gz)}.
+ {(ftp://ftp.cs.indiana.edu/pub/scheme-repository/imp/STk-2.1.tar.Z)}.
+
+ (2000-12-16)
+
+STMP
+
+ Did you mean {SMTP}?
+
+stochastic
+
+ {probabilistic}
+
+stock-keeping unit
+
+ <database> (SKU) /skyoo/ (rarely seen expanded) A common term
+ for a unique numeric identifier, typically in a {database}.
+ Originally this was used only for products, but has spread in
+ usage.
+
+ Compare with {UID} for sense development.
+
+ (1998-09-27)
+
+STOIC
+
+ {STring Oriented Interactive Compiler}
+
+stomp on
+
+ To inadvertently overwrite something important, usually
+ automatically. "All the work I did this weekend got stomped
+ on last night by the nightly server script." Compare
+ {scribble}, {mangle}, {trash}, {scrog}, {roach}.
+
+ [{Jargon File}]
+
+STONE
+
+ A Structured and Open Environment: a project supported by the
+ German Ministry of Research and Technology (BMFT) to design,
+ implement and distribute a SEE for research and teaching.
+
+Stone Age
+
+ <jargon> In computer folklore, an ill-defined period from
+ {ENIAC} (ca. 1943) to the mid-1950s; the great age of
+ electromechanical {dinosaurs}. Sometimes used for the entire
+ period up to 1960-61 (see {Iron Age}); however, it is more
+ descriptive to characterise the latter period in terms of a
+ "Bronze Age" era of {transistor}-logic, pre-{ferrite core
+ memory} machines with {drum} or {CRT} mass storage (as opposed
+ to just {mercury delay lines} and/or relays).
+
+ More generally, the term is used pejoratively for ancient
+ hardware or software, even by survivors from the {Stone Age}.
+
+ [{Jargon File}]
+
+ (2003-09-27)
+
+stone knives and bearskins
+
+ (From the Star Trek Classic episode "The City on the Edge of
+ Forever") A term traditionally used to describe (and
+ deprecate) computing environments that are grotesquely
+ primitive in light of what is known about good ways to design
+ things. As in "Don't get too used to the facilities here.
+ Once you leave SAIL it's stone knives and bearskins as far as
+ the eye can see".
+
+ Compare {steam-powered}.
+
+ [{Jargon File}]
+
+ (1995-01-24)
+
+Stoneman
+
+ The requirements, written by the {HOLWG} of the US {DoD} in
+ Feb 1980, that led to APSE.
+
+ ["Requirements for Ada Programming Support Environments:
+ STONEMAN", US Dept of Defense, Feb 1980].
+
+ (1995-01-24)
+
+stop bit
+
+ In serial communications, where each bit of the message is
+ transmitted in sequence, stop bits are extra "1" bits which
+ follow the data and any {parity} bit. They mark the end of a
+ unit of transmission (normally a byte or character).
+
+ For example, characters on an {EIA-232} {serial line} may have
+ one or two stop bits added. Some {UARTs} even allow for 1.5
+ stop bits but one is probably the most commonly used. A
+ serial connection may be described as, for example, "8N1"
+ which means eight data bits, no {parity} and one stop bit.
+
+ (1995-01-24)
+
+stoppage
+
+ /sto'p*j/ Extreme {lossage} that renders something (usually
+ something vital) completely unusable. "The recent system
+ stoppage was caused by a {fried} transformer."
+
+ [{Jargon File}]
+
+ (1995-01-24)
+
+storage
+
+ <storage> (Or "memory") A device into which data can be
+ entered, in which it can be held, and from which it can be
+ retrieved at a later time. The distinguishing characteristics
+ of a device are its capacity (the number of bytes it can
+ hold), its {access speed}, whether it is {volatile} (loses
+ data when the power is turned off), removeable and/or
+ writeable. Common examples are {DRAM}, {hard disk}, {CD-ROM},
+ {Flash memory}.
+
+ (2009-02-23)
+
+Storage Allocation and Coding Program
+
+ <language> (STAC) A symbolic {macro-assembler} for the
+ {English Electric} {DEUCE}.
+
+ ["DEUCE STAC Programming Manual", DEUCE News No. 38, Report
+ K/AA y 1 DEUCE Library Service, Data Processing and COntrol
+ Systems DIvision, English Electric Company, Kidsgrove, June].
+
+ (1998-06-08)
+
+Storage Area Network
+
+ <storage> (SAN) A high-speed subnetwork of shared storage
+ devices. A storage device is a machine that contains nothing
+ but a disk or disks for storing data.
+
+ A SAN's architecture works in a way that makes all storage
+ devices available to all servers on a LAN or WAN. As more
+ storage devices are added to a SAN, they too will be
+ accessible from any server in the larger network. The server
+ merely acts as a pathway between the end user and the stored
+ data.
+
+ Because stored data does not reside directly on any of a
+ network's servers, server power is used for business
+ applications, and network capacity is released to the end
+ user.
+
+Storage Management Services
+
+ <storage> (SMS) Software that enables network administrators
+ to route {backup} data from various devices on a network to
+ another device such as a server or a {magnetic tape} backup
+ unit. This is done either to make use of a high-capacity
+ storage system such as a tape {juke-box} or for disaster
+ protection.
+
+ (1996-02-18)
+
+storage media
+
+ <storage> Devices on which {data} is stored, as opposed to the
+ device ("drive") used to read and write data from and to the
+ media. The term typically applies to removeable storage such
+ as {magnetic tape} or {flash memory}, rather than fixed
+ devices like a {hard disk}.
+
+ (2009-02-23)
+
+store
+
+ <jargon> In some varieties of Commonwealth hackish, the
+ preferred synonym for {core}. Thus, "bringing a program into
+ store" means that a program is being {swap}ped in from
+ {backing store} to {main store}.
+
+ [{Jargon File}]
+
+ (2006-12-06)
+
+store and forward
+
+ <messaging> (Or "message switching") A kind of {message
+ passing} system where a complete message is received before
+ any of it is passed on to the next node. This means that each
+ message is using at most one interprocessor link at any time
+ but intermediate nodes will require more storage buffers than
+ under the alternative, {wormhole routing}.
+
+ E-mail transmission is an example of {store and forward}
+ message passing.
+
+ (1995-02-16)
+
+stored procedure
+
+ <database> A {subroutine} stored in a {database} and executed
+ by the {database management system}. The subroutine may be
+ written in the same language in which the database is queried
+ and may be precompiled to improve performance.
+
+ Typically a stored procedure encapsulates some business
+ process. Performing this on the database server avoids the
+ network overhead of transferring input data to the client for
+ processing. This would be particularly significant if
+ processing lots of data and returning a small result set like
+ a total or maximum. Stored procedures also provide consistent
+ implementation of the business logic to clients written in
+ different languages and running in different environments.
+
+ Some financial systems allow databases access through stored
+ procedures alone, this restricts actions on the data to a
+ small number of auditable queries.
+
+ Sybase SQL Server ({Adaptive Server Enterprise}) was the first
+ commercially successful RDBMS to support stored procedures.
+
+ (2004-03-04)
+
+storm
+
+ {broadcast storm}
+
+Story of Mel
+
+ {The story of Mel}
+
+STP
+
+ {shielded twisted pair}
+
+StP
+
+ {Software through Pictures}
+
+STP4
+
+ A statistical language.
+
+Strachey, Christopher
+
+ {Christopher Strachey}
+
+Strand
+
+ 1. {AND-parallel} {logic programming} language. Essentially
+ flat {Parlog83} with sequential-and and sequential-or
+ eliminated.
+
+ ["Strand: New Concepts on Parallel Programming", Ian Foster et
+ al, P-H 1990]. {Strand88} is a commercial implementation.
+
+ 2. A query language, implemented on top of {INGRES} (an
+ {RDBMS}). ["Modelling Summary Data", R. Johnson, Proc ACM
+ SIGMOD Conf 1981].
+
+Strand88
+
+ A commercial implementation of {Strand} from Strand Software
+ Technologies Ltd., UK and Strand Software, Beaverton, OR, USA.
+ E-mail: <strand88@sstl.uucp>.
+
+Stratus
+
+ <company> One of the leading manufacturers of {fault-tolerant}
+ computer systems. While virtually all of Stratus' core
+ hardware and software is sold into the financial services,
+ telecommunications, travel and transportation, and gaming
+ these markets, a broad range of {middleware} and
+ {applications} are developed and marketed by Stratus, its
+ subsidiaries, and third party partners.
+
+ Yearly sales $609M, profits $43.5M (1996).
+
+ {(http://stratus,com)}.
+
+ (1997-04-24)
+
+Strawman
+
+ The first of the series of {DoD} requirements that led to
+ {Ada} ({Woodenman}, {Tinman}, {Ironman}, {Steelman}).
+ Strawman was produced by the {HOLWG} in Apr 1975.
+
+ (1995-01-30)
+
+STREAM
+
+ ["STREAM: A Scheme Language for Formally Describing Digital
+ Circuits", C.D. Kloos in PARLE: Parallel Architectures and
+ Languages Europe, LNCS 259, Springer 1987].
+
+ (1995-01-30)
+
+stream
+
+ 1. <communications> An {abstraction} referring to any flow of
+ data from a source (or sender, producer) to a single sink (or
+ receiver, consumer). A stream usually flows through a channel
+ of some kind, as opposed to {packets} which may be addressed
+ and routed independently, possibly to multiple recipients.
+ Streams usually require some mechanism for establishing a
+ channel or a "{connection}" between the sender and receiver.
+
+ 2. <programming> In the {C} language's buffered input/ouput
+ library functions, a stream is associated with a file or
+ device which has been opened using {fopen}. Characters may be
+ read from (written to) a stream without knowing their actual
+ source (destination) and buffering is provided transparently
+ by the library routines.
+
+ 3. <operating system> Confusingly, {Sun} have called their
+ modular {device driver} mechanism "{STREAMS}".
+
+ 4. <operating system> In {IBM}'s {AIX} {operating system}, a
+ stream is a {full-duplex} processing and data transfer path
+ between a driver in {kernel space} and a process in {user
+ space}.
+
+ [IBM AIX 3.2 Communication Programming Concepts,
+ SC23-2206-03].
+
+ 5. <communications> {streaming}.
+
+ 6. <programming> {lazy list}.
+
+ (1996-11-06)
+
+streaming
+
+ <communications> Playing {sound} or {video} in {real time} as
+ it is downloaded over the {Internet} as opposed to storing it
+ in a local file first. A {plug-in} to a {web browser} such as
+ {Netscape Navigator} decompresses and plays the data as it is
+ transferred to your computer over the {web}.
+ Streaming audio or video avoids the delay entailed in
+ downloading an entire file and then playing it with a {helper
+ application}. Streaming requires a fast connection and a
+ computer powerful enough to execute the decompression
+ {algorithm} in {real time}.
+
+ (1996-11-06)
+
+Streaming SIMD Extensions
+
+ <architecture> (SSE) {Intel Corporation}'s {floating point}
+ {SIMD} extention of their {Pentium} {microprocessor}
+ architecture. SSE was formerly know as KNI (Katmai New
+ Instructions). It was introduced with the {Pentium III}.
+
+ {Intel Pentium III
+ (http://developer.intel.com/design/pentiumiii/prodbref/)}.
+
+ {ipoem (http://ipoem.com/technology/Docs/pentium4.html)}.
+
+ (2003-07-13)
+
+stream-oriented
+
+ {connection-oriented}
+
+STREAMS
+
+ <operating system> A collection of {system calls}, {kernel}
+ resources, and kernel utility routines that can create, use,
+ and dismantle a {stream}. A "stream head" provides the
+ interface between the stream and the user processes. Its
+ principal function is to process STREAMS-related user system
+ calls. A "stream module" processes data that travel bewteen
+ the stream head and driver. The "stream end" provides the
+ services of an external input/output device or an internal
+ software driver. The internal software driver is commonly
+ called a {pseudo-device} driver.
+
+ The STREAMS concept has been formalised in {Unix} {System V}.
+ For example, {SVR4} implements {sockets} and {pipes} using
+ STREAMS, resulting in pipe(2) openning bidirectional pipes.
+
+ [IBM AIX 3.2 Communication Programming Concepts, SC23-2206-03].
+
+ (1999-06-29)
+
+strength reduction
+
+ An optimisation where a function of some systematically
+ changing variable is calculated more efficiently by using
+ previous values of the function. In a {procedural language}
+ this would apply to an expression involving a loop variable
+ and in a {declarative language} it would apply to the argument
+ of a {recursive} function. E.g.
+
+ f x = ... (2**x) ... (f (x+1)) ...
+
+ ==>
+
+ f x = f' x (2**x)
+ where
+ f ' x z = ... z ... (f' (x+1) 2*z) ...
+
+ Here the expensive operation (2**x) has been replaced by the
+ cheaper 2*z in the recursive function f'. This maintains the
+ invariant that z = 2**x for any call to f'.
+
+ (1995-01-31)
+
+STRESS
+
+ STRuctual Engineering Systems Solver.
+
+ A system for structural analysis problems in Civil
+ Engineering. STRESS was superseded by {STRUDL}.
+
+ ["STRESS: A User's Manual", S.J. Fenves et al, MIT Press
+ 1964].
+
+ [Sammet 1969, p. 612].
+
+ (1995-01-31)
+
+stress testing
+
+ <testing> Testing aimed at investigating the behaviour of a
+ software or hardware equipment in out of ordinary operating
+ conditions.
+
+ (1998-03-27)
+
+strict
+
+ A function f is strict in an argument if
+
+ f bottom = bottom
+
+ (See {bottom}). In other words, the result depends on the
+ argument so evaluation of an application of the function
+ cannot terminate until evaluation of the argument has
+ terminated.
+
+ If the result is only {bottom} when the argument is bottom
+ then the function is also {bottom-unique}.
+
+ See also {strict evaluation}, {hyperstrict}.
+
+ (1995-01-25)
+
+strict evaluation
+
+ {Call-by-value} evaluation order is sometimes called "strict
+ evaluation" because, in a sequential system, it makes
+ functions behave as though they were {strict}, in the sense
+ that evaluation of a function application cannot terminate
+ before evaluation of the argument. Similarly, languages are
+ called strict if they use {call-by-value} argument passing.
+
+ Compare {eager evaluation}, {lazy evaluation}.
+
+ (1994-12-21)
+
+strided
+
+ /str:'d*d/ (scientific computing) Said of a sequence of memory
+ reads and writes to addresses, each of which is separated from
+ the last by a constant interval called "the stride length", or
+ just "the stride". These can be a worst-case access pattern
+ for {cache} schemes when the stride length is a multiple of
+ the {cache line} size.
+
+ Strided references are often generated by loops through an
+ {array}, and (if the data is large enough that access-time is
+ significant) it can be worthwhile to tune for better locality
+ by inverting double loops or by partially unrolling the outer
+ loop of a loop nest.
+
+ [{Jargon File}]
+
+ (1994-12-21)
+
+string
+
+ <programming> A sequence of {data} values, usually {bytes},
+ which usually stand for {characters} (a "character string").
+ The {mapping} between values and characters is determined by
+ the {character set} which is itself specified implcitly or
+ explicitly by the environment in which the string is being
+ interpreted.
+
+ The most common character set is {ASCII} but, since the late
+ 1990s, there has been increased interest in larger character
+ sets such as {Unicode} where each character is represented by
+ more than eight {bits}.
+
+ Most programming languages consider strings (e.g.
+ "124:shabooya:\n", "hello world") basically distinct from
+ numbers which are typically stored in fixed-length {binary} or
+ {floating-point} representation.
+
+ A {bit string} is a sequence of {bits}.
+
+ (1999-12-21)
+
+String EXpression Interpreter
+
+ {String Oriented Symbolic Language}
+
+stringly typed
+
+ <humour, programming> A humourous play on "{strongly typed}",
+ coined by Mark Simpson, for an implementation that uses
+ strings instead of more appropriate types, thus preventing
+ {compile-time} {type checking}.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2012-06-25)
+
+STring Oriented Interactive Compiler
+
+ <language> (STOIC) A language from the Smithsonian
+ Astrophysical Observatory. STOIC is similar to {FORTH} for
+ strings and includes many {VAX}-specific items.
+
+ (1998-09-27)
+
+String Oriented Symbolic Language
+
+ <language> (SNOBOL) A {string processing language} for {text}
+ and {formula} manipulation, developed by David J. Farber, Ralph E.
+ Griswold and Ivan P. Polonsky at {Bell Labs} in 1962.
+
+ SNOBOL had only simple {control structures} but provided a
+ rich string-matching formalism of power comparable to {regular
+ expressions} but implemented differently. People used it
+ for simple {natural language processing} analysis tasks well
+ into the 1980s. Since then, {Perl} has come into favour for
+ such tasks.
+
+ SNOBOL was originally called "SEXI" - String EXpression
+ Interpreter. In spite of the suggestive name, SNOBOL is not
+ related to {COBOL}. Farber said the name SNOBOL was largely
+ contrived at the time the original JACM article was published
+ when one of the implementors said something like, "This
+ program doesn't have a snowball's chance in hell of ...". The
+ expansion to "String Oriented Symbolic Language" was contrived
+ later.
+
+ Implementations include (in no particular order): {SNOBOL2},
+ {SNOBOL3}, {SNOBOL4}, {FASBOL}, {SITBOL}, {MAINBOL}, {SPITBOL}
+ and {vanilla}.
+
+ See also {EZ}, {Poplar}, {SIL} and {Icon}.
+
+ {SNOBOL 4 (http://snobol4.org/)}.
+
+ {David Farber (http://cis.upenn.edu/%7Efarber/)}.
+
+ {Ralph Griswold (http://cs.arizona.edu/people/ralph/)}.
+
+ ["SNOBOL, A String Manipulating Language", R. Griswold et al,
+ J ACM 11(1):21, Jan 1964].
+
+ (2004-04-29)
+
+String PRocessING language
+
+ <language> (SPRING)
+
+ ["From SPRING to SUMMER: Design, Definition and Implementation
+ of Programming Languages for String Manipulation and Pattern
+ Matching", Paul Klint, Math Centre, Amsterdam 1982].
+
+ (1996-02-06)
+
+string reduction
+
+ A {reduction system} where an expression is represented as a
+ string of function names, constants and parentheses. It is
+ reduced by replacing parts of the string representing subterms
+ by their value.
+
+ It is harder to represent sharing of subexpressions in string
+ reduction than in {graph reduction}.
+
+ (1995-02-06)
+
+stripe
+
+ {data striping}
+
+stripe set
+
+ {data striping}
+
+striping
+
+ {data striping}
+
+STROBES
+
+ {Shared Time Repair of Big Electronic Systems}
+
+stroke
+
+ The oblique stroke character, "/", ASCII 47.
+
+ See {ASCII} for other synonyms.
+
+ [{Jargon File}]
+
+StrongARM
+
+ <processor> A collaborative project between {Digital Equipment
+ Corporation} and {Advanced RISC Machines} Ltd. (ARM) announced
+ on 1995-02-06 licensing the {ARM} {RISC} architecture to
+ {Digital Semiconductor} for the development of
+ high-performance, low power {microprocessors}.
+
+ The StrongARM family of 32-bit RISC products developed under
+ the agreement are faster versions of the existing ARM
+ processors with a somewhat different {instruction set}. They
+ are targetted at applications such as next-generation
+ {personal digital assistants} with improved user interfaces
+ and communications; {interactive television} and set-top
+ products; video games and {multimedia} {edutainment} systems
+ with realistic imaging, motion and sound; and digital imaging,
+ including low cost digital image capture and photo-quality
+ scanning and printing.
+
+ The StrongARM family has limited software compatibility with
+ the {ARM6}, {ARM7} and {ARM8} families due to its separate
+ {caches} for data and instructions which causes
+ {self-modifying code} to fail.
+
+ The {SA-110} is the first member of the family.
+
+ (1998-09-07)
+
+strongly connected component
+
+ (SCC) A subset, S, of the nodes of a {directed graph} such
+ that any node in S is reachable from any other node in S and S
+ is not a subset of any larger such set. SCCs are {equivalence
+ class}es under the {transitive closure} of the "directly
+ connected to" {relation}.
+
+ (1995-02-06)
+
+strongly typed
+
+ {strong typing}
+
+strong typing
+
+ <programming> Strict enforcement of {type} rules with no
+ exceptions. Incorrect type usage can be detected either at
+ {run time} or at {compile time}. Strong typing catches more
+ type errors than {weak typing}, resulting in fewer hard
+ errors. In a strongly typed language, conversion between
+ types requires the use of explicit conversion functions
+ ("casts") as opposed to {implicit type coercion}.
+
+ Typing strength is a continuum; {ML} is more strongly typed
+ than {Java}, which is more strongly typed than {C}.
+
+ Strong or weak typing is independent of the choice between
+ {static typing} and {dynamic typing}. Among strongly typed
+ languages, {Ada}, {Java}, {Haskell} and {ML} are statically
+ typed, whereas {Python} and {Ruby} are dynamically typed.
+
+ (2004-07-20)
+
+Stroustrup, Bjarne
+
+ {Bjarne Stroustrup}
+
+struct
+
+ <programming> A data type in {C} and {C++} corresponding to a
+ {record} in {Ada} or {Pascal} or a {tuple} in {functional
+ programming}. A struct has one or more members, each of which
+ may have different types. It is used to group associated data
+ together.
+
+ (1995-02-14)
+
+structural recursion
+
+ The process of transforming an expression by expressing its
+ structure as a syntax tree and applying a certain
+ transformation rule to each kind of node, starting from the
+ top. Rules for non-{leaf nodes} will normally return a result
+ which depends on applying the rules recursively to its
+ sub-nodes. Examples include {syntax} analysis, {code
+ generation}, {abstract interpretation} and {program
+ transformation}.
+
+ (1995-01-11)
+
+structured analysis
+
+ One of a number of requirements analysis methods used in
+ software engineering.
+
+Structured Analysis and Design Technique
+
+ <modeling> (SADT) A {function modeling} method for analysing
+ and communicating the functional perspective of a system.
+ SADT was commissioned by The United States Air Force.
+
+ {IDEF0} was derived from SADT.
+
+ (2007-01-08)
+
+structured design
+
+ <programming> (SD) One of a number of systematic {top-down
+ design} techniques used in {software engineering}, usually
+ after {structured analysis}.
+
+ (1995-04-28)
+
+structure diagram
+
+ <programming, data> A pictorial representation of the
+ composition, grouping and relationship of data items.
+
+ (1998-06-11)
+
+structured language
+
+ {block-structured}
+
+structured programming
+
+ <programming> Any software development technique that includes
+ {structured design} and results in the development of a
+ program consisting of blocks of code whose internal details
+ are independent. Structured programming is usually done in a
+ {block-structured} language.
+
+ (2004-09-29)
+
+Structured Query Language
+
+ {SQL}
+
+Structure of Management Information
+
+ (SMI) The rules used to define the objects that can be
+ accessed via a {network management protocol}. This {protocol}
+ is defined in {STD} 16, {RFC} 1155.
+
+ See also {Management Information Base}.
+
+ (1994-11-14)
+
+strudel
+
+ <character> Common (spoken) name for the commercial at sign,
+ "@", {ASCII} 64.
+
+ [{Jargon File}]
+
+ (1995-03-13)
+
+STRUDL
+
+ STRUctured Design Language.
+
+ Dynamic and {finite-element analysis}, steel and concrete
+ structures. Subsystem of {ICES}. ["ICES STRUDL-II
+ Engineering User's Manual", R68-91, CE Dept MIT (Nov 1968)
+ Sammet 1969, p.613].
+
+STSC APL
+
+ Implementation of APL by Scientific {Time-Sharing} Corporation
+
+stub
+
+ 1. <programming> A dummy procedure used when linking a program
+ with a {run-time library}. The stub routine need not contain
+ any code and is only present to prevent "undefined label"
+ errors at link time.
+
+ 2. <programming, networking> A local procedure in a {remote
+ procedure call}. The {client} calls the stub to perform some
+ task and need not necessarily be aware that RPC is involved.
+ The stub transmits parameters over the network to the {server}
+ and returns the results to the caller.
+
+ (1995-11-09)
+
+stub network
+
+ A {network} which only carries {packets} to and from local
+ {hosts}. Even if it has paths to more than one other network,
+ it does not carry traffic for other networks. See also
+ {backbone}, {transit network}.
+
+stubroutine
+
+ /stuhb'roo-teen/ [contraction of "stub subroutine"] Tiny,
+ often vacuous placeholder for a {subroutine} that is to be
+ written or fleshed out later.
+
+ [{Jargon File}]
+
+STUDENT
+
+ D.G. Bobrow 1964. Early query system. Sammet 1969, p.664.
+
+Student PL/I
+
+ <language> A translator-{interpreter} for a {PL/I} subset
+ derived from {SPL}.
+
+ ["Student PL/I Compiler", R.A. Vowels, RMIT, Melbourne, 1971].
+
+ (1996-01-19)
+
+studly
+
+ Impressive; powerful. Said of code and designs which exhibit
+ both complexity and a virtuoso flair. Has connotations
+ similar to {hairy} but is more positive in tone. Often in the
+ emphatic "most studly" or as noun-form "studliness". "Smail
+ 3.0's configuration parser is most studly."
+
+ [{Jargon File}]
+
+studlycaps
+
+ <jargon> /stuhd'lee-kaps/ A hackish form of silliness similar
+ to {BiCapitalisation} for trademarks, but applied randomly and
+ to arbitrary text rather than to trademarks. ThE oRigiN and
+ SigNificaNce of thIs pRacTicE iS oBscuRe.
+
+ (1995-03-01)
+
+Stuffit
+
+ <tool, file format> (filename extension: .sit) A file
+ {archiving} and {compression} utility, developed by {Aladdin
+ Systems, Inc.}. Stuffit was originally developed for the
+ {Macintosh} and is still the Mac standard tool for compression
+ and archiving (compressing multiple files into one). Stuffit
+ is now also available for {Microsoft Windows} and {Linux}.
+ Compared to the standard Windows tool, {WinZip}, it is faster
+ and gives better compression.
+
+ Stuffit archives can be extracted with Stuffit Expander.
+
+ {Stuffit Home (http://stuffit.com/)}.
+
+ (2003-09-20)
+
+Stupids
+
+ Term used by {samurai} for the {suits} who employ them.
+ Succinctly expresses an attitude at least as common, though
+ usually better disguised, among other subcultures of hackers.
+ There may be intended reference here to an SF story originally
+ published in 1952 but much anthologised since, Mark Clifton's
+ "Star, Bright". In it, a super-genius child classifies humans
+ into a very few "Brights" like herself, a huge majority of
+ "Stupids", and a minority of "Tweens", the merely ordinary
+ geniuses.
+
+ [{Jargon File}]
+
+stupid-sort
+
+ Synonym {bogo-sort}.
+
+Sturgeon's Law
+
+ "Ninety percent of everything is crap". Derived from a quote
+ by science fiction author Theodore Sturgeon, who once said,
+ "Sure, 90% of science fiction is crud. That's because 90% of
+ everything is crud." Oddly, when Sturgeon's Law is cited, the
+ final word is almost invariably changed to "crap". Compare
+ {Ninety-Ninety Rule}. Though this maxim originated in SF
+ fandom, most hackers recognise it and are all too aware of its
+ truth.
+
+ [{Jargon File}]
+
+STX
+
+ {Start Of Text}
+
+style
+
+ <web> The visual presentation or formatting of {web
+ content}, chiefly either {HTML} content with style controlled
+ by {Cascading Style Sheets} (CSS) or {XML} content controlled
+ by {XSL}. Style is distinguished from meaning, which is
+ encoded with {semantic markup}. The latter deals with logical
+ divisions of content such as headings, lists and paragraphs.
+
+ (2008-02-25)
+
+su
+
+ <operating system, tool, security> (substitute user) The
+ {Unix} command which allows you to become another user after
+ entering their {password}. su is most often used without
+ arguments in which case it defaults to user {root}. Some
+ versions of Unix only allows this command to be used by
+ members of the {wheel} group.
+
+ {Unix manual page}: su(1).
+
+ (1996-09-08)
+
+SUB
+
+ {Substitute}
+
+subband encoding
+
+ An audio {compression} technique where the sound is split into
+ frequency bands and then parts of the signal which the ear
+ cannot detect are removed, e.g. a quiet sound masked by a loud
+ one. The remaining signal is encoded using variable bit-rates
+ with more bits per sample being used in the mid frequency
+ range.
+
+ Subband encoding is used in {MPEG-1}.
+
+ (1994-11-02)
+
+subclass
+
+ {class hierarchy}
+
+subject
+
+ <programming> In {subject-oriented programming}, a subject is
+ a collection of {classes} or class fragments whose {class
+ hierarchy} models its domain in its own, subjective way. A
+ subject may be a complete application in itself, or it may be
+ an incomplete fragment that must be composed with other
+ subjects to produce a complete application. Subject
+ composition combines class hierarchies to produce new subjects
+ that incorporate functionality from existing subjects.
+
+ (1999-08-31)
+
+subject index
+
+ <information science> An information resource that contains
+ references to other resources, categorised by subject, usually
+ in a {hierarchy}.
+
+ {Yahoo} is the most popular {Internet} subject index. Like
+ most {other subject indices
+ (http://yahoo.com/Computers_and_Internet/Internet/World_Wide_Web/Searching_the_Web/Web_Directories/)},
+ Yahoo is arranged {ontologically}.
+
+ Subject indices are not to be confused with {search engines},
+ which are based not on subject, but instead on {relevance},
+ although (1) this difference is often (possibly rightly)
+ hidden from the unsophisticated user, and (2) future
+ integration of {knowledge representation} into relevance
+ ranking {algorithms} will make this a hazy distinction.
+
+ (1997-04-09)
+
+subject-oriented programming
+
+ <programming> Program composition that supports building
+ {object-oriented} systems as compositions of {subjects},
+ extending systems by composing them with new subjects, and
+ integrating systems by composing them with one another
+ (perhaps with {glue} or adapter subjects).
+
+ The flexibility of subject composition introduces novel
+ opportunities for developing and modularising object-oriented
+ programs. Subject-oriented programming-in-the-large involves
+ dividing a system into subjects and writing rules to compose
+ them correctly. It complements {object-oriented programming},
+ solving a number of problems that arise when OOP is used to
+ develop large systems or suites of interoperating or
+ integrated applications.
+
+ {IBM subject-oriented programming
+ (http://research.ibm.com/sop/)}.
+
+ (1999-08-31)
+
+sublanguage
+
+ <database, language> One of the languages associated with a
+ {DBMS}, for example a {data-definition language} or {query
+ language}.
+
+ (1999-10-18)
+
+subnet
+
+ A portion of a {network}, which may be a physically
+ independent network segment, which shares a {network address}
+ with other portions of the network and is distinguished by a
+ subnet number. A subnet is to a network what a network is to
+ an {internet}.
+
+subnet address
+
+ The {subnet} portion of an {IP address}. In a subnetted
+ {network}, the {host} portion of an IP address is split into a
+ subnet portion and a host portion using an {address mask} (the
+ subnet mask).
+
+subnet mask
+
+ {address mask}
+
+subnet number
+
+ {subnet address}
+
+subroutine
+
+ <programming> (Or "procedure") A sequence of {instructions}
+ for performing a particular task. Most programming languages,
+ including most {machine languages}, allow the programmer to
+ define subroutines. This allows the subroutine code to be
+ called from multiple places, even from within itself (in which
+ case it is called {recursive}). The programming language
+ implementation takes care of returning control to (just after)
+ the calling location, usually with the support of call and
+ return instructions at {machine language} level.
+
+ Most languages also allow {arguments} to be passed to the
+ subroutine, and one, or occasionally more, {return values} to
+ be passed back.
+
+ A {function} is often very similar to a subroutine, the main
+ difference being that it is called chiefly for its return
+ value, rather than for any {side effects}.
+
+ (1996-10-01)
+
+subscribe
+
+ <messaging> To request to receive messages posted to a
+ {mailing list} or {newsgroup}. In contrast to the mundane use
+ of the word this is often free of charge.
+
+ (1997-03-27)
+
+Subscriber Identity Module
+
+ <telecommunications, wireless> (SIM or "SIM card") A component,
+ usually in the form of a miniature {smart-card}, that is
+ theoretically tamper-proof and is used to associate a {mobile
+ subscriber} with a {mobile network} subscription. The SIM holds
+ the subscriber's unique {MSISDN} along with secret information
+ such as a private {encryption key} and encryption and digital
+ signature algorithms. Most SIMs also contain {non-volatile
+ storage} for network and device management, contact lists, text
+ messages sent and received, logos and in some cases even small
+ {Java} {programs}.
+
+ (2007-01-06)
+
+subscribing
+
+ {subscribe}
+
+\subseteq
+
+ Like a U on its right side with a line under it. For sets x
+ and y, x \subseteq y if all elements of x are also elements of
+ y.
+
+ (1995-02-03)
+
+Subset-Equational Language
+
+ (SEL) A {declarative} language for set processing by Bharat
+ Jayaraman with subset and equational program clauses; {pattern
+ matching} over sets (it supports efficient iteration over
+ sets); annotations to say which functions distribute over
+ union in which arguments (for point-wise/incremental
+ computation over sets); defining {transitive closures} through
+ circular constraints (implemented by mixed
+ top-down/{memoisation} and bottom-up strategy);
+ {meta-programming} and simple {higher-order} programming;
+ modest user-interface including tracing.
+
+ The SEL {compiler}, written in {Quintus Prolog}, generates
+ {WAM}-like code, extended to deal with set-matching,
+ {memoisation}, and the novel control structure of the
+ language. The {run-time system} is written in {C}.
+
+ {(ftp://ftp.cs.buffalo.edu/users/bharat/SEL2)}.
+
+ E-mail: Bharat Jayaraman <bharat@cs.buffalo.edu>.
+
+ ["Towards a Broader Basis for Logic Programming",
+ B. Jayaraman, TR CS Dept, SUNY Buffalo, 1990].
+
+ ["Set Abstraction in Functional and Logic Programming",
+ F.S.K. Silbermann <fs@cs.tulane.edu> et al, ACM Proc 1989].
+
+ (1994-12-15)
+
+Substitute
+
+ <character> (SUB) {ASCII} character 26.
+
+ [Why?]
+
+ (1996-06-28)
+
+substrate
+
+ <hardware> The body or base layer of an {integrated circuit},
+ onto which other layers are deposited to form the circuit.
+ The substrate is usually Silicon, though Sapphire is used for
+ certain applications, particularly military, where radiation
+ resistance is important. The substrate is originally part of
+ the {wafer} from which the {die} is cut. It is used as the
+ electrical {ground} for the circuit.
+
+ (1996-04-07)
+
+subtype
+
+ <programming> If S is a subtype of T then an expression of
+ {type} S may be used anywhere that one of type T can and an
+ {implicit type conversion} will be applied to convert it to
+ type T.
+
+ In {object oriented programming}, this means that {objects} of
+ type S must accept every {message} that one of type T would.
+
+ (1997-07-28)
+
+subtyping
+
+ {subtype}
+
+SuccessoR
+
+ A language for {distributed computing} derived from {SR}.
+
+ ["SuccessoR: Refinements to SR", R.A. Olsson et al, TR 84-3, U
+ Arizona 1984].
+
+ (1994-12-15)
+
+successor
+
+ {daughter}
+
+sucking mud
+
+ (Or "pumping mud") (Applied Data Research) Crashed or
+ {wedged}. Usually said of a machine that provides some
+ service to a network, such as a {file server}. This Dallas
+ regionalism derives from the East Texas oilfield lament, "Shut
+ 'er down, Ma, she's a-suckin' mud". Often used as a query.
+ "We are going to reconfigure the network, are you ready to
+ suck mud?"
+
+ [{Jargon File}]
+
+ (1994-12-15)
+
+Sue
+
+ The system language used to write an {operating system} for
+ the {IBM 360}. It is a cross between {Pascal} and {XPL}. It
+ allows type checked {separate compilation} of internal
+ procedures using a program library.
+
+ ["The System Language for Project Sue", B.L. Clark e al,
+ SIGPLAN Notices 6(9):79-88 (Oct 1971)].
+
+ (1994-12-01)
+
+sufficiently small
+
+ {suitably small}
+
+SUGAR
+
+ A simple {lazy functional language} designed at {Westfield
+ College}, University of London, UK and used in Principles of
+ Functional Programming, Hugh Glaser et al, P-H 1984.
+
+ (1994-12-01)
+
+suicideware
+
+ <jargon> A program which entirely stops functioning after a
+ predefined date. Used to ensure that {beta versions} don't
+ remain in circulation indefinitely or in {demo versions} to
+ ensure that they can only be used to try out the program.
+
+ (1997-05-26)
+
+SUIF
+
+ Stanford University Intermediate Format.
+
+ A register-oriented intermediate language.
+
+ (1994-12-01)
+
+suit
+
+ 1. Ugly and uncomfortable "business clothing" often worn by
+ non-hackers. Invariably worn with a "tie", a strangulation
+ device that partially cuts off the blood supply to the brain.
+ It is thought that this explains much about the behaviour of
+ suit-wearers.
+
+ 2. A person who habitually wears suits, as distinct from a
+ techie or hacker.
+
+ See {loser}, {burble}, {management}, {Stupids}, {SNAFU
+ principle}, and {brain-damaged}.
+
+ [{Jargon File}]
+
+ (1998-07-01)
+
+suitably small
+
+ <jargon, mathematics> (From mathematical jargon) An expression
+ used ironically to characterise unquantifiable behaviour that
+ differs from expected or required behaviour. For example,
+ suppose a newly created program came up with a correct
+ full-screen display, and one publicly exclaimed: "It works!"
+ Then, if the program dumped {core} on the first mouse click,
+ one might add: "Well, for suitably small values of `works'."
+
+ Compare the characterisation of pi under {for values of}.
+
+ [{Jargon File}]
+
+ (1997-09-21)
+
+Suite Synthetique des Benchmarks de l'AFUU
+
+ <benchmark> (SSBA, AFUU Synthetic Benchmark Suite) A {public
+ domain} {benchmark} suite produced by the {AFUU}.
+
+ Version: 2.3 (1995-07-14).
+
+ (1996-06-11)
+
+sum
+
+ 1. <theory> In {domain theory}, the sum A + B of two {domains}
+ contains all elements of both domains, modified to indicate
+ which part of the union they come from, plus a new {bottom}
+ element. There are two constructor functions associated with
+ the sum:
+
+ inA : A -> A+B inB : B -> A+B
+ inA(a) = (0,a) inB(b) = (1,b)
+
+ and a disassembly operation:
+
+ case d of {isA(x) -> E1; isB(x) -> E2}
+
+ This can be generalised to arbitrary numbers of domains.
+
+ See also {smash sum}, {disjoint union}.
+
+ 2. <tool> A {Unix} utility to calculate a 16-bit {checksum} of
+ the data in a file. It also displays the size of the file,
+ either in {kilobytes} or in 512-byte blocks. The checksum may
+ differ on machines with 16-bit and 32-bit ints.
+
+ {Unix manual page}: sum(1).
+
+ (1995-03-16)
+
+Summary Object Interchange Format
+
+ <web, protocol> (SOIF) The attribute-value pair
+ record format which {Harvest Brokers} use to exchange
+ {Harvest} content summaries.
+
+ SOIF provides a means of bracketing collections of summary
+ objects, allowing {Harvest Brokers} to retrieve SOIF content
+ summaries for many objects in a single, efficient compressed
+ stream. Harvest Brokers provide support for querying SOIF
+ data using structured attribute-value queries and many other
+ types of queries.
+
+ {(http://ust.hk/Harvest/brokers/soifhelp.html)}.
+
+ (1996-09-16)
+
+SUMMER
+
+ String manipulation and pattern matching language by Klint &
+ Sint at {CWI} in the late 1970s. It was recently used as the
+ input and implementation language for the {Dataflow Compiler
+ Project} at {CWI}.
+
+ ["An Overview of the SUMMER Programming Language", Paul Klint,
+ 7th POPL, ACM 1980, pp. 47-55].
+
+SUMMER SESSION
+
+ An early system on {MIT}'s {Whirlwind}.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1995-01-19)
+
+sum of products
+
+ 1. <mathematics, logic> Any mathematical {expression} in which
+ an addition operator is applied to two or more subexpressions
+ each of which is an application of a multiplication operator.
+ The most common case would be scalar addition and
+ multiplication, e.g.
+
+ ab + cd
+
+ but the term is used for other kinds of operators with similar
+ properties, such as AND and OR in {Boolean algebra}, e.g.
+
+ (a AND b) OR (c AND d)
+
+ 2. <types> {algebraic data type}.
+
+ (2008-02-04)
+
+sum of products type
+
+ {algebraic data type}
+
+Sun
+
+ {Sun Microsystems}
+
+Sun-2 Workstation
+
+ <computer> A {Unix} {workstation} produced by {Sun
+ Microsystems, Inc.}, based on the {Motorola 68000}. Followed
+ by the {Sun-3 Workstation}.
+
+ [Details? Dates?]
+
+ (2001-03-11)
+
+Sun-3 Workstation
+
+ <computer> A {Unix} {workstation} produced by {Sun
+ Microsystems, Inc.} in the 1980s, based on the {Motorola
+ 68020}. Successor to the {Sun-2 Workstation}, followed by the
+ {Sun-4 Workstation}. The Sun-3 had a custom {MMU}. A couple
+ of mutant models used an entirely different architecture.
+
+ [Details? Dates?]
+
+ (2001-03-11)
+
+Sun-4 Workstation
+
+ <computer> A {Unix} {workstation} produced by {Sun
+ Microsystems, Inc.} in the late 1980s[?], based on {SPARC}
+ processors. The Sun-4 followed the {Sun-3 Workstation}.
+ Later SPARC-based workstations were called "{SPARCstations}".
+
+ [Details? Dates? Was "Sun-4" a SPARCstation?]
+
+ (2001-03-11)
+
+sun lounge
+
+ <jargon> (Great Britain) The room where all the {Sun}
+ {workstations} live. The humour in this term comes from the
+ fact that it's also in mainstream use to describe a solarium,
+ and all those Sun workstations clustered together give off an
+ amazing amount of heat.
+
+ [{Jargon File}]
+
+ (1995-01-19)
+
+Sun Microsystems, Inc.
+
+ <company> One of the first, and now biggest, US computer
+ manufacturers. They also manufacture in Europe. The Sun-2
+ and 3 series of {workstations} and {servers} were based on the
+ {Motorola} {680x0} family of {microprocessors} and the Sun-4
+ series on the {SPARC}. Sun also produce their own version of
+ {Unix}, originally called {SunOS} and now {Solaris}. Their
+ {Network File System} has become the {de facto standard} for
+ sharing files between Unix systems.
+
+ Sun own {MySQL AB}. Sun was bought by {Oracle Corporation} on
+ 2009-04-20.
+
+ Quarterly sales $1403M, profits $78M (Aug 1994).
+
+ {(http://sun.com/)}. {Sun World Online
+ (http://sun.com/sunworldonline/)}.
+
+ Address: 2550 Garcia Ave., Mt. View, CA 94043 -1100 USA.
+
+ (1995-10-14)
+
+SunOS
+
+ <operating system> {Sun Microsystems}' version of {Unix} for
+ Sun {workstations}. SunOS is similar to {BSD Unix} with some
+ {SVR4} features and {OpenWindows} 3.0.
+
+ After version 4, SunOS was integrated into Sun's {Solaris}
+ "operating environment".
+
+ (1999-03-26)
+
+sunspots
+
+ 1. Notional cause of an odd error. "Why did the program
+ suddenly turn the screen blue?" "Sunspots, I guess."
+
+ 2. Also the cause of {bit rot} - from the myth that sunspots
+ will increase {cosmic rays}, which can flip single bits in
+ memory. See also {phase of the moon}.
+
+ [{Jargon File}]
+
+sun-stools
+
+ Unflattering hackerism for {SunTools}, a pre-{X} windowing
+ environment notorious in its day for size, slowness, and
+ misfeatures. {X}, however, is larger and slower; see
+ {second-system effect}.
+
+SunView
+
+ A windowing system from {Sun Microsystems}, superseded by
+ {NeWS}.
+
+SUNY
+
+ {State University of New York}
+
+SUPER
+
+ The successor to {LOGLISP}, based on {LNF}.
+
+ ["New Generation Knowledge Processing: Final Report on the
+ SUPER System", J Alan Robinson et al, CASE Center TR 8707,
+ Syracuse U, 1987].
+
+ (1994-11-24)
+
+Super 7
+
+ <hardware, standard> An upgrade to {Socket 7} to support {AGP}
+ and a 100 MHz {system bus},, supported by non-{Intel}
+ {processor} and {motherboard} manufacturers such as {AMD} and
+ {Cyrix}.
+
+ Due to faster access to {L2 cache} and memory, Super 7 gives a
+ 10% performance boost over Socket 7 motherboards for the same
+ processor. Super 7 motherboards should support all Socket 7
+ processors.
+
+ (1999-08-04)
+
+Superbrain
+
+ <computer> A {personal computer} released in 1980 by {Intertec}.
+ The Superbrain had two {Z80A} {microprocessors} running at 4 MHz,
+ one for the main processing and the other for peripheral
+ activities. It had an integrated {keyboard} and {display}. It
+ was sold with the {CP/M} {operating system}, {Microsoft Basic}, an
+ {8080} {assembler} and {Microsoft Cobol 74}.
+
+ The base model, the "Superbrain 10", had no drives, only a network
+ connection. Other models added one or two 5" {floppy disc} units.
+ The "Jr" had 170K drives (single-sided), the "QD" had 340 KB
+ drives (double-sided) and the "SD" had 780k.
+
+ Intertec did not sell or support a hard drive or an {S-100} bus
+ for these machines.
+
+ The network version of the SuperBrain was called CompuStar. The
+ network was a large gray parallel cable. CompuStar had three
+ "file servers" that accepted up to 255 machines. These were the
+ "DSS-10" with a 10MB 8" Winchester drive; the "CDC" with 96MB
+ consisting of 80MB fixed and a 16MB removable platter; and the
+ "Priam" with a 144MB 14" platter winchester. Intertec
+ manufactured the controllers for the last two and an enclosure and
+ power supply for the Priam. CDC had to go on-site to install the
+ 96MB.
+
+ The SuperBrain was succeeded in 1982 by the {SuperBrain II}.
+
+ {(http://www.old-computers.com/museum/computer.asp?st=1&c=204)}.
+
+ (2013-12-30)
+
+SuperBrain II
+
+ <computer> The 1982 successor to the {Superbrain} with a faster
+ and enhanced {disk operating system} and improved {video} and
+ {graphics}.
+
+ {(http://www.old-computers.com/museum/computer.asp?st=1&c=204)}.
+
+ (2013-12-30)
+
+superclass
+
+ {class hierarchy}
+
+supercombinators
+
+ {Combinators} with coarser granularity than those proposed by
+ {David Turner}. A {functional program} is translated to a set
+ of functions without {free variables}. The members of the set
+ are selected to be optimal for that program. Supercombinators
+ were proposed by John Hughes at {University of Edinburgh}.
+
+supercompilation
+
+ A function program transformation technique invented by
+ Turchin. A program is evaluated symbolically in order to
+ observe the possible history of computation states called
+ configurations. Based on this Turchin's REFAL compiler would
+ try to construct a better program.
+
+supercomputer
+
+ <computer> A broad term for one of the fastest computers
+ currently available. Such computers are typically used for
+ {number crunching} including scientific {simulations},
+ (animated) {graphics}, analysis of geological data (e.g. in
+ petrochemical prospecting), structural analysis, computational
+ fluid dynamics, physics, chemistry, electronic design, nuclear
+ energy research and meteorology. Perhaps the best known
+ supercomputer manufacturer is {Cray Research}.
+
+ A less serious definition, reported from about 1990 at The
+ {University Of New South Wales} states that a supercomputer is
+ any computer that can outperform {IBM}'s current fastest, thus
+ making it impossible for IBM to ever produce a supercomputer.
+
+ (1996-12-13)
+
+SuperDrive
+
+ <storage> {Apple Computer, Inc.}'s name for a combined
+ {DVD-ROM}, {DVD-RW}, {CD-RW} drive that appeared in the {iMac}
+ in 2002.
+
+ (2009-05-05)
+
+superhighway
+
+ {information superhighway}
+
+SuperJanet
+
+ An initiative started in 1989, under the Computer Board, with
+ the aim of developing of a national {broadband} network to
+ support UK higher education and research. The preparatory
+ work culminated in 1992 with the award of a contract worth 18M
+ pounds to British Telecom to provide networking services over
+ a four year period that extends to March 1997.
+
+ The BT contract will provide a national network with two
+ components: a high speed, configurable bandwidth network
+ serving up to 16 sites, initially using {PDH} to be replaced
+ with {SDH}, and a high speed switched data service ({SMDS})
+ serving 50 or more sites. The primary role of the PDH/SDH
+ component will be to support the development and deployment of
+ an {ATM} network. These components will be complemented by
+ several high performance {Metropolitan Area Networks} each
+ serving several closely located sites. The aim is to provide,
+ within the first year of the project, a pervasive network
+ capable of supporting a large and diverse user community.
+
+ The network has two parts, an {IP} data network and an ATM
+ network, both operating at 34Mbit/s. Early in August 1993 the
+ pilot IP network was transferred to full service and was
+ configured to provide a trunk network for JIPS, the {JANET IP
+ Service}.
+
+ In November 1993 work was well advanced on the next phase
+ which aims to extend SuperJANET to a large number of sites.
+ The pilot four site ATM network will be extended to serve
+ twelve sites and will expand the scope of the video network.
+ The principal vehicle used for the expansion of the data
+ network will be the {SMDS} service provided by {BT}. Most of
+ the work associated with the development of this phase is
+ expected to be completed by the end of March 1994.
+
+ [Joint Network Team, Network News 40, ISSN 0954 - 0636].
+
+ {(ftp://osiris.jnt.ac.uk/pub/newsfiles/documents/netwnews/news40+/news40.para)}.
+
+ [Current status?]
+
+ (1994-12-15)
+
+SUPERMAC
+
+ A general-purpose {macro} language, embeddable in existing
+ languages as a run-time library.
+
+ ["SUPERMAC - A Macro Facility That can be Added to Existing
+ Compilers", P.J. Brown, Soft Prac & Exp 10(6):431-434].
+
+ (1994-12-15)
+
+super minicomputer
+
+ <computer> Any {minicomputer} distinguished by having
+ {intelligent peripherals} or multiple processors. The {DEC
+ PDP-8} was a minicomputer, the PDP-11 could be a minicomputer
+ or a super minicomputer depending upon the sub-model.
+
+ (2004-08-25)
+
+SuperPaint
+
+ <graphics> A pioneering {graphics} program and {framebuffer}
+ computer system developed by {Richard Shoup} at {Xerox PARC}.
+ Design started in 1972 and the system produced its first
+ stable image in April 1973. SuperPaint was one of the first
+ computers used for creative work, video editing and animation,
+ all which would become major sections within the entertainment
+ industry and major components of industrial design.
+
+ SuperPaint had a {graphical user interface} and could capture
+ images from video input or combine them with digital data.
+ SuperPaint was the first program with features such as
+ changing {hue, saturation and value}, a {colour palette},
+ custom {polygons} and lines, virtual paintbrushes and pencils,
+ auto-filling of images and {anti-aliasing}.
+
+ {Richard Shoup's website
+ (http://www.rgshoup.com/prof/SuperPaint/)}.
+
+ (2008-11-27)
+
+Super Pascal
+
+ <language> A {Pascal} variant used in the reference below.
+ Super Pascal adds
+ non-numeric {labels}, a {return statement} and {expressions} as
+ names of {types}.
+
+ ["Data Structures and Algorithms", A. Aho, Hopcroft & Ullman,
+ A-W 1983]
+
+ (2004-08-25)
+
+superpipelined
+
+ 1. Traditional {pipelined} architectures have a single
+ pipeline stage for each of: instruction fetch, instruction
+ decode, memory read, {ALU} operation and memory write. A
+ superpipelined {processor} has a {pipeline} where each of
+ these logical steps may be subdivided into multiple {pipeline}
+ stages.
+
+ 2. Marketese for {pipelined}.
+
+superprogrammer
+
+ A prolific programmer; one who can code exceedingly well and
+ quickly. Not all hackers are superprogrammers, but many are.
+ Productivity can vary from one programmer to another by three
+ orders of magnitude. For example, one programmer might be
+ able to write an average of three lines of working code in one
+ day, while another, with the proper tools, might be able to
+ write 3,000. This range is astonishing; it is matched in very
+ few other areas of human endeavour.
+
+ The term "superprogrammer" is more commonly used within such
+ places as IBM than in the hacker community. It tends to
+ stress naive measures of productivity and to underweight
+ creativity, ingenuity, and getting the job *done* - and to
+ sidestep the question of whether the 3,000 lines of code do
+ more or less useful work than three lines that do the {Right
+ Thing}. Hackers tend to prefer the terms {hacker} and
+ {wizard}.
+
+ [{Jargon File}]
+
+superscalar
+
+ <architecture> A superscalar architecture is a {uniprocessor}
+ that can execute two or more {scalar} operations in parallel.
+ Some definitions include {superpipelined} and {VLIW}
+ architectures; others do not. Superscalar architectures
+ (apart from superpipelined architectures) require multiple
+ {functional units}, which may or may not be identical to each
+ other. In some superscalar processors the order of
+ instruction execution is determined statically (purely at
+ compile-time), in others it is determined dynamically (partly
+ at run time).
+
+super source quench
+
+ A special packet designed to shut up an {Internet} host. The
+ {Internet Protocol} (IP) has a control message called Source
+ Quench that asks a host to transmit more slowly on a
+ particular connection to avoid congestion. It also has a
+ Redirect control message intended to instruct a host to send
+ certain packets to a different local router. A "super source
+ quench" is actually a redirect control packet, forged to look
+ like it came from a local router, that instructs a host to
+ send all packets to its own local loopback address. This will
+ effectively tie many Internet hosts up in knots. Compare
+ {godzillagram}, {breath-of-life packet}.
+
+ [{Jargon File}]
+
+SuperTalk
+
+ Silicon Beach Software. A superset of HyperTalk used in
+ SuperCard.
+
+superuser
+
+ [Unix] Synonym {root}, {avatar}. This usage has spread to
+ non-Unix environments; the superuser is any account with all
+ {wheel} bits on. A more specific term than {wheel}.
+
+ [{Jargon File}]
+
+Super VGA
+
+ {Super Video Graphics Array}
+
+Super Video Graphics Adapter
+
+ {Super Video Graphics Array}
+
+Super Video Graphics Adaptor
+
+ {Super Video Graphics Array}
+
+Super Video Graphics Array
+
+ <hardware> (SVGA) A {video display} {standard} created by
+ {VESA} for {IBM PC} compatible personal computers. The
+ resolution is 800 x 600 4-bit {pixels}. Each pixel can
+ therefore be one of 16 colours.
+
+ See {Video Graphics Array}.
+
+ [Is there a palette? Standard document? Adapter, Adaptor, or
+ Array?]
+
+ (1995-01-12)
+
+supervisor mode
+
+ (Or "{supervisor state}") An execution mode on some processors
+ which enables execution of all instructions, including
+ {privileged instructions}. It may also give access to
+ different a {address space}, to {memory management} hardware
+ and to other peripherals. This is the mode in which the
+ {operating system} usually runs.
+
+ Opposite: {user mode}.
+
+ (1995-02-15)
+
+Supervisory Control and Data Acquisition
+
+ <application> (SCADA) Systems are used in industry to monitor
+ and control plant status and provide logging facilities.
+ SCADA systems are highly configurable, and usually interface
+ to the plant via {PLCs}.
+
+ (1997-02-11)
+
+SuperZap
+
+ <tool, IBM> An {IBM} {utility program} used to quickly {patch}
+ {operating system} or {application program} executable {code}
+ in preference to editing the {source code} and recompiling.
+
+ The SuperZAP program was a quick hack written by one IBM
+ Engineer, possibly from IBM UK, in the late 1960s to directly
+ fix executable files. He needed to fix a bug but it would
+ have taken hours to rebuild the vast {OS/360} executables.
+
+ The {S/360} architecture has an instruction ZAP (Zero and Add
+ Packed) for {packed decmial} arithmetic, that sets the byte at
+ a given address to a given value. Superzap used this to write
+ data given as a string of hex digits to a given location in an
+ executable file in a matter of seconds.
+
+ Soon the IBM development labs were releasing all Programming
+ Temporary Fixes (PTFs) to OS/360 in this form. OS/360
+ included a version called IMASPZAP or AMASPZAP which persisted
+ through {MVS}, {MVS/SP}, {MVS/XA}, {OS/390} and probably still
+ remains in {z/OS}, the distant descendent of OS/360.
+
+ [Private 2004-02-05 e-mail from Chris Gage, IBM employee and
+ SuperZap user, 1970-].
+
+ (2007-03-15)
+
+Supplementary Ideographic Plane
+
+ <text, standard> (SIP) The third plane (plane 2) defined in
+ {Unicode}/{ISO 10646}, designed to hold all the {ideographs}
+ descended from Chinese writing (mainly found in Vietnamese,
+ Korean, Japanese and Chinese) that aren't found in the {Basic
+ Multilingual Plane}. The BMP was supposed to hold all
+ ideographs in modern use; unfortunately, many Chinese dialects
+ (like Cantonese and Hong Kong Chinese) were overlooked; to
+ write these, characters from the SIP are necessary. This is
+ one reason even non-academic software must support characters
+ outside the BMP.
+
+ {Unicode home (http://unicode.org)}.
+
+ (2002-06-19)
+
+support
+
+ <job> After-sale handholding; something many software vendors
+ promise but few deliver. To hackers, most support people are
+ useless - because by the time a hacker calls support he or she
+ will usually know the software and the relevant manuals better
+ than the support people. A hacker's idea of support is an
+ electronic exchange with the software's designer.
+
+ [{Jargon File}]
+
+ (1995-02-15)
+
+supremum
+
+ {least upper bound}
+
+Sure
+
+ ["Towards a Broader Basis for Logic Programming", Bharat
+ Jayaraman, TR CS Dept, SUNY Buffalo, 1990].
+
+ (1995-01-05)
+
+surfing
+
+ ("Internet surfing") Used by analogy to describe the ease with
+ which an expert user can use the waves of information flowing
+ around the {Internet} to get where he wants. The term became
+ popular in the early 1990s as access to the {Internet} became more
+ widespread and tools such as {web browsers} made its use simpler
+ and more pleasant.
+
+ (1995-01-05)
+
+SURGE
+
+ Sorter, Updater, Report Generator, Etc. IBM 704, 1959.
+ Sammet 1969, p.8.
+
+surjection
+
+ <mathematics> A function f : A -> B is surjective or onto or a
+ surjection if f A = B. I.e. f can return any value in B.
+ This means that its {image} is its {codomain}.
+
+ Only surjections have {right inverses}, f' : B -> A where
+ f (f' x) = x since if f were not a surjection there would be
+ elements of B for which f' was not defined.
+
+ See also {bijection}, {injection}.
+
+ (1995-05-27)
+
+surjective
+
+ {surjection}
+
+surrogate key
+
+ <database> A unique {primary key} generated by the {RDBMS}
+ that is not derived from any data in the database and whose
+ only significance is to act as the primary key.
+
+ A surrogate key is frequently a sequential number (e.g. a
+ {Sybase} "{identity column}") but doesn't have to be. Having
+ the key independent of all other columns insulates the
+ database relationships from changes in data values or database
+ design and guarantees uniqueness.
+
+ Some database designers use surrogate keys religiously
+ regardless of the suitability of other {candidate keys}.
+ However, if a good key already exists, the addition of a
+ surrogate key will merely slow down access, particularly if it
+ is indexed.
+
+ Compare: {intelligent key}.
+
+ (1999-12-07)
+
+suspension
+
+ In {lazy evaluation}, a suspension (or in Henderson's
+ terminology, a "recipe") is a {closure} with a flag indicating
+ whether the expression has been evaluated or not. When the
+ expression is evaluated the first time, this flag is set.
+ Subsequent requests for the value of the expression will not
+ attempt to re-evaluate it.
+
+ (1995-02-06)
+
+Suzie COBOL
+
+ /soo'zee koh'bol/ 1. ({IBM}, probably from Frank Zappa's "Suzy
+ Creamcheese") A coder straight out of training school who
+ knows everything except the value of {comments} in plain
+ English. Also (fashionable among personkind wishing to avoid
+ accusations of sexism) "Sammy Cobol" or (in some non-IBM
+ circles) "Cobol Charlie".
+
+ 2. (proposed) Meta-name for any {code grinder}, analogous to
+ {J. Random Hacker}.
+
+ [{Jargon File}]
+
+ (1995-02-06)
+
+sv
+
+ <networking> The {country code} for El Salvador.
+
+ (1999-01-27)
+
+SVC
+
+ 1. <operating system> {Supervisor Call}.
+
+ 2. <networking> {switched virtual connection}.
+
+ (2001-10-25)
+
+SVG
+
+ {Scalable Vector Graphics}
+
+SVGA
+
+ <hardware> {Super Video Graphics Array} (not
+ "Adapter").
+
+ (1995-11-16)
+
+SVGA monitor
+
+ <hardware, graphics> A {monitor} capable of displaying the
+ output of an {SVGA} card.
+
+ (1997-02-25)
+
+SVID
+
+ {System V Interface Definition}
+
+S-Video
+
+ <multimedia> A {video} format offering a higher quality signal
+ than {composite video}, but a lower quality than {component
+ video}. This mid-level format divides the signal into two
+ channels - {luminance} and {chrominance}.
+
+ [Used where and for what?]
+
+ (1998-06-25)
+
+SVR4
+
+ {AT&T}/{USL} {Unix} {System V} Release 4.
+
+ (1995-03-28)
+
+SVRC
+
+ <body> {Software Verification Research Centre}.
+
+ (1995-11-14)
+
+SVS
+
+ {OS/VS2}
+
+swab
+
+ /swob/ The {PDP-11} swap byte instruction mnemonic, as
+ immortalised in the {dd} option "conv=swab".
+
+ 1. To solve the {NUXI problem} by swapping bytes in a file.
+
+ 2. The program in V7 Unix used to perform this action, or
+ anything functionally equivalent to it.
+
+ See also {big-endian}, {little-endian}, {middle-endian},
+ {bytesexual}.
+
+ [{Jargon File}]
+
+SWAG
+
+ <jargon> Scientific (or Silly) Wild Ass Guess. A term used by
+ technical teams when establishing high level sizings for large
+ projects.
+
+ (2000-08-09)
+
+swap
+
+ <operating system> To move a program from fast-access memory
+ to a slow-access memory ("swap out"), or vice versa ("swap
+ in"). The term often refers specifically to the use of a
+ {hard disk} (or a {swap file}) as {virtual memory} or "swap
+ space".
+
+ When a program is to be executed, possibly as determined by a
+ {scheduler}, it is swapped into {core} for processing; when it
+ can no longer continue executing for some reason, or the
+ scheduler decides its {time slice} has expired, it is swapped
+ out again.
+
+ This contrasts with "paging" systems in which only parts of a
+ program's memory is transfered.
+
+ [{Jargon File}]
+
+ (1996-11-22)
+
+swap file
+
+ <operating system> A file used by a {program} or, more often,
+ an {operating system} as {swap space}. A swap file is usually
+ allocated as a long contiguous section of a {hard disk} to
+ reduce access time. The disk space used for a swap file can
+ not be used for other things. Under {Microsoft Windows}, swap
+ files are recommended not to exceed three times the available
+ {RAM} and are usually 150 percent of the RAM size.
+
+ (1996-11-15)
+
+swapped in
+
+ {swap}
+
+swapped out
+
+ {swap}
+
+swapping
+
+ {swap}
+
+swap space
+
+ <operating system> An area of disk (e.g. a {swap file}) used
+ to store the state of a process that has been {swap}ped out.
+ Under a {virtual memory} system, it is the amount of swap
+ space rather than the amount of {physical memory} which
+ determines the maximum size of a single process and the
+ maximum total size of all active processes.
+
+ [{Jargon File}]
+
+ (1994-11-03)
+
+Sweden
+
+ <networking> {Country code}: se.
+
+SweetLambda
+
+ Sugared {lambda-calculus}(?).
+
+swf
+
+ <filename extension> /S W F/ The {filename extension} for
+ {Adobe} {Shockwave} {Flash} animated {vector graphics} files,
+ common on the {web}.
+
+ A rarely used alternative expansion is "Small Web Format".
+
+ (2007-09-07)
+
+Swing
+
+ <programming> {Java}'s {graphical user interface} (GUI)
+ package that provides a large collection of {widgets}
+ (buttons, labels, lists etc.) that behave similarly on
+ different {platforms}. Swing features "pluggable look &
+ feel", allowing the program to look like a {Windows}, {Motif}
+ or {Macintosh) application. It is implemented using the
+ {Model View Controller} (MVC) architecture and makes extensive
+ use of nested "containers" to control the handling of {events}
+ such as keystrokes.
+
+ {(http://java.sun.com/j2se/1.3/docs/api/javax/swing/package-summary.html)}.
+
+ (2007-05-30)
+
+SWI-Prolog
+
+ <programming> A {Prolog} by Jan Wielemaker
+ <jan@swi.psy.uva.nl> like a superset of {Edinburgh Prolog}.
+ Version 1.7.2. Docking Station is distributed under {General
+ Public License}. It runs on {Sun-4}, {Sun-3}, {Linux}, {DEC}
+ {MIPS} (incomplete), {RS/6000}, {PS2}/{AIX}, {Atari ST},
+ {Gould PN}, {NeXT}, {VAX}, {HP-UX} (problems), {MS-DOS}, and
+ {OS/2}.
+
+ {(ftp://swi.psy.uva.nl/pub/SWI-Prolog)}.
+
+ {OS/2 (ftp://mpii02999.ag2.mpi-sb.mpg.de/pub/toolw/SWI/)}.
+
+ Mailing list: prolog-request@swi.psy.uva.nl.
+
+ (2000-03-23)
+
+Swiss Army Code
+
+ <programming, humour> {Code} for an {application} that is
+ suffering from {feature creep}. Swiss Army Code does many
+ things, but does none of them well.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2014-06-06)
+
+switch
+
+ 1. <programming> {switch statement}.
+
+ 2. <software> {command line option}.
+
+ 3. <networking> {packet switch}, {circuit switch}.
+
+ (1999-01-14)
+
+Switched Multimegabit Data Service
+
+ <networking> (SMDS) An emerging high-speed {datagram}-based
+ public data {network} service developed by {Bellcore} and
+ expected to be widely used by telephone companies as the basis
+ for their data networks.
+
+ See also {Metropolitan Area Network}.
+
+ (1997-01-31)
+
+switched virtual circuit
+
+ {virtual circuit}
+
+switched virtual connection
+
+ <networking> (SVC) A {virtual connection} in an {ATM} network
+ set up on demand by the {signalling control point}.
+
+ Contrast with {permanent virtual connection}.
+
+ (2001-06-29)
+
+switching
+
+ <networking> Establishing the correct path through a network
+ for a single packet of data ({packet switching}) or a
+ persistent end-to-end connection ({circuit switching}).
+
+ (2007-08-16)
+
+switching hub
+
+ <networking> A {circuit switching} {hub}.
+
+ (1999-01-01)
+
+switch statement
+
+ <programming> (Or case statement, multi-way branch) A
+ construct found in most {high-level languages} for selecting
+ one of several possible blocks of code or branch destinations
+ depending on the value of an expression. An example in {C} is
+
+ switch (foo(x, y))
+ {
+ case 1: printf("Hello\n"); /* fall through */
+ case 2: printf("Goodbye\n"); break;
+ case 3: printf("Fish\n"); break;
+ default: fprintf(stderr, "Odd foo value\n"); exit(1);
+ }
+
+ The break statements cause execution to continue after the
+ whole switch statemetnt. The lack of a break statement after
+ the first case means that execution will {fall through} into
+ the second case. Since this is a common programming error you
+ should add a comment if it is intentional.
+
+ If none of the explicit cases matches the expression value
+ then the (optional) default case is taken.
+
+ A similar construct in some {functional languages} returns the
+ value of one of several expressions selected according to the
+ value of the first expression. A distant relation to the
+ modern switch statement is {Fortran}'s {computed goto}.
+
+ (1997-01-30)
+
+swizzle
+
+ To convert external names, array indices, or references within
+ a data structure into address pointers when the data structure
+ is brought into main memory from external storage (also called
+ "pointer swizzling"); this may be done for speed in chasing
+ references or to simplify code (e.g. by turning lots of name
+ lookups into pointer dereferences). The converse operation is
+ sometimes termed "unswizzling".
+
+ See also {snap}.
+
+ [{Jargon File}]
+
+SWL
+
+ {Software Writer's Language}
+
+SWT
+
+ {Standard Widget Toolkit}
+
+swung dash
+
+ <character> A {character} similar to {tilde} but appearing
+ in the same vertical position as a {dash}, i.e. half way up
+ rather than at the top like tilde. {ASCII} does not include a
+ swung dash so tilde is used instead.
+
+ It is commonly used for "approximates" or "is approximately
+ equal to".
+
+ (1997-06-28)
+
+sy
+
+ <networking> The {country code} for Syria.
+
+ (1999-01-27)
+
+Sybase, Inc.
+
+ <company> A software vendor focused on {database} management
+ software.
+
+ Yearly sales: $903.9 million (1997).
+
+ Address: 6475 Christie Ave., Emeryville, California, USA.
+
+ {(http://sybase.com)}.
+
+ (1998-05-18)
+
+Sybase SQL Server
+
+ {Adaptive Server Enterprise}
+
+SYDEL
+
+ A system language, fully typed, with inline {assembly code},
+ by Jan Garwick, ca 1974.
+
+SYGMA
+
+ A symbolic generator and macro assembler by A.P. Ershov et al
+ of Novosibirsk. For the {BESM-6}, {M-220} and {Minsk-22}.
+
+ ["SYGMA, A Symbolic Generator and Macroassembler", A.P. Ershov
+ et al, in Symbol Manipulation Languages and Techniques,
+ D.G. Bobrow ed, N-H 1968, pp.226- 246].
+
+SYLK
+
+ {Symbolic Link}
+
+syllogism
+
+ /sil'oh-jiz`*m/ <logic> Deductive reasoning in which a
+ conclusion is derived from two premises. The conclusion
+ necessarily follows from the premises so that, if these are
+ true, the conclusion must be true, and the syllogism amounts
+ to demonstration. To put it another way, the premises {imply}
+ the conclusion.
+
+ For example, every virtue is laudable; kindness is a virtue;
+ therefore kindness is laudable.
+
+ Strangely, a syllogism can still be true if the premises are
+ false.
+
+ Compare {inference rule}.
+
+ [Relationship between premises?]
+
+ (2009-10-28)
+
+Sylvan
+
+ [Distributed language?]
+
+Symantec
+
+ <company> Software manufacturer of utility and development
+ applications for {Windows} and {Macintosh} platforms.
+ Products include ACT!, Norton Utilities, Norton AntiVirus,
+ Symantec AntiVirus for Macintosh, Symantec Cafe.
+
+ {(http://symantec.com/)}.
+
+ (1997-03-10)
+
+SYMBAL
+
+ SYMbolic ALgebra. A {symbolic mathematics} language with
+ {ALGOL}-like syntax by Max Engeli, late 60's. Implemented for
+ {CDC 6600}.
+
+ ["User's Manual for the Formula Manipulation Language SYMBAL",
+ M. Engeli, TRM-8.00, Comp Ctr UT Austin, June 1968].
+
+SymbMath
+
+ <mathematics, tool> A small {symbolic mathematics} package for
+ {MS-DOS} which can learn new facts.
+
+ Latest version: 2.1.1.
+
+ {(Home (http://symbmath.com/)}.
+
+ (2001-03-26)
+
+SYMBOLANG
+
+ Lapidus & Goldstein, 1965. Symbol manipulating Fortran
+ subroutine package for IBM 7094, later CDC 6600.
+
+ ["Some Experiments in Algebraic Manipulation", CACM 8:501-508
+ 1965].
+
+ (1995-03-16)
+
+Symbolic Assembler Program
+
+ <language> (SAP) The {assembly language} for the {IBM 704},
+ defined in the late 1950s.
+
+ (1994-12-12)
+
+SYMBOLIC ASSEMBLY
+
+ <language> An early system on the {IBM 705}.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (1996-01-15)
+
+Symbolic Automatic INTegrator
+
+ <mathematics, tool> (SAINT) A {symbolic mathematics} program
+ written in {Lisp} by J. Slagle at {MIT} in 1961.
+
+ [Sammet 1969, p. 410].
+
+ (1994-12-08)
+
+symbolic inference
+
+ The derivation of new facts from known facts and {inference
+ rules}. This is one of the fundamental operations of
+ {artificial intelligence} and {logic programming} languages
+ like {Prolog}.
+
+ Inference is a basic part of human reasoning. For example
+ given that all men are mortal and that Socrates is a man, it
+ is a trivial step to infer that Socrates is mortal. We might
+ express these symbolically:
+
+ man(X) => mortal(X).
+ man(socrates).
+
+ ("if X is a man then X is mortal" and "Socrates is a man").
+ Here, "man", "mortal" and "socrates" are just arbitrary
+ symbols which the computer manipulates without reference to or
+ knowledge of their external meaning. A {forward chaining}
+ system (a {production system}) could use these to infer the
+ new fact
+
+ mortal(socrates).
+
+ simply by matching the left-hand-side of the implication
+ against the fact and substituting socrates for the variable X.
+
+ (1994-10-28)
+
+Symbolic Link
+
+ <file format> (SYLK) A {Microsoft} file format for
+ {spreadsheets}, (not to be confused with {symbolic link}).
+
+ SYLK format existed in one form or another in as early as
+ 1987, and was part of {Excel} v1.0. It is is an outgrowth of
+ {VisiCalc} {DIF} file format.
+
+ SYLK format is ascii text and represents information about
+ both formula, value, and some formatting information, which
+ makes it something like an {RTF} for spreadsheets. It is used
+ as a general tabular data exchange format.
+
+ {(http://netghost.narod.ru/gff/graphics/summary/micsylk.htm)}.
+
+ [Reference?]
+
+ (2004-04-08)
+
+symbolic link
+
+ <file system> (Or "symlink", "soft link" (by contrast with
+ "{hard link}"), "{shortcut}", "{alias}") A special type of
+ {Unix} file which refers to another file by its {pathname}. A
+ symbolic link is created with the "ln" (link) command:
+
+ ln -s OLDNAME NEWNAME
+
+ Where OLDNAME is the target of the link (usually a pathname)
+ and NEWNAME is the pathname of the link itself.
+
+ Most operations ({open}, {read}, {write}) on the symbolic link
+ automatically {dereference} it and operate on its target
+ (OLDNAME). Some operations (e.g. removing) work on the link
+ itself (NEWNAME).
+
+ In contrast with {hard links}, there are no restrictions on
+ where a symbolic link can point, it can refer to a file on
+ another file system, to itself or to a file which does not
+ even exist (e.g. when the target of the symlink is removed).
+ Such problems will only be detected when the link is accessed.
+
+ (1997-10-22)
+
+symbolic logic
+
+ <logic> The discipline that treats formal {logic} by means of
+ a formalised artificial language or symbolic calculus, whose
+ purpose is to avoid the ambiguities and logical inadequacies
+ of {natural language}.
+
+ (1995-12-24)
+
+Symbolic Mathematical Laboratory
+
+ <tool, mathematics> An on-line system under {CTSS} for
+ {symbolic mathematics}. It used a {display screen} and a
+ {light pen}.
+
+ [Sammet 1969, p.514].
+
+ (1995-04-16)
+
+symbolic mathematics
+
+ <mathematics, application> (Or "symbolic math") The use of
+ computers to manipulate mathematical equations and expressions
+ in symbolic form, as opposed to manipulating the numerical
+ quantities represented by those symbols. Such a system might
+ be used for symbolic integration or differentiation,
+ substitution of one expression into another, simplification of
+ an expression, change of subject etc.
+
+ One of the best known symbolic mathematics software packages
+ is {Mathematica}. Others include {ALAM}, {ALGY}, {AMP},
+ {Ashmedai}, {AXIOM*}, {CAMAL}, {CAYLEY}, {CCalc}, {CLAM},
+ {CoCoA}(?), {ESP}, {FLAP}, {FORM}, {FORMAL}, {Formula ALGOL},
+ {GAP}, {JACAL}, {LiE}, {Macaulay}, {MACSYMA}, {Magic Paper},
+ {MAO}, {Maple}, {Mathcad}, {MATHLAB}, {MuMath}, {Nother},
+ {ORTHOCARTAN}, {Pari}, {REDUCE}, {SAC-1}, {SAC2}, {SAINT},
+ {Schoonschip}, {Scratchpad I}, {SHEEP}, {STENSOR}, {SYMBAL},
+ {SymbMath}, {Symbolic Mathematical Laboratory}, {TRIGMAN},
+ {UBASIC}.
+
+ {Usenet} newsgropup: {news:sci.math.symbolic}.
+
+ (1995-04-12)
+
+Symbolic Optimal Assembly Program
+
+ <language> (SOAP) The {IBM 650}'s {assembly language}.
+ "Optimal" refers to rearranging instructions on slowly
+ rotating {drum memory}.
+
+ Versions: SOAP I, SOAP II, CASE SOAP III.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (1994-11-04)
+
+Symbolic Optimum DEUCE Assembly Program
+
+ <language> (SODA) The symbolic {assembler} for a {one-level
+ storage} {virtual machine} for the {English ELectric} {DEUCE}.
+
+ ["SODA Manual of Operation", R. C. Brigham and C. G. Bell,
+ School of Elec Eng, U New S Wales, Sydney, NSW, 1958].
+
+ (1994-11-04)
+
+Symbolics, Inc.
+
+ <company> The company which produced the {Lisp Machine}.
+
+ {The Symbolics Museum (http://SMBX.org/)}.
+
+ [Summary?]
+
+ (2003-11-24)
+
+Symbol Manipulation Program
+
+ (SMP) {Steven Wolfram}'s earlier symbol manipulation program,
+ before he turned to {Mathematica}.
+
+ ["SMP Handbook", C. Cole, S. Wolfram et al, Caltech 1981].
+
+ (1995-01-29)
+
+symlink
+
+ {symbolic link}
+
+symmetric
+
+ <mathematics> 1. A {relation} R is symmetric if, for all x and
+ y,
+
+ x R y => y R x
+
+ If it is also {antisymmetric} (x R y & y R x => x == y) then
+ x R y => x == y, i.e. no two different elements are related.
+
+ 2. In {linear algebra}, a member of the {tensor product} of a
+ {vector space} with itself one or more times, is symmetric if
+ it is a {fixed point} of all of the {linear isomorphisms} of
+ the tensor product generated by {permutations} of the ordering
+ of the copies of the vector space as factors. It is said to
+ be antisymmetric precisely if the action of any of these
+ linear maps, on the given tensor, is equivalent to
+ multiplication by the sign of the permutation in question.
+
+ (1996-09-22)
+
+symmetric key cryptography
+
+ <cryptography> A {cryptography} system in which both parties
+ have the same encryption {key}, as in {secret key
+ cryptography}.
+
+ Opposite: {public-key cryptography}.
+
+ (1998-06-09)
+
+Symmetric LISP
+
+ A parallel {Lisp} in which environments are {first-class}
+ objects. It is implemented in {Common LISP}.
+
+ ["Parallelism, Persistence and Meta-Cleanliness in the
+ Symmetric Lisp Processor", D. Gelernter et al, SIGPLAN Notices
+ 22(7):274-282 (July 1987)].
+
+ ["A Programming Language Supporting First-Class Parallel
+ Environments", S. Jagannathan, MIT-LCS/TR 434, 1989].
+
+ E-mail: Suresh Jagannathan <suresh@research.nj.nec.com>.
+
+ (1995-03-16)
+
+symmetric multiprocessing
+
+ <parallel> (SMP) Two or more similar {processors} connected
+ via a high-{bandwidth} link and managed by one {operating
+ system}, where each processor has equal access to I/O devices.
+ This is in contrast to the "{compute server}" kind of
+ {parallel processor} where a {front-end processor} handles all
+ I/O to disks, terminals and {local area network} etc.
+
+ The processors are treated more or less equally, with
+ {application programs} able to run on any or perhaps all
+ processors in the system, interchangeably, at the operating
+ system's discretion. Simple MP usually involves assigning
+ each processor to a fixed task (such as managing the file
+ system), reserving the single main CPU for general tasks.
+
+ {OS/2} currently supports so-called HMP (Hybrid
+ Multiprocessing), which provides some elements of symmetric
+ multiprocessing, using add-on IBM software called MP/2. OS/2
+ SMP was planned for release in late 1993.
+
+ (1995-03-19)
+
+symmetric multiprocessor
+
+ {symmetric multiprocessing}
+
+Symphony
+
+ <tool, product> {Lotus Development}'s successor to their
+ {Lotus 1-2-3} spreadsheet. Unlike 1-2-3, Symphony allowed a
+ limited form of {multitasking}. The user could switch
+ manually between it and {MS-DOS} and separate graph and
+ spreadsheet windows could be opened simultaneously and would
+ be updated automatically when cells were changed. In
+ addition, a small word processor could be opened in a third
+ window. These all could be printed out on the same report.
+ Symphony could read and write Lotus 1-2-3 files and had
+ interactive graphical output and a word processor, thus making
+ it effectively a report generator. Unlike 1-2-3, Symphony was
+ not a great commercial success.
+
+ (1995-03-28)
+
+SYMPL
+
+ <language> SYsteMs Programming Language.
+
+ {CDC}'s derivative of {Jovial}. SYMPL is a non-{re-entrant}
+ {block structured} language with extensive {bit manipulation}
+ facilities, which is linkable with {Fortran}. Major parts of
+ CDC systems during the 1970s were written in SYMPL.
+
+ (1995-02-14)
+
+SYN
+
+ 1. <character> {Synchronous idle}.
+
+ 2. <language> A syntactic specification language for {COPS}.
+
+ ["Metalanguages of the Compiler Production System COPS",
+ J. Borowiec, in GI Fachgesprach "Compiler-Compiler", ed
+ W. Henhapl, Tech Hochs Darmstadt 1978, pp. 122-159].
+
+ 3. [TCP/IP SYN request?]
+
+ (1996-04-17)
+
+sync
+
+ /sink/ (Or "synch") 1. To synchronise, to bring into
+ synchronisation.
+
+ 2. <file system> To force ("{flush}") all pending buffered
+ disk writes to the disk.
+
+ 3. More generally, to force a number of competing processes or
+ agents to a state that would be "safe" if the system were to
+ crash, i.e. to {checkpoint} in the {database} sense.
+
+ [{Jargon File}]
+
+ (1994-11-11)
+
+Synchronized Multimedia Integration Language
+
+ <hypertext, language, multimedia, text, web> (SMIL)
+ A language based on {Extensible Markup Language} (XML), that
+ enables people without programming or scripting backgrounds to
+ author multimedia presentations in a simple {text editor}.
+ SMIL is suitable for use on the {web}.
+
+ For example, a developer can write SMIL to display an {image}
+ after an {audio} track ends.
+
+ SMIL uses two main tags: parallel and sequential. It refers
+ to media objects by URLs, allowing them to be shared between
+ presentations and stored on different servers for {load
+ balancing}. The language can also associate different media
+ objects with different bandwidths.
+
+ SMIL 1.0 became an official recommendation of the {World Wide
+ Web Consortium} W3C in June 1998.
+
+ {W3C (http://w3c.org/audiovideo/)}.
+
+ (2000-04-21)
+
+synchronous
+
+ <operating system, communications> 1. Two or more processes
+ that depend upon the occurrences of specific events such as
+ common timing signals.
+
+ 2. Occurring at the same time or at the same rate or with a
+ regular or predictable time relationship or sequence.
+
+ Opposite: {asynchronous}.
+
+ (1996-04-11)
+
+Synchronous Data Link Control
+
+ <communications> (SDLC) An {IBM} {protocol}.
+
+ A discipline conforming to subsets of the {ADCCP} of {ANSI}
+ and the {HDLC} of the {International Organization for
+ Standardization}. SDLC manages synchronous, code-transparent,
+ bit-serial communication which can be {duplex} or
+ {half-duplex}; switched or non-switched; {point-to-point},
+ {multipoint}, or loop.
+
+ Compare {Binary Synchronous Communication}.
+
+ (1995-03-22)
+
+Synchronous Digital Hierarchy
+
+ <communications, standard> (SDH) An international digital
+ telecommunications network hierarchy which standardises
+ transmission around the bit rate of 51.84 megabits per second,
+ which is also called STS-1. Multiples of this bit rate
+ comprise higher bit rate streams. Thus STS-3 is 3 times
+ STS-1, STS-12 is 12 times STS-1, and so on. STS-3 is the
+ lowest bit rate expected to carry {ATM} traffic, and is also
+ referred to as STM-1 (Synchronous Transport Module-Level 1).
+
+ The SDH specifies how payload data is framed and transported
+ synchronously across {optical fibre} transmission links without
+ requiring all the links and nodes to have the same
+ synchronized clock for data transmission and recovery
+ (i.e. both the clock frequency and phase are allowed to have
+ variations, or be {plesiochronous}).
+
+ SDH offers several advantages over the current {multiplexing}
+ technology, which is known as {Plesiochronous Digital
+ Hierarchy}. Where PDH lacks built-in facilities for automatic
+ management and routing, and locks users into proprietary
+ methods, SDH can improve network reliability and performance,
+ offers much greater flexibility and lower operating and
+ maintenance costs, and provides for a faster provision of new
+ services.
+
+ Under SDH, incoming traffic is synchronized and enhanced with
+ {network management} bits before being multiplexed into the
+ STM-1 fixed rate {frame}.
+
+ The fundamental clock frequency around which the SDH or
+ {SONET} framing is done is 8 KHz or 125 microseconds.
+
+ SONET ({Synchronous Optical Network}) is the American version
+ of SDH.
+
+ (1995-03-02)
+
+Synchronous DRAM
+
+ {Synchronous Dynamic Random Access Memory}
+
+Synchronous Dynamic Random Access Memory
+
+ <storage> (SDRAM, Synchronous DRAM) A form of {DRAM} which
+ adds a separate {clock} signal to the control signals. SDRAM
+ chips can contain more complex {state machines}, allowing them
+ to support "burst" access modes that clock out a series of
+ successive {bits} (similar to the {nibble mode DRAM}).
+
+ (2007-05-08)
+
+Synchronous Graphics RAM
+
+ {Synchronous Graphics Random Access Memory}
+
+Synchronous Graphics Random Access Memory
+
+ <storage> (SGRAM, Synchronous Graphics RAM) A type of
+ {Synchronous DRAM} optimised for use in {graphics} hardware.
+ Extra features can include {burst operation}, {block write}
+ and {write per bit}. SGRAMs are designed to provide the very
+ high {throughput} needed for graphics-intensive operations
+ such as 3d {rendering} and {full-motion video}.
+
+ (1996-11-28)
+
+Synchronous idle
+
+ <character> (SYN) The {mnemonic} for {ASCII} character 22.
+
+ [Why?]
+
+ (1996-06-28)
+
+synchronous key encryption
+
+ <algorithm, cryptography> Data {encryption} using two
+ interlocking keys where enything encoded using one key may be
+ decoded using the other key. This means if someone makes one
+ of the two keys publicly available (as in {public-key
+ encryption}) and keeps the other private, then anyone may send
+ them a message or data that only they can decode, giving
+ privacy, and furthermore, the sender may also encrypt that
+ same message additionally with their own private key, making
+ it impossible to read without decoding first with *their*
+ __public__ key by the receiver, this gives authenticity.
+
+ It is a very powerful system. One cannot determine one key
+ from the other, nor can they crack the encryption by computing
+ all combinations, because, depending on the size of the keys
+ (sometimes as large as 1024 bytes, though having grown from
+ smaller versions in popular implementations of the software
+ which does this), the amount of computing power required to
+ crack the code is unavailable, even supercomputers would take
+ more than a hundred years to crack it.
+
+ {PGP} is a publicly availble software implementation written
+ by Phil Zimmermann.
+
+ (1994-10-10)
+
+Synchronous Optical NETwork
+
+ <networking> (SONET) A {broadband} networking {standard} based
+ on point-to-point {optical fibre} networks. SONET will
+ provide a high-bandwidth "pipe" to support {ATM}-based
+ services.
+
+ The SONET standard will establish a digital {hierarchical
+ network} with a consistent worldwide transport scheme. SONET
+ has been designed to take advantage of fibre, in contrast to
+ the {plain old telephone system} which was designed for copper
+ wires.
+
+ SONET carries {circuit-switched} data in {frames} at speeds in
+ multiples of 51.84 megabits per second (Mbps) up to 48 * 51.84
+ Mbps = 2.488 {gigabits} per second. Since SONET uses multiple
+ channels to transmit data, each SONET {frame} can be
+ considered to be a two-dimensional table of bytes that is 9
+ rows high and 90 columns deep. For every {OC-n} level, SONET
+ can transmit n number of frames at a given time. Groups of
+ frames are called {superframes}.
+
+ SONET is the American version of {SDH}.
+
+ [Wulf Losee; Corporate Computing 8.92; STACKS; LAN Magazine
+ 10.93].
+
+ (1994-11-30)
+
+syncronous
+
+ <spelling> It's spelled "{synchronous}".
+
+ (1996-12-13)
+
+synflood
+
+ <networking> To {flood} another machine with bogus {TCP/IP}
+ {SYN} requests.
+
+ (1997-04-07)
+
+synonym ring
+
+ <information science> A list of words with related meanings
+ used to broaden the scope of a word search. As well as
+ returning documents which contain a sought-for word a search
+ using a synonym ring might also return documents which contain
+ words in the same synonym ring as a sought-for word. Synonym
+ rings are produced manually and are usually specific to a
+ certain field, e.g. legal knowhow.
+
+ (1997-04-09)
+
+syntactic salt
+
+ The opposite of {syntactic sugar}, a feature designed to make
+ it harder to write bad code. Specifically, syntactic salt is
+ a hoop the programmer must jump through just to prove that he
+ knows what's going on, rather than to express a program
+ action. Some programmers consider required type declarations
+ to be syntactic salt. A requirement to write "end if", "end
+ while", "end do", etc. to terminate the last block controlled
+ by a control construct (as opposed to just "end") would
+ definitely be syntactic salt. Syntactic salt is like the real
+ thing in that it tends to raise hackers' blood pressures in an
+ unhealthy way. Compare {candygrammar}.
+
+ [{Jargon File}]
+
+syntactic sugar
+
+ Term coined by Peter Landin for additions to the syntax of a
+ language which do not affect its expressiveness but make it
+ "sweeter" for humans to use. Syntactic sugar gives the
+ programmer an alternative way of coding that is more succinct
+ or more like some familiar notation. It does not affect the
+ expressiveness of the formalism (compare {chrome}).
+
+ Syntactic sugar can be easily translated ("desugared") to
+ produce a program in some simpler "core" syntax. E.g. C's
+ "a[i]" notation is syntactic sugar for "*(a + i)". In a
+ (curried) functional language, all operators are really
+ functions and the use of {infix notation} "x+y" is syntactic
+ sugar for function application "(+) x y".
+
+ Alan Perlis once quipped, "Syntactic sugar causes cancer of
+ the semicolon."
+
+ The variants "syntactic saccharin" and "syntactic syrup" are
+ also recorded. These denote something even more gratuitous,
+ in that they serve no purpose at all. Compare {candygrammar},
+ {syntactic salt}.
+
+syntax
+
+ <language> The structure of valid strings in a given language,
+ as described by a {grammar}. For example, the syntax of a
+ binary number could be expressed as
+
+ binary_number = bit [ binary_number ]
+
+ bit = "0" | "1"
+
+ meaning that a binary number is a bit optionally followed by a
+ binary number and a bit is a literal zero or one digit.
+
+ The meaning of the language is given by its {semantics}.
+
+ See also {abstract syntax}, {concrete syntax}.
+
+ (1994-10-31)
+
+Syntax-Case
+
+ <language> A {macro} system for {Scheme} by R. Kent Dybvig
+ <dyb@cs.indiana.edu>. It is superior to the low-level system
+ described in the Revised^4 Report ({R4RS}). Pattern variables
+ are ordinary identifiers with essentially the same status as
+ lexical variable names and {macro} {keywords}. The {syntax}
+ is modified to recognise and handle references to pattern
+ variables. Version 2.1 works with {Chez Scheme} and the
+ {Macintosh} port runs under {MacGambit} 2.0
+
+ {(ftp://iuvax.cs.indiana.edu/pub/scheme/syntax-case.tar.Z)}.
+ {Macintosh (ftp://maya.dei.unipd.it/pub/mac/gambit/)}.
+
+ ["Syntactic Abstraction in Scheme",
+ Robert Hieb, R. Kent Dybvig and Carl Bruggeman
+ IUCS TR #355, 6/92 (revised 7/3/92)].
+
+ ["Writing Hygienic Macros in Scheme with Syntax-Case", R. Kent
+ Dybvig, IUCS TR #356, 6/92 (revised 7/3/92)].
+
+ (1992-07-06)
+
+syntax directed translation
+
+ A technique where the structure of a language processor (e.g. a
+ compiler) is based on the structure of the language's
+ {abstract syntax}. There might be one procedure in the
+ translator corresponding to each category in the abstract
+ syntax. That procedure is responsible for processing
+ constructs of that category. Each procedure would call others
+ corresponding to the construct's subconstituents and then
+ combine their results to give the overall result for that
+ construct.
+
+Syntax/Semantic Language
+
+ <language> (S/SL) A high level {specification language} for
+ {recursive descent parsers} developed by J.R. Cordy
+ <cordy@cs.queensu.ca> and R.C. Holt <holt@uwaterloo.ca> at the
+ University of Toronto in 1980.
+
+ S/SL is a small language that supports cheap recursion and
+ defines input, output, and error token names (& values),
+ semantic mechanisms (class interfaces whose methods are really
+ escapes to routines in a host programming language but allow
+ good abstraction in the pseudo-code) and a pseudo-code program
+ that defines the syntax of the input language by the token
+ stream the program accepts. Alternation, control flow and
+ one-symbol look-ahead constructs are part of the language.
+
+ The S/SL processor compiles this pseudo-code into a table
+ (byte-codes) that is interpreted by the S/SL table-walker
+ (interpreter). The pseudo-code language processes the input
+ language in recursive descent LL1 style but extensions allow
+ it to process any LRk language relatively easily. S/SL is
+ designed to provide excellent syntax error recovery and
+ repair. It is more powerful and transparent than yacc but
+ slower.
+
+ S/SL has been used to implement production commercial
+ compilers for languages such as {PL/I}, {Euclid}, {Turing},
+ {Ada}, and {COBOL}, as well as {interpreters}, {command
+ processors}, and domain specific languages of many kinds.
+
+ {(ftp://ftp.cs.queensu.ca/pub/cordy/ssl)}.
+
+ ["Specification of S/SL: Syntax/Semantic Language", J.R. Cordy
+ and R.C. Holt, Computer Systems Research Institute, University
+ of Toronto, 1980].
+
+ ["An Introduction to S/SL: Syntax/Semantic Language",
+ R.C. Holt, J.R. Cordy, and D.B. Wortman; ACM Transactions on
+ Programming Languages and Systems (TOPLAS), Vol 4, No. 2,
+ April 1982, pp 149-178].
+
+ ["Hierarchic Syntax Error Repair", D.T. Barnard and R.C. Holt,
+ International Journal of Computing and Information Sciences,
+ Vol. 11, No. 4, August 1982, Pages 231-258.]
+
+ (2003-10-30)
+
+syntax tree
+
+ <mathematics, theory, language> A {tree} representing the
+ {abstract syntax} of some {tokens} in a {language}.
+
+ (1998-11-12)
+
+synthesis
+
+ <programming, specification> The process of deriving
+ (efficient) programs from (clear) specifications.
+
+ See also {program transformation}.
+
+ (1996-08-23)
+
+Synthesizer Specification Language
+
+ (SSL) A specification language based on {term algebra} and
+ {attribute grammars}. SSL is used by the {Synthesizer
+ Generator}, a generator for {language-based editors} such as
+ the {Cornell Program Synthesizer}.
+
+ ["Generating Language Based Environments", T. Reps, MIT Press
+ 1984].
+
+ (1994-12-16)
+
+sypware
+
+ {spyware}
+
+SyQuest Technology, Inc.
+
+ <company, hardware> An early entrant into the removable {hard
+ disk} market for {personal computers}. For may years SyQuest
+ held the market, particularly as a method of transferring
+ large {desktop publisher} documents to printers. SyQuest aim
+ their products to give personal computer users "endless" hard
+ drive space for data-intensive applications like {desktop
+ publishing}, {Internet} information management, pre-press,
+ {multimedia}, {audio}, {video}, {digital photography}, fast
+ {backup}, data exchange, {archiving}, confidential data
+ security and easy portability for the road.
+
+ At the top of their current (Mar 1997) range are two drives,
+ The {SyJet} 1.5 {GB} a 3.5 inch, double platter removable
+ drive and the {EZFlyer} 230 {MB} also on 3.5 inch media. A
+ cartridge holding over 4.7GB is promised before the end of
+ 1997.
+
+ In recent years they have not fared as well in the market,
+ whilst {Iomega} has cornered the {Small Office/Home Office}
+ (SOHO) market. Over the period 1995 to 1997 sales declined
+ resulting in a series of losses. In the first quarter of 1997
+ these losses had been reduced to $6.8 million with net
+ revenues increasing to $48.3 million. This compares to a net
+ loss of $33.8 million, or $2.98 per share, on net revenues of
+ $78.7 million for the same period the year before. It would
+ appear that substantial restructuring has occurred over the
+ past few years.
+
+ {(http://syquest.com/)}.
+
+ (1997-03-27)
+
+sysadmin
+
+ {system administrator}
+
+sysape
+
+ /sys'ayp/ A rather derogatory term for a computer operator; a
+ play on {sysop} common at sites that use the banana hierarchy
+ of problem complexity (see {one-banana problem}).
+
+ [{Jargon File}]
+
+Sysdeco Mimer AB
+
+ <company> Part of the international software group Sysdeco
+ Group AS. They developed the {MIMER} {RDBMS}.
+
+ {(http://mimer.se/)}.
+
+ Address: Uppsala, Sweden.
+
+ (1995-11-11)
+
+sys-frog
+
+ /sis'frog/ (the {PLATO} system) A playful variant of
+ "{sysprog}".
+
+ [{Jargon File}]
+
+ (1994-11-04)
+
+SYSKEY
+
+ <cryptography, operating system, security> A utility that
+ {encrpyts} the {hashed} {password} information in a {SAM}
+ database using a 128-bit {encryption key}.
+
+ SYSKEY was an optional feature added in {Windows NT} 4.0 SP3.
+ It was meant to protect against {offline} password {cracking}
+ attacks so that the SAM database would still be secure even if
+ someone had a copy of it. However, in December 1999, a
+ security team from {BindView (http://bindview.com/)} found
+ a security hole in SYSKEY which indicates that a certain form
+ of {cryptoanalytic} attack is possible offline. A
+ {brute-force attack} then appeared to be possible.
+
+ Microsoft later collaborated with BindView to issue a fix
+ (dubbed the 'Syskey Bug') which appears to have been settled
+ and SYSKEY pronounced secure enough to resist brute-force
+ attack.
+
+ According to Todd Sabin of the BindView team RAZOR, the
+ pre-RC3 versions of {Windows 2000} were also affected.
+
+ {BindView Security Advisory
+ (http://packetstorm.securify.com/9912-exploits/bindview.syskey.txt)}.
+
+ {BindView press release
+ (http://bindview.com/news/99/1222.html)}.
+
+ {Microsoft bulletin
+ (http://microsoft.com/Security/Bulletins/ms99-056.asp)}.
+
+ (2000-07-16)
+
+SYSLISP
+
+ System language used in the implementation of Portable
+ Standard Lisp. Mentioned in "The Evolution of Lisp",
+ G.L. Steele et al, SIGPLAN Notices 28(3):231-270 (Mar 1993).
+
+sysop
+
+ {system operator}
+
+Sysplex
+
+ <operating system> An {IBM} term for communicating {MVS}
+ systems. See also "{Parallel Sysplex}".
+
+ (1996-11-23)
+
+sysprog
+
+ {Systems programmer}
+
+system
+
+ 1. The {supervisor} program or {operating system} on a
+ computer.
+
+ 2. The entire computer system, including input/output devices,
+ the {supervisor} program or {operating system} and possibly
+ other {software}.
+
+ 3. Any large program.
+
+ 4. Any method or {algorithm}.
+
+ [{Jargon File}]
+
+System/360
+
+ <computer> The generic name for the {CPUs} and architecture
+ released by {IBM} on 1964-04-07. The 360 was marketed as a
+ general purpose computer with 'all round' functionality -
+ hence 360 (degrees).
+
+ Models ranged from the 360/20 to the 360/65 and later the
+ 360/95, with typical memory configurations from 16K to 1024K.
+
+ Elements of the architecture, such as the basic {instruction
+ set} are still in use on IBM {mainframes} today. Operating
+ System/360 ({OS/360}) was developed for System/360. Other
+ associated {operating systems} included {DOS}, {OS/MFT} and
+ {OS/MVT}.
+
+ The 360 architecture was based on an 8-bit {byte}, 16 general
+ purpose {registers}, 24-bit addressing, and a PSW (Program
+ Status Word) including a location counter.
+
+ {Gene Amdahl}, then an IBM employee, is generally acknowledged
+ as the 360's chief architect. He later went on to found
+ {Amdahl Corporaton}, a manufacture of {PCM} {mainframe}
+ equipment.
+
+ The 360's predecessors were the smaller {IBM 1401} and the
+ large {IBM 7090} series. If was followed by the {IBM 370}.
+
+ See also {ABEND}, {ALC}, {BAL}, {Big Red Switch}, {HCF}, {mode
+ bit}, {PL360}, {PL/S}.
+
+ (2004-06-06)
+
+System/370
+
+ <hardware, IBM> (S/370) An {IBM} {mainframe} {computer}
+ introduced in 1970 as a successor to the {IBM 360}.
+ Enhancements included the ability to support {virtual memory}
+ and improved main storage. Two models were available
+ initially: 165 and 155, with {cycle times} of 80 and 115
+ nanoseconds.
+
+ {Press Release
+ (http://www-1.ibm.com/ibm/history/exhibits/mainframe/mainframe_PR370.html)}.
+
+ (2004-06-06)
+
+System 5
+
+ {System V}
+
+System 7.5
+
+ <operating system> A version of {Mac OS}, the latest release as
+ of Oct 1996 was 7.5.5. Superseded by Mac OS 7.6 around March
+ 1997.
+
+ {Mac OS home (http://macos.apple.com/)}.
+
+ [Dates? Features?]
+
+ (1997-03-23)
+
+System Account Manager
+
+ <cryptography, operating system, security> (SAM) A {password}
+ {database} stored as a {registry file} in {Windows NT} and
+ {Windows 2000}.
+
+ The System Account Manager (SAM) database stores users'
+ passwords in a {hashed} format. Since a {hash function} is
+ one-way, this provides some measure of security for the
+ storage of the passwords. In an attempt to enhance the
+ security of the SAM database against {offline cracking},
+ Microsoft introduced the {SYSKEY} utility in {Windows NT} 4.0.
+
+ (2000-07-19)
+
+system administration
+
+ <job> Activities performed by a system administrator (or
+ "admin", "sysadmin", "site admin") such as monitoring security
+ configuration, managing allocation of {user names} and
+ {passwords}, monitoring disk space and other resource use,
+ performing {backups}, and setting up new hardware and
+ software.
+
+ system administrators often also help users, though in a large
+ organisation this may be a separate job.
+
+ Compare {postmaster}, {sysop}, {system management}, {systems
+ programmer}.
+
+ [Other tasks?]
+
+ (1999-05-02)
+
+system administrator
+
+ {system administration}
+
+system analysis
+
+ {systems analysis}
+
+system analyst
+
+ {systems analysis}
+
+system board
+
+ {motherboard}
+
+system call
+
+ <operating system, programming> The mechanism used by an
+ {application program} to request service from the {operating
+ system}. System calls often use a special {machine code}
+ instruction which causes the processor to change mode (e.g. to
+ "supervisor mode" or "{protected mode}"). This allows the OS
+ to perform restricted actions such as accessing hardware
+ devices or the {memory management unit}.
+
+ (1995-03-01)
+
+system catalog
+
+ <database> The {data dictionary} of a {DBMS}. The system
+ catalogue stores {meta-data} including the {schemas} of the
+ {databases}. It is a mini-database, and is usually stored
+ using the DBMS itself in special {tables} called {system
+ tables}. It maybe referred to as being "on line", as it is
+ active, and can be queried by users like any other table.
+
+ (1999-04-27)
+
+System Control Language
+
+ <language> (SCL) The {command language} for the {VME/B}
+ {operating system} on the {ICL2900}. SCL was {block
+ structured} and supported strings, lists of strings
+ ("superstrings"), {integer}, {Boolean}, and {array} types.
+ You could trigger a {block} whenever a condition on a variable
+ value occured. It supported {macros} and default arguments.
+ Commands were treated like procedure calls.
+
+ ["VME/B SCL Syntax", Intl Computers Ltd. 1980].
+
+ (2003-01-08)
+
+Systeme International
+
+ {Système International d'Unités}
+
+System F
+
+ {polymorphic lambda-calculus}
+
+System International
+
+ {Système International d'Unités}
+
+system management
+
+ <job> Activities performed by a system manager, aiming to
+ minimise the use of excessive, redundant resources to address
+ the overlapping requirements of performance balancing, network
+ management, reducing outages, system maintenance costs,
+ diagnosis and repair, and migration to new hardware and
+ software system versions.
+
+ Compare: {system administration}.
+
+ (1995-11-10)
+
+System Management Bus
+
+ <hardware, protocol> (SMBus, SMB) A simple two-wire {bus} used
+ for communication with low-bandwidth devices on a motherboard,
+ especially power related chips such as a laptop's rechargeable
+ battery subsystem (see {Smart Battery Data}). Other devices
+ might include temperature sensors and lid switches.
+
+ A device can provide manufacturer information, indicate its
+ model/part number, save its state for a {suspend} event,
+ report different types of errors, accept control parameters,
+ and return status. The SMB is generally not user configurable
+ or accessible.
+
+ The bus carries clock, data, and instructions and is based on
+ {Philip's} {I2C} serial bus protocol. Support for SMBus devices
+ is provided on {Windows 2000}. {Windows 98} does not support
+ such devices.
+
+ The {PIIX4} {chipset} provides SMBus functionality. Vendors
+ using SMBus would be required to pay royalties.
+
+ {SMBus website
+ (http://sbs-forum.org/smbus/)}.
+
+ {Software to interrogate a SMB motherboard
+ (http://online.de/home/podien/SMB.HTM)}.
+
+ {SMB devices, Part 8 Kernel Mode Driver Design Guide, Win2000 DDK
+ (http://microsoft.com/ddk/)}.
+
+ (1999-08-08)
+
+System Management Mode
+
+ <hardware> (SMM) A reduced power consumption state provided by
+ some {Intel} {microprocessors}. When a {CPU} enters SMM it
+ saves its current state in a special area of {static RAM}
+ called SMRAM (System Management {RAM}) and then runs a
+ program, also stored in SMRAM, the SMM handler.
+
+ SMM is implemented in all {Intel} "SL" suffixed CPUs. In June
+ 1993, Intel announced it was discontinuing its SL range and
+ instead making all its current processors SL enhanced.
+
+ See also {Auto Idle}.
+
+ (1994-11-09)
+
+System Management Server
+
+ <operating system> (SMS) Software used by {Microsoft} {Windows
+ NT system administrators} to manage {personal computers} on
+ any size network. SMS can distribute software to desktops
+ from one central location, detect every machine on the
+ network, track software and hardware configurations, send key
+ information back to a central database, and perform other
+ tasks.
+
+ {Home
+ (http://microsoft.com/ntserver/management/exec/overview/sms.asp)}.
+
+ (1999-03-24)
+
+system manager
+
+ {system management}
+
+system mangler
+
+ <humour> A humorous synonym for "{system manager}", possibly
+ from the fact that one major {IBM} {operating system} had a
+ {root} account called SYSMANGR. The term refers specifically
+ to a systems programmer in charge of administration, software
+ maintenance, and updates at some site. Unlike {admin}, this
+ term emphasises the technical end of the skills involved.
+
+ [{Jargon File}]
+
+ (1995-11-10)
+
+system operator
+
+ <job, jargon> (Always abbreviated to "sysop") /sis'op/ A term
+ used in the {BBS} world for the operator of a bulletin-board
+ system (who is usually also the owner).
+
+ A common neophyte mistake on {FidoNet} is to address a message
+ to "sysop" in an international {echo}, thus sending it to
+ hundreds of sysops around the world.
+
+ Contrast: {system administrator}.
+
+ (1999-10-20)
+
+System Product Interpreter
+
+ {Restructured EXtended eXecutor}
+
+system programming language
+
+ {Ousterhout's dichotomy}
+
+System R
+
+ <database> A {database} system built as a research project at
+ {IBM San Jose Research} (now {IBM Almaden Research Center}) in
+ the 1970s. System R introduced the {SQL} language and also
+ demonstrated that a {relational system database} could provide
+ good {transaction processing} performance.
+
+ {(http://mcjones.org/System_R/)}.
+
+ (1998-09-29)
+
+Systems Administrators Guild
+
+ <body, job> (SAGE) A special technical group of the {USENIX
+ Association}.
+
+ {(http://usenix.org/sage)}.
+
+ [Details?]
+
+ (2001-01-27)
+
+systems analysis
+
+ <job> Study of the design, specification, feasibility, cost,
+ and implementation of a computer system for business. What a
+ systems analyst does.
+
+ (1997-04-25)
+
+Systems Analysis Definition
+
+ <programming> (SAD) The analysis of the role of a proposed
+ system and the identification of the requirements that it
+ should meet. SAD is the starting point for system design.
+ The term is most commonly used in the context of commercial
+ programming, where software developers are often classed as
+ either {systems analysts} or programmers. The systems
+ analysts are responsible for identifying requirements
+ (i.e. systems analysis) and producing a design. The
+ programmers are then responsible for implementing it.
+
+ (1996-03-07)
+
+systems analyst
+
+ {systems analysis}
+
+Systems Application Architecture
+
+ <programming> (SAA) {IBM}'s family of standard interfaces
+ which enable {software} to be written independently of
+ {hardware} and {operating system}.
+
+ (1997-04-25)
+
+Systems Development Life Cycle
+
+ <programming> (SDLC, or "Software...") Any logical process used by
+ a {systems analyst} to develop or redesign an {information
+ system}. SDLC includes {requirements}, design, {development},
+ {integration}, {testing}, {validation}, training, user ownership,
+ operations, analysis and maintenance.
+
+ An SDLC should result in a system that meets or exceeds customer
+ expectations, within time and cost estimates, works effectively
+ and efficiently in the current and planned {Information
+ Technology} {infrastructure}, is cheap to maintain and
+ cost-effective to enhance.
+
+ {(http://www.sdlc.ws/what-is-sdlc/)}.
+
+ {US DOJ SDLC
+ (http://www.justice.gov/jmd/irm/lifecycle/table.htm)}.
+
+ (2013-11-12)
+
+systems jock
+
+ {jock}
+
+Systems Network Architecture
+
+ <networking> (SNA) {IBM}'s proprietary high level networking
+ {protocol} {standard}, used by IBM and IBM compatible
+ {mainframes}.
+
+ Also referred to as "Blue Glue", SNA is a bletcherous protocol
+ once widely favoured at commercial shops. The official IBM
+ definition is "that which binds blue boxes together." It may
+ be relevant that {Blue Glue} is also a 3M product commonly
+ used to hold down carpets in {dinosaur pens}.
+
+ [{Jargon File}]
+
+ (1994-11-23)
+
+system software
+
+ <operating system> Any {software} required to support the
+ production or execution of {application programs} but which is
+ not specific to any particular application.
+
+ System software typically includes an {operating system} to
+ control the execution of other programs; user environment
+ software such as a {command-line interpreter}, {window
+ system}, {desktop}; development tools for building other
+ programs such as {assemblers}, {compilers}, {linkers},
+ {libraries}, {interpreters}, {cross-reference generators},
+ {version control}, {make}; {debugging}, {profiling} and
+ monitoring tools; utility programs, e.g. for sorting,
+ printing, and editting.
+
+ Different people would classify some or all of the above as
+ part of the operating system while others might say the
+ operating system was just the {kernel}. Some might say system
+ software includes {utility programs} like {sort}.
+
+ (2007-02-02)
+
+systems operator
+
+ {system operator}
+
+systems programmer
+
+ <job> (sysprog) A generic job title that covers a variety of
+ specialist roles such as writing low-level code that talks to
+ directly to the {operating system} on a {server}.
+
+ Typical skills required are experience of specific operating
+ systems, networking ({TCP/IP}, {ATM}, {Ethernet}, {DNS}),
+ electronic mail ({POP}, {IMAP}, {SMTP}), {web servers},
+ {RDBMS}, operating system and network security, and hardware
+ ({SCSI}, {hard disks}, and {backup} devices).
+
+ Contrast: {system administration}.
+
+ (1999-09-14)
+
+systems programming
+
+ {systems programmer}
+
+system testing
+
+ <testing> (Or "application testing") A type of {testing} to
+ confirm that all code modules work as specified, and that the
+ system as a whole performs adequately on the {platform} on
+ which it will be deployed.
+
+ System testing should be performed by testers who are trained
+ to plan, execute, and report on application and system code.
+ They should be aware of scenarios that might not occur to the
+ end user, like testing for null, negative, and format
+ inconsistent values. A tester should be able to repeat the
+ steps that caused an error.
+
+ (2003-09-24)
+
+system unit
+
+ <hardware> The main body of a computer, consisting of a
+ plastic or metal enclosure, the {motherboard}, and (typically)
+ internal {disk drives}, a {power supply}, cooling fans, and
+ whatever circuit boards plugged into the mother board, such as
+ a {video card}.
+
+ The system unit is occasionally referred to as the {CPU},
+ though this really means {central processing unit}.
+
+ (2000-08-10)
+
+System V
+
+ 1. The other major versions of the {Unix} {operating system}
+ apart from {BSD}. Developed by {AT&T}. Later versions of
+ Unix such as {SunOS} combined the best features of {System V}
+ and {BSD} Unix.
+
+ (1994-10-31)
+
+ [Differences?]
+
+ 2. A supplier of {Unix} {open systems} for {Intel x86}
+ processors. They supply products from {SCO} and {Solaris} and
+ offer general support for {Unix}, {TCP/IP}, and {Internet}.
+ They serve and create third-party {WWW} pages and provide
+ on-line support for commercial and non-commercial applications.
+
+ {(http://systemv.com/)}.
+
+ See also {System V Interface Definition}.
+
+ (1994-12-12)
+
+System V Interface Definition
+
+ (SVID) A standard allowing source code portability between
+ different {platforms} running Unix System V.
+
+ (1995-03-28)
+
+Système International
+
+ {Système International d'Unités}
+
+Système International d'Unités
+
+ <unit, standard> (SI - International System of Units) The
+ standard set of units of measurement set by the 11th General
+ Conference on Weights and Measures in 1960. There are seven
+ base units: the {metre} (length), the {kilogram} (mass), the
+ {second} (time), the {ampere} (electrical current), the kelvin
+ (temperature), the mole (number of atoms) and the candela
+ (luminous intensity). These are defined either in terms of
+ physical properties such as the speed of light or, in the case
+ of mass, by a "prototype" lump of platinum-iridium kept at
+ {BIPM}. Derived units like meters per second (speed) are
+ formed by combining base units. SI also specifies a list of
+ {prefixes} (multipliers like "k" for 1000).
+
+ {SI Home (http://www.bipm.org/en/si/)}.
+
+ (2014-07-08)
+
+systolic array
+
+ <architecture, parallel> (By analogy with the regular pumping
+ of blood by the heart) An arrangement of processors in an
+ array (often rectangular) where data flows synchronously
+ across the array between neighbours, usually with different
+ data flowing in different directions. H. T. Kung and Charles
+ Leiserson publish the first paper describing systolic arrays
+ in 1978 [reference?].
+
+ Each processor at each step takes in data from one or more
+ neighbours (e.g. North and West), processes it and, in the
+ next step, outputs results in the opposite direction (South
+ and East).
+
+ An example of a systolic {algorithm} might be matrix
+ multiplication. One matrix is fed in a row at a time from the
+ top of the array and is passed down the array, the other
+ matrix is fed in a column at a time from the left hand side of
+ the array and passes from left to right. Dummy values are
+ then passed in until each processor has seen one whole row and
+ one whole column. At this point, the result of the
+ multiplication is stored in the array and can now be output a
+ row or a column at a time, flowing down or accross the array.
+
+ See also {Ruby}, {SISAL}.
+
+ (1998-07-01)
+
+SysVile
+
+ {Missed'em-five}
+
+sz
+
+ <networking> The {country code} for Swaziland.
+
+ (1999-01-27)
+
+T
+
+ 1. True. A {Lisp} compiler by Johnathan A. Rees in 1982 at
+ {Yale University}. T has {static scope} and is a
+ near-superset of {Scheme}. {Unix} source is available. T is
+ written in itself and compiles to efficient native code. Used
+ as the basis for the Yale {Haskell} system. Maintained by
+ David Kranz <kranz@masala.lcs.mit.edu>.
+
+ Latest version: 3.1.
+
+ {(ftp://ftp.ai.mit.edu/pub/systems/t3.1)}.
+
+ A {multiprocessing} version of T is available
+ {(ftp://masala.lcs.mit.edu/pub/mult)}.
+
+ Runs on {Decstation}, {SPARC}, {Sun-3}, {Vax} under {Unix},
+ {Encore}, {HP}, {Apollo}, {Macintosh} under {A/UX}.
+
+ E-mail: <t3-bugs@cs.yale.edu> (bugs).
+ E-mail: <t-project@cs.yale.edu>.
+
+ (1991-11-26)
+
+ ["The T Manual", Johnathan A. Rees <jar@zurich.ai.mit.edu> et
+ al, Yale U, 1984].
+
+ 2. A {functional language}.
+
+ ["T: A Simple Reduction Language Based on Combinatory Term
+ Rewriting", Ida et al, Proc of Prog Future Generation
+ Computers, 1988].
+
+ 3. (lower case) The {Lisp} {atom} used to represent "true",
+ among other things. "false" is represented using the same
+ atom as an empty list, {nil}. This {overloading} of the basic
+ constants of the language helps to make Lisp {write-only
+ code}.
+
+ 4. In transaction-processing circles, an abbreviation for
+ "transaction".
+
+ 5. (Purdue) An alternative spelling of "{tee}".
+
+\t
+
+ {horizontal tabulation}
+
+T1
+
+ <communications> An {AT&T} term for a {digital carrier}
+ facility used to transmit a {DS1} formatted digital signal at
+ 1.544 megabits per second.
+
+ T1 transmission uses a bipolar {Return To Zero} {alternate
+ mark inversion} line coding scheme to keep the DC carrier
+ component from saturating the line.
+
+ Although some consider T1 signaling obsolete, much equipment
+ operates at the "T1 rate" and such signals are either
+ combined for transmission via faster circuits, or
+ demultiplexed into 64 kilobit per second circuits for
+ distribution to individual subscribers.
+
+ T1 signals can be transported on {unshielded twisted pair}
+ telephone lines. The transmitted signal consists of pips of a
+ few hundred nanoseconds width, each inverted with respect to
+ the one preceding. At the sending end the signal is 1 volt,
+ and as received, greater than 0.01 volts. This requires
+ repeaters about every 6000 feet.
+
+ The information is contained in the timing of the signals, not
+ the polarity. When a long sequence of bits in the transmitted
+ information would cause no pip to be sent, "{bit stuffing}" is
+ used so the receiving apparatus will not lose track of the
+ sending clock.
+
+ A T1 circuit requires two twisted pair lines, one for each
+ direction. Some newer equipment uses the two lines at half
+ the T1 rate and in {full-duplex} mode; the sent and received
+ signals are separated at each end by components collectively
+ called a "hybrid". Although this technique requires more
+ sophisticated equipment and lowers the line length, an
+ advantage is that half the sent and half the received
+ information is mixed on any one line, making low-tech wiretaps
+ less a threat.
+
+ See also {Integrated Services Digital Network}.
+
+ (1994-11-23)
+
+T1 line
+
+ {T1}
+
+T1 rate
+
+ {T1}
+
+T3
+
+ <communications> A {digital carrier} facility used to transmit
+ a {DS3} formatted digital signal at 44.736 megabits per
+ second.
+
+ See also {Integrated Services Digital Network}.
+
+ (1994-11-23)
+
+T3 line
+
+ {T3}
+
+TA
+
+ {Terminal Adaptor}
+
+TAA
+
+ {Track Average Amplitude}
+
+TAB
+
+ {HT}
+
+table
+
+ <database> A collection of {records} in a {relational database}.
+
+ (1997-06-04)
+
+table locking
+
+ <database> A technique used in {database management systems},
+ where an entire {table} is locked while data in it is being
+ updated.
+
+ Other techniques are {row-level locking} and {MVCC}.
+
+ (1999-06-18)
+
+tablespace
+
+ <oracle, database, storage> A logical unit of storage, used by
+ an {Oracle} database, that is made up of one or more
+ {operating system} files. Each table, {index} or other object
+ that requires storage is located on a tablespace.
+
+ The {database administrator} typically assigns a default and a
+ temporary tablespace to each user and grants a quota on each
+ so they can create tables and indexes.
+
+ (2006-08-24)
+
+TABLET
+
+ A {query language}.
+
+ ["Human Factor Comparison of a Procedural and a Non-procedural
+ Query Language", C. Welty et al, ACM Trans Database Sys
+ 6(4):626-649 (Dec 1981)].
+
+ (1994-11-23)
+
+TABLOG
+
+ <language> A programming language based on {first order
+ predicate logic} with equality that combines {relational
+ programming} and {functional programming}. It has functional
+ notation and {unification} as its binding mechanism. TABLOG
+ supports a more general subset of standard {first order logic}
+ than {Prolog}. It employs the Manna-Waldinger
+ '{deductive-tableau}' proof system as an {interpreter} instead
+ of {resolution}.
+
+ (1997-06-19)
+
+tab-separated values
+
+ <file format> (TSV) A file format used as a portable
+ representation of a {database}. Each line represents one
+ entry or {record}; and in every line, each field is separated
+ from the next by a tab character ({HT}).
+
+ Compare {CSV}.
+
+ (2001-03-16)
+
+TABSOL
+
+ <language> A language extension for {GECOM} written in the
+ form of {truth tables} which was compiled into code for the
+ tests and actions described. TABSOL was developed by
+ T.F. Kavanaugh, and was in use around 1964-5.
+
+ (1996-09-15)
+
+ [Proc FJCC 18:117-136, AFIPS (Fall 1960)].
+
+ (1996-09-16)
+
+Tabulating Machine Company
+
+ <company> The company founded in 1896 by {Herman Hollerith} to
+ exploit his invention of the {punched card}. It became part
+ of {IBM} in 1924.
+
+ (1996-01-02)
+
+TAC
+
+ 1. Translator Assembler-Compiler. For {Philco 2000}.
+
+ 2. {Terminal Access Controller}.
+
+TACL
+
+ Tandem Advanced Command Language. Tandem, about 1987. The
+ shell language used in Tandem computers.
+
+TACPOL
+
+ <language> A {PL/I}-like language used by the US Army for
+ command and control.
+
+ (2001-01-31)
+
+Tactile User Interface
+
+ <interface> (TUI) {Hardware} and {software} to provide access
+ to computer-based graphical[?] information using touch, often
+ intended for blind people. See also {haptics}.
+
+ (2003-10-17)
+
+tag
+
+ <language, text> An {SGML}, {HTML}, or {XML} {token}
+ representing the beginning (start tag: "<p ...>") or end (end
+ tag: "</p>") of an {element}. In normal SGML {syntax} (and
+ always in {XML}), a tag starts with a "<" and ends with an
+ ">".
+
+ In {HTML} jargon, the term "tag" is often used for an
+ "{element}".
+
+ (2001-01-31)
+
+Tagged Image File Format
+
+ <file format, graphics> (TIFF) A {file format} used for
+ still-image {bitmaps}, stored in tagged fields. {Application
+ programs} can use the tags to accept or ignore fields,
+ depending on their capabilities.
+
+ While TIFF was designed to be extensible, it lacked a core of
+ useful functionality, so that most useful functions (e.g.
+ {lossless} 24-bit colour) requires nonstandard, often
+ redundant, extensions. The incompatibility of extensions has
+ led some to expand "TIFF" as "Thousands of Incompatible File
+ Formats".
+
+ Compare {GIF}, {PNG}, {JPEG}.
+
+ (1997-10-11)
+
+tagged queueing
+
+ <hardware> A method allowing a device or {controller} to
+ process commands received from a {device driver} out of order.
+ It requires that the device driver attaches a tag to each
+ command which the controller or device can later use to
+ identify the response to the command.
+
+ Tagged queueing can speed up processing considerably if a
+ controller serves devices of very different speeds, such as an
+ {SCSI} controller serving a mix of {CD-ROMs} and high-speed
+ {disks}. In such cases if a request to fetch data from the
+ CD-ROM is shortly followed by a request to read from the disk,
+ the controller doesn't have to wait for the CD-ROM to fetch
+ the data, it can instead instruct the disk to fetch the data
+ and return the value to the device driver, while the CD-ROM is
+ probably still {seeking}.
+
+ (1997-07-04)
+
+tagged types
+
+ <programming> {Ada}'s type mechanism in which types can be
+ extended via {single inheritance}.
+
+ (2000-02-21)
+
+tag name
+
+ {generic identifier}
+
+tail call optimisation
+
+ {last call optimisation}
+
+tail call optimization
+
+ {last call optimisation}
+
+tail circuit
+
+ <communications> A circuit which connects the {serial lines}
+ of two {modems} together.
+
+ [Why do that?]
+
+ (1996-10-16)
+
+tail recursion
+
+ <programming> When the last thing a function (or procedure)
+ does is to call itself. Such a function is called tail
+ recursive. A function may make several {recursive} calls but
+ a call is only tail-recursive if the caller returns
+ immediately after it. E.g.
+
+ f n = if n < 2 then 1 else f (f (n-2) + 1)
+
+ In this example both calls to f are recursive but only the
+ outer one is tail recursive.
+
+ Tail recursion is a useful property because it enables {tail
+ recursion optimisation}.
+
+ If you aren't sick of them already, see {recursion} and {tail
+ recursion}.
+
+ [{Jargon File}]
+
+ (2006-04-16)
+
+tail recursion modulo cons
+
+ <programming, compiler> A generalisation of {tail recursion}
+ introduced by D.H.D. Warren. It applies when the last thing a
+ function does is to apply a constructor functions (e.g. cons)
+ to an application of a non-primitive function. This is
+ transformed into a tail call to the function which is also
+ passed a pointer to where its result should be written. E.g.
+
+ f [] = []
+ f (x:xs) = 1 : f xs
+
+ is transformed into (pseudo {C}/{Haskell}):
+
+ f [] = []
+ f l = f' l allocate_cons
+
+ f' [] p = { *p = nil;
+ return *p
+ }
+ f' (x:xs) p = { cell = allocate_cons;
+ *p = cell;
+ cell.head = 1;
+ return f' xs &cell.tail
+ }
+
+ where allocate_cons returns the address of a new cons cell, *p
+ is the location pointed to by p and &c is the address of c.
+
+ [D.H.D. Warren, DAI Research Report 141, University of
+ Edinburgh 1980].
+
+ (1995-03-06)
+
+tail recursion optimisation
+
+ <programming> (TRO) Discarding the calling environment ({call
+ stack} {frame}) when the last thing a function or procedure
+ does is to call itself. This is important when a procedure
+ calls itself {recursive}ly many times since, without tail
+ recursion optimisation, the environments of earlier
+ invocations would fill up the memory only to be discarded when
+ (if) the last call terminated.
+
+ Tail recursion optimisation is a special case of {last call
+ optimisation} but it allows the further optimisation that some
+ arguments may be passed in situ, possibly in {registers}. It
+ allows recursive functions to be compiled into {iterative}
+ loops.
+
+ See also {conversion to iteration}, {tail recursion modulo
+ cons}.
+
+ (2006-04-16)
+
+tail-strict
+
+ A tail-strict function evaluates every cons cell in its (list)
+ argument. It will therefore fail to terminate if its argument
+ is an infinite list or if any tail of its argument fails to
+ terminate. The archetypal tail-strict function is length.
+ See also Head-strict, Hyper-strict.
+
+TAL
+
+ {Transaction Application Language}
+
+TALE
+
+ Typed Applicative Language Experiment. M. van Leeuwen. Lazy,
+ purely applicative, polymorphic. Based on typed second order
+ lambda-calculus. "Functional Programming and the Language
+ TALE", H.P. Barendregt et al, in Current Trends in
+ Concurrency, LNCS 224, Springer 1986, pp.122-207.
+
+Taligent
+
+ A company founded jointly by Apple and IBM in March 1992. HP
+ announced in January, 1994 that it would buy a 15% stake in
+ Taligent. They are working on an "object-oriented operating
+ system", due to be finished sometime in 1995. However,
+ various independent pieces of Taligent will likely appear to
+ be used with other operating systems, e.g. IBM's WorkplaceOS.
+ Pink is an older name for Taligent, dating back to work that
+ Apple did before the formation of Taligent.
+
+talk
+
+ <chat, tool, networking, messaging> A {Unix} program and
+ {protocol} supporting conversation between two or more users
+ who may be logged into the same computer or different
+ computers on a network. Variants include {ntalk}, {ytalk},
+ and {ports} or {emulators} of these programs for other
+ {platforms}.
+
+ {Unix} has the {talk} program and {protocol} and its variants
+ {xtalk} and {ytalk} for the {X Window System}; {VMS} has
+ {phone}; {Windows for Workgroups} has {chat}. {ITS} also has
+ a talk system. These split the screen into separate areas for
+ each user.
+
+ {Unix}'s {write} command can also be used, though it does not
+ attempt to separate input and output on the screen.
+
+ Users of such systems are said to be in {talk mode} which has
+ many conventional abbreviations and idioms. Most of these
+ survived into {chat} jargon, but many fell out of common use
+ with the migration of {user} prattle from talk-like systems to
+ {chat} systems in the early 1990s. These disused
+ talk-specific forms include:
+
+ "BYE?" - are you ready to close the conversation? This is the
+ standard way to end a talk-mode conversation; the other person
+ types "BYE" to confirm, or else continues the conversation.
+
+ "JAM"/"MIN" - just a minute
+
+ "O" - "over" (I have stopped talking). Also "/" as in x/y - x
+ over y, or two newlines (the latter being the most common).
+
+ "OO" - "over and out" - end of conversation.
+
+ "\" - Greek {lambda}.
+
+ "R U THERE?" - are you there?
+
+ "SEC" - wait a second.
+
+ "/\/\/" - laughter. But on a {MUD}, this usually means
+ "earthquake fault".
+
+ See also {talk bomb}.
+
+ (1998-01-25)
+
+talk bomb
+
+ {flash}
+
+talker system
+
+ {talk}
+
+talk mode
+
+ <chat> Using a {talk} system. E.g., "{B1FF} had me in talk
+ mode for hours last night. I had to bring his box down just
+ to get him to shut up."
+
+ The (1980s?) term now is as dated as talk itself which has
+ been largely replaced by {chat}.
+
+ [{Jargon File}]
+
+ (1998-01-19)
+
+TALL
+
+ <language> TAC List Language.
+
+ ["TALL - A List Processor for the Philco 2000", J. Feldman,
+ CACM 5(9):484-485 (Sep 1962)].
+
+ (1995-03-01)
+
+tall card
+
+ <hardware> An expansion card for the {IBM PC AT}. These can
+ be larger than {IBM PC} or {IBM PC XT} cards because the AT
+ case is bigger.
+
+ When IBM introduced the PS/2 model 30 (its last gasp at
+ supporting the {ISA}) they made the case lower and many
+ industry-standard tall cards wouldn't fit. This was felt to
+ be a reincarnation of the {connector conspiracy}, done with
+ less style.
+
+ See also {short card}.
+
+ [{Jargon File}]
+
+ (1995-03-01)
+
+Tandem Application Language
+
+ {Transaction Application Language}
+
+Tandem Computers
+
+ <company> A US computer manufacturer.
+
+ Quarterly sales $544M, profits $49M (Aug 1994).
+
+ (1994-09-26)
+
+Tandy
+
+ <company> A US company, the parent company of {Radio Shack},
+ makers of the {TRS-80} and other early {personal computers}.
+
+ (1995-02-28)
+
+Tanenbaum, Andrew
+
+ {Andrew Tanenbaum}
+
+Tangible User Interface
+
+ <interface> An attempt to give physical form to digital
+ information, making bits directly manipulable and perceptible
+ by people. Tangible Interfaces will make bits accessible
+ through augmented physical surfaces (e.g. walls, desktops,
+ ceilings, windows), graspable objects (e.g. building blocks,
+ models, instruments) and ambient media (e.g. light, sound,
+ airflow, water-flow, kinetic sculpture) within physical
+ environments.
+
+ {MIT Tangible Media Group (http://tangible.media.mit.edu/)}.
+
+ (2003-10-17)
+
+tanked
+
+ 1. <jargon> Same as {down}, used primarily by {Unix} hackers.
+
+ See also {hosed}.
+
+ 2. Popularised as a synonym for "drunk" by Steve Dallas in the
+ late lamented "Bloom County" comic strip.
+
+ [{Jargon File}]
+
+ (1995-02-28)
+
+TANSTAAFL
+
+ /tan'stah-fl/ (From Robert Heinlein's classic "The
+ Moon is a Harsh Mistress") "There Ain't No Such Thing As A
+ Free Lunch".
+
+ Often invoked when someone is balking at the prospect of using
+ an unpleasantly {heavyweight} technique, or at the poor
+ quality of some piece of {free software}, or at the
+ {signal-to-noise ratio} of unmoderated {Usenet} newsgroups.
+ "What? Don't tell me I have to implement a {database} back end
+ to get my address book program to work!" "Well, TANSTAAFL you
+ know." This phrase owes some of its popularity to the high
+ concentration of science-fiction fans and political
+ libertarians in hackerdom.
+
+ [{Jargon File}]
+
+ (1995-02-28)
+
+TAO
+
+ <language> 1. A {Lisp} dialect with {concurrency},
+ {object-orientation} and logic.
+
+ ["Concurrent Programming in TAO - Practice and Experience",
+ I. Takeuchi in Parallel Lisp: Languages and Systems, T. Ito et
+ al eds, LNCS 441, Springer 1989, pp. 271-299].
+
+ (2006-02-06)
+
+ 2. A programming language for {APE/Quadrics} {parallel}
+ computers, largely modelled on {FORTRAN} and evolved from the
+ even more primitive {APESE} language. TAO is particularly
+ hard to work with, due to the lack of systematics, poor
+ documentation and a primitive compiler.
+
+ [Reference? Dates?]
+
+ (2006-02-06)
+
+TAOS
+
+ {Technology for Autonomous Operation Survivability}
+
+TAP
+
+ {Telocator Alphanumeric Protocol}
+
+tap
+
+ {hit}
+
+tape
+
+ 1. {magnetic tape}.
+
+ 2. {paper tape}.
+
+ (1996-05-25)
+
+tape archive
+
+ {tar}
+
+tape drive
+
+ {magnetic tape drive}
+
+tape head
+
+ <hardware> The electromagnetic component in a {magnetic tape
+ drive} which reads and writes magnetic tape as it passes over
+ it. Tape heads need to be cleaned periodically to remove the
+ oxide particles which accumulate on them and can lead to
+ errors.
+
+ (1997-03-12)
+
+Tape Operating System
+
+ <operating system> (TOS) An {IBM} {operating system} for
+ {System 360}, used in the early days around 1965 to support
+ the {IBM 360} model 30 et al. TOS was a predecessor to IBM's
+ {Disk Operating System}.
+
+ TOS died out really early as disks such as the 2311 and 2314
+ became common with the {IBM 360} whereas thet had been a real
+ luxury on the {IBM 7090}.
+
+ [Relationship to {BOS}?]
+
+ (1999-01-20)
+
+TAPI
+
+ {Telephony Application Programming Interface}
+
+tar
+
+ <file format> ("Tape ARchive", following {ar}) {Unix}'s
+ general purpose {archive} utility and the file format it uses.
+ Tar was originally intended for use with {magnetic tape} but,
+ though it has several {command line options} related to tape,
+ it is now used more often for packaging files together on
+ other media, e.g. for distribution via the {Internet}.
+
+ The resulting archive, a "tar file" (humourously, "tarball")
+ is often compressed, using {gzip} or some other form of
+ compression (see {tar and feather}).
+
+ There is a {GNU} version of tar called {gnutar} with several
+ improvements over the standard versions.
+
+ {Filename extension}: .tar
+
+ {MIME type}: unregistered, but commonly application/x-tar
+
+ {Unix manual page}: tar(1).
+
+ Compare {shar}, {zip}.
+
+ (1998-05-02)
+
+tar and feather
+
+ <jargon> (A sick contrivance from the {Unix} {tar} command and
+ the Ku Klux Klan torture method) To create a transportable
+ archive from a group of files by first sticking them together
+ with {tar} (the Tape ARchiver) and then {compress}ing the
+ result. The latter action is dubbed "feathering" (purely for
+ contrived effect) by analogy to what you do with an aeroplane
+ propeller to decrease wind resistance, or with an oar to
+ reduce water resistance; smaller files, after all, slip
+ through comm links more easily.
+
+ [{Jargon File}]
+
+ (1997-05-26)
+
+tarball
+
+ {tar}
+
+targa
+
+ <graphics, file format> A graphics data format for {bitmap}
+ {images}. It uses 24 bits per {pixel} and is a common output
+ format for {ray tracing} programs.
+
+ (1995-01-05)
+
+Targa Graphics Adaptor
+
+ <graphics, file format> (TGA) The Truevision Targa Graphics
+ Adaptor file format.
+
+ The TGA format is a common {bitmap} file format for storage of
+ 24-bit images. It supports {colourmaps}, {alpha channels},
+ {compression} and comments.
+
+ {Filename extension}: .tga.
+
+ More information is available from
+ {Truevision (http://truevision.com/)} and
+ {The Graphics File Format Page
+ (http://dcs.ed.ac.uk/~mxr/gfx/)}.
+
+ [What does it have to do with graphics adaptors?]
+
+ (1997-08-07)
+
+target
+
+ {SCSI target}
+
+Target-Machine Description Language
+
+ (TMDL) The machine-description language used in the
+ Graham-Glanville {code generator}.
+
+ ["Table-Driven Code Generation", S.L. Graham, IEEE Computer
+ 13(8):25-34 (Aug 1980)].
+
+ (1995-02-21)
+
+TARTAN
+
+ A simple language proposed to meet the {Ironman} requirements.
+
+ ["TARTAN - Language Design for the Ironman Requirements:
+ Reference Manual", Mary Shaw et al, SIGPLAN Notices
+ 13(9):36-58 (Sep 1978)].
+
+ (1995-01-05)
+
+taskbar
+
+ <operating system> The part of the {Microsoft Windows}
+ {graphical user interface} (GUI) typically occupying a fixed
+ strip along the bottom of the screen, showing a rectangular
+ icon for each running {application}.
+
+ The taskbar also contains the {Start menu} at its left-hand
+ end and the {notification area} at the right-hand end. Other
+ {toolbars} can be added such as the {Quick Launch toolbar}.
+
+ Clicking an application's taskbar icon makes its windows
+ visible in front of other windows and gives one of them the
+ {input focus}, or if it is already in front, minimises it.
+ Right-clicking an icon gives a {window manager} menu, possibly
+ customised by the application. Right-clicking the taskbar
+ itself performs global window manager actions such as
+ minimising all windows and also allows you to set taskbar
+ properties. The taskbar can be locked in position or resized
+ or dragged to the top, left or right of the screen.
+
+ (2007-06-13)
+
+Task Control Block
+
+ <architecture> An {MVS} {control block} used to communicate
+ information about {tasks} within an {address space} that are
+ connected to an {MVS} subsystem such as {MQSeries} for
+ {MVS/ESA} or {CICS}.
+
+ {FAQ
+ (http://www-4.ibm.com/software/ts/mqseries/library/manuals/csqfao/CSQFAO22.HTM)}.
+
+ (2000-12-30)
+
+task scheduling
+
+ <algorithm> The assignment of start and end times to a set of
+ tasks, subject to certain {constraints}. Constraints are
+ typically either time constraints (the payload must be
+ installed before the payload bay doors are closed) or resource
+ constraints (this task requires a small crane and a crane
+ operator).
+
+ In the case where the tasks are programs to run concurrently
+ on a computer, this is also known as {multitasking}.
+
+ (1998-04-25)
+
+TASM
+
+ Turbo Assembler. {MS-DOS} assembler from Borland.
+
+TASS
+
+ Template ASSembly language. Intermediate language produced by
+ the Manchester SISAL compiler.
+
+taste
+
+ 1. (primarily MIT) The quality of a program that tends to be
+ inversely proportional to the number of features, hacks, and
+ {kluges} it contains. Taste refers to sound judgment on the
+ part of the creator. See also {elegant}, {flavour}.
+
+ 2. Alternative spelling of "{tayste}".
+
+ [{Jargon File}]
+
+tatar
+
+ <human language> A Turkic language spoken by about five
+ million Tatars in Russia, Ukraine, Turkey and elsewhere; the
+ official language of the Republic of Tatarstan (Russian
+ Federation).
+
+ {language codes}: tt, tat.
+
+ (2006-12-11)
+
+tau
+
+ <mathematics> The mathematical constant that is the circumference
+ of a circle divided by its radius, equal to twice {pi}.
+
+ Some have suggested that pi is the wrong choice of constant to
+ describe the geometry of circles etc. and tau = 2*pi would have
+ been better. Most practising mathematicians think this is silly.
+ The {xkcd} comic strip facetiously {proposed
+ (http://xkcd.com/1292/)} a compromise of 1.5*pi or "pau".
+
+ {The Pi Manifesto (http://www.thepimanifesto.com/)}.
+
+ (2013-12-10)
+
+tautological probability
+
+ <logic> A notion introduced by Florentin Smarandache whereby
+ the probability of some event is more than one. Tautological
+ probability is used for universally true {propositions},
+ i.e. those which do not depend on time, space, subjectivity,
+ etc.
+
+ [Florentin Smarandache, "A Unifying Field in Logics. /
+ Neutrosophy: Neutrosophic Probability, Set, and
+ Logic", American Research Press, Rehoboth 1999].
+
+ (2001-04-06)
+
+tautological set
+
+ <logic> A notion introduced by Florentin Smarandache: An
+ element x(T, I, F) belongs more than sure to the {set} M; here
+ T, I, F are real subsets representing the truth,
+ indeterminacy, and falsity percentages respectively, and
+ sup(T)>100.
+
+ tautological set are used for universally true {propositions}
+ where no parameter such as time, space, or subjectivity
+ influences the truth value.
+
+ [{Florentin Smarandache, "A Unifying Field in Logics. /
+ Neutrosophy: Neutrosophic Probability, Set, and
+ Logic", American Research Press, Rehoboth, 1999
+ (http://gallup.unm.edu/~smarandache/neut-ad.htm)}]
+
+ (1999-11-24)
+
+tautology
+
+ <logic> A {proposition} which is always true.
+
+ Compare: {paradox}.
+
+ {The Linguistic Smarandache Tautologies,
+ (http://gallup.unm.edu/~smarandache/tautolog.txt)}.
+
+ (1999-07-28)
+
+TAWK
+
+ {Tiny AWK}
+
+Taxis
+
+ ["A Language Facility for Designing Database-Intensive
+ Applications", J. Mylopoulos et al, ACM Trans Database Sys
+ 5(2):185-207 (June 1980)].
+
+tayste
+
+ {crumb}
+
+taz
+
+ {tgz}
+
+TB
+
+ {terabyte}
+
+TBF
+
+ {Mean Time Between Failures}
+
+TBIL
+
+ {Tiny Basic Interpreter Language}
+
+TBK
+
+ {Tool Builder Kit}
+
+Tbl
+
+ 1. A language by M.E. Lesk for formatting tables, implemented
+ as a {preprocessor} to {nroff}.
+
+ (1994-11-01)
+
+ 2. Table Building Language. A simple language by Robert
+ Freiburghouse of {MIT} which combines user-defined actions
+ into an {abstract machine}. It can be used to build
+ table-driven predictive {parsers} and {code generators} in the
+ {MULTICS} {Fortran} compiler and several {PL/I} compilers,
+ including {VAX}-11 PL/I.
+
+ ["Engineering A Compiler: VAX-11 Code Generation and
+ Optimisation", P. Anklam et al, Digital Press 1977].
+
+ (1994-11-01)
+
+tc
+
+ <networking> The {country code} for the Turks and Caicos
+ Islands.
+
+ (1999-01-27)
+
+T-carrier system
+
+ <communications> A series of wideband digital data
+ transmission formats originally developed by the {Bell System}
+ and used in North America and Japan.
+
+ The basic unit of the T-carrier system is the {DS0}, which has
+ a transmission rate of 64 Kbps, and is commonly used for one
+ {voice circuit}.
+
+ Originally the 1.544 megabit per second {T1} format carried 24
+ pulse-code modulated, time-division multiplexed speech signals
+ each encoded in 64 kilobit per second streams, leaving 8
+ kilobits per second of framing information which facilitates
+ the synchronisation and demultiplexing at the receiver. {T2}
+ and {T3} circuits channels carry multiple T1 channels
+ multiplexed, resulting in transmission rates of up to 44.736
+ Mbps.
+
+ The T-carrier system uses {in-band signaling}, resulting in
+ lower transmission rates than the {E-carrier system}. It uses
+ a restored polar signal with {303-type} data stations.
+
+ Asynchronous signals can be transmitted via a standard which
+ encodes each change of level into three bits; two which
+ indicate the time (within the current synchronous frame) at
+ which the transition occurred, and the third which indicates
+ the direction of the transition. Although wasteful of line
+ bandwidth, such use is usually only over small distances.
+
+ T1 lines are made free of direct current signal components by
+ in effect capacitor coupling the signal at the transmitter and
+ restoring that lost component with a "slicer" at the receiver,
+ leading to the description "restored polar".
+
+ [Telecommunications Transmission Engineering, Vol. 2,
+ Facilities, AT&T, 1977].
+
+ (2001-04-08)
+
+TCB
+
+ 1. <jargon> {Trouble Came Back}.
+
+ 2. <security> ({Orange Book}) {Trusted Computing Base}.
+
+ 3. <operating system> {Task Control Block}.
+
+ [{Jargon File}]
+
+ (1998-07-02)
+
+TCGS
+
+ {Twente Compiler Generator System}
+
+TC/IX
+
+ The LynxOS kernel ported to the MIPS R3000 RISC processor by
+ CDC.
+
+Tcl
+
+ {Tool Command Language}
+
+Tcl Consortium
+
+ <body> A non-profit agency dedicated to promoting {Tcl}.
+
+ {(http://tclconsortium.org/)}.
+
+ (1998-11-27)
+
+tcl-debug
+
+ A debugger for {Tcl} by Don Libes <libes@cme.nist.gov> that
+ can be easily embedded in other applications. It is included
+ with many other Tcl libraries.
+
+ {(ftp://ftp.cme.nist.gov/pub/expect/tcl-debug.tar.Z)}.
+
+ (1994-10-31)
+
+Tcl-DP
+
+ Tcl-DP extends {Tcl}'s "send" by removing the restriction that
+ you can only send to other clients of the same X11 server.
+ Version 3.0 library by Larry Rowe.
+
+ {(ftp://toe.cs.berkeley.edu/pub/multimedia/Tcl-DP)}.
+
+tclhttpd
+
+ <tool> An {embeddable} {Tcl}-based {web server}.
+
+ [Details?]
+
+ (1998-11-27)
+
+TclX
+
+ {Extended Tcl}
+
+TCM
+
+ {Trellis Code Modulation}
+
+TCO
+
+ {Total Cost of Ownership}
+
+Tcode
+
+ Intermediate language used by the Spineless Tagless G-machine
+ (an abstract machine based on graph reduction) designed as a
+ target for compilation of non-strict functional languages.
+ "The Spineless tagless G- machine", S. Peyton Jones et al,
+ Fourth Intl Conf Func Prog Langs and Comp Arch pp.184-201, ACM
+ Sept 1989.
+
+TCOL
+
+ CMU. Tree-based intermediate representation produced by the
+ PQCC compiler generator. "An Overview of the Production
+ Quality Compiler- Compiler Projects", B.W. Leverett et al,
+ IEEE Computer 13(8): 38-49 (Aug 1980). (See LG).
+
+TCOL.Ada
+
+ CMU, 1980. An intermediate representation for Ada, was merged
+ with AIDA to form Diana. "TCOL.Ada: Revised Report on an
+ Intermediate Representation for the DOD Standard Programming
+ Language", J.M. Newcomer et al, CMU-CS-79-128 (June 1979).
+
+TCP
+
+ {Transmission Control Protocol}
+
+TCPIP
+
+ Normally written "{TCP/IP}".
+
+TCP/IP
+
+ <protocol> {Transmission Control Protocol} over
+ {Internet Protocol}.
+
+ The {de facto} {standard} {Ethernet} {protocols} incorporated
+ into {4.2BSD} {Unix}. TCP/IP was developed by {DARPA} for
+ {internetworking} and encompasses both {network layer} and
+ {transport layer} protocols. While {TCP} and {IP} specify two
+ protocols at specific {protocol layers}, TCP/IP is often used
+ to refer to the entire {DoD} {protocol} suite based upon
+ these, including {telnet}, {FTP}, {UDP} and {RDP}.
+
+ See also {ICMP}, {SMTP}, {SNMP}.
+
+ (1995-03-17)
+
+tcsh
+
+ <Unix, operating system> A {Unix} {shell} by Christos Zoulas
+ <christos@ee.cornell.edu>, based on {csh}. tcsh adds {WYSIWYG}
+ command line editing, command name {completion}, input {history}
+ and various other features.
+
+ Version 6.04 runs under many versions of {Unix} and under
+ {OpenVMS}. tcsh has been largely replaced by {bash}.
+
+ {(ftp://ftp.spc.edu/)}.
+
+ (2014-09-14)
+
+Tcsim
+
+ {Time Complex Simulator}
+
+TCVN 5773
+
+ <human language, standard> A 1993 {Vietnamese} character
+ {standard} that includes {Han} characters.
+
+ (2001-01-02)
+
+TCVN 6056
+
+ <human language, standard> A 1995 {Vietnamese} character
+ {standard} that includes {Han} characters.
+
+ (2001-01-02)
+
+td
+
+ <networking> The {country code} for Chad.
+
+ (1999-01-27)
+
+TDD
+
+ 1. <testing> {test-driven development}.
+
+ 2. <communications> {Telecommunications Device for the Deaf}.
+
+TDEL
+
+ {thick film dielectric electroluminescence}
+
+TDF
+
+ <language> An {intermediate language}, a close relative of
+ {ANDF}. A TDF program is an {ASCII} stream describing an
+ {abstract syntax tree}.
+
+ TDF became part of {TenDRA} in abut 2001.
+
+ ["TDF Specification", Defence Research Agency/Electronics
+ Division, Great Malvern, England, +44 684 895314].
+
+ (2003-05-13)
+
+TDFL
+
+ Dataflow language. "TDFL: A Task-Level Dataflow Language", P.
+ Suhler et al, J Parallel Dist Comp 9(2):103-115 (Jun 1990).
+
+TDI
+
+ {Transport Driver Interface}
+
+TDM
+
+ 1. {Technical Data Management}
+
+ 2. {Time Division Multiplexing}
+
+TDMA
+
+ {time division multiple access}
+
+TDR
+
+ {time domain reflectometer}
+
+Teamwork
+
+ <product, software, tool> A {SASD} tool from {Sterling
+ Software}, formerly {CADRE Technologies}, which supports the
+ {Shlaer/Mellor} {Object-Oriented} method and the
+ {Yourdon-DeMarco}, {Hatley-Pirbhai}, {Constantine} and {Buhr}
+ notations.
+
+ Teamwork was abandoned when {Computer Associates}
+ acquired Sterling Software in March 2000.
+
+ (2002-05-29)
+
+Technical/Office Protocol
+
+ (TOP) An {applications layer} {network} {application} and
+ {protocol stack} for {office automation} developed by {Boeing}
+ following the {OSI model}. This {protocol} is very similar to
+ {MAP} except at the lowest levels, where it uses {Ethernet}
+ ({IEEE} {802.3}) rather than {Token Bus} ({IEEE} {802.4}).
+
+Technion
+
+ <body> Israel Institute of Technology.
+
+ {(http://technion.ac.il/)}.
+
+ {(ftp://ftp.technion.ac.il/)}.
+
+ Address: Haifa, Israel.
+
+ (1995-05-09)
+
+technology
+
+ <jargon> {Marketroid} jargon for "{software}", "{hardware}",
+ "{protocol}" or something else too technical to name.
+
+ The most flagrant abuse of this word has to be "{Windows NT}"
+ (New Technology) - {Microsoft}'s attempt to make the
+ incorporation of some ancient concepts into their OS sound
+ like real progress. The irony, and even the meaning, of this
+ seems to be utterly lost on Microsoft whose {Windows 2000}
+ start-up screen proclaims "Based on NT Technology", (meaning
+ yet another version of NT, including some {Windows 95}
+ features at last).
+
+ See also: {solution}.
+
+ (2001-06-28)
+
+Technology Enabled Relationship Manager
+
+ {Customer Relationship Management}
+
+Technology of Object-Oriented Languages and Systems
+
+ <event> (TOOLS) One of the oldest {object-oriented}
+ conferences, with 18 published proceedings volumes. TOOLS is
+ organised by {Interactive Software Engineering}.
+
+ (1995-12-29)
+
+TechRef
+
+ /tek'ref/ [{MS-DOS}] The original "IBM PC Technical Reference
+ Manual", including the {BIOS} listing and complete schematics
+ for the PC. The only PC documentation in the issue package
+ that's considered serious by real hackers.
+
+ [{Jargon File}]
+
+TECO
+
+ <editor, text> /tee'koh/ (Originally an acronym for "[paper]
+ Tape Editor and COrrector"; later, "Text Editor and
+ COrrector"]) A {text editor} developed at {MIT} and modified
+ by just about everybody. With all the dialects included, TECO
+ may have been the most prolific editor in use before {Emacs},
+ to which it was directly ancestral. The first {Emacs} editor
+ was written in TECO.
+
+ It was noted for its powerful programming-language-like
+ features and its unspeakably {hairy} {syntax} (see {write-only
+ language}). TECO programs are said to resemble {line noise}.
+ Every string of characters is a valid TECO program (though
+ probably not a useful one); one common game used to be predict
+ what the TECO commands corresponding to human names did.
+
+ As an example of TECO's obscurity, here is a TECO program that
+ takes a list of names such as:
+
+ Loser, J. Random
+ Quux, The Great
+ Dick, Moby
+
+ sorts them alphabetically according to surname, and then puts
+ the surname last, removing the comma, to produce the
+ following:
+
+ Moby Dick
+ J. Random Loser
+ The Great Quux
+
+ The program is
+
+ [1 J^P$L$$
+ J <.-Z; .,(S,$ -D .)FX1 @F^B $K :L I $ G1 L>$$
+
+ (where ^B means "Control-B" (ASCII 0000010) and $ is actually
+ an {alt} or escape (ASCII 0011011) character).
+
+ In fact, this very program was used to produce the second,
+ sorted list from the first list. The first hack at it had a
+ {bug}: GLS (the author) had accidentally omitted the "@" in
+ front of "F^B", which as anyone can see is clearly the {Wrong
+ Thing}. It worked fine the second time. There is no space to
+ describe all the features of TECO, but "^P" means "sort" and
+ "J<.-Z; ... L>" is an idiomatic series of commands for "do
+ once for every line".
+
+ By 1991, {Emacs} had replaced TECO in hacker's affections but
+ descendants of an early (and somewhat lobotomised) version
+ adopted by {DEC} can still be found lurking on {VMS} and a
+ couple of {crufty} {PDP-11} {operating systems}, and ports of
+ the more advanced MIT versions remain the focus of some
+ antiquarian interest.
+
+ See also {retrocomputing}.
+
+ {(ftp://usc.edu/)} for {VAX}/{VMS}, {Unix}, {MS-DOS},
+ {Macintosh}, {Amiga}.
+
+ [Authro? Home page?]
+
+ (2001-03-26)
+
+tee
+
+ <tool, operating system> A {Unix} command which copies its
+ {standard input} to its {standard output} (like {cat}) but
+ also to a file given as its argument. tee is thus useful in
+ {pipelines} of {Unix} commands (see {plumbing}) where it
+ allows you to create a duplicate copy of the data stream.
+ E.g.
+
+ egrep Unix Dictionary | tee /dev/tty | wc -l
+
+ searches for lines containing the string "Unix" in the file
+ "Dictionary", prints them to the terminal (/dev/tty) and
+ counts them.
+
+ {Unix manual page}: tee(1).
+
+ [{Jargon File}]
+
+ (1996-01-22)
+
+TEI
+
+ 1. <communications> {Terminal Endpoint Identifier}.
+
+ 2. <text, project> {Text Encoding Initiative}.
+
+ (1997-03-11)
+
+telco
+
+ <communications, company> (from telephone company) A company
+ providing phone services to end users. The company may or may
+ not provide other phone services such operating
+ long-distance/international backbones but the name telco
+ usually emphasises its operation as a local service provider.
+
+ Compare: {PTT}.
+
+ (1998-05-18)
+
+TELCOMP
+
+ <language> A variant of {JOSS}.
+
+ [Sammet 1969, p.217].
+
+ (1997-04-07)
+
+Telecommunication Display Device
+
+ {Telecommunications Device for the Deaf}
+
+Telecommunications Device for the Deaf
+
+ <communications> (TDD) A terminal device used widely by deaf
+ people for text communication over telephone lines.
+
+ The acronym TDD is sometimes expanded as "Telecommunication
+ Display Device" but is generally considered to be derived from
+ "Telecommunications Device for the Deaf". The deaf themselves
+ do not usually use the term "TDD", but prefer simply "{TTY}"
+ -- possibly the original term. The ambiguity between this and
+ the other meanings of "{TTY}" is generally not problematic.
+ The acronym "TTD" is also common [Teletype for the deaf?].
+
+ The standard most used by TDDs is reportedly a survivor of
+ {Baudot code}. It uses {asynchronous} transmission of 1400 Hz
+ and 1600 Hz tones at 45.5 or 50 {baud}, with one {start bit},
+ 5 data bits and 1.5 {stop bits}. This is generally
+ incompatible with standard {modems}.
+
+ A typical TDD is a device about the size of a small {laptop
+ computer} (resembling, in fact, a circa 1983 Radio Shack
+ {Model 100} computer) with a {QWERTY keyboard}, and small
+ screen (often one line high, often made of an array of
+ {LEDs}). There is often a small printer for making
+ transcripts of terminal sessions. An {acoustic coupler}
+ connects it to the telephone handset.
+
+ With the falling cost of {personal computers} and the
+ widespread use of {Internet} {talk} systems, there is now
+ little reason to use this {Stone Age} technology.
+
+ [Standards? {i18n}?]
+
+ (2006-10-08)
+
+Telecommunications Industry Association
+
+ <body, standard> (TIA) An association that sets {standards}
+ for communications cabling.
+
+ Cables that TIA set standards for include: {EIA}/TIA-568A
+ and EIA/TIA-568B category three, four and five cable.
+
+ {(http://tiaonline.org/)}.
+
+ [Details?]
+
+ (2000-04-24)
+
+telecommuting
+
+ The practice of working at home and communicating with your
+ fellow workers through the phone, typically with a computer
+ and modem. Telecommuting saves the employee getting to and
+ from work and saves the employer from supplying support
+ services such as heating and cleaning, but it can also deprive
+ the worker of social contact and support.
+
+ (1995-01-05)
+
+teledildonics
+
+ <application, virtual reality> /tel"*-dil-do"-niks/ Sex in a
+ computer simulated {virtual reality}, especially
+ computer-mediated sexual interaction between the VR presences
+ of two humans. This practice is not yet possible except in
+ the rather limited form of erotic conversation on {MUDs} and
+ the like. The term, however, is widely recognised in the VR
+ community as a {ha ha only serious} projection of things to
+ come. "When we can sustain a multi-sensory surround good
+ enough for teledildonics, *then* we'll know we're getting
+ somewhere."
+
+ [{Jargon File}]
+
+ (1995-02-06)
+
+telegraphy
+
+ <communications, history> A historical term for communication,
+ either wired or wireless, using {Morse code}. The term is
+ used in contrast with {telephony} meaning voice transmission.
+ Telegraphy is sometimes (somewhat incorrectly) referred to as
+ "{continuous wave}" or CW transmission.
+
+ (2009-11-24)
+
+telematics
+
+ The combination of telecommunications and computing. Data
+ communications between systems and devices.
+
+ (1995-02-07)
+
+TelEnet
+
+ The old name for {Sprintnet}. TELENET used to provide a
+ service called {PC Pursuit}.
+
+ Not to be confused with {telnet} the program and {protocol}.
+
+ (1994-10-17)
+
+TELEPAC
+
+ <networking> The Swiss {PTT} {X.25} network.
+
+ (1995-11-09)
+
+Telephone Application Program Interface
+
+ <programming, communications> (TAPI) Officially it's
+ {Telephony Application Programming Interface}.
+
+ (1995-11-27)
+
+telephony
+
+ <communications> Communication, often two-way, of spoken
+ information, by means of electrical signals carried by wires
+ or radio waves. The term was used to indicate transmission of
+ the voice, as opposed to {telegraphy} (done in {Morse code}
+ and usually called "{continuous wave}" or CW transmission),
+ radio teletypewriter (RTTY) transmission (also called FSK for
+ "{Frequency Shift Keying}", the modulation scheme used by such
+ machines), and later, facimile.
+
+ (1995-03-14)
+
+Telephony Application Programming Interface
+
+ <programming, communications> (TAPI, or "Telephone Application
+ Program Interface") A {Windows 95} {Application Program
+ Interface} enabling hardware independent access to telephone
+ based communication. TAPI covers a rather wide area of
+ services from initialising the equipment (e.g. a {modem}) and
+ placing a call to {voice mail} or control of a remote
+ computer.
+
+ [Telephone or Telephony?]
+
+ (1995-12-05)
+
+Telephony User Interface
+
+ <communications> (TUI) Either a software interface to
+ telephony (e.g. a phone-capable PC) or a {DTMF}-based
+ interface to software (e.g. voicemail).
+
+ (2003-10-21)
+
+Telerat
+
+ <abuse, hardware> /tel'*-rat/ Unflattering hackerism for
+ "{Teleray}", a line of extremely losing {terminals}.
+
+ [{Jargon File}]
+
+ (1995-01-19)
+
+Telescope User Interface
+
+ <hardware, interface> (TUI) A remote control interface for a
+ telescope.
+
+ (2003-10-21)
+
+Telescript
+
+ A communications-oriented programming language using "active
+ software agents", released by {General Magic} in 1994. What
+ {PostScript} did for cross-{platform}, device-independent
+ documents, Telescript aims to do for cross-{platform},
+ network-independent messaging. Telescript protects
+ programmers from many of the complexities of network
+ {protocols}.
+
+ (1995-01-16)
+
+Teletype
+
+ <hardware, product> ({tty}) A trademark for a hard-copy
+ {teletypewriter} produced by {Teletype Corporation}.
+
+ (2000-04-02)
+
+teletype
+
+ {teletypewriter}
+
+Teletype Corporation
+
+ <company> The company which made {Teletype} {teletypewriters}.
+
+ Address: Skokie, Illinois, USA.
+
+ (2000-04-03)
+
+teletypewriter
+
+ <hardware> (Nearly always abbreviated to "teletype" or
+ "{tty}") An obsolete kind of {terminal}, with a noisy
+ mechanical {printer} for output, a very limited {character
+ set}, and poor print quality.
+
+ See also {bit-paired keyboard}.
+
+ (2000-04-02)
+
+TeleUSE
+
+ An {interface builder} for {Motif}.
+
+television
+
+ <hardware> A dedicated {push media} device for receiving
+ {streaming video} and {audio}, either by terrestrial radio
+ broadcast, satellite or cable.
+
+ (1997-11-23)
+
+Television Interface Adaptor
+
+ <hardware, graphics> (TIA) The graphics chip in the {Atari
+ 2600}, also used as a sound chip for some arcade game.
+
+ (1999-12-06)
+
+TELNET
+
+ /tel'net/ 1. The {Internet} {standard} {protocol} for remote
+ login. Runs on top of {TCP/IP}. Defined in {STD} 8, {RFC
+ 854} and extended with options by many other RFCs. {Unix}
+ {BSD} networking software includes a program, telnet, which
+ uses the protocol and acts as a {terminal emulator} for the
+ remote login session. Sometimes abbreviated to TN. {TOPS-10}
+ had a similar program called {IMPCOM}.
+
+ 2. The US nationwide network into which one dials to access
+ {CompuServe}. It was created by John Goltz, one of the
+ founders and system {guru} of {CompuServe}. He later worked
+ for {Tymshare}, one of CompuServe's big competitors.
+
+ [{Jargon File}]
+
+ (2004-09-14)
+
+Telocator Alphanumeric Protocol
+
+ <communications, protocol> (TAP, or "IXO", "PET") A {protocol}
+ for submitting requests to a {pager} service. IXO/TAP is an
+ {ASCII}-based, {half-duplex} {protocol} that allows the
+ submission of a numeric or alphanumeric message.
+
+ {Examples, protocol description, clarifications
+ (ftp://mirror.lcs.mit.edu/telecom-archives/technical)}.
+
+ See also {RFC 1568}.
+
+ (1996-04-07)
+
+Telon
+
+ {CA-Telon}
+
+TELOS
+
+ 1. The {LeLisp} Version 16 Object System. Also used in
+ {EuLisp}. The {object-oriented} {core} of {EuLisp}.
+ Incorporates ideas from {CLOS}, {ObjVLisp} and {OakLisp}.
+ Total merging of {types} with {class}es and message-passing
+ with normal function {application}.
+
+ 2. A {Pascal}-based {AI} language.
+
+ ["Design Rationale for TELOS, a Pascal-based AI Language",
+ Travis et al, SIGPLAN Notices 12(8) (Aug 1977)].
+
+TELSIM
+
+ Busch, ca 1966. Digital simulation.
+
+ [Sammet 1969, p. 627].
+
+template
+
+ <text> A {document} that contains {parameters}, identified by some
+ special {syntax}, that are replaced by {actual arguments} by the
+ template processing system. For example:
+
+ Dear <guest>, <host> would like to invite you
+ to a party at <location> on <date> at <time>.
+
+ Where the words in angle brackets are the parameters to be
+ replaced by the name of an actual guest, etc.
+
+ More sophisticated systems allow repetition, where a section
+ is repeated in a single output document using a list of
+ inputs; conditional sections or (nested) inclusion of other
+ templates.
+
+ See also {class template}.
+
+ (2007-10-14)
+
+template code
+
+ <programming> {Pseudocode} generated by an automated {CASE}
+ system and requiring further hand-coding before compilation.
+
+ (2008-10-22)
+
+template wizard
+
+ <application> Software to guide the creation of some kind of
+ {template}. Examples include {Excel}'s Template Wizard add-in
+ for creating databases to receive form data. Most {web
+ authoring} tools include facilities for inserting text into
+ template page designs.
+
+ (2008-10-22)
+
+TEMPLOG
+
+ Extension of {Prolog} to handle a clausal subset of
+ first-order {temporal logic} with discrete time. Proposed by
+ M. Abadi and Z. Manna of {Stanford University}.
+
+ ["Temporal Logic in Programming", M. Abadi et al, INtl Symp
+ Logic Prog pp.4-16 (1987)].
+
+TEMPO
+
+ A programming language with simple {syntax} and {semantics}
+ designed for teaching semantic and pragmatic aspects of
+ programming languages.
+
+ ["TEMPO: A Unified Treatment of Binding Time and Parameter
+ Passing Concepts in Programming Languages", N.D. Jones et al,
+ LNCS 66, Springer 1978].
+
+Tempo
+
+ <operating system> The original code name for {Mac OS} version
+ 8.
+
+ (1997-10-15)
+
+temporal database
+
+ <database> A {database} that can store and retrieve temporal
+ data, that is, data which depends on time in some way.
+
+ [More details? Examples?]
+
+ (1996-05-25)
+
+temporal logic
+
+ <logic> An extension of {predicate calculus} which includes
+ notation for arguing about *when* statements are true. Time
+ is discrete and extends indefinitely into the future. Three
+ {prefix} operators, represented by a circle, square and diamond
+ mean "is true at the next time instant", "is true from now on"
+ and "is eventually true". x U y means x is true until y is
+ true. x P y means x precedes y.
+
+ There are two types of formula: "state formulae" about things
+ true at one point in time, and "path formulae" about things
+ true for a sequence of steps. An example of a path formula is
+ "x U y", and example of a state formula is "next x" or a
+ simple atomic formula such at "waiting".
+
+ "true until" in this context means that a state formula holds
+ at every point in time up to a point when another formula
+ holds. "x U y" is the "strong until" and implies that there
+ is a time when y is true. "x W y" is the "weak until" in
+ which it is not necessary that y holds eventually.
+
+ There are two types of temporal logic used: branching time and
+ linear time. The basic propositional temporal logic cannot
+ differentiate between the two, though. Linear time considers
+ only one possible future, in branching time you have several
+ alternative futures. In branching temporal logic you have the
+ extra operators "A" (for "all futures") and "E" (for "some
+ future"). For example, "A(work U go_home)" means "I will work
+ until I go home" and "E(work U go_home)" means "I may work
+ until I go home".
+
+ (1997-01-21)
+
+Tempura
+
+ Language based on temporal logic. "Executing Temporal Logic
+ Programs", B. Moszkowski, Camb U Press 1986.
+
+Ten15
+
+ <language> A universal {intermediate language}, a predecessor
+ to {TDF}.
+
+ {Ten15 Home (http://mca-ltd.com/martin/Ten15)}.
+
+ ["Ten15: An Overview", P. Core et al, Royal Signals Radar
+ Establishment TR 3977, Sept 1986].
+
+ [Polymorphic?]
+
+ (2003-05-13)
+
+tendinitis
+
+ {overuse strain injury}
+
+TenDRA
+
+ <language> {TenDRA home (http://tendra.org/)}.
+
+ [Summary?]
+
+ (2003-05-13)
+
+ten-finger interface
+
+ The interface between two networks that cannot be directly
+ connected for security reasons; refers to the practice of
+ placing two terminals side by side and having an operator read
+ from one and type into the other.
+
+ [{Jargon File}]
+
+tennis elbow
+
+ {overuse strain injury}
+
+tense
+
+ Of programs, very clever and efficient. A tense piece of code
+ often got that way because it was highly {bum}med, but
+ sometimes it was just based on a great idea. A comment in a
+ clever routine by Mike Kazar, once a grad-student hacker at
+ CMU: "This routine is so tense it will bring tears to your
+ eyes." A tense programmer is one who produces tense code.
+
+ [{Jargon File}]
+
+tensor product
+
+ <mathematics> A function of two {vector spaces}, U and V,
+ which returns the space of {linear maps} from V's {dual} to U.
+
+ Tensor product has natural symmetry in interchange of U and V
+ and it produces an {associative} "multiplication" on vector
+ spaces.
+
+ Wrinting * for tensor product, we can map UxV to U*V via:
+ (u,v) maps to that linear map which takes any w in V's dual to
+ u times w's action on v. We call this linear map u*v. One
+ can then show that
+
+ u * v + u * x = u * (v+x)
+ u * v + t * v = (u+t) * v
+ and
+ hu * v = h(u * v) = u * hv
+
+ ie, the mapping respects {linearity}: whence any {bilinear
+ map} from UxV (to wherever) may be factorised via this
+ mapping. This gives us the degree of natural symmetry in
+ swapping U and V. By rolling it up to multilinear maps from
+ products of several vector spaces, we can get to the natural
+ associative "multiplication" on vector spaces.
+
+ When all the vector spaces are the same, permutation of the
+ factors doesn't change the space and so constitutes an
+ automorphism. These permutation-induced iso-auto-morphisms
+ form a {group} which is a {model} of the group of
+ permutations.
+
+ (1996-09-27)
+
+tenured graduate student
+
+ <job> One who has been in graduate school for 10 years (the
+ usual maximum is 5 or 6): a "ten-yeared" student (get it?).
+ Actually, this term may be used of any grad student beginning
+ in his seventh year. Students don't really get tenure, of
+ course, the way professors do, but a tenth-year graduate
+ student has probably been around the university longer than
+ any untenured professor.
+
+ [{Jargon File}]
+
+ (1996-09-27)
+
+tera-
+
+ {prefix}
+
+terabyte
+
+ <unit, data> (TB) A unit of {data} equal to one trillion {bytes}.
+ A terabyte is 10^12 bytes or 1000^4 bytes or 1000 {gigabytes}.
+
+ A {terabyte} is roughly the amount of data in 117 {DVDs} (at 8.5
+ {gigabytes} each).
+
+ 1000 terabytes are one {petabyte}.
+
+ (Note the spelling - one 'r'). See {prefix}.
+
+ (2013-11-03)
+
+teraflop
+
+ <unit> 10^12 {flops}.
+
+ Intel beat Hitachi to the record of 1.06 teraflops, on 04 Dec
+ 1996, unofficially in Beverton, Oregon, using 7264 {Pentium
+ Pro} chips.
+
+ (1997-07-21)
+
+teraflop club
+
+ <body> /te'r*-flop kluhb/ (From {tera-} and {flops}) A
+ mythical association of people who consume outrageous amounts
+ of computer time in order to produce a few simple pictures of
+ glass balls with intricate ray-tracing techniques. {Caltech}
+ professor James Kajiya is said to have been the founder.
+
+ [{Jargon File}]
+
+ (1997-07-21)
+
+TERM
+
+ 1. <networking> A program by Michael O'Reilly
+ <michael@iinet.com.au> for people running {Unix} who have
+ {Internet} access via a {dial-up} connection, and who don't
+ have access to {SLIP}, or {PPP}, or simply prefer a more
+ lightweight {protocol}. TERM does end-to-end
+ error-correction, {compression} and {mulplexing} across serial
+ links. This means you can {upload} and {download} files as
+ the same time you're reading your news, and can run {X}
+ {clients} on the other side of your {modem} link, all without
+ needing {SLIP} or {PPP}.
+
+ Latest version: 1.15.
+
+ {(ftp://tartarus.uwa.edu.au/pub/oreillym/term/term115.tar.gz)}.
+
+ 2. <business> {Technology Enabled Relationship Management}.
+
+ (1999-10-04)
+
+TERMAC
+
+ An interactive matrix language.
+
+ ["Users Guide to TERMAC", J.S. Miller et al, MIT Dec 1968].
+
+ (1994-11-04)
+
+termcap
+
+ <operating system> (terminal capabilities) A {Unix} database
+ listing different types of terminal (or {terminal emulation})
+ and the character {strings} to send to make the terminal
+ perform certain functions such as move the {cursor} up one
+ line or clear the screen.
+
+ Programs written using termcap can work on any terminal in the
+ database which supports the necessary functions. Typical
+ programs are {text editors} or file viewers like {more}. The
+ termcap routines look for an {environment variable} "TERM" to
+ determine which terminal the user is using.
+
+ {terminfo} is a later version of termcap.
+
+ (1998-10-30)
+
+terminak
+
+ /ter'mi-nak`/ [Caltech, ca. 1979] Any malfunctioning computer
+ terminal. A common failure mode of Lear-Siegler ADM 3a
+ terminals caused the "L" key to produce the "K" code instead;
+ complaints about this tended to look like "Terminak #3 has a
+ bad keyboard. Pkease fix." See {AIDX}, {Nominal
+ Semidestructor}, {Open DeathTrap}, {ScumOS}, {sun-stools},
+ {Telerat}, {HP-SUX}.
+
+ [{Jargon File}]
+
+ (1995-04-14)
+
+terminal
+
+ 1. <hardware> An electronic or electromechanical device for
+ entering data into a computer or a communications system and
+ displaying data received. Early terminals were called
+ {teletypes}, later ones {VDUs}. Typically a terminal
+ communicates with the computer via a {serial line}.
+
+ 2. <electronics> The end of a {line} where signals are either
+ transmitted or received, or a point along the length of a line
+ where the signals are made available to apparatus.
+
+ 3. <electronics> Apparatus to send and/or receive signals on a
+ {line}.
+
+ (1995-10-02)
+
+Terminal Access Controller
+
+ <hardware, networking> (TAC) A device which connects
+ {terminals} to the {Internet}, usually using dial-up {modem}
+ connections and the {TACACS} {protocol}.
+
+ (1997-11-27)
+
+terminal adapter
+
+ {Terminal Adaptor}
+
+Terminal Adaptor
+
+ <networking, hardware> (TA) Equipment used to adapt
+ {Integrated Services Digital Network} (ISDN) {Basic Rate
+ Interface} (BRI) channels to existing terminal equipment
+ standards such as {EIA-232} and {V.35}. A Terminal Adaptor is
+ typically packaged like a {modem}, either as a {stand-alone}
+ unit or as an interface card that plugs into a computer or
+ other communications equipment (such as a {router} or {PBX}).
+ A Terminal Adaptor does not interoperate with a {modem}; it
+ replaces it.
+
+ [ISDN {FAQ}].
+
+ (1994-10-03)
+
+terminal brain death
+
+ The extreme form of {terminal illness}. What someone who has
+ obviously been hacking continuously for far too long is said
+ to be suffering from.
+
+ [{Jargon File}]
+
+terminal emulation
+
+ What a {terminal emulator} does.
+
+terminal emulator
+
+ <communications> A program that allows a computer to act like
+ a (particular brand of) terminal, e.g. a {vt-100}. The
+ computer thus appears as a terminal to the {host} computer and
+ accepts the same {escape sequences} for functions such as
+ cursor positioning and clearing the screen.
+
+ {xterm} is a terminal emulator for the {X Window System}.
+
+ (1995-02-16)
+
+terminal illness
+
+ {raster burn}
+
+terminal junkie
+
+ (UK) A {wannabee} or early {larval stage} hacker who spends
+ most of his or her time wandering the directory tree and
+ writing {noddy} programs just to get a fix of computer time.
+ Variants include "terminal jockey", "console junkie", and
+ {console jockey}. The term "console jockey" seems to imply
+ more expertise than the other three (possibly because of the
+ exalted status of the {console} relative to an ordinary
+ terminal).
+
+ See also {twink}, {read-only user}.
+
+ [{Jargon File}]
+
+ (1995-02-16)
+
+terminal node
+
+ {leaf}
+
+Terminal Oriented Real Time Operating System
+
+ <operating system> (TORTOS) An {operating system} developed
+ from {MVT} at Health Sciences Computing, UCLA by Dr. Patrica
+ Britt from the late 1960s to the mid 1970s.
+
+ Dr. Britt was a senior scientist at {IBM}, who become the
+ Assistant Director of HSCF.
+
+ TORTOS pre-dated {TSO} and provided {batch}, {real-time} and
+ {time sharing} on an {IBM 360}/91.
+
+ (2004-07-02)
+
+Terminal Oriented Social Science
+
+ <project> (TOSS) The Cambridge Project {Project MAC} was an
+ ARPA-funded political science computing project. They worked
+ on topics like survey analysis and simulation, led by Ithiel
+ de Sola Pool, J.C.R. Licklider and Douwe B. Yntema. Yntema
+ had done a system on the {MIT} Lincoln Labs {TX-2} called the
+ {Lincoln Reckoner}, and in the summer of 1969 led a Cambridge
+ Project team in the construction of an experiment called TOSS.
+ TOSS was like {Logo}, with {matrix} operators. A major
+ feature was multiple levels of {undo}, back to the level of
+ the {login} session. This feature was cheap on the Lincoln
+ Reckoner, but absurdly expensive on {Multics}.
+
+ (1997-01-29)
+
+Terminal Productivity eXecutive
+
+ <operating system> (TPX) A multiple session manager used to
+ access {mainframe} applications. It was written by {Morgan
+ Stanley}, acquired by {Duquesne Systems} and is now owned by
+ {Computer Associates}. TPX allows you to work in multiple
+ mainframe applications concurrently; lock and unlock your TPX
+ screen; place your applications on hold; logon to TPX from a
+ different terminal without losing your place; customize your
+ TPX menu and send a screen image to another TPX user.
+
+ TPX runs on {MVS} and {VM}. On VM, like {VTAM}, it uses the
+ MVS-like facilities of {GCS}. It has a complete {scripting}
+ facility and lets you see other user's sessions. The
+ {client-server} version allows each managed session to open in
+ its own window. Richard Kuebbing has built a complete e-mail
+ system into it.
+
+ {Unicenter CA-TPX
+ (http://www3.ca.com/Solutions/Product.asp?ID=1531)}.
+
+ (2005-09-29)
+
+terminal server
+
+ A device which connects many {terminals} ({serial lines}) to a
+ {local area network} through one network connection. A
+ terminal server can also connect many network users to its
+ asynchronous ports for {dial-out} capabilities and printer
+ access.
+
+ (1995-02-16)
+
+Terminal User Interface
+
+ {Textual User Interface}
+
+Terminate and Stay Resident
+
+ (TSR) A type of {DOS} utility which, once loaded, stays in
+ memory and can be reactivated by pressing a certain
+ combination of keys.
+
+termination analysis
+
+ A program analysis which attempts to determine whether
+ evaluation of a given expression will definitely terminate.
+
+ Evaluation of a constant is bound to terminate, as is
+ evaluation of a non-{recursive} function applied to arguments
+ which are either not evaluated or which can themselves be
+ proved to terminate. A recursive function can be shown to
+ terminate if it can be shown that the arguments of the
+ recursive calls are bound to reach some value at which the
+ recursion will cease.
+
+ Termination analysis can never guarantee to give the correct
+ answer because this would be equivalent to solving the
+ {halting problem} so the answer it gives is either "definitely
+ terminates" or "don't know".
+
+ (1994-10-20)
+
+terminator
+
+ <electronics> A resistor connected to a signal wire in a {bus}
+ or {network} for the purpose of impedance matching to prevent
+ reflections.
+
+ For example, a 50 ohm resistor connected across the end of an
+ {Ethernet} cable. {SCSI} chains and some {LocalTalk} wiring
+ schemes also require terminators.
+
+ (1995-05-17)
+
+term rewriting system
+
+ (TRS) A collection of {rewrite rules} used to transform terms
+ (expressions, strings in some formal language) into equivalent
+ terms. See {reduction}.
+
+ (1994-11-04)
+
+Terms Of Service
+
+ <networking> (TOS) The rules laid down by an on-line service
+ provider such as AOL that members must obey or risk being
+ "TOS-sed" (disconnected).
+
+ (1999-04-02)
+
+ternary
+
+ <programming> A description of an {operator} taking three
+ arguments. The only common example is {C}'s ?: operator which
+ is used in the form "CONDITION ? EXP1 : EXP2" and returns EXP1
+ if CONDITION is true else EXP2. {Haskell} has a similar "if
+ CONDITION then EXP1 else EXP2" operator.
+
+ See also {unary}, {binary}.
+
+ (1998-07-29)
+
+terpri
+
+ /ter'pree/ TERminate PRInt line. [{LISP 1.5} and later,
+ {MacLISP}] To output a {newline}. Still used in {Common
+ LISP}. On some early {operating systems} and hardware, no
+ characters would be printed until a complete line was formed,
+ so this operation terminated the line and emitted the output.
+
+ [{Jargon File}]
+
+ (1996-06-24)
+
+terrabyte
+
+ <spelling> It's spelled "{terabyte}".
+
+ (1997-01-23)
+
+Terse
+
+ Language for decryption of hardware logic.
+
+ ["Hardware Logic Simulation by Compilation", C. Hansen, 25th
+ ACM/IEEE Design Automation Conf, 1988].
+
+test
+
+ <testing> The process of exercising a product to identify
+ differences between expected and actual behaviour. Typically
+ testing is bottom-up: {unit testing} and {integration testing}
+ by developers, {system testing} by testers, and {user
+ acceptance testing} by users.
+
+ {Test coverage} attempts to assess how complete a test has
+ been.
+
+ 2. The second stage in a {generate and test} search
+ {algorithm}.
+
+ [{Jargon File}]
+
+ (2003-09-24)
+
+test coverage
+
+ <testing> A measure of the proportion of a program exercised
+ by a {test suite}, usually expressed as a percentage. This
+ will typically involve collecting information about which
+ parts of a program are actually executed when running the test
+ suite in order to identify which branches of {conditional
+ statements} which have been taken.
+
+ The most basic level of test coverage is {code coverage
+ testing} and the most methodical is {path coverage testing}.
+ Some intermediate levels of test coverage exist, but are
+ rarely used.
+
+ The standard {Unix} tool for measuring test coverage is
+ {tcov}, which annotates {C} or {Fortran} source with the
+ results of a test coverage analysis. {GCT} is a {GNU}
+ equivalent.
+
+ (2001-05-20)
+
+test-driven development
+
+ <programming, testing> (TDD) An iterative {software
+ development} process where each iteration consists
+ of the developer writing an automated {test case}
+ for an unimplemented improvement or function, then
+ producing code to pass that test and finally
+ {refactoring} the code to acceptable standards.
+
+ {Kent Beck}, who is credited with having developed or
+ "rediscovered" the technique, stated in 2003 that TDD
+ encourages simple designs and inspires confidence.
+
+ TDD is related to the humourous definition of programming
+ as the process of {debugging an empty file}.
+
+ (2012-05-01)
+
+testing
+
+ {test}
+
+TET
+
+ Test Environment Toolkit project coordinated by {X/Open}.
+
+TeX
+
+ <publication> /tekh/ An extremely powerful {macro}-based text
+ formatter written by {Donald Knuth}, very popular in academia,
+ especially in the computer-science community (it is good
+ enough to have displaced {Unix} {troff}, the other favoured
+ formatter, even at many {Unix} installations).
+
+ The first version of TeX was written in the programming
+ language {SAIL}, to run on a {PDP-10} under Stanford's {WAITS}
+ {operating system}.
+
+ Knuth began TeX because he had become annoyed at the declining
+ quality of the typesetting in volumes I-III of his monumental
+ "Art of Computer Programming" (see {Knuth}, also {bible}). In
+ a manifestation of the typical hackish urge to solve the
+ problem at hand once and for all, he began to design his own
+ typesetting language. He thought he would finish it on his
+ sabbatical in 1978; he was wrong by only about 8 years. The
+ language was finally frozen around 1985, but volume IV of "The
+ Art of Computer Programming" has yet to appear as of mid-1997.
+ (However, the third edition of volumes I and II have come
+ out). The impact and influence of TeX's design has been such
+ that nobody minds this very much. Many grand hackish projects
+ have started as a bit of {toolsmithing} on the way to
+ something else; Knuth's diversion was simply on a grander
+ scale than most.
+
+ {Guy Steele} happened to be at Stanford during the summer of
+ 1978, when Knuth was developing his first version of TeX.
+ When he returned to {MIT} that fall, he rewrote TeX's {I/O} to
+ run under {ITS}.
+
+ TeX has also been a noteworthy example of free, shared, but
+ high-quality software. Knuth offers monetary awards to people
+ who find and report a bug in it: for each bug the award is
+ doubled. (This has not made Knuth poor, however, as there
+ have been very few bugs and in any case a cheque proving that
+ the owner found a bug in TeX is rarely cashed). Though
+ well-written, TeX is so large (and so full of cutting edge
+ technique) that it is said to have unearthed at least one bug
+ in every {Pascal} system it has been compiled with.
+
+ TeX fans insist on the correct (guttural) pronunciation, and
+ the correct spelling (all caps, squished together, with the E
+ depressed below the baseline; the mixed-case "TeX" is
+ considered an acceptable {kluge} on {ASCII}-only devices).
+ Fans like to proliferate names from the word "TeX" - such as
+ TeXnician (TeX user), TeXhacker (TeX programmer), TeXmaster
+ (competent TeX programmer), TeXhax, and TeXnique.
+
+ Several document processing systems are based on TeX, notably
+ {LaTeX} Lamport TeX - incorporates document styles for books,
+ letters, slides, etc., {jadeTeX} uses TeX as a backend for
+ printing from {James' DSSSL Engine}, and {Texinfo}, the {GNU}
+ document processing system. Numerous extensions to TeX exist,
+ among them {BibTeX} for bibliographies (distributed with
+ LaTeX), {PDFTeX} modifies TeX to produce {PDF} and {Omega}
+ extends TeX to use the {Unicode} character set.
+
+ For some reason, TeX uses its own variant of the {point}, the
+ {TeX point}.
+
+ See also {Comprehensive TeX Archive Network}.
+
+ {(ftp://labrea.stanford.edu/tex/)}.
+
+ E-mail: <tug@tug.org> (TeX User's group, Oregon, USA).
+
+ (2002-03-11)
+
+TeX-78
+
+ <language, text> The original version of {TeX}.
+
+ (1997-11-20)
+
+TeX-82
+
+ <language, text> The version of {TeX} described in The
+ TeXbook, Donald Knuth, A-W 1984.
+
+ (1997-11-20)
+
+Texas Instruments
+
+ <company> (TI) A US electronics company.
+
+ A TI engineer, {Jack Kilby} invented the {integrated circuit}
+ in 1958. Three TI employees left the company in 1982 to start
+ {Compaq}.
+
+ The {COOL} and {OATH} {C++} {class} libraries were developed
+ at TI, as were {PDL2} and the {ASC} computer, {PC-Scheme} and
+ {Texas Instruments Pascal}.
+
+ {(ftp://ti.com/)}.
+
+ (1994-09-26)
+
+Texinfo
+
+ A {GNU} documentation system that uses a single source file to
+ produce both on-line information and printed output. You can
+ read the on-line information, known as an "{Info} file", with
+ an Info documentation-reading program. By convention, Texinfo
+ source file names end with a ".texi" or ".texinfo" extension.
+
+ You can write and format Texinfo files into Info files within
+ {GNU Emacs}, and read them using the Emacs Info reader. If
+ you do not have Emacs, you can format Texinfo files into Info
+ files using "{makeinfo}" and read them using "info". {TeX} is
+ used to typeset Texinfo files for printing.
+
+ Texinfo is available from your nearest {GNU archive site}.
+
+ Latest version: 3.1, as of 1993-03-23.
+
+ (1994-10-05)
+
+TeX point
+
+ <unit, text> The variant of the {point} used by {TeX}, equal
+ to 0.3514598035 mm, or 1/72.27 inch.
+
+ [Why yet another variant?]
+
+ (2002-03-11)
+
+text
+
+ 1. Executable code, especially a "pure code" portion shared
+ between multiple instances of a program running in a
+ {multitasking} {operating system}.
+
+ Compare {English}.
+
+ 2. Textual material in the mainstream sense; data in ordinary
+ {ASCII} or {EBCDIC} representation (see {flat ASCII}). "Those
+ are text files; you can review them using the editor."
+
+ These two contradictory senses confuse hackers too.
+
+ [{Jargon File}]
+
+ (1995-03-16)
+
+text-based
+
+ <jargon> Working under a non-window-based {operating system}
+ (e.g. {MS-DOS}) as opposed to a {graphical user interface}
+ (e.g. {Microsoft Windows}).
+
+ An MS-DOS text-based program uses a screen with a fixed array
+ of 80x25 or 80x40 characters. Examples are {WordPerfect}
+ before version 5.1 and {Microsoft Word}.
+
+ (1995-03-16)
+
+text editor
+
+ <tool, text> A utility program for creating and modifying
+ {text files}. This differs from a {word processor} in that
+ the word processors often embed special control codes or
+ {escape sequences} in the file to control formatting.
+
+ (1996-11-15)
+
+Text Encoding Initiative
+
+ <text, project, standard> (TEI) A project working to establish
+ a standard for interchanging {electronic text} for scholarly
+ research. The TEI has adopted {SGML} and implemented the TEI
+ standard as an SGML {Document Type Definition}.
+
+ The TEI was incorporated as a not-for-profit consortium in
+ December 2000, with host sites in Bergen, Oxford, Virginia,
+ and Providence RI, USA.
+
+ {(http://tei-c.org/)}.
+
+ See also {Corpus Processing}.
+
+ [Any connection with {Computational Linguistics} or {Natural
+ Language Processing}?]
+
+ (2001-03-23)
+
+text file
+
+ <file format> A {file} containing no "invisible" {control
+ characters}, only {printable} letters, numbers and symbols,
+ usually from the {ASCII} {character set}.
+
+ A text file can be produced with a {text editor} and can
+ usually be imported into any {word processor} though it will
+ probably appear unformatted.
+
+ Compare {binary file}, {flat file}, {rich text file}.
+
+ (1996-11-15)
+
+Text Processing Utility
+
+ <language> (TPU) A {DEC} language for creation of
+ text-processing interfaces, used to implement DEC's
+ {Extensible VAX Editor} (EVE).
+
+ (2000-05-08)
+
+Text Reckoning And Compiling
+
+ <language> (TRAC) An interactive macro generator language for
+ string manipulation by Calvin N. Mooers and Peter Deutsch of
+ {Sun Microsystems}. TAC derived ideas from {Macro SAP}.
+ There are versions for {PDP-1}, {PDP-8}, {PDP-10} and
+ {PDP-11}.
+
+ See also {MINT}, {SAM76}.
+
+ E-mail: Preston Briggs <preston@rice.edu>.
+
+ ["TRAC: A Procedure- Describing Language for the Reactive
+ Typewriter", Calvin N. Mooers, CACM 9(3):215-219 (Mar 1966).
+ Rockford Research Inst, 1972].
+
+ [Sammet 1969, pp.448-454].
+
+ ["Macro Processors", A.J. Cole, Cambridge U Press].
+
+ (1994-12-21)
+
+text segment
+
+ {code segment}
+
+Text To Speech
+
+ <application> (TTS) Automatic conversion of text streams to
+ voice.
+
+ [Details?]
+
+ (1997-05-11)
+
+Textual User Interface
+
+ <interface> (TUI) Either a {text-based} version of a {GUI}, or
+ a {full-screen} version of a {CLI}.
+
+ (2003-10-21)
+
+texture
+
+ <graphics> A measure of the variation of the intensity of a
+ surface, quantifying properties such as smoothness, coarseness
+ and regularity. It's often used as a {region descriptor} in
+ {image analysis} and {computer vision}.
+
+ The three principal approaches used to describe texture are
+ statistical, structural and spectral. Statistical techniques
+ characterise texture by the statistical properties of the grey
+ levels of the points comprising a surface. Typically, these
+ properties are computed from the grey level {histogram} or
+ grey level {cooccurrence matrix} of the surface.
+
+ Structural techniques characterise texture as being composed
+ of simple primitives called "texels" (texture elements), that
+ are regularly arranged on a surface according to some rules.
+ These rules are formally defined by {grammars} of various
+ types.
+
+ Spectral techiques are based on properties of the Fourier
+ spectrum and describe global periodicity of the grey levels of
+ a surface by identifying high energy peaks in the spectrum.
+
+ (1995-05-11)
+
+tf
+
+ <networking> The {country code} for French southern
+ territories.
+
+ (1999-01-27)
+
+TFDL
+
+ <language> ["TFDL : A Task-level Dataflow Language",
+ P.A. Suhler et al, J Parallel and Distrib Comput 9:103-115
+ (1990)].
+
+ (1995-05-11)
+
+TFT
+
+ {Thin Film transistor}
+
+TFTP
+
+ {Trivial File Transfer Protocol}
+
+tg
+
+ <networking> The {country code} for Togo.
+
+ (1999-01-27)
+
+TGA
+
+ {Targa Graphics Adaptor}
+
+T-gen
+
+ A general-purpose {object-oriented} tool for the automatic
+ generation of string-to-{object} translators. It was written
+ in {Smalltalk} by Justin Graver <graver@comm.mot.com> and runs
+ in the Smalltalk programming environment. T-gen supports the
+ generation of both {top-down parsers} ({LL parsers}) and
+ {bottom-up parsers} ({LR parsers}), which will automatically
+ generate {derivation trees}, {abstract syntax trees} or
+ arbitrary {Smalltalk} {objects}. The simple specification
+ {syntax} and {graphical user interface} are intended to
+ enhance the learning, comprehension and usefulness of T-gen.
+
+ Latest version: 2.1.
+
+ Runs on {Smalltalk-80}, {ParcPlace Objectworks}/{Smalltalk
+ 4.0} or 4.1.
+
+ {(ftp://st.cs.uiuc.edu/pub/st80_r41/T-gen2.1/)}.
+
+ (1992-10-18)
+
+TGS-II
+
+ Translator Generator System. Contained {TRANDIR}.
+
+ [Sammet 1969, p. 640].
+
+TGS Systems
+
+ <company> Suppliers of {Prograph}.
+
+ Telephone: +1 (902) 429 5642.
+
+ (1995-03-31)
+
+tgz
+
+ <filename extension, compression> (Or less often "taz", Tar
+ GNU zip) A {filename extension} for a file or directory which
+ has been archived with {tar} and then compressed with {gzip}.
+ The full form ".tar.gz" is also common on proper {file
+ systems} not limited to {8.3} file names.
+
+ (1996-11-03)
+
+th
+
+ <networking> The {country code} for Thailand.
+
+ (1999-01-27)
+
+thanks in advance
+
+ <jargon> (Usually "TIA") A conventional {Usenet}
+ net.politeness ending a posted request for information or
+ assistance. Sometimes written "advTHANKSance" or
+ "aTdHvAaNnKcSe".
+
+ [{Jargon File}]
+
+ (1999-02-09)
+
+That's not a bug, that's a feature!
+
+ The {canonical} first parry in a debate about a purported
+ {bug}. The complainant, if unconvinced, is likely to retort
+ that the bug is then at best a {misfeature}.
+
+ See also {feature}.
+
+ [{Jargon File}]
+
+ (1995-02-02)
+
+T.H.E
+
+ <operating system> The {operating system} in which
+ {semaphores} were first used.
+
+ [Details?]
+
+ (1999-10-12)
+
+The Cuckoo's Egg
+
+ A great book (and subsequent BBC TV series) telling the true
+ story of Clifford Stoll, an astronomy professor at {UCB}'s
+ {Lawrence Berkeley Lab}. A 75-cent accounting error alerted
+ him to the presence of an unauthorised user (a {cracker}) on
+ his system. The cracker, code named "Hunter", was breaking
+ into US computer systems and stealing sensitive military and
+ security information. Hunter was part of a spy ring paid in
+ cash and cocaine, and reporting to the KGB.
+
+ ["The Cuckoo's Egg", Clifford Stoll, London: Bodley Head,
+ 1990, ISBN 0-370-31433-6, ISBN 0-671-72688-9].
+
+ [FTP?]
+
+ (1994-11-15)
+
+The Dojo Toolkit
+
+ <library, programming> A modular, {open source} {JavaScript}
+ library. Dojo is designed for easy development of JavaScript-
+ or {AJAX} based applications and websites. It is supported
+ by the Dojo Foundation, which is sponsored by {IBM}, {AOL},
+ {Sun} and others.
+
+ The name is from the Japanese term meaning "place of the way",
+ used for a formal place of training.
+
+ (2008-07-23)
+
+The Force
+
+ A {data parallel} language by Harry Jordan
+ <harry@boulder.colorado.edu> which extends {Fortran} for
+ {shared memory} {multiprocessors}. It features parallel
+ "case" statements and {critical sections}.
+
+ ["The Force", H. Jordan, in "The Characteristics of Parallel
+ Algorithms", L. Jamieson et al eds, MIT Press 1987,
+ pp. 395-436].
+
+ (1994-12-14)
+
+The Internet Account
+
+ An {Internet} provider in Sydney, Australia who provides
+ {SLIP}, {PPP} and {CLI} accounts for the same rates.
+ <riscman@geko.com.au> handles {Acorn} software.
+
+ {(http://geko.com.au/)}.
+
+ {(ftp://ftp.geko.com.au/pub/)}.
+
+ E-mail: <accounts@geko.com.au>.
+
+ Telephone: +61 (2) 968 4333. Fax: +61 (2) 968 4334.
+
+ Address: PO BOX 473, Crows Nest, NSE 2065, Australia.
+
+ (1995-02-02)
+
+The MathWorks, Inc.
+
+ <company> The company marketing {MATLAB}.
+
+ {(http://mathworks.com/)}.
+
+ E-mail: <info@mathworks.com>.
+
+ Address: 3 Apple Hill Drive, Natick, Massachusetts 01760-2098 USA.
+
+ Telephone: +1 (508) 647-7000. Fax: +1 (508) 647-7101.
+
+ (2005-08-13)
+
+The Metadata Company
+
+ <company> A company founded by Jack E. Myers, originally known
+ as Metadata Information Partners. Myers trademarked the word
+ "Metadata" (unhyphenated with initial capital, as opposed to
+ the general term {metadata}) to represent
+ implementations of his {MetaModel} and to designate his
+ company.
+
+ Myers claims that a data and publication search in the summer
+ of 1969 failed to discover any use either of the word
+ "metadata" or "meta data".
+
+ {(http://metadata.com/)}.
+
+ E-mail: <metadata@metadata.com>.
+
+ Address: 444 West Ocean Blvd, Suite 1600, Long Beach CA 90802,
+ USA.
+
+ (2010-05-15)
+
+The Microsoft Network
+
+ <networking> (MSN) {Microsoft}'s {ISP} and online content
+ service, launched in October 1996. Not to be confused with
+ {Microsoft Networking}.
+
+ MSN was originally based on custom software and protocols,
+ however Microsoft saw the error of their ways and adopted
+ Internet standards. MSN now provides standard {WWW} and
+ {email} facilities, albeit with Microsoft's {Internet
+ Explorer} {web-browser} and the {Outlook Express} email
+ software.
+
+ The service also provides "Community Services" including
+ {newsgroups}, {forums}, and {chat}.
+
+ {(http://msn.com/)}.
+
+ (1998-08-11)
+
+The Mythical Man-Month
+
+ <publication> Fred Brooks's excellent 1975 book on {software
+ engineering}.
+
+ See also {Brooks's Law}.
+
+ ["The Mythical Man-Month: Essays on Software Engineering",
+ Fred Brooks, Addison-Wesley, 1975, ISBN 0-201-00650-2].
+
+ (1996-06-20)
+
+The Network
+
+ {network, the}
+
+THEO
+
+ A {frame language}.
+
+ ["Theo: A Framework for Self-Improving Systems", Mitchell et
+ al, in Architectures for Intelligence, K. VanLehn ed, Erlbaum,
+ 1989].
+
+ (1994-12-14)
+
+theology
+
+ 1. Ironically or humorously used to refer to {religious
+ issues}.
+
+ 2. Technical fine points of an abstruse nature, especially
+ those where the resolution is of theoretical interest but is
+ relatively {marginal} with respect to actual use of a design
+ or system. Used especially around software issues with a
+ heavy AI or language-design component, such as the smart-data
+ vs. smart-programs dispute in AI.
+
+ [{Jargon File}]
+
+The Open Group
+
+ <body> (Formerly "X/Open") A vendor- and technology-neutral
+ consortium of buyers and suppliers of {information systems}
+ that aims to ease integration by testing and certifying
+ products against {open standards}.
+
+ {The Open Group Home (http://opengroup.org)}.
+
+ (2006-07-13)
+
+theory
+
+ The consensus, idea, plan, story, or set of rules that is
+ currently being used to inform a behaviour. This usage is a
+ generalisation and (deliberate) abuse of the technical
+ meaning. "What's the theory on fixing this TECO loss?"
+ "What's the theory on dinner tonight?" ("Chinatown, I
+ guess.") "What's the current theory on letting lusers on
+ during the day?" "The theory behind this change is to fix the
+ following well-known screw...."
+
+ (1994-12-14)
+
+theory change
+
+ <artificial intelligence> The study of methods used to
+ incorporate new information into a {knowledge base} when the
+ new information may conflict with existing information.
+
+ {Belief revision} is one area of theory change.
+
+ [Others?]
+
+ (1995-03-20)
+
+The Real-Time Operating System Nucleus
+
+ <project> (TRON) A project to develop an {operating system}
+ and {man-machine interface} that can work with other operating
+ systems to provide an environment for many small distributed
+ computers to cooperate in {real time}. TRON is headed by
+ Dr. Ken Sakamura of the {University of Tokyo} and supported by
+ most of the major Japanese computer makers and {NTT}.
+
+ {(http://atip.org/public/atip.reports.91/tron.html)}.
+
+ (2003-05-23)
+
+There's More Than One Way To Do It
+
+ <programming, philosophy> (TMTOWTDI) One of the design principles
+ of {Perl}. The Perl {man page} ends with a note:
+
+ The Perl motto is "There's more than one way to do it."
+ Divining how many more is left as an exercise to the reader.
+
+ (2001-03-15)
+
+Theseus
+
+ <language> A language based on {Euclid}, never implemented.
+
+ ["Theseus - A Programming Language for Relational Databases",
+ J.E. Shopiro, ACM Trans Database Sys 4(4):493-517, Mar 1979].
+
+ (1994-12-14)
+
+The story of Mel
+
+ {The story of Mel, a Real Programmer}
+
+The story of Mel, a Real Programmer
+
+ <programming, person> A 1983 article by Ed Nather about {hacker}
+ {Mel Kaye}. The full text follows.
+
+ A recent article devoted to the macho side of programming made
+ the bald and unvarnished statement, "Real Programmers write in
+ FORTRAN".
+
+ Maybe they do now, in this decadent era of Lite beer, hand
+ calculators and "user-friendly" software but back in the Good
+ Old Days, when the term "software" sounded funny and Real
+ Computers were made out of {drums} and {vacuum tubes}, Real
+ Programmers wrote in {machine code} - not {Fortran}, not
+ {RATFOR}, not even {assembly language} - {Machine Code}, raw,
+ unadorned, inscrutable {hexadecimal} numbers, directly.
+
+ Lest a whole new generation of programmers grow up in
+ ignorance of this glorious past, I feel duty-bound to
+ describe, as best I can through the generation gap, how a Real
+ Programmer wrote code. I'll call him Mel, because that was
+ his name.
+
+ I first met Mel when I went to work for {Royal McBee Computer
+ Corporation}, a now-defunct subsidiary of the typewriter company.
+ The firm manufactured the {LGP-30}, a small, cheap (by the
+ standards of the day) {drum}-memory computer, and had just
+ started to manufacture the RPC-4000, a much-improved, bigger,
+ better, faster -- drum-memory computer. Cores cost too much,
+ and weren't here to stay, anyway. (That's why you haven't
+ heard of the company, or the computer.)
+
+ I had been hired to write a {Fortran} compiler for this new
+ marvel and Mel was my guide to its wonders. Mel didn't
+ approve of compilers.
+
+ "If a program can't rewrite its own code," he asked, "what
+ good is it?"
+
+ Mel had written, in {hexadecimal}, the most popular computer
+ program the company owned. It ran on the {LGP-30} and played
+ blackjack with potential customers at computer shows. Its
+ effect was always dramatic. The LGP-30 booth was packed at
+ every show, and the IBM salesmen stood around talking to each
+ other. Whether or not this actually sold computers was a
+ question we never discussed.
+
+ Mel's job was to re-write the blackjack program for the
+ {RPC-4000}. ({Port}? What does that mean?) The new computer
+ had a one-plus-one addressing scheme, in which each machine
+ instruction, in addition to the {operation code} and the
+ address of the needed {operand}, had a second address that
+ indicated where, on the revolving drum, the next instruction
+ was located. In modern parlance, every single instruction was
+ followed by a {GO TO}! Put *that* in {Pascal}'s pipe and
+ smoke it.
+
+ Mel loved the RPC-4000 because he could optimize his code:
+ that is, locate instructions on the drum so that just as one
+ finished its job, the next would be just arriving at the "read
+ head" and available for immediate execution. There was a
+ program to do that job, an "optimizing assembler", but Mel
+ refused to use it.
+
+ "You never know where its going to put things", he explained,
+ "so you'd have to use separate constants".
+
+ It was a long time before I understood that remark. Since Mel
+ knew the numerical value of every operation code, and assigned
+ his own drum addresses, every instruction he wrote could also
+ be considered a numerical constant. He could pick up an
+ earlier "add" instruction, say, and multiply by it, if it had
+ the right numeric value. His code was not easy for someone
+ else to modify.
+
+ I compared Mel's hand-optimised programs with the same code
+ massaged by the optimizing assembler program, and Mel's always
+ ran faster. That was because the "{top-down}" method of
+ program design hadn't been invented yet, and Mel wouldn't have
+ used it anyway. He wrote the innermost parts of his program
+ loops first, so they would get first choice of the optimum
+ address locations on the drum. The optimizing assembler
+ wasn't smart enough to do it that way.
+
+ Mel never wrote time-delay loops, either, even when the balky
+ {Flexowriter} required a delay between output characters to
+ work right. He just located instructions on the drum so each
+ successive one was just *past* the read head when it was
+ needed; the drum had to execute another complete revolution to
+ find the next instruction. He coined an unforgettable term
+ for this procedure. Although "optimum" is an absolute term,
+ like "unique", it became common verbal practice to make it
+ relative: "not quite optimum" or "less optimum" or "not very
+ optimum". Mel called the maximum time-delay locations the
+ "most pessimum".
+
+ After he finished the blackjack program and got it to run,
+ ("Even the initialiser is optimised", he said proudly) he got
+ a Change Request from the sales department. The program used
+ an elegant (optimised) {random number generator} to shuffle
+ the "cards" and deal from the "deck", and some of the salesmen
+ felt it was too fair, since sometimes the customers lost.
+ They wanted Mel to modify the program so, at the setting of a
+ sense switch on the console, they could change the odds and
+ let the customer win.
+
+ Mel balked. He felt this was patently dishonest, which it
+ was, and that it impinged on his personal integrity as a
+ programmer, which it did, so he refused to do it. The Head
+ Salesman talked to Mel, as did the Big Boss and, at the boss's
+ urging, a few Fellow Programmers. Mel finally gave in and
+ wrote the code, but he got the test backward, and, when the
+ sense switch was turned on, the program would cheat, winning
+ every time. Mel was delighted with this, claiming his
+ subconscious was uncontrollably ethical, and adamantly refused
+ to fix it.
+
+ After Mel had left the company for greener pa$ture$, the Big
+ Boss asked me to look at the code and see if I could find the
+ test and reverse it. Somewhat reluctantly, I agreed to look.
+ Tracking Mel's code was a real adventure.
+
+ I have often felt that programming is an art form, whose real
+ value can only be appreciated by another versed in the same
+ arcane art; there are lovely gems and brilliant coups hidden
+ from human view and admiration, sometimes forever, by the very
+ nature of the process. You can learn a lot about an
+ individual just by reading through his code, even in
+ hexadecimal. Mel was, I think, an unsung genius.
+
+ Perhaps my greatest shock came when I found an innocent loop
+ that had no test in it. No test. *None*. Common sense said
+ it had to be a closed loop, where the program would circle,
+ forever, endlessly. Program control passed right through it,
+ however, and safely out the other side. It took me two weeks
+ to figure it out.
+
+ The RPC-4000 computer had a really modern facility called an
+ {index register}. It allowed the programmer to write a
+ program loop that used an indexed instruction inside; each
+ time through, the number in the index register was added to
+ the address of that instruction, so it would refer to the next
+ datum in a series. He had only to increment the index
+ register each time through. Mel never used it.
+
+ Instead, he would pull the instruction into a machine
+ register, add one to its address, and store it back. He would
+ then execute the modified instruction right from the register.
+ The loop was written so this additional execution time was
+ taken into account -- just as this instruction finished, the
+ next one was right under the drum's read head, ready to go.
+ But the loop had no test in it.
+
+ The vital clue came when I noticed the index register bit, the
+ bit that lay between the address and the operation code in the
+ instruction word, was turned on-- yet Mel never used the index
+ register, leaving it zero all the time. When the light went
+ on it nearly blinded me.
+
+ He had located the data he was working on near the top of
+ memory -- the largest locations the instructions could address
+ -- so, after the last datum was handled, incrementing the
+ instruction address would make it overflow. The carry would
+ add one to the operation code, changing it to the next one in
+ the instruction set: a jump instruction. Sure enough, the
+ next program instruction was in address location zero, and the
+ program went happily on its way.
+
+ I haven't kept in touch with Mel, so I don't know if he ever
+ gave in to the flood of change that has washed over
+ programming techniques since those long-gone days. I like to
+ think he didn't. In any event, I was impressed enough that I
+ quit looking for the offending test, telling the Big Boss I
+ couldn't find it. He didn't seem surprised.
+
+ When I left the company, the blackjack program would still
+ cheat if you turned on the right sense switch, and I think
+ that's how it should be. I didn't feel comfortable hacking up
+ the code of a Real Programmer."
+
+ [Posted to {Usenet} by its author, Ed Nather <utastro!nather>, on
+ 1983-05-21].
+
+ {Jargon File
+ (http://www.catb.org/jargon/html/story-of-mel.html)}.
+
+ [{On the trail of a Real Programmer
+ (http://www.jamtronix.com/blog/2011/03/25/on-the-trail-of-a-real-programmer/)},
+ 2011-03-25 blog post by "jonno" at Jamtronix]
+
+ [When did it happen? Did Mel use hexadecimal or octal?]
+
+ (2003-09-12)
+
+The World Of Cryton
+
+ (TWOC) A {BBS} for the {Acorn} {Archimedes}.
+
+ Telephone: +44 (1749) 670 030 (24hrs, most speeds).
+
+ (1994-11-08)
+
+the X that can be Y is not the true X
+
+ Yet another instance of hackerdom's peculiar attraction to
+ mystical references - a common humorous way of making
+ exclusive statements about a class of things. The template is
+ from the "Tao te Ching": "The Tao which can be spoken of is
+ not the true Tao." The implication is often that the X is a
+ mystery accessible only to the enlightened. See the
+ {trampoline} entry for an example, and compare {has the X
+ nature}.
+
+ [{Jargon File}]
+
+thicket
+
+ <jargon> Multiple {files} output from some operation.
+
+ The term has been heard in use at {Microsoft} to describe the
+ set of {files} output when {Microsoft Word} does "Save As a
+ {Web} Page" or "Save as {HTML}". The process can result in a
+ main {XML} or {HTML} {file}, a {graphic} {file} for each
+ {image} in the original, a {CSS} {file}, etc.
+
+ This can be an issue as {XML} can be used as the default
+ format in {Office 2000}, and {document management systems}
+ can't yet cope with the relationship between the {files} in a
+ thicket when checking in and out.
+
+ (2001-09-01)
+
+thick Ethernet cable
+
+ {RG8}
+
+thick film dielectric electroluminescence
+
+ <hardware> (TDEL) A phenomenon used in some {flat panel}
+ displays.
+
+ (2007-06-04)
+
+thicknet
+
+ {10base5}
+
+thin client
+
+ <networking> A simple {client} program or hardware device
+ which relies on most of the function of the system being in
+ the {server}.
+
+ {Gopher} clients, for example, are very thin; they are
+ {stateless} and are not required to know how to interpret and
+ display objects much more complex than menus and plain text.
+ Gopher servers, on the other hand, can search {databases} and
+ provide {gateways} to other services.
+
+ By the mid-1990s, the model of decentralised computing where
+ each user has his own full-featured and independent
+ {microcomputer}, seemed to have displaced a centralised model
+ in which multiple users use thin clients (e.g. {dumb
+ terminals}) to work on a shared {minicomputer} or {mainframe}
+ server. Networked {personal computers} typically operate as
+ "fat clients", often providing everything except some file
+ storage and printing locally.
+
+ By 1996, reintroduction of thin clients is being proposed,
+ especially for {LAN}-type environments (see the {cycle of
+ reincarnation}). The main expected benefit of this is ease of
+ maintenance: with fat clients, especially those suffering from
+ the poor networking support of {Microsoft} {operating
+ systems}, installing a new application for everyone is likely
+ to mean having to physically go to every user's workstation to
+ install the application, or having to modify client-side
+ configuration options; whereas with thin clients the
+ maintenance tasks are centralised on the server and so need
+ only be done once.
+
+ Also, by virtue of their simplicity, thin clients generally
+ have fewer hardware demands, and are less open to being
+ screwed up by ambitious {lusers}.
+
+ Never one to miss a bandwagon, Microsoft bought up {Insignia
+ Solutions, Inc.}'s "{NTRIGUE}" Windows remote-access product
+ and combined it with {Windows NT} version 4 to allow thin
+ clients (either hardware or software) to communicate with
+ applications running under on a server machine under {Windows
+ Terminal Server} in the same way as {X} had done for {Unix}
+ decades before.
+
+ (1999-02-01)
+
+thin Ethernet cable
+
+ {RG58}
+
+ThingLab
+
+ A {simulation} system written in {Smalltalk-80}. It solves
+ {constraints} using {value inference}.
+
+ Version: ThingLab II.
+
+ ["The Programming Language Aspects of ThingLab, A
+ Constraint-Oriented Simulation Laboratory", A. Borning, ACM
+ TOPLAS 3(4):353-387 (Oct 1981)].
+
+Think C
+
+ An extension of {ANSI C} for the {Macintosh} by {Symantec
+ Corporation}. It supports {object-oriented} programming
+ techniques similar to {C++}.
+
+Thinking Machines Corporation
+
+ <company> The company that introduced the {Connection Machine
+ parallel computer} ca 1984. Four of the world's ten most
+ powerful {supercomputers} are Connection Machines. Thinking
+ Machines is the leader in scalable computing, with software
+ and applications running on parallel systems ranging from 16
+ to 1024 processors. In developing the Connection Machine
+ system, Thinking Machines also did pioneering work in parallel
+ software.
+
+ The 1993 technical applications market for massively parallel
+ systems was approximately $310 million, of which Thinking
+ Machines Corporation held a 29 percent share. Thinking
+ Machines planned to become a software provider by 1996, by
+ which time the parallel computing market was expected to have
+ grown to $2 billion.
+
+ Thinking Machines Corporation has 200 employees and offices
+ worldwide.
+
+ Address: 245 First Street, Cambridge, MA 02142-1264, USA.
+ Telephone: +1 (617) 234 1000. Fax: +1 (617) 234 4444.
+
+ (1994-12-01)
+
+thinko
+
+ <jargon> /thing'koh/ (Or "braino", by analogy with "{typo}") A
+ momentary, correctable {glitch} in mental processing,
+ especially one involving recall of information learned by
+ rote; a bubble in the stream of consciousness.
+
+ See also {brain fart}. Compare {mouso}.
+
+ [{Jargon File}]
+
+ (1996-04-20)
+
+thinnet
+
+ {cheapernet}
+
+third generation computer
+
+ <architecture> A computer built with small-scale integration
+ {integrated circuits}, designed after the mid-1960s.
+
+ Third generation computers use {semiconductor} memories in
+ addition to, and later instead of, {ferrite core memory}. The
+ two main types of semiconductor memory are {Read-Only Memory}
+ (ROM) and read-and-write memories called {random-access
+ memory} (RAM).
+
+ A technique called {microprogramming} became widespread and
+ simplified the design of the {CPUs} and increased their
+ flexibility. This also made possible the development of
+ {operating systems} as {software} rather than as hard-wiring.
+
+ A variety of techniques for improving processing efficiency
+ were invented, such as {pipelining}, (parallel operation of
+ {functional units} processing a single instruction), and
+ {multiprocessing} (concurrent execution of multiple programs).
+
+ As the execution of a program requires that program to be in
+ memory, the concurrent running of several programs requires
+ that all programs be in memory simultaneously. Thus the
+ development of techniques for concurrent processing was
+ matched by the development of {memory management} techniques
+ such as {dynamic memory allocation}, {virtual memory}, and
+ {paging}, as well as {compilers} producing {relocatable code}.
+
+ The {LILLIAC IV} is an example of a third generation computer.
+
+ The CTSS ({Compatible Time-Sharing System}) was developed at
+ {MIT} in the early 1960s and had a considerable influence on
+ the design of subsequent timesharing operating systems.
+
+ An interesting contrasting development in this generation was
+ the start of mass production of small low-cost
+ "{minicomputers}".
+
+third generation language
+
+ <language> (3GL, "{high level language}") A language designed
+ to be easier for a human to understand, including things like
+ named variables. A fragment might be
+
+ let c = c + 2 * d
+
+ Fortran, ALGOL and COBOL are early examples of this sort of
+ language. Most "modern" languages ({BASIC}, {C}, {C++}) are
+ third generation. Most 3GLs support {structured programming}.
+
+ See also {second generation language}, {fourth generation
+ language}.
+
+ (1996-05-30)
+
+third normal form
+
+ {database normalisation}
+
+This can't happen
+
+ {can't happen}
+
+this dictionary
+
+ {Free On-line Dictionary of Computing}
+
+This time, for sure!
+
+ <exclamation> Ritual affirmation frequently uttered during
+ protracted {debugging} sessions involving numerous small
+ obstacles (e.g. attempts to bring up a {UUCP} connection). For
+ the proper effect, this must be uttered in a fruity imitation
+ of Bullwinkle J. Moose.
+
+ Also heard: "Hey, Rocky! Watch me pull a rabbit out of my
+ hat!" The {canonical} response is, of course, "But that trick
+ *never* works!"
+
+ See {hacker humour}.
+
+ [{Jargon File}]
+
+ (1995-09-27)
+
+thn
+
+ {thumbnail}
+
+Thomas
+
+ <language> A language compatible with the language
+ {Dylan}(TM). Thomas is NOT {Dylan}(TM).
+
+ The first public release of a translator to {Scheme} by Matt
+ Birkholz, Jim Miller, and Ron Weiss, written at {Digital
+ Equipment Corporation}'s {Cambridge Research Laboratory} runs
+ (slowly) on {MIT}'s {CScheme}, DEC's {Scheme->C}, Marc
+ Feeley's {Gambi}, {Macintosh}, {PC}, {Vax}, {MIPS}, {Alpha},
+ {680x0}.
+
+ {(ftp://gatekeeper.pa.dec.com/pub/DEC/Thomas)}.
+
+ Mailing list: <info-thomas@crl.dec.com>.
+
+ ["Dylan(TM) an object-oriented dynamic language", {Apple
+ Computer}, Eastern Research and Technology, April 1992].
+
+ (1992-09-11)
+
+thrash
+
+ To move wildly or violently, without accomplishing anything
+ useful. {Paging} or {swapping} systems that are overloaded
+ waste most of their time moving data into and out of {core}
+ (rather than performing useful computation) and are therefore
+ said to thrash. Thrashing can also occur in a {cache} due to
+ {cache conflict} or in a {multiprocessor} (see {ping-pong}).
+
+ Someone who keeps changing his mind (especially about what to
+ work on next) is said to be thrashing. A person frantically
+ trying to execute too many tasks at once (and not spending
+ enough time on any single task) may also be described as
+ thrashing.
+
+ Compare {multitask}.
+
+ [{Jargon File}]
+
+thrashing
+
+ {thrash}
+
+thread
+
+ 1. See {multithreading}.
+
+ 2. See {threaded code}.
+
+ 3. {topic thread}.
+
+ [{Jargon File}]
+
+threaded
+
+ {thread}
+
+threaded code
+
+ <programming> A technique for implementing {virtual machine}
+ {interpreters}, introduced by J.R. Bell in 1973, where each
+ {op-code} in the virtual machine {instruction set} is the
+ address of some (lower level) code to perform the required
+ operation. This kind of virtual machine can be implemented
+ efficiently in {machine code} on most processors by simply
+ performing an {indirect jump} to the address which is the next
+ instruction.
+
+ Many {Forth} implementations use threaded code and nowadays
+ some use the term "threading" for almost any technique used to
+ implement Forth's virtual machine.
+
+ {(http://complang.tuwien.ac.at/forth/threaded-code.html)}.
+
+ ["James R. Bell", "Threaded Code", CACM, 1973, 16, 6, pp
+ 370-372].
+
+ ["An Architectural Trail to Threaded Code Systems", Kogge,
+ P. M., IEEE Computer, March 1982].
+
+ (1998-09-02)
+
+threading
+
+ {thread}
+
+Thread Language Zero
+
+ <language> (TL0) The {instruction set} of the TAM ({Threaded
+ Abstract Machine}), used to implement {Id}.
+
+ ["Fine-grain Parallelism with Minimal Hardware Support", David
+ Culler et al, SIGPLAN Notices 26(4):164-175, ASPLOS-IV Proc,
+ Apr 1991].
+
+ (1995-03-13)
+
+thread-safe
+
+ <programming> A description of code which is either
+ {re-entrant} or protected from multiple simultaneous execution
+ by some form of {mutual exclusion}.
+
+ (1997-01-30)
+
+three-finger salute
+
+ {Vulcan nerve pinch}
+
+three-letter acronym
+
+ <jargon> (TLA) The {canonical}, self-describing {acronym} for the
+ name of a species with which computing terminology is infested.
+ Examples include {MCA}, {FTP}, {SNA}, {CPU}, {MMU}, {DMU}, {FPU},
+ {TLA}.
+
+ This dictionary contains many {TLAs}.
+
+ Sometimes used by extension for any confusing acronym. People
+ who like this looser usage argue that not all TLAs have three
+ letters, just as not all four-letter words have four letters.
+ One also hears of "ETLA" (Extended Three-Letter Acronym) being
+ used to describe four-letter acronyms. The term "SFLA"
+ (Stupid Four-Letter Acronym) has also been reported.
+
+ See also {YABA}.
+
+ The self-effacing phrase "TDM TLA" (Too Damn Many...) is used to
+ bemoan the plethora of TLAs in use. In 1989, a random of the
+ journalistic persuasion asked hacker Paul Boutin "What do you
+ think will be the biggest problem in computing in the 90s?"
+ Paul's straight-faced response: "There are only 17,000
+ three-letter acronyms." (To be exact, there are 26^3 = 17,576.)
+
+ (2014-08-14)
+
+three-tier
+
+ <architecture> A {client-server} architecture in which the
+ {user interface}, functional process logic ("business rules")
+ and data storage and access are developed and maintained as
+ independent {modules}, most often on separate {platforms}.
+
+ Apart from the usual advantages of modular software with well
+ defined interfaces, the three-tier architecture is intended to
+ allow any of the three tiers to be upgraded or replaced
+ independently as requirements or technology change. For
+ example, an upgrade of desktop {operating system} from
+ {Microsoft Windows} to {Unix} would only affect the {user
+ interface} code.
+
+ Typically, the user interface runs on a desktop {PC} or
+ {workstation} and uses a standard {graphical user interface},
+ functional process logic may consist of one or more separate
+ modules running on a {workstation} or application {server},
+ and an {RDBMS} on a database server or {mainframe} contains
+ the data storage logic. The middle tier may be multi-tiered
+ itself (in which case the overall architecture is called an
+ "n-tier architecture").
+
+ (1998-05-13)
+
+throughput
+
+ 1. The rate at which a processor can work expressed in
+ instructions per second or jobs per hour or some other unit of
+ performance.
+
+ 2. <communications> {data transfer rate}.
+
+ (2001-05-22)
+
+thud
+
+ 1. Yet another {metasyntactic variable} (see {foo}). It is
+ reported that at {CMU} from the mid-1970s the canonical series
+ of these was "foo", "bar", "thud", "blat".
+
+ 2. Rare term for the hash character, "#" (ASCII 35). See
+ {ASCII} for other synonyms.
+
+ [{Jargon File}]
+
+Thumb
+
+ <processor> An extension to the {Advanced RISC Machine}
+ architecture, announced on 06 March 1995 by {Advanced RISC
+ Machines} Ltd. By identifying the critical subset of the ARM
+ {instruction set} and encoding it into 16 bits, ARM has
+ succeeded in reducing typical program size by 30-40% from
+ ARM's already excellent code density. Since this Thumb
+ instruction set uses less memory for program storage, cost is
+ further reduced.
+
+ All Thumb-aware {processor cores} combine the capability to
+ execute both the 32-bit ARM and the 16-bit Thumb instruction
+ sets. Careful design of the Thumb instructions allow them to
+ be decompressed into full ARM instructions transparently
+ during normal instruction decoding without any performance
+ penalty. This differs from other 32-bit processors, like the
+ {Intel 486SX}, with a 16-bit data bus, which require two
+ 16-bit memory accesses to execute every 32-bit instruction and
+ so halve performance.
+
+ The patented Thumb decompressor has been carefully designed
+ with only a small amount of circuitry additional to the
+ existing instruction decoder, so chip size and thus cost do
+ not significantly increase. Designers can easily interleave
+ fast ARM instructions (for performance critical parts of a
+ program) with compact Thumb code to save memory.
+
+ (1995-03-14)
+
+thumb
+
+ <jargon> The slider or "bubble" on a window system
+ {scrollbar}. So called because moving it allows you to browse
+ through the contents of a text window in a way analogous to
+ thumbing through a book.
+
+ [{Jargon File}]
+
+ (1995-03-14)
+
+thumbnail
+
+ <file format, graphics> (From "thumbnail sketch") A file
+ format used by {Graphics Workshop} for {Microsoft Windows}.
+ {Filename extension}: ".thn".
+
+ [What's in the files?]
+
+ (1996-05-28)
+
+Thunderbird
+
+ <messaging, open source> A complete {free}, {open-source}
+ {e-mail client} from the {Mozilla Foundation} and therefore a
+ true code descendent of the e-mail code in {Netscape
+ Navigator}. The first non-{beta release} was in late 2004.
+ The {Firefox} web browser is from the same source.
+
+ {Thunderbird Home
+ (http://mozilla.org/products/thunderbird)}.
+
+ (2005-01-26)
+
+thunk
+
+ <programming> /thuhnk/ 1. "A piece of coding which provides an
+ address", according to P. Z. Ingerman, who invented thunks in
+ 1961 as a way of binding {actual parameters} to their formal
+ definitions in {ALGOL 60} {procedure} calls. If a procedure
+ is called with an expression in the place of a {formal
+ parameter}, the compiler generates a thunk which computes the
+ expression and leaves the address of the result in some
+ standard location.
+
+ 2. The term was later generalised to mean an expression,
+ frozen together with its {environment} (variable values), for
+ later evaluation if and when needed (similar to a
+ "{closure}"). The process of unfreezing these thunks is
+ called "forcing".
+
+ 3. A {stubroutine}, in an {overlay} programming environment,
+ that loads and jumps to the correct overlay.
+
+ Compare {trampoline}.
+
+ There are a couple of onomatopoeic myths circulating about the
+ origin of this term. The most common is that it is the sound
+ made by data hitting the {stack}; another holds that the sound
+ is that of the data hitting an {accumulator}. Yet another
+ suggests that it is the sound of the expression being unfrozen
+ at argument-evaluation time. In fact, according to the
+ inventors, it was coined after they realised (in the wee hours
+ after hours of discussion) that the type of an argument in
+ {ALGOL 60} could be figured out in advance with a little
+ {compile-time} thought, simplifying the evaluation machinery.
+ In other words, it had "already been thought of"; thus it was
+ christened a "thunk", which is "the past tense of "think" at
+ two in the morning".
+
+ 4. ({Microsoft Windows} programming) {universal thunk},
+ {generic thunk}, {flat thunk}.
+
+ [{Jargon File}]
+
+ (1997-10-11)
+
+TIA
+
+ 1. <chat> Thanks in advance.
+
+ 2. <body> {Telecommunications Industry Association}.
+
+ 3. <software> The {Internet Adapter}.
+
+ 4. <graphics, hardware> {Television Interface Adaptor}.
+
+ (1999-12-06)
+
+tick
+
+ 1. A {jiffy} (sense 1). 2. In simulations, the discrete unit
+ of time that passes between iterations of the simulation
+ mechanism. In AI applications, this amount of time is often
+ left unspecified, since the only constraint of interest is the
+ ordering of events. This sort of AI simulation is often
+ pejoratively referred to as "tick-tick-tick" simulation,
+ especially when the issue of simultaneity of events with long,
+ independent chains of causes is {handwave}d. 3. In the FORTH
+ language, a single quote character.
+
+ [{Jargon File}]
+
+TickIT
+
+ A software industry quality assessment scheme.
+
+Tickle
+
+ <text, tool> A {text editor}, file translator and {TCL}
+ {interpreter} for the {Macintosh}.
+
+ Version 5.0v1. The text editor breaks the 32K limit (like
+ {MPW}).
+
+ The file translation utilities support {drag and drop}
+ handling via tcl scripts of {BinHex}, {MacBinary}, {Apple
+ Computer} Single/Double, {StuffIt} (with engine), {Unix}
+ {compress}, {Unix} {tar} and {UUencode} files as well as text
+ translation.
+
+ Tickle implements tcl 7.0 with {tclX} extensions and
+ {Macintosh} equivalents of {Unix}'s {ls}, {pwd}, {cd}
+ commands. It provides Macintosh access to {Resource Manager},
+ {Communications Toolbox}, {OSA} Components (and
+ {AppleScript}), {Editions} (publish and subscribe) and {Apple
+ Events} (including AEBuild and AEPrint). {OSA Script} support
+ allows programming of any OSA scripting component within
+ Tickle interpreter windows. It provides the OSAtcl and OSAJ
+ {J}/{APL} extensions and creates "Ticklets" which are small
+ {application programs} that carry only the tcl script and use
+ code in the OSAtcl component to drive an application that
+ allows {drag and drop} with tcl scripts. Tickle is scriptable
+ and recordable.
+
+ {(ftp://ftp.msen.com/pub/vendor/ice/tickle/Tickle5.0v1.hqx)}.
+
+ E-mail: <time@ice.com>.
+
+ (1994-10-12)
+
+tickle a bug
+
+ To cause a normally hidden bug to manifest itself through some
+ known series of inputs or operations. "You can tickle the bug
+ in the Paradise VGA card's highlight handling by trying to set
+ bright yellow reverse video."
+
+ [{Jargon File}]
+
+tick-list features
+
+ ({Acorn Computers}) Features in software or hardware that
+ customers insist on but never use (calculators in desktop TSRs
+ and that sort of thing). The American equivalent would be
+ "checklist features", but this jargon sense of the phrase has
+ not been reported.
+
+ (1995-01-06)
+
+TIFF
+
+ {Tagged Image File Format}
+
+tiger team
+
+ (US military jargon) 1. Originally, a team whose purpose is to
+ penetrate security, and thus test security measures. These
+ people are paid professionals who do hacker-type tricks,
+ e.g. leave cardboard signs saying "bomb" in critical defence
+ installations, hand-lettered notes saying "Your codebooks have
+ been stolen" (they usually haven't been) inside safes, etc.
+ After a successful penetration, some high-ranking security
+ type shows up the next morning for a "security review" and
+ finds the sign, note, etc. and all hell breaks loose. Serious
+ successes of tiger teams sometimes lead to early retirement
+ for base commanders and security officers (see the {patch}
+ entry for an example).
+
+ 2. Recently, and more generally, any official inspection team
+ or special {firefighting} group called in to look at a
+ problem.
+
+ A subset of tiger teams are professional {crackers}, testing
+ the security of military computer installations by attempting
+ remote attacks via networks or supposedly "secure"
+ communication channels. Some of their escapades, if
+ declassified, would probably rank among the greatest hacks of
+ all times. The term has been adopted in commercial
+ computer-security circles in this more specific sense.
+
+ [{Jargon File}]
+
+tight loop
+
+ <programming> A {loop} of code that executes without releasing
+ any resources to other programs or the {operating system}.
+
+ Consider the following pointless {BASIC} loop that counts
+ upward indefinitely
+
+ 10 i = i + 1
+ 20 GOTO 10
+
+ Run on a single-user system such as {MS-DOS} this will not
+ cause any problems. Run on a {cooperative multitasking}
+ operating system such as {Windows 3}, the system would appear
+ to freeze.
+
+ A {pre-emptive multitasking} operating system such as
+ {UNIX} or {Windows NT} would "steal" cycles away from
+ the program and continue to run other programs.
+
+ See also {busy-wait} and {multitasking}.
+
+ (1999-05-06)
+
+tilde
+
+ <character> "~" {ASCII} character 126.
+
+ Common names are: {ITU-T}: tilde; squiggle; {twiddle}; not.
+ Rare: approx; wiggle; {swung dash}; enyay; {INTERCAL}: sqiggle
+ (sic).
+
+ Used as {C}'s prefix {bitwise negation} {operator}; and in
+ {Unix} {csh}, {GNU Emacs}, and elsewhere, to stand for the
+ current user's {home directory}, or, when prefixed to a {login
+ name}, for the given user's home directory.
+
+ The "swung dash" or "approximation" sign is not quite the same
+ as {tilde} in typeset material but the ASCII tilde serves for
+ both (compare {angle brackets}).
+
+ [Has anyone else heard this called "tidal" (as in wave)?]
+
+ (1996-10-18)
+
+TILE Forth
+
+ <language> A {Forth} {interpreter} in {C} for {Unix} by Mikael
+ Patel <mip@sectra.se>. TILE Forth comes with many Forth
+ libraries. It conforms to the {Forth83} {standard} and is
+ distributed under {GPL}.
+
+ Latest version: 2.1, as of 1991-11-13.
+
+ Availalbe via {FTP} from a {GNU archive site}.
+
+ (1991-11-13)
+
+Tim Berners-Lee
+
+ <person> The man who invented the {web} while
+ working at the Center for European Particle Research (CERN).
+ Now Director of the {web Consortium}.
+
+ Tim Berners-Lee graduated from the Queen's College at Oxford
+ University, England, 1976. Whilst there he built his first
+ computer with a soldering iron, {TTL} gates, an {M6800}
+ processor and an old television.
+
+ He then went on to work for {Plessey Telecommunications}, and
+ D.G. Nash Ltd (where he wrote software for intelligent
+ printers and a {multi-tasking} {operating system}), before
+ joining CERN, where he designed a program called 'Enquire',
+ which was never published, but formed the conceptual basis for
+ today's {web}.
+
+ In 1984, he took up a fellowship at CERN, and in 1989, he
+ wrote the first {web server}, "{httpd}", and the
+ first client, "WorldWideWeb" a {hypertext} browser/editor
+ which ran under {NEXTSTEP}. The program "WorldWideWeb" was
+ first made available within CERN in December, and on the
+ {Internet} as a whole in the summer of 1991.
+
+ In 1994, Tim joined the {Laboratory for Computer Science}
+ (LCS) at the {Massachusetts Institute of Technology} (MIT).
+ In 1999, he became the first holder of the {3Com} Founders
+ chair. He is also the author of "Weaving the Web", on the
+ past present and future of the Web.
+
+ In 2001, Tim was made a fellow of The Royal Society.
+
+ Tim is married to Nancy Carlson. They have two children, born
+ 1991 and 1994.
+
+ {(http://w3.org/People/Berners-Lee/Longer.html)}.
+
+ (2001-06-17)
+
+time bomb
+
+ <software, security> A subspecies of {logic bomb} that is
+ triggered by reaching some preset time, either once or
+ periodically. There are numerous legends about time bombs set
+ up by programmers in their employers' machines, to go off if
+ the programmer is fired or laid off and is not present to
+ perform the appropriate suppressing action periodically.
+
+ Interestingly, the only such incident for which we have been
+ pointed to documentary evidence took place in the Soviet Union
+ in 1986! A disgruntled programmer at the Volga Automobile
+ Plant (where the Fiat clones called Ladas were manufactured)
+ planted a time bomb which, a week after he'd left on vacation,
+ stopped the entire main assembly line for a day. The case
+ attracted lots of attention in the Soviet Union because it was
+ the first cracking case to make it to court there. The
+ perpetrator got 3 years in jail.
+
+ [{Jargon File}]
+
+ (2001-09-15)
+
+time complexity
+
+ <complexity> The way in which the number of steps required by
+ an {algorithm} varies with the size of the problem it is
+ solving. Time complexity is normally expressed as an order of
+ magnitude, e.g. O(N^2) means that if the size of the problem
+ (N) doubles then the algorithm will take four times as many
+ steps to complete.
+
+ See also {computational complexity}, {space complexity}.
+
+ (1996-05-08)
+
+Time Complex Simulator
+
+ <simulation> (Tcsim) {Complex arithmetic} version of {Tsim}.
+
+ Contact: {ZOLA Technologies}.
+
+ (1996-01-18)
+
+time division multiple access
+
+ {time division multiplexing}
+
+time division multiplexing
+
+ <communications> (TDM) A type of {multiplexing} where two or
+ more channels of information are transmitted over the same
+ link by allocating a different time interval ("slot" or
+ "slice") for the transmission of each channel. I.e. the
+ channels take turns to use the link. Some kind of periodic
+ synchronising signal or distinguishing identifier is usually
+ required so that the receiver can tell which channel is which.
+
+ TDM becomes inefficient when traffic is intermittent because
+ the time slot is still allocated even when the channel has no
+ data to transmit. {Statistical time division multiplexing}
+ was developed to overcome this problem.
+
+ Compare {wavelength division multiplexing}, {frequency division
+ multiplexing}, {code division multiplexing}.
+
+ (2001-06-27)
+
+Time Domain Reflectometer
+
+ <hardware, networking> (TDR) An electronic device for
+ detecting and locating short- or open-circuits in an
+ {Ethernet} cable. TDRs can also measure how the {characteristic
+ impedance} of a line varies along its length.
+
+ (1995-12-28)
+
+timeout
+
+ A period of time after which an error condition is raised if
+ some event has not occured. A common example is sending a
+ message. If the receiver does not acknowledge the message
+ within some preset timeout period, a transmission error is
+ assumed to have occured.
+
+ (1995-11-09)
+
+time quantum
+
+ {time slice}
+
+time-sharing
+
+ <operating system> (Or "timesharing") An {operating system}
+ feature allowing several users to run several tasks
+ concurrently on one processor, or in parallel on many
+ processors, usually providing each user with his own terminal
+ for input and output. {time-sharing} is {multi-user}
+ {multitasking}.
+
+ (2009-11-23)
+
+Time Sharing Option
+
+ <operating system> (TSO) System software from {IBM} that
+ provides {time-sharing} on an IBM {mainframe} running in an
+ {MVS} environment.
+
+ (2003-08-15)
+
+time shifting
+
+ <programming> A technique used to work around problems due to
+ the {Year 2000} and the "millennium bug". Time shifting
+ involves translating date fields in a database back by a fixed
+ number of years to avoid year 2000 problems with the {database
+ management system}.
+
+ Typically dates are shifted back 28 years so that the occurrence
+ of leap years and days of the week match with the actual year.
+
+ (2003-08-15)
+
+Time Simulator
+
+ <simulation> (Tsim) A {stack}-based {simulation} language.
+
+ Contact: {ZOLA Technologies}.
+
+ (1999-10-04)
+
+time sink
+
+ (By analogy with "heat sink" or "current sink") A project that
+ consumes unbounded amounts of time.
+
+ [{Jargon File}]
+
+ (1995-02-07)
+
+time slice
+
+ <operating system> (Or "time quantum", "quantum") The period
+ of time for which a process is allowed to run uninterrupted in
+ a {pre-emptive multitasking} {operating system}.
+
+ The {scheduler} is run once every time slice to choose the
+ next process to run. If the time slice is too short then the
+ scheduler will consume too much processing time but if it is
+ too long then processes may not be able to respond to external
+ events quickly enough.
+
+ (1998-11-06)
+
+times-or-divided-by
+
+ <jargon> (By analogy with "plus-or-minus") A term occasionally
+ used when describing the uncertainty factor associated with a
+ estimate, for either humorous or brutally honest effect.
+
+ For example, a software project usually has a scheduling
+ uncertainty factor of at least two.
+
+ [{Jargon File}]
+
+ (2009-05-29)
+
+time T
+
+ /ti:m T/ An unspecified but usually well-understood time,
+ often used in conjunction with a later time T+1. "We'll meet
+ on campus at time T or at Louie's at time T+1" means, in the
+ context of going out for dinner: "We can meet on campus and go
+ to Louie's, or we can meet at Louie's itself a bit later."
+ (Louie's was a Chinese restaurant in Palo Alto that was a
+ favourite with hackers.) Had the number 30 been used instead
+ of the number 1, it would have implied that the travel time
+ from campus to Louie's is 30 minutes; whatever time T is (and
+ that hasn't been decided on yet), you can meet half an hour
+ later at Louie's than you could on campus and end up eating at
+ the same time.
+
+ See also {since time T equals minus infinity}.
+
+ [{Jargon File}]
+
+ (1994-12-12)
+
+Time to Live
+
+ (TTL) A field in the {Internet Protocol} header which
+ indicates how many more {hops} this packet should be allowed
+ to make before being discarded or returned.
+
+ (1994-12-12)
+
+time zone
+
+ One of approximately 24 longitudinal divisions of the globe,
+ nominally 15 degrees wide, in which clocks show the same time.
+ Some zones follow the boundaries of states or territories,
+ others differ from neighbouring zones by more or less than one
+ hour.
+
+ Computers can be programmed to take into account the time zone
+ each user is working in, which is not necessarily the same as
+ the zone the computer is in.
+
+ See also {TZ}.
+
+ (1997-07-20)
+
+TINC
+
+ {There Is No Cabal}
+
+Tinman
+
+ <language> The third of the series of DoD requirements that
+ led to {Ada}. Written by HOLWG, DoD, Jan 1976.
+
+ See {Strawman}, {Woodenman}, {Ironman}, {Steelman}.
+
+ (1976-01-01)
+
+tinman+
+
+ Macro language for Apple II? Published in DDJ?
+
+TINT
+
+ Interpreted version of {JOVIAL}.
+
+ [Sammet 1969, p. 528].
+
+tint
+
+ {hue}
+
+Tiny
+
+ 1. A language which provides {concurrency} through
+ {message-passing} to named message {queues}.
+
+ 2. A tool written by Michael Wolfe <mwolfe@cse.ogi.edu> at
+ {Oregon Graduate Institute of Science & Technology} for
+ examining {array} data dependence {algorithms} and {program
+ transformations} for scientific computations.
+
+ {Extended Tiny} was used to implement the {Omega test}.
+ Michael Wolfe has also made extensions to his version of tiny.
+
+ (1994-12-12)
+
+Tiny BASIC
+
+ <language> A dialect of {BASIC} developed by Dr. Wang [Wong?]
+ in the late 1970s. Tiny BASIC was 2K bytes in size and was
+ loaded from {paper tape}. It ran on almost any {Intel 8080}
+ or {Zilog Z80} {microprocessor} for which the user could
+ provide the necessary I/O driver software.
+
+ Tiny BASIC was distributed as [the first ever?] {freeware}.
+ The program listing contained the following phrases "All
+ Wrongs reserved" and "{CopyLeft}", he obviously wasn't
+ interested in money.
+
+ See also {Tiny Basic Interpreter Language}.
+
+ [More info?]
+
+ (1997-09-12)
+
+Tiny Basic Interpreter Language
+
+ <language> (TBIL) The inner {interpreter} of Tom Pittman's set
+ of {Tiny Basics} in Dr Dobb's Journal.
+
+ (1997-09-12)
+
+Tiny Clos
+
+ A core part of {Common Lisp Object System} (CLOS) ported to
+ {Scheme} and rebuilt using a MOP ({Metaobject Protocol}).
+ This should be interesting to those who want to use MOPs
+ without using a full {Common Lisp} or {Dylan}.
+
+ The first release works with {MIT Scheme} 11.74.
+
+ {(ftp://parcftp.xerox.com/pub/mops/)}. E-mail: Gregor
+ Kiczales <gregor@parc.xerox.com>. Mailing list: mops
+ (administered by <gregor@parc.xerox.com>).
+
+ (1992-12-14)
+
+TIP
+
+ 1. {Texas Instruments Pascal}.
+
+ 2. A {Unix} program for interactive communication via {serial
+ lines}.
+
+ {Unix manual page}: tip(1).
+
+TIPL
+
+ 1. Teach IPL. An interpretive {IPL} teaching system.
+
+ [Sammet 1969, p. 393].
+
+ 2. A dialect of {IGL}.
+
+tip of the ice-cube
+
+ [IBM] The visible part of something small and insignificant.
+ Used as an ironic comment in situations where "tip of the
+ iceberg" might be appropriate if the subject were at all
+ important.
+
+ [{Jargon File}]
+
+tired iron
+
+ [IBM] Hardware that is perfectly functional but far enough
+ behind the state of the art to have been superseded by new
+ products, presumably with sufficient improvement in
+ bang-per-buck that the old stuff is starting to look a bit
+ like a {dinosaur}.
+
+tits on a keyboard
+
+ <jargon> Small bumps on certain keycaps to help touch-typists
+ find the home keys (ASDF and JKL;) without looking. They are
+ found on the "F" and "J" of a {QWERTY} and the "5" of a
+ {numeric keypad}. The {Macintosh}, perverse as usual, has, or
+ had, them on the "D" and "K" keys.
+
+ This term is based on the vernacular American expression "as
+ useful as tits on a boar" (or boar-hog, bull, bullfrog, or
+ many other variants), meaning "not useful".
+
+ [{Jargon File}]
+
+ (1998-02-25)
+
+tj
+
+ <networking> The {country code} for Tajikistan.
+
+ (1999-01-27)
+
+Tk
+
+ <programming, graphics> A {GUI} library, generally used with
+ {TCL} by {John Ousterhout}, but also available from within {C}
+ or {Perl}. Tk is available for {X Window System}, {Microsoft
+ Windows} and {Macintosh}. Tk looks very similar to {Motif}.
+
+ Version 3.5.
+
+ {(ftp://ftp.cs.berkeley.edu/ucb/tcl/)}.
+
+ (1995-11-09)
+
+tk
+
+ <networking> The {country code} for Tokelau.
+
+ (1999-01-27)
+
+TK-90X
+
+ <computer> A Brazilian {clone}, manufactured by {Micro
+ Digital}, of the British {Sinclair Research} {ZX Spectrum}
+ {8-bit} {microcomputer}. It differed from the standard
+ Spectrum by adding an {Interface 2}-compatible {joystick}
+ {interface}, and extra {BASIC} commands to aid {programming}
+ and {graphics}-editing. Because of these differences, it was
+ slightly incompatible with the standard Spectrum.
+
+ A later model, the TK-95, which boasted an improved keyboard
+ (similar to the {Commodore 64}'s) and a more compatible {ROM},
+ was little more than a {Timex} {TC2048} (another Spectrum
+ clone) in disguise.
+
+ {comp.sys.sinclair FAQ
+ (http://kendalls.demon.co.uk/cssfaq/)}.
+
+ ["comp.sys.sinclair FAQ", D Burke M Fayzullin P Kendall et al,
+ pub. Philip Kendall 1998]
+
+ (1998-11-09)
+
+TK-95
+
+ {TK-90X}
+
+T. Kohonen
+
+ <person> A researcher at the {University of Helsinki} who has
+ been studying {neural networks} for many years with the idea
+ of modelling as closely as possible the behaviour of
+ biological systems. His name is commonly associated with a
+ particular kind of neural network in which there are only two
+ kinds of {neurons} (see {McCulloch-Pitts}), input and others.
+ All the input neurons are connected to all others and the
+ others are connected only to their other nearest neighbors.
+ The training {algorithm} is a relatively simple one based on
+ the geometric layout of the neurons, and makes use of
+ {simulated annealing}.
+
+ (1994-10-19)
+
+TK!Solver
+
+ Software Arts 1983. Numerical constraint-oriented language.
+ "The TK!Solver Book", M. Konopasek et al, McGraw-Hill 1984.
+
+TL0
+
+ {Thread Language Zero}
+
+TL1
+
+ Transaction Language 1.
+
+ A subset of {ITU-T}'s {MML} from {Bellcore}, with simpler
+ syntax. TL1 is similar to {USL}. It is used in
+ communications between telephone operating systems and remote
+ network test equipment.
+
+ [OTGR, TR-TSY-000439, section 12, Bellcore].
+
+ (1994-12-14)
+
+TLA
+
+ {three-letter acronym}
+
+TLAs
+
+ <jargon> As of 2014-08-14, {this dictionary} included 1285
+ {three-letter acronyms}, which is 7% of the 26^3 = 17576 possible.
+
+ Here's a {grep} command to find them:
+
+ egrep '^[A-Z][A-Z][A-Z]$' Dictionary
+
+ or a {GNU} {Emacs} command:
+
+ (occur "^[A-Z][A-Z][A-Z]$")
+
+ Here they are:
+
+ {AAC}, {AAL}, {AAP}, {ABC}, {ABI}, {ABM}, {ABP}, {ABR}, {ACA},
+ {ACE}, {ACF}, {ACK}, {ACL}, {ACM}, {ACP}, {ACT}, {ADC}, {ADL},
+ {ADM}, {ADO}, {ADR}, {ADS}, {ADT}, {AED}, {AEP}, {AES}, {AFJ},
+ {AFK}, {AFP}, {AFS}, {AGL}, {AGP}, {AIA}, {AID}, {AIR}, {AIT},
+ {AIX}, {AKC}, {AKL}, {ALC}, {ALF}, {ALM}, {ALP}, {ALU}, {AMD},
+ {AMI}, {AML}, {AMO}, {AMP}, {AMS}, {AND}, {ANI}, {ANL}, {ANR},
+ {ANS}, {ANU}, {AOL}, {AOP}, {AOS}, {APA}, {APC}, {APE}, {API},
+ {APL}, {APM}, {APT}, {AQL}, {ARC}, {ARL}, {ARM}, {ARP}, {ARQ},
+ {ART}, {ASA}, {ASE}, {ASF}, {ASK}, {ASL}, {ASM}, {ASN}, {ASP},
+ {ASR}, {AST}, {ATA}, {ATK}, {ATM}, {ATS}, {ATX}, {AUI}, {AUP},
+ {AVC}, {AVI}, {AVS}, {AWE}, {AWG}, {AWT}, {AYT}, {BAD}, {BAL},
+ {BAP}, {BBC}, {BBL}, {BBS}, {BCC}, {BCD}, {BCL}, {BCS}, {BDC},
+ {BDL}, {BEA}, {BEG}, {BEL}, {BER}, {BFI}, {BGA}, {BGP}, {BIP},
+ {BLT}, {BMF}, {BMP}, {BNC}, {BNF}, {BOA}, {BOF}, {BOS}, {BPI},
+ {BPR}, {BPS}, {BQS}, {BRB}, {BRH}, {BRI}, {BRS}, {BSA}, {BSD},
+ {BSI}, {BSL}, {BSS}, {BST}, {BTB}, {BTS}, {BTW}, {BWQ}, {CAD},
+ {CAE}, {CAF}, {CAI}, {CAL}, {CAM}, {CAN}, {CAP}, {CAR}, {CAS},
+ {CAT}, {CAV}, {CBD}, {CBN}, {CBR}, {CBT}, {CBV}, {CCD}, {CCL},
+ {CCP}, {CCR}, {CCS}, {CDA}, {CDC}, {CDE}, {CDF}, {CDL}, {CDM},
+ {CDR}, {CDS}, {CDW}, {CEN}, {CER}, {CFD}, {CFP}, {CGA}, {CGI},
+ {CGM}, {CHI}, {CID}, {CIF}, {CIL}, {CIM}, {CIO}, {CIR}, {CIS},
+ {CIX}, {CJK}, {CLI}, {CLM}, {CLP}, {CLR}, {CLU}, {CLV}, {CLX},
+ {CMA}, {CMC}, {CML}, {CMM}, {CMP}, {CMS}, {CMU}, {CMZ}, {CNC},
+ {CNI}, {CNN}, {CNR}, {COM}, {COS}, {CPE}, {CPI}, {CPL}, {CPM},
+ {CPS}, {CPU}, {CRC}, {CRL}, {CRM}, {CRT}, {CSG}, {CSL}, {CSM},
+ {CSO}, {CSP}, {CSR}, {CSS}, {CSU}, {CSV}, {CTC}, {CTI}, {CTL},
+ {CTS}, {CTY}, {CUA}, {CUL}, {CUT}, {CVS}, {CWI}, {DAA}, {DAC},
+ {DAG}, {DAS}, {DAT}, {DAU}, {DBA}, {DBC}, {DBH}, {DCA}, {DCC},
+ {DCE}, {DCG}, {DCI}, {DCL}, {DCP}, {DCS}, {DCT}, {DDB}, {DDE},
+ {DDL}, {DDM}, {DDN}, {DDO}, {DDP}, {DDR}, {DDS}, {DDT}, {DDW},
+ {DEA}, {DEC}, {DED}, {DEK}, {DER}, {DES}, {DEX}, {DFA}, {DFC},
+ {DFD}, {DFS}, {DFT}, {DGL}, {DIB}, {DID}, {DIL}, {DIM}, {DIN},
+ {DIP}, {DLC}, {DLE}, {DLG}, {DLL}, {DLM}, {DLP}, {DLT}, {DMA},
+ {DME}, {DMI}, {DML}, {DMM}, {DMS}, {DMU}, {DMZ}, {DNF}, {DNS},
+ {DOA}, {DOE}, {DOF}, {DOL}, {DOM}, {DOS}, {DPA}, {DPB}, {DPL},
+ {DPN}, {DPP}, {DPS}, {DRM}, {DSA}, {DSE}, {DSI}, {DSL}, {DSM},
+ {DSN}, {DSO}, {DSP}, {DSR}, {DSS}, {DST}, {DSU}, {DSW}, {DTD},
+ {DTE}, {DTP}, {DTR}, {DTS}, {DUA}, {DVD}, {DVI}, {DXF}, {EAF},
+ {EAG}, {EAI}, {EAX}, {ECC}, {ECL}, {ECM}, {ECP}, {EDA}, {EDF},
+ {EDI}, {EDL}, {EDM}, {EDP}, {EDS}, {EER}, {EFF}, {EFI}, {EFL},
+ {EFT}, {EGA}, {EGP}, {EIA}, {EJB}, {ELF}, {ELI}, {ELP}, {EMA},
+ {EMC}, {EMI}, {EML}, {EMM}, {EMS}, {EMX}, {ENQ}, {ENS}, {EOF},
+ {EOL}, {EOR}, {EOT}, {EOU}, {EPL}, {EPP}, {EPS}, {ERA}, {ERC},
+ {ERD}, {ERM}, {ERP}, {ESA}, {ESC}, {ESD}, {ESF}, {ESI}, {ESL},
+ {ESP}, {ESR}, {ETB}, {ETC}, {ETL}, {ETM}, {ETX}, {EVE}, {EXE},
+ {FAC}, {FAD}, {FAP}, {FAQ}, {FAT}, {FCB}, {FCP}, {FCS}, {FDC},
+ {FDD}, {FDT}, {FEA}, {FEC}, {FED}, {FEL}, {FFP}, {FFT}, {FGL},
+ {FHS}, {FIR}, {FIX}, {FLI}, {FMQ}, {FMS}, {FMV}, {FNC}, {FOD},
+ {FPA}, {FPM}, {FPU}, {FQL}, {FRA}, {FRL}, {FSB}, {FSF}, {FSK},
+ {FSL}, {FSM}, {FSP}, {FTP}, {FTW}, {FTX}, {FUD}, {FXO}, {FXS},
+ {FYA}, {FYI}, {GAL}, {GAN}, {GAP}, {GAT}, {GCC}, {GCL}, {GCR},
+ {GCT}, {GDA}, {GDB}, {GDI}, {GEA}, {GEI}, {GEM}, {GFR}, {GFS},
+ {GHC}, {GIF}, {GIN}, {GIP}, {GIS}, {GKS}, {GLB}, {GLS}, {GLU},
+ {GMD}, {GMT}, {GNN}, {GNU}, {GOL}, {GOM}, {GPF}, {GPL}, {GPM},
+ {GPS}, {GPV}, {GPX}, {GRE}, {GRG}, {GSI}, {GSL}, {GSM}, {GSS},
+ {GTL}, {GUI}, {GVL}, {GWM}, {HAL}, {HCF}, {HCI}, {HCS}, {HDA},
+ {HDC}, {HDD}, {HDF}, {HDL}, {HDM}, {HEP}, {HFC}, {HID}, {HLL},
+ {HMA}, {HMP}, {HNC}, {HOL}, {HPF}, {HPL}, {HPR}, {HSB}, {HSC},
+ {HSM}, {HSV}, {HTH}, {HVD}, {IAB}, {IAD}, {IAL}, {IAM}, {IAP},
+ {IAR}, {IAS}, {IAW}, {IBM}, {ICA}, {ICE}, {ICI}, {ICL}, {ICQ},
+ {ICT}, {ICW}, {IDD}, {IDE}, {IDL}, {IEC}, {IEF}, {IEN}, {IFC},
+ {IFF}, {IFP}, {IFS}, {IFX}, {IGC}, {IGL}, {IGP}, {IGS}, {IGU},
+ {IHS}, {IHV}, {IIL}, {IIR}, {IIS}, {IIT}, {ILF}, {IMD}, {IML},
+ {IMO}, {IMP}, {IMR}, {IMS}, {IOI}, {IOS}, {IOW}, {IPA}, {IPC},
+ {IPE}, {IPL}, {IPS}, {IPT}, {IPX}, {IQL}, {IRC}, {IRL}, {IRM},
+ {IRQ}, {ISA}, {ISE}, {ISF}, {ISL}, {ISO}, {ISP}, {IST}, {ISV},
+ {ITP}, {ITS}, {ITU}, {IVR}, {IVY}, {IXC}, {IXO}, {JAD}, {JAZ},
+ {JCL}, {JCP}, {JDK}, {JES}, {JIT}, {JMS}, {JNI}, {JPL}, {JRE},
+ {JRL}, {JRN}, {JSA}, {JSF}, {JSP}, {JTB}, {JTC}, {JTS}, {JVM},
+ {KAP}, {KBS}, {KCL}, {KEE}, {KFX}, {KIS}, {KLB}, {KMS}, {KNI},
+ {KRC}, {KRL}, {KRS}, {KSL}, {KSR}, {KTH}, {KVM}, {LAN}, {LAP},
+ {LAT}, {LAU}, {LAX}, {LBA}, {LBE}, {LBL}, {LBX}, {LCC}, {LCD},
+ {LCF}, {LCL}, {LCP}, {LCS}, {LDB}, {LDL}, {LDP}, {LDT}, {LEC},
+ {LED}, {LEO}, {LER}, {LGN}, {LIF}, {LIS}, {LKA}, {LLC}, {LLP},
+ {LML}, {LNF}, {LOC}, {LOL}, {LOM}, {LOP}, {LPC}, {LPF}, {LPG},
+ {LPI}, {LPL}, {LPS}, {LPT}, {LRC}, {LRU}, {LSA}, {LSB}, {LSE},
+ {LSL}, {LSP}, {LSR}, {LTL}, {LTR}, {LUG}, {LUN}, {LVD}, {LWP},
+ {MAC}, {MAD}, {MAL}, {MAN}, {MAO}, {MAP}, {MAS}, {MAU}, {MBS},
+ {MCA}, {MCC}, {MCI}, {MCL}, {MCP}, {MCS}, {MDA}, {MDF}, {MDI},
+ {MDL}, {MFC}, {MFE}, {MFM}, {MHS}, {MIB}, {MIF}, {MIG}, {MII},
+ {MIS}, {MIT}, {MIX}, {MJS}, {MLL}, {MMI}, {MML}, {MMO}, {MMS},
+ {MMU}, {MMX}, {MNP}, {MOO}, {MOS}, {MPC}, {MPG}, {MPI}, {MPL},
+ {MPP}, {MPV}, {MPX}, {MQG}, {MRI}, {MRP}, {MRS}, {MSB}, {MSM},
+ {MSN}, {MSS}, {MSX}, {MTA}, {MTS}, {MTU}, {MUA}, {MUD}, {MUP},
+ {MVC}, {MVS}, {MXI}, {NAG}, {NAK}, {NAS}, {NAT}, {NAU}, {NBS},
+ {NBT}, {NCD}, {NCP}, {NCS}, {NDL}, {NDS}, {NEC}, {NFA}, {NFS},
+ {NFT}, {NGL}, {NIC}, {NIH}, {NII}, {NIL}, {NIS}, {NLM}, {NLP},
+ {NLS}, {NLX}, {NMI}, {NMU}, {NNI}, {NOC}, {NOL}, {NOR}, {NOS},
+ {NOT}, {NPC}, {NPL}, {NQS}, {NRZ}, {NSE}, {NSF}, {NSI}, {NSS},
+ {NTP}, {NTU}, {NVL}, {NVS}, {OAP}, {OBE}, {OBJ}, {OCL}, {OCP},
+ {OCR}, {OCS}, {OCX}, {ODA}, {ODC}, {ODI}, {ODP}, {ODS}, {ODT},
+ {OEM}, {OFA}, {OIC}, {OID}, {OIL}, {OLC}, {OLE}, {OMA}, {OMF},
+ {OMG}, {OMR}, {OMS}, {OMT}, {ONC}, {OOA}, {OOD}, {OOF}, {OOP},
+ {OPC}, {OPF}, {OPS}, {ORB}, {ORM}, {OSA}, {OSD}, {OSE}, {OSF},
+ {OSI}, {OSP}, {OTI}, {OTP}, {OTT}, {OWL}, {PAD}, {PAL}, {PAM},
+ {PAP}, {PAT}, {PAW}, {PBD}, {PBM}, {PBX}, {PCA}, {PCB}, {PCF},
+ {PCI}, {PCL}, {PCM}, {PCN}, {PCS}, {PCU}, {PDA}, {PDC}, {PDF},
+ {PDH}, {PDL}, {PDM}, {PDP}, {PDS}, {PDU}, {PEM}, {PEP}, {PER},
+ {PEX}, {PFE}, {PFL}, {PFP}, {PGA}, {PGP}, {PHP}, {PIC}, {PID},
+ {PIE}, {PIL}, {PIM}, {PIN}, {PIP}, {PIT}, {PKE}, {PKI}, {PLC},
+ {PLD}, {PLL}, {PMC}, {PML}, {PMP}, {PNG}, {PNP}, {POA}, {POC},
+ {POE}, {POM}, {POP}, {POR}, {POS}, {PPC}, {PPD}, {PPL}, {PPM},
+ {PPN}, {PPP}, {PQS}, {PRA}, {PRI}, {PRL}, {PSA}, {PSD}, {PSF},
+ {PSI}, {PSK}, {PSL}, {PSN}, {PSO}, {PSU}, {PTF}, {PTI}, {PTN},
+ {PTT}, {PUB}, {PVC}, {PVM}, {PWM}, {QAM}, {QBE}, {QCA}, {QIC},
+ {QMW}, {QNX}, {QPE}, {RAD}, {RAL}, {RAM}, {RAS}, {RCC}, {RCL},
+ {RCS}, {RDF}, {RDI}, {RDL}, {RDP}, {RDS}, {REC}, {REM}, {REP},
+ {REX}, {RFC}, {RFE}, {RFI}, {RFP}, {RFT}, {RGB}, {RIP}, {RJE},
+ {RKM}, {RLE}, {RLF}, {RLL}, {RMI}, {RMS}, {RNF}, {ROM}, {RPC},
+ {RPG}, {RPI}, {RPL}, {RPM}, {RPN}, {RPT}, {RRL}, {RRS}, {RSA},
+ {RSI}, {RSL}, {RSN}, {RSS}, {RTF}, {RTI}, {RTL}, {RTM}, {RTP},
+ {RTS}, {RTT}, {RWP}, {SAA}, {SAC}, {SAD}, {SAL}, {SAM}, {SAN},
+ {SAP}, {SAR}, {SAS}, {SBD}, {SBE}, {SBM}, {SBR}, {SCA}, {SCC},
+ {SCI}, {SCL}, {SCM}, {SCO}, {SDE}, {SDF}, {SDH}, {SDI}, {SDK},
+ {SDL}, {SDM}, {SDP}, {SDS}, {SEA}, {SEC}, {SED}, {SEE}, {SEI},
+ {SEL}, {SEM}, {SEP}, {SET}, {SEX}, {SFA}, {SFL}, {SGI}, {SHA},
+ {SIA}, {SIG}, {SIL}, {SIM}, {SIP}, {SIR}, {SKU}, {SMB}, {SMG},
+ {SMI}, {SML}, {SMM}, {SMP}, {SMS}, {SMT}, {SNA}, {SNI}, {SNR},
+ {SOA}, {SOE}, {SOH}, {SOJ}, {SOL}, {SOM}, {SOS}, {SPC}, {SPD},
+ {SPE}, {SPG}, {SPI}, {SPL}, {SPM}, {SPS}, {SPX}, {SQE}, {SQL},
+ {SQR}, {SRI}, {SRL}, {SRP}, {SSA}, {SSD}, {SSE}, {SSI}, {SSL},
+ {SSO}, {SSR}, {STB}, {STD}, {STP}, {STX}, {SUB}, {SVC}, {SVG},
+ {SVS}, {SWL}, {SWT}, {SYN}, {TAA}, {TAB}, {TAC}, {TAL}, {TAO},
+ {TAP}, {TBF}, {TBK}, {TCB}, {TCM}, {TCO}, {TCP}, {TDD}, {TDF},
+ {TDI}, {TDM}, {TDR}, {TEI}, {TET}, {TFT}, {TGA}, {TIA}, {TIP},
+ {TLA}, {TLB}, {TLD}, {TLI}, {TLS}, {TMG}, {TNC}, {TNX}, {TOK},
+ {TOP}, {TOS}, {TPA}, {TPF}, {TPL}, {TPO}, {TPS}, {TPU}, {TPX},
+ {TRO}, {TRS}, {TSO}, {TSP}, {TSR}, {TSV}, {TTD}, {TTL}, {TTS},
+ {TUB}, {TUI}, {TXL}, {UAN}, {UAT}, {UAW}, {UBD}, {UCB}, {UCP},
+ {UCS}, {UCX}, {UDF}, {UDP}, {UFO}, {UIL}, {UIS}, {UKC}, {ULP},
+ {UMB}, {UML}, {UNC}, {UNI}, {UPS}, {URC}, {URI}, {URL}, {URN},
+ {USB}, {USE}, {USL}, {USP}, {USR}, {UTC}, {UTF}, {UTP}, {VAL},
+ {VAN}, {VAR}, {VAX}, {VBA}, {VCD}, {VCL}, {VCR}, {VDL}, {VDM},
+ {VDT}, {VDU}, {VEE}, {VEL}, {VGA}, {VGX}, {VHE}, {VHS}, {VIF},
+ {VIM}, {VLB}, {VLM}, {VME}, {VML}, {VMS}, {VOS}, {VPL}, {VPN},
+ {VQF}, {VRC}, {VSE}, {VSF}, {VSP}, {VSX}, {VTC}, {VTS}, {VTW},
+ {VUE}, {VUP}, {VXI}, {WAM}, {WAN}, {WAP}, {WBS}, {WCL}, {WDM},
+ {WEB}, {WEP}, {WFL}, {WFW}, {WGL}, {WIC}, {WLL}, {WMA}, {WMI},
+ {WML}, {WMV}, {WOM}, {WPA}, {WPG}, {WPI}, {WRT}, {WSL}, {WTF},
+ {WTH}, {WWW}, {XDL}, {XDR}, {XFS}, {XGA}, {XIE}, {XML}, {XMM},
+ {XMS}, {XNF}, {XNS}, {XON}, {XPC}, {XPG}, {XPL}, {XRN}, {XSB},
+ {XSD}, {XSI}, {XSL}, {XTI}, {XTP}, {XUI}, {XUL}, {XVT}, {XXX},
+ {YSM}, {ZAP}, {ZFC}, {ZIF}, {ZIL}, {ZOG}, {ZUG}
+
+ (2014-08-14)
+
+TLB
+
+ {Translation Look-aside Buffer}
+
+TLD
+
+ {top-level domain}
+
+TLI
+
+ {Transport Layer Interface}
+
+TL/I
+
+ <language> An intermediate language for {Turing Machines}.
+
+ ["Examples of Formal Semantics", D. Knuth in Symp on Semantics
+ of Algorithmic Languages, E. Engeler ed, LNM 188, Springer
+ 1971, pp. 212-235].
+
+ (1994-12-02)
+
+T Lisp
+
+ {T}
+
+TLS
+
+ {Transport Layer Security protocol}
+
+TM
+
+ 1. {Turing Machine}.
+
+ 2. A formal {database specification language}.
+
+ [{Jargon File}]
+
+tm
+
+ <networking> The {country code} for Turkmenistan.
+
+ Heavily used for {vanity domains} because it looks
+ like the abbreviation for "trademark".
+
+ (1999-01-27)
+
+(TM)
+
+ (Trademark) An {ASCII} rendition of the trademark-superscript
+ symbol, appended to phrases that the author feels should be
+ recorded for posterity.
+
+ It is sometimes used ironically as a form of protest against
+ the recent spate of {software patents}, {algorithm} patents
+ and "{look and feel}" lawsuits.
+
+ [{Jargon File}]
+
+ (1994-12-02)
+
+TMDL
+
+ {Target-Machine Description Language}
+
+TMG
+
+ TransMoGrifier.
+
+ An early language for writing {recursive descent} compilers.
+ It was {macro}ed from the {IBM 1604} to the {IBM 709} to the
+ {IBM 7094} to the {GE-635}, where it was used by McIlroy and
+ Morris to write the {EPL} compiler for {Multics}.
+
+ ["TMG - A Syntax-Directed Compiler", R.M. McClure, Proc ACM
+ 20th Natl Conf (1965)].
+
+ [Sammet 1969, p.636].
+
+ (1994-12-02)
+
+TMRC
+
+ /tmerk'/ The Tech Model Railroad Club at {MIT}, one of the
+ wellsprings of {hacker} culture. The 1959 "Dictionary of the
+ TMRC Language" compiled by Peter Samson included several terms
+ that became basics of the hackish vocabulary (see especially
+ {foo}, {mung}, and {frob}).
+
+ By 1962, TMRC's legendary layout was already a marvel of
+ complexity (and has grown in the thirty years since; all the
+ features described here are still present). The control
+ system alone featured about 1200 relays. There were {scram
+ switch}es located at numerous places around the room that
+ could be thwacked if something undesirable was about to occur,
+ such as a train going full-bore at an obstruction. Another
+ feature of the system was a digital clock on the dispatch
+ board, which was itself something of a wonder in those bygone
+ days before cheap LEDS and seven-segment displays. When
+ someone hit a scram switch the clock stopped and the display
+ was replaced with the word "FOO"; at TMRC the scram switches
+ are therefore called "foo switches".
+
+ Steven Levy, in his book "Hackers", gives a stimulating
+ account of those early years. TMRC's Power and Signals group
+ included most of the early {PDP-1} hackers and the people who
+ later bacame the core of the {MIT} {AI Lab} staff. This
+ dictionary accordingly includes a number of entries from the
+ TMRC dictionary (via the Hacker Jargon File).
+
+ [{Jargon File}]
+
+ (2008-06-30)
+
+TMRCie
+
+ /tmerk'ee/, (MIT) A denizen of {TMRC}.
+
+TMS 9900
+
+ <processor> One of the first true 16-bit {microprocessors},
+ released by {Texas Instruments} in June 1976 (the first are
+ probably {National Semiconductor} {IMP-16} or {AMD-2901} {bit
+ slice processors} in 16-bit configuration). It was designed
+ as a single chip version of the {TI 990} {minicomputer}
+ series, much like the {Intersil 6100} was a single chip
+ {PDP-8}, and the {Fairchild 9440} and {Data General mN601}
+ were both one chip versions of {Data General}'s {Nova}.
+ Unlike the IMS 6100, however, the TMS 9900 had a mature, well
+ thought out design.
+
+ It had a 15-bit {address space} and two internal 16 bit
+ {registers}. One unique feature was that all user {registers}
+ were actually kept in memory - this included {stack pointers}
+ and the {program counter}. A single workspace {register}
+ pointed to the 16 {register set} in {RAM}, so when a
+ subroutine was entered or an {interrupt} was processed, only
+ the single workspace register had to be changed - unlike some
+ {CPUs} which required dozens or more register saves before
+ acknowledging a {context switch}.
+
+ This was feasible at the time because {RAM} was often faster
+ than the {CPUs}. A few modern designs, such as the {INMOS}
+ {transputer}, use this same design using {caches} or {rotating
+ buffers}, for the same reason of faster {context switch}es.
+ Other chips of the time, such as the {650x} series had a
+ similar philosophy, using {index registers}, but the TMS 9900
+ went the farthest in this direction.
+
+ That wasn't the only positive feature of the chip. It had
+ good {interrupt} handling features and very good instruction
+ set. Serial I/O was available through address lines. In
+ typical comparisons with the {Intel 8086}, the TMS9900 had
+ smaller and faster programs. The only disadvantage was the
+ small {address space} and need for fast {RAM}.
+
+ Despite very poor support from Texas Instruments, the TMS 9900
+ had the potential at one point to surpass the {Intel 8086} in
+ popularity.
+
+ (1994-11-30)
+
+tn
+
+ <networking> The {country code} for Tunisia.
+
+ (1999-01-27)
+
+tn3270
+
+ A program, similar to {telnet}, used to connect to remote
+ {IBM} {mainframe} {hosts}, many of which do not understand
+ telnet. The program emulates a {3270}-type terminal.
+
+ For many tn3270 versions, the "clear screen" function is
+ activated by typing Control-Z. When logged on to an IBM host
+ and "HOLDING" or "MORE..." appears at the lower right corner
+ of the screen, the "clear screen" function must be entered to
+ display the next screen. tn3270 emulations usually include
+ {function key} definitions.
+
+ (1994-11-03)
+
+TNC
+
+ <hardware> A threaded version of a {BNC}.
+
+ (1996-12-21)
+
+TNSTAAFL
+
+ {TANSTAAFL}
+
+TNX
+
+ <chat> Thanks. Also "TNX 1.0E6" or "{TNXE6}" - thanks a
+ million.
+
+ (1996-05-19)
+
+TNXE6
+
+ Thanks a million. "E" is used in many programming languages
+ to separate the mantissa and exponent of a {floating-point}
+ constant so a number ending in "E6" means "times ten to the
+ power six", i.e. times a million.
+
+to
+
+ <networking> The {country code} for Tonga.
+
+ Heavily used for {vanity domains} because it looks like the
+ English word "to".
+
+ (1999-01-27)
+
+to a first approximation
+
+ 1. When one is doing certain numerical computations, an
+ approximate solution may be computed by any of several
+ heuristic methods, then refined to a final value. By using
+ the starting point of a first approximation of the answer, one
+ can write an algorithm that converges more quickly to the
+ correct result.
+
+ 2. In jargon, a preface to any comment that indicates that the
+ comment is only approximately true. The remark "To a first
+ approximation, I feel good" might indicate that deeper
+ questioning would reveal that not all is perfect (e.g. a
+ nagging cough still remains after an illness).
+
+ [{Jargon File}]
+
+toast
+
+ <jargon> 1. Any completely inoperable system or component,
+ especially one that has just crashed and burned: "Uh, oh ... I
+ think the serial board is toast."
+
+ 2. To cause a system to crash accidentally, especially in a
+ manner that requires manual rebooting. "Rick just toasted the
+ {firewall machine} again."
+
+ Compare {fried}.
+
+ (1995-05-01)
+
+toaster
+
+ <jargon> 1. The archetypal really stupid {application} for an
+ {embedded} {microprocessor} controller; often used in comments
+ that imply that a scheme is inappropriate technology (but see
+ {elevator controller}). "{DWIM} for an assembler? That'd be
+ as silly as running {Unix} on your toaster!"
+
+ 2. A very, very dumb computer. "You could run this program on
+ any dumb toaster."
+
+ See {bitty box}, {Get a real computer!}, {toy}, {beige
+ toaster}.
+
+ 3. A {Macintosh}, especially the {Classic Mac}. Some hold
+ that this is implied by sense 2.
+
+ 4. A peripheral device. "I bought my box without toasters,
+ but since then I've added two boards and a second disk drive".
+
+ This is not usually to be taken literally but, to show off the
+ expansion capabilities of the {Risc PC}, {Acorn Computers
+ Ltd.} built a seven-slice machine (which they called "the
+ rocket-ship") and installed every imaginable peripheral. In a
+ spare {drive bay} of the top slice they installed a toaster.
+ This machine was exhibited at various shows where it attracted
+ attention by occasionally ejecting a pizza.
+
+ [{Jargon File}]
+
+ (1997-07-18)
+
+toasternet
+
+ <networking> 1. A low cost, low tech, publicly accessible
+ local community {network}. This is probably an extension of
+ the term "{toaster}" used to mean a small, cheap, slow
+ computer.
+
+ {community networks
+ (gopher://gopher.well.sf.ca.us/00/Community/communets/about.nets)}.
+
+ 2. The title of some informal notes on {IP address}ing,
+ ("Toasternet Part I and II"), circulated on the {IETF}
+ {mailing list} during November 1991 and March 1992.
+
+ Subsequent work was published in June 1993 in {RFC 1475} and
+ {RFC 1476} and the "{CATNIP}" {Internet-Draft} by Robert
+ L. Ullmann
+
+ (1995-05-01)
+
+to a zeroth approximation
+
+ <jargon> (From "to a first approximation") A *really* sloppy
+ approximation; a wild guess.
+
+ Compare {social science number}.
+
+ [{Jargon File}]
+
+ (1994-12-12)
+
+toggle
+
+ To change a {bit} from whatever state it is in to the other
+ state; to change from 1 to 0 or from 0 to 1. This comes from
+ "toggle switches", such as standard light switches, though the
+ word "toggle" actually refers to the mechanism that keeps the
+ switch in the position to which it is flipped rather than to
+ the fact that the switch has two positions. There are four
+ things you can do to a bit: set it (force it to be 1), clear
+ (or zero) it, leave it alone, or toggle it.
+
+ [{Jargon File}]
+
+ (1994-12-12)
+
+TOK
+
+ Referred to in Ursula K. LeGuin's "Always Coming Home." Seems
+ to be similar to the original {BASIC}.
+
+ (1994-12-12)
+
+token
+
+ 1. <grammar> A basic, grammatically indivisible unit of a
+ language such as a {keyword}, operator or identifier.
+ Compare: {lexeme}.
+
+ 2. <convention> (Or "{pumpkin}") An abstact concept passed
+ between cooperating agents to ensure synchronised access to a
+ shared resource. Such a token is never duplicated or
+ destroyed (unless the resource is) and whoever has the token
+ has exclusive access to the resource it controls. See for
+ example {token ring}.
+
+ If several programmers are working on a program, one
+ programmer will "have the token" at any time, meaning that
+ only he can change the program whereas others can only read
+ it. If someone else wants to modify it he must first obtain
+ the token.
+
+ (1999-02-23)
+
+token bus
+
+ <networking> (IEEE 802.4) A networking protocol which mediates
+ access to a {bus} topology network as though it were a {token
+ ring}. This eliminates the {collisions} found in {carrier
+ sense collision detect} protocols. {Nodes} can be configured
+ to pass the token in any order, not necessarily related to
+ their physical ordering on the bus. The token is sent from
+ one node to its successor in the logical ring by broadcast on
+ the bus and is ignored by the other nodes.
+
+ (1996-12-13)
+
+token ring
+
+ A computer {local area network} arbitration scheme in which
+ conflicts in the transmission of messages are avoided by the
+ granting of "tokens" which give permission to send. A station
+ keeps the token while transmitting a message, if it has a
+ message to transmit, and then passes it on to the next
+ station.
+
+ Often, "Token Ring" is used to refer to the {IEEE 802.5} token
+ ring {standard}, which is the most common type of token ring.
+
+ {Usenet} newsgroup: {news:comp.dcom.lans.token-ring}.
+
+TomeRaider
+
+ <application, file format> A {cross-platform} reference and
+ {e-book reader} program and file format. TomeRaider files are
+ highly compressed and cross-referenced. The reader displays
+ the text and can follow the {hypertext links} embedded in the
+ text.
+
+ {TomeRaider Home (http://www.tomeraider.com/)}.
+
+ (2008-02-15)
+
+Tom Knight
+
+ <person> A noted {hacker} at {MIT}.
+
+ {(http://ai.mit.edu/people/tk/tk.html)}.
+
+ (1996-12-12)
+
+tone
+
+ {brightness}
+
+Tony Hoare
+
+ {Anthony Hoare}
+
+tool
+
+ 1. <tool> A program used primarily to create, manipulate,
+ modify, or analyse other programs, such as a compiler or an
+ editor or a cross-referencing program. Opposite: {app},
+ {operating system}.
+
+ 2. A {Unix} {application program} with a simple, "transparent"
+ (typically text-stream) interface designed specifically to be
+ used in programmed combination with other tools (see {filter},
+ {plumbing}).
+
+ 3. <jargon> ({MIT}: general to students there) To work; to
+ study (connotes tedium). The {TMRC} Dictionary defined this
+ as "to set one's brain to the grindstone". See {hack}.
+
+ 4. <jargon, person> ({MIT}) A student who studies too much and
+ hacks too little. MIT's student humour magazine rejoices in
+ the name "Tool and Die".
+
+ [{Jargon File}]
+
+ (1996-12-12)
+
+toolbar
+
+ <operating system> A common {graphical user interface}
+ component, consisting of a permanently visible row of button
+ {icons} that, when clicked with the {mouse}, cause the program
+ to perform some action such as printing the current document
+ or changing the {mode} of operation.
+
+ The toolbar buttons often invoke functions accessible via
+ {menus} but they are easier to use since they are permanently
+ visible. A typical use would be in a {paint} program where
+ the toolbar allows the users to select one of the various
+ painting "tools" - brush, pencil, bucket etc.
+
+ Some {application programs} under some {operating systems} may
+ allow the user to customise the functions accessible via
+ toolbars; in others, the choice is fixed by the programmer.
+
+ (2003-10-24)
+
+toolbook
+
+ <tool> A {Microsoft Windows} utility to make easy-to-use
+ applications with a {graphical user interface}. E.g. a guided
+ tour of some software.
+
+ (1995-03-14)
+
+Toolbuilder
+
+ {Tool Builder Kit}
+
+Tool Builder Kit
+
+ <tool> (TBK) A product from {IPSYS} which allows users to
+ develop {CASE} tools appropriate to any {software engineering}
+ {methodology}.
+
+ (1996-05-08)
+
+Tool Command Language
+
+ <language> /tik*l/ (Tcl) An interpreted string processing
+ language for issuing commands to {interactive} programs,
+ developed by {John Ousterhout} at {UCB}. Each {application
+ program} can extend tcl with its own set of commands.
+
+ Tcl is like a text-oriented {Lisp}, but lets you write
+ algebraic expressions for simplicity and to avoid scaring
+ people away. Though originally designed to be a "scripting
+ language" rather than for serious programming, Tcl has been
+ used successfully for programs with hundreds of thousands of
+ lines.
+
+ It has a peculiar but simple {syntax}. It may be used as an
+ embedded {interpreter} in application programs. It has
+ {exceptions} and {packages} (called libraries), {name-spaces}
+ for {procedures} and {variables}, and provide/require. It
+ supports {dynamic loading} of {object code}. It is {eight-bit
+ clean}. It has only three variable types: strings, lists and
+ {associative arrays} but no {structures}.
+
+ Tcl and its associated {GUI} {toolkit}, {Tk} run on all
+ flavors of {Unix}, {Microsoft Windows}, {Macintosh} and {VMS}.
+ Tcl runs on the {Amiga} and many other {platforms}.
+
+ Latest version: 8.0.3, as of 1998-09-25.
+
+ See also {expect} (control interactive programs and pattern
+ match on their output), {Cygnus Tcl Tools}, {[incr Tcl]} (adds
+ classes and inheritence to Tcl), {Scriptics} (John
+ Ousterhout's company that is the home of Tcl development and
+ the TclPro tool suite), {Tcl Consortium} (a non-profit agency
+ dedicated to promoting Tcl), {tclhttpd} (an embeddable
+ Tcl-based web server), {tclx} (adds many commands to Tcl),
+ {tcl-debug}.
+
+ {comp.lang.tcl FAQ at MIT
+ (ftp://rtfm.mit.edu/pub/usenet-by-group/comp.answers/tcl-faq/)}.
+ or {at purl.org (http://purl.org/NET/Tcl-FAQ/)}.
+
+ {Scriptics downloads
+ (http://scriptics.com/software/download.html)}.
+ {Kanji (ftp://srawgw.sra.co.jp/pub/lang/tcl/jp/)}.
+
+ {Usenet} newsgroups: {news:comp.lang.tcl.announce},
+ {news:comp.lang.tcl}.
+
+ ["Tcl: An Embeddable Command Language", J. Ousterhout, Proc
+ 1990 Winter USENIX Conf].
+
+ (1998-11-27)
+
+TOOLS
+
+ {Technology of Object-Oriented Languages and Systems}
+
+toolsmith
+
+ The software equivalent of a tool-and-die specialist; one who
+ specialises in making the {tools} with which other programmers
+ create applications. Many hackers consider this more fun than
+ applications per se; to understand why, see {uninteresting}.
+ Jon Bentley, in the "Bumper-Sticker Computer Science" chapter
+ of his book "More Programming Pearls", quotes Dick Sites from
+ DEC as saying "I'd rather write programs to write programs
+ than write programs".
+
+ [{Jargon File}]
+
+TOP
+
+ {Technical/Office Protocol}
+
+top-down design
+
+ <programming> (Or "stepwise refinement"). The software design
+ technique which aims to describe functionality at a very high
+ level, then partition it repeatedly into more detailed levels
+ one level at a time until the detail is sufficient to allow
+ coding. This approach to software design probably originated
+ at {IBM}, and grew out of {structured programming} practices.
+
+ (1996-08-04)
+
+Top-Down Model
+
+ <programming> A method for estimating the overall cost and
+ effort of the proposed software project from global properties
+ of the project. The total cost and schedule is partitioned
+ into components for planning purposes.
+
+ (1996-05-29)
+
+topic drift
+
+ <messaging> Term used on GEnie, {Usenet} and other electronic
+ fora to describe the tendency of a {thread} to drift away from
+ the original subject of discussion (and thus, from the Subject
+ header of the originating message).
+
+ Often used in gentle reminders that the discussion has strayed
+ off any useful track. "I think we started with a question
+ about Niven's last book, but we've ended up discussing the
+ sexual habits of the common marmoset. Now *that's* topic
+ drift!"
+
+ [{Jargon File}]
+
+ (1996-05-29)
+
+topic group
+
+ {forum}
+
+topic map
+
+ <information science> A collection of "topics", their
+ relationships, and information sources. A topic map captures the
+ subjects of which information sources speak, and the relationships
+ between them, in a way that is implementation independent.
+
+ A topic is a symbol within the computer that represents
+ something in the world such as the play Hamlet, the playwright
+ William Shakespeare, or the "authorship" relationship.
+
+ Topics can have names. They can also have occurrences, that
+ is, information resources that are considered to be relevant
+ in some way to their subject. Topics can play roles in
+ relationships.
+
+ Thus, topics have three kinds of characteristics: names,
+ sources, and roles played in relationships. The assignment of
+ such characteristics is considered to be valid within a
+ certain scope, or context.
+
+ Topic maps can be merged. Merging can take place at the
+ discretion of the user or application (at runtime), or may be
+ indicated by the topic map's author at the time of its
+ creation.
+
+ (2003-07-19)
+
+topic thread
+
+ <messaging> (From {Usenet}, {GEnie}, {CompuServe}) A more or
+ less continuous chain of postings on a single subject, sent to
+ a {forum} such as a {Usenet} newsgroup. To "follow a thread"
+ is to read a series of postings sharing a common subject.
+
+ On Usenet these are connected by "Reference" headers. The
+ better {newsreaders} can present news in thread order
+ automatically.
+
+ (2008-02-06)
+
+top-level domain
+
+ <networking> The last and most significant component of an
+ {Internet} {fully qualified domain name}, the part after the
+ last ".". For example, {host} wombat.doc.ic.ac.uk is in
+ top-level domain "uk" (for United Kingdom).
+
+ Every other country has its own top-level domain, including
+ ".us" for the U.S.A. Within the .us domain, there are
+ subdomains for the fifty states, each generally with a name
+ identical to the state's postal abbreviation. These are
+ rarely used however. Within the .uk domain, there is a .ac.uk
+ subdomain for academic sites and a .co.uk domain for
+ commercial ones. Other top-level domains may be divided up in
+ similar ways.
+
+ In the US and some other countries, the following top-level
+ domains are used much more widely than the country code:
+
+ .com - commercial bodies
+ .edu - educational institutions
+ .gov - U. S. government
+ .mil - U. S. armed services
+ .net - network operators
+ .org - other organisations
+
+ Since the rapid commercialisation of the Internet in the 1990s
+ the ".com" domain has become particularly heavily populated
+ with every company trying to register its company name as a
+ subdomain of .com, e.g. "netscape.com" so as to make it easy
+ for customers to guess or remember the {URL} of the comany's
+ {home page}.
+
+ United Nations entities use the domain names of the countries
+ where they are located. The UN headquarters facility in New
+ York City, for example, is un.org.
+
+ Several new top-level domains are about to be added (Oct
+ 1997):
+ .nom - individual people
+ .rec - recreational organisations
+ .firm - businesses such as law, accounting, engineering
+ .store - commercial retail companies
+ .ent - entertainment facilities and organisations
+
+ (1997-10-08)
+
+topology
+
+ 1. <mathematics> The branch of mathematics dealing with
+ {continuous transformations}.
+
+ 2. <networking> Which {hosts} are directly connected to which
+ other hosts in a {network}. {Network layer} processes need to
+ consider the current network topology to be able to {route}
+ {packets} to their final destination reliably and efficiently.
+
+ (2001-03-29)
+
+TOPS-10
+
+ /tops-ten/ DEC's proprietary OS for the fabled {PDP-10}
+ machines, long a favourite of hackers but now effectively
+ extinct. A fountain of hacker folklore. See also {ITS},
+ {TOPS-20}, {TWENEX}, {VMS}, {operating system}. TOPS-10 was
+ sometimes called BOTS-10 (from "bottoms-ten") as a comment on
+ the inappropriateness of describing it as the top of anything.
+
+ [{Jargon File}]
+
+TOPS-20
+
+ {TWENEX}
+
+Tornado
+
+ <programming> The {software development environment}
+ previously distributed with {VxWorks}.
+
+ (1996-11-29)
+
+Toronto Euclid
+
+ <language> The standard dialect of {Euclid}, as compared to
+ {Ottawa Euclid}.
+
+ (1996-11-29)
+
+torrent
+
+ {BitTorrent}
+
+TORTOS
+
+ {Terminal Oriented Real Time Operating System}
+
+TOS
+
+ <operating system> /toss/
+
+ 1. {IBM}'s {Tape Operating System}.
+
+ 2. The {operating system} of the {Atari} ST range of
+ computers. This range included the 512ST, 1040ST and the F,
+ FM and E variations (e.g.1040STE). Later, 32-bit machines
+ (TT, Falcon030 and MegaSTE) were developed using a new version
+ of TOS, called {MultiTOS} which was based on {MinT}.
+
+ TOS went through several revisions starting initially as a
+ derivative of {CP/M}, but developing into a remarkably
+ complete and flexible operating system. Features include: a
+ {flat memory model}, {MS-DOS}-compatible disk format and
+ support for {MIDI} and {SCSI} (in later versions). TOS was
+ designed to run Atari's version of the {GEM} {GUI}.
+
+ There is some argument as to what TOS stands for, the main
+ candidates being "Tramiel Operating System" (named after
+ Atari's head at the time) or simply "The Operating System".
+
+ 3. <networking> {Terms Of Service}.
+
+ 4. Star Trek The Original Series as opposed to ST-TNG or
+ ST-DS9.
+
+ (1999-04-02)
+
+Toshiba Corporation
+
+ <company> A Japanese technology manufacturer with 364
+ subsidiaries worldwide. Toshiba makes and sells electronics
+ for home, office, industry and health care including
+ information and communication systems, electronic components,
+ heavy electrical apparatus, consumer products and medical
+ diagnostic imaging equipment.
+
+ In FY 2003-4, Toshiba employed 161,286 people.
+
+ {Toshiba Home (http://toshiba.co.jp/)}.
+
+ (2005-01-19)
+
+TOSS
+
+ {Terminal Oriented Social Science}
+
+total function
+
+ <mathematics> A {function} which is defined for all arguments
+ of the appropriate type. The opposite is a {partial
+ function}.
+
+ (1997-01-10)
+
+totally ordered
+
+ <mathematics> Having a {total ordering}.
+
+ (1997-01-10)
+
+totally ordered set
+
+ <mathematics> A {set} with a {total ordering}.
+
+total ordering
+
+ <mathematics> A {relation} R on a set A which is a {partial
+ ordering}; i.e. it is reflexive (xRx), transitive (xRyRz =>
+ xRz) and antisymmetric (xRyRx => x=y) and for any two elements
+ x and y in A, either x R y or y R x.
+
+ See also {equivalence relation}, {well-ordered}.
+
+ (1995-02-16)
+
+toto
+
+ <programming> /toh-toh'/ The default scratch file name among
+ French-speaking programmers - in other words, a francophone
+ {foo}. The phonetic mutations "titi", "tata", and "tutu"
+ canonically follow "toto", analogously to {bar}, {baz} and
+ {quux} in English.
+
+ [{Jargon File}]
+
+ (1995-04-18)
+
+touchpad
+
+ <hardware> (Or "trackpad") A stationary {pointing device} used
+ mainly on {laptop computers}. Touchpads provide a small, flat
+ surface that you slide your finger over using the same
+ movements as you would a {mouse}. They were originally
+ developed to provide a more natural and intuitive connection
+ for the computer user than the mouse.
+
+ Touchpads use a principle called coupling {capacitance}, and
+ requires a {conductive} pointer such as a finger. They
+ contain a two-layer grid of {electrodes} which are connected
+ to an {integrated circuit} (IC) mounted under the pad. The
+ upper layer contains vertical electrode strips while the lower
+ layer is composed of horizontal electrode strips. Capacitance
+ from each of the horizontal electrodes to each of the vertical
+ electrodes is measured by the IC. A finger near the
+ intersection of two electrodes modifies the capacitance
+ between them, since a finger has very different {dielectric}
+ properties than air. The position of the finger is precisely
+ determined based on these changes at various locations.
+
+ According to one correspondent, you can use any part of your
+ body, which is not surprising, but not a McDonalds Chicken
+ McCrispy. You can use reheated Pizza Hut Christmas Pizza
+ though.
+
+ {Synaptics (http://synaptics.com/product.htm)}.
+
+ (2000-11-01)
+
+touch screen
+
+ <hardware> An input device that allows user to interact with
+ computer by touching the display screen.
+
+ Often this uses beams of infrared light that are projected
+ across the screen surface. Interrupting the beams generates
+ an electronic signal identifying the location of the screen.
+ Software interprets the signal and performs the required
+ operation.
+
+ (1995-04-13)
+
+tourist
+
+ <jargon> A guest on the system, especially one who generally
+ logs in over a network from a remote location for {comm mode},
+ {electronic mail}, {games} and other trivial purposes. A
+ tourist is one step below a {luser}.
+
+ Hackers often spell this {turist}, perhaps by some sort of
+ tenuous analogy with {luser} (this also expresses the {ITS}
+ culture's penchant for six-letterisms).
+
+ Compare {twink}, {read-only user}.
+
+ [{Jargon File}]
+
+ (1995-03-10)
+
+tourist information
+
+ Information in an on-line display that is not immediately
+ useful, but contributes to a viewer's gestalt of what's going
+ on with the software or hardware behind it. Whether a given
+ piece of info falls in this category depends partly on what
+ the user is looking for at any given time. The "bytes free"
+ information at the bottom of an {MS-DOS} "dir" display is
+ tourist information; so (most of the time) is the TIME
+ information in a {Unix} "ps(1)" display.
+
+ [{Jargon File}]
+
+Towers of Hanoi
+
+ <games> A classic computer science problem, invented by
+ Edouard Lucas in 1883, often used as an example of
+ {recursion}.
+
+ "In the great temple at Benares, says he, beneath the dome
+ which marks the centre of the world, rests a brass plate in
+ which are fixed three diamond needles, each a cubit high and
+ as thick as the body of a bee. On one of these needles, at
+ the creation, God placed sixty-four discs of pure gold, the
+ largest disc resting on the brass plate, and the others
+ getting smaller and smaller up to the top one. This is the
+ Tower of Bramah. Day and night unceasingly the priests
+ transfer the discs from one diamond needle to another
+ according to the fixed and immutable laws of Bramah, which
+ require that the priest on duty must not move more than one
+ disc at a time and that he must place this disc on a needle so
+ that there is no smaller disc below it. When the sixty-four
+ discs shall have been thus transferred from the needle on
+ which at the creation God placed them to one of the other
+ needles, tower, temple, and Brahmins alike will crumble into
+ dust, and with a thunderclap the world will vanish."
+
+ The recursive solution is: Solve for n-1 discs recursively,
+ then move the remaining largest disc to the free needle.
+
+ Note that there is also a non-recursive solution: On
+ odd-numbered moves, move the smallest sized disk clockwise.
+ On even-numbered moves, make the single other move which is
+ possible.
+
+ ["Mathematical Recreations and Essays", W W R Ball, p. 304]
+
+ {The rec.puzzles Archive
+ (http://rec-puzzles.org/sol.pl/induction/hanoi)}.
+
+ (2003-07-13)
+
+Tower Technology Corporation
+
+ A company, established in 1992 by the merger of two {OOT}
+ companies, with the intention of supplying high performance
+ {Eiffel} compilation systems. Tower provides development
+ tools, reusable {class} libraries, and services supporting
+ large scale system development.
+
+ {(http://cm.cf.ac.uk/Tower/)}.
+
+ E-mail: <tower@twr.com> (orders and inquiries), <outlook@twr.com>
+ (The Eiffel Outlook Journal).
+
+ Telephone: +1 (512) 452 9455 (8:30 to 5:30 CST business days).
+ Fax: +1 (512) 452 1721. Sales +1 (800) 285-5124 (Free, USA
+ and Canada only).
+
+ Address: Tower Technology, 1501 W. Koenig Lane, Austin, TX
+ 78756, USA.
+
+ (1994-12-12)
+
+toy
+
+ A computer system; always used with qualifiers.
+
+ 1. "nice toy": One that supports the speaker's hacking style
+ adequately.
+
+ 2. "just a toy": A machine that yields insufficient
+ {computrons} for the speaker's preferred uses. This is not
+ condemnatory, as is {bitty box}; toys can at least be fun. It
+ is also strongly conditioned by one's expectations; Cray XMP
+ users sometimes consider the Cray-1 a "toy", and certainly all
+ RISC boxes and mainframes are toys by their standards. See
+ also {Get a real computer!}.
+
+ [{Jargon File}]
+
+Toy/Ada
+
+ <language> A {compiler} for a subset of {Ada}, written in
+ {SML/NJ} by Amit Bhatiani at Rose-Hulman University.
+
+ {(ftp://master.cs.rose-hulman.edu/pub/)}.
+
+ (1992-04-08)
+
+toy language
+
+ <language> A language useful for instructional purposes or as
+ a proof-of-concept for some aspect of computer-science theory,
+ but inadequate for general-purpose programming. {Bad Things}
+ can result when a toy language is promoted as a general
+ purpose solution for programming (see {bondage-and-discipline
+ language}); the classic example is {Pascal}. Several
+ moderately well-known formalisms for conceptual tasks such as
+ programming {Turing Machines} also qualify as toy languages in
+ a less negative sense.
+
+ See also {MFTL}.
+
+ [{Jargon File}]
+
+ (1995-05-09)
+
+Toyohashi University Parallel Lisp Environment
+
+ <language> (TUPLE) A parallel {Lisp} based on {KCL}.
+
+ ["Memory Management and Garbage Collection of an Extended
+ Common Lisp System for Massively Parallel SIMD Architecture",
+ Taiichi Yuasa, in Memory Management, IWMM92, Springer 1992,
+ 490-507].
+
+ (1994-11-08)
+
+toy problem
+
+ [AI] A deliberately oversimplified case of a challenging
+ problem used to investigate, prototype, or test algorithms for
+ a real problem. Sometimes used pejoratively. See also
+ {gedanken}, {toy program}.
+
+ [{Jargon File}]
+
+toy program
+
+ <programming> 1. A trivial program that can be readily
+ comprehended.
+
+ 2. A program for which the effort of initial coding dominates
+ the costs through its {life cycle}.
+
+ See also {noddy}.
+
+ (1996-05-19)
+
+tp
+
+ <networking> The {country code} for East Timor.
+
+ (1999-01-27)
+
+TPA
+
+ {Transient Program Area}
+
+TPF
+
+ {Transaction Processing Facility}
+
+TP/IX
+
+ <networking, protocol> An {Internet} {protocol}, described in
+ {RFC 1475}, which changes {TCP} and {UDP} headers to give a
+ 64-bit {IP address}, a 32-bit {port} number, and a 64 bit
+ sequence number.
+
+ (1995-04-03)
+
+TPL
+
+ 1. Table Producing Language. "The Bureau of Labor Statistics
+ Table Producing Language (TPL)", R.C. Mendelssohn, Proc ACM
+ Annual Conf (1974).
+
+ 2. Fleming Nielson. A concurrent {functional language}.
+
+ 3. Terminal Programming Language. Texas Inst, late 70's.
+ Used on the TI-990/1 Small Business Computer and the TI-771
+ Intelligent Terminal.
+
+TPO
+
+ {twisted pair only}
+
+TPS
+
+ Tree Pruning System. "An Adaptive Tree Pruning System: A
+ Language for Programming Heuristic Tree Searches",
+ E.W. Kozdrowicki, Proc ACM 23rd Natl Conf 1968.
+
+tptc
+
+ A {Turbo Pascal} to {Turbo C} translator. Comes with full
+ source.
+
+ {(ftp://wuarchive.wustl.edu/mirrors/msdos/turbopas/tptc17*.zip)}.
+
+TPU
+
+ {Text Processing Utility}
+
+TPX
+
+ {Terminal Productivity eXecutive}
+
+tr
+
+ <networking> The {country code} for Turkey.
+
+ (1999-01-27)
+
+TRAC
+
+ {Text Reckoning And Compiling}
+
+traceroute
+
+ <networking> A {TCP/IP} utility, originally {Unix}, which
+ allows the user to determine the {route} {packets} are taking
+ to a particular {host}. Traceroute works by increasing the
+ "{time to live}" value of packets and seeing how far they get,
+ until they reach the given destination; thus, a lengthening
+ trail of hosts passed through is built up.
+
+ (2007-02-02)
+
+trace scheduling
+
+ <processor> A method of controlling and coordinating the
+ operation of multiple hardware elements of a {Very Long
+ Instruction Word} processor. It was developed by Josh Fisher
+ at the now-defunct {Multiflow Computer} Corporation
+
+ [Details?]
+
+ (1995-03-01)
+
+track
+
+ <storage> The part of a {disk} which passes under one
+ read/write head while the head is stationary. The number of
+ tracks on a disk surface therefore corresponds to the number
+ of different radial positions of the head(s). The collection
+ of all tracks on all surfaces at a given radial position is
+ known a {cylinder} and each track is divided into {sectors}.
+
+ (1997-07-15)
+
+track ball
+
+ {tracker ball}
+
+tracker ball
+
+ <hardware> A {pointing device} consisting of a ball housed in
+ a socket containing sensors to detect rotation of the ball
+ about two axes - like an upside-down {mouse}. The user rolls
+ the ball with his thumb or the palm of his hand to move a
+ cursor. Tracker balls are common on {CAD} {workstations} for
+ ease of use and on modern {portable computers}, where there
+ may be no desk space on which to use a {mouse}. Some clip
+ onto the side of the keyboard and have integral buttons which
+ have the same function as mouse buttons.
+
+ (1996-08-04)
+
+tracking
+
+ <text> The horizontal spacing between {characters} in a line of
+ {text}. Tracking is set when a {font} is designed but can often
+ be altered in order to change the appearance of the text or for
+ special effects. It applies to both {proportional fonts} and
+ {monospaced fonts}.
+
+ Tracking should not be confused with {kerning} which deals with
+ the spacing between certain pairs of characters in a proportional
+ font.
+
+ See also {leading}.
+
+ (2013-12-05)
+
+tracking cookie
+
+ <web> An {HTTP cookie} used to identify a user of a
+ {website} in order to log which pages they visit. The site owner
+ can use this information to optimise the site, e.g. for marketing
+ purposes.
+
+ (2013-12-05)
+
+tracking file
+
+ {tracking cookie}
+
+trackpad
+
+ {touchpad}
+
+TrackPoint
+
+ <hardware> (Or "pointing stick", "nipple") A small knob found
+ in the middle of some {keyboards} that works like a very short
+ {isometric joystick}. Pressing it toward or away from you or
+ from side to side moves the {pointer} on the screen. Ted
+ Selker brought the concept of an in-keyboard pointing device
+ to {IBM} in September 1987. TrackPoint was introduced in 1992
+ on the {IBM} {ThinkPad} and later on some {desktops}.
+
+ It takes up virtually no extra room on the box or the work
+ area and also requires minimal movement of the hands from the
+ keyboard.
+
+ Many imitations of highly variable quality appeared. Pointing
+ sticks have also been used in many other {notebook} brands,
+ including {TI}, {HP}, {Compac}, {Dell}, {Toshiba}
+ (e.g. Portege 4000's "AccuPoint II"), and {AST} (e.g. Ascentia
+ 910N).
+
+ "TrackPoint" and "Trackpoint" are IBM trademarks.
+
+ {(http://research.ibm.com/mathsci/cmc/trackpoint.htm)}.
+
+ [INTERACT'90, North Holland Pub Co, pp. 700-706].
+
+ (2003-10-15)
+
+tractor feed
+
+ {sprocket feed}
+
+TrafoLa
+
+ <language> A {functional programming} language designed in the
+ {PROSPECTRA} {ESPRIT} project to support declarative
+ specification of {program transformations}. It provides
+ higher-order {pattern matching} on expression trees with
+ {backtracking}.
+
+ [Heckmann88].
+
+ (1996-06-07)
+
+Trafola-H
+
+ A specification language for program transformations.
+ Functional, statically typed, polymorphic, with extended
+ constructs for pattern-matching. "Trafola-H Reference
+ Manual", R. Heckmann et al, U Saarlandes, Saarbrucken 1991.
+
+trampoline
+
+ An incredibly {hairy} technique, found in some {HLL} and
+ program-overlay implementations (e.g. on the Macintosh), that
+ involves on-the-fly generation of small executable (and,
+ likely as not, self-modifying) code objects to do indirection
+ between code sections. These pieces of {live data} are called
+ "trampolines". Trampolines are notoriously difficult to
+ understand in action; in fact, it is said by those who use
+ this term that the trampoline that doesn't bend your brain is
+ not the true trampoline. See also {snap}.
+
+ [{Jargon File}]
+
+ (2003-03-26)
+
+TRANDIR
+
+ TRANslation DIRector. A language for syntax-directed
+ compiling. Sammet 1969, p.640.
+
+TRANQUIL
+
+ 1966. ALGOL-like language with sets and other extensions, for
+ the Illiac IV. "TRANQUIL: A Language for an Array Processing
+ Computer", N.E. Abel et al, Proc SJCC 34 (1969).
+
+TRANS
+
+ TRAffic Network Simulation Language. "A Model for Traffic
+ Simulation and a Simulation Language for the General
+ Transportation Problem", Proc FJCC 37 (1970).
+
+transaction
+
+ A unit of interaction with a {DBMS} or similar system. It
+ must be treated in a coherent and reliable way independent of
+ other transactions. See {atomic}.
+
+Transaction Application Language
+
+ <language> (TAL) Not "Tandem Application Language". A
+ {block-structured}, {procedural} language optimised for use on
+ {Tandem} {hardware}. TAL is a cross between {C} and {Pascal} and
+ is the primary system programming language on {Tandem} computers.
+ Tandem has no {assembler} and originally had no C or Pascal.
+
+ [Was TAL derived from HP's System Programming Language?]
+
+ (2001-07-09)
+
+Transaction Processing Facility
+
+ <operating system> (TPF) A {real-time} {mainframe} {operating
+ system} released by {IBM} around 1976. TPF is particularly
+ suited to organisations dealing in very high I/O message
+ switching and large global networks. Current users include
+ British Airways (reservations), VISA International
+ (authorisations), Holiday Inn, and Quantas.
+
+ TPF was traditionally a {370/Assembler} environment although
+ the latest, release 4.1, contains {C}. Formerly known as ACP
+ (Airline Control Program), it was renamed "TPF" to suggests
+ its greater scope.
+
+ It is common for TPF sites to use IBM's {MVS} and {VM}
+ operating systems for {off-line} processing.
+
+ (1996-08-27)
+
+transceiver
+
+ <networking> Transmitter-receiver, any device that performs
+ both functions.
+
+ For example, on an {Ethernet} network, a transceiver is the
+ hardware that connects a {host} interface (e.g. an {Ethernet}
+ controller) to a {local area network}. Ethernet transceivers
+ contain electronics that apply signals to the cable and sense
+ other host's signals and collisions. See also {CSMA/CD}.
+
+ (2008-08-04)
+
+TRANSCODE
+
+ <language> An early system on the {Ferut} computer.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (2008-08-04)
+
+transducer
+
+ 1. A device for converting sound, temperature, pressure, light
+ or other signals to or from an electronic signal.
+
+ 2. {Finite State Machine}.
+
+ (1995-02-15)
+
+transfer
+
+ 1. <data> {data transfer}.
+
+ 2. <programming> {transfer of control}.
+
+ 3. <messaging> The movement of {electronic mail} between
+ servers by a {Message Transfer Agent}.
+
+transfer none
+
+ {introspection annotation}
+
+transfer of control
+
+ <programming> To cause {execution} of a {program} to continue
+ from a different address instead of proceding sequentially to
+ the next instruction. This may happen as a result of a {jump}
+ instruction or some kind of {interrupt}.
+
+ This term is more common when discussing {machine code}, the
+ {high-level language} equivalent is a {goto} statement.
+
+ (2009-06-09)
+
+transfer rate
+
+ {data transfer rate}
+
+transfer syntax
+
+ <networking, protocol> The actual representation of data as it
+ is transmitted over a {network} (as opposed to {abstract
+ syntax}).
+
+ (1998-05-19)
+
+transfinite induction
+
+ <mathematics> {Induction} over some (typically large)
+ {ordinal}.
+
+ (1995-03-30)
+
+transformation
+
+ {program transformation}
+
+transient
+
+ 1. <electronics> A sudden, brief increase in {current} or
+ {voltage} in a circuit that can damage sensitive components
+ and instruments.
+
+ (2003-06-12)
+
+ 2. <software> A software object with a short and limited
+ lifetime which is not saved for later reuse.
+
+ (1998-04-19)
+
+Transient Program Area
+
+ <operating system> (TPA) The region of memory {CP/M} set aside
+ for user programs.
+
+ (2001-11-01)
+
+transistor
+
+ <electronics> A three terminal {semiconductor} amplifying
+ device, the fundamental component of most active electronic
+ circuits, including digital electronics. The transistor was
+ invented on 1947-12-23 at {Bell Labs}.
+
+ There are two kinds, the {bipolar transistor} (also called the
+ junction transistor), and the {field effect transistor} (FET).
+
+ Transistors and other components are interconnected to make
+ complex {integrated circuits} such as {logic gates},
+ {microprocessors} and memory.
+
+ (1995-10-05)
+
+Transistor-Transistor Logic
+
+ (TTL) A common semiconductor technology for building discrete
+ digital logic integrated circuits. It originated from {Texas
+ Instruments} in 1965.
+
+ There have been several series of TTL logic:
+
+ 7400: 10 ns propagation time, 10 mW/gate power consumption,
+ obsolete;
+
+ 74L00: Low power: higher resistances, less dissipation
+ (1 mW), longer propagation time (30 ns);
+
+ 74H00: High power: lower resistances, more dissipation: less
+ sensitivity for noise;
+
+ 74S00: Schottky-clamped: faster switching (3 ns, 19 mW) by
+ using Schottky diodes to prevent the transistors from
+ saturation;
+
+ 74LS00: Low power, Schottky-clamped (10 ns, 2 mW);
+
+ 74AS00: Advanced Schottky: faster switching, less
+ dissipation, (1.5 ns, 10 mW);
+
+ 74ALS00: Advanced Low power Schottky (4 ns, 1.3 mW).
+
+ For each 74xxx family there is a corresponding 54xxx family.
+ The 74 series are specified for operation at 0 - 70 C whereas
+ the 54 (military) series can operate at -55 - 125 C
+
+ See also {CMOS}, {ECL}.
+
+TRANSIT
+
+ <language> A subsystem of {ICES}.
+
+ [Sammet 1969, p.616].
+
+ (2003-07-12)
+
+transition ad
+
+ {interstitial}
+
+transitive
+
+ A relation R is transitive if x R y & y R z => x R z.
+ Equivalence relations, pre-, partial and total orders are all
+ transitive.
+
+transitive closure
+
+ The transitive closure R* of a relation R is defined by
+
+ x R y => x R* y
+ x R y and y R* z => x R* z
+
+ I.e. elements are related by R* if they are related by R
+ directly or through some sequence of intermediate related
+ elements.
+
+ E.g. in graph theory, if R is the relation on nodes "has an
+ edge leading to" then the transitive closure of R is the
+ relation "has a path of zero or more edges to". See also
+ Reflexive transitive closure.
+
+transit network
+
+ A {network} which passes traffic between other networks in
+ addition to carrying traffic for its own {hosts}. It must
+ have paths to at least two other networks.
+
+ See also {backbone}, {stub}.
+
+ (1995-01-30)
+
+Translation Look-aside Buffer
+
+ <storage, architecture> (TLB) A table used in a {virtual
+ memory} system, that lists the {physical address} {page}
+ number associated with each {virtual address} {page} number.
+ A TLB is used in conjunction with a {cache} whose tags are
+ based on virtual addresses. The virtual address is presented
+ simultaneously to the TLB and to the cache so that cache
+ access and the virtual-to-physical address translation can
+ proceed in parallel (the translation is done "on the side").
+ If the requested address is not cached then the physical
+ address is used to locate the data in main memory. The
+ alternative would be to place the translation table between
+ the cache and main memory so that it will only be activated
+ once there was a cache miss.
+
+ (1995-01-30)
+
+Transmission Control Protocol
+
+ <networking, protocol> (TCP) The most common {transport layer}
+ {protocol} used on {Ethernet} and the {Internet}. It was
+ developed by {DARPA}.
+
+ TCP is the {connection-oriented} protocol built on top of
+ {Internet Protocol} (IP) and is nearly always seen in the
+ combination {TCP/IP} (TCP over IP). It adds {reliable
+ communication} and {flow-control} and provides {full-duplex},
+ process-to-process connections.
+
+ TCP is defined in {STD 7} and {RFC} 793.
+
+ {User Datagram Protocol} is the other, connectionless,
+ protocol that runs on top of IP.
+
+ (2001-06-14)
+
+transparent
+
+ 1. <jargon> Not visible, hidden; said of a system which
+ functions in a manner not evident to the user. For example,
+ the {Domain Name System} transparently resolves a {fully
+ qualified domain name} into an {IP address} without the
+ user being aware of it.
+
+ Compare this to what {Donald Norman
+ (http://atg.apple.com/Norman/)} calls "invisibility",
+ which he illustrates from the user's point of view:
+
+ "You use computers when you use many modern automobiles,
+ microwave ovens, games, CD players and calculators. You don't
+ notice the computer because you think of yourself as doing the
+ task, not as using the computer." ["The Design of Everyday
+ Things", New York, Doubleday, 1989, p. 185].
+
+ 2. <theory> Fully defined, known, predictable; said of a
+ sub-system in which matters generally subject to volition or
+ stochastic state change have been chosen, measured, or
+ determined by the environment. Thus for transparent systems,
+ output is a known function of the inputs, and users can both
+ predict the behaviour and depend upon it.
+
+ (1996-06-04)
+
+transparent audio coding
+
+ <audio, compression> A {lossy audio compression} {algorithm}
+ is transparent if the original and decoded signal are
+ indistinguishable to the human ear. The bit rate depends on
+ the {codec} and the audio material. Some codecs (e.g. {AAC},
+ {MP3}) are optimized for transparent coding at a low data
+ rate, others (e.g. {VQF}, {MP3Pro}, {AAC}+{SBR}, {WMA}) for
+ distinguisable but pleasant reproduction at lower bit rates.
+
+ Typical data rates in {kbps} for different codecs are:
+
+ MP1 288-320
+ MP2 224-256
+ MP3 160-224
+ MPEG-2 AAC 128-160
+ MPEG-4 AAC 112-144
+ MPEGplus 160-200
+
+ (2001-12-23)
+
+Transport Driver Interface
+
+ <networking> (TDI) Developed by {SUN}, {IBM}, and {Microsoft}
+ (and others?), the TDI is a {software} {interface} between the
+ {protocols} and {application programing interface} layers of
+ the {Windows NT network model}.
+
+ (1997-11-05)
+
+transport layer
+
+ <networking> (Or "host-host layer") The middle layer in the
+ {OSI} seven layer model. The transport layer determines how
+ to use the {network layer} to provide a virtual error-free,
+ point to point connection so that host A can send messages to
+ host B and they will arrive un-corrupted and in the correct
+ order. It establishes and dissolves connections between
+ hosts. It is used by the {session layer}.
+
+ An example transport layer {protocol} is {Transmission Control
+ Protocol} (TCP).
+
+ {OSI} documents: {ITU} Rec. X.214 (ISO 8072), ITU Rec. X.224
+ (ISO 8073).
+
+ (1997-12-07)
+
+Transport Layer Interface
+
+ <networking, programming> (TLI, or "Transport Level
+ Interface") A {protocol}-independent interface for accessing
+ network facilities, modelled after the {ISO} {transport layer}
+ (level 4), that first appeared in {Unix SVR3}.
+
+ TLI is defined by {SVID} as transport mechanism for networking
+ interfaces, in preference to {sockets}, which are biased
+ toward {IP} and friends. A disavantage is that a process
+ cannot use read/write directly, but has to use backends using
+ {stdin} and {stdout} to communicate with the network
+ connection. TLI is implemented in SVR4 using the {STREAMS}
+ interface. It adds no new {system calls}, just a library,
+ libnsl_s.a. The major functions are t_open, t_bind,
+ t_connect, t_listen, t_accept, t_snd, t_rcv, read, write.
+
+ According to the {Solaris} t_open {man page}, XTI (X/OPEN
+ Transport Interface) evolved from TLI, and supports the TLI
+ {API} for compatibility, with some variations on semantics.
+
+ (1999-06-10)
+
+Transport Layer Security protocol
+
+ <networking, protocol> (TLS) A {protocol} designed to allow
+ {client/server} applications to communicate over the
+ {Internet} without {eavesdropping}, {tampering}, or {message
+ forgery}.
+
+ TLS is defined in {RFC 2246}.
+
+ (2003-10-03)
+
+Transport Level Interface
+
+ {Transport Layer Interface}
+
+Transport Service Access Point
+
+ <networking> (TSAP) Part of the {OSI} {IP Presentation
+ Addressing schema}.
+
+ A TSAP identifes the {service access point} between the
+ {session layer} and the {transport layer}.
+
+ (1999-08-01)
+
+transputer
+
+ <processor, parallel> (Note lower case) A family of
+ {microprocessors} from {Inmos} with interprocessor links,
+ programmable in {occam}.
+
+ [More details?]
+
+ (1994-11-18)
+
+TRANS-USE
+
+ <language> An early system on the {IBM 1130}.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (2004-09-14)
+
+trap
+
+ 1. A program interrupt, usually an interrupt caused by some
+ exceptional situation in the user program. In most cases, the
+ OS performs some action, then returns control to the program.
+
+ 2. To cause a trap. "These instructions trap to the monitor."
+ Also used transitively to indicate the cause of the trap.
+ "The monitor traps all input/output instructions."
+
+ This term is associated with assembler programming
+ ("interrupt" or "exception" is more common among {HLL}
+ programmers) and appears to be fading into history among
+ programmers as the role of assembler continues to shrink.
+ However, it is still important to computer architects and
+ systems hackers (see {system}, sense 1), who use it to
+ distinguish {deterministic}ally repeatable exceptions from
+ timing-dependent ones (such as I/O interrupts).
+
+ [{Jargon File}]
+
+trap door
+
+ Or "trapdoor" 1. {back door}.
+
+ 2. {trap-door function}
+
+trap-door function
+
+ <cryptography, mathematics> A special class of {one-way
+ function}, which is reversible if you know a certain secret
+ associated with the function.
+
+ {(http://rsasecurity.com/rsalabs/faq/2-3-2.html)}.
+ {(http://ieor.berkeley.edu/~jshu/knapsack/Review/OverviewPK.html)}.
+
+ (2003-05-22)
+
+trash
+
+ To destroy, e.g. the contents of a data structure. The most
+ common of the family of near-synonyms including {mung},
+ {mangle}, and {scribble}.
+
+ [{Jargon File}]
+
+ (1994-11-03)
+
+Trash-80
+
+ Derogatory name for {Tandy}'s {TRS-80}.
+
+ (1994-11-03)
+
+traveling salesman problem
+
+ <spelling> US spelling of {travelling salesman problem}.
+
+ (1996-12-13)
+
+travelling salesman
+
+ {travelling salesman problem}
+
+travelling salesman problem
+
+ <algorithm, complexity> (TSP or "shortest path", US:
+ "traveling") Given a set of towns and the distances between
+ them, determine the shortest path starting from a given town,
+ passing through all the other towns and returning to the first
+ town.
+
+ This is a famous problem with a variety of solutions of
+ varying complexity and efficiency. The simplest solution (the
+ {brute force} approach) generates all possible routes and
+ takes the shortest. This becomes impractical as the number of
+ towns, N, increases since the number of possible routes is
+ !(N-1). A more intelligent {algorithm} (similar to {iterative
+ deepening}) considers the shortest path to each town which can
+ be reached in one hop, then two hops, and so on until all
+ towns have been visited. At each stage the algorithm
+ maintains a "frontier" of reachable towns along with the
+ shortest route to each. It then expands this frontier by one
+ hop each time.
+
+ {Pablo Moscato's TSP bibliography
+ (http://densis.fee.unicamp.br/~moscato/TSPBIB_home.html)}.
+ {Fractals and the TSP
+ (http://ing.unlp.edu.ar/cetad/mos/FRACTAL_TSP_home.html)}.
+
+ (1998-03-24)
+
+traversal
+
+ <data> Processing {nodes} in a {graph} one at a time, usually
+ in some specified order. Traversal of a tree is {recursive}ly
+ defined to mean visiting the {root node} and traversing its
+ children. Visiting a node usually involves transforming it in
+ some way or collecting data from it.
+
+ In "pre-order traversal", a node is visited __before__ its
+ children. In "post-order" traversal, a node is visited
+ __after__ its children. The more rarely used "in-order"
+ traversal is generally applicable only to binary trees, and is
+ where you visit first a node's left child, then the node
+ itself, and then its right child.
+
+ For the binary tree:
+
+ T
+ / \
+ I S
+ / \
+ D E
+
+ A pre-order traversal visits the nodes in the order T I D E S.
+ A post-order traversal visits them in the order D E I S T. An
+ in-order traversal visits them in the order D I E T S.
+
+ (2001-10-01)
+
+traverse
+
+ {traversal}
+
+trawl
+
+ To sift through large volumes of data (e.g. {Usenet} postings,
+ FTP archives, or the {Jargon File}) looking for something of
+ interest.
+ [{Jargon File}]
+
+tree
+
+ <mathematics, data> A {directed acyclic graph}; i.e. a {graph}
+ wherein there is only one route between any pair of {nodes},
+ and there is a notion of "toward top of the tree" (i.e. the
+ {root node}), and its opposite direction, toward the {leaves}.
+ A tree with n nodes has n-1 edges.
+
+ Although maybe not part of the widest definition of a tree, a
+ common constraint is that no node can have more than one
+ parent. Moreover, for some applications, it is necessary to
+ consider a node's {daughter} nodes to be an ordered {list},
+ instead of merely a {set}.
+
+ As a data structure in computer programs, trees are used in
+ everything from {B-trees} in {databases} and {file systems}, to
+ {game trees} in {game theory}, to {syntax trees} in a human or
+ computer {languages}.
+
+ (1998-11-12)
+
+tree-killer
+
+ <jargon, abuse> (Sun) 1. A printer.
+
+ 2. A person who wastes paper. This epithet should be
+ interpreted in a broad sense; "wasting paper" includes the
+ production of {spiffy} but {content-free} documents. Thus,
+ most {suits} are tree-killers.
+
+ This term may derive from {J.R.R. Tolkien's "Lord of the
+ Rings"
+ (http://sf.www.lysator.liu.se/sf_archive/sf-texts/SF_resource_guide/sfrgft.htm)}.
+ in which Treebeard the Ent uses it to refer to the orcs'
+ master, Saruman of Isengard. Saruman represents, among other
+ things, technology at its most misguided.
+
+ See also: {dead tree}.
+
+ [{Jargon File}]
+
+ (1999-11-03)
+
+TREET
+
+ E.C. Haines, 1964. An experimental variant of LISP1.5,
+ implemented on the STRETCH computer. Basic structure was a
+ trinary tree.
+
+ ["The TREET {Time-Sharing} System", H.A. Bayard et al, Proc
+ 2nd Symp Symb and Alg Manip, ACM (Mar 1971)].
+
+ [Sammet 1969, pp.457-461].
+
+TREETRAN
+
+ A {Fortran IV} subroutine package for tree manipulation.
+
+Tree Transformation Language
+
+ <functional programming> (TXL) A hybrid {functional language} and
+ {rule-based language} developed by J.R. Cordy
+ <cordy@cs.queensu.ca> et al of {Queen's University}, Canada in
+ 1988. TXL is suitable for performing {source to source analysis}
+ and transformation and for {rapid prototyping} of new languages
+ and language processors. It uses {structural transformation}
+ based on {term rewriting}.
+
+ TXL has been particularly successful in {software engineering}
+ tasks such as {design recovery}, {refactoring}, and
+ {reengineering}. Most recently it has been applied to
+ {artificial intelligence} tasks such as recognition of
+ hand-written mathematics, and to transformation of {structured
+ documents} in {XML}.
+
+ TXL takes as input an arbitrary {context-free grammar} in
+ {extended BNF}-like notation, and a set of {show-by-example}
+ transformation rules to be applied to inputs parsed using the
+ grammar. TXL supports the notion of {agile parsing}, the
+ ability to tailor the grammar to each particular task using
+ "grammar overrides".
+
+ Latest version: FreeTXL 10.3, as of 2003-10-26.
+
+ {TXL Home (http://txl.ca/)}.
+
+ ["TXL: A Rapid Prototyping System for Programming Language
+ Dialects", J.R. Cordy, C.D.; Halpern and D. Promislow,
+ Computer Languages, Vol. 16, No. 1, January 1991, pp 97-107]
+
+ ["Source Transformation in Software Engineering using the TXL
+ Transformation System", J.R. Cordy, T.R. Dean, A.J. Malton and
+ K.A. Schneider, Journal of Information and Software
+ Technology, Vol. 44, No. 13, October 2002, pp 827-837]
+
+ ["Recognizing Mathematical Expressions Using Tree
+ Transformation", R. Zanibbi, D. Blostein and J.R. Cordy, IEEE
+ Transactions on Pattern Analysis & Machine Intelligence,
+ Vol. 24, No. 11, November 2002, pp 1455-1467]
+
+ ["Agile Parsing in TXL", T.R. Dean, J.R. Cordy, A.J. Malton
+ and K.A. Schneider, Journal of Automated Software Engineering,
+ Vol. 10, No. 4, October 2003, pp 311-336]
+
+ (2003-11-04)
+
+treeware
+
+ <jargon> /tree'weir/ Printouts, books, {documentation}, and
+ other information media made from pulped dead trees by a
+ {tree-killer}.
+
+ [{Jargon File}]
+
+ (1999-01-15)
+
+Trellis
+
+ 1. An {object-oriented} language from the University of
+ Karlsruhe(?) with {static type-checking} and {encapsulation}.
+
+ 2. An {object-oriented} application development system from
+ {DEC}, based on the {Trellis} language. (Formerly named Owl).
+
+ E-mail: Jerry Smith <smith@pipe.enet.dec.com>
+
+ ["Persistent and Shared Objects in trellis/owl", P. O'Brien et
+ al, Proc 1986 IEEE Workshop on Object-Oriented Database
+ Systems, IEEE, NY 1986].
+
+Trellis Code Modulation
+
+ (TCM) A modulation technique with hardware {error detection
+ and correction}.
+
+ [Details?]
+
+ (1995-02-22)
+
+Trident
+
+ <company> A {video card} manufacturer.
+
+ [More info?]
+
+ (1997-07-16)
+
+trigger
+
+ <database> An action causing the automatic invocation of a
+ procedure, for instance to preserve {referential integrity}.
+ A triggers goes into effect when a user attempts to modify
+ data with an insert, delete, or update command. A trigger can
+ instruct the system to take any number of actions when a
+ specified change is attempted. By preventing incorrect,
+ unauthorized, or inconsistent changes to data, triggers help
+ maintain the integrity of the database.
+
+ [Sybase SQL Server Release 10.0 Transact-SQL User's Guide].
+
+ (1995-02-22)
+
+trigger finger
+
+ {overuse strain injury}
+
+TRIGMAN
+
+ A system for {symbolic mathematics}, especially celestial
+ mechanics.
+
+ (1994-12-14)
+
+trillion
+
+ <mathematics> In Britain, France, and Germany, 10^18 or a
+ million cubed.
+
+ In the USA and Canada, 10^12.
+
+ [Elsewhere?]
+
+ (1996-10-03)
+
+Trilogy
+
+ <language> A {strongly typed} {logic programming} language
+ with numerical {constraint}-solving over the {natural
+ numbers}, developed by Paul Voda <voda@voda.ii.fmph.uniba.sk>
+ at {UBC} in 1988. Trilogy is syntactically a blend of
+ {Prolog}, {Lisp}, and {Pascal}. It contains three types of
+ {clauses}: {predicates} ({backtracking} but no assignable
+ variables), procedures (if-then-else but no backtracking;
+ assignable variables), and {subroutines} (like procedures, but
+ with input and {system calls}; callable only from top level or
+ from other subroutines).
+
+ Development of Trilogy I stopped in 1991. Trilogy II,
+ developed by Paul Voda 1988-92, was a {declarative} general
+ purpose programming language, used for teaching and to write
+ {CL}.
+
+ {(http://fmph.uniba.sk/~voda)}.
+
+ ["The Constraint Language Trilogy: Semantics and
+ Computations", P. Voda, Complete Logic Systems, 741 Blueridge
+ Ave, North Vancouver BC, V7R 2J5].
+
+ (2000-04-08)
+
+triple DES
+
+ <cryptography> A {product cipher} which, like {DES}, operates
+ on 64-bit data blocks. There are several forms, each of which
+ uses the DES cipher 3 times. Some forms use two 56-bit keys,
+ some use three. The DES "modes of operation" may also be used
+ with triple-DES.
+
+ (1995-05-11)
+
+tri state
+
+ <hardware> A feature of some {digital} electronic devices
+ which allows a connector (pin) to either act as a normal
+ output, driving a signal onto a line, or to be "tri stated" -
+ set to a high-impedance ("high Z") condition. This allows
+ other outputs to drive signals onto the line. Often the same
+ connector also functions as an input when its output circuitry
+ is tri stated.
+
+ Tri-state outputs are typically used for the connection of
+ several digital circuits to a shared {bus} onto which any one
+ of them may output data for the others to input.
+
+ (1996-07-26)
+
+trit
+
+ <unit> /trit/ (By analogy with "{bit}") One base-3 digit; the
+ amount of information conveyed by a selection among one of
+ three equally likely outcomes. Trits arise, for example, in
+ the context of a {flag} that should actually be able to assume
+ *three* values - such as yes, no, or unknown. Trits are
+ sometimes jokingly called "3-state bits". A trit may be
+ semi-seriously referred to as "a bit and a half", although it
+ is linearly equivalent to 1.5849625 bits (that is, log2(3)
+ bits).
+
+ [{Jargon File}]
+
+ (1995-05-11)
+
+Triton
+
+ <processor> {Intel}'s {Pentium} {core} logic {chip set}. In
+ addition to the traditional features, this chip set supports:
+ {EDO DRAM} to increase the {bandwidth} of the {DRAM}
+ interface; "{pipelined} {burst SRAM}" for a cheaper, faster
+ {second level cache}; "{bus master} {IDE}" control logic to
+ reduce processor load; a plug and play port for easy
+ implementation of functions such as audio.
+
+ The Triton I chipset (official name 82430FX) consists of 4
+ chips: one 82437FX TSC (Triton Sysetm Controller), two 82438FX
+ TDP (Triton Data Path), and one 82371FB PIIX (PCI IDE
+ Xcellerator). It supports {PB Cache}, {EDO DRAM}, and a
+ maximum {PCI} and memory burst data transfer rate of 100
+ {megabytes} per second.
+
+ There are also {Moble Triton} (82430MX), {Triton II}
+ (82430HX), and the {Triton VX} (82430VX) chip sets.
+
+ {Introduction
+ (http://asus.com.tw/Products/TB/triton-intro.html)}.
+
+ (1996-04-03)
+
+Triton II
+
+ <processor> (Official name 82430HX) A version of {Intel}'s
+ {Triton} processor chip set with all the features of the
+ Triton I plus support for {ECC}, {parity RAM}, two-way {SMP},
+ {USB}, and {Concurrent PCI} to improve speed.
+
+ It consists of one 82439HX TXC and one 82371SB PIIX3.
+
+ (1996-04-03)
+
+Triton VX
+
+ <processor> (Official name 82430VX) A version of {Intel}'s
+ {Triton} processor chip set with all the features of the
+ Triton I plus support for {SDRAM}, {USB}, and a {UMA} option.
+
+ Triton VX consists of one 82437VX TVC, two 82438VX TVP, and
+ one 82371SB PIIX3.
+
+ (1996-04-03)
+
+Trivial File Transfer Protocol
+
+ <networking> (TFTP) A simple file transfer protocol used for
+ {down-load}ing {boot code} to {diskless workstations}.
+
+ TFTP is defined in {RFC 1350}.
+
+ [Details? Other uses? Relationship to {FTP}?]
+
+ (1997-08-30)
+
+TRO
+
+ {tail recursion optimisation}
+
+troff
+
+ <text, tool> /T'rof/ or /trof/ The grey eminence of {Unix}
+ text processing; a formatting and phototypesetting program,
+ written originally in {PDP-11} {assembly code} and then in
+ barely-structured early {C} by the late Joseph Ossanna,
+ modelled after the earlier {ROFF} which was in turn modelled
+ after {Multics}' {RUNOFF} by Jerome Saltzer (*that* name came
+ from the expression "to run off a copy"). A companion
+ program, {nroff}, formats output for terminals and line
+ printers.
+
+ In 1979, Brian Kernighan modified troff so that it could drive
+ phototypesetters other than the Graphic Systems CAT. His
+ paper describing that work ("A Typesetter-independent troff",
+ AT&T CSTR #97) explains troff's durability. After discussing
+ the program's "obvious deficiencies - a rebarbative input
+ syntax, mysterious and undocumented properties in some areas,
+ and a voracious appetite for computer resources" and noting
+ the ugliness and extreme hairiness of the code and internals,
+ Kernighan concludes:
+
+ None of these remarks should be taken as denigrating
+ Ossanna's accomplishment with TROFF. It has proven a
+ remarkably robust tool, taking unbelievable abuse from a
+ variety of preprocessors and being forced into uses that
+ were never conceived of in the original design, all with
+ considerable grace under fire.
+
+ The success of {TeX} and desktop publishing systems have
+ reduced troff's relative importance, but this tribute
+ perfectly captures the strengths that secured troff a place in
+ hacker folklore; indeed, it could be taken more generally as
+ an indication of those qualities of good programs that, in the
+ long run, hackers most admire.
+
+ {groff} is {GNU}'s implementation of {roff} in {C++}.
+
+ [{Jargon File}]
+
+ (1995-03-21)
+
+troglodyte
+
+ <jargon> (Commodore) 1. A hacker who never leaves his cubicle.
+ The term "Gnoll" (from Dungeons & Dragons) is also reported.
+
+ 2. A curmudgeon attached to an obsolescent computing
+ environment. The combination "ITS troglodyte" was flung
+ around some during the {Usenet} and {e-mail} wringle-wrangle
+ attending the 2.x.x revision of the {Jargon File}; at least
+ one of the people it was intended to describe adopted it with
+ pride.
+
+ [{Jargon File}]
+
+ (1995-01-11)
+
+troglodyte mode
+
+ <jargon> (Rice University) Programming with the lights turned
+ off, sunglasses on, and the terminal inverted (black on white)
+ because you've been up for so many days straight that your
+ eyes hurt (see {raster burn}). Loud music blaring from a
+ stereo stacked in the corner is optional but recommended.
+
+ See {larval stage}, {hack mode}.
+
+ [{Jargon File}]
+
+ (1995-03-21)
+
+trojan
+
+ {Trojan horse}
+
+Trojan horse
+
+ <application, security> (Or just "trojan") A term coined by
+ {MIT}-hacker-turned-NSA-spook Dan Edwards for a malicious,
+ security-breaking program that is disguised as something
+ benign, such as a directory lister, archiver, game or (in one
+ notorious 1990 case on the Mac) a program to find and destroy
+ {virus}es! A Trojan horse is similar to a {back door}.
+
+ See also {RFC 1135}, {worm}, {phage}, {mockingbird}.
+
+ [{Jargon File}]
+
+ (2008-06-19)
+
+TROLL
+
+ An {array} language for {continuous simulation}, econometric
+ modelling or statistical analysis.
+
+ ["TROLL Reference Manual", D0062, Info Proc Services, MIT
+ (1973-76)].
+
+troll
+
+ An {electronic mail} message, {Usenet} posting or other
+ (electronic) communication which is intentionally incorrect,
+ but not overtly controversial (compare {flame bait}), or the
+ act of sending such a message. Trolling aims to elicit an
+ emotional reaction from those with a hair-trigger on the reply
+ key. A really subtle troll makes some people lose their
+ minds.
+
+ (1994-10-17)
+
+TRON
+
+ 1. <project> {The Real-Time Operating System Nucleus}.
+
+ 2. <language, programming, testing, tool> (TRace ON) A
+ {command} used when {debugging} {programs} written in
+ early {line-numbered} {BASIC} that contained {GOTO} and
+ {GOSUB} statements.
+
+ When the TRON command had been {executed}, the program ran
+ with a {window} open indicating the line number being
+ executed at that instant.
+
+ The {TROFF} (an abbreviation for "TRace OFF") command turned
+ the {tracing} off.
+
+ (2003-02-02)
+
+tron
+
+ <jargon> ({NRL}, {CMU}, probably from the film "Tron") To
+ become inaccessible except via {electronic mail} or {talk}
+ especially when one is normally available via telephone or in
+ person.
+
+ Compare {spod}.
+
+ [{Jargon File}]
+
+ (1994-11-03)
+
+Trouble Came Back
+
+ <jargon> (TCB) An {IBM} term for an intermittent or
+ difficult-to-reproduce problem that has failed to respond to
+ neglect or {shotgun debugging}.
+
+ Compare {heisenbug}.
+
+ (1998-07-02)
+
+TRS
+
+ {term rewriting system}
+
+TRS-80
+
+ <computer> A series of {personal computers} sold by {Tandy
+ Radio Shack}. The '80' refers to the use of {Zilog Z-80}
+ processor (NOT {Intel 80x8x}).
+
+ There were 7.5 computers in the TRS-80 line: Models I, II,
+ III, 4, 100, 102, 200. The Model 4P was a portable version of
+ the Model 4 with no tape drive -- only 2 1/2-height single
+ sided disk drives.
+
+ Later models that Radio Shack produced were not TRS-80
+ machines -- they were based on the {Intel 80x8x} architecture.
+ These included Tandy 1000, Tandy 2000, Tandy 3000, and others.
+ The 1000 had a proprietary Color card. The 2000 was a
+ powerful machine for its time, but was based on the {Intel
+ 80186}, so when {IBM} didn't build a computer based on this
+ chip, it failed. It was used to design a boat for the
+ America's Cup.
+
+ The TRS-80 {GUI}, DeskMate, was proprietary, but no more than
+ {Windoze} at the time.
+
+ Many joke about "{TRaSh-80}" machines but several models were
+ in fact classics of their time.
+
+ (1996-02-18)
+
+Truchet point
+
+ <unit, text> An obsolete variant of the {point}, equal to
+ 0.188 mm.
+
+ (2002-03-11)
+
+True BASIC
+
+ <language> A compiled {BASIC}, by John Kemeny and Thomas
+ E. Kurtz, requiring no {line numbers}.
+
+ (1996-03-24)
+
+true colour
+
+ <graphics> A system where the red, green, and blue components
+ of a colour are stored in {display memory}, as opposed to
+ storing {logical colours} and using a {colour palette} to
+ convert them to red, green, blue components.
+
+ The advantage of true colour over a palette is that it does
+ not restrict the range of colours which can be displayed on
+ screen simultaneously. For example, if eight bits are used to
+ store each component of each {pixel} then a total of 2^24
+ (about 17 million) different colours can be displayed at once
+ which would require a (very expensive) palette with 3 * 2^24
+ bytes (about 50 megabytes) of memory.
+
+ The disadvantage of true colour is that image transformations
+ which would normally be done by changing the palette must be
+ done to every pixel of the image which can be much slower.
+
+ Compare {high colour}.
+
+ (1996-03-24)
+
+true hacker
+
+ <person> (By analogy with "trufan" from SF fandom) One who
+ exemplifies the primary values of hacker culture, especially
+ competence and helpfulness to other hackers. A high
+ compliment. "He spent 6 hours helping me bring up UUCP and
+ netnews on my FOOBAR 4000 last week - manifestly the act of a
+ true-hacker".
+
+ Compare {demigod}, opposite: {munchkin}.
+
+ [{Jargon File}]
+
+ (1996-01-07)
+
+TRUENAME
+
+ <operating system> An {undocumented} {DOS} command to find the
+ {UNC} name of a file or directory on a network drive.
+
+ (2003-10-21)
+
+TrueType
+
+ <text, standard> An {outline font} {standard} first developed
+ by {Apple Computer}, and later embraced by {Microsoft}, as a
+ competitor to {Adobe Systems, Inc.}'s {PostScript} which is
+ still more popular.
+
+ (1995-03-16)
+
+Trumpet
+
+ A {news reader} for {Microsoft Windows}, using the {WinSock}
+ library. There is also an {MS-DOS} version. Trumpet is
+ {shareware} from Australia.
+
+ {(ftp://ftp.utas.edu.au/pc/trumpet)}.
+
+ {(ftp://ftp.demon.co.uk/pub/ibmpc/winsock/stacks/trumpwsk/)}.
+
+ {news:alt.winsock.trumpet}.
+
+ [Author?]
+
+ (1995-01-12)
+
+TRUSIX
+
+ {TRUSted Unix operating system}
+
+truth table
+
+ <logic> A table listing all possible combinations of inputs
+ and the corresponding output of a {Boolean} function such as
+ {AND}, {OR}, {NOT}, {IMPLIES}, {XOR}, {NAND}, {NOR}. Truth
+ tables can be used as a means of representing a function or as
+ an aid in designing a circuit to implement it.
+
+ (1998-07-30)
+
+TS
+
+ Typed Smalltalk.
+
+ A {Smalltalk} by Ralph Johnson <johnson@speedy.cs.uiuc.edu> of
+ the {University of Illinois}.
+
+ ["TS: An Optimising Compiler for Smalltalk", R.E. Johnson et
+ al, SIGPLAN Notices 23(11) (Nov 1988)].
+
+ (1995-01-12)
+
+TSAP
+
+ {Transport Service Access Point}
+
+TSEE
+
+ Technical and Engineering Environment: part of the RTEE
+ toolset.
+
+TSIA
+
+ <messaging> Title Says It All. Something to put in the body
+ of a {electronic mail} message or {bulletin board} posting
+ when no body is really necessary because the title or subject
+ header contains the whole message.
+
+ (2000-02-10)
+
+Tsim
+
+ {Time Simulator}
+
+TSL-1
+
+ Task Sequencing Language. Language for specifying sequences
+ of tasking events in Ada programs.
+
+ ["Task Sequencing Language for Specifying Distributed Ada
+ Systems", D.C. Luckham et al in PARLE: Parallel Architectures
+ and Langs Europe, LNCS 259, Springer 1987, pp.444-463].
+
+TSO
+
+ {Time Sharing Option}
+
+TSP
+
+ {travelling salesman problem}
+
+TSR
+
+ {Terminate and Stay Resident}
+
+TSV
+
+ {tab-separated values}
+
+tt
+
+ <networking> The {country code} for Trinidad and Tobago.
+
+ (1999-01-27)
+
+TTD
+
+ {Telecommunications Device for the Deaf}
+
+TTFN
+
+ <chat> ta-ta for now - goodbye for now. Used in the UK, USA
+ and probably elsewhere.
+
+ (1998-07-02)
+
+TTL
+
+ 1. {transistor-transistor logic}.
+
+ 2. {Time to Live}.
+
+TTS
+
+ {Text To Speech}
+
+tty
+
+ <hardware> /tit'ee/ ({ITS} pronunciation, but some {Unix}
+ people say it this way as well; this pronunciation is not
+ considered to have sexual undertones), /T T Y/
+
+ 1. {teletypewriter}.
+
+ 2. (Especially {Unix}) Any terminal at all; sometimes used to
+ refer to the particular terminal controlling a given job (it
+ is also the name of a Unix command which outputs the name of
+ the current controlling terminal).
+
+ 3. ({Unix}) Any {serial port}, whether or not the device
+ connected to it is a terminal; so called because under Unix
+ such devices have names of the form tty*. Ambiguity between
+ senses 2 and 3 is common but seldom bothersome.
+
+ 4. A {TDD}.
+
+ [{Jargon File}]
+
+ (1995-11-23)
+
+TTYL
+
+ <chat> talk to you later.
+
+ (1998-01-18)
+
+TUB
+
+ {Technische Universita't Berlin}. (Berlin technical
+ university).
+
+TUBA
+
+ <networking, protocol> An {Internet} {protocol}, described in
+ {RFC 1347}, {RFC 1526} and {RFC 1561}, and based on the {OSI}
+ {Connectionless Network Protocol} (CNLP).
+
+ TUBA is one of the proposals for {Internet Protocol Version
+ 6}.
+
+ (1995-04-03)
+
+tube
+
+ 1. <hardware> A {CRT} terminal. Never used in the mainstream
+ sense of TV; real hackers don't watch TV, except for Loony
+ Toons, Rocky & Bullwinkle, Trek Classic, the Simpsons, and the
+ occasional cheesy old swashbuckler movie.
+
+ 2. <electronics> {electron tube}.
+
+ 3. <jargon> (IBM) To send a copy of something to someone
+ else's terminal. "Tube me that note."
+
+ [{Jargon File}]
+
+ (1996-02-05)
+
+tube time
+
+ Time spent at a terminal or console. More inclusive than
+ hacking time; commonly used in discussions of what parts of
+ one's environment one uses most heavily. "I find I'm spending
+ too much of my tube time reading mail since I started this
+ revision."
+
+ [{Jargon File}]
+
+Tuckals
+
+ An old statistical package still in use on some {VM}
+ computers.
+
+ (1995-11-28)
+
+TUI
+
+ <interface>
+
+ 1. {Textual User Interface}.
+
+ 2. Terminal User Interface. Alternative name for {Textual
+ User Interface}.
+
+ 3. <communications> {Telephony User Interface}.
+
+ 4. {Tangible User Interface}.
+
+ 5. {Tactile User Interface}.
+
+ 6. {Telescope User Interface}.
+
+ (2003-10-17)
+
+Tukey, John
+
+ {John Tukey}
+
+Tuki
+
+ An intermediate code for functional languages. "Another
+ Implementation Technique for Applicative Languages", H. Glaser
+ et al, ESOP86, LNCS 213, Springer 1986.
+
+tunafish
+
+ <humour, operating system> In hackish lore, refers to the
+ mutated punchline of an age-old joke to be found at the bottom
+ of the manual pages of "tunefs(8)" in the original {4.2BSD}
+ distribution. The joke was removed in later releases once
+ commercial sites started using 4.2. Tunefs relates to the
+ "tuning" of {file-system} parameters for optimum performance,
+ and at the bottom of a few pages of wizardly inscriptions was
+ a "BUGS" section consisting of the line "You can tune a file
+ system, but you can't tunafish". Variants of this can be seen
+ in other BSD versions, though it has been excised from some
+ versions by humourless management droids. The [nt]roff source
+ for SunOS 4.1.1 contains a comment apparently designed to
+ prevent this: "Take this out and a Unix Demon will dog your
+ steps from now until the "time_t's wrap around."
+
+ [{Jargon File}]
+
+ (1997-01-12)
+
+tune
+
+ <jargon> (From musical, possibly via automotive, usage) To
+ {optimise} a program or system for a particular environment,
+ especially by adjusting numerical parameters designed as
+ {hooks} for tuning, e.g. by changing "#define" lines in C.
+ One may "tune for time" (fastest execution), "tune for space"
+ (least memory use), or "tune for configuration" (most
+ efficient use of hardware).
+
+ See {bum}, {hot spot}, {hand-hacking}.
+
+ [{Jargon File}]
+
+ (1999-06-05)
+
+tunneling
+
+ <spelling US spelling of {tunnelling}.
+
+tunnelling
+
+ <networking> (US: "tunneling") A networking technique used to
+ carry data encoded in one protocol, A, over a channel using
+ another protocol, B. Protocol A is said to be "encapsulated" in
+ protocol B and treats B as though it were a {data link layer}.
+ Tunnelling is used to get data between {administrative domains}
+ which use a protocol that is not supported by the {internet}
+ connecting those domains.
+
+ A historical example would be transmitting written text via {Morse
+ code} - instead of having someone carry the text on paper, it is
+ converted to (or encapsulated as) Morse code at one end and
+ converted back to written text at the other.
+
+ A more recent example would be tunnelling {IPv6} over an {IPv4}
+ network that does not support IPv6 natively. Tunnelling
+ techniques such as {6to4} or {6rd} are used to encapsulate {IPv6}
+ in the absence of native {dual-stack} support.
+
+ (2013-10-07)
+
+Tunny Emulator
+
+ <hardware, cryptography> A special-purpose computer designed
+ at {Bletchley Park} (UK) based upon the reverse engineering of
+ the Lorenz Cypher. The Lorenz Cypher was used by the German
+ army to encrypt high command orders for transmission via
+ teleprinter (the {Enigma} was a field-use cypher).
+
+ Once the key to a message was discovered (by the computer
+ {Colossus}) the Tunny machine would be set to decrypt the
+ message. The process took about four days from intercept to
+ printout. The original Tunny machine was built about 1943 and
+ scrapped after the war. In 2011 a working model was re-built
+ at Bletchley Park where it is on display.
+
+ (2012-03-25)
+
+TUPLE
+
+ {Toyohashi University Parallel Lisp Environment}
+
+tuple
+
+ <programming> In {functional languages}, a data object
+ containing two or more components. Also known as a product
+ type or pair, triple, quad, etc. Tuples of different sizes
+ have different types, in contrast to lists where the type is
+ independent of the length. The components of a tuple may be
+ of different types whereas all elements of a list have the
+ same type.
+
+ Examples of tuples (in {Haskell} notation) are: (1,2),
+ ("Tuple",True), (w,(x,y),z). The degenerate tuple type with
+ zero components, written (), is known as the unit type since
+ it has only one possible value which is also written ().
+
+ The implementation of tuples in a language may be either
+ "{lifted}" or not. If tuples are lifted then (bottom, bottom)
+ /= bottom (where {bottom} represents non-termination) and the
+ evaluation of a tuple may fail to terminate. E.g. in Haskell:
+
+ f (x, y) = 1 --> f bottom = bottom
+ f (bottom, bottom) = 1
+
+ With lifted tuples, a tuple pattern is refutable. Thus in
+ Haskell, {pattern matching} on tuples is the same as pattern
+ matching on types with multiple constructors ({algebraic data
+ types}) - the expression being matched is evaluated as far as
+ the top level constructor, even though, in the case of tuples,
+ there is only one possible constructor for a given type.
+
+ If tuples are unlifted then (bottom, bottom) = bottom and
+ evaluation of a tuple will never fail to terminate though any
+ of the components may. E.g. in {Miranda}:
+
+ f (x, y) = 1 --> f bottom = 1
+ f (bottom, bottom) = 1
+
+ Thus in Miranda, any object whose type is compatible with a
+ tuple pattern is assumed to match at the top level without
+ evaluation - it is an {irrefutable} pattern. This also
+ applies to user defined data types with only one constructor.
+ In Haskell, patterns can be made irrefutable by adding a "~"
+ as in
+
+ f ~(x, y) = 1.
+
+ If tuple constructor functions were {strict} in all their
+ arguments then (bottom, x) = (x, bottom) = bottom for any x
+ so matching a refutable pattern would fail to terminate if
+ any component was bottom.
+
+ (2012-03-25)
+
+tuple calculus
+
+ <database> A form of {relational calculus} in which a
+ variable's only permitted values are {tuples} of a given
+ {relation}.
+
+ {Codd}'s unimplemented language {ALPHA} and the subsequent
+ {QUEL} are examples of the tuple calculus.
+
+ (1998-10-05)
+
+Tuple Space Smalltalk
+
+ ["Using Tuple Space Communication in Distributed
+ Object-Oriented Languages", S. Matsuoka et al, SIGPLAN Notices
+ 23(11):276-284 (Nov 1988)].
+
+ (1994-11-08)
+
+tupling
+
+ A {program transformation} where several results are returned
+ from a single traversal of a data structure. E.g.
+
+ mean l = sum l / length l
+
+ ==>
+
+ mean l = s/n
+ where
+ (s,n) = sumLen l
+
+ sumLen [] = (0,0)
+ sumLen (x:xs) = (s+x, n+1)
+ where
+ (s,n) = sumLen xs
+
+ In {procedural} languages this technique is known as
+ {horizontal loop combination} because it uses one loop to
+ calculate several results.
+
+ Another form of tupling transformation is used to avoid
+ repeated evaluation where a function generates several
+ identical calls to itself. By analysing the pattern of
+ recursion (see {descent function}) it is possible to arrange
+ for these identical calls to share results. E.g.
+
+ fib 0 = 1
+ fib 1 = 1
+ fib n = fib (n-1) + fib (n-2)
+
+ ==>
+
+ fib n = v where (_,v) = fibt n
+ fibt 0 = (1,1)
+ fibt n = (u+v,u) where (u,v) = fibt (n-1)
+
+ (1995-01-12)
+
+Turbo C
+
+ <language> {Borland}'s {C} {compiler} for {IBM PCs}.
+
+ Turbo C, version 1.0, was introduced by Borland in 1987. It
+ offered the first integrated edit-compile-run development
+ environment for {C} on {IBM PCs}. It ran in 384KB of memory.
+ It allowed inline assembly, supported all memory models, and
+ offered optimisations for speed, size, {constant folding}, and
+ {jump elimination}.
+
+ Version 1.5 shipped on five 360 KB diskettes of uncompressed
+ files, and came with sample C programs, including a stripped
+ down spreadsheet called mcalc.
+
+ Turbo C 2.0 has a debugger, a fast assembler, and an extensive
+ graphics library.
+
+ Turbo C has been largely supplanted by {Turbo C++}, introduced
+ circa September, 1990 for both {MS-DOS} and {Microsoft
+ Windows}.
+
+ ["Compiling the facts on C", Richard Hale Shaw, PC Magazine,
+ September 13, 1988, pages 115-183].
+
+ (1996-10-31)
+
+Turbo C++
+
+ <language> {Borland}'s first {C}/{C++} {integerated
+ development environment}, including a {compler}, a {linker}, a
+ high-level {debugger}, a code editor and other tools.
+
+ Turbo C++ conformed to {AT&T}'s C++ 2.0 language
+ specification. The development environment and {command line}
+ tools originally ran under {MS-DOS}. A 1992 version ran on
+ {Windows 3.1}. Version 1 came in two forms: Turbo C++ and
+ Turbo C++ Professional. The latter included {Turbo
+ Assembler}, {Turbo Debugger} and {Turbo Profile}.
+
+ It superceded the C-only {Turbo C} and was itself superceded
+ by {C++ Builder}.
+
+ {(http://community.borland.com/article/0,1410,21751,00.html)}
+
+ (2008-01-21)
+
+Turbo Debugger
+
+ <programming> A {source-level debugger} designed for use with
+ {Borland} and other {compilers}.
+
+ {(http://borland.com/)}.
+
+ (1999-04-23)
+
+turbo nerd
+
+ {computer geek}
+
+Turbo Pascal
+
+ <language, product> {Borland International}'s {Pascal}.
+ Perhaps the first integrated development environment for
+ {MS-DOS}.
+
+ Versions 1.0-3.0: standard Pascal with a few extensions
+ Versions 4.0 (1987) and 5.0: {separate compilation}. Version
+ 5.5: {object-oriented}. Version 6.0: {Turbo Vision} OOP
+ library.
+
+ {(http://borland.com/Product/ProdInfo.html)}.
+
+ {tptc} translates Turbo Pascal to {Turbo C}.
+
+ (1995-05-01)
+
+Turbo Prolog
+
+ A {strongly typed} Prolog-like {logic programming} language.
+ 1986. It has user-defined domains. Programs are arranged in
+ sections: DOMAINS, CLAUSES, PREDICATES, DATABASE and GOAL. It
+ is currently known as {PDC Prolog} and is distributed by
+ {Prolog Development Center}, Atlanta +1 404 873 1366. E-mail:
+ <pdc@mcimail.com>.
+
+Turing
+
+ 1. {Alan Turing}.
+
+ 2. R.C. Holt <holt@csri.toronto.edu> & J.R. Cordy
+ <cordy@cs.queensu.ca>, U Toronto, 1982. Descendant of
+ Concurrent Euclid, an airtight super-Pascal. Used mainly for
+ teaching programming at both high school and university level.
+
+ Available from Holt Software Assocs, Toronto.
+
+ Versions for Sun, {MS-DOS}, Mac, etc.
+
+ E-mail: <distrib@turing.toronto.edu>.
+
+ ["Turing Language Report", R.C. Holt & J.R. Cordy, Report
+ CSRI-153, CSRI, U Toronto, Dec 1983].
+
+ ["The Turing Programming Language", R.C. Holt & J.R. Cordy,
+ CACM 31(12) (Dec 1988)].
+
+Turing Machine
+
+ <computability> A hypothetical machine defined in 1935-6 by
+ {Alan Turing} and used for {computability theory} proofs. It
+ consists of an infinitely long "tape" with symbols (chosen
+ from some {finite set}) written at regular intervals. A
+ pointer marks the current position and the machine is in one
+ of a finite set of "internal states". At each step the
+ machine reads the symbol at the current position on the tape.
+ For each combination of current state and symbol read, a
+ program specifies the new state and either a symbol to write
+ to the tape or a direction to move the pointer (left or right)
+ or to halt.
+
+ In an alternative scheme, the machine writes a symbol to the
+ tape *and* moves at each step. This can be encoded as a write
+ state followed by a move state for the write-or-move machine.
+ If the write-and-move machine is also given a distance to move
+ then it can emulate an write-or-move program by using states
+ with a distance of zero. A further variation is whether
+ halting is an action like writing or moving or whether it is a
+ special state.
+
+ [What was Turing's original definition?]
+
+ Without loss of generality, the symbol set can be limited to
+ just "0" and "1" and the machine can be restricted to start on
+ the leftmost 1 of the leftmost string of 1s with strings of 1s
+ being separated by a single 0. The tape may be infinite in
+ one direction only, with the understanding that the machine
+ will halt if it tries to move off the other end.
+
+ All computer {instruction sets}, {high level languages} and
+ computer architectures, including {parallel processors}, can
+ be shown to be equivalent to a Turing Machine and thus
+ equivalent to each other in the sense that any problem that
+ one can solve, any other can solve given sufficient time and
+ memory.
+
+ Turing generalised the idea of the Turing Machine to a
+ "Universal Turing Machine" which was programmed to read
+ instructions, as well as data, off the tape, thus giving rise
+ to the idea of a general-purpose programmable computing
+ device. This idea still exists in modern computer design with
+ low level {microcode} which directs the reading and decoding
+ of higher level {machine code} instructions.
+
+ A {busy beaver} is one kind of Turing Machine program.
+
+ Dr. Hava Siegelmann of {Technion} reported in Science of 28
+ Apr 1995 that she has found a mathematically rigorous class of
+ machines, based on ideas from {chaos} theory and {neural
+ networks}, that are more powerful than Turing Machines. Sir
+ Roger Penrose of {Oxford University} has argued that the brain
+ can compute things that a Turing Machine cannot, which would
+ mean that it would be impossible to create {artificial
+ intelligence}. Dr. Siegelmann's work suggests that this is
+ true only for conventional computers and may not cover {neural
+ networks}.
+
+ See also {Turing tar-pit}, {finite state machine}.
+
+ (1995-05-10)
+
+Turingol
+
+ <language> A {high-level language} for programming {Turing
+ Machines} by {Donald Knuth}. It was the subject of the first
+ construction of a nontrivial {attribute grammar}.
+
+ ["Semantics of Context-Free Languages", D. Knuth, Math Sys Thy
+ 2:127-145 (1975)].
+
+ (1995-10-08)
+
+Turing Plus
+
+ Systems programming language, a concurrent descendant of
+ Turing.
+
+ ["The Turing Plus Report", R.C. Holt & J.R. Cordy, CSRI, U
+ Toronto, Feb 1987].
+
+ Available from Holt Software Assocs, Toronto
+ <distrib@hsa.on.ca>.
+
+Turing tar-pit
+
+ A place where anything is possible but nothing of interest is
+ practical. {Alan M. Turing} helped lay the foundations of
+ computer science by showing that all machines and languages
+ capable of expressing a certain very primitive set of
+ operations are logically equivalent in the kinds of
+ computations they can carry out, and in principle have
+ capabilities that differ only in speed from those of the most
+ powerful and elegantly designed computers. However, no
+ machine or language exactly matching Turing's primitive set
+ has ever been built (other than possibly as a classroom
+ exercise), because it would be horribly slow and far too
+ painful to use.
+
+ A "Turing tar-pit" is any computer language or other tool that
+ shares this property. That is, it's theoretically universal
+ but in practice, the harder you struggle to get any real work
+ done, the deeper its inadequacies suck you in. Compare
+ {bondage-and-discipline language}.
+
+ A tar pit is a geological occurence where subterranean tar
+ leaks to the surface, creating a large puddle (or pit) of tar.
+ Animals wandering or falling in get stuck, being unable to
+ extricate themselves from the tar. La Brea, California, has a
+ museum built around the fossilized remains of mammals and
+ birds found in such a tar pit.
+
+ [{Jargon File}]
+
+ (1998-06-27)
+
+Turing test
+
+ <artificial intelligence> A criterion proposed by {Alan
+ Turing} in 1950 for deciding whether a computer is
+ intelligent. Turing called it "the Imitation Game" and
+ offered it as a replacement for the question, "Can machines
+ think?"
+
+ A human holds a written conversation on any topic with an
+ unseen correspondent (nowadays it might be by {electronic
+ mail} or {chat}). If the human believes he is talking to
+ another human when he is really talking to a computer then the
+ computer has passed the Turing test and is deemed to be
+ intelligent.
+
+ Turing predicted that within 50 years (by the year 2000)
+ technological progress would produce computing machines with a
+ capacity of 10**9 bits, and that with such machinery, a
+ computer program would be able to fool the average questioner
+ for 5 minutes about 70% of the time.
+
+ The {Loebner Prize} is a competition to find a computer
+ program which can pass an unrestricted Turing test.
+
+ {Julia (http://fuzine.mt.cs.cmu.edu/mlm/julia.html)} is a
+ program that attempts to pass the Turing test.
+
+ See also {AI-complete}.
+
+ {Turing's paper
+ (http://cogprints.ecs.soton.ac.uk/archive/00000499/00/turing.html)}.
+
+ (2004-02-17)
+
+turist
+
+ /too'rist/ Variant spelling of {tourist}. Possibly influenced
+ by {luser} and "{Turing}".
+
+ [{Jargon File}]
+
+TURN
+
+ <messaging, protocol> An {SMTP} command with which a {client}
+ asks the {server} to open an SMTP connection to the client,
+ thus reversing their roles.
+
+ Superseded by {ETRN}.
+
+ (1997-11-21)
+
+turn-key
+
+ <jargon, application> A term which describes a complete system
+ (hardware and software) which can be used for a specific
+ application without requiring further programming or software
+ installation. The user can just "turn the key" (switch it on)
+ and use it.
+
+ Compare {end-to-end solution}.
+
+ (2006-03-30)
+
+turtle graphics
+
+ <graphics> The line drawings produced by programs in {LOGO}.
+
+ (2003-05-04)
+
+TUTOR
+
+ A Scripting language on {PLATO} systems from {CDC}.
+
+ ["The TUTOR Language", Bruce Sherwood, Control Data, 1977].
+
+Tuxedo
+
+ <database, networking> {Cross-platform} distributed
+ {transaction monitor} {middleware} marketed by {BEA systems}.
+ Tuxedo supports the production of {scalable} {client-server}
+ applications and the coordination of {transactions} spanning
+ heterogeneous {databases}, {operating systems}, and
+ {hardware}.
+
+ {BEA Home (http://beasys.com/)}.
+
+ [Connection with {Novell, Inc.}?]
+
+ (2003-01-08)
+
+TV
+
+ {television}
+
+tv
+
+ <networking> The {country code} for Tuvalu.
+
+ Heavily used for {vanity domains} by TV stations.
+
+ (1999-01-27)
+
+tw
+
+ <networking> The {country code} for Taiwan.
+
+ (1999-01-27)
+
+TWAIN
+
+ <graphics, standard> An {image capture} {API} for {Microsoft
+ Windows} and {Apple Macintosh} {operating systems} that
+ enables the user to control a {scanner} or {digital camera}
+ from {image processing} software.
+
+ TWAIN was first released on 1992-02-29 and is currently
+ ratified at version 2.0 as of 2005-11-28. It is maintained by
+ the TWAIN Working Group.
+
+ Kevin Bier, chairman-emeritus of the TWAIN Working Group and
+ the one of the original co-author/editors of TWAIN 1.0, chose
+ the name TWAIN after reading letters by Mark Twain. It was
+ unofficially considered to mean "toolkit without an important
+ name."
+
+ The word "twain" is an archaic form meaning "two". It appears
+ in Kipling's "The Ballad of East and West" - "...and never the
+ twain shall meet...", reflecting the difficulty, at the time,
+ of connecting scanners and personal computers. It was
+ up-cased to TWAIN to make it more distinctive. This led
+ people to believe it was an acronym, and then to a contest to
+ come up with an expansion. None were selected, but the entry
+ "Technology Without An Interesting Name" continues to haunt
+ the standard.
+
+ {The TWAIN Working Group (http://twain.org/)}.
+
+ (2000-02-25)
+
+tweak
+
+ 1. To change slightly, usually in reference to a value. Also
+ used synonymously with {twiddle}. If a program is almost
+ correct, rather than figure out the precise problem you might
+ just keep tweaking it until it works. See {frobnicate} and
+ {fudge factor}; also see {shotgun debugging}.
+
+ 2. To {tune} or {bum} a program; preferred usage in the UK.
+
+ [{Jargon File}]
+
+tweening
+
+ <graphics> An {interpolation} technique where an {animation}
+ program generates extra frames between the key frames that the
+ user has created. This gives smoother animation without the
+ user having to draw every frame.
+
+ A scene is described by a mathematical model - a set of two-
+ or three-dimensional objects whose positions in are given by
+ sets of coordinates. Tweening uses mathematical formulae to
+ generate these coordinates at a sequence of discrete times.
+ The simplest system would move each point at a constant rate
+ in a straight line between its initial and final positions,
+ though other kinds of path are possible. The coordinates at
+ each time step are used to generate (or "render") a
+ two-dimensional image of the scene which forms one "frame" of
+ the animation.
+
+ Tweening is similar to {morphing} except that morphing is
+ usually performed by interpolating between corresponding
+ points marked by the user on two images, rather than between
+ two configurations of a model.
+
+ (1995-04-04)
+
+tweeter
+
+ {woofer}
+
+TWENEX
+
+ <operating system> /twe'neks/ The TOPS-20 {operating system}
+ by {DEC} - the second proprietary OS for the {PDP-10} -
+ preferred by most PDP-10 hackers over TOPS-10 (that is, by
+ those who were not {ITS} or {WAITS} partisans). TOPS-20 began
+ in 1969 as {Bolt, Beranek & Newman}'s {TENEX} operating system
+ using special paging hardware. By the early 1970s, almost all
+ of the systems on the {ARPANET} ran TENEX. DEC purchased the
+ rights to TENEX from BBN and began work to make it their own.
+ The first in-house code name for the operating system was
+ VIROS (VIRtual memory Operating System); when customers
+ started asking questions, the name was changed to SNARK so DEC
+ could truthfully deny that there was any project called VIROS.
+ When the name SNARK became known, the name was briefly
+ reversed to become KRANS; this was quickly abandoned when
+ someone objected that "krans" meant "funeral wreath" in
+ Swedish (though some Swedish speakers have since said it means
+ simply "wreath"; this part of the story may be apocryphal).
+
+ Ultimately DEC picked TOPS-20 as the name of the operating
+ system, and it was as TOPS-20 that it was marketed. The
+ hacker community, mindful of its origins, quickly dubbed it
+ TWENEX (a contraction of "twenty TENEX"), even though by this
+ point very little of the original TENEX code remained
+ (analogously to the differences between AT&T V6 Unix and BSD).
+ DEC people cringed when they heard "TWENEX", but the term
+ caught on nevertheless (the written abbreviation "20x" was
+ also used). TWENEX was successful and very popular; in fact,
+ there was a period in the early 1980s when it commanded as
+ fervent a culture of partisans as Unix or ITS - but DEC's
+ decision to scrap all the internal rivals to the VAX
+ architecture and its relatively stodgy VMS OS killed the
+ DEC-20 and put a sad end to TWENEX's brief day in the sun.
+ DEC attempted to convince TOPS-20 users to convert to {VMS},
+ but instead, by the late 1980s, most of the TOPS-20 hackers
+ had migrated to Unix.
+
+ [{Jargon File}]
+
+ (1995-04-01)
+
+Twente Compiler Generator System
+
+ <language, tool> (TCGS) A {compiler generator} developed at
+ the {University of Twente}, The Netherlands.
+
+ (1998-04-27)
+
+Twentel
+
+ A {functional language}.
+
+ ["The TWENTEL System (Version 1).", H. Kroeze, CS Dept TR, U
+ Twente, 1986].
+
+twiddle
+
+ 1. <character> The {tilde} character.
+
+ 2. <jargon> (To make) a small or insignificant change.
+ E.g. twiddling a program often fixes one bug and generates
+ several new ones (see also {shotgun debugging}). Bits are
+ often twiddled. Twiddling a switch or knob implies much less
+ sense of purpose than toggling or {tweak}ing it; see
+ {frobnicate}. {Bit twiddling} connotes aimlessness, and at
+ best doesn't specify what you're doing to the bit; to
+ "{toggle} a bit" has a more specific meaning.
+
+ [{Jargon File}]
+
+ (1995-01-31)
+
+TWIG
+
+ Tree-Walking Instruction Generator.
+
+ A {code generator} language. {ML-Twig} is an {SML/NJ}
+ variant.
+
+ ["Twig Language Manual", S.W.K. Tijang, CS TR 120, Bell Labs,
+ 1986].
+
+ (1995-01-31)
+
+twilight zone
+
+ [IRC] Notionally, the area of cyberspace where {IRC}
+ operators live. An {op} is said to have a "connection to the
+ twilight zone".
+
+ [{Jargon File}]
+
+twink
+
+ /twink/ [UCSC] Equivalent to {read-only user}. Also reported
+ on the {Usenet} group soc.motss; may derive from gay slang for
+ a cute young thing with nothing upstairs (compare mainstream
+ "chick").
+
+twinning
+
+ <storage> Keeping a {mirror} of a {magnetic tape}.
+
+ (1997-07-18)
+
+Twin Vector Quantization
+
+ <audio, compression> (VQF) Part of the {MPEG-4} {standard}
+ dealing with time domain weighted interleaved {vector
+ quantization}.
+
+ [Why "VQF"?]
+
+ (2001-12-17)
+
+twip
+
+ <unit, graphics> (TWentIeth of a Point) 1/20 of a {Postscript
+ point}, or 1/1440th of an inch. There are thus 1440 twips to
+ an inch or about 567 twips to a centimeter.
+
+ Twips are used in {Microsoft} formats and products, notably
+ {Rich Text Format}, {Visual BASIC}, {Visual C++}, and {printer
+ drivers}; and in {IBM} {AFP} products.
+
+ Twips were devised in the olden days to describe the sizes of
+ characters produced by {dot matrix printers} that were
+ constrained to multiples of either 12 or 10 dots per inch.
+
+ [Is it definitely relative to a __Postscript__ point, as opposed
+ to one of the other definitions of {point}?]
+
+ (2002-03-11)
+
+twirling baton
+
+ <graphics> The overstrike sequence -/|\-/|\- which produces an
+ animated twirling baton. If you output it with a single
+ {backspace} between characters, the baton spins in place. If
+ you output the sequence BS SP between characters, the baton
+ spins from left to right. If you output BS SP BS BS between
+ characters, the batton spins from right to left.
+
+ The twirling baton was a popular component of animated
+ signature files on the pioneering {PLATO} educational
+ {time-sharing} system. The "{archie}" {Internet} service is
+ perhaps the best-known baton program today; it uses the
+ twirling baton as an idler indicating that the program is
+ working on a query.
+
+ [{Jargon File}]
+
+ (1995-02-23)
+
+twisted pair
+
+ <hardware> A type of cable in which pairs of conductors are
+ twisted together to randomise possible {cross-talk} from
+ nearby wiring. Inadequate twisting is detectable using modern
+ cable testing instruments.
+
+ (1995-02-23)
+
+twisted pair only
+
+ <networking> (TPO) A network connection to an {Ethernet}
+ {PCMCIA} card using {twisted pair} cable.
+
+ [Other options?]
+
+ (1997-05-12)
+
+Twitter
+
+ <messaging> A free {Internet} service for posting short
+ messages, known as "tweets", via a central server, which are
+ then sent to all users who have chosen to follow you or to a
+ specific user. A variety of {client} programs are available
+ in addition to the {website}. Launched in about 2008.
+
+ {Twitter home (http://twitter.com/)}.
+
+ (2009-06-10)
+
+twm
+
+ Tab Window Manager.
+
+ A {window manager} for the {X Window System}. Twm provides
+ {titlebars}, shaped windows, several forms of icon management,
+ user-defined macro functions, {click-to-type} and
+ pointer-driven {keyboard focus}, and user-specified key and
+ pointer button bindings. It can be extensively configured by
+ a startup file.
+
+ Twm was written by Tom LaStrange, {Solbourne Computer}; Jim
+ Fulton, MIT {X Consortium}; Steve Pitschke, {Stardent
+ Computer}; Keith Packard, MIT X Consortium; Dave Sternlicht,
+ MIT X Consortium; Dave Payne, {Apple Computer}.
+
+ An extended version, {vtwm}, provides a {virtual desktop}.
+
+ [Why "Tab"?]
+
+ (1995-02-14)
+
+.twmrc
+
+ <operating system> (Tab Window Manager run commands) The
+ configuration file for {twm}.
+
+ See also {rc}.
+
+ (1996-04-09)
+
+two-binary, one-quaternary
+
+ <communications> (2B1Q) A {physical layer} encoding used for
+ {Integrated Services Digital Network} {basic rate interface}.
+ 2B1Q represents two {bits} (2B - a "dibit") using one of four
+ signal levels (1Q - a "quadratude"). The first bit of the
+ dibit is indicated by polarity: positive indicates a binary 1
+ and negative indicates a 0. The second half of the dibit is
+ indicated by voltage magnitude: 1 Volt indicates a binary 1
+ and 3 Volts indicates binary 0.
+
+ (2003-01-10)
+
+twonkie
+
+ /twon'kee/ The software equivalent of a Twinkie (a variety of
+ sugar-loaded junk food, or (in gay slang) the male equivalent
+ of "chick"); a useless "feature" added to look sexy and
+ placate a {marketroid}.
+
+ Compare {Saturday-night special}.
+
+ The term may also be related to "The Twonky", title menace of
+ a classic SF short story by Lewis Padgett (Henry Kuttner and
+ C. L. Moore), first published in the September 1942
+ "Astounding Science Fiction" and subsequently much
+ anthologised.
+
+ [{Jargon File}]
+
+ (1994-10-20)
+
+two-phase commit
+
+ <database> A technique for maintaining {integrity} in
+ distributed {databases}. Where a system uses two or more
+ database, a transaction among the distibuted database should
+ be {atomic} ("all or nothing"). This is done by handling the
+ transaction in two phases. First the databases prepare the
+ transaction, confirm that it is possible to process it, and
+ lock the relevant record.
+
+ Once all the required databases confirm that the transaction
+ is viable, the system instructs them all to {commit} it -
+ i.e. to make it permanent. If it is not possible to process
+ it, the system will instruct the databases to {rollback}
+ (undo) the transaction.
+
+ (2000-02-28)
+
+twos complement
+
+ <data> A system used in some computers to represent negative
+ numbers in {binary}. Each {bit} of the number is inverted
+ (zeros are replaced with ones and vice versa), as for {ones
+ complement}, but then one (000...0001) is added (ignoring
+ overflow). This avoids the two representations for zero found
+ in ones complement by using all ones to represent -1.
+
+ ...
+ 000...00011 = +3
+ 000...00010 = +2
+ 000...00001 = +1
+ 000...00000 = 0
+ 111...11111 = -1
+ 111...11110 = -2
+ 111...11101 = -3
+ ...
+
+ This representation simplifies the logic required for addition
+ and subtraction, at the expense of a little extra complexity
+ for negation.
+
+ (1994-10-31)
+
+two-to-the-N
+
+ An amount much larger than {N} but smaller than {infinity}.
+ "I have 2-to-the-N things to do before I can go out for lunch"
+ means you probably won't show up.
+
+ Numbers of the form two-to-the-N are very important in
+ computing because they represent the value of bit N of a
+ binary number (counting from 0) and the number of things you
+ can count with an N bit number.
+
+ [{Jargon File}]
+
+ (1994-12-06)
+
+two-valued logic
+
+ <logic> (Commonly known as "{Boolean algebra}") A mathematical
+ system concerning the two {truth values}, TRUE and FALSE and
+ the functions {AND}, {OR}, {NOT}. Two-valued logic is one of
+ the cornerstones of {logic} and is also fundamental in the
+ design of {digital electronics} and {programming languages}.
+
+ The term "Boolean" is used here with its common meaning -
+ two-valued, though strictly {Boolean algebra} is more general
+ than this.
+
+ Boolean functions are usually represented by {truth tables}
+ where "0" represents "false" and "1" represents "true". E.g.:
+
+ A | B | A AND B
+ --+---+--------
+ 0 | 0 | 0
+ 0 | 1 | 0
+ 1 | 0 | 0
+ 1 | 1 | 1
+
+ This can be given more compactly using "x" to mean "don't
+ care" (either true or false):
+
+ A | B | A AND B
+ --+---+--------
+ 0 | x | 0
+ x | 0 | 0
+ 1 | 1 | 1
+
+ Similarly:
+
+ A | NOT A A | B | A OR B
+ --+------ --+---+--------
+ 0 | 1 0 | 0 | 0
+ 1 | 0 x | 1 | 1
+ 1 | x | 1
+
+ Other functions such as {XOR}, {NAND}, {NOR} or functions of
+ more than two inputs can be constructed using combinations of
+ AND, OR, and NOT. AND and OR can be constructed from each
+ other using {DeMorgan's Theorem}:
+
+ A OR B = NOT ((NOT A) AND (NOT B))
+ A AND B = NOT ((NOT A) OR (NOT B))
+
+ In fact any Boolean function can be constructed using just NOR
+ or just NAND using the identities:
+
+ NOT A = A NOR A
+ A OR B = NOT (A NOR B)
+
+ and {DeMorgan's Theorem}.
+
+ (2003-06-18)
+
+TX-0
+
+ The first transistorised computer, the direct ancestor of the
+ {PDP-1} built at {MIT}'s Lincoln Lab in 1957.
+
+ (1994-12-06)
+
+TXL
+
+ {Tree Transformation Language}
+
+TYMCOM-X
+
+ <operating system> {Tymshare}'s {operating system} which ran
+ for many years on Tymshare's {PDP-10s}. It was a descendent
+ of {TOPS-10} but had many of the important features of
+ {TOPS-20} such as real {paging} and controllable/spawnable
+ processes. TYMCOM-X, one of the best kept secrets in the
+ PDP-10 folklore, was written by Bill Weiher, Vance Socci
+ <vsocci@vcctech.com>, Allen Ginzburg, Karen Kolling, Art
+ Atkinson, Gary Morgenthaler (founder of the company that
+ produced {IDRIS}), Todd Corenson and Murray Bowles. Some
+ copies still run today. Most {TYMNET} development was done
+ under TYMCOM-X and Tymshare sold a TYMCOM-X system to {TRW} to
+ use in their credit reporting network, which was based on a
+ purchased copy of TYMNET circa 1979.
+
+ [E-mail from Vance Socci 1994-05-20].
+
+ (1995-11-09)
+
+TYMNET
+
+ <networking, history> A United States-wide commercial computer
+ network, created by {Tymshare, Inc.} some time before 1970,
+ and used for {remote login} and file transfer. The network
+ public went live in November 1971.
+
+ In its original implementation, it consisted of fairly simple
+ circuit-oriented {nodes}, whose circuits were created by
+ central network supervisors writing into the appropriate
+ nodes' "permuter tables". The supervisors also performed
+ login validations as well as circuit management. Circuits
+ were character oriented and the network was oriented toward
+ interactive character-by-character {full-duplex}
+ communications circuits.
+
+ The network had more than one supervisor running, but only one
+ was active, the others being put to sleep with "sleeping pill"
+ messages. If the active supervisor went down, all the others
+ would wake up and battle for control of the network. After
+ the battle, the supervisor with the highest pre-set priority
+ would dominate, and the network would then again be controlled
+ by only one supervisor. (During the takeover battle, the net
+ consisted of subsets of itself across which new circuits could
+ not be built). Existing circuits were not affected by
+ supervisor switches.
+
+ There was a clever scheme to switch the echoing function
+ between the local node and the host based on whether or not a
+ special character had been typed by the user. Data transfers
+ were also possible via "auxiliary circuits".
+
+ The Tymshare hosts (which ran customer code) were {SDS 940},
+ {DEC} {PDP-10}, and eventually {IBM 370} computers. {Xerox}
+ {XDS 940} might have been used if Xerox, who bought the design
+ for the SDS 940 from Scientific Data Systems, had ever built
+ any.
+
+ The switches were originally {Varian Data Machines} 620i. The
+ {Interdata 8/32} was never used because the performance was
+ disappointing. The TYMNET Engine, based loosely on the
+ Interdata 7/32, was developed instead to replace the Varian
+ 620i. In the early 1990s, newer "Turbo" nodes based on the
+ {Motorola 68000} began to replace the 7/32s. These were later
+ replaced with {SPARCs}.
+
+ PDP-10s supported (and still do in 1999) cross-platform
+ development and billing.
+
+ {Tymshare, Inc.} originally wrote and implemented TYMNET to
+ provide nationwide access for their {time-sharing} customers.
+
+ La Roy Tymes booted up the public TYMNET in November of 1971
+ and, as of March 2002, it had been running ever since without
+ a single system crash.
+
+ TYMNET was the largest commercial network in the United States
+ in its heyday, with nodes in every major US city and a few
+ overseas as well. Tymshare acquired a French subsidiary,
+ {SLIGOS}, and had TYMNET nodes in Paris, France.
+
+ Tymshare sold the TYMNET network software to {TRW}, who
+ created their own private network (which was not called
+ TYMNET). In about 1979, TYMNET Inc. was spun off from
+ Tymshare, Inc. to continue administration and development of
+ the network.
+
+ TYMNET outlived its parent company Tymshare and was acquired
+ by {MCI}. As of May 1994 they still ran three {DEC KL-10s}
+ under {TYMCOM-X}, although they planned to decommission them
+ soon.
+
+ The original creators of TYMNET included: Ann Hardy, Norm
+ Hardy, Bill Frantz. La Roy Tymes (who always insisted that
+ his name was NOT the source of the name) wrote the first
+ supervisor which ran on the 940. Joe Rinde made many
+ significant technical and marketing contributions. La Roy
+ wrote most of the code of the network proper. Several others
+ wrote code in support of development and administration. Just
+ recently (1999) La Roy, on contract, wrote a version of the
+ supervisor to run on {SPARC} hardware.
+
+ The name TYMNET was suggested by Vigril Swearingen in a weekly
+ meeting between Tymshare technical and marketing staff in
+ about 1970.
+
+ {(http://cap-lore.com/ETH.html)}.
+
+ [E-mail from La Roy Tymes]
+
+ (2002-11-26)
+
+Tymshare, Inc.
+
+ <company> The US company that created the {TYMNET} network.
+
+ (1999-03-17)
+
+type
+
+ <theory, programming> (Or "data type") A set of values from
+ which a {variable}, {constant}, {function}, or other
+ {expression} may take its value. A type is a classification
+ of data that tells the {compiler} or {interpreter} how the
+ programmer intends to use it. For example, the process and
+ result of adding two variables differs greatly according to
+ whether they are integers, floating point numbers, or strings.
+
+ Types supported by most programming languages include
+ {integers} (usually limited to some range so they will fit in
+ one {word} of storage), {Booleans}, {floating point numbers},
+ and characters. {Strings} are also common, and are
+ represented as {lists} of characters in some languages.
+
+ If s and t are types, then so is s -> t, the type of
+ {functions} from s to t; that is, give them a term of type s,
+ functions of type s -> t will return a term of type t.
+
+ Some types are {primitive} - built-in to the language, with no
+ visible internal structure - e.g. Boolean; others are
+ composite - constructed from one or more other types (of
+ either kind) - e.g. {lists}, {arrays}, {structures}, {unions}.
+ {Object-oriented programming} extends this with {classes}
+ which encapsulate both the structure of a type and the
+ operations that can be performed on it.
+
+ Some languages provide {strong typing}, others allow {implicit
+ type conversion} and/or {explicit type conversion}.
+
+ (2003-12-22)
+
+type-ahead
+
+ <operating system> The facility where the user can type more
+ characters before the system has fully responded to those
+ already typed. Type-ahead is common on most current systems.
+ It allows the user to type without worrying that the computer
+ may miss input because it is temporarily busy,
+ e.g. reformating a page, checking spelling, or simply
+ suffering from network latency. There is usually some limit
+ to the amount of input the system can buffer, beyond which it
+ __will__ lose input.
+
+ [Equivalent term for {speech recognition}?]
+
+ (2003-06-15)
+
+type-ahead search
+
+ {incremental search}
+
+type assignment
+
+ <theory> A mapping of the {free variables} of some expression
+ E to types. This is used in {type inference} to deduce the
+ type of E and its subexpressions.
+
+ (2002-02-22)
+
+type class
+
+ A set of types for which certain operations or {methods} are
+ defined. E.g. the class Number might have methods for addition
+ and subtraction. {Class}es are a feature of {object oriented
+ languages} and of the {functional programming} language
+ {Haskell}. See also {inheritance}.
+
+typed lambda-calculus
+
+ <theory> (TLC) A variety of {lambda-calculus} in which every
+ term is labelled with a {type}.
+
+ A {function application} (A B) is only synctactically valid if
+ A has type s --> t, where the type of B is s (or an {instance}
+ or s in a {polymorphic} language) and t is any type.
+
+ If the types allowed for terms are restricted, e.g. to
+ {Hindley-Milner types} then no term may be applied to itself,
+ thus avoiding one kind of non-terminating evaluation.
+
+ Most {functional programming} languages, e.g. {Haskell}, {ML},
+ are closely based on variants of the typed lambda-calculus.
+
+ (1995-03-25)
+
+TypedProlog
+
+ <language> A {strongly typed} {logic programming} language.
+
+ (1995-03-25)
+
+typeface
+
+ <text> The style or design of a {font}. Other independent
+ parameters are size, boldness (thickness of lines), and
+ obliqueness (a sheer transformation applied to the characters,
+ not to be confused with a specifically designed italic font).
+
+ (1996-08-02)
+
+type inference
+
+ <programming> An {algorithm} for ascribing types to
+ expressions in some language, based on the types of the
+ constants of the language and a set of type inference rules
+ such as
+
+ f :: A -> B, x :: A
+ --------------------- (App)
+ f x :: B
+
+ This rule, called "App" for application, says that if
+ expression f has type A -> B and expression x has type A then
+ we can deduce that expression (f x) has type B. The
+ expressions above the line are the premises and below, the
+ conclusion. An alternative notation often used is:
+
+ G |- x : A
+
+ where "|-" is the turnstile symbol ({LaTeX} \vdash) and G is a
+ type assignment for the free variables of expression x. The
+ above can be read "under assumptions G, expression x has type
+ A". (As in Haskell, we use a double "::" for type
+ declarations and a single ":" for the {infix} list constructor,
+ cons).
+
+ Given an expression
+
+ plus (head l) 1
+
+ we can label each subexpression with a type, using type
+ variables X, Y, etc. for unknown types:
+
+ (plus :: Int -> Int -> Int)
+ (((head :: [a] -> a) (l :: Y)) :: X)
+ (1 :: Int)
+
+ We then use {unification} on {type variables} to match the
+ {partial application} of plus to its first argument against
+ the App rule, yielding a type (Int -> Int) and a substitution
+ X = Int. Re-using App for the application to the second
+ argument gives an overall type Int and no further
+ substitutions. Similarly, matching App against the
+ application (head l) we get Y = [X]. We already know X = Int
+ so therefore Y = [Int].
+
+ This process is used both to infer types for expressions and
+ to check that any types given by the user are consistent.
+
+ See also {generic type variable}, {principal type}.
+
+ (1995-02-03)
+
+type scheme
+
+ A typing of an expression which may include {type variables}.
+ E.g.
+
+ \ x . x :: a -> a
+
+ where a is a {generic type variable} which may be instantiated
+ to any type.
+
+ (1994-10-31)
+
+typo
+
+ {typographical error}
+
+typographical error
+
+ (typo) An error while inputting text via keyboard, made
+ despite the fact that the user knows exactly what to type in.
+ This usually results from the operator's inexperience at
+ keyboarding, rushing, not paying attention, or carelessness.
+
+ Compare: {mouso}, {thinko}.
+
+ (1996-04-20)
+
+TYPOL
+
+ <language> A specialised {logic programming} language.
+
+ ["TYPOL: A Formalism to Implement Natural Semantics",
+ T. Despeyroux, RR 94, INRIA, 1988].
+
+ (1994-10-31)
+
+typo squatter
+
+ <web> A {domain squatter} who registers a {domain
+ name} that is a common {typographical error} for a popular
+ {website} so that people will visit their site accidentally,
+ e.g. {(http://goggle.com/)} for {(http://google.com/)}.
+
+ (2007-07-13)
+
+tyt
+
+ <chat> Take your time.
+
+ (2004-02-15)
+
+TZ
+
+ <operating system> The {Unix} {environment variable}
+ containing the current {time zone} identifier, e.g. "GMT",
+ "EST".
+
+ In early versions of Unix this variable simply contained the
+ standard identifier for the zone, an offset in hours from GMT
+ and an identifier to use during daylight saving time
+ (e.g. "GMT0BST"). In later systems it stores the name of a
+ file containing the details of a particular zone such as the
+ dates when DST is in force.
+
+ {Unix manual page}: ctime(3V).
+
+ (1997-07-20)
+
+tz
+
+ <networking> The {country code} for Tanzania.
+
+ (1999-01-27)
+
+ua
+
+ <networking> The {country code} for the Ukraine.
+
+ (1999-01-27)
+
+UAN
+
+ User Action Notation. A notation from {VPI} for
+ representation of activity in a {graphical user interface}.
+
+ [H. Hartson et al, ACM Trans on Info Sys, July 1990].
+
+ (1994-10-31)
+
+UART
+
+ {Universal Asynchronous Receiver/Transmitter}
+
+UAT
+
+ {User Acceptance Testing}
+
+UAW
+
+ <spelling> Misspelling of "{IAW}"?
+
+UBASIC
+
+ Yuji Kida <kida@rkmath.rikkyo.ac.jp>.
+
+ An extension of {BASIC} for {symbolic mathematics} and {number
+ theory}.
+
+ UBASIC supports {bignums}, fractions, complex numbers,
+ polynomials and integer factorisation. It runs under {MS-DOS}
+ and is written in {assembly language}.
+
+ Latest version: 8.
+
+ {(ftp://ftp.simtel.com/math/utk/software/msdos/number.theory/ubasic/)}.
+
+ [Review, W.D. Neumann, Notices of AMS 36 (May/June 1989)]
+
+ ["A math-oriented high-precision BASIC", Notices of the A.M.S,
+ 38 (Mar 1991)].
+
+ (1992-07-06)
+
+UBD
+
+ {User Brain Damage}
+
+ubiquitous computing
+
+ Computers everywhere. Making many computers available
+ throughout the physical environment, while making them
+ effectively invisible to the user. Ubiquitous computing is
+ held by some to be the Third Wave of computing. The First
+ Wave was many people per computer, the Second Wave was one
+ person per computer. The Third Wave will be many computers
+ per person. Three key technical issues are: power
+ consumption, user interface, and wireless connectivity.
+
+ The idea of ubiquitous computing as invisible computation was
+ first articulated by Mark Weiser in 1988 at the Computer
+ Science Lab at {Xerox PARC}.
+
+ {(http://ubiq.com/hypertext/weiser/weiser.html)}.
+
+ (1994-12-23)
+
+uC++
+
+ Micro-C++. A extension of {C++}, by Peter A Ruhr
+ <pabuhr@plg.uwaterloo.ca> of the {University of Waterloo},
+ with {light-weight concurrency} {coroutines} and {mutual
+ exclusion}.
+
+ Version 3.7 for {Unix} uses {GCC} 2.3.3 and requires {dmake}
+ 3.0+ and the setitimer and sigcontext library calls. It
+ runs on {Sequent}, {Sun-4}, {Sun-3}, {Ultrix}, {SGI},
+ {RS/6000}, {HP-PA}.
+
+ {(ftp://plg.uwaterloo.ca/pub/uSystem/u++-3.7.tar.Z)}.
+
+ [Software--Practice and Experience, 22(2):137-172, February
+ 1992].
+
+ (1993-06-10)
+
+UCB
+
+ {University of California at Berkeley}
+
+UCHO
+
+ <audio, software> (Polish for "ear") A program by Stanislaw
+ Raczynski for analysing {wav} audio files to determine which
+ musical notes are sounding at each instant. UCHO can output
+ the results as a {MIDI} file.
+
+ {UCHO home (http://www.stanr.com/ucho/ucho.htm)}.
+
+ (2008-03-17)
+
+U-Code
+
+ Universal Pascal Code. Intermediate language, a
+ generalisation of P-code for easier optimisation. Developed
+ originally for the Los Alamos Cray-1 and the Lawrence
+ Livermore S-1. A refined version currently used by MIPS
+ compilers is descended from one at Stanford U. "Machine
+ Independent Pascal Code Optimisation", D.R. Perkins et al,
+ SIGPLAN Notices 14(8): 201-201 (1979). "A Transporter's Guide
+ to the Stanford U-Code Compiler System", P. Nye et al, TR CSL
+ Stanford U, June 1983. (See HPcode).
+
+UCP
+
+ {Universal Computer Protocol}
+
+UCS
+
+ {Universal Character Set}
+
+UCSD Pascal
+
+ {Pascal-P}
+
+UCS transformation format
+
+ <standard, character> (UTF) A set of standard {character
+ encodings} in accordance with {ISO 10646}.
+
+ One of a set of standard character encodings, the most widely
+ used of which are UTF-8, UTF-16, and UTF-32. The code tables
+ in ISO 10646 and in the {Unicode} standard are identical,
+ although the Unicode standard includes additional material.
+
+ UTF-8 is the most widely used encoding, at least on {Unix}
+ systems. Since it does not include any bytes like '\0' or '/'
+ which have a special meaning in filenames and other {C}
+ library function parameters, and 7-bit ASCII characters have
+ the same encoding under both {ASCII} and UTF-8, the required
+ changes to existing software are minimised.
+
+ Other UTFs: UTF-1 and UTF-7 are not widely used.
+
+ {UTF-8 and Unicode FAQ for Unix/Linux
+ (http://cl.cam.ac.uk/~mgk25/unicode.html#ucs)}.
+
+ (2002-01-15)
+
+UCX
+
+ {Universal Communications X}
+
+udb
+
+ {Universal Debugger}
+
+UDDI
+
+ {Universal Description, Discovery, and Integration}
+
+UDF
+
+ {Universal Disk Format}
+
+UDMA
+
+ {ATA-4}
+
+UDP
+
+ {User Datagram Protocol}
+
+uemacs
+
+ {MicroEmacs}. ("u" looks a bit like the Greek letter micro).
+
+UFO
+
+ <language> (United Functions and Objects) A hybrid
+ {functional} and {object-oriented} language designed by John
+ Seargant at {Manchester University} for general-purpose
+ parallel computation.
+
+ To a first approximation, UFO is a strict, higher-order
+ functional language with an object-oriented type system, and
+ strong support for numeric computation in the form of
+ SISAL-style arrays and loops. Parallelism is implicit, and
+ applies at various different levels of granularity, thereby
+ facilitating implementations on a wide range of parallel
+ architectures.
+
+ It is planned to run it on a 64 processor {KSR} machine.
+
+ (1996-08-22)
+
+UFO bug
+
+ <humour> A {bug} reported over and over again by users who believe
+ it is real even after they have been shown that it doesn't exist.
+
+ [{Dodgy Coder
+ (http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].
+
+ (2013-02-07)
+
+ug
+
+ <networking> The {country code} for Uganda.
+
+ (1999-01-27)
+
+UGLIAC
+
+ <language> An early system on the {Datatron 200} series.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (2013-02-07)
+
+UHELP
+
+ A {linear programming} system.
+
+ ["UHELP User's Manual", D. Singh, Indus Eng Dept, U Houston
+ (Oct 1969)].
+
+UI
+
+ 1. {user interface}.
+
+ 2. {Unix International}.
+
+uid
+
+ <programming, database>
+
+ 1. {user identifier}.
+
+ 2. unique identifier - of any sort, possibly following sense 1.
+
+ Compare with {SKU} for sense-development.
+
+ (1998-09-27)
+
+UIDL
+
+ {Unique ID Listing}
+
+UIL
+
+ {User Interface Language}
+
+UIMS
+
+ User Interface Management System: a system supporting the
+ development and execution of user interfaces, usually on top
+ of windowing systems.
+
+UIMX
+
+ An interface builder for Motif from Visual Edge.
+
+UIS
+
+ <graphics, programming> A {VMS} graphics programming interface
+ package for {VAXstations}.
+
+ (1998-10-25)
+
+uk
+
+ <networking> The {country code} for United Kingdom.
+
+ (1999-01-27)
+
+UKC
+
+ {University of Kent at Canterbury}
+
+UKERNA
+
+ {United Kingdom Education and Research Networking Association}
+
+UKUUG Ltd.
+
+ <body> The UK's Unix and Open Systems User Group is a
+ non-profit organisation and technical forum for the advocacy
+ of {open systems}, particularly {Unix} and Unix-like
+ {operating systems}, the promotion of free and {open source}
+ software, and the advancement of open programming {standards}
+ and networking {protocols}.
+
+ UKUUG aims to cater for all those working in, or interested in
+ open systems and open standards.
+
+ It has been known as UKUUG since 1977, but produced its first
+ magazine - UK Universities UNIX Newsletter - in December 1976.
+
+ UKUUG used to stand for "United Kingdom Unix Users Group" but
+ is now just "UKUUG Ltd."
+
+ {UKUUG Home (http://ukuug.org/)}.
+
+ (2006-08-23)
+
+ULCC
+
+ {University of London Computing Centre}
+
+Ulm's Modula-2 System
+
+ <language> A {Modula-2} {compiler}, library and tools by
+ Andreas Borchert <borchert@mathematik.uni-ulm.de>. The
+ compiler is derived from the {ETHZ} compiler for the {Lilith}
+ system. Version 2.2.1 conforms to {PIM3}. It requires {gas}
+ version 1.36 (to be found in the same directory). Commercial
+ use requires a licence. It runs on {Sun-3}, {Nixdorf}
+ {Targon}/31, {Concurrent} 3200 Series.
+
+ {(ftp://titania.mathematik.uni-ulm.de/pub/soft/modula/ulm/sun3/modula-2.2.1.tar.Z)}.
+
+ (1992-03-02)
+
+ULP
+
+ 1. <language> A small structured language for use on
+ {microprocessors}.
+
+ ["User's Guide to the ULP Language for the PDP-11", CS TR 536,
+ U Maryland, May 1977].
+
+ 2. <protocol> {Upper Layer Protocol}.
+
+ (1999-02-17)
+
+Ultra64
+
+ <hardware, games> A {Nintendo} games machine, unveiled in May
+ 1995.
+
+ [Details?]
+
+ (1995-05-10)
+
+Ultra-ATA
+
+ {ATA-4}
+
+Ultra DMA
+
+ {ATA-4}
+
+Ultra-SCSI
+
+ <hardware> An extension of {SCSI-2} proposed by a group of
+ manufacturers which doubles the transfer speed of {Fast-SCSI}
+ to give 20MByte/s on an 8-bit connection and 40MByte/s on a
+ 16-bit connection.
+
+ (1995-04-19)
+
+Ultrix
+
+ <operating system> A version of {Unix} based on the {Berkeley}
+ version, designed and implemented by {DEC} to run on their
+ {VAX} and {DECstation} processors.
+
+ (1994-10-26)
+
+um
+
+ <networking> The {country code} for United States minor
+ outlying islands.
+
+ (1999-01-27)
+
+UMB
+
+ 1. {Upper Memory Block}.
+
+ 2. A university(?).
+
+ (1996-01-10)
+
+UMB Scheme
+
+ A {Scheme} system including an editor and debugger by William
+ Campbell <bill@cs.umb.edu>. Conforms to the {R4RS}.
+
+ {(ftp://nexus.yorku.ca/pub/scheme/)}.
+
+ (1994-10-28)
+
+UMDL
+
+ {University of Michigan Digital Library Project}
+
+UML
+
+ {Unified Modeling Language}
+
+uML
+
+ {Micro ML}
+
+UMTS
+
+ {Universal Mobile Telecommunications System}
+
+unary
+
+ 1. <programming> (or "{monadic}") A description of a
+ {function} or {operator} which takes one {argument}, e.g. the
+ unary minus operator which negates its argument. The term is
+ part of the same sequence as {nullary} and {binary}.
+
+ 2. <data, humour> Base one. A number base with only one
+ digit, namely zero, and which can therefore only be used to
+ express the number zero. Attempting to add one to zero
+ results in an infinite sequence of carries. Numbers in unary
+ notation can be represented particularly efficiently however
+ since each digit requires no storage.
+
+ (2001-02-25)
+
+UNC
+
+ {Universal Naming Convention}
+
+UNCL
+
+ {Universal Naming Code Locater}
+
+UNCOL
+
+ UNiversal Computer Oriented Language. A universal
+ intermediate language, discussed but never implemented.
+
+ ["A First Version of UNCOL", T.B. Steel, Proc JCC 19:371-378
+ (Winter 1961)].
+
+ [Sammet 1969, p.708].
+
+uncompression
+
+ {compression}
+
+uncountable
+
+ {countable}
+
+uncurry
+
+ {uncurrying}
+
+uncurrying
+
+ <programming> Transforming a {curried function} of the
+ form f x y z = ... to one of the form f (x, y, z) = ... ,
+ i.e. all {arguments} are passed as one {tuple}.
+
+ (1998-07-02)
+
+undefined
+
+ <programming> The value of a {variable} that has not been set or a
+ function that does not return anything. In some programming
+ languages, e.g. {Perl}, {JavaScript}, undefined is a named
+ constant that can be used to explicitly set a variable or return
+ undefined or can be passed as an {actual argument}. Other
+ languages, e.g. {Java}, call it "{null}", but note that the null
+ in relational database programming is subtly different.
+
+ Many languages provide a {built-in function} to test whether an
+ expression is undefined, e.g. Perl's defined() function.
+
+ Attempting to operate on an undefined value, e.g. add it to a
+ number or append it to a string, may either raise an error or
+ result in the undefined value being converted ({cast}) to some
+ appropriate value, e.g. {false}, zero or {empty string}, according
+ to the {type} of expression.
+
+ This definition is an example of a {paradox}.
+
+ (2012-12-02)
+
+undefined external reference
+
+ [Unix] A message from {Unix}'s linker, {ld}. Used in speech
+ to flag loose ends or dangling references in an argument or
+ discussion.
+
+ [{Jargon File}]
+
+underflow
+
+ <programming> (or "floating point underflow", "floating
+ underflow", after "{overflow}") A condition that can occur
+ when the result of a {floating-point} operation would be
+ smaller in magnitude (closer to zero, either positive or
+ negative) than the smallest quantity representable. Underflow
+ is actually (negative) {overflow} of the {exponent} of the
+ {floating point} quantity. For example, an eight-bit {twos
+ complement} exponent can represent multipliers of 2^-128 to
+ 2^127. A result less than 2^-128 would cause underflow.
+
+ Depending on the {processor}, the programming language and the
+ {run-time system}, underflow may set a status bit, raise an
+ {exception} or generate a {hardware} {interrupt} or some
+ combination of these effects. Alternatively, it may just be
+ ignored and zero substituted for the unrepresentable value,
+ though this might lead to a later {divide by zero} error which
+ cannot be so easily ignored.
+
+ (2006-11-09)
+
+Undernet
+
+ <networking> An {Internet Relay Chat} network dating from the
+ 1990s, when it broke away from the main (still larger) IRC
+ network, {EFNet}.
+
+ {(http://undernet.org/)}.
+
+ {The History of the Undernet
+ (http://www2.undernet.org:8080/~cs93jtl/unet_history.txt)}.
+
+ (1995-11-09)
+
+underscore
+
+ <character> _, {ASCII} 95.
+
+ Common names: {ITU-T}: underline; underscore; underbar; under.
+ Rare: score; backarrow; skid; {INTERCAL}: flatworm.
+
+ See also {left arrow}.
+
+ (1995-03-06)
+
+under the hood
+
+ [hot-rodder talk] 1. The underlying implementation of a
+ product (hardware, software, or idea). Implies that the
+ implementation is not intuitively obvious from the appearance,
+ but the speaker is about to enable the listener to {grok} it.
+ "Let's now look under the hood to see how ...."
+
+ 2. Can also imply that the implementation is much simpler than
+ the appearance would indicate: "Under the hood, we are just
+ fork/execing the shell."
+
+ 3. Inside a chassis, as in "Under the hood, this baby has a
+ 40MHz 68030!"
+
+ [{Jargon File}]
+
+undocumented feature
+
+ {feature}
+
+U-NET Limited
+
+ A {dial-up} {Internet} access provider based in Warrington,
+ UK. Speeds 4800 - 28.8kbps. The currently support {Microsoft
+ Windows} and {RISC OS} users. For 12 pounds to join and 12
+ pounds per month or 100 pounds per year you get a full {SLIP}
+ account with a pernament {IP address} and {POP3} {electronic
+ mail} account. Membership includes a disk with {Mosaic},
+ {Eudora}, {Trumpet2}, Newsreader, {FTP} and {Telnet} and full
+ {Internet} access. Users can choose their own {user name} and
+ {hostname}. Allows some extra services such as more than one
+ POP3 account per access account. User name is significant so
+ that a company can have accounts with the same hostname
+ (i.e. their company name) but the mail going to diffent
+ machines. Mail in users POP3 account is accessible from
+ anywhere not just via the dial-up connection. On your next
+ business trip you can still check your {e-mail} (provided you
+ can get onto the Internet).
+
+ {(http://u-net.com/)}.
+
+ E-mail: <hi@u-net.com>.
+
+ (1994-11-18)
+
+unfold
+
+ {inline}
+
+unfold/fold
+
+ A {program transformation} where a {recursive} call to a
+ function is {unfold}ed to an instance of the function's body
+ and then later an instance of the function's body is replaced
+ by a call. E.g.
+
+ sumdouble l = sum (double l)
+
+ double l = case l of
+ [] -> []
+ x:xs -> 2*x + double xs
+
+ ==> (unfold double)
+
+ sumdouble l = sum (case l of
+ [] -> []
+ x:xs -> 2*x : double xs)
+
+ ==> (distribute over case)
+
+ sumdouble l = case l of
+ [] -> sum []
+ x:xs -> sum (2*x : double xs)
+
+ ==> (unfold sum)
+
+ sumdouble l = case l of
+ [] -> 0
+ x:xs -> 2*x + sum (double xs)
+
+ ==> (fold sumdouble)
+
+ sumdouble l = case l of
+ [] -> 0
+ x:xs -> 2*x + sumdouble xs
+
+ (1994-11-03)
+
+UNI
+
+ 1. <standard, body> {Ente Nazionale Italiano di Unificazione}.
+
+ 2. <networking> {User Network Interface}.
+
+ (1999-02-01)
+
+unicast
+
+ <networking> Sending {packets} to a single destination, used
+ in contrast to {broadcast} or {multicast}. The term is
+ generally only used when talking about low level
+ communications, typically at the {network layer},
+ e.g. {Internet Protocol}.
+
+ (2008-06-23)
+
+Unicode
+
+ 1. <character> A 16-bit {character set} standard, designed and
+ maintained by the non-profit consortium Unicode Inc.
+
+ Originally Unicode was designed to be universal, unique, and
+ uniform, i.e., the code was to cover all major modern written
+ languages (universal), each character was to have exactly one
+ encoding (unique), and each character was to be represented by
+ a fixed width in bits (uniform).
+
+ Parallel to the development of Unicode an {ISO}/{IEC}
+ standard was being worked on that put a large emphasis on
+ being compatible with existing character codes such as {ASCII}
+ or {ISO Latin 1}. To avoid having two competing 16-bit
+ standards, in 1992 the two teams compromised to define a
+ common character code standard, known both as Unicode and
+ {BMP}.
+
+ Since the merger the character codes are the same but the two
+ standards are not identical. The ISO/IEC standard covers only
+ coding while Unicode includes additional specifications that
+ help implementation.
+
+ Unicode is not a {glyph encoding}. The same character can be
+ displayed as a variety of {glyphs}, depending not only on the
+ {font} and style, but also on the adjacent characters. A
+ sequence of characters can be displayed as a single glyph or a
+ character can be displayed as a sequence of glyphs. Which
+ will be the case, is often font dependent.
+
+ See also Jörgen Bettels and F. Avery Bishop's paper {Unicode:
+ A universal character code
+ (http://research.compaq.com/wrl/DECarchives/DTJ/DTJB02/DTJB02SC.TXT)}.
+
+ (2002-08-06)
+
+ 2. <language> A pre-{Fortran} on the {IBM 1130}, similar to
+ {MATH-MATIC}.
+
+ [Sammet 1969, p.137].
+
+ (2004-09-14)
+
+UniCOMAL
+
+ {COMmon Algorithmic Language}
+
+Unicorny
+
+ <humour, programming> A {feature} that's so early in the planning
+ stages that it might as well be imaginary.
+
+ [{Dodgy Coder(http://www.dodgycoder.net/2011/11/yoda-conditions-pokemon-exception.html)}].1
+
+ (2013-06-17)
+
+unicos
+
+ A {Unix} variant for {Cray} computers.
+
+ [More details?]
+
+ (1994-12-06)
+
+Uniface
+
+ 1. <database, programming, product> A {4GL} development
+ environment and system integration tool marketed by
+ {Compuware}. Uniface is database independent, with interfaces
+ to more than 14 {database management systems} and file
+ retrieval systems including {DB2}, {IMS}, {SQL Server},
+ {Oracle}, {RDB}, {Sybase}. It is currently supported on {MS
+ Windows} (98, ME, NT, 2000, XP, 2003), various {Unix}
+ flavours, {Linux}, {OpenVMS}, {IBM iSeries} ({AS/400}), {IBM
+ zSeries} ({MVS}) and various {web servers}. Uniface can
+ integrate with {SAP}, {COM}, {Java}, {BEA Tuxedo}, {CICS}, and
+ various {CORBA} implementations.
+
+ {Uniface user group Germany (http://c-b-g.org/)}.
+ {Profesional Uniface Users Universe (http://puuu.org/)}.
+ {Free tutorials (http://march-hare.com.au/)}.
+
+ 2. <text> Synonym of {bitmap font}.
+
+ (1999-01-05)
+
+unification
+
+ <programming> The generalisation of {pattern matching} that is
+ the {logic programming} equivalent of {instantiation} in
+ {logic}. When two {terms} are to be unified, they are
+ compared. If they are both constants then the result of
+ unification is success if they are equal else failure. If one
+ is a variable then it is bound to the other, which may be any
+ term (which satisfies an "{occurs check}"), and the
+ unification succeeds. If both terms are structures then each
+ pair of sub-terms is unified {recursive}ly and the unification
+ succeeds if all the sub-terms unify.
+
+ The result of unification is either failure or success with a
+ set of variable bindings, known as a "{unifier}". There may
+ be many such unifiers for any pair of terms but there will be
+ at most one "{most general unifier}", other unifiers simply
+ add extra bindings for sub-terms which are variables in the
+ original terms.
+
+ (1995-12-14)
+
+Unified Han
+
+ {Han character}
+
+Unified Modeling Language
+
+ <language> (UML) A non-proprietary, third generation {modelling
+ language}. The Unified Modeling Language is an open method
+ used to specify, visualise, construct and document the
+ artifacts of an {object-oriented} software-intensive system
+ under development. The UML represents a compilation of "best
+ engineering practices" which have proven successful in
+ modelling large, complex systems.
+
+ UML succeeds the concepts of {Booch}, {OMT} and {OOSE} by
+ fusing them into a single, common and widely usable modelling
+ language. UML aims to be a standard modelling language which
+ can model {concurrent} and distributed systems.
+
+ UML is not an {industry standard}, but is taking shape under
+ the auspices of the {Object Management Group} (OMG). OMG has
+ called for information on object-oriented methodologies, that
+ might create a rigorous software modelling language. Many
+ industry leaders have responded in earnest to help create the
+ standard.
+
+ See also: {STP}, {IDE}.
+
+ {OMG UML Home (http://uml.org/)}.
+
+ {Rational UML Resource Center
+ (http://rational.com/uml/index.jsp)}.
+
+ (2002-01-03)
+
+unifier
+
+ The unifier of a set of expressions is a set of substitutions
+ of terms for variables such that the expressions are all
+ equal.
+
+ See also {most general unifier}, {unification}.
+
+ (1994-12-06)
+
+UNIFORM
+
+ An intermediate language developed for reverse engineering
+ both {COBOL} and {Fortran}.
+
+ ["The REDO Compendium", H. van Zuylen ed, Wiley 1993].
+
+ (1994-12-06)
+
+Uniform Naming Convention
+
+ {Universal Naming Convention}
+
+Uniform Resource Citation
+
+ <web> (URC) A set of attribute/value pairs
+ describing an object. Some of the values may be {URIs} of
+ various kinds. Others may include, for example, athorship,
+ publisher, datatype, date, copyright status and shoe size. A
+ URC is not normally considered as a string, but a set of
+ fields and values with some defined free formatting.
+
+ (1995-03-24)
+
+Uniform Resource Locater
+
+ {Uniform Resource Locator}
+
+Uniform Resource Locator
+
+ <web> (URL, previously "Universal") A {standard}
+ way of specifying the location of an object, typically a {web
+ page}, on the {Internet}. Other types of object are described
+ below. URLs are the form of address used on the {World-Wide
+ Web}. They are used in {HTML} documents to specify the target
+ of a {hypertext link} which is often another HTML document
+ (possibly stored on another computer).
+
+ Here are some example URLs:
+
+ http://w3.org/default.html
+ http://acme.co.uk:8080/images/map.gif
+ http://foldoc.org/?Uniform+Resource+Locator
+ http://w3.org/default.html#Introduction
+ ftp://wuarchive.wustl.edu/mirrors/msdos/graphics/gifkit.zip
+ ftp://spy:secret@ftp.acme.com/pub/topsecret/weapon.tgz
+ mailto:fred@doc.ic.ac.uk
+ news:alt.hypertext
+ telnet://dra.com
+
+ The part before the first colon specifies the access scheme or
+ {protocol}. Commonly implemented schemes include: {ftp},
+ {http} (web), {gopher} or {WAIS}. The "file"
+ scheme should only be used to refer to a file on the same
+ host. Other less commonly used schemes include {news},
+ {telnet} or mailto ({e-mail}).
+
+ The part after the colon is interpreted according to the
+ access scheme. In general, two slashes after the colon
+ introduce a {hostname} (host:port is also valid, or for {FTP}
+ user:passwd@host or user@host). The {port} number is usually
+ omitted and defaults to the standard port for the scheme,
+ e.g. port 80 for HTTP.
+
+ For an HTTP or FTP URL the next part is a {pathname} which is
+ usually related to the pathname of a file on the server. The
+ file can contain any type of data but only certain types are
+ interpreted directly by most {browsers}. These include {HTML}
+ and images in {gif} or {jpeg} format. The file's type is
+ given by a {MIME} type in the HTTP headers returned by the
+ server, e.g. "text/html", "image/gif", and is usually also
+ indicated by its {filename extension}. A file whose type is
+ not recognised directly by the browser may be passed to an
+ external "viewer" {application}, e.g. a sound player.
+
+ The last (optional) part of the URL may be a query string
+ preceded by "?" or a "fragment identifier" preceded by "#".
+ The later indicates a particular position within the specified
+ document.
+
+ Only alphanumerics, reserved characters (:/?#"<>%+) used for
+ their reserved purposes and "$", "-", "_", ".", "&", "+" are
+ safe and may be transmitted unencoded. Other characters are
+ encoded as a "%" followed by two {hexadecimal} digits. Space
+ may also be encoded as "+". Standard {SGML} "&<name>;"
+ character entity encodings (e.g. "&eacute;") are also accepted
+ when URLs are embedded in HTML. The terminating semicolon may
+ be omitted if &<name> is followed by a non-letter character.
+
+ {The authoritative W3C URL specification
+ (http://w3.org/hypertext/WWW/Addressing/Addressing.html)}.
+
+ (2000-02-17)
+
+Uniform Resource Name
+
+ <web> (URN, previously Uniform/Universal Resource
+ Number) 1. Any {URI} which is not a {URL}.
+
+ 2. A particular scheme which is currently (1991-4) under
+ development by the {IETF}, which should provide for the
+ resolution using {Internet} {protocols} of names which have a
+ greater persistence than that currently associated with
+ Internet {host} names or organisations (as used in {URLs}).
+ Uniform Resource Names will be URI schemes that improve on
+ URLs in reliability over time, including authenticity,
+ replication, and high availability.
+
+ When defined, a URN in sense 1 will be an example of a URN in
+ sense 2.
+
+ {(http://w3.org/pub/WWW/Addressing/Addressing.html)}.
+
+ (2006-04-18)
+
+Uniform Resource Number
+
+ Former name for {Uniform Resource Name}.
+
+Unify
+
+ <database, product> A {relational database} produced by {Unify
+ Corporation}.
+
+ (1995-03-15)
+
+unify
+
+ <algorithm> To perform {unification}.
+
+ (1995-03-15)
+
+Unify Corporation
+
+ <company> Developers of the {Unify} {relational database}. At
+ one time, before {Sybase}, they were a competitor of {Oracle},
+ et al.
+
+ {(http://unify.com/)}.
+
+ {(ftp://ftp.unify.com/)}.
+
+ (1995-03-15)
+
+Unihan
+
+ {Han character}
+
+uninstaller
+
+ <operating system> A {utility} program to remove another
+ {application program} from a computer's disks.
+
+ Most commonly found on {IBM PCs}, as applications tend to
+ leave files in various places on the {hard disc}, so special
+ software is required to tidy up after them.
+
+ Ken Spreitzer <ken@maximized.com> claims to have written the
+ original PC program called "UnInstaller", first licensed to
+ {MicroHelp} and now (Feb 1998) sold by {CyberMedia}.
+
+ Compare with {installer}.
+
+ (1998-02-09)
+
+uninteresting
+
+ <jargon> 1. Said of a problem that, although {nontrivial}, can
+ be solved simply by throwing sufficient resources at it.
+
+ 2. Also said of problems for which a solution would neither
+ advance the state of the art nor be fun to design and code.
+
+ Hackers regard uninteresting problems as intolerable wastes of
+ time, to be solved (if at all) by lesser mortals. *Real*
+ hackers (see {toolsmith}) generalise uninteresting problems
+ enough to make them interesting and solve them - thus
+ solving the original problem as a special case (and, it must
+ be admitted, occasionally turning a molehill into a mountain,
+ or a mountain into a tectonic plate).
+
+ See {WOMBAT}, {SMOP}. Compare {toy problem}. Oppose
+ {interesting}.
+
+ [{Jargon File}]
+
+ (1995-03-10)
+
+Uninterruptible Power Supply
+
+ <hardware> (UPS) A battery powered {power supply unit} that is
+ guaranteed to provide power to a computer in the event of
+ interruptions in the incoming mains electrical power.
+ Different rating UPSs will provide power for different lengths
+ of time.
+
+ Modern UPSs connect to the computer's {serial port} and
+ provide information such as battery time remaining, allowing
+ the computer to shut down {gracefully} before complete loss of
+ power.
+
+ (1996-12-11)
+
+union
+
+ 1. <theory> An operation on two {sets} which returns the set of
+ all elements that are a member of either or both of the sets;
+ normally written as an infix upper-case U symbol. The operator
+ generalises to zero or more sets by taking the union of the
+ current partial result (initially the empty set) with the next
+ argument set, in any order.
+
+ For example, (a, b, c) U (c, d, e) = (a, b, c, d, e)
+
+ 2. <programming> A {type} whose values may be of one of a number
+ of other types, the current type depending on conditions that are
+ only known at {run-time}. A {variable} of union type must be
+ allocated sufficient storage space to hold the largest component
+ type. Some unions include extra information to say which type of
+ value the union currently has (a "tagged union"), others rely on
+ the program to keep track of this independently.
+
+ A union contrasts with a {structure} or {record} which stores
+ values of all component types at once.
+
+ 3. <database> An {SQL} {operator} that concatenates two result
+ sets, that must have the same number and types of {columns}.
+ The operator may be followed by the word "ALL" to indicate
+ that results that appear in both sets should appear twice in
+ the output.
+
+ (2002-02-26)
+
+Unipalm Group plc
+
+ <company> A company floated in March 1994.
+
+ {(http://unipalm.co.uk/index.html)}.
+
+ (1996-12-11)
+
+Unipress Software, Inc.
+
+ <company> A developer and distributor of {Unix} software.
+ They produce PC-UNIX connectivity software, development tools
+ and applications and provide technical support and
+ maintenance, porting services, training and consulting.
+
+ {(http://unipress.com/)}.
+
+ (1996-12-11)
+
+uniprocessor
+
+ <processor> (From "uni" - one) A computer with a single
+ {central processing unit}, in contrast to a {parallel
+ processor}. Most {personal computers} are currently (March
+ 1997) uniprocessors. Some more expensive computers, typically
+ {servers}, have multiple processors to provide increased
+ {throughput}.
+
+ See also {symmetric multiprocessor} and {massively parallel
+ processor}.
+
+ (1997-03-23)
+
+UNIQUE
+
+ <language> A {portable} {job control language}.
+
+ ["The UNIQUE Command Language - Portable Job Control",
+ I.A. Newman, Proc DATAFAIR 73, 1973, pp. 353-357].
+
+ (1994-11-22)
+
+Unique ID Listing
+
+ <messaging> (UIDL) A system used by {POP3} {electronic mail}
+ {servers} to uniquely identify a mail message. Normally, a
+ message is identified by its position in the list of messages
+ but this will change when an earlier message is deleted. The
+ UIDL is a fixed string of characters which is unique to the
+ message. The UIDL of a message never changes and will never
+ be reused, even when the message has been deleted from the
+ user's {mailbox}.
+
+ {RFC 1725 (http://ds0.internic.net/rfc/rfc1725.txt)}.
+
+ (1997-04-16)
+
+unique key
+
+ <database> A {key} which identifies only one body of
+ information out of several.
+
+ (1997-04-26)
+
+unique sales point
+
+ <product> (USP) A feature that the salesman hopes will
+ convince you to buy his product instead of another.
+
+ (1999-10-21)
+
+Unir Tech
+
+ <company> The company with the exclusive license from {Bell
+ Labs} to distribute {C+@}. Unir is owned and operated by
+ well-known anti-{IETF} ranter, Jim Fleming.
+
+ Telephone: +1 (800) 222-8647.
+
+ (2002-05-19)
+
+UNISAP
+
+ An early system on {UNIVAC} I or II.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1994-11-22)
+
+Unisys Corporation
+
+ <company> The company formed in 1984-5 when {Burroughs
+ Corporation} merged with {Sperry Corporation}. This was when
+ the phrase "{dinosaurs mating}" was coined.
+
+ Unisys is one of the largest providers of information
+ services, technology, and software in the world. They employ
+ about 49,000 people and do business in some 100 countries. In
+ 1994 about 80 percent of revenue was derived from commercial
+ information systems and services, with the remainder coming
+ from electronic systems and services for the defense market.
+ The defense business was sold to {Loral} in early 1995.
+ Slightly more than half of Unisys's revenue is from business
+ in the United States.
+
+ They specialise in providing business-critical solutions,
+ based on open information networks, for organisations that
+ operate in transaction-intensive environments. These
+ organisations include financial services companies, airlines,
+ telecommunications companies, government agencies, and other
+ commercial enterprises.
+
+ In August 1994, quarterly sales were $1799M and profits $50M.
+
+ {(http://unisys.com/)}.
+
+ (1995-03-21)
+
+United Kingdom Unix Users Group
+
+ {UKUUG Ltd.}
+
+United Technologies Research Cente
+
+ (UTRC) {http://utrcwww.utc.com/}.
+
+ (1994-11-29)
+
+Unit Separator
+
+ <character> (US) {ASCII} character 31.
+
+ (1996-06-29)
+
+unit testing
+
+ <testing> The type of {testing} where a developer (usually the
+ one who wrote the code) proves that a code module (the "unit")
+ meets its requirements.
+
+ (2003-09-24)
+
+UNITY
+
+ A high-level parallel language.
+
+ A translator into {MPL} is available by
+ {(ftp://sanfrancisco.ira.uka.de/pub/maspar/maspar_unity.tar.Z)}.
+
+ See also {MasPar Unity}.
+
+ ["Parallel Program Design", K.M. Chandry and Misra, A-W 1988].
+
+ (1994-11-29)
+
+Univac
+
+ <processor, company> A brand of computer.
+
+ There is a historical placard in the United States Census
+ Bureau that has the following, "The Bureau of the Census
+ dedicated the world's first electronic general purpose data
+ processing computer, UNIVAC I, on June 14, 1951.
+ Eckert-Mauchly Computer Corporation".
+
+ The {Eckert-Mauchly Computer Corporation} designed and built
+ Univac. Over the years, rights to the Univac name changed
+ hands several times. Circa 1987, {Sperry Univac} merged with
+ the {Burroughs Corporation} to form {Unisys Corporation}.
+
+ (1994-11-22)
+
+Universal algebra
+
+ <logic> The {model theory} of {first-order} {equational
+ logic}.
+
+ (1997-02-25)
+
+Universal Asynchronous Receiver/Transmitter
+
+ <communications, hardware> (UART) An {integrated circuit} used
+ for serial communications, containing a transmitter
+ (parallel-to-serial converter) and a receiver
+ (serial-to-parallel converter), each clocked separately.
+
+ The parallel side of a UART is usually connected to the {bus}
+ of a computer. When the computer writes a byte to the UART's
+ transmit data register (TDR), the UART will start to transmit
+ it on the serial line. The UART's status register contains a
+ {flag} bit which the computer can read to see if the UART is
+ ready to transmit another byte. Another status register bit
+ says whether the UART has received a byte from the {serial
+ line}, in which case the computer should read it from the
+ receive data register (RDR). If another byte is received
+ before the previous one is read, the UART will signal an
+ "overrun" error via another status bit.
+
+ The UART may be set up to {interrupt} the computer when data
+ is received or when ready to transmit more data.
+
+ The UART's serial connections usually go via separate {line
+ driver} and {line receiver} {integrated circuits} which
+ provide the power and voltages required to drive the serial
+ line and give some protection against noise on the line.
+
+ Data on the {serial line} is formatted by the {UART} according
+ to the setting of the UART's control register. This may also
+ determine the transmit and receive baud rates if the UART
+ contains its own clock circuits or "{baud} rate generators".
+ If incorrectly formated data is received the UART may signal a
+ "{framing error}" or "{parity} error".
+
+ Often the clock will run at 16 times the baud rate (bits per
+ second) to allow the receiver to do {centre sampling} - i.e. to
+ read each bit in the middle of its allotted time period. This
+ makes the UART more tolerant to variations in the {clock rate}
+ ("jitter") of the incoming data.
+
+ An example of a late 1980s UART was the {Intel 8450}. In the
+ 1990s, newer UARTs were developed with on-chip {buffers}.
+ This allowed higher transmission speed without data loss and
+ without requiring such frequent attention from the computer.
+ For example, the {Intel} {16550} has a 16 byte {FIFO}.
+ Variants include the {16C550}, {16C650}, {16C750}, and
+ {16C850}.
+
+ The term "Serial Communications Interface" (SCI) was first
+ used at {Motorola} around 1975 to refer to their start-stop
+ asyncronous serial interface device, which others were calling
+ a UART.
+
+ See also {bit bang}.
+
+ [Is this the same as an {ACIA}?]
+
+ (2003-07-13)
+
+Universal Character Set
+
+ <character, standard> (UCS, ISO/IEC 10646) A 1993 {ISO} and
+ {IEC} standard {character set}, also known as "Universal
+ Multiple-Octet Coded Character Set".
+
+ UCS comes in a 16-bit variant called UCS-2 and a 32-bit
+ variant called UCS-4, which is composed of 16-bit UCS-2
+ "planes". So far only one 16-bit plane has been defined,
+ which is known as the {Basic Multilingual Plane}.
+
+ The implementation of UCS is still in its infancy, though some
+ moves, such as the {Java} language defining a character to be
+ 16 bits, are suggestive.
+
+ [Relationship with {Unicode}?]
+
+ (1997-07-04)
+
+Universal Communications X
+
+ <communications> (UCX) A software implementation of the
+ ubiquitous {TCP/IP} suite of {communications} {protocols} for
+ {Digital Equipment Corporation}'s {OpenVMS} {operating
+ system}.
+
+ Users of the {UCX} product can connect to heterogeneous
+ {networks} to access and {download} files, send {electronic
+ mail}, run and develop {applications}, and monitor activity.
+
+ {"Software Product Description, DIGITAL TCP/IP Services for
+ OpenVMS, Version 4.2",
+ (http://digital.com/info/QAW009/QAW009HM.HTM)}.
+
+ (2000-12-15)
+
+Universal Computer Protocol
+
+ <communications, protocol> An earlier form of {External
+ Machine Interface} (EMI).
+
+ (2007-09-10)
+
+Universal Debugger
+
+ <tool, parallel> (udb) {KSR}'s interactive {source level
+ debugger} for serial and parallel programs written in {KSR},
+ {Fortran}, {KSR C} and {KSR1} {assembly language}.
+
+ Udb is a source level debugger for testing and debugging
+ serial and parallel programs; it is compatible with {GDB} and
+ {dbx}. The user can direct udb either by typing commands or
+ graphically through an {X}-based window interface; the latter
+ provides simultaneous display of source code, I/O and
+ instructions. For parallel programs, operations can be
+ carried out per-{thread}.
+
+ {Home
+ (http://tc.cornell.edu/Parallel.Tools/tools/udb.html)}.
+
+ (1995-05-07)
+
+Universal Description, Discovery, and Integration
+
+ <standard, protocol> (UDDI) The service discovery {protocol}
+ for {Web Services} through which companies can find one
+ another to conduct business. This standard was unveiled by
+ {Ariba}, {IBM}, {Microsoft}, and 33 other companies in
+ September 2000.
+
+ (2002-06-28)
+
+Universal Disk Format
+
+ <storage, standard> (UDF) A {CD-ROM} {file system} {standard}
+ that is required for {DVD ROMs}. UDF is the {OSTA}'s
+ replacement for the {ISO 9660} file system used on CD-ROMs,
+ but will be mostly used on DVD. {DVD multimedia} disks use
+ UDF to contain {MPEG} {audio} and {video} {streams}.
+
+ To read DVDs you need a DVD drive, the {kernel} driver for the
+ drive, MPEG video support, and a UDF driver. DVDs containing
+ both UDF filesystems and ISO 9660 filesystems can be read
+ without UDF support.
+
+ UDF can also be used by {CD-R} and {CD-RW} recorders in
+ {packet writing} mode.
+
+ (1999-09-01)
+
+Universal Naming Convention
+
+ <networking> (UNC) The type of {file system} {path} used in
+ {Microsoft Windows} networking to completely specify a
+ directory on a {file server}.
+
+ The basic format is:
+
+ \\servername\sharename
+
+ where "servername" is the {hostname} or {IP address} of a
+ network file server, and "sharename" is the name of a shared
+ directory on the server. This is related to the conventional
+ {MS-DOS} "C:\windows" style of directory name. E.g.
+
+ \\server1\dave
+
+ might be set up to point to
+
+ C:\users\homedirs\dave
+
+ on a server called "server1".
+
+ It is possible to execute a program using this convention
+ without having to specifically link a drive, by running:
+
+ \\server\share\directory\program.exe
+
+ The {undocumented} DOS command, TRUENAME can be used to find
+ out the UNC name of a file or directory on a network drive.
+
+ Even Microsoft don't know whether UNC stands for "Universal
+ Naming Convention" or "Uniform Naming Convention", both appear
+ on their website, sometimes withing the same document, but
+ with a preference for "Universal".
+
+ (2008-12-09)
+
+universal quantifier
+
+ {quantifier}
+
+Universal Resource Identifier
+
+ <web> (URI, originally "UDI" in some {WWW}
+ documents) The generic set of all names and addresses which
+ are short strings which refer to objects (typically on the
+ {Internet}). The most common kinds of URI are {URLs} and
+ {relative URLs}.
+
+ URIs are defined in {RFC 1630}.
+
+ {W3 specification
+ (http://w3.org/hypertext/WWW/Addressing/URL/URI_Overview.html)}.
+
+ (1997-07-16)
+
+Universal Resource Locator
+
+ {Uniform Resource Locator}
+
+Universal Serial Bus
+
+ <hardware, standard> (USB) An external {peripheral} interface
+ {standard} for communication between a computer and external
+ {peripherals} over an inexpensive cable using {biserial}
+ transmission.
+
+ USB is intended to replace existing {serial ports}, {parallel
+ ports}, {keyboard}, and {monitor} connectors and be used with
+ {keyboards}, {mice}, {monitors}, {printers}, and possibly some
+ low-speed {scanners} and removable {hard drives}. For faster
+ devices existing {IDE}, {SCSI}, or emerging {FC-AL} or
+ {FireWire} interfaces can be used.
+
+ USB works at 12 Mbps with specific consideration for low cost
+ peripherals. It supports up to 127 devices and both
+ {isochronous} and {asynchronous} data transfers. Cables can
+ be up to five metres long and it includes built-in power
+ distribution for low power devices. It supports {daisy
+ chaining} through a tiered star multidrop topology. A USB
+ cable has a rectangular "Type A" plug at the computer end and
+ a square "Type B" plug at the peripheral end.
+
+ Before March 1996 Intel started to integrate the necessary
+ logic into {PC} {chip sets} and encourage other manufacturers
+ to do likewise. It was widely available by 1997. Later
+ versions of {Windows 95} included support for it. It was
+ standard on {Macintosh} computers in 1999.
+
+ The USB 2.0 specification was released in 2000 to allow USB to
+ compete with {Firewire} etc. USB 2.0 is backward compatible
+ with USB 1.1 but works at 480 Mbps.
+
+ {usb.org (http://usb.org/)}.
+
+ (2004-01-31)
+
+universal thunk
+
+ <programming, operating system> A software mechanism allowing
+ a {Windows 3.1} {application} to call a {32-bit} {dynamically
+ linked library} (DLL) under {Win32s}.
+
+ The {Windows 3.1} {application} which wants to call an entry
+ in a 32-bit DLL instead calls a corresponding entry in a
+ {16-bit} DLL. The programmer must also include {code} to
+ detect whether the {32-bit} DLL is loaded. A {32-bit} {EXE}
+ loads the {32-bit} DLL.
+
+ See also {Generic Thunk}, {Flat Thunk}.
+
+ ["Calling a Win32 DLL from a Windows 3.1 Application", Win32
+ SDK Knowledge Base, Article ID Q97785].
+
+ [Better explanation?]
+
+ (1997-10-11)
+
+Universal Time
+
+ <time, standard> (UT) The mean solar time along the prime
+ meridian (0 longitude) that runs through the Greenwich
+ Observatory outside of London, UK, where the current system
+ originated. UT is tied to the rotation of the Earth in
+ respect to the fictitious "mean Sun".
+
+ {Greenwich Mean Time} (GMT) was measured from Greenwich mean
+ midday until 1925 when the reference point was changed from
+ noon to midnight and the name changed to "Universal Time".
+
+ There are three separate definitions, UT0, UT1, and UT2,
+ depending on which corrections have been applied to the
+ Earth's motion. {Coordinated Universal Time} is kept within
+ 0.9 seconds of UT1, by addition of leap seconds to
+ {International Atomic Time}.
+
+ (2001-08-02)
+
+Universal Time Coordinated
+
+ <time, standard> An incorrect term for {Coordinated Universal
+ Time}.
+
+ (2001-08-01)
+
+universe of discourse
+
+ <artificial intelligence> In {ontology}, the set of all {entities}
+ that can be represented in some {declarative language} or other
+ {formal system}.
+
+ Each entity is represented by a name and may have some
+ human-readable description of its meaning. Formal {axioms}
+ constrain the interpretation and well-formed use of these
+ names.
+
+ (2005-07-29)
+
+University of Arizona
+
+ <body, education> The University was founded in 1885 as a Land
+ Grant institution with a three-fold mission of teaching,
+ research and public service. Today, the University is one of
+ the top 20 research universities in the nation, with a student
+ enrollment of more than 35,000, a faculty and staff of 12,500,
+ and a 345-acre campus.
+
+ {(http://arizona.edu/)}.
+
+ Address: Tucson, Arizona, USA.
+
+University of California at Berkeley
+
+ <body, education> (UCB)
+
+ See also {Berzerkley}, {BSD}.
+
+ {(http://berkeley.edu/)}.
+
+ Note to British and Commonwealth readers: that's /berk'lee/,
+ not /bark'lee/ as in British Received Pronunciation.
+
+ (1994-11-29)
+
+University of Durham
+
+ <body, education> A busy research and teaching community in
+ the historic cathedral city of Durham, UK (population 61000).
+ Its work covers key branches of science and technology and
+ traditional areas of scholarship. Durham graduates are in
+ great demand among employers and the University helps to
+ attract investment into the region. It provides training,
+ short courses, and expertise for industry. Through its
+ cultural events, conferences, tourist business and as a major
+ employer, the University contributes in a wide social and
+ economic sense to the community.
+
+ Founded in 1832, the University developed in Durham and
+ Newcastle until 1963 when the independent University of
+ Newcastle upon Tyne came into being. Durham is a collegiate
+ body, with 14 Colleges or Societies which are a social and
+ domestic focus for students. In 1992, the Universities of
+ Durham and Teesside launched University College,
+ Stockton-on-Tees, which has 190 students in the first year.
+
+ {(http://dur.ac.uk/)}.
+
+ (1995-03-17)
+
+University of East London
+
+ <body, education> (UEL) A UK University with six academic
+ Faculties: Design and The Built Environment, East London
+ Business School, Institute Of Health and Rehabilitation,
+ Faculty Of Science, Social Sciences and Technology.
+
+ {(http://uel.ac.uk/)}.
+
+ (1994-11-29)
+
+University of Edinburgh
+
+ <body, education> A university in the centre of Scotland's
+ capital. The University of Edinburgh has been promoting and
+ setting standards in education for over 400 years. Granted
+ its Royal Charter in 1582 by James VI, the son of Mary Queen
+ of Scots, the University was founded the following year by the
+ Town Council of Edinburgh, making it the first
+ post-Reformation university in Scotland, and the first civic
+ university to be established in the British Isles.
+
+ Known in its early years as King James College, or the Tounis
+ (Town's) College, the University soon established itself
+ internationally, and by the 18th century Edinburgh was a
+ leading centre of the European Enlightenment and one of the
+ continent's principal universities. The University's close
+ relationship with the city in which it is based, coupled with
+ a forward-looking, international perspective, has kept
+ Edinburgh at the forefront of new research and teaching
+ developments whilst enabling it to retain a uniquely Scottish
+ character.
+
+ Edinburgh's academics are at the forefront of developments in
+ the study and application of languages, medicine,
+ micro-electronics, biotechnology, computer-based disciplines
+ and many other subjects. Edinburgh's standing as a world
+ centre for research is further enhanced by the presence on and
+ around University precincts of many independently-funded, but
+ closely linked, national research institutes
+
+ {(http://ed.ac.uk/)}.
+
+ Address: Old College, South Bridge, Edinburgh, Scotland EH8
+ 9YL, UK.
+
+ Telephone: +44 (131) 650 1000.
+
+ See also {ABSET}, {ABSYS}, {Alice}, {ASL+}, {Baroque},
+ {C++Linda}, {Cogent Prolog}, {COWSEL}, {Echidna}, {Edinburgh
+ Prolog}, {Edinburgh SML}, {EdML}, {ELLIS}, {ELSIE},
+ {ESLPDPRO}, {Extended ML}, {Hope}, {IMP}, {LCF}, {Lisp-Linda},
+ {Marseille Prolog}, {metalanguage}, {MIKE}, {ML}, {ML Kit},
+ {ML-Linda}, {Multipop-68}, {Nuprl}, {Oblog}, {paraML},
+ {Pascal-Linda}, {POP-1}, {POP-2}, {POPLER}, {Prolog},
+ {Prolog-2}, {Prolog-Linda}, {Scheme-Linda}, {Skel-ML},
+ {Standard ML}, {Sticks&Stones}, {supercombinators},
+ {SWI-Prolog}, {tail recursion modulo cons}, {WPOP}.
+
+ (1995-12-29)
+
+University of Hawaii
+
+ <body, education> A University spread over 10 campuses on 4
+ islands throughout the state.
+
+ {(http://hawaii.edu/uhinfo.html)}.
+
+ See also {Aloha}, {Aloha Net}.
+
+ (1995-12-10)
+
+University of Iceland
+
+ <body, education> The Home of {Fjolnir}.
+
+ {(http://rhi.hi.is/)}.
+
+ (1995-03-17)
+
+University of London Computing Centre
+
+ <body, education> (ULCC) One of the UK's national high
+ performance computing centres. It provides networking
+ services and large-scale computing facilities which are used
+ by researchers from all over the UK.
+
+ ULCC was founded in 1968 to provide a service for education
+ and research. It has been at the forefront of advanced
+ research computing since its foundation, initially providing
+ large-scale {CDC}-based facilities, then from 1982 to 1991 a
+ national {Cray} {vector} supercomputing service. Its high
+ performance computing facilities are now centred on a 6
+ processor, 4 Gbyte {Convex C3860} {supercomputer} (Neptune)
+ with a Convex C3200 front-end (Pluto).
+
+ ULCC is the main site for national and international network
+ connections in the UK. They run the {Network Operations and
+ Service Centre} for the {JANET Internet Protocol Service}
+ (JIPS), the largest of the {JANET} {NOCs} and various
+ international links and relays on behalf of {UKERNA}.
+
+ ULCC's pilot {National Data Repository} service provides a
+ network-accessible digital archive and filestore, based on a
+ robotic tape system with 6 terabytes of storage. Although the
+ data is stored on tape, you can access it very quickly, as if
+ it were on-line. It is made available to you via high-speed
+ links to the {JANET} and {SuperJANET} networks.
+
+ {(http://ulcc.ac.uk/)}.
+
+ (1994-11-29)
+
+University of Michigan
+
+ <body, education> A large cosmopolitan university in the
+ Midwest USA. Over 50000 students are enrolled at the
+ University of Michigan's three campuses. The students come
+ from 50 states and over 100 foreign countries. 70% of the
+ University's students graduated in the top 10% of their high
+ school class. 90% rank in the top 20% of their high school
+ class. 60% of the students receive financial aid.
+
+ The main Ann Arbor Campus lies in the Huron River valley, 40
+ miles west of Detroit. The campus boasts 2700 acres with 200
+ buildings, six million volumes in 23 libraries, nine museums,
+ seven hospitals, hundreds of laboratories and institutes, and
+ over 18000 {microcomputers}.
+
+ {(http://umich.edu/)}.
+
+ (1995-02-23)
+
+University of Michigan Digital Library Project
+
+ <project> (UMDL) The {University of Michigan}'s part of the
+ {Digital Library Initiative}.
+
+University of Minnesota
+
+ <body, education> The home of {Gopher}.
+
+ {(http://umn.edu/)}.
+
+ Address: Minneapolis, Minnesota, USA.
+
+ (1995-01-30)
+
+University of Nijmegen
+
+ <body, education> Katholieke University of Nijmegen (KUN),
+ Nijmegen, the Netherlands.
+
+ KUN's {Computing Science Institute (http://cs.kun.nl/csi)}.
+ is known for the {Clean}, {Comma}, {Communicating Functional
+ Processes}, and {GLASS} projects.
+
+ {(http://kun.nl/)}.
+
+ (1995-11-07)
+
+University of Pennsylvania
+
+ <body, education> The home of {ENIAC} and {Machiavelli}.
+
+ {(http://upenn.edu/)}.
+
+ Address: Philadelphia, PA, USA.
+
+ [More info?]
+
+ (1995-02-21)
+
+University of Tasmania
+
+ <body, education>
+
+ {(ftp://ftp.utas.edu.au/)}.
+
+ (1995-01-25)
+
+University of Twente
+
+ <body, education> A university in the east of The Netherlands
+ for technical and social sciences. It was founded in 1961,
+ making it one of the youngest universities in The Netherlands.
+ It has 7000 students studying Applied Educational Science;
+ Applied Mathematics; Applied Physics; Chemical Technology;
+ Computer Science; Electrical Engineering; Mechanical
+ Engineering; Philosophy of science, Technology and Society;
+ Educational Technology.
+
+ {(http://nic.utwente.nl/uthomuk.htm)}.
+
+ (1995-04-16)
+
+Unix
+
+ <operating system> /yoo'niks/ (Or "UNIX", in the authors'
+ words, "A weak pun on Multics") Plural "Unices". An
+ interactive {time-sharing} {operating system} invented in 1969
+ by {Ken Thompson} after {Bell Labs} left the {Multics}
+ project, originally so he could play games on his scavenged
+ {PDP-7}. {Dennis Ritchie}, the inventor of {C}, is considered
+ a co-author of the system.
+
+ The turning point in Unix's history came when it was
+ reimplemented almost entirely in C during 1972 - 1974, making
+ it the first {source-portable} OS. Unix subsequently
+ underwent mutations and expansions at the hands of many
+ different people, resulting in a uniquely flexible and
+ {developer}-friendly environment.
+
+ By 1991, Unix had become the most widely used {multi-user}
+ general-purpose operating system in the world. Many people
+ consider this the most important victory yet of hackerdom over
+ industry opposition (but see {Unix weenie} and {Unix
+ conspiracy} for an opposing point of view).
+
+ Unix is now offered by many manufacturers and is the subject
+ of an international standardisation effort [called?].
+ Unix-like operating systems include {AIX}, {A/UX}, {BSD},
+ {Debian}, {FreeBSD}, {GNU}, {HP-UX}, {Linux}, {NetBSD},
+ {NEXTSTEP}, {OpenBSD}, {OPENSTEP}, {OSF}, {POSIX}, {RISCiX},
+ {Solaris}, {SunOS}, {System V}, {Ultrix}, {USG Unix}, {Version
+ 7}, {Xenix}.
+
+ "Unix" or "UNIX"? Both seem roughly equally popular, perhaps
+ with a historical bias toward the latter. "UNIX" is a
+ registered trademark of {The Open Group}, however, since it is
+ a name and not an acronym, "Unix" has been adopted in this
+ dictionary except where a larger name includes it in upper
+ case. Since the OS is {case-sensitive} and exists in many
+ different versions, it is fitting that its name should reflect
+ this.
+
+ {The UNIX Reference Desk
+ (http://geek-girl.com/unix.html)}.
+
+ {Spanish fire extinguisher
+ (ftp://linux.mathematik.tu-darmstadt.de/pub/linux/people/okir/unix_flame.gif)}.
+
+ [{Jargon File}]
+
+ (2001-05-14)
+
+Unix box
+
+ {box}
+
+Unix brain damage
+
+ Something that has to be done to break a network program
+ (typically a mailer) on a non-{Unix} system so that it will
+ interoperate with Unix systems. The hack may qualify as "Unix
+ brain damage" if the program conforms to published {standards}
+ and the {Unix} program in question does not. Unix brain
+ damage happens because it is much easier for other (minority)
+ systems to change their ways to match non-conforming behaviour
+ than it is to change all the hundreds of thousands of Unix
+ systems out there.
+
+ An example of Unix brain damage is a {kluge} in a mail server
+ to recognise bare line feed (the Unix newline) as an
+ equivalent form to the Internet standard newline, which is a
+ carriage return followed by a line feed. Such things can make
+ even a hardened {jock} weep.
+
+ [{Jargon File}]
+
+Unix conspiracy
+
+ [ITS] According to a conspiracy theory long popular among
+ {ITS} and {TOPS-20} fans, Unix's growth is the result of a
+ plot, hatched during the 1970s at Bell Labs, whose intent was
+ to hobble AT&T's competitors by making them dependent upon a
+ system whose future evolution was to be under AT&T's control.
+ This would be accomplished by disseminating an operating
+ system that is apparently inexpensive and easily portable, but
+ also relatively unreliable and insecure (so as to require
+ continuing upgrades from AT&T). This theory was lent a
+ substantial impetus in 1984 by the paper referenced in the
+ {back door} entry.
+
+ In this view, Unix was designed to be one of the first
+ computer viruses (see {virus}) - but a virus spread to
+ computers indirectly by people and market forces, rather than
+ directly through disks and networks. Adherents of this "Unix
+ virus" theory like to cite the fact that the well-known
+ quotation "Unix is snake oil" was uttered by DEC president
+ Kenneth Olsen shortly before DEC began actively promoting its
+ own family of Unix workstations. (Olsen now claims to have
+ been misquoted.)
+
+Unix International
+
+ <body> (UI) A consortium including {Sun}, {AT&T} and others
+ formed to promote an open environment based on {Unix} {System
+ V}, including the {Open Look} windowing system.
+
+Unixism
+
+ <operating system, jargon> A piece of code or a coding
+ technique that depends on the protected {multitasking}
+ environment with relatively low process-spawn overhead that
+ exists on {virtual-memory} {Unix} systems.
+
+ Common {Unixisms} include: gratuitous use of "{fork}"; the
+ assumption that certain undocumented but well-known features
+ of Unix libraries such as "{stdio}" are supported elsewhere;
+ reliance on obscure side-effects of {system calls} (use of
+ "sleep" with a 0 argument to tell the scheduler that you're
+ willing to give up your time-slice, for example); the
+ assumption that freshly allocated memory is zeroed; and the
+ assumption that {fragmentation} problems won't arise from
+ never freeing memory.
+
+ Compare {vaxocentrism}. See also {New Jersey}.
+
+ [{Jargon File}]
+
+ (1995-02-27)
+
+Unix man page
+
+ {Unix manual page}
+
+Unix manual page
+
+ <operating system> (Or "man page") A part of {Unix}'s
+ extensive on-line documentation. To read a manual page from
+ the Unix command line, type:
+
+ man [-s<section>] <page>
+
+ e.g. "man ftp" (the section number can usually be omitted).
+ Pages are traditionally referred to using the notation
+ "page(section)", e.g. ftp(1).
+
+ Under {SunOS} (which is fairly typical), Section 1 covers
+ commands, 2 {system calls}, 3 C library routines, 4 devices
+ and networks, 5 file formats, 6 games and {demos}, 7
+ miscellaneous, 8 system administration. Each section has an
+ introduction which can be obtained with, e.g., "man 2 intro".
+
+ Manual pages are stored as {nroff} source files. Formatted
+ versions are also usually cached. Man pages for most versions
+ of Unix are available on-line in {HTML}.
+
+ {Unix manual page}: man(1).
+
+ {Linux man pages (http://www.kernel.org/doc/man-pages/)}.
+
+ {Solaris man pages (http://docs.sun.com/app/docs/coll/40.10)}.
+
+ (2010-01-19)
+
+Unix System V
+
+ {System V}
+
+Unix to Unix Copy
+
+ <networking, messaging> (uucp) A {Unix} utility program and
+ {protocol} that allows one Unix system to send files to
+ another via a {serial line} which may be a cable going
+ directly from one machine's {serial port} to another's or may
+ involve a {modem} at each end of a telephone line.
+
+ Software is also available to allow uucp to work over
+ {Ethernet} though there are better alternatives in this case,
+ e.g. {FTP} or {rcp} for file transfer, {SMTP} for {electronic
+ mail} or {NNTP} for {news}.
+
+ The term is now also used to describe the large international
+ network which uses UUCP to pass {Usenet} {news} and
+ {electronic mail}, also known as "UUCPNET".
+
+ {Unix manual page}: uucp(1).
+
+ See also {cu}, {uuencode}.
+
+ (1997-01-12)
+
+UnixWare
+
+ <operating system> {Novell}'s implementation of {Unix} {System
+ 5} heavily based on Release 4.2 but with enhancements and new
+ bundled products.
+
+ In 1993 Novell acquired {Unix Systems Laboratories} from
+ {AT&T} along with the Unix trademark. UnixWare was the result
+ of Novell's efforts to make Unix interoperable with {Novell
+ NetWare}.
+
+ In 1995 Novell sold UnixWare and the rights to the Unix
+ operating system to {SCO} at a time when UnixWare was gainnig
+ popularity. It was later the first 64-bit operating system on
+ the {Intel} {platform}, and, in 1999, is the world's
+ fastest-growing commercial operating system.
+
+ [Any connection with {X/Open}? URL?]
+
+ (1999-11-10)
+
+Unix weenie
+
+ <jargon> ({ITS}) 1. A derogatory play on "{Unix wizard}",
+ common among hackers who use {Unix} by necessity but would
+ prefer alternatives. The implication is that although the
+ person in question may consider mastery of Unix arcana to be a
+ wizardly skill, the only real skill involved is the ability to
+ tolerate (and the bad taste to wallow in) the incoherence and
+ needless complexity that is alleged to infest many Unix
+ programs. "This shell script tries to parse its arguments in
+ 69 bletcherous ways. It must have been written by a real Unix
+ weenie."
+
+ 2. A derogatory term for anyone who engages in uncritical
+ praise of {Unix}. Often appearing in the context "stupid Unix
+ weenie".
+
+ See {Weenix}, {Unix conspiracy}, {weenie}.
+
+ [{Jargon File}]
+
+ (1995-02-27)
+
+Unix wizard
+
+ <job> Someone with a deep understanding of {Unix}.
+
+ See {wizard}.
+
+ (1995-05-11)
+
+Unlicense
+
+ <legal> A template for dedicating {software} to the {public
+ domain}. It combines a {copyright} waiver like that of the
+ {SQLite} project with the no-warranty statement from the
+ {MIT}/{X11} license.
+
+ {(http://unlicense.org/)}.
+
+ (2014-07-31)
+
+unnormalised
+
+ {normalisation}
+
+unproto
+
+ A translator from {ANSI C} to {K&R C} by Wietse Venema
+ <wietse@wzv.win.tue.nl>.
+
+ {(ftp://ftp.win.tue.nl/pub/Unix/unproto4.shar.Z)}.
+
+unshar
+
+ A {Unix} utility that removes {e-mail} and {news} {header}
+ lines from its input, and feeds the remainder (which is
+ presumed to be a {shar file}) to /bin/sh to unpack it. unshar
+ is designed for unpacking archives directly from the news or
+ mail systems simply by {piping} a message into it.
+
+unshielded twisted pair
+
+ <hardware> (UTP) Normal telephone wire (in the USA). It may
+ be used for computer to computer communications, e.g. using a
+ version of {Ethernet} or {localtalk}. It is much cheaper than
+ standard "full-spec" Ethernet cable. It comes in five
+ "catagories":
+
+ cat. wires transmission
+ 1 two voice no data (telephone cable)
+ 2 four data up to 4 Mbps
+ 3 four data up to 10 Mbps
+ 4 four data up to 16 Mbps
+ 5 four data up to 100 Mbps
+
+ (2003-07-04)
+
+unswizzle
+
+ The opposite of {swizzle}.
+
+ [{Jargon File}]
+
+ (1995-02-15)
+
+until
+
+ {while loop}
+
+untyped
+
+ <programming> A {variable} which can hold values of any {type}
+ or a {programming language} in which some or all variables are
+ like this.
+
+ An example would be {VBScript}, or {Visual Basic}'s {variant}
+ type.
+
+ (2003-12-22)
+
+unwind-protect
+
+ ({MIT}) A {Lisp} operator which evaluates an expression and
+ then, even if that expression causes a {non-local exit},
+ evaluates zero or more other expressions. This can be used to
+ ensure that essential "clean-up" operations are performed even
+ in the presence of errors.
+
+ [{Jargon File}]
+
+ (1994-11-03)
+
+unwind the stack
+
+ During the execution of a {procedural} language, one is said
+ to "unwind the stack" from a called {procedure} up to a caller
+ when one discards the {stack frame} and any number of frames
+ above it, {pop}ping back up to the level of the given caller.
+ In {C} this is done with "{longjmp}"/"{setjmp}", in {Lisp}
+ with "{throw}/{catch}". See also {smash the stack}.
+
+ [{Jargon File}]
+
+UN*X
+
+ <operating system, convention> Used to refer to the {Unix}
+ {operating system} (a trademark of {AT&T}) in writing, but
+ avoiding the need for the ugly (TM) typography. Also used to
+ refer to any or all varieties of Unixoid operating systems.
+ Ironically, lawyers now say that the requirement for the
+ TM-postfix has no legal force, but the asterisk usage is
+ entrenched anyhow.
+
+ It has been suggested that there may be a psychological
+ connection to practice in certain religions (especially
+ Judaism) in which the name of the deity is never written out
+ in full, e.g. "YHWH" or "G--d" is used.
+
+ See also {glob}.
+
+ (1998-04-17)
+
+unzip
+
+ 1. <tool, compression> To extract files from an archive
+ created with {PKWare}'s {PKZIP} archiver.
+
+ 2. <tool, compression> A program to list, test, or extract
+ files from a {ZIP} archive, commonly found on {MS-DOS}
+ systems. zip, creates ZIP archives; both programs are
+ compatible with archives created by {PKWARE}'s {PKZIP} and
+ {PKUNZIP} for {MS-DOS}.
+
+ (1995-03-06)
+
+up
+
+ <jargon> Working, in order. E.g. "The down escalator is up."
+
+ Opposite: {down}.
+
+ [{Jargon File}]
+
+ (1995-03-06)
+
+uparrow
+
+ <character> The graphic which the 1963 version of {ASCII} had
+ in place of the {caret} character, {ASCII} 94.
+
+ (1995-03-06)
+
+\uparrow
+
+ <character> An upward pointing arrow in {LaTeX}.
+
+ See {closure}.
+
+ (1995-03-16)
+
+UPenn
+
+ {University of Pennsylvania}
+
+upgradability
+
+ <jargon> (Or "upgradeability") How easily {upgrades} to a
+ system can be produced and applied. E.g. "Buying a PC with
+ more {PCI} slots gives you increased upgradeability."
+
+ (1999-10-11)
+
+upgrade
+
+ 1. A new or better version of some {hardware} or {software}.
+
+ Often used in {marketroid}-speak to mean "{bug fix}".
+
+ 2. The act of developing or installing a new version.
+
+ (1995-03-14)
+
+upgradeability
+
+ {upgradability}
+
+upload
+
+ /uhp'lohd/ To transfer programs or data over a digital
+ communications link from a smaller or peripheral "client"
+ system to a larger or central "host" one.
+
+ Opposite: {download}.
+
+ [{Jargon File}]
+
+ (1994-10-27)
+
+UPMAIL Tricia Prolog
+
+ {(ftp://ftp.csd.uu.se/pub/Tricia/README)}.
+
+ E-mail: <tricia-request@csd.uu.se>.
+
+ [Description?]
+
+ (1994-10-27)
+
+upper bound
+
+ An upper bound of two elements x and y under some {relation}
+ <= is an element z such that x <= z and y <= z.
+
+ ("<=" is written in {LaTeX} as {\sqsubseteq}).
+
+ See also {least upper bound}.
+
+ (1995-02-15)
+
+Upper Layer Protocol
+
+ <protocol> 1. (ULP, or upper-layer protocol)
+ Any {protocol} residing in {OSI} layers five or above.
+
+ The {Internet} protocol suite includes many upper layer
+ protocols representing a wide variety of applications
+ e.g. {FTP}, {NFS}, {RPC}, and {SMTP}. These and other network
+ applications use the services of {TCP/IP} and other {lower
+ layer protocols} to provide users with basic network services.
+
+ 2. A protocol higher in the OSI reference model than the
+ current reference point. Upper Layer Protocol is often used
+ to refer to the next-highest protocol in a particular
+ {protocol stack}.
+
+ (1999-02-17)
+
+upper memory block
+
+ <storage> (UMB) Up to 64 {kilobytes} of the {expanded memory
+ page frame} above the first 64 kilobytes. The UMB can be used
+ to store {TSR} programs or {device drivers} thereby freeing
+ parts of the precious {conventional memory}. The UMB is
+ provided by special memory manager programs; many {EMMs} can
+ provide UMB as well.
+
+ (1996-01-10)
+
+Upper Side-Band modulation
+
+ <communications> (USB) A kind of {modulation} applied to a
+ sinusoidal {carrier}.
+
+ [Details?]
+
+ (1997-07-16)
+
+Upright Database Technology AB
+
+ <company> The Swedish company that developed the {Mimer SQL}
+ database.
+
+ (2002-06-03)
+
+UPS
+
+ 1. {uninterruptible power supply}.
+
+ 2. A source level {C} debugger that runs under {X11} or
+ {SunView} by Mark Russell <mtr@ukc.ac.uk>. Ups includes a {C}
+ {interpreter} which allows you to add fragments of code simply
+ by editing them into the source window. Version 2.1.
+
+ Ported to {Sun}, {DECstation}, {VAX} {Ultrix}, {HLH}
+ {Clipper}.
+
+ {(ftp://export.lcs.mit.edu/contrib/)}. Mailing list:
+ ups-users-request@ukc.ac.uk.
+
+ Unofficial enhancements by Rod Armstrong <rod@sj.ate.slb.com>
+ {(ftp://sj.ate.slb.com/misc/Unix/ups/contrib/rob)}.
+
+ (1991-05-20)
+
+upstream
+
+ <networking> Fewer {network} {hops} away from a {backbone} or
+ {hub}. For example, a small {ISP} that connects to the
+ {Internet} through a larger ISP that has their own connection
+ to the backbone is {downstream} from the larger ISP, and the
+ larger ISP is {upstream} from the smaller ISP.
+
+ (1999-08-05)
+
+upthread
+
+ Earlier in the discussion (see {thread}), i.e. "above". See
+ also {followup}.
+
+ [{Jargon File}]
+
+upward closure
+
+ {closure}
+
+Uranus
+
+ Hideyuki Nakashima <nakashim@el.go.jp>, 1993. A logic-based
+ knowledge representation language. An extension of Prolog
+ written in Common Lisp, with Lisp-like syntax. Extends Prolog
+ with a multiple world mechanism, plus term descriptions to
+ provide functional programming.
+
+ {(ftp://etlport.etl.go.jp/pub/uranus/ftp)}.
+
+urban legend
+
+ <publication> A story, which may have started with a grain of
+ truth, that has been embroidered and retold until it has
+ passed into the realm of myth. It is an interesting
+ phenomenon that these stories get spread so far, so fast and
+ so often. Urban legends never die, they just end up on the
+ {Internet}! Some legends that periodically make their rounds
+ include "The Infamous Modem Tax", "Craig Shergold/Brain
+ Tumor/Get Well Cards", and "The $250 Cookie Recipe".
+
+ (1996-05-08)
+
+URC
+
+ {Uniform Resource Citation} (previously Universal).
+
+urchin
+
+ {munchkin}
+
+URI
+
+ {Universal Resource Identifier}
+
+URL
+
+ {Uniform Resource Locator}
+
+URL forwarding
+
+ {URL redirection}
+
+URL redirection
+
+ <web> (Or "URL forwarding")
+
+ When a {web server} tells the {client} {browser} to obtain a
+ certain requested page from a different location. This is
+ controlled by {directives} in the server's configuration files
+ or a "Location: header output by a {CGI} script.
+
+ The web server stores all its documents in a {directory tree}
+ rooted at some configured directory, known as its "document
+ root". Normally the {URI} part of the {URL} (the part after
+ the {hostname}) is used as a {relative path} from the document
+ root to the desired file or directory. A redirect directive
+ allows the server administrator to specify exceptions to this
+ general mapping from URL to file name by telling the browser
+ "try this URL instead". The new URL may be on the same server
+ or a different one and may itself be subject to redirection.
+
+ The user is normally unaware of this process except that it
+ may introduce extra delay while the browser sends the new
+ request and the browser will usually display the new URL
+ rather than the one the user originally requested.
+
+ (1997-07-15)
+
+URN
+
+ {Uniform Resource Name}
+
+URouLette
+
+ (After {URL} and roulette, the gambling game) A {World-Wide
+ Web} service which selects other web pages at random.
+
+ {(http://kuhttp.cc.ukans.edu/cwis/organizations/kucia/uroulette/uroulette.html)}.
+
+ (1994-11-24)
+
+US
+
+ {Unit Separator}
+
+us
+
+ <networking> The {country code} for the United States.
+
+ Usually used only by schools, libraries, and some state and
+ local governments. Other US sites, and many international
+ ones, use the non-national {top-level domains} .com, .edu etc.
+
+ (1999-01-27)
+
+usability
+
+ <programming> The effectiveness, efficiency, and satisfaction
+ with which users can achieve tasks in a particular environment
+ of a product. High usability means a system is: easy to learn
+ and remember; efficient, visually pleasing and fun to use; and
+ quick to recover from errors.
+
+ {(http://orrnet.com/)}.
+
+ (1999-04-01)
+
+USAModSim
+
+ <language> United States Army {ModSim} compiler.
+
+ Version 1.0 runs on {SPARC}/{SunOS}, {Silicon Graphics},
+ {MS-DOS}.
+
+ {(ftp://max.cecer.army.mil/ftp/isle)}.
+
+ E-mail: Charles Herring <herring@lincoln.cecer.army.mil>.
+
+ (1993-12-29)
+
+usa.net
+
+ {Internet Express}
+
+US-ASCII
+
+ <character> The 7-bit version of {ASCII}, which preceded (and
+ is the basis for) 8-bit versions such as {Latin-1}, {MacASCII}
+ and later, even larger coded character sets such as {Unicode}.
+
+ US-ASCII is defined in Standard ANSI X3.4-1986,
+ "US-ASCII. Coded Character Set - 7-Bit American Standard Code
+ for Information Interchange".
+
+ (1998-10-18)
+
+USB
+
+ 1. <architecture> {Universal Serial Bus}.
+
+ 2. <communications> {Upper Side-Band modulation}.
+
+ (1997-07-16)
+
+USB 2.0
+
+ {Universal Serial Bus}
+
+USB Adapter Card Support
+
+ <communications, software> A set of software extensions that
+ provide support for {USB} adapter cards installed in the {PCI}
+ bus or {Cardbus} slots in {Macintosh} computers that do not
+ have built-in USB ports.
+
+ (2001-11-28)
+
+USB drive
+
+ <storage> A {hard disk drive} connected via {Universal Serial
+ Bus} (USB). May also refer to some kind of {memory stick}
+ connected via USB.
+
+ (2008-05-21)
+
+USE
+
+ <language> An early system on the {IBM 1130}.
+
+ [Listed in CACM 2(5):16, May 1959].
+
+ (2004-09-14)
+
+Usenet
+
+ <messaging> /yoos'net/ or /yooz'net/ (Or "Usenet news", from
+ "Users' Network") A distributed {bulletin board} system and
+ the people who post and read articles thereon. Originally
+ implemented in 1979 - 1980 by Steve Bellovin, Jim Ellis, Tom
+ Truscott, and Steve Daniel at Duke University, and supported
+ mainly by {Unix} machines, it swiftly grew to become
+ international in scope and, before the advent of the
+ {web}, probably the largest decentralised
+ information utility in existence.
+
+ Usenet encompasses government agencies, universities, high
+ schools, businesses of all sizes, and home computers of all
+ descriptions. In the beginning, not all Usenet hosts were on
+ the Internet. As of early 1993, it hosted over 1200
+ {newsgroups} ("groups" for short) and an average of 40
+ megabytes (the equivalent of several thousand paper pages) of
+ new technical articles, news, discussion, chatter, and
+ {flamage} every day. By November 1999, the number of groups
+ had grown to over 37,000.
+
+ To join in you originally needed a {news reader} program but
+ there are now several web gateways, cheifly {Google Groups
+ (http://groups.google.com/)} (originally {Deja News}). Some
+ {web browsers} include news readers and {URLs} beginning
+ "news:" refer to Usenet newsgroups.
+
+ {Network News Transfer Protocol} is a {protocol} used to
+ transfer news articles between a news {server} and a {news
+ reader}. The {uucp} {protocol} was sometimes used to transfer
+ articles between servers, though this is probably rare now
+ that most sites are on the {Internet}.
+
+ {(http://openmarket.com/info/internet-index/current-sources.html)}.
+
+ {Notes on news
+ (http://ifi.uio.no/~larsi/notes/notes.html)} by Lars Magne
+ Ingebrigtsen <larsi@ifi.uio.no>.
+
+ [Gene Spafford <spaf@cs.purdue.edu>, "What is Usenet?",
+ regular posting to {news:news.announce.newusers}].
+
+ (1999-12-17)
+
+Usenet news
+
+ {Usenet}
+
+Usenetter
+
+ <networking> A (regular) user of {Usenet}.
+
+ (1996-09-08)
+
+USENIX
+
+ <body> Since 1975, the USENIX Association has provided a forum
+ for the communication of the results of innovation and
+ research in {Unix} and modern {open systems}. It is well
+ known for its technical conferences, tutorial programs, and
+ the wide variety of publications it has sponsored over the
+ years.
+
+ USENIX is the original not-for-profit membership organisation
+ for individuals and institutions interested in {Unix} and
+ {Unix}-like systems, by extension, {X}, {object-oriented}
+ technology, and other advanced tools and technologies, and the
+ broad interconnected and interoperable computing environment.
+
+ USENIX's activities include an annual technical conference;
+ frequent specific-topic conferences and symposia; a highly
+ regarded tutorial program covering a wide range of topics,
+ introductory through advanced; numerous publications,
+ including a book series, in cooperation with The {MIT Press},
+ on advanced computing systems, proceedings from USENIX
+ symposia and conferences, the quarterly journal "Computing
+ Systems", and the biweekly newsletter; "login: ";
+ participation in various {ANSI}, {IEEE} and {ISO} {standards}
+ efforts; sponsorship of local and special technical groups
+ relevant to Unix. The chartering of SAGE, the {System
+ Administrators Guild} as a Special Technical Group within
+ USENIX is the most recent.
+
+ {(http://usenix.org)}.
+
+ {Usenet} newsgroup: {news:comp.org.usenix}.
+
+ (1994-12-07)
+
+user
+
+ 1. <person> Someone doing "real work" with the computer, using
+ it as a means rather than an end. Someone who pays to use a
+ computer. A programmer who will believe anything you tell
+ him. One who asks silly questions without thinking for two
+ seconds or looking in the documentation. Someone who uses a
+ program, however skillfully, without getting into the
+ internals of the program. One who reports {bugs} instead of
+ just fixing them. See also {luser}, {real user}.
+
+ Users are looked down on by {hackers} to some extent because
+ they don't understand the full ramifications of the system in
+ all its glory. The term is relative: a skilled hacker may be
+ a user with respect to some program he himself does not hack.
+ A LISP hacker might be one who maintains LISP or one who uses
+ LISP (but with the skill of a hacker). A LISP user is one who
+ uses LISP, whether skillfully or not. Thus there is some
+ overlap between the two terms; the subtle distinctions must be
+ resolved by context.
+
+ 2. <jargon> Any person, organisation, process, device,
+ program, {protocol}, or system which uses a service provided
+ by others.
+
+ The term "{client}" (as in "{client-server}" systems) is
+ rather more specific, usually implying two processes
+ communicating via some protocol.
+
+ [{Jargon File}]
+
+ (1996-04-28)
+
+user acceptance testing
+
+ <testing> The type of {testing} where monitored users
+ determine whether a system meets all their requirements, and
+ will support the business for which it was designed.
+
+ (2003-09-24)
+
+user base
+
+ <jargon> The number of users of some product or standard.
+
+ This term typically arises in discussions of {backward
+ compatibility} or {lock-in}.
+
+ (1998-01-15)
+
+User Brain Damage
+
+ <humour> (UBD) A description (usually abbreviated) used to
+ close a trouble report obviously due to utter cluelessness on
+ the user's part. Compare {pilot error}; opposite: {PBD}; see
+ also {brain-damaged}, {PEBCAK}.
+
+ (1998-08-27)
+
+User Datagram Protocol
+
+ <protocol> (UDP) {Internet} {standard} {network layer},
+ {transport layer} and {session layer} {protocols} which
+ provide simple but {unreliable} {datagram} services. UDP is
+ defined in {STD 6}, {RFC 768}. It adds a {checksum} and
+ additional process-to-process addressing information [to
+ what?]. UDP is a {connectionless protocol} which, like {TCP},
+ is layered on top of {IP}.
+
+ UDP neither guarantees delivery nor does it require a
+ connection. As a result it is lightweight and efficient, but
+ all error processing and retransmission must be taken care of
+ by the {application program}.
+
+ {Unix manual page}: udp(4).
+
+ [Postel, Jon, User Datagram Protocol, RFC 768, Network
+ Information Center, SRI International, Menlo Park, Calif.,
+ August 1980].
+
+ (1998-02-11)
+
+user-friendly
+
+ Programmer-hostile. Generally used by hackers in a critical
+ tone, to describe systems that hold the user's hand so
+ obsessively that they make it painful for the more experienced
+ and knowledgeable to get any work done. See {menuitis},
+ {drool-proof paper}, {Macintrash}, {user-obsequious}.
+
+ [{Jargon File}]
+
+user id
+
+ {user identifier}
+
+user identifier
+
+ <operating system> 1. (Or "uid", "user id") A number or name
+ which is unique to a particular user of a computer or group of
+ computers which share user information. The {operating
+ system} uses the uid to represent the user in its data
+ structures, e.g. the owner of a file or process, the person
+ attempting to access a system resource etc.
+
+ A user database, e.g. {Unix}'s /etc/passwd file or {NIS}, maps
+ the uid to other information about that user such as their
+ {user name}, {password}, {home directory} and real name.
+
+ 2. {user name}.
+
+ (1997-03-01)
+
+user interface
+
+ (UI) The aspects of a computer system or program which can be
+ seen (or heard or otherwise perceived) by the human user, and
+ the commands and mechanisms the user uses to control its
+ operation and input data.
+
+ A {graphical user interface} emphasises the use of pictures
+ for output and a pointing device such as a {mouse} for input
+ and control whereas a {command line interface} requires the
+ user to type textual commands and input at a keyboard and
+ produces a single stream of text as output.
+
+ A user interface contrasts with, but is typically built on top
+ of, an {Application Program Interface} (API).
+
+ See also {user interface copyright}.
+
+ (1995-02-20)
+
+user interface copyright
+
+ There have been several attempts, mostly by big US software
+ companies, to enforce patents and {copyright} on user
+ interfaces. Such legal action aims to restrict the use of
+ certain command languages or {graphical user interfaces} to
+ products from one software supplier. This is undesirable
+ because it either forces users to buy software from the
+ company whose interface they have learned or to learn more
+ than one interface. An analogy is often drawn with the user
+ interface of a car - the arrangement of pedals and steering
+ wheel etc. If each car manufacturer was forced to use a
+ different interface this would be very bad for car users.
+
+ Following a non-jury trial, which began in early January 1987,
+ a federal judge ruled on 1990-06-28 that keyboard commands and
+ on-screen images produced by {Lotus Development Corporation}'s
+ popular {1-2-3} {spreadsheet} are protected by {copyright}.
+ {Paperback Software International} and subcontractor
+ Stephenson Software Ltd. who lost the case, argued that the
+ copyright applies only to the inner workings of the software.
+ US District Judge Robert Keeton wrote that "The user interface
+ of 1-2-3 is its most unique element and is the aspect that has
+ made 1-2-3 so popular. That defendants went to such trouble
+ to copy that element is a testament to its substantiality".
+ Defence attorneys had argued that the Lotus commands
+ represented "instructions for a machine rather than the
+ expression of an idea".
+
+ Soon after this decision, on 1990-07-02, Lotus sued {Borland
+ International} and the {Santa Cruz Operation} for producing
+ {spreadsheets} (Quattro, Quattro Pro and SCO Professional)
+ whose interfaces could be configured to look like 1-2-3's.
+
+ (1994-11-16)
+
+User Interface Language
+
+ <language, graphics> (UIL) A language for specifying {widget}
+ hierarchies etc. in {OSF}/Motif and {DECwindows}.
+
+ (1997-03-01)
+
+user name
+
+ <operating system, security> (Or "logon") A unique name for
+ each user of computer services which can be accessed by
+ several persons.
+
+ Users need to identify themselves for accounting, {security},
+ logging, and {resource management}. Usually a person must
+ also enter a {password} in order to access a service. Once
+ the user has logged on the {operating system} will often use a
+ (short) {user identifier}, e.g. an integer, to refer to them
+ rather than their user name.
+
+ User names can usually be any short string of alphanumeric
+ characters. Common choices are first name, initials, or some
+ combination of first name, last name, initials and an
+ arbitrary number. User names are often assigned by {system
+ administrators} according to some local policy, or they may be
+ chosen by the users themselves.
+
+ User names are often also used as {mailbox} names in
+ {electronic mail} addresses.
+
+ (1997-03-16)
+
+User Network Interface
+
+ <communications, networking> (UNI) An interface point between
+ {ATM} end users and a private {ATM switch}, or between a
+ private ATM switch and the {public carrier} ATM network.
+
+ The physical and {protocol} specifications for UNIs are
+ defined by the {ATM Forum}'s UNI documents, which allow for
+ various types of physical interfaces.
+
+ See also: {NNI}
+
+ (1999-01-23)
+
+user-obsequious
+
+ <jargon> Emphatic form of {user-friendly}. Connotes a system
+ so verbose, inflexible, and determinedly simple-minded that it
+ is nearly unusable. "Design a system any fool can use and
+ only a fool will want to use it."
+
+ See {WIMP}, {Macintrash}.
+
+ See also {user-unctuous}.
+
+ [{Jargon File}]
+
+ (1999-06-27)
+
+user-unctuous
+
+ <jargon> (By analogy with {user-friendly} and
+ {user-obsequious}) User-interfaces that attempt to soothe (or,
+ some would say, stupify) users instead of cooperating with
+ them. Common "features" of user-unctuous systems include:
+ icons of happy faces; mellow colors; melodic sound effects or
+ even mood music; help tips appearing unbidden and at unhelpful
+ moments; and a cloying tone either in system messages ("Oops!
+ I couldn't seem to find my old preferences file! I do think
+ I'll have to make a new one! Please press OK to continue!")
+ or in labelling of system components (such as the main hard
+ drive being labelled "Your Hard Drive" -- or, with infantile
+ pronoun-reversal, "My Hard Drive").
+
+ (1999-06-27)
+
+Use the Source Luke
+
+ <humour, programming> (UTSL) (A pun on Obi-Wan Kenobi's "Use
+ the Force, Luke!" in "Star Wars") A more polite version of
+ {RTFS}. This is a common way of suggesting that someone would
+ be better off reading the source code that supports whatever
+ feature is causing confusion, rather than making yet another
+ futile pass through the manuals, or broadcasting questions on
+ {Usenet} that haven't attracted {wizards} to answer them.
+
+ Once upon a time in {Elder Days}, everyone running {Unix} had
+ source. After 1978, {AT&T}'s policy tightened up, so this
+ objurgation was in theory appropriately directed only at
+ associates of some outfit with a Unix {source licence}. In
+ practice, bootlegs of Unix source code (made precisely for
+ reference purposes) were so ubiquitous that one could utter it
+ at almost anyone on {the network} without concern.
+
+ Nowadays, free Unix clones are becoming common enough that
+ almost anyone can read source legally. The most widely
+ distributed is probably {Linux}. {FreeBSD}, {NetBSD},
+ {386BSD}, {jolix} also have their followers. Cheap commercial
+ Unix implementations with source such as {BSD/OS} from {BSDI}
+ are accelerating this trend.
+
+ (1996-01-02)
+
+USG Unix
+
+ {operating system} /U-S-G yoo'niks/ Refers to AT&T {Unix}
+ commercial versions after {Version 7}, especially System III
+ and System V releases 1, 2, and 3. So called because during
+ most of the lifespan of those versions AT&T's support crew was
+ called the "Unix Support Group".
+
+ Compare {BSD}.
+
+ [{Jargon File}]
+
+ (1997-02-20)
+
+usim
+
+ <simulation> A {Motorola 6809} {emulator} and {assembler}.
+
+ (2014-06-24)
+
+USL
+
+ 1. Query language, close to natural English.
+
+ 2. User System Language. Bellcore, "Operations Technology
+ Generic Requirements: User System Interface", TR-825.
+
+ 3. Unix System Laboratories: the software subsidiary of
+ {AT&T}, responsible for {Unix} {System V} and related
+ software.
+
+USP
+
+ {unique sales point}
+
+USR
+
+ {U.S. Robotics, Inc.}
+
+usr
+
+ User. The "/usr" directory hierarchy on {Unix} systems. Once
+ upon a time, in the early days of Unix, this area actually
+ held users' home directories and files. Since these tend to
+ expand much faster than system files, /usr would be mounted on
+ the biggest disk on the system. The root directory, "/" in
+ contrast, contains only what is needed to {boot} the {kernel},
+ after which /usr and other disks could be mounted as part of
+ the multi-user start-up process.
+
+ /usr has been used as the "everything else" area, with many
+ "system" files such as compiler libraries (/usr/include,
+ /usr/lib), utilty programs (/usr/bin, /usr/ucb), games
+ (/usr/games), local additions (/usr/local), manuals
+ (/usr/man), temporary files and queues for various {daemons}
+ (/usr/spool). These optional extras have grown in size as
+ Unix has evolved and disks have dropped in price. Under later
+ versions of {SunOS}, the user files have fled /usr altogether
+ for a new "/home" {partition} and temporary files have moved
+ to "/var". This allows /usr to be mounted read-only with some
+ gain in security and performance since access times are not
+ updated for files on read-only file systems.
+
+US Robotics
+
+ {U.S. Robotics, Inc.}
+
+U.S. Robotics, Inc.
+
+ <company> A US {modem} manufacturer.
+
+ {(http://usr.com/)}.
+
+ {(ftp://ftp.usr.com/)}.
+
+ Finger: usr.com.
+
+ E-mail: <support@usr.com>, <salesinfo@usr.com> (USA and Canada),
+ <eurosupport@usr.com>, <eurosales@usr.com> (Europe),
+ <intlsales@usr.com> (other).
+
+ (1995-03-14)
+
+USSA
+
+ Object-oriented state language by B. Burshteyn, Pyramid, 1992.
+
+ {Documentation (ftp://primost.cs.wisc.edu/pub/ussa.ps.Z)}.
+
+UTC
+
+ {Coordinated Universal Time}
+
+UTF
+
+ {UCS transformation format}
+
+UTF-8
+
+ <character> (UCS transformation format 8) An
+ {ASCII}-compatible multibyte {Unicode} and {UCS} encoding,
+ used by {Java} and {Plan 9}.
+
+ The {Unicode character} set occupies a 16-bit code space. The
+ most obvious Unicode encoding (known as UCS-2) consists of a
+ sequence of 16-bit words. Such strings can contain bytes like
+ '\0' or '/' which have a special meaning in filenames and
+ other {C} library function parameters. In addition, the
+ majority of {Unix} tools expects ASCII files and can't read
+ 16-bit words as characters without major modifications. For
+ these reasons, UCS-2 is not a suitable external encoding of
+ Unicode in filenames, text files, environment variables, etc.
+
+ The {ISO 10646} {Universal Character Set} (UCS), a superset of
+ Unicode, occupies a 31-bit code space and the obvious UCS-4
+ encoding for it (a sequence of 32-bit words) has the same
+ problems.
+
+ The UTF-8 encoding of Unicode and UCS avoids the problems of
+ fixed-length Unicode encodings because an ASCII file encoded
+ in UTF is exactly same as the original ASCII file and all
+ non-ASCII characters are guaranteed to have the most
+ significant bit set (bit 0x80). This means that normal tools
+ for text searching etc. work as expected.
+
+ UTF-8 is defined in {RFC 2279}.
+
+ ["File System Safe UCS Transformation Format (FSS_UTF)",
+ X/Open Preliminary Specification, X/Open Company Ltd.,
+ Document Number: P316. This information also appears in
+ ISO/IEC 10646, Annex P].
+
+ {Plan 9 UTF manual entry
+ (ftp://ftp.uu.net/doc/obi/Bell.Labs/plan9pm/09utf.ps.Z)}.
+
+ (1998-07-29)
+
+utility
+
+ {utility software}
+
+utility-coder
+
+ <language> A language for data manipulation and report
+ generation.
+
+ ["User's Manual for utility-coder", Cambridge Computer
+ Association, Jul 1977].
+
+ (1997-12-09)
+
+utility program
+
+ {utility software}
+
+utility software
+
+ <tool> (Or utility program, tool) Any {software} that performs
+ some specific task that is secondary to the main purpose of
+ using the computer (the latter would be called {application
+ programs}) but is not essential to the operation of the
+ computer ({system software}).
+
+ Many utilities could be considered as part of the {system
+ software}, which can in turn be considered part of the
+ {operating system}.
+
+ The following are some broad categories of utility software,
+ specific types and examples.
+
+ * Disks
+
+ {disk formatter}: {FDISK}, {format}
+
+ {defragmenter}
+
+ {disk checker}: {fsck}
+
+ {disk cleaner}
+
+ {system profiler}
+
+ {backup}
+
+ {file system compression}
+
+ * Files and directories
+
+ list directory: {ls}, {dir}
+
+ copy, move, remove: {cp}, {mv}, {rm}, {xcopy}
+
+ {archive}: {tar}
+
+ {compression}: {zip}
+
+ format conversion: {atob}
+
+ comparison: {diff}
+
+ sort: {sort}
+
+ * Security
+
+ {authentication}: {login}
+
+ {antivirus software}: {avast}, {Norton Antivirus}
+
+ {firewall}: {Zone Alarm}, {Windows firewall}
+
+ {encryption}: {gpg})
+
+ * Editors for general-purpose formats (as opposed to specific
+ formats like a {word processing} document)
+
+ {text editor}: {Emacs}
+
+ {binary editor}, {hex editor}
+
+ * Communications
+
+ {mail transfer agent}: {sendmail}
+
+ e-mail notification: {biff}
+
+ file transfer: {ftp}, {rcp}, {Firefox}
+
+ file synchronisation: {unison}, {briefcase}
+
+ chat: {Gaim}, {cu}
+
+ directory services: {bind}, {nslookup}, {whois}
+
+ network diagnosis: {ping}, {traceroute}
+
+ remote access: {rlogin}, {ssh}
+
+ * Software development
+
+ {compiler}: {gcc}
+
+ build: {make}, {ant}
+
+ {codewalker}
+
+ {preprocessor}: {cpp}
+
+ {debugger}: {adb}, {gdb}
+
+ {installation}: {apt-get}, {msiexec}, {patch}
+
+ {compiler compiler}: {yacc}
+
+ * Hardware
+
+ device configuration: {PCU}, {devman}, {stty}
+
+ (2007-02-02)
+
+UTOPIST
+
+ <language> A specification language for {attribute grammars}
+ developed by E. Tyugu of the Academy of Science Estonia,
+ Tallinn in 1983.
+
+ ["Synthesis of a Semantic Processor from an Attribute
+ Grammar", Prog and Comp Soft, 9(1):29-39, Jan 1983].
+
+ (2007-02-02)
+
+UTP
+
+ {unshielded twisted pair}
+
+UTRC
+
+ {United Technologies Research Cente}
+
+UTSL
+
+ <humour> {Use the Source Luke}
+
+ [{Jargon File}]
+
+ (1996-01-02)
+
+uucp
+
+ {Unix to Unix Copy}
+
+UUCPNET
+
+ The international {store and forward} network consisting of
+ all the world's connected {Unix} machines (and others running
+ some clone of the {UUCP} software). Any machine reachable
+ only via a {bang path} is on UUCPNET. See {network address}.
+
+ [{Jargon File}]
+
+uudecode
+
+ A Unix program to convert the ASCII output of uuencode back to
+ binary. See uuencode for details.
+
+uuencode
+
+ <communications> (Unix-to-Unix encode) A {Unix} program for
+ encoding {binary} data as {ASCII}. Uuencode was originally
+ used with {uucp} to transfer binary files over {serial lines}
+ which did not preserve the top bit of characters, but is now
+ used for sending binary files by {e-mail} and posting to
+ {Usenet} newsgroups etc. The program uudecode reverses the
+ effect of uuencode, recreating the original binary file
+ exactly.
+
+ Uuencoded data starts with a line of the form
+
+ begin <mode> <file>
+
+ where <mode> is the files read/write/execute permissions as
+ three {octal} digits and <file> is the name to be used when
+ recreating the binary data.
+
+ Uuencode repeatedly takes in a group of three bytes, adding
+ trailing zeros if there are less than three bytes left. These
+ 24 bits are split into four groups of six which are treated as
+ numbers between 0 and 63. Decimal 32 is added to each number
+ and they are output as ASCII characters from 32 (space) to
+ 32+63 = 95 (underscore). Each group of sixty output
+ characters (corresponding to 45 input bytes) is output as a
+ separate line preceded by an 'M' (ASCII code 77 = 32+45). At
+ the end of the input, if there are N output characters left
+ after the last group of sixty and N>0 then they will be
+ preceded by the character whose code is 32+N. Finally, a line
+ containing just a single space is output, followed by one
+ containing just "end".
+
+ Sometimes each data line has an extra dummy character added to
+ avoid problems which mailers that strip trailing spaces.
+ These characters are ignored by uudecode.
+
+ Despite using this limited range of characters, there are
+ still some problems encountered when uuencoded data passes
+ through certain old computers. The worst offenders are
+ computers using non-ASCII character sets such as EBCDIC.
+
+ {Base 64} encoding is probably now more commonly used than
+ uuencode.
+
+ (2004-07-17)
+
+UUNET PIPEX
+
+ <company> An {Internet provider}, part of the Unipalm Group.
+ PIPEX launched their Internet service in March 1992, and by
+ November 1993 provided Internet service to 150 customer sites
+ in the UK. Each site is either a complete commercial company
+ or a branch of one, or a public-sector organisation. They
+ provide a commercial {internetworking} service, with 24-hour
+ support, and a resilient backbone with multiple international
+ links. PIPEX provides for individual users through their
+ "PIPEX Dial" service, and has a number of re-sellers connected
+ to its backbone, including {CityScape}, {Direct Connection}
+ and the {IBM PC User Group}, who also offer such services.
+
+ {(http://pipex.net)}.
+
+ E-mail: <support@pipex.net>.
+
+ Address (Head office): Cambridge ?
+
+ Address: King St. London EC2V(?)
+
+ (1996-10-13)
+
+UUPC
+
+ {UUCP} for {MS-DOS}, {Microsoft Windows}, and {OS/2}.
+
+ E-mail: <server@netmail.com> with subject SEND INDEX.
+
+uy
+
+ <networking> The {country code} for Uruguay.
+
+ (1999-01-27)
+
+uz
+
+ <networking> The {country code} for Uzbekistan.
+
+ (1999-01-27)
+
+V
+
+ Upper case V, {ASCII} character 86, known in {INTERCAL} as
+ book.
+
+ 1. A testbed for distributed system research.
+
+ 2. Wide-spectrum language used in the knowledge-based
+ environment {CHI}. "Research on Knowledge-Based Software
+ Environments at Kestrel Inst", D.R. Smith et al, IEEE Trans
+ Soft Eng SE-11(11):1278-1295 (1985).
+
+V.10
+
+ <communications, standard> An {ITU-T} recommendation on
+ electrical characteristics for {unbalanced} {double-current
+ interchange circuits} operating at {data signalling rates}
+ nominally up to 100 kbps. This recommendation is also
+ included but not published in {ITU-T} X series under alias
+ number X.26. The circuit defined in this standard is used in
+ other {serial line} standards such as {EIA-232} and {EIA-423},
+ that implement {single ended} communication.
+
+ (2002-10-05)
+
+V.11
+
+ <communications, standard> An {ITU-T} recommendation on
+ electrical characteristics for {balanced} {double-current}
+ {interchange circuits} operating at {data signalling rates} up
+ to 10 Mbps. V.11 is also included but not published in the as
+ {ITU-T} X.27. V.11 is used in other {serial line} standards
+ such as {EIA-422} and {EIA-485}, that implement {differential
+ line} communication.
+
+ (2003-04-06)
+
+V.17
+
+ <protocol, standard> An {ITU-T} {modem} {protocol} for 14400
+ {bps} {half duplex} communications with {fall back} to 12000
+ {bps}, 9600 {bps} and 7200 {bps}.
+
+ (2004-07-26)
+
+V.21
+
+ <protocol, standard> An {ITU-T} {modem} {protocol} for 300
+ {bps} two-wire {full-duplex} communications using {Frequency
+ Shift Keying} {modulation}.
+
+ All modern modems support both V.21 and the close variant,
+ Bell 103.
+
+ (1996-07-22)
+
+V.22
+
+ <protocol, standard> An {ITU-T} {modem} {protocol} which
+ allowed data rates of 1200 {bps}. {V.22bis} doubled this.
+
+ (2004-07-26)
+
+V.22bis
+
+ <protocol, standard>{V.22} twice. An {ITU-T} {modem}
+ {protocol} which allowed a data rate of 2400 bits per second,
+ twice that of {V.22}.
+
+V.23
+
+ <protocol, standard> An {ITU-T} {modem} {protocol} which
+ allowed {half-duplex} (unidirectional) data transmission at
+ 1200 bits per second with a 75 {bps} {back channel} and {fall
+ back} to 600/75 bps. This was the main standard used for
+ {British Telecom}'s {Prestel} service.
+
+ (2004-07-26)
+
+V.24
+
+ <standard> The {ITU-T} {standard} defining interchange
+ circuits between {DTE} and {DCE}. V.24 is the {ITU-T}
+ equivalent of {EIA} standard {EIA-232C}, though V.24 only
+ specifies the meaning of the signals, not the connector or the
+ voltages used.
+
+ V.24 recommends 12 {modem} {carrier} frequencies that will not
+ interfere with {Dual Tone Multi-Frequency} or other telephone
+ control tones. These are:
+
+ GROUP A = 920 Hz, 1000 Hz, 1080 Hz, 1160 Hz
+ GROUP B = 1320 Hz, 1400 Hz, 1480 Hz, 1560 Hz
+ Group C = 1720 Hz, 1800 Hz, 1880 Hz, 1960 Hz
+
+ (2004-08-02)
+
+V.25
+
+ <communications, standard> A {standard} allowing an
+ {auto-answer} {modem} to determine the correct {modulation}
+ standard to use.
+
+ (2001-04-06)
+
+V.25 bis
+
+ <communications, standard> A cryptic command language for
+ {modems}.
+
+ (2004-08-02)
+
+V.27 ter
+
+ <protocol, standard> An {ITU-T} {modem} {protocol} which
+ allowed 4800 {bps} communications with {fall back} to 2400
+ bps. V27.ter was used by {Fax machines}.
+
+ (2004-07-26)
+
+V.28
+
+ <communications, standard> An {ITU-T} physical interface
+ {standard} for {serial} data communications equipment,
+ formally titled "Electrical Characteristics for Unbalanced
+ Double-Current Interchange Circuits". The combination of V.28
+ and {V.24} is equivalent to the {EIA}'s {RS-232} and uses the
+ same 25-pin connectors.
+
+ (2001-04-06)
+
+V.29
+
+ <communications, standard> An {ITU-T} {modem} {protocol} which
+ allows 9600 {bps} {half duplex} or {four wire} communications
+ with {fall back} to 7200 {bps} and 4800 {bps}. V.29 is used
+ by {fax} machines.
+
+ (2004-07-30)
+
+V.32
+
+ <communications, standard> An {ITU-T} standard {protocol} for
+ {modems} transmitting at 9600 bits per second with {fall back}
+ to 4800 {bps}. {V.32bis} extended this to 14400 bps.
+
+ V32 and V.32bis acheive bidirectional data transmission not by
+ having different sets of tones at each end but by subtracting
+ what is sent from what is received.
+
+ (2004-07-30)
+
+V.32bis
+
+ <communications, standard> V.32 twice. An extension of the
+ {ITU-T} {V.32} {modem} {protocol} allowing 14400 bits per
+ second with {fall back} to 12000{bps}, 9600{bps}, 7200{bps}
+ and 4800 {bps}.
+
+ The {modem} should select the appropriate speed according to
+ the current line conditions.
+
+ See also {V.32ter}.
+
+ (1994-12-15)
+
+V.32ter
+
+ An extension of the {ITU-T} {V.32bis} {modem} {protocol}.
+ While waiting for {V.34}, many {modem} manufacturers decided
+ to extend V.32bis to 19.2 kbps. This was known as V.32ter
+ which some {marketroids} rechristened V.32 terbo which is not
+ only misspelled but misses the fact that V.32ter means the
+ third revision of V.32.
+
+ (1994-12-15)
+
+V.34
+
+ <protocol> An {ITU-T} {standard} {modem} serial line
+ {protocol} using {symbol rates} of 2400, 2743, 2800, 3000,
+ >3200 and 3429 and up to 28800 bits per second.
+
+ The official V.34 draft recommendation was titled:
+
+ Modem operating at data signalling rates of up to 28 800
+ bit/s for use on the general switched telephone network and
+ on leased point-to-point 2-wire telephone-type circuits.
+
+ During the lengthy process of approval by {ITU-T}, many
+ manufacturers released 28.8 kbps modems described as "V.FAST".
+ The V.34 recommendation was ratified by {ITU-T} on 20
+ September 1994. {Rockwell} and {US Robotics} both have seats
+ on the ITU-T, and have both released {chip set}/{BIOS}
+ combinations that they feel will meet V.34. V.34 modems will
+ also support {V.FC} if the manufacturer currently supports
+ V.FC (e.g. {Rockwell}). Some (all?) V.34 modems will also
+ support {line probing}.
+
+ {ITU document
+ (http://itu.int/itudoc/itu-t/rec/v/v34_25302.html)}.
+
+ (1998-07-03)
+
+V.35
+
+ <communications, standard> The {ITU-T} {standard} for data
+ transmission at 48 kilobits per second over 60 - 108 KHz group
+ band circuits. It contains the 34-pin {V.34} connector
+ specifications normally implemented on a modular {RJ-45}
+ connector.
+
+ (1995-03-02)
+
+V.42
+
+ <communications, standard> An {ITU-T} standard {protocol} for
+ {error correction} between {modems}, which includes {MNP} up
+ to level 4 and {asynchronous} to {synchronous} conversion.
+
+ (2004-08-02)
+
+V.42bis
+
+ <communications, standard> An extension of the {ITU-T} {V.42}
+ standard {modem} {protocol} to included {compression} using a
+ {Lempel-Ziv} related technique, which detects frequently
+ occurring character strings and replaces them with tokens.
+ This is similar to the {Unix} {compress} utility. Typical
+ {compression} for text is 50% or better; with nearly 20% gain
+ from {synchronous} conversion this gives reduces transmission
+ time by almost 60%.
+
+ [Details? On-line spec?]
+
+ (2004-08-02)
+
+V.90
+
+ <protocol> An {ITU-T} {standard} {modem} serial line
+ {protocol} allowing download speeds of up to 56 {kbps} with
+ upload speeds of 33.6 {kbps}. {V.90} modems are designed for
+ connections that are digital at one end and have only one
+ digital-to-analogue conversion.
+
+ As of 1998-02-06 the V.90 standard, formerly called V.pcm, has
+ been given final approval by {ITU-T}. On 1998-10-27 the ITU-T
+ announced that approval of the V.90 standard was completed.
+ Interoperability testing is complete or in progress for
+ several modem manufacturers. The V.90 standard reconciles two
+ competing standards, {X2} and {K56flex}.
+
+ The {ITU-T} has initiated the approval process for a new
+ all-digital version of the protocol, to be known as {V.91}.
+
+ {ITU Press Release 98-04
+ (http://itu.int/newsroom/press/releases/1998/98-04.html)}.
+ and {NP-3
+ (http://itu.int/newsroom/press/releases/1998/NP-3.html)}.
+
+ (1999-01-25)
+
+V.91
+
+ <protocol> An all-digital version of the {V.90} {protocol},
+ undergoing {ITU-T} approval.
+
+ (1999-01-13)
+
+va
+
+ <networking> The {country code} for the Vatican.
+
+ (1999-01-27)
+
+vacuum tube
+
+ {electron tube}
+
+vadding
+
+ <games> /vad'ing/ (From VAD, a permutation of ADV,
+ i.e. {ADVENT}, used to avoid a particular {admin}'s continual
+ search-and-destroy sweeps for the game) A leisure-time
+ activity of certain hackers involving the covert exploration
+ of the "secret" parts of large buildings - basements, roofs,
+ freight elevators, maintenance crawlways, steam tunnels, and
+ the like. A few go so far as to learn locksmithing in order
+ to synthesise vadding keys. The verb is "to vad" (compare
+ {phreaking}; see also {hack}, sense 9). This term dates from
+ the late 1970s, before which such activity was simply called
+ "hacking"; the older usage is still prevalent at {MIT}.
+
+ Vadding (pronounced /vay'ding/) was also popular {CMU}, at
+ least as early as 1986. People who did it every night were
+ called the "vaders," possibly after "elevator," which was one
+ of the things they played with, or "invader," or "Darth
+ Vader". This game was usually played along with
+ no-holds-barred hide-and-seek. CMU grad students were the
+ known to pry open the inner doors of elevators between floors
+ to see the graffiti on the inside of the outer doors.
+
+ The most extreme and dangerous form of vadding is "elevator
+ rodeo", also known as "elevator surfing", a sport played by
+ wrasslin' down a thousand-pound elevator car with a 3-foot
+ piece of string, and then exploiting this mastery in various
+ stimulating ways (such as elevator hopping, shaft exploration,
+ rat-racing, and the ever-popular drop experiments). Kids,
+ don't try this at home!
+
+ See also {hobbit}.
+
+ [{Jargon File}]
+
+ (1996-01-07)
+
+VAL
+
+ 1. Value-oriented Algorithmic Language. J.B. Dennis, MIT
+ 1979. Single assignment language, designed for MIT dataflow
+ machine. Based on CLU, has iteration and error handling,
+ lacking in recursion and I/O. "A Value- Oriented Algorithmic
+ Language", W.B. Ackermann et al, MIT LCS TR-218, June 1979.
+ "The VAL Language: Description and Analysis", J.R. McGraw,
+ TOPLAS 4(1):44-82 (Jan 1982).
+
+ 2. <language, robotics> Variable Assembly Language.
+ Unimation. Language for industrial robots. Version: VAL II -
+ "VAL II: A New Robot Control System for Automatic
+ Manufacturing", B.E. Shimano et al, Proc IEEE Intl Conf on
+ Robotics 1984, pp.278-292.
+
+ 3. VHDL Annotation Language. Stanford.
+ {(ftp://wilbur.stanford.edu/pub/valbin-sun3-4.0-0.1.3.tar.Z)}.
+ Source in Ada available from Larry M. Augustin
+ <lma@sierra.stanford.edu>.
+
+Valencia Simple Tasker
+
+ <operating system> (VSTa) A small {microkernel} based
+ {Unix}-like {operating system}, taking ideas from {QNX} and
+ {Plan 9}, available under {GPL}.
+
+ {(http://chat.net/~jeske/VSTa/)}.
+
+ (1999-03-03)
+
+valency
+
+ {degree}
+
+Valid
+
+ A {dataflow} language.
+
+ ["A List-Processing-Oriented Data Flow Machine Architecture",
+ Makoto Amamiya et al, AFIPS NCC, June 1982, pp. 143-151].
+
+ (1995-02-14)
+
+validation
+
+ The stage in the {software life-cycle} at the end of the
+ development process where software is evaluated to ensure that
+ it complies with the requirements.
+
+ (1995-02-14)
+
+value
+
+ {brightness}
+
+Value Added Network
+
+ <networking> (VAN) A privately owned {network} that provides a
+ specific service, such as legal research or access to a
+ specialised database, for a fee. A Value Added Network
+ usually offers some service or information that is not readily
+ available on public networks.
+
+ A Value Added Network's customers typically purchase {leased
+ lines} that connect them to the network or they use a {dial-up
+ number}, given by the network owner, to gain access to the
+ network.
+
+ (1998-11-10)
+
+value added reseller
+
+ <company> (VAR, or "value added retailer") A company which
+ sells something (e.g. computers) made by another company (an
+ {OEM}) with extra components added (e.g. specialist software).
+
+ (1995-02-14)
+
+value added retailer
+
+ {value added reseller}
+
+valve
+
+ <electronics> UK term for a {vacuum tube}.
+
+ (1996-01-10)
+
+vampire tap
+
+ <networking, hardware> A device to connect a {network node} to
+ an {RG8} thick {ethernet} cable without affecting other
+ connected nodes.
+
+ A vampire tap has an interface box with a "V" shaped groove
+ along one side. A sharp needle protrudes from the center of
+ the groove. The cable is clamped into the groove by a grooved
+ plate held in position by two thumb screws. With sufficient
+ practise, tightening the screws forces the needle through the
+ cable jacket and into contact with the cable's center wire
+ while other spikes bite into the outer conductor. The
+ interface box has a 15 pin connector to connect to the network
+ {node}.
+
+ The vampire tap is often built into the {transceiver}, with a
+ more flexible multi-wire "drop cable" to connect the
+ transceiver to the node.
+
+ (2004-08-25)
+
+VAN
+
+ {Value Added Network}
+
+vanilla
+
+ 1. (Default flavour of ice cream in the US) Ordinary
+ {flavour}, standard. When used of food, very often does not
+ mean that the food is flavoured with vanilla extract! For
+ example, "vanilla wonton soup" means ordinary wonton soup, as
+ opposed to hot-and-sour wonton soup. Applied to hardware and
+ software, as in "Vanilla {Version 7} {Unix} can't run on a
+ vanilla {PDP 11}/34." Also used to orthogonalise chip
+ nomenclature; for instance, a 74V00 means what TI calls a
+ 7400, as distinct from a 74LS00, etc. This word differs from
+ {canonical} in that the latter means "default", whereas
+ vanilla simply means "ordinary". For example, when hackers go
+ to a chinese restaurant, hot-and-sour wonton soup is the
+ {canonical} wonton soup to get (because that is what most of
+ them usually order) even though it isn't the vanilla wonton
+ soup.
+
+ [{Jargon File}]
+
+ (1994-11-04)
+
+ 2. {Snobol4} by {Catspaw, Inc.} for {MS-DOS}.
+
+ {(ftp://cs.arizona.edu/snobol4/vanilla.arc)}.
+
+ (1992-02-05)
+
+vanity domain
+
+ <networking> A {domain} you register for the sole purpose of
+ having your own domain so you can have an easily remembered
+ {URL} and {e-mail} address. The domain is usually served
+ (often {vhost}ed) off someone else's machines.
+
+ This is as opposed to a domain you register because you have
+ machines of your own which are already on the Internet and
+ which you want to make addressable via something other than
+ {dot address}es.
+
+ Whereas vanity domains were almost unheard-of in 1980s, since
+ the invention and popularisation of the {Web} in the mid-1990s
+ and the desire for {URLs} which consist only of memorable
+ domain names (e.g., "http://pbs.org") for everything from
+ movies to car wax, vanity domains have come to be the rule
+ instead of the exception.
+
+ (1997-09-11)
+
+vannevar
+
+ <jargon> /van'*-var/ A bogus technological prediction or a
+ foredoomed engineering concept, especially one that fails by
+ implicitly assuming that technologies develop linearly,
+ incrementally, and in isolation from one another when in fact
+ the learning curve tends to be highly nonlinear, revolutions
+ are common, and competition is the rule. The prototype was
+ Vannevar Bush's prediction of "electronic brains" the size of
+ the Empire State Building with a Niagara-Falls-equivalent
+ cooling system for their tubes and relays, a prediction made
+ at a time when the semiconductor effect had already been
+ demonstrated. Other famous vannevars have included
+ {magnetic-bubble memory}, {LISP machines}, {videotex}, and a
+ paper from the late 1970s that computed a purported ultimate
+ limit on areal density for {integrated circuits} that was in
+ fact less than the routine densities of 5 years later.
+
+ [{Jargon File}]
+
+ (2000-02-29)
+
+Vannevar Bush
+
+ <person> Dr. Vannevar Bush, 1890-1974. The man who invented
+ {hypertext}, which he called {memex}, in the 1930s.
+
+ Bush did his undergraduate work at Tufts College, where he
+ later taught. His masters thesis (1913) included the
+ invention of the Profile Tracer, used in surveying work to
+ measure distances over uneven ground. In 1919, he joined
+ {MIT}'s Department of Electrical Engineering, where he stayed
+ for twenty-five years. In 1932, he was appointed
+ vice-president and dean. At this time, Bush worked on optical
+ and photocomposition devices, as well as a machine for rapid
+ selection from banks of microfilm.
+
+ Further positions followed: president of the Carnegie
+ Institute in Washington, DC (1939); chair of National Advisory
+ Committee for Aeronautics (1939); director of Office of
+ Scientific Research and Development. This last role was as
+ presidential science advisor, which made him personally
+ responsible for the 6,000 scientists involved in the war
+ effort. During World War II, Bush worked on radar antenna
+ profiles and the calculation of artillery firing tables. He
+ proposed the development of an {analogue computer}, which
+ later became the {Rockefeller Differential Analyser}.
+
+ Bush is the pivotal figure in hypertext research. His
+ ground-breaking 1945 paper, "As We May Think," speculated on
+ how a machine might be created to assist human reasoning, and
+ introduced the idea of an easily accessible, individually
+ configurable storehouse of knowledge. This machine, which he
+ dubbed "memex," in various ways anticipated {hypermedia} and
+ the {World Wide Web} by nearly half a century.
+
+ {Electronic Labyrinth article
+ (http://jefferson.village.virginia.edu/elab/hfl0034.html)}.
+
+ {Bush's famous article, "As We May Think"
+ (http://theatlantic.com/unbound/flashbks/computer/bushf.htm)}.
+
+ (2001-06-17)
+
+vaporware
+
+ <jargon> /vay'pr-weir/ (UK "vapourware") Products announced
+ far in advance of any release (which may or may not actually
+ take place). The term came from {Atari} users and was later
+ applied by {Infoworld} to {Microsoft}'s continuous lying about
+ {Microsoft Windows}.
+
+ See also {brochureware}.
+
+ [{Jargon File}]
+
+ (2004-11-16)
+
+vapourware
+
+ <spelling> UK spelling of "{vaporware}".
+
+ (2004-11-16)
+
+VAR
+
+ {Value Added Reseller} (or retailer).
+
+var
+
+ {variable}
+
+varchar
+
+ <database> A {database} {data type} for storing
+ variable-length strings of {ASCII} data. The amount of
+ storage space used depends on the length of the strings, in
+ contrast to the ordinary "char" type. The maximum length of
+ string must still be specified, e.g. varchar(256).
+
+ (2009-02-25)
+
+variable
+
+ <programming> (Sometimes "var" /veir/ or /var/) A named memory
+ location in which a program can store intermediate results and
+ from which it can read it them. Each {programming language}
+ has different rules about how variables can be named, typed,
+ and used. Typically, a value is "assigned" to a variable in
+ an {assignment} statement. The value is obtained by
+ evaluating an expression and then stored in the variable. For
+ example, the assignment
+
+ x = y + 1
+
+ means "add one to y and store the result in x". This may look
+ like a mathematical equation but the mathematical equality is
+ only true in the program until the value of x or y changes.
+ Furthermore, statements like
+
+ x = x + 1
+
+ are common. This means "add one to x", which only makes sense
+ as a state changing operation, not as a mathematical equality.
+
+ The simplest form of variable corresponds to a single-{word}
+ of {memory} or a {CPU} {register} and an assignment to a
+ {load} or {store} {machine code} operation.
+
+ A variable is usually defined to have a {type}, which never
+ changes, and which defines the set of values the variable can
+ hold. A type may specify a single ("atomic") value or a
+ collection ("aggregate") of values of the same or different
+ types. A common aggregate type is the {array} - a set of
+ values, one of which can be selected by supplying a numerical
+ {index}.
+
+ Languages may be {untyped}, {weakly typed}, {strongly typed},
+ or some combination. {Object-oriented programming} languages
+ extend this to {object} types or {classes}.
+
+ A variable's {scope} is the region of the program source
+ within which it represents a certain thing. Scoping rules are
+ also highly language dependent but most serious languages
+ support both {local variables} and {global variables}.
+ {Subroutine} and {function} {formal arguments} are special
+ variables which are set automatically by the language runtime
+ on entry to the subroutine.
+
+ In a {functional programming} language, a variable's value
+ never changes and change of state is handled as recursion over
+ lists of values.
+
+ (2004-11-16)
+
+Variational Graphics eXtended
+
+ <software> (VGX) {Software} developed by {SDRC} for use in 3D
+ {CAD} {solid modelling}.
+
+ (1998-02-06)
+
+VAX
+
+ <computer> /vaks/ (Virtual Address eXtension) The most
+ successful {minicomputer} design in industry history, possibly
+ excepting its immediate ancestor, the {PDP-11}. Between its
+ release in 1978 and its eclipse by {killer micros} after about
+ 1986, the VAX was probably the {hacker}'s favourite machine,
+ especially after the 1982 release of {4.2BSD} {Unix}.
+ Especially noted for its large, {assembly
+ code}-programmer-friendly {instruction set} - an asset that
+ became a liability after the {RISC} revolution.
+
+ VAX is also a British brand of {carpet cleaner
+ (http://vax.co.uk/)} whose advertising slogan, "Nothing
+ sucks like a VAX!" became a battle-cry of RISC partisans. It
+ is even sometimes claimed that DEC actually entered a
+ licencing deal that allowed them to market VAX computers in
+ the UK in return for not challenging the carpet cleaner
+ trademark in the US.
+
+ The slogan originated in the late 1960s as "Nothing sucks like
+ Electrolux", Electrolux AB being a rival Swedish company. It
+ became a classic textbook example of the perils of not knowing
+ the local idiom, which is ironic because, according to the
+ Electrolux press manager in 1996, the double entendre was
+ intentional. VAX copied the slogan in their promotions in
+ 1986-1987, and it surfaced in New Zealand TV ads as recently
+ as 1992!
+
+ [{Jargon File}]
+
+ (2000-09-28)
+
+VAX DOCUMENT
+
+ A document preparation system from {DEC}.
+
+VAXectomy
+
+ <jargon> /vak-sek't*-mee/ (By analogy with "vasectomy")
+ Removal of a {VAX}. {DEC}'s {Microvax}en, especially, are
+ much slower than newer {RISC}-based {workstations} such as the
+ {SPARC}. Thus, if one knows one has a replacement coming, VAX
+ removal can be cause for celebration.
+
+ [{Jargon File}]
+
+ (1995-02-20)
+
+VAXen
+
+ /vak'sn/ (From "oxen", perhaps influenced by "vixen") The
+ plural canonically used among hackers for the {DEC} {VAX}
+ computers. "Our installation has four PDP-10s and twenty
+ vaxen."
+
+ See {boxen}.
+
+ [{Jargon File}]
+
+ (1995-02-20)
+
+vaxherd
+
+ /vaks'herd/ ["oxherd"] An operator who tends one or more
+ {VAXen}.
+
+ [{Jargon File}]
+
+vaxism
+
+ /vak'sizm/ A piece of code that exhibits {vaxocentrism} in
+ critical areas. Compare {PC-ism}, {Unixism}.
+
+VAX MIPS
+
+ <benchmark> (Or VAX Unit of Performance, VUP) The processing
+ power normally attributed to a {Digital Equipment Corporation}
+ {VAX} 11/780. Future VAX systems were rated according to this
+ scale (e.g. VAX 8350's being 2.7 VUPs per CPU). A {MicroVAX}
+ II is normally associated with 0.9 VUPs and at a later time
+ the MicroVUP was coined to rate VAX {workstations}. The use
+ of the VUP by Digital Equipment Corporation has been replaced
+ with more standard benchmarks ({SPECint} and {SPECfp}) in the
+ {DEC Alpha} processor systems.
+
+ (1996-08-22)
+
+vaxocentrism
+
+ /vak"soh-sen"trizm/ [analogy with "ethnocentrism"] A notional
+ disease said to afflict C programmers who persist in coding
+ according to certain assumptions that are valid (especially
+ under Unix) on {VAXen} but false elsewhere. Among these are:
+
+ 1. The assumption that dereferencing a null pointer is safe
+ because it is all bits 0, and location 0 is readable and 0.
+ Problem: this may instead cause an illegal-address trap on
+ non-VAXen, and even on VAXen under OSes other than BSD Unix.
+ Usually this is an implicit assumption of sloppy code
+ (forgetting to check the pointer before using it), rather than
+ deliberate exploitation of a misfeature.
+
+ 2. The assumption that characters are signed.
+
+ 3. The assumption that a pointer to any one type can freely be
+ cast into a pointer to any other type. A stronger form of
+ this is the assumption that all pointers are the same size and
+ format, which means you don't have to worry about getting the
+ casts or types correct in calls. Problem: this fails on
+ word-oriented machines or others with multiple pointer
+ formats.
+
+ 4. The assumption that the parameters of a routine are stored
+ in memory, on a stack, contiguously, and in strictly ascending
+ or descending order. Problem: this fails on many RISC
+ architectures.
+
+ 5. The assumption that pointer and integer types are the same
+ size, and that pointers can be stuffed into integer variables
+ (and vice-versa) and drawn back out without being truncated or
+ mangled. Problem: this fails on segmented architectures or
+ word-oriented machines with funny pointer formats.
+
+ 6. The assumption that a data type of any size may begin at
+ any byte address in memory (for example, that you can freely
+ construct and dereference a pointer to a word- or
+ greater-sized object at an odd char address). Problem: this
+ fails on many (especially RISC) architectures better optimised
+ for {HLL} execution speed, and can cause an illegal address
+ fault or bus error.
+
+ 7. The (related) assumption that there is no padding at the
+ end of types and that in an array you can thus step right from
+ the last byte of a previous component to the first byte of the
+ next one. This is not only machine- but compiler-dependent.
+
+ 8. The assumption that memory address space is globally flat
+ and that the array reference "foo[-1]" is necessarily valid.
+ Problem: this fails at 0, or other places on segment-addressed
+ machines like Intel chips (yes, segmentation is universally
+ considered a {brain-damaged} way to design machines (see
+ {moby}), but that is a separate issue).
+
+ 9. The assumption that objects can be arbitrarily large with
+ no special considerations. Problem: this fails on segmented
+ architectures and under non-virtual-addressing environments.
+
+ 10. The assumption that the stack can be as large as memory.
+ Problem: this fails on segmented architectures or almost
+ anything else without virtual addressing and a paged stack.
+
+ 11. The assumption that bits and addressable units within an
+ object are ordered in the same way and that this order is a
+ constant of nature. Problem: this fails on {big-endian}
+ machines.
+
+ 12. The assumption that it is meaningful to compare pointers
+ to different objects not located within the same array, or to
+ objects of different types. Problem: the former fails on
+ segmented architectures, the latter on word-oriented machines
+ or others with multiple pointer formats.
+
+ 13. The assumption that an "int" is 32 bits, or (nearly
+ equivalently) the assumption that "sizeof(int) ==
+ sizeof(long)". Problem: this fails on {PDP-11s}, {Intel
+ 80286}-based systems and even on {Intel 80386} and {Motorola
+ 68000} systems under some compilers.
+
+ 14. The assumption that "argv[]" is writable. Problem: this
+ fails in many embedded-systems C environments and even under a
+ few flavours of Unix.
+
+ Note that a programmer can validly be accused of vaxocentrism
+ even if he or she has never seen a VAX. Some of these
+ assumptions (especially 2--5) were valid on the {PDP-11}, the
+ original {C} machine, and became endemic years before the VAX.
+ The terms "vaxocentricity" and "all-the-world"s-a-VAX
+ syndrome' have been used synonymously.
+
+ [{Jargon File}]
+
+VAXset
+
+ A set of software development tools from DEC, including a
+ language-sensitive editor, compilers etc.
+
+VAXstation
+
+ A family of {workstations} from {DEC} based on their {VAX}
+ computer architecture.
+
+ (1995-02-03)
+
+VAX/VMS
+
+ {VMS}
+
+VB
+
+ {Visual BASIC}
+
+VBA
+
+ {Visual Basic for Applications}
+
+vbell
+
+ {visible bell}
+
+VBScript
+
+ {Visual BASIC Script}
+
+vbx
+
+ <filename extension> The {filename extension} for {Visual
+ Basic Extension}.
+
+ (1995-02-03)
+
+vc
+
+ <networking> The {country code} for Saint Vincent and the
+ Grenadines.
+
+ (1999-01-27)
+
+VCC filtering
+
+ <electronics> A technique for reducing the amount of {Radio
+ Frequency Interference} spread via power supply connections.
+ {VCC} is a common name for the non-{ground} power supply line
+ in circuits based on {bipolar transistors}.
+
+ When part of a circuit generates lots of radio-frequency
+ noise, that portion of the {power plane} can be isolated from
+ the rest of the circuit and power delivered to it via a {low
+ pass filter}, usually a {PI filter}, as shown in the diagram
+ below.
+
+ source ________inductor_________ load
+ | |
+ capacitor capacitor
+ | |
+ ground ground
+
+ This helps to shield the rest of the circuit from the noise
+ generated by the load.
+
+ (1998-01-26)
+
+VCD
+
+ {Video Compact Disc}
+
+VCID
+
+ {Virtual Circuit Identifier}
+
+VCL
+
+ {Visual Component Library}
+
+VCODE
+
+ 1. The {intermediate language} used in the compilation of
+ {NESL}.
+
+ ["Implementation of a Portable Nested Data-Parallel Language",
+ Guy Blelloch et al, in Fourth ACM SIGPLAN Symposium on Princ
+ and Practice of Parallel Programming, ACM, 1993].
+
+ 2. The {intermediate language} used in the compilation of
+ {C+@}.
+
+ (1995-01-12)
+
+VCPI
+
+ {Virtual Control Program Interface}
+
+VCR
+
+ {Video Cassette Recorder}
+
+vdiff
+
+ /vee'dif/ Visual diff. The operation of finding differences
+ between two files by {eyeball search}. The term "optical
+ diff" has also been reported, and is sometimes more
+ specifically used for the act of superimposing two nearly
+ identical printouts on one another and holding them up to a
+ light to spot differences. Though this method is poor for
+ detecting omissions in the "rear" file, it can also be used
+ with printouts of graphics, a claim few if any diff programs
+ can make. See {diff}.
+
+ [{Jargon File}]
+
+VDL
+
+ {Vienna Definition Language}
+
+VDM
+
+ 1. Vienna Definition Method
+
+ 2. {Virtual Device Metafile}.
+
+VDM++
+
+ {Object-oriented extension} of {VDM-SL}. ["Object-Oriented
+ Specification in VDM++", in Object Oriented Specification Case
+ Studies, K. Lano et al eds, P-H 1993].
+
+VDM-SL
+
+ {Vienna Development Method Specification Language}
+
+VDSL
+
+ {Very high bit-rate Digital Subscriber Line}
+
+VDT
+
+ {video display terminal}
+
+VDU
+
+ {Visual Display Unit}
+
+vdx
+
+ {virtual network bios driver}
+
+ve
+
+ <networking> The {country code} for Venezuela.
+
+ (1999-01-27)
+
+vector
+
+ 1. <mathematics> A member of a {vector space}.
+
+ 2. <graphics> A line or movement defined by its end points, or
+ by the current position and one other point. See {vector
+ graphics}.
+
+ 3. <operating system> A memory location containing the address
+ of some code, often some kind of {exception} handler or other
+ {operating system} service. By changing the vector to point
+ to a different piece of code it is possible to modify the
+ behaviour of the operating system.
+
+ Compare {hook}.
+
+ 4. <programming> A one-dimensional {array}.
+
+ (1996-09-30)
+
+Vector C
+
+ <language> A variant of {C} from {CMU}(?), similar to {ACTUS}.
+
+ (1996-09-30)
+
+vector font
+
+ {outline font}
+
+vector graphics
+
+ <graphics> (Sometimes called "object-oriented" graphics,
+ though it's nothing to do with {object-oriented programming}).
+ The representation of separate shapes such as lines, polygons
+ and text, and groups of such objects, as opposed to {bitmaps}.
+ The advantage of vector graphics ("drawing") programs over
+ bitmap ("paint") editors is that multiple overlapping elements
+ can be manipulated independently without using differenet
+ layers for each one. It is also easier to render an object at
+ different sizes and to transform it in other ways without
+ worrying about image {resolution} and {pixels}.
+
+ (2001-02-06)
+
+vector processor
+
+ {array processor}
+
+vector space
+
+ <mathematics> An {additive group} on which some ({scalar})
+ {field} has an {associative} multiplicative action which
+ distributes over the addition of the vector space and respects
+ the addition of the (scalar) field: for vectors u, v and
+ scalars h, k; h(u+v) = hu + hv; (h+k)u = hu + ku; (hk)u =
+ h(ku).
+
+ [Simple example?]
+
+ (1996-09-30)
+
+VECTRAN
+
+ <language> {Fortran} with {array} extensions.
+
+ ["The VECTRAN Language: An Experimental Language for
+ Vector/Matrix Array Processing", Report G320- 3334, IBM, Aug
+ 1975].
+
+ (1996-01-19)
+
+VEE
+
+ {HP VEE}
+
+veeblefeetzer
+
+ {veeblefetzer}
+
+veeblefester
+
+ <jargon, abuse> /vee'b*l-fes"tr/ (From "Born Loser" comix via
+ {Commodore}; probably originally from "Mad" Magazine's
+ "Veeblefeetzer" parodies ca. 1960) Any obnoxious person
+ engaged in the (alleged) professions of marketing or
+ management.
+
+ Antonym of {hacker}. Compare {suit}, {marketroid}. See also
+ {veeblefetzer}.
+
+ [veeblefeetzer or veeblefetzer?]
+
+ [{Jargon File}]
+
+ (1996-03-31)
+
+veeblefetzer
+
+ <jargon> /vee'b*l-fetz'*/ (Or "veeblefeetzer"?) A purposely
+ nonsensical sounding word applied to any sort of obscure or
+ complicated object, e.g. a piece of computer code, model
+ railroad equipment, auto parts, etc.
+
+ The more immediate origin of the word is "Mad" Magazine. In
+ the late 1950s and early 1960s it used the word along the same
+ lines, especially in its send-ups of big business. "North
+ American Veeblefetzer" was the subject of satires of an annual
+ reports, an in-house newsletter, and more. A Veeblefetzer, in
+ their case, was a robot-like device that did something or
+ other.
+
+ The more distant source was probably a 19th century yiddish
+ word, possibly with limited usage. In German, "Fetzer" is any
+ contraption, while "Veeble" is a likely corruption of "Webel"
+ -- meaning weaving. Textile mills of this period were crammed
+ with very complicated, wildly active and very loud pieces of
+ machinery.
+
+ See also {veeblefester}.
+
+ [veeblefeetzer or veeblefetzer?]
+
+ (1996-03-31)
+
+VEL
+
+ {LISP70}
+
+Vendor Independent Messaging
+
+ <networking> (VIM) An {electronic mail} {API} promoted by an
+ industry group headed by {Lotus Development}. VIM is a
+ competitor to {Microsoft}'s {MAPI}.
+
+ [Features?]
+
+ (1995-03-28)
+
+ventilator card
+
+ {lace card}
+
+Ventura Publisher
+
+ {Corel VENTURA}
+
+Venus flytrap
+
+ {firewall machine}
+
+verbage
+
+ <spelling, jargon> /ver'b*j/ Speech or writing with an excess of
+ words or of obscure words.
+
+ Although identical in meaning, and almost in spelling, to the
+ common word {verbiage}, Patrick Flatley believes he was the first
+ to coin the word "verbage", as a portmanteau of "verbal" and
+ "garbage", in the article cited below (itself a prime example of
+ verbiage).
+
+ [Fordham University student newspaper, "The Observer",
+ 1982-10-06, p6].
+
+ (2011-12-21)
+
+verbiage
+
+ <jargon> {documentation}, especially documentation that is verbose
+ and/or obscure as in the common meaning of the term.
+
+ [{Jargon File}]
+
+ (2011-12-21)
+
+Verdi
+
+ (named after the Italian composer Giuseppe Verdi (1813-1901))
+ Provable systems language. Descendant of Ottawa Euclid.
+
+verification
+
+ The process of determining whether or not the products of a
+ given phase in the life-cycle fulfil a set of established
+ requirements.
+
+Verilog
+
+ <language> A {Hardware Description Language} for electronic
+ design and gate level {simulation} by {Cadence Design
+ Systems}.
+
+ {xnf2ver} is an {XNF} to Verilog translator.
+
+ ["The Verilog Hardware Description Language", Donald E. Thomas
+ & Philip Moorby, Kluwer, 1991].
+
+ (1999-04-16)
+
+Verilog SA
+
+ <company> A French {real-time software engineering} company.
+
+ (1999-04-16)
+
+Veronica
+
+ <information science> Very Easy Rodent-Oriented Net-wide Index
+ to Computerized Archives. Veronica offers a keyword search of
+ most {gopher} menu titles in the entire gopher web. As
+ {archie} is to {FTP} archives, Veronica is to {Gopherspace}.
+ A Veronica search produces a menu of Gopher items, each of
+ which is a direct pointer to a Gopher data source. Because
+ Veronica is accessed through a Gopher Client, it is easy to
+ use, and gives access to all types of data supported by the
+ Gopher {protocol}.
+
+ To try Veronica, select it from the "Other Gophers" menu on
+ Minnesota's gopher server, or point your gopher at:
+
+ Name=veronica (search menu items in most of GopherSpace)
+ Type=1
+ Port=70
+ Path=1/veronica
+ Host=gopher.scs.unr.edu
+
+ {(gopher://gopher.scs.unr.edu/1/veronica)}.
+
+Versa Module Europa
+
+ <hardware> (VME) A flexible open-ended bus system which makes
+ use of the {Eurocard} standard.
+
+ VME was introduced in 1981 by {Motorola}, {Philips},
+ {Thompson}, and {Mostek}. It was intended to be a flexible
+ environment supporting a variety of computing intensive tasks,
+ and has become a rather popular protocol in the computer
+ industry. It is defined by the {IEEE} standard 1014-1987.
+
+ (1997-03-10)
+
+version
+
+ <programming> One of a sequence of copies of a program, each
+ incorporating new modifications. Each version is usually
+ identified by a number, commonly of the form X.Y where X is
+ the major version number and Y is the release number.
+ Typically an increment in X (with Y reset to zero) signifies a
+ substantial increase in the function of the program or a
+ partial or total re-implementation, whereas Y increases each
+ time the progam is changed in any way and re-released.
+
+ Version numbers are useful so that the user can know if the
+ program has changed ({bugs} have been fixed or new functions
+ added) since he obtained his copy and the programmer can tell
+ if a bug report relates to the current version. It is thus
+ always important to state the version when reporting bugs.
+ Statements about compatibility between different software
+ components should always say which versions they apply to.
+
+ See {change management}.
+
+ (1997-12-07)
+
+Version 7
+
+ <operating system> (V7) The unsupported release of {Unix}
+ ancestral to all current commercial versions. {Brian
+ Kernighan} announced the release of V7 in summer 1979, at the
+ {Unix User's} Group meeting in Toronto.
+
+ Before the release of the {POSIX}/{SVID} {standards}, V7's
+ features were often treated as a {Unix} portability baseline.
+ Some old-timers impatient with commercialisation and {kernel
+ bloat} still maintain that V7 was the Last True Unix.
+
+ See {BSD}, {USG Unix}, {System V}.
+
+ [{Jargon File}]
+
+ (1996-05-22)
+
+vertical application
+
+ <application, jargon> An {application program} supporting one
+ specific industry process, e.g. for {e-commerce} purchasing
+ applications, the entire distribution process including order
+ entry, shipping, and customer service.
+
+ Compare {horizontal application}.
+
+ (2000-03-28)
+
+vertical bar
+
+ <character> The character "|", {ASCII} code 124.
+
+ Common names: bar; or; or-bar; v-bar; pipe; vertical bar.
+ Rare: {ITU-T}: vertical line; gozinta; thru; pipesinta;
+ {INTERCAL}: spike.
+
+ "Pipe", "gozinta", "thru" and "pipesinta" refer to the use of
+ "|" in {Unix} shells to create a {pipe}.
+
+ Some keyboards show both a solid vertical bar (code 124) and a
+ broken vertical bar (code 166).
+
+ [Does anyone call either kind of vertical bar "{pling}"?
+ Other codes?]
+
+ (1998-09-20)
+
+vertical encoding
+
+ <processor> An {instruction set} where a field (a bit or group
+ of bits) of the instruction word is decoded (either by
+ {hard-wired} {logic} or {microcode}) to generate signals to
+ control the {functional units}, as opposed to {horizontal
+ encoding} where the instruction word bits are used as the
+ control signals directly.
+
+ With vertical encoding, which combinations of signals and
+ operations are possible is dictated by the decoding logic; the
+ instruction field can only select one of these preprogrammed
+ combinations. This has the advantage that many control
+ signals can be generated based on only a few instruction word
+ bits and only valid combinations of control signals can be
+ generated, e.g. only one source driving a {bus} at once. An
+ {instruction set} may use a mixture of horizontal and vertical
+ encoding within each instruction.
+
+ (1995-04-23)
+
+vertical loop combination
+
+ {fusion}
+
+vertical microcode
+
+ <processor> {Microcode} using {vertical encoding}.
+
+ (1995-04-23)
+
+Vertical Redundancy Check
+
+ <storage, communications> (VRC) An {error checking} method
+ performed on one 8-bit {ASCII} character, where the 8th bit is
+ used as the {parity bit}.
+
+ The resulting parity bit is constructed by {XOR}ing the
+ {word}. The result is a "1" if there is an odd number of 1s,
+ and a "0" if there is an even number of 1s in the word. This
+ method is unreliable because if an odd number of {bits} are
+ distorted, the check will not detect the error. The
+ {Longitudinal Redundancy Check} is an improvement.
+
+ (2001-04-28)
+
+vertical refresh rate
+
+ <hardware> Synonym for {refresh rate}.
+
+ (1996-02-09)
+
+vertical scan rate
+
+ <hardware> Synonym for {refresh rate}.
+
+ (1996-02-09)
+
+Very Efficient Speculative Parallel Architecture
+
+ <project> (VESPA, Portuguese for "wasp") An {Edinburgh
+ University} project using {speculative multithreading} to
+ improve single-application and multiprogramming performance,
+ and to increase {fault tolerance} and reliability. The project
+ aims to develop a compilation environment to generate
+ efficient speculative parallel code, including speculative
+ parallelisation and speculative helper threads. Other
+ research involves the development of optimized thread-level
+ speculative architectures and novel uses of speculative
+ multithreading, such as fault-tolerance.
+
+ {VESPA Home
+ (http://homepages.inf.ed.ac.uk/mc/Projects/VESPA/vespa.html)}.
+
+ (2008-04-04)
+
+Very high bit-rate Digital Subscriber Line
+
+ <communications, protocol> (VDSL) A form of {Digital
+ Subscriber Line} similar to {ADSL} but providing higher speeds
+ at reduced lengths.
+
+ (1998-05-18)
+
+Very Large Database
+
+ <database> (VLDB) A {database} that can use a {Very Large
+ Memory} model to keep as much data as possible in {physical
+ memory}.
+
+ (Oracle
+ {http://oracle.com/platforms/dec/collateral/vlmwp_3.html}).
+
+ (1998-07-07)
+
+Very Large Memory
+
+ <architecture> (VLM) A {processor} and {operating system} that
+ can use more than 4GB of {RAM}, which is the limit for systems
+ using {32-bit} addresses.
+
+ VLM architectures allow {application programs} and {Very Large
+ Databases} with more than 4GB of data to be placed entirely in
+ {physical memory}, with large performance enhancements.
+
+ Some recent processors like the {DEC Alpha} can process 64
+ bits of data at a time and use addresses wider than 32 bits.
+
+ {Digital Unix (http://unix.digital.com/unix/64bit/)}.
+
+ (Solaris {http://sun.com/solaris/64bit.html}).
+
+ (SGI {http://sgi.com/Technology/standard/faq.html}).
+
+ (Unix 98
+ {http://UNIX-systems.org/version2/whatsnew/login_64bit.html}).
+
+ [How wide are the address busses?]
+
+ (1998-07-07)
+
+Very Large Scale Integration
+
+ <hardware> (VLSI) A term describing semiconductor {integrated
+ circuits} composed of hundreds of thousands of {logic elements} or
+ memory cells.
+
+ (1995-01-11)
+
+Very Long Instruction Word
+
+ <language, architecture> (VLIW) Used to describe a {machine
+ code} {instruction set} implemented using {horizontal
+ microcode}. A horizontally encoded instruction word which
+ encodes four or more operations might be considered "very
+ long".
+
+ VLIW architectures are sometimes classified as a type of
+ static {superscalar} architecture. They are static in the
+ sense that which units operate in parallel is determined by
+ the instruction rather than by {dynamic scheduling} at {run
+ time}.
+
+ Producing code for VLIW machines is difficult; {trace
+ scheduling} is a helpful compiler technique.
+
+ The most famous VLIW machine was built by (the late)
+ {Multiflow Computer, Inc.}
+
+ (1994-11-11)
+
+Very Small Aperture Terminal
+
+ <communications> (VSAT) A kind of {ground station} used to
+ contact a communications satellite such as INMARSAT.
+
+ (1995-03-28)
+
+VESA
+
+ {Video Electronics Standards Association}
+
+VESA Local Bus
+
+ <hardware, standard> (VL, VLB) A {local bus} defined by the
+ {Video Electronics Standards Association}, mostly used in
+ {personal computers} based on the {Intel 486}. See also
+ {PCI}.
+
+ (1995-03-31)
+
+VESPA
+
+ {Very Efficient Speculative Parallel Architecture}
+
+V.FAST
+
+ {V.34}
+
+VFAT
+
+ <operating system> A standard developed by {Microsoft} to
+ enable long file names on standard {FAT} {partitions}. VFAT
+ suffers from all the drawbacks of FAT and adds more problems
+ but moving to it is very easy.
+
+ (1996-12-23)
+
+V.FC
+
+ <communications, protocol> A serial line {protocol} supported
+ by some {modems}. Uses {symbol rates} of 2400, 2800, 3000,
+ >3200 and 3429 and up to 28800 {baud}.
+
+ {V.34} modems will also support V.FC if the manufacturer
+ currently supports V.FC.
+
+ The first V.FC modems were shipped in November 1993 and there
+ have been many thousands sold. There will probably be in
+ excess of a million V.FC modems installed by the end of 1994.
+
+ V.FC was intended to take some of the techniques being
+ proposed for V.34 and put them into a real modem that people
+ could use. This also gave a lot of people the opportunity to
+ try out 28.8 kilobit per second operation for the first time.
+ There was never any intention from {Hayes} or {Rockwell} (who
+ worked together for two years on V.FC) that V.FC would be
+ compatible with V.34 - even if they had wanted it, others
+ would have made sure it didn't happen! In fact, they made the
+ start-up deliberately different from V.34 so that it would be
+ easy to distinguish between the two and easier to make
+ dual-mode V.FC/V.34 modems.
+
+ V.FC is quite different from V.34. Most of the
+ signal-processing {algorithms}, whilst based on the same
+ theory, are implemented in different ways. V.34 has some
+ extra things like a {secondary channel} and a special mode for
+ 28.8 kilobit per second fax.
+
+ The Rockwell V.FC implementation uses a single-chip
+ mask-programmed {DSP} for all the signal processing functions.
+ You can also buy a modem controller chip from Rockwell to go
+ with it which implements AT commands, error-control and
+ {compression}. Hayes made their own controller using the
+ {Motorola} {68302} processor. When it comes to an upgrade
+ from V.FC to V.34 you have to have a new, masked DSP chip and
+ new controller {firmware} to implement all the V.34-specific
+ features. This means that Rockwell-DSP based modems must be
+ returned to the manufacturer for upgrade. Upgraded modems
+ will talk to either V.FC or V.34 modems.
+
+vg
+
+ <networking> The {country code} for the British Virgin
+ Islands.
+
+ (1999-01-27)
+
+VGA
+
+ <hardware> {Video Graphics Array} (not "Adapter").
+
+ (1995-11-16)
+
+VGQF
+
+ A query language.
+
+vgrep
+
+ <jargon> /vee'grep/ (Or "optical grep") Visual {grep}.
+ Finding patterns in a file by eye rather than digitally.
+
+ Compare {vdiff}.
+
+ [{Jargon File}]
+
+ (1998-02-06)
+
+VGX
+
+ {Variational Graphics eXtended}
+
+VHDL
+
+ Very High Speed Integrated Circuit (VHSIC) Hardware
+ Description Language. A large high-level {VLSI} design
+ language with Ada-like syntax. The DoD standard for hardware
+ description, now standardised as IEEE 1076.
+
+ ["VHSIC Hardware Description Language", M.R. Shahdad et al,
+ IEEE Computer 18(2):94-103 (Feb 1985)].
+
+VHE
+
+ {Virtual Home Environment}
+
+VHLL
+
+ Very-{High-Level Language}.
+
+ A {bondage-and-discipline language} that the speaker happens
+ to like; {Prolog} and Backus's {FP} are often called VHLLs.
+
+ (1994-12-07)
+
+vhost
+
+ {virtual host}
+
+VHS
+
+ 1. {Very High Speed}.
+
+ 2. {storage} Video Home System.
+
+ JVC's video cassette format.
+
+ 3. {Virtual Host Storage}.
+
+vi
+
+ 1. <tool> {Visual Interface}.
+
+ 2. <networking> The {country code} for the U. S. Virgin
+ Islands.
+
+ [{Jargon File}]
+
+ (1999-01-27)
+
+VIC-20
+
+ <computer> A home computer made by {Commodore} with a {6502}
+ {CPU}, similar in style to the {Commodore 64} and {Commodore
+ C16}. The VIC-20 was released before the C64, and after the
+ {Commodore PET}(?). It was intended to be more of a low-end
+ home computer than the PET.
+
+ The VIC-20 had connectors for game cartridges and a {tape
+ drive} (compatible with a C64). It came with five {kilobytes}
+ of {RAM}, but 1.5 KB were used by the system for various
+ things, like the video display (which had an unusual 22x20
+ char/line screen layout), and other dynamic aspects of the
+ {operating system} (such as it was). The RAM was expandable
+ with a plug-in cartridge which used the same expansion port as
+ games. Port expander boxes were available to allow more than
+ one cartridge to be connected at a time.
+
+ RAM cartridges were available in several sizes: 3K, 8K, 16K
+ and 32K. The internal memory map was re-organised with the
+ addition of each size cartridge, leading to the situation that
+ some programs would only work if the right amount of memory
+ was available. The 32K cartridges were all third-party and
+ had switches to allow the RAM to be enabled in sections so
+ that any expansion size could be achieved.
+
+ {BASIC} programs could use at most 24 KB of RAM. Any extra
+ occupied the location usually used by ROM cartridges
+ (i.e. games). This allowed people to copy ROM cartridges to
+ tape and distribute them to their friends, who could load the
+ tape into the top 8k of their 32k RAM packs.
+
+ The name "VIC" came from the Video Interface Chip that was
+ also used in the other, later, Commodore 8-bit computers.
+
+ (2000-03-28)
+
+victim cache
+
+ <architecture> An extension to a {direct mapped cache} that
+ adds a small, secondary, {fully associative cache} to store
+ cache blocks that have been ejected from the main cache due to
+ a capacity or conflict miss. These ejected blocks are likely
+ to be needed again so storing them in the secondary cache
+ should increase performance.
+
+ Victim caches with as few as five places have been found to
+ reduce conflict misses, especially for small, direct-mapped
+ data caches. E.g. a four-place victim cache removed 20% to
+ 95% (depending on program) of such misses in a 4-KB cache.
+
+ {(http://www.scism.sbu.ac.uk/ccsv/josephmb/CS-L2-MT/week12.html)}.
+
+ (2007-02-23)
+
+video
+
+ <graphics> Moving images presented as a sequence of {static
+ images} (called "frames") representing snapshots of the scene,
+ taken at regularly spaced time intervals, e.g. 50 frames per
+ second. Apart from the frame rate, other important properties
+ of a video are the {resolution} and {colour depth} of the
+ individual images.
+
+ Digital video data is typically stored and transmitted in a
+ format like {MPEG} or {H.264} that includes synchoronised
+ {sound}.
+
+ Unlike broadcast {television}, digital video on a computer or
+ network uses {compression}. Compression is even more
+ important for video that for static images due to the large
+ amount of data involved in even a short video. Furthermore,
+ compression allows video to be transmitted via a channel whose
+ bandwidth is less than the raw data rate implied by the
+ resolution and frame rate. This allows the recipient to start
+ displaying the video before the transmission is complete, a
+ process known as {streaming}.
+
+ Compression can be relatively slow but decompression is done
+ in {real-time} with the picture quality and {frame rate}
+ varying with the processing power available and the size and
+ scaling of the picture.
+
+ There are many types of software for displaying video on
+ computers including {Windows Media Player} from {Microsoft},
+ {QuickTime} from {Apple Computer}, {DivX}, {VLC}, {RealPlayer}
+ and {Acorn Computers}' {Replay}.
+
+ (2011-01-04)
+
+video adapter
+
+ {graphics adaptor}
+
+video card
+
+ {graphics adaptor}
+
+Video Compact Disc
+
+ <storage> (VCD) A storage format used for film distribution.
+
+ [Details? Relationship to audio CD?]
+
+ (2004-02-15)
+
+video compression
+
+ {Compression} of sequences of images. Video compression
+ {algorithms} use the fact that there are usually only small
+ changes from one "frame" to the next so they only need to
+ encode the starting frame and a sequence of differences
+ between frames. This is known as "inter-frame coding" or "3D
+ coding".
+
+ {MPEG} is a committee producing {standards} in this area and
+ also the name of their standard {algorithm}. {H.261} is
+ another standard.
+
+ See also {Integrated Information Technology}, {3DO},
+ {full-motion video}, {Online Media}.
+
+video conference
+
+ An instance of {video conferencing}.
+
+video conferencing
+
+ <communications> A discussion between two or more groups of
+ people who are in different places but can see and hear each
+ other using electronic communications. Pictures and sound are
+ carried by the telecommunication network and such conferences
+ can take place across the world.
+
+ To overcome the {bandwidth} and {latency} limitations of
+ current networks (especially the {PSTN}), some form of {video
+ compression} is often used.
+
+ (1995-05-01)
+
+video dial tone
+
+ <communications> A means by which telephone companies can
+ deliver "television" programs on a {common carrier} basis and,
+ by law, provide equal access to all.
+
+ [What does this mean?]
+
+ (1996-12-01)
+
+video display standard
+
+ {display standard}
+
+video display terminal
+
+ {visual display unit}
+
+Video Electronics Standards Association
+
+ <body, standard> (VESA) An industry {standards} organisation
+ created in 1989 or 1990 mostly(?) concerned with {IBM}
+ compatible {personal computers}. The first standard it
+ created was the 800 x 600 pixel {Super VGA} (SVGA) display and
+ its software interface. It also defined the {VESA Local Bus}
+ (VLB).
+
+ See also {PCI}.
+
+ {(http://vesa.org/)}.
+
+ (1995-11-16)
+
+Video Graphics Adapter
+
+ {Video Graphics Array}
+
+Video Graphics Adaptor
+
+ {Video Graphics Array}
+
+Video Graphics Array
+
+ <hardware> (VGA) A {display standard} for {IBM PCs}, with 640
+ x 480 {pixels} in 16 colours and a 4:3 {aspect ratio}. There
+ is also a text mode with 720 x 400 pixels.
+
+ IBM technical references define the *product name* of their
+ original VGA display board as "Video Graphics Array", in
+ contrast to the preceding boards, the "{Color Graphics
+ Adapter}" (CGA) and "{Enhanced Graphics Adapter}" (EGA).
+
+ See also {Super Video Graphics Adapter}.
+
+ (1995-01-12)
+
+video memory
+
+ <storage> The memory in a computer's {graphics adaptor}, used
+ to store the image displayed on a {bitmap display}. Often
+ this is built using {VRAM} chips. There is normally a simple
+ correspondence between groups of {bits} in video memory and
+ the dots or "{pixels}" on the screen, such that writing to a
+ given group of bits will alter the appearance of a single dot.
+ If each pixel corresponds to eight bits then it can have any
+ of 256 colours (or shades of grey on a monochrome display).
+
+ The video display electronics is responsible for reading the
+ data from video memory and converting it into the necessary
+ signals to drive the display. Often this includes a {colour
+ palette} which converts pixel values into {RGB} triplets.
+
+ (1996-11-01)
+
+Video on Demand
+
+ <communications> (VoD) A planned system using {video
+ compression} to supply programs to viewers when requested, via
+ {ISDN} or cable.
+
+ (1994-11-02)
+
+video RAM
+
+ {video random-access memory}
+
+video random-access memory
+
+ <hardware> (VRAM) Fast memory designed for storing the image
+ to be displayed on a computer's {monitor}. VRAM may be built
+ from special memory {integrated circuits} designed to be
+ accessed sequentially.
+
+ VRAM must be fast enough to supply data to the display
+ electronics at the speed at which the screen is scanned. Thus
+ for example, for a {resolution} of 1280x1024 eight-bit
+ {pixels} at a {refresh rate} of 70 Hz, the {video memory}
+ would need to supply 1280x1024x70 = 90 Mbyte/s or one byte
+ every 11 ns. The VRAM may be {dual ported} in order to allow
+ the display electronics and the {CPU} to access it at the same
+ time.
+
+ In an {IBM PC} the VRAM is located on the display interface
+ card and 0.5 - 2 MB is typical.
+
+ {A VRAM Song (http://fweep.com/vram.html)}!
+
+ (2001-02-14)
+
+video terminal
+
+ {visual display unit}
+
+videotex
+
+ An obsolete electronic service offering people the privilege
+ of paying to read the weather on their television screens
+ instead of having somebody read it to them for free while they
+ brush their teeth. The idea bombed everywhere it wasn't
+ government-subsidised, because by the time videotex was
+ practical the installed base of personal computers could hook
+ up to {time-sharing} services and do the things for which
+ videotex might have been worthwhile better and cheaper.
+ Videotex planners badly overestimated both the appeal of
+ getting information from a computer and the cost of local
+ intelligence at the user's end. Like the {gorilla arm}
+ effect, this has been a cautionary tale to hackers ever since.
+ See also {vannevar}.
+
+ [{Jargon File}]
+
+Vienna Definition Language
+
+ (VDL) IBM Vienna Labs. A language for formal, algebraic
+ definition via operational semantics. Used to specify the
+ semantics of PL/I. See also {VDM}.
+
+ ["The Vienna Definition Language", P. Wegner, ACM Comp Surveys
+ 4(1):5-63 (Mar 1972)].
+
+Vienna Definition Method
+
+ {Vienna Development Method}
+
+Vienna Development Method
+
+ <programming, specification> (VDM) A program development
+ method based on formal specification using the {Vienna
+ Development Method Specification Language} (VDM-SL).
+
+ [Details?]
+
+ [Is there such a thing as "Vienna Definition Method"?]
+
+ (2000-11-02)
+
+Vienna Development Method Specification Language
+
+ <programming, specification> (VDM-SL, Meta-IV) A
+ model-oriented {specification language}, upon which the
+ {Vienna Development Method} is based. An {ISO} draft was
+ released in April 1993.
+
+ Version: BSI/VDM.
+
+ {(ftp://gateway.dec.com/pub/vdmsl_standard)}.
+
+ ["The Vienna Development Method: The Meta-Language",
+ D. Bjorner et al eds, LNCS 61, Springer 1978].
+
+ ["The VDM-SL Reference Guide", J. Dawes, Pitman 1991].
+
+ ["Systematic Software Development Using VDM", C.B. Jones, P-H
+ 1989].
+
+ (2000-11-02)
+
+Vienna Fortran
+
+ A {data-parallel} extension of {Fortran 77} for distributed
+ memory multiprocessors by Hans Zima
+ <zima@sophie.par.univie.ac.at>, Vienna University.
+
+ ["Programming In Vienna Fortran", B. Chapman et al, Scientific
+ Programming 1(1):31-50 (Aug 1992)].
+
+Vietnamese
+
+ <human language> An Asian language that, like other {CJKV}
+ languages, requires 16-bit {character encodings} but, unlike
+ them, does not use {Han characters}.
+
+ While normal Vietnamese has not used Han characters since the
+ 18th century, the {standards} {TCVN 5773} and {TCVN 6056}
+ contain Han characters and may be used by computers and
+ academics.
+
+ (2001-01-01)
+
+viewer
+
+ <tool> A program to allow a file to be read (or played) but
+ not changed. Viewers are often freely distributable, even
+ when the editor application is not. This allows you to create
+ files with the editor and make the viewer available to other
+ users to view your files, e.g. on a {website}. Examples
+ include the Word and Adobe Acrobat viewers.
+
+ (1997-08-29)
+
+ViewPoints
+
+ <programming> A framework for distributed and {concurrent}
+ software engineering which provides an alternative approach to
+ traditional centralised software development environments.
+
+ Decentralised process models are used to drive consistency
+ checking and conflict resolution. The process models use
+ pattern matching on local development histories to determine
+ the particular state of the development process, and employ
+ rules to trigger situation-dependent assistance to the user.
+ Communication between such process models facilitates the
+ decentralised management of explicitly defined consistency
+ constraints.
+
+ [Ulf Leonhardt]
+
+ (1995-03-27)
+
+Views
+
+ A Smalltalk extension for computer algebra. "An Object
+ Oriented Approach to Algebra System Design", K. Abdali et al,
+ in Symp Symb Alg Manip, ACM 1986, pp.24-30.
+
+VIF
+
+ VHDL Interface Format. Intermediate language used by the
+ Vantage VHDL compiler. "A VHDL Compiler Based on Attribute
+ Grammar Methodology", R. Farrow et al, SIGPLAN NOtices
+ 24(7):120-130 (Jul 1989).
+
+Vi Improved
+
+ <text, tool> (VIM) (Previously "vi iMitation"), An improved
+ version of {vi}, available for many {platforms}. VIM allows
+ multiscreen editing, more flexible insert/command {mode}
+ handling, better {C} indentation and much more.
+
+ {(http://vim.org/)}.
+
+ (1999-06-15)
+
+VIM
+
+ 1. <messaging> {Vendor Independent Messaging}.
+
+ 2. <text, tool> {Vi Improved}.
+
+ (1999-06-15)
+
+Vincennes LISP
+
+ <language> (VLISP) A dialect of {Lisp} resulting from
+ development, starting in 1971, of {Lisp} {interpreters} and
+ {compilers} at the {University of Paris VIII - Vincennes}.
+ VLISP interpreters and compilers were designed to run on small
+ computers.
+
+ {Documentation
+ (http://www.artinfo-musinfo.org/en/issues/vlisp/)}.
+
+ {History of Lisp
+ (http://www.softwarepreservation.org/projects/LISP/index.html#VLISP_)}.
+
+ [Relationship to {VLISP} by Greussay at Paris VI?]
+
+ (2008-03-16)
+
+vines
+
+ <networking, product> A family of {local area network}ing
+ products from {Banyan}.
+
+ (1995-03-01)
+
+Vine Technology
+
+ <company> A company which provides professional consulting
+ services in the areas of networking, real-time systems,
+ graphic arts, and {web} server advertisement space.
+
+ {(http://vine.com/)}.
+
+ E-mail: <webmaster@vine.com>.
+
+ (1995-03-03)
+
+Vint Cerf
+
+ <person> (Vinton G. Cerf) The co-inventor with {Bob Kahn} of
+ the {Internet} and its base {protocol}, {TCP/IP}. Like {Jon
+ Postel}, he was crucial in the development of many
+ higher-level protocols, and has written several dozen {RFCs}
+ since the late 1960s.
+
+ Vinton Cerf is senior vice president of Internet Architecture
+ and Technology for {MCI WorldCom}. His team of architects and
+ engineers design advanced Internet frameworks for delivering a
+ combination of data, information, voice and video services for
+ business and consumer use.
+
+ In December 1997, President Clinton presented the U.S.
+ National Medal of Technology to Cerf and his partner, Robert
+ E. Kahn, for founding and developing the Internet.
+
+ Prior to rejoining MCI in 1994, Cerf was vice president of the
+ Corporation for National Research Initiatives (CNRI). As vice
+ president of MCI Digital Information Services from 1982-1986,
+ he led the engineering of {MCI Mail}, the first commercial
+ e-mail service to be connected to the Internet.
+
+ During his tenure from 1976-1982 with the U.S. Department of
+ {Defense Advanced Research Projects Agency} (DARPA), Cerf
+ played a key role leading the development of Internet and
+ Internet-related data packet and security technologies.
+
+ Cerf served as founding president of the {Internet Society}
+ from 1992-1995 and is currently chairman of the Board. Cerf
+ is a member of the U.S. Presidential Information Technology
+ Advisory Committee (PITAC) and the Advisory Committee for
+ Telecommunications (ACT) in Ireland.
+
+ Cerf is a recipient of numerous awards and commendations in
+ connection with his work on the Internet. In December 1994,
+ People magazine identified Cerf as one of that year's "25 Most
+ Intriguing People."
+
+ In addition to his work on behalf of MCI and the Internet,
+ Cerf serves as technical advisor to production for "Gene
+ Roddenberry's Earth: Final Conflict," the number one
+ television show in first-run syndication. He also made a
+ special guest appearance in May 1998. Cerf also holds an
+ appointment as distinguished visiting scientist at the Jet
+ Propulsion Laboratory where he is working on the design of an
+ interplanetary Internet.
+
+ Cerf holds a Bachelor of Science degree in Mathematics from
+ Stanford University and Master of Science and Ph.D. degrees in
+ Computer Science from UCLA. He also holds honorary Doctorate
+ degrees from the Swiss Federal Institute of Technology,
+ Zurich; Lulea University of Technology, Sweden; University of
+ the Balearic Islands, Palma; Capitol College and Gettysburg
+ College.
+
+ {(http://mci.com/cerfsup/)}.
+
+ (1999-02-25)
+
+Vinton Cerf
+
+ {Vint Cerf}
+
+Viola
+
+ An experimental {hypercard}-like interpreted {hypertext}
+ system by Pei Y. Wei of {Berkeley}.
+
+ (1994-11-30)
+
+virgin
+
+ Unused; pristine; in a known initial state. "Let's bring up a
+ virgin system and see if it crashes again." (Especially
+ useful after contracting a {virus} through {SEX}.) Also, by
+ extension, buffers and the like within a program that have not
+ yet been used.
+
+ [{Jargon File}]
+
+ (1994-11-30)
+
+virgule
+
+ <character> Rare, and ambiguous: {slash} or {comma}.
+
+ "Virgule" (or rather, Latin "virgula", meaning "little rod"
+ or, vividly enough, "little penis") was the name of a
+ punctuation character shaped like a small {slash} and used in
+ the Latin writing system much like a modern {comma} -- hence
+ the ambiguity of this term in modern English.
+
+ Compare French "virgule" and Italian "virgola", meaning
+ "comma" (not "slash"); Italian "doppia virgola" and
+ "virgoletta", both meaning "{double quote}".
+
+ (1997-04-08)
+
+Viron
+
+ ["Five Paradigm Shifts in Programming Language Design and
+ Their Realisation in Viron, a Dataflow Programming
+ Environment", V. Pratt, 10th POPL, ACM 1983, pp. 1-9].
+
+ (1994-11-30)
+
+virtual
+
+ <jargon, architecture> (Via the technical term {virtual
+ memory}, probably from the term "virtual image" in optics)
+ 1. Common alternative to {logical}; often used to refer to the
+ artificial objects (like addressable {virtual memory} larger
+ than physical memory) created by a computer system to help the
+ system control access to shared resources.
+
+ 2. Simulated; performing the functions of something that isn't
+ really there. An imaginative child's doll may be a virtual
+ playmate.
+
+ Opposite of {real} or physical.
+
+ [{Jargon File}]
+
+ (1994-11-30)
+
+virtual 86 mode
+
+ <processor, programming> (Or "virtual mode" or "virtual 8086
+ mode") An operating mode provided by the {Intel 80386} and
+ later processors to allow {real mode} programs to run under
+ {operating systems} which use {protected mode}. In this
+ sub-mode of protected mode, an operating environment is
+ created which mimics the address calculation in real mode.
+
+ In virtual 86 mode the segment {MMU} is practically turned off
+ and the {segment registers} exhibit the same behaviour as in
+ real mode. The {page}d MMU, however, still operates. This
+ means that the one megabyte {address space} of real mode can
+ be remapped in four kilobyte {pages} to anywhere in the 32 bit
+ {physical address} space. Each page can be protected
+ separately from read or write accesses.
+
+ Virtual mode is handled on a per-task-basis, so each
+ {exception} (from protection violations or {interrupts})
+ switches the processor back into protected mode. It is
+ therefore possible to have multiple tasks in virtual mode
+ which run {concurrent}ly under the control of an operating
+ system which runs in protected mode.
+
+ Most operating system services in {MS-DOS} systems are called
+ by {software interrupts}, which are a kind of exception. If
+ an MS-DOS application runs in virtual mode under the control
+ of a protected mode operating system, each call to MS-DOS
+ causes a switch to protected mode. The operating system
+ emulates the MS-DOS service and switches back to the
+ application in virtual mode. From the viewpoint of the
+ application nothing differs from real mode.
+
+ {Microsoft Windows}, {Windows NT}, and {OS/2} use this feature
+ to implement "DOS-boxes" in which both MS-DOS and real mode
+ {application programs} can run.
+
+virtual address
+
+ 1. <architecture> A memory location accessed by an
+ {application program} in a system with {virtual memory} such
+ that intervening hardware and/or software maps the virtual
+ address to real ({physical}) memory. During the course of
+ execution of an application, the same virtual address may be
+ mapped to many different {physical addresses} as data and
+ programs are {paged out} and {paged in} to other locations.
+
+ 2. In {IBM}'s {VM} {operating system}, {Virtual Device
+ Location}.
+
+ (2001-01-02)
+
+virtual cache
+
+ A {cache} which uses {virtual address}, i.e. it is between the
+ processor and the {memory management unit}. A virtual cache
+ cannot recognise external access to physical address, e.g. from
+ {DMA}. The whole cache must be flushed when swapping between
+ tasks which share same virtual {address space}.
+
+ (1994-11-30)
+
+virtual circuit
+
+ <networking> A {connection-oriented} {network} service which
+ is implemented on top of a network which may be either
+ connection-oriented or {connectionless} ({packet switching}).
+
+ The term "switched virtual circuit" was coined needlessly to
+ distinguish an ordinary virtual circuit from a {permanent
+ virtual circuit}. (One of the perpetrators of this confusion
+ appears to be ["Networking Essentials", 1996, Microsoft Press,
+ ISBN 1-55615-806-8], a book aimed at people preparing for the
+ {MCSE} exam on {LANs} and {WANs}).
+
+ Not to be confused with {switched virtual connection}.
+
+ (2001-10-26)
+
+Virtual Circuit Identifier
+
+ <networking> (VCID) An identifier used for the {routing} of a
+ {virtual circuit}. An {ATM} {switch} may route according to a
+ Virtual Circuit Identifier, a {Virtual Path Identifier}, or a
+ combination.
+
+ (2001-05-16)
+
+virtual connection
+
+ <networking> 1. (VC) A connection or a path through an {ATM}
+ network. The word "{virtual}" indicates that the connection
+ is {logical} rather than {physical}.
+
+ Nothing to do with a {virtual circuit} on a {packet switching}
+ network.
+
+ [Fred Halsall, "Data Communications, Computer Networks and
+ Open Systems", 1996, Addison Wesley].
+
+ 2. A communications link that appears to be a direct
+ connection between sender and receiver, although physically
+ the link can be routed through a more circuitous path, running
+ over {virtual circuits} instead of a private network built
+ primarily with {dedicated lines}.
+
+ A virtual connection can provide full-time connection among
+ many sites, including those configured for {SNA}/{SDLC}
+ {protocol}. A virtual connection can handle any transmission
+ protocol and is supported worldwide. It can provide high
+ throughput and low delay for {LAN} and {Internet}
+ applications, peer-to-peer connectivity, client-server
+ computing, and other distributed processing applications.
+
+ [Same as {virtual circuit}?]
+
+ (2001-10-26)
+
+Virtual Control Program Interface
+
+ (VCPI) An alternative, and incompatible method for doing the
+ same thing as {DOS Protected Mode Interface} (DPMI).
+
+ (1995-01-12)
+
+Virtual Device Driver
+
+ <operating system> (VxD) A {device driver} under {Windows
+ 3.x}/{Windows 95} running as part of the {kernel} and thus
+ having access to the memory of the kernel and all running
+ processes as well as raw access to the hardware. VxD's
+ usually have the {filename extension} .386 under Windows 3.x
+ and .vxd under Windows 95. VxD's written for Windows 3.x can
+ be used under Windows 95 but not vice versa.
+
+ (1997-02-27)
+
+Virtual Device Location
+
+ (Or "Virtual Address") The address of a device (e.g. disk,
+ printer, terminal) belonging to a "guest" {operating system}.
+ Such an address is mapped to a physical device. VM may remap
+ several virtual disks to different parts of a single physical
+ disk.
+
+ (1995-02-22)
+
+virtual disk
+
+ {RAM disk}
+
+Virtual Home Environment
+
+ (VHE) A tool for using {NFS} on {HP UX}.
+
+ (1994-12-07)
+
+virtual host
+
+ <networking> Most computers on the {Internet} have a single
+ {IP address}; however, often via special {kernel}
+ patches, a given computer can be made to respond to several
+ {IP} addresses and provide different {services} (typically
+ different {Web} services) on each. Each of these different IP
+ addresess (which generally each have their own {hostname}) act
+ as if they were distinct hosts on distinct machines, even
+ though they are actually all one host. Hence, they are
+ {virtual} hosts. A common use is when an {Internet Service
+ Provider} "hosts" {web} or other services for
+ several of their customers on one computer but giving the
+ appearence that they are separate servers.
+
+ (1997-09-11)
+
+Virtual LAN
+
+ <networking> Software defined groups of {host} on a {local
+ area network} (LAN) that communicate as if they were on the
+ same wire, even though they are physically on different {LAN
+ segments} throughout a site. To define a virtual LAN, the
+ {network administrator} uses a virtual LAN management utility
+ to establish membersip rules that determine which hostss are
+ in a specific virtual LAN. Many models may exist but two seem
+ to dominate:
+
+ (1) Vitual Segment (or Port-Group) Virtual LAN. These are
+ switched at the {data link layer} ({OSI} layer 2). Virtual
+ segments turn an arbitrary number of physical segments into a
+ single virtual segment that funtions as a self-contained
+ traffic domain.
+
+ (2) Virtual Subnet Virtual LAN: These are switched at the
+ {Network Layer} ({OSI} layer 3). Subnet-oriented virtual LANs
+ are based on {subnet address}es used by {IP}, {IPX}, and other
+ {network layer} {protocols} to normally identify physical
+ networks. Administrators assign one subnet address to a
+ number of switch {ports} (which may be on different switches
+ and over a backbone). Once identified as a virtual subnet,
+ the selected LANs function as a {bridge group} - traffic is
+ bridged at Layer 2 within the virtual subnet and routed at
+ Layer 3 between virtual subnets.
+
+ ["The many faces of virtual LANs", Steven King, Network
+ World, 1994/5?].
+
+ (1995-04-03)
+
+Virtual Loadable Module
+
+ <networking> (VLM) {Novell}'s term for software modules that
+ can be dynamically loaded to extend the functionality of the
+ "VLM" {NetWare Requester} for {MS-DOS} that became standard
+ beginning with {Novell NetWare} 4.
+
+ (1995-01-11)
+
+Virtual Local Area Network
+
+ <networking> (VLAN) A logical grouping of two or more {nodes}
+ which are not necessarily on the same physical {network
+ segment} but which share the same {IP} {network number}. This
+ is often associated with {switched Ethernet}.
+
+ IEEE 802.1Q is a VLAN standard.
+
+ [Confirm? Better description? Reference?]
+
+ (2002-08-30)
+
+Virtual Machine
+
+ <operating system> (VM) An {IBM} pseudo-{operating system}
+ {hypervisor} running on {IBM 370}, {ESA} and {IBM 390}
+ architecture computers.
+
+ VM comprises CP ({Control Program}) and CMS ({Conversational
+ Monitor System}) providing Hypervisor and personal computing
+ environments respectively. VM became most used in the early
+ 1980s as a Hypervisor for multiple {DOS/VS} and {DOS/VSE}
+ systems and as IBM's internal operating system of choice. It
+ declined rapidly following widespread adoption of the {IBM PC}
+ and hardware partitioning in {microcode} on IBM {mainframes}
+ after the {IBM 3090}.
+
+ VM has been known as VM/SP (System Product, the successor to
+ {CP/67}), VM/XA, and currently as VM/ESA (Enterprise Systems
+ Architecture). VM/ESA is still in used in 1999, featuring a
+ {web} interface, {Java}, and {DB2}. It is still a major IBM
+ operating system.
+
+ {(http://vmdev.gpl.ibm.com/)}.
+
+ ["History of VM"(?), Melinda Varian, Princeton University].
+
+ (1999-10-31)
+
+virtual machine
+
+ 1. An {abstract machine} for which an {interpreter} exists.
+ Virtual machines are often used in the implementation of
+ portable executors for {high-level languages}. The HLL is
+ compiled into code for the virtual machine (an {intermediate
+ language}) which is then executed by an {interpreter} written
+ in {assembly language} or some other portable language like
+ {C}.
+
+ Examples are {Core War}, {Java Virtual Machine}, {OCODE},
+ {OS/2}, {POPLOG}, {Portable Scheme Interpreter}, {Portable
+ Standard Lisp}, {Parallel Virtual Machine}, {Sequential Parlog
+ Machine}, {SNOBOL Implementation Language}, {SODA},
+ {Smalltalk}.
+
+ 2. A software emulation of a physical computing environment.
+
+ The term gave rise to the name of {IBM}'s {VM} {operating
+ system} whose task is to provide one or more simultaneous
+ execution environments in which operating systems or other
+ programs may execute as though they were running "on the bare
+ iron", that is, without an eveloping Control Program. A major
+ use of VM is the running of both outdated and current versions
+ of the same operating system on a single {CPU} complex for the
+ purpose of system migration, thereby obviating the need for a
+ second processor.
+
+ (2002-04-15)
+
+Virtual Machine/Conversational Monitor System
+
+ <operating system> (VM/CMS) An {IBM} {time-sharing} and
+ personal computing environment executing under {Virtual
+ Machine} (VM) in a virtual machine environment. VM/CMS is
+ designed to support large numbers of {interactive} users. It
+ relies on numerous {APIs} into the {Control Program} (CP) to
+ provide very efficient single-user processing
+
+ VM/CMS was only adopted some time after the original design of
+ {Virtual Machine} as a more efficient personal computing
+ environment than {MVS/TSO}.
+
+ (1999-01-19)
+
+Virtual Machine Environment
+
+ <operating system> (VME) {ICL}'s {mainframe} {operating
+ system}.
+
+ (1995-06-28)
+
+Virtual Machine/ESA
+
+ {Virtual Machine}
+
+Virtual Machine/System Product
+
+ {Virtual Machine}
+
+Virtual Machine/XA
+
+ {Virtual Machine}
+
+virtual memory
+
+ <memory management> A system allowing a computer program to
+ behave as though the computer's memory was larger than the
+ actual {physical} {RAM}. The excess is stored on {hard disk}
+ and copied to RAM as required.
+
+ Virtual memory is usually much larger than physical memory,
+ making it possible to run programs for which the total code
+ plus data size is greater than the amount of RAM available.
+ This is known as "{demand paged} virtual memory". A page is
+ copied from disk to RAM ("paged in") when an attempt is made
+ to access it and it is not already present. This paging is
+ performed automatically by collaboration between the {CPU},
+ the {memory management unit} (MMU), and the {operating system}
+ {kernel}. The program is unaware of virtual memory, it just
+ sees a large {address space}, only part of which corresponds
+ to physical memory at any instant.
+
+ The virtual {address space} is divided into {pages}. Each
+ {virtual address} output by the {CPU} is split into a
+ (virtual) {page} number (the most significant bits) and an
+ offset within the page (the N least significant bits). Each
+ page thus contains 2^N {bytes} (or whatever the unit of
+ addressing is). The offset is left unchanged and the {memory
+ management unit} (MMU) maps the virtual page number to a
+ {physical} page number. This is recombined with the offset to
+ give a {physical address} - a location in {physical memory}
+ ({RAM}).
+
+ The performance of a program will depend dramatically on how
+ its memory access pattern interacts with the paging scheme.
+ If accesses exhibit a lot of {locality of reference},
+ i.e. each access tends to be close to previous accesses, the
+ performance will be better than if accesses are randomly
+ distributed over the program's {address space} thus requiring
+ more paging.
+
+ In a {multitasking} system, physical memory may contain pages
+ belonging to several programs. Without {demand paging}, an OS
+ would need to allocate physical memory for the whole of every
+ active program and its data. Such a system might still use an
+ {MMU} so that each program could be located at the same
+ {virtual address} and not require run-time relocation. Thus
+ virtual addressing does not necessarily imply the existence of
+ virtual memory. Similarly, a {multitasking} system might load
+ the whole program and its data into physical memory when it is
+ to be executed and copy it all out to disk when its
+ {timeslice} expired. Such "swapping" does not imply virtual
+ memory and is less efficient than paging.
+
+ Some {application programs} implement virtual memory wholly in
+ software, by translating every virtual memory access into a
+ file access, but efficient virtual memory requires hardware
+ and operating system support.
+
+ (2002-11-26)
+
+Virtual Memory System
+
+ <operating system> (VMS) {DEC}'s proprietary {operating
+ system} originally produced for its {VAX} {minicomputer}.
+
+ VMS V1 was released in August 1978. VMS was renamed "OpenVMS"
+ around version 5.5. The first version of VMS on {DEC Alpha}
+ was known as OpenVMS for AXP V1.0, and the correct way to
+ refer to the operating system now is OpenVMS for VAX or
+ OpenVMS for Alpha. The renaming also signified the fact that
+ the {X/Open} consortium had certified OpenVMS as having a high
+ support for {POSIX} standards.
+
+ VMS is one of the most secure operating systems on the market
+ (making it popular in financial institutions). It currently
+ (October 1997) has the best {clustering} capability (both
+ number and distance) and is very scalable with {binaries}
+ portable from small desktop {workstations} up to huge
+ {mainframes}.
+
+ Many {Unix} fans generously concede that VMS would probably be
+ the {hacker}'s favourite commercial OS if Unix didn't exist;
+ though true, this makes VMS fans furious.
+
+ {FAQ
+ (http://cis.ohio-state.edu/hypertext/faq/bngusenet/comp/os/vms/top.html)}.
+
+ {Usenet} newsgroup: {news:comp.os.vms}.
+
+ [How does its performance compare with other OSes?]
+
+ (1999-06-03)
+
+virtual path
+
+ <networking> The location of a file or directory on a
+ particular {server}, as seen by a remote {client} accessing it
+ via {web} (or similar distributed document
+ service).
+
+ A virtual path provides access to files outside the default
+ directory and subdirectories. It appears in the form
+ ".../~name/..." where "~name" is replaced with actual path
+ configured by the administrator. An {access control list} can
+ be associated with a virtual path.
+
+ (1995-04-13)
+
+virtual point of presence
+
+ (virtual PoP) A point, via which users can connect to an
+ {Internet access provider}, which is not operated by the
+ provider. The user is charged by the telephone company for
+ the call to the virtual point of presence which relays his
+ call via some third party circuit to the Internet provider's
+ central location. This is in contrast to a physical {point of
+ presence} (PoP) which is operated by the Internet provider
+ themselves. The advantage of a virtual PoP is that the
+ provider can keep all their {modems} in one location, thus
+ improving availability and maintenance, but users do not have
+ to pay long-distance call charges to that point.
+
+ (1994-12-13)
+
+virtual PoP
+
+ {virtual point of presence}
+
+Virtual Private Network
+
+ <networking, security> (VPN) The use of {encryption} in the
+ lower {protocol layers} to provide a secure connection through
+ an otherwise insecure network, typically the {Internet}. VPNs
+ are generally cheaper than real private networks using private
+ lines but rely on having the same encryption system at both
+ ends. The encryption may be performed by {firewall} software
+ or possibly by {routers}.
+
+ Link-level (layer 2 and 3) encryption provides extra
+ protection by encrypting all of each {datagram} except the
+ link-level information. This prevents a listener from
+ obtaining information about network structure. While
+ link-level encryption prevents traffic analysis (a form of
+ attack), it must encrypt/decrypt on every {hop} and every
+ path.
+
+ Protocol-level encryption (layer 3 and 4) encryption encrypts
+ protocol data but leaves protocol and link headers clear.
+ While protocol-level encryption requires you to
+ encrypt/decrypt data only once, and it encrypts/decrypts only
+ those sessions that need it, headers are sent as clear text,
+ allowing traffic analysis.
+
+ Application (layer 5 up) encryption is based on a particular
+ application and requires that the application be modified to
+ incorporate encryption.
+
+ {Cisco
+ (http://cisco.com/univercd/cc/td/doc/product/lan/cat5000/cnfg_nts/rsm/rsm_pa/4801encr.htm)}.
+
+ (1999-11-15)
+
+virtual reality
+
+ (VR)
+
+ 1. <application> Computer simulations that use 3D graphics and
+ devices such as the {data glove} to allow the user to interact
+ with the simulation.
+
+ 2. <games> A form of network interaction incorporating aspects
+ of role-playing games, interactive theater, improvisational
+ comedy, and "true confessions" magazines. In a virtual
+ reality forum (such as {Usenet}'s {news:alt.callahans}
+ newsgroup or the {MUD} experiments on {Internet} and
+ elsewhere), interaction between the participants is written
+ like a shared novel complete with scenery, "foreground
+ characters" that may be personae utterly unlike the people who
+ write them, and common "background characters" manipulable by
+ all parties. The one iron law is that you may not write
+ irreversible changes to a character without the consent of the
+ person who "owns" it, otherwise, anything goes.
+
+ See {bamf}, {cyberspace}.
+
+ [{Jargon File}]
+
+ (1995-01-30)
+
+Virtual Reality Modeling Language
+
+ <virtual reality, language> (VRML) A draft specification for
+ the design and implementation of a {platform}-independent
+ language for {virtual reality} scene description.
+
+ VRML 1.0 was released on 1995-05-26.
+
+ {(http://vrml.org/)}.
+
+ {Wired (http://vrml.wired.com/)}.
+
+ {Hypermail Archive (http://vrml.wired.com/arch/)}.
+
+ Mailing list: <majordomo@wired.com> (message body: "subscribe
+ www-vrml your-email-address").
+
+ (1995-07-20)
+
+Virtual Sequential Access Method
+
+ {Virtual Storage Access Method}
+
+virtual server
+
+ <web> A configuration of a {web}
+ {server} that appears to {clients} as an independent server
+ but which is actually running on a computer that is shared by
+ any number of other virtual servers. Each virtual server can
+ be configured as an independent {website}, with its own
+ {hostname}, content, and security settings.
+
+ {DNS} maps the hostnames of all virtual servers on one
+ physical server to its {IP address}. The web server software
+ then uses the "Host" header in the {HTTP} request to determine
+ which virtual server the request was for, and then processes
+ the request using that virtual server's configuration.
+
+ Virtual servers allow {Internet Service Providers} to share
+ one computer between multiple {websites} while allowing the
+ owner of each website to use and administer the server as
+ though they had complete control.
+
+ (2003-06-23)
+
+virtual shredder
+
+ The jargon equivalent of the {bit bucket} at shops using
+ {IBM}'s {VM/CMS} {operating system}. VM/CMS officially
+ supports a whole bestiary of virtual card readers, virtual
+ printers, and other phantom devices; these are used to supply
+ some of the same capabilities {Unix} gets from {pipes} and
+ {I/O redirection}.
+
+ [{Jargon File}]
+
+ (1995-01-30)
+
+Virtual Software Factory
+
+ <programming, tool> (VSF) A product from {Systematica} which
+ allows users to develop {CASE} tools appropriate to any
+ software engineering methodology.
+
+ (1997-06-09)
+
+Virtual Storage Access Method
+
+ <database> (VSAM) An {IBM} disk file storage scheme first used
+ in {S/370} and virtual storage. VSAM comprises three access
+ methods: {Keyed Sequenced Data Set} (KSDS), {Relative Record
+ Data Set} (RRDS), and {Entry Sequenced Data Set} (ESDS).
+
+ Both {IMS/DB} and {DB2} are implemented on top of VSAM and use
+ its underlying data structures.
+
+ ["Storage" or "Sequential"?]
+
+ (2002-07-26)
+
+Virtual Storage Extended
+
+ <operating system> (VSE, formerly DOS/VSE) is a
+ {multitasking}, {IBM 370}-architected {operating system}
+ similar to {Multiple Virtual Storage} (MVS).
+
+ VSE run jobs in {partitions} rather than {address spaces}, and
+ uses {POWER} for input/output rather than {JES}, but is
+ largely similar to MVS. Subsequent VSE/{ESA} releases gave
+ VSE the {XA-370} channel architecture, 31-bit virtual and real
+ storage support, and data spaces. VSE is the {IBM} operating
+ system on one-third of installed {IBM 4381s} and a significant
+ proportion of {IBM 9370s} as well. It offers {transaction
+ processing} and {batch processing} capabilities well beyond
+ {Virtual Machine}'s current capabilities, and has a close
+ affinity with MVS.
+
+ (1997-06-09)
+
+Virtual Telecommunications Access Method
+
+ (VTAM) A data communications access method compatible with
+ {IBM}'s {Systems Network Architecture}.
+
+ [More detail?]
+
+ (1995-01-30)
+
+virus
+
+ <security> (By analogy with biological viruses, via science
+ fiction) A program or piece of code, a type of {malware},
+ written by a {cracker}, that "infects" one or more other
+ programs by embedding a copy of itself in them, so that they
+ become {Trojan horses}. When these programs are executed, the
+ embedded virus is executed too, thus propagating the
+ "infection". This normally happens invisibly to the user.
+
+ A virus has an "engine" - code that enables it to propagate
+ and optionally a "payload" - what it does apart from
+ propagating. It needs a "host" - the particular hardware and
+ software environment on which it can run and a "trigger" - the
+ event that starts it running.
+
+ Unlike a {worm}, a virus cannot infect other computers without
+ assistance. It is propagated by vectors such as humans
+ trading programs with their friends (see {SEX}). The virus
+ may do nothing but propagate itself and then allow the program
+ to run normally. Usually, however, after propagating silently
+ for a while, it starts doing things like writing "cute"
+ messages on the terminal or playing strange tricks with the
+ display (some viruses include {display hacks}). Viruses
+ written by particularly antisocial {crackers} may do
+ irreversible damage, like deleting files.
+
+ By the 1990s, viruses had become a serious problem, especially
+ among {IBM PC} and {Macintosh} users (the lack of security on
+ these machines enables viruses to spread easily, even
+ infecting the operating system). The production of special
+ {antivirus software} has become an industry, and a number of
+ exaggerated media reports have caused outbreaks of near
+ hysteria among users. Many {lusers} tend to blame
+ *everything* that doesn't work as they had expected on virus
+ attacks. Accordingly, this sense of "virus" has passed into
+ popular usage where it is often incorrectly used for other
+ types of {malware} such as {worms} or {Trojan horses}.
+
+ See {boot virus}, {phage}. Compare {back door}. See also
+ {Unix conspiracy}.
+
+ [{Jargon File}]
+
+ (2003-06-20)
+
+viruses
+
+ {virus}
+
+visible bell
+
+ <communications> (Or "visual bell") A program option (whether
+ in a terminal program, {termcap} setting, or as a
+ {stand-alone} program) which outputs the {bell} {character
+ code} as a visual signal (e.g., a flashing status bar or menu
+ bar).
+
+ Generally intended for deaf or hearing-disabled users who
+ couldn't hear the normal auditory beep; also widely used by
+ users who simply don't want their machines {feep}ing at them
+ or disturbing other users.
+
+ [Implementations?]
+
+ (1997-04-07)
+
+VisiCalc /vi'zi-calk/
+
+ <application, tool, business, history> The first {spreadsheet}
+ program, conceived in 1978 by {Dan Bricklin}, while he was an
+ MBA student at Harvard Business School. Inspired by a
+ demonstration given by {Douglas Engelbart} of a
+ {point-and-click} {user interface}, Bricklin set out to design
+ an {application} that would combine the intuitiveness of
+ pencil and paper calculations with the power of a
+ {programmable pocket calculator}.
+
+ Bricklin's design was based on the (paper) financial
+ spreadsheet, a kind of document already used in business
+ planning. (Some of Bricklin's notes for VisiCalc were
+ scribbled on the back of a spreadsheet pad.) VisiCalc was
+ probably not the first application to use a spreadsheet model,
+ but it did have a number of original features, all of which
+ continue to be fundamental to spreadsheet software. These
+ include {point-and-type} editing, {range} {replication}, and
+ formulas that update automatically with changes to other
+ {cells}.
+
+ VisiCalc is widely credited with creating the sudden demand
+ for desktop computers that helped fuel the {microcomputer}
+ boom of the early 1980s. Thousands of business people with
+ little or no technical expertise found that they could use
+ VisiCalc to create sophisticated financial programs. This
+ makes VisiCalc one of the first {killer apps}.
+
+ {Dan Bricklin's Site (http://bricklin.com/visicalc.htm)}.
+
+ (2003-07-05)
+
+visionary
+
+ 1. One who hacks vision, in the sense of an Artificial
+ Intelligence researcher working on the problem of getting
+ computers to "see" things using TV cameras. (There isn't any
+ problem in sending information from a TV camera to a computer.
+ The problem is, how can the computer be programmed to make use
+ of the camera information? See {SMOP}, {AI-complete}.)
+
+ 2. [IBM] One who reads the outside literature. At IBM,
+ apparently, such a penchant is viewed with awe and wonder.
+
+ [{Jargon File}]
+
+visit
+
+ <programming> To process a {node} while {traversing} a
+ {graph}.
+
+ (2001-09-30)
+
+Visual BASIC
+
+ <language> (VB) A popular {event-driven} {visual programming}
+ system from {Microsoft Corporation} for {Microsoft Windows}.
+ VB is good for developing Windows interfaces, it invokes
+ fragments of {BASIC} code when the user performs certain
+ operations on graphical objects on-screen. It is widely used
+ for in-house {application program} development and for
+ prototyping. It can also be used to create {ActiveX} and
+ {COM} components.
+
+ Version 1 was released in 1991 [by Microsoft?].
+
+ Latest version: 6, as of 1999-11-26.
+
+ {(http://msdn.microsoft.com/vbasic/)}.
+ {History (http://iessoft.com/scripts/vbhistry.asp)}.
+ {Strollo Software (http://op.net/~jstrollo/vblinks.html)}.
+ {Books
+ (http://wrox.com/Consumer/Default.asp?Category=Visual+Basic)}.
+
+ (1999-11-26)
+
+Visual Basic for Applications
+
+ <programming> (VBA) {Microsoft}'s common language for
+ manipulating components of its {Microsoft Office} suite. It
+ is used as the {macro} language for these applications and is
+ the primary means of customising and extending them. A VBA
+ program operates on {objects} representing the application and
+ the entities it manipulates, e.g. a {spreadsheet} or a range
+ of cells in {Microsoft Excel}.
+
+ [Relationship to {Visual BASIC}? URL?]
+
+ (1999-09-12)
+
+Visual BASIC Script
+
+ <language> (VBScript) Microsoft's {scripting language} which
+ is an extension of their {Visual Basic} language. VBScript
+ can be used with {Microsoft Office} applications and others.
+ It can also be embedded in {web pages} but can only be
+ understood by {Internet Explorer}.
+
+ Visual Basic is a {BASIC} variant with {object-oriented}
+ features. Objects include applications, windows and
+ selections.
+
+ [Relationship with {ASP}? {VBA}?]
+
+ (1998-07-05)
+
+visual bell
+
+ {visible bell}
+
+Visual C++
+
+ A {C} and {C++} programming environment sold by {Microsoft}
+ Corporation.
+
+ {Usenet} newsgroup: {news:comp.lang.c++}.
+
+ [Differences? Features?]
+
+ (1994-12-21)
+
+Visual Component Library
+
+ <programming> {VCL} A {application framework} library for
+ {Microsoft Windows} and {Borland Software Corp.}'s {Delphi}
+ and {C++Builder} {rapid application development} software.
+ VCL was originally designed for Delphi but is now also used
+ for C++Builder. This replaces {OWL} {Object Windows Library}
+ as Borland's Windows C++ framework of choice. VCL
+ encapsulates the C-based {Win32 API} into a much easier to
+ use, {object-oriented} form. Like its direct rival,
+ {Microsoft Foundation Class Library} (MFC), VCL includes
+ classes to create Windows programs.
+
+ The VCL component class can be inherited to create new VCL
+ components, which are the building blocks of Delphi and
+ C++Builder applications. VCL components are somewhat in
+ competition with {ActiveX} controls, though a VCL wrapper can
+ be created to make an ActiveX control seem like a VCL
+ component.
+
+ {Home
+ (http://borland.com/bcppbuilder/productinfo/feaben/visual.html)}.
+
+ (2001-07-09)
+
+Visual dBASE
+
+ <language> A {Rapid Application Development} suite with a
+ compiler and {intranet} tools to enable developers to publish
+ data on the {web}. Originally a {Borland} product,
+ the first version released by {dBase, Inc.} was Visual dBase
+ 5.7.
+
+ (2003-11-24)
+
+Visual Display Unit
+
+ <hardware> (VDU, or "video terminal", "video display
+ terminal", VDT, "display terminal") A device incorporating a
+ {cathode ray tube} (CRT) display, a keyboard and a {serial
+ port}. A VDU usually also includes its own display
+ electronics which store the received data and convert it into
+ electrical waveforms to drive the CRT.
+
+ VDUs fall into two categories: {dumb terminals} and
+ {intelligent terminals} (sometimes called "programmable
+ terminals").
+
+ Early VDUs could only display characters in a single preset
+ {font}, and these were confined to being layed out in a
+ rectangular grid, reproducing the functionality of the
+ paper-based {teletypes} they were designed to replace.
+
+ Later models added graphics facilities but were still driven
+ via serial communications, typically with several VDUs
+ attached to a single multi-user computer. This contrasts with
+ the much faster single {bitmap displays} integrated into most
+ modern single-user {personal computers} and {workstations}.
+
+ The term "Display Screen Equipment" (DSE) is used almost
+ exclusively in connection with the health and safety issues
+ concerning VDUs.
+
+ {Working with VDUs - UK Heath and Safety Executive
+ (http://hse.gov.uk/pubns/indg36.pdf)}.
+
+ (2002-11-09)
+
+Visual FoxPro
+
+ <database> A {Microsoft} {database} derived from {Fox
+ Software}'s {FoxPRO}.
+
+ Latest version: 5.0, as of 2000-06-21.
+
+ {(http://msdn.microsoft.com/vfoxpro/)}.
+
+ [Features? Dates?]
+
+ (2000-08-06)
+
+Visual Interface
+
+ <tool, text> (vi) /V-I/, /vi:/, *never* /siks/ A {screen
+ editor} {crufted} together by {Bill Joy} for an early {BSD}
+ release. vi became the de facto standard {Unix} editor and a
+ nearly undisputed hacker favourite outside of {MIT} until the
+ rise of {Emacs} after about 1984.
+
+ It tends to frustrate new users no end, as it will neither
+ take commands while expecting input text nor vice versa, and
+ the default setup provides no indication of which mode the
+ editor is in (one correspondent accordingly reports that he
+ has often heard the editor's name pronounced /vi:l/).
+ Nevertheless it is still widely used (about half the
+ respondents in a 1991 {Usenet} poll preferred it), and even
+ some Emacs fans resort to it as a mail editor and for small
+ editing jobs (mainly because it starts up faster than the
+ bulkier versions of Emacs).
+
+ See {holy wars}.
+
+ (1995-10-03)
+
+visualisation
+
+ <graphics> Making a visible presentation of numerical data,
+ particularly a graphical one. This might include anything
+ from a simple X-Y graph of one dependent variable against one
+ independent variable to a {virtual reality} which allows you
+ to fly around the data.
+
+ {Gnuplot} is the {Free Software Foundation}'s utility for
+ producing various kinds of graphs.
+
+ {Usenet} newsgroup: {news:comp.graphics}.
+
+ The {Computer Graphics Resource Listing} contains pointers to
+ several visualisation tools.
+
+ {comp.graphics FAQ
+ (ftp://src.doc.ic.ac.uk/usenet/news-info/comp.graphics/)}.
+
+ {Electronic Visualization Laboratory, University of Illinois
+ at Chicago (http://ncsa.uiuc.edu/EVL/docs/Welcome.html)}.
+
+ (2002-02-21)
+
+visual language
+
+ {visual programming language}
+
+visual programming
+
+ 1. Writing programs in a language which manipulates visual
+ information or supports visual interaction.
+
+ 2. Writing programs in a {visual programming language}.
+
+ 3. Writing programs in a {visual programming environment}.
+
+visual programming environment
+
+ Software which allows the use of visual expressions (such as
+ graphics, drawings, animation or {icons}) in the process of
+ programming. These visual expressions may be used as
+ graphical interfaces for textual programming languages. They
+ may be used to form the syntax of new visual programming
+ languages leading to new paradigms such as {programming by
+ demonstration} or they may be used in graphical presentations
+ of the behaviour or structure of a program.
+
+ (1995-02-23)
+
+visual programming language
+
+ <language> (VPL) Any programming language that allows the user
+ to specify a program in a two-(or more)-dimensionsional way.
+ Conventional textual languages are not considered
+ two-dimensional since the {compiler} or {interpreter}
+ processes them as one-dimensional streams of characters. A
+ VPL allows programming with visual expressions - spatial
+ arrangements of textual and graphical symbols.
+
+ VPLs may be further classified, according to the type and
+ extent of visual expression used, into {icon}-based languages,
+ {form}-based languages and {diagram languages}. {Visual
+ programming environments} provide graphical or iconic elements
+ which can be manipulated by the user in an interactive way
+ according to some specific spatial grammar for program
+ construction.
+
+ A visually transformed language is a non-visual language with
+ a superimposed visual representation. Naturally visual
+ languages have an inherent visual expression for which there
+ is no obvious textual equivalent.
+
+ {Visual Basic}, {Visual C++} and the entire {Microsoft} Visual
+ family are not, despite their names, visual programming
+ languages. They are textual languages which use a graphical
+ {GUI builder} to make programming interfaces easier. The user
+ interface portion of the programming environment is visual,
+ the languages are not. Because of the confusion caused by the
+ multiple meanings of the term "{visual programming}", Fred
+ Lakin has proposed the term "executable graphics" as an
+ alternative to VPL.
+
+ Some examples of visual programming languages are {Prograph},
+ {Pict}, {Tinkertoy}, {Fabrik}, {CODE 2.0} and {Hyperpascal}.
+
+ {(http://cogs.susx.ac.uk/users/ianr/vpl.html)}.
+ {(http://cuiwww.unige.ch/eao/www/readme.html)}.
+
+ {Usenet} newsgroup: {news:comp.lang.visual} (NOT for {Visual
+ Basic} or {Visual C++}).
+
+ (1995-02-10)
+
+VisualWorks
+
+ <language> A modern commercial implementation of the
+ {Smalltalk} programming language. VisualWorks descends
+ directly from the original {Smalltalk-80} by {Xerox PARC} and
+ was originally developed (for some time under the name
+ Objectworks\Smalltalk) by {ParcPlace Systems}. VisualWorks
+ relies on {dynamic translation} as its {virtual machine}
+ technology.
+
+ {VisualWorks Wiki (http://wiki.cs.uiuc.edu/VisualWorks)}.
+
+ (2003-05-15)
+
+VITAL
+
+ A {semantics} language using {FSL}, developed by Mondshein in
+ 1967.
+
+ [Sammet 1969, p. 641].
+
+ (1995-02-23)
+
+VIVID
+
+ A numerical {constraint}-oriented language.
+
+ ["VIVID: The Kernel of a Knowledge Representation Environment
+ Based on the Constraints Paradigm of Computation", J. Maleki,
+ Proc 20th Annual Hawaii Intl Conf on System Sciences (Jan
+ 1987) pp.591-597].
+
+ (1995-02-23)
+
+viz
+
+ A {visual language} for specification and programming.
+
+ ["viz: A Visual Language Based on Functions", C.M. Holt, 1990
+ IEEE Workshop on Visual Langs, Oct 1990, pp.221-226].
+
+ (1995-02-23)
+
+VLAN
+
+ {Virtual Local Area Network}
+
+VLB
+
+ {VESA local bus}
+
+VLDB
+
+ {Very Large DataBase}
+
+ [How large?]
+
+ (1996-12-21)
+
+Vlisp
+
+ <language>
+
+ 1. A {Lisp} dialect developed by Patrick Greussay
+ <pg@litp.ibp.fr> in about 1973 with a fast {interpreter} and a
+ portable {virtual machine}. Vlisp introduced the
+ "{chronology}", a dynamic environment for implementing
+ {interrupts}. It led to {Le_Lisp}. See also {ObjVlisp}.
+
+ ["Contribution a la Definition Interpretive et a
+ l'Implementation des Lambda-Langages", P. Greussay, These
+ d'Etat, U Paris VI, Nov 1977].
+
+ [Relationship to {Vincennes LISP}?]
+
+ 2. {Vincennes LISP}.
+
+ (2008-03-16)
+
+VLIW
+
+ {Very Long Instruction Word}
+
+VLM
+
+ 1. <architecture> {Very Large Memory}.
+
+ 2. <networking> {Virtual Loadable Module}.
+
+ (1998-02-24)
+
+VLSI
+
+ {Very Large Scale Integration}
+
+VLSM
+
+ {Variable Length Subnet Masks}
+
+VM
+
+ {Virtual Machine}
+
+VM/CMS
+
+ {Virtual Machine/Conversational Monitor System}
+
+VME
+
+ 1. <hardware> {Versa Module Europa}.
+
+ See {VMEbus}.
+
+ 2. <operating system> {Virtual Machine Environment}.
+
+VMEbus
+
+ A widely accepted backplane interconnection bus system
+ developed by a consortium of companies led by {Motorola}, now
+ standardised as {IEEE} 1014.
+
+ (1995-06-01)
+
+VME Microsystems International Corporation
+
+ <company> (VMIC)
+
+ Address: Huntsville, AL, USA.
+
+ Telephone: +1 800 322 3616.
+
+ (1995-06-01)
+
+VM/ESA
+
+ {Virtual Machine}
+
+VML
+
+ VODAK Model Language. Language for an extensible
+ {object-oriented database}.
+
+ ["Object-Oriented Modeling for Hypermedia Systems Using the
+ Object-Oriented VODAK Model Language (VML)" Wolfgang Klas et
+ al, in Object-Oriented Database Management Systems, NATO ASI
+ Series, Springer 1993].
+
+ E-mail: <aberer@darmstadt.gmd.de>.
+
+VMS
+
+ {Virtual Memory System}
+
+VM/SP
+
+ {Virtual Machine}
+
+VM/XA
+
+ {Virtual Machine}
+
+vn
+
+ <networking> The {country code} for Vietnam.
+
+ (1999-01-27)
+
+vocoder
+
+ <communications> Hardware or software which implements a
+ {compression} {algorithm} particular to voice.
+
+ For example {Qualcomm} uses a vocoding algorithm to compresses
+ voice data in digital communication systems such as wireless
+ {CDMA} and {Eudora} voice attach.
+
+ (1998-04-29)
+
+vocoding
+
+ {vocoder}
+
+VoD
+
+ {video on demand}
+
+voice mail
+
+ <messaging, business> Any system for sending, storing and
+ retrieving {audio} messages, like a telephone answering
+ machine.
+
+ A voice mailbox is typically associated with a telephone
+ number or extension. When the number is called and the line
+ is busy or not answered, the caller hears a message left by
+ the owner and is given instructions for leaving a message or
+ other available options, such as paging the individual or
+ being transferred to an operator. The owner of a mailbox can
+ change the outgoing message or listen to incoming messages
+ after entering a {PIN}. Members of a voice mail system can
+ generally forward or {broadcast} messages to other members'
+ boxes.
+
+ The experience of two people trying to reach other by
+ telephone but always reaching each other's voice mail is
+ referred to as "(tele)phone tag".
+
+ (1996-11-03)
+
+voice-net
+
+ Hackish way of referring to the {plain old telephone system},
+ comparing it to a digital {network}. {Usenet} {sig blocks}
+ sometimes include the sender's telephone number next to a
+ "Voice:" or "Voice-Net:" header; variants of this are
+ "Voicenet" and "V-Net".
+
+ Compare {paper-net}, {snail-mail}.
+
+ [{Jargon File}]
+
+ (1995-02-16)
+
+Voice over IP
+
+ <communications> (VoIP) Any technology providing {voice
+ telephony} services over {IP}, including {CODECs}, {streaming}
+ {protocols} and {session control}. The major advantage of
+ VoIP is lower cost, by avoiding dedicated voice circuits.
+
+ Currently VoIP is being deployed on internal corporate
+ networks, and, via the {Internet}, for low cost (and low
+ quality) international calls. It is also used for telephony
+ applications such as voice and fax mail.
+
+ The {ITU} standard is {H.323}, which is a whole suite of
+ protocols, while the {IETF} has developed the much simpler
+ {SIP} to solve the session control problem and {MGCP}/{Megaco}
+ to solve the gateway problem.
+
+ (2003-11-30)
+
+voice recognition
+
+ {speech recognition}
+
+VoIP
+
+ {Voice over IP}
+
+volatile
+
+ 1. <programming> {volatile variable}.
+
+ 2. <storage> See {non-volatile storage}.
+
+ (1997-06-05)
+
+volatile memory
+
+ {non-volatile storage}
+
+volatile storage
+
+ {non-volatile storage}
+
+volatile variable
+
+ <programming> A variable in a computer program which can be
+ modified by processes other than the program. For example, a
+ variable that stores the value of a timer chip (either because
+ it is located at the address of the hardware device or because
+ it is updated on {interrupts}) needs to be volatile to be
+ useful.
+
+ A {static} variable, on the other hand, maintains its value
+ until the program changes it or it is no longer needed. In
+ addition, volatile variables can be held in the {stack}
+ whereas static variables are usually stored in a program's
+ {data segment}.
+
+ (1995-05-17)
+
+voltage
+
+ <electronics> (Or "potential difference", "electro-motive
+ force" (EMF)) A quantity measured as a signed difference
+ between two points in an electrical circuit which, when
+ divided by the {resistance} in {Ohms} between those points,
+ gives the current flowing between those points in {Amperes},
+ according to {Ohm's Law}. Voltage is expressed as a signed
+ number of Volts (V). The voltage gradient in Volts per metre
+ is proportional to the force on a charge.
+
+ Voltages are often given relative to "earth" or "ground" which
+ is taken to be at zero Volts. A circuit's earth may or may
+ not be electrically connected to the actual earth.
+
+ The voltage between two points is also given by the charge
+ present between those points in {Coulombs} divided by the
+ {capacitance} in {Farads}. The capacitance in turn depends on
+ the {dielectric constant} of the insulators present.
+
+ Yet another law gives the voltage across a piece of circuit as
+ its {inductance} in {Henries} multiplied by the rate of change
+ of current flow through it in Amperes per second.
+
+ A simple analogy likens voltage to the pressure of water in a
+ pipe. Current is likened to the amount of water (charge)
+ flowing per unit time.
+
+ (1995-12-04)
+
+Volume Table Of Contents
+
+ <storage> (VTOC) /V-tock/ A special {file} on a {disk}, which
+ contains a list of all the ordinary files on the disk and
+ their {addresses}. Also called a {directory}.
+
+ The term is used mostly with large {mainframe} {disk drives}.
+ Storage administrators will often refer to the VTOC to obtain
+ information on the number of files stored on a disk.
+
+ (1997-04-15)
+
+von Neumann architecture
+
+ <architecture, computability> A computer {architecture}
+ conceived by mathematician {John von Neumann}, which forms the
+ core of nearly every computer system in use today (regardless
+ of size). In contrast to a {Turing machine}, a von Neumann
+ machine has a {random-access memory} (RAM) which means that
+ each successive operation can read or write any memory
+ location, independent of the location accessed by the previous
+ operation.
+
+ A von Neumann machine also has a {central processing unit}
+ (CPU) with one or more {registers} that hold data that are
+ being operated on. The CPU has a set of built-in operations
+ (its {instruction set}) that is far richer than with the
+ Turing machine, e.g. adding two {binary} {integers}, or
+ branching to another part of a program if the binary integer
+ in some register is equal to zero ({conditional branch}).
+
+ The CPU can interpret the contents of memory either as
+ instructions or as data according to the {fetch-execute
+ cycle}.
+
+ Von Neumann considered {parallel computers} but recognized the
+ problems of construction and hence settled for a sequential
+ system. For this reason, parallel computers are sometimes
+ referred to as non-von Neumann architectures.
+
+ A von Neumann machine can compute the same class of functions
+ as a universal {Turing machine}.
+
+ [Reference? Was von Neumann's design, unlike Turing's,
+ originally intended for physical implementation?]
+
+ {(http://salem.mass.edu/~tevans/VonNeuma.htm)}.
+
+ (2003-05-16)
+
+von Neumann integer
+
+ <mathematics> A {finite} {von Neumann ordinal}.
+
+ The von Neumann integer N is a {finite} set with N elements
+ which are the von Neumann integers 0 to N-1. Thus
+
+ 0 = {} = {}
+ 1 = {0} = {{}}
+ 2 = {0, 1} = {{}, {{}}}
+ 3 = {0, 1, 2} = {{}, {{}}, {{}, {{}}}}
+ ...
+
+ The set of von Neumann integers is {infinite}, even though
+ each of its elements is finite.
+
+ [Origin of name?]
+
+ (1995-03-30)
+
+von Neumann, John
+
+ {John von Neumann}
+
+von Neumann machine
+
+ {von Neumann architecture}
+
+von Neumann ordinal
+
+ <mathematics> An implementation of {ordinals} in {set theory}
+ (e.g. {Zermelo Fränkel set theory} or {ZFC}). The von Neumann
+ ordinal alpha is the {well-ordered set} containing just the
+ ordinals "shorter" than alpha.
+
+ "Reasonable" set theories (like ZF) include Mostowski's
+ Collapsing Theorem: any {well-ordered set} is {isomorphic} to
+ a von Neumann ordinal. In really screwy theories (e.g. NFU --
+ New Foundations with Urelemente) this theorem is false.
+
+ The finite von Neumann ordinals are the {von Neumann
+ integers}.
+
+ (1995-03-30)
+
+voodoo programming
+
+ <jargon> (From George Bush's "voodoo economics") The use by
+ guess or cookbook of an obscure or {hairy} system, feature, or
+ algorithm that one does not truly understand. The implication
+ is that the technique may not work, and if it doesn't, one
+ will never know why. Almost synonymous with {black magic},
+ except that black magic typically isn't documented and
+ *nobody* understands it.
+
+ Compare {magic}, {deep magic}, {heavy wizardry}, {rain dance},
+ {cargo cult programming}, {wave a dead chicken}.
+
+ [{Jargon File}]
+
+ (1995-03-10)
+
+Voronoi diagram
+
+ <mathematics, graphics> (Or "Voronoi tessellation", "Voronoi
+ decomposition", "Dirichlet tessellation", After {Georgy
+ Feodosevich Voronoy}) For a {set} S of points in a {Euclidean
+ space}, the {partition} Vor(S) of the plane into the {voronoi
+ polygons} associated with the {members} of S, where each
+ polygon is defined by the set of points nearer to some given
+ point in S than to any other point in S.
+
+ The Voronoi diagram is the {dual} of the {Delaunay
+ triangulation} of S.
+
+ (2008-04-18)
+
+Voronoi polygon
+
+ <mathematics, graphics> For a member s of a {set} S of points
+ in a {Euclidean space}, the {locus} of points in the plane
+ that are closer to s than to any other member of S.
+
+ (1997-08-03)
+
+VOS
+
+ <operating system> An {operating system} used in {Stratus}
+ computers.
+
+ See also {FTX}.
+
+ [Details?]
+
+ (1998-07-06)
+
+Voters Telecommunications Watch
+
+ <body> (VTW) A non-profit organisation based in New York,
+ founded by Shabbir J. Safdar to protect the rights of
+ {Internet} users. The VTW has actively opposed regulation of
+ {encryption} and restrictions on Internet free speech. VTW
+ created the animated "Free Speech" fireworks icon that has
+ been displayed on many web pages since June 12, 1996, the day
+ that a three-judge panel in Philadelphia ruled the {CDA}
+ unconstitutional.
+
+ {(http://vtw.org)}.
+
+ (1996-11-03)
+
+voxel
+
+ <jargon> (By analogy with "{pixel}") Volume element.
+
+ The smallest distinguishable box-shaped part of a
+ three-dimensional space. A particular voxel will be
+ identified by the x, y and z coordinates of one of its eight
+ corners, or perhaps its centre. The term is used in three
+ dimensional modelling.
+
+ (1995-03-10)
+
+V.pcm
+
+ {V.90}
+
+VPL
+
+ 1. {visual programming} language.
+
+ ["VPL: An Active, Declarative Visual Programming System,
+ D. Lau-Kee et al, 1991 IEEE Workshop on Vis Langs, Oct 1991,
+ pp. 40-46].
+
+ 2. A {dataflow} language for interactive image processing.
+
+VPN
+
+ {Virtual Private Network}
+
+VP-Planner
+
+ <tool, product> A {spreadsheet} from {Paperback Software}. It
+ has a graph menu within the spreadsheet program (with {CGA}
+ graphics). The graphs are updated every time the graph screen
+ is activated.
+
+ (1995-03-28)
+
+VQF
+
+ {Twin Vector Quantization}
+
+VR
+
+ {virtual reality}
+
+VRAM
+
+ {video random-access memory}
+
+VRC
+
+ {Vertical Redundancy Check}
+
+Vrije Universiteit, Amsterdam
+
+ <education, body> The "Free University of Amsterdam", founded
+ in 1880 by Abraham Kuyper (who later became Prime Minister of
+ The Netherlands). Originally only open to Reformed
+ Christians, it is now open to all.
+
+ {Andrew Tanenbaum} is a professor there.
+
+ Not to be confused with the much older Universiteit van
+ Amsterdam.
+
+ {(http://vu.nl/)}.
+
+ (2005-11-05)
+
+VRML
+
+ {Virtual Reality Modeling Language}
+
+VRTX
+
+ Virtual Real-Time Executive.
+
+ A {real-time} {operating system} from {ReadySystems} for the
+ {Motorola 68000} family of {microprocessors}.
+
+ {MPV} is a {multi-processing} extension.
+
+ (1994-11-08)
+
+VSAM
+
+ {Virtual Storage Access Method}
+
+VSAT
+
+ <communications> {Very Small Aperture Terminal}.
+
+VSCM
+
+ <language, LISP> A highly {portable} implementation of
+ {Scheme}, written in {ANSI C} and {Scheme}. VSCM features
+ {exception} and {interrupt} handling, executable portable
+ memory images, {coroutines} and {continuations} with multiple
+ arguments.
+
+ Portability is achieved by exclusive use of legal ANSI C
+ features.
+
+ Version II Nov9 by Matthias Blume <blume@cs.princeton.edu>
+ included {run-time support} and a {bytecode compiler}. It
+ conforms to R4RS and IEEE P1178 and runs on {Unix} and
+ {Macintosh}.
+
+ VSCM is no longer actively developed - the author recommends
+ {StandardML}.
+
+ {(http://cs.princeton.edu/~blume/vscm/)}.
+
+ (2001-01-02)
+
+VSE
+
+ {Virtual Storage Extended}
+
+V series
+
+ <communications, standard> A set of standards published by the
+ {CCITT} for "Data Communication over the Telephone Network".
+ The following standards describe the important {modulation}
+ techniques: {V.17}, {V.21}, {V.22}, {V.22 bis}, {V.23}, {V.27
+ ter}, {V.29}, {V.32}, {V.32 bis}. Other V standards include
+ {V.24}, {V.25 bis}, {V.42}, {V.42 bis}.
+
+ (2004-07-20)
+
+VSF
+
+ {Virtual Software Factory}
+
+VSP
+
+ Very Simple Prolog+.
+
+VSTa
+
+ <operating system> {Valencia Simple Tasker}.
+
+VSX
+
+ Verification Suite for {X/open}.
+
+VT
+
+ <character> Vertical Tab, the {mnemonic} for {ASCII} 11.
+
+ (1996-06-24)
+
+vt100
+
+ <hardware> {DEC}'s definitive {CRT} {video terminal} of the
+ early/mid 1980s. Its {control codes} and {escape sequences}
+ still form the basis of the {xterm} set and of the {ANSI} or
+ {IBM PC} standards. VT100 compatibility is still provided by
+ most {terminal emulators}.
+
+ [On-line documentation?]
+
+ (1995-03-28)
+
+vt220
+
+ <hardware> A {DEC} {video terminal}, the successor to the
+ {VT100} series.
+
+ [On-line documentation?]
+
+ (1995-03-28)
+
+VTAM
+
+ {Virtual Telecommunications Access Method}
+
+VTC
+
+ {video teleconferencing}
+
+VTOC
+
+ {Volume Table Of Contents}
+
+VTS
+
+ A suite of test programs for Motif from {OSF}.
+
+VTW
+
+ {Voters Telecommunications Watch}
+
+vu
+
+ <networking> The {country code} for Vanuatu.
+
+ (1999-01-27)
+
+VUE
+
+ Visual User Environment: a desktop manager for Unix from
+ Hewlett-Packard.
+
+VUIT
+
+ Visual User Interface Tool: a WYSIWYG editor from DEC for
+ building human interfaces to applications using {OSF}/Motif.
+ It provides an interactive interface to UIL and the Motif
+ toolkit.
+
+VULCAN
+
+ 1. <database> A version of {JPLDIS} ported to {CP/M} by Wayne
+ Ratliff around 1980. VULCAN evolved into {dBASE II}.
+
+ 2. <database> The {dBASE}-like {interpreter} and {compiler}
+ sold by {RSPI} with their {Emerald Bay} product. [Same as 1?]
+
+ 3. <language> An early string manipulation language.
+
+ ["VULCAN - A String Handling Language with Dynamic Storage
+ Control", E.P. Storm et al, Proc FJCC 37, AFIPS, Fall 1970].
+
+ 4. <language> A {concurrent} {object-oriented} {logic
+ programming} language implemented as a {preprocessor} for
+ {FCP} by Kahn et al at {Xerox PARC}.
+
+ ["Vulcan: Logical Concurrent Objects", K. Kahn et al in
+ Research Directions in Object- Oriented Programming,
+ A.B. Shriver et al eds, MIT Press 1987].
+
+ (2004-09-01)
+
+Vulcan death grip
+
+ <jargon> A variant of {Vulcan nerve pinch} derived from a Star
+ Trek {classic} epsisode where a non-existant "Vulcan death
+ grip" was used to fool Romulans that Spock had killed Kirk.
+
+ (1996-10-27)
+
+Vulcan nerve pinch
+
+ <jargon> (Or "three-finger salute", Vulcan death grip; from
+ the old "Star Trek" TV series via {Commodore} {Amiga}
+ {hackers}) The keyboard combination that forces a {soft boot}
+ or jump to {ROM monitor} (on machines that support such a
+ feature).
+
+ On an Amiga this is done with Ctrl/Right Amiga/Left Amiga; on
+ {IBM PCs} and many {microcomputers} it is Ctrl/Alt/Del; on
+ {Suns}, L1-A; on some {Macintoshes}, it is <Cmd>-<Power
+ switch>! Silicon Graphics users are obviously the most
+ dextrous however, as these machines use the five-finger
+ combination: Left Shift/Left Ctrl/Left Alt/Keypad Divide/F12.
+
+ Compare {quadruple bucky}.
+
+ [{Jargon File}]
+
+ (2000-04-04)
+
+vulnerability
+
+ <security> A {bug} or {feature} of a system that exposes it to
+ possible attack, a flaw in the system's security.
+
+ A common example of a vulnerability due to a bug is {buffer
+ overrun}, where carefully constructed input can allow an
+ attacker to insert arbitrary code into a running program and
+ have it executed.
+
+ The most serious vulnerabilities are those in network
+ software, especially if they exploit traffic that is allowed
+ through the {firewall} like {HTTP}, for example exploiting a
+ bug in a {web browser}.
+
+ The {Open Source Vulnerability Database} lists many
+ vulnerabilities.
+
+ (2007-12-02)
+
+vulture capitalist
+
+ <abuse> A pejorative hackerism for "venture capitalist",
+ deriving from the common practice of pushing contracts that
+ deprive inventors of control over their own innovations and
+ most of the money they ought to have made from them.
+
+ [{Jargon File}]
+
+ (1995-04-14)
+
+VUP
+
+ {VAX MIPS}
+
+VxD
+
+ {Virtual Device Driver}
+
+VXI
+
+ {VMEbus Extension for Instrumentation}
+
+VxWorks
+
+ <operating system> A {real-time} {multitasking} {operating
+ system} from {Wind River Systems}. Originally it used the
+ {VRTX} {kernel} but this has been replaced by Wind River's own
+ "Wind kernel 2.4".
+
+ Before version 5.3 VxWorks included a {software development
+ environment} but this is now called "Tornado".
+
+ Latest version: 5.3, as of 1996-11-28.
+
+ (1996-11-29)
+
+W2K
+
+ {Windows 2000}
+
+W3
+
+ A {web browser} for {Emacs} by William M. Perry
+ <wmperry@indiana.edu>.
+
+ (1994-12-16)
+
+W3C
+
+ {World Wide Web Consortium}
+
+W3 Consortium
+
+ {World Wide Web Consortium}
+
+WA-12
+
+ Workflow Analysis in 12 different organisations. A project
+ from the Department of Computer Science from the {University
+ of Twente}, Enschede, The Netherlands. The final report of
+ this project is available to the public (ISBN 90-365-0683-2).
+
+wabbit
+
+ /wab'it/ [almost certainly from Elmer Fudd's immortal line
+ "You wascawwy wabbit!"] 1. A legendary early hack reported on
+ a System/360 at RPI and elsewhere around 1978; this may have
+ descended (if only by inspiration) from hack called RABBITS
+ reported from 1969 on a Burroughs 55000 at the University of
+ Washington Computer Center. The program would make two copies
+ of itself every time it was run, eventually crashing the
+ system.
+
+ 2. By extension, any hack that includes infinite
+ self-replication but is not a {virus} or {worm}. See {fork
+ bomb} and {rabbit job}, see also {cookie monster}.
+
+ [{Jargon File}]
+
+Wabi
+
+ {Windows Application Binary Interface}
+
+WabiServer
+
+ <operating system, tool> An addition to {Wabi} which allows
+ the {Microsoft Windows} application to run on a {server},
+ e.g. a powerful {Intel}-based computer, with users accessing
+ it from their desktop which can be a cheap computer such as an
+ {X terminal}.
+
+ (1997-01-08)
+
+wacco
+
+ A {BNF}-based LL(?) {parser generator}.
+
+ Posted to comp.sources.misc.
+
+Wafe
+
+ <programming> (From Widget Athena front end) A package by
+ Gustaf Neumann <Gustaf.Neumann@uni-essen.de> implementing a
+ symbolic interface to the {Athena} {widgets} and
+ {OSF}/{Motif}. A typical Wafe {application} consists of two
+ parts: a front-end (Wafe) and an application program which
+ runs as a separate process. The distribution contains sample
+ application programs in {Perl}, {GAWK}, {Prolog}, {TCL}, {C},
+ and {Ada} talking to the same Wafe binary.
+
+ The current Wafe version is 1.0.15. It supports Athena as
+ distributed with {X} releases 4-6 and Motif versions 1.1, 1.2,
+ and 2.0 but new distribution are only tested against {X}
+ releases 5 and 6, and Motif versions 1.2.4 and 2.0.
+
+ {HOME (http://wu-wien.ac.at/wafe)},
+ {(ftp://ftp.wu-wien.ac.at/pub/src/X11/wafe/)}.
+
+ Mailing list: listserv@wu-wien.ac.at ("subscribe Wafe <Your
+ Name>").
+
+ (1996-07-09)
+
+WAFL
+
+ WArwick Functional Language. Warwick U, England. LISP-like.
+
+WAIS
+
+ {Wide Area Information Servers}
+
+WAITS
+
+ /wayts/ The mutant cousin of {TOPS-10} used on a handful of
+ systems at {SAIL} up to 1990. There was never an "official"
+ expansion of WAITS (the name itself having been arrived at by
+ a rather sideways process), but it was frequently glossed as
+ "West-coast Alternative to ITS". Though WAITS was less
+ visible than ITS, there was frequent exchange of people and
+ ideas between the two communities, and innovations pioneered
+ at WAITS exerted enormous indirect influence. The early
+ screen modes of {Emacs}, for example, were directly inspired
+ by WAITS's "E" editor - one of a family of editors that were
+ the first to do "real-time editing", in which the editing
+ commands were invisible and where one typed text at the point
+ of insertion/overwriting. The modern style of multi-region
+ windowing is said to have originated there, and WAITS alumni
+ at XEROX PARC and elsewhere played major roles in the
+ developments that led to the XEROX Star, the Macintosh, and
+ the Sun workstations. {Bucky bits} were also invented there
+ thus, the ALT key on every IBM PC is a WAITS legacy. One
+ notable WAITS feature seldom duplicated elsewhere was a
+ news-wire interface that allowed WAITS hackers to read, store,
+ and filter AP and UPI dispatches from their terminals; the
+ system also featured a still-unusual level of support for what
+ is now called "multimedia" computing, allowing analog audio
+ and video signals to be switched to programming terminals.
+
+ Ken Shoemake adds:
+
+ Some administrative body told us we needed a name for the
+ operating system, and that "SAIL" wouldn't do. (Up to that
+ point I don't think it had an official name.) So the anarchic
+ denizens of the lab proposed names and voted on them.
+ Although I worked on the OS used by CCRMA folks (a parasitic
+ subgroup), I was not writing WAITS code. Those who were,
+ proposed "SAINTS", for (I think) Stanford AI New Time-sharing
+ System. Thinking of ITS, and AI, and the result of many
+ people using one machine, I proposed the name WAITS. Since I
+ invented it, I can tell you without fear of contradiction that
+ it had no official meaning. Nevertheless, the lab voted that
+ as their favorite; upon which the disgruntled system
+ programmers declared it the "Worst Acronym Invented for a
+ Time-sharing System"! But it was in keeping with the creative
+ approach to acronyms extant at the time, including
+ self-referential ones. For me it was fun, if a little
+ unsettling, to have an "acronym" that wasn't. I have no idea
+ what the voters thought. :)
+
+ [{Jargon File}]
+
+ (2003-11-17)
+
+wait state
+
+ <architecture> A delay of one or more {clock} cycles added to
+ a processor's instruction execution time to allow it to
+ communicate with slow external devices. The number and
+ duration of wait states may be pre-configured or they may be
+ controlled dynamically via certain control lines.
+
+ (1996-10-16)
+
+waldo
+
+ /wol'doh/ [Robert A. Heinlein's story "Waldo"] 1. A mechanical
+ agent, such as a gripper arm, controlled by a human limb.
+ When these were developed for the nuclear industry in the
+ mid-1940s they were named after the invention described by
+ Heinlein in the story, which he wrote in 1942. Now known by
+ the more generic term "telefactoring", this technology is of
+ intense interest to NASA for tasks like space station
+ maintenance.
+
+ 2. At Harvard (particularly by Tom Cheatham and students),
+ this is used instead of {foobar} as a metasyntactic variable
+ and general nonsense word. See {foo}, {bar}, {foobar},
+ {quux}.
+
+ [{Jargon File}]
+
+walk
+
+ <programming> To Traverse a data structure, especially an
+ {array} or {linked-list} in {core}.
+
+ See also {codewalker}, {silly walk}, {clobber}.
+
+ (2001-04-12)
+
+walking drives
+
+ <jargon> An occasional failure mode of {magnetic-disk drives}
+ back in the days when they were huge, clunky {washing
+ machines}. Those old {dinosaur} parts carried terrific
+ angular momentum; the combination of a misaligned spindle or
+ worn bearings and stick-slip interactions with the floor could
+ cause them to "walk" across a room, lurching alternate corners
+ forward a couple of millimeters at a time. There is a legend
+ about a drive that walked over to the only door to the
+ computer room and jammed it shut; the staff had to cut a hole
+ in the wall in order to get at it! Walking could also be
+ induced by certain patterns of drive access (a fast seek
+ across the whole width of the disk, followed by a slow seek in
+ the other direction). Some bands of old-time hackers figured
+ out how to induce disk-accessing patterns that would do this
+ to particular drive models and held disk-drive races.
+
+ [{Jargon File}]
+
+ (2009-05-14)
+
+walk off the end of
+
+ <programming> To attempt to process past the start or end of
+ an {array}, {list} or medium after stepping through it. Often
+ the result of an {off-by-one error}.
+
+ Compare {clobber}, {roach}, {smash the stack}.
+
+ (2009-05-14)
+
+wall
+
+ <communications> {Unix}'s "write all" command which sends a
+ message to everyone currently logged in.
+
+ [{Jargon File}]
+
+ (2009-05-14)
+
+wall clock time
+
+ <software> The elapsed time between when a {process} starts to
+ run and when it is finished. This is usually longer than the
+ {processor time} consumed by the process because the {CPU} is
+ doing other things besides running the {process} such as
+ running other user and {operating system} processes or waiting
+ for disk or {network} {I/O}.
+
+ (1998-03-13)
+
+wall follower
+
+ <robotics> A person or {algorithm} that compensates for lack
+ of sophistication or native stupidity by efficiently following
+ some simple procedure shown to have been effective in the
+ past. Used of an algorithm, this is not necessarily
+ pejorative; it recalls "Harvey Wallbanger", the winning robot
+ in an early AI contest (named, of course, after the cocktail).
+ Harvey successfully solved mazes by keeping a "finger" on one
+ wall and running till it came out the other end. This was
+ inelegant, but it was mathematically guaranteed to work on
+ simply-connected mazes - and, in fact, Harvey outperformed
+ more sophisticated robots that tried to "learn" each maze by
+ building an internal representation of it. Used of humans,
+ the term *is* pejorative and implies an uncreative,
+ bureaucratic, by-the-book mentality.
+
+ See also {code grinder}.
+
+ [{Jargon File}]
+
+ (2003-02-03)
+
+wallpaper
+
+ 1. A file containing a listing (e.g. assembly listing) or a
+ transcript, especially a file containing a transcript of all
+ or part of a login session. (The idea was that the paper for
+ such listings was essentially good only for wallpaper, as
+ evidenced at {Stanford}, where it was used to cover windows).
+
+ The term is now rare, especially since other systems have
+ developed other terms for it (e.g. PHOTO on {TWENEX}).
+ However, the {Unix} world doesn't have an equivalent term, so
+ perhaps wallpaper will take hold there. The term probably
+ originated on {ITS}, where the commands to begin and end
+ transcript files were ":WALBEG" and ":WALEND", with default
+ file "WALL PAPER" (the space was a path delimiter).
+
+ 2. The background pattern used on graphical workstations under
+ the {Microsoft Windows} {graphical user interface} to
+ {MS-DOS}.
+
+ (1994-12-22)
+
+wall plate
+
+ <hardware> A small rectangular panel, usually made of plastic,
+ fixed to the wall, on which sockets and switches are mounted.
+ These connect to wiring hidden in the wall. Common examples
+ would be electrical mains and telephone sockets.
+
+ (2009-03-19)
+
+wall time
+
+ (Or "wall clock time") 1. "Real world" time (what the clock on
+ the wall shows), as opposed to the {system clock}'s idea of
+ time.
+
+ 2. The real running time of a program, as opposed to the
+ number of {ticks} required to execute it (on a {time-sharing}
+ system these always differ, as no one program gets all the
+ ticks, and on multiprocessor systems with good thread support
+ one may get more processor time than real time).
+
+ [{Jargon File}]
+
+WAM
+
+ Intermediate language for compiled Prolog, used by the Warren
+ Abstract Machine. "An Abstract Prolog Instruction Set",
+ D.H.D. Warren, TR 309, SRI 1983.
+
+WAN
+
+ {Wide Area Network}
+
+Wang Laboratories
+
+ <body> Computer manufacturer, known for their {office
+ automation} products and the {Wang PC}.
+
+ Quarterly sales $208M, profits $3M (Aug 1994).
+
+ (2008-05-28)
+
+wango
+
+ /wang'goh/ Random bit-level {grovel}ling going on in a system
+ during some unspecified operation. Often used in combination
+ with {mumble}. For example: "You start with the ".o" file,
+ run it through this postprocessor that does mumble-wango - and
+ it comes out a snazzy object-oriented executable."
+
+ [{Jargon File}]
+
+Wang PC
+
+ <computer> {Personal computers} made by {Wang Laboratories}.
+ Wang's PCs had an {operating system} (based on {MS-DOS}) which
+ was not compatible with the {IBM PC}. The Wang {floppy disk}
+ format was compatible with the IBM PC. However, running an
+ IBM "exe" program would generally crash a Wang PC unless a
+ special Industry-Standard emulator program was running on the
+ Wang. This program required the addition of a special card to
+ the Wang PC. It enabled the Wang PC to run most, but not all,
+ software written for the IBM PC. Most Wang software made use
+ of two special keys: CANCEL and EXECUTE. These keys were used
+ to carry out commands, make menu selections, and so on. The
+ Wang OS was menu-driven.
+
+ (2008-05-28)
+
+wank
+
+ /wangk/ [Columbia University: probably by mutation from
+ Commonwealth slang "wank", to masturbate] Used much as {hack}
+ is elsewhere, as a noun denoting a clever technique or person
+ or the result of such cleverness. May describe (negatively)
+ the act of hacking for hacking's sake ("Quit wanking, let's go
+ get supper!") or (more positively) a {wizard}. "wanky"
+ describes something particularly clever (a person, program, or
+ algorithm). Conversations can also get wanky when there are
+ too many wanks involved. This excess wankiness is signalled
+ by an overload of the "wankometer" (compare {bogometer}).
+ When the wankometer overloads, the conversation's subject must
+ be changed, or all non-wanks will leave. Compare
+ "neep-neeping" (under {neep-neep}). Usage: US only. In
+ Britain and the Commonwealth this word is *extremely* rude and
+ is best avoided unless one intends to give offense.
+
+wannabee
+
+ /won'*-bee/ (Or, more plausibly, spelled "wannabe") [Madonna
+ fans who dress, talk, and act like their idol; probably
+ originally from biker slang] A would-be {hacker}. The
+ connotations of this term differ sharply depending on the age
+ and exposure of the subject. Used of a person who is in or
+ might be entering {larval stage}, it is semi-approving; such
+ wannabees can be annoying but most hackers remember that they,
+ too, were once such creatures. When used of any professional
+ programmer, CS academic, writer, or {suit}, it is derogatory,
+ implying that said person is trying to cuddle up to the hacker
+ mystique but doesn't, fundamentally, have a prayer of
+ understanding what it is all about. Overuse of hacker terms
+ is often an indication of the {wannabee} nature. Compare
+ {newbie}.
+
+ Historical note: The wannabee phenomenon has a slightly
+ different flavour now (1993) than it did ten or fifteen years
+ ago. When the people who are now hackerdom's tribal elders
+ were in {larval stage}, the process of becoming a hacker was
+ largely unconscious and unaffected by models known in popular
+ culture - communities formed spontaneously around people who,
+ *as individuals*, felt irresistibly drawn to do hackerly
+ things, and what wannabees experienced was a fairly pure,
+ skill-focussed desire to become similarly wizardly. Those
+ days of innocence are gone forever; society's adaptation to
+ the advent of the microcomputer after 1980 included the
+ elevation of the hacker as a new kind of folk hero, and the
+ result is that some people semi-consciously set out to *be
+ hackers* and borrow hackish prestige by fitting the popular
+ image of hackers. Fortunately, to do this really well, one
+ has to actually become a wizard. Nevertheless, old-time
+ hackers tend to share a poorly articulated disquiet about the
+ change; among other things, it gives them mixed feelings about
+ the effects of public compendia of lore like this one.
+
+ [{Jargon File}]
+
+want list
+
+ {wish list}
+
+WAP
+
+ {Wireless Application Protocol}
+
+WAP Forum
+
+ <body> The official body developing {Wireless Application
+ Protocol}.
+
+ {(http://wapforum.org/)}.
+
+ (2000-02-10)
+
+warchalk
+
+ <networking> A system of runes and annotations chalked on
+ walls or other surfaces to indicate to interested parties the
+ presence of a {wireless} network {node} in the vicinity.
+
+ Warchalking was inspired by "hobo language" - the signs used
+ by American itinerants during the Depression years to indicate
+ where they might find a meal.
+
+ {(http://blackbeltjones.com/warchalking/)}.
+
+ (2002-06-26)
+
+Ward Christensen
+
+ <person> The inventor of {XMODEM} and of the {BBS}. Ward did
+ physics in college and programmed {mainframes} for {IBM}.
+
+ Ward and friend Randy Suess set up their BBS on first on
+ 1978-02-16 in Chicago. It ran on an {S-100} computer with 64k
+ {RAM} and two single-sided 8" 250kB {diskettes}.
+
+ {Freeware Hall of Fame
+ (http://freewarehof.org/ward.html)}.
+
+ (2005-09-20)
+
+Ward Cunnigham
+
+ <person> The creator of the first {wiki}.
+
+ (2004-07-11)
+
+wardialer
+
+ <security> Almost certainly a shortened version of "WarGames
+ dialer", from the film {WarGames}.
+
+ 1. {carrier scanner}
+
+ 2. A program which attempts to break a {password} of known
+ length by iterating thru all possible combinations of
+ characters that could make up that password.
+
+ This approach is not feasable for cracking most passwords
+ these days. However, as late as the mid-1980s, some
+ long-distance companies required only very short numeric
+ access codes (e.g. five digits) to verify the identity of
+ their customers. Wardialers were created which would, running
+ unattended, call up long-distance providers' local connect
+ numbers and iteratively try possible access codes. Codes
+ which worked were logged for later illicit use.
+
+ These wardialers had a high success rate because of the small
+ range of possibilities to iterate through, e.g. 10000 for a
+ five digit access code, compared to hundreds of trillions of
+ combinations for an eight-character alphanumeric code.
+
+ Long-distance providers soon required longer passwords and
+ took advantage of technology for rapidly tracing the phone
+ numbers that wardialers were being run from, such that running
+ wardialers became pointless and dangerous.
+
+ (1997-03-16)
+
+wardriving
+
+ <security> (From {wardialer} in the "carrier scanner" sense of
+ that word) To drive around with a {laptop} with a {wireless
+ card}, and an antenna, looking for accessible {wireless
+ networks}.
+
+ (2003-06-24)
+
+-ware
+
+ ["software"] Commonly used to form terms for classes of
+ software. For examples, see {careware}, {crippleware},
+ {crudware}, {freeware}, {fritterware}, {guiltware},
+ {liveware}, {meatware}, {payware}, {psychedelicware},
+ {shareware}, {shelfware}, {vaporware}, {wetware}.
+
+ [{Jargon File}]
+
+warez
+
+ <software, legal> /weirz/ A term {software pirates} use to
+ describe {cracked} games or applications made available to the
+ {Internet}, at no cost, usually via {FTP} or {telnet}. Often
+ the pirate will make use of a site with lax security.
+
+ (1994-11-29)
+
+WarGames
+
+ <recreation> (Not "War Games") A 1983 film about a schoolboy
+ {cracker} using a {wardialer} to try to break into a games
+ company's computer and accidentally connecting to a {backdoor}
+ into "Whopper", a ficticious {C3} computer at Norad (USAF).
+ He then procedes to unwittingly initiate global thermonuclear
+ warfare. Playing naughts and crosses finally teaches Whopper
+ that the only way to win the game is never to play.
+
+ {IMDb (http://us.imdb.com/Title?WarGames+%281983%29)}.
+
+ (1999-03-08)
+
+warlording
+
+ <jargon> The act of excoriating a bloated, ugly or derivative
+ {sig block}. Common grounds for warlording include the
+ presence of a signature rendered in a {BUAF}, over-used or
+ cliched {sig quotes}, ugly {ASCII art}, or simply excessive
+ size. The original "Warlord" was a {BIFF}-like {newbie}
+ c. 1991 who featured in his sig a particularly large and
+ obnoxious ASCII graphic resembling the sword of Conan the
+ Barbarian in the 1981 John Milius movie; the group name
+ alt.fan.warlord was sarcasm, and the characteristic mode of
+ warlording is devastatingly sarcastic praise.
+
+ {Usenet} newsgroup: {news:alt.fan.warlord}.
+
+ [{Jargon File}]
+
+ (1994-11-29)
+
+warm boot
+
+ <operating system> A {boot} from {power on}, where the {CPU}
+ and {peripherals} are already powered up (warm).
+
+ A warm boot might be performed after a {software} {crash} or
+ a {hardware} {reset}.
+
+ Contrast {cold boot}. See also {reboot}.
+
+ [{Jargon File}]
+
+ (1998-04-28)
+
+Warm Silence Software
+
+ A small company run by(?) Robin Watts, producing {software}
+ for the {Acorn} {Archimedes}.
+
+ {(http://comlab.ox.ac.uk/oucl/users/robin.watts/)}.
+
+ (1994-11-01)
+
+Warp
+
+ {OS/2}
+
+wart
+
+ A small, {crock}y {feature} that sticks out of an otherwise
+ {clean} design. Something conspicuous for localised ugliness,
+ especially a special-case exception to a general rule. For
+ example, in some versions of "csh(1)", single quotes
+ literalise every character inside them except "!". In ANSI C,
+ the "?" syntax used for obtaining ASCII characters in a
+ foreign environment is a wart. See also {miswart}.
+
+ [{Jargon File}]
+
+washing machine
+
+ <storage> An old-style 14-inch {hard disk} in a floor-standing
+ cabinet. So called because of the size of the cabinet and the
+ "top-loading" access to the media packs - and, of course, they
+ were always set on "spin cycle". The thick channel cables
+ connecting these were called "{bit hoses}". The
+ washing-machine idiom transcends language barriers; it is even
+ used in Russian hacker jargon.
+
+ See also {walking drives}.
+
+ (1995-02-15)
+
+Wasserman
+
+ A.I. Wasserman (Tony), president of {IDE}.
+
+ (1995-02-15)
+
+WATBOL
+
+ WATerloo COBOL.
+
+ A {COBOL} for {IBM} {MVS}.
+
+ (1995-02-15)
+
+Watcom C/C++
+
+ <language, product> A compiler and development tools for
+ multi-{platform}, 16 and 32-bit applications. Watcom C/C++
+ 10.0 has an integrated development environment (IDE) and
+ development tools. It includes the {SOMobjects Toolkit} to
+ enable access to {IBM}'s {System Object Model} (SOM) and
+ {Distributed System Object Model} (DSOM). It supports 16 bit
+ {MS DOS}, {Microsoft Windows} 3.x, {OS/2} 1.x, and 32 bit
+ platforms including extended DOS, OS/2 2.x, {Windows NT},
+ {Win32s}, 32-bit Windows 3.x, {Novell NLM} and {AutoCAD}
+ {ADS}/{ADI}.
+
+ (1995-04-18)
+
+Watcom International
+
+ <company> A provider of application development tools and {IBM
+ PC}-based {SQL} {database} {servers}.
+
+ Founded in 1974, Watcom initially focused on scientific and
+ engineering markets establishing itself as a supplier of
+ programming and information tools worldwide, serving customers
+ in 60 countries with highly regarded products such as
+ {WATFOR}-77 for {mainframes}, {minicomputers} and {PCs}.
+
+ Since the introduction of {Watcom C} in 1988, the company has
+ emerged as an industry leader in optimising compilers for 16
+ and 32-bit {Intel-based} {IBM PCs}.
+
+ Moving into the {client/server} market in 1992, Watcom
+ introduced {Watcom SQL}, including {SQL} {database} {servers}
+ for multi-user networks and single-user {stand-alone}
+ applications. The product has since been incorporated into
+ {Powersoft}'s {PowerBuilder} development environment and the
+ {Powersoft Enterprise Series}. In June, 1993, Watcom launched
+ {VX*REXX}, an integrated visual development environment for
+ {OS/2}.
+
+ In February 1994, Watcom became a wholly-owned subsidiary of
+ {Powersoft Corporation} which merged with {Sybase Inc.}
+ on 13 February 1995. Today the company addresses a broad
+ range of application developers, including corporate {MIS}
+ professionals, system integrators, {VARs} and independent
+ software vendors.
+
+ Watcom has strategic relationships with {IBM}, {Lotus},
+ {Microsoft}, {Intel} and {Novell}. Based on its academic
+ roots, Watcom maintains a research relationship with the
+ nearby {University of Waterloo}.
+
+ Watcom's products include the {Watcom SQL} {databases},
+ {Watcom C/C++}, and {Watcom VX*REXX} 2.1.
+
+ Ian McPhee is President and Chief Executive Officer, David
+ Boswell is Vice President of Sales and Marketing, Craig Dynes
+ is Vice President of Finance and David Yach is Vice President
+ of Development.
+
+ Headquarters: Waterloo, Ontario, Canada.
+
+ (1995-04-18)
+
+Watcom SQL
+
+ <database, product> A family of {databases} from {Watcom
+ International}, based on scalable technology and a {SQL}
+ {database engine}. Version 4.0 adds {stored procedures} and
+ {triggers}. It is designed for environments ranging from
+ large departmental networks with a diverse range of PC client
+ systems, to peer-to-peer {workgroups}, to {stand-alone} PCs.
+ It is available in stand-alone versions for {Microsoft
+ Windows}, {Windows NT}, {OS/2} and {MS DOS}; and {multi-user}
+ network server versions for {Microsoft Windows}, {Windows NT},
+ {OS/2}, {NetWare NLM} and {MS DOS}.
+
+ (1995-04-18)
+
+Watcom VX*REXX
+
+ <programming, tool> A visual development environment for
+ creating {OS/2} applications with {graphical user interfaces}.
+ It includes a project management facility, visual designer and
+ an interactive {source level debugger}. Version 2.1
+ introduced the VX*REXX Client/Server Edition for
+ {client/server} {GUI} application development on {OS/2} by
+ incorporating {database} {objects}. Using {IBM}'s {DRDA}
+ support on OS/2, users can access {DB2} for {MVS}, DB2/400 for
+ {AS/400}, and DB2/VSE and VM (SQL/DS) for {VM} and {VSE}.
+ Also supported are {Watcom SQL} and {ODBC}-enabled databases.
+ Since the VX*REXX visual development environment is based on
+ IBM's {object-oriented} {SOM} technology, VX*REXX applications
+ are open and extensible through the addition of new SOM
+ objects.
+
+ (1995-04-18)
+
+Waterfall Model
+
+ <programming> A {software life-cycle} or {product life-cycle}
+ model, described by W. W. Royce in 1970, in which development
+ is supposed to proceed linearly through the phases of
+ {requirements analysis}, design, implementation, testing
+ (validation), integration and maintenance. The Waterfall
+ Model is considered old-fashioned or simplistic by proponents
+ of {object-oriented design} which often uses the {spiral
+ model} instead.
+
+ Earlier phases are sometimes called "upstream" and later ones
+ "downstream".
+
+ Compare: {iterative model}.
+
+ [W. W. Royce, "Managing the Development of Large Software
+ Systems", Proceedings of IEEE WESCON, August 1970].
+
+ (1997-11-23)
+
+water MIPS
+
+ <jargon> Large, water-cooled computers of either today's
+ {ECL}-{supercomputer} flavour or yesterday's traditional
+ {mainframe} type.
+
+ See {MIPS}
+
+ [{Jargon File}]
+
+ (1995-03-25)
+
+WATFIV
+
+ WATerloo Fortran IV. U Waterloo, Canada. Student-friendly
+ variant of Fortran IV.
+
+WATFOR
+
+ WATerloo FORtran. U Waterloo, Canada. Student-friendly
+ variant of {Fortran}. "WATFOR - The University of Waterloo
+ Fortran IV Compiler", P.W. Shantz et al, CACM 10(1):41-44 (Jan
+ 1967).
+
+wav
+
+ <multimedia, file format, filename extension> (waveform)
+ /wav/, /dot wav/ A {sound} format developed by {Microsoft} and
+ used extensively in {Microsoft Windows}. Conversion tools are
+ available to allow most other {operating systems} to play .wav
+ files.
+
+ .wav files are also used as the sound source in {wavetable}
+ synthesis, e.g. in E-mu's {SoundFont}. In addition, .wav
+ files are also supported by some {MIDI} sequencers as add-on
+ audio. That is, pre-recorded .wav files are played back by
+ control commands written in the sequence script.
+
+ {Specification (http://qzx.com/pc-gpe/wav.txt)}.
+
+ (1997-10-11)
+
+WAVE
+
+ <language, robotics> A {robotics} language.
+
+ ["WAVE: A Model-Based Language for Manipulator Control",
+ R.P. Paul, Ind Robot 4(1):10-17, 1979].
+
+ (1996-09-08)
+
+wave a dead chicken
+
+ <jargon> To perform a ritual in the direction of crashed
+ software or hardware that one believes to be futile but is
+ nevertheless necessary so that others are satisfied that an
+ appropriate degree of effort has been expended. "I'll wave a
+ dead chicken over the source code, but I really think we've
+ run into an OS bug".
+
+ Compare {voodoo programming}, {rain dance}.
+
+ [{Jargon File}]
+
+ (1996-09-08)
+
+wave division multiplexing
+
+ <spelling> A common misnomer for {wavelength division
+ multiplexing}.
+
+ (2002-07-16)
+
+Waveform Generation Language
+
+ <testing> (WGL) A {data description language} for test program
+ description.
+
+ [Reference? What kind of test programs?]
+
+ (2001-05-20)
+
+wavelength division multiplexing
+
+ <communications> (WDM) {Multiplexing} several {Optical Carrier
+ n} signals on a single {optical fibre} by using different
+ wavelengths (colours) of {laser} light to carry different
+ signals.
+
+ The device that joins the signals together is known as a
+ {multiplexor}, and the one that splits them apart is a
+ {demultiplexor}. With the right type of fibre you can have a
+ device that does both and that ought to be called a "mudem"
+ but isn't.
+
+ The first WDM systems combined two signals and appeared around
+ 1985. Modern systems can handle up to 128 signals and can
+ expand a basic 9.6 {Gbps} fibre system to a capacity of over
+ 1000 Gbps.
+
+ WDM systems are popular with telecommunications companies
+ because they allow them to expand the capacity of their fibre
+ networks without digging up the road again. All they have to
+ do is to upgrade the (de)multiplexors at each end. However
+ these systems are expensive and complicated to run. There is
+ currently no {standard}, which makes it awkward to integrate
+ with older but more standard {SONET} systems.
+
+ Note that this term applies to an optical {carrier} (which is
+ typically described by its wavelength), whereas {frequency
+ division multiplexing} typically applies to a {radio} carrier
+ (which is more often described by frequency). However, since
+ wavelength and frequency are inversely proportional, and since
+ radio and light are both forms of electromagnetic radiation,
+ the distinction is somewhat arbitrary.
+
+ See also {time division multiplexing}, {code division
+ multiplexing}.
+
+ [Is "wave division multiplexing", as in "dense wave division
+ multiplexing" (DWDM) just a trendy abbreviation?]
+
+ (2002-07-16)
+
+wavelet
+
+ <mathematics> A waveform that is bounded in both {frequency}
+ and duration. Wavelet tranforms provide an alternative to
+ more traditional {Fourier transforms} used for analysing
+ waveforms, e.g. sound.
+
+ The {Fourier transform} converts a signal into a continuous
+ series of {sine waves}, each of which is of constant frequency
+ and {amplitude} and of infinite duration. In contrast, most
+ real-world signals (such as music or images) have a finite
+ duration and abrupt changes in frequency.
+
+ Wavelet transforms convert a signal into a series of wavelets.
+ In theory, signals processed by the wavelet transform can be
+ stored more efficiently than ones processed by Fourier
+ transform. Wavelets can also be constructed with rough edges,
+ to better approximate real-world signals.
+
+ For example, the United States Federal Bureau of Investigation
+ found that Fourier transforms proved inefficient for
+ approximating the whorls of fingerprints but a wavelet
+ transform resulted in crisper reconstructed images.
+
+ {SBG Austria (http://mat.sbg.ac.at/~uhl/wav.html)}.
+
+ ["Ten Lectures on Wavelets", Ingrid Daubechies].
+
+ (1994-11-09)
+
+wavetable
+
+ <hardware, music> A type of {sound generator} often built in a
+ {sound card}. A wavetable contains digitised samples of real
+ instrument sounds or effect (FX) sounds. A wavetable chip
+ often also contains a drum kit sound to faciliate rhythm
+ accompaniment.
+
+ A recorded wavetable sound may be edited and enhanced by
+ various effects (reverb, chorus) and layered with other
+ waveforms before writing it to {ROM} or {RAM}. The latter
+ type serves as user sound memory.
+
+ A wavetable generator is typically controlled by {MIDI} input.
+ When a MIDI note-on signal is detected, the output part of a
+ wavetable generator generates a sound with definitive pitch,
+ typically a musical note.
+
+ Wavetable sounds are used in games and music. The more
+ realistic wavetable sounds have all but replaced the earlier
+ synthetic FM (frequency modulation) sound generation in sound
+ cards but to ensure compatibility with older games etc., an FM
+ part is usually included.
+
+ The best known wavetable sound generators includes the {E-mu
+ 8000} chip, used in {Creative Labs}' {Sound Blaster} AWE-32
+ card family and in E-mu keyboards. Other wavetable cards are
+ Gravis Ultra-Sound (GUS), ESS Cards, Opti, Zoltrix and many
+ Roland cards.
+
+ {E-Mu (http://emu.com /)}.
+ {AWE-32(http://edu.isy.liu.se/~d93jesno/awe32.html)}.
+ {Creative Labs (http://creaf.com/)}.
+
+ (1997-11-04)
+
+wavetable synthesis
+
+ {wavetable}
+
+WaZOO
+
+ <protocol> Warp-zillion Opus-to-Opus. {Fidonet}'s
+ {session layer} {protocol}. Although it mentions {Opus} (a
+ specific {BBS} from the 1980s), WaZOO is the session protocol
+ used for the Fidonet network. Because WaZOO is much more
+ efficient than other mechanisms (e.g., {FTP}), it is sometimes
+ used for automated or batch communications in other parts of
+ the {Internet}.
+
+ {(ftp://ftp.psg.com/pub/fidonet/stds/fts-0006.txt)}.
+
+ (1995-11-16)
+
+wb
+
+ <chat> Welcome Back.
+
+WBEM
+
+ {Web-Based Enterprise Management}
+
+WBMP
+
+ {wireless bitmap}
+
+WBS
+
+ {Work Breakdown Structure}
+
+WCDMA
+
+ {Wideband Code Division Multiple Access}
+
+WCL
+
+ A {Common Lisp} implementation in a shared library by Wade
+ Hennessey <wade@leland.Stanford.edu>. WCL is not a complete
+ Common Lisp, but it does have the full development environment
+ including {dynamic file loading} and debugging. A modified
+ version of {GDB} provides mixed-language debugging.
+
+ Version 2.14 includes a shared library, run-time support and
+ source debugger. It requires {GNU} {GCC} 2.1 (not 2.2.2) and
+ runs on {SPARC} under {SunOS}.
+
+ {(ftp://sunrise.stanford.edu/pub/wcl/)}. Mailing list:
+ <wcl-request@sunrise.stanford.edu>. E-mail:
+ <wcl@sunrise.stanford.edu>.
+
+ [Proceedings of the 1992 Lisp and Functional Programming
+ Conference].
+
+ (1992-10-28)
+
+WD
+
+ {Western Digital}
+
+WDASM
+
+ <tool> (Probably "Windows disassembler") An {interactive}
+ {Intel 486} {disassembler} for {Windows 3.1} written by Eric
+ Grass at the University of Missouri, St. Louis. WDASM
+ supports multiple disassembly formats.
+
+ {(ftp://ftp.simtel.com/cica/win3/util/wdasm15.zip)}.
+
+ (1993-06-01)
+
+WDM
+
+ {wavelength division multiplexing}
+
+WE
+
+ A {hypertext} {authoring} system developed at the {University
+ of North Carolina}.
+
+ (1994-11-07)
+
+Weak Head Normal Form
+
+ <reduction, lambda calculus> (WHNF) A {lambda expression} is
+ in weak head normal form (WHNF) if it is a {head normal form}
+ (HNF) or any {lambda abstraction}. I.e. the top level is not
+ a {redex}.
+
+ The term was coined by {Simon Peyton Jones} to make explicit
+ the difference between {head normal form} (HNF) and what
+ {graph reduction} systems produce in practice. A lambda
+ abstraction with a reducible body, e.g.
+
+ \ x . ((\ y . y+x) 2)
+
+ is in WHNF but not HNF. To reduce this expression to HNF
+ would require reduction of the lambda body:
+
+ (\ y . y+x) 2 --> 2+x
+
+ Reduction to WHNF avoids the {name capture} problem with its
+ need for {alpha conversion} of an inner lambda abstraction and
+ so is preferred in practical {graph reduction} systems.
+
+ The same principle is often used in {strict} languages such as
+ {Scheme} to provide {call-by-name} evaluation by wrapping an
+ expression in a lambda abstraction with no arguments:
+
+ D = delay E = \ () . E
+
+ The value of the expression is obtained by applying it to the
+ empty argument list:
+
+ force D = apply D ()
+ = apply (\ () . E) ()
+ = E
+
+ (1994-10-31)
+
+weakly typed
+
+ {weak typing}
+
+weak typing
+
+ <programming> Strict enforcement of {type} rules but with
+ well-defined exceptions or an explicit type-violation
+ mechanism.
+
+ Weak typing is "friendlier" to the programmer than {strong
+ typing}, but catches fewer errors at compile time.
+
+ {C} and {C++} are weakly typed, as they automatically {coerce}
+ many types e.g. {ints} and {floats}. E.g.
+
+ int a = 5;
+ float b = a;
+
+ They also allow ignore {typedefs} for the purposes of type
+ comparison; for example the following is allowed, which would
+ probably be disallowed in a strongly typed language:
+
+ typedef int Date; /* Type to represent a date */
+ Date a = 12345;
+ int b = a; /* What does the coder intend? */
+
+ C++ is stricter than C in its handling of enumerated types:
+
+ enum animal {CAT=0,DOG=2,ANT=3};
+ enum animal a = CAT; /* NB The enum is optional in C++ */
+ enum animal b = 1; /* This is a warning or error in C++ */
+
+ (2000-07-04)
+
+weasel
+
+ <jargon, abuse> (Cambridge) A naive user, one who deliberately
+ or accidentally does things that are stupid or ill-advised.
+ Roughly synonymous with {loser}.
+
+ [{Jargon File}]
+
+ (1995-03-21)
+
+WEB
+
+ <language> {Donald Knuth}'s self-documenting {literate
+ programming}, with {algorithms} and {documentation} intermixed
+ in one file. They can be separated using {Weave} and
+ {Tangle}. Versions exist for {Pascal} and {C}. {Spiderweb}
+ can be used to create versions for other languages.
+ {FunnelWeb} is a production-quality literate-programming tool.
+
+ {(ftp://princeton.edu/)}, {(ftp://labrea.stanford.edu/)}.
+
+ ["Literate Programming", D.E. Knuth, Computer J 27(2):97-111,
+ May 1984].
+
+ (1996-05-10)
+
+Web
+
+ {World-Wide Web}
+
+Web 2.0
+
+ <jargon> A loosely defined term for {web applications} that go
+ beyond displaying individual pages of static content and allow
+ a community of users to interact with the site and each other
+ by adding or updating the content.
+
+ Examples include social-networking sites like {Facebook} and
+ other web-based communities, hosted services like {Google
+ Docs}, web applications like {GMail}, video-sharing sites
+ ({Youtube}), wikis ({Wikipedia}), {web logs}, {mashups} and
+ {folksonomies}.
+
+ While Web 2.0 applications often use advanced web features
+ like {AJAX} to improve the speed of interaction, the term is
+ more about the type of applications than the technology used.
+
+ The term was coined by Darcy DiNucci in 1999, though she was
+ discussing designing websites for new hardware platforms.
+
+ (2009-11-18)
+
+web2c
+
+ <tool> A utility by Karl Berry <karl@claude.cs.umb.edu> to
+ translate {WEB} to {C}.
+
+ Latest version: 5-851d.
+
+ {FTP UCI (ftp://ics.uci.edu/TeX/web2c.tar.Z)}. {FTP Gernamy
+ (ftp://ftp.th-darmstadt.de/pub/tex/src/web2c/web2c.tar.Z)}.
+
+ (1996-05-10)
+
+web address
+
+ {Uniform Resource Locator}
+
+web authoring
+
+ <web> Creating {web content}, e.g. {HTML} pages,
+ {images}, {JavaScript} or {Flash}, for use on the {World-Wide
+ Web}. {Web authoring} typically does not include generating
+ the actual text or "copy" of web pages but is cheifly
+ concerned with its presentation.
+
+ (2009-02-06)
+
+Web-Based Enterprise Management
+
+ <standard, system management> (WBEM) A {DMTF} management
+ {standard} using the {Common Information Model} to represent
+ systems, {applications}, {networks}, {devices} and other
+ managed components; developed to unify the management of
+ {distributed computing} environments.
+
+ {WBEM Home (http://dmtf.org/standards/wbem/))}
+
+ (2005-02-19)
+
+web browser
+
+ <web> A {browser} for the {web}.
+
+ (1996-03-23)
+
+webcam
+
+ <web, hardware, video> (web camera) Any
+ video camera whose output is available for viewing via the
+ {Internet} or an {intranet}. Typically a webcam would be a
+ slow-scan {CCD} video camera connected to a video capture card
+ in a computer. Images from the camera are captured
+ periodically and made available on a web page. In 1999 there
+ are hundreds of webcams in operation around the world showing
+ everything from bedrooms to traffic.
+
+ [List?]
+
+ (1999-01-11)
+
+webcasting
+
+ <multimedia, web> (From "web" and
+ "broadcast", sometimes just called "push") {Multicasting} on
+ the {Internet}. Webcasting implies {real-time} {streaming}
+ transmission of encoded {video} (or {audio}) under the control
+ of the {server} to multiple recipients who all receive the
+ same content at the same time. This is in contrast to normal
+ web browsing which is controlled from the {browser} by
+ individual users and may take arbitrarily long to deliver a
+ complete document.
+
+ {Pointcast} and {Marimba} were early pioneers.
+
+ {International Webcasting Association
+ (http://webcasters.org/)}.
+
+ (2003-07-08)
+
+WebCGM
+
+ <graphics, file format> A {Web}-oriented version of the
+ {Computer Graphic Metafile} file format.
+
+ (1999-02-16)
+
+WebCOMAL
+
+ {COMmon Algorithmic Language}
+
+web cramming
+
+ <web, legal> Any kind of fraudulent charges made to
+ the telephone account of the victim, typically a small
+ business or non-profit group, e.g. while claiming to provide
+ web design or hosting for little or no charge.
+
+ ["Computer Forensics and Cyber Crime": Marjie T. Britz].
+
+ (2007-03-16)
+
+WebCrawler
+
+ <web> A free {web} {search engine} developed by Brian Pinkerton at
+ the {University of Washington} and now moved to {America Online,
+ Inc}. WebCrawler collects {URLs} by searching the {Internet} and
+ allows users to perform keyword searches through a web {browser}.
+
+ {(http://webcrawler.com/)}.
+
+ (1995-11-28)
+
+webhead
+
+ <web> A compulsive or frequent user of, or
+ contributor to, the {web}.
+
+ (1994-07-21)
+
+web host
+
+ <web, business> A company that supplies {web
+ hosting}.
+
+ (2008-04-15)
+
+web hosting
+
+ <web, business> Running {web servers} for other
+ businesses or individuals, usually as a commercial venture.
+ Basic web hosting would allow customers to upload own {web
+ site} content - {HTML} pages, {images}, {video} - typically
+ via {FTP}, to a shared web server which other people can
+ access via the {Internet}.
+
+ A {web hosting (http://webhostingsearch.com/)} businesses may
+ provide any or all of the functions required by a website
+ including: networking, HTTP server software, content storage,
+ {content management}, running customer or off-the-shelf {CGI}
+ programs, {ASP} scripts or other server extentions, {load
+ balancing}, {streaming content}, {domain name} registration,
+ {DNS} serving, {electronic mail} storage and forwarding,
+ {database}, {shell account}, content design and creation,
+ {search engine optimisation}, {web log} analysis and web
+ applications such as on-line shopping with financial
+ transaction processing.
+
+ (2011-12-24)
+
+weblint
+
+ <hypertext, tool> (After {lint}) A {syntax} checker and style
+ checker for {HTML}. Weblint is a {Perl} script which does for
+ HTML pages what the traditional {lint} picks does for {C}
+ programs.
+
+ Version: 1.020 (1997-12-07).
+
+ {(http://cre.canon.co.uk/~neilb/weblint/)}.
+
+ (1997-12-07)
+
+web log
+
+ {blog}
+
+web mail
+
+ <messaging> An {electronic mail} {user agent} that is
+ accessible on the web (via {HTTP}). {HoTMail} was one of the
+ first (bought by {Microsoft}), {Google}'s {GMail} is another
+ popular example.
+
+ (2007-02-13)
+
+webmaster
+
+ <web> (Sometimes "webmistress") The alias or role
+ of the person(s) responsible for the development and
+ maintenance of one or more {web servers} and/or some or all of
+ the {web pages} at a {website}. The term does not imply any
+ particular level of skill or mastery (see "{webmonkey}").
+
+ The webmaster's {e-mail address} often appears on the {home
+ page} of the site. Failing that, you could try sending e-mail
+ to {postmaster} (from which the term is probably derived) or
+ {root} at that {host}, possibly after removing an initial
+ "www.".
+
+ (1999-04-01)
+
+webmistress
+
+ {webmaster}
+
+webmonkey
+
+ <web> a largely unskilled {Web} worker - one with a
+ passable understanding of {HTML} but little else.
+
+ It is often supposed that, in the New Media food chain, there
+ is nothing lower than a webmonkey. Alas, there is: people who
+ barely have the skills to use FrontPage; these people are
+ called "typists".
+
+ The {B1FF} of webmonkeys is personified as {Bobo the
+ Webmonkey}.
+
+ Compare {actor/singer/waiter/webmaster}.
+
+ And compare {sysape}, {one-banana problem}, {scratch monkey},
+ {monkey up}, and {Infinite-Monkey Theorem} for other simian
+ allusions.
+
+ (1998-04-04)
+
+WebObjects
+
+ <operating system> {Apple Computer, Inc.}'s {application
+ server} {framework} for developing dynamic {web applications}.
+
+ WebObjects applications accept {HTTP} requests either directly
+ (usually on a specific {port}) or via an adaptor that sits
+ between them and the web server. Adaptors are either {CGI}
+ programs or web server plug-ins ({NSAPI} or {ISAPI}).
+
+ The server processes special tags in {HTML} pages to produce
+ dynamic but standard HTML. Tools are provided to easily set
+ and get object properties and invoke methods from these tags.
+ Applications can maintain {state} over multiple {HTTP}
+ request-response transactions (which are intrinsically
+ stateless). Applications can also use Apple's {Enterprise
+ Object Framework} {object relational mapping} libraries for
+ {object persistence} and database access.
+
+ WebObjects was originally based on {Objective C} and a simple
+ scripting language but now is more likely to be used with
+ {Java}. Versions are available for {OS X}, {Windows} and
+ {Unix}.
+
+ Apple acquired WebObjects from {NeXT}, along with {Steve
+ Jobs}.
+
+ {WebObjects Home (http://apple.com/webobjects/)}.
+
+ (2005-01-14)
+
+web page
+
+ <web> A block of data available on the {World-Wide
+ Web}, identified by a {URL}. In the simplest, most common
+ case, a web page is a file written in {HTML}, stored on the
+ {server}. It may refer to {images} which appear as part of
+ the page when it is displayed by a {web browser}. It is also
+ possible for the server to generate pages dynamically in
+ response to a request, e.g. using a {CGI} script.
+
+ A web page can be in any format that the browser or a {helper
+ application} can display. The format is transmitted as part
+ of the headers of the response as a {MIME} type,
+ e.g. "text/html", "image/gif".
+
+ An HTML web page will typically refer to other web pages and
+ {Internet} resources by including {hypertext} links.
+
+ A {website} often has a {home page} (usually just the
+ hostname, e.g. http://foldoc.org/). It may also have
+ individual home pages for each user with an account at the
+ site.
+
+ (1999-03-21)
+
+web proxy
+
+ {HTTP proxy server}
+
+Web Request Broker
+
+ <web> (WRB) Part of {Oracle Corporation}'s
+ {WebServer} suite of programs. It is a high-performance,
+ {multi-threaded} {HTTP} server which allows {clients}'
+ requests to be directly translated into {Oracle 7} {database}
+ scripts, and automatically translates the results of the query
+ back into {HTML} for delivery to the client {browser}.
+
+ {Oracle WebServer
+ (http://oracle.com/products/websystem/webserver/html/ws2_info.html)}.
+
+ (1997-03-14)
+
+web server
+
+ {HTTP server}
+
+Web Service Definition Language
+
+ <architecture> (WSDL) An {XML} format for describing network
+ {services} as a set of endpoints operating on messages
+ containing either "document oriented" or "procedure oriented"
+ information. The operations and messages are described
+ abstractly, and then bound to a concrete network protocol and
+ message format to define an endpoint. Related concrete
+ endpoints are combined into abstract endpoints
+ (services).
+
+ WSDL is typically used with {SOAP} over {HTTP} but it is
+ extensible to allow description of endpoints and their
+ messages independent of what message formats or network
+ protocols.
+
+ [Reference?]
+
+ (2004-06-21)
+
+Web Services
+
+ <standard, programming, software> A family of {standards}
+ promoted by the {W3C} for working with other business,
+ {developers} and {programs} through open {protocols},
+ {languages} and {APIs}, including {XML}, {Simple Object Access
+ Protocol}, {WSDL} and {UDDI}.
+
+ {W3C Web Services (http://w3.org/2002/ws)}.
+
+ (2004-06-23)
+
+Web Services Business Process Execution Language
+
+ <programming> (WSBPEL, BPEL4WS) An {OASIS} technical committee
+ considering ways to enable users to describe {business processes}
+ as {web services} and define how they can be connected to
+ accomplish specific tasks.
+
+ {(http://oasis-open.org/committees/tc_home.php?wg_abbrev=wsbpel)}.
+
+ (2006-08-15)
+
+website
+
+ <web> (Or "web site") Any computer on the {Internet} running a
+ {web server} process. A particular website is usually identified
+ by the {hostname} part of a {URL}. Multiple hostnames may
+ actually map to the same computer in which case they are known as
+ "{virtual servers}".
+
+ (2005-07-12)
+
+web smith
+
+ <web> A person who creates {web pages}. Not
+ necessarily the same as a {webmaster}.
+
+ (1997-02-05)
+
+Webster
+
+ 1. {Webster's Dictionary}.
+
+ 2. A {web browser} for the {Acorn} {Archimedes}. The {HTML} files
+ may reside locally or be retrieved using a "fetcher". An {HTTP}
+ fetcher for use with {KA9Q} is supplied.
+
+ Version: 0.05.
+
+ {HENSA Gopher
+ (gopher://micros.hensa.ac.uk:70/11/micros/arch/riscos/c/c164)}.
+ {Demon FTP
+ (ftp://ftp.demon.co.uk/pub/archimedes/developers/)}.
+
+ (1995-02-21)
+
+Webster's Dictionary
+
+ {Hypertext interface
+ (http://c.gp.cs.cmu.edu:5103/prog/webster)}.
+
+ (1996-04-10)
+
+wedged
+
+ 1. To be stuck, incapable of proceeding without help. This is
+ different from having crashed. If the system has crashed, it
+ has become totally non-functioning. If the system is wedged,
+ it is trying to do something but cannot make progress; it may
+ be capable of doing a few things, but not be fully
+ operational. For example, a process may become wedged if it
+ {deadlocks} with another (but not all instances of wedging are
+ deadlocks). See also {gronk}, {locked up}, {hosed}. 2. Often
+ refers to humans suffering misconceptions. "He's totally
+ wedged - he's convinced that he can levitate through
+ meditation." 3. [Unix] Specifically used to describe the
+ state of a TTY left in a losing state by abort of a
+ screen-oriented program or one that has messed with the line
+ discipline in some obscure way.
+
+ There is some dispute over the origin of this term. It is
+ usually thought to derive from a common description of
+ recto-cranial inversion; however, it may actually have
+ originated with older "hot-press" printing technology in which
+ physical type elements were locked into type frames with
+ wedges driven in by mallets. Once this had been done, no
+ changes in the typesetting for that page could be made.
+
+ [{Jargon File}]
+
+wedgie
+
+ (Fairchild) A bug. Probably related to {wedged}.
+
+wedgitude
+
+ /wedj'i-t[y]ood/ The quality or state of being {wedged}.
+
+ [{Jargon File}]
+
+Weeble
+
+ /wee'b*l/ An egg-shaped plastic toy person with a weight in
+ the bottom so that, if tipped over, they would right
+ themselves and stand up again. They were popular in the UK
+ during the 1970s and were famous for the slogan "Weebles
+ wobble but they don't fall down", unlike some computers
+ (pretty tenuous link with computing).
+
+ (1994-11-29)
+
+weeds
+
+ 1. Refers to development projects or {algorithms} that have no
+ possible relevance or practical application. Comes from "off
+ in the weeds". Used in phrases like "lexical analysis for
+ {microcode} is serious weeds."
+
+ 2. At {CDC}/{ETA} before its demise, the phrase "go off in the
+ weeds" was equivalent to {IBM}'s {branch to Fishkill} and
+ mainstream hackerdom's {jump off into never-never land}.
+
+ [{Jargon File}]
+
+weenie
+
+ 1. [on BBSes] Any of a species of {luser} resembling a less
+ amusing version of {BIFF} that infests many {BBS}es. The
+ typical weenie is a teenage boy with poor social skills
+ travelling under a grandiose {handle} derived from fantasy or
+ heavy-metal rock lyrics. Among {sysops}, "the weenie problem"
+ refers to the marginally literate and profanity-laden
+ {flamage} weenies tend to spew all over a newly-discovered
+ BBS.
+
+ Compare {spod}, {computer geek}, {terminal junkie}.
+
+ 2. Among hackers, when used with a qualifier (for example, as
+ in {Unix weenie}, {VMS} weenie, {IBM} weenie) this can be
+ either an insult or a term of praise, depending on context,
+ tone of voice, and whether or not it is applied by a person
+ who considers him or herself to be the same sort of weenie.
+ It implies that the weenie has put a major investment of time,
+ effort and concentration into the area indicated; whether this
+ is good or bad depends on the hearer's judgment of how the
+ speaker feels about that area. See also {bigot}.
+
+ 3. The {semicolon} character, ";" ({ASCII} 59).
+
+ (1995-01-18)
+
+Weenix
+
+ /wee'niks/ An {ITS} fan's derogatory term for {Unix}, derived
+ from {Unix weenie}. According to one noted ex-{ITS}er, it is
+ "the operating system preferred by Unix Weenies: typified by
+ poor modularity, poor reliability, hard file deletion, no file
+ version numbers, case sensitivity everywhere, and users who
+ believe that these are all advantages". Some {ITS} fans
+ behave as though they believe Unix stole a future that
+ rightfully belonged to them.
+
+ [{Jargon File}]
+
+ (1995-01-18)
+
+weighted search
+
+ <information science> A search based on frequencies of the
+ {search terms} in the documents being searched. Weighted
+ search is often used by {search engines}. It produces a
+ numerical score for each possible document. A document's
+ score depends on the frequency of each {search term} in that
+ document compared with the overall frequency of that term in
+ the entire corpus of documents. A common approach is called
+ tf.idf which stands for term frequency * inverse document
+ frequency. Term frequency means "the more often a term occurs
+ in a document, the more important it is in describing that
+ document."
+ {http://ciir.cs.umass.edu/cmpsci646/ir4/tsld034.htm} Inverse
+ document frequency means the more documents a term appears in,
+ the less important the term is.
+
+ A simple weighted search is just a list of search terms,
+ for example: car automobile
+
+ Weighted search is often contrasted with {boolean search}.
+ It is possible to have a search that syntactically is a
+ boolean search but which also does a weighted search.
+
+ See also {query expansion}.
+
+ For a detailed technical discussion see Chapter 5,
+ "Search Strategies", in the reference below.
+
+ [{"Information Retrieval", C. J. van Rijsbergen,
+ (http://dcs.gla.ac.uk/Keith/Chapter.5/Ch.5.html)}].
+
+ (1999-08-28)
+
+well-behaved
+
+ 1. [primarily {MS-DOS}] Said of software conforming to system
+ interface guidelines and standards. Well-behaved software
+ uses the {operating system} to do chores such as keyboard
+ input, allocating memory and drawing graphics. Oppose
+ {ill-behaved}.
+
+ 2. Software that does its job quietly and without
+ counterintuitive effects. Especially said of software having
+ an interface spec sufficiently simple and well-defined that it
+ can be used as a {tool} by other software. See {cat}.
+
+ [{Jargon File}]
+
+well-connected
+
+ Said of a computer installation, asserts that it has reliable
+ {electronic mail} links with the network and/or that it relays
+ a large fraction of available {Usenet} newsgroups.
+ "Well-known" can be almost synonymous, but also implies that
+ the site's name is familiar to many (due perhaps to an archive
+ service or active {Usenet} users).
+
+well-known port
+
+ <networking> A {TCP or {UDP} {port} with a number in the range
+ 0-1023 (originally 0-255). The well-known port numbers are
+ assigned by the {IANA} and on most systems can only be used by
+ system (or root) processes or by programs executed by
+ privileged users.
+
+ (2002-10-06)
+
+well-ordered set
+
+ <mathematics> A set with a {total ordering} and no infinite
+ descending {chains}. A total ordering "<=" satisfies
+
+ x <= x
+
+ x <= y <= z => x <= z
+
+ x <= y <= x => x = y
+
+ for all x, y: x <= y or y <= x
+
+ In addition, if a set W is well-ordered then all non-empty
+ subsets A of W have a least element, i.e. there exists x in A
+ such that for all y in A, x <= y.
+
+ {Ordinals} are {isomorphism classes} of {well-ordered sets},
+ just as {integers} are {isomorphism classes} of finite sets.
+
+ (1995-04-19)
+
+WEP
+
+ {Wireless Encryption Protocol}
+
+Wesley Clark
+
+ <person> One of the designers of the {Laboratory Instrument
+ Computer} at {MIT} who subsequently had a quiet hand in many
+ seminal computing events, such as the development of the
+ {Internet}, the first really good description of the
+ {metastability} problem in computer logic.
+
+ {(http://pretext.com/mar98/features/story1.htm)}.
+
+ (1999-03-29)
+
+Western Digital Corporation
+
+ <company> A company founded in 1970 as a specialised
+ semiconductor manufacturer, which today manufactures and sells
+ {microcomputer} products including small form factor {hard
+ disk drives} for {personal computers}, {integrated circuits}
+ and circuit boards for graphics, storage, communications,
+ {battery management}, and logic functions.
+
+ {(http://wdc.com/)}.
+
+ (1995-04-12)
+
+Westmount
+
+ <company> A Dutch software engineering vendor of {RTEE} and
+ other products.
+
+ (1998-04-27)
+
+wetware
+
+ <jargon> /wet'weir/ (Probably from the novels of Rudy Rucker,
+ or maybe Stanislav Lem) The human nervous system, as opposed
+ to electronic computer {hardware} or {software}. "Wetware has
+ 7 plus or minus 2 temporary {registers}." Also, human beings
+ (programmers, operators, administrators) attached to a
+ computer system, as opposed to the system's hardware or
+ software.
+
+ See {liveware}, {meatware}.
+
+ [True origin? Dates?]
+
+ [{Jargon File}]
+
+ (1996-08-19)
+
+wf
+
+ <networking> The {country code} for the Wallis and Futuna
+ Islands.
+
+ (1999-01-27)
+
+WFL
+
+ Work Flow Language. Burroughs, ca 1973. A job control
+ language for the B6700/B7700 under MCP. WFL was a compiled
+ block-structured language similar to ALGOL 60, with
+ subroutines and nested begin-end's.
+
+ ["Work Flow Management User's Guide", Burroughs Manual
+ 5000714, 1973].
+
+ ["Burroughs B6700/B7700 Work Flow Language", R.M. Cowan in
+ "Command Languages", C. Unger ed, N-H 1975].
+
+ (1996-01-18)
+
+WfMC
+
+ {Workflow Management Coalition}
+
+WFW
+
+ {Windows for Workgroups}
+
+WFWG
+
+ {Windows for Workgroups}
+
+WG
+
+ {Working Group}
+
+WGL
+
+ {Waveform Generation Language}
+
+whack
+
+ According to arch-hacker James Gosling, to "...modify a
+ program with no idea whatsoever how it works." (See
+ {whacker}.) It is actually possible to do this in nontrivial
+ circumstances if the change is small and well-defined and you
+ are very good at {glark}ing things from context. As a trivial
+ example, it is relatively easy to change all "stderr" writes
+ to "stdout" writes in a piece of C filter code which remains
+ otherwise mysterious.
+
+ [{Jargon File}]
+
+whacker
+
+ [University of Maryland: from {hacker}] 1. A person, similar
+ to a {hacker}, who enjoys exploring the details of
+ programmable systems and how to stretch their capabilities.
+ Whereas a hacker tends to produce great hacks, a whacker only
+ ends up whacking the system or program in question. Whackers
+ are often quite egotistical and eager to claim {wizard}
+ status, regardless of the views of their peers. 2. A person
+ who is good at programming quickly, though rather poorly and
+ ineptly.
+
+whales
+
+ {like kicking dead whales down the beach}
+
+whalesong
+
+ The peculiar clicking and whooshing sounds made by a {PEP}
+ {modem} such as the {Telebit} {Trailblazer} as it tries to
+ synchronise with another PEP modem for their special
+ high-speed mode. This sound isn't anything like the normal
+ two-tone handshake between conventional modems and is
+ instantly recognizable to anyone who has heard it more than
+ once. It sounds, in fact, very much like whale songs. This
+ noise is also called "the moose call" or "moose tones".
+
+whatis
+
+ <tool> 1. A {Unix} command which searches for a given string
+ in the headings of all {man} pages.
+
+ 2. A command which searches the {archie} {Software Description
+ Database} for a given string, with case being ignored.
+
+ (1995-11-12)
+
+What's a spline?
+
+ [XEROX PARC] This phrase expands to: "You have just used a
+ term that I've heard for a year and a half, and I feel I
+ should know, but don't. My curiosity has finally overcome my
+ guilt." The PARC lexicon adds "Moral: don't hesitate to ask
+ questions, even if they seem obvious."
+
+ [{Jargon File}]
+
+What You Get Is What You Never Thought You Had
+
+ <jargon> (WYGIWYNTYH) A jibe at {WYSIWYG} systems that fail in
+ their stated aim by rendering documents differently on screen
+ and on paper.
+
+ (1999-06-15)
+
+What You See Is All You Get
+
+ <jargon> (WYSIAYG) /wiz'ee-ayg/ Describes a user interface
+ under which "What You See Is *All* You Get"; an unhappy
+ variant of {WYSIWYG}. Visual, "{point-and-drool interfaces}"
+ are easy to learn but often lack depth; they often frustrate
+ advanced users who would be better served by a command-style
+ interface. When this happens, the frustrated user has a
+ WYSIAYG problem.
+
+ This term is most often used of editors, {word processors},
+ and document formatting programs. WYSIWYG "{desktop
+ publishing}" programs, for example, are a clear win for
+ creating small documents with lots of fonts and graphics in
+ them, especially things like newsletters and presentation
+ slides. When typesetting book-length manuscripts, on the
+ other hand, scale changes the nature of the task; one quickly
+ runs into WYSIAYG limitations, and the increased power and
+ flexibility of a command-driven formatter like {TeX} or
+ {Unix}'s {troff} becomes not just desirable but a necessity.
+
+ Compare {YAFIYGI}.
+
+ (1999-03-03)
+
+What You See Is What You Get
+
+ <jargon> (WYSIWYG) /wiz'ee-wig/ Describes a user interface for
+ a document preparation system under which changes are
+ represented by displaying a more-or-less accurate image of the
+ way the document will finally appear, e.g. when printed. This
+ is in contrast to one that uses more-or-less obscure commands
+ that do not result in immediate visual feedback.
+
+ True WYSIWYG in environments supporting multiple fonts or
+ graphics is rarely-attained; there are variants of this term
+ to express real-world manifestations including WYSIAWYG (What
+ You See Is *Almost* What You Get) and WYSIMOLWYG (What You See
+ Is More or Less What You Get). All these can be mildly
+ derogatory, as they are often used to refer to dumbed-down
+ {user-friendly} interfaces targeted at non-programmers; a
+ hacker has no fear of obscure commands (compare {WYSIAYG}).
+ On the other hand, {Emacs} was one of the very first WYSIWYG
+ editors, replacing (actually, at first overlaying) the
+ extremely obscure, command-based {TECO}.
+
+ See also {WIMP}.
+
+ (1999-03-03)
+
+wheel
+
+ [slang "big wheel" for a powerful person] A person who has an
+ active {wheel bit}. "We need to find a wheel to unwedge the
+ hung tape drives." (See {wedged}).
+
+ [{Jargon File}]
+
+wheel bit
+
+ A privilege bit that allows the possessor to perform some
+ restricted operation on a {time-sharing} system, such as read
+ or write any file on the system regardless of protections,
+ change or look at any address in the running monitor, crash or
+ reload the system, and kill or create jobs and user accounts.
+ The term was invented on the TENEX operating system, and
+ carried over to TOPS-20, XEROX-IFS, and others. The state of
+ being in a privileged logon is sometimes called "wheel mode".
+ This term entered the Unix culture from TWENEX in the
+ mid-1980s and has been gaining popularity there (especially at
+ university sites). See also {root}.
+
+wheel wars
+
+ [Stanford University] A period in {larval stage} during which
+ student hackers hassle each other by attempting to log each
+ other out of the system, delete each other's files, and
+ otherwise wreak havoc, usually at the expense of the lesser
+ users.
+
+ [{Jargon File}]
+
+When It's Done
+
+ <jargon> A manufacturer's non-answer to questions about
+ product availability. This answer allows the manufacturer to
+ pretend to communicate with their customers without setting
+ themselves any deadlines or revealing how behind schedule the
+ product really is. It also sounds slightly better than "We
+ don't know".
+
+ (1999-08-22)
+
+Whetstone
+
+ <benchmark> The first major {synthetic benchmark} program,
+ intended to be representative for numerical ({floating-point}
+ intensive) programming. It is based on statistics gathered by
+ Brian Wichmann at the {National Physical Laboratory} in
+ England, using an {Algol 60} {compiler} which translated Algol
+ into instructions for the imaginary Whetstone machine. The
+ compilation system was named after the small town of Whetstone
+ outside the City of Leicester, England, where it was designed.
+
+ The later {dhrystone} benchmark was a pun on Whetstone.
+
+ Source code: {C
+ (ftp://netlib.att.com/netlib/benchmark/whetstonec.Z)}, {single
+ precision Fortran
+ (ftp://netlib.att.com:/netlib/benchmark/whetstones.Z)},
+ {double precision Fortran
+ (ftp://netlib.att.com:/netlib/benchmark/whetstoned.Z)}.
+
+ ["A Synthetic Benchmark", H.J. Curnow and B.A. Wichmann, The
+ Computer Journal, 19,1 (1976), pp. 43-49].
+
+ (1994-11-14)
+
+Which Stands For Nothing
+
+ <language> (WSFN) A beginner's language with emphasis on
+ graphics produced by {Atari} in 1983 for {Atari} home
+ computers. There is also {Advanced WSFN}.
+
+ (1996-06-12)
+
+while
+
+ {while loop}
+
+while loop
+
+ <programming> The {loop} construct, found in nearly all
+ {procedural languages}, that executes one or more instructions
+ (the "loop body") repeatedly so long as some {condition}
+ evaluates to true. In contrast to a {repeat loop}, the loop
+ body will not be executed at all if the condition is false on
+ entry to the while.
+
+ For example, in {C}, a while loop is written
+
+ while (<expr>) <statement>;
+
+ where <expr> is any expression and <statement> is any
+ statement, including a compound statement within braces
+ "{..}".
+
+ A {for loop}, e.g. in the {C} language, extends the while loop
+ syntax to collect pre-loop initialisation and loop-end logic
+ into the beginning of the statement.
+
+ Perl provides the "until" loop that loops until the loop
+ condition is true.
+
+ (2009-10-07)
+
+Whirlwind
+
+ <computer> An early computer from the {MIT Research Laboratory
+ for Electronics}.
+
+ Whirlwind used {electrostatic memory} and ran {Laning and
+ Zierler} (1953); and {ALGEBRAIC}, {COMPREHENSIVE} and {SUMMER
+ SESSION} (all 1959).
+
+ [Details, reference?]
+
+ (2002-06-03)
+
+White Book
+
+ 1. <language, publication> {K&R}.
+
+ 2. <language, publication, file format> The fourth book in
+ {Adobe Systems, Inc.}'s {PostScript} series, describing the
+ previously-secret format of {Type 1} {fonts}. The other three
+ official guides are known as the {Blue Book}, the {Green
+ Book}, and the {Red Book}.
+
+ ["Adobe Type 1 Font Format, version 1.1", Addison-Wesley, 1990
+ (ISBN 0-201-57044-0)].
+
+ 3. <hardware, standard> {White book CD-ROM}.
+
+ [{Jargon File}]
+
+ (1996-12-03)
+
+White book CD-ROM
+
+ <hardware, standard> A more open {CD-ROM} {standard} than
+ {Green Book CD-ROM}. All films mastered on CD-ROM after March
+ 1994 use White Book. Like Green Book, it is {ISO 9660}
+ compliant, uses mode 2 form 2 addressing and can only be
+ played on a {CD-ROM} drive which is {XA} (Extended
+ Architecture) compatible. White book CDs are labelled "Video
+ CD".
+
+ (1994-11-02)
+
+white box testing
+
+ <programming> (Or "clear", "glass", "open") Software testing
+ approaches that examine the program structure and derive test
+ data from the program logic.
+
+ Structural testing is sometimes referred to as clear-box
+ testing since white boxes are considered opaque and do not
+ really permit visibility into the code.
+
+ (1996-05-10)
+
+White pages
+
+ A directory service for locating individuals by name (by
+ analogy with the telephone directory). The {Internet}
+ supports several {databases} that contain basic information
+ about users, such as {electronic mail} addresses, telephone
+ numbers and postal addresses. These databases can be searched
+ to get information about particular individuals. See
+ {Knowbot}, {Netfind}, {whois}, {X.500}, {finger}.
+
+white paper
+
+ <publication> A short treatise whose purpose is to educate
+ industry customers. See, e.g., {Architecture Neutral
+ Distribution Format}.
+
+ (1997-10-24)
+
+white point
+
+ <graphics> A set of three {colour coordinates} that define the
+ colour white in {image processing} applications.
+
+ (2008-03-10)
+
+whitespace
+
+ <character> (From the colour it produces on white paper) Any
+ contiguous sequence of {spaces}, {tabs}, {carriage returns},
+ and/or {line feeds}. Whitespace might also possibly include
+ {form feed} characters. The term is common on {Unix}.
+
+ See also {non-printing character}.
+
+ (1996-09-04)
+
+white trash
+
+ <abuse, hardware> A pejorative term for {Intel}-based
+ {microcomputers}, used by {NeXT} users at UK law firm
+ Linklaters & Paines to contrast these machines with their
+ black NeXT boxes.
+
+ (1996-09-04)
+
+WHNF
+
+ {weak head normal form}
+
+whois
+
+ An {Internet} directory service for looking up names of people
+ on a remote server. Many servers respond to {TCP} queries on
+ {port} 43, in a manner roughly analogous to the {DDN} {NIC}
+ whois service described in {RFC} 954. Other sites provide
+ this directory service via the {finger} {protocol} or accept
+ queries by {electronic mail} for directory information. On
+ {Unix} the client command is
+
+ whois -h server_name person_name
+
+ You can also type "telnet server_name 43" and then type the
+ person's name on a separate line. For a list of whois
+ servers, FTP/Gopher: sipb.mit.edu. Or
+
+ whois -h sipb.mit.edu whois-servers
+
+ As the above command demonstrates, whois can find information
+ about things other than users, e.g. domains, networks and
+ hosts.
+
+ See also {finger}, {X.500}, {white pages}.
+
+whole number
+
+ {integer}
+
+Whopper
+
+ {WarGames}
+
+WHQL
+
+ {Windows Hardware Quality Labs}
+
+WIBNI
+
+ ({Bell Labs}) Wouldn't It Be Nice If.
+
+ What most requirements documents and specifications consist
+ entirely of.
+
+ Compare {IWBNI}.
+
+ [{Jargon File}]
+
+ (1994-11-24)
+
+WIC
+
+ {WAN Interface Card}
+
+Wide Area Information Servers
+
+ <networking, information science> (WAIS) A distributed
+ information retrieval system. WAIS is supported by {Apple
+ Computer}, {Thinking Machines} and Dow Jones. {Clients} are
+ able to retrieve documents using keywords. The search returns
+ a list of documents, ranked according to the frequency of
+ occurrence of the keyword(s) used in the search. The client
+ can retrieve text or {multimedia} documents stored on the
+ {server}. WAIS offers simple {natural language} input,
+ indexed searching for fast retrieval, and a "relevance
+ feedback" mechanism which allows the results of initial
+ searches to influence future searches. It uses the {ANSI
+ Z39.50} service. {Public domain} implementations are
+ available.
+
+ Other information retrieval systems include {archie},
+ {Gopher}, {Prospero}, and {web}.
+
+ {Usenet} newsgroup: {news:comp.infosystems.wais}.
+
+ {Telnet (telnet://sunsite.unc.edu)}.
+
+ (1995-03-13)
+
+Wide Area Network
+
+ <networking> (WAN) A {network}, usually constructed with
+ {serial lines}, extending over distances greater than one
+ kilometre.
+
+ Compare {local area network}, {metropolitan area network}.
+
+ (1994-11-24)
+
+Wide Area Telecommunications Service
+
+ <communications> (WATS) A special service provided by an
+ {inter-exchange carrier} that allows a customer to use a
+ specific {trunk} to make calls to specific geographic zones or
+ to receive calls at a specified number at a discounted price.
+
+ (2006-05-01)
+
+Wideband ATM
+
+ <networking> An enhanced form of {ATM} networking that
+ transfers digital data over {local area networks}, originally
+ at 0.96 {Gbps}, now (Aug 1996) at 1.0 Gbps.
+
+ (1996-08-23)
+
+Wide SCSI
+
+ <hardware, standard> A variant on the {SCSI-2} interface. It
+ uses a 16-bit bus - double the width of the original {SCSI}-1
+ - and therefore cannot be connected to a SCSI-1 bus. It
+ supports transfer rates up to 20 MB/s, like {Fast SCSI}.
+
+ There is also a SCSI-2 definition of Wide-SCSI with a 32 bit
+ data bus. This allows up to 40 megabytes per second but is
+ very rarely used because it requires a large number of wires
+ (118 wires on two connectors). Thus Wide SCSI usually means
+ 16 bit-wide SCSI.
+
+ (1995-04-21)
+
+widget
+
+ 1. A meta-thing. Used to stand for a real object in didactic
+ examples (especially database tutorials). Legend has it that
+ the original widgets were holders for buggy whips. "But
+ suppose the parts list for a widget has 52 entries..."
+
+ 2. [possibly evoking "window gadget"] In graphical user
+ interfaces, a combination of a graphic symbol and some program
+ code to perform a specific function. E.g. a scroll-bar or
+ button. Windowing systems usually provide widget libraries
+ containing commonly used widgets drawn in a certain style and
+ with consistent behaviour.
+
+ [{Jargon File}]
+
+wi-fi
+
+ <networking> Either of two different incompatible radio-based
+ {LAN} {protocols}, namely {802.11b} (which speaks {DSSS} at
+ 2.4GHz) and {802.11a} (which speaks {OFDM} at 5GHz).
+
+ The term was invented by the marketing departments of wi-fi
+ equipment manufacturers. It is, notionally, short for
+ "wireless fidelity", on the analogy of hi-fi for "high
+ fidelity" audio.
+
+ (2003-09-02)
+
+Wi-Fi Protected Access
+
+ <networking, security> (WPA) A security scheme for {wireless
+ networks}, developed by the networking industry in response to
+ the shortcomings of {Wired Equivalent Privacy} (WEP). WPA
+ uses {Temporal Key Integrity Protocol} (TKIP) {encryption} and
+ provides built-in {authentication}, giving security comparable
+ to {VPN} tunneling with WEP, with the benefit of easier
+ administration and use.
+
+ {WPA-PSK} is a simplified form of WPA.
+
+ (2007-05-11)
+
+Wi-Fi Protected Access Pre-Shared Key
+
+ <networking, security> (WPA-PSK) A simplified but still
+ powerful form of {WPA}, most suitable for home {wireless
+ networking}. As with {WEP}, you set a static key or pass
+ phrase, but WPA-PSK uses {TKIP} to automatically change the
+ keys periodically, making it much more difficult to break the
+ encryption.
+
+ (2007-05-11)
+
+wiggles
+
+ [scientific computation] In solving partial differential
+ equations by finite difference and similar methods, wiggles
+ are sawtooth (up-down-up-down) oscillations at the shortest
+ wavelength representable on the grid. If an algorithm is
+ unstable, this is often the most unstable waveform, so it
+ grows to dominate the solution. Alternatively, stable (though
+ inaccurate) wiggles can be generated near a discontinuity by a
+ Gibbs phenomenon.
+
+wiki
+
+ <communications> Any collaborative {website} that users can
+ easily modify via the web, often without restriction. A wiki
+ allows anyone, using a {web browser}, to create, edit or
+ delete content that has been placed on the site, including the
+ work of other authors.
+
+ Text is entered using some simple {mark-up language} which is
+ then rendered as {HTML}. A feature common to many of the
+ different implementations is that any word in mixed case
+ LikeThis (a "wikiword") is rendered as a link to a page of
+ that name, which may or may not exist.
+
+ Wikis work surprisingly well, with the most famous example,
+ {Wikipedia}, having become one of the most popular sites on
+ the web. Contributors tend to be more numerous and more
+ persistent than vandals, and old versions of pages are always
+ available. Like many simple concepts, open editing has
+ profound effects on usage. Allowing everyday users to create
+ and edit any page encourages democratic use of the web and
+ promotes content composition by nontechnical users.
+
+ In contrast, a {web log}, typically authored by an individual,
+ does not allow visitors to change the original posted
+ material, only add comments.
+
+ Wiki wiki means "quick" in Hawaiian. The first wiki was
+ created by {Ward Cunningham} in 1995.
+
+ {wiki.org (http://wiki.org/)}.
+
+ (2010-05-07)
+
+WiLAN
+
+ {wireless local area network}
+
+Wild_LIFE
+
+ Logic, Inheritance, Functions and Equations
+
+ parts: interpreter, manual, tests, libraries, examples
+
+ Paradise Project, DEC Paris Research Laboratory.
+
+ {(ftp://gatekeeper.dec.com/pub/plan/Life.tar.Z)} - Wild_LIFE
+ interpreter from Paradise project at DEC's Paris Research Lab
+
+ LIFE is an experimental programming language with a powerful
+ facility for structured type inheritance. It reconciles
+ styles from functional programming, logic programming, and
+ object-oriented programming. LIFE implements a constraint
+ logic programming language with equality (unification) and
+ entailment (matching) constraints over order-sorted feature
+ terms. The Wild_LIFE interpreter has a comfortable user
+ interface with incremental query extension ability. It
+ contains an extensive set of built-in operations as well as an
+ X Windows interface.
+
+ A semantic superset of LOGIN and LeFun. Syntax is similar to
+ prolog.
+
+ bugs: <life-bugs@prl.dec.com>
+
+ ports: MIPS-Ultrix
+
+ Mailing list: life-request@prl.dec.com
+
+ E-mail: Peter Van Roy <vanroy@prl.dec.com>
+
+ (1992-12-14)
+
+wild card
+
+ <operating system, programming, text> (From card games in
+ which certain cards, often the joker, can act as any other
+ card) A special character or character sequence which matches
+ any character in a string comparison, like ellipsis ("...") in
+ ordinary written text.
+
+ In {Unix} filenames '?' matches any single character and '*'
+ matches any zero or more characters. In {regular
+ expressions}, '.' matches any one character and "[...]"
+ matches any one of the enclosed characters.
+
+ See also {Backus-Naur Form}.
+
+ (1997-07-16)
+
+Wilf Hey
+
+ <person> The person who originally developed {Report Program
+ Generator} and coined the phrase GIGO (garbage in: garbage
+ out).
+
+ In 2004, after more than forty years in computing, he was
+ writing for {PC Plus} magazine in the UK and doing Wilf's
+ programmers workshop amongst other things. He died on
+ 2007-01-01 after a long illness.
+
+ (2007-01-06)
+
+William Gibson
+
+ <person> Author of {cyberpunk} novels such as Neuromancer
+ (1984), Count Zero (1986), Mona Lisa Overdrive, and Virtual
+ Light (1993).
+
+ Neuromancer, a novel about a computer {hacker}/criminal
+ "cowboy" of the future helping to free an {artificial
+ intelligence} from its programmed bounds, won the Hugo and
+ Nebula science fiction awards and is credited as the seminal
+ cyberpunk novel and the origin of the term "{cyberspace}".
+
+ Gibson does not have a technical background and supposedly
+ purchased his first computer in 1992.
+
+ (1996-06-11)
+
+William Hamilton
+
+ <person> A mathematician who posed {Hamilton's problem}.
+
+ {Biography
+ (http://gregory.dcs.st-and.ac.uk/~history/ShortBiogs/H.html#Hamilton)}.
+
+ [Summary?]
+
+ (1995-11-02)
+
+William Joy
+
+ <person> (Bill Joy) Author of the {C shell} and {vi}, he was
+ also one of the people at the {University of California at
+ Berkeley} responsible for the {Berkeley Software Distribution}
+ of {Unix}. He also wrote a book on {Unix}.
+
+ He was a co-founder of {Sun Microsystems, Inc.}, where he is
+ still (1997) Vice-President of Research. Among his many
+ projects for Sun have been helping to design the {Network File
+ System} and the {SPARC} architechture.
+
+ {Biography
+ (http://sun.com/aboutsun/media/ceo/mgt_joy.html)}.
+
+ See also {dinosaur}.
+
+ [Book ref? E-mail?]
+
+ (2000-10-30)
+
+WIMP
+
+ <operating system> Windows, Icons, Menus and Pointers
+ (or maybe Windows, Icons, Mouse, {Pull-down menus}).
+
+ The style of {graphical user interface} invented at {Xerox
+ PARC}, popularised by the {Apple Macintosh} and now available
+ in other varieties such as the {X Window System},
+ {OSF}/{Motif}, {NeWS}, {RISC OS} and {Microsoft Windows}.
+
+ See {menuitis}, {user-obsequious}, {window system}.
+
+ (2007-09-12)
+
+WIMP environment
+
+ {WIMP}
+
+win
+
+ <jargon> (Said of people, computers, {algorithms}, programs)
+ (To be) a success at a given task.
+
+ E.g. "{WYSIWYG} is a clear win for small documents".
+
+ "winnitude" is the quality that something which wins has.
+ "winning" is often (ab)used as an adjective.
+
+ Synonyms: {cuspy}, {elegant}. Antonym: {lose}. Compare
+ {lossy}, {lossless}.
+
+ [{Jargon File}]
+
+ (1996-09-08)
+
+Win2K
+
+ {Windows 2000}
+
+Win32
+
+ <programming> An {application programming interface} that is
+ common to all {Microsoft}'s 32-bit Windows {operating
+ systems}. These currently include: {Windows 95}, {Windows
+ 98}, {Windows NT} and {Windows CE}.
+
+ [Relationship with {Win32s}?]
+
+ (1997-12-20)
+
+Win32s
+
+ <operating system> A free extension for {Microsoft Windows},
+ released by {Microsoft}. Win32s is a software layer on top of
+ Windows which allows {32-bit applications} (e.g. {Mosaic}) to
+ run on Windows. Both stand-alone Windows and {Windows for
+ Workgroups} run as 16 bit, and both can use Win32s to run
+ 32-bit applications.
+
+ (1996-07-08)
+
+Win 95
+
+ {Windows 95}
+
+Win 98
+
+ {Windows 98}
+
+winchester
+
+ <hardware> An informal generic term for floating head
+ {magnetic disk} drives in which the read-write head planes
+ over the disk surface on an air cushion.
+
+ The name arose because the original 1973 engineering prototype
+ for what later became the {IBM 3340} featured two 30-megabyte
+ volumes; 30--30 became "Winchester" when somebody noticed the
+ similarity to the common term for a famous Winchester rifle
+ (in the latter, the first 30 referred to caliber and the
+ second to the grain weight of the charge).
+
+ [{Jargon File}]
+
+ (1994-12-06)
+
+windowing
+
+ {window system}
+
+windowing system
+
+ {window system}
+
+window manager
+
+ <operating system> A part of a {window system} which arranges
+ windows on a screen. It is responsible for moving and
+ resizing windows, and other such functions common to all
+ applications.
+
+ Examples from the {X Window System} are {twm}, {gwm}, {olwm}.
+
+ (1994-12-06)
+
+Window RAM
+
+ {Window Random Access Memory}
+
+Window Random Access Memory
+
+ <hardware, storage> (WRAM, Window RAM) A kind of {RAM} which
+ is faster than {VRAM}.
+
+ WRAM is used in the Matrox MGA Millennium {video display card}
+ and almost certainly elsewhere.
+
+ [More details?]
+
+ (1996-06-05)
+
+Windows
+
+ <operating system> See {Microsoft Windows}, {Windows NT}.
+
+ (1997-11-23)
+
+Windows 1
+
+ <operating system> The first incarnation of {Microsoft
+ Windows}, released in 1985. It took a total of 55
+ programmer-years to develop, and only allowed tiled windows.
+
+ (1996-07-08)
+
+Windows 2
+
+ <operating system> The second version of {Microsoft Windows},
+ released in 1987. Windows 2 had considerably more features
+ than {Windows 1}, such as overlapping windows and {icons}.
+ When {Windows/386} was released, Windows 2 was renamed
+ Windows/286.
+
+Windows 2000
+
+ <operating system> (Win2k, W2k, NT5, Windows NT 5.0) An
+ {operating system} developed by {Microsoft Corporation} for
+ {PCs} and {servers}, as the successor to {Windows NT 4}.0.
+ Early {beta} versions were referred to as "Windows NT 5.0".
+ Windows 2000 was officially released on 2000-02-17.
+
+ Windows 2000 is most commonly used on {Intel} {x86} and
+ {Pentium} processors, with a {DEC Alpha} version rumoured.
+ Unlike Windows NT 4.0, Windows 2000 is not available for
+ {PowerPC} or {MIPS}.
+
+ Windows 2000's {user interface} is very similar to {Windows
+ 95} or Windows NT 4.0 with integrated {Internet Explorer}, or
+ to {Windows 98}.
+
+ It is available in four flavours:
+
+ - Professional: the {client} version, meant for desktop
+ {workstations}, successor to Windows NT Workstation.
+
+ - Server: "entry-level" server, designed for small
+ deployments, and departmental file, print, or {intranet}
+ servers.
+
+ - Advanced Server: high throughput, larger scale servers
+ and applications, and small to medium scale {websites}.
+
+ - Data Center Server: software for large-scale server
+ {clusters} (in development as of 2000-03-14).
+
+ New features in Windows 2000 include:
+
+ - {Active Directory}.
+
+ - Greatly improved built-in security mechanisms, including
+ {Kerberos}-based {authentication}, {public key} support, an
+ {encrypting} {file system}, and {IPsec} support.
+
+ - Integrated {web browser} - {Internet Explorer} 5.0.
+
+ - Integrated {web server} - {IIS} 5.0
+
+ - Terminal services for displaying application interfaces on
+ remote computers (similar to {X-Windows}).
+
+ - File protection that prevents user programs from
+ accidentally deleting or overwriting critical system files.
+
+ - Improved hardware support, including {Plug-and-Play}, {DVD},
+ {IEEE-1394} (FireWire), {USB}, {infra-red}, {PCMCIA}, {ACPI},
+ {laptop computers}.
+
+ - Improved user interface, including a single point to control
+ the entire system.
+
+ - Improved management tools, including remote administration.
+
+ Minimum system requirements, according to Microsoft, are
+ {Pentium}-133 {MHz} {CPU}, 64 {MB} {RAM}, 650 {MB} of {hard
+ disk} space. These are for W2K Professional, others require
+ more.
+
+ Many {operating systems} compete with Windows 2000, including
+ the {Apple} {MacOS}, {Linux}, {FreeBSD}, {OpenBSD}, {NetBSD},
+ {Sun} {Solaris}, {IBM} {AIX}, {Hewlett-Packard} {HP-UX}, {SGI}
+ {Irix}. Novell's NDS also provides a service similar to
+ Active Directory.
+
+ Windows 2000 will be followed by {Windows XP} Professional and
+ {Windows 2002}.
+
+ {(http://microsoft.com/windows2000/)}.
+
+ {Usenet} newsgroups: {(news:microsoft.public.windows2000)},
+ {(news:comp.os.ms-windows)}.
+
+ (2002-01-28)
+
+Windows/286
+
+ {Windows 2}
+
+Windows 2K
+
+ {Windows 2000}
+
+Windows 3.0
+
+ <operating system> A complete rework of {Microsoft Windows}
+ with many new facilities such as the ability to address memory
+ beyond 640k. It was released in 1990, and vigorous
+ development of applications by third parties helped Microsoft
+ sell over 10 million copies.
+
+ (1996-07-08)
+
+Windows 3.1
+
+ <operating system> A version of {Microsoft Windows} with many
+ improvements over {Windows 3.0}, including {True Type Fonts},
+ {Object Linking and Embedding} (OLE) and {Mouse Trails} for
+ use with {LCD} Devices. It also saw the loss of {Real Mode},
+ which meant it would no longer run on {Intel 8086} processors
+ (did anyone ever do this anyway?).
+
+ Sometimes described as "stand-alone Windows", in contrast to
+ {Windows for Workgroups 3.1}. {Windows 3.11} is a free
+ bug-fix update. 3.1's successors are {Windows 95} and
+ {Windows NT}.
+
+ (1996-07-08)
+
+Windows 3.11
+
+ <operating system> A free minor bug-fix for {Windows 3.1}.
+
+ (1996-07-08)
+
+Windows/386
+
+ <operating system> A version of {Microsoft Windows} released
+ in late 1987. Windows/386 was basically the same as its
+ predecessor, Windows/286 (as {Windows 2} was renamed), but
+ with the capability to run multiple {MS-DOS} applications
+ simultaneously in {extended memory}.
+
+ (1996-07-08)
+
+Windows 4GL
+
+ <tool, database> (INGRES/Windows 4GL) A graphical tool running
+ on top of a {workstation}'s native {windowing system}, to help
+ developers to build user interfaces to {INGRES} applications.
+
+ (1996-07-09)
+
+Windows 94
+
+ <operating system, humour> A facetious name for {Windows 95},
+ so called because it was originally meant to ship in 1994.
+
+ (1998-09-07)
+
+Windows 95
+
+ <operating system> (Win95) {Microsoft}'s successor to their
+ {Windows 3.11} {operating system} for {IBM PCs}. It was known
+ as "Chicago" during development. Its release was originally
+ scheduled for late 1994 but eventually happened on 11 Jul
+ 1995, followed by Service Release 1 on 1995-12-31 and OSR2
+ (OEM Service Release 2) on 1996-08-24.
+
+ In contrast to earlier versions, Windows 95 is a complete
+ operating system rather than a {graphical user interface}
+ running on top of {MS-DOS}.
+
+ It provides {32-bit application} support, {pre-emptive
+ multitasking}, threading and built-in networking ({TCP/IP},
+ {IPX}, {SLIP}, {PPP}, and {Windows Sockets}). It includes
+ {MS-DOS} 7.0, but takes over completely after booting. The
+ {graphical user interface}, while similar to previous Windows
+ versions, is significantly improved.
+
+ Windows 95 has also been described as "32-bit extensions and a
+ graphical shell for a 16-bit patch to an 8-bit operating
+ system originally coded for a 4-bit microprocessor, written by
+ a 2-bit company that can't stand 1-bit of competition".
+
+ The successor to Windows 95 was {Windows 98}.
+
+ (1998-07-19)
+
+Windows 98
+
+ <operating system> {Microsoft}'s 1998 update to {Windows 95}
+ that adds:
+
+ * Hardware support for {Universal Serial Bus} (USB).
+
+ * Internet Connection Sharing (IGC) - multiple PCs share a
+ single connection to the Internet.
+
+ * Microsoft {WebTV} for Windows - watch TV on your PC.
+
+ * Support for new graphic, sound, and multimedia formats.
+
+ * {Internet Explorer} release 5.
+
+ * Windows 98 {Service Pack} - {year 2000} updates.
+
+ Windows 98 was followed logically by {Windows ME} but
+ chronologically by {Windows 2000 Professional Edition}.
+
+ {(http://microsoft.com/windows98)}.
+
+ (2002-01-19)
+
+Windows 9X
+
+ <operating system> A shorthand meaning {Windows 95} or
+ {Windows 98}.
+
+ (2004-03-28)
+
+Windows Application Binary Interface
+
+ <operating system, tool> (WABI) A software package from {Sun
+ Microsystems} to allow certain {Microsoft Windows}
+ applications under the {X Window System}. Wabi 2.2 runs under
+ {Solaris} on {SPARC}, {Intel}, and {PowerPC}. Wabi works by
+ providing translated versions of the three core Windows
+ libraries, {user.dll}, {kernel.dll}, and {gdi.dll} which
+ redirect Windows calls to Solaris equivalents. For code other
+ than core library calls Wabi either executes the instructions
+ directly on the hardware, if it is Intel, or emulates them,
+ either one instruction at a time or by translating a block of
+ instructions and caching the result (e.g. for a loop).
+
+ {WabiServer} allows the Windows application and X display to
+ be on different computers.
+
+ {Overview (http://sun.com/solaris/products/wabi/)}.
+
+ (1997-01-08)
+
+Windows CE
+
+ <operating system> /C E/ A version of the {Microsoft Windows}
+ {operating system} that is being used in a variety of
+ {embedded} products, from {handheld} PCs to specialised
+ industrial {controllers} and consumer electronic devices.
+ Programming for Windows CE is similar to programming for other
+ {Win32} {platforms}.
+
+ Windows CE was developed to be a customisable operating system
+ for embedded {applications}. Its {kernel} borrows much from
+ other Microsoft {32-bit} operating systems, while eliminating
+ (or replacing) those operating system features that are not
+ needed for typical Windows CE-based applications. For
+ example, as on {Windows NT}, all applications running on
+ Windows CE run in a fully {preemptive multitasking}
+ environment, in fully {protected memory} spaces.
+
+ The {Win32} (API) for Windows CE is smaller than the Win32 API
+ for the other 32-bit Windows operating systems. It includes
+ approximately half the interface methods of the Windows NT
+ version of the API. But the Win32 API for Windows CE also
+ includes features found in no other Microsoft operating
+ system. The notification API, for example, makes it possible
+ to handle user or application notification events (such as
+ timer events) at the operating-system level, rather than in a
+ running application. The {touch screen} API and the built-in
+ support for the Windows CE {database} are not found in other
+ Windows operating systems. The touch screen API makes it easy
+ to manage screen calibration and user interactions for
+ {touch-sensitive displays}, while the database API provides
+ access to a data storage facility.
+
+ {(http://channels.microsoft.com/windowsce/developer/default.htm)}.
+
+ {(http://channels.microsoft.com/windowsce/developer/technical/default.htm)}.
+
+ (1997-12-20)
+
+Windows for Workgroups
+
+ <operating system> (WFW, WFWG) A version of {Windows 3.1}
+ which works with a network. Although stand-alone 3.1 can be
+ networked, the installation and configuration is much improved
+ with Windows for Workgroups (3.1). Windows for Workgroups
+ 3.11 was a significant upgrade to WFW 3.1, adding 32-bit file
+ access, fax capability and higher performance.
+
+ (1996-07-08)
+
+Windows Hardware Quality Labs
+
+ <body, standard> (WHQL) A {Microsoft} body that produces and
+ supports the {Microsoft} {Hardware Compatibility Test} kit for
+ current Microsoft {operating systems}. Products are tested
+ with the kit to ensure that they meet Microsoft standards for
+ compatibility with {Windows} and to qualify to use the
+ "Designed for Microsoft Windows" logos.
+
+ {(http://microsoft.com/hwdq/hwtest/)}.
+
+ (2002-11-13)
+
+window shopping
+
+ <jargon> A term used among users of {WIMP} environments like
+ the {X Window System} or the {Macintosh} at the US Geological
+ Survey for extended experimentation with new window colours,
+ {fonts}, and {icon} shapes. This activity can take up hours
+ of what might otherwise have been productive working time. "I
+ spent the afternoon window shopping until I found the coolest
+ shade of green for my active window borders --- now they
+ perfectly match my medium slate blue background." Serious
+ window shoppers will spend their days with bitmap editors,
+ creating new and different icons and background patterns for
+ all to see. Also: "window dressing", the act of applying new
+ fonts, colours, etc.
+
+ See {fritterware}, compare {macdink}.
+
+ [{Jargon File}]
+
+ (1996-07-08)
+
+Windows Internet Naming Service
+
+ <networking> (WINS) Software which resolves {NetBIOS} names to
+ {IP addresses}.
+
+ [Details?]
+
+ (1998-02-14)
+
+Windows Management Interface
+
+ <Microsoft, system management> (WMI) {Microsoft}'s
+ implementation of {Web-Based Enterprise Management}, a {DMTF}
+ initiative to establish standards for accessing and sharing
+ {system management} information over an {enterprise} {network}.
+
+ (2005-02-15)
+
+Windows ME
+
+ {Windows Millennium Edition}
+
+Windows Messaging
+
+ <messaging> {Microsoft}'s {Internet} {electronic mail}
+ application, formerly called {Microsoft Exchange}.
+
+ (1998-07-05)
+
+windows messaging
+
+ <messaging> An {inter-process communication} facility usually
+ provided by vendors of {graphical user interfaces} for
+ {concurrent} {operating systems}, such as {Microsoft}, The {X
+ Consortium} and {Apple}.
+
+ The system software translates hardware {interrupts} from
+ various input devices into messages according to the current
+ input context (e.g. the active {window} of the frontmost
+ {application}). Each message is a short piece of information.
+ A message's format depends on its type, which is usually
+ encoded in its first field. The message is sent to the
+ {client} application using some communication {protocol}
+ (e.g. {shared memory}, internal {socket}, network socket).
+ The client application dispatches the message and performs any
+ actions required. The messages can also be sent by client
+ applications. This provides convenient and flexible
+ inter-process communication.
+
+ (1998-07-06)
+
+Windows Millennium Edition
+
+ <operating system> (Windows ME) An update of {Microsoft}
+ {Windows 98}, released in 2000. ME included updates of
+ packaged software and new software such as {Windows Media
+ Player} 7, {Windows Movie Maker}. It also has an updated
+ {user interface} with new colours and icons, but few major
+ changes. Windows ME was followed by {Windows XP}.
+
+ (2003-05-13)
+
+Windows NT
+
+ <operating system> (Windows New Technology, NT) {Microsoft}'s
+ 32-bit {operating system} developed from what was originally
+ intended to be {OS/2} 3.0 before {Microsoft} and {IBM} ceased
+ joint development of OS/2. NT was designed for high end
+ {workstations} (Windows NT 3.1), servers (Windows NT 3.1
+ Advanced Server), and corporate networks (NT 4.0 Enterprise
+ Server). The first release was {Windows NT 3.1}.
+
+ Unlike {Windows 3.1}, which was a graphical environment that
+ ran on top of {MS-DOS}, Windows NT is a complete operating
+ system. To the user it looks like Windows 3.1, but it has
+ true {multi-threading}, built in networking, security, and
+ {memory protection}.
+
+ It is based on a {microkernel}, with 32-bit addressing for up
+ to 4Gb of {RAM}, virtualised hardware access to fully protect
+ applications, installable file systems, such as {FAT}, {HPFS}
+ and {NTFS}, built-in networking, {multi-processor} support,
+ and {C2 security}.
+
+ NT is also designed to be hardware independent. Once the
+ machine specific part - the {Hardware Abstraction Layer} (HAL)
+ - has been ported to a particular machine, the rest of the
+ operating system should theorertically compile without
+ alteration. A version of NT for {DEC}'s {Alpha} machines was
+ planned (September 1993).
+
+ NT needs a fast {386} or equivalent, at least 12MB of {RAM}
+ (preferably 16MB) and at least 75MB of free disk space.
+
+ NT 4.0 was followed by {Windows 2000}.
+
+ {Usenet} newsgroups: {news:comp.os.ms-windows.nt.setup},
+ {news:comp.os.ms-windows.nt.misc}.
+
+ (2002-06-10)
+
+Windows NT 3.1
+
+ <operating system> {Microsoft}'s first version of {Windows
+ NT}, released in September 1993, price UKP 395, after having
+ been in {beta-test} for as long as anyone could remember.
+
+ The person responsible for {VMS} on the {DEC VAX} [who?] was
+ also responsible for Windows NT. Incrementing each letter in
+ VMS yields WNT.
+
+ {(http://win2000mag.com/Articles/Index.cfm?ArticleID=4494)}.
+
+ (2000-08-12)
+
+Windows NT 3.5
+
+ <operating system> A much improved version of {Microsoft}'s
+ {Windows NT 3.1}. NT is now (July 1996) supplied as "Windows
+ NT 3.5 Workstation" and "Windows NT 3.5 Server". It has
+ better {OLE} support, higher performance and requires less
+ memory.
+
+ (1996-07-08)
+
+Windows NT 4
+
+ <operating system> A version of {Microsoft}'s {Windows NT}
+ {operating system}, originally code named "Cairo". It was
+ supposed to ship in the first half of 1995. Details are
+ scarce, but it is intended to provide an {object-oriented}
+ version of Windows.
+
+ (1996-07-09)
+
+Windows NT 5
+
+ {Windows 2000}
+
+Windows NT Network Model
+
+ <networking> The network model used by {Windows NT}. The
+ model has the following layers:
+
+ User Applications (e.g. Excel)
+ {APIs}
+ File System Drivers
+ {TDI}
+ Protocols
+ {NDIS} v4
+ NDIS Wrapper
+ NDIS Card Driver
+ {Network Adapter Card}
+
+ Compare {OSI} seven layer model.
+
+ (1997-11-05)
+
+Windows Open Service Architecture
+
+ <architecture, library, Microsoft> (WOSA) One of the mainstays of
+ {Microsoft Windows}: the ethos of {abstraction} of core
+ {services}.
+
+ For each extension, Windows {Open} Services {Architecture}
+ defines an {API} and an {SPI}, as well as a universal
+ interface (usually placed in a single {DLL}) that both comply
+ to.
+
+ These then {transparent}ly let the {operating system} speak to
+ {device drivers}, {database managers}, and other {low level}
+ entities.
+
+ These extensions include, among others, {ODBC} (called the
+ "crowning jewel of WOSA"), {TAPI}, {WOSA/XFS}, {SAPI} and
+ {MAPI}, and their supporting services, as well as the
+ abstraction of access to {printers}, {modems}, and {networking
+ services}, which run identically over {TCP/IP}, {IPX/SPX}, and
+ {NetBEUI}.
+
+ (2000-08-16)
+
+Windows Registry
+
+ <operating system> The database used by {Microsoft} {Windows
+ 95} and later to store all sorts of configuration information
+ such as which program should be used to open a .doc file,
+ {DLL} registration information, application-specific settings
+ and much more.
+
+ The Registry is stored in .dat files, one in the user's
+ profile containing their per-user settings and one in the
+ Windows directory containing settings that are global to all
+ users. These are loaded into memory at login.
+
+ The loaded data appears as a tree with five main branches:
+ HKEY_CLASSES_ROOT, HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE,
+ HKEY_USERS, HKEY_CURRENT_CONFIG. HKEY_CLASSES_ROOT defines
+ file types and actions, HKEY_CURRENT_USER is an alias for one
+ of the sub-trees of HKEY_USERS and contains user settings that
+ override the global defaults in HKEY_LOCAL_MACHINE.
+
+ The branches of the tree are called "keys" and are identified
+ by paths like
+ HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion.
+ Any node in the tree can have zero or more "values" which are
+ actually bindings of a name and a value, e.g. "Logon User
+ Name" = "Denis". The value can be of type string, binary,
+ dword (long integer), multi-string value or expandable string
+ value.
+
+ Windows includes a Registry Editor (regedit.exe).
+
+ (2008-01-20)
+
+Windows sockets
+
+ <networking, standard> (Winsock) A specification for
+ {Microsoft Windows} network software, describing how
+ applications can access network services, especially {TCP/IP}.
+ Winsock is intended to provide a single {API} to which
+ application developers should program and to which multiple
+ network software vendors should conform. For any particular
+ version of {Microsoft Windows}, it defines a binary interface
+ ({ABI}) such that an application written to the Windows
+ Sockets API can work with a conformant {protocol}
+ implementation from any network software vendor.
+
+ Winsock was conceived at Fall Interop '91 during a {Birds of a
+ Feather} session.
+
+ Windows Sockets is supported by {Microsoft Windows}, {Windows
+ for Workgroups}, {Win32s}, {Windows 95} and {Windows NT}. It
+ will support protocols other than {TCP/IP}. Under {Windows
+ NT}, {Microsoft} will provide Windows Sockets support over
+ {TCP/IP} and {IPX}/{SPX}. {DEC} will be implementing
+ {DECNet}. {Windows NT} will include mechanisms for multiple
+ {protocol} support in Windows Sockets, both 32-bit and 16 bit.
+
+ Mark Towfiq said, "The next rev. of Winsock will not be until
+ toward the end of 1993. We need 1.1 of the {API} to become
+ firmly settled and implemented first."
+
+ {Windows Sockets API
+ (ftp://sunsite.unc.edu/pub/micro/pc-stuff/ms-windows/winsock)}.
+ or {(ftp://microdyne.com/pub/winsock)} or send a message
+ "help" to either <ftpmail@SunSite.UNC.Edu> or
+ <ftpmail@DECWRL.DEC.Com>.
+
+ {Windows Sockets specification (ftp://rhino.microsoft.com)}.
+
+ Currently NetManage (NEWT), Distinct, FTP and Frontier are
+ shipping Winsock {TCP/IP} stacks, as is {Microsoft} (Windows
+ NT and {TCP/IP} for WFW), Beame & Whiteside Software (v1.1
+ compliant), and Sun PC-NFS. Windows 95 has "dial-up
+ networking" which supports Winsock and TCP/IP.
+
+ winsock.dll is available from some {TCP/IP} stack vendors.
+ {Novell} has one in beta for their {Lan Workplace} for {DOS}.
+
+ Peter Tattam <peter@psychnet.psychol.utas.edu.au> is
+ alpha-testing a shareware Windows Sockets compliant {TCP/IP}
+ stack {(ftp://ftp.utas.edu.au/pc/trumpet/winsock/winsock.zip)}.
+ and {(ftp://ftp.utas.edu.au/pc/trumpet/winsock/winpkt.com)}.
+
+ {The Consummate Winsock App List
+ (http://wwwvms.utexas.edu/~Neuroses/cwsapps.html)}.
+
+ [Adapted from: Aboba, Bernard D., comp.protocols.tcp-ip.ibmpc
+ Frequently Asked Questions, 1993 {Usenet}: {news:news.answers},
+ {(ftp://netcom1.netcom.com/pub/mailcom/IBMTCP/)}].
+
+ [Current status?]
+
+ (1996-06-20)
+
+Windows XP
+
+ <operating system> The version of the {Microsoft Windows}
+ {operating system} that, when it was released on 2001-10-25,
+ finally merged the {Windows 95} - {Windows ME} strain with the
+ {Windows NT} - {Windows 2000} one. XP comes in two main
+ versions: {Windows XP Professional Edition} and a simplified
+ subset for home users, {Windows XP Home Edition}.
+
+ {Windows XP home page (http://microsoft.com/windowsxp/)}.
+
+ (2009-08-12)
+
+Windows XP Pro
+
+ {Windows XP Professional Edition}
+
+Windows XP Professional Edition
+
+ <operating system> ("Windows XP Pro", "XP Pro") The version of
+ {Microsoft}'s {Windows XP} {operating system} intended for
+ businesses and advanced users. The alternative, {Windows XP
+ Home Edition}, is a subset of Pro without {Remote Desktop},
+ {Multi-processor support}, {Automated System Recovery},
+ {Dynamic Disk Support}, {Fax}, {Internet Information
+ Services}, {Encrypting File System}, {File-level access
+ control}, {Active Directory}, {Group Policy}, {IntelliMirror},
+ {Roaming profiles} and other features.
+
+ {Pro-Home Comparison
+ (http://www.winsupersite.com/showcase/windowsxp_home_pro.asp)}.
+
+ (2009-08-12)
+
+window system
+
+ Software which allows a {workstation}'s screen to be divided
+ into rectangular areas which act like a separate input/output
+ devices under the control of different {application} programs.
+ This gives the user the ability to see the output of several
+ processes at once and to choose which one will receive input
+ by selecting its window, usually by pointing at it with a
+ {mouse}.
+
+ Examples are the {X Window System}, and proprietary systems on
+ the {Macintosh} and {NeXT}, {NeWS} on {Suns} and {RISC OS} on
+ the {Archimedes}. See also {WIMP}.
+
+Windoze
+
+ {Microsloth Windows}
+
+Wind River Systems
+
+ <company> A company founded in 1981, now a world leader in
+ {embedded systems}, providing {real-time operating systems}
+ and development tools. Wind River's development tools enable
+ customers to standardise designs across projects and quickly
+ develop feature-rich products.
+
+ Wind River Systems employs over 500 people worldwide (1998).
+ Service and support is provided through its U.S. headquarters
+ and overseas operations in the U.K., France, Germany,
+ Scandinavia and Japan.
+
+ {(http://wrs.com/)}.
+
+ Address: Alameda, California, USA.
+
+ (1998-11-06)
+
+winged comments
+
+ <programming> {Comments} set on the same line as code, as
+ opposed to {boxed comments}.
+
+ In {C}, for example:
+
+ d = sqrt(x*x + y*y); /* distance from origin */
+
+ Generally these refer only to the action(s) taken on that
+ line.
+
+ [{Jargon File}]
+
+ (1997-07-21)
+
+winkey
+
+ <chat> winkey face.
+
+ See {emoticon}.
+
+ [{Jargon File}]
+
+ (1996-09-08)
+
+WinMaker Pro
+
+ {RoboDemo}
+
+WINS
+
+ {Windows Internet Naming Service}
+
+Winsock
+
+ {Windows sockets}
+
+WinSoft Products Ltd
+
+ <company> The company which produces {EMBLA Pro}.
+
+ {(http://ftech.co.uk/~winsoft)}.
+
+ E-mail: WinSoft Products Ltd <info@winsoft.ftech.co.uk>
+
+ (1996-03-11)
+
+wintel
+
+ <jargon, architecture> A term describing any computer
+ {platform} consisting of some version of {Microsoft Windows}
+ running on an {Intel 80x86} processor or compatible.
+
+ Despite the dominance of the wintel platform, in its many
+ forms, from {MS-DOS} on an {Intel 8088} to {Windows 2000} on a
+ {Pentium II Xeon}, there are many "non-wintel" {platforms} in
+ use. These include {Acorn}, {Amiga}, {Apple}, {ARM}, {Atari},
+ {A\Box}, {Be}, {Network Computer}, {OS/2}, {PowerPC}, {Psion},
+ {Linux} and all other {Unix} systems.
+
+ {Convergence International (http://convergence.org/)}.
+
+ (1999-09-15)
+
+WINZIP
+
+ <tool> A {Microsoft Windows} {archiving} and {compression}
+ program, distributed by Nico Mak Computing, Inc. WINZIP has a
+ {graphical user interface} {front end} and is compatible with
+ {PKZIP}. WINZIP can be obtained as {shareware}, on
+ evaluation, or as a licenced copy. It is much easier to use
+ then PKZIP for DOS, and includes a helpful, help file.
+
+ {(http://winzip.com/)}.
+
+ (2000-02-27)
+
+wired
+
+ {hard-wired}
+
+wirehead
+
+ <jargon> /wi:r'hed/ (Probably from SF slang for an electrical
+ brain-stimulation addict) 1. A hardware hacker, especially one
+ who concentrates on communications hardware.
+
+ 2. An expert in {local-area networks}. A wirehead can be a
+ network software wizard too, but will always have the ability
+ to deal with network hardware, down to the smallest component.
+ Wireheads are known for their ability to lash up an {Ethernet}
+ {terminator} from spare resistors, for example.
+
+ [{Jargon File}]
+
+ (1995-02-28)
+
+wireless
+
+ <networking> A term describing a computer {network} where
+ there is no physical connection (either copper cable or {fibre
+ optics}) between sender and receiver, but instead they are
+ connected by radio.
+
+ Applications for wireless networks include multi-party
+ {teleconferencing}, distributed work sessions, {personal
+ digital assistants}, and electronic newspapers. They include
+ the transmission of voice, video, {images}, and data, each
+ traffic type with possibly differing {bandwidth} and
+ quality-of-service requirements. The wireless network
+ components of a complete source-destination path requires
+ consideration of mobility, {hand-off}, and varying
+ transmission and {bandwidth} conditions. The wired/wireless
+ network combination provides a severe bandwidth mismatch, as
+ well as vastly different error conditions. The processing
+ capability of fixed vs. mobile terminals may be expected to
+ differ significantly. This then leads to such issues to be
+ addressed in this environment as {admission control},
+ {capacity assignment} and {hand-off} control in the wireless
+ domain, flow and error control over the complete end-to-end
+ path, dynamic bandwidth control to accommodate bandwidth
+ mismatch and/or varying processing capability.
+
+ {Usenet} newsgroup {news:comp.std.wireless}.
+
+ (1995-02-27)
+
+Wireless Application Protocol
+
+ <protocol, standard> (WAP) An open international {standard}
+ for applications that use {wireless} communication,
+ e.g. {Internet} access from a mobile phone.
+
+ The official body developing WAP is the {WAP Forum}.
+
+ {(http://wapforum.org/)}.
+
+ {Technical data (http://wapforum.org/what/technical.htm)}.
+
+ [More detailed summary?]
+
+ (2000-02-10)
+
+wireless bitmap
+
+ <graphics, file format> (WBMP) A {bitmap} for display on a
+ {WAP} mobile phone.
+
+ Currently (2001) the only type of WBMP file defined is a
+ simple black-and-white {image} file with one {bit} per {pixel}
+ and no {compression}.
+
+ [{WAP Forum (http://wapforum.org/)}, "WAP-190-WAE-Spec" or
+ "Wireless Application Protocol, Wireless Application
+ Environment Specification"].
+
+ (2001-05-23)
+
+wireless hotspot
+
+ <networking> A public place where you can connect to a
+ {wireless local area network}, usually by paying.
+
+ (2009-05-28)
+
+wireless local area network
+
+ <networking> (WLAN /W-lan/, or "LAWN" /lorn/, sometimes
+ "WiLAN" /wi-lan/) A communication system that transmits and
+ receives data using modulated electromagnetic waves,
+ implemented as an extension to, or as an alternative for, a
+ {wired} {LAN}. WLANs are typically found within a small
+ {client} {node}-dense locale (e.g. a campus or office
+ building), or anywhere a traditional network cannot be
+ deployed for logistical reasons.
+
+ Benefits include user mobility in the coverage area, speed and
+ simplicity of physical setup, and {scalability}. Being a
+ military spin-off, WLANs also provide security features such
+ as {encryption}, {frequency hopping}, and {firewalls}. Some
+ of these are intrinsic to the {protocol}, making WLANs at
+ least as secure as wired networks, and usually more so. The
+ drawbacks are high initial cost (mostly {hardware}), limited
+ range, possibility of mutual interference, amd the need to
+ security-enable clients.
+
+ The established protocols are covered by {IEEE 802.11
+ (http://standards.ieee.org/getieee802/)}. Recent developments
+ include the {Bluetooth} project and other WPAN, or {Personal
+ Area Network} initiatives, accessible through {IEEE 802.15
+ working group (http://grouper.ieee.org/groups/802/15/)}.
+
+ {Wireless Lan Association (http://wlana.org/)}.
+
+ {Usenet} newsgroups: {news:comp.dcom.lans.misc},
+ {news:comp.std.wireless}.
+
+ (2003-09-23)
+
+Wireless Local Loop
+
+ <communications> (WLL, radio in the loop, RITL, fixed-radio
+ access, FRA) Connecting subscribers to the {public switched
+ telephone network} (PSTN) using radio signals instead of
+ copper wires. The wireless link may be all or part of the
+ connection between the subscriber and the switch. WLL
+ includes cordless access systems, proprietary fixed radio
+ access and fixed cellular systems.
+
+ (2008-03-15)
+
+Wireless Transport Layer Security
+
+ <standard, security> (WTLS) The {WAP} {standard} related to
+ security. WTLS is based upon its {TCP/IP} counterpart,
+ {Secure Sockets Layer}.
+
+ [Reference?]
+
+ (2003-06-17)
+
+wirewater
+
+ <jargon> {programming fluid}. This melds the mainstream slang
+ adjective "wired" (stimulated, up, hyperactive) with
+ "firewater"; however, it refers to caffeinacious rather than
+ alcoholic beverages.
+
+ [{Jargon File}]
+
+ (1995-02-27)
+
+WISCII
+
+ <character, data> A version of {ASCII} used by {Wang} on their
+ {personal computers} and {mini computers} in the 1980s.
+ WISCII was used on the {Wang PC}, {APC}, {OIS}, {Alliance} and
+ {VS}. The 7-bit characters were the same as ASCII, but the
+ extended 8-bit characters were Wang-specific.
+
+ (2008-05-28)
+
+wish list
+
+ <jargon> A list of desired {features} or {bug fixes} that
+ probably won't get done for a long time, usually because the
+ person responsible for the code is too busy or can't think of
+ a clean way to do it. "OK, I'll add automatic filename
+ completion to the wish list for the new interface."
+
+ Compare {tick-list features}.
+
+ [Does anybody call this a "want list"?]
+
+ [{Jargon File}]
+
+ (1998-04-28)
+
+Wisp
+
+ ["An Experiment with a Self-Compiling Compiler for a Simple
+ List-Processing Language", M.V. Wilkes, Ann Rev Automatic
+ Programming 4:1-48. (1964)].
+
+within delta of
+
+ {delta}
+
+within epsilon of
+
+ {epsilon}
+
+wizard
+
+ 1. A person who knows how a complex piece of software or
+ hardware works (that is, who {groks} it); especially someone
+ who can find and fix bugs quickly in an emergency. Someone is
+ a {hacker} if he or she has general hacking ability, but is a
+ wizard with respect to something only if he or she has
+ specific detailed knowledge of that thing. A good hacker
+ could become a wizard for something given the time to study
+ it.
+
+ 2. A person who is permitted to do things forbidden to
+ ordinary people; one who has {wheel} privileges on a system.
+
+ 3. A Unix expert, especially a Unix systems programmer. This
+ usage is well enough established that "Unix Wizard" is a
+ recognised job title at some corporations and to most
+ headhunters.
+
+ See {guru}, {lord high fixer}. See also {deep magic}, {heavy
+ wizardry}, {incantation}, {magic}, {mutter}, {rain dance},
+ {voodoo programming}, {wave a dead chicken}.
+
+ 4. An interactive help utility that guides the user through a
+ potentially complex task, such as configuring a {PPP} driver
+ to work with a new {modem}. Wizards are often implemented as
+ a sequence of {dialog boxes} which the user can move forward
+ and backward through, filling in the details required. The
+ implication is that the expertise of a human wizard in one of
+ the above senses is encapsulated in the software wizard,
+ allowing the average user to perform expertly.
+
+ [{Jargon File}]
+
+ (1998-09-07)
+
+Wizard Book
+
+ <publication> {Hal Abelson}, {Gerald Sussman} and Julie
+ Sussman's "Structure and Interpretation of Computer Programs"
+ (MIT Press, 1984; ISBN 0-262-01077-1), an excellent computer
+ science text used in introductory courses at MIT. So called
+ because of the wizard on the jacket. One of the {bibles} of
+ the LISP/Scheme world. Also, less commonly, known as the
+ {Purple Book}.
+
+ [{Jargon File}]
+
+ (1995-01-10)
+
+wizardly
+
+ Pertaining to wizards. A wizardly {feature} is one that only
+ a wizard could understand or use properly.
+
+ [{Jargon File}]
+
+wizard mode
+
+ <games> [{rogue}] A special access mode of a program or
+ system, usually password protected, that permits some users
+ godlike privileges. Generally not used for {operating
+ systems} themselves ("root mode" or "wheel mode" would be used
+ instead). This term is often used with respect to games that
+ have editable state.
+
+WizDOM
+
+ Software for distributed {Unix} {system management} from
+ {TIVOLI Systems} of Austin, Texas, USA.
+
+ (1995-02-10)
+
+wk1
+
+ <filename extension> (worksheet) The {filename extension} used
+ by early versions of the {Lotus 1-2-3} {spreadsheet} program
+ including release 2.01 (1987). All files created by the user
+ are given this extension.
+
+ (1995-11-28)
+
+WLAN
+
+ {wireless local area network}
+
+WLL
+
+ {Wireless Local Loop}
+
+WMA
+
+ {Windows Media Audio}
+
+wmf
+
+ <filename extension> The {filename extension} for a {Windows
+ Metafile}.
+
+ (1995-04-25)
+
+WMI
+
+ {Windows Management Interface}
+
+WML
+
+ {Wireless Markup Language}
+
+WMV
+
+ {Windows Media Video}
+
+WNPP
+
+ {Work Needed and Prospective Packages}
+
+WO
+
+ {WebObjects}
+
+Wolfram Research, Inc.
+
+ <company> The company founded by Stephen Wolfram in August
+ 1987 to develop {Mathematica} which was released in June 1988
+ for the {Macintosh} and is now available on over 20
+ {platforms}. The company has offices in the United Kingdom
+ and Tokyo, Japan.
+
+ {(http://wri.com/)}.
+
+ E-mail: <info@wri.com>.
+
+ (1995-02-10)
+
+WOM
+
+ {write-only memory}
+
+woman
+
+ <tool> A replacement for the {Unix} {man} {documentation}
+ browsing command. Version 1.157 of woman runs under/on
+ {386BSD}, {OSF}, {Apollo} {Domain/OS}, {BSD}, {HP-UX}, {IBM}
+ {RS-6000}, {Irix}, {Linux}, {Solaris}, {Sony} {NEWS}, {SunOS},
+ {Ultrix}, {Unicos}.
+
+ Posted to comp.sources.reviewed Volume 3, Issue 50 on 05 Jul
+ 1993 by Arne Henrik Juul <arnej@pvv.unit.no>, archive-name
+ woman-1.157.
+
+ {FTP USC, USA
+ (ftp://usc.edu/archive/usenet/sources/comp.sources.reviewed/volume3/woman-1.157/)}.
+ {FTP Imperial, UK
+ (ftp://src.doc.ic.ac.uk/usenet/comp.sources.reviewed/volume3/woman-1.157/)}.
+
+ (1995-03-21)
+
+WOMBAT
+
+ Waste Of Money, Brains, And Time.
+
+ Problems which are both profoundly {uninteresting} in
+ themselves and unlikely to benefit anyone interesting even if
+ solved. Often used in fanciful constructions such as
+ "wrestling with a wombat".
+
+ See also {crawling horror}, {SMOP}.
+
+ [{Jargon File}]
+
+ (1995-03-10)
+
+wombat
+
+ 1. <programming> A {metasyntactic variable} in {Commonwealth
+ Hackish}.
+
+ 2. <computer> {wombat.doc.ic.ac.uk}.
+
+ [{Jargon File}]
+
+ (1995-03-10)
+
+wombat.doc.ic.ac.uk
+
+ <computer> (Named after the Australian marsupial, vombatus
+ ursinus). The {Internet} {host} from which {this dictionary}
+ was originally served. {IP address} 146.169.22.42.
+ Formerly a {SPARCstation ELC}. Kindly provided by the
+ Computing Department, {Imperial College}, London. Replaced by
+ foldoc.doc.ic.ac.uk (a {Linux} box}) in June 1999. Alias
+ foldoc.org added 2000-07-18, courtesy of Karl O. Pinc.
+
+ (2000-10-09)
+
+Woodenman
+
+ HOLWG, DoD, 1975. Second of the series of DoD requirements
+ that led to Ada. "Woodenman Set of Criteria and Needed
+ Characteristics for a Common DoD High Order Programming
+ Language", David A. Fisher, Inst for Def Anal Working Paper,
+ Aug 1975. (See Strawman, Tinman, Ironman, Steelman).
+
+woofer
+
+ <jargon> (University of Waterloo) Some varieties of wide paper
+ for printers have a perforation 8.5 inches from the left
+ margin that allows the 3.5 inch excess on the right-hand side
+ to be torn off when the print format is 80 columns or less
+ wide. If done with sufficient aplomb this makes a sound like
+ the "woof" of a dog. If the large part is the "woofer" then
+ the small part must obviously be the "tweeter", following the
+ names for the large and small cones in a hi-fi loudspeaker.
+
+ These terms have been in use at Waterloo since 1972, but are
+ unknown elsewhere.
+
+ Compare {chad}.
+
+ [{Jargon File}]
+
+ (1997-03-21)
+
+WOOL
+
+ Window Object Oriented Language. A small {Common Lisp}-like
+ extension language. It claims to be the fastest interpreted
+ language in {C} with {run-time types}. Colas Nahaboo
+ <colas@sophia.inria.fr>. Version 1 is used as the kernel
+ language of the {GWM} window manager. Version 2 has an object
+ system.
+
+ {(ftp://export.lcs.mit.edu/contrib/gwm)}.
+
+Worcester Polytechnic Institute
+
+ (WPI) A well-regarded, small engineering college.
+
+ Address: Worcester, MA, USA.
+
+ (1995-03-01)
+
+Word
+
+ {Microsoft Word}
+
+word
+
+ <storage> A fundamental unit of storage in a computer. The
+ size of a word in a particular computer architecture is one of
+ its chief distinguishing characteristics.
+
+ The size of a word is usually the same as the width of the
+ computer's {data bus} so it is possible to read or write a
+ word in a single operation. An instruction is usually one or
+ more words long and a word can be used to hold a whole number
+ of characters. These days, this nearly always means a whole
+ number of {bytes} (eight bits), most often 32 or 64 bits. In
+ the past when six bit {character sets} were used, a word might
+ be a multiple of six bits, e.g. 24 bits (four characters) in
+ the {ICL 1900} series.
+
+ (1994-11-11)
+
+Word for Windows
+
+ <text, tool, product> The version of {Microsoft Word} which
+ runs under {Microsoft Windows}.
+
+ Version 6.0.
+
+ (1995-04-14)
+
+WordNet
+
+ <human language> A large {lexical} database of English,
+ developed under the direction of George A. Miller. Nouns,
+ verbs, adjectives and adverbs are grouped into sets of
+ {cognitive synonyms} ("synsets"), each expressing a distinct
+ concept. Synsets are interlinked by means of
+ conceptual-{semantic} and lexical relations. The resulting
+ network of words and concepts can be navigated with the
+ browser. WordNet is freely available for download. WordNet's
+ structure makes it a useful tool for {computational
+ linguistics} and {natural language processing}.
+
+ {WordNet home (http://wordnet.princeton.edu/)}.
+
+ (2007-04-20)
+
+WordPerfect
+
+ 1. <text, tool, product> A {word processor} for a wide range
+ of computers. The first version was sold in 1980 for {Data
+ General} machines, and by the end of 1993 versions were on
+ sale for {MS-DOS}, {Microsoft Windows} and {Macintosh}
+ computers. WordPerfect 6.0 for {Unix} was scheduled for
+ introduction in May 1994.
+
+ Versions: WordPerfect 6.1 for Windows, WordPerfect 3.1 for
+ Macintosh/Power Macintosh, WordPerfect 6.0 for UNIX,
+ WordPerfect 6.0 for DOS, WordPerfect 7.0 for {Windows 95}.
+
+ [Distinguishing features?]
+
+ {(http://corel.com/products/wordperfect/)}.
+
+ 2. {WordPerfect Corporation}.
+
+ (1995-07-05)
+
+WordPerfect Corporation
+
+ <company> The original developers of the {WordPerfect} {word
+ processor} and a variety of other {applications} for {personal
+ computers}. WordPerfect was founded in Provo, Utah, USA in
+ 1979 by Alan Ashton and Bruce Bastion as "Satellite Software
+ International". The company name was changed to Wordperfect
+ Corporation in 1986. The company was bought by {Novell, Inc.}
+ in 1994, who then sold it to {Corel Corporation} in 1996.
+
+ (1997-03-12)
+
+word processing
+
+ {word processor}
+
+word processor
+
+ <text, tool> A program used to create and print (chiefly
+ textual) documents that might otherwise be prepared on a
+ typewriter. The key advantage of word processor is its
+ ability to make changes easily, such as correcting spelling,
+ changing margins, or adding, deleting, and relocating entire
+ blocks of text. Once created, the document can be printed
+ quickly and accurately and saved for later modifications.
+
+ Today most popular word processors, such as {Microsoft Word},
+ offer a much greater range of facilities than the first such
+ programs.
+
+ Compare {text editor}.
+
+ (1995-04-14)
+
+word size
+
+ <processor> The number of bits that a {CPU} can process at one
+ time. Processors with many different word sizes have existed
+ though powers of two (8, 16, 32, 64) have predominated for
+ many years. A processor's word size is often equal to the
+ width of its external data bus though sometimes the bus is
+ made narrower than the CPU (often half as many bits) to
+ economise on packaging and circuit board costs.
+
+ (1995-04-23)
+
+word spamming
+
+ <web, information science> Repeating a word many
+ times in a {web page}, in a (usually futile) attempt to
+ increase its {relevance} ranking in a {search engine}'s index
+ (to "{spam}" the index).
+
+ "Repeating a word over and over in a Web page (known as word
+ spamming) has no effect on the [page's] ranking [in the
+ index]." -- {Altavista FAQ
+ (http://altavista.digital.com/cgi-bin/query?pg=tmpl&v=faq.html)}.
+
+ See also {spamdex}.
+
+ (1997-04-09)
+
+WordTech
+
+ <company> Manufacturers of {Quicksilver}.
+
+ Address: Orinda, CA, USA.
+
+ (1995-05-11)
+
+word wrap
+
+ <text> A feature of {word processors} and most {text editors}
+ where a word which would extend past the right hand margin is
+ moved to the following line. This is more sophisticated than
+ character wrap which only moves to the next line for the first
+ character past the right margin and thus will break some words
+ in the middle. The program may actually insert a new line in
+ the text at the point where it is wrapped or it may only
+ display it as though it contained a new line at that point.
+
+ (1996-07-24)
+
+workaround
+
+ <jargon, programming> A temporary {kluge} used to bypass, mask
+ or otherwise avoid a {bug} or {misfeature} in some system.
+ Customers often find themselves living with workarounds for
+ long periods of time rather than getting a {bug fix}.
+
+ [{Jargon File}]
+
+ (1998-06-25)
+
+Work Breakdown Structure
+
+ <project> (WBS) A division of a project into tasks and
+ subtasks. The tasks are numbered to indicate their
+ relationship to each other. WBSs are indespensible for
+ project planning, particularly when estimating time and
+ resource requirements. Some industries use established work
+ breakdown structure systems for billing and reporting
+ purposes.
+
+ (2001-05-09)
+
+workflow
+
+ 1. <operating system> The {scheduling} of independent jobs on
+ a computer.
+
+ See also {time-sharing}, {WFL}.
+
+ 2. <job> The set of relationships between all the activities
+ in a project, from start to finish. Activities are related by
+ different types of trigger relation. Activities may be
+ triggered by external events or by other activities.
+
+ 3. The movement of documents around an organisation for
+ purposes including sign-off, evaluation, performing activities
+ in a process and co-writing.
+
+ [Stef Joosten et.al. "An empirical study about the practice of
+ workflow management", {WA-12} report, 1994].
+
+ (1995-03-27)
+
+Workflow Management Coalition
+
+ <body> (WfMc) A non-profit, international organisation of
+ {workflow} vendors, users, and analysts committed to
+ establishing {standards} for {workflow} terminology,
+ {interoperability}, and connectivity.
+
+ WfMC was founded in 1993 and now (1999) has over 130 members.
+
+ {(http://aiim.org/wfmc)}.
+
+ (1999-08-01)
+
+workgroup
+
+ {Computer Supported Cooperative Work}
+
+working as designed
+
+ <jargon> (IBM) Conforming to a wrong or inappropriate
+ specification; useful, but misdesigned. Frequently used as a
+ sardonic comment on a program's utility or as a bogus reason
+ for not accepting a criticism or suggestion. At {IBM}, this
+ sense is used in official documents!
+
+ See {BAD}.
+
+ [{Jargon File}]
+
+ (1995-04-04)
+
+working memory
+
+ <storage, architecture> The parts of {main memory} ({RAM})
+ currently in use.
+
+ In a {production system}, working memory contains the facts,
+ both initial and generated.
+
+ (2005-06-17)
+
+working set
+
+ <architecture> The set of all pages (in a {paging} {virtual
+ memory} system) used by a {process} during some time interval.
+
+ As a result of {locality of reference}, the working set
+ frequently consists of a relatively small fraction of a
+ process's total virtual memory pages. While a process's
+ entire working set is in {physical memory} the process will
+ run without {page faults}. If the working set is too large
+ for available physical memory, the process causes frequent
+ {page faults}.
+
+ In a {multitasking} environment, information about which pages
+ are in each process's working set allows the memory management
+ system to improve {CPU} efficiency by {prepaging} (also called
+ the {working set model}).
+
+ ["Modern Operating Systems", Andrew S. Tanenbaum, pub.
+ Prentice Hall, Inc. 1992].
+
+ (1997-04-09)
+
+working set model
+
+ {prepaging}
+
+Work Needed and Prospective Packages
+
+ <Debian> (WNPP) A document, maintained on the {Debian} {web
+ site} {here (http://debian.org/devel/wnpp/)}, providing a
+ current list of packages which are either orphaned (withdrawn
+ from distribution), maintained but its developer would like to
+ find a new person, currently being worked on to include in the
+ distribution, or good ideas with no one working on them.
+
+ WNPP is also a pseudo package on the Debian Bug Tracking
+ System. Developers update the WNPP document by filing,
+ modifying or closing bugs agains the psuedo package.
+
+ (2000-09-06)
+
+work path
+
+ <graphics> In {Adobe Photoshop}, a temporary {path} that
+ appears in the Paths palette and defines the outline of a
+ shape.
+
+ (2009-03-02)
+
+worksheet
+
+ {spreadsheet}
+
+workstation
+
+ <computer> A general-purpose computer designed to be used by
+ one person at a time and which offers higher performance than
+ normally found in a {personal computer}, especially with
+ respect to graphics, processing power and the ability to carry
+ out several tasks at the same time.
+
+ (1995-05-04)
+
+World Time
+
+ {Coordinated Universal Time}
+
+World-Wide Wait
+
+ <humour> A pejorative expansion of {WWW} reflecting on the
+ slowness of some network connections and sites.
+
+ (1997-03-30)
+
+World-Wide Web
+
+ <web, networking, hypertext> (WWW, W3, The Web) An {Internet}
+ {client-server} {hypertext} distributed information retrieval
+ system.
+
+ Basically, the web consists of documents or {web pages} in {HTML}
+ format (a kind of {hypertext}), each of which has a unique {URL}
+ or "web address". {Links} in a page are URLs of other pages which
+ may be part of the same {website} or a page on another site on a
+ different {web server} anywhere on the {Internet}.
+
+ As well as HTML pages, a URL may refer to an image, some code
+ ({JavaScript} or {Java}), {CSS}, a {video} stream or other kind of
+ object. The vast majority of URLs start with "http://",
+ indicating that the page needs to be fetched using the {HTTP}
+ {protocol}. Other possibile "schemes" are {HTTPS}, which
+ {encrypts} the request and the resulting page or {FTP}, the
+ original protocol for transferring files over the Internet.
+ {RTSP} is a {streaming protocol} that allow a continuous feed of
+ {audio} or {video} from the server to the browser. {Gopher} was a
+ predecessor of HTTP and {Telnet} starts an {interactive}
+ {command-line} session with a remote server.
+
+ The web is accessed using a {client} program known as a {web
+ browser} that runs on the user's computer. The browser fetches and
+ displays pages and allows the user to follow {links} by clicking
+ on them (or similar action) and to input queries to the server. A
+ variety of browsers are freely available, e.g. {Internet
+ Explorer}, {Google Chrome}, {Safari}. Early examples were {NCSA}
+ {Mosaic} and {Netscape} {Navigator}.
+
+ Queries can be entered into "forms" which allow the user to enter
+ arbitrary text and select options from customisable menus and
+ other controls. The server processes each request - either a
+ simple URL or data from a form - and returns a response, typically
+ a page of HTML.
+
+ The World-Wide Web originated from the {CERN} High-Energy Physics
+ laboratories in Geneva, Switzerland. In the early 1990s, the
+ developers at CERN spread word of the Web's capabilities to
+ scientific and academic audiences worldwide. By September 1993,
+ the share of Web traffic traversing the {NSFNET} {Internet}
+ {backbone} reached 75 {gigabytes} per month or one percent. By
+ July 1994 it was one {terabyte} per month.
+
+ The {World Wide Web Consortium} is the main standards body for
+ the web.
+
+ Following the widespread availability of web browsers and servers
+ from about 1995, many companies realised they could use the same
+ software and protocols on their own private internal {TCP/IP}
+ networks giving rise to the term "{intranet}".
+
+ {This dictionary} is accessible via the Web at
+ {(http://foldoc.org/)}. If you are reading a plain text version
+ of this dictionary then you will see lots of curly brackets and
+ strings like
+
+ {(http://hostname/here/there/page.html)}.
+
+ These are transformed into hypertext links when you access it
+ via the Web.
+
+ {An article by John December
+ (http://sunsite.unc.edu/cmc/mag/1994/oct/webip.html)}.
+
+ {W3 servers, clients and tools (http://w3.org/Status.html)}.
+
+ (2014-08-23)
+
+World Wide Web Consortium
+
+ <web, body> (W3C) The main standards body for the
+ {web}. W3C works with the global community to
+ establish international {standards} for {client} and {server}
+ {protocols} that enable on-line commerce and communications on
+ the {Internet}. It also produces reference software.
+
+ W3C was created by the {Massachusetts Institute of Technology}
+ (MIT) on 25 October 1994. {Netscape Communications
+ Corporation} was a founding member. The Consortium is run by
+ {MIT LCS} and {INRIA}, in collaboration with {CERN} where the
+ web originated. W3C is funded by industrial members but its
+ products are freely available to all. The director is Tim
+ Berners-Lee who invented the {web} at the Center
+ for European Particle Research (CERN).
+
+ {(http://w3.org/)}.
+
+ (1996-11-03)
+
+World Wide Web Worm
+
+ <web> (WWWW) One of the first automatic indexing tools for the
+ {web}, being developed in September 1994 by Oliver McBryan
+ <mcbryan@cs.colorado.edu> at the {University of Colorado}. The
+ worm created a database of 300,000 {multimedia} objects which can
+ be obtained or searched for keywords via the web.
+
+ {(http://cs.colorado.edu/home/mcbryan/WWWW.html)}.
+
+ (1996-05-19)
+
+WORM
+
+ {Write-Once Read-Many}
+
+worm
+
+ <networking, security> (From "Tapeworm" in John Brunner's
+ novel "The Shockwave Rider", via {XEROX PARC}) A program that
+ propagates itself over a network, reproducing itself as it
+ goes. Compare {virus}. Nowadays the term has negative
+ connotations, as it is assumed that only {crackers} write
+ worms.
+
+ Perhaps the best-known example was the {Great Worm}.
+
+ Compare {Trojan horse}.
+
+ [{Jargon File}]
+
+ (1996-09-17)
+
+wormhole
+
+ {back door}
+
+wormhole routing
+
+ <messaging> A property of a {message passing} system in which
+ each part of a message is transmitted independently and one
+ part can be forwarded to the next {node} before the whole
+ message has been received. All parts of a single message
+ follow the same route.
+
+ The independent parts are normally small, e.g. one 32-bit
+ word. This reduces the {latency} and the storage requirements
+ on each node when compared with {message switching} where a
+ node receives the whole message before it starts to forward it
+ to the next node. It is more complex than message switching
+ because each node must keep track of the messages currently
+ flowing through it.
+
+ With {cut-through switching}, wormhole routing is applied to
+ {packets} in a {packet switching} system so that forwarding of
+ a packet starts as soon as its destination is known, before
+ the whole packet had arrived.
+
+ (2003-05-15)
+
+WOSA
+
+ {Windows Open Services Architecture}
+
+WOSA Extensions for Financial Systems
+
+ {Extensions for Financial Services}
+
+WOSA/XFS
+
+ {Extensions for Financial Services}
+
+wound around the axle
+
+ {infinite loop}
+
+WPA
+
+ {Wi-Fi Protected Access}
+
+WPA Pre-Shared Key
+
+ {Wi-Fi Protected Access Pre-Shared Key}
+
+WPA-PSK
+
+ {Wi-Fi Protected Access Pre-Shared Key}
+
+WPG
+
+ {Workstation Products Group}
+
+WPI
+
+ {Worcester Polytechnic Institute}
+
+WPL+
+
+ Word-oriented language internal to PRODOS Applewriter 2.1.
+ Available on GEnie.
+
+WPOP
+
+ WonderPop. Robert Rae <rhr@aiai.ed.ac.uk>, Edinburgh 1976.
+ An implementation of POP for the PDP-10 that used cages for
+ different data types. Introduced processes, properties, and
+ some typed identifiers.
+
+wps
+
+ <unit> (Obsolete) Words per second (mostly used for {Telex}
+ and {TWX} transmission).
+
+ (1997-01-07)
+
+WRAM
+
+ {Window Random Access Memory}
+
+wrap around
+
+ (Or "wraparound", "wrap") The action of a counter that starts
+ again at zero or at "minus infinity" (see {infinity}) after
+ its maximum value has been reached, and continues
+ incrementing, either because it is programmed to do so or
+ because of an overflow (as when a car's odometer starts again
+ at 0).
+
+ [{Jargon File}]
+
+wrapper
+
+ <programming> Code which is combined with another piece of
+ {code} to determine how that code is executed. The wrapper
+ acts as an interface between its caller and the wrapped code.
+ This may be done for compatibility, e.g. if the wrapped code
+ is in a different programming language or uses different
+ calling conventions, or for security, e.g. to prevent the
+ calling program from executing certain functions. The
+ implication is that the wrapped code can only be accessed via
+ the wrapper.
+
+ (1998-12-15)
+
+wrats nest
+
+ <hardware, jargon> (From "wrap" and "rats nest") A
+ {wire-wrapping} defect where all of the wire piles up around
+ the bottom of the post instead of wrapping smoothly around it.
+ It looks like a little bird nest.
+
+ (1997-03-18)
+
+wrb
+
+ {Web Request Broker}
+
+write
+
+ 1. <chat> {Unix}'s simple {talk} command and {protocol}.
+ write has been largely superseded by {talk} and then {irc}.
+
+ An enhancement, {RWP}, has been proposed.
+
+ 2. <tool> A simple {text editor} for {Windows}.
+
+ (1998-04-28)
+
+WRITEACOURSE
+
+ <language> A {CAI} language for {IBM 360}.
+
+ ["WRITEACOURSE: An Educational Programming Language", E. Hunt
+ et al, Proc FJCC 33(2) 1968].
+
+ (1998-04-28)
+
+write-back
+
+ <memory management> A {cache} architecture in which data is
+ only written to main memory when it is forced out of the
+ cache.
+
+ Opposite of {write-through}. See also {no-write allocation}.
+
+ (1996-06-12)
+
+write buffer
+
+ {buffered write-through}
+
+Write-Once Read-Many
+
+ <storage> (WORM) Any type of storage medium to which data can
+ be written to only a single time, but can be read from any
+ number of times. Typically this is an {optical disk} whose
+ surface is permanently etched using a laser in order to record
+ information. WORM media have a significantly longer shelf
+ life than magnetic media and thus are used when data must be
+ preserved for a long time.
+
+ (1996-04-01)
+
+write-only code
+
+ [a play on "read-only memory"] Code so arcane, complex, or
+ ill-structured that it cannot be modified or even comprehended
+ by anyone but its author, and possibly not even by him/her. A
+ {Bad Thing}.
+
+ [{Jargon File}]
+
+write-only language
+
+ A language with syntax (or semantics) sufficiently dense and
+ bizarre that any routine of significant size is automatically
+ {write-only code}. A sobriquet applied occasionally to C and
+ often to APL, though {INTERCAL} and {TECO} certainly deserve
+ it more.
+
+write-only memory
+
+ 1. <jargon, humour> (WOM) The obvious antonym to "{read-only
+ memory}" (ROM).
+
+ Out of frustration with the long and seemingly useless chain
+ of approvals required of component specifications, during
+ which no actual checking seemed to occur, an engineer at
+ {Signetics} once created a specification for a write-only
+ memory and included it with a bunch of other specifications to
+ be approved. This inclusion came to the attention of
+ Signetics {management} only when regular customers started
+ calling and asking for pricing information. Signetics
+ published a corrected edition of the data book and requested
+ the return of the "erroneous" ones. Later, around 1974,
+ Signetics bought a double-page spread in "Electronics"
+ magazine's April issue and used the spec as an April Fools'
+ Day joke. Instead of the more conventional characteristic
+ curves, the 25120 "fully encoded, 9046 x N, Random Access,
+ write-only-memory" data sheet included diagrams of "bit
+ capacity vs. Temp.", "Iff vs. Vff", "Number of pins remaining
+ vs. number of socket insertions", and "AQL vs. selling price".
+ The 25120 required a 6.3 VAC VFF supply, a +10V VCC, and VDD
+ of 0V, +/- 2%.
+
+ 2. {bit bucket}.
+
+ [{Jargon File}]
+
+ (2007-03-24)
+
+write protect
+
+ <storage> A feature of certain {removable media} storage
+ devices that tells the system whether or not it should allow
+ the data on the media to be modified. Write protecting an
+ item of media prevents accidental overwriting of valuable
+ data.
+
+ For example, the write protect tab on a 3.5-inch {floppy
+ disks} is a small sliding plastic square that can either cover
+ or expose a hole near the edge of the disk cover. The drive
+ wil only allow the disk to be written to if the hole is
+ closed.
+
+ (2007-03-24)
+
+write-through
+
+ <architecture> (Or "write-thru") A {cache} architecture in
+ which data is written to main memory at the same time as it is
+ cached.
+
+ Opposite of {write-back}. See also {buffered write-through},
+ {posted write-through}, {no-write allocation}.
+
+ (1996-06-12)
+
+write-thru
+
+ {write-through}
+
+writing system
+
+ <human language, character> The set of {glyphs} used for
+ representing a given human language in written form, generally
+ along with their conventions for use.
+
+ (1998-10-19)
+
+Wrong Thing
+
+ <jargon> A design, action, or decision that is clearly
+ incorrect or inappropriate. Often capitalised; always
+ emphasised in speech as if capitalised. The opposite of the
+ {Right Thing}; more generally, anything that is not the Right
+ Thing. In cases where "the good is the enemy of the best",
+ the merely good - although good - is nevertheless the Wrong
+ Thing. "In C, the default is for module-level declarations to
+ be visible everywhere, rather than just within the module.
+ This is clearly the Wrong Thing."
+
+ [{Jargon File}]
+
+WRT
+
+ with regard to, with respect to.
+
+ws
+
+ <networking> The {country code} for Samoa.
+
+ (1999-01-27)
+
+WSBPEL
+
+ {Web Services Business Process Execution Language}
+
+WSDL
+
+ {Web Service Definition Language}
+
+WSFN
+
+ {Which Stands For Nothing}
+
+WSL
+
+ Waterloo Systems Language. A {C}-like systems programming
+ language.
+
+ ["Waterloo Systems Language: Tutorial and Language Reference",
+ F.D. Boswell, WATFAC Publications Ltd., Waterloo, Canada.
+ ISBN 0-919884-00-8].
+
+WTF
+
+ who/what/why the fuck? The universal interrogative particle.
+ Also {WTH}.
+
+WTFPL
+
+ {Do What the Fuck You Want to Public License}
+
+WTH
+
+ who/what/why the hell? Also {WTF}.
+
+WTLS
+
+ {Wireless Transport Layer Security}
+
+Wumpus
+
+ {Hunt the Wumpus}
+
+WWW
+
+ {web}
+
+WWW browser
+
+ <hypertext, web> A {browser} for use on the
+ {web}.
+
+ (1996-10-28)
+
+WWWW
+
+ {web Worm}
+
+WYGIWYNTYH
+
+ {What You Get Is What You Never Thought You Had}
+
+WYSIAYG
+
+ {What You See Is All You Get}
+
+WYSIWYG
+
+ {What You See Is What You Get}
+
+WYSWYG
+
+ {What You See Is What You Get}
+
+X
+
+ 1. <convention> Used in various speech and writing contexts
+ (also in lowercase) in roughly its algebraic sense of "unknown
+ within a set defined by context" (compare {N}). Thus, the
+ abbreviation {680x0} stands for 68000, 68010, 68020, 68030 or
+ 68040, and {80x86} stands for {Intel 80186}, {Intel 80286},
+ {Intel 80386} or {Intel 80486}. A {Unix} hacker might write
+ these as 680[0-4]0 and 80[1-4]86 or 680?0 and 80?86
+ respectively; see {glob}.
+
+ 2. <graphics> An alternative name for the {X Window System}.
+
+ 3. <storage> A suffix for the speed of a {CD-ROM} drive
+ relative to standard music CDs (1x). 32x is common in
+ September 1999.
+
+ [{Jargon File}]
+
+ (1999-09-15)
+
+X-1
+
+ <language> An early system on the {UNIVAC I} or II.
+
+ [Listed in CACM 2(5):16 (May 1959)].
+
+ (1995-05-10)
+
+X11R4
+
+ Version 11 release 4 of the X protocol. See {X Window
+ System}.
+
+X11R5
+
+ Version 11 release 5 of the X protocol. Released in June
+ 1994. See {X Window System}.
+
+X11R6
+
+ <operating system> Version 11 release 6 of the {X Window
+ System}.
+
+ [Release date?]
+
+ (1995-01-20)
+
+X.12
+
+ <standard> The American equivalent of UN/{EDIFACT} and various
+ other national and industry {EDI} messaging {protocols}. The
+ first {Y2K ready} version of X.12 is version 4010.
+
+ [What's "UN"? Details? Differences from EDIFACT?]
+
+ (1999-09-10)
+
+X2
+
+ <protocol> A proprietary modem standard developed by {US
+ Robotics} for 56 {kbps} communications. Not taken up as
+ widely as {K56flex} and will shortly be superseded by the
+ official {V.90} standard.
+
+ (1998-09-08)
+
+X.208
+
+ {Abstract Syntax Notation 1}
+
+X.209
+
+ {Basic Encoding Rules}
+
+X.21
+
+ <communications, standard> A digital signaling interface
+ recommended by {ITU-T} that includes specifications for
+ {DTE}/{DCE} physical interface elements, alignment of {call
+ control} characters and error checking, elements of the call
+ control phase for {circuit switched} services, data transfer
+ at up to 2 {Mbps}, and {test loops}. 64 {kbps} is the most
+ commonly used transfer rate.
+
+ (2000-02-28)
+
+X.214
+
+ {transport layer}
+
+X.215
+
+ {session layer}
+
+X.216
+
+ {presentation layer}
+
+X.217
+
+ {Association Control Service Element}
+
+X.219
+
+ {Remote Operations Service Element}
+
+X.224
+
+ {transport layer}
+
+X.225
+
+ {session layer}
+
+X.226
+
+ {presentation layer}
+
+X.227
+
+ {Association Control Service Element}
+
+X.229
+
+ {Remote Operations Service Element}
+
+X.25
+
+ <protocol, standard> An {ITU-T} {standard} {protocol} suite
+ for the {DTE}-{DCE} interface in a {packet-switched} network,
+ approved by {ISO}. X.25 defines standard {physical layer},
+ {data link layer} and {network layers} (layers 1 through 3).
+ It was developed to describe how data passes into and out of
+ public data communications networks. X.25 networks are in use
+ throughout the world.
+
+ Document: {ISO} 8208.
+
+ Several other {ITU-T} recommendations are relevant to {packet
+ switching}: {X.3}, {X.28}, {X.29}, {X.75}.
+
+ (1996-08-10)
+
+X.28
+
+ The {ITU-T} standard specifying how to control a {PAD} from
+ {character-mode} {DTE}, approved by {ISO}.
+
+ (1995-01-31)
+
+X.29
+
+ The {ITU-T} {standard}, approved by {ISO}, specifying
+ procedures for the exchange of control information and user
+ data between a {PAD} and a remote {packet-mode} {DTE}.
+ {Character-mode} {DTEs} are often referred to as X.29
+ terminals.
+
+ (1995-01-31)
+
+X.3
+
+ The {ITU-T} {standard}, approved by {ISO}, which specifies the
+ basic functions and user-selectable capabilities of a {PAD}.
+
+ (1995-01-31)
+
+X3J16
+
+ The {C++} {standard} technical committee.
+
+X3T10
+
+ <body> The {ATA} standards body.
+
+ (1996-10-16)
+
+X.400
+
+ <messaging> The set of {ITU-T} communications standards
+ covering {electronic mail} services provided by data networks.
+ X.400 was widely used in Europe and Canada.
+
+ X.400 addresses tend to be much longer than {RFC 822} ones.
+ They consist of a set of bindings for country (c),
+ {administrative domain} (a), {primary management domain} (p),
+ surname (s), given name (g).
+
+ For example, the X.400 address,
+
+ c=gb;a=attmail;p=Universal Export;s=Bond;g=James;
+
+ might be equivalent to RFC 822
+
+ James.Bond@UniversalExport.co.uk
+
+ [Reference?]
+
+ (2003-06-24)
+
+X.409
+
+ <standard, messaging> Part of the {X.400} {electronic mail}
+ specification which included the original definition of
+ {Abstract Syntax Notation 1}.
+
+ [What was it about?]
+
+ (1998-08-06)
+
+X.500
+
+ <standard, networking> The set of {ITU-T} {standards} covering
+ electronic directory services such as {white pages},
+ {Knowbot}, {whois}.
+
+ Compare: {LDAP}.
+
+ (1994-12-06)
+
+X.680
+
+ <standard>
+
+ [Is it {Coordinated Universal Time} or {Abstract Syntax
+ Notation 1}?]
+
+ (1999-12-09)
+
+X.75
+
+ The {ITU-T} {standard} specifying the {protocols} for
+ communication between two {PSDNs}.
+
+ (1995-01-31)
+
+x86
+
+ {Intel 80x86}
+
+x86 processor socket
+
+ <hardware, standard> One of the series of standard sockets
+ into which you can plug various {x86} {microprocessors}.
+ These vary in the number of pins, package, voltages, bus
+ speeds, and supported processors. {Motherboards} often have
+ {clock multipliers} so that the processor runs at a multiple
+ of the bus speed.
+
+ Socket 1, 169 pin {LIF}/{ZIF} {PGA} (17x17), 5v, 16-33 MHz
+ {486 SX}, {486 DX}, {486 DX2}, {DX4 Overdrive}. Socket 1 was
+ the first standard {Intel 486} socket.
+
+ Socket 2, 238 pin LIF/ZIF PGA (19x19), 5v, 25-50 MHz 486 SX,
+ 486 DX, 486 DX2, 486 DX4, DX4 & {Pentium Overdrive}. Updated
+ Socket 1, added support for Pentium Overdrive processors.
+
+ Socket 3, 237 pin LIF/ZIF PGA (19x19), 3.3/5v, 25-50 MHz 486
+ SX, 486 DX, 486 DX2, 486 DX4, DX4 & Pentium Overdrive.
+ Supports 5V & 3.3V processors, considered the latest 486
+ socket.
+
+ Socket 4, 273 pin LIF/ZIF PGA (21x21), 5v, 60/66 MHz Pentium
+ 60/66 and Pentium Overdrive, only 5v.
+
+ Socket 5, 296 pin LIF/ZIF, 320 pin LIF/ZIF {SPGA} (19x19 or
+ 37x37), 3.3v, 50/60/66 MHz Pentium 75 - 133MHz, Pentium
+ Overdrive, only 3.3v.
+
+ Socket 6, 235 pin ZIF PGA (19x19), 3.3v, 25-40MHz. Unpopular
+ advanced Socket 3, rarely seen / paper spec 486 DX4, Pentium
+ Overdrive, only 3.3v.
+
+ See also {Socket 7}, {Socket 8}, {Super 7}, {Slot 1}, {Slot
+ 2}, {Slot A}.
+
+ {CPU Sockets chart
+ (http://users.erols.com/chare/sockets.htm)}.
+
+ {CPU Sockets (http://webm3308.ntx.net/cpusockets.htm)}.
+
+ (1999-08-05)
+
+XA
+
+ {Extended Architecture}
+
+ A specification for drives which can play {CD-ROMs} in {Green
+ book CD-ROM} format.
+
+ (1994-12-06)
+
+Xaw
+
+ The {Athena} {Widget} Set. A set of widgets distributed with
+ the {X Window System}.
+
+ (1994-11-02)
+
+Xbase
+
+ Generic term for the {dBASE} family of {database} languages.
+ Coined in response to threatened litigation over use of the
+ copyrighted trademark "dBASE."
+
+xbeeb
+
+ A {BBC Microcomputer} {emulator} for {Unix} and {X11} by James
+ Fidell <jfid@mfltd.co.uk>. Posted to {alt.sources}.
+
+ {(ftp://ftp.pipex.net/incoming/xbeeb)}.
+
+ (1994-08-18)
+
+xbm
+
+ <filename extension> X bit map. The {filename extension} for
+ files containing {bitmaps} for use in the {X Window System}.
+
+ These are actually {include files} which can be #include'd
+ into {C} program source to define images as initialised data.
+
+ (1995-03-14)
+
+XC
+
+ A {declarative} extension of {C++}.
+
+ ["XC - A Language for Embedded Rule Based Systems", E. Nuutila
+ et al, SIGPLAN Notices 22(9):23-32 (Sep 1987)].
+
+X client
+
+ An application process in the {X Window System}. It gains
+ access to windowing services via the Xlib library. These are
+ translated by the system into {X protocol} messages to an {X
+ server}.
+
+X Consortium
+
+ A vendor consortium supporting development, evolution and
+ maintenance of the {X Window System}. The X Consortium is an
+ independent, not-for-profit company. It was formed in 1993 as
+ the successor to the {MIT} X Consortium, a research group of
+ the MIT {Laboratory for Computer Science}.
+
+ {(ftp://ftp.x.org)}. {(http://x.org/)}.
+
+ [Members?]
+
+Xcoral
+
+ A multiwindow mouse-based text editor, for the {X Window
+ System} with a built-in browser to navigate through {C}
+ functions and {C++} {class}es hierarchies. Xcoral provides
+ variables width {fonts}, menus, {scrollbars}, {buttons},
+ search, regions, kill-buffers and 3D look. Commands are
+ accessible from menus or standard key bindings. Xcoral is a
+ direct {Xlib} {client} and runs on colour or monochrome X
+ displays.
+
+ {Version 1.72 (ftp://ftp.inria.fr/X/contrib/clients/xcoral*)}.
+
+ (1993-03-14)
+
+xdbx
+
+ <programming, tool> An {X Window System} front end for {dbx}
+ developed by Po Cheung at MCC.
+
+ Latest version: 2.1, as of 1992-02-22.
+
+ Posted to comp.sources.x volumes 11, 12, 13, 14, 16.
+
+ (2000-07-12)
+
+X-Designer
+
+ <programming, tool> A {user interface builder} for {Motif}
+ from {Imperial Software Technology}.
+
+ {(http://ist.co.uk/xd/)}.
+
+ (1995-10-26)
+
+X.desktop
+
+ A desktop manager for {Unix} from {IXI}.
+
+XDL
+
+ <language> An {object-oriented} extension to {ITU-T}'s {SDL}.
+
+ ["XDL: An Object-Oriented Extension to SDL", S.J. Ochuodho et
+ al].
+
+ (1995-10-12)
+
+XDR
+
+ {eXternal Data Representation}
+
+XDS 530
+
+ {Xerox Data Systems Model 530}
+
+XDS 940
+
+ {Xerox Data Systems Model 940}
+
+xDSL
+
+ {Digital Subscriber Line}
+
+Xemacs
+
+ <text, tool> (Originally "Lucid Emacs") A text editor for the
+ {X Window System}, based on {GNU} {Emacs} version 19, produced
+ by a collaboration of {Lucid, Inc.}, {SunPro} (a division of
+ {Sun Microsystems, Inc.}), and the {University of Illinois}.
+
+ Lucid chose to build part of {Energize}, their {C}/{C++}
+ development environment on top of GNU Emacs. Though their
+ product is commercial, the work on GNU Emacs is {free
+ software}, and is useful without having to purchase the
+ product. They needed a version of Emacs with mouse-sensitive
+ regions, multiple fonts, the ability to mark sections of a
+ buffer as read-only, the ability to detect which parts of a
+ buffer has been modified, and many other features.
+
+ The existing version of {Epoch} was not sufficient; it did not
+ allow arbitrary {pixmaps} and {icons} in buffers, "undo" did
+ not restore changes to regions, regions did not overlap and
+ merge their attributes. Lucid spent some time in 1990 working
+ on Epoch but later decided that their efforts would be better
+ spent improving Emacs 19 instead.
+
+ Lucid did not have time to get their changes accepted by the
+ {FSF} so they released Lucid Emacs as a forked branch of
+ Emacs. Roughly a year after Lucid Emacs 19.0 was released, a
+ beta version of the FSF branch of Emacs 19 was released.
+ Lucid continued to develop and support Lucid Emacs, merging in
+ bug fixes and new features from the FSF branch as appropriate.
+
+ A compatibility package was planned to allow Epoch 4 code to
+ run in Lemacs with little or no change. (As of 19.8, Lucid
+ Emacs ran a descendant of the Epoch redisplay engine.)
+
+ [Update?]
+
+ (2000-05-16)
+
+XENIX
+
+ <operating system> A commercial version of {Unix} for
+ {microprocessor}-based computers, released by {Microsoft} in
+ 1980. In 1992, {SCO} became Microsoft's co-development partner
+ and the alternate source for the product.
+
+ (1999-12-07)
+
+Xeon
+
+ {Pentium II Xeon}
+
+xerox
+
+ {XEROX Corporation}
+
+XEROX Corporation
+
+ <company> A US company, founded in 1906, specialising in document
+ related technology and services including photocopiers, printers
+ and office software. Xerox's acquisition of {Affiliated Computer
+ Services} added business process and document management to their
+ product range. In 2013 they have 140,000 employees.
+
+ Their research centre, {XEROX PARC}, prototyped several
+ revolutionary advances in computing, which the company failed to
+ exploit, including the {WIMP} desktop metaphor and {XEROX Network
+ Services}.
+
+ {(http://xerox.com/)}.
+
+ (2013-04-30)
+
+Xerox Data Systems Model 530
+
+ <computer> (XDS 530) A computer from the {Scientific Data
+ Systems} range, announced sometime after 1968 when {Xerox}
+ bought out SDS. The XDS 530 was probably under development at
+ SDS before the buy-out but only announced afterwards.
+
+ (2004-06-17)
+
+Xerox Data Systems Model 940
+
+ <computer> (SDS 940, XDS 940) A {time-sharing} system,
+ announced in February 1966, developed by {Scientific Data
+ Systems} with help from The {University of California at
+ Berkeley} and {Tymshare}. SDS 940 was {backward compatible}
+ with SDS's previous systems (except the 12-bit {SDS 92}). It
+ had {monitor} and user modes, dynamic program relocation,
+ automatic memory fragmentation, and system protection.
+
+ After 1968 {Xerox} bought out SDS and renamed the SDS machines
+ "Xerox Data Systems" (XDS). Xerox then produced the {XDS
+ 530}.
+
+ (2004-06-17)
+
+XEROX Network Services
+
+ <networking> (XNS)
+
+ [Is this the same as/a misnomer for {Xerox Network System}?]
+
+ (2003-10-05)
+
+Xerox Network System
+
+ <networking> (XNS) A proprietary network architecture
+ developed by the Xerox Office Systems Division of {Xerox
+ corporation} at {Xerox PARC} in the late 1970s/early 1980s to
+ run on {LAN} ({Ethernet}) and {WAN} networks. The XNS
+ {protocol stack} provided {routing} and {packet delivery}.
+
+ Implementations exist for {4.3BSD} derived systems and the
+ {Xerox Star} computers. Novell based much of the lower layers
+ of their protocol suite IPX/SPX on XNS.
+
+ The main components are: Internet datagram protocol (IDP),
+ Routing information protocol (RIP), Packet Exchange protocol
+ (PEP), and Sequences packet protocol (SPP).
+
+ XNS has strong parellels to {TCP/IP} in that the {network
+ layer}, IDP, is roughly equivalent to IP. RIP has the same
+ functions (and obviously name) as the routing information
+ protocol, RIP. SPP, a connectionless transport layer
+ protocol, is similar to {UDP}. PEP is also in the transport
+ layer but is connection-oriented and similar to TCP.
+
+ XNS specifically is no longer in use due to the all
+ pervasiveness of IP.
+
+ XNS denotes not only the protocol stack, but also an
+ architecture of standard programming interfaces, conventions,
+ and service functions for {authentication}, directory, filing,
+ {e-mail}, and {remote procedure call}. XNS is also the name
+ of Xerox's implementation.
+
+ Many PC networking companies, such as {3Com}, {Banyan},
+ {Novell}, and {Ungermann-Bass Networks} used or use a
+ variation of XNS as their primary transport protocol. XNS was
+ desigined to be used across a variety of communication media,
+ processors, and office applications. UB, (now a part of
+ {Tandem Computers}) adopted XNS in developing its {Net/One}
+ XNS routing protocol.
+
+ [Or is it "Service(s)"? Date?]
+
+ (2003-11-10)
+
+XEROX PARC
+
+ /zee'roks park'/ {Xerox Corporation}'s Palo Alto Research
+ Center.
+
+ For more than a decade, from the early 1970s into the
+ mid-1980s, PARC yielded an astonishing volume of
+ ground-breaking hardware and software innovations. The modern
+ mice, windows, and icons ({WIMP}) style of software interface
+ was invented there. So was the {laser printer} and the
+ {local-area network}; {Smalltalk}; and PARC's series of D
+ machines anticipated the powerful {personal computers} of the
+ 1980s by a decade. Sadly, the prophets at PARC were without
+ honour in their own company, so much so that it became a
+ standard joke to describe PARC as a place that specialised in
+ developing brilliant ideas for everyone else.
+
+ The stunning shortsightedness and obtusity of XEROX's
+ top-level {suits} has been well described in the reference
+ below.
+
+ ["Fumbling The Future: How XEROX Invented, Then Ignored, the
+ First Personal Computer" by Douglas K. Smith and Robert
+ C. Alexander (William Morrow & Co., 1988, ISBN
+ 0-688-09511-9)].
+
+ [{Jargon File}]
+
+ (1995-01-26)
+
+Xerox Star
+
+ {Xerox 8010}
+
+XFree86 Project, Inc.
+
+ <operating system, graphics> A non-profit organisation that
+ produces XFree86, a freely redistributable implementation of
+ the {X Window System} that runs on {Unix} and Unix-like
+ operating systems and {OS/2}. The XFree86 Project has
+ traditionally focused on {Intel x86} based {platforms} (hence
+ the "86"), but the current release supports other platforms.
+
+ {(http://xfree86.org/)}.
+
+ (1999-04-02)
+
+XFS
+
+ {Extensions for Financial Services}
+
+Xfun
+
+ A {polymorphic} {functional language} which is a cross between
+ {SML} and {Russell}, developed by S. Dalmas
+ <dalmas@sophia.inria.fr> of {INRIA} in 1991, and intended for
+ {computer algebra}.
+
+ ["A Polymorphic Functional language Applied to Symbolic
+ Computation", S. Dalmas, Proc Intl Symp Symb Alg Comp,
+ Berkeley 1992].
+
+ (1995-02-03)
+
+XGA
+
+ {eXtended Graphics Array}
+
+XGA-2
+
+ {eXtended Graphics Array}
+
+XHTML
+
+ {Extensible HyperText Markup Language}
+
+Xi
+
+ A {VLSI} design language.
+
+ ["The Circuit Design Language Xi", S.I. Feldman, unpublished
+ memo, Bell Labs, 1982].
+
+ [Mentioned in Computational Aspects of VLSI, J.D. Ullman, CS
+ Press 1984].
+
+ (1995-02-03)
+
+XIE
+
+ {X Image Extension}
+
+Xilinx, Inc.
+
+ <company> The electronics company who invented the {FPGA}.
+
+ Xilinx was founded in San Jose, California, in 1984, and
+ invented the {field-programmable gate array}. They claim to
+ command more than half of the world market for these devices
+ today. More recent innovations include {complex programmable
+ logic devices}.
+
+ {(http://xilinx.com/)}.
+
+ Address: 2100 Logic Drive, San Jose, CA 95124, USA.
+
+ (1998-09-25)
+
+Xilinx Netlist Format
+
+ <language, electronics> (XNF) A {Hardware Description
+ Language} for electronic circuit design, developed by {Xilinx,
+ Inc.}.
+
+ {Xilinx}-developed tools use XNF and handle the details of the
+ {FPGA} architecture. Converters are available for a number of
+ widely-used {HDLs} - for example {Verilog} ({xnf2ver}) - so
+ that designers can use familiar tools to develop Logic Cell
+ Array designs. In addition, XNF can be converted to the input
+ language of different {logic simulators}.
+
+ {Specification
+ (ftp://ftp.xilinx.com/pub/documentation/xactstep6/xnfspec.pdf)}.
+
+ (1999-03-31)
+
+X Image Extension
+
+ (XIE) Extensions to the {X protocol} to handle {images}.
+
+ (1995-02-03)
+
+Xlib
+
+ X library: program interface to the {X Window System}.
+
+xlisp
+
+ {eXperimental LISP}
+
+xls
+
+ <filename extension> {Excel} {spreadsheet}.
+
+ (1995-10-17)
+
+XML
+
+ {Extensible Markup Language}
+
+XML schema
+
+ <data> {XML} data that describes the relationship between
+ elements and attributes in some other class of XML data. A
+ schema may or may not include data type representations. XML
+ schemas are a more advanced alternative to {DTD}s.
+
+ {(http://vbxml.com/conference/wrox/2000_vegas/text/kurt_schema.asp)}
+
+ (2006-08-23)
+
+XML Template Pages
+
+ <web> (XTP) {JSP} transformed by {XSL} stylesheets.
+ An XTP page is basically a JSP page which specifies an XSL
+ stylesheet. The XSL specifies how selected tags in the XTP
+ page should be rewritten. All other tags are passed through
+ unchanged and so treated as standard JSP. JSP programmers can
+ use XTP used as an easy introduction to XSL, incrementally
+ applying styles to their pages.
+
+ {Caucho (http://caucho.com/resin/ref/xtp.xtp)}.
+
+ (2003-07-13)
+
+XML User-Interface Language
+
+ <language> (XUL) An {XML}-based language created for the
+ {Mozilla} {browser} for development of {cross-platform} {user
+ interfaces}. XUL supports input {controls} such as
+ {textboxes} and {checkboxes}, {toolbars}, {menus}, {dialogs},
+ {trees}, {keyboard shortcuts}, and more.
+
+ {XULPlanet (http://xulplanet.com/)}.
+
+ (2003-06-14)
+
+XMM
+
+ {Extended Memory Manager}
+
+XMODEM
+
+ <communications> {Ward Christensen}'s file transfer
+ {protocol}, probably the most widely available protocol used
+ for file transfer over {serial lines} (e.g. between {modems}).
+ XMODEM uses 128-byte {packets} with {error detection},
+ allowing the receiver to request retransmission of a corrupted
+ packet. XModem is fairly slow but reliable.
+
+ Several variations have been proposed with increasing packet
+ sizes (e.g. {XMODEM-1K}) and different error detection ({CRC}
+ instead of {checksum}) to take advantage of faster modems.
+ Sending and receiving programs can negotiate to establish the
+ best protocol they both support.
+
+ John Mahr wrote the original XMODEM CRC error correction code.
+ This implementation was backward compatible with Christensen's
+ original checksum code. It improved the error detection from
+ 98% to 99.97% and improved the reliability of transmitting
+ {binary files}.
+
+ Standard XMODEM specifies a one-second {timeout} during the
+ reception of characters in the data block portion of a packet.
+
+ Chuck Forsberg improved upon XMODEM by developing {YMODEM} and
+ {ZMODEM}.
+
+ [Chuck Forsberg, "XMODEM/YMODEM Protocol Reference"].
+
+ (2005-09-16)
+
+XMODEM-1K
+
+ A version of {XMODEM} using 1 kilobyte {packets}.
+
+xmosaic
+
+ {Mosaic} for the {X Window System}.
+
+XMS
+
+ <storage> {Extended Memory Specification}.
+
+ (1996-01-10)
+
+XNF
+
+ {Xilinx Netlist Format}
+
+xnf2ver
+
+ An {XNF} to {Verilog} translator by Martin J. Colley
+ <martin@essex.ac.uk>.
+
+ This program was written by a postgraduate student as part of
+ his M.Sc course. It was designed to form part a larger system
+ operating with the Cadence Edge 2.1 framework. This should be
+ born in mind when considering the construction and/or
+ operation of the program.
+
+ {(ftp://punisher.caltech.edu/pub/dank/xnf2ver.tar.Z)}.
+
+XNS
+
+ {Xerox Network System} or Xerox Network Services.
+
+ [Which?]
+
+XOFF
+
+ {control-S}
+
+XON
+
+ {control-Q}
+
+XON/XOFF
+
+ {software handshaking}
+
+Xopen
+
+ {X/Open}
+
+X/Open
+
+ <body> An international consortium of vendors who defined the
+ X/Open {Common Applications Environment} to provide
+ {applications} {portability}. They also produced the {X/open
+ Portability Guide} (XPG).
+
+ (1994-12-01)
+
+X/open Portability Guide
+
+ (XPG) A document which defines the interfaces of the {X/Open}
+ {Common Applications Environment}.
+
+ Version: XPG3.
+
+ (1994-12-01)
+
+X/Open System Interface
+
+ <standard> (XSI) Part of the {X/Open} {Common Applications
+ Environment}.
+
+ (1994-11-03)
+
+xor
+
+ {exclusive or}
+
+XP
+
+ {Windows XP}
+
+XPC
+
+ eXplicitly Parallel C.
+
+ A dialect of {Parallel C} which is efficiently compilable to
+ both {SIMD} and {MIMD} architectures. Only research
+ implementations exist.
+
+ ["Toward Semantic Self-Consistency in Explicitly Parallel
+ Languages," M.J. Phillip & H.G. Dietz, Proc 4th Intl Conf on
+ Supercomputing, Santa Clara, CA, May 1989, v.1, pp.398-407].
+
+ (1994-12-01)
+
+XperCASE
+
+ A structure diagram editor for developing, re-engineering,
+ maintaining and documenting programs, developed by {Siemens}
+ AG, Austria. It runs under {Microsoft Windows}.
+
+ {(ftp://src.doc.ic.ac.uk/computing/systems/ibmpc/simtel/windows3/xperspx1.zip)}.
+
+ E-Mail: <100141.2120@compuserve.com>.
+
+ (1994-12-01)
+
+XPG
+
+ {X/open Portability Guide}
+
+XPG3
+
+ Version 3 of the {X/open Portability Guide}.
+
+XPL
+
+ A small dialect of {PL/I} used for compiler writing from
+ Stanford, 1967-69. XPL has
+ one-dimensional {arrays}. I/O is achieved with character
+ pseudo-variable INPUT and OUTPUT, e.g.
+
+ OUTPUT = 'This is a line';
+
+ It has inline {machine code}. "Programmers are given all the
+ rope they ask for. Novices tend to hang themselves fairly
+ frequently." XPL has been implemented on {IBM 360}, {Univac
+ 1100}, {ICL System 4}, {CDC 6000} and {Cyber} series, {XDS
+ Sigma-5} and {Sigma-7} and {DEC} {PDP-10}.
+
+ An optimising XPL compiler (version 1) by Robin Vowels
+ <robin_vowels@rmit.edu.au> is a standard implementation of XPL
+ and is based on McKeeman, Horning, and Wortman's improved
+ {XCOM} (which employs hashed symbol table generation). It
+ includes the extra built-in function COREHALFWORD.
+
+ The following areas have been optimised: procedures calls when
+ the argument and corresponding parameter are of the same type,
+ and when the argument is a constant; constant subscripts; use
+ of CORELHALFWORD and COREWORD; string constants of length one;
+ iterative DO statements by transferring code to the end of the
+ loop.
+
+ String constants of length one do not require a descriptor,
+ hence more descriptors are available for string variables.
+ Comparison operations are treated as commutative, and an
+ improved Commute algorithm is used. Halfword instructions are
+ generated for BIT(16) variables.
+
+ These areas have been improved or re-written: calls on OUTPUT,
+ catenation, integer-to-string conversion, multiply, divide,
+ and MOD. An emitter for SS-type instructions has been added.
+ The compiler achieves an 11% reduction in object code
+ compiling itself, an 11% increase in compilation rate, a 55%
+ increase in compilation speed when the $E toggle is set.
+ Special treatment for catenating a string to an integer
+ substantially decreases consumption of the free string area,
+ and decreases string moves. The latter improvement is most
+ noticeable on small core machines.
+
+ Core requirements: less than the improved XCOM on which it is
+ based (approx. 98000 bytes). Symbol table size is 468.
+ Ported to {IBM} {System 370}. The compiler is written in XPL.
+ The code generators are machine-specific.
+
+ ["A Compiler Generator," W.M. McKeeman et al, P-H 1970].
+
+ [JCC, AFIPS 1968].
+
+ (1993-08-07)
+
+xpm
+
+ <file format> X11 Pixmap.
+
+ A {pixmap} image {file format} for the {X Window System}.
+
+ (1995-04-28)
+
+XPOP
+
+ <language> An extensible {macro assembly} language with
+ user-redefinable {grammar}, for use with {FAP}.
+
+ ["XPOP: A Meta-language Without Metaphysics", M.I. Halpern,
+ Proc FJCC 25:57-68, AFIPS (Fall 1964)].
+
+ (1995-04-28)
+
+XP Pro
+
+ {Windows XP Professional Edition}
+
+Xpress Transport Protocol
+
+ <networking, protocol> (XTP) A {transport layer} {protocol}
+ for high-speed networks promoted by the {XTP Forum}. XTP
+ provides protocol options for error control, {flow control},
+ and rate control. Instead of separate protocols for each type
+ of communication, XTP controls {packet} exchange patterns to
+ produce different models, e.g. reliable {datagrams},
+ {transactions}, unreliable {streams}, and reliable {multicast}
+ connections.
+
+ {XTP Home (http://ca.sandia.gov/xtp/)}.
+
+ Contrast with {Transmission Control Protocol}. XTP does not
+ employ {congestion} avoidance {algorithms}.
+
+ (2003-03-22)
+
+X protocol
+
+ <networking, protocol> A {standard} {protocol} used by
+ {clients} (applications) and {servers} in the {X Window
+ System} for exchanging requests for window operations.
+
+ (1995-04-28)
+
+xref
+
+ /X'ref/ 1. cross-reference.
+
+ 2. A cross-reference generator tool by Jim Leinweber.
+
+ (1985?)
+
+ [{Jargon File}]
+
+XRemote
+
+ A {serial line} protocol for the {X Window System}.
+
+XRN
+
+ A newsreader program for {Usenet} news running under the {X
+ Window System}.
+
+XSB
+
+ <logic programming> XSB extends the standard functionality of
+ Prolog (being a descendant of PSB- and SB-Prolog) to include
+ implementations of OLDT (tabling) and HiLog terms. OLDT
+ resolution is extremely useful for recursive query
+ computation, allowing programs to terminate correctly in many
+ cases where Prolog does not. HiLog supports a type of
+ higher-order programming in which predicate symbols can be
+ variable or structured. This allows unification to be
+ performed on the predicate symbols themselves in addition to
+ the arguments of the predicates. Of course, Tabling and HiLog
+ can be used together.
+
+ Version 1.2
+
+ ports: Sun, Solaris, NeXT, Linux, 386 BSD, IRIX, HP-UX
+
+ portability: Generally to 32-bit machines.
+
+ interpreter, preprocessor(HiLog), documentation
+
+ XSB research group / SUNY at Stony Brook
+
+ {(ftp://sbcs.sunysb.edu/pub/XSB/XSB.tar.Z)}.
+
+ (130.245.1.15) E-mail: <xsb-contact@cs.sunysb.edu>.
+
+ (1993-07-28)
+
+XScheme
+
+ <language> {Scheme} in {C} with {object-oriented} extensions
+ by David Betz.
+
+ Version 0.28 runs on {IBM PC}, {Macintosh}, {Atari} and
+ {Amiga}.
+
+ {(ftp://labrea.stanford.edu/comp.sources.amiga/volume90)}.
+ {(ftp://nexus.yorku.ca/pub/scheme/)}.
+
+ {Usenet} newsgroup: {news:comp.lang.lisp.x}.
+
+ (1992-02-02)
+
+x-scm
+
+ <language> An accessory for the {scm} {Scheme} {interpreter},
+ by Larry Campbell, that provides an environment for building
+ {Motif} and {OpenLook} {application programs}. There is some
+ support as well for raw {Xlib} applications, but not enough
+ yet to be useful.
+
+ Posted to {alt.sources}.
+
+ (1992-08-10)
+
+XSD
+
+ {XML Schema Definition}
+
+X server
+
+ <graphics, operating system> A process, in an {X Window
+ System} which controls a {bitmap display} device and usually
+ also a {keyboard} and {mouse} or other {pointing device}. The
+ X server performs operations on request from {client}
+ {applications}, which may be on the same computer or a
+ different computer connected via a {network}.
+
+ Note that typical {client-server} architectures do
+ {input-output} on the client and processing on the server
+ whereas in X the terms are reversed as the X server is serving
+ IO rather than processing resources to the application.
+
+ If the two computers are not both {Unix} machines (e.g. one is
+ a {Windows} machine running {VNC}) or if a more secure
+ connection is required (e.g. tunneling with {ssh}), the
+ clients may talk to a {proxy} X server that forwards the
+ requests to another machine where the real IO takes place.
+
+ (2006-08-29)
+
+XSI
+
+ {X/Open System Interface}
+
+XSL
+
+ {Extensible Stylesheet Language}
+
+XSLT
+
+ {Extensible Stylesheet Language Transformations}
+
+XT
+
+ {IBM PC XT}
+
+Xt
+
+ The {intrinsics} of the {X Window System} Toolkit.
+
+ [What does that mean?]
+
+XT bus architecture
+
+ <hardware, architecture> (After the {IBM PC XT}) An eight-bit
+ {ISA} bus architecture used by {Intel 8086} and {Intel 8088}
+ systems in the {IBM PC} and {IBM PC XT} in the 1980s. It
+ predates the 16-bit ISA architecture used on the {Intel 80286}
+ based machines.
+
+ The XT bus has four {DMA} channels, of which three are brought
+ out to the {expansion slots}. Of these three, two are
+ normally allocated to machine functions:
+
+ DMA channel Expansion Standard function
+ 0 No {dynamic RAM} refresh
+ 1 Yes add-on cards
+ 2 Yes {floppy disk} controller
+ 3 Yes {hard disc} controller
+
+ (1997-09-15)
+
+xterm
+
+ <operating system> A {terminal emulator} program for the {X
+ Window System}. A user can have many different invocations of
+ xterm running at once on the same display, each of which
+ provides independent input and output for the process running
+ in it (normally a {shell}).
+
+ (1996-08-23)
+
+X terminal
+
+ <hardware> An {intelligent terminal} which operates as an {X
+ server} directly connected to {Ethernet}.
+
+ Not to be confused with the program {xterm} which is an {X
+ client}.
+
+ (1996-08-23)
+
+XTI
+
+ {X/open Transport Interface}
+
+XTP
+
+ {Xpress Transport Protocol}
+
+ {XML template pages}
+
+XTP Forum
+
+ <body> A consortium of for- and non-profit companies and
+ research organisations promoting {Xpress Transport Protocol}.
+
+ {XTP Forum Home (http://ca.sandia.gov/xtp/forum.html)}.
+
+ (2003-03-22)
+
+XTRAN
+
+ {Fortran}-like, interactive language.
+
+XUI
+
+ X User Interface: program interface to the {X Window System}
+ supported by {DEC}.
+
+XUL
+
+ {XML User-Interface Language}
+
+Xv++
+
+ A library of classes from Interface Engineering, Stevenage,
+ providing a C++ Application Programmer's Interface to the
+ XView toolkit.
+
+XVGA
+
+ {eXtended Video Graphics Array}
+
+XView
+
+ A toolkit from Sun, derived from SunView, providing an Open
+ Look user interface for X applications.
+
+XVT
+
+ eXtensible Virtual Toolkit: a product allowing applications to
+ be developed independent of GUI.
+
+X-Windows
+
+ <spelling> A common misnomer for the {X Window System}.
+
+ (1997-06-10)
+
+X Window System
+
+ <operating system, graphics> A specification for
+ device-independent windowing operations on {bitmap display}
+ devices, developed initially by {MIT}'s Project {Athena} and
+ now a {de facto standard} supported by the {X Consortium}. X
+ was named after an earlier window system called "W". It is a
+ window system called "X", not a system called "X Windows".
+
+ X uses a {client-server} protocol, the {X protocol}. The
+ server is the computer or {X terminal} with the screen,
+ keyboard, mouse and server program and the clients are
+ {application programs}. Clients may run on the same computer
+ as the server or on a different computer, communicating over
+ {Ethernet} via {TCP/IP} protocols. This is confusing because
+ {X clients} often run on what people usually think of as their
+ server (e.g. a file server) but in X, it is the screen and
+ keyboard etc. which is being "served out" to the applications.
+
+ X is used on many {Unix} systems. It has also been described
+ as over-sized, over-featured, over-engineered and incredibly
+ over-complicated. X11R6 (version 11, release 6) was released
+ in May 1994.
+
+ {(http://x.org/)}.
+
+ See also {Andrew project}, {PEX}, {VNC}, {XFree86}.
+
+ {Usenet} newsgroups: {news:comp.windows.x}, {news:comp.x},
+ {news:comp.windows.x.apps}, {news:comp.windows.x.intrinsics},
+ {news:comp.windows.x.announce}, {news:comp.sources.x},
+ {news:comp.windows.x.motif}, {news:comp.windows.x.pex}.
+
+ (1999-04-02)
+
+XWIP
+
+ X Window Interface for Prolog. A package for {Prologs}
+ following the {Quintus} {foreign function} interface
+ (e.g. {SICStus Prolog}). XWIP provides a (low-level)
+ {Xlib}-style interface to {X}. The current version was
+ developed and tested on SICStus 0.7 and {MIT} {X11} R5 under
+ {SunOS} 4.1.1. It should be adaptable to many other {Unix}
+ configurations. Version 0.6.
+
+ {(ftp://export.lcs.mit.edu/contrib/xwip-0.6.tar.Z)}. E-mail:
+ <xwip@cs.ucla.edu>.
+
+ (1993-02-25)
+
+xxgdb
+
+ An {X11} front end for {gdb} by Pierre Willard
+ <pierre@la.tce.com>. Version 1.06.
+
+ Posted to comp.sources.x volumes 11, 12, 13, 14, & 16.
+
+ (1992-02-22)
+
+XXX
+
+ /X-X-X/ A marker that attention is needed. Commonly used in
+ program comments to indicate areas that are {kluge}d or need
+ to be. Some hackers liken "XXX" to the notional heavy-porn
+ movie rating. Compare {FIXME}.
+
+ [{Jargon File}]
+
+Xy-pic
+
+ <graphics, publication> A package for {typesetting} graphs and
+ diagrams using {TeX}. It is structured as several modules,
+ each defining a custom notation for a particular kind of
+ graphical object or structure. Example objects are arrows,
+ curves, and frames. These can be organised in matrix,
+ {directed graph}, path, polygon, knot, and 2-cell structure.
+
+ Xy-pic works with {LaTeX}, {AMS-LaTeX}, {AMS-TeX}, and {plain
+ TeX}, and has been used to typeset complicated diagrams from
+ many application areas including {category theory}, {automata}
+ theory, {algebra}, {neural networks} and {database} theory.
+
+ {(http://ens-lyon.fr/~krisrose/Xy-pic.html)}.
+
+ (1997-11-20)
+
+xyzzy
+
+ <games> The {canonical} "magic word" from the {ADVENT}
+ adventure game, in which the idea is to explore an underground
+ cave with many rooms and to collect the treasures you find
+ there. If you type "xyzzy" at the appropriate time, you can
+ move instantly between two otherwise distant points. If,
+ therefore, you encounter some bit of {magic}, you might remark
+ on this quite succinctly by saying simply "Xyzzy!"
+ "Ordinarily you can't look at someone else's screen if he has
+ protected it, but if you type quadruple-bucky-clear the system
+ will let you do it anyway." "Xyzzy!" Xyzzy has actually been
+ implemented as an undocumented no-op command on several OSes;
+ in Data General's AOS/VS, for example, it would typically
+ respond "Nothing happens", just as {ADVENT} did if the magic
+ was invoked at the wrong spot or before a player had performed
+ the action that enabled the word. In more recent 32 bit
+ versions, by the way, AOS/VS responds "Twice as much happens".
+ See also {plugh}.
+
+ [{Jargon File}]
+
+Y
+
+ 1. General purpose language syntactically like {RATFOR},
+ semantically like {C}. Lacks structures and pointers. Used
+ as a source language for Jack W. Davidson and Christopher
+ W. Fraser's peephole optimiser which inspired {GCC} {RTL} and
+ other optimisation ideas.
+
+ {(ftp://ftp.cs.princeton.edu/pub/y+po.tar.Z)}. It is a copy
+ of the original distribution from the {University of Arizona}
+ during the early 80's, totally unsupported.
+
+ ["The Y Programming Language", D.R. Hanson, SIGPLAN Notices
+ 16(2):59-68 (Feb 1981)].
+
+ [Jack W. Davidson and Christopher W. Fraser, "The Design and
+ Application of a Retargetable Peephole Optimiser", TOPLAS,
+ Apr. 1980].
+
+ [Jack W. Davidson, "Simplifying Code Through Peephole
+ Optimisation" Technical Report TR81-19, The University of
+ Arizona, Tucson, AZ, 1981].
+
+ [Jack W. Davidson and Christopher W. Fraser, "Register
+ Allocation and Exhaustive Peephole Optimisation"
+ Software-Practice and Experience, Sep. 1984].
+
+ 2. See {fixed point combinator}.
+
+Y2K
+
+ {Year 2000}
+
+YA-
+
+ {Yet Another}
+
+Yaa
+
+ Yet Another Assembler - Macro assembler for GCOS 8 and Mark
+ III on Bull DPS-8 machines. Available from Bull as part of U
+ Waterloo Tools package (maintained by <pjf@thinkage.on.ca>).
+
+YABA
+
+ /ya'b*/ [Cambridge] Yet Another Bloody Acronym. Whenever some
+ program is being named, someone invariably suggests that it be
+ given a name that is acronymic. The response from those with
+ a trace of originality is to remark ironically that the
+ proposed name would then be "YABA-compatible". Also used in
+ response to questions like "What is {WYSIWYG}?" See also
+ {YA-}, {TLA}.
+
+ [{Jargon File}]
+
+yacc
+
+ {Yet Another Compiler Compiler}
+
+YADE
+
+ {Yet Another DSSSL Engine}
+
+YAFIYGI
+
+ <abuse> /yaf'ee-y*-gee/ You asked for it, you got it.
+
+ The command-oriented {ed}/{vi}/{nroff}/{TeX} style of {word
+ processing} or other user interfaces which are not {WYSIWYG}.
+ What you actually asked for is often not immediately apparent.
+
+ This precise sense of "You asked for it, you got it" seems to
+ have first appeared in Ed Post's classic parody "{Real
+ Programmers} don't use Pascal"; the acronym is a more recent
+ (as of 1993) invention.
+
+ [{Jargon File}]
+
+ (1995-03-13)
+
+YAGNI
+
+ {You aren't gonna need it}
+
+Yahoo
+
+ <web> Yet Another Hierarchical
+ Officious/Obstreperous/Odiferous/Organized Oracle.
+
+ (Or a member of a race of brutes in Swift's Gulliver's Travels
+ who have the form and all the vices of man, or an uncouth or
+ rowdy person).
+
+ Probably the biggest hierarchical index of the {World-Wide
+ Web}. Originally at {Stanford University}, Yahoo moved to its
+ own site in April 1995. It allows you to move up and down the
+ heirarchy, to search it and to suggest additions. It also
+ features "What's New", "What's Popular", "What's Cool" and a
+ random link.
+
+ {(http://yahoo.com/)}.
+
+ (1995-04-05)
+
+Yale Haskell
+
+ <language> A fully integrated {Haskell} programming
+ environment. It provides tightly coupled interactive editing,
+ {incremental compilation} and dynamic execution of Haskell
+ programs. Two major modes of compilation, correspond to
+ {Lisp}'s traditional "interpreted" and "compiled" modes.
+ Compiled and interpreted modules may be freely mixed in any
+ combination.
+
+ Yale Haskell is run using either a command-line interface or
+ as an {inferior process} running under the {Emacs} editor.
+ Using the Emacs interface, simple two-keystroke commands
+ evaluate expressions, run dialogues, compile {modules}, turn
+ specific compiler diagnostics on and off and enable and
+ disable various {optimisers}. Commands may be queued up
+ arbitrarily, thus allowing, for example, a compilation to be
+ running in the background as the editing of a source file
+ continues in Emacs in the foreground.
+
+ A "scratch pad" may be automatically created for any module.
+ Such a pad is a logical extension of the module, in which
+ additional function and value definitions may be added, but
+ whose evaluation does not result in recompilation of the
+ module.
+
+ A tutorial on Haskell is also provided in the Emacs
+ environment. A {Macintosh} version of Yale Haskell includes
+ its own integrated programming environment, complete with an
+ Emacs-like editor and {pull-down menus}.
+
+ Yale Haskell is a complete implementation of the Haskell
+ language, but also contains a number of extensions, including:
+
+ (1) Instead of stream based I/O, a {monadic I/O} system is
+ used. Although similar to what will be part of the new
+ {Haskell 1.3} report, the I/O system will change yet again
+ when 1.3 becomes official.
+
+ (2) Haskell programs can call both {Lisp} and {C} functions
+ using a flexible foreign function interface.
+
+ (3) Yale Haskell includes a {dynamic typing} system. Dynamic
+ typing has been used to implement {derived instances} in a
+ user extensible manner.
+
+ (4) A number of small Haskell 1.3 changes have been added,
+ including {polymorphic recursion} and the use of @_@ in an
+ expression to denote {bottom}. Although the 1.3 report is not
+ yet complete, these changes will almost certainly be part of
+ the new report.
+
+ (5) A complete Haskell level {X Window System} interface,
+ based on {CLX}.
+
+ (6) A number of {annotations} are available for controlling
+ the optimiser, including those for specifying both function
+ and data constructor {strict}ness properties, "{inlining}"
+ functions, and specialising {over-loaded} functions. Many
+ standard {prelude} functions have been specialised for better
+ performance using these annotations.
+
+ (7) {Separate compilation} (including {mutually recursive}
+ {modules}) is supported using a notion of a UNIT file, which
+ is a kind of localised {makefile} that tells the compiler
+ about compiler options and logical dependencies amongst
+ program files.
+
+ (8) Yale Haskell supports both standard and "{literate}"
+ Haskell syntax.
+
+ Performance of Yale Haskell's compiled code has been improved
+ considerably over previous releases. Although still not as
+ good as the Glasgow ({GHC}) and Chalmers ({HBC}) compilers,
+ the flexibility afforded by the features described earlier
+ makes Yale Haskell a good choice for large systems
+ development. For some idea of performance, Hartel's latest
+ "Nuc" benchmark runs at about the same speed under both Yale
+ Haskell and hbc. (Our experiments suggest, however, that Yale
+ Haskell's compiled code is on average about 3 times slower
+ than hbc.)
+
+ Binaries are provided for {Sun}/{SPARC} and {Macintosh}, but
+ it is possible to build the system on virtually any system
+ that runs one of a number of {Common Lisp} implementations:
+ {CMU Common Lisp}, {Lucid Common Lisp}, {Allegro Common Lisp}
+ or {Harlequin LispWorks}. {akcl}, {gcl} and {CLisp} do not
+ have adaquate performance for our compiler. The current
+ version is 2.1.
+
+ {Yale (ftp://nebula.cs.yale.edu/pub/haskell/yale)}.
+ (128.36.13.1). {UK
+ (ftp://ftp.dcs.glasgow.ac.uk/pub/haskell/yale/)}. {Sweden
+ (ftp://ftp.cs.chalmers.se/pub/haskell/yale/)}. E-mail:
+ <haskell-request@cs.yale.edu>,
+ <haskell-request@dcs.glasgow.ac.uk>.
+
+ (1993-07-14)
+
+Yamaha
+
+ <company> A Japanese company best known for consumer
+ electronics and motorbikes. They make music synthesizers,
+ {CD-Rom Writers} and HiFi sound equipment.
+
+ {(http://yamaha.com/)}.
+
+ (1997-04-29)
+
+YAML
+
+ {YAML Ain't Markup Language}
+
+YAML Ain't Markup Language
+
+ <data, language> (YAML) A data {serialisation} language
+ designed to be readable and writable by humans and to work
+ well with modern programming languages.
+
+ YAML uses printable {Unicode} characters to represent both
+ structure and data. The structural syntax is simple and
+ terse. For example, indentation is used for structure, colons
+ separate pairs, and dashes are used for list items.
+
+ YAML can represent mappings ({hashes} or dictionaries),
+ sequences ({arrays} or lists), {scalars} (strings or numbers),
+ or any combination of the above. It has a simple {typing
+ system} and {reference} syntax. Its structures will be
+ particularly familiar to programmers using {Perl}, {Python},
+ {PHP}, {Ruby}, or {Javascript}, but YAML can be used with any
+ programming language.
+
+ YAML is, in some respects, a simpler alternative to XML,
+ though it does not share the constraints imposed by XML's
+ {SGML} legacy and has somewhat different aims.
+
+ {YAML Home (http://yaml.org/)}.
+
+ (2004-02-02)
+
+yank
+
+ <jargon> (From the colloquial meaning "to pull suddenly") To
+ insert a copy of some saved text at the current position in a
+ document being edited.
+
+ The term is used in the {Unix} {text editors} {GNU Emacs} and
+ {vi} but "{paste}" is more common elsewhere.
+
+ [Used elsewhere?]
+
+ (1998-07-01)
+
+YAPS
+
+ Yet Another Production System? {College Park Software}. A
+ commercial {production system} rule language, simpler than
+ {OPS5}. YAPS allows {knowledge bases} to be attached to
+ instances of {CLOS} {objects}.
+
+ E-mail: Liz Allen <liz@grian.cps.altadena.cs.us>.
+
+YASOS
+
+ {Yet Another Scheme Object System}
+
+YAUN
+
+ /yawn/ Yet Another Unix Nerd.
+
+ Reported from the San Diego Computer Society (predominantly a
+ {microcomputer} users' group) as a good-natured punning insult
+ aimed at {Unix} zealots.
+
+ [{Jargon File}]
+
+ (1994-11-11)
+
+Yay
+
+ {Yet Another Yacc}
+
+ye
+
+ <networking> The {country code} for Yemen.
+
+ (1999-01-27)
+
+Year 2000
+
+ <programming> (Y2K, or "millennium bug") A common name for all
+ the difficulties the turn of the century, or dates in general,
+ bring to computer users.
+
+ Back in the 1970s and 1980s, the turn of the century looked so
+ remote and memory/disk was so expensive that most programs
+ stored only the last two digits of the year. These produce
+ surprising results when dealing with dates after 1999. They
+ may believe that 1 January 2000 is before 31 December 1999
+ (00<99), they may miscalculate the day of week, etc. Some
+ programs used the year 99 as a special marker; there are
+ rumours that some car insurance policies were cancelled
+ because a year of 99 was used to mark deleted records.
+
+ Complete testing of date-dependent code is virtually
+ impossible, especially where the system under test relies on
+ other systems such as customers' or suppliers' computers.
+ Despite this, the predicted "millennium meltdown" never
+ occurred. Various fixes and work-arounds were successfully
+ applied, e.g. {time shifting}.
+
+ And yes, the year 2000 was a leap year (multiples of 100
+ aren't leap years unless they're also multiples of 400).
+
+ {PPR Corp Y2K FAQ
+ (http://pprcorp.com/y2k/y2kfaq_j97.html)}.
+
+ (2003-08-15)
+
+Yellow
+
+ A language from {SRI} proposed to meet the {Ironman}
+ requirements which led to {Ada}.
+
+ ["On the YELLOW Language Submitted to the DoD", E.W. Dijkstra,
+ SIGPLAN Notices 13(10):22-26, Oct 1978].
+
+ (1994-11-09)
+
+Yellow Book
+
+ 1. <publication> {Yellow Book, Jargon}.
+
+ 2. {Yellow Book CD-ROM}.
+
+ [{Jargon File}]
+
+ (1996-12-03)
+
+Yellow Book CD-ROM
+
+ A {CD-ROM} format which is {ISO 9660} compliant and uses mode
+ 1 addressing. Discs of this type can be played on most drives
+ and would be appropriate for most {multimedia} {applications}
+ which have been developed for {personal computers}.
+
+ (1994-11-02)
+
+Yellow Book, Jargon
+
+ <publication> The print version of the {Jargon File}, titled
+ "The New Hacker's Dictionary". It includes essentially all
+ the material the File, plus a Foreword by {Guy L. Steele, Jr.}
+ and a Preface by Eric S. Raymond. Most importantly, the book
+ version is nicely typeset and includes almost all of the
+ infamous Crunchly cartoons by the Great Quux, each attached to
+ an appropriate entry. The first, second, and third editions
+ correspond to versions 2.9.6, 3.0.0, and 4.0.0 of the File,
+ respectively.
+
+ ["The New Hacker's Dictionary", 3rd edition, MIT Press, 1996
+ (ISBN 0-262-68092-0)].
+
+ (1996-12-03)
+
+Yellow Box
+
+ <operating system> {Apple Computer, Inc.}'s new development
+ {platform} for building {desktop}, {server}, and {web}
+ applications. Yellow Box is a rich {object-oriented}
+ environment that is tightly integrated with {Java} and allows
+ you to deploy applications across five platforms: {Rhapsody},
+ {Rhapsody for Intel}, {Windows 95}, {Windows NT}, and {Mac OS}.
+ All Yellow Box-based products are an evolution of {OpenStep} -
+ an operating system-independent, object-oriented application
+ platform from {NeXT}.
+
+ Integrating the cross-platform robustness of OpenStep with
+ Apple's market-leading digital media and graphics technologies
+ will differentiate the Yellow Box from other development
+ platforms.
+
+ "Yellow Box for Windows" is the {run-time} software
+ (implemented as {dynamically linked libraries}) that allows
+ {Yellow Box} applications to run under {Windows 95} and
+ {Windows NT}. Applications that use it will feature a full
+ native Windows user interface.
+
+ {(http://wais.sensei.com.au/macarc/appdir/1996/0077.html)}.
+
+ (1997-10-15)
+
+Yellow Pages
+
+ {Network Information Service}
+
+yellow wire
+
+ (IBM) Repair wires used when connectors (especially ribbon
+ connectors) got broken due to some schlemiel pinching them, or
+ to reconnect cut traces after the field engineer mistakenly
+ cut one. Compare {blue wire}, {purple wire}, {red wire}.
+
+ [{Jargon File}]
+
+Yerk
+
+ <language> (After Yerkes Observatory) An {object-oriented}
+ language based on a {Forth} {Kernel} with some major
+ modifications. It was originally known as {Neon}, developed
+ and sold as a product by {Kriya Systems} from 1985 to 1989.
+ Several people at The {University of Chicago} have maintained
+ Yerk since its demise as a product. Because of possible
+ trademark conflict they named it Yerk, which is not an acronym
+ for anything, but rather stands for Yerkes Observatory, part
+ of the Department of Astronomy and Astrophysics at U of C.
+
+ Version 3.62.
+
+ {(ftp://oddjob.uchicago.edu/pub/Yerk/)}.
+
+ E-mail: Bob Lowenstein <rfl@oddjob.uchicago.edu>.
+
+ (1994-11-23)
+
+Yet Another
+
+ <jargon> (YA-, after {Unix}'s {yacc} - Yet Another
+ Compiler-Compiler) A humorous allusion often used in titles to
+ acknowledge that the topic is not original, though the content
+ is. As in "Yet Another AI Group" or "Yet Another {Simulated
+ Annealing} {Algorithm}". If used of others' work, it
+ describes something of which there are already far too many.
+
+ In hackish acronyms the "YA" prefix almost invariably expands
+ to {Yet Another}, e.g. {YABA}, {YAUN}.
+
+ [{Jargon File}]
+
+ (1996-11-26)
+
+Yet Another Compiler Compiler
+
+ <tool, language> (yacc) The {LALR} {parser generator} found on
+ most {Unix} systems. Also, the language used to describe the
+ {syntax} of another language to yacc (the program).
+
+ Implementations: {ayacc}, {YAY}, {perln-byacc},
+
+ SASL-Yacc - "Yacc in {SASL} - An Exercise in Functional
+ Programming", Simon Peyton-Jones, Software Prac & Exp
+ 15:807-820 (1985). Mentions also a BCPL implementation.
+
+ Yacc++ - 1990. An {object-oriented} rewrite of yacc, supports
+ {regular expressions}, produces an {LR1 grammar} parser.
+
+ ["YACC Meets C++", S.C. Johnson, USENIX Spring '88 Conf].
+
+ Chris Clark, Compiler Resources Inc, +1 (508) 435-5016.
+
+ MLYACC - Implementation and output in {SML/NJ}.
+ {(ftp:research.att.com/dist/ml/75.tools.tar.Z)}.
+
+ A version, by David Poole at Montana University has been
+ retargeted to {Turbo Pascal}.
+
+ {(ftp://iecc.com/pub/file/lyprg.zip)}.
+
+ See also {Bison}, {yet another}, {Yet Another Yacc}.
+
+ {Unix manual page}: yacc(1).
+
+ ["YACC - Yet Another Compiler Compiler", S.C. Johnson, CS TR
+ 32, Bell Labs (Jul 1975)].
+
+ [Was there ever an "ACC" - "Another Compiler Compiler"? If
+ so, what was the first compiler compiler called?]
+
+ (2000-11-15)
+
+Yet Another Scheme Object System
+
+ <language> (YASOS) A system for {object-oriented programming}
+ in {Scheme}.
+
+ E-mail: Ken Dickey <kend@newton.apple.com>
+
+ (2010-02-28)
+
+Yet Another Yacc
+
+ <tool> (Yay) An extension of {Yacc} with {LALR2} parsing.
+
+ Yay is available from {Bull} as part of the {University of
+ Waterloo Tools} package maintained by <pjf@thinkage.on.ca>.
+
+ (1994-11-09)
+
+YGMTPO
+
+ <chat> ({Usenet}) "You Greatly Misunderstood The Purpose Of".
+
+ (1998-03-03)
+
+YLISP
+
+ A variant of {Xlisp} from {Hewlett-Packard} for the HP-95LX
+ {palmtop}.
+
+ {(ftp://hpcsos.col.hp.com/mirrors/.scsi5/hp95lx/languages)}.
+
+ (1994-11-23)
+
+YMMV
+
+ {Your mileage may vary}
+
+YMODEM
+
+ A file transfer {protocol} used between {modems}. YMODEM was
+ developed by Chuck Forsberg as the successor to {XMODEM} and
+ was itself succeeded by {ZMODEM}. XMODEM used 128-byte
+ {packets}, YMODEM can also use 1 kilobyte packets. Whereas
+ YMODEM is a batch protocol, {YMODEM-G} is a non-stop version.
+
+ File sizes are included in the YMODEM header when sending both
+ binary and text files. Thus files transferred via YMODEM
+ should preserve their exact length. File modification times
+ may also be present in the YMODEM header.
+
+ YModem can {fall back} to smaller packets when necessary but
+ there is no backward compatibility with XModem's error
+ detection.
+
+ [Chuck Forsberg, "XMODEM/YMODEM Protocol Reference"].
+
+ (1995-02-02)
+
+YMODEM-G
+
+ A non-stop "streaming" version of {YMODEM} designed for
+ "error-free" connections with proper flow control; the
+ transmitting program sends packets to the receiver as fast as
+ it can without waiting for acknowledgements. Any errors cause
+ the entire file transfer to abort.
+
+yocto-
+
+ {prefix}
+
+Yoda condition
+
+ <programming> The programming practise of using
+
+ if (constant == variable)
+
+ e.g.
+
+ if (4 == foo)
+
+ instead of the more natural
+
+ if (variable == constant)
+
+ It is named after the Star Wars character Yoda who says things
+ like "Strong is Vader". It may have been invented as a way to
+ prevent coding errors like
+
+ if (count = 5)
+
+ (accidentally using a single "=" ({assignment}) instead of a
+ double "==" (comparison)). The above is syntactically valid
+ whereas the Yoda equivalent would give a compile-time error.
+
+ (2012-06-25)
+
+YOL Computers
+
+ <company> A company in London, UK that sells computer and
+ network systems, established in 2001.
+
+ {(http://yolc.com/)}.
+
+ (2008-01-28)
+
+yotta-
+
+ {prefix}
+
+yottabyte
+
+ <unit, data> (YB) A unit of {data} equal to 10^24 {bytes} but see
+ {binary prefix} for other definitions. A yottabyte is 1000^8
+ bytes or 1000 {zettabytes}.
+
+ It is estimated that the {web} contains about one yottabyte of
+ data (2013).
+
+ 1000 yottabytes has been called one {brontobyte}.
+
+ See {prefix}.
+
+ (2013-11-04)
+
+You are not expected to understand this
+
+ [Unix] The canonical comment describing something {magic} or
+ too complicated to bother explaining properly. From an
+ infamous comment in the context-switching code of the V6
+ {Unix} {kernel}.
+
+ [{Jargon File}]
+
+You aren't gonna need it
+
+ <programming> (YAGNI) A motto of {extreme programming} expressing
+ the principle that functionality should not be implemented until
+ it is needed. The traditional {waterfall model} makes it
+ difficult to add features after the specification has been signed
+ off, tempting the specifier to add features that may never be used
+ but which take time to program, debug, test and document.
+
+ (2014-03-27)
+
+Yourdon
+
+ 1. <programming> The {Yourdon methodology}.
+
+ 2. <person> {Edward Yourdon}.
+
+ 3. <company> {Yourdon, Inc.}.
+
+ (1995-04-07)
+
+Yourdon/Constantine
+
+ <programming> (Or "Constantine/Yourdon") A {structured design}
+ {methodology} involving {structure charts}, developed by Larry
+ Constantine.
+
+ (1995-04-07)
+
+Yourdon/Demarco
+
+ <programming> (Or "DeMarco/Yourdon") A {structured analysis}
+ {methodology} involving {data flow diagrams}, etc. developed
+ by {Edward Yourdon} and Tom DeMarco.
+
+ (1995-04-07)
+
+Yourdon, Inc.
+
+ <company> The company founded in 1974 by {Edward Yourdon} to
+ provide educational, publishing, and consulting services in
+ state-of-the-art software engineering technology. Over the
+ next 12 years, the company grew to a staff of over 150 people,
+ with offices throughout North America and Europe. As CEO of
+ the company, Yourdon oversaw an operation that trained over
+ 250,000 people around the world; the company was sold in 1986
+ and eventually became part of {CGI}, the French software
+ company that is now part of {IBM}. The publishing division,
+ Yourdon Press (now part of Prentice Hall), has produced over
+ 150 technical computer books on a wide range of software
+ engineering topics; many of these "classics" are used as
+ standard university computer science textbooks.
+
+ (1995-04-16)
+
+Yourdon methodology
+
+ <programming> The {software engineering} {methodology}
+ developed by {Edward Yourdon} and colleagues in the 1970s and
+ 1980s. "Yourdon methodology" is a generic term for all of the
+ following methodologies: {Yourdon/Demarco},
+ {Yourdon/Constantine}, {Coad/Yourdon}.
+
+ (1995-04-07)
+
+Your mileage may vary
+
+ <jargon> (YMMV) The disclaimer American car manufacturers
+ attached to EPA mileage ratings. A humourous way of saying
+ that the thing under discussion will not necessarily give you
+ the same results as the author. Often used to convey the
+ hardware dependence of Unix {freeware} distributions.
+
+ [{Jargon File}]
+
+ (2012-02-16)
+
+youtube.com
+
+ {YouTube, Inc.}
+
+YouTube, Inc.
+
+ <web, video> An on-line {video} {file sharing} {web
+ site}, founded on 2005-02-14 by Chad Hurley, Steve Chen, and
+ Jawed Karim. Anyone can upload video clips to the site and
+ these can then be viewed by others. In 2007, many such sites
+ exist but YouTube is the best known.
+
+ YouTube is funded by Sequoia Capital. In November 2006,
+ YouTube was bought by {Google Inc.}. YouTube has partnership
+ deals with content providers such as {CBS}, {BBC}, Universal
+ Music Group, Sony Music Group, Warner Music Group, NBA, The
+ Sundance Channel and many more.
+
+ {YouTube Home (http://youtube.com/)}.
+
+ (2007-09-28)
+
+Yow!
+
+ <exclamation> /yow/ (From "Zippy the Pinhead" comics) A
+ favoured hacker expression of humorous surprise or emphasis.
+ "Yow! Check out what happens when you twiddle the foo option
+ on this display hack!"
+
+ Compare {gurfle}.
+
+ [{Jargon File}]
+
+ (1995-03-07)
+
+yoyo mode
+
+ <jargon> The state in which a computer is said to be when it
+ rapidly alternates several times between being up and being
+ down. Interestingly (and perhaps not by coincidence), many
+ hardware vendors give out free yoyos at {Usenix} exhibits.
+
+ {Sun Microsystems} gave out logoised yoyos at SIGPLAN '88.
+ Tourists staying at one of Atlanta's most respectable hotels
+ were subsequently treated to the sight of 200 of the country's
+ top computer scientists testing yo-yo {algorithms} in the
+ lobby.
+
+ [Is it "yoyo" or "yo-yo"?]
+
+ [{Jargon File}]
+
+ (1995-03-07)
+
+YP
+
+ Yellow Pages. The original name for {Sun}'s
+ {Network Information Service}.
+
+ (1995-03-07)
+
+YSM
+
+ {Yourdon Structured Method}
+
+yt
+
+ <networking> The {country code} for Mayotte.
+
+ (1999-01-27)
+
+YTalk
+
+ Version: V3.0 Patch Level 1.
+
+ <networking, tool> A multi-user chat program by Britt Yenne
+ <yenne@austin.eds.com>. YTalk works almost exactly like the
+ standard {Unix} {talk} program and even communicates with the
+ same talk {daemon}(s), but YTalk supports multiple
+ connections.
+
+ Multiple user names may be given as command-line arguments, in
+ the form "name#tty@host" where the optional "#tty" specifies a
+ particular tty.
+
+ YTalk is able to communicate with both existing versions of
+ {Unix} talk daemons. Once connected, typing {escape} gives
+ access to a menu of commands to add or delete users, trace
+ to a file, or set options. If run under the {X Window
+ System}, YTalk will use separate X windows for each user in
+ the conversaton, otherwise it will split the terminal screen
+ between them.
+
+ E-mail: <ytalk@austin.eds.com>.
+
+ [FTP?]
+
+ (1995-04-04)
+
+yu
+
+ <networking> The {country code} for the former Yugoslavia.
+
+ (1999-01-27)
+
+Yu-Shiang Whole Fish
+
+ /yoo-shyang hohl fish/ An obsolete name for the Greek
+ character gamma ({extended SAIL ASCII} code 9, Unicode glyph
+ 0x0263) which with a loop in its tail looks like a little fish
+ swimming down the page. The term is actually the name of a
+ Chinese dish in which a fish is cooked whole (not {parse}d)
+ and covered with Yu-Shiang (or Yu-Hsiang) sauce. Used
+ primarily by people on the {MIT} {LISP Machine}, which could
+ display this character on the screen. Tends to elicit
+ incredulity from people who hear about it second-hand.
+
+ [{Jargon File}]
+
+ (1995-01-31)
+
+Z
+
+ /zed/ <language, specification> 1. (After {Zermelo-Fränkel set
+ theory}) A {specification language} developed by the
+ {Programming Research Group} at Oxford University around 1980.
+ Z is used for describing and modelling computing systems. It
+ is based on {axiomatic set theory} and {first order predicate
+ logic}. Z is written using many non-{ASCII} symbols. It was
+ used in the {IBM} {CICS} project.
+
+ See also {Z++}.
+
+ ["Understanding Z", J.M. Spivey, Cambridge U Press 1988].
+
+ 2. <language, simulation> A {stack}-based, complex arithmetic
+ {simulation} language from {ZOLA Technologies}.
+
+ (1995-08-11)
+
+Z++
+
+ <language> An {object-oriented} extension of {Z}.
+
+ ["Z++, an Object-Oriented Extension to Z", Lano, Z User
+ Workshop, Oxford 1990, Springer Workshops in Computing, 1991,
+ pp.151-172].
+
+ (1995-04-22)
+
+Z-1013
+
+ <computer> A {Z80} {clone} home computer running at 1 MHz.
+ The Z-1013 computer was introduced in 1986 in East Germany.
+ The computer contained a {tape} for storing and loading
+ {programs} and had an unusual {keyboard}.
+
+ (2004-03-24)
+
+Z180
+
+ <processor> An 8-bit microprocessor, code compatible with the
+ {Zilog Z80} and based on a design from {Hitachi} which is in
+ turn based on the Zilog Z80.
+
+ [Manufacturer?]
+
+ (1995-04-22)
+
+Z3
+
+ <computer> The third computer designed and built by {Konrad
+ Zuse} and the first {digital computer} to successfully run
+ real programs. The computer was ready in 1941, five years
+ before {ENIAC}.
+
+ Zuse began his work on program-driven calculating machines in
+ 1935. His two predessors of the Z3, the Z1 and Z2, were
+ unsuccessful mechanical calculating machines. The Z3 was
+ delivered to the Deutsche Versuchsanstalt für Luftfahrt
+ (German Experimental Department of Aeronautics) in Berlin and
+ was used for deciphering coded messages. A 1960
+ reconstruction of the Z3 is in the Deutsche Museum in Munich.
+
+ The Z3 used about 2600 relays of the kind used in
+ telecommunications. Zuse wrote and implemented the language
+ {Plankalkül} on the Z3. Programs were punched into cinefilm.
+
+ Zuse built some more computers after World War II, including
+ the Z3's successor, the Z4, which was set up at ETH Zurich,
+ Switzerland.
+
+ Of the potential rival claimants to the title of first
+ programmable computer, {Babbage} (UK, c1840) planned but was
+ not able to build a {decimal}, programmable machine.
+ {Atanasoff}'s {ABC}, completed in 1942 was a special purpose
+ calculator, like those of {Pascal} (1640) and {Leibniz}
+ (1670). Eckert and Mauchly's {ENIAC} (US), as originally
+ released in 1946, was programmable only by manual rewiring or,
+ in 1948, with switches. None of these machines was freely
+ programmable. Neither was {Turing} et al.'s {Colossus} (UK,
+ 1943-45). {Aiken}'s {MARK I} (1944) was programmable but
+ still decimal, without separation of storage and control.
+
+ [Features? Where was it designed? Contemporaries?]
+
+ {(http://cs.tu-berlin.de/~zuse)}.
+
+ {(http://epemag.com/zuse)}.
+
+ (2003-10-01)
+
+Z39.50
+
+ {ANSI Z39.50}
+
+Z8
+
+ {Zilog Z8}
+
+Z80
+
+ {Zilog Z80}
+
+Z8000
+
+ {Zilog Z8000}
+
+za
+
+ <networking> The {country code} for South Africa.
+
+ (1999-01-27)
+
+ZAP
+
+ 1. <language> A language for expressing program
+ transformations.
+
+ ["A System for Assisting Program Transformation",
+ M.S. Feather, ACM TOPLAS 4(1):1-20, Jan 1982].
+
+ 2. {Zero and Add Packed}.
+
+ (2001-03-25)
+
+zap
+
+ <jargon> 1. To modify, usually to correct; especially used
+ when the action is performed with a debugger or binary
+ patching tool. Also implies surgical precision. "Zap the
+ debug level to 6 and run it again."
+
+ In the {IBM} {mainframe} world, binary patches are applied to
+ programs or to the {operating system} with a program called
+ "{superzap}", whose file name is "IMASPZAP" (possibly
+ contrived from I M A SuPerZAP).
+
+ See also {Zero and Add Packed}.
+
+ 2. To {fry} a chip with static electricity. "Uh oh - I think
+ that lightning strike may have zapped the disk controller."
+
+ (1998-07-08)
+
+ZAPP
+
+ Zero Assignment Parallel Processor. A virtual tree machine
+ architecture in which a process tree is dynamically mapped
+ onto a fixed, strongly connected network of processors
+ communicating by message passing. The basic operation of each
+ node is to apply a divide and conquer function which takes
+ four arguments: (1) a function 'primitive' which takes a
+ problem description (PD) and returns true if it can be solved
+ without division, (2) a function 'solve' which takes a
+ primitive PD and returns its solution, (3) a function 'divide'
+ which takes a PD and returns a list of PDs of smaller problems
+ and (4) a function 'combine' which returns the solution to a
+ problem by combining a list of solutions of subproblems.
+
+ Each node has a copy of the code and one is given the initial
+ problem description. Task distribution is by process stealing
+ in which a process constructs a descriptor for each subtask
+ and idle (lightly loaded) processors can steal a descriptor
+ from a physically connected neighbour.
+
+Z-buffer
+
+ <graphics> An {array} used to store the maximum Z {coordinate}
+ of any feature plotted at a given (X, Y) location on the
+ screen, used for {hidden line removal} in a 2D rendering of a
+ 3D scene. The Z axis is perpendicular to the screen with
+ values increasing toward the viewer so that any point whose Z
+ coordinate is less than the corresponding Z-buffer value will
+ be hidden behind some feature which has already been plotted.
+
+ (1997-07-18)
+
+ZEBRA
+
+ A data management package in the {CERN Program Library}.
+
+Zed
+
+ 1978. Software Portability Group, U Waterloo. {Eh}, with
+ types added. Similar to {C}. Implementation language for the
+ {Thoth} realtime operating system. Added a few simple types
+ for greater efficiency on byte-addressed machines. String
+ constants in case statements. Enforces the naming convention:
+ MANIFESTS, Externals and locals. "Porting the Zed Compiler",
+ G.B. Bonkowski et al, SIGPLAN Notices 14(8):92-97 (Aug 1979).
+
+Zen
+
+ [Kehoe, B., "Zen and the Art of the Internet", February 1992.]
+
+ [{Jargon File}]
+
+zen
+
+ <jargon> To figure out something by meditation or by a sudden
+ flash of enlightenment. Originally applied to {bugs}, but
+ occasionally applied to problems of life in general. "How'd
+ you figure out the buffer allocation problem?" "Oh, I zenned
+ it."
+
+ Contrast {grok}, which connotes a time-extended version of
+ zenning a system. Compare {hack mode}. See also {guru}.
+
+ (1996-09-17)
+
+ZENO
+
+ U Rochester 1978. Euclid with asynchronous message-passing.
+ "Preliminary ZENO Language Description", J.E. Ball et al,
+ SIGPLAN Notices 14(9):17-34 (Sep 1979).
+
+zepto
+
+ {prefix}
+
+Zermelo Fränkel set theory
+
+ <mathematics> A {set theory} with the {axioms} of {Zermelo set
+ theory} (Extensionality, Union, Pair-set, Foundation,
+ Restriction, Infinity, Power-set) plus the Replacement {axiom
+ schema}:
+
+ If F(x,y) is a {formula} such that for any x, there is a
+ unique y making F true, and X is a set, then
+
+ {F x : x in X}
+
+ is a set. In other words, if you do something to each element
+ of a set, the result is a set.
+
+ An important but controversial {axiom} which is NOT part of ZF
+ theory is the {Axiom of Choice}.
+
+ (1995-04-10)
+
+Zermelo set theory
+
+ <mathematics> A {set theory} with the following set of
+ {axioms}:
+
+ Extensionality: two sets are equal if and only if they have
+ the same elements.
+
+ Union: If U is a set, so is the union of all its elements.
+
+ Pair-set: If a and b are sets, so is
+
+ {a, b}.
+
+ Foundation: Every set contains a set disjoint from itself.
+
+ Comprehension (or Restriction): If P is a {formula} with one
+ {free variable} and X a set then
+
+ {x: x is in X and P(x)}.
+
+ is a set.
+
+ Infinity: There exists an {infinite set}.
+
+ Power-set: If X is a set, so is its {power set}.
+
+ Zermelo set theory avoids {Russell's paradox} by excluding
+ sets of elements with arbitrary properties - the Comprehension
+ axiom only allows a property to be used to select elements of
+ an existing set.
+
+ {Zermelo Fränkel set theory} adds the Replacement axiom.
+
+ [Other axioms?]
+
+ (1995-03-30)
+
+ZERO
+
+ <language> An {object oriented} extension of {Z}.
+
+ ["Object Orientation in Z", S. Stepney et al eds, Springer
+ 1992].
+
+ [{Jargon File}]
+
+ (1995-03-30)
+
+zero
+
+ 1. <character> 0, {ASCI} character 48. Numeric zero, as
+ opposed to the letter "O" (the 15th letter of the English
+ alphabet). In their unmodified forms they look a lot alike,
+ and various {kluges} invented to make them visually distinct
+ have compounded the confusion.
+
+ If your zero is centre-dotted and letter-O is not, or if
+ letter-O looks almost rectangular but zero looks more like an
+ American football stood on end (or the reverse), you're
+ probably looking at a modern character display (though the
+ dotted zero seems to have originated as an option on {IBM
+ 3270} controllers). If your zero is slashed but letter-O is
+ not, you're probably looking at an old-style {ASCII} graphic
+ set descended from the default typewheel on the venerable
+ {ASR-33} {Teletype} (Scandinavians, for whom slashed-O is a
+ letter, curse this arrangement).
+
+ If letter-O has a slash across it and the zero does not, your
+ display is tuned for a very old convention used at {IBM} and a
+ few other early mainframe makers (Scandinavians curse *this*
+ arrangement even more, because it means two of their letters
+ collide). Some {Burroughs}/{Unisys} equipment displays a zero
+ with a *reversed* slash. And yet another convention common on
+ early {line printers} left zero unornamented but added a tail
+ or hook to the letter-O so that it resembled an inverted Q or
+ cursive capital letter-O.
+
+ [{Jargon File}]
+
+ (1995-01-24)
+
+ 2. To set to zero. Usually said of small pieces of data, such
+ as bits or words (especially in the construction "zero out").
+
+ 3. To erase; to discard all data from. Said of disks and
+ directories, where "zeroing" need not involve actually writing
+ zeroes throughout the area being zeroed. One may speak of
+ something being "logically zeroed" rather than being
+ "physically zeroed".
+
+ See {scribble}.
+
+ (1999-02-07)
+
+Zero and Add Packed
+
+ <language> (ZAP) An {IBM 360}/370 {assembly language}
+ instruction used when performing {packed arithmatic} to
+ initialise an {accumulator}.
+
+ (2001-03-25)
+
+zero assignment
+
+ <programming> A property of a {programming language} in which
+ there are no {variables} but only {functions}.
+
+ See also {single assignment}.
+
+ (2003-12-22)
+
+zero-content
+
+ {content-free}
+
+Zero Insertion Force
+
+ <hardware> (ZIF) A kind of socket for {integrated circuits}.
+ A ZIF socket can be opened and closed by means of a lever or
+ screw. When open, there the chip may be placed in the socket
+ without any pressure at all, the socket is then closed,
+ causing its contacts to grip the pins of the chip. Such
+ sockets are used where chips must be inserted and removed
+ frequently, such as in test equipment. They are more
+ expensive and usually take up more space than conventional IC
+ sockets.
+
+ (1994-12-05)
+
+zeroth
+
+ <jargon> First.
+
+ Since zero is the lowest value of an {unsigned} {integer},
+ which is one of the most fundamental types in programming and
+ {hardware} design, it is often natural to count from zero
+ rather than one, especially when the integer is actually an
+ {index} or {offset}, as used when addressing {hardware} and
+ {arrays}.
+
+ Hackers, computer scientists and pure mathematicians often
+ like to call the first chapter of a publication "Chapter 0",
+ especially if it is of an introductory nature (one of the
+ classic instances was in the First Edition of {K&R}).
+
+ Zero-based numbering tends to reduce {fencepost errors},
+ though it cannot eliminate them entirely.
+
+ Logically, the next item after the zeroth should be the
+ "oneth" but this is never used.
+
+ [Dijkstra, "Why Numbering Should Start at Zero"
+ {(http://www.cs.utexas.edu/users/EWD/transcriptions/EWD08xx/EWD831.html)}].
+
+ [{Jargon File}]
+
+ (2010-02-28)
+
+ZEST
+
+ An {object-oriented} extension of {Z}.
+
+ ["Object Orientation in Z", S. Stepney et al eds, Springer
+ 1992].
+
+ZetaLisp
+
+ <language> The {Maclisp} dialect used on the {LISP Machine}.
+ The many extensions to Maclisp include {vectors}, {closures},
+ {flavors}, {stack groups}, {locatives}, and {invisible
+ pointers}. Currently supported by {Lisp Machines, Inc.} and
+ {Symbolics}.
+
+ ["LISP Machine Manual", D. Weinreb and D. Moon, MIT AI Lab,
+ 1981].
+
+ (1997-03-18)
+
+zetta-
+
+ {prefix}
+
+zettabyte
+
+ <unit, data> (ZB) A unit of {data} equal to 10^21 {bytes} but see
+ {binary prefix} for other definitions. A zetabyte is 1000^7 bytes
+ or 1000 {exabytes}.
+
+ 1000 zettabytes are one {yottabyte}.
+
+ See {prefix}.
+
+ (2013-11-04)
+
+Zeus
+
+ {Berkeley Yacc}
+
+ZFC
+
+ <mathematics> {Zermelo Fränkel set theory} plus the {Axiom of
+ Choice}. A favourite {axiomatisation} of {set theory}.
+
+ (1995-03-29)
+
+ZF expression
+
+ <programming> (After {Zermelo Fränkel set theory}). {David
+ Turner}'s name for {list comprehension}.
+
+ (1995-03-27)
+
+ZIF
+
+ {Zero Insertion Force}
+
+zigamorph
+
+ /zig'*-morf/ 1. {Hex} FF (11111111) when used as a {delimiter}
+ or {fence} character. Usage: primarily at {IBM} shops.
+
+ 2. [proposed] The {Unicode} non-character +UFFFF
+ (1111111111111111), a character code which is not assigned to
+ any character, and so is usable as end-of-string.
+
+ [{Jargon File}]
+
+ZIL
+
+ <games> Zork Implementation Language. Language used by
+ {Infocom}'s Interactive Fiction adventure games. Interpreted
+ by the {zmachine}, for {Unix} and {Amiga}.
+
+ {(ftp://plains.nodak.edu/Minix/st.contrib.Infocom.tar.Z)}.
+
+Zilog
+
+ <company> The {microprocessor} manufacturer who produced the
+ {Zilog Z80} in July 1976 (as used by {Sinclair} in the
+ {ZX-80}, {ZX-81} and {ZX Spectrum} computers) and later the
+ {Zilog Z8000}.
+
+ Zilog was founded in 1974 and became a wholly owned subsidiary
+ of Exxon Corp. by 1980. The company's management and
+ employees purchased Zilog back from Exxon in 1989. Zilog
+ became a publicly-held company in February, 1991. In March of
+ 1998, Zilog was privatised, as a result of the merger and
+ recapitalisation transaction by Texas Pacific Group (TPG).
+
+ Zilog now produce a range of 8-bit {microcontrollers}, 8-, 16-
+ and 32-bit {microprocessors}, and {digital signal processors},
+ covering the home entertainment, communications, and {embedded
+ systems} markets.
+
+ {(http://zilog.com/)}.
+
+ Address: 910 East Hamilton Avenue, Suite 110, Campbell,
+ CA 95008, USA.
+
+ (1998-09-14)
+
+Zilog Z280
+
+ An enhanced version of the {Zilog Z80} with a 16 bit
+ architecture, introduced in July, 1987. It added an {MMU} to
+ expand addressing to 16Mb, features for {multitasking}, a 256
+ byte {cache}, and a huge number of new {op codes} (giving a
+ total of over 2000!). Its internal clock runs at 2 or 4 times
+ the external clock (e.g. a 16MHz CPU with a 4MHz bus).
+
+ (1994-10-31)
+
+Zilog Z8
+
+ <processor> A family of {microcontrollers} from {Zilog} with
+ on-chip {RAM} and {ROM}. The Z8 is not related to the {Zilog
+ Z80}, it uses a totally different architecture and
+ {instruction set}.
+
+ Competitors include the {Motorola 6805}/68HC05 family or the
+ {Intel 8051}-family (or i51-family or MCS51-family - there is
+ no standard family name).
+
+ (1995-04-22)
+
+Zilog Z80
+
+ <processor> An 8-bit {microprocessor}. It was released in
+ July 1976 with a 2.5 MHz {clock rate}. The Z80 was a much
+ improved {Intel 8080} (as was the {Intel 8085}). It also used
+ 8-bit data and 16-bit addressing, and could execute all of the
+ {8080} {op codes} as well as 80 new ones, instructions that
+ included 1, 4, 8 and 16-bit operations and even block move and
+ block I/O instructions. The {register set} was doubled, with
+ two banks of registers (including A and F) that could be
+ switched between. This allowed fast {operating system} or
+ {interrupt} {context switch}es. It features 3 types of
+ interrupt mode.
+
+ The Z80 also added two {index registers} (IX and IY) and
+ relocatable {vectored interrupts} (via the 8-bit IV register).
+ Like many processors (including the {8085}), the Z80 featured
+ many undocumented op codes. Chip area near the edge was used
+ for added instructions, but fabrication made the failure of
+ these high. Instructions that often failed were just not
+ documented, increasing chip yield. Later fabrication made
+ these more reliable.
+
+ The thing that really made the Z80 popular was the memory
+ interface - the CPU generated it's own {RAM} {refresh}
+ signals, which meant easier design and lower system cost.
+ That and its {8080} compatibility and {CP/M}, the first
+ standard {microprocessor} {operating system}, made it the
+ first choice of many systems.
+
+ In addition to the original Z80 (2.5 MHz) there are the {Zilog
+ Z80A} (4 MHz), {Zilog Z80B} (6MHz) and {Zilog Z80H} (8 MHz)
+ versions. The popular {Hitachi HD64180} processor family adds
+ peripherals and an {MMU} to the Z80.
+
+ The {Zilog Z280} was an enhanced version with an {MMU} and
+ many new {op codes}.
+
+ The Z80 was used in the first {Nintendo} {Game Boy}. A
+ {Sharp} Z80 work-alike was used in the {GameBoy Color},
+ running at 4 MHz for GameBoy software or at 8 MHz for Game Boy
+ Color software. The Z80 was used in the {Sega Master System}
+ and the {Game Gear}. It was also used in the {Sega Genesis}
+ for hardware reverse compatibility with the Sega Master System
+ through a special cartridge.
+
+ {Gaby Chaudry site (http://gaby.de/z80/)}.
+
+ (2004-06-10)
+
+Zilog Z8000
+
+ <processor> A {microprocessor} from {Zilog} introduced not
+ long after the {Intel 8086}, but with superior features. It
+ was basically a 16-bit processor, but could address up to 23
+ bits in some versions by using {segment registers} (to supply
+ the upper 7 bits). There was also an unsegmented version, but
+ both could be extended further with an additional {MMU} that
+ used 64 {segment registers}.
+
+ Internally, the Z8000 had sixteen 16-bit {registers}, but
+ register size and use were exceedingly flexible. The Z-8000
+ registers could be used as sixteen 8-bit registers (only the
+ first half were used like this), sixteen 16-bit registers,
+ eight 32-bit registers, or four 64-bit registers, and included
+ 32-bit multiply and divide. They were all general purpose
+ registers - the {stack pointer} was typically register 15,
+ with register 14 holding the stack segment (both accessed as
+ one 32-bit register for painless address calculations).
+
+ The Z8000 featured two modes, one for the {operating system}
+ and one for user programs. The user mode prevented the user
+ from messing about with {interrupt} handling and other
+ potentially dangerous stuff.
+
+ Finally, like the {Zilog Z80}, the Z8000 featured automatic
+ {DRAM refresh} circuitry. Unfortunately it was somewhat slow,
+ but the features generally made up for that. Initial {bugs}
+ also hindered its acceptance (partly because it did not use
+ {microcode}). There was a radiation resistant military
+ version.
+
+ There was a later 32-bit, {pipelined} version, the {Zilog
+ Z80000}.
+
+ (1997-12-16)
+
+Zilog Z80000
+
+ <processor> A later version of the {Zilog Z8000}, expanded to
+ 32 bits internally and with a 6-stage {pipeline}.
+
+ (1997-12-16)
+
+Zilog Z80A
+
+ <processor> A version of the {Zilog Z80} {microprocessor} with
+ a 4 MHz {clock rate}.
+
+ (1995-04-24)
+
+zip
+
+ 1. <tool, compression, file format> To create a compressed
+ {archive} (a "zip file") from one or more files using
+ {PKWare}'s {PKZIP} or a compatible {archiver}. Its use is
+ spreading from {MS-DOS} now that portable implementations of
+ the {algorithm} have been written.
+
+ zip is also the name of a {Unix} archiving utility compatible
+ with {PKZIP}. {unzip} is the corresponding de-archiver.
+
+ See also {gzip}, {tar and feather}.
+
+ (1996-08-26)
+
+ 2. <storage> {Zip Drive}.
+
+ [{Jargon File}]
+
+ 3. <functional programming> {zip function}.
+
+Zipcode
+
+ <language> A parallel language at {Lawrence Livermore}(?).
+
+ (1996-08-26)
+
+Zip disc
+
+ {Zip drive}
+
+Zip disk
+
+ {Zip drive}
+
+Zip Drive
+
+ <hardware, storage> A {disk drive} from {Iomega Corporation}
+ which takes removable {hard disks} storig 100 to 750
+ {megabytes}. Both internal and external drives are
+ manufactured, making the drive suitable for {backup}, mass
+ storage or for moving files between computers. Software is
+ included to help with file organisation. The internal {SCSI}
+ model offers up to 60 MB / minute transfer rate.
+
+ The Zip drive was awarded {Byte}'s Readers' {Hardware Choice
+ Award 1996 (http://byte.com/art/9607/sec11/art1.htm)}. It was
+ superceded by the {Jaz} drive which takes one {gigbyte} disks.
+
+ (2008-01-21)
+
+zip file
+
+ {zip}
+
+zip function
+
+ <functional programming> A {function} that takes two lists and
+ returns a list of pairs. The idea can easily be extended to
+ take N lists and return a list of N-{tuples}.
+
+ (2008-03-29)
+
+zipped
+
+ {zip}
+
+zipped file
+
+ {zip}
+
+zipperhead
+
+ <abuse> An {IBM} term for a person with a closed mind.
+
+ [{Jargon File}]
+
+ (1994-11-30)
+
+zm
+
+ <networking> The {country code} for Zambia.
+
+ (1999-01-27)
+
+ZMODEM
+
+ <protocol> A file transfer protocol with error checking and
+ crash recovery. Developed by Chuck Forsberg. Its transfer
+ rate is similar to {YMODEM-g}. Like YMODEM-g, ZMODEM does not
+ wait for positive acknowledgement after each block is sent,
+ but rather sends blocks in rapid succession. If a ZMODEM
+ transfer is cancelled or interrupted for any reason, the
+ transfer can be resurrected later and the previously
+ transferred information need not be resent.
+
+ {FTP Oakland
+ (ftp://oak.oakland.edu/pub/simtelnet/msdos/zmodem/)}, {FTP PDX
+ (ftp://ftp.cs.pdx.edu/pub/zmodem/)}.
+
+ Telephone: +1 900 737 7836.
+
+ (1996-07-02)
+
+ZOG
+
+ <hypertext> A high-performance {hypertext} system developed at
+ {Carnegie-Mellon University}.
+
+ (1994-11-30)
+
+ZOLA Technologies
+
+ <company> Producers of the {Z} {simulation} language.
+
+ (1994-11-30)
+
+zombie
+
+ 1. <operating system> {zombie process}.
+
+ 2. <chat> A {ghost}.
+
+ [{Jargon File}]
+
+ (1997-10-08)
+
+zombie process
+
+ <operating system> (Or "defunct process") A {Unix} {process}
+ that has terminated (either because it has been killed by a
+ {signal} or because it has called {exit}()) and whose {parent
+ process} has not yet received notification of its termination
+ by executing (some form of) the {wait}() {system call}.
+
+ A zombie process exists solely as a {process table} entry and
+ consumes no other resources. This entry is retained to hold
+ the child's exit status until the parent process wants to
+ retrieve it. The parent can also be notified asynchronously
+ via a signal of the child's termination.
+
+ Zombie processes can be seen in "ps" listings occasionally
+ (with a status "Z" in some versions).
+
+ Compare {orphan process}.
+
+ (1997-10-08)
+
+zone
+
+ A logical group of {network} devices on {AppleTalk}.
+
+ (1994-11-30)
+
+Zoo
+
+ {Berkeley Yacc}
+
+zoo
+
+ <tool, file format> A data {compression} program and format by
+ Rahul Dhesi. Zoo is reported to use the same {Lempel Ziv}
+ algorithm as {LHA}. It is available for many {platforms} and
+ {source} is available. .zoo archives are handled by many
+ other PC archiving programs.
+
+ Version 2.10 was released in 1989. Search the web for zoo210
+ to obtain an executable.
+
+ {Description (http://sources.isc.org/archiver/zoo2.txt)}.
+
+ (2000-07-05)
+
+zoom
+
+ <graphics> To show a smaller area of an {image} at a higher
+ magnification ("zoom in") or a larger area at a lower
+ magnification ("zoom out"), as though using a zoom lense on a
+ camera.
+
+ Unlike in an optical system, zooming in on a computer {image}
+ does not necessarily increase the amount of detail displayed
+ since this is limited by what is actually stored in the image.
+ Similarly, you cannot zoom out beyond the full size of the
+ image.
+
+ (1997-10-24)
+
+Zoomer
+
+ <computer> A {PDA} from {Casio}, based on the {GEOS}
+ {microkernel} {operating system}.
+
+ {(http://biostat.washington.edu/zoomer.html)}.
+ {(http://eit.com/mailinglists/zoomer/resources.html)}.
+
+ {Usenet} newsgroup: {news:comp.sys.pen},
+ {news:comp.sys.handhelds}, {news:comp.sys.palmtops}.
+
+ (1995-01-23)
+
+ZOPL
+
+ <language> A {block structured}, untyped low-level language
+ used on computers manufactured by {Geac}.
+
+ [Dates? Reference? Stands for?]
+
+ (2002-02-24)
+
+zorch
+
+ /zorch/ 1. [TMRC] To attack with an inverse heat sink.
+
+ 2. [TMRC] To travel with velocity approaching lightspeed.
+
+ 3. [MIT] To propel something very quickly. "The new comm
+ software is very fast; it really zorches files through the
+ network."
+
+ 4. [MIT] Influence. Brownie points. Good karma. The
+ intangible and fuzzy currency in which favours are measured.
+ "I'd rather not ask him for that just yet; I think I've used
+ up my quota of zorch with him for the week."
+
+ 5. [MIT] Energy, drive, or ability. "I think I'll {punt} that
+ change for now; I've been up for 30 hours and I've run out of
+ zorch."
+
+ 6. [MIT] To flunk an exam or course.
+
+ 7. Computing power.
+
+ [{Jargon File}]
+
+ (1997-07-09)
+
+Zork
+
+ <games> /zork/ The second of the great early experiments in
+ computer fantasy gaming; see {ADVENT}. Zork was originally
+ written on {MIT-DM} during the late 1970s, later distributed
+ with {BSD Unix} as a patched, sourceless {RT-11} {Fortran}
+ binary (see {retrocomputing}) and commercialised as "The Zork
+ Trilogy" by {Infocom}. The Fortran source was later rewritten
+ for portability and released to {Usenet} under the name
+ "Dungeon".
+
+ Both Fortran "Dungeon" and translated {C} versions are
+ available from many {FTP archives}.
+
+ [{Jargon File}]
+
+ (1998-09-21)
+
+zorkmid
+
+ <games> /zork'mid/ The canonical unit of currency in
+ hacker-written games. This originated in {Zork} but has
+ spread to {nethack} and is referred to in several other games.
+
+ [{Jargon File}]
+
+ (1998-09-21)
+
+z/OS
+
+ <operating system> An {operating system} from {IBM}.
+ According to IBM, it is a secure, scalable, high-performance
+ enterprise operating system on which to build and deploy
+ Internet and {Java}-enabled applications, providing a
+ comprehensive and diverse application execution environment.
+
+ {(http://ibm.com/servers/eserver/zseries/zos/)}.
+
+ (2008-01-22)
+
+zr
+
+ <networking> The old {country code} for Zaire.
+
+ "{cd}" is now used instead, since Zaire changed its name to
+ the Democratic Republic of the Congo.
+
+ (1999-01-27)
+
+zsh
+
+ {Z shell}
+
+Z shell
+
+ (zsh) 1. {sh} with list processing and {database}
+ enhancements.
+
+ Version 2.1.o (before 1995-10-30).
+
+ {(ftp://cs.ucsd.edu/pub/zsh/zsh2.1.0.tar.Z)}.
+
+ 2. A {Unix} command interpreter {shell} by Paul Falstad
+ <pf@ttisms.com> some time before 1993-03-23. It is similar
+ to, but not completely compatible with, {ksh}, with many
+ additions to please {csh} users and some {tcsh} features. zsh
+ supports editing of multi-line commands in a single buffer;
+ variable editing; a command buffer stack; {recursive}
+ {glob}bing; manipulation of {arrays}; and spelling correction.
+
+ zsh uses {GNU} {autoconf} so should compile and run on any
+ modern version of UNIX, and many not-so-modern.
+
+ Latest version: 4.0.6, as of 2002-10-02.
+
+ {zsh home (http://zsh.org/)}.
+
+ (1995-10-31)
+
+ZUG
+
+ A low-level {Awk}(?) from {Geac}.
+
+ (1995-01-23)
+
+Zulu time
+
+ {Coordinated Universal Time}
+
+ZUSE
+
+ <language> An LL(1) {parser generator} by Arthur Pyster of the
+ {University of California at Santa Barbara}. ZUSE requires
+ {Pascal}.
+
+ (1986-09-23)
+
+Zuse
+
+ <language> (After {Konrad Zuse}) A descendant of {Ada},
+ {Modula-2}, {Mesa} and {Oberon-1}, described by Christian
+ Collberg <collberg@dna.lth.se> in his PhD thesis 1991.
+
+ Zuse supports several levels of information hiding. The Zuse
+ type system includes fully hidden types (similar to {Modula-2}
+ {opaque types} but without any implementation restriction),
+ semi-open pointer types (same as {Modula-2} {opaque types}),
+ extensible {record types} (similar to {Oberon-1} public
+ projection types but without the compiler hint), {enumeration}
+ types, extensible enumeration types, and extensible {subrange
+ types}.
+
+ A type can also be protected by specifying the operations that
+ particular modules may perform (similar to {C++} {friend
+ classes} and {Ada} {private types}). Zuse also includes
+ hidden and extensible constants and hidden inline procedures.
+ In order to support the higher levels of information hiding
+ the implementation employs partial intermediate code linking.
+
+ A version for {Sun-3} is available.
+
+ (1999-02-18)
+
+Zuse, Konrad
+
+ {Konrad Zuse}
+
+zw
+
+ <networking> The {country code} for Zimbabwe.
+
+ (1999-01-27)
+
+ZX-80
+
+ <computer> {Sinclair}'s cheap {personal computer} with
+ built-in {BASIC}, launched at the end of January 1980 at a
+ computer fair in Wembley, UK. The processor was an {NEC
+ 780-C} running at 3.25 MHz. It had 1KB of {RAM}, externally
+ expandable to 16KB, and 4KB of ROM. It had RF video output to
+ a TV, displaying 24 lines by 32 characters of monochrome text.
+ An audio cassette recorder was used to save programs.
+
+ The ZX-80 was sold in kit form for £79.95 or ready-built for
+ £99.95. It was used by many UK hobbyists as a means of learning
+ the basics of computing. Some remember the 1KB ZX-80 for the
+ claim in its advertising that you could control a nuclear power
+ station with it.
+
+ The ZX-80 was succeeded by the {ZX-81}.
+
+ {(http://home.t-online.de/home/p.liebert/zx80_eng.htm)}.
+
+ {Planet Sinclair (http://nvg.ntnu.no/sinclair/)}.
+
+ {The Sinclair Story
+ (http://sincuser.f9.co.uk/046/sstory.htm)}.
+
+ (2002-08-30)
+
+ZX-81
+
+ <computer> An even more successful version of the {Sinclair}
+ {ZX-80}, featuring a large {uncommitted logic array} instead
+ of much discrete logic, an improved {BASIC}, and rather more
+ expandability (it could take 16kb {RAM} packs). It was
+ launched around 1981 and was eventually replaced by the
+ {Spectrum}.
+
+ (1995-11-04)
+
+zxnrbl
+
+ <jargon> /sner'b*l/ Incorrect data introduced by transmission
+ errors; any corrupted or uninterpretable data.
+
+ The word originated in a 1978 advertisement for a
+ Mockingboard, which "makes frogs croak, princesses shriek, and
+ martians zxnrbl."
+
+ "It's not misspelled on the original page. The Internet must
+ have zxnrbled it on the way to you."
+
+ (1997-03-16)
+
+ZX Spectrum
+
+ <computer> {Sinclair}'s first personal computer with a colour
+ display. The Spectrum used the {Zilog Z80} processor like its
+ predecessors the {ZX-80} and {ZX-81}. It was originally
+ available in 16k and 48k versions using cassette tape and
+ later grew to 128k and sprouted {floppy disks}. It had a
+ wider and more solid case and a marginally better "dead flesh"
+ keyboard. Unlike the earlier models, it didn't require the
+ presence of a cold carton of milk to prevent it overheating.
+ It was possibly the most popular home computer in the UK for
+ many years.
+
+ The {TK-90X} was a clone.
+
+ (1995-11-04)
+
+Zynet Ltd.
+
+ <company> A UK {Internet service provider} offering full
+ {Internet Protocol} connection by any reasonable means for any
+ number of computers from individual {dial-ups} to {leased
+ line} connections to entire networks.
+
+ Zynet is a sister company of {Minerva Software} and thus claim
+ a better than average understanding of the needs and
+ idiosyncracies of {Acorn} systems and will be offering special
+ services for education.
+
+ {(http://zynet.co.uk/)}.
+
+ E-mail: <zynet@zynet.co.uk>.
+
+ Telephone: +44 (1392) 426 160. Fax: +44 (1392) 421 762.
+
+ Address: Minerva House, Baring Crescent, Exeter EX1 1TL, UK.
+
+ (1995-01-31)
+
+ZyXEL
+
+ A {modem} manufacturer.
+
+ {(ftp://ftp.zyxel.com/pub/other/zyxel)}.
+
+ E-mail: <tech@zyxel.com>, <sales@zyxel.com>.
+
+ Telephone: +1 800-255-4101 (Sales), +1 714-693-0808 (tech), +1
+ 714-693-0762 (BBS), +1 714-693-8811 (fax).
+
+ Address: 4920 E. La Palma, Anaheim, CA 92807, USA.
+
+ (1994-10-31)
+
+|
+
+ {vertical bar}
+
+~
+
+ {tilde}
+
+
+ {pound sign}